24 results on '"heat generation"'
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2. Methodical Aspects of Pricing in the Heat Energy Markets under the Auction Approach
- Author
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Kyzym Mykola O., Khaustova Viktoriia Ye., Kotliarov Yevhen I., and Salashenko Tetiana I.
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heat energy markets ,market competition ,heat auction ,heat generation ,regulated access ,declared pricing ,auction pricing models ,independent heat producers ,renewable energy sources ,Business ,HF5001-6182 - Abstract
The development of competition in the heat energy markets with main heating networks is possible on the basis of the organization of unilateral heat auctions between heat producers. A prerequisite for opening competition in the heat energy markets is the separation of heat generation and heat networks, as well as the provision of regulated access to heat networks for independent producers. In terms of time segmentation, it is advisable to introduce: annual auctions, where basic heat needs are being contracted; monthly auctions – for peak needs, and daily auctions – for hourly imbalances. The article proposes organizational and technological regulations for conducting annual heat auctions, which should cover 80–90% of heat needs. Heat auctions should function according to the declared pricing method, where the producers who are the auction winners receive income for the contracted volumes of heat generation at a given price, while consumers pay a single weighted average price. Heat auctions operate under centralized dispatching, which provides for the coordination of physical and commercial heat energy flows, taking into account the technical specifics of heat networks. The article substantiates variants of economic and mathematical models of auction pricing in the heat energy market with different configurations of heat networks. As such a configuration, are considered heating networks with: 1) unlimited flow connections; 2) insulated heat producers; 3) system restrictions on throughput capacities within the heating area; 4) one-way and 5) two-way flows between adjacent heating areas. Establishment of a fair price for heat energy is reduced to solving the function of minimizing the weighted average price of heat energy for consumers under the following conditions: a) full satisfaction of consumer demand for thermal energy; b) technical capabilities of heat generation; c) connections and throughput capacities of heating networks within the heating area; d) directions of flows and capacity between adjacent heating areas. Each heat network represents a unique configuration of these conditions, therefore, the solution of the economic and mathematical problem of setting the auction price for heat energy will be different in each local heat market. Approbation of the proposed approach proves that with a large number of regulatory and systemic restrictions within the heating area, the price of thermal energy will increase, while bilateral flows of thermal energy between adjacent heating areas lead to a decrease in the price of thermal energy. The proposed methodological aspects of auction pricing for thermal energy should be introduced in large and medium-sized settlements with trunk networks, which will allow independent heat producers who work on renewable energy sources or have excess and waste heat to integrate into the market, contributing to the decarbonization of the city and the country as a whole.
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- 2024
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3. Usage of Rapeseed Oil and Ethanol in a Diesel Engine
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Vitaly A. Likhanov and Oleg P. Lopatin
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diesel engine ,ethanol ,rapeseed oil ,combustion ,heat generation ,toxicity ,exhaust gases ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Technology (General) ,T1-995 - Abstract
Introduction. Alternative fuels in IC-engines make it possible to reduce the harmful effects of exhaust gases on the environment without the use of expensive cleaning systems, diversify the fuel market, and reduce the consumption of non-renewable energy recourses, while research aimed at studying the use of alternative fuels makes it possible to find optimal options for replacing non-renewable raw materials. The purpose of the work is to study the effect of using ethanol in a standard tractor diesel engine with volumetric mixing and combustion from flare resulting from the autoignition of a rapeseed oil pilot portion and to optimize separate cyclic fuel deliveries to obtain maximum energy and environmental effect. Materials and Methods. The article deals with the description of the results of the use of rapeseed oil and ethanol in a serial tractor diesel engine of dimension 2F 10.5/12.0 with separate fuel injection directly into the combustion chamber. In the course of experimental studies, the working process was indicated by a piezo quartz pressure sensor installed in the cylinder head, fuel and air consumption were measured, and samples of exhaust gases to study the gas composition and determine the content of toxic components and smokiness were taken. Results. The exact ethanol and rapeseed oil delivery was determined; the values of the average effective pressure, the average temperature of gases in the cylinder, and active and full heat generation were obtained. It is shown that with an increase in the cyclic ethanol delivery, the proportion of heat from kinetic combustion increases, while the diesel process is characterized by an increase in the proportion of diffusion combustion when the load increases. The analysis of the processes inside the cylinder when the engine runs on ethanol and rapeseed oil in comparison with the traditional diesel process is carried out. Discussion and Conclusion. The use of rapeseed oil and ethanol can completely replace the traditional fuel of petroleum origin for an operating diesel engine by installing additional fuel equipment and modifying the head of cylinder block through mounting an additional nozzle. In this case, the environmental performance of the diesel engine improves significantly.
- Published
- 2022
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4. Influence of pad geometry and method of oil supply on the thermal state of GTE rotor tilting-pad journal bearing
- Author
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E. F. Parovay
- Subjects
cfd methods ,pad ,gas turbine engine ,rotor support ,journal bearing ,performance ,tilting-pad journal bearing ,thermal state ,heat generation ,oil nozzle ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
High heat generation in the hydrodynamic wedge is one of the main factors limiting application of pad journal bearings as bearings for rotors of aircraft gas turbine engines. The goal of the research is to study the influence of the oil supply method on the bearing thermal state and to determine the design factors reducing the bearing temperature. The study was carried out with the use of bearings with diameters of 100320 mm with different design of the oil supply: through oil dispensing grooves in the pads, through oil nozzles in the inter-pad space, using lead-in chamfers for the pads, with oil bypass channels. The tasks posed were solved by using volumetric geometric models with the tools of computational fluid dynamics in the ANSYS CFX package in which differential equations describing the model are solved by the finite element method. The patterns of temperature and pressure distribution over the surface of the lower, most loaded bearing pad were obtained for various options of oil supply and different geometry of bearing pads; values of the bearing load carrying capacity, maximum pressure in the working gap, the oil mass flow through the elements of the oil supply; dependences of the bearing static performance on the distance between the shaft and nozzles. Oil supply through oil dispensing grooves made in pads is a factor that negatively affects the bearing thermal state, which is associated with so-called locking of the working gap. It is shown that implementation of oil supply through the space between the pads is more efficient. The use of a lead-in chamfer with plain inserts simplifies oil supply to the working gap. The design solutions described make it possible to reduce the maximum oil temperature in the bearing by 36 degrees Celsius.
