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70 results on '"Tubular heat exchanger"'

1. Experimental study of vapor compression refrigeration system enhanced via tubular heat exchanger incorporating single/dual phase change materials

Author: M. Ismail, W.K. Zahra, and Hamdy Hassan
Subjects: Vapor compression refrigeration, Tubular heat exchanger, Thermal energy storage, Phase change material, Coefficient of performance, Energy and exergy, Engineering (General). Civil engineering (General), TA1-2040
Abstract: Vapor compression refrigeration (VCR) systems operating in hot climates suffer from high condenser temperatures that reduce their performance. One interesting approach being investigated to improve VCR performance is incorporating phase change materials (PCMs) into VCR systems that have not yet been expanded experimentally. So, this work experimentally studies the effect of using tubular PCM heat exchanger to cool the VCR condenser. The impact of two PCMs types suitable for warm climate conditions: SP24 and SP26, and combination of them on the VCR energy and exergy performance is investigated for two inlet ambient air temperatures. The impact on the exit air and PCMs temperatures, and VCR unit's pressure-enthalpy curve, VCR coefficient of performance, and power consumption is also examined. The results show that PCM-equipped systems significantly enhance the VCR exergy efficiency and coefficient of performance, especially at higher ambient temperature. Compared to the system without PCM, the power consumption can be reduced by up to 10.4% with PCM, while the exergy efficiency and coefficient of performance can be improved by 13.7% and 13.4%, respectively. While PCM SP24 provides the best performance, PCM SP26 has longer effective cooling period. A combination of SP24 and SP26 balances the performance and effective cooling period.
Published: 2023
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2. Numerical Simulation of Heat Transfer Performance of a Dimpled Tubular Heat Exchanger.

Author: Wang, Zunce, Wang, Yimin, Zhang, Jinglong, Li, Sen, and Xu, Yan
Subjects: HEAT exchangers, HEAT transfer in turbulent flow, HEAT pipes, HEAT transfer, COMPUTER simulation
Abstract: The processing of dimple on the outer wall of tube will produce corresponding protrusion dimple on the inner wall. The turbulent flow and heat transfer performance of a tubular heat exchanger containing a dimpled inner tube is studied numerically. The results show that the main reason for the enhancement of heat transfer ability of the dimple is the flow vortex in the concave dimple and the shock to the wall induced by the protrusion dimple. Compared with the smooth wall of the tube, the maximum enhancement of heat transfer was 1.94 times in concave dimple and 2.74 times in protrusion dimple. By comparing the heat transfer performance, flow resistance, and comprehensive heat transfer factor of the tube and shell of different sizes of exchange heat pipe, it is determined that the combination of inner and outer wall dimple size of 10–15 mm is a structure with better comprehensive heat transfer performance. [ABSTRACT FROM AUTHOR]
Published: 2022
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3. Numerical Simulation of Heat Transfer Performance of a Dimpled Tubular Heat Exchanger

Author: Zunce Wang, Yimin Wang, Jinglong Zhang, Sen Li, and Yan Xu
Subjects: dimple, tubular heat exchanger, heat transfer performance, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract: The processing of dimple on the outer wall of tube will produce corresponding protrusion dimple on the inner wall. The turbulent flow and heat transfer performance of a tubular heat exchanger containing a dimpled inner tube is studied numerically. The results show that the main reason for the enhancement of heat transfer ability of the dimple is the flow vortex in the concave dimple and the shock to the wall induced by the protrusion dimple. Compared with the smooth wall of the tube, the maximum enhancement of heat transfer was 1.94 times in concave dimple and 2.74 times in protrusion dimple. By comparing the heat transfer performance, flow resistance, and comprehensive heat transfer factor of the tube and shell of different sizes of exchange heat pipe, it is determined that the combination of inner and outer wall dimple size of 10–15 mm is a structure with better comprehensive heat transfer performance.
Published: 2022
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4. Evaluation of the energy storage performance of PCM nano-emulsion in a small tubular heat exchanger

Author: Liu Liu, Jing Li, Jianlei Niu, and Jian-Yong Wu
Subjects: PCM emulsion, Cooling energy storage, Tubular heat exchanger, Charging and discharging rate, Thermal storage capacity, Engineering (General). Civil engineering (General), TA1-2040
Abstract: PCM emulsions have attracted considerable interest as the media for thermal energy storage (TES) owing to their high thermal storage capacity, desirable fluidity and thermal conductivity. However, the direct transportation of PCM emulsions in TES systems for both charging and discharging is rarely reported. In this work, a PCM-in-water nano-emulsion was prepared with n-hexadecane and suitable surfactants for cooling energy storage at a charging and discharging temperature range of 20–5 °C and 5–15 °C, respectively. It was applied to a tubular heat exchanger system to evaluate its TES performance for a cooling panel of 0.2 m2 total surface area. The thermal storage performance was notably increased with the flow rate of emulsion through the exchanger tube. The volumetric thermal storage capacity of charging was 50% higher than that of water. The cooling energy could be rapidly released in the discharging process, 79% of the stored energy at averaging 25 W during most of the discharging period. The emulsion remained stable throughout the test period. Overall, the results demonstrated that the PCM nano-emulsion has the unique characteristics of high static stability, and high energy releasing efficiency and the promising potential for air-conditioning application in buildings.
Published: 2021
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5. Geometry dependence of heating in a U-tube heat exchanger for pasteurization.

Author: de la Torre, Jerry James M., Culaba, Alvin B., and Martinez, Romualdo C.
Subjects: *HEAT exchangers, *FOOD pasteurization, *COMPUTATIONAL fluid dynamics, *HEAT flux, *COCONUT water, *HEAT transfer fluids
Abstract: A serpentine tube heat exchanger is physically constrained by its bend radius. The U-tube bend section of a tubular heat exchanger is thus interesting broadly in terms of fluid flow and heat transfer. This paper presents the tube size dependence of heating profile of this U-tube as is commonly encountered in the design of pasteurizers. Analytical and computational modeling were employed in investigating the heat capacity, heat flux, heating rate and energy use of a U-tube at increasing diameters 9.52, 12.70, 19.05 and 25.40 mm, each at constant 1 mm thickness. SolidWorks 2016 was used in geometric modeling while Ansys v16 was used for transient thermal computational fluid dynamics simulation of the conduit (SS316L) and the product (coconut water). The initial conditions were 5,000 W m-2 K--1 convective heat supply at 95°C and 92°C surface temperature for the conduit and the product, respectively. Both the tube and the product were initially at 30°C. The tube, whose heating profile was independent of size, reached 90°C in 2.1 s. For the product, as the tube size increases, the heat capacity increases exponentially (Qp = 108.3e0.1831x), the heat flux drops down 57% within 40 s, while both the heating rate (Tt =60s = -48ln(x) + 183.65) and the energy use (Qu = -29.65lnx + 235.36) drops logarithmically. These results are beneficial to designers and engineers in sizing of heaters, minimizing fouling and optimizing energy efficiency as well as pasteurizer processing capacity. [ABSTRACT FROM AUTHOR]
Published: 2021

6. Influence of coupling air conditioner with hybrid PCMs on building interior conditions and consumed power: Experimental investigation.

Author: Ismail, M. and Hassan, Hamdy
Subjects: *HEAT storage, *VAPOR compression cycle, *AIR-cooled condensers, *HEAT exchangers, *AIR conditioning, *PHASE change materials, *REFRIGERATION & refrigerating machinery, *THERMAL comfort, *ABSORPTIVE refrigeration
Abstract: • Coupling PCMs with an air conditioner condenser for its performance is studied experimentally. • Rising PCM quantity from 7 to 11 kg, reduces air conditioner consumption by 7.8 % and 10.4 %, respectively. • Integrating 11 kg PCM yields 0.5 °C room temperature reduction compared with air conditioners without PCM. • The higher system performance is achieved for 4 h of system working during the day time. • Enhancing the PCM's lower thermal conductivity using nanoparticles for more system performance could be studied. Air conditioning systems are vital for modern comfort but consume a substantial portion of global energy, contributing to environmental concerns and rising energy costs. PCMs can store and release energy during phase transitions, making them promise to reduce cooling loads. This study endeavors to empirically investigate the influence of integrating hybrid Phase Change Materials (PCMs), specifically PCMSP24E and PCMSP26E, with a real vapor compression refrigeration system. The primary focus is on assessing the consequential effects on the energy consumption of the refrigeration system and the interior environmental conditions within a building, including temperature and relative humidity. The energy usage of the split air conditioner wherein the outdoor unit is attached to PCMs tube heat exchanger for precooling the incoming air is investigated. Experiments reveal that PCM precooling effectively reduces the ambient air temperature entering the air conditioning condenser, leading to substantial energy savings. Increasing the PCM quantity enhances the system performance and refrigeration unit power saving. With 11 kg of PCMs, energy consumption by the air conditioning system decreases by 10.4 %, and indoor air temperature and relative humidity reduce by 0.5° and 5 %, respectively. Hence, PCM integration ensures a more consistent indoor temperature profile, enhancing occupant comfort and reducing temperature fluctuations. [ABSTRACT FROM AUTHOR]
Published: 2024
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7. Fouling modelling in a UHT unit based on plant data.

Author: Lam, Thai and Lam, Thai
Abstract: Heat treatment of dairy products is essential for food safety, one way to perform this is ultra-high temperature (UHT) processing. During the process, macronutrients and minerals form fouling deposits which impairs heat transfer. Eventually the fouling needs to be removed chemically by alkaline and acidic detergents. Fouling buildup and removal are dependent on both internal parameters such as the physical properties of the product and external parameters such as time, flow rate, temperature, and concentration. Modelling fouling development and removal on an industrial scale is valuable from an economical and environmental perspective. By optimizing how long production and cleaning cycles should be the productivity can be increased and the chemical waste as well as the energy consumption can be decreased. Although many models for fouling have been developed, each model is highly dependent on the type of heat exchanger, the product, and the operational parameters. Furthermore, they do not account for upstream and downstream processes which can affect the operator’s decision. This thesis takes a data-driven approach to construct fouling development and removal models from 27 months’ worth of data that was retrieved from a specific heat exchanger. The raw dataset was divided into production and cleaning in place (CIP) cycles. Each cycle had specific requirements that had to be fulfilled e.g., for production they should be longer than 5 hours. CIP cycles were further divided into caustic and acidic cycles. However, due to deviations from standard operating procedures (SOP) and unreliable conductivity meters, caustic and acidic cycles could not be reliably differentiated, therefore 10 reliable CIP cycles were used instead. Regression models were developed for the production and cleaning cycles, where the fouling during production increased linearly with time while cleaning cycles had a more complicated relationship with fouling., Dairy products need to be heat-treated to be safe for consumption, one way to do so is by using ultra high temperature (UHT) treatment, which involves heating products to temperatures of 135°C. This ensures that harmful bacteria are eliminated and allows for storage at room temperature, in contrast to pasteurization. However, at this temperature large deposits of minerals, fats, carbohydrates, and proteins form which is known as fouling. As a fouling layer is created between the hot and cold fluid, the pressure drop increases which leads to a deteriorated performance. To compensate for the increased pressure drop, the flow rate of the heating medium can be increased but after a certain point the fouling layer becomes too thick and chemical cleaning is required. Chemical cleaning is performed using alkaline and acidic solutions to dissolve the proteins and minerals respectively. In a UHT plant there are many heat exchangers and other units, each with their own sensors. Each sensor takes a measurement every minute which results in a very large dataset. Based on Tetra Pak know how, one specific heat exchanger which had the highest amount of fouling was chosen. The sensors selected was the temperature of the product and heating medium, the flow rates, and the conductivity. In general, higher temperatures lead to more fouling because more reactions can occur between carbohydrates, protein, minerals, and fat, while higher flow rates lead to less fouling due to the forces exerted on the fouling layer by the liquid. Other factors that affect fouling is time and concentration of the detergents. The conductivity was selected to monitor which detergent is used: acid or base. There are different approaches to modelling fouling: data driven models or physical models. Data-driven models is a pure statistical approach while physical models use mass and energy balances. It is often difficult to find a physical model that is appropriate for industrial applications due to variations
Published: 2023

8. Numerical investigation of the thermal performance optimization inside a heat exchanger tube using different novel combination of perforations on Y-shaped insert.

