Thermodynamic performance analyses for CCHP system coupled with organic Rankine cycle and solar thermal utilization under a novel operation strategy

Abstract

The combination of an organic Rankine cycle (ORC) and solar collector (ST) with combined cooling heating and power (CCHP) system has the potential to improve its thermodynamic performances. Therefore, in this paper, fully considering thermal cascade utilization, a novel CCHP system combining ORC and ST is proposed, which uses solar energy and exhaust heat as ORC driving heat sources. Compared with traditional CCHP and CCHP-ST systems, the advantages of the CCHP-ORC-ST system are demonstrated. A collaborative optimization method considering both system configuration optimization and operation strategy is proposed, which realizes the improvement of system energy efficiency and economy. Based on the collaborative optimization method, the CCHP system with different integrated configurations is applied to commercial and office buildings. Through parameter analysis, the effects of parameters (such as the rated capacity of internal combustion engine and ORC evaporation temperature, etc.) are discussed. The findings portrays that the cost per unit supply area of the CCHP-ORC-ST system in typical years of office and commercial buildings is about 19.8 $/m2 and 25.9 $/m2. Compared with the CCHP system, the cost-saving rates of the CCHP-ORC-ST system in commercial and office buildings increase by 15.0% and 27.0%, respectively. The CCHP-ORC-ST system can flexibly utilize ORC to generate more electricity, improving energy efficiency and reducing wasted heat. Consequently, the proposed CCHP-ORC-ST system based on the collaborative optimization method can determine the optimal system configuration and operation design for energy savings and consumption reduction.