Novel design of a CCHP system to boost nearly zero-carbon building concept

The accumulation of carbon dioxide in the atmosphere is responsible for global warming. To address this issue, this study develops and optimizes a novel and economically viable combined cooling, heating, and power (CCHP) system for an educational building with minimal CO2 emissions. The main components of the system include a gas turbine cycle, a molten carbonate fuel cell, a heating system, an electric chiller, and an absorption chiller. Optimization is conducted based on a 4E (energy, exergy, economic, and environmental) analysis using TRNSYS and MATLAB software. The optimized CCHP system has a unit product cost of $52.44/h with an overall exergy efficiency of 44.34 %, generating 0.39 kg of CO2/kWh. Furthermore, the objective of a nearly zero-carbon system is achieved by integrating carbon capture and storage (CCS) into the original CCHP system. A novel cryogenic carbon capture unit is implemented to capture CO2 from the flue gas. Integrating CCS reduces CO2 emissions by up to 91 %, presenting a cost-effective approach to carbon offset. Although there is a modest increase in operational costs ($53.46/h) and a slight decrease in exergy efficiency (43.3 %), these trade-offs are necessary to attain an environmentally responsible system. Overall, the optimized CCHP system with the integrated CCS shows potential as an energy-efficient solution for the selected educational building while reducing CO2 emissions.