Numerical Investigation Of The Heat Transfer And Fluid Flow Of Finned-tube And The Flow Characteristics Of A Condenser Unit In Direct Air-cooled Power Plant

The air-side heat transfer and fluid flow of double rows rectangular finned elliptical tubes and single row flat wave-finned tube are investigated numerically. The air velocity and temperature distributions on the surface of these two kinds of fins are obtained at different flow velocities. And the results indicate that the air-side heat transfer and flow characteristic of single row flat wave-finned tube is greater than double rows rectangular finned elliptical tubes.The parameters including fin spacing and fin height that influence single row flat wave-finned tube are optimized. The j to f factor ratio reaches maximum when fin spacing is 4.5 mm and fin height is 11 mm respectively when other geometry structure parameter are given.The flow characteristics of a condenser unit in direct air-cooled power plant which are influenced by crosswind velocity, platform height, environment temperature, windbreak height and the angle of incident flow are analyzed numerically. The results indicate that the crosswind velocity and environment temperature increasing depress the mass flow rate through the radiator, and also decrease the mass flow rate of fan; and the effect of platform height is slight; the suction capacity of fan is improved with the windbreak downward continuation, and the effect is so slight when windbreak upward continuation; and there is a great impact on the flow characteristic when the angle of incident flow is changed, the mass flow rate of fan increase with the angle raise.The current results can not only provide instructions for the design and optimization of the finned-tubes, but also serve as the reference for designing and operation of direct air-cooled condenser.