摘要
根据传热学原理,建立了U型管集热器的能量平衡方程,根据方程在FLUENT中建立动态模拟仿真模型。利用模型分析了U型管的入口速度、太阳辐射量和外形尺寸对真空管内的温度场和流场的影响。模拟结果表明U型管内的流场一般不受入口速度的影响。模拟结果还表明:较高的入口速度、较强的太阳辐射量或较大的U型管内径时,集热器有较高的效率;相反较小的入口速度、较高的太阳辐射量或是较小的U型管内径时,真空管的出口平均温度较高;与入口流速、太阳辐照度和玻璃管长度因素相比,合适的U型管的内径对于优化真空管的结构和提高其热效率起着更为重要的作用。
In this study, the energy balance equations for each part of U-tube solar collector were established. In order to analyze the collector thermal efficiency in detail, a computational fluid dynamics model was developed for different operating conditions. The flow and thermal performance was evaluated by means of the computational model for changing inlet flow velocity, different solar irradiance and varied configuration. Simulation results presented that faster incoming flow rate, lower solar irradiance or bigger U-tube diameter will lead to lower outlet temperature, whereas slower incoming flow rate, higher solar irradiance or smaller U-tube diameter result in higher thermal efficiency. Furthermore, within the specified range, the flow structure in the U-tube uninfluenced by the inlet flow rate.
出处
《能源技术》
2010年第3期169-174,共6页
Energy Technology
关键词
U型管集热器
动态模拟
能量平衡方程
热性能
U-tube solar collector
energy balance equation
dynamic simulation
thermal performance
