1000 MW超超临界机组烟风系统余热利用的研究

Research on Waste Heat Utilization of Flue Gas Systemin 1000 MW Ultra Supercritical Unit

对于大型燃煤火力发电厂,在火力发电的生产过程中,煤炭燃烧过程产生的大量热能,约有60%的热能以凝汽器冷源热损失、锅炉排烟热损失等形式被浪费掉。其中锅炉排烟热损失是电站锅炉运行中最重要的一项热损失,占锅炉热损失的50%以上。通过在超超临界锅炉尾部烟道的不同位置设置低温省煤器并基于能量梯级利用原则来回收利用烟气余热,并对2种可能的余热回收方案进行了热经济性计算以及分析。结果表明:2种方案的余热综合利用均有良好的经济性,且方案1优于方案2。

For large coal-fired thermal power plants,during the thermal power generation process,about 60%of the thermal energy generated by the coal combustion process is wasted in the form of condenser cold source heat loss and boiler flue gas heat loss.Among them,the boiler flue gas heat loss is the most important one in the operation of power station boilers,accounting for more than 50%of the boiler heat loss.In this paper,low-temperature economizers are installed at different positions in the flue gas tail pass of the ultra-supercritical boiler,and the waste heat of the flue gas is recycled based on the principle of energy cascade utilization.Two waste heat recovery schemes are calculated for thermal economy and exergy analysis.The results show that the comprehensive utilization of the waste heat of the two schemes has good economy,and the scheme 1 is better than the scheme 2.