基于量纲分析的双轴槽式太阳能系统集热性能研究

针对影响双轴跟踪槽式太阳能系统集热效率的多种因素,文章采用量纲分析法建立了集热效率预测模型,构建了包括Re数在内的5个无量纲量。实验测试了不同工况下系统的集热性能,通过多元线性回归对集热效率预测模型进行了求解。研究结果表明:在文章研究范围内,Re对集热效率的影响较大,太阳辐照量、集热管几何参数以及传热工质物性等对集热效率影响相对较小;在集热效率预测模型复测样本范围内,集热效率计算值和实测值之间的最大相对误差不超过15%。文章建立的双轴跟踪槽式太阳能系统集热效率预测模型精度较高,可为槽式太阳能系统的工程设计和优化运行提供理论依据。

Experimental research on thermal performance of thedual-axis trough collector based on dimensional analysis

For a variety of factors affecting thermal efficiency of the dual-axis tracking trough collector,a prediction model of thermal efficiency according to dimensional analysis is put forward and retested by experimental data.The results show that in the prediction model,five non-dimensional quantities including Re are constructed,and the correlation between them and thermal efficiency is analyzed.It can be seen that the influence of Re is larger,and the effects of solar radiation,geometric parameters of collector tube,and fluid properties are low relatively.The maximum relative error between prediction model calculations and measured values of the thermal efficiency in the retest sample range is less than 15%.The accuracy of the prediction model is high,which can provide a theoretical basis for the engineering application and optimization of the trough concentrating system.