Numerical analysis of flow heat transfer characteristics in solar chimneys integrated with seawater desalination

An unsteady-state mathematical model of the heat transfer and flow of the integrated system under no-load condition has been developed. The field distribution characteristics of the pressure, velocity and temperature of the integrated system have been researched. An optimization method based the temperature field distribution at the region where the wind turbine is placed has been proposed. The results show that the relative pressure within the system is negative value everywhere. The relative pressure and temperature are larger, the flowing is slowed down and the temperature distribution is non-uniform at the bottom of the center of the heat collector. The maximum negative pressure appears at the junction between the outlet of collector and the inlet of chimney, thus the place is the ideal region which the wind turbine will be installed. Optimizing the geometric dimensions of the local flow passage, the negative pressure and draft force can be significantly improved, and the speed can also be improved, and the energy loss can be obviously reduced. The flowing characteristics of the airflow in the collector changes little after the optimization of the geometric dimensions, the optimization does not basically affect on the freshwater production in the still.