Author: Ifraj, Nowroze Farhan, Fahad, Mostafa Kamal, Tahsin, Sharzil Huda, Haque, Mohammad Rejaul, and Haque, M Merajul
Subjects: *HEAT exchangers, *NUSSELT number, *PRESSURE drop (Fluid dynamics), *REYNOLDS number, *TUBES, *HEAT transfer, *TRAPEZOIDS
Abstract: Metallic inserts have been receiving considerable interest in recent research as a means of enhancing passive thermal performance. Nevertheless, little research has been conducted on Y-shaped inserts with different perforations. The purpose of this study is to seek out optimum performance in terms of heat transfer employing hexagonal, trapezoidal, kite, and hybrid shapes with Perforation Indexes (PI) of 10%, 20%, and 30%. While conducting the analyses, air is utilized as the working fluid, using Reynolds numbers (Re) ranging from 3000 to 21000. The findings demonstrate that Nusselt number (Nu) values of up to 225 can be achieved at Re = 21000 for trapezoidal designs with a PI of 20%. In contrast, such case seems to have the lowest friction factor (f) of 0.07, yielding in the most optimized thermal performance. With PI = 10%, hexagonal perforations have the maximum f of 0.24, making it particularly prone to pressure drop. When compared to the smooth tube, Nu improved up to 6.15 times and f enhanced up to 5.03 times. The trapezoidal configuration with PI = 20% yielded the highest thermal performance factor, a TPF of 3.68, making it the best optimal case in terms of both thermal and hydraulic performance. [ABSTRACT FROM AUTHOR]
Published: 2023
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9. Heating a Granular Bed by a Tubular Heat Exchanger.

Author: Pitsukha, E. A., Teplitskii, Yu. S., Roslik, A. R., and Buchilko, É. K.
Subjects: *THERMAL conductivity, *COMPUTER simulation, *GRANULAR materials, *HEAT exchangers, *HEAT transfer
Abstract: Modeling of the process of thermal fluidization of a ventilated granular bed by means of a heat exchanger in the form of horizontal tubes positioned inside the bed is carried out. [ABSTRACT FROM AUTHOR]
Published: 2018
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10. Numerical study of ice slurry flow and heat transfer in successive U-bends as part of tubular heat exchangers.

Author: Rezaei, Mohammad and Pakravan, Hossein Ali
Subjects: *HEAT exchangers, *HEAT transfer, *NUSSELT number, *SLURRY, *GRANULAR flow, *ICE, *VORTEX generators, *MASS transfer
Abstract: Using ice slurry can assist the energy saving in cooling systems. Ice slurries are used as secondary refrigerant in large cooling systems. They are mixtures of tiny ice particles in water and an antifreezing agent. The cooling can be stored in ice particles during off-peak conditions and released during peak condition. The stored cooling in ice slurry must be delivered to the desired system through a heat exchanger. Successive U-bend pipes commonly exist in tubular heat exchangers. However, this configuration has not been investigated yet for ice slurries. The present study aims to investigate the heat transfer of these mixtures in successive in-plane U-bends as part of heat exchangers. Mass transfer between ice slurry and fluid is the main important part of this problem which is considered in the present study. For the simulation of ice slurry, the Eulerian two-fluid numerical method is used along with the consideration of mass transfer between two phases and the kinetic theory of granular flow for ice particles viscosity. Nusselt number and pressure drops are mainly studied for different geometric configurations. The length between two bends are changed from 50 to 400 mm and the radius of curvatures of the bends are changed from 50 to 100 mm. The results of the study indicated that the average Nusselt number increases with the radius of curvature and distance between two U-bend pipes. Two successive U-bends neutralize each other's centrifigual effects, then ice particles have chances to rearrange and reduce the wall temperature in each bend. This effect is more prominent in higher distances between two bends and higher radii of curvature. At low radius of curvatures, the variation of distance between two bends has stronger effect on heat transfer of the system; in such a way that by doubling the distance between two bends, the Nusselt number increases 4.1% and 1.5% respectively for radius of curvatures 50 mm and 100 mm. Also it was shown that by increasing the radius of curvature and distance between two U-bend pipes the skin friction coefficient increases. It can be seen that by increasing the ratio of the distance between two bends to the radius, the performance evaluation criterion (PEC) increases. [ABSTRACT FROM AUTHOR]
Published: 2023
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11. Puesta en marcha y evaluación de la medición de temperatura para un experimento de transferencia de calor de película descendente

Author: Amutio Just, Javier
Subjects: Tubular heat exchanger, Calibración, Inclined plate, RTDs, Máster Universitario en Tecnología Energética para Desarrollo Sostenible-Màster Universitari en Tecnologia Energètica per Al Desenvolupament Sostenible, Variaciones de temperatura, Placa inclinada, Falling film flow, Flujo de película descendente, Thermocouples, Temperature variations, Termopares, Heat transfer, Calibration, MAQUINAS Y MOTORES TERMICOS, Intercambiador de calor tubular, Transferencia de calor
Abstract: [ES] El proyecto de tesis de máster consiste en un equipo experimental que pretende emular diferentes etapas de la transferencia de calor circunferencial alrededor de un tubo horizontal con una placa inclinada, con el fin de aportar conocimientos sobre la transferencia de calor a baja temperatura con flujo de película descendente. Consiste en un recipiente de vacío en el que el flujo de película descendente se distribuye sobre la placa calefactora inclinada y se evapora parcialmente. La placa está equipada con termopares incrustados en cinco posiciones. Además, se utiliza una sonda termopar insertada en la película para medir la temperatura en el flujo de película descendente. El espesor de la película se mide con un sensor confocal de cromaticidad. La temperatura del líquido en la entrada y la salida se mide con un termómetro de resistencia Pt100. El caudal másico y la densidad del fluido de trabajo se miden con un caudalímetro Coriolis. Las principales tareas del proyecto consisten en Evaluación del comportamiento de los termopares frente a las variaciones de temperatura del sensor de referencia externo, instalación de los termopares en la placa, calibración de los termopares y de los termómetros de resistencia, verificación de la medición de la temperatura de la placa mediante termografía infrarroja, instalación de la sonda de termopar y desarrollo de los primeros experimentos de medición de la temperatura de la película en condiciones de evaporación al vacío para obtener valores consistentes del coeficiente de transferencia de calor con agua como fluido de trabajo., [EN] The master's thesis project consists of experimental equipment that aims to emulate different stages of circumferential heat transfer around a horizontal tube with an inclined plate in order to provide knowledge on low-temperature heat transfer with falling film flow. It consists of a vacuum vessel in which the falling film flow is distributed over the inclined heating plate and partially evaporates. The plate is equipped with thermocouples embedded in five positions. In addition, a thermocouple probe inserted in the film is used to measure the temperature in the falling film stream. The film thickness is measured with a confocal chromaticity sensor. The liquid temperature at the inlet and outlet is measured with a Pt100 resistance thermometer. The mass flow and density of the working fluid is measured with a Coriolis flowmeter. The main tasks of the project consist of: Evaluation of the behaviour of the thermocouples against temperature variations in the external reference sensor, installation of the thermocouples on the plate, calibration of the thermocouples and resistance thermometers, verification of the plate temperature measurement by infrared thermography, installation of the thermocouple probe and development of the first experiments measuring the film temperature under vacuum evaporation conditions in order to obtain consistent values of heat transfer coefficient with water as a working fluid., [DE] Das Masterarbeitsprojekt besteht aus einer Versuchsanlage, mit der verschiedene Stadien der Umfangswärmeübertragung um ein horizontales Rohr mit einer geneigten Platte nachgebildet werden sollen, um Erkenntnisse über die Niedertemperatur-Wärmeübertragung mit Fallfilmströmung zu gewinnen. Sie besteht aus einem Vakuumgefäß, in dem der Fallfilmstrom über die geneigte Heizplatte verteilt wird und teilweise verdampft. Die Platte ist mit Thermoelementen ausgestattet, die an fünf Stellen angebracht sind. Außerdem wird mit einer in den Film eingeführten Thermoelement-Sonde die Temperatur im Fallfilmstrom gemessen. Die Schichtdicke wird mit einem konfokalen Chromatizitätssensor gemessen. Die Flüssigkeitstemperatur am Einlass und Auslass wird mit einem Pt100-Widerstandsthermometer gemessen. Der Massenstrom und die Dichte der Arbeitsflüssigkeit werden mit einem CoriolisDurchflussmesser gemessen. Die Hauptaufgaben des Projekts bestehen in: Bewertung des Verhaltens der Thermoelemente gegenüber Temperaturschwankungen im externen Referenzsensor, Installation der Thermoelemente auf der Platte, Kalibrierung der Thermoelemente und Widerstandsthermometer, Überprüfung der Plattentemperaturmessung durch InfrarotThermografie, Installation der Thermoelement-Sonde und Entwicklung der ersten Experimente zur Messung der Filmtemperatur unter Vakuumverdampfungsbedingungen, um konsistente Werte des Wärmeübergangskoeffizienten mit Wasser als Arbeitsflüssigkeit zu erhalten.
Published: 2022

12. Multi-objective optimization of a tubular heat exchanger enhanced with delta winglet vortex generator and nanofluid using a hybrid CFD-SVR method.

