Heat transfer analysis and experimental verification of casted heat exchanger in non-icing and icing conditions in winter

Abstract

Seawater-source heat pump systems (SWHP) are recognized to be outstanding heating, cooling and water heating systems. A large number of SWHP systems have been used in residential and commercial buildings in coastal areas due to the attractive advantages of high efficiency and environmental friendliness. In this paper, two mathematical models that described heat transfer process of casted heat exchanger (CHE) adopted by SWHP systems in the icing and non-icing conditions in winter have been developed and validated by an experimental study. The CHE is consisted of pipes immersed in the seawater and used for transferring heat between the seawater and the heat exchanger pipes of the SWHP. In addition, a computer code has been implemented to simulate the effects of flow rate of the secondary refrigerant, length of the CHE and the temperature of the seawater on the heat transfer performance. The effect of the ice outside the pipe due to the low seawater temperature on heat transfer has been discussed and the comparison of the heat transfer rate in two conditions demonstrates that the effect of icing on heat transfer performance is great. As a result, application of SWHP systems with CHE in coastal areas in China is feasible due to the favorable geographical conditions and environment.