1350MW二次再热发电机组热力系统设计分析  

Analysis of the Design of a Thermal System for a 1350MW Secondary Reheat Power Generator Unit

作　　者：阎维平[1] 赵永明[1] 李海新[1] 刘立衡 

机构地区：[1]华北电力大学能源与动力机械工程学院,河北保定071003 [2]国电科学技术研究院,江苏南京210000

出　　处：《热能动力工程》2014年第1期35-40,106,共6页Journal of Engineering for Thermal Energy and Power

摘　　要：综合考虑锅炉侧和汽轮机侧的设计协调,构建了1 350 MW二次再热机组原则性热力系统。针对不同给水泵汽轮机配置进行了计算与分析,定量分析了背压抽汽式与凝汽式小水泵汽轮机两方案对再热蒸汽流量、机组热耗和回热加热器设计等的影响。结果表明:额定工况下,背压抽汽式给水泵汽轮机系统的一、二次再热器蒸汽流量分别比凝汽式系统小266 t/h和289 t/h,从而有利于锅炉对流受热面设计;背压抽汽式系统的4号、5号加热器进汽温度相比凝汽式系统分别降低350℃和297℃,有利于加热器设计和运行。但背压抽汽式系统比凝汽式系统机组热耗高约为6 kJ/kWh。部分负荷下的计算结果表明背压抽汽式系统一、二次再热蒸汽流量仍小于凝汽式系统,机组热耗相比凝汽式系统仍稍高。With the design coordination between both sides of the boiler and steam turbine being taken into account in a comprehensive way,set up was a 1350 MW secondary reheat unit principle thermal system. For different configurations of the feedwater pump steam turbines,a calculation and analysis were performed with the influence of two versions of feedwater pump-purposed steam turbines on the reheat steam flow rate,heat rate of the unit and design of the reheater etc. being quantitatively analyzed,namely,back pressure and extraction type and condensing type steam turbine. It has been found that under the rated load operating condition,the steam flow rates of the primary and secondary reheater of the back pressure and extraction type feedwater pump steam turbine thermal system are 266 and289 t / h smaller than those of the condensing type one,thus making for the design of the convection heating surface of the boiler. Compared with the steam inlet temperatures of No. 4 and 5 heaters in the condensing type steam turbine system,those of the back pressure and extraction type steam turbine thermal system will lower by 350 and 297℃ respectively,favorable for the design and operation of the heaters. However,the heat rate of the back pressure and extraction type steam turbine thermal system version is 6 kJ / kW. h higher than that of the condensing type steam turbine thermal system version. Under the partial load operating conditions,the calculation results show that the primary and secondary reheat steam flow rates of the back pressure and extraction type steam turbine thermal system is still lower than those of the condensing type steam turbine thermal system and the heat rate of the former is still a bit excessively high.

关 键 词：二次再热 热力系统 锅炉对流受热面设计 给水泵汽轮机 

分 类 号：TM621.4[电气工程—电力系统及自动化]