THERMODYNAMIC ANALYSIS ON HEAT PUMP WATER HEATERS BASED ON RECIPROCATING FLOW HEATING
Water heating is one of the largest energy consumers in all residential sites. Due to its high efficiency, air-source heat pump water heaters are attracting more and more attention from both users and researchers. In this paper we investigated a new heat pump water heater system which is based on cold water reciprocating flow heating in the condenser. The new system includes conventional refrigeration part and water loop part. The water loop part consists of two water tanks (i.e. heating tank and storage tank), water flow direction alteration device and connectors (e.g. pipes and valves). In order to avoid or reduce internal heat leak caused by the direct contact or mixing of cold and hot water, each water tank is separated into two cavities by a floating plate connected with flexible furl-canister for sealing. In the water heating process, the condensing temperature increases discretely with the increasing in water temperature. When the water is heated to a specified temperature, the hot water in heating tank is then moved to storage tank in accordance with specified logic. We firstly compared the present cycle with reversed half-Lorenz cycle and calculated the effect of water flow direction alternation number (n) on COP. When n approaches infinite, the present cycle becomes reversed half-Lorenz cycle. Secondly, the effects of the clearance volume in water loop and the heat leak in water tanks were evaluated for a specified prototype. The results emphasize the importance of small clearance volume and weak heat leakage. Finally, entropy generation analysis was performed. The results point out the evolution path of design optimization qualitatively, i.e. the path of increasing n and decreasing the clearance volume and the heat leakage in water tanks.
Houlei Zhang Xinzhi Liu Li Wang Shifa Chen
School of Power Engineering Nanjing University of Science and Technology Nanjing, China, 210094 School of Power Engineering Nanjing University of Science and Technology Nanjing, China, 21009
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
355-361
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）