自然循环槽式太阳能中高温集热系统实验研究

Experimental investigation of a natural circulation parabolic trough collector system for medium-high temperature steam generation

介绍了规模为50kW的自然循环槽式太阳能中高温集热系统,并对系统在不同太阳辐照和排汽压力工况下的传热特性及稳定性进行了实验研究.结果表明,系统稳定运行的最低有效辐照条件为垂直镜面辐照度254～272W/m2;在较好的辐照条件下,本系统能够实现当天0.5MPa稳定排汽;在连续3d良好辐照条件下,系统产生的饱和蒸汽压力达到0.8MPa.在不同压力工况排汽过程中,由于辐照强度较小,管道热损失偏大,热管流量和携带热量偏小,自然循环换热系统均出现了不同程度的过冷换热现象.

A 50 kW natural circulation parabolic trough collector （PTC） system for medium-high tempera- ture steam generation was proposed. Experimental investigation of thermal performance and stability was performed under different solar irradiation and discharging steam pressure conditions. Results show that the requirement of minimum solar irradiation perpendicular to the mirror for system working steadily is 254-272 W/㎡. In good irradiation condition of summer, this system can generate steam at pressure up to 0.5 MPa stably in one day. When three days continuous heating is performed, the pressure of saturated steam generated by the system reaches to 0.8 MPa. During the steam producing process at different pres- sure, there is subcooling heat transfer happening due to insufficient solar radiation and thermal losses of pipes which result in inadequate heat fluxes in heat pipe.