scholarly journals DETERMINATION OF THE AVERAGE WALL TEMPERATURE OF THE PLATE IN A RECUPERATIVE HEAT EXCHANGER WITH A CORRUGATED MESH INSERT

2021 ◽  
Vol 11 (1) ◽  
pp. 46-55
Author(s):  
Arman B. KOSTUGANOV ◽  
Vitaly V. DEMIDOCHKIN
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Wall Temperature ◽  
Arithmetic Means ◽  
Average Value ◽  
Average Temperature ◽  
Coeffi Cients ◽  
Heat Transfer Coeffi ◽  
Recuperative Heat Exchanger

This article discusses the issue of determining the value the average wall temperature of the plate of a recuperative heat exchanger type “air-to-air” with a corrugated mesh insert based on the results processing the data of a physical experiment to determine the thermohydraulic characteristics such heat exchange surfaces. It has been established that the temperature fi eld of heat exchange surfaces of this type is nonuniform, depends on the conditions of heat exchange and hydraulic regimes of air fl ow. Therefore, the adoption of the arithmetic means value of the measured surface temperatures as the calculated average temperature of the heat exchanger wall entails signifi cant errors in the subsequent processing of experimental data and fi nal the values of the heat transfer coeffi cients, the values the Nusselt criterion and the criterion equations of heat transfer. It is proposed to determine the average value the wall temperature of the heat exchanger based on the results of measurements the wall’s temperatures, the estimate of the coordinates the center of distribution the results of measurements the wall temperatures, the equations of heat balance and heat transfer.

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.

Research on the Construction Technology of Radial Underground Heat Exchanger and its Heat Exchange Performance

2014 ◽  
Vol 580-583 ◽  
pp. 2488-2491
Author(s):  
Rong Hui Wang ◽  
Qing Hua Wang ◽  
Ye Feng
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Surface Temperature ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Ground Heat Exchanger ◽  
Construction Technology ◽  
Exchange Performance ◽  
Radial Heat

5 radial heat exchange wells were designed, and the different angle drilling, drilling pipe, and grouting backfill construction technology was studied. In addition, the heat transfer performance of the buried radial heat exchange wells was tested. The results show that, design of pipe equipment is feasible, construction is convenient, and the ratio of backfill material is reasonable; the heat transfer performance of 90 °buried tube is the best. The smaller the angle with the ground heat exchanger, the greater the heat exchange performance is affected by the surface temperature.

Crystallization Fouling in Plate Heat Exchangers

1993 ◽  
Vol 115 (3) ◽  
pp. 584-591 ◽  
Author(s):  
B. Bansal ◽  
H. Mu¨ller-Steinhagen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Velocity ◽  
Wall Temperature ◽  
Heat Exchangers ◽  
Calcium Sulfate ◽  
Surface Reaction ◽  
Heat Transfer Surface ◽  
Plate Heat

Crystallization fouling of calcium sulfate was investigated in a plate and frame heat exchanger. The effects of flow velocity, wall temperature, and CaSO4, concentration on the fouling rates have been investigated and the distribution of scale along the heat transfer surface has been observed. The measured fouling curves are compared with predictions from a surface reaction controlled model.

scholarly journals Influence of fins designs, geometries and conditions on the performance of a plate-fin heat exchanger-experimental perspective

2019 ◽  
Vol 13 (1) ◽  
pp. 4368-4379
Author(s):  
M. I. N. Ma’arof ◽  
Girma T. Chala ◽  
Hazran Husain ◽  
Muhammad S. S. Mohamed
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Simple Form ◽  
Surface Characteristics ◽  
Total Surface Area ◽  
Cooling Device ◽  
Quality Aspect ◽  
Efficient Heat Transfer

A fin heat exchanger is a simple form of cooling device that is built for efficient heat transfer from one medium to another. Generally, it involves medium such as fluid to perform heat exchange via convective heat transfer. This study is aimed at investigating the effects of diverse designs (arrangements of the fins), qualities (the total surface area of the fin for heat exchange) and conditions (the surface characteristics) of fin heat exchanger on the degree of heat transfer from the experimental perspective. The fin heat exchanger was fabricated and tested. It was observed that by varying the arrangement and condition of the fins, the rate of heat transfer could be affected. However, varying the quality of the fin didn’t have much impact. Nevertheless, the quality aspect of the fin heat exchanger could play a significant role for heat exchanger of larger in scale and dimension. The coating, that is the condition of the fins, aided in decreasing the temperature at a much higher margin at all fan speeds.  

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 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.

Study on Turbulent Buffeting Characteristics of Liquid Lead Bismuth

2014 ◽  
Author(s):  
Yun-Bo Li ◽  
Tao Zhou ◽  
Qi-Jun Huo ◽  
Bai-Xu Chen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Fatigue Damage ◽  
Liquid Lead ◽  
Transfer Tube ◽  
Heat Exchange Tube ◽  
Vertical Heat ◽  
Cross Number ◽  
Center Distance

In Pb Bi loop, the turbulent buffeting phenomenon of lead bismuth fluid in heat exchanger, may cause fatigue damage of heat transfer tube. Through the establishment of Pb-Bi loop heat exchanger model, invent a program for calculation, we can get the turbulent buffeting characteristics. The results show that: As the increases of heat exchange tube cross number, the buffeting coefficients pipeline is greater, the probability of occurrence of turbulent buffeting phenomenon is more low; The greater lead bismuth flow velocity is, the more prone to turbulent buffeting phenomenon. With vertical heat tube center distance increases, the buffeting coefficients decreased first and then increased, when the buffeting coefficients reached the minimum value, the turbulent buffeting phenomenon is most intense; As the horizontal heat pipe center distance is bigger, turbulent buffeting phenomenon is becoming less clear.

scholarly journals Phase Change and Heat Transfer Characteristics of a Corrugated Plate Heat Exchanger

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 26 ◽  
Author(s):  
Huashan Su ◽  
Chaoqun Hu ◽  
Zhenjun Gao ◽  
Tao Hu ◽  
Gang Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Nusselt Number ◽  
Heat Exchange ◽  
Phase Change ◽  
Plate Heat Exchanger ◽  
Wall Surface ◽  
Flow Passage ◽  
Plate Heat ◽  
Average Temperature

In order to reveal the evolution law of heat transfer during phase change in a corrugated plate flow passage of a plate heat exchanger, a two-dimensional two-channel model was established to simulate the process of heat transfer during phase change in an unsteady flow passage. The results show that when the time was <3/5T, the average Nusselt number and average heat flux of the heat exchange wall surface decreased with time, the average temperature of the cold fluid outlet increased, the average temperature of the hot fluid outlet decreased, and the volume fraction of the gas phase was no higher than 0.2. When the time was >3/5T, the average Nusselt number and the average heat flux of the heat exchange wall, as well as the outlet average temperature of the cold and hot fluid, reached stability, while the volume fraction of the gas phase increased rapidly. During the whole heat transfer process, the change in Nusselt number and heat flux along the heat transfer wall surface was basically the same, and its value fluctuated along the wall surface, displaying extrema at the exit, entrance, and corrugated corner. The temperature of the heat exchange wall fluctuated and increased along the Y-axis, and began stabilizing after a time >3/5T. As time went on, the temperature gradient of the hot and cold fluid outlet and the temperature difference between the two sides of the heat exchange wall decreased, whereas the relative parameters of the heat flow inlet section of the corrugated passage reached stability before those of the cold flow inlet section. The whole simulation process fully reflects the heat transfer mechanism during phase change in a corrugated plate flow passage of a plate heat exchanger.

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