Experimental and theoretical investigation of regenerative total heat exchanger with periodic flow for air-conditioning systems

2017 ◽  
Vol 81 ◽  
pp. 123-133 ◽  
Author(s):  
Chih-Chung Chang ◽  
Sih-Li Chen ◽  
Tzu-Yuan Lin ◽  
Yuan-Ching Chiang
2003 ◽  
Author(s):  
Tony D. Chen

Air-cooled heat exchangers with three tube rows are commonly seen in domestic air-conditioning systems. The analytical solutions of heat exchanger effectiveness for three-row plate fin-and-tube heat exchangers with alternating circuitries have been derived and expressed explicitly in terms of heat capacity ratio and number of transfer units in the recent study. These set of exact solutions serve as a basic tool in designing heat exchanger circuitry to its most accurate possible effectiveness. Comparison of plate-fin-tube heat exchanger effectiveness between airside unmixed and mixed for three-row configurations shows that the effectiveness could be different from 0.3 to 2.4% for the NTUs (Number of Thermal Units) range from 1.0 to 3.0. On the other hand, the result of the comparison of effectiveness between identical and alternating circuiting for 3-row crossflow heat exchangers shows that alternating circuiting could have less effectiveness than identical circuiting from 0.4 to 8.8% in the NTUs range from 1.0 to 3.0. Nevertheless, alternating circuit has its benefit for lower NTU cases, result shows that it could have 1.7 to 0.1% advantages over identical flow arrangement for 2-row heat exchangers with NTUs range from 1.0 to 2.0.


Author(s):  
Jianghong Wu ◽  
Shuangfeng Wang ◽  
Yunting Ge

Two type condensers of R22 residential air conditioning systems were investigated in this study. Two R22 residential air-conditioning systems, one with a microchannel condenser and the other with a round-tube condenser, were examined experimentally, while the other components of the two systems were identical except the condensers. Based on the principle of the microchannel condensation, the analysis of heat transfer along parallel heat exchanger was conducted. The non-uniform air velocity distribution at the face of the microchannel condenser and refrigerant distribution in headers were taken into account in this research. The mechanism and possibility of the superior thermal performance as compared with conventional fin-tube heat exchangers were discussed. In addition, the maximum of thermal performance influenced by the running parameter was experimentally measured. The experimental results show that with one third face area of round tube heat exchanger, microchannel condenser’s pressure drop increase around 12–23% and refrigeration output increase 2–5%, refrigerant charge decreases around 50%, it is found to be a promising candidate for residential air conditioning condenser.


2018 ◽  
Vol 130 ◽  
pp. 1319-1327 ◽  
Author(s):  
Chih-Chung Chang ◽  
Jyun-De Liang ◽  
Sih-Li Chen

2014 ◽  
Vol 899 ◽  
pp. 231-234 ◽  
Author(s):  
Petr Horák ◽  
Adam Pavel ◽  
Iva Ambrožová

This article describes a new type of hollow-fiber heat exchanger that provides similar heating performance to conventional metal heat exchangers commonly used in air conditioning systems but at lower cost and greater simplicity. While factors such as fragility and element fouling have yet to be optimized, the exchanger shows great promise for application in buildings aiming at close-to-zero energy consumption.


2017 ◽  
Vol 140 ◽  
pp. 154-170 ◽  
Author(s):  
Demis Pandelidis ◽  
Sergey Anisimov ◽  
William M. Worek ◽  
Paweł Drąg

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