提高主再热汽温对600MW亚临界空冷机组运行特性的影响分析

Analysis of improving primary and reheat steam temperature's influence on the operating characteristics of 600MW subcritical air cooling unit

针对亚临界空冷机组实际运行过程中煤耗偏高的问题，提出提高主再热蒸汽温度的改造方案，并以桌典型600MW亚临界空冷机组为例，详细分析了主再热汽温变化对机组运行特性的影响，从热力学角度揭示了提高蒸汽初参数的经济性；在此基础上，又对机组在不同工况下初参数变化对能耗的影响进行了计算分析。研究结果表明：对于案例机组，在100％THA工况下，当将其主再热蒸汽温度由5380C提高至5800C时，机组的发电效率可提高0．61％，供电煤耗可降低4．73g／kWh，节能效果显著。且随着负荷的降低，机组的热力性能还会进一步提高，当负荷在80％～40％THA工况变化时，提高初温后机组的供电煤耗可降低5．00～5．70g／kWh。

For high coal consumption of subcritical air-cooled unit during actual operation,the rehabilitation program of increasing the primary and reheat steam temperature was proposed in this paper. Taking a typical 600 MW subcritical air-cooled unit as example,a detailed analysis of the impact of the primary and reheat steam temperature change on operating characteristics of the unit and economic performance of increasing steam initial parameter from the thermodynamic point were performed. On this basis,the impact of steam initial parameter on the unit'energy consumption at different conditions was calculated. The results show ed that:for case unit,at 100% THA condition,when the primary and reheat steam temperature increased from 538 ℃to 580 ℃,the pow er generation efficiency can be increased by 0. 61%and unit pow er supply coal consumption can be reduced 4. 73 g/k Wh.The energy-saving effect is remarkable. And with the decrease of the load,thermal performance of the unit will be further enhanced. When the load changed at 80% ~ 40% THA working conditions,supply coal consumption of the unit when improving the steam ' s initial temperature can be reduced by 5. 00 ~ 5. 70 g/k Wh.