Numerical simulation of single spiral heat storage tank for solar thermal power plant

•The storage time of the storage tank has been investigated by using a single spiral heat exchanger tube.•The influence of inlet velocity and inlet temperature on the charge time have been discussed.•The results show that the charge time of the storage tank is about 72,000 s before the other factors have been changed.

Thermal energy storage is a key technology for the solar thermal power plants. This paper set up a single spiral heat storage tank using concrete as heat storage material and Cu-water nano-fluid as heat transfer fluid. In this paper, temperature distribution and the effects of the parameters i.e., inlet temperature and inlet velocity, on the charge time of the storage tank have been investigated based on numerical simulation. The results show that the charge time of the storage tank is about 72,000 s before the other factors have been changed. The charge time of the storage tank increases with the decrease of the inlet temperature and inlet velocity.