Author: Ekrani, Seyed Mahdi, Ganjehzadeh, Shayan, and Esfahani, Javad Abolfazli
Subjects: *VORTEX generators, *HEAT exchangers, *PROPERTIES of fluids, *NANOFLUIDS, *BOUNDARY layer (Aerodynamics), *PRESSURE drop (Fluid dynamics)
Abstract: The present study improves the thermal-hydraulic performance of a circular tube equipped with a delta winglet vortex generator by providing a numerical model, investigating the effect of two additional parameters, and developing a support vector regression (SVR) for prediction and optimization. The additional parameters are the angle of attack and SiO 2 concentration, while the data on the variation of thermohydraulic parameters with pitch and blockage is already available in the literature. The boundary layer disruption and swirling flow caused by the delta winglet result in heat transfer enhancement. The presence of such inserts also increases the pressure drop in the heat exchanger. The nanofluid further enhances heat transfer by boosting the thermophysical properties of the fluid. The hybrid method, CFD-SVR, is carried out for turbulent water flow at Reynolds numbers ranging from 4200 to 16200. The delta winglets are in pair arrangement with ten angles of attack from 25 ∘ to 70 ∘ with 5 ∘ increments. The addition of SiO 2 with volumetric concentrations varies from φ = 0 to 0.5% has been explored. The diameter of the tube (D) is 50 mm, while the pitch ratio (P/D) and blockage ratio (B/D) vary from 1 to 3 and 0.1 to 0.2, respectively. Finally, the data of this study and the previously published experimental data were fed into an SVR to find the best possible arrangement of delta winglet for a tubular heat exchanger. The highest achieved thermal enhancement factor (TEF) was found to be 2.18 with α = 25°, P R = 0.83, B R = 0.13, and φ = 0.5% at the least Re number. [Display omitted] [ABSTRACT FROM AUTHOR]
Published: 2023
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13. Borulu Bir Isı Değiştiricide Kullanılan Nanoakışkanların Isıl ve Hidrolik Performansa Olan Etkisinin Sayısal Olarak İncelenmesi

Author: ÖĞÜT, Elif and DİLKİ, Seda
Subjects: Nanofluids, Tubular heat exchanger, heat transfer, CFD, Engineering, Mühendislik, Nanoakışkan, borulu ısı eşanjörü, ısı transferi, HAD
Abstract: Energy is one of the world's critical resources. For this reason, energy saving and efficiency is an important study subject. In order to save energy, there are theoretical and experimental studies in the literature due to the need for the improvement of heat transfer and the compactness of the heat exchangers, and the search for new fluids that will provide heat transfer improvement instead of the traditional fluids used in heat exchangers.In this study, the nanofluids obtained by changing the ratios of Al2O3 and SiO2 high nanoparticles volume fraction instead of low nanoparticles volume fraction and by changing the ratios of the base fluid ethylene glycol-water mixtures, where efficient results were obtained in providing heat transfer improvement, the thermal and hydraulic performance of a concentric, intertwined, parallel and counter flow in a tubular heat exchanger, using hot and cold fluids at different volumetric flows, was investigated numerically. Water on the hot fluid side, 0:100%, 40:60%, 60:40% and 100:0% on the cold fluid side, into different ratios of EG-water at 0%, 2%, 4%, 6% nanoparticles volume fractions and different Reynolds numbers (6000 – 8000 – 12000 – 16000 - 20000) nanofluids obtained by adding Al2O3 and SiO2 nanoparticles were used. According to the results of numerical studies, when the fixed volumetric flow value of hot fluid water is 3 l/min, the constant volumetric flow value of nanofluids is 0.9 l/min and Reynolds number 20000, Al2O3-100:0% EG/water and SiO2-100:0% EG/water. The Nusselt number of nanofluids increased by 15.4% and 9.1%, respectively, compared to 0:100% EG/water. The results showed that the pressure drop in a counter flow tubular heat exchanger is high, as well as the heat exchanger performance is better than the parallel flow, the Nusselt number increases with the solid volume concentration contained in the nanofluid, and both the 0:100% ratio and the SiO2 of the Al2O3-100:0% EG/water nanofluid. SiO2 -100:0% EG/water indicates that it is more effective in increasing the performance of the heat exchanger compared to nanofluid., Enerji dünyanın kritik kaynaklarının başında gelmektedir. Bu sebeple enerji tasarrufu ve verimlilik önemli bir çalışma konusudur. Enerji tasarrufunun sağlanabilmesi için ısı transferinin iyileştirilmesi ile ısı değiştiricilerin kompaktlığı gibi ihtiyaçların doğması ile ısı değiştiricilerde kullanılan geleneksel akışkanların yerine ısı transferi iyileştirmesini sağlayacak yeni akışkan arayışı sebebiyle literatürde teorik ve deneysel çalışmalar bulunmaktadır. Bu çalışmada ısı transferi iyileştirmesinin sağlanmasında verimli sonuçların elde edildiği Al2O3 ve SiO2 nanoparçacıklarının düşük katı hacim yerine yüksek katı hacim oranlarında ve temel akışkan etilen glikol-su karışımlarının oranları değiştirilerek farklı hacimsel debilerde sıcak ve soğuk akışkanların kullanıldığı, eş merkezli, iç içe borulu, paralel ve zıt akışlı bir ısı değiştiricinin ısıl ve hidrolik performansı sayısal olarak incelenmiştir. Sıcak akışkan tarafında su, soğuk akışkan tarafında %0:100, %40:60, %60:40 ve %100:0 olmak üzere farklı oranlardaki etilen glikol-su karışımı içerisine %0, %2, %4, %6 katı hacim konsantrasyonlarında ve farklı Reynolds sayılarında (6000 – 8000 – 12000 – 16000 - 20000) Al2O3 ve SiO2 nanoparçacıkların eklenmesiyle elde edilen nanoakışkanlar kullanılmıştır. Sayısal çalışmaların sonuçlarına göre, zıt akış altında sıcak akışkan olan suyun sabit hacimsel debi değeri 3 l/dk, nanoakışkanların sabit hacimsel debi değeri 0,9 l/dk ve Reynolds sayısı 20000 alındığında, %6 katı hacim oranı için Al2O3-%100:0 EG/su ve SiO2-%100:0 EG/su nanoakışkanlarının Nusselt sayısında, %0:100 EG/su oranına kıyasla sırasıyla %15,4 ve %9,1 oranında artış olmuştur. Sonuçlar, zıt akışlı bir ısı değiştiricideki basınç düşümünün yüksek değerlerde olmasının yanında, Isı değiştirici performasının paralel akışa göre daha iyi olduğunu, nanoakışkanın içerdiği katı hacim oranın artmasıyla Nusselt sayısının arttığını ve Al2O3-%100:0 EG/su nanoakışkanının hem %0:100 EG/su oranına hem de SiO2- %100:0 EG/su nanoakışkanına göre ssı değiştiricinin performansını artırmada daha etkili olduğunu göstermektedir.
Published: 2021

14. EXPERIMENATAL INVESTIGATION OF THERMAL CHARACTERISTICS ONCROSS FLOW TUBULAR HEATEXCHANGER FOR INDIRECT EVAPORATIVE COOLING

Author: Hemant Darokar, Rohit Pandit, Hemchandra Pant, Hemant Darokar, Rohit Pandit, and Hemchandra Pant
Abstract: The demandfor cooling system increases worldwide. Indirect Evaporative cooling can be used to cool air from the surface of heat exchanger without change in humidity. As there is no contact between water and air due to cross flow heat exchanger. Primary air stream is cooled by secondary air stream after evaporation of water in wetted surface of cross flow tubular heat exchanger made of PVC pipe and tested it in summer condition. By measuring humidity and DBT thermal characteristic such as cooling capacity, heat transferred per unit time, wet bulb effectiveness, COP, Dew point effectivenessis calculated.Temperature difference between inlet temperature (from atmosphere) and outlet temperature (to room) up to 8 to 10 ºCis achievedwith constant Humidity.
Published: 2021

15. Experimental characterization of a double tube heat exchanger with different corrugated tubes and shells.

Author: Moya-Rico, J.D., Molina, A.E., Córcoles, J.I., and Almendros-Ibáñez, J.A.
Subjects: *THERMAL hydraulics, *HEAT exchangers, *HEAT transfer coefficient, *HEAT transfer fluids, *TUBES, *REYNOLDS number, *DOUBLE walled carbon nanotubes
Abstract: The aim of this paper was to study the influence of a double tube heat exchanger (DTHX) on thermo-hydraulic performance, considering 21 different shell–tube configurations including smooth and corrugated inner and outer tubes. In order to emulate the behavior of high-viscosity food-industry fluids, a 60°brix solution of water and sugar was used as the Heat Transfer Fluid (HTF). A total of 504 experimental tests were carried out, varying the flow velocity (Reynolds number) and the shell corrugation parameters (helix pitch P and groove depth d). The results from three different shells, one smooth and two corrugated shells, and seven different inner tubes, one smooth and six corrugated with a groove depth between 0.5 mm and 1.2 mm are presented. The comparison of the three shells with an inner smooth tube shows significant heat transfer rate enhancements using a light groove depth (CC1) in the outer tube of the DTHX, increasing both the average efficiency and the P E C indicator (Performance evaluation criteria) by 5% compared with the smooth shell. No improvements are found when a higher groove depth (CC2) in the outer tube of the DTHX is used. Regarding the results with different inner tubes, the tubes with the highest groove depth in the tested range (between 0.5 and 1.2 mm), CO11 and CO12 (with a groove depth of 1.1 and 1.2 mm, respectively), show the best results, regardless of the type of shell. Corrugated tube CO12 shows the best results in terms of efficiency, with an average increment of 19% compared with the smooth inner tube. Regarding P E C , CO11 shows an average increment of 9% in the analyzed P E C indicator compared with the smooth inner tube. • The thermo-hydraulic performance of a double tube heat exchanger was evaluated. • 21 different shell–tube configurations were experimentally tested. • The shell with a groove depth of 0.6 mm increases 5.5% the heat transfer coefficient. • The inner tube C012 gets a increase of 19% in the thermal efficiency. [ABSTRACT FROM AUTHOR]
Published: 2022
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16. Effect of advanced surfaces on the ammonia absorption process with NH3/LiNO3 in a tubular bubble absorber.

