Analysis Of Thermal Performance Of Building Component Louvered Solar Collector

With the continuous innovation of energy technology,renewable energy has gradually become the focus of energy research around the world.my country has a large land area base and sufficient solar energy resources are available for use,which has a unique advantage for my country’s research on solar energy technology.At present,human beings mainly realize the utilization of solar energy resources through the following four types of technologies:solar photochemical utilization,solar thermal utilization,solar bio-utilization,and solar power generation.Solar thermal utilization technology.Among them,the solar thermal conversion technology has been developed extremely mature at home and abroad,and has been developed relying on industrialization.my country’s solar collector industry has developed extremely rapidly in the past two decades,and the domestic assembly line production of solar collectors is very competitive in the international market.The integrated installation of solar collectors with buildings is of great significance in the field of building energy conservation.The louver-type solar collector is essentially a flat-plate collector,but the louver-type collector divides the continuous large lighting area into smaller lighting areas,firstly avoiding the light pollution caused by the traditional flat-plate collector;Secondly,the louvered collector can be flexibly arranged on the window walls,balconies and roofs of the building,and it is easy to be integrated with the building;The louvered collector can be installed according to any geographic latitude and different seasons Optimal use of inclination angle;Through the louvered structure,the air interlayer has the smaller coefficient of convective heat transfer,so that,it is very easy for the flat-plate collector to have the higher thermal efficiency.This paper takes the monolithic louver collector and louver collector hot water system as the research object,and builds two sets of test platforms,respectively,for the louver collector and the louver collector hot water system.The thermal efficiency has been experimentally studied,and the main contents are as follows:1.The structural characteristics of the louver-type collector were elaborated,the heat transfer process of the louver-type collector was analyzed by theoretical calculation,the heat network diagram was drawn,and the energy loss of each part was analyzed,and it was found that the top heat loss accounted for the main proportion,And give the mathematical expression of the top heat loss coefficient.The heat transfer method of the hundred-page collector is explained by theoretical calculation.2.Setting up a single-piece louvered solar collector thermal performance test platform to test the thermal efficiency of the single-piece louvered collector and using the least square method to perform linear fitting on the measured efficiency of the experiment and the calculated normalized temperature difference.Thus,the efficiency equation of the collector is obtained.It is found that during the winter operation of the louvered solar collector,when the inclination angle of the collector increases,the instantaneous efficiency of the collector is improved.When the inclination angle of the collector changes from 0°to 60°,the efficiency of the collector is increased by 8.9%.When the inclination angle is 60°,the instantaneous efficiency of the collector can reach 82.3%;and the instantaneous efficiency of the collector increases with the working fluid.The flow rate increases,but the rate of increase gradually decreases,and finally stabilizes.When the mass flow of working fluid increases from0.002kg/s to 0.0035kg/s,the instantaneous efficiency of the collector increases by 12.9%.According to the equation of the instantaneous efficiency of the collector,the heat transfer factor F_Rand the total heat loss coefficient U_Lof the collector can be calculated.It is found that F_Rincreases with the increase of the working fluid flow rate,and U_Lgradually decreases with the increase of the working fluid flow rate.Small finally tends to a fixed value.3.Designing a thermal performance test platform for the hot water system of the louver collector,using the instant method to test the instantaneous efficiency of the louver collector system and the flat plate collector;using the calorimetric method to test the hot water of the louver collector The average daily efficiency of the system and the flat-plate collector hot water system,and when the volume of the hot water storage tank of the louvered collector hot water system is changed from 40L to 60L,the average daily efficiency has been improved.4.Using the daily average efficiency test platform,the top heat loss coefficient of the louver collector and the flat plate collector was measured.It was found that the top heat loss coefficient of the louver collector was smaller than that of the flat plate collector.This was due to the louver type collector.The heat collector has a small air square cavity structure,and the reasonable structure size forms an approximate honeycomb effect,which inhibits the convection heat transfer inside the heat collector square cavity.