Research on interconnected operation characteristics of combined cooling heating and power system based on load difference

The two combined cooling, heating, and power (CCHP) systems in the region can be connected through the power and heat grids to realize interconnected operation, taking advantage of the spatial and temporal complementarity of load demand and significantly improving the overall performance of the regional energy system. In this paper, a mathematical model of the interconnected combined cooling, heating, and power (ICCHP) system is first constructed, and three operation strategies, namely following electric load (FEL), following thermal load (FTL), and following hybrid electric-heating load (FHL), are considered. The combined performance index (CPI) of the two CCHP systems under interconnected and independent operation is calculated based on the conventional split-supply (SP) system by combining the strategies. Subsequently, a load characterization parameter (the time interval at which the load is shifted along the time axis) is proposed to further investigate the effect of load difference on the performance of the ICCHP system. The results indicate that the system performance of CCHP systems with different building users in the interconnected mode of operation is improved compared to the independent mode of operation, which is mainly due to the energy complementary characteristics between different load demands and operation strategies. In particular, when both CCHP systems are operated with the FTL strategy, the CPI of the systems in the three interconnection scenarios improves the most compared to when they are operated independently, which are 9.14 %, 9.37 %, and 5.02 %, respectively. Overall, when CCHP systems for two different building users operate interconnected, the reduction in the difference in load peak and valley durations results in a reduction in ICCHP system performance.