Experimental investigation on thermal characteristics of a novel mesh flat-plate heat receiver in a solar power tower system

In solar power tower systems, the heating surface of a heat receiver is prone to local overheating, thermal fatigue, and thermal ratcheting under nonstationary, nonuniform, and high-heat-flow-density loads, resulting in failure of the heat receiver. Therefore, this paper proposes a novel high-temperature, mesh, flat-plate heat receiver (FPHR) comprising multiple micro heat pipe loops. A series of tests were conducted to investigate the heat transfer characteristics and cooling start-up performance of the mesh FPHR. The results indicate that the larger cooling rates can reduce successful start-up times by more than 12%, and the FPHR has excellent isothermal performance (<35.05 °C) and heat transfer performance, which can withstand high-heat-flow-density loads and effectively prevent the harm caused by thermal stress. In addition, the nonuniform heating condition has a greater impact on the isothermal performance of FPHR, and the maximum temperature difference of the heat absorption surface with the change of the tilt angle is only reduced by 2.03 °C. The efficiency of the FPHR can exceed 83.98% and the air outlet temperature can exceed 714.5 °C. The results will contribute to the further development of heat receivers used in solar power tower systems. • A novel mesh flat-plate heat receiver used in SPT system is proposed. • Large cooling rates significantly reduce the time for successful cold starts. • The mesh and metal fibre felt ensure good isothermal performance together. • The heat receiver can adapt to a wide range of heat fluxes. • Nonuniform heating has a greater impact on the isothermal performance.