Performance Investigation Of Solar Air Collectors With Slit-perforated Corrugated Plate And Corrugated Mesh Wire

Due to the environmental pollution caused by burning coal for heating,it is important to use clean energy to replace coal.Solar air collectors have the characteristics of simple structure and low cost and produce no pollution,which are suitable for supplying heat in rural area in winter.Therefore,the investigation about noval solar air collectors is always the focus for people.First of all,the paper conducts the numerical analysis for different absorber plates.The paper put forward four noval kinds of absorber plates,respectively corrugated plate with slit perforation,corrugated plate with circle perforation,V-corrugated plate with slit perforation and V-corrugated plate with circle perforation.Therefore,the geometric model of small-scale solar air collector is eastablished,and FLUENT software is used to analyse the characteristic of different absorber plates.Among these four plates,corrugated plate with slit perforation has higher heat transfer coefficient and lower flow resistence,which is considered the best absorber plate.According to the conclusion that“corrugated plate with slit perforation is the best absorber plate”,solars air collector with slit-perforated corrugated plate is put forward.And due to the corrugated mesh wire's characteristic of high heat-transfer efficiency and low flow resistence,solar air collector with corrugated mesh wire is also put forward.According to the relationship of heat transfer and heat balance equations,their mathematic models are eastablished.At the same time,the experimental system is set up and test the solar air collector.Comparing numerical and experimental results,the mathematic model is proved correct.Using the right model,a parametric analysis is conducted on key parameters.Thermal efficiency,temperature rise and effective efficiency are value indexes.The condition is as follows:solar radiation intensity is 800 W/m~2,outside temperature is 286K,inlet air temperature is 294K.For solar air collector with slit-perforated corrugated plate,the height of absorber plate is 1.8~3.5m;the width of absorber plate is 0.5~1.0m;the slit length is 10-140mm;the slit pitch is 60-150mm;the air volume flow rate is75~100m~3/h.For solar air collector with corrugated mesh wire,the height of absorber plateis 1.8~3.5m;the width of absorber plate is 0.5~1.0m;the mesh number is 45-50;the air volume flow rate is 100-170 m~3/h.When the above conditions occur,the temperature rise can arrive over 10K and thermal and effective efficiency can arrive over 65%.At last,in the same collector size and operation condition,compared with the solar air collector with circle perforation in the previous study,thermal efficiency of collector with slit-perforated corrugated plate and corrugated mesh wire are 2.1%and3.2%higher,and arrive at 66.71%and 67.81%.Solar air collector with corrugated mesh wire has higher thermal efficiency and lower flow resistence;and this kind of collector is better and has larger application and development potential.