Thermodynamic Performance Analysis Based on Integrated System of Hydrogen Production, Pumped Thermal Electricity Storage and Photovoltaic Technology

In order to realize the efficient utilization of solar energy, this paper proposes an integrated system coupling pumped thermal electricity storage (PTES) with proton-exchange membrane (PEM) for hydrogen production based on solar photovoltaic thermal (PVT) technology. Firstly, the physical and mathematical models of the integrated system are constructed, and the hydrogen production <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{M}_{\mathrm{H} 2}$</tex>, total thermal efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text{en}}$</tex> and exergy efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text{ex}}$</tex> are selected as the key performance indicators of the system. Meanwhile, a typical day of four seasons in Chuxiong, Yunnan Province was selected for the system variable operating condition performance analysis. The results show that DNI has a significant effect on the system key performance indicators <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{MH}_{2}, \eta_{\text{en}}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text{ex}}$</tex>, and shows a roughly increasing and then decreasing relationship with DNI. The maximum obtainable <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{MH}_{\mathbf{H 2}}$</tex> is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.553 ~\text{kg} / \mathrm{h}$</tex> in the typical day in spring, and the minimum is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.484 ~\text{kg} / \mathrm{h}$</tex> in winter. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {ex }}$</tex> changes were basically consistent with the trend of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {en }}$</tex>. In summer, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {en }}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {ex }}$</tex> are the largest and basically remain constant, with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {en }}$</tex> maintaining around 40.15 % and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {ex }}$</tex> basically remaining at 14.4 %; in winter, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {en }}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta_{\text {ex }}$</tex> are the smallest and fluctuate the most. This study provides a theoretical reference for the future application of renewable energy in the multigeneration system.