Development of a dynamic model for a hybrid photovoltaic thermal collector – Solar air heater with fins

Abstract

A dynamic model for a hybrid Photovoltaic Thermal Collector-Solar Air Heater (PVT-SAH) with longitudinal fins was developed to enable assessment of the potential of the system to provide high temperature outlet air (60-90 °C) under dynamic boundary conditions. The model description includes the method for discretising the system into a number of control volumes, the energy balance equations for each control volume and the implementation of the numerical solution. Model validation has been successfully undertaken by using empirical verification of model predictions with an experimental facility and by comparing the model outputs with the reference data from the literature. The dynamic PVT-SAH model was then used under variable boundary conditions and its performance was compared with an equivalent steady state model. Significant Time Constants (TC) were observed and it was found that the steady state model could overestimate the thermal energy gains of PVT-SAH by 35% when compared with the predictions of the dynamic model. Additional simulations were run under fixed boundary conditions to shown the effect of fins on the performance of the PVT-SAH system. Finally, to demonstrate the benefits of using such a dynamic PVT-SAH model, a case study was used and the effect of length ratio of PVT to SAH was investigated by using a range of performance criteria. Additional simulations were run under fixed boundary conditions to shown the effect of fins on the performance of the PVT-SAH system. Finally, to demonstrate the benefits of using such a dynamic PVT-SAH model, a case study was used and the effect of length ratio of PVT to SAH was investigated by using a range of performance criteria.

Numerical study on photovoltaic/thermal systems with extended surfaces

“…Their findings suggest that implementing finned air channels in a PV/T system improves overall heat transfer and performance when compared with the thin metal sheet configuration. Fan et al investigated a hybrid PV/T–solar air heater system with fins using a two‐dimensional (2D) control volume approach and the Crank‐Nicolson scheme. After the validation process of the numerical model, effects of several working parameters such as the solar irradiance, number of fins, and fin height were investigated.…”

Energy and Exergy Evaluation of Multi-channel Photovoltaic/Thermal Hybrid System: Simulation and Experiment

“…In this study, 15 channels were described as optimal for receiving the maximal amount of energy efficiency. Fan et al [24] investigated the dynamics and solving of governing equations using the Crank-Nicolson method for a PV/T system similar to reported data [22,23], which are connected to a solar-powered air heater in series mode. They finally compared the response of modeling the system stable state and dynamical mode-modeling and reported that a stable state response could well predict the behavior of the system.…”

“…To overcome the mentioned shortages, in this research the development of static modeling and a novel accurate solution of a MCPV/T system with multi-flow channels as well as validation of the equations obtained with experimental results have been considered which is completely different from the numerical method stated in literature [22][23][24]. The contact of air to the back surface of Tedlar PVF Film is direct and a novel fan positioning is considered in the middle of the system.…”

Innovative thermo-solar air heater

“…The Solar-HVAC has been considered as an alternative to reduce contribution of the primary energy and in this respect, are developed solutions based on the direct transformation of the solar energy in internal energy of the transport medium [2,3,4,5].…”

“…This basic principle is successfully applied to the solar air heaters in passive houses keeping a minimal comfortable temperature of 15 o C [6] during cold seasons.…”