超临界600MW机组除氧器排汽回收对发电煤耗影响的定量研究

Quantitative Study on Influence of Exhaust Steam Recovery of Deaerator on Coal Consumption of Power Generation for Supercritical 600MW unit

以超临界600MW机组为研究对象,利用EBSILON软件建立除氧器排汽回收对机组发电煤耗影响定量分析的模型,在VWO、THA、75%THA和50%THA工况下,不同流量的除氧器排汽不回收和不同回收方式对机组发电煤耗的影响进行定量计算分析。结果表明,除氧器排汽不回收导致机组发电煤耗增加且负荷越低发电煤的增量越高,发电煤耗增量随除氧器排汽量的变化呈线性关系;除氧器排汽回收至低压加热器使机组发电煤耗降低且负荷越低发电煤耗降低量越高,发电煤耗的降低量随排汽回收量的变化同样呈线性关系,除氧器排汽回收至5号低压加热器时机组发电煤耗的降低量最大,回收至8号低压加热器时机组发电煤耗的降低量最小。研究结果可为燃煤机组开展运行优化调整、除氧器排汽回收改造和改造后经济运行提供理论指导。

In this paper,a 600MW supercritical unit is taken as the research object A model of the effect of exhaust steam recovery from deaerator on coal consumption in generating units was developed using the software Quantitative analysis,under VWO,THA,75%THA and 50%THA working conditions,the effects of different exhaust steam recovery modes and exhaust steam recovery flow rate on coal consumption of generating units are quantitatively calculated and analyzed.The results show that,non-recovery of exhaust steam from deaerator leads to increase of coal consumption in generating unit,the lower the load is,the higher the increment of coal consumption is,and the increment of coal consumption is linear with the change of exhaust steam quantity of deaerator;the exhaust steam of deaerator is recovered to the low pressure heater to reduce the coal consumption of generating unit,the lower the load is,the higher the reduction of coal consumption is,and the reduction of coal consumption is also linear with the change of exhaust steam recovery,when the deaerator exhaust steam is recovered to No.5 low-pressure heater,the coal consumption of generating unit is reduced the most,and when the deaerator exhaust steam is recovered to No.8 low-pressure heater,the coal consumption of generating unit is reduced the least.The research results can provide theoretical guidance for coal-fired units to carry out operation optimization adjustment,deaerator exhaust steam recovery transformation and economic operation after transformation.