Abstract
The energy saving characteristic is investigated for a gas engine cogeneration system combined with a photovoltaic array and a gas engine heat pump with power generation or a gas-fired absorption chiller heater with input of exhaust heat, when it is installed into a hospital as an example of commercial buildings. The on-off status and load of each piece of equipment are determined to minimize the primary energy consumption of electricity and natural gas purchased from utility companies. This optimization problem is formulated as a mixed-integer linear programming one and is solved using a commercially available solver. A numerical study shows that the gas engine cogeneration system is superior to a conventional system in the energy saving characteristic: the energy saving rate of the system with the gas engine heat pump with power generation is about 11%, and that of the system with the gas-fired absorption chiller heater with input of exhaust heat is about 8%.
