A novel multi-objective optimization method for CCHP-GSHP coupling systems

Combined cooling, heating and power system is widely used in buildings nowadays due to its environment-friendly, operation cost saving and energy-saving characteristics. Ground source heat pump is also an energy-saving and environment-friendly technology. Integrating them may make their perspective advantages to full play. In this paper, the optimal model of CCHP-GSHP coupling system is constructed based on environment, economy and energy criteria simultaneously. The variables are the rated electric capacity of power generation unit, the ratio of cooling supplied by ground source heat pump to total cooling load, the ratio of heating supplied by ground source heat pump to total heating load and the value to determine whether run the power generation unit. Genetic algorithm is selected to solve the optimization problem. The model can be utilized in optimizing the capacity and operation of coupling system. A case analysis is used to prove the practicability of this optimal model. The optimal objective values of this model are: carbon dioxide emission reduction rate is 33.88%; annual total cost saving rate is 8.62%; primary energy saving rate is 15.24%; multi-objective value is 19.25%. At last, the sensitivity analysis of electricity and gas cost is also proposed.