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The development of an accident tolerant nuclear fuel for water-cooled reactors would redefined the status of these reactors from traditional active safety to passive safety systems. As a possible solution toward enhancing the safety of light-water reactors (LWRs), loose-coated particles of enriched uranium dioxide (UO2) fuel with the ability to retain gaseous and metallic fission products in the case of a loss of cooling event can be introduced inside Silicon-Carbide cladding tubes of the fuel assembly (see Figs. 1(a) and 1(b)). These coated particles are treated as a bed from where heat is transferred to the cladding tube and the helium gas movement is due to natural convection. A slender geometrical model with tube-to-particle diameter ratio N = 2.503 and porosity ε = 0.546 mimicking the proposed nuclear fuel in the cladding was numerically simulated. This study is to investigate the heat transfer characteristics and flow distribution under buoyancy driven force expected in the cladding tube of the proposed nuclear fuel using a commercial code. Random packing of the particles is achieved by discrete element method (DEM) simulation with the aid of starccm+. The temperature contour and velocity vector plots obtained can be said to be good illustration of anticipated heat transfer and transport phenomenon to occur in the proposed fuel design. Simulated results for particle-to-fluid heat transfer coefficient, Nusselt number, and Rayleigh number which are of prime importance when analyzing natural convection heat transfer performance in fixed bed reactors were validated. Results from this work show close agreement with results obtained in established numerical and experimental works.

Internet usage, data transfer, and required computing power have seen rapid growth in recent years. Consequently, the number of data centers and their power densities are increasing at an ever-faster rate. Data centers have a huge demand for cooling energy, which is typically dissipated into the environment as waste heat. Due to the mostly urban location of data centers, the usage of their waste heat can play a leading role in decarbonizing urban heat supply. At the Technical University of Darmstadt, a concept for waste heat utilization from the university’s own high-performance computer (HPC) was developed. The HPC is cooled with hot water at 40 °C to 45 °C, and the temperature level of the waste heat is further increased via a heat pump before it is fed into the return line of the university’s district heating network at 60 °C to 75 °C. The high source temperatures ensure a very efficient operation of the heat pump. This concept was installed on site in 2020 and put into operation at the beginning of 2021. To collect information about the performance of the system, a measurement concept was implemented, which collects data about heat flows and temperatures at various points in the system as well as the electric energy demand of the heat pump. This data is analyzed and measures to optimize the waste heat utilization are derived.

Due to the rapid economic development in recent years, water-chiller is being used more and more in hotels, restaurants, resorts, and industrial zones in Vietnam. The cooling tower’s cooling water quality is an important factor in determining the effect on electrical consumption and the coefficient of performance of a water-cooled chiller. Therefore, it is necessary to maintain the quality of cooling water during the operation time of the water-cooled chiller. The aim of this work is to investigate the effects of the pulse frequency and operational parameters such as current density, pulse duty cycle, and energy consumption on the performance of removing hardness ion of electrochemical cooling water treatment for the cooling tower of the water-cooled chiller. The results show that the highest efficiency of the total hardness removal corresponding to a pulse frequency of 1 kHz, a pulse duty cycle of 0.7, and a current density of 80A/m2.

In this study, the electrical and thermal efficiency of the natural convection water-cooled photovoltaic panel (PV) is compared with the standard PV module. PV modules are made up of polycrystalline solar cells. As it is known that, an increase in PV panel temperature results in a decrease in electrical efficiency. The aim of this study is to increase PV panel electrical efficiency. PV panel characteristic values such as air/PV panel temperature, solar radiation, voltage, current, and power are recorded for both panels to the computer simultaneously. The thermal and electrical energy performance of PV panels are analyzed comparatively. The results are presented in detail. The water circulation structure is mounted under the PV module by using a glue that has good heat conductivity. The structure contains an S-shaped pipe and a plate made of copper. The plate is used for better heat absorption from the PV panel which is mounted downside of the panel with glue. The efficiency of the PV module with having a proposed cooling system and normal PV module is analyzed. For the overall efficiency, it is observed that the water-cooled PV system is better than the standard PV module by % 6.2.

