Review of computer models of air-based, curtainwall-integrated PV/T collectors

Photovoltaic-thermal (PV/T) collectors provide renewable energy, and they are instrumental to achieve grid independency. A subset of these collectors is collectors that are integrated into building envelope. The so-called “building-integrated” PV/T collectors have seen a dramatic rise in popularity recently. This recent popularity has necessitated systematic design optimization. To benefit design optimization, a review of computer models of these collectors was performed. This review was performed by objectively assessing international findings on roof-integrated and curtain-wall integrated PV/T collectors. The scope of this review was thermal collection efficiency. The significance of this review was to identify the weakest link in computer models that should one day lead to more accurate computer models. This weak link is the internal heat transfer rate. To overcome this weakness, a model calibration method was proposed that is based on case-by-case parameter identification. In addition, a detailed dimensional analysis was performed that allowed a new Π group to be introduced to Nusselt (Nu) number correlations of developing, turbulent parallel-plate flow. This Π group is the Stanton number as applied to the inter-channel radiative heat transfer coefficient (Str). Commonly implemented Nu number correlations do not account for this heat transfer rate. They only account for collector geometry, collector air flow inertia and collector air viscosity.