Precooling Evaporative Condenser's Heat-transfer Mechanism And Experimental Investigation

In modern society, the refrigeration system has been widely used in all departments of national economy and people's daily life. In recent years, under the pressure of shortage of water and power resources in our country, higher demands for energy conversation of the refrigeration system are required, which hasten the attention and the usage of the evaporative condenser. Evaporative condenser has many advantages, such as energy conversation, water-saved, compact structure and small usage of ground area. Although the technology is more advanced, the design of the evaporative condenser in the refrigeration system is lack of enough experimental datum and theoretical guidance.In this paper, using the method that combin theoretical study and experimental validation, basic knowledge of heat transfer theory and experimental correlation of a variety condenser heat transfer coefficient, dividing the precooling evaporative condenser into two parts: finned tube condenser and evaporative condenser, we establish heat transfer mathematical model respectively. After the establishment of mathematical heat transfer model, use experimental studies to validate the established mathematical heat transfer model is correct or not and improve it. Finally, use the heat transfer mathematical model of precooling evaporative condenser to research.the heat transfer mechanism.Experiments show that the relative error of heat transfer quantity of finned tube condenser and actual heat transfer quantity is between 25.15% and 27.51%; the relative error of heat transfer quantity of evaporative condenser and actual heat transfer quantity is between 11.37% and 17.08% . Errors are within the scope of permissible, therefore, the heat transfer model of precooling evaporative condenser is basically right. When we investigate the heat-transfer mechanism of precooling evaporative condenser by using the heat transfer model, we find that: in lower temperature conditions in winter, it can reach a satisfactory cooling effect by just using cooling air when air blower is open and pump is closed.