330MW冷热电联产机组热经济性分析

Thermal economic analysis of a 330MW extraction-condensing steam unit

某热电厂供热负荷为工业抽汽和民用采暖。在非采暖季节,热电厂的热负荷减小,使得机组煤耗增加,同时造成民用供热网管闲置。对此,将原供热机组改为冷热电联产机组。改后计算结果表明:当电动式制冷机制冷系数<3.5时,冷热电联产节能效益显著;当电动式制冷机制冷系数>4时,冷热电联产在低热电比下经济性变差。建议采用提高溴冷机热力系数或减小工业抽汽负荷、增加制冷负荷的方法,提高冷热电联产机组的经济效益。

Heating load of a thermal power plant is used for industrial extraction steam heating and civil heat supply.During the non-heating season,the heating load of thermal power plant reduces,resulting in an increase in unit coal consumption and waste of civil heating network.Therefore,the original heat and power cogeneration unit was transformed into combined cooling heating and power（CCHP）unit.Calculation after the retrofitting shows that：energy-saving benefit of the CCHP unit was obvious when the electric refrigerator refrigeration coefficient was less than 3.5;while thermal economy of the CCHP unit under low thermal electricity ratio decreased when the electric refrigerator refrigeration coefficient was larger than 4.So,ways of improving the thermal coefficient of lithium bromide-water refrigerator,reducing industrial extraction steam load and increasing cooling load were suggested to be adopted to improve the economic benefits of the CCHP system.