耦合碳捕集的直接空冷燃煤机组特性分析和背压优化  

Characteristics Analysis and Backpressure Optimization of Direct Air-cooling Coal-fired Power Plants Integrated With Carbon Capture System

作　　者：朱明娟 刘煜东 吴啸[1] 沈炯[1] ZHU Mingjuan;LIU Yudong;WU Xiao;SHEN Jiong(National Engineering Research Center of Power Generation Control and Safety(School of Energy and Environment,Southeast University),Nanjing 210096,Jiangsu Province,China;Huaneng International Power Jiangsu Energy Development Co.,Ltd.,Nanjing 210015,Jiangsu Province,China)

机构地区：[1]大型发电装备安全运行与智能测控国家工程研究中心(东南大学能源与环境学院),江苏省南京市210096 [2]华能国际电力江苏能源开发有限公司,江苏省南京市210015

出　　处：《中国电机工程学报》2023年第14期5471-5482,共12页Proceedings of the CSEE

基　　金：国家自然科学基金项目(面上项目)(51976030);江苏省碳达峰碳中和科技创新–重大科技示范项目(BE2022602)。

摘　　要：配置碳捕集技术将大幅改变直接空冷燃煤机组中汽机–给水和冷端系统的工质与能量分配,导致安全风险和经济损失。为提高耦合碳捕集的直接空冷燃煤机组发电效率,该文建立发电–碳捕集系统的全工况动态机理模型,分析变捕集率条件下子系统状态和整体经济性,揭示出捕集率对背压–发电功率和背压–风机耗功的影响规律,提出以热耗率最小为优化目标,以捕集率、锅炉负荷和环境参数为边界条件的背压优化方法。结果表明:每增大1%的CO_(2)捕集率对应1.06MW发电功率损失和15.2kJ/(kW·h)热耗率增量;背压优化降低了发电热耗约200~260kJ/(kW·h);捕集率为90%时,最优背压低至3.85kPa;高温、大风和高负荷时,捕集率的变化对最优背压影响较大。结果可为空冷燃煤–碳捕集整体系统的变工况高效运行提供决策依据。Carbon capture drastically changes the mass and energy flows in the turbine-feedwater system and cold-end system of the direct air-cooling coal-fired power plant,leading to safety risks and economic losses.In order to improve the efficiency of direct air-cooling coal-fired power plants integrated with carbon capture systems,this paper develops a plant-wide dynamic first-principle model of this integrated system;characteristics of subsystems and the integrated system under variable capture rates are investigated.The influences of the carbon capture rate change on the backpressure-generator power and the backpressure-fan power characteristics are evaluated.A backpressure optimization method with the capture rate,boiler load and environmental parameters as the boundary conditions is proposed to minimize the heat consumption rate.Simulation results show that each 1%increase in capture rate results in a 1.06 MW reduction in power and a 15kJ/(kW·h)increase in heat rate;the backpressure optimization can reduce the heat rate by 200~260kJ/(kW·h);the optimal backpressure is as low as 3.85kPa at 90%capture rate;the optimal back pressure is more sensitive to the change of capture rate at higher air temperature,higher wind speed and higher load conditions.This paper provides insights into a direct air-cooling coal-fired power plants integrated with solvent-based carbon capture system for operators,which facilitates flexible and efficient operation.

关 键 词：直接空冷凝汽器 燃煤机组 化学吸收碳捕集 机理建模 特性分析 背压优化 

分 类 号：TK219[动力工程及工程热物理—动力机械及工程]