One of the major problems in electric arc furnace is the high temperature which results in thermal stresses and cracks within the material of the furnace surrounding walls. An effective cooling technique is needed to avoid such problems. For this purpose, a novel roof configuration of an electric arc furnace is used to provide efficient cooling to reduce the temperature in the roof material. The roof consists of two solid materials, namely, copper and alumina brick. The roof cooling is achieved by a water circulation within the roof. A numerical model using finite element method was implemented to solve the heat conduction equation with the complicated boundary conditions to find out the effects of using brick material with geometrical size variations for different values of thermal conductivity on the temperature distribution within the roof. The results showed that the decrease in brick material thermal conductivity resulted in a significant decrease in the top surface temperature of the furnace roof. The results showed that rectangular brick material is the best option in the roof to keep it at low temperature.

Background Microwaves (MWs) deliver relatively high temperatures into biological tissue and cover a large ablation zone. This study aims to evaluate the efficacy and effectiveness of water-cooled double-needle MW ablation arrays in assisting the hepatic transection of an in vivo pig model. Methods Our research program comprised computer modeling, tissue-mimicking phantom experiments, and in vivo pig liver experiments. Computer modeling was based on the finite element method (FEM) to evaluate ablation temperature distributions. In tissue-mimicking phantom and in vivo pig liver ablation experiments, the performances of the water-cooled MW ablation array and conventional clamp crushing liver resection were compared. Results FEM showed that the maximum lateral ablation diameter at 100 W output and a duration of 60 s was 3 cm (assessed at 50 °C isotherm). In the phantom, the maximum transverse ablation diameter of the double-needle MW ablation increased rapidly to 3 cm in 60 s at 50 W. The blood loss and blood loss per transection area in Group A were significantly lower than those in Group B (18 (7–26) ml vs. 34 (19–57) ml, and 2.4 (2–3.1) ml/cm2 vs. 6.9 (3.2–8.3) ml/cm2, respectively) (p

Одним из путей улучшения массо-габаритных характеристик судовых водоохлаждаемых реакторов интегрального типа с естественной циркуляцией теплоносителя является реализация пароконденсатного цикла в первом контуре, при котором насыщенный пар с высокой степенью сухости генерируется непосредственно в активной зоне и затем конденсируется в парогенера­торе, отдавая тепло рабочему телу второго контура. Тепловыделяющий канал активной зоны с непосредственной генерацией насыщенного пара состоит из кольцевого твэла и установленной в его полости нетепловыделяющей трубки с навивкой для закрутки потока теплоносителя. Закрутка потока внутри твэла предотвращает кризис кипения на его внутренней поверхности (на наружной поверхности твэла имеет место закризисный режим теплоотдачи), что обеспечивает допустимые значения температур топлива и оболочек твэла при достаточно высокой плотности энерговыделений, характерных для активных зон судовых реакторов. В статье описаны особенности теплогидравлического расчета каналов активной зоны, парогенератора-конденсатора и контура естественной циркуляции интегрального реактора с пароконденсатным циклом в первом контуре. Представлены результаты расчета характеристик реакторов тепловой мощностью 150 и 25 МВт. Показано, что размеры интегральных реакторов с естественной циркуляцией теплоносителя при реализации пароконденсатного цикла в первом контуре не превышают размеры характерные для интегральных водоохлаждаемых реакторов с принудительной циркуляцией теплоносителя, предназначенных к использованию на объектах морской техники. One of the ways to improve the weight and size characteristics of integrated water-cooled reactors with natural coolant circulation is to implement a steam condensate cycle in the primary circuit, in which dry saturated steam is generated directly in the core and then condenses in the steam generator. The fuel channel of the core with the direct generation of saturated steam consists of an annular fuel rod and a non-fuel pipe installed in its cavity with a winding for swirling the coolant flow. The swirling of the flow inside the fuel element prevents a burn up its internal surface (there is a post-crisis heat transfer regime on the external surface of the fuel element), which ensures acceptable temperatures of the fuel and its cladding at a sufficiently high energy density typical for marine reactor core. The article discusses the features of thermal-hydraulic calculations of the core channel, steam generator – condenser and natural circulation circuit of integral type reactor with the steam-condensate cycle in the primary circuit. It is presents the characteristics of marine reactors with a thermal capacity of 150 and 25 MW. It is shown that size of the marine integrated reactors with natural coolant circulation and a steam condensate cycle in the primary circuit is similar to size of reactor with enforced coolant circulation.

