Application And Heat Transfer Characteristics Of Ice Storage Air-conditioning

Thermal storage air conditioning is an important approach to shift electric demand from on-peak electric rate period to off-peak periods, and a branch of modern air conditioning system. Experimental research and the technical and economic analysis of thermal storage air conditioning has important theoretical value and practical signification.Ice storage tank is a very important part in the whole system which stores or releases cooling capacity with solid-liquid phase change. Heat exchange in ice storage tank is very complex, it is a non-linear question in mathematics. We must make some hypothesis to resolve it. Ice-on-coil tank is actually a kind of shell-tube heat exchanger with static PCM on the shell side. The operation of the ice tank deals with solid-liquid chang process outside the tube bundles in an enclose space. The performance of ice storage tank is related to the efficiency and investment of the whole ice storage system. So it is the center of the research on ice storage technique to research the performance of charging and discharging process of ice storage tank.The research works in this paper mainly focus on the following aspects. At first, in this thesis, the basic theory of thermal storage air conditioning technical is presented. Based on test data of real operation of ice-storage air conditioning, such as: the operation characteristic of water cooled screw chiller of one pair of operating modes, the heat-transfer character of internal-melt ice storage tank,and so on, this thesis gave out the demonstration that ice-storage air conditioning is practicable in technical, and the evaluation of the operation of system was also given out.Then, in this paper, the heat transfer process is analyzed based on the character of phase change heat transfer. The bundle-model is established on the basis of the hypothesis and the method of thermal resistance net. Through solving the model, the effects of structure parameters such as: material of coils, size of coils and diameter of coils are analyzed. And the physical characteristic, the inlet temperature and flow rate of brine is also considered. Studies have shown that themodel is able to simulate both charging and discharging modes.Finally, combined with a project example, the technical and economic analysis of ice-storage air conditioning gave out the demonstration that ice-storage air conditioning is beneficial in economic and it is mainly determined by the electric utilities charge of local place.Xu Xiaoyu(Refrigeration and Cryogenic Engineering) Directed by Associate Professor Cao Hongfen...