Heat Transfer Characteristics And Operation Optimization Of660MW Direct Air-cooled Condenser

Direct air-cooled condenser used ambient air to condense exhaust steam, the cooling air was provided by the large-diameter axial fan, the operating conditions of air cooling fan had a huge impact on condenser. Different operating way of the air cooling fan would directly affect the plant power consumption, the unit output, and the unit standard coal consumption rate. Therefore, with the changing of unit working conditions and environmental parameters, the air cooling fan operation mode would be regulated flexibly. The fan ran in the optimal mode under different environment conditions, to ensure the safe and economic operation of air-cooled units.In this paper, power plant air cooling system was described in detail. Through the analysis of condenser heat transfer model and calculation of the exhaust pressure, studied the influence law of exhaust heat load, air-cooled unit inlet air temperature and face air velocity on condenser pressure, got the variable conditions characteristic of air-cooled condenser. Meanwhile discussed the operation characteristics of air cooling fan, and took a660MW direct air cooling units as an example, calculated and analyzed the impact of different operation modes of fan on the condenser pressure.The air-cooled island optimized running test was made for a660MW direct air cooling units. Under different unit load and ambient temperature, by changing the frequency of air cooling fan, got the exhaust pressure, the unit output, air-cooled island power consumption and unit net power under different fan running ways. Through comparison and analysis, optimal fan operation mode and the best control unit backpressure under different conditions were obtained. The result could provide a reference for economic operation of air cooling fan under different environment parameters and unit load.