槽式太阳能集热管传热特性的研究

Study on Heat-transfer Characteristics of Trough Solar Collectors

以槽式太阳能集热管为研究对象,根据传热特性建立一维稳态传热模型;利用模型分析影响集热管热损失的因素,研究集热管出口参数受工质入口压力、流量和光照强度等因素的影响规律;并将模拟结果和文献的三维模型作对比。结果表明:发射率是影响集热管热损失的重要因素;压力越小或者流量和光照强度越大,集热管的效率就越高;一维模型虽然有所简化,但模拟的流体出口温度与三维模型的平均绝对误差只有0.68K,且模拟的吸热量和试验值更加吻合。

Taking the trough solar collector as an object of study, a 1D steady-state model was set up according to its heat-transfer mechanism, with which factors affecting the heat loss of collector were analyzed, while the influence of inlet pressure, mass flow rate and solar irradiation on the outlet parameters was studied. The simulation results were subsequently compared with relevant literature data obtained by 3D models. Results show that the absorber emissivity is one of the crucial factors influencing the heat loss of collector. The collector efficiency increases with reducing inlet pressure, rising mass flow rate and rising solar irradiation. Although the 1D model is much simpler, its simulation result of average outlet temperature is only 0.68 K higher than the 3D model, and the average heat gain of 1D model agrees more well with experimental data.