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- 2022
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5. Evaluation of Combustion Performance and Heat Release in Preheated Fuel Consumed Diesel Engines
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Sergey А. Plotnikov, Anatoly N. Kartashevich, and Marina V. Motovilova
- Subjects
indicator diagram ,heat generation ,fuel heating ,combustion process ,diesel engine ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Technology (General) ,T1-995 - Abstract
Introduction. The expansion of the fleet of tractors and vehicles causes increased requirements for internal combustion engines. This problem can be solved by improving the work process in a diesel engine that can be achieved by heating the diesel fuel in the fuel supply system. External thermal action is carried out on the high pressure line directly in front of the injectors. Materials and Methods. To analyze and calculate the process of combustion and heat release in a diesel engine with preliminary thermal fuel preparation, bench tests were carried out using the National Instruments software and the necessary equipment. Results. Experimental data of the diesel fuel combustion process in the cylinder of the 4CHN 11.0/12.5 engine are obtained. The analysis of the combustion performance and heat release of diesel with a preliminary high-temperature effect on the fuel was carried out. Indicator diagrams, graphs of heat release, the maximum average temperature of gases in the engine cylinder, and graphs of active and total heat release were constructed. The experimental data showed a decrease in the ignition delay period, the maximum cycle temperature in the engine cylinders, and an acceleration of the start of heat release and combustion process. The values of the parameters of the diesel fuel combustion process are obtained. Discussion and Conclusion. On the basis of the conducted studies, the dependencies of the parameters of the combustion process of a diesel engine with fuel heating to high temperatures are revealed. Indicator diagrams allow drawing a conclusion about the influence of the fuel heating temperature on the intensification of the combustion process. There is an acceleration of the beginning of heat release, a decrease in the rate of pressure build-up and in the rigidity of the engine.
- Published
- 2021
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6. Analyzing the Tendencies in the Development of Centralized Heat Supply in Ukraine
- Author
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Kyzym Mykola O., Kotliarov Yevhen I., and Khaustova Viktoriia Ye.
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district heat supply ,heat supply system of localities ,heat energy ,heat provision ,heat generation ,development tendencies ,heat supply enterprises ,the state policy ,tariffs ,organizational-technological modernization ,Business ,HF5001-6182 - Abstract
The article is aimed at defining the main tendencies in the development of centralized heat supply in Ukraine. Objective prerequisites for the use of centralized heating sources, as well as levels of development of heat supply systems of settlements are identified. It is determined that the development of heat supply systems largely depends on climatic conditions and the climatic characteristics of certain cities of Ukraine are considered. The main stages of construction of district heating systems in localities of Ukraine are formed. Types of heat supply of cities of Ukraine are identified. The genesis of development of heat generation and heat supply processes in Ukraine is researched. The peculiarities of formation of the national legislative framework for regulation of issues on production and consumption of heat energy are analyzed. The provisions of the Concept for the implementation of the State policy in the sphere of heat supply are analyzed. Based on the carried out analysis, it is determined the following: firstly, the imbalance of financial capabilities and needs for financing investment projects of heat supplying enterprises, as well as a shortage of investment resources, which requires careful substantiation of investment programs, directions and order of modernization and reconstruction of available capacities; secondly, shifting the focus to the powers of local authorities (through decentralization of public administration), which received broad powers to license and set tariffs for heat energy, but at the same time received a wider range of obligations to maintain heat supply systems in working condition; thirdly, the lack of medium- and long-term planning for the development of heat supply systems in localities, which largely explains the current state of the heat supply sector. It is substantiated that such features of the current state of heat supply in Ukraine require the development of new approaches to planning and implementation of works on organizational-technological modernization of heat supply in conditions of limited financial resources.
- Published
- 2021
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7. Efficiency of using alternative sources of heat in electric melting of metal
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S. V. Korneev and I. A. Trusova
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еlectric arc furnace ,oxy-fuel burners ,natural gas ,injectors ,heat generation ,efficiency ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The paper considers ways to assess the efficiency of using alternative sources of heat when melting alloys in electric arc furnaces. The focus is on increasing furnace productivity and reducing production costs. The analysis of the use of various systems for intensifying melting in arc furnaces and their main indicators is carried out. An assessment of the efficiency of fuel use in electric arc furnaces has been carried out. The expected economic effect from the introduction of alternative energy sources in electric furnaces has been calculated. It is shown that the economic effect from the introduction of alternative energy sources on electric arc furnaces depends significantly on the increase in furnace productivity.
- Published
- 2020
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8. General principles of hard-soft-technologies application to modelling of operation process in internal combustion engines
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Gashchuk P. and Nikipchuk Serhij
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internal combustion engine ,model working space ,heat generation ,heat consumption ,modelling ,hard–soft technology ,General Works - Abstract
The perfection of the piston engines in the constructive-mechanical sense without revolutionary changes in the technology of design and manufacturing is difficult to raise, but the perfection in the thermodynamic sense is a “broad field” for the useful activity of engineering science. In order to penetrate as much as possible into the phenomenon of transformation of forms of energy - chemical to thermal, and then – thermal to mechanical, it is necessary to have a rich cognitive ability and a properly adequate model of “constantly variables” in the time of the intraomotor processes. To create such a model purely analytical and algorithmic means, as it turned out, is hardly possible, and therefore always in parallel with the theoretical studies have to be applied also experimental, requiring the use of special bench equipment. The combination on natural and virtual approaches to the modelling of processes that occur in the internal combustion engines enables to increase considerably the information support of engines design processes. This approach can be named the hard-soft-technology of comprehension. The aim is to specify the principles of rational combination of natural and virtual modelling environments into a united system employing, in this way, the hard–soft–technology of operating process modelling in the internal combustion engines. Generally, it is only the reality that is able to implacably “integrate”, so to say, the system of descriptive equations in any possible form. Consequently, the harmonious combination of natural modelling and virtual modelling within the framework of any paradigm enables to enhance the comprehension of mechanic energy production principles in the thermal engines. Proceeding from a general and to a considerable extent theoretical description of heat transmission and taking into consideration the Newton heat–transfer equation and the theory of similarity, however, when an adequate evaluation of heat emission through the walls of the engine’s operation space is discussed, the corrective measures performed solely by means of direct measurements are required. It is the direct measurements in the natural environment of engine’s operating space thermal parameters that create the informative grounds for theoretical generalizations in the virtual environment.
