【摘要】 为缓解目前县级城市供热量不足与供电量过剩的矛盾,基于等效焓降法模型并采用Thermoflow建模分析,计算和探讨了将现役50 MW燃煤机组的蒸汽参数提高到12 MPa/625℃高参数的可行性及机组纯凝发电与热电联产的主要经济指标,并与现役50 MW(8. 82 MPa/535℃)、600MW亚临界(16. 7 MPa/538℃/538℃)以及1 000 MW超超临界机组(25 MPa/600℃/600℃)的经济指标进行了比较。以华北某供热面积为250万m2的县城为例,比较了采用小容量高蒸汽参数背压机组近距离供热与1 000 MW机组远距离供热的经济性。结果表明:设计小容量高蒸汽参数机组的思路可行,机组纯凝运行时的热指标远远优于现役50 MW机组,与亚临界600 MW机组相当,并高于超超临界1 000 MW机组50%以下负荷时的经济指标。采暖期小容量高蒸汽参数背压机组供热煤耗率比1 000 MW机组高1. 857 kg/GJ,高5%,但综合供热管道散热损失、铺设费用及循环水泵电耗等,供热经济性明显优于1 000 MW机组。更多还原

【Abstract】 In order to alleviate the contradiction between insufficient heat supply and excess power supply in current county-level cities,and based on the equivalent enthalpy drop model and adopting thermoflow modeling analysis,the feasibility of increasing the steam conditions of 50 MW coal-fired units in service to 12 MPa/625℃ and the main economic indexes of pure condensing power generation and cogeneration of units were calculated and explored. The economic indexes were compared with those of 50 MW(8. 82 MPa/535℃),subcritical 600 MW(16. 7 MPa/538℃/538℃) and ultra-supercritical 1 000 MW units(25 MPa/600℃/600℃). Taking a county town with a heating area of 2. 5 million m~2 in north China for an example,the economy of using small capacity and high steam conditions back pressure unit for short distance heating and 1 000 MW unit for long distance heating is compared. The results show that: the idea of designing a small capacity and high steam condition unit is feasible,the thermal index of the unit during pure condensing operation is much better than that of the 50 MW unit in service,which is equivalentto that of the subcritical 600 MW unit and is higher than that of the ultra-supercritical 1 000 MW unit under 50% load. During the heating period,the coal consumption rate for heating of the back pressure unit with small capacity and high steam conditions is 1. 857 kg/GJ higher than that of the 1 000 MW unit,which is 5% higher,however,the economy of heating is obviously better than that of the 1 000 MW unit due to the heat dissipation loss of the heating pipeline,the laying cost and the power consumption of the circulating pump,etc.更多还原