摘要
针对某600MW间接空冷机组在高背压供热的基础上利用大型蒸汽射汽器,提出了一种适应调峰运行的四级背压乏汽深度利用系统。有效解决了热电联产机组低负荷乏汽供热能力降低的难题,提高了机组低负荷下的乏汽供热能力。对二级背压乏汽供热系统的供热特性进行了试验研究,分析得出机组背压和循环水温度是影响乏汽利用的关键因素,以汽轮机排汽热损失最小为目标,建立了四级背压乏汽供热系统能耗分析模型。通过能耗分析模型对某600MW机组四级背压乏汽深度利用系统在不同供热时段调峰运行下的性能进行了计算分析。在低负荷段,高压侧的背压受到汽轮机排汽流量的限制,通过循环冷却系统降低低压侧的背压可提高系统能效。不论是与常规的中排供热的方式相比,还是与二级背压乏汽供热相比,四级背压乏汽深度利用系统低负荷下的供热能力明显提升。在对外供热量一样的情况下,四级背压乏汽深度利用系统相比较二级背压乏汽供热,机组的发电出力可降低131MW。
A four stage back pressure depleted steam deep utilization system suitable for peak shaving operation is proposed for a 600MW indirect air-cooled unit,which utilizes a large steam injector on the basis of high back pressure heating.Effectively solving the problem of reducing the low load exhaust steam heating capacity of cogeneration units,and improving the exhaust steam heating capacity of units under low load.Experimental research was conducted on the heating characteristics of a two-stage backpressure exhaust steam heating system,and it was found that the unit backpressure and circulating water temperature are the key factors affecting the utilization of exhaust steam.A four stage backpressure exhaust steam heating system energy consumption analysis model was established with the goal of minimizing the heat loss of steam turbine exhaust.The performance of the four stage back pressure exhaust steam deep utilization system of a 600MW unit under peak shaving operation during different heating periods was calculated and analyzed using an energy consumption analysis model.In the low load section,the back pressure on the high-pressure side is limited by the exhaust flow rate of the turbine.Reducing the back pressure on the low-pressure side through a circulating cooling system can improve system energy efficiency.Whether compared to the conventional exhaust heating method or the second stage back pressure exhaust steam heating method,the heating capacity of the fourth stage back pressure exhaust steam deep utilization system under low load is significantly improved.Compared to the two-stage backpressure exhaust steam heating system,the fourth stage backpressure exhaust steam deep utilization system can reduce the power generation output of the unit by 131MW while meeting the external heating needs.
作者
张良
张攀
ZHANG Liang;ZHANG Pan(Beijing Guodian Shanghaimiao Power Generation Co.,Ltd.,Ordos 016299,China;Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,Beijing 100084,China)
出处
《汽轮机技术》
北大核心
2024年第1期48-52,共5页
Turbine Technology
关键词
热电解耦
蒸汽射汽器
四级背压乏汽供热
thermal-electric decoupling
steam ejector
four-stage back-pressure exhaust steam heating