- Published
- 2018
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9. Postcollisional evolution features of the intracontinental structures formed by overthrusting
- Author
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O.I. Parphenuk
- Subjects
collision ,overthrusting ,evolution ,heat generation ,heat flow value ,thermal conductivity ,rheology ,temperature ,solidus ,Geology ,QE1-996.5 - Abstract
The investigation of intracontinental collision structures is conducted based on the complex model of the thermal and mechanical evolution of overthrusting process for the rheologically layered lithosphere, which includes brittle upper crust, the lower crust and lithospheric upper mantle with different effective viscosity values. Finite element models with Lagrangian approach were used for the problem simulation. It was shown that thermal evolution of continental orogens essentially results from the geometry and topography due to thrusting and postcollision stage. This work concentrates on the thermal parameters influence on the evolution of collision zones aimed to the study of possibility of granite melt formation. Calculations for mean continental initial temperature distribution lead to the conclusion of possibility of granite melt formation for the case of “wet” granite solidus. The horizon of temperatures higher than “wet” granite solidus appears at the level of 30-40 km, moving upward to the depth 15-20 km at postcollision stage. The early postcollision evolution shows some heat flow increase due to the thickening of the upper crust with maximum heat generation rate. Further history leads to the stable heat flow values because additional loading redistribution resulting from the denudation of surface uplift and corresponding sedimentation is small due to the local erosion in our model. It was shown that surface heat losses after the termination of horizontal shortening depend to a greater extent on radiogenic heat generation rather than thermal conductivity value in the upper crust.
- Published
- 2018
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10. Deformation and Heat Generation in Cylindrical Samples from Low-Carbon Steel with Group Recess when Stretched
- Author
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Yurij V. Vasilevich, Evgenij A. Moyseychik, and Alexander E. Moyseychik
- Subjects
low-carbon steel ,cylindrical samples ,group grooves ,deformation ,heat generation ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
The paper shows that in the root of rectangular grooves of stretched steel cylindrical rods of circular cross section containing groups of equally distant grooves with the same geometry, with an increase in the distance between the grooves, the relative narrowing at the point of fracture decreases by 1.5 or more times when the ratio of the width of the protrusions to the width of grooves changes from 1 to 4. It is obtained that at a constant deformation rate of a specific element the change in the temperature of its points will be proportional to the stresses acting in the elements NTE. It is established that in the cylindrical rods made of low-carbon steel with groups of grooves and protrusions along the length under the influence of an increasing load, the emergence of zones of limiting states, fracture nucleation sites and their development in elements can be determined by the thermal method with a probability of not less than 95 %.
- Published
- 2018
11. ANALYSIS OF THERMAL STATE OF TRACTION BRUSHLESS PERMANENT MAGNET MOTOR FOR MINE ELECTRIC LOCOMOTIVE
- Author
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A. V. Matyuschenko
- Subjects
brushless motor ,heat generation ,temperature ,losses ,permanent magnet ,coil ,current ,resistance ,mathematical model ,FEM ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Purpose. The study was conducted to analyze thermal state of the traction permanent magnet synchronous motor for mine electric battery locomotive when operating in continuous and short-time duty modes. These operating modes are selected for study, as they are typical for mine electric locomotives. Methodology. Thermal calculation was performed by means of FEM in three-dimensional formulation of problem using Jmag-Designer. Results. The modeling results of thermal state of the PMSM in continuous and short-time duty operation modes showed good agreement with experimental results. The results showed that the temperature of PM is higher than temperature of the stator winding in continuous operation mode. It was found that PM temperature might reach excessive values because of the high presence of eddy current losses in neodymium PM. Therefore, special attention in the design and testing of PMSM should be paid to the temperature of PM in various operation modes. Practical value. It was recommended to use high temperature permanent magnets in traction PMSM to avoid demagnetization of PM and performance degradation.
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- 2016
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12. HEAT GENERATION AND RESISTANCE TO DEFORMATION OF STRUCTURAL STEEL
- Author
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A. E. Moyseychik and Yu. V. Vasilevich
- Subjects
heat generation ,deformation resistance ,structural steel ,luminescence effects ,Technology - Abstract
The purpose of this paper is to determine dependence between heat generation and resistance to deformation of structural steel.It has been assumed on the basis of the represented data that in the course of deformation of structural steel physicochemical interactions of dislocations and impurity atoms occurring in the slip bands result in heat generation and temperature increase of product surface. Interdependence of heat generation and elastic-plastic deformation has been experimentally proved by set of experiments on low-carbon steel plate extension. In the case of deformation its intensity and rate are considered as main factors that determine local material heating in the pre-fracture nucleus and temperature directly exerts its influence on diffusion processes and changes in physical and mechanical characteristics of the material in the pre-fracture nucleus. The obtained average heating temperature for the pre-fracture nucleus is equal approximately (20–90)°С for low-carbon steel ВСт3сп while using quasi-static extension. The paper presents data pertaining to steel plate deformation that point to the fact that elastic-plastic deformation is accompanied by deformation heat generation and a crack initiation is caused by thermo mechanical process. Heat is formed in the slip bands and their direction corresponds to the maximum shearing stresses. Surface temperature in the zone of crack initiation has reached 88 °С in the pre-fracture stage. The Davidenkov-Spiridonova formula has been derived while using a concept of "surface energy" and Laplace's formula. This formula makes it possible to determine resistance to deformation of a stretched round steel rod in the stage of neck formation. The paper shows formula’s dependence on the deformation heat generation.
