Solar Driven Organic Rankine Cycle System and Hydrogen Fuel Production with Waste Heat Recovery

Abstract

Energy systems that rely on non-renewable sources like fossil fuels are contributing to climate change by emitting more carbon dioxide. It is crucial to shift towards renewable energy sources such as solar, wind, biomass, and geo-thermal to meet our energy needs. Organic Rankine Cycle (ORC) is a thermodynamic cycle which utilizes an organic fluid with higher molecular mass and lower vaporization temperature than water-like organic fluids such as refrigerants. ORC technology powered by solar energy and waste heat plays an essential role in reducing carbon emission impact. It is becoming one of the most promising approaches to recovering waste heat using regenerative cycles. In this work, ORC driven by solar energy was performed in CYCLE tempo. The heat from solar panels was given as an input to run the ORC power system in the primary circuit. The system involves an evaporator, steam turbines (high pressure and low pressure), a condenser, a feed pump, a waste heat source and R134a as the working fluid for the primary ORC. In the secondary circuit, R245fa was used to produce additional power. Hence, the total power produced by the integration of these two circuits was 5.114 MW and a share of total electricity was utilized for hydrogen production by reversible fuel cells (i) Solid Oxide Electrolysis Fuel Cell (SOEFC) and (ii) Proton Exchange Membrane Fuel Cell (PEMFC). They also compared the results of these fuel cells. The net power of 3.114 MW was available to meet local energy demands as well.