槽式太阳能集热器传热模型及性能分析

槽式太阳能集热器一维和二维传热数学模型是一组非线性代数方程,为改进求解的稳定性和计算精度,将槽式太阳能集热器一维和二维传热模型的求解看作有约束优化问题,建立了集热器传热过程求解的有约束优化数学模型,应用MATLAB软件优化函数fmincon进行求解。分析了传热流体入口温度及太阳能辐射热流密度变化对集热器性能的影响。采用fmincon函数求解集热器传热过程,计算速度快,计算过程稳定。分析表明,传热流体温度变化对集热器效率的影响大于太阳能辐射热流密度对集热器效率的影响。

Performance analysis and heat transfer model building of parabolic trough solar collector

One-dimensional and two-dimensional heat transfer mathematic model of the parabolic trough solar collector are a set of nonlinear algebra equations. In order to promote the stability and accuracy of the solution, the calculation of the heat transfer model of the parabolic trough solar energy collector is treated as constrained optimum problem, the energy conservation equations and heat transfer equations are converted into optimization model, the optimization model is solved by using fmincon function in MATLAB optimization tool box. The influences of heat transfer fluid inlet temperature and solar radiation flux to heat collector coefficient are analyzed. The solution of heat collector heat transfer process is faster and more stable by using fmincon function. Results show that the variation of heat transfer fluid inlet temperature plays more important role on heat collector coefficient than that of the variation of solar radiation flux.