- Published
- 2015
13. Interaction of cement particles with water or mechanism of hydration and hardening of cement
- Author
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Vasiliy Agafonovich Lotov
- Subjects
cement ,hydration ,dispersion of particles ,hardening ,heat generation ,induction period ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
The relevance of the research is caused by the necessity to deepen theoretical conceptions about the mechanism of cement water interaction for more efficient use of Portland cement. The aim of the study is to determine the behavior of the cement-water system during hydration and hardening with microcalorimetry new design. Object: Portland cement CEM 1 42,5 B (M500 D0). Methods: thermodynamic analysis of the cement-water system based on Gibbs equation, which is the combined expression of the first and the second laws of thermodynamics; calorimetric studies of the cement-water system with the original design of the differential microcalorimeter; magnetodynamic method of monitoring acoustic waves in the cement-water system. The results of the research. The paper demonstrates the possibility of using the basic law of thermodynamics in identifying the mechanism of cement hydration and hardening. It was found that the heat generated by cement hydration is consumed on dispersion of cement particles to nanoscale state. The surface and near-surface protonation of cement mineral particles play the main role in dispersing. Formation of cement stone structure begins with the unification of nanoscale particles in their recrystallization and transition to denser condition. This results in occurrence of free volume and free water in hardening system. Free water interacts with not hydrated surface of cement grains. This cement water interaction cycle is repeated throughout a long period of cement hardening and formation of cement stone structure. The dispersion of cement particles is accompanied by acoustic oscillations in the system frequency from 3-100 Hz to 20 kHz with intensity of low frequency oscillations of 3-10 decibels. Different periods of hydration are accompanied by vibrations of different intensity.
- Published
- 2018
14. Thermal deformations of the spindle head of a numerically controlled lathe
- Subjects
ÑепловÑе деÑоÑмаÑии ,нагÑев ,thermal deformations ,ÑпинделÑÐ½Ð°Ñ Ð±Ð°Ð±ÐºÐ° ,heat generation ,heating ,ÑепловÑделение ,spindle headstock ,lathe ,ÑокаÑнÑй ÑÑанок - Abstract
Тема наÑÑно-иÑÑледоваÑелÑÑкой ÑабоÑÑ: «ТепловÑе деÑоÑмаÑии ÑпинделÑной бабки ÑокаÑного ÑÑанка Ñ ÑиÑловÑм пÑогÑаммнÑм ÑпÑавлением».ÐÐ°Ð½Ð½Ð°Ñ ÑабоÑа поÑвÑÑена изÑÑÐµÐ½Ð¸Ñ ÑпинделÑной бабки, иÑÑоÑников Ñепла и ÑемпеÑаÑÑÑного пÑоÑÑÑанÑÑва. ÐадаÑи, коÑоÑÑе ÑеÑалиÑÑ Ð² Ñ Ð¾Ð´Ðµ ÑабоÑÑ: анализ возможнÑÑ Ð¿ÑиÑин ÑепловÑÑ Ð´ÐµÑоÑмаÑий пеÑедней бабки, иÑÑледование ÑепловÑÑ Ð´ÐµÑоÑмаÑий ÑпинделÑной бабки в завиÑимоÑÑи Ð¾Ñ ÑемпеÑаÑÑÑÑ ÐºÐ¾ÑпÑÑа.РпÑоÑеÑÑе ÑабоÑÑ Ð±Ñли изÑÑÐµÐ½Ñ ÑбоÑоÑнÑе ÑеÑÑежи Ñзла ÑпинделÑной бабки, ÑÑководÑÑва по ÑкÑплÑаÑаÑии и паÑпоÑÑа ÑазлиÑнÑÑ ÑокаÑнÑÑ ÑÑанков, пÑоанализиÑÐ¾Ð²Ð°Ð½Ñ ÐºÐ¾Ð½ÑÑÑÑкÑии ÑпинделÑнÑÑ Ð±Ð°Ð±Ð¾Ðº.Ð ÑезÑлÑÑаÑе вÑÐ¿Ð¾Ð»Ð½ÐµÐ½Ð¸Ñ ÑабоÑÑ Ð±Ñли пÑоанализиÑÐ¾Ð²Ð°Ð½Ñ Ð²Ð¾Ð·Ð¼Ð¾Ð¶Ð½Ñе иÑÑоÑники Ñепла и пÑиÑÐ¸Ð½Ñ Ð½Ð°Ð³Ñева ÑпинделÑной бабки, пÑоведен ÑкÑпеÑÐ¸Ð¼ÐµÐ½Ñ Ð´Ð»Ñ Ð¾Ð¿ÑÐµÐ´ÐµÐ»ÐµÐ½Ð¸Ñ Ð¿Ð¾Ð´Ñема бабки в Ð¼Ð¾Ð¼ÐµÐ½Ñ ÑÑÑановивÑегоÑÑ Ñежима ÑабоÑÑ ÑÑанка, маÑемаÑиÑеÑки оÑÐµÐ½ÐµÐ½Ñ Ð¿Ð¾Ð³ÑеÑноÑÑи ÑезÑлÑÑаÑов полÑÑеннÑÑ Ð¸Ð·Ð¼ÐµÑений., The topic of the research work: "Thermal deformations of the spindle headstock of a numerically controlled lathe".This work is devoted to the study of the spindle headstock, heat sources and temperature space. Tasks that were solved during the work: analysis of possible causes of thermal deformations of the headstock, study of thermal deformations of the spindle headstock depending on the temperature of the housing.In the process of work, assembly drawings of the spindle head assembly, operating manuals and passports of various lathes were studied, the designs of spindle heads were analyzed.As a result of the work, possible sources of heat and the causes of heating of the spindle headstock were analyzed, an experiment was conducted to determine the lifting of the headstock at the time of the steady-state operation of the machine, the errors of the results of the measurements were mathematically estimated.
