scholarly journals Analysis of ribbed tube heating in the cooling system

2021 ◽  
Vol 2119 (1) ◽  
pp. 012151
Author(s):  
A F Gizzatullina ◽  
O V Mischenkova ◽  
F N Pushkarev ◽  
A N Terentyev
Keyword(s):  
Heat Exchange ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Cooling System ◽  
Integrated Platform

Abstract The paper presents the solution of the conjugated heat exchange problem in a cylindrical ribbed tube using the open integrated platform OpenFOAM. The obtained results allow estimating the fluid heating along the channel as well as the temperature difference on the walls of the tube. It is shown that the minimum temperature difference of the fluid is observed in the center of the tube, and the maximum one is closer to the tube walls.

scholarly journals Theoretical study on the influence of sprayed water temperature and minimum temperature difference to the efficiency of a humidification – dehumidification desalination unit

2016 ◽  
Vol 19 (2) ◽  
pp. 34-43
Author(s):  
Quoc Kien Vo ◽  
Hiep Chi Le ◽  
Tuyen Van Nguyen ◽  
Trinh Thi Minh Nguyen
Keyword(s):  
Heat Exchange ◽  
Water Temperature ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Rate Ratio ◽  
Theoretical Study ◽  
Flow Rate Ratio ◽  
Mass Flow Rate Ratio

The main content of the paper focuses on the theoretical study of the heat exchange between sprayed water and air in a humidification – dehumidification unit. The gained results [7] have been validated by using Hou data [1] and show that, in order to achieve the maximum GOR, the mass flow rate ratio between sprayed water and air depends on the sprayed water temperature and the minimum temperature difference ∆tmin. Particularly, the spayed water temperature should be from 70oC to 75oC when the minimum temperature difference ∆tmin= 5oC.

MODELING THE EFFECT OF HEAT EXCHANGE ON THE EFFICIENCY OF A THERMOELECTRIC COOLER

2020 ◽  
Vol 2 ◽  
pp. 132-135
Author(s):  
O.I. MARKOV
Keyword(s):  
Numerical Calculation ◽  
Heat Exchange ◽  
Solid State ◽  
Numerical Modelling ◽  
Temperature Difference ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Maximum Temperature Difference ◽  
Peltier Cooler ◽  
Account Heat

Numerical modelling thermal and thermoelectric processes in a branch of solid–state thermoelectric of Peltier cooler is performed, taking into account heat exchange by convection and radiation. The numerical calculation of the branch was carried out in the mode of the maximum temperature difference.

scholarly journals Heat exchange performance optimization of a wheel loader cooling system based on computational fluid dynamic simulation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880398 ◽  
Author(s):  
Chao Yu ◽  
Sicheng Qin ◽  
Yang Liu ◽  
Bosen Chai
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Thermal Management ◽  
Cooling System ◽  
Management Model ◽  
Maximum Deviation ◽  
Engine Compartment ◽  
Wheel Loader ◽  
Exchange Performance ◽  
Transmission Oil

This study establishes a thermal management model to improve the heat exchange performance and uniformity of the flow-field distribution in the engine compartment of a wheel loader. Flow-field analyses are performed for an XG956 wheel loader in a virtual wind tunnel using the combined engine compartment thermal management model and computational fluid dynamics. The Fluent calculations revealed various problems. For example, the inlet flow rate at both sides of the engine compartment is small, which accounts for about 8.5% of the total flow, and the flow uniformity of radiator becomes worse with the increase in the air flow. The original cooling system is improved based on the simulation results and then verified by field testing. A comparison of the test data with the simulations indicates that the values obtained using the thermal management model of the engine compartment are largely in agreement with the experimental values, with a maximum deviation of the heat transfer rate at the rated speed of 5.1%. The research method presented in this article could further help to increase the productivity of the non-road mobile machinery cooling system and lower design costs. The temperature of pressurized air, hydraulic oil, transmission oil, and engine cooling fluid decreased by 22.5%, 8.7%, 2.2%, and 8.4% in the improved loader, respectively.

