Analytical Study And Optimizing Structure Of Cold End Heat Exchangers For The Direct Air-Cooling Unit

The direct air-cooling condense dynamic simulation model was established based on understanding the system composition and heat transfer, with S-A turbulent model, numerical simulation of radiator was took, effect of fin type and ratio of major axis A of the ellipitical tube to its minor axis B respectively on heat-exchange efficiency were analysised, and the concept of the optimal ratio of major axis A of the ellipitical tube to its minor axis B were gave. The characteristics of U-finned tube was analyzed, the physical model of the heat transfer process, Then the relationships of the values of under different frontal wind velocity with the U-finned tube heat transfer were investigated, also the best finned ratio was obtained. Take a 600MW unit as a example, the unit's cold system characteristic curves were drawn, then some relationships with the back pressure, the speed of wind,the temperature and the displacement were analysised, it has great value in guiding operation of direct air-cooled units.