| The air-source heat pump of heat recovery system is a novel saving-energy heat pump device. The system adopts several technologies, such as recovery of condensing heat, phase change energy storage technology and heat pump energy supply, etc. It can realize cooling and heating, at the same time, it can also satisfy the need of domestic hot water simultaneously. Therefore, the air-source heat pump of heat recovery system is obviously in favor of development economy, environment and society. The system can realize seven operation modes by switching some valves, such as space-cooling mode, space-heating mode, water-heating mode, space-cooling and water-heating mode, space-heating and water-heating mode, dual stage coupling mode and defrosting mode. It combines the advantage of heat pump energy supply and latent thermal energy storage which can be used for discontinuous hot water supply.Respectively analyzed the thermal properties and working performance of the refrigerant and phase change material, finally selected R410A as refrigerant and Fecl3·6H2O as phase change material for the air-source heat pump of heat recovery system. At the same time, established a phase change model under the nature convection influence, analyzed the storing and releasing performance of phase change material, the variation of solid-liquid interface, temperature field, velocity field, liquid fraction, heat transfer coefficient, heat flux were found out.The heat accumulator equipment was designed, and a mathematic model for heat-transfer process of phase change material in heat accumulator was developed based on enthalpy method and dispersed with finite difference method, and solved by alternating direction implicit method and iteration method. Taking Fecl3·6H2O as phase change material, without regarding to heat dissipation, the process of thermal storage and release in heat accumulator was simulated.The initial structure of the air-source heat pump of heat recovery system was designed, which combined phase change energy storage technology. Eventually, the influence of inlet temperature and velocity were analyzed. Then the air-source heat pump of heat recovery system was optimized using the results.An experimental apparatus had been built and run well. According to the analysis of the experiment result in winter condition, the performance of the air-source heat pump of heat recovery system was reviewed and the energy saving character was testified.This paper gives reference to the matching of the parameters and the optimal design of the system, and supplies theory support and technology accumulation for its popularization and application. |
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