The present work aims at to explore the possibility of juliflora biodiesel as alternative fuel in a single cylinder, water cooled constant speed, direct injection diesel engine. The Performance par...

Tidepools are not uncommon in Antarctica, but there appear to be no data on the physical environment within polar tidepools and only anecdotal information on their biology. Here we report a high resolution record of temperature in an Antarctic tidepool made over two summers and the intervening winter. During the summer open water season the highest daily mean, and also the maximum temperatures, were recorded during the period of continuous daylight around the summer solstice. This short-term variability of temperature in the tidepool greatly exceeded that in the nearby open ocean, indicating the need for a eurythermal physiology in tidepool biota. In winter the tidepool froze over, the unfrozen water cooled to − 5.5 °C, and freeze concentration increased its salinity to roughly three times normal seawater. A polar tidepool isolated from the sea in winter is probably inimical to many larger marine organisms, which must populate the tidepool afresh each summer.

Photovoltaic (PV) panels can increase their efficiency and durability by using water-cooled systems. In this paper, the authors present a methodology to establish the degradation rate (DR) of PV panels related to their durability and efficiency under cooled versus no-cooled conditions. A long-term feasibility analysis of PV power plants with some suggested modifications are discussed in detail. A standard system was designed to cool down the PV modules. The simulations used with this purpose are based on several publications with relevant aspects carried out in the literature using Matlab-based modeling data. Such results were then confirmed by Homer program to predict the efficiency and durability of PV panels within a lifetime period of 25 years. To illustrate the methodology proposed here, the simulation parameters were used for the city of Santa Maria-RS, Brazil. The results allowed to conclude that cooling combined with heated water for domestic usage can decrease the PV degradation rate by 3% and provide an increased efficiency by almost 30% with respect to the PV panels without such cooling approaches. Therefore, the final results conclude that installation of water-cooled PV panels is an attractive and feasible option for a short- and long-term efficiency improvement with great impact on the expansion and durability of PV power plants.

The effect of thermal cycling was carried out on steel bars (0.4 %C). A single run was performed at a lower temperature of 320C and an upper temperature of 5000C cooled in water and seawater. For several numbers of cycles up to 30 cycles for an accurate determination of heating and cooling times. The effect of thermal cycling on the corrosion rate was evaluated. The effect of thermal cycling on the following properties was evaluated the corrosion rate. The comparison between the effect of thermal cycling on carbon steel (0.4% C) seawater cooled (previous results, sea-water cooled [1]) and the effect of thermal cycling on carbon steel (0.4 C %) (in this manuscript, water-cooled) has been studied. From the obtained test results (previous and in this paper, it was found that the type of corrosion is uniform, the corrosion rate of the first stage gradually increases with the number of thermal cycling up to 15 cycles, then it takes steady-state up to 30 cycles. It was found that the rate of corrosion (previous results, seawater cooled) is more than (the results in this paper, water-cooled).

