scholarly journals MATHEMATICAL MODELING OF HEAT EXCHANGE IN DIRECT FLAT CHANNELS AND DIRECT ROUND PIPES WITH ROUGH WALLS UNDER THE SYMMETRIC HEAT SUPPLY

Author(s):  
I E. Lobanov
2018 ◽  
Vol 1 (1) ◽  
pp. 74
Author(s):  
Lobanov Lgor Evgenjevich

In recent years, the numbers of patents have been devoted to the development of rough pipes. The technique theoretical settlement determine of factor of hydraulic resistance for round pipes with rough walls is developed on the basis of a principle of a superposition of complete viscosity in turbulent a layer mainly distinguished from the existing theories. The received results of account for the extended range of determining parameters much distinguished from appropriate given for round pipes with turbulizers, specify a level и intensification of heat exchange.


1994 ◽  
Vol 51 (3-4) ◽  
pp. 122-127
Author(s):  
A. A. Zhilin ◽  
A. N. Zamyatin ◽  
V. K. Shiff

2021 ◽  
Vol 10 (3) ◽  
pp. 86-92
Author(s):  
Rinaldy Valendry

A three-channel concentric pipes heat exchanger is a development or improvement of a two-channel concentric heat exchange apparatus. This study was conducted to determine the output temperature of each channel, and compare the results of theoretical calculations using mathematical modeling of experimental results conducted in the field. So that obtained difference of value between result of experiment to result of theory calculation. In this study have 3 variations of temperature data that is 50 °C, 55°C, and 60 °C with two streams namely CounterFlow and PararellFLow and discharge 2.5 l/minute, while cold fluid with 25 °C discharge 1.5 l/minute. From the above analysis it can be concluded that the temperature of the hot fluid coming out of the APK in the experiment tends to be higher than the temperature of the hot fluid coming out of the APK on theoretical calculations of mathematical modeling methods. Meanwhile, the cold cold fluid temperature coming out of the APK in experimental tends to be lower than the temperature of the cold fluid coming out of the APK on theoretical calculations of mathematical modeling methods.


2020 ◽  
Vol 178 ◽  
pp. 01026
Author(s):  
Natalia Rydalina ◽  
Oleg Stepanov ◽  
Elena Antonova

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.


REPORTS ◽  
2021 ◽  
Vol 4 (338) ◽  
pp. 37-42
Author(s):  
V.G. Borulko ◽  
Yu.G. Ivanov ◽  
D.A. Ponizovkin ◽  
N.A. Shlychkova ◽  
N.M. Kostomakhin

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Qing Zhang ◽  
Weiya Ge ◽  
Junyuan Jia ◽  
Fujin Tian ◽  
Xiaojun Chang ◽  
...  

The ground-coupled ground-source heat pump (GSHP) system is a common method for shallow geothermal energy exploitation and utilization. GSHP has a great heat exchange rate and wide application range. In order to effectively exploit shallow geothermal energy in the central urban area of Danyang City, Jiangsu Province, based on finite volume method, it is adopted to simulate the amount of recoverable shallow geothermal energy in the study area through ground-coupled heat exchange. The simulation is conducted on the development trend of thermal transport and thermal balance in the study area from early June 2015 to the end of May 2025 to obtain the temperature distribution at different times. Under the presupposed working conditions, with the operation of a ground-coupled GSHP, thermal accumulation occurs in parts of the study area. To mitigate the problem of thermal accumulation, two schemes are proposed: (1) adding auxiliary cooling towers and (2) increasing the amount heated domestic water in spring and autumn. Both schemes mitigate thermal accumulation. For Scheme  1, the total heat supply for shallow geothermal energy in the central urban area of Danyang City in winter is 2.91 × 106 kW, and the total heat release in summer is 3.53 × 106 kW. For Scheme  2, the total heat release in summer is 3.52 × 106 kW and the total heat supply in winter is 2.90 × 106 kW. A ground-coupled GSHP system has significant applicability in the central urban area of Danyang City, where shallow geothermal energy has good exploitation prospects.


Author(s):  
Aleksey Bal'chugov ◽  
Mihail Vazhenin ◽  
Borislav Kustov

It has been experimentally established that the ideal displacement model adequately describes the heat transfer process in a horizontal heat exchange pipe cooled by atmospheric air


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