Comparison of two kinds of solar collector/energy storage

The traditional solar assisted heat pump with energy storing usually has an intermediate heat transfer vessel transferring, the energy from solar collector to PCM as well as between PCM and the heat pump heat exchangers, which means one more heat transfer unit and more heat loss. A new integral solar assisted heat pump system with energy storage, integrating the solar collector, energy storage vessel and evaporator together, was brought forward. This paper was aiming to find out a better choice of solar energy collector/energy storage vessel between vacuum tube solar collector/energy storage vessel and plate solar collector/energy storage vessel by simulation method. The temperature distribution, energy releasing rate and liquid fractions during the energy releasing process in summer and winter were simulated and compared. The results show that the vacuum tube solar collector/energy storing vessel has a better thermal performance but part of the Phase Change Material (PCM) won't melt in winter with CaCl2 center dot 6H(2)O as the PCM. Although the heat transfer resistance of the PCM in the plate collector is bigger than that of the vacuum tube during energy releasing process, adjusting the evaporator locations can improve it, and reducing the height of the PCM can solve the melting problem in winter. In conclusion, the plate collector/energy storage vessel is more reliable and more suitable for experimental setups in Nanjing.