提升大型火电机组出力应对电网峰值负荷的分析

Discussion on Increasing Thermal Power Unit Output to Meet the Power Grid Peak Load

针对大型火电机组调峰问题,提出一种通过解列高压加热器、增加机组发电功率以应对电网短时峰值负荷的调峰方式。以典型600 MW等级燃煤汽轮发电机组为例,基于热力平衡原理,计算分析解列高压加热器以快速提升机组发电功率的技术、经济与安全性。计算结果表明:最高级高压加热器解列后,汽轮机蒸汽流通量加大,发电机组输出功率增加,机组净效率下降,供电标准煤耗增加。此种调峰方式锅炉输出的蒸汽流量与参数不变,不影响锅炉工质承压管道的安全;但燃煤量增加,增加了结渣风险,且要求减温水调节有一定的裕度。与采用备用机组等其他传统调峰比较,虽然短时降低了机组的经济性,但具有无需设备改造、负荷提升迅速、减少电网储备容量,节约电站建设投资等优点。

It is proposed a way to deal with short-term peak load of the power grid through splitting a high pressure regenerative feed-water heater to increase the output of the thermal power unit. Taking a typical 600 MW coal-fired power plant as an example, the computation and analysis of the technical and economical efficiency and safety of splitting a high pressure regenerative feed-water heater are made, which can quickly increase the output of the pow- er unit based on thermodynamic equilibrium theory. The result shows that with the liquidity of the steam turbine in- creasing, output of generator increases, the net efficiency of the unit fells, and standard coal consumption increa- ses after splitting the first high pressure regenerative feed-water heater. Boiler steam flow and output parameters are unchanged, so the safety of the boiler pressure pipeline is not affected. The risk of slagging increases because of the coal combustion increasing, and it also requires the attemperation water having some margin. Compared with the use of other conventional peaking units, such as backup units, although it reduces the economical efficiency of units in short time, yet has advantages of no equipment modification, increasing load quickly, reducing power re- serve capacity, saving power plant construction investment and so on.