一种太阳能集热器流体平均温度计算方法

A Calculation Method of Average Fluid Temperature in Solar Collector

太阳能集热器是进行光热转换的重要设备,既可以应用于塔式热发电技术进行集中式能源利用,也可以应用于碟式热发电技术进行分布式能源利用,因此评估太阳能集热器的热性能十分重要。为此,提出了一种计算太阳能集热器流体平均温度的新方法,经实验验证,计算结果与实验数据符合较好,证明该方法可以较好地预测太阳能集热器的流体平均温度。为了更好地掌握太阳能集热器的热性能,研究了不同参数对太阳能集热器热效率的影响,结果表明:当输入功率恒定时,增大流量可以有效提高太阳能集热器的效率;当流量恒定时,太阳能集热器效率随着输入功率的增加会先升高后降低;太阳能集热器的效率与入口温度成反比,与环境温度成正比。

The solar collector is an important equipment for photo-thermal conversion.It can be used not only for centralized energy utilization by tower thermal power generation technology,but also for distributed energy utilization by disc thermal power generation technology.Therefore,it is necessary to evaluate the thermal performance of solar collectors.A new method was proposed to calculate the average fluid temperature of solar collectors.The experimental results show that the calculation results are in good agreement with the experimental data,which proves that the method can predict the average fluid temperature of solar collector.The effect of different parameters on thermal efficiency was also investigated to better acquire the thermal performance of solar collectors.The results show that when the input power is constant,increasing the flow rate can effectively improve the efficiency of solar collector.When the flow rate is constant,the efficiency of solar collector increases first and then decreases with the increase of input power.The efficiency of solar collector is inversely proportional to the inlet temperature and proportional to the ambient temperature.