- Published
- 2022
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15. The participation of cyanide-resistant respiration in heat generation and antioxidative defense of cell in winter wheat shoots under cold influence
- Author
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Grabelnych O.I., T.P. Pobezhimova, A.M. Korzun, S.A. Voznenko, N.A. Koroleva, N.S. Pavlovskaya, O.A. Borovik, and V.K. Voinikov
- Subjects
alternative oxidase ,heat generation ,reactive oxygen species ,low temperature stress ,Triticum aestivum L. ,Biochemistry ,QD415-436 - Abstract
It was shown, that activation of the cyanide-resistant respiration by treatment of 30 mkM antimycine A and 10 mM hydrogen peroxide during 24 hours induced the intensification of heat generation by tissues of winter wheat shoots and decreased death of shoots under subsequent action of freezing temperature -6 0C (3 hours). At the same time the activation of alternative pathway in winter wheat shoots under long-term action of low temperature effectively prevented the reactive oxygen species (ROS) production in electron transport chain (ETC) of mitochondria, which was induced by oxidizing substrate and antimycine A.
- Published
- 2011
16. Конструкция и тепловая работа колпаковых печей для термической обработки рулонов холоднокатанной стали
- Subjects
ТЕПЛОГЕНЕРАЦИЯ ,HEATING UNIFORMITY ,PROTECTIVE ATMOSPHERE ,СИСТЕМЫ ОТОПЛЕНИЯ ,HEAT GENERATION ,BELL FURNACE ,КОЛПАКОВАЯ ПЕЧЬ ,РУЛОНЫ ,COLD-ROLLED STEEL STRIP ,ХОЛОДНОКАТАННАЯ СТАЛЬНАЯ ЛЕНТА ,ТЕМПЕРАТУРНЫЙ И ТЕПЛОВОЙ РЕЖИМЫ ,COILS ,TEMPERATURE AND THERMAL CONDITIONS ,РАВНОМЕРНОСТЬ НАГРЕВА ,HEATING SYSTEMS ,ЗАЩИТНАЯ АТМОСФЕРА - Abstract
Холоднокатанная стальная лента после прокатки сворачивается в рулоны, которые подвергаются рекристаллиационному высокотемпературному отжигу в колпаковых печах. Термическая обработка рулонов осуществляется в защитной атмосфере водорода и азота. Для этого садка из 2-5 рулонов закрывается герметичным стальным муфелем, под которым циркулирует защитная атмосфера. Муфель накрывают футерованным нагревательным колпаком, внутренняя поверхность которого разогревается либо с помощью электронагревателей, либо газовыми горелками. Тепловой режим термообработки формируется технологами и проходит несколько этапов: нагрев садки рулонов до заданной температуры, выдержка для выравнивания температуры по объему рулонов, охлаждение садки под колпаком и муфелем и дальнейшее охлаждение на воздухе. Электрическая и топливная теплогенерация должны обеспечивать строгое выполнение режима термообработки. Равномерность нагрева стопы рулонов зависит, прежде всего, от конструкции печи, которая может быть выполнена в одностопном и многостопном вариантах, а также от способа теплообмена в системе: нагревательный колпак – муфель – поверхность рулонов и осуществляется излучением и конвекцией. Передача теплоты в объеме рулонов осложнена анизатропностью теплофизических свойств свернутых рулонов, которые снижают скорость прохождения теплового потока теплопроводностью с поверхности рулона в его центр. Поэтому изучение равномерности нагрева рулонов, в целях совершенствования температурных и тепловых режимов, должно проводиться при исследованиях на действующей печи конкретной конструкции. Cold-rolled steel strip after rolling is rolled into coils, which are subjected to high-temperature recrystallization annealing in bell furnaces. Heat treatment of rolls is carried out in a protective atmosphere of hydrogen and nitrogen. For this, a cage of 2-5 rolls is closed with a sealed steel muffle, under which a protective atmosphere circulates. The muffle is covered with a lined heating cap, the inner surface of which is heated either by electric heaters or by gas burners. The thermal regime of heat treatment is formed by the technologists and goes through several stages: heating the charge of the rolls to a predetermined temperature, holding to equalize the temperature over the volume of the rolls, cooling the charge under the bell and muffle, and further cooling in air. Electric and fuel heat generation must ensure strict implementation of the heat treatment regime. The uniformity of heating of a stack of rolls depends, first of all, on the design of the furnace, which can be performed in one-stop and multi-stop versions, as well as on the method of heat exchange in the system: heating cap - muffle - surface of rolls and is carried out by radiation and convection. The transfer of heat in the volume of the rolls is complicated by the anisatropy of the thermophysical properties of the rolled rolls, which reduce the rate of passage of the heat flow by thermal conductivity from the surface and the roll to its center. Therefore, the study of the uniformity of heating the rolls, in order to improve the temperature and thermal conditions, should be carried out during research on an operating furnace of a specific design.
