Study on the performance of indirect air-cooled system influenced by environmental temperature

Abstract

In order to explore the mechanism of the performance of Air-cooled system influenced by environmental temperature, indirect air-cooled towers with surface condensers in power plant were studied in this paper. Through a proper simplification, the geometric models of indirect air-cooled towers and other major buildings around which may affect the fluid flow were established. When it comes to the air-cooled towers, which were located in the central region of flow and heat transfer, the structure type of the towers and the radiators should be clearly presented. Flow resistance and heat transfer characteristics of radiators were correctly and objectively taken into account, the reliability of which was verified by field test. Numerical simulation study on the thermal performance of the indirect air-cooled system with surface condensers was conducted by creating corresponding mathematical and physical models on the condition of designed wind director and velocity. At the same time, the thermal performance of indirect air-cooled towers under different environmental temperature was studied. The results showed that, the volume flow rate of air into the indirect cooling tower under different environmental temperature is basically unchanged. With temperature rising up, the density of air reduces, which leaded to a decrease on the mass flow rate of air into tower. Besides, the trends and changing laws of performance parameters from the level of segments and the tower are achieved. What’s more, the flow traces of air and flue gas in towers were basically similar which were clearly divided by a temperature line, but the two flows always melt into a whole one at the export of towers. The conclusions would be of guide significance to the optimal operation and design of indirect air-cooled system.