A unique thermal system coupled with thermal energy and carbon capturing and storage options

In this work, a Municipal Solid Waste (MSW) and solar thermal driven trigeneration system for power, space heating, and freshwater production is developed and thermodynamically assessed. The novelty of this work includes the use of MSW composition listed for Ontario, as fuel feed to an air-Brayton cycle, as well as coupling a heat pump to it through water conduits, to carry out thermal desalination and space heating applications. Related calculations are carried out using corresponding mass, energy, entropy, and exergy balance equations of key system components, and Engineering Equation Solver (EES). The integrated heat pump utilizes R134a refrigerant and is driven by solar thermal collectors during periods when sunlight is available, and through sensible thermal energy storage otherwise. Under nominal operating conditions, an irradiance of 800 W/m² is considered, and the energy and exergy efficiencies of 37.43 % and 24.55 %, are achieved, respectively. Moreover, a coefficient of performance of 2.72 is obtained for the same operating conditions. For more location specific calculations, the solar profile for the Durham region in Ontario, Canada, is used and values are obtained as yearly averages for irradiance. This results in a variation of energy and exergy efficiencies across a diurnal operation, where they range between 52.56 % to 43.98 % and 35.67 % to 29.27 %, respectively. The thermal energy storage charging capacity ranges between 2,625 kWh to 12,985 kWh during the day, and results in a uniform discharge capacity of 6,297 kWh for periods of no sunlight where energy and exergy efficiencies are obtained to be 49.43 % and 33.3 %, respectively. The variation of the reference temperature is also considered where the exergy efficiency decreases from 24.55 % to 23.38 %, as the reference temperature increases from 296.15 K to 340 K for 800 W/m² irradiance. Finally, corresponding exergy destruction calculations are carried out to determine potential room for improvement.