A Novel Solar Receiver for Supercritical CO2 Brayton Cycle

In recent years, supercritical CO2 (s-CO2) Brayton-cycle engines attract more and more attention for its advantages of simple structure, compact layout, high efficiency and energy saving. Plenty efforts are made to apply them in many areas of power generation including concentrated solar power (CSP) plants. In the application of CSP plants, s-CO2 Brayton cycle has an extra advantage of low water consumption versus Rankin cycle, which is very helpful for its spreading in water shortage area. For an efficient collaboration of this thermodynamic cycle and concentrated solar thermal system, a new s-CO2 tubular receiver applying porous media and circulating air flow is proposed in this study. The heat transfer area is similar to 13 times larger than the heat loss area, which enables the proposed receiver to obtain the efficiency of similar to 95%. With the volumetric absorption concept applied, this receiver can absorb the sunlight volumetrically and has smaller heat loss area, which also enables it to operate at high solar flux. The proposed receiver is the suitable combination of the air based volumetric receivers and tubular receivers, which may provide a new approach for receiver design. (C) 2019 The Authors. Published by Elsevier Ltd.