Mathematical modeling of the thermal regime in solar photovoltaic thermal panel

Abstract

Design of a combined solar photovoltaic thermal panel (PV/T) for the simultaneous generation of electrical and thermal energy was proposed in this study. The basis of the new design is a traditional solar panel with poly-Si solar cells. A flat channel with a heat transfer fluid is added to the front size of such a panel. This channel is bounded by cover glass. A non-stationary mathematical model was developed for determination of temperature regime in the PV/T panel. This model consists to the system of nonlinear ordinary differential equa-tions, which describes mutual influence of external and internal heat flows and temperatures. A Math-software was created based on the developed mathematical model. The numerical studies were conducted in in real-time mode for selected geographical location of the PV/T panel. Heat flux density from the Sun, wind speed and ambient temperature were determined based on data from open worldwide climate databases. As result of computer modeling, the typical temperature distributions in each layer of the PV/T panel during daylight hours were founded. It was determined that the heat transfer fluid moving in a transparent channel from the front side of the solar panel does not cool the solar cell. This heat transfer fluid ensures only their thermal stability at the corresponding value of the specific mass flow rate. With an increase of the specific mass flow rate of the heat transfer fluid, the growth of solar cells tem-perature is observed under unchanged environmental conditions. An the same time, the pro-posed design of the PV/T panel ensures a significant increase of the heat transfer fluid tem-perature. This makes it possible to use it in low-potential heat generation systems. This leads to an increase in the economic efficiency of solar panels, economy of occupied areas, optimi-zation of system of production, consumption and storge of thermal and electrical energy.