Simulation of a solar tower thermal power plant using TRNSYS

The solar tower thermal power technology is a method to achieve the large-scale utilization of solar energy. A user defined TYPE of the heat receiver for the solar tower thermal power plant (STTPP) is established in the TRNSYS program with Fortran codes. Full-year simulation of the STTPP is investigated based on different input parameters, weather conditions and plant control strategies by taking Beijing as a case study. Through this case, the influences of the receiver diameter, flow form and inlet/outlet temperature on the thermal efficiency, total pump power, power efficiency and 'solar-thermal-electricity' transfer efficiency are studied. Simulation results show that the thermal efficiency of receiver rises with the decrease of pipe diameter. The lower the inlet temperature is; the lower the annual pump power consumption is, and the higher the power efficiency would be. An instantaneous increase of the receiver outlet temperature would reduce the power efficiency. The plant control strategies suggest that the "south-in-north-out" arrangement of the heat receiver working fluid holds the highest power efficiency but lowest annual pump power consumption. The annual power generation increases effectively by introducing the hot and cold molten salt storage tanks. The annual power efficiency increases with the power plant capacity.