低温场景超临界CO_(2)循环燃煤发电系统研究

Study on Supercritical CO_(2) Cycle Coal-fired Power Generation System for Low Temperature Scenario

超临界CO_(2)循环在低温场景下,循环终端温度降低,循环压比增大,可以与燃煤锅炉很好地匹配,组成高效的燃煤发电机组。根据气候和煤炭分布,我国北方煤炭基地(如蒙东、北疆)在冬、春季有长达4个月以上的低温条件,有利于构建高效的超临界CO_(2)燃煤发电机组。对于3~15℃的终温工况,对超临界CO_(2)循环发电机组进行热力计算,并对机组的经济和社会效益作初步分析。结果表明:初始参数620℃/30 MPa的超临界CO_(2)循环发电机组在9℃以下低温场景下,可获得48%以上的全厂净发电效率,高于二次再热超超临界汽轮发电机组。超临界CO_(2)循环燃煤发电可补充可再生能源发电在冬、春季的发电量缺口,并可通过“北电南送”实现北方煤炭资源的高效利用。

Supercritical CO_(2) cycle can be used in the low temperature scenario to reduce the end temperature of the cycle and increase the cycle pressure ratio,which can well match with the coal-fired boiler to form a high-efficiency coal-fired power plant.Considering the climate and coal mine distribution,the coal mine bases in northern China,such as eastern Inner Mongolia and northern Xinjiang,have low atmospheric temperature conditions for more than four months in winter and spring,which is good for the constrution of high-efficiency supercritical CO_(2) coal-fired power plants.For the end temperature condition of 3-15℃,the thermodynamic calculation of supercritical CO_(2) cycle was carried out,and the economic and social benefits of the unit were analyzed.The results show that the supercritical CO_(2) cycle generator with 620℃/30 MPa initial parameters can obtain more than 48%of the net plant power generation efficiency in the low temperature scenario below 9℃,which is expected to surpass the efficiency of double-reheat ultra supercritical steam turbine unit.Supercritical CO_(2) cycle coal-fired power plants can supplement the power generation gap of renewable energy generation in winter and spring,and realize the efficient utilization of coal resources in the north through“North to South Power Transmission”.