Abstract: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.

Keywords:waste heat of flue gas, condensation water, heat exchanger, coal consumption, extraction steam