Experimental Study On Heat And Mass Transfer Of Horizontal Oval Tube Evaporative Condenser

The increasing shortage of energy and water resources has seriously affected the normal operation of high-energy-consumption and high-water-consuming industries such as power plants,chemical industries,and metallurgy,which in turn has constrained China's economic development;Under the background of vigorously building a conservation-minded society in our country,it is imperative to find a highly efficient and energy-saving heat exchange equipment.The evaporative condenser has the advantages of energy saving,water saving,and compact structure due to its use of indirect evaporative cooling technology.Its application prospects are very broad.In this paper,the heat and mass transfer performance of the evaporative condenser is studied with the aid of theoretical analysis and experimental research.The main work and research contents are as follows:(1)The test bench for the heat and mass transfer of the evaporative condenser is set up.The effects of spray density,oncoming wind speed,ambient temperature and humidity on the heat and mass transfer performance of an evaporative condenser were studied.Under the given experimental conditions,the optimum spray density is 0.125 kg/(ms),and the optimal on-stream wind speed is 3.91m/s.The influence of the wet bulb temperature on the heat transfer performance of the evaporative condenser is greater than the relative humidity.The effects of the difference between the inlet steam flow rate,the steam saturation temperature,the steam temperature and the average wall temperature on the average condensation heat transfer coefficient in the pipe were studied.The increase of inlet steam flow rate and saturation temperature promotes the average condensation heat transfer coefficient in the pipe.In the above two operating conditions,the average condensation heat transfer coefficient increased by 61.27% and 80.95%,respectively.The increase in the difference between steam and pipe wall temperature hinders the average condensation heat transfer coefficient,In the range of heat transfer temperature difference,the average condensation heat transfer coefficient decreased by 27.25%.(2)The empirical correlation of the average condensation heat transfer coefficient in the tube,the empirical correlation of wall-water film heat transfer coefficients and the water film-air mass transfer coefficients are obtained by the regression fitting of the experimental data by the least square method.The correlation formula is compared with those obtained by other scholars.