A novel off-design model to optimize combined cooling, heating and power system with hybrid chillers for different operation strategies

Abstract A combined cooling, heating and power system with hybrid chillers is designed, which mainly includes power generation unit, ground source heat pump system, boiler, absorption chiller, electric chiller and heating exchanger. In order to better reflect the actual operation of the system, the main devices of system are considered as off-design models. A novel parameter named start factor of off-design devices is proposed to improve devices efficiency. Under following electric load and following thermal load operating strategies, the optimal capacity and comprehensive performance of the system devices are obtained. By different off-design models, seven system models are built to analysis under two operating strategies. Moth flame optimization is selected as the optimization method to get model results. The results show that most start-factor system models can improve the system performance. Under the following electric load operating strategy, the typical start-factor model is compared with the traditional model (the energy saving: 8.25%; the cost saving: 7.47%; the carbon dioxide emission reduction: 7.22%). Under the following thermal load operating strategies operating strategy, the typical start-factor model is compared with the traditional model (the energy saving: 23.10%; the cost saving: 22.33%; the carbon dioxide emission reduction: 22.80%).