褐煤热泵预干燥超临界CO_(2)循环发电系统理论研究  

Theoretical Study of Supercritical CO_(2) Lignite-fired Power Plant Integrated With Heat Pump Pre-drying Lignite System

作　　者：张旭伟 张一帆[1] 李红智[1] 吴家荣 乔永强 ZHANG Xuwei;ZHANG Yifan;LI Hongzhi;WU Jiarong;QIAO Yongqiang(Xi'an Thermal Power Research Institute Co.Ltd.,Xi'an 710054,China)

机构地区：[1]西安热工研究院有限公司,西安710054

出　　处：《工程热物理学报》2023年第7期1753-1761,共9页Journal of Engineering Thermophysics

基　　金：国家重点研发计划项目(No.2020YFF0218104)。

摘　　要：褐煤含水量高,直接燃烧发电存在效率低、投资大的问题。为此,本文提出了一种集成褐煤热泵预干燥的超临界二氧化碳循环发电系统,并建立了超临界二氧化碳循环发电系统和褐煤热泵预干燥系统的耦合计算模型,以某660MW发电系统为例,对直燃褐煤发电系统和褐煤热泵预干燥发电系统进行对比分析。结果表明:褐煤发电系统通过热泵干燥褐煤可以使系统发电效率提高1.44%,发电标准煤耗率降低8.06g·(kWh)^(-1);[火用]分析发现,预干燥褐煤使得锅炉燃烧损降低高达4.47%,排烟[火用]耗散降低0.35%,从而使系统[火用]效率提高1.29%,燃烧[火用]损和排烟[火用]耗散降低是系统节能的主要原因;干燥机效率、褐煤干燥程度和热泵COP越高,褐煤热泵预干燥发电系统节能效果越显著。Lignite has high water content,and direct combustion for power generation has problems of low efficiency and large investment.Therefore,the supercritical CO_(2) lignite-fired power plant integrated with heat pump pre-drying lignite system was proposed and the coupled thermal calculation model for the supercritical CO_(2) cycle power cycle and the heat pump pre-drying lignite system was established.Then,based on a 660 MW reference case,the thermodynamic performances of the lignite direct-fired power plant and the lignite-fired power plant integrated with heat pump pre-drying lignite system are compared and analyzed.The results show that the heat pump drying lignite can increase the power generation efficiency by 1.44%and reduce the standard coal consumption rate by 8.06 g·(kWh)^(-1).Exergy analysis further shows that the heat pump drying lignite reduces the combustion exergy destruction of the boiler by 4.47%and reduces the boiler exhaust exergy loss by 0.35%,which increases the exergy efficiency of the lignite-fired power plant by 1.29%.And the reduction of the combustion exergy destruction and exhaust exergy loss of the boiler is the main reason for the energy saving.The higher the dryer efficiency,the lignite drying degree and heat pump COP,the more significant the energy-saving effect of the lignite-fired power plant integrated with heat pump pre-drying lignite system.

关 键 词：超临界二氧化碳动力循环 燃煤电站 褐煤热泵预干燥 [火用]分析 

分 类 号：TK114[动力工程及工程热物理—热能工程]