基于塔式太阳能聚光的管式高温空气吸热器试验研究

EXPERIMENTAL STUDY OF TUBULAR AIR RECEIVER FOR SOLAR TOWER

耦合储能的太阳能高温空气布雷顿循环发电系统,兼具发电稳定和变负荷快速响应的优势,是极具发展潜力的灵活调峰电源。为构建太阳能布雷顿循环系统,研制了管式高温空气吸热器,在塔式聚光条件下开展了试验研究。试验结果表明,太阳直射辐射突降31.1%时吸热器出口温度仅变化0.3%,有利于保障太阳能布雷顿循环的稳定运行;试验工况下吸热温度最高可达904℃,热功率最大为56 kW,达到建立十千瓦级太阳能布雷顿循环系统的基本要求。基于试验数据开展了吸热器优化研究,当吸热器采光孔直径减少20%时,吸热器热效率可增大15.6%;当入口压力增大100 kPa同时吸热管内径增大1.6 mm时,吸热器压损可进一步降低81%。该研究期望为太阳能布雷顿循环及管式空气吸热器优化提供重要参考。

Solar air Brayton cycle with energy storage is a potential flexible peak regulating power source,which has the advantages of stable power generation and quick response capability.A high temperature tubular air receiver was designed and fabricated for solar air Brayton cycle,whose thermal performance was studied under real concentrating conditions at the solar tower test platform of ZJU.The experimental results show that the outlet temperature changes only 0.3% when the DNI drop by 31.1% suddenly,indicating a good operating stability of a solar Brayton system with the receiver.The outlet temperature of pressured air reaches 904℃,with the maximum thermal power of 56 kW,matching the requirements of a 10 kW solar Brayton cycle system.Design optimization was conducted for the receiver based on experimental data,and the efficiency can be increased further by 15.6% when the aperture diameter decreases by 20% and the pressure loss can be decreased by 81% when the inlet pressure is increased 100 k Pa and the inner diameter of absorber tubes is increased 1.6 mm.The study indicates a practical way to improve the performance of high temperature tubular air receiver.