Minimum temperature difference detected by the thermal radiation of objects

1994 ◽  
Vol 35 (5) ◽  
pp. 715-732 ◽  
Author(s):  
Igor I. Taubkin ◽  
Michael A. Trishenkov ◽  
Nikolai V. Vasilchenko
Keyword(s):  
Thermal Radiation ◽  
Temperature Difference ◽  
Minimum Temperature

Experimental Investigation of Lab-Scale, Heat Exchanger Prototypes Designed to Provide Refugia for Trout

2021 ◽  
Author(s):  
Rajib Uddin Rony ◽  
Adam Gladen ◽  
Sarah LaVallie ◽  
Jeremy Kientz
Keyword(s):  
Heat Exchanger ◽  
Temperature Difference ◽  
Large Scale ◽  
Cold Water ◽  
Cooling System ◽  
Tube Bundle ◽  
Small Scale ◽  
Scaled Model ◽  
Average Temperature ◽  
Average Temperature Difference

Abstract In recent years Spring Creek in South Dakota, a popular fishing location, has been experiencing higher surface water temperatures, which negatively impact cold-water trout species. One potential solution is to provide localized refugia of colder water produced via active cooling. The present work focuses on the design and testing of a small-scale prototype heat exchanger, for such a cooling system. Various prototypes of the heat exchanger were tested in a 1/10th-scaled model of a section of the creek. A staggered, tube-bundle heat exchanger was used. The prototypes consisted of just the heat exchanger placed directly in the scaled-stream model and of the heat exchanger placed inside an enclosure with an aperture. The results show that, without the enclosure, the average temperature difference is 0.64 °C, with a corresponding heat transfer requirement of 1.63 kW/°C of cooling. However, with an enclosure, the average temperature difference is 1.95 °C, which required 0.59 kW/°C of cooling. Modifications to the enclosure decrease the average temperature difference but also decrease the standard deviation of the temperature difference. Thus, the cooling effect is more evenly spread throughout the water in the enclosure. This indicates that the enclosure design can be used to balance the requirements of obtaining a desired temperature difference with a relatively low spatial variation in that temperature difference. These results will be used to guide the design of the large-scale heat exchanger prototype.

Comparison of a Thermoacoustic Refrigerator Stack Performance: Mylar Spiral, Celcor Substrates and 3D Printed Stacks

2019 ◽  
Vol 27 (03) ◽  
pp. 1950021
Author(s):  
N. A. Zolpakar ◽  
N. Mohd-Ghazali
Keyword(s):  
Optimal Design ◽  
Temperature Difference ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Design Parameters ◽  
Optimized Design ◽  
Multi Objective Genetic Algorithm ◽  
Potential Alternative ◽  
3D Printed ◽  
Thermoacoustic Refrigeration

Although the thermoacoustic refrigeration (TAR) system has been recognized as a potential alternative environmentally cooling system, the low coefficient of performance (COP) has yet to make it marketable. One major factor contributing towards the low COP is the fabrication method applied to the stack component which is the most important component in the TAR. In this paper, comparison of the performance of a (i) 3D printed stack, (ii) a hand fabricated Mylar stack and (iii) an off-the-shelf Celcor substrates stack has been done; these being based on optimized design parameters using Multi-Objective Genetic Algorithm (MOGA). The performance is determined from the temperature attained at the cold end of the stack and the temperature difference across the stack. Experimental results showed that the 3D printed stack has the best performance by achieving a temperature, [Formula: see text]C at the cold end and a temperature difference of [Formula: see text]C across the stack, about 60% of the designed temperature difference even though the fabricated 3D printed stack deviated from the optimal design due to fabrication constraint as compared to that of the Mylar stack which was closer to the optimal design. This 3D printing of the stack promises a big potential in the improvement of the TAR performance because of the consistency achievable with the precise dimensions of the stack.

scholarly journals Research on Heat Transfer Performance of Micro-Channel Backplane Heat Pipe Air Conditioning System in Data Center

2020 ◽  
Vol 10 (2) ◽  
pp. 583
Author(s):  
Liping Zeng ◽  
Xing Liu ◽  
Quan Zhang ◽  
Jun Yi ◽  
Xianglong Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Pipe ◽  
Temperature Difference ◽  
Air Conditioning ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Micro Channel ◽  
Filling Rate ◽  
Air Conditioning System

This paper deals with the heat transfer performance of a micro-channel backplane heat pipe air conditioning system. The optimal range of the filling rate of a micro-channel backplane heat pipe air conditioning system was determined in the range of 65–75%, almost free from the interference of working conditions. Then, the influence of temperature and air volume flow rate on the heat exchange system were studied. The system maximum heat exchange is 7000–8000 W, and the temperature difference between the inlet and outlet of the evaporator and the condenser is almost 0 °C. Under the optimum refrigerant filling rate, the heat transfer of the micro-channel heat pipe backplane system is approximately linear with the temperature difference between the inlet air temperature of the evaporator and the cooling distribution unit (CDU) inlet water temperature in the range of 18–28 °C. The last part compares the heat transfer characteristics of two refrigerants at different filling rates. The heat transfer, pressure, and refrigerant temperature of R134a and R22 are the same with the change of filling rate, but the heat transfer of R134a is lower than that of R22. The results are of great significance for the operational control and practical application of a backplane heat pipe system.

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