scholarly journals Experimental Research of a Regenerative Heat Exchanger

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 100
Author(s):  
Nikolay Monarkin ◽  
Tat’yana Monarkina
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Air Temperature ◽  
Experimental Research ◽  
Heat Exchangers ◽  
Regenerative Heat ◽  
Proposed Model ◽  
Experimental Values

Stationary switching regenerative heat exchangers (SSRHEs) are used for the ventilation of premises. The mathematical modeling of heat exchange between air and a regenerative nozzle is used to design the SSRHEs and determine their main parameters. The numerical solution of the proposed mathematical model has been experimentally tested for adequacy. The calculated and experimental values of the air temperature at the ends of the SSRHE are compared. It is determined that the proposed model is adequate and can be used in further research.

scholarly journals MATHEMATICAL MODEL FOR THE STUDY AND DESIGN OF A ROTARY-VANE GAS REFRIGERATION MACHINE

2016 ◽  
Vol 52 (3) ◽  
Author(s):  
V. V. Trandafilov ◽  
M. G. Khmelniuk ◽  
O. Y. Yakovleva
Keyword(s):  
Mathematical Model ◽  
Heat Exchanger ◽  
Coefficient Of Performance ◽  
Operating Cycle ◽  
Regenerative Heat ◽  
Regenerative Heat Exchanger ◽  
Proposed Model ◽  
Compression And Expansion ◽  
Geometric Variables ◽  
Polytrope Index

This paper presents a mathematical model of calculating the main parameters the operating cycle, rotary-vane gas refrigerating machine that affect installation, machine control and working processes occurring in it at the specified criteria. A procedure and a graphical method for the rotary-vane gas refrigerating machine (RVGRM) are proposed. A parametric study of the main geometric variables and temperature variables on the thermal behavior of the system is analyzed. The model considers polytrope index for the compression and expansion in the chamber. Graphs of the pressure and temperature in the chamber of the angle of rotation of the output shaft are received. The possibility of inclusion in the cycle regenerative heat exchanger is appreciated. The change of the coefficient of performance machine after turning the cycle regenerative heat exchanger is analyzed. It is shown that the installation of a regenerator RVGRM cycle results in increased COP more than 30%. The simulation results show that the proposed model can be used to design and optimize gas refrigerator Stirling.

scholarly journals Application of porous materials in heat exchangers of heat supply system

2020 ◽  
Vol 22 (3) ◽  
pp. 3-13
Author(s):  
N. V. Rydalina ◽  
B. G. Aksenov ◽  
O. A. Stepanov ◽  
E. O. Antonova
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Porous Materials ◽  
Heat Exchangers ◽  
Porous Metals ◽  
Porous Aluminum ◽  
Heat Exchange Equipment

Heat exchange capacity increase is one of the main concerns in the process of manufacturing modern heat exchange equipment. Constructing heat exchangers with porous metals is an advanced technique of heat exchange increase. A construction of heat exchangers with porous aluminum is described in this paper. The first heat transfer agent (hot water) flows through thin copper tubes installed within the porous aluminum. The second heat transfer agent (freon) flows through the pores of aluminum. Laboratory facility was created to study such a heat exchanger. Series of experiments were carried out. The purpose of the research presented here is to create a mathematical model of heat exchangers with porous metals, to perform analytical calculation of the heat exchangers and to confirm the results with the experimental data. In this case, one can`t use the standard methods of heat exchangers calculation because the pores inner surface area is indeterminate. The developed mathematical model is based on the equation describing the process of cooling the porous plate. A special mathematical technique is used to take into account the effect of tubes with water. The model is approximate but its solution is analytic. It is convenient. One can differentiate it or integrate it, which is very important. Comparison of calculated and experimental data is performed. Divergence of results is within the limits of experimental error. If freon volatilizes inside the heat exchanger, the heat of phase transition has to be taken into account alongside with heat capacity. The structure of the mathematical model makes it possible. The results presented in this paper prove the practicability of using porous materials in heat exchange equipment.

