集成热泵干燥的褐煤发电系统理论研究

Theoretical Study of Lignite-Fired Power System Integrated With Heat Pump Drying

对褐煤干燥提质是提高褐煤发电系统发电效率的有效手段,热泵干燥是一种节能干燥技术。因此,本文考虑在褐煤发电系统中集成热泵干燥技术,设计了系统流程,并建立了该系统热效率、分析模型。进而,结合某600MW直接燃褐煤发电机组实例,对该系统的节能潜力进行了计算,结果表明:燃烧过程损降低是褐煤预干燥节能的本质,而通过热泵干燥在基准工况下可以降低机组供电标准煤耗率达11.54 g.kWh^(-1)。最后,分析了主要系统参数对系统能效的影响规律,结果表明:干燥机热效率、热泵热力完善度越高,褐煤干燥程度越大,系统供电标准煤耗率的降低量越大。

Lignite pre-drying is an effective way to improve the plant thermal efficiency of lignite-fired power system.Heat pump drying is a kind of energy conservation drying technology.Therefore,the lignite-fired power system integrated with heat pump drying was proposed in this paper.The preliminary system was designed,and theoretical models of energy and exergy analyses were then developed.With a reference case of 600 MW conventional lignite-fired power plant as the benchmark,the energy saving potential of lignite-fired power system integrated with heat pump drying was calculated.Results show that the decrease of exergy destruction in combustion is the essence of energy saving,and the standard coal consumption rate of power supply could be decreased by 11.54 g·kWh-（-1） because of heat pump drying.The influence of main parameters on system energy efficiency were analyzed,and results show that the decrease of the standard coal consumption rate of power supply increases with the dryer thermal efficiency,the second-law efficiency of heat pump and the pre-drying degree of lignite.