Numerical Simulation And Experimental Research On Characteristics Of Phase-change Energy Storage Exchangers In Dual Source Heat Pump System

So far, China has become the largest energy producer and consumer in the world.Energetically promoting energy conservation and developing new energytechnologies with technology innovation are imminent. The project take advantage ofsolar and air source which are two kinds of clean energy, Integrating solar thermalutilization and phase change energy storage technology into heat pump techniques,developed a new type of dual heat source heat pump energy storage coupled systems.The system is Dual Spiral Coils Heat Exchanger with Latent Heat EnergyStorage (DSCHE-LHES), which consists of two spiral coils and a cylindricalcontainer filled with phase change material RT6. Phase change heat transfer theoriesare summarized in this paper. A three-dimensional incompressible transient model iscreated by GAMBIT. Based on the enthalpy method, we establish the mathematicalmodel of phase change energy storage heat exchanger. Using a Solidification/Meltingmodel of FLUENT simulates the coupled heat transfer process. The PCM flowfield、liquid fraction and heat flux with time in natural convection condition areanalyzed. Finally conclude the phase change energy storage time. However, lowthermal conductivity and long storage time is restricted in engineering application.Then nano Al powders/RT6CPCM are prepared and heat conduction significantlyenhanced.For further research, we analyze the influence of the phase change time atdifferent velocity of flow and different inlet temperature by experiment. Wedetermine the optimal import flow velocity and temperature under different workingconditions afterwards. In the end, the numerical results of the model were comparedwith the data from the experiments. Results indicate that the model is basicallycorrect and feasible. This research provides theoretic basic and reference to design forair-conditioning system with energy storage.