烟气余热利用对燃煤机组影响的综合分析  

Synthetical Analysis of the Heat Recovery Effects on Coal-Fired Power Units

作　　者：刘桂才[1] 廖艳芬[1] 马晓茜[1] 宋景慧 

机构地区：[1]华南理工大学电力学院广东省能源高效清洁利用重点实验室,广东广州510640 [2]广东电网有限责任公司电力科学研究院,广东广州510080

出　　处：《锅炉技术》2017年第6期8-12,45,共6页Boiler Technology

基　　金：基金项目 广东省能源高效清洁利用重点实验室(2013A061401005);能源高效清洁利用广东普通高校重点实验室(KLB10004)

摘　　要：国内大型燃煤电厂的排烟温度一般在120℃~140℃。若通过低压省煤器对烟气余热进行利用,可降低排烟温度,提高机组的热经济性,同时机组的厂用电等诸多系统也将受到影响。基于迭代校核和等效焓降法,结合某1 000MW燃煤机组,综合分析了在多种工况下余热利用改造对锅炉效率、汽轮机做功、引风机、凝结水泵、除尘器、脱硫系统的影响。结果表明:余热利用改造后,50%THA、75%THA和THA工况下供电标煤耗分别降低2.654g/(kW·h)、2.394g/(kW·h)和2.003g/(kW·h),电厂每年可节省标煤约1.27万吨。The exhaust gas temperature of large coal-fire unit in China is usually between 120 ℃-140 ℃. If the flue gas heat is recovered by low pressure economizer, the exhaust gas temperature will be reduced, and the thermal economical performance will be improved. However, lots of systems such as auxiliary power system in the units will be influenced. In this paper, based on iteration-check and the equivalent enthalpy drop method, combined with a 1 000 MW coal-fire unit, the influences of heat recovery transformation on boiler efficiency, working of turbine, induced draft fan, condensate pump, precipitators and FGD system were comprehensive analyzed. The results show that the coal consumption rate of power supply will be reduced by 2. 654 g/（kW.h）, 2. 394 g/（kW.h） and 2. 003 g/（kW.h） under 50% THA,75%THA and THA after the retrofit of heat recovery, respectively. And the power plant will save about 12,700 tons of coal.

关 键 词：余热利用 等效焓降法 供电煤耗 热经济性 

分 类 号：X701[环境科学与工程—环境工程]