Numerical Simulation of Ammonia Phase Change Heat Exchanger Which Used for Composite Air-cooling Circulatory System

Direct air cooling system has some problems. Such as, exhaust steam pressure increased with ambient temperature (dry bulb temperature) rising, furthermore cause the high coal consumption of power supply, heavy pollution, the weak environmental adaptability. To solve above problems, the literature [1] puts forward a new indirect air cooling system. In this system, water cooling steam-condenser is transformed into ammonia phase change heat exchanger whose structure is similar to shell-and-tube heat exchanger. In the tube, ammonia-liquid displaces cooling water of water cooling steam-condenser. Latent heat of ammonia-liquid can improve steam condensation effect. Ammonia phase change heat exchanger is simplified as a single horizontal tube. Simulate ammonia-liquid flowing in it by FLUENT. Shah's heat transfer model for boiling region is used to predict heat transfer coefficient. Compare the predicted with numerical value what calculated by FLUENT. Prove the feasibility of composite air-cooling circulatory system.