A hybrid operating strategy of combined cooling, heating and power system for multiple demands considering domestic hot water preferentially: A case study

•Propose a HET method for a CCHP system driven by natural gas and solar energy.•Consider variable system electric-thermal performance during 24 h.•Meet the domestic hot water demand preferentially.•Discuss variable electric-thermal ratio load conditions.•Compare the HET with FEL and FTL for hotel applications.

A hybrid electric-thermal (HET) following method is proposed for a combined cooling, heating and power (CCHP) system driven by natural gas and solar energy, focusing on the supply matching of domestic hot water, space cooling/heating and electricity. The domestic hot water thermal demand (Class A) is set to be met preferentially due to its immediateness and timeliness, and the space cooling/heating (Class B) thermal demand matching condition will be discussed from the view of comfort reliability. Detailed strategy methods under summer and winter conditions are presented. Variable electric-thermal ratio (RA, the ratio of the thermal demand of domestic hot water to the electric demand, RB, the ratio of the thermal demand of space cooling/heating to the electric demand) load conditions are analyzed and a comparison of HET between the base following electric load and following thermal load strategies is discussed for hotel applications. The criteria including primary energy consumption, carbon dioxide emission, operation cost and exergy efficiency is employed to evaluate the performances in the HET strategy. The results indicate that HET can achieve more benefits than the base operation strategies.