Numerical Study On Spray Cooling Heat Transfer Of Ethanol Water

Spray cooling is a cooling technology with a relatively good cooling effect.It can meet the heat dissipation requirements of high-power electronic devices and has a promising application prospect.However,the various parameters of the spray process are coupled to each other,and they are not fully understood,so they need to be studied.This paper is to use computational fluid dynamics to study the spray cooling heat transfer characteristics and influencing factors.In this paper,based on CFD commercial software,the spray cooling calculation model is established using Euler-Lagrangian method,the spray cooling heat transfer process using ethanol water and pure water as working medium is simulated,and this phenomenon is studied as follows:(1)The steady-state calculation model of spray cooling was established,including continuous-phase model,turbulent model,discrete-phase model and attached-wall liquid film model.After verifying the mesh independence,the numerical calculation results are compared with the experimental results under the corresponding working conditions,and the reliability of the numerical model is proved.The overall distribution characteristics were analyzed,including the calculation of domain velocity distribution characteristics,water mole fraction characteristics,wall temperature characteristics,and liquid film thickness characteristics.(2)The numerical simulations of spray cooling heat transfer with pure water and 4% aqueous ethanol as working fluids were carried out.By changing the effects such as spray pressure and spray height,the effects of spray parameters on wall temperature,liquid film thickness,liquid film velocity,heat transfer coefficient,etc.,were studied.By changing the heat flux,the characteristics of spray cooling in the low temperature zone and the nucleate boiling zone can be compared and analyzed.By using the x-direction feature map instead of the cloud map,the steady-state results under different conditions are compared and the reasons are analyzed,and the reasons for the characteristics change of the low-temperature zone and the nuclear boiling zone are obtained,The operating conditions for changing the spray height,spray pressure,spray angle,and wall area under two working fluids were calculated,and a series of data were obtained.The research was conducted using the method of studying the spray cooling heat transfer phenomenon of ethanol working fluid.Finally,through the comparison of the heat transfer coefficients of each working condition,the analysis results of the parameters of spray cooling heat transfer were obtained.