Numerical simulation of geothermal‐PVT hybrid system with PCM storage tank

Abstract

As the increase in greenhouse emissions, climate changes, and other irreversible repercussions stems from environmentally destructive energies such as fossil fuels, exploiting solar and geothermal energy as unlimited clean sources of energy in the renewable energy technologies can survive the planet earth, which is facing a catastrophe on a global scale. The main purpose of this research is to study Techno analysis of the combined ground source heat pump (GSHP) and photovoltaic thermal collectors (PVTs) with a "phase-change material" (PCM) storage tank to fulfill the energy demands of a residential building. In the first step of this study, in order to model the heat pump behavior in multi-usage operation modes (heating and cooling), a numerical transient simulation of a water-to-water GSHP, which includes a vertical U-type ground source heat exchanger (GSHX) and a variable speed drive (VSD) compressor, was conducted by developing a numerical code in Engineering Equation Solver software. To study the thermodynamic aspect of the hybrid system in terms of exergy and energy, a transient numerical simulation was accomplished using the TRNSYS program. Also, the impact of effective characteristics of ingredients such as areas of PVT panels and the volume of the storage tank of PCMs on the performance of the hybrid system are investigated. On top of that, the two types of the GSHP-PVT-PCMs and GSHP-PV from the energy and exergy points of view are compared. The obtained results demonstrate that the irreversibility of the solar modules of the GSHP-PVT-PCMs is 6.6% lower than that of the GSHP-PV. Furthermore, the calculation of the annual required load of the building for these two kinds of hybrid systems shows that the use of collectors in this combined system has reduced the total load of the building by 6.5%. The use of collectors in the GSHP-PVT-PCM gives rise to a difference in the value of solar factor (SF) of this system by 1.4% more than the one for the hybrid system without thermal collectors.

Thermophysical properties of $n$-hexadecane: Combined Molecular Dynamics and experimental investigations

“…They were used at the 2004 Athens Olympics as a "precool" vest invented by the Australian Institute of Sport [1,2]. PCMs based systems are also inescapable to increase the efficiency of the storage of thermal energy produced from renewable sources such as solar [3] and geothermal energy [4]. Moreover, PCMs-based storage cells allow to collect industrial wasted energy for further re-usage, e.g.…”