scholarly journals Thermal processes in the stack of perishable cargo transported in the heated isothermal car

2021 ◽  
Vol 2131 (2) ◽  
pp. 022044
Author(s):  
O Voron ◽  
V Moiseev
Keyword(s):  
Heat Exchange ◽  
Temperature Regime ◽  
Thermal Regime ◽  
Heating System ◽  
Rolling Stock ◽  
Thermophysical Characteristics ◽  
Glass Containers ◽  
Exchange Processes ◽  
Specialized Equipment ◽  
Regular Thermal Regime

Abstract The article deals with the organization of heat exchange processes when using a new heating system for the cargo room of the isothermal car. Using the example of considering a stack formed from glass containers with fruit juices packed in cardboard boxes, the equivalent thermophysical characteristics of the cargo in the stack are formulated. Analytical methods are used to determine the main regularities of the regular thermal regime and the nature of thermo-gravitational flows in the cargo room of the car. The possibilities of improving the design of the heating system of the cargo room of isothermal rolling stock for the transportation of perishable cargo are considered. The possibilities of modernization of specialized equipment allowing optimization of the temperature regime in the cargo room of the car are presented. The article deals with the organization of heat exchange processes when using a new heating system for the cargo room of the isothermal car. Using the example of considering a stack formed from glass containers with fruit juices packed in cardboard boxes, the equivalent thermophysical characteristics of the cargo in the stack are formulated. Analytical methods are used to determine the main regularities of the regular thermal regime and the nature of thermo-gravitational flows in the cargo room of the car. The possibilities of improving the design of the heating system of the cargo room of isothermal rolling stock for the transportation of perishable cargo are considered. The possibilities of modernization of specialized equipment allowing optimization of the temperature regime in the cargo room of the car are presented.

scholarly journals MODELLING OF TEMPERATURE FIELD DISTRIBUTION IN BIOLOGICAL TISSUE THERMAL LESION

2021 ◽  
Vol 297 (3) ◽  
pp. 208-215
Author(s):  
JULIA SHTEFURA ◽  
◽  
KOSTIANTYN SHEVCHENKO ◽  
OLEH KOZYR ◽  
OLEKSII STATSENKO ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Temperature Field ◽  
Heat Exchange ◽  
Field Distribution ◽  
Thermal Regime ◽  
Biological Tissue ◽  
Thermal Model ◽  
Temperature Field Distribution ◽  
Thermal Lesion ◽  
Exchange Processes

Early determination of the thermal lesion degree in case of scald accelerates the treatment process and increases its effectiveness. The thermal lesion degree can be evaluated by determining the temperature difference between healthy and injured areas of biological tissue. For this purpose, a model of biological tissue in the form of a multilayer structure can be used. Heat exchange processes in such a structure are described by a generalized thermal model. Such structure contains conditionally flat heat sources located in each layer, which have the form of a developed network of blood vessels. The considered model of biological tissue quite accurately describes the heat exchange processes in body tissues. The article considers heat exchange processes that take place in biological tissue and a number of assumptions that should be used to mathematically describe these processes were identified. During the analysis of heat transfer process, the equations of temperature distribution in the tissue layers and the boundary conditions that describe the thermal interaction of the model with the environment are determined. As a result, the model of the stationary thermal regime of a biological tissue fragment in the form of a generalized thermal model and a mathematical model of the temperature field distribution in this fragment is obtained. This model is determined by many parameters, which are divided into 3 groups: thermophysical parameters; structural and topological parameters; parameters of the blood vascular system. Models of the particular fragment thermal regime are unequivocally determined by a combination of these parameters. For the analysis of temperature in any point of biological tissue modelled part mathematical model of temperature field distribution in stationary mode was developed. This model allows reasonable approach to the thermal lesion degree evaluation on the basis of the surface temperature difference between healthy and injured areas of tissue.

Increase of Heat Exchange Processes Efficiency at Production Site

2017 ◽  
pp. 18-21
Author(s):  
A.F. Khasanova ◽  
◽  
M.A. Gallyamov ◽  
Z.A. Zakirova ◽  
◽  
...  
Keyword(s):  
Heat Exchange ◽  
Production Site ◽  
Exchange Processes

scholarly journals ON THE SOLUTION OF ENERGY BALANCE EQUATION SYSTEM TO PREDICT TEMPERATURE DISTRIBUTION IN THE BUILDING ELEMENTS WITH VENTILATED AIR GAP

2014 ◽  
Vol 21 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Edmundas Monstvilas ◽  
Karolis Banionis ◽  
Jurga Poderytė ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Exchange ◽  
Balance Equation ◽  
Heat Balance ◽  
Internal Surface ◽  
Equation System ◽  
Energy Balance Equation ◽  
Air Gap ◽  
Exchange Processes ◽  
Calculation Results ◽  
Thermal Indicators

The article presents the solution of heat balance equation system, describing heat exchange processes in ventilated envelopes, which was applied to derive formulas for the calculation of temperatures in the ventilated layers of the envelopes. The accurateness of the formulas was assessed by experimental research and analysis of the calculation results. During the process of heat exchange balance equation solution, the equations were simplified by introducing the following restriction into the derived formulas: they may only be applied for the ventilated envelopes with steel or similar coatings as their external layers, i.e. coatings having small heat capacity and minor difference between the external and internal surface temperatures. The derived formulas enable the calculation of the temperatures of the ventilated envelopes in the distance which does not exceed a half of the ventilated air gap length measuring from the air entrance into the gap. However, this restriction does not impede the estimation of the average thermal indicators of the ventilated envelopes.