Methods of Mathematical Modeling of the Leaching Process of Cobalt-Containing Solutions

2021 ◽  
Vol 316 ◽  
pp. 661-666
Author(s):  
Nataliya V. Mokrova
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Chemical Kinetics ◽  
Group Method ◽  
Data Handling ◽  
Multistage Processes ◽  
Leaching Process ◽  
Proposed Model ◽  
Simulation Results ◽  
The Mathematical Model

Current cobalt processing practices are described. This article discusses the advantages of the group argument accounting method for mathematical modeling of the leaching process of cobalt solutions. Identification of the mathematical model of the cascade of reactors of cobalt-producing is presented. Group method of data handling is allowing: to eliminate the need to calculate quantities of chemical kinetics; to get the opportunity to take into account the results of mixed experiments; to exclude the influence of random interference on the simulation results. The proposed model confirms the capabilities of the group method of data handling for describing multistage processes.

scholarly journals A Nodes-Based Non-Structural Model Considering a Series Structure for Heat Exchanger Network Synthesis

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 695
Author(s):  
Yue Xu ◽  
Heri Ambonisye Kayange ◽  
Guomin Cui
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Structural Model ◽  
Cost Effective ◽  
Maximum Energy ◽  
Network Synthesis ◽  
Heat Exchanger Network ◽  
Proposed Model ◽  
Effective Network ◽  
Heat Exchanger Network Synthesis

The aim of heat exchanger network synthesis is to design a cost-effective network configuration with the maximum energy recovery. Therefore, a nodes-based non-structural model considering a series structure (NNM) is proposed. The proposed model utilizes a simple principle based on setting the nodes on streams such that to achieve optimization of a heat exchanger network synthesis (HENS) problem. The proposed model uses several nodes to quantify the possible positions of heat exchangers so that the matching between hot and cold streams is random and free. Besides the stream splits, heat exchangers with series structures are introduced in the proposed model. The heuristic algorithm used to solve NNM model is a random walk algorithm with compulsive evolution. The proposed model is used to solve four scale cases of a HENS problem, the results show that the costs obtained by NNM model can be respectively lower 3226 $/a(Case 1), 11,056 $/a(Case 2), 2463 $/a(Case 3), 527 $/a(Case 4) than the best costs listed in literature.

scholarly journals Experimental research on heat transfer in a coupled heat exchanger

2013 ◽  
Vol 17 (5) ◽  
pp. 1437-1441
Author(s):  
Yin Liu ◽  
Jing Ma ◽  
Guang-Hui Zhou ◽  
Ren-Bo Guan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Experimental Research ◽  
Heating Efficiency ◽  
Air Source Heat Pump ◽  
Heating Capacity ◽  
Different Temperatures ◽  
Double Pipe ◽  
Pipe Heat

The heat exchanger is a devise used for transferring thermal energy between two or more different temperatures. The widespreadly used heat exchanger can only achieve heat exchange between two substances. In this paper, a coupled heat exchanger is proposed, which includes a finned heat exchanger and a double pipe heat exchanger, for multiple heat exchange simultaneously. An experiment is conducted, showing that the average heating capacity increases more than 35%, and the average heating efficiency increases more than 55%, compared with the ordinary air-source heat pump.

scholarly journals The use of porous metals in the design of heat exchangers to increase the intensity of heat exchange

2020 ◽  
Vol 178 ◽  
pp. 01026
Author(s):  
Natalia Rydalina ◽  
Oleg Stepanov ◽  
Elena Antonova
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Analytical Form ◽  
Test Facility ◽  
Porous Metals ◽  
Heat Supply Systems ◽  
Set Up ◽  
Supply Systems

Heat exchangers are widely used in heat supply systems. To increase the efficiency of heat supply systems, heat exchangers with porous metals are proposed to design. There was a test facility set up to study new types of heat exchangers. The countercurrent flow of heat carriers was activated in those heat exchangers. Freon moved through the heat exchanger pores, and water moved through the inner tubes. It should be noted that the porous materials in the heat exchangers differed in the coefficient of porosity. To be compared, one of the heat exchangers did not contain any porous material. The first test cycle proved the feasibility of using porous metals in heat exchange equipment. Afterwards, a simplified mathematical model of the heat exchanger was compiled. Such an analytical form makes a solution convenient for engineering calculations. Numerical calculations based on this model were compared with the experimental data. Heat transfer intensity of materials with different porosity was compared.

scholarly journals The influence of main parameters of regenerative heat exchanger on its energy efficiency

