The Experimental And Simulation Analysis Of Evaporative Cooler

Evaporative coolers are used more and more widely such as in chemical,petroleum and metallurgical industry due to its energy-conserving and environmentally friendly characteristics.Because of the complexity of the heat tranfer process which many factors affect,the energy and water consumption is still high.This paper investigates its performance by experimental investigation,mathmatical model and CFD simulation which is presented as following:(1)An middle size industrial evaporative cooler experimental stage was established and the effects of flow mass rate and deluge water mass flow rate was investigated.The results show that the latent heat is almost 80%of the total heat transfer rate,and the empirical formulas for water film heat transfer coefficient and air-water mass transfer coefficient were derived;(2)Based on fundamental principle and Poppe assumption,both one dimension and two dimension models of evaporative cooler were derived,which the simplified model bases on.By applying the enthalpy linear assumption,The NTU model was also derived;The simulation code was programmed on Matlab and the simulation results were compared with experimental data to verify the mathematical model.The simulation results show that all of those models can predict the working substance outlet temperature and heat mass transfer rate correctly.Except the simplified model which has large errors in small deluge water mass flow rate,the others calculation results of outlet air parameters agree well with experimental data.Those parameters distribution along verical and its length directions were investigated by one-dimension and two-dimension Poppe models.The distribution of sensitive and latant heat transfer rate were also analyzed.(3)The evaporative cooler performance was investigated by using ANSYS FLUENT while the Specise Transport model and Eularian Wall Film model were aplied.Leting empirical formula of heat transfer coefficient equals Lewis modified formula,the thermal conductivity formula was derived.The flow field,temperature field and moisture content field was studied.The parameters distibution along the same tube rows and the effect of clearance between tube bundles was analyzed.