集成新型锅炉烟气热能回收系统的600MW机组全工况性能分析

Performance Analyses of a 600MW Coal-Fired Power Plant Integrated With a Novel Boiler Exhaust Heat Recovery System at Overall Working Conditions

提出了新型锅炉烟气热能回收系统,并对该系统进行了全工况性能分析,建立了汽轮机、换热设备的变工况计算模型,以600MW机组为例,计算获得了机组基准工况下的节能潜力,研究了负荷、环境条件等变化时机组的能耗特性,以及部分负荷条件下内部运行参数对机组能耗特性的影响规律。结果表明：基准工况下,新型锅炉烟气热能回收系统可降低供电煤耗达3.11g·（kW·h）^-1;机组节能潜力随着负荷率的下降略有上升,随着环境温度上升而小幅上升,新型锅炉烟气热能回收系统的变工况性能良好;机组在不同负荷运行时,分流烟道的分流系数对机组节煤量的影响最大,是机组变工况运行需要精细控制的运行参数。

The novel boiler exhaust heat recovery system could decrease the coal consumption rate of coal-fired power plants by decreasing the irreversibility in the air pre-heater. The aim of this paper is to investigate the performances of this system at overall working conditions. The calculation models of steam turbines and heat exchangers under off-design conditions were developed. Then a reference case of a 600 MW power unit was analyzed, including： the energy saving potential at benchmark condition, the influence of power load and environmental temperature on the energy consumption characteristics of power unit, and the influence of internal operational parameters on the energy consumption characteristics at partial load. Results show that： the novel boiler exhaust heat recovery system could decrease the coal consumption rate of power supplying by 3.11 g·（kW·h）^-1; the energy saving potential of this system increased with environmental temperature and power load, which showed that this system expressed good performances at off-design conditions; the ratio of flue-gas led to the low temperature economizer had great influence on the unit energy saving potential, which should be controlled precisely at partial loads.