This paper investigates the influence of using the Peltier module in enhancing the water-cooled internal combustion engine. The result of demonstrating model will be compared with the current vehicle (Sahin 1996, single overhead cam 1400 cm3) specification. Thermo Electric Cooler (TEC) or Peltier module converts the electric energy to heat energy. The performance of thermoelectric devices is still a challenge, and many approaches have been researched to overcome such obstacles. The result of modeling system temperature difference is from 40 % to 50 % established cooling system temperature difference on the former vehicle.

The urge to replace hydrofluorocarbons which possess high global warming potentials has taken center stage in the air conditioning industry due to both international and local policies such as the ...

The correlation between microstructure and pitting corrosion resistance of transient liquid phase (TLP) bonded 2205 duplex stainless steel (DSS) using BNi-6 interlayer (Ni–10.8 wt% P) was investigated. Experimental results revealed that not only progress of the isothermal solidification (IS), but also cooling procedure after the TLP bonding considerably affected the pitting corrosion resistance of the TLP bonded specimen. Potentiodynamic polarization (PDP) results revealed that pitting potential of the furnace cooled TLP specimen (FC-TLP) was increased from + 0.274 to + 0.557 V by completing the IS. SEM/EDS analyses showed that the bonding zone (BZ) was the weakest zone to pitting corrosion before completing the IS and the pitting attacks severely occurred in the bonding zone (BZ) centerline. After completion of the IS, the pitting corrosion preferentially occurred in vicinity of (Mo–P) rich intermetallic precipitates in the diffusion affected zone (DAZ) of FC-TLP specimen. Microstructural studies also revealed that water quenching after the TLP bonding prevented the formation of (Mo–P) rich intermetallic precipitates in the DAZ. It resulted in the significant increase of the pitting potential of water cooled TLP specimen to + 1.096 V after IS completion, which was very close to that of the as-received BM (+ 1.220 V).

The fundamental thermophysical features of the heat exchange process between the heated wall of a vertical channel and the light-water coolant of supercritical parameters concerning the conditions of heat-generating assemblies channels and cores of perspective energy nuclear reactors are considered. The available methods and recommendations for determining the limits of thermal load are analyzed. It is a guarantee the absence of the characteristic dangerous mode possibility of deteriorated heat exchange in these conditions and corresponding sharp rise in the channels wall temperature, which threatens their destruction. The physical nature of the occurrence of degraded heat transfer regimes remains unclear, and the existing approaches to the implementation of thermohydraulic calculation in such conditions are not sufficiently justified. The complex nature of intercellular heat and mass transfer in the fuel assembly and the presence of individual thermohydraulic cells with reduced levels of heat transfer intensity indicate that the existing method of determining the area of degraded heat transfer in the reactor core channels with supercritical parameters of the coolant is significantly simplified. Insufficient data and research results have been revealed to create adequate methods of heat-hydraulic calculation, suitable for taking into account the peculiarities of the heat transfer process complex flow under conditions of supercritical parameters of the coolant. The application of such methods should be the basis for ensuring the safe operation of prospective reactors and minimizing potential losses of a different nature from accidents caused by the destruction of cores through unacceptable heat transfer modes. To this end, the main direction of further research is identified.

This study is aimed at reducing NOx, Smoke, HC, CO emissions from single-cylinder, four-stroke, and water cooled diesel engine. The research engine is fueled with diesel and two blends of butanol a...

The commercial feasibility of the first fusion power plant generation adopting D-T plasma is strongly dependent upon the self-sustainability in terms of tritium fuelling. Within such a kind of reactor, the component selected to house the tritium breeding reactions is the breeding blanket, which is further assigned to heat power removal and radiation shielding functions. As a consequence of both its role and position, the breeding blanket is heavily exposed to both surface and volumetric heat loads and, hence, its design requires a typical multiphysics approach, from the neutronics to the thermo-mechanics. During last years, a great deal of effort has been put in the optimization of the breeding blanket design, with the aim of maximizing the tritium breeding and heat removal performances without undermining its structural integrity. In this paper, a derivative-free optimization method named “Complex method” is applied for the design optimization of the European DEMO Water-Cooled Lithium Lead breeding blanket concept. To this purpose, a potential performances-based objective function, focusing on the maximization of the tritium breeding, is defined and a multiphysics numerical model of the blanket is developed in order to solve the coupled thermo-mechanical problem, while the optimization algorithm leads the design towards a minimum optimum point compliant with the prescribed requirements. Once the optimized design is obtained, its nuclear and thermo-structural performances are assessed by means of specific neutron transport and multiphysics simulations, respectively. Finally, the structural integrity is verified by means of the application of the RCC-MRx design criteria.

