Experimental Study And Heat Transfer Intensification Of Evaporative Condensers

With the rapid development of China’s economy,the contradiction between the supply and demand of energy and water resources has become increasingly prominent.The development of energy-saving technologies and the reduction of water consumption have gradually become the basic consensus among practitioners in various fields.The evaporative condenser,as a kind of energy and water-saving high-efficiency heat transfer equipment,has been rapidly developed and applied in such an energy background.However,domestic scholars have started their research on it relatively late,and the determination of various optimal working parameters is rather vague,and there is a large space for optimisation of its structure.For these reasons,this paper conducts an experimental study on the coil structure and heat transfer mechanism of evaporative condensers,which is as follows.1.The heat mass transfer process of evaporative condenser is analysed,a mathematical model of heat mass transfer in evaporative cooling unit is established,and the theoretical optimized efficiency of plate-and-tube type coils compared with light tubes is obtained by combining the calculation of fin efficiency,and the deviation of the theoretical optimized efficiency from the actual optimized efficiency is analysed as a possible cause of process limitation.2.A new type of evaporative condenser heat exchanger coil with fin plates is designed and experimentally compared with a common light tube to obtain the optimised heat transfer efficiency.3.Based on the experimental study,the variation curves of heat dissipation,cooling capacity and COP of the coil with spray density and air speed respectively are obtained,the inner mechanism causing the variation is analysed,and the optimum spray density values under achieving some of the objectives are derived.4.A flow-solid heat transfer simulation was carried out for the plate and tube and the light tube,verifying the optimized efficiency of heat transfer between the plate and air under dry conditions compared with the light tube,and analysing the heat transfer characteristics and the flow characteristics of the airflow organisation during the heat transfer between the air and the plate and tube.5.Various problems that arise during the actual operation of evaporative condensers and the corresponding solutions are summarised,and practical structural and system optimisation methods are proposed.