- Published
- 2021
17. Pipe cooling of massive foundation slabs during the construction period
- Subjects
строительный период ,massive concrete and reinforced concrete structures ,construction period ,температурное поле ,массивные бетонные и железобетонные конструкции ,гидратация цемента ,cement hydration ,трубное охлаждение ,термическая трещиностойкость ,thermal crack resistance ,pipe cooling ,temperature field ,heat generation ,термонапряженное состояние ,тепловыделение ,thermal stress state - Abstract
В настоящее время при проектировании и строительстве массивных бетонных и железобетонных конструкций, ответственных и уникальных зданий и сооружений много внимания уделяется вопросам регулирования температурного режима в строительный период. В данной работе исследовалось трубное охлаждение, как метод регулирования термонапряженного состояния. Задачи, которые решались в ходе исследования: 1. Описание алгоритма расчета температурного режима массивной бетонной конструкции; 2. Анализ температурных полей и напряжений, деформаций в конструкции; 3. Расчет термонапряженного состояния конструкции при различных режимах трубного охлаждения; 4. Анализ изменения и определения температурных трещин с изменением режима трубного охлаждения; 5. Нахождение безопасных режимов бетонирования объектов с использованием систем охлаждения. В данной работе проведены расчеты термической трещиностойкости фундаментной плиты реакторного отделения турецкой АЭС «АККУЮ» при регулировании термонапряженного состояния за счет трубного охлаждения. Расчеты велись с учетом влияния температуры твердения на теплофизические и деформативные характеристики бетона. По результатам анализа расчетных исследований выбирается оптимальная технология трубного охлаждения фундаментной плиты для обеспечения термической трещиностойкости конструкции., Now, when designing and building massive concrete and reinforced concrete structures of critical and unique buildings and structures, big attention was paid to the regulation of the temperature regime the construction period. In this paper, pipe cooling was studied as a method for regulating the thermally stressed state. Tasks that were solved during the research: 1. Description of the algorithm for calculating the temperature regime of a massive concrete structure; 2. Analysis of temperature fields and stresses and deformations in the structure; 3. Calculation of the thermal stress state of the structure under different modes of pipe cooling; 4. Analysis of changes and determination of temperature cracks with changes in the pipe cooling mode; 5. Finding safe modes of concreting objects using cooling systems. In this master’s thesis, calculations of the thermal crack resistance of the foundation plate of the reactor department of the Turkish NPP «AKKUY» under the influence of pipe cooling on the thermally stressed state. Calculations carried out taking into account the effect of hardening temperature on the thermophysical and deformation normative characteristics of concrete. Based on the results of the analysis of design studies, the optimal technology of pipe cooling of the foundation plate is selected to ensure thermal crack resistance of the structure.
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- 2020
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18. Моделирование сажеобразования в цилиндре дизеля
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diesel ,дымность ,сажа ,smoke ,heat generation ,отработавшие газы ,тепловыделение ,soot ,дизель ,exhaust gases - Abstract
Сажа – главная составляющая твердых частиц, содержащихся в отработавших газах дизелей; образуется из продуктов термического разложения углеводородного топлива. Предложена математическая модель для прогнозирования дымности отработавших газов дизелей на различных нагрузочных и скоростных режимах. По результатам численного моделирования получено текущее содержание компонентов газовой смеси в реакционной зоне в зависимости от угла поворота коленчатого вала и определены такие показатели сажесодержания в объеме цилиндра, как минимальный средний диаметр частиц, максимальная масса сажи, угол, соответствующий максимальному содержанию сажи, суммарная масса частиц сажи в цилиндре и суммарное сажевыделение. Проведены лабораторно-стендовые исследования дизеля 2Ч 10,5/12,0 с определением индикаторного давления, индикаторной температуры газов в цилиндре, скорости тепловыделения и показателей токсичности и дымности отработавших газов. Результаты моделирования дымности отработавших газов дизеля подтверждены экспериментальными измерениями на различных режимах работы., Soot is the main component of the solid particles contained in exhaust gases of diesel engines, which is formed from the products of thermal decomposition of hydrocarbon fuel. A mathematical model for predicting the fluidity of exhaust gases of diesel engines at different load and speed modes of operation is proposed. The current content of the gas mixture components in the reaction zone, depending on the angle of rotation of the crankshaft, was obtained by numerical simulation. Such indicators of soot content in the cylinder volume as the minimum average diameter of the particles, the maximum soot mass, the angle of the maximum soot content, the total mass of soot particles in the cylinder and the total soot release were determined. Laboratory and bench studies of diesel 2F 10.5/12.0 have been carried out, determining indicator pressure, indicator temperature of the gases in the cylinder, heat release rate and indicators of toxicity and smoke exhaust gases. The results of simulation of smokiness of the diesel exhaust gases are confirmed by experimental measurements in different operating modes.
- Published
- 2019
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19. Heat generation based on wood fuel as a basis for improving energy effi ciency in the timber industry
- Author
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Mekhrentsev, A. V. and Korzh, M. A.
- Subjects
ДРЕВЕСНОЕ ТОПЛИВО ,BIOENERGY ,ТЕПЛОГЕНЕРАЦИЯ ,FUEL CHIPS ,БИОЭНЕРГЕТИКА ,ЛЕСНОЕ ХОЗЯЙСТВО ,HEAT GENERATION ,ENERGY SAVING ,WOOD FUEL ,FUEL AND TECHNOLOGICAL TERMINALS ,ЭНЕРГОСБЕРЕЖЕНИЕ ,PELLETS ,ТОПЛИВНАЯ ЩЕПА ,EXPORT OF CHIPS ,НОРМИРОВАННОЕ ТОПЛИВО ,STANDARDIZED FUEL ,FORESTRY ,ТОПЛИВНО-ТЕХНОЛОГИЧЕСКИЕ ТЕРМИНАЛЫ ,ЭКСПОРТ ЩЕПЫ ,ПЕЛЛЕТЫ - Abstract
Теплогенерация на основе древесного топлива повышает энергоэффективность в лесопромышленном производстве. Древесное топливо является возобновимым и экологичным ресурсом и рассматривается как эффективная замена топливу из ископаемых ресурсов. Применение нормированных видов древесного топлива позволяет снизить затраты на теплогенерацию. Древесное топливо имеет самые низкие показатели выделения углекислого газа, а также отсутствие серы при сгорании, что обеспечивает экологичность применения данного вида топлива. Важными организационными мероприятиями по переходу на древесные виды топлива являются создание унифицированных муниципальных топливно-технологических терминалов, расширение производства топливной щепы при рубках ухода, а также экспорт избыточной топливной щепы. Эти мероприятия позволяют увеличить количество высокопроизводительных рабочих мест. Heat generation based on wood fuel increases energy effi ciency in the timber industry. Wood fuel is a renewable and environmentally friendly resource and is seen as an effective substitute for fossil fuels. The use of standardized types of wood fuel can reduce the cost of heat generation. Wood fuel has the lowest rates of carbon dioxide emissions, as well as the absence of sulfur during combustion, which ensures environmental friendliness of this type of fuel. Important organizational measures for the transition to wood fuels are the creation of unifi ed municipal fuel technology terminals, the expansion of the production of fuel chips during logging operations, as well as the export of excess fuel chips. These activities increase the number of high-performance jobs.