An experimental study on the resistance of concrete containing air-cooled slag (AS) and water-cooled slag (WS) against freeze–thaw cycles was conducted. For comparison, the durability of ASTM Type I ordinary Portland cement (OPC) concrete exposed to the same freeze–thaw environment was examined. To evaluate the durability of concrete exposed to the freeze–thaw environment, an experiment was conducted according to ASTM C 666 procedure A. Furthermore, the relative dynamic modulus of elasticity, surface electrical resistivity, and compressive strength of concrete specimens were measured after exposing them to freeze–thaw cycles for a predetermined period, and the results were compared with those of OPC concrete. The relationship between the freeze and thaw resistances of concrete and the air-void system (spacing factor and specific surface area) was identified. Furthermore, the microstructure of concrete exposed to freeze–thaw cycles was observed using scanning electron microscopy to identify the interfacial transition zone, cracks, and micropores. Experimental results showed that the resistance of blended cement concrete containing WS and AS against freeze–thaw cycles was significantly higher than that of OPC concrete. The concrete in which 10% of OPC was replaced by AS exhibited a similar durability as that of the concrete in which 40% of OPC was replaced only by WS. Therefore, it is expected that blended cement concrete containing WS and AS based on an appropriate mix proportion design will exhibit excellent durability in regions experiencing freezing temperatures.

An electrical generator is one of the most efficient large-scale machines. It converts mechanical to electrical energy with an efficiency coefficient of approximately 99%. The remaining 1% can mainly be contributed to heat losses. Direct cooling is only necessary for larger turbogenerators with more than 250 MVA where the cooling media is introduced via hollow conductors within the stator bars. Turbogenerators of approximately up to 700 MVA nowadays use exclusively hydrogen (H2) gas as a cooling media. Even larger turbogenerators have to introduce direct water cooling. The water chemistry of the stator cooling water is typically of neutral pH and has a conductivity of less than 0.1 μS/cm. Two zones of the oxygen (O2) concentration have been established through the last 50 years, one at low dissolved O2 concentration with less than 20 ppb, the other with high concentrations of more than 2 ppm. The latter has to continuously inject CO2 free air to ensure to always keep the oxygen concentration above 2 ppm. The first part of this publication shows several incidents with the air injection system in different Nuclear Power Plants in the US, resulting in unfavorable stator cooling water chemistry. This led to a reduced cooling efficiency, resulting in several chemical online cleanings being necessary. The second part of this work presents a technical solution to overcome the issues associated with the reduced stator cooling. It continuously injects and monitors the air injected into the system. Additionally, it also measures the hydrogen leakage rate.

Pyogenic granuloma is a benign growth characterized by active vascular proliferation and is prone to occurring during pregnancy. Given the complicated conditions of this special group of patients, it is controversial to perform removal therapy before delivery. Here, two giant pregnancy pyogenic granulomas of a patient at 34 weeks gestation were safely, completely and minimally invasively removed by water-cooled Nd: YAG laser without anesthetic agents, suturing or antibiotics. No recurrence was observed after 1 year. This removal therapy immediately relieved the problem of patient nutrition intake and greatly improved the quality of her prenatal preparation. Thus, this report highlights that complete excision of pyogenic granulomas during pregnancy can be performed before delivery when urgent circumstances are considered, and a water-cooled Nd: YAG laser can be applied as a powerful tool in this treatment.

