火电厂大型汽轮机变负荷运行能耗分析与优化

发布时间：2018-03-29 12:16

本文选题：火电厂　切入点：汽轮机　出处：《长沙理工大学》2014年硕士论文

【摘要】：随着国民经济的快速发展和国内用电结构的改变,当前我国电网负荷的峰谷差值越来越大,很多大型汽轮机组也不得不参与电网调峰工作,且参与调峰的时间越来越长,使得机组经常处于变负荷运行工况。汽轮机组变负荷运行时,由于机组的实际运行参数与设计参数不同,导致整个机组的经济性和安全性会明显降低,如何在确保机组安全运行的前提下,提高机组在变负荷工况时的热经济性是我们急需研究的工作。在电厂汽轮机组变负荷运行热经济性的主要影响因素中,唯有机组的运行方式是能够通过人工操作改变的。所以,研究电厂机组在变负荷下各种运行方式对机组的影响具有极其重要的意义。当前电厂汽轮机组变负荷运行时常采用定压运行、滑压运行和复合滑压运行等主要运行方式。论文结合当今火电厂大型汽轮机的现场运行实际,分析了汽轮机变负荷工况下不同运行方式的特点,比较研究了不同变负荷运行方式对机组热经济性和安全性的影响。论文同时以湖南某电厂600 MW汽轮机组为例,通过计算和分析,比较了汽轮机组不同负荷下定压运行和滑压运行的汽耗率、热耗率、绝对电效率、调节级温度、高压缸排汽温度等重要指标。研究证明,复合滑压运行在高负荷区保持定压运行、低负荷下采用滑压运行方式,既可以提高机组的热经济性、降低机组能耗,又能够保证设备的运行安全性、改善整个机组的调峰性能。论文针对汽轮机复合滑压运行的特点,总结了一套汽轮机变负荷运行优化方法。借助汽轮机调节级特性参数,并考虑汽轮机进汽阀门的压力损失,提出了汽轮机复合滑压运行滑压曲线的通用求取方法。在此基础上,进一步通过运行参数的试验寻优,最终得到汽轮机复合滑压运行优化试验曲线。论文还以该电厂600 MW汽轮机为例,通过计算得到了汽轮机复合滑压运行曲线,并将该曲线与制造厂运行曲线进行对比,验证了该方法的正确性,并在曲线参数基础上得到了汽轮机复合滑压运行优化试验曲线。最后,采用工程应用良好的图形化编辑语言LABVIEW为开发环境,编制了汽轮机变负荷运行能耗优化应用软件,以作为汽轮机组变负荷运行优化计算的辅助工具。
[Abstract]:With the rapid development of national economy and the change of domestic power structure, the peak and valley difference of power grid load in our country is increasing, and many large steam turbine units have to participate in the peak-shaving work of power grid, and the time of peak shaving is getting longer and longer. When the turbine unit is running at variable load, the actual operation parameters of the turbine unit are different from the design parameters, so the economy and safety of the whole unit will be obviously reduced. Under the premise of ensuring the safe operation of the unit, it is urgent for us to study how to improve the thermal economy of the unit under variable load conditions. Only the operating mode of the unit can be changed by manual operation. It is of great significance to study the influence of various operation modes of power plant units on the units under variable load. At present, constant pressure operation is often used in the variable load operation of steam turbine units in power plants. The paper analyzes the characteristics of different operation modes of steam turbine under variable load condition in combination with the field operation practice of large steam turbine in thermal power plant, such as sliding pressure operation and compound sliding pressure operation. The effects of different load changing operation modes on thermal economy and safety of generating units are compared and studied. At the same time, taking a 600MW steam turbine unit in a Hunan power plant as an example, the calculation and analysis are carried out. The steam consumption rate, heat consumption rate, absolute electric efficiency, regulating stage temperature, exhaust steam temperature of high pressure cylinder and so on under different loads of steam turbine unit under constant pressure operation and sliding pressure operation are compared. The operation of compound sliding pressure can not only improve the thermal economy of the unit, reduce the energy consumption of the unit, but also ensure the safety of the equipment, while maintaining the constant pressure operation in the high load area and adopting the sliding pressure operation mode under the low load. According to the characteristics of complex sliding pressure operation of steam turbine, this paper summarizes a set of optimization methods for variable load operation of steam turbine. With the help of the characteristic parameters of turbine regulating stage, the pressure loss of steam turbine inlet valve is considered. A general method for calculating the sliding pressure curve of steam turbine complex sliding pressure operation is put forward. On the basis of this, the optimization of the operation parameters is further sought through the test. Finally, the optimal test curve of the complex sliding pressure operation of steam turbine is obtained. Taking the 600 MW steam turbine in the power plant as an example, the complex sliding pressure operation curve of the turbine is calculated and compared with the operation curve of the manufacturer. The correctness of the method is verified, and the optimized test curve of turbine complex sliding pressure operation is obtained on the basis of curve parameters. Finally, the graphical editing language LABVIEW, which is well applied in engineering, is used as the development environment. The application software of energy consumption optimization for steam turbine variable load operation is developed, which can be used as an auxiliary tool for the optimization calculation of steam turbine unit variable load operation.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621

【共引文献】