- Published
- 2019
20. Use of computer modelling for the Khankala geothermal waters sustainable exploitation
- Author
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Farkhutdinov, Anvar Mansurovich, Farkhutdinov, Iskhak Mansurovich, Cherkasov, Sergey Vladimirovich, Ismagilov, Rustem Ayratovich, and Khairulina, Larisa Alexandrovna
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Materials Science (miscellaneous) ,Management, Monitoring, Policy and Law ,doublet ,modelling ,Resource (project management) ,термальные подземные воды ,Waste Management and Disposal ,Geothermal gradient ,Hydrogeology ,renewable energy resources ,Petroleum engineering ,возобновляемые ресурсы энергии ,business.industry ,устойчивая эксплуатация ,Mode (statistics) ,Ханкальское месторождение ,Geotechnical Engineering and Engineering Geology ,моделирование ,Renewable energy ,Fuel Technology ,Heat generation ,Sustainability ,Environmental science ,Khankala field ,Economic Geology ,дублеты ,geothermal waters ,business ,Groundwater ,sustainable exploitation - Abstract
Актуальность исследования обусловлена необходимостью достижения устойчивости в эксплуатации термальных подземных вод. Снижение температуры геотермального резервуара при обратной закачке использованного флюида является важнейшей проблемой долгосрочной эксплуатации, прогноз которой возможен с помощью компьютерного моделирования. Цель: дать прогноз изменения температурного режима в ходе эксплуатации Ханкальского месторождения, рассмотреть различные сценарии разработки и предложить возможные решения достижения устойчивости в разработке месторождения. Объекты: Ханкальское месторождение; дублетная циркуляционная система Ханкальской геотермальной станции. Методы: компьютерное моделирование изменения температуры ресурса термальных подземных вод; оценка и анализ возможных вариантов периодической эксплуатации месторождения; оценка суммарной выработки тепла и конечной темпертуры геотермального резервуара на момент остановки для различных вариантов эксплуатации. Результаты. На Ханкальском месторождении снижение температуры в продуктивной скважине начнется через 6–7 лет после разработки в запланированном режиме. Периодическая короткая эксплуатация и остановка (10-летний цикл, 100 лет суммарно) позволяют выработать больше тепла по сравнению с более продолжительной эксплуатацией (50-летний цикл, 100 лет суммарно), вместе с тем второй вариант дает возможность достичь более высокого восстановления температуры в продуктивной скважине. В случае значительного снижения температуры после некоторого периода эксплуатации XIII пласта предлагается периодическое использование различных продуктивных горизонтов (IV–VII, XVI или XXII) для обеспечения устойчивости работы геотермальной станции. Разработка XIII пласта возможна после периода остановки благодаря относительно высокой скорости восстановления температуры. Следует размещать скважины параллельно двум главным разломам Ханкальского месторождения, при этом продуктивную скважину – в южной, а нагнетательную – в северной части, так как естественный поток подземных вод может замедлить расширение холодного фронта до продуктивной скважины. Установка и периодическое использование двух или более циркуляционных систем могут обеспечить наибольшую устойчивость при долгосрочной эксплуатации. Однако рациональность этого метода, требующего больших дополнительных затрат на начальном этапе реализации проекта, представляет собой сложный вопрос. Выбор режима эксплуатации требует учета гидрогеологических, геотермальных, экономических и технических аспектов при совместном участии гидрогеологов, специалистов по геотермии, технологов и экономистов. The relevance of the research is caused by the need of achieving sustainability in exploitation of geothermal waters. Temperature drop of geothermal reservoir during the reinjection of used fluid is the most important problem of long term operation, the forecast of which is possible with the help of computer modelling. The main aim of the research is to forecast the temperature changes during the Khankala field exploitation, consider various development scenarios and propose possible solutions to achieve sustainability in field operation. Objects of the research are the Khankala field; doublet circulation system of the Khankala geothermal station. Methods: computer modelling of temperature changes of the geothermal resource; assessment and analysis of possible variants for periodic exploitation of the field; calculation of the total heat generation and the final temperature of the geothermal reservoir at the time of shutdown for various operating options. Results. Temperature drop in a production well will start after 6-7 years of exploitaion in the planned mode at the Khankala field. Periodic short-term operation and shutdown (10-year cycle, 100 years in total) allows more heat to be generated compared with longer operation (50-year cycle, 100 years in total), while the second variant makes it possible to achieve a higher temperature recovery in the production well. In the case of a significant decrease in temperature after a certain period of the XIII layer exploitation, periodic use of various productive layers (IV-VII, XVI or XXII) is proposed to ensure the sustainability of the geothermal station. Development of the XIII layer is possible after a period of stopping due to the relatively high rate of temperature recovery. Wells should be placed parallel to the two main faults of the Khankala field, with the production well in the south and the injection well in the northern part, since the natural flow of groundwater can slow down the expansion of the cold front to the production well. The installation and periodic use of two or more circulation systems can provide the greatest stability in long-term operation. However, the rationality of this method, which requires large additional costs at the initial stage of project implementation, is a complex issue. The choice of operating mode requires consideration of hydrogeological, geothermal, economic and technical aspects with the joint participation of hydrogeologists, geothermal specialists, technologists and economists.
