MODELING AND SIMULATION OF COOLING TOWER PERFORMANCE

Abstract

The:design of a cross flow multi cell evaporative cooling tower involves the estunation,,-4 liquid and gas flow through the cell which are difficult to estimate accuratejv The present work deals with parameters other than these which are easy to iedict. The minimum exit water temperature occurring at the fill bottom outer end and the maximum exit water temperature occurring at the fill bottom inner end along with wet bulb temperature and inlet water temperature constitute the complete data set for computing water to air flow ratio and fill performance characteristic (FC). The fill performance characteristic is a single composite non-dimensional parameter involving dimensions of the cell half, configuration of the packing and the water flow rate. It represents the overall potential of packing to cool water and is a sole function of mass flow ratio of water to air for a given design. The model equationbtained relating the heat transfer rate at the interface to th the heat lost by water and e—heat gained by air respectively, being coupled and nonlinear, a numerical scheme based on finite difference technique is employed to solve for the temperature, saturation enthalpy and air humidity over an m x n matrix. Further, the discussion is carried out on effect of other parameters on the design variables thus obtained . It also aims at carrying out sensitivity analysis of parameters like Liquid to Gas mass flow ratio, approach, wet bulb temperature, inlet air temperature etc., on the exit water temperature. With the obtained design variables, the simulation of the performance of existing cooling tower at IFFCO Aonla is carried out by predicting the outlet temperature of water at a given inlet air and water conditions.