Structure Optimization And Simulation Of Spoiler Type Solar Flat Air Collector

Flat panel solar air col lector has the advantages of simple structure,low cost,easy storage,installat ion and maintenance,etc.its installation volume in China is growing rapidly year by year,widely used in the drying of agricultural and sideline products and other fields.It is the core equipment of solar drying system,and its heat collection efficiency directly affects the quality of drying products and the operation cost of drying system.Therefore,the solar panel air collector It is of great significance to study the efficiency of gas collector.The internal structure of plate solar air col lector has an important influence on its heat transfer performance.In this paper,a kind of plate solar air col lector is designed.By adding a spoiler inside the collector to form a serpentine gas channel,the gas flow into the col lector is disturbed,and the convective heat transfer between the gas and the heat absorbing plate is increased to improve the efficiency of the col lector.The number and length of spoilers in the col lector cavity have different effects on the flow field and temperature field of internal gas.In order to explore the optimal length and number of spoilers,the following experimental research and simulation analysis are carried out:The performance test system of flat solar air col lector is built to test.The factors and levels in the test process are as follows:the wind speed of blower is 0.5m/s,2.5m/s and 4.5m/s;the number of col lector spoilers is 4,6,8 and 10;the length of col lector spoilers is 50.5cm,60.5cm and 70.5cm.Analysis of the test data shows that when the wind speed is 4.5m/s,the number of spoilers is 4 and the length is 50.5cm,the efficiency of the col lector is the highest.From the overall test data,when the number of spoi lers is 4,the test results show that the efficiency is higher than other numbers of spoilers;when the number is fixed,the optimal length of spoilers is 50.5cm;different wind speed of fans has a greater impact on the efficiency of collectors,and the optimal wind speed of fans should be 4.5m/s.Based on CFD(fluid mechanics calculation)theory and COMSOL multi physics,the heat transfer model of flat solar air col lector is established,and the fluid flow field and temperature field in the col lector are analyzed.It is found that increasing the length and number of spoilers has a certain loss on the gas flow through the collector,so the more the number of spoilers in the first place,the lower the heat transfer performance of the col lector when the length is longer.The optimization scheme is put forward:the spoiler with smooth surface is perforated to dredge the air flow gathered locally in the channel.It is found that the temperature field in the flat plate col lector is more evenly distributed in the flow field,and the gas flow rate and temperature at the out let of the col lector are obviously improved,which proves the feasibility of the optimization scheme.