Thermodynamic assessment of a novel multi-generation solid oxide fuel cell-based system for production of electrical power, cooling, fresh water, and hydrogen

Abstract

The thermodynamic assessment of a novel multi-generation system producing electrical power, cooling load, potable and sanitary water, and hydrogen is conducted from the viewpoints of energy and exergy analyses. The proposed system consists of a solid oxide fuel cell as the prime mover, a gas turbine, a biomass combustion subsystem, an organic Rankin cycle integrated with an ejector refrigeration cycle, a desalination subsystem, and a proton exchange membrane electrolyser subsystem. The produced fresh water is utilized to produce potable and sanitary water, and hydrogen. Considering the fact that flat plate collectors are employed to raise the water temperature to the operating temperature of the electrolyser, 12 daylight hours of a day are dedicated to sanitary water and hydrogen production by means of the electrolyser and the rest night hours are devoted to potable water production. During the commissioning period of the hydrogen production subsystem, the effect of three crucial parameters including, current density, fuel utilization factor, and solid oxide fuel cell inlet temperature on several variables related to the system has been investigated. It is concluded that under the baseline design conditions, the net electrical power, the cooling load, and the overall energy and exergy efficiencies are correspondingly equal to 4392 kW, 164.2 kW, 77.58%, and 47.14%. Furthermore, the molar rate of the potable and sanitary water, and hydrogen production are 53.27, 52.50, and 0.7695 mol/s, respectively.