Multi-objective optimization of a novel CCHP system with organic flash cycle based on different operating strategies.

Combined cooling, heating and power (CCHP) systems have recently received considerable attention, which can meet multiple energy demands of the users. In this study, a novel CCHP system combining the organic flash cycle (OFC) and solar thermal utilization (ST) system is proposed. Two operating strategies based on the following electric load (FEL) are designed for the building complex in Beijing: the FEL strategy with the negative feedback (NFEL) and the FEL strategy considering flexibility (FFEL). The multi-objective optimization of the operating strategy is performed and solved by the genetic algorithm and the random forest algorithm. The results show that the time of the simplified model by the random forest is reduced by 94.5%. The cost of the three strategies decreases and then increases as the power rating of the internal combustion engine (ICE) increases. When the weight factors are inconsistent, the optimal power rating of the ICE increases and the optimal flash temperature decreases for different strategies. The contribution of the heating provision of the NFEL strategy is 8% higher than that of the FEL strategy. The levelized cost of the FFEL strategy is 6.1% and 2.9% lower than the FEL and NFEL strategies. • A novel CCHP system with organic flash cycle and ST system is proposed. • A FEL strategy considering flexibility are designed for the building complex. • A multi-objective optimization is performed using the genetic algorithm. • The random forest algorithm is used to simplify the OFC thermodynamic model. [ABSTRACT FROM AUTHOR]