Numerical Simulation Of Heat Transfer Performance And Structural Optimization For Dual-function Solar Collector

As an economic and convenient heat exchange equipment,the solar flat plate collector has been widely used in daily life and production.The dual-function solar collector combines the functions of collecting hot water and collecting hot air,which can not only provide domestic hot water,but also provide heating air for heating in the heating seasons,which can significantly improve the utilization efficiency of the solar collector.In this paper,the numerical simulation method is used to analyze the heat transfer performance of the flat plate collector under the hot-air mode,hot-water mode and dualeffect mode,The influence of key parameters on the heat transfer performance of the flat plate collector under three working modes is studied.And to optimize the structure of the flat plate collector,L-shaped parallel fins are added on the heat absorption plate and then baffles are added on these fins,these fins can strengthen the heat transfer of the heat absorbing plate to the air.Numerical simulations are carried to study influences of the air efficiency and the hot water efficiency after optimization,according to the simulation results,the heat transfer performance of each model is comprehensively compared.Finally,in order to optimize the flow curve of air in the channel and the options of inlet and outlet are changed,the heat transfer performance before and after the change is analyzed.The results show that: in the hot air mode,the heat loss of the glass cover plate is the highest;in the hot water mode,the high temperature area distribution of the plate is Vshaped,and the heat loss of the glass cover plate and the absorbed heat plate temperature is significantly lower than that in the hot air mode;in the dual-effect mode,the average temperature of the absorbed heat plate is lower than that in the hot air mode and the hot water mode.The total heat collection efficiency of the collector is the highest and the heat loss is the smallest.The instantaneous heat collection efficiency of air is 6.58%,the instantaneous heat collection efficiency of water is 68.94%,and the total instantaneous heat collection efficiency is 75.52%.In single mode,with the increase of air and water mass flow rate,the heat collection efficiency increases.In dual-effect mode,the instantaneous heat collection efficiency of water and air in the collector is constrained by each other.With the increase of the inlet temperature of the air and water,the heat transfer efficiency of the collector is decreasing,and the instantaneous heat transfer efficiency of water and air in the collector is constrained by each other too.With the increase of the light transmittance of the glass cover plate,the solar radiation from the glass cover plate to the heat absorption plate increases,and the heat collection efficiency of the collector increases under the three working modes.With the increase of the thickness of the air layer,the heat loss of the glass cover plate decreases continuously.Under the three working modes,the heat collection efficiency of the collector increases.Under the same conditions,compared with the flat dual-effect collector,the heat collection efficiency of the L-type parallel fin collector is improved in the heat air mode,the hot water mode and the double effect mode.Changing the height of the fins,the heat collection efficiency in the heat air mode increases with the increase of the fin height,the heat collection efficiency in the hot water mode decreases with the increase of the fin height,and In the dual-effect mode,the total heat collection efficiency increases first and then decreases with the increase of the fin height.When the fin height is 18 mm,the heat collection air efficiency is the highest,and when the fin height is 15 mm,the total heat collection efficiency is the highest.Compared with the L-type parallel fin collector,the parallel fin with baffles collector improves the heat collection efficiency in the mode of collecting hot air and water,and decreases the heat collection efficiency in the mode of collecting dual-effect.After changing the option of inlet and outlet,the dead zone of air flow can be effectively improved,the utilization efficiency of the heat absorbing plate is increased,and the heat collecting efficiency of several models is improved.Figure [56] table [2] reference [47]...