The Numerical Simulation And Analysis Of Transient Thermal Performance Of Louver Type Solar Collector

In this paper, a transient3-D mathematical model for louver type solar collectors in thestuffy conditions is developed with FLUENT software. The method of this paper is findingthe optimal geometric parameters of the component of the louver type solar collector. At last,it has validated the louver type solar heat collector whose structure has been optimized. Whenit optimizes each part of structure parameter, boundary conditions loading to each part aresubstituted with equivalent boundary conditions of the whole louver type solar collectors. Itdiscusses in accordance with the order of pipe of the collector, collector tube plate core, andfinally the louver type solar heat collector. It has fitted pipe surface heat transfer coefficientsof the collector with multiple non-linear and got its Expression, then computed collectorefficiency factors. On the basis of collector efficiency factor, it has obtained optimizationstructural parameters of louver type solar pipe diameter, the width of the absorber plate, theabsorber plate thickness, the space between glass cover plate and the absorber plate and so on.When it discusses pipe internal surface heat transfer coefficients of the collector, thevarious factors of the ratio of pipe length to diameter l/d, heat flux density q, angle ofinclination influence of pipe internal surface heat transfer coefficients of the collector areinvestigated. Finally it sum up to surface heat transfer coefficient criterion Nu=0.944G(*rP0r.1)4d/l)0.05of slim and round pipes in horizontal.With the parameterrelated to absorber plate thicknessk=0.04,0.06,0.08,0.1,0.2,0.3,0.4changes, it plots thecurve of collector efficiency factor of F ’and the absorber plate width of W and getsoptimization value of the absorber plate thickness and the absorber plate width Wδ=0.5mm， W=150mm. Based on the collector instantaneous efficiency analysis of pipediameter optimization Do=20mm.tracking with air natural convection Rayleigh number andthe top heat loss and to control due to strong convection heat exchange between air cavitywith the surrounding environment to produce the minimum amount as the ultimate goal, Itsimulates air layer heat convection in the cavity of the louver type solar collector and analysisto the spacing between the glass the cover plate and the absorber plate should beH=22mm.Based on the gradual optimization of every parameter,optimal louver type solarstructure parameters collector are pipe diameter Do=20mm, the absorber plate widthW=150mm, absorber plate thickness=0.5mm, plate spacing H=22mm.In order to prove the reliability of results, It similarity comprises intermediate segmentoptimization processes and existing theories and shows that the fitting results of this paperand the calculation results have a certain credibility. Finally, the instantaneous efficiency of heat exchange of the louver type solar energy are calculated, the calculated theoretical is high.When Solar radiation intensity is800W/m2, ambient temperature is steady. Comparison oflouver type solar collector and the traditional flat plate heat collector found: louver type solarcollector yield useful can be improved than traditional flat plate heat collector by33%,instantaneous efficiency increased by14.3%.