发电机组混合式低压加热器改造的变工况性能分析

摘要

针对火电厂给水回热系统的表面式加热器存在传热温差，热经济性能不如加热蒸汽与给水直接接触的混合式加热器的问题，对某600 MW 超临界发电机组的低压加热器进行不同方案的混合式加热器改造，建立机组仿真模型，计算分析不同改造方案在额定出力工况下的热经济性能，并对其中的最优方案进行变工况热经济性能计算分析。研究表明，优选方案在各种工况运行下均具有较佳的热经济性能，在低负荷工况时性能优势尤为突出。%In allusion to problem of heat transfer temperature difference and heat economic performance of surface heater of feedwater regenerative system in thermal power plant being inferior to hybrid heater which directly combines heating vapor and feedwater,this paper introduces different schemes for transforming low pressure heater of some 600 MW supercritical generator unit into hybrid heater.Simulation model for the unit was established and heat economic performance of different transformation schemes under rated output working condition was calculated and analyzed.Meanwhile,calculating analysis on heat economic performance of variable working condition of the optimal scheme was conducted.The research indicates that the optimized scheme is provided with better heat economic performance under various working conditions and perform-ance advantages are particularly prominent under low load working condition.