350 MW循环流化床锅炉机组冷渣器与暖风器系统综合优化

Comprehensive optimization of slag cooler and air heater system in a 350 MW circulating fluidized bed boiler unit

针对现阶段循环流化床(circulating fluidized bed,CFB)锅炉机组冷渣器余热利用效率偏低、暖风器热耗较大的问题,提出一种冷渣器与暖风器综合优化系统,并以某典型350 MW CFB锅炉机组为例,对优化系统在不同工况下的热力性能进行了详细的计算分析;在此基础上,对优化系统在冬季不同环境温度下的节能效果进行计算分析,并对其经济性能进行探究分析。结果表明:以案例机组为例,在冷渣器可用余热量不变的情况下,优化系统冬季工况下可使机组发电煤耗率降低2.0 g/(kW·h),非冬季工况下可使机组发电煤耗率降低0.9 g/(kW·h),最终机组年均净收益可增加271万元,节能效果与经济收益显著;同时,冬季工况下,环境温度越低,优化系统的节能效果越显著。

Aiming at solving the problems of low efficiency of slag cooler’s waste heat utilization system and large heat consumption of air heater in current circulating fluidized bed(CFB) boiler units, a comprehensive optimization system for slag cooler and air heater system is proposed. Taking a typical 350 MW CFB boiler unit as an example, the thermal performance of the optimized system under different working conditions is analyzed in detail. On this basis, the energy saving effect of the optimized system at different ambient temperatures in winter is calculated, and its economic performance is explored. The results show that, taking the case unit as an example, under the condition that the available residual heat of the slag cooler remains unchanged, the power generation coal consumption rate of the unit applying the optimized system in winter can reduce by 2.0 g/(kW·h), and that in other seasons can reduce by 0.9 g/(kW·h). The average annual net income of the unit can increase by 2.71 million yuan, and both the energy saving effect and economic benefits are significant. In addition, the energy saving effect of the optimized system in winter will be more significant when the ambient temperature is lower.