Author: Amaris, Carlos, Bourouis, Mahmoud, and Vallès, Manel
Subjects: *SURFACES (Technology), *AMMONIA analysis, *HEAT radiation & absorption, *CHEMICAL processes, *ALUMINUM
Abstract: Abstract: An experimental study was conducted to investigate the effect of advanced surfaces on the ammonia absorption process in tubular bubble absorbers using NH3/LiNO3 as a working pair at operating conditions of interest for absorption chillers. The tubular bubble absorber is a vertical double-pipe heat exchanger in which absorption takes place in the inner tube. In order to compare the effect of surface enhancement, a smooth tube and an internally micro-finned tube were tested. The inner tube of the absorber is made of aluminium and has an outer diameter of 8.0mm and the micro-finned tube has internal helical micro-fins measuring 0.3mm in length. The effect of tube length on absorption was also studied using two tube lengths (1 and 3m) and two tube diameters (8 and 9.5mm). Our results show that the absorption rate achieved with the micro-finned tube is up to 1.7 times higher than with the smooth tube at a solution mass flow rate of 40kgh−1. We also found that absorption mass flux increases when tube diameter is reduced and decreases when tube length is increased. [Copyright &y& Elsevier]
Published: 2014
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17. Modeling of continuous thermal processing of a non-Newtonian liquid food under diffusive laminar flow in a tubular system

Author: Kechichian, Viviane, Crivellari, Gabriel P., Gut, Jorge A.W., and Tadini, Carmen C.
Subjects: *MATHEMATICAL models, *THERMAL analysis, *NON-Newtonian fluids, *DIFFUSION, *LAMINAR flow, *CONSERVATION laws (Physics), *TEMPERATURE effect, *MATHEMATICAL optimization
Abstract: Abstract: The classic conservative approach for thermal process design can lead to over-processing, especially for laminar flow, when a significant distribution of temperature and of residence time occurs. In order to optimize quality retention, a more comprehensive model is required. A model comprising differential equations for mass and heat transfer is proposed for the simulation of the continuous thermal processing of a non-Newtonian food in a tubular system. The model takes into account the contribution from heating and cooling sections, the heat exchange with the ambient air and effective diffusion associated with non-ideal laminar flow. The study case of soursop juice processing was used to test the model. Various simulations were performed to evaluate the effect of the model assumptions. An expressive difference in the predicted lethality was observed between the classic approach and the proposed model. The main advantage of the model is its flexibility to represent different aspects with a small computational time, making it suitable for process evaluation and design. [Copyright &y& Elsevier]
Published: 2012
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18. Evaluation of the energy storage performance of PCM nano-emulsion in a small tubular heat exchanger

Author: Jianlei Niu, Liu Liu, Jing Li, and Jianyong Wu
Subjects: Tubular heat exchanger, Fluid Flow and Transfer Processes, PCM emulsion, Work (thermodynamics), Materials science, Thermal storage capacity, 020209 energy, 02 engineering and technology, Atmospheric temperature range, Engineering (General). Civil engineering (General), Thermal energy storage, 01 natural sciences, Energy storage, Cooling energy storage, 010406 physical chemistry, 0104 chemical sciences, Volumetric flow rate, Charging and discharging rate, Thermal conductivity, Heat exchanger, Emulsion, 0202 electrical engineering, electronic engineering, information engineering, TA1-2040, Composite material, Engineering (miscellaneous)
Abstract: PCM emulsions have attracted considerable interest as the media for thermal energy storage (TES) owing to their high thermal storage capacity, desirable fluidity and thermal conductivity. However, the direct transportation of PCM emulsions in TES systems for both charging and discharging is rarely reported. In this work, a PCM-in-water nano-emulsion was prepared with n-hexadecane and suitable surfactants for cooling energy storage at a charging and discharging temperature range of 20–5 °C and 5–15 °C, respectively. It was applied to a tubular heat exchanger system to evaluate its TES performance for a cooling panel of 0.2 m2 total surface area. The thermal storage performance was notably increased with the flow rate of emulsion through the exchanger tube. The volumetric thermal storage capacity of charging was 50% higher than that of water. The cooling energy could be rapidly released in the discharging process, 79% of the stored energy at averaging 25 W during most of the discharging period. The emulsion remained stable throughout the test period. Overall, the results demonstrated that the PCM nano-emulsion has the unique characteristics of high static stability, and high energy releasing efficiency and the promising potential for air-conditioning application in buildings.
Published: 2021
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19. Flow process and heating conditions modulate the characteristics of whey protein aggregates

Author: Cécile Le Floch-Fouéré, François Martin, Romain Jeantet, Thierry Six, Marie Hennetier, Domitille de Guibert, Guillaume Delaplace, Yingying Gu, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Ecole d'Ingénieurs de Purpan (INP - PURPAN), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), BBA industrial association and the Regional Councils of Brittany (grant n° 13008651) and Pays de la Loire (grant n° 2014-07081) who funded this work through the interregional PROFIL project, carried out by the association 'Pole Agronomique Ouest'., Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, EI Purpan, Agro-physiology Laboratory Toulouse, Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL)
Subjects: Whey protein, Materials science, échangeur tubulaire, Flow (psychology), agrégat protéique, tubular heat exchanger, fractionnement, Residence time (fluid dynamics), 03 medical and health sciences, 0404 agricultural biotechnology, 0302 clinical medicine, écoulement, traitement en continu, Heat exchanger, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Aggregate (composite), protéine fractale, Turbulence, protéine de lactosérum, agrégat fractal, fractionnement physique, Laminar flow, 04 agricultural and veterinary sciences, whey protein, protéine de lactoserum, contrôle de processus, 040401 food science, traitement thermique de l'aliment, Chemical engineering, Scientific method, 030221 ophthalmology & optometry, agrégat, propriété physicochimique du lait, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition, Food Science, traitement thermique
Abstract: Whey protein fractal aggregates reveal different texturizing properties depending on their size. This study characterize the effect of three process parameters (flow regime, heating residence time (RTh) and heating temperature) on the size and shape of aggregates formed at a semi-industrial scale using a dynamic tubular heat exchanger, and identify the mechanisms involved in their formation. The study showed that physicochemical parameters are not the unique levers to modulate agregates properties but process parameters are also efficient. Asymetrical-Flow-Field-Flow-Fractionation was used to highlight the significant increase of aggregate size produced under transient regime conditions compared to laminar and turbulent regimes. Even larger aggregates were obtained while increasing the heating temperature from 80 to 85 °C since the unfolding aggregation of protein was controlled by the aggregation step. Moreover, RTh showed no effect on aggregate formation. This study paves the way to the control of aggregate properties obtained in a continuous dynamic mode.
Published: 2020
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20. Hydrothermal performance comparison of modified twisted tapes and wire coils in tubular heat exchanger using hybrid nanofluid.

Author: Singh, Sumit Kumar and Sarkar, Jahar
Subjects: *HEAT exchangers, *NANOFLUIDS, *HEAT transfer coefficient, *PRESSURE drop (Fluid dynamics), *REYNOLDS number, *HEAT transfer
Abstract: A comparative experimental study to examine the hydrothermal behaviors of the double tube heat exchanger with various modified twisted tape and wire coil inserts is performed using Al 2 O 3 +MWCNT hybrid nanofluid. The investigation is performed for Reynolds number of 8000–40000, nanofluid flow rate of 5–25 lpm and volume concentration of 0.01%. The effects of using various enhancers (V-cut twisted tapes and tapered wire coils) and hybrid nanofluid on the hydrothermal characteristics are assessed for different enhancer arrangements such as different twist ratios, V-cut depth ratios, V-cut width ratios, converging type (C-type) wire coil, diverging (D-type) wire coil and converging-diverging type (C-D type) wire coil. The test reveals that the pressure drop and heat transfer coefficient increase with reducing twist ratio, increasing depth ratio and reducing width ratio. D-type wire coil exhibits higher heat transfer performance with the penalty of pressure drop than that of other arrangements. V-cuts twisted tape of minimum twist ratio, maximum depth and width ratios yields maximum PEC and FOM. V-cut twisted tapes show a higher performance index than the tapered wire coil as the augmentation in pressure drop is slightly significant. D-type wire coil shows the minimum value of entropy generation among all other arrangements. • Performance of concentric tube heat exchanger is studied with inserts using hybrid nanofluid. • Experiment is performed for various V-cut twisted tape and tapered wire coil configurations. • D-type wire coil exhibits higher heat transfer performance with the penalty of pressure drop. • V-cut twisted tapes show higher hydrothermal performance as compared to tapered wire coil. • D-type wire coil exhibits minimum value of entropy generation among all the arrangements. [ABSTRACT FROM AUTHOR]
Published: 2021
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21. Augmented heat transfer in tubular heat exchanger fitted with V-baffled tapes.

Author: Promvonge, Pongjet and Skullong, Sompol
Subjects: *HEAT exchangers, *HEAT transfer, *TURBULENT heat transfer, *HEAT transfer fluids, *REYNOLDS number
Abstract: Effects of insertion of a straight tape mounted with double-sided V-baffles used as a longitudinal vortex generator (LVG) on turbulent convection heat transfer behaviors in a constant heat-fluxed tube in the Reynolds number (Re) range of 4120 to 25,800 are experimentally and numerically investigated. In the present experiment, the V-baffles at a fixed attack angle (α = 30°) were placed on the tape with two arrangements: V-apex pointing downstream and upstream (hereinafter called "V-down" and "V-up"). The V-down and up tapes with three baffle height ratios, (R B = b / D = 0.20, 0.15, 0.10) and pitch ratios, (R P = P / D = 1.5, 1.0, 0.5) were tested. Data of the current smooth or plain tube were also examined for comparison. The experimental results have shown that the employ of the V-down tape generally yields higher heat transfer, friction loss and thermal performance than that of the V-up one. A new derived thermal-performance enhancement factor (TEF) is proposed. The maximum TEF of the V-down tape is around 2.07 at R B = 0.15, R P = 1.0 and is, in average, about 1.4% higher than the V-up one having its peak of 2.04. A 3D numerical V-baffled-tube flow model was also simulated to examine the fluid flow and heat transfer patterns. The numerical validation was seen in close agreement with available experimental data. Numerical heat transfer contours and flow structures were also reported. • A novel V-baffled tape is introduced for performance improvement in a tubular heat exchanger. • The insertion of V-down tape yields superior thermal performance over the V-up. • Thermal characteristics in the tubular heat exchanger are experimentally and numerically examined. • Optimum parameters of V-baffled tapes and their correlations are reported. [ABSTRACT FROM AUTHOR]
Published: 2020
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22. Nonlinear control of a shell and tube heat exchanger

Author: Dostál, Petr, Bobál, Vladimír, Vojtěšek, Jiří, Dostál, Petr, Bobál, Vladimír, and Vojtěšek, Jiří
Abstract: The paper deals with design and simulation of nonlinear adaptive control of a shell and tube heat exchanger. The method is based on factorization of the controller on a nonlinear static part and an adaptive linear dynamic part. The nonlinear static part is derived using inversion and subsequent exponential approximation of simulated or measured steady-state characteristics of the exchanger. The linear dynamic part is then obtained from an external linear model of nonlinear elements of the closed-loop. The parameters of the external linear model are recursively estimated via a corresponding delta model. The control law in the 1DOF and 2DOF control system structures is derived using the polynomial approach. Proceedings 28th European Conference on Modelling and Simulation © ECMS Flaminio Squazzoni, Fabio Baronio, Claudia Archetti, Marco Castellani (Editors).
Published: 2014

