1000MW超临界二氧化碳燃煤机组锅炉设计研究

Study on 1000MW Coal-Fired Unit Boiler Design for Supercritical Carbon Dioxide

超临界二氧化碳(S-CO2)燃煤发电技术被认为是未来火力发电领域非常有潜力的方案之一.针对1000MW的30.70 MPa/606℃/604℃超临界二氧化碳机组,进行S-CO2锅炉燃烧热力计算方法研究,重点改进了S-CO2锅炉炉膛分段计算方法,并利用该方法提出了S-CO2锅炉及动力循环设计方案,实现锅炉效率94.54%,发电标准煤耗252.65 g/(kW·h).将该锅炉与同等级常规燃煤锅炉比较,除末级旁路受热面外的其余受热面工质进出口温度均大于常规锅炉;由于循环效率的提高,S-CO2锅炉的总换热量比常规锅炉低273MWth,其换热量分布由辐射换热向对流换热转移;S-CO2锅炉除炉膛外其余受热面出口烟气温度均高于常规锅炉;S-CO2锅炉辐射受热面换热面积略增,高温对流受热面换热面积减小,低温对流受热面换热面积增加,总换热面积增加了44%.

The supercritical CO2(S-CO2)coal-fired power generation technology is considered as one of the most promising solutions in the field of thermal power generation in the future.In this paper,a 1000MW 30.70MPa/606℃/604℃S-CO2 unit is taken as an example,and the thermodynamic calculation methods for S-CO2 boilers are studied.In partcular,the calculation method for the S-CO2 boiler based on the section division of furnace is improved,with which a design scheme for the S-CO2 boiler and power cycle is put forward,achieving a boiler efficiency of 94.54%and a coal consumption rate of 252.65 g/(kW·h).Compared with those of the conventional boiler of the same level,the inlet and outlet temperatures of heating surfaces(except FBH)in the S-CO2 boiler are all higher.Owing to the increase in cyclic efficiency,the total heat absorption of the S-CO2 boiler is 273MWth lower than that of the conventional boiler,and its heat transfer distribution changes from radiation heat transfer to convection heat transfer.The temperature of flue gas at the outlet of heating surfaces except the furnace is higher than that of the conventional boiler.The heat transfer area of radiation heating surface slightly increases,the heat transfer area of high-temperature convection heating surface decreases,the heat transfer area of low-temperature convection heating surface increases,and the total heat transfer area increases by 44%.