Mathematical modeling of closed cooling tower and investigation of the effect of important operating parameters on tower performance
Volume Title: 1
1Shiraz University of thechnology
2Shiraz university of Technology Shiraz/Iran
The purpose of this paper is the mathematical modeling of closed cooling towers and the effect of important operational parameters on its performance. To achieve this goal, the governing equations of the system were obtained using mass and energy conservation laws. Then these equations are solved using the quadratic Rang-Kutta numerical method. To evaluate the model, the results of the modeling were compared with the laboratory data available in the literature. Comparison of the results showed that there is good agreement between them. Also, the effect of various operating parameters such as cooled water temperature, spray water temperature, air temperature and air humidity on the tower performance was investigated. Also, the effect of evaporation or non-evaporation of spray water on the outlet water temperature was investigated. The modeling results showed that the outlet water temperature decreased from top to bottom of the tower. The sprayed water temperature is the same at the beginning and end of the tower but varies throughout the tower. The air temperature decreases along with the tower (from the bottom to the top of the tower) but the enthalpy of the air increases due to the increase in absolute humidity. The results also showed that the outlet water temperature increased with increasing humid air temperature. It was also found that spray water evaporation had little effect on tower performance.
Closed cooling tower; counter current flow; Mathematical modeling; heat and mass transfer; tower performance