Plant life extension from the initial licensed life to beyond 60 years is now being discussed for light water cooled nuclear powered reactors (LWRs). Reliable prediction for material degradation is extremely important to keep the reliability of LWRs during such long-term operation. One of the specific perspectives for this prediction is to take into account the changes in material properties during long-term operation, such as cavity formation, even at the LWR operating temperature. The mechanism of cavity formation and the associated phenomena are closely intertwined with interdisciplinary technological and scientific knowledge. Therefore, historical key knowledge from both phenomenological and fundamental research studies related to cavity formation was first reviewed to understand the overall picture. Subsequently, current research results related to long-term stress corrosion cracking initiation in the LWR environment were summarized to explain what is known, what is still unknown, and what are the critical remaining subjects.

One of the main defects of a photovoltaic (PV) module is that its output power significantly declines when its surface’s temperature increases. In this study, to solve this problem, two novel methods are proposed to compensate the power reduction of a PV module originating from temperature rise by converting the waste heat of the PV module into electric power. The first method utilizes a novel thermally regenerative electrochemical cycle (TREC) device proposed and constructed in this study, while the second method uses a commercial thermoelectric generator (TEG) module. In the first method, the proposed TREC device has been attached to behind a commercial PV module KC200GT to convert its waste heat caused by temperature rise into electric power, while in the second method, a commercial water cooled TEG module DW-WC-100W has been attached to behind the PV module to convert its waste heat. Based on the two methods, two systems have been constructed, and associated experimental results are presented. The two systems are also compared to each other from different viewpoints. The comparison shows that the TREC device proposed and constructed in this study not only has less cost and weight compared to that of the commercial TEG module, but also significantly produces more power to compensate the power reduction of the PV module, so that, it compensates about 85% of the power reduction at noon, while the commercial TEG module compensates only about 23%. Compensating about 85% of the power reduction of a PV module resulting from temperature rise and constructing a novel TREC device to achieve this goal are the novelty and contributions of this work.

Background: Genicular nerve radiofrequency lesioning (RFL) is an interventional approach to chronic knee pain. It is currently unknown whether conventional thermal RFL (CT-RFL) or watercooled RFL (WC-RFL) yields better outcomes. Objective: The objective of this research was to analyze and compare outcomes of genicular nerve conventional thermal radiofrequency lesioning (CT-RFL) vs water-cooled radiofrequency lesioning (WC-RFL) for the treatment of chronic knee pain. Study Design: We used retrospective chart review. Setting: The research took place in an outpatient pain clinic at a large academic medical center. Methods: Patients who participated in the study were those aged 18 and older who received genicular nerve RFL for chronic knee pain between January 1, 2014 and December 31, 2016. Random intercepts models were used to examine Visual Analog Scale (VAS) pain scores across the first year of follow-up, adjusting for age, gender, and prior history of knee surgery. Results: Overall, VAS scores were significantly reduced from baseline (mean = 6.66, standard deviation [SD] = 1.36) by 1.46 points during the first follow-up month (95% confidence interval [CI], 0.6-2.3, P = .001), 2.22 points during the second follow-up month (95% CI, 1.4-3.1, P = < .001), and 1.24 points during the sixth follow-up month (95% CI, 0.1-2.4, P = .035) but were not significantly reduced at other months during the one-year followup time period. There was no statistically significant difference in follow-up pain scores (mean difference = 0.73, 95% CI, -0.14-1.59, P = .116) or rates of complications (P = .10, 2-tailed Fisher exact test) between RFL types. Limitations: Study shortcomings include patient loss to follow-up, heterogeneity of CT-RFL techniques, and heterogeneity of study patients. Conclusions: Genicular RFL is a promising strategy for long-term management of treatment-resistant chronic knee pain. In this study, no significant difference in outcomes was detected between CT-RFL and WC-RFL techniques. Larger prospective studies are warranted to compare outcomes of these techniques and guide future care. Key words: Radiofrequency lesioning, knee pain, chronic pain, osteoarthritis, genicular, cooled radiofrequency lesioning, water-cooled radiofrequency lesioning, conventional radiofrequency lesioning

Introduction: Microwaves (MWs) quickly deliver relatively high temperatures into tumors and cover a large ablation zone. We present a research protocol for using water-cooled double-needle MW ablat...

