利用回热系统凝结水供热的新型生物质热电联产系统的性能分析  

Performance analysis of a novel biomass cogeneration system using condensate water of heat regenerative system for heating

作　　者：薛小军[1] 王义函 陈衡[1] 徐钢[1] 雷兢[1] XUE Xiaojun;WANG Yihan;CHEN Heng;XU Gang;LEI Jing(Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学热电生产过程污染物监测与控制北京市重点实验室,北京102206

出　　处：《热力发电》2021年第3期91-97,共7页Thermal Power Generation

基　　金：国家重点研发计划项目(2017YFB0602104);国家自然科学基金项目(51806062)。

摘　　要：在常规生物质热电联产机组中,采用汽轮机抽汽加热热网水。汽水换热过程中,存在较大的㶲损失。为了减小供热系统的㶲损失,本文提出了一种新型生物质热电联产系统。采用回热系统的凝结水代替汽轮机抽汽,利用板式换热器加热热网水。不仅减少机组抽汽,提高机组出功;而且采用水水换热还可提高换热效果。本文以国内某典型35 MW生物质热电联产机组为案例,对其进行了系统改造,并进行了详细的热力学分析和经济性分析。研究表明,新型系统供电标杆单耗降低了18.29 g/(kW·h),综合效率和发电效率分别提高了0.85百分点和1.01百分点。另外,对新型系统经济性分析结果表明,采用改造后的供热系统可以获得很大的经济效益,年化新增净收益可达361.88万元。In conventional biomass cogeneration unit,steam extracted from the turbine is used to heat the supplywater,and there is a great exergy loss in the process of steam-water heat exchanger.To reduce exergy loss of the heating system,a biomass cogeneration system was proposed.In this system,the heating system uses condensate water of the heat regenerative system instead of steam extraction of the turbine,and a plate heat exchanger is used to heat the supply-water.It not only can increase the power put of the unit by reducing the steam extraction,but also can improve the effect of heat transfer via water-water heat exchange.Moreover,a typical 35 MW biomass cogeneration unit is taken as a case to carry out system retrofitting and thermodynamic analysis and economic analysis.The results show that,the power supply pole per unit consumption of the new system reduces by 18.29 g/(kW·h),the comprehensive efficiency and power generation efficiency increases by 0.85 percentage points and 1.01 percentage points,respectively.After the retrofitting,the heating supply system gains large financial benefits,of which the annualized net new income can reach 3.6188 million yuan.

关 键 词：生物质 热电联产机组 供热系统 凝结水 热力学分析 经济性分析 

分 类 号：TM621[电气工程—电力系统及自动化]