Experimental and numerical evaluation of a lab-scale external solar receiver

Solar power tower system with an external receiver is one of the most promising technologies for electricity generation and has a high concentration ratio and a high operating temperature range. In this paper, a lab-scale external receiver with xenon lamps, using molten salt as a heat transfer fluid, was established, and its optical and thermodynamic properties were evaluated. Experimental and numerical methods were used to analyze the performance of the receiver. For the base case (100% light power, no wind, 2.3 kg/s mass flow, and 400 °C inlet temperature), the deviation in the maximum temperature of the wall determined through numerical simulation and thermal imager measurement was 1.8%; the deviation in the back temperature of the receiver identified through simulation and thermocouple measurement was 0.22%. The performance of the receiver under different working conditions was also explored. Experimental and simulation results had good agreement at different mass flow rates, light power, and wind speed, and the deviation under each condition was less than 5%. The experimental results showed that the temperature rise of molten salt increased from 4.3 °C to 7.4 °C when the inlet temperature increased from 375 °C to 500 °C; the temperature rise of molten salt increased from 1.8 °C to 5.3 °C when the power of the xenon lamps increased from 20% to 100%; the temperature rise of molten salt decreased from 8.3 °C to 5.3 °C when the mass flow rate increased from 1.4 kg/s to 2.3 kg/s; and the temperature rise of molten salt decreased from 5.3 °C to 3.6 °C when the wind velocity increased from 0 to 10 m/s. The practical and simulation results present useful reference sources for fellow researchers and practitioners in the sector of the solar power tower system.