宽负荷工业供汽方案及其热经济性研究

Study on industrial steam supply scheme and its thermal economy for wide load operation

深入研究热电联产机组在宽负荷运行条件下的供热抽汽能力及供热可靠性,并精确掌握电功率-热负荷-标准煤耗的关系特性,是电厂合理开发工业供汽市场并进行精细化管理的关键。本文以国内某亚临界330 MW热电联产机组为研究对象,分析机组在不同负荷区间下的供热抽汽能力及供热可靠性,利用基于EBSILON软件建立的评估模型,计算分析了不同运行工况下的电功率-热负荷-标准煤耗的关系特性。结果表明:基于中压联合汽阀参调的热再抽汽方案是提高热电联产机组宽负荷工业供汽可靠性的有效手段,可极大提升机组供热能力及供热可靠性;不同供汽流量条件下机组标准煤消耗量随发电功率呈线性增加且增加速率基本一致,而不同发电功率条件下机组标准煤消耗量随热再供汽量呈线性增加且增加速率基本一致。为实现热电联产电厂工业供汽盈利能力最大化,建议采用基于标准煤单价、上网电价、调峰补贴政策及机组安全控制等边界条件下的厂级工业供汽优化调度模式。

Deeply studying the heat extraction capacity and heat reliability of the unit under wide load operation condition,and accurately grasping the relationship between and among the electric power,heat load and standard coal consumption is the key for power plants to reasonably develop the industrial steam supply market and carry out refined management.By taking a subcritical 330 MW cogeneration unit in China as the research project,the heat extraction capacity and reliability of the unit in different load ranges are analyzed.Based on the evaluation model established by EBSILON software,the relevant characteristics of power heat load standard coal consumption under different operating conditions are calculated and analyzed.The results show that,the scheme of heat reextraction based on medium pressure combined steam valve is an effective mean to improve the reliability of wide load industrial steam supply for the combined heat and power generation units,which can greatly improve the heating capacity and reliability of the units.The standard coal consumption of the set increases linearly with the generation power and the increase rate is basically the same under different steam supply flow conditions,while the standard coal consumption of the set increases linearly with the heat resupply steam and the increase rate is basically the same under different power conditions.In order to maximize the profitability of industrial steam supply in cogeneration power plants,it is suggested to adopt the optimal operation mode of industrial steam supply under the boundary conditions of standard coal unit price,on-grid price,peak-rush subsidy policy and unit safety control.