摘要
为提高燃煤机组烟气余热和水协同回收系统的节能减排及技术经济性能,保障系统的安全运行,论文建立了系统多参数优化以及变工况特性分析模型,以330MW机组为例,研究获得了系统的优化参数以及节能节水潜力,并依据系统变工况特性提出了系统全工况优化运行的调控策略。基准工况优化计算结果表明:设计工况下的系统综合节水率为15.34kg·s^(-1),系统综合节煤率达4.12g·(kW·h)^(-1)。系统的变工况特性研究表明:烟气余热和水协同回收系统内工质温度和节煤率均随着环境温度的降低而降低,当环境温度降低至-20℃时,烟气余热和水协同回收系统综合节煤率降低38.7%,低温烟气冷却器进口循环水温度降至70℃以下,此时系统运行安全受到威胁。为此,论文提出系统全工况优化运行策略,该策略不仅可以维持低温烟气冷却器进口循环水温度在70℃之上保障系统安全,同时,可以实现烟气冷凝过程余热的有效利用。
To enhance energy saving, emission reduction and economic performance of waste heat and water co-recovery system of boiler exhaust fluegas, and to guarantee the system safe operation, the multi-parameter optimization and off-design characteristics analysis model of the system are developed. With a 330 MW power plant as the reference case, the optimized parameters, water-saving and energy-saving potentials of the system were obtained. According to the off-design characteristics of the system, the control strategy of the system under all operating conditions was proposed. The optimization results of the benchmark conditions show that the comprehensive water saving rate of the system is 15.34 kg·s^(-1), and the comprehensive coal saving rate of the system reaches 4.12 g·(kW·h)^(-1). The research on the system off-design characteristics shows that the working fluid temperature and coal saving rate of the system decrease with the ambient temperature. When the ambient temperature drops to -20℃, the compressive coal saving rate of the system decreases by 38.7%, and the inlet circulating water temperature of the low-temperature fluegas cooler decreases below 70 ℃, threatening the safety of system operation. Therefore, an optimal operation strategy of the system under all working conditions was proposed. This strategy can not only maintain the inlet circulating water temperature of the low-temperature fluegas cooler above 70℃ to ensure the safety of the system, but also realize the effective utilization of the waste heat of the fluegas condensation process.
作者
杨凯旋
封又琳
刘明
严俊杰
YANG Kaixuan;FENG Youlin;LIU Ming;YAN Junjie(State Key Laboratory of Multiphase Flow in Power Engineering(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2021年第13期4566-4575,共10页
Proceedings of the CSEE
基金
国家重点研发计划项目(2018YFB0604303)
国家自然科学基金项目(51776146)。
关键词
燃煤机组
余热回收
水回收
协同回收
多参数优化
运行策略
coal fired power plants
waste heat recovery
water recovery
co-recovery
multi-parameter optimization
operation strategy