2020 ◽  
Vol 178 ◽  
pp. 01024
Author(s):  
Nikolay Monarkin ◽  
Anton Sinitsyn ◽  
Mikhail Pavlov ◽  
Timur Akhmetov
Keyword(s):  
Energy Efficiency ◽  
Heat Capacity ◽  
Heat Exchanger ◽  
Wall Thickness ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Regenerative Heat ◽  
Flow Through ◽  
Geometric Length

The influence of various parameters of stationary switching regenerative heat exchangers used for ventilation on its thermal efficiency was studied. Considered are the geometric (length, diameter and wall thickness of a single equivalent nozzle channel), thermophysical (density and heat capacity of the nozzle material) and operation (air flow through the regenerator and the time of one stage of accumulation/regeneration of thermal energy) parameters.

scholarly journals Horizontal earth-air heat exchanger for preheating external air in the mechanical ventilation system

2018 ◽  
Vol 13 (1) ◽  
pp. 71-76
Author(s):  
Vasyl Zhelykh ◽  
Olena Savchenko ◽  
Vadym Matusevych
Keyword(s):  
Heat Transfer ◽  
Mechanical Ventilation ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Convective Heat Transfer Coefficient ◽  
Ventilation System ◽  
Heat Pipes ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Abstract To save traditional energy sources in mechanical ventilation systems, it is advisable to use low-energy ground energy for preheating or cooling the outside air. Heat exchange between ground and outside air occurs in ground heat exchangers. Many factors influence the process of heat transfer between air in the heat exchanger and the ground, in particular geological and climatic parameters of the construction site, parameters of the ventilation air in the projected house, physical and geometric parameters of the heat exchanger tube. Part of the parameters when designing a ventilation system with earth-air heat exchangers couldn’t be changed. The one of the factors, the change which directly affects the process of heat transfer between ground and air, is convective heat transfer coefficient from the internal surface of the heat exchanger tube. In this article the designs of a horizontal earthair heat exchanger with heat pipes was proposed. The use of heat pipes in designs of a horizontal heat exchanger allows intensification of the process of heat exchange by turbulence of air flow inside the heat exchanger. Besides this, additionally heat transfer from the ground to the air is carried out at the expense of heat transfer in the heat pipe itself.

scholarly journals Evaluation and Improvement of Thermal Energy of Heat Exchangers with SWCNT, GQD Nanoparticles and PCM (RT82)

2020 ◽  
Vol 79 (1) ◽  
pp. 153-168
Author(s):  
Mohammadreza Hasandust Rostami ◽  
Gholamhassan Najafi ◽  
Ali Motevalli ◽  
Nor Azwadi Che Sidik ◽  
Muhammad Arif Harun
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Phase Change Materials ◽  
Single Wall Carbon Nanotubes ◽  
In Series

Today, due to the reduction of energy resources in the world and its pollutants, energy storage methods and increase the thermal efficiency of various systems are very important. In this research, the thermal efficiency and energy storage of two heat exchangers have been investigated in series using phase change materials (RT82) and single wall carbon nanotubes (SWCNT) and graphene quantum dot nanoparticles (GQD) In this research, two heat exchangers have been used in combination. The first heat exchanger was in charge of storing thermal energy and the second heat exchanger was in charge of heat exchange. The reason for this is to improve the heat exchange of the main exchanger (shell and tube) by using heat storage in the secondary exchanger, which has not been addressed in previous research. The results of this study showed that using two heat exchangers in series, the thermal efficiency of the system has increased. Also, the heat energy storage of the double tube heat exchanger was obtained using phase change materials in the single-walled carbon nanotube composition of about 3000 W. The average thermal efficiency of the two heat exchangers as the series has increased by 52%. In general, the effect of the two heat exchangers on each other was investigated in series with two approaches (energy storage and energy conversion) using fin and nanoparticles, which obtained convincing results.

scholarly journals Features of creation and use of effective heat exchangers

2020 ◽  
Vol 216 ◽  
pp. 01124
Author(s):  
Shavkat Agzamov ◽  
Sevinar Nematova
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Prandtl Number ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Heat Transfer Equation ◽  
The Heat Transfer Coefficient ◽  
Outside Diameter

The article discusses the features of the creation and use of efficient heat exchanger. Designs of pipes with a developed heat exchange is presented. The procedure for determining the degree of development of the heat exchanging surface, the heat transfer coefficient, and the calculation of the heat transfer equation are given. As a result of creating efficient heat exchangers, three main parameters are used: the pipe outside diameter; the estimated flow rate; the Prandtl number.

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