抛物面槽式太阳能集热器热力性能研究

Research on the thermal performance of the solar parabolic trough collectors

在已有集热器传热模型的基础上,进行简化,不失模型精度以及主要影响因素均能反应的前提下,简化了模型,便于工程的计算与分析。结果表明,集热器热效率随着流体温度的升高而变小,流体温度小于300℃时,无论集热器处于何种运行工况以及何种流量,其热效率都为60~70%;当真空区域空气压力小于13 332.2 Pa时,集热器效率变化较快,大于13 332.2 Pa时,效率几乎不变;集热器效率随着太阳辐射强度的增加而变大,450~950 W/m2是集热器运行的最佳辐射区间;当风速小于5 m/s时,大气温度越高,集热器热效率越高。

Based on the existed model,a simplified heat transfer model was put up.The simplified model was certificated to be accurate and convenient to the engineering.The results show that the higher the fluid temperature is,the lower the thermal efficiency of the collector is.When the fluid temperature is lower than 300℃,no matter what operation condition and fluid rate is,the efficiency is 60~70%.When the air pressure is lower than 13332.2Pa in the vacuum area,the efficiency varies fast,while higher than 13332.2Pa,the efficiency is nearly constant.The efficiency becomes higher as radiation becomes higher.The best range is 450~950W/m2.When the wind speed is less than 5m/s,the higher the atmosphere temperature is,higher the thermal efficiency of the collector is.