Study On The Thermodynamic Performance And Application Of Photovoltaic/Thermal Coupled PEM Hydrogen Production System

Hydrogen energy,an abundant,green,low-carbon,and widely applicable secondary energy source,is considered a significant direction for future energy revolution.China has a strong foundation in hydrogen production and a large-scale application market,demonstrating notable advantages in the development of hydrogen energy.However,the hydrogen energy industry in China also faces issues such as high hydrogen production costs and significant carbon emissions.At present,fossil energy dominates China’s hydrogen production materials,accounting for approximately 80%,and significant carbon dioxide emissions occur during the production process.Although renewable hydrogen(green hydrogen)is the key development direction for the future,the cost of renewable energy power generation in China is still higher than that of fossil fuel power generation,and the cost of hydrogen production through water electrolysis mainly depends on electricity prices.Therefore,the economic feasibility of renewable hydrogen production has not yet gained a competitive edge.This article focuses on the performance comparison of two popular systems in recent years:photovoltaic/thermal(PV/T)coupled hydrogen production systems and Concentrated photovoltaic/thermal(CPV/T)coupled hydrogen production systems,providing new simulation results and operational mode references for the development of renewable hydrogen production.Firstly,a study on the thermodynamic performance of the photovoltaic-thermal coupled hydrogen production system was conducted.By comparing related literature,the incremental conductance method was adopted as the maximum power point tracking algorithm(MPPT)for the photovoltaic system,and the simulation was carried out in conjunction with the solar radiation intensity and ambient temperature of a specific location on a particular day.Subsequently,the heat balance algorithm solving process for the PV/T system was proposed,and the light,heat,and electricity conversion conditions of the PV/T system under the given environmental conditions were solved using the process simulation software gPROMS.Furthermore,the gPROMS program and the simultaneous equation method were used to build a PEM hydrogen production system that controls the inlet temperature of the circulating water,and the thermodynamic performance evaluation indicators were determined.The study found that under appropriate operating parameters,controlling the anode inlet water temperature at 70℃ and not exceeding 64.71℃ for the inlet water temperature of the circulating water,the hydrogen production system has a high energy conversion efficiency and hydrogen production rate while ensuring operational safety.Subsequently,under the aforementioned optimal operating parameters,a PV/T coupled hydrogen production system was constructed,and a simulation study was conducted based on the actual environmental parameters of a certain day.The results showed that the overall energy conversion efficiency ranged from 39.0%to 49.1%,and the hydrogen production was higher and the energy efficiency was lower under higher solar radiation intensity and ambient temperature conditions.Finally,the simulation of the Concentrated photovoltaic-thermal(CPV/T)system was conducted.Then,three CPV/T coupled hydrogen production systems based on different cooling water treatment methods were constructed.The results showed that the direct water inlet method had greater advantages in terms of light-to-hydrogen conversion efficiency and system stability.A comparison between the photovoltaicthermal coupled hydrogen production system and the Concentrated photovoltaicthermal coupled hydrogen production system revealed that the latter performed better in terms of energy conversion efficiency,hydrogen production,and overall thermal efficiency,reaching 55.7%,0.0989 kg/s,and 14.6%,respectively.However,the energy efficiency and overall thermal efficiency advantages were smaller under high solar radiation conditions,indicating that the CPV/T coupled hydrogen production system is not recommended for operation under extremely high solar radiation conditions.Finally,the system showed good environmental performance,with a daily standard coal saving rate of 15.5 tons and a carbon dioxide emission reduction rate of 38.0 tons.This research provides new simulation results and operational parameter references for the development of photovoltaic-thermal coupled hydrogen production technology,contributing to promoting technological advancements in this field.