太阳能平板集热器热性能关键参数影响研究

Study on the Influence of Key Parameters of Thermal Performance of Solar Flat-panel Collector

通过改变影响太阳能平板集热器热性能的关键参数:通道间距、流体流量、吸热板热流密度、流体进口温度,研究流体流动与传热规律。结果表明,通道间距为0.5~1.0 mm时,流体的传热系数、温升速率、压降的变化明显比通道间距为1.0~2.5 mm时高,通道间距越小,温升速率越快;随着流体流量增大,流体出口温度逐渐减小,温升速率保持稳定,阻力系数减少,压降逐渐增大,强化传热评价因子逐渐增加;吸热板热流密度越大,流体出口温度越高,温升速率越快;流体进口温度越高,流体出口温度越高,进出口温差和温升速率保持稳定。

By changing the key parameters that affect the thermal performance of the solar flat plate collector:channel spacing,fluid flow,heat flow density of the heat sink,fluid inlet temperature,the flow and heat transfer laws of the fluid are studied.The results show that when the channel spacing is 0.5~1.0 mm,the changes of heat transfer coefficient,temperature rise rate and pressure drop of fluid are significantly higher than those when the channel spacing is 1.0~2.5 mm.The smaller the channel spacing is,the faster the temperature rise rate of fluid is;With the increase of fluid flow,the outlet temperature of fluid decreases gradually,the temperature rise rate remains stable,the resistance coefficient decreases,the pressure drop increases,and the comprehensive thermal performance evaluation factor increases gradually;The higher the heat flux of the heat absorbing plate is,the higher the fluid outlet temperature is,and the faster the temperature rise rate is;The higher the fluid inlet temperature is,the higher the fluid outlet temperature is,and the temperature difference between the inlet and outlet and the temperature rise rate remain stable.