二次再热机组加热锅炉二次风的抽汽过热度利用系统  

Steam Extraction Superheat Degree Utilization System of Secondary Air of Heating Boiler of Secondary Reheat Unit

作　　者：赵家毅 李千军 杨涛[1] 苏世玮 

机构地区：[1]华中科技大学能源与动力工程学院,湖北武汉430074 [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：《广东电力》2018年第1期11-16,共6页Guangdong Electric Power

基　　金：国家重点基础研究发展计划(973)资助项目(2015CB251504)

摘　　要：针对二次再热机组常规抽汽过热度利用系统第一级抽汽压损过大导致机组效率降低的问题,提出了一种加热锅炉二次风抽汽过热度利用系统。建立了机组常规抽汽过热利用系统和加热锅炉二次风抽汽过热利用系统的热力学模型,计算不同工况条件下热力参数和经济性指标变化,并进行了对比分析。结果表明:在汽轮机热耗率验收(turbine heat acceptance,THA)工况下,相比于外置式蒸汽冷却器方案,加热锅炉二次风方案在有效降低抽汽过热度同时,能够提高二次风温度近40℃,减少机组冷源损失近24 MW,降低机组发电煤耗率0.36 g/(k W·h);在中低负荷时,机组冷源损失和发电煤耗率略微增加,节能效果降低。In allusion to the problem of low efficiency of the unit caused by great pressure loss of the first steam extraction of the conventional steam extraction superheat degree utilization system of the secondary reheat unit,the paper proposes to use a secondary air steam extraction superheat degree utilization system of the reheating boiler. It builds thermal dynamic models for the conventional utilization system and the proposed utilization system for the unit so as to calculate and compare changes of thermal parameters and economy indexes under different conditions. Corresponding results indicate that compared with the scheme of external steam cooler,this secondary air scheme of heating boiler can both effectively reduce steam extraction superheat degree and improve secondary air temperature by nearly 40 ℃ as well as reduce coal source loss by nearly 24 MW and generation coal consumption of the unit by 0. 36 g/( kWh) under the condition of turbine heat acceptance( THA). In addition,under the condition of medium and low load,cold source loss and generation coal consumption rate of the unit increase slightly,which has reduced energy saving effect.

关 键 词：二次再热 抽汽过热度 锅炉二次风 冷源损失 发电煤耗率 

分 类 号：TK219[动力工程及工程热物理—动力机械及工程] TM621.4[电气工程—电力系统及自动化]