Numerical analysis on performance of mechanical draft wet cooling towers based on the condensation plume module

Abstract

To illustrate the characteristics of the mechanical draft wet cooling tower (MDWCT) with the condensation plume module, a 3D numerical model is employed. The two cases, plume abatement with water saving and non-plume-abatement with non-water-saving, are compared, and the analyzed parameters include the ventilation rate, plume generation, water saving rate, and cooling characteristic. Results that the plume abatement and water saving for MDWCT are achieved at the cost by reducing thermal performance, and the outlet water temperature is raised by 1℃ compared with the non-plume-abatement with the non-water-saving condition. For plume abatement with water saving conditions, the air temperature and moisture content in the MDWCT will be reduced twice to achieve plume abatement and water saving. When the inlet water temperature is much higher than the ambient temperature, the plume abatement has become very difficult. The water saving rate is improved as the relative humidity, inlet water temperature and flow rate add, while that is reduced with the ambient air temperature adds. By adjusting the operating parameters, the water saving rate can be reduced to a minimum of 1.35 % and increased to a maximum of 14.95 %.