直接空冷机组最佳经济背压优化  

Optimization of the optimal economic back pressure for direct air-cooling units

作　　者：梁伟平[1] 张金帅 LIANG Weiping;ZHANG Jinshuai(Department of Automation,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学自动化系,河北保定071003

出　　处：《热力发电》2018年第10期96-102,共7页Thermal Power Generation

摘　　要：针对直接空冷机组运行在非最佳经济背压下煤耗高、经济性下降等问题,通过热力学计算和机理分析,建立了机组出力增量与风机功率增量的数学模型,求取机组出力净增量极大值对应的最佳经济背压。通过变工况计算,建立不同工况段的经济背压表并拟合其函数关系式,根据拟合的机组出力、风机功率与背压的关系曲线,构建背压优化专家系统。同时,针对空冷岛冬季的防冻需求,设计了分段式防冻保护顺序控制逻辑。实际应用结果表明:采用本文提出的空冷岛优化系统后,供电煤耗降低约1.556 g/(kW·h),机组经济效益提高,防冻保护动作灵敏有效。Aimed at solving the problems of high coal consumption and economic efficiency decline occurred in direct air-cooling units running at non-optimal economic back pressure,mathematical models of unit output power increment and fan power increment were established in this article through thermodynamic calculation and mechanism analysis,and the best economic pressure was obtained via calculating the maximum increment of the unit net output.Moreover,through variable condition calculation,the economic back pressure form and its fitting function for different working conditions was built up.The expert system of back pressure optimization was constructed according to the fitting curves of generating force,fan power and back pressure.The sequential control logic of the segmented antifreeze protection was designed to meet the requirements of freezing protection in the air-cooled island in winter.The actual engineering results show that,after the proposed air-cooled island optimization system was applied,the coal consumption for power supply decreased by 1.556 g/(kW·h),indicating the unit economy was improved,and the antifreeze protection action was sensitive and effective.

关 键 词：直接空冷 变工况 经济背压 防冻保护 专家系统 顺序控制 优化 

分 类 号：TM611.1[电气工程—电力系统及自动化]