EngRN: Heat Transfer (Topic)最新文献

{"title":"Intensification of the Flow Process of Grain Drying Using Two-sided Infrared Irradiation","authors":"V. Palamarchuk, Sergii Gyrych, O. Vasilishina, O. Pahomska","doi":"10.15587/2706-5448.2021.225528","DOIUrl":"https://doi.org/10.15587/2706-5448.2021.225528","url":null,"abstract":"The object of research is the process of infrared drying of grain of agricultural crops. In the process of processing seeds of cereals and oilseeds is a fairly large number of technological operations, among which one of the most important is drying. Maintaining the required grain moisture is a major factor influencing its shelf life and quality. Therefore, an urgent and important problem is the intensification of the process of drying seeds of cereals and oilseeds at low energy consumption.<br><br>The process of infrared drying of grain has significant advantages over the most common convective drying due to the fact that no organic fuel is used. Infrared rays are characterized by high thermal action of products, so the demand for the use of infrared radiation in agricultural, food and processing industries for drying grain, bulk ingredients, thermal disinfection, etc. is growing. The principle of operation of the infrared method is that the moisture inside the grain absorbs infrared rays, due to which it is heated. In other words, energy is directly supplied to moisture, which is why we managed to achieve not only high efficiency but also high efficiency.<br><br>To increase the efficiency of removing moisture from the grain by infrared irradiation, it is necessary to increase the area of contact of grains with infrared rays. Given the permeability of infrared rays and the layer of grain on the working body of the conveyor, it is possible to use several ways to increase the area of irradiation. The first method is to apply the vibration of the working body to mix the layers of grain, which contributes to a more uniform processing of products. The second method described in this paper is to use a larger number of emitters, which are located not only above the tray of the conveyor, but also below it. The tray must be made of infrared-permeable material.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114547550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of a Two-Flow Gas Purification From Carbon Oxides (IV) by Methyldiethanolamine Solution","authors":"Andriy Kontsevoy, S. Kontsevoi","doi":"10.15587/2706-5448.2020.214440","DOIUrl":"https://doi.org/10.15587/2706-5448.2020.214440","url":null,"abstract":"The object of research is the stage of purification of process gas of ammonia production with a capacity of 1360–1500 t/day in a two-section plate absorber. The paper substantiates the possibility to replace the monoethanolamine (MEA) absorbent solution with the activated solution of methyl diethanolamine (aMDEA) on the example of the Ukrainian multi-tonnage production, working under the two-flow purification scheme. One of the most problematic areas is the lack of a mathematical model for the absorption of carbon monoxide (IV) by a new absorbent for two-flow purification schemes. In the course of the study, the method of compiling the material balance was used, which takes into account the peculiarities of the interaction of the aMDEA components with CO2, and numerical integration to calculate the number of plates.<br><br>An algorithm for calculating material and heat balances for finely and roughly regenerated solutions has been developed and implemented in Excel. The algorithm and the program provide for multivariate calculations with varying concentration parameters for gas and solution and their temperature. Thermal calculations take into account the adiabatic heating due to the exothermic absorption reaction and determine the temperature of the solutions at the outlet of each part of the absorber. Analysis of the material balance calculations in comparison with the data on the MEA solution shows a decrease in the solution consumption by 5.5 % when using aMDEA, which will help to reduce the energy costs for pumping and regeneration. By kinetic calculation, the number of plates for the absorber was determined to be 13. With the number of 15 in a standard absorber, the calculated number of plates allows the gas to be purified to a content of 0.01 % CO2. An increase in the temperature of the solutions at the inlet to both sections by 10 degrees does not significantly affect the number of plates. Thus, mathematical modeling of a two-section plate absorber showed a real possibility of replacing an 18 % MEA solution with a 40 % aMDEA solution. It is proposed to implement this on existing equipment without changing the technological scheme.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131030457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature Effect on the Thermal-Physical Properties of Fire-Protective Mineral Wool Cladding of Steel Structures Under the Conditions of Fire Resistance Tests","authors":"S. Pozdieiev, O. Nuianzin, O. Borsuk, Oksana Binetska, A. Shvydenko, B. Alimov","doi":"10.15587/1729-4061.2020.210710","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.210710","url":null,"abstract":"The value of the thermal conductivity coefficient depending on the temperature of the samples of steel rod fragments with fire-retardant cladding has been determined in the present research. The thermal conductivity coefficient of mineral wool fire-retardant cladding was determined; special patterns of its dependence on temperature were revealed. This is explained by the thermal decomposition with the release of thermal energy of inclusions between the fibers of mineral wool and its fibers at a temperature of 750 °C. The apparent minimum of the thermal conductivity factor for fire-retardant mineral wool cladding with a thickness of more than 50 mm is observed at a temperature of about 100 °C. This happens due to the fact that at this temperature the free moisture contained between the fibers of the mineral wool evaporates. Generalized temperature dependence of the thermal conductivity coefficient of mineral wool fire-retardant cladding has also been derived, in a tabular form. It can be used for calculating the temperature in steel structures with such fire protection. The thickness range for application is up to 80 mm for the specific heat capacity of 1,000 J/(kg °C) and a density of 200 kg/m 3 . It is shown how the obtained dependence can be used for predicting heating in steel structures with fire-retardant mineral wool cladding. The relative error between the calculated