23. Effect of advanced surfaces on the ammonia absorption process with NH 3/LiNO3 in a tubular bubble absorber

Author: Universitat Rovira i Virgili, Amaris, Carlos; Bourouis, Mahmoud; Vallès, Manel, Universitat Rovira i Virgili, and Amaris, Carlos; Bourouis, Mahmoud; Vallès, Manel
Abstract: An experimental study was conducted to investigate the effect of advanced surfaces on the ammonia absorption process in tubular bubble absorbers using NH3/LiNO3 as a working pair at operating conditions of interest for absorption chillers. The tubular bubble absorber is a vertical double-pipe heat exchanger in which absorption takes place in the inner tube. In order to compare the effect of surface enhancement, a smooth tube and an internally micro-finned tube were tested. The inner tube of the absorber is made of aluminium and has an outer diameter of 8.0 mm and the micro-finned tube has internal helical micro-fins measuring 0.3 mm in length. The effect of tube length on absorption was also studied using two tube lengths (1 and 3 m) and two tube diameters (8 and 9.5 mm). Our results show that the absorption rate achieved with the micro-finned tube is up to 1.7 times higher than with the smooth tube at a solution mass flow rate of 40 kg h−1. We also found that absorption mass flux increases when tube diameter is reduced and decreases when tube length is increased.
Published: 2014

24. Modelling and measurement of residence time distribution in tubular Joule effect heaters with and without geometric modifications

Author: André, Christophe, Boissier, Benjamin, Fillaudeau, Luc, Hautes Etudes d’Ingénieur [Lille] (HEI), Laboratoire de Génie des Procédés et Technologie Alimentaires (LGPTA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Recherche Agronomique (INRA), JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV.BIO]Life Sciences [q-bio]/Biotechnology, residence time distribution, tubular heat exchanger, Biotechnologies, Joule effect
Abstract: In food industry, heat treatment of highly viscous fluids in continuous process is more and more common and the process should perform homogenous thermal treatment in order to ensure quality and safety of the final product. To improve treatment homogeneity, geometric modifications could be used even in laminar regime inducing flow perturbation and mixing. In this work, our objectives were (i) to investigate residence time distribution (RTD) for industrial indirect Joule effect heaters (JEH) with smooth (ST) and modified (MT) tubes, (ii) to demonstrate and quantify the efficiency of geometrical modifications and (iii) to propose a general reactor model including flow regime (10
Published: 2006

25. Vliv podélného promíchávání na statické a dynamické vlastnosti trubkového výměníku tepla.

Author: Baroň, Přemysl and Baroň, Přemysl
Abstract: Trubkový výměník tepla patří do třídy systémů se spojitě rozloženými parametry popsanými parciálními diferenciálními rovnicemi (PDR). V případě, že je uvažováno s podélným promícháváním proudícího média, obsahuje příslušná PDR i druhou parciální derivaci teploty podle prostorové proměnné. Úlohou této diplomové práce je vyšetřit, jaký je vliv koeficientu promíchávání na statické a dynamické vlastnosti výměníku. Diplomová práce obsahuje matematické modely výměníku tepla s protiproudým chlazením, metody pro řešení ustáleného stavu i dynamiky, odpovídající simulační modely, použité zdrojové kódy pro MATLAB a simulace statických a dynamických charakteristik., Tubular heat exchangers belong to a class of continuously distributed parameter systems described by partial differential equations (PDEs). Under consideration of an axial dispersion in the flowing medium, the relevant PDEs include in addition to the first order also the second order temperature derivetives with respect to the space variable. The objective of this thesis is to investigate an effect of the axial dispersion factor on the heat exchanger static and dynamic characteristics. The thesis contains mathematical models of the heat exchanger with the countercurrent cooling, methods for solution of the steady state and dynamics, correspondent simulation models, MATLAB simulation programmes, and, simulated static and dynamic characteristics., Ústav automatizace a řídicí techniky, obhájeno
Published: 2010

26. Numero-Fuzzy Modell zur Beschreibung des Foulings bei der Erhitzung von Milch

Author: Petermeier, Johannes, Delgado, A. (Univ.-Prof. Dr.-Ing. (habil.)), Delgado, Antonio (Prof. Dr. habil.), and Hinrichs, J. (Univ.-Prof. Dr.-Ing. (habil.), Universität Hohenheim)
Subjects: Technische Chemie, Fouling, Tubular Heat Exchanger, Milk heating, fuzzy-logic, Model, ddc:660, ddc:630, Röhrenwärmetauscher, Milcherhitzung, Fuzzy-Logik, Landwirtschaft, Veterinärmedizin
Abstract: Die vorliegende Arbeit beschreibt einen hybriden Ansatz, der numerische Methoden mit Fuzzy-Systemen für die Beschreibung des Proteinfoulings bei der Erhitzung von Milch kombiniert. Zur Modellvalidierung werden aus dem Prozessleitsystem einer Industrieanlage zur Milcherhitzung gewonnene Prozessparameter (Temperatur, Druck) herangezogen und hinsichtlich des Foulings untersucht. Der numerische Teil des Numero-Fuzzy-Hybrids setzt ein Finite-Volumen-Modell ein. Modellansätze und daten für das Produkt (Milch) entstammen der Literatur. Die Integration des in einer Vielzahl von in der Literatur genannten Experimenten gewonnenen qualitativen Wissens über die Milchansatzbildung wird über Fuzzy-Systeme integriert. Ein Ansatz zur Untersuchung der Sensitivität der eingesetzten Fuzzy-Systeme, der auf einer differenzierbaren Approximation dieser beruht, wird vorgestellt. The work describes a hybrid approach combining numerical methods with fuzzy-systems for the description of fouling during the heating of milk. For model validation process parameters (temperature, pressure) of an industrial milk heating plant are taken from the process control system and studied with respect to fouling. The numerical part of the numero-fuzzy-hybrid uses a finite-volume-model. Approaches and data for modelling the product (milk) are taken from literature. The integration of the qualitative knowledge obtained in numerous experiments being documented in literature is integrated using fuzzy-systems. An approach to study the sensitivity of the implemented fuzzy-systems by means of a differentiable approximation is presented.
Published: 2005

27. Návrhový výpočet únavy trubkového kondenzátoru páry s pevnými trubkovnicemi

Author: Pernica, Marek, Vincour, Dušan, Cablková, Zuzana, Pernica, Marek, Vincour, Dušan, and Cablková, Zuzana
Abstract: Diplomová práce se věnuje návrhovému výpočtu únavy trubkového kondenzátoru páry s pevnými trubkovnicemi, který je v provozu použit jako pojistný pro kondenzaci páry z turbíny. Toto zařízení je zatíženo teplotou a tlakem, které vyvolávají napětí. Vzhledem k možnosti jeho častého najíždění na provozní stav a sjíždění na klidový stav mohou vznikat napěťové cykly. Praktickou částí práce je návrhový výpočet, proveden dle normy ČSN EN 13445–3 s využitím metody konečných prvků, zkratkou MKP. Teoretická část práce obsahuje rešerši dostupných norem pro hodnocení únavové životnosti výměníků tepla, základní znalosti týkající se problematiky únavového poškození a případy reálného poškození únavou v praxi., The diploma thesis is devoted to the design of the fatigue calculation of the tubular steam condenser with fixed tube sheets, which is in operation as a safety equipment for the steam condenser from the turbine. This device is loaded with temperature and pressure that induces tension. Due to the possibility of frequently starting it up to the operational state and going down to the rest state, stress cycles can occur. The practical part of the thesis is the design calculation, carried out according to ČSN EN 13445–3 standards using the finite element method, abbreviated FEM. The theoretical part of the diploma includes a search of available standards for evaluating the fatigue life of heat exchangers, basic knowledge regarding the issue of fatigue damage and cases of real fatigue damage in practice.

28. Pevnostní výpočet trubkovnice tepelného výměníku se zaměřením na ekonomické zhodnocení

Author: Buzík, Jiří, Vincour, Dušan, Horniak, Patrik, Buzík, Jiří, Vincour, Dušan, and Horniak, Patrik
Abstract: Bakalářská práce je zaměřena na pevnostní výpočet trubkovnice zadaného tepelného výměníku s pláštěm. Jde o trubkový výměník s pevnými trubkovnicemi a přímými trubkami. Navrhovaná trubkovnice je integrální s pláštěm, těsněná ke komoře s přírubovým okrajem. První část práce je věnována seznámení se s problematikou tepelných výměníků a trubkovnic. Výpočtová část práce se zabývá pevnostním návrhem tloušťky trubkovnice na základě normy ČSN EN 13 445. Ve výpočtové části jsou uvedeny vstupní parametry, základní podmínky výpočtu, rovnice potřebné pro výpočet maximálních napětí působících ve výměníku a pevnostní podmínky kontrolovaných součástí. Závěrem této části je zhodnocení dosažených výsledků vypočtených za pomoci programovacího jazyka Python v prostředí Spyder. Kontrola správnosti výsledků je provedena na základě výpočtů v programu Visual Vessel Design (VVD). Poslední částí práce je ekonomické zhodnocení celého návrhu na základě rozdílné volby kontrolovaného materiálu trubkovnice., This bachelor thesis is focused on strength design of assigned shell-and-tube heat exchanger. This heat exchanger have fixed tube sheets and straight tubes. Designed tube sheet is integrated with shell and flanged to the channel. First part of the thesis serves as introduction on the issue of heat exchangers and tube sheets. Following chapters are dedicated to the strength design of tube sheet thickness based on the ČSN EN 13 445 standard. These chapters are dealing with input parameters, basic requirements of calculation, equations essential for calculation of stress in heat exchanger and analysis of stresses in heat exchanger with the use of proper strength conditions. Conclusion of these chapters is evaluation of calculated results from personal scipt written in Python language using Spyder environment. Correctness of these results is ensured by their comparison with the output of Visual Vessel Design (VVD) program. Final part of the thesis is economic evaluation of whole tube sheet design based on possibility of choosing different analyzed material.

