半圆形波纹吸热板太阳能空气集热器数值模拟

Numerical Simulation of Semi-circular Corrugated Endothermic Plate Solar Air Collector

以采用半圆形波纹吸热板的平板型太阳能空气集热器(以下简称集热器)作为研究对象,在风道进口空气温度为276 K、外界空气温度为273 K条件下,采用Fluent软件,模拟分析半圆形波纹吸热板的半圆半径(变化范围为5~30 mm)、风道进口空气流速(变化范围为1.0~3.0 m/s)对风道内空气温度分布(包括风道出口空气温度)、集热器集热效率、空气压力损失的影响。集热器由半圆形波纹吸热板平均分为上下风道(分设空气进出口)。总体上,上下风道内空气温度均沿着流动方向逐渐升高,下风道的空气温度高于上风道。风道进口空气流速为2.0 m/s时,随着半圆半径的增大,上下风道空气出口温度均呈增大趋势,集热效率也随之增大,说明增大半圆半径对增强空气扰动的效果明显。半圆半径为30 mm时,随着风道进口空气流速的增大,上下风道出口温度均呈下降趋势,集热效率与空气压力损失均呈增大趋势。在选取风道进口空气流速时,除考虑集热效率外,空气压力损失也是需要考虑的因素,这关系到送风机的耗电与集热器的承压能力。

Taking a semi-circular corrugated endothermic plate flat-plate solar air collector(hereinafter referred to as the collector)as the study object,at the duct inlet air temperature of 276 K and the outside air temperature of 273 K,the influence of semicircle radius of semi-circular corrugated endothermic plate(variation range of 5 to 30 mm)and duct inlet air flow rate(variation range of 1.0 to 3.0 m/s)on the air temperature distribution within the duct(including duct outlet air temperature),collector efficiency and air pressure loss is simulated and analyzed using Fluent software.The collector is divided into upper and lower air ducts by semi-circular corrugated endothermic panel(divided into air inlet and outlet).Overall,the air temperatures in upper and lower air ducts gradually increase along the flow direction,the air temperature in lower air duct is higher than that in upper air duct.When the duct inlet air flow rate is 2.0 m/s,with the increase of the radius of the semicircle,the air outlet temperatures of upper and lower air ducts show an upward trend,and the heat collection efficiency also increases,indicating the effect of increasing the radius of the semicircle on enhancing the air disturbance is obvious.When the radius of the semicircle is 30 mm,as the duct inlet air flow rate increases,the air outlet temperatures of upper and lower air ducts show a downward trend,the heat collection efficiency and air pressure loss show an upward trend.When selecting the air duct inlet air flow rate,in addition to considering the collection efficiency,the air pressure loss is also a factor to be considered,which is related to the power consumption of the blower and the pressure bearing capacity of the collector.