A Study of New Type Integrated Solar Hot Water Heater

• Main Authors: Po-En Yang, 楊博恩
• Other Authors: 黃秉鈞
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/74023807025264965644

碩士 === 國立臺灣大學 === 機械工程學研究所 === 94 === The main purpose of the present project is to develop a new type of solar water heater that eliminates some disadvantages of the conventional systems. Three sets of loop heat pipe (LHP) were integrated into the heat transfer module, by thus the heat absorbed from solar heat collector is transfer into the hot water tank. LHP devices can transfer the collected heat in a downward direction, therefore the hot water tank can be located in the lower part of the solar collector. While the location of a conventional naturally-circulated solar water heater tank is confined to the upper part of solar collector, this new type LHP assisted solar water heater reduces the system bulkiness, as well as the complexity of on-site construction. A feasibility test shows that a thermosiphon-LHP unit is capable to transfer collected heat to its condenser immersed in a hot water tank. The results show that the thermal resistance of this unit is 0.34℃/W, and that of the LHP part is 0.16℃/W. Two raw models of solar water heaters with 50 liters and 80 liters hot water tanks were designed according to the results of the previous feasibility test. In addition an automatic monitoring system was designed and set up for these two solar water heaters test according to national standard CNS B7277. The designed system was analyzed and tested on-site. The thermal resistance of the whole system is 0.369℃/W, and that of the thermal efficiency is 0.4, the discrepancy between the system analysis and on-site test are 8 % for thermal resistance and thermal efficiency. It is derived from the analysis that increase in LHP numbers can increase the thermal efficiency to 0.6, due to the reduction of thermal resistance of the thermosiphon units.