利用烟气余热加热凝结水方案

Scheme of heating condensation water using waste heat of flue gas

利用烟气余热加热器凝结水可降低电厂煤耗,提高发电效率。为探索此种余热利用形式的最佳方案,研究进入余热利用换热器凝结水温度、流量对机组功率增加的影响,对某燃煤机组利用烟气余热加热凝结水的4种改造方案进行分析对比,指出最佳方案应充分利用烟气允许温降条件下的所有余热,合理调节进入余热利用换热器的凝结水流量与温度,尽可能节约高品质的抽汽。对于最佳方案,通过计算可得到进余热利用换热器的最佳凝结水流量及温度。研究方法可为以后工程的烟气余热利用优化设计提供指导。

The scheme of heating condensation water using waste heat of flue gas could reduce coal consumption and increase generating efficiency of power plant. In order to get the best scheme of this waste heat utilization form,this paper studied the influences of temperature and flow rate of condensation water that entering waste heat utilization exchanger on the unit power increase,and made a contrastive analysis of four different transformation schemes for a certain coal-fired power unit. It was pointed out that the best scheme should take full advantage of waste heat under the allowed temperature drop of flue gas,properly adjust the temperature and flow rate of condensation water,and save the high quality extraction steam as much as possible. For the best scheme,the optimal temperature and flow rate of condensation water could be obtained through calculation. The study method in this paper could provide guidance for future engineering optimization design of waste heat utilization of flue gas.