Optimum Study On The Structure Of The Glass Hybrid Wall Powered By Solar Energy Based On "Chimney Effect"

In recent years,with the increasing energy consumption of heating ventilation andAir conditioning,take advantage of natural ventilation to improve indoor thermalcomfort,enhance indoor air quality,in order to save energy is particularlyimportant."Chimney effect" is caused by thermal force, the air will beheated,reducing its density and causing it to rise. Solar chimney as a means ofstrengthen the natural ventilation that can use solar energy to increase air densitydifference between inside and outside of the chimney, as to provide buoyancy for theair inside the chimney, so the air to be heated and rising.This article makes a theoretical analysis of solar chimney from two aspects,thenatural ventilation principle and energy balance. Analysis the effect of solar radiationintensity （Q_in）and the glass hybrid wall air channel aspect ratio of （W/H）on the finalheat gain of air （Q gain）,to provide a basis for the optimization design of solar chimney.For the numerical simulation research,COMSOL3.5software is used to simulatethe glass hybrid wall powered by solar energy based on “chimney effect”. Analysis theeffect of solar radiation intensity （Q_in）and the glass hybrid wall air channel aspect ratio of（W/H）on the air temperature、air velocity field、air mass flow rate、and thefinal heat gain of air.The study find:1、when solar radiation intensity change from100W·m^-2～400W·m^-2,air massflow rate increase with the ratio of W/H augmentation;2、when solar radiation intensity is500W·m^-2, air mass flow rate increase andthen decreases with the ratio of W/H augmentation. maximally taking value atthe ratio of W/H=0.6；3、when solar radiation intensity is100W·m^-2、200W·m^-2、300W·m^-2、400W·m^-2、500W·m^-2,corresponding to the ratio of W/H is0.6、0.6、0.4、0.2、0.1,the finalheat gain of air achieve the maximum value。In the experiment study aspect,we builted an experimental setup of the glasshybrid wall powered by solar energy.The experimental glass hybrid wall powered by solar energy has internal dimensions of1.0m high,1.0m length and the channel depthis varied between10cm and60cm.The radiation of solar ray is simulated by nine bathbully lamp heater.The solar radiation ranged from120.44W·m^-2to957.89W·m^-2.Experimental result showed that:1．in our study scope(Q_in=120.44W·m^-2～957.89W·m^-2，H=1m,W=0.1m～0.6m),when the solar radiation is a certain value,the air mass flow rate increase withthe ratio of W/H augmentation;2．when the solar radiation is a certain value,the final heat gain of air increase andthen decreases with the ratio of W/H augmentation. when the solar radiation isa certain value, air temperature decrease with the ratio of W/H augmentation.3．when the solar radiation is a certain value, air velocity decrease with the ratioof W/H augmentation.The conclusion of this research is that, in our study scope(Q_in=120.44W·m^-2～957.89W·m^-2，H=1m,W=0.1m～0.6m), when the solar radiation is a certain value, airflow rate increase with the ratio of W/H augmentation; the final heat gain of airincrease and then decreases with the ratio of W/H augmentation, when the radio ofW/H scope is0.3to0.5, the final heat gain of air achieve the maximum value.Simulation results and experimental results are consistent,but the numericaldifference.This work can provide the basis for the structural optimization design of solarchimney and achieve the purpose of energy saving for solar chimney system.