and experimental data was calculated. The Cochrane, Student, and Fischer criteria for the results of temperature calculation in steel structures with fire-retardant mineral wool cladding between the calculated and experimental data accept values that do not exceed the tabular quantities. This means that the results of the calculation using the obtained temperature dependence of the thermal conductivity coefficient are adequate","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129705982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Substantiating the Criteria of Choosing Project Solutions for Climate Control Systems Based on Renewable Energy Sources","authors":"Lilija Nakashydze, T. Hilorme, I. Nakashydze","doi":"10.15587/1729-4061.2020.201527","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.201527","url":null,"abstract":"The choice of project solutions for systems of providing climatic conditions in premises, based on different types of renewable energy sources, was substantiated. The means proposed to solve project tasks, imply the use of the interaction between different stakeholders, the number of subsystems necessary for effective functioning in the open system, that is taking into account the synergetic effect. It was proved that the introduction of complex climate control and energy supply system will allow uniting the functions inherent to disparate engineering systems, and ensure the transformation and redistribution of various types of energy flows, which will minimize operating costs. The hierarchical structure of the problem of approval of alternative project solutions of the climatic systems based on the Analytic Hierarchy Process method was constructed, which allows obtaining a set of optimal variants. The application of the corresponding tool apparatus of Data Envelopment Analysis enables constructing a system of evaluation of the energy efficiency of projects of complex climatic control and power supply systems using different types of renewable energy sources. The functional intended to select the optimum variant of a project solution of the climate control and energy supply system was constructed. The proposed project solutions were examined from the position of determining the minimization of the total consumption of energy resources and operating costs of three alpha-stakeholders. The proposed indicator of relative integrated energy efficiency allows making an optimum choice of complex systems with disparate input and output characteristics","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131165174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined Caloric Effect in Directionally Solidified Ni 45Co 5Mn 37In 13 Alloy","authors":"Pengyu Cheng, Zhenjia Zhou, Jiaxing Chen, Zongbin Li, Zhengming Zhang, Dunhui Wang, Youwei Du","doi":"10.2139/ssrn.3603391","DOIUrl":"https://doi.org/10.2139/ssrn.3603391","url":null,"abstract":"Solid-state refrigeration technology has become a promising candidate to replace the traditional environment-harmful vapor compression refrigeration. However, the narrow temperature region becomes a critical problem hindering the application of caloric materials to a refrigerator. Here, we report a potential way to solve this problem by combining different caloric effects in one refrigerant. A multiferroic ferromagnetic shape memory alloy Ni45Co5Mn37In13can exhibit large magnetocaloric effect and elastocaloric effect simultaneously. Since the working temperature regions of two caloric effects are adjacent, a broad refrigeration temperature span can be realized in Ni45Co5Mn37In13 alloy by applying magnetic field or external stress at different temperature.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"198200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122060645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Efficiency of Using Energy Resources in Heat Supply Systems of Buildings With Variable Operation Mode","authors":"O. Klymchuk, Alla Denysova, G. Balasanian, L. Ivanova","doi":"10.21303/2461-4262.2020.001252","DOIUrl":"https://doi.org/10.21303/2461-4262.2020.001252","url":null,"abstract":"As a research result, characteristic indicators of the efficiency of using various heat sources in combined heat supply systems were determined. During the study, various schemes for integrating heat accumulators in heat supply systems were considered. Water was used as a battery, which also acts as a coolant. Mathematical modeling of processes in combined heat supply systems using intermittent heating is carried out. The characteristic operating modes of the elements of heat supply systems that take into account the operating modes of heat consumers are determined. Mathematical modeling was carried out using a software package that allows to obtain the distribution of heat power of the heat supply system by its main elements and its characteristic operation modes. According to the research results, a coefficient of thermal power reduction and a coefficient of efficiency of using the heat accumulator volume were proposed. These coefficients allow to evaluate the efficiency of heat sources and the efficiency of using the volume of the heat storage tank. Based on the obtained data, the task was set to optimize the daily load of the heat source, taking into account the installation of the storage tank. \u0000The research results can be used for the reconstruction of heat supply systems of buildings with a two-period operation mode (operation duty) using both traditional and renewable heat sources. This will significantly increase the efficiency of the use of elements of the heat supply system, even out the daily heat generation schedule and increase the service life of the main equipment","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133839914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an Intensive Microwave-Thermal Treatment Technology for Heterogenic Environments","authors":"B. Demianchuk, N. Kolesnychenko, A. Ugol’nikov, A. Lapkin","doi":"10.15587/1729-4061.2020.192827","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.192827","url":null,"abstract":"The study suggests a technology of intensive, energy-efficient microwave-thermal mass transfer during washing and drying of agricultural and industrial products in a non-resonant microwave chamber with a uniform heating field. The chamber is equipped with a vacuum pump and an ultrasonic generator and is functionally connected to the evaporator and condenser of the heat pump. The traveling wave mode in the microwave chamber and intense evaporation are facilitated by the