29. Návrh výměníku tepla pro zlepšení efektivity průmyslového provozu

Author: Freisleben, Vít, Kilkovský, Bohuslav, Hofbauer, Jan, Freisleben, Vít, Kilkovský, Bohuslav, and Hofbauer, Jan
Abstract: Práce se zabývá návrhem trubkového výměníku tepla s křížovým tokem pro předehřev spalovacího vzduchu pro technologickou jednotku spalující odpadní produkty při výrobě kyseliny akrylové. Nejdříve je v programu Chemcad provedena simulace na základě známých provozních dat technologické jednotky pro predikci chování technologického celku s navrženým výměníkem. Dále jsou disktovány podstatné mechanismy přenosu tepla, na které navazuje přehled typů výměníků tepla používaných pro předehřev spalovacího vzduchu. Před samotným návrhem je provedena optimalizace výkonu na základě doby návratnosti. Tepelně-hydraulický návrh je potom proveden metodou F-LMTD v programu GNU Octave. Ověření výsledků výpočtu je provedeno za pomocí programu HTRI Xchanger Suite®. Na závěr jsou diskutovány ekonomické a ekologické přínosy navrhnutého výměníku., In thesis is done thermal-hydraulic design of cross-flow tubular heat exchanger for combustion air preheating. In software Chemcad is done simulation of technological unit based on known operating data, which is used for behavior prediction of unit after heat exchanger installation. Then there are discussed essential mechanisms of heat transfer. After that there is overview of different heat exchanger types used for combustion air preheating. Before particular design there is performed optimalization of heat duty of heat exchnger based on payback time. Thermal-hydraulic design is performed using F-LMTD method in software GNU Octave. Obtained results are verified using software HTRI Xchanger Suite®. At the end there are discussed economical and ecological benefits of designed heat exchanger.

30. Pevnostní výpočet trubkovnice tepelného výměníku se zaměřením na ekonomické zhodnocení

Author: Buzík, Jiří, Vincour, Dušan, Horniak, Patrik, Buzík, Jiří, Vincour, Dušan, and Horniak, Patrik
Abstract: Bakalářská práce je zaměřena na pevnostní výpočet trubkovnice zadaného tepelného výměníku s pláštěm. Jde o trubkový výměník s pevnými trubkovnicemi a přímými trubkami. Navrhovaná trubkovnice je integrální s pláštěm, těsněná ke komoře s přírubovým okrajem. První část práce je věnována seznámení se s problematikou tepelných výměníků a trubkovnic. Výpočtová část práce se zabývá pevnostním návrhem tloušťky trubkovnice na základě normy ČSN EN 13 445. Ve výpočtové části jsou uvedeny vstupní parametry, základní podmínky výpočtu, rovnice potřebné pro výpočet maximálních napětí působících ve výměníku a pevnostní podmínky kontrolovaných součástí. Závěrem této části je zhodnocení dosažených výsledků vypočtených za pomoci programovacího jazyka Python v prostředí Spyder. Kontrola správnosti výsledků je provedena na základě výpočtů v programu Visual Vessel Design (VVD). Poslední částí práce je ekonomické zhodnocení celého návrhu na základě rozdílné volby kontrolovaného materiálu trubkovnice., This bachelor thesis is focused on strength design of assigned shell-and-tube heat exchanger. This heat exchanger have fixed tube sheets and straight tubes. Designed tube sheet is integrated with shell and flanged to the channel. First part of the thesis serves as introduction on the issue of heat exchangers and tube sheets. Following chapters are dedicated to the strength design of tube sheet thickness based on the ČSN EN 13 445 standard. These chapters are dealing with input parameters, basic requirements of calculation, equations essential for calculation of stress in heat exchanger and analysis of stresses in heat exchanger with the use of proper strength conditions. Conclusion of these chapters is evaluation of calculated results from personal scipt written in Python language using Spyder environment. Correctness of these results is ensured by their comparison with the output of Visual Vessel Design (VVD) program. Final part of the thesis is economic evaluation of whole tube sheet design based on possibility of choosing different analyzed material.

31. Konstrukční návrh zařízení pro studijní účely krize varu

Author: Martinec, Jiří, Škorpík, Jiří, Vojáčková, Jitka, Martinec, Jiří, Škorpík, Jiří, and Vojáčková, Jitka
Abstract: Tato diplomová práce se zabývá konstrukčním návrhem zařízení pro studijní účely krize varu. V první části je vysvětlena problematika krize varu a jsou zde příklady experimentálních zařízení ve světě. V další části je konstrukční návrh smyčky doprovázený návrhy jednotlivých zařízení, kterými je separátor, kondenzátor, výměník, čerpadlo, nádrž na vodu, elektrický ohřívák. Dále jsou zde uvedeny návrhy regulace tlaku, teploty a průtoku., This thesis deals with a design concept of the facility for the educational objectives of the boiling crisis. In the first part, the issue of boiling crisis is explained. There are also examples of some experimental facilities in the world. The second part includes design concept of a loop, which is accompanied by designs of individual devices, such as separator, condenser, exchanger, pump, water tank, electric heater. The thesis also states designs of throttle control, temperature control and flow control.

32. Konstrukční návrh zařízení pro studijní účely krize varu

Author: Martinec, Jiří, Škorpík, Jiří, Vojáčková, Jitka, Martinec, Jiří, Škorpík, Jiří, and Vojáčková, Jitka
Abstract: Tato diplomová práce se zabývá konstrukčním návrhem zařízení pro studijní účely krize varu. V první části je vysvětlena problematika krize varu a jsou zde příklady experimentálních zařízení ve světě. V další části je konstrukční návrh smyčky doprovázený návrhy jednotlivých zařízení, kterými je separátor, kondenzátor, výměník, čerpadlo, nádrž na vodu, elektrický ohřívák. Dále jsou zde uvedeny návrhy regulace tlaku, teploty a průtoku., This thesis deals with a design concept of the facility for the educational objectives of the boiling crisis. In the first part, the issue of boiling crisis is explained. There are also examples of some experimental facilities in the world. The second part includes design concept of a loop, which is accompanied by designs of individual devices, such as separator, condenser, exchanger, pump, water tank, electric heater. The thesis also states designs of throttle control, temperature control and flow control.

33. Řešení systému chlazení odplynů pro odstranění obsažených rozpouštědel

Author: Jegla, Zdeněk, Kilkovský, Bohuslav, Blažek, Pavel, Jegla, Zdeněk, Kilkovský, Bohuslav, and Blažek, Pavel
Abstract: Diplomová práce řeší problematiku hledáním nejvhodnějšího řešení chlazení vzdušiny pro odstranění obsažených rozpouštědel. Řešení vychází z reálného a již fungujícího zařízení farmaceutického provozu. Chladící systém je koncipován jako soustava tří trubkových výměníků. V prvním výměníku je vzdušina ochlazována vodou, ve druhém ledovou vodou a ve třetím výměníku se k chlazení využívá solanka R31. Účelem soustavy výměníků je ochlazení vzdušiny vedoucí ke zkondenzování obsaženého rozpouštědla, kterým je převážně aceton., Diploma thesis deals with searching of the most appropriate solution of air mass cooling to clear away contained solvents. The solution is based on real and operated pharmaceutical unit. The cooling system is solved as systém of three tubular heat exchangers. In the first heat exchanger the air mass is cooled down by water, in the second by ice-cold water and brine R32 is used for cooling in the third heat exchanger. Heat exchanger system is solved for cooling the air mass which results in condensation of contained solvent – acetone.

34. Řešení systému chlazení odplynů pro odstranění obsažených rozpouštědel

Author: Jegla, Zdeněk, Kilkovský, Bohuslav, Blažek, Pavel, Jegla, Zdeněk, Kilkovský, Bohuslav, and Blažek, Pavel
Abstract: Diplomová práce řeší problematiku hledáním nejvhodnějšího řešení chlazení vzdušiny pro odstranění obsažených rozpouštědel. Řešení vychází z reálného a již fungujícího zařízení farmaceutického provozu. Chladící systém je koncipován jako soustava tří trubkových výměníků. V prvním výměníku je vzdušina ochlazována vodou, ve druhém ledovou vodou a ve třetím výměníku se k chlazení využívá solanka R31. Účelem soustavy výměníků je ochlazení vzdušiny vedoucí ke zkondenzování obsaženého rozpouštědla, kterým je převážně aceton., Diploma thesis deals with searching of the most appropriate solution of air mass cooling to clear away contained solvents. The solution is based on real and operated pharmaceutical unit. The cooling system is solved as systém of three tubular heat exchangers. In the first heat exchanger the air mass is cooled down by water, in the second by ice-cold water and brine R32 is used for cooling in the third heat exchanger. Heat exchanger system is solved for cooling the air mass which results in condensation of contained solvent – acetone.

35. Návrhový výpočet únavy trubkového kondenzátoru páry s pevnými trubkovnicemi

Author: Pernica, Marek, Vincour, Dušan, Cablková, Zuzana, Pernica, Marek, Vincour, Dušan, and Cablková, Zuzana
Abstract: Diplomová práce se věnuje návrhovému výpočtu únavy trubkového kondenzátoru páry s pevnými trubkovnicemi, který je v provozu použit jako pojistný pro kondenzaci páry z turbíny. Toto zařízení je zatíženo teplotou a tlakem, které vyvolávají napětí. Vzhledem k možnosti jeho častého najíždění na provozní stav a sjíždění na klidový stav mohou vznikat napěťové cykly. Praktickou částí práce je návrhový výpočet, proveden dle normy ČSN EN 13445–3 s využitím metody konečných prvků, zkratkou MKP. Teoretická část práce obsahuje rešerši dostupných norem pro hodnocení únavové životnosti výměníků tepla, základní znalosti týkající se problematiky únavového poškození a případy reálného poškození únavou v praxi., The diploma thesis is devoted to the design of the fatigue calculation of the tubular steam condenser with fixed tube sheets, which is in operation as a safety equipment for the steam condenser from the turbine. This device is loaded with temperature and pressure that induces tension. Due to the possibility of frequently starting it up to the operational state and going down to the rest state, stress cycles can occur. The practical part of the thesis is the design calculation, carried out according to ČSN EN 13445–3 standards using the finite element method, abbreviated FEM. The theoretical part of the diploma includes a search of available standards for evaluating the fatigue life of heat exchangers, basic knowledge regarding the issue of fatigue damage and cases of real fatigue damage in practice.

36. Návrh výměníku tepla pro zlepšení efektivity průmyslového provozu

Author: Freisleben, Vít, Kilkovský, Bohuslav, Freisleben, Vít, and Kilkovský, Bohuslav
Abstract: Práce se zabývá návrhem trubkového výměníku tepla s křížovým tokem pro předehřev spalovacího vzduchu pro technologickou jednotku spalující odpadní produkty při výrobě kyseliny akrylové. Nejdříve je v programu Chemcad provedena simulace na základě známých provozních dat technologické jednotky pro predikci chování technologického celku s navrženým výměníkem. Dále jsou disktovány podstatné mechanismy přenosu tepla, na které navazuje přehled typů výměníků tepla používaných pro předehřev spalovacího vzduchu. Před samotným návrhem je provedena optimalizace výkonu na základě doby návratnosti. Tepelně-hydraulický návrh je potom proveden metodou F-LMTD v programu GNU Octave. Ověření výsledků výpočtu je provedeno za pomocí programu HTRI Xchanger Suite®. Na závěr jsou diskutovány ekonomické a ekologické přínosy navrhnutého výměníku., In thesis is done thermal-hydraulic design of cross-flow tubular heat exchanger for combustion air preheating. In software Chemcad is done simulation of technological unit based on known operating data, which is used for behavior prediction of unit after heat exchanger installation. Then there are discussed essential mechanisms of heat transfer. After that there is overview of different heat exchanger types used for combustion air preheating. Before particular design there is performed optimalization of heat duty of heat exchnger based on payback time. Thermal-hydraulic design is performed using F-LMTD method in software GNU Octave. Obtained results are verified using software HTRI Xchanger Suite®. At the end there are discussed economical and ecological benefits of designed heat exchanger.