The transition from Generation 2 to Generation 3/3+ and 4 reactors, as well as the development of small modular reactors (SMR), place new demands on computational programs designed to simulate conditions of normal operation, operational occurrences, design basis accidents and severe accidents. On the one hand, most passive safety systems of advanced and innovative plants operate at low pressures even down to vacuum conditions and the driving forces are low compared to active systems. On the other hand, the containment is no longer just a barrier to retain radioactive material in the event of leakage of the cooling system, but it is an important link in the passive cooling chain. This requires an expansion and improvement of the existing simulation programs for the cooling circuit and containment, as well as the realization of a coupling between these simulation programs. The new AC2 program package combines the proven simulation codes ATHLET/ATHLET-CD and COCOSYS in one software suite to hit this target. The individual components of the suite are continuously extended and validated for their application to novel safety systems. This makes it possible to simulate the entire spectrum of accidents for Generation 3/3+, 4 and light water cooled SMR systems with just one program package. This publication gives an overview of the current state of development of AC2 and its individual modules.

The water-cooled ceramic breeder (WCCB) blanket is one candidate for the Chinese Fusion Engineering Testing Reactor (CFETR), and it is being developed at the Institute of Plasma Physics of the Chinese Academy of Sciences. This paper presents an updated WCCB blanket concept design that is expected to cover the CFETR operation modes of 200 MW, 500 MW, 1 GW, and 1.5 GW fusion power and achieve tritium self-sufficiency with the latest core parameters (major radius R = 7.2 m; minor radius a = 2.2 m) and mission. The feasibility of the new blanket design is evaluated considering neutronics and thermal-hydraulics aspects.

China Fusion Engineering Test Reactor (CFETR), the next fusion device in China, is proposed to bridge the gaps between ITER and the demonstration reactor (DEMO). The Water Cooled Ceramic Breeder (WCCB) blanket, one candidate option of breeding blanket conception for CFETR, impacts the toroidal field (TF) ripple in CFETR, as the reduced activation ferritic/martensitic (RAFM) steel was used as its structure material. The purpose of this paper is to investigate and evaluate the ripple effect of WCCB blanket on TF ripple in CFETR. An analysis is performed using three-dimensional finite element model with 16 TF coils and WCCB blanket modules. ANSYS code is employed for this study. The results indicated that the TF ripple was less than 0.5% at all points in target separatrix when it was estimated with TF coils only. We also calculated TF ripple in case of WCCB blanket modules and various port configuration schemes. It is found that TF ripple cannot meet the design requirements by the presence of WCCB blanket modules, even in difference port configuration. Discussions are made on the implication of the WCCB blanket modules and ports on TF ripple. Potential methods for reducing the TF ripple are studied in this paper.

The present paper investigates the performance, combustion and emission analysis of various biodiesel blends prepared from animal fat methyl ester (AF100) and waste cooked oil (WCO) 8–10 h used. A...