microwave field energy concentrator in the volume of the environment and the absorbing ferrite coating, which converts the ballast energy of the field into thermal energy on a perforated partition for products. This helps to reduce the significant cost of time and energy in the case of washing and drying heterogenic environments.The article substantiates the direction of developing the physicotechnical foundations of microwave-thermal treatment of environments with the aim of washing products using ultrasonic and microwave generators in a vacuum chamber to intensify the process. The authors show the necessity of developing the theory and practice of manufacturing and using radio-absorbing materials converting field energy to thermal energy. A coordinated integration of the upgraded microwave and additional convection drying technologies is proposed for the purpose to harmonize economical, intensive and environmentally friendly mass transfer of moisture during drying of the processed environment. It was found that the achievement and use of a synergistic effect, namely the energy efficiency of the process of complete drying in the middle of the chamber, contributes to the intensive evaporation of moisture from products in a uniform electromagnetic field in the chamber and the current dehumidification of moist air by the heat pump evaporator. Dry air is supplied into the microwave chamber after it is heated by the heat pump condenser. This contributes to a significantly more effective washing and drying of products. The application of this circuit solution and the optimal parameters of the regime in practice make it possible to solve the contradictory problem of increasing the efficiency and environmental friendliness of the processes in everyday life as well as in agricultural and industrial production.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126561269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Energy Storage Technology for Application in Transport Refrigeration","authors":"A.U.C. Ndanduleni, Z. Huan","doi":"10.2139/ssrn.3656548","DOIUrl":"https://doi.org/10.2139/ssrn.3656548","url":null,"abstract":"This paper reviews the use of an alternative refrigeration system in refrigerated vehicles by using thermal energy storage systems. The application of thermal energy storage systems in transport refrigeration focusing particularly on latent heat phase change materials PCMs that have been used in recent years is reviewed. The majority of PCMs are found in building applications for space heating and cooling, greenhouse heating applications, solar cookers, and storage of solar energy for water heating. The focus of this work is on latent heat storage (LHS) materials for road transport refrigeration and their benefits in the refrigeration of perishable foodstuffs for short- and long-distance transportation. The benefits of using LHS materials over a conventional mechanical vapour compression system are explored. This paper also centres on the need to develop new PCMs with high thermal cycles and minimal degradation to ensure effective performance in the transport refrigeration industry. Criteria for selecting suitable PCMs for different applications were summarised, and classification of PCMs based on their melting temperature and latent heat were tabulated. Heat transfer materials for increasing PCM performance were analysed as well as the effect of container material corrosion on PCM stability. The different thermal techniques for determining the properties of PCMs were summarised, and the accuracy of each technique was explored based on similar research work by other researchers. The PCMs that have been used in transport refrigeration as well as the thermo-physical criteria that are needed for different applications were analysed.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122986459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forced Convection Upon Heat Sink of AL-Cu for Design Optimization by Experimental and CFD Analysis for Cooling of ICs in CPU","authors":"S. D, Dr. S. Ramamurthy, J. Ansari","doi":"10.2139/ssrn.3510013","DOIUrl":"https://doi.org/10.2139/ssrn.3510013","url":null,"abstract":"A heat sink device is used with specific power input at 100V and 20W by the heater attached at the base plate of copper and then obtaining the average temperature of Heat sink by the help of 10 thermocouples .Two specimens of heat sinks were designed and were tested for mass flow rate and heat transfer coefficient. With base of 1.5mm&2.5mmtip thickness and another specimen with dimensions as tip0.5mm and1.00mmbase thickness are used By experimenting and CFD simulations,optimization of heat sink design was done.Then correlation and Validation foe both the specimen was done and were found satisfactory results.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123380846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Study of the Flow Through Helical Passage Heat Exchanger Used for Solar Air Refrigeration System","authors":"Sonawane C. R, Chintan Kantharia, Karan Shah, Neel Patel, Prikesh Bhatia, Sanket Shah","doi":"10.2139/ssrn.3102098","DOIUrl":"https://doi.org/10.2139/ssrn.3102098","url":null,"abstract":"Producing compact and high effective heat exchanger system is always a challenge. These heat exchanger systems can effectively be used in many application starting from cooling electrical circuits, absorbing and storing heat from say solar ducts/panels, etc. It has been seen that the heat transfer will be more for the turbulent flows or flows where mixing dominates with higher heat transfer coefficient values. In this paper, we have developed such a small concentric annulus heat exchanger having a helical flow passage. This compact heat exchanger is utilized to replace electric heat source supplied to the Electrolux refrigerator. The helical flow is produced by providing a helical rubber baffle between the two concentric annulus pipes. Presently only one helix is studied. The flow through helical passage concentric annulus heat exchanger is simulated for various Reynolds numbers. The pressure drop, local and average heat transfer coefficient is studied and presented here. Due to the helix, the flow is very complex as well as interesting. The mushroom-shaped temperature contours are observed. At the last, the simulated results are validated with experimental values and their matching is found good.","PeriodicalId":424061,"journal":{"name":"EngRN: Heat Transfer (Topic)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128089617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}