Thermodynamic Analysis of a Central Heating System Combing the Urban Heat Network With Geothermal Energy

2013 ◽  
Author(s):  
Xiao Wang ◽  
Lin Fu ◽  
Xiling Zhao ◽  
Hua Liu
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Pump ◽  
Geothermal Energy ◽  
Heating System ◽  
Heat Network ◽  
Pump System ◽  
Absorption Heat Pump ◽  
Central Heating ◽  
Exchange Unit

In recent years, with the continuous urban expansion, the central heating sources are commonly insufficient in the areas of Northern China. Besides, the increasing heat transfer temperature difference results in more and more exergy loss between the primary heat network and the secondary heat network. This paper introduces a new central heating system which combines the urban heat network with geothermal energy (CHSCHNGE). In this system, the absorption heat exchange unit, which is composed of an absorption heat pump and a water to water heat exchanger, is as alternative to the conventional water to water heat exchanger at the heat exchange station, and the doing work ability of the primary heat network is utilized to drive the absorption heat pump to extract the shallow geothermal energy. In this way, the heat supply ability of the system will be increased with fewer additional energy consumptions. Since the water after driving the absorption heat pump has high temperature, it can continue to heat the supply water coming from the absorption heat pump. As a result, the water of the primary heat network will be stepped cooled and the exergy loss will be reduced. In this study, the performance of the system is simulated based on the mathematical models of the heat source, the absorption heat exchange unit, the ground heat exchanger and the room. The thermodynamic analyses are performed for three systems and the energy efficiency and exergy efficiency are compared. The results show that (a) the COP of the absorption heat exchange unit is 1.25 and the heating capacity of the system increases by 25%, which can effectively reduce the requirements of central heating sources; (b) the PER of the system increases 14.4% more than that of the conventional co-generation central heating system and 54.1% more than that of the ground source heat pump system; (c) the exergy efficiency of the CHSCHNGE is 17.6% higher than that of the conventional co-generation central heating system and 45.6% higher than that of the ground source heat pump system.

scholarly journals Solar Dryer with Integrated Energy Unit

2021 ◽  
Vol 2(50) ◽  
Author(s):  
Sergey Korobka ◽  
◽  
Sergey Syrotyuk ◽  
Dmitry Zhuravel ◽  
Boris Boltianskyi ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Solar Energy ◽  
Moisture Transfer ◽  
Diagnostic Techniques ◽  
Material Surface ◽  
Drying Process ◽  
Energy Unit ◽  
Solar Dryer ◽  
Exchange Processes ◽  
Deformed State

The work is devoted to the issue of the rational use of the solar energy in the technological process of fruit drying based on the use of solar drying devices, which are applied in various sections of the agro-industrial centers of Ukraine. The aim of this research was intensification of the fruits drying process using the solar energy by combining an air collector and drying chamber into a single power unit. To achieve the aim the heat exchange diagnostic techniques with alternative potentials of diffusion and moisture transfer was developed. This technique differs from those existing for the heat exchange research in that it allows the intensity of the moisture evaporation from a unit of the material surface to be calculated, based on the synthesis of the moisture content and the irreversible major laws of processes of the heat exchange characteristics of the fruits drying using the solar dryer. The above model makes it possible to diagnose the heat exchange processes and analyze the mathematical model of the heat exchange processes. It also allows modeling the changeable diffusion and moisture transfer potentials based on the dependences obtained and for the purpose of a further application in the methods and devices development to control the strain-deformed state of the fruits during the drying process. The method is offered for the calculation of diffusion and moisture transfer during drying fruits in the solar dryer.

scholarly journals The influence of the charge shape on heat exchange of a recessed nozzle

2021 ◽  
Vol 2057 (1) ◽  
pp. 012013
Author(s):  
B Ya Benderskiy ◽  
A A Chernova
Keyword(s):  
Heat Exchange ◽  
Power Plant ◽  
Combustion Products ◽  
Triangular Form ◽  
Topological Features ◽  
Exchange Processes ◽  
Charge Shape ◽  
Intensification Of Heat Exchange ◽  
Thermally Conductive ◽  
Control Volumes

Abstract The paper deals with the numerical simulation of the flow of thermally conductive viscous gaseous combustion products in the flow paths of a power plant. The influence of the shape of the mass supply surface on the gas dynamics and heat exchange near the recessed nozzle of the power plant is investigated. The coupled problem of heat exchange is solved by the method of control volumes. It is shown that the compensator geometry determines the localization of both the topological features of the flow near the recessed nozzle and the position of local maximums of the heat transfer coefficient. It has been revealed that The use of a channel with a star-shaped cross section and a triangular form of compensator rays leads to an intensification of heat exchange processes near a recessed nozzle.

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