Performance improvement of natural draft dry cooling system by interior and exterior windbreaker configurations

摘要

Ambient winds are basically unfavorable to the thermo-flow performances of natural draft dry cooling system, and may result in a reduced thermal efficiency for the power generating unit in power plants, so it is of benefit to the natural draft dry cooling system to propose the measures against the adverse effects of ambient winds. For a typical natural draft dry cooling system, the computational models of the flow and heat transfer of cooling air coupled with the energy balances of circulating water and exhaust steam are developed, by which the performance improvement due to the interior and exterior windbreaker configurations is investigated. The flow and temperature fields of cooling air, the flow rate and heat rejection of each sector, the outlet water temperature of heat exchanger for the natural draft dry cooling systems with and without windbreaker configurations, and the corresponding turbine back pressures are obtained. The results show that the exterior windbreakers are superior to the interior ones in thermo-flow performances. The turbine back pressure can be reduced by the windbreaker configurations in the presence of ambient winds, especially at high wind speeds.