- Published
- 2019
21. Исследования показателей тепловыделения газовых двигателей
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сгорание ,throttling ,эффективный КПД ,дросселирование ,внутрицилиндровые процессы ,temperature ,indicator charts ,full load curve ,gas engine ,intra-cylinder processes ,коэффициент избытка воздуха ,температура ,внешняя скоростная характеристика ,газовоздушная смесь ,индикаторные диаграммы ,effective coefficient of performance ,heat generation ,газовый двигатель ,тепловыделение ,excess air coefficient ,gas-air mixture ,combustion - Abstract
В комплексной стратегии возрождения производства оборудования для горной промышленности и обеспечении ее конкурентоспособности предусмотрено широкое использование газовых двигателей различного назначения. Экспериментальные исследования рабочего цикла газового двигателя являются одной из основных задач при определении характеристики тепловыделения. Для этого на различных режимах были зафиксированы индикаторные диаграммы, которые были подвергнуты анализу с целью определения основных параметров, характеризующих внутрицилиндровые процессы. Согласно программе эксперимента были определены максимальное давление цикла, скорость нарастания давления, характеристика тепловыделения, показатели первой фазы тепловыделения, продолжительность второй фазы сгорания, а также влияние угла опережения зажигания на период воспламенения.Представлены результаты экспериментального исследования влияния рабочего процесса газового двигателя с учетом изменения угла опережения зажигания на период воспламенения и определены параметры максимального давления цикла, скорости нарастания давления и характеристики тепловыделения. При обработке данных построены интегральные характеристики, рассчитаны параметры рабочего цикла и определена динамика тепловыделения двигателя., A comprehensive strategy for reviving the production of mining industry equipment and ensuring its competitiveness includes the wide use of gas engines for various purposes. Experimental studies of the working cycle of a gas engine are one of the main tasks in determining the heat generation characteristics. To this end, indicator charts were recorded in various modes, which were subjected to analysis in order to determine the key parameters characterizing intra-cylinder processes. According to the experimental program, the maximum cycle pressure, the rate of pressure build-up, the heat generation characteristic, the first heat generation phase, the duration of the second combustion phase, and the effect of the ignition advance angle for the ignition period were determined.The results of an experimental study of the influence of gas engine working process with allowance for the change in the ignition advance angle for the ignition period are described and the parameters of the maximum cycle pressure, the rate of pressure build-up, and the heat generation characteristics are determined. In the processing of data, integral charts are constructed, the working cycle parameters are calculated, and the dynamics of the engine heat generation is determined., №229(1) (2018)
- Published
- 2018
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22. ЭФФЕКТИВНОЕ УПРАВЛЕНИЕ СИСТЕМОЙ ТЕПЛОГЕНЕРАЦИИ В АВТОНОМНЫХ ПРОИЗВОДСТВЕННЫХ ПОМЕЩЕНИЯХ
- Subjects
электроснабжение ,equithermal regulation ,equithermal mode ,воздушный тепловой насос ,эквитермальный режим ,heat generation ,теплогенерация ,air heat pump ,electricity supply ,эквитермическое регулирование - Abstract
В статье рассмотрены теоретические аспекты работы эффективного современного отопления с использованием оборудования, обеспечивающего управляемость системы и теплогенерирующей установки, погодозависимое регулирование, возможность программировать изменение температурных режимов (управляемое термостатирование), реализовывать их независимо для разных помещений, дистанционное управление, минимизацию тепловой инерционности системы. Реализация такого способа управления как программируемое термостатирование для теплоснабжения помещений, заключающееся в изменении установки температуры отапливаемых помещений согласно заданной программы, позволяет устанавливать температуру помещений в соответствии с потребностями в нагреве в текущий момент времени, что даёт возможность существенно снижать затраты потребляемой энергии на отопление., The article considers the theoretical aspects of modern and efficient heating using equipment, to ensure controllability of the system and the heat generating unit, a modulating regulation, the ability to program the change in temperature regimes (temperature control), and implement them independently for different areas, remote control, minimizing the thermal inertia of the system. The implementation of such a control method as programmable temperature control for heating of premises, which consists in changing the temperature of the heated space according to a given program, allows you to set the temperature of rooms in accordance with the requirements of heating in current time that makes it possible to significantly reduce the cost of energy consumed for heating.
- Published
- 2017
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23. Analysis of thermal state of traction brushless permanent magnet motor for mine electric locomotive
- Subjects
FEM ,математическая модель ,нагрев ,катушка ,вентильный двигатель ,current ,losses ,resistance ,температура ,постоянный магнит (ПМ) ,метод конечных элементов ,brushless motor ,permanent magnet ,heat generation ,coil ,mathematical model - Abstract
Выполнен поверочный тепловой расчет тягового вентильного двигателя с постоянными магнитами посредством конечно-элементной цепно-полевой математической модели на платформе JMAG-Designer в трехмерной постановке задачи. Получено распределение температуры и графики нагрева деталей двигателя. Проведен сравнительный анализ расчетных и экспериментальных данных теплового состояния двигателя в часовом и длительном режимах работы. Purpose. The study was conducted to analyze thermal state of the traction permanent magnet synchronous motor for mine electric battery locomotive when operating in continuous and short-time duty modes. These operating modes are selected for study, as they are typical for mine electric locomotives. Methodology. Thermal calculation was performed by means of FEM in three-dimensional formulation of problem using JmagDesigner. Results. The modeling results of thermal state of the PMSM in continuous and short-time duty operation modes showed good agreement with experimental results. The results showed that the temperature of PM is higher than temperature of the stator winding in continuous operation mode. It was found that PM temperature might reach excessive values because of the high presence of eddy current losses in neodymium PM. Therefore, special attention in the design and testing of PMSM should be paid to the temperature of PM in various operation modes. Practical value. It was recommended to use high temperature permanent magnets in traction PMSM to avoid demagnetization of PM and performance degradation.
- Published
- 2016
24. Energy balance of the Earth’s tectonosphere
- Author
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V. Gordienko
- Subjects
Energy conservation ,Radiogenic nuclide ,Heat generation ,Energy balance ,Geochemistry ,Crust ,upper mantle ,radiogenic heat generation ,deep processes ,Heat flow ,Geology ,Earth (classical element) - Abstract
Concentration of K, U and Th has been investigated in the rocks of the Earth’s crust and upper mantle of platforms, geosynclines and oceans. The coinsidence has been found between total modern heat emanation in the crust and upper mantle of three types of regions with significant differences in the distribution of sources in depth. The values of upper mantle rocks radiogenic heat generation in these regions are about 0.04, 0.06 and 0.08 μW/m 3 respectively. Correspondence of heat generation to geological history, heat flow and deep temperatures has been set for platforms. Implementation of energy conservation law in geological processes has been proven.
- Published
- 2015
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