37. Návrh ohříváku ropy

Author: Baláš, Marek, Toman, Filip, Baláš, Marek, and Toman, Filip
Abstract: Táto diplomová práca sa zaoberá návrhom tepelných výmenníkov pre ohrev surovej ropy. V prvej časti je spracovaný teoretický základ prenosu tepla, vlastností tepelných výmenníkov a vlastností ropy. V druhej časti je vypracovaný návrh dvoch tepelných výmenníkov. V prvom variante bola v trubkách umiestnená ropa a na strane plášťa bola umiestnená para. Pre druhý variant bolo umiestnenie médií vymenené. Návrhová časť pozostáva z návrhu geometrie trubiek, plášťa a prepážok. Ďalej bol prevedený tepelný a hydraulický výpočet. V závere boli navrhnuté varianty porovnané a bolo vybrané výhodnejšie prevedenie., This diploma thesis deals with the design of heat exchangers for crude oil heating. The first part deals with the theoretical basis of heat transfer, heat exchanger properties and oil properties. In the second part, a design of two heat exchangers was developed. In the first variant, oil was placed in the pipes and steam was placed on the shell side. For the second variant, the media placement has been swapped. The design part consists of the design of the geometry of the tubes, the shell, and the baffles. Furthermore, thermal, and hydraulic calculations were performed. At the end, the proposed variants were compared, and a more advantageous design was selected.

38. Pevnostní výpočet trubkovnice tepelného výměníku se zaměřením na ekonomické zhodnocení

Author: Buzík, Jiří, Vincour, Dušan, Buzík, Jiří, and Vincour, Dušan
Abstract: Bakalářská práce je zaměřena na pevnostní výpočet trubkovnice zadaného tepelného výměníku s pláštěm. Jde o trubkový výměník s pevnými trubkovnicemi a přímými trubkami. Navrhovaná trubkovnice je integrální s pláštěm, těsněná ke komoře s přírubovým okrajem. První část práce je věnována seznámení se s problematikou tepelných výměníků a trubkovnic. Výpočtová část práce se zabývá pevnostním návrhem tloušťky trubkovnice na základě normy ČSN EN 13 445. Ve výpočtové části jsou uvedeny vstupní parametry, základní podmínky výpočtu, rovnice potřebné pro výpočet maximálních napětí působících ve výměníku a pevnostní podmínky kontrolovaných součástí. Závěrem této části je zhodnocení dosažených výsledků vypočtených za pomoci programovacího jazyka Python v prostředí Spyder. Kontrola správnosti výsledků je provedena na základě výpočtů v programu Visual Vessel Design (VVD). Poslední částí práce je ekonomické zhodnocení celého návrhu na základě rozdílné volby kontrolovaného materiálu trubkovnice., This bachelor thesis is focused on strength design of assigned shell-and-tube heat exchanger. This heat exchanger have fixed tube sheets and straight tubes. Designed tube sheet is integrated with shell and flanged to the channel. First part of the thesis serves as introduction on the issue of heat exchangers and tube sheets. Following chapters are dedicated to the strength design of tube sheet thickness based on the ČSN EN 13 445 standard. These chapters are dealing with input parameters, basic requirements of calculation, equations essential for calculation of stress in heat exchanger and analysis of stresses in heat exchanger with the use of proper strength conditions. Conclusion of these chapters is evaluation of calculated results from personal scipt written in Python language using Spyder environment. Correctness of these results is ensured by their comparison with the output of Visual Vessel Design (VVD) program. Final part of the thesis is economic evaluation of whole tube sheet design based on possibility of choosing different analyzed material.

39. Pevnostní výpočet trubkovnice tepelného výměníku se zaměřením na ekonomické zhodnocení

Author: Buzík, Jiří, Vincour, Dušan, Buzík, Jiří, and Vincour, Dušan
Abstract: Bakalářská práce je zaměřena na pevnostní výpočet trubkovnice zadaného tepelného výměníku s pláštěm. Jde o trubkový výměník s pevnými trubkovnicemi a přímými trubkami. Navrhovaná trubkovnice je integrální s pláštěm, těsněná ke komoře s přírubovým okrajem. První část práce je věnována seznámení se s problematikou tepelných výměníků a trubkovnic. Výpočtová část práce se zabývá pevnostním návrhem tloušťky trubkovnice na základě normy ČSN EN 13 445. Ve výpočtové části jsou uvedeny vstupní parametry, základní podmínky výpočtu, rovnice potřebné pro výpočet maximálních napětí působících ve výměníku a pevnostní podmínky kontrolovaných součástí. Závěrem této části je zhodnocení dosažených výsledků vypočtených za pomoci programovacího jazyka Python v prostředí Spyder. Kontrola správnosti výsledků je provedena na základě výpočtů v programu Visual Vessel Design (VVD). Poslední částí práce je ekonomické zhodnocení celého návrhu na základě rozdílné volby kontrolovaného materiálu trubkovnice., This bachelor thesis is focused on strength design of assigned shell-and-tube heat exchanger. This heat exchanger have fixed tube sheets and straight tubes. Designed tube sheet is integrated with shell and flanged to the channel. First part of the thesis serves as introduction on the issue of heat exchangers and tube sheets. Following chapters are dedicated to the strength design of tube sheet thickness based on the ČSN EN 13 445 standard. These chapters are dealing with input parameters, basic requirements of calculation, equations essential for calculation of stress in heat exchanger and analysis of stresses in heat exchanger with the use of proper strength conditions. Conclusion of these chapters is evaluation of calculated results from personal scipt written in Python language using Spyder environment. Correctness of these results is ensured by their comparison with the output of Visual Vessel Design (VVD) program. Final part of the thesis is economic evaluation of whole tube sheet design based on possibility of choosing different analyzed material.

40. Konstrukční návrh zařízení pro studijní účely krize varu

Author: Martinec, Jiří, Škorpík, Jiří, Martinec, Jiří, and Škorpík, Jiří
Abstract: Tato diplomová práce se zabývá konstrukčním návrhem zařízení pro studijní účely krize varu. V první části je vysvětlena problematika krize varu a jsou zde příklady experimentálních zařízení ve světě. V další části je konstrukční návrh smyčky doprovázený návrhy jednotlivých zařízení, kterými je separátor, kondenzátor, výměník, čerpadlo, nádrž na vodu, elektrický ohřívák. Dále jsou zde uvedeny návrhy regulace tlaku, teploty a průtoku., This thesis deals with a design concept of the facility for the educational objectives of the boiling crisis. In the first part, the issue of boiling crisis is explained. There are also examples of some experimental facilities in the world. The second part includes design concept of a loop, which is accompanied by designs of individual devices, such as separator, condenser, exchanger, pump, water tank, electric heater. The thesis also states designs of throttle control, temperature control and flow control.

41. Řešení systému chlazení odplynů pro odstranění obsažených rozpouštědel

Author: Jegla, Zdeněk, Kilkovský, Bohuslav, Jegla, Zdeněk, and Kilkovský, Bohuslav
Abstract: Diplomová práce řeší problematiku hledáním nejvhodnějšího řešení chlazení vzdušiny pro odstranění obsažených rozpouštědel. Řešení vychází z reálného a již fungujícího zařízení farmaceutického provozu. Chladící systém je koncipován jako soustava tří trubkových výměníků. V prvním výměníku je vzdušina ochlazována vodou, ve druhém ledovou vodou a ve třetím výměníku se k chlazení využívá solanka R31. Účelem soustavy výměníků je ochlazení vzdušiny vedoucí ke zkondenzování obsaženého rozpouštědla, kterým je převážně aceton., Diploma thesis deals with searching of the most appropriate solution of air mass cooling to clear away contained solvents. The solution is based on real and operated pharmaceutical unit. The cooling system is solved as systém of three tubular heat exchangers. In the first heat exchanger the air mass is cooled down by water, in the second by ice-cold water and brine R32 is used for cooling in the third heat exchanger. Heat exchanger system is solved for cooling the air mass which results in condensation of contained solvent – acetone.

42. Návrhový výpočet únavy trubkového kondenzátoru páry s pevnými trubkovnicemi

Author: Pernica, Marek, Vincour, Dušan, Pernica, Marek, and Vincour, Dušan
Abstract: Diplomová práce se věnuje návrhovému výpočtu únavy trubkového kondenzátoru páry s pevnými trubkovnicemi, který je v provozu použit jako pojistný pro kondenzaci páry z turbíny. Toto zařízení je zatíženo teplotou a tlakem, které vyvolávají napětí. Vzhledem k možnosti jeho častého najíždění na provozní stav a sjíždění na klidový stav mohou vznikat napěťové cykly. Praktickou částí práce je návrhový výpočet, proveden dle normy ČSN EN 13445–3 s využitím metody konečných prvků, zkratkou MKP. Teoretická část práce obsahuje rešerši dostupných norem pro hodnocení únavové životnosti výměníků tepla, základní znalosti týkající se problematiky únavového poškození a případy reálného poškození únavou v praxi., The diploma thesis is devoted to the design of the fatigue calculation of the tubular steam condenser with fixed tube sheets, which is in operation as a safety equipment for the steam condenser from the turbine. This device is loaded with temperature and pressure that induces tension. Due to the possibility of frequently starting it up to the operational state and going down to the rest state, stress cycles can occur. The practical part of the thesis is the design calculation, carried out according to ČSN EN 13445–3 standards using the finite element method, abbreviated FEM. The theoretical part of the diploma includes a search of available standards for evaluating the fatigue life of heat exchangers, basic knowledge regarding the issue of fatigue damage and cases of real fatigue damage in practice.

