光煤互补发电系统集成方案研究与性能分析

INTEGRATION SCHEME RESEARCH AND PERFORMANCE ANALYSIS OF SOLAR AIDED COAL-FIRED POWER GENERATION SYSTEM

通过建立槽式太阳能集热器热效率的计算模型,分析在考虑不同方案集热器热效率差异的基础上集成单个加热器互补系统的热力性能。以600 MW光煤互补发电系统为例,研究南京地区典型日变辐照强度下光煤互补发电系统的性能,探究最佳集成方案。结果表明,虽然低辐照强度下集成1号高加方案的光电转换效率最高,但由于1号高加给水的吸热量小,易出现集热器集热量供大于求的情况,导致高辐照强度下系统的光电转换效率较低;在不考虑集热器集热量供大于求的情况下,集成2号高加方案光电效率十分接近集成1号高加,因此同时集成1号、2号高加不仅在辐照强度较低时拥有与集成1号高加几乎相同的光电转换效率,还具有由于给水吸热量大而不易出现集热量供大于求的优点。因而集成1~2号高加方案最优。

Through establishing the computation model of thermal efficiency of trough solar collector, the thermal performance of integrated single heater complementary system is analyzed considering the thermal efficiency difference of the collectors for different schemes. Taking 600 MW solar aided coal-fired complementary power generation system as an example, the performance of solar aided coal-fired complementary power generation system in typical daily irradiation intensity in Nanjing area is studied for exploring the optimal integration scheme. The results show that though integration scheme No. 1 heater has the highest photoelectric conversion efficiency at low irradiation intensity, however it is easy for collectors to collect more heat to exceed the demand as the heat amount absorbed by the feed water is small, leading to lower photoelectric conversion efficiency in high irradiation intensity. If excluding collector heat collection oversupply, the photoelectric conversion efficiency of the integrated No. 2 heater is very close to integrated No. I heater. Therefore, simultaneous integration of No. 1 and No. 2 heaters not only has the same photoelectric conversion efficiency as that of integrated No. 1 heater when the irradiation intensity is low, but also it is not easy to have the overheating due to the large amount of heat is absorbed by the feed water. Thus, integration scheme integrating No. 1-2 heaters is the optimal scheme.