Thermodynamic analyses and optimization of a novel CCHP system integrated organic Rankine cycle and solar thermal utilization

摘要

Combined cooling, heating and power systems (CCHP) have received wide attention recently because of its prominent role in energy utilization. It could both decrease the energy consumption and improve the overall energy efficiency. In this paper, a novel coupled CCHP system was proposed which is composed of a conventional CCHP system, a solar thermal utilization (ST) subsystem and an organic Rankine cycle (ORC) subsystem. The CCHP-ST-ORC system has been evaluated thermodynamically, and compared with CCHP system and CCHP-ST system, which is based on the G(ICE) (rated internal combustion engine capacity) of 100 kW. Further, through the parametric study for CCHP-ST-ORC system, the effect of several operating parameters on the system thermodynamic performance is explored. Finally, a new operation strategy for CCHP-ST-ORC system was proposed and adopted in a residential building, which presents a better thermodynamic economy than CCHP-ST system. As the result, CCHP-ST-ORC system could generate an additional electricity of 5.1 kW compared with other two systems, which is at the expense of 39.3 kW heat. Further, it could expand the maximum power generation to 108 kW. The case study shows that the primary energy ratio of CCHP-ST-ORC system is 60.2% that is much higher than the 37.6% of CCHP-ST system. The results also indicate that the CCHP-ST-ORC system consumes 9.81 x 10(4)m(3)/year of natural gas, with a 12.4% reduction in energy consumption than CCHP-ST system. Therefore, these findings can promote the sustainable development of new energy utilization models, especially the coupling CCHP system.