300MW汽轮机变负荷运行热经济性及安全性研究

Safety and Thermal Economic Analysis on Variable Load Operation of 300MW Steam Turbine

能源结构的变化要求火电机组担任电网调峰,消纳新能源等任务,需要长期处于变负荷的运行状态。汽轮机变负荷运行包括滑压运行和定压运行两种方式,不同运行方式下的机组变负荷热经济性和安全性不同。以某电厂300MW汽轮机组为例,首先比较了变负荷下两种运行方式的汽耗率、热耗率、绝对电效率等参数的变化规律,进而说明不同运行方式下的热经济性问题。随后,为了讨论不同运行方式下的机组安全性问题,还比较并分析了变负荷下两种运行方式的调节级温度和高压缸排汽温度等指标。研究结果表明,某些负荷下机组采用滑压运行,既能够提高经济性,降低机组能耗,又能够保证机组变负荷下运行的安全性。

With the changing of the energy structure, thermal power units are required to undertake tasks of peaking demand of power grid and the absorption of new energy resources. There are two kinds of operation model, sliding pressure model and constant pressure model, under variable load operation, and the thermal economic and safety are different under these two operation models. Taking an 300MW steam turbine of a certain power plant as an example, this paper compared the steam rate, hear rate and absolute electrical efficiency of the two operation models under load changing, and the thermal economic analysis of the two operation types was made. Then, in order to discuss the safety problem of these two operation models, this paper compared the temperature of governing stage and exhaust temperature of high pressure cylinder under variable load operation. The results showed that adopting sliding pressure model, not only the thermal economic would be increased, but also the operation safety would be guaranteed under certain loads.