扩容蒸发式光煤互补发电系统变辐照特性研究

Study on Thermodynamic Performance of Volume Expanding Evaporative Solar System Hybrid with Coal Fired Power Generation System under Varying Radiations

为避免槽式太阳能集热器内变热流量传热和汽液非均匀分布产生,提出了扩容蒸发式太阳能蒸汽发生系统。采用NASA SSE6.0数据库收集的辐照数据,将扩容蒸发式太阳能直接蒸汽发生系统与燃煤机组互补组成复合发电系统,建立复合发电系统的变工况计算模型,并以600 MW机组为例进行了复合发电系统变辐照情况下的日、月、年热力性能分析。研究结果显示:复合发电系统日发电功率与辐照强度曲线变化趋势类似,各月复合发电系统的发电量呈现出夏季较高的趋势,6月份达到峰值2.95×10~8 kW·h,集热场效率与其趋势相反,机组热功转换率夏季较高,全年为32%～35%;太阳能平均热功转换效率为22.5%,研究结果可为太阳能与燃煤机组互补发电系统的工程应用提供新的方向和思路。

To avoid heat flux variations and non-uniform vapor-liquid distribution in parabolic collectors,the volume expanding evaporative solar steam generation system is proposed.Using actual solar radiation data from NASA SSE6.0 database,a 600 MW coal-fired power plant hybrid with a volume expanding evaporative steam generation system was established.Turbine stages at offdesign condition were calculated with DNI data over a one-year period.And the daily,monthly and yearly thermodynamic performance of the hybrid system in Lhasa area was analyzed respectively.The results exhibit the same trends in steam mass flow,daily power generation and DNI with the monthly power generation reaching the maximum in June(2.95×108 kW·h of electric energy produced),while the solar collector efficiency shows the opposite tendency.Moreover,the cycle thermal efficiency of power generation is relatively higher in summer,which typically ranges from 32%to 35%throughout the whole year.Annual solar thermal efficiency is approximately 22.5%by average.The results may provide a novel direction toward the application of solar energy system hybrid with coal-fired power generation.