Reduced Activation Ferritic/Martensitic (RAFM) steel is selected as structural material for the water cooled ceramic breeder (WCCB) blanket for China Fusion Engineering Test Reactor (CFETR). Due to the magnetization of RAFM steel, the toroidal field (TF) ripple is generated by the WCCB blanket. The TF ripple induces significant losses of high-energy particles, and then causes issues of heat load on plasma-facing components (PFCs) and energy balance of plasma. Hence, TF ripple generated by WCCB blanket is calculated, and several effective optimization methods are explored in this paper. The simulation results indicate that TF ripple in plasma target separatrix is greater than design limits ( δ T F 0.5 % ) in present design. Four methods are employed to study and evaluate the effect of decreasing TF ripple including installing ferromagnetic inserts, using correction coils, changing the related parameter of diagnostic system and moving the WCCB blanket, respectively. Based on the analysis results, it is found that these four methods can reduce TF ripple to some extend through different optimizing methods. The location of five TF ripple peaks of a 22.5° sector are at 0°, ±3.07° and ±7.67° respectively. The TF ripple can only reduce from 0.25% to 0.21% at ±3.07° plane using optimization method of installing ferromagnetic inserts. The rest of the location has almost little impact. The TF ripple can only reduce from 0.31% to 0.20% at 0° plane using correction coils, but the peak value will increase to 0.33% at ±3.07° plane. Moving diagnostic system 40 mm outward in radial direction will effectively decrease the TF ripple from 3.54% to 0.37% at -3.07° plane. Moving WCCB blankets 20 mm outward in radial direction makes the maximum TF ripple from 0.56% to 0.09%. Discussions are made about the effect of the optimization methods for reducing TF ripple.

디젤엔진의 유해 배기가스를 저감하는 기술인 EGR 시스템에 쿨러를 장착하여 재순환되는 배기가스의 온도를 낮추는 cooled EGR 시스템은 기존의 EGR과 비교하여 연비와 soot의 증가 없이 NOx의 저감에 효과가 있다. 본 연구에서는 cooled EGR 시스템에 사용되는 EGR 쿨러의 개선을 위해 기존 EGR 쿨러를 사용해 측정한 실험데이터를 기초로 수치해석을 실시하였다. 수치해석에 사용한 EGR 쿨러는 shell&tube 형식을 사용하였고, 물을 이용하여 EGR 가스의 냉각을 실시하였다. 수치해석에는 상용프로그램인 ANSYS CFX를 사용하였고, 수치해석을 통한 냉각성능을 비교를 위해 EGR 쿨러, EGR 가스 및 냉각수의 온도를 실험데이터와 비교하였다. 그 결과, 수치해석 결과의 유효성을 검증하였으며, EGR cooler의 설계를 위한 수치해석 데이터를 확보하였다.

In this present study, the emissions characteristics of four-stroke, single cylinder water cooled diesel engine fueled with neat biodiesel were investigated. Titanium dioxide nano-additive is added...

The Water Cooled Ceramic Breeder (WCCB) blanket is one of the blanket candidates of Chinese Fusion Engineering Test Reactor (CFETR). The core parameters of CFETR have been updated to major radius R = 7.2 m, minor radius a = 2.2 in 2018. Accordingly, the WCCB blanket design was also updated to satisfy multiple operation modes of CFETR with the fusion power of 200 MW, 500 MW, 1.0 GW and 1.5 GW. The WCCB blanket is characterized by 3 independent cooling systems (CSs), namely CS1 for the cooling of the First Wall (FW), CS2&3 for Breeding Zones (BZs). At 200 MW of low fusion power, CS3 is idle. At 500 MW to 1.5 GW of high fusion power, all 3 CSs are put into use to ensure adequate cooling. So it is indispensable to evaluate the feasibility of the updated WCCB blanket from the thermal hydraulic and safety point of view. A system analysis code RELAP5, was employed to model the blanket. The steady states were analyzed under 200 MW, 500 MW, 1.0 GW and 1.5 GW of fusion power. Then, the Loss of Flow Accident (LOFA) was simulated with different assumptions to verify the robustness of 3 cooling systems design under different initial postulations. Simulation results show that important thermal hydraulic parameters, such as pressure and temperature, can basically meet the design criterion, which preliminarily verifies the feasibility of the WCCB blanket from the thermal hydraulic safety point of view. Comprehensive system design and analysis is under way.