Operation Optimization And Practice Of Direct Air-cooling System In A135MW Coal-fired Circulating Fluidized Bed Power Plant

The direct air cooling system of power generation unit has been widely used in the area with rich coal but inadequate water. The direct air cooling system has significant influence on the thermal economic performance of the generation unit. Therefore, many researchers have paid more attention and the corresponding achievement has been obtained.In this thesis, the flow field of a direct air-cooling system is simulated by considering the surrounding environmental conditions. Based on the simulated results of varying degrees of fouling on finned tubes and the actual situation of the factory in Shanxi International Electricity Co., about three times of washing the surface is required for the surface of the direct air-cooled condenser. Moreover, windbreak, downward extended wind wall, air intake, and increased wind deflector wall height will helpful for the low vacuum operation problem when the high-temperature summer is coming. The spray humidification system was suggested to reduce the inlet air temperature of direct air cooling condenser, which can increase the output of the unit in hot summer.Following the above investigation, a mathematical model for improving fan operation was proposed by considering its effect on the performance of the direct air cooling unit and power consumption. Then, this model was coded and applied into a135MW unit on the circulating fluidized-bed boiler and reasonable results are achieved.