43. Návrhový výpočet únavy trubkového kondenzátoru páry s pevnými trubkovnicemi

Author: Pernica, Marek, Vincour, Dušan, Pernica, Marek, and Vincour, Dušan
Abstract: Diplomová práce se věnuje návrhovému výpočtu únavy trubkového kondenzátoru páry s pevnými trubkovnicemi, který je v provozu použit jako pojistný pro kondenzaci páry z turbíny. Toto zařízení je zatíženo teplotou a tlakem, které vyvolávají napětí. Vzhledem k možnosti jeho častého najíždění na provozní stav a sjíždění na klidový stav mohou vznikat napěťové cykly. Praktickou částí práce je návrhový výpočet, proveden dle normy ČSN EN 13445–3 s využitím metody konečných prvků, zkratkou MKP. Teoretická část práce obsahuje rešerši dostupných norem pro hodnocení únavové životnosti výměníků tepla, základní znalosti týkající se problematiky únavového poškození a případy reálného poškození únavou v praxi., The diploma thesis is devoted to the design of the fatigue calculation of the tubular steam condenser with fixed tube sheets, which is in operation as a safety equipment for the steam condenser from the turbine. This device is loaded with temperature and pressure that induces tension. Due to the possibility of frequently starting it up to the operational state and going down to the rest state, stress cycles can occur. The practical part of the thesis is the design calculation, carried out according to ČSN EN 13445–3 standards using the finite element method, abbreviated FEM. The theoretical part of the diploma includes a search of available standards for evaluating the fatigue life of heat exchangers, basic knowledge regarding the issue of fatigue damage and cases of real fatigue damage in practice.

44. Návrhový výpočet únavy trubkového kondenzátoru páry s pevnými trubkovnicemi

Author: Pernica, Marek, Vincour, Dušan, Pernica, Marek, and Vincour, Dušan
Abstract: Diplomová práce se věnuje návrhovému výpočtu únavy trubkového kondenzátoru páry s pevnými trubkovnicemi, který je v provozu použit jako pojistný pro kondenzaci páry z turbíny. Toto zařízení je zatíženo teplotou a tlakem, které vyvolávají napětí. Vzhledem k možnosti jeho častého najíždění na provozní stav a sjíždění na klidový stav mohou vznikat napěťové cykly. Praktickou částí práce je návrhový výpočet, proveden dle normy ČSN EN 13445–3 s využitím metody konečných prvků, zkratkou MKP. Teoretická část práce obsahuje rešerši dostupných norem pro hodnocení únavové životnosti výměníků tepla, základní znalosti týkající se problematiky únavového poškození a případy reálného poškození únavou v praxi., The diploma thesis is devoted to the design of the fatigue calculation of the tubular steam condenser with fixed tube sheets, which is in operation as a safety equipment for the steam condenser from the turbine. This device is loaded with temperature and pressure that induces tension. Due to the possibility of frequently starting it up to the operational state and going down to the rest state, stress cycles can occur. The practical part of the thesis is the design calculation, carried out according to ČSN EN 13445–3 standards using the finite element method, abbreviated FEM. The theoretical part of the diploma includes a search of available standards for evaluating the fatigue life of heat exchangers, basic knowledge regarding the issue of fatigue damage and cases of real fatigue damage in practice.

45. Návrh výměníku tepla pro zlepšení efektivity průmyslového provozu

Author: Freisleben, Vít, Kilkovský, Bohuslav, Freisleben, Vít, and Kilkovský, Bohuslav
Abstract: Práce se zabývá návrhem trubkového výměníku tepla s křížovým tokem pro předehřev spalovacího vzduchu pro technologickou jednotku spalující odpadní produkty při výrobě kyseliny akrylové. Nejdříve je v programu Chemcad provedena simulace na základě známých provozních dat technologické jednotky pro predikci chování technologického celku s navrženým výměníkem. Dále jsou disktovány podstatné mechanismy přenosu tepla, na které navazuje přehled typů výměníků tepla používaných pro předehřev spalovacího vzduchu. Před samotným návrhem je provedena optimalizace výkonu na základě doby návratnosti. Tepelně-hydraulický návrh je potom proveden metodou F-LMTD v programu GNU Octave. Ověření výsledků výpočtu je provedeno za pomocí programu HTRI Xchanger Suite®. Na závěr jsou diskutovány ekonomické a ekologické přínosy navrhnutého výměníku., In thesis is done thermal-hydraulic design of cross-flow tubular heat exchanger for combustion air preheating. In software Chemcad is done simulation of technological unit based on known operating data, which is used for behavior prediction of unit after heat exchanger installation. Then there are discussed essential mechanisms of heat transfer. After that there is overview of different heat exchanger types used for combustion air preheating. Before particular design there is performed optimalization of heat duty of heat exchnger based on payback time. Thermal-hydraulic design is performed using F-LMTD method in software GNU Octave. Obtained results are verified using software HTRI Xchanger Suite®. At the end there are discussed economical and ecological benefits of designed heat exchanger.

46. Návrh ohříváku ropy

Author: Baláš, Marek, Toman, Filip, Baláš, Marek, and Toman, Filip
Abstract: Táto diplomová práca sa zaoberá návrhom tepelných výmenníkov pre ohrev surovej ropy. V prvej časti je spracovaný teoretický základ prenosu tepla, vlastností tepelných výmenníkov a vlastností ropy. V druhej časti je vypracovaný návrh dvoch tepelných výmenníkov. V prvom variante bola v trubkách umiestnená ropa a na strane plášťa bola umiestnená para. Pre druhý variant bolo umiestnenie médií vymenené. Návrhová časť pozostáva z návrhu geometrie trubiek, plášťa a prepážok. Ďalej bol prevedený tepelný a hydraulický výpočet. V závere boli navrhnuté varianty porovnané a bolo vybrané výhodnejšie prevedenie., This diploma thesis deals with the design of heat exchangers for crude oil heating. The first part deals with the theoretical basis of heat transfer, heat exchanger properties and oil properties. In the second part, a design of two heat exchangers was developed. In the first variant, oil was placed in the pipes and steam was placed on the shell side. For the second variant, the media placement has been swapped. The design part consists of the design of the geometry of the tubes, the shell, and the baffles. Furthermore, thermal, and hydraulic calculations were performed. At the end, the proposed variants were compared, and a more advantageous design was selected.

47. Návrh výměníku tepla pro zlepšení efektivity průmyslového provozu

Author: Freisleben, Vít, Kilkovský, Bohuslav, Freisleben, Vít, and Kilkovský, Bohuslav
Abstract: Práce se zabývá návrhem trubkového výměníku tepla s křížovým tokem pro předehřev spalovacího vzduchu pro technologickou jednotku spalující odpadní produkty při výrobě kyseliny akrylové. Nejdříve je v programu Chemcad provedena simulace na základě známých provozních dat technologické jednotky pro predikci chování technologického celku s navrženým výměníkem. Dále jsou disktovány podstatné mechanismy přenosu tepla, na které navazuje přehled typů výměníků tepla používaných pro předehřev spalovacího vzduchu. Před samotným návrhem je provedena optimalizace výkonu na základě doby návratnosti. Tepelně-hydraulický návrh je potom proveden metodou F-LMTD v programu GNU Octave. Ověření výsledků výpočtu je provedeno za pomocí programu HTRI Xchanger Suite®. Na závěr jsou diskutovány ekonomické a ekologické přínosy navrhnutého výměníku., In thesis is done thermal-hydraulic design of cross-flow tubular heat exchanger for combustion air preheating. In software Chemcad is done simulation of technological unit based on known operating data, which is used for behavior prediction of unit after heat exchanger installation. Then there are discussed essential mechanisms of heat transfer. After that there is overview of different heat exchanger types used for combustion air preheating. Before particular design there is performed optimalization of heat duty of heat exchnger based on payback time. Thermal-hydraulic design is performed using F-LMTD method in software GNU Octave. Obtained results are verified using software HTRI Xchanger Suite®. At the end there are discussed economical and ecological benefits of designed heat exchanger.

48. Návrh ohříváku ropy

Author: Baláš, Marek, Toman, Filip, Baláš, Marek, and Toman, Filip
Abstract: Táto diplomová práca sa zaoberá návrhom tepelných výmenníkov pre ohrev surovej ropy. V prvej časti je spracovaný teoretický základ prenosu tepla, vlastností tepelných výmenníkov a vlastností ropy. V druhej časti je vypracovaný návrh dvoch tepelných výmenníkov. V prvom variante bola v trubkách umiestnená ropa a na strane plášťa bola umiestnená para. Pre druhý variant bolo umiestnenie médií vymenené. Návrhová časť pozostáva z návrhu geometrie trubiek, plášťa a prepážok. Ďalej bol prevedený tepelný a hydraulický výpočet. V závere boli navrhnuté varianty porovnané a bolo vybrané výhodnejšie prevedenie., This diploma thesis deals with the design of heat exchangers for crude oil heating. The first part deals with the theoretical basis of heat transfer, heat exchanger properties and oil properties. In the second part, a design of two heat exchangers was developed. In the first variant, oil was placed in the pipes and steam was placed on the shell side. For the second variant, the media placement has been swapped. The design part consists of the design of the geometry of the tubes, the shell, and the baffles. Furthermore, thermal, and hydraulic calculations were performed. At the end, the proposed variants were compared, and a more advantageous design was selected.

49. Řešení systému chlazení odplynů pro odstranění obsažených rozpouštědel

Author: Jegla, Zdeněk, Kilkovský, Bohuslav, Jegla, Zdeněk, and Kilkovský, Bohuslav
Abstract: Diplomová práce řeší problematiku hledáním nejvhodnějšího řešení chlazení vzdušiny pro odstranění obsažených rozpouštědel. Řešení vychází z reálného a již fungujícího zařízení farmaceutického provozu. Chladící systém je koncipován jako soustava tří trubkových výměníků. V prvním výměníku je vzdušina ochlazována vodou, ve druhém ledovou vodou a ve třetím výměníku se k chlazení využívá solanka R31. Účelem soustavy výměníků je ochlazení vzdušiny vedoucí ke zkondenzování obsaženého rozpouštědla, kterým je převážně aceton., Diploma thesis deals with searching of the most appropriate solution of air mass cooling to clear away contained solvents. The solution is based on real and operated pharmaceutical unit. The cooling system is solved as systém of three tubular heat exchangers. In the first heat exchanger the air mass is cooled down by water, in the second by ice-cold water and brine R32 is used for cooling in the third heat exchanger. Heat exchanger system is solved for cooling the air mass which results in condensation of contained solvent – acetone.

50. Konstrukční návrh zařízení pro studijní účely krize varu

Author: Martinec, Jiří, Škorpík, Jiří, Martinec, Jiří, and Škorpík, Jiří
Abstract: Tato diplomová práce se zabývá konstrukčním návrhem zařízení pro studijní účely krize varu. V první části je vysvětlena problematika krize varu a jsou zde příklady experimentálních zařízení ve světě. V další části je konstrukční návrh smyčky doprovázený návrhy jednotlivých zařízení, kterými je separátor, kondenzátor, výměník, čerpadlo, nádrž na vodu, elektrický ohřívák. Dále jsou zde uvedeny návrhy regulace tlaku, teploty a průtoku., This thesis deals with a design concept of the facility for the educational objectives of the boiling crisis. In the first part, the issue of boiling crisis is explained. There are also examples of some experimental facilities in the world. The second part includes design concept of a loop, which is accompanied by designs of individual devices, such as separator, condenser, exchanger, pump, water tank, electric heater. The thesis also states designs of throttle control, temperature control and flow control.

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