The Simulation Of Coil Heat Exchanger In Solar-powered Water Heater System

Environmental protection,energy saving,economic,and security in one of the green and efficient energy equipment,solar water heaters is the most mature,most widely used and the fastest growing industrial areas in solar energy utilization technology.At the same time, heat exchanger,as the internal core component of solar water heater,there is a revolutionary significance in optimizing it for energy conservation in the now of increasing scarcity of energy. Coil heat exchanger is a heat transfer equipment which has been widely used in the petrochemical industry.It has an important role to optimize the design of the coil size and heat transfer parameters in improving heat transfer efficiency and optimizing the heat exchanger.It brokes through the previous limitations of which focused on the computing of mathematical theory model in analysis of the heat exchanger. With appropriate simplification, dimensional finite element model of coil heat exchanger,including pressure tank and coils has been established.On this basis,the temperature distribution inside of Heat exchanger and the factors of the results of heat exchanger has been analyzed.Three key factors, snake pipe materials, coiled diameter and pitch has been chosen, to analyze the process and results of heat exchanger under different conditions,to verify the best design of coil heat exchangerThe temperature distribution inside the coil heat exchanger has got though temperature field analysis.The near the location of inlet and outlet is lower relatively,the water temperature around coil particular away from the tank inlet and outlet is higher almost more than 60°C.Most of the water temperature inside the water tank has been more than 40°C,low only around the tank wall,between in the 35-40°C. Temperature inside the water tank has met the basic requirements of hot water.Some results show through the analysis of heat exchanger with different structures.First, taking into account the cost of production and production processes and other factors, stainless steel coil heat exchanger is more effective than a brass or aluminum one.Second, within a certain range, the coiled diameter increase, the water temperature but lower,beyond that the water temperature increase with the diameter. Heat transfer efficiency and layout of the structure production costs,and many other factors should be considered before the coils diameter is determined.Third,the water temperature increases with the coiled pitch.However,the increase of water temperature is significantly reduced.A convenient method for optimal design of the the heat exchanger result has been found through the the finite element simulation on coil heat exchanger,which has a certain reference value for optimal design of heat exchanger.