From existing equations, which have been validated by experimental measurements in the literature, the photovoltaic (PV) cell efficiency for the photovoltaic solar thermal collector (PVT), cooled by forced fluid flow, is shown to be a function of the mass flow rate. This study shows, with calculus, that there is, in general, a critical mass flow rate which corresponds to the maximum PV cell efficiency. The derived new equations are applicable to laminar regime and transition or turbulent flow regimes. These equations can yield directly the critical mass flow rate, as compared with existing methods that use observation on the results obtained by repeated computational trials.

根据现有的方程式（已通过文献中的实验测量结果进行了验证），显示了通过强制流体流动冷却的光伏太阳能集热器（PVT）的光伏（PV）电池效率与质量流量的关系。这项研究表明，通过微积分，通常会有一个临界质量流率，它对应于最大PV电池效率。推导的新方程式适用于层流状态和过渡或湍流状态。与对重复计算试验获得的结果进行观测的现有方法相比，这些方程式可以直接得出临界质量流量。