Influence investigation of hot molten salt temperature on operation and mechanical behaviours of latent heat storage tank

Abstract

This paper presents an effect evaluation of initial hot molten salt temperature on behaviours of a thermally stratified latent heat storage (LHS) tank using phase change material (PCM) capsules. The influence of initial hot molten salt temperature on the heat storage, heat release and mechanical behaviours of the LHS tank are evaluated. The simulation results show that the initial hot molten salt temperature has relatively great influences on both the heat storage and heat release behaviours of the LHS tank. A higher initial hot molten salt temperature can reduce both the thermocline thickness and total heat storage duration of the tank in the heat storage process, and can increase the maximum heat storage and heat release powers, final effective heat storage and heat release quantities and peak maximum mechanical stress of the tank. When the initial hot molten salt temperature reaches 873.0 K, the peak maximum mechanical stress of the tank is 141.7 MPa. Therefore, to achieve a better operation behaviour of the LHS tank, the initial hot molten salt temperature should be appropriately increased while ensuring that the peak maximum mechanical stress of the tank does not exceed the yield stress and a certain margin can be kept.

Keywords

• PCM heat storage tank
• Latent heat storage
• Concentrated solar power
• Operation behaviour
• Mechanical behaviour