A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the po...A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the power and refrigeration cycle, respectively. A performance comparison and analysis for the combined system was presented. The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1% in thermal efficiency and 6.7% in exergy efficiency than that of basic ORC-VCRC. Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system. Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure, respectively. However, superheated temperature at expander inlet has little impact on the two indicators. It can achieve higher overall COP, net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC.展开更多
A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by T...A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by TRNSYS. The comparative analysis of the characteristics of attenuation and delay proves that the operation of radiant cooling system increases the degree of temperature attenuation of the room and reduces the inner surface temperature of the wall significantly, but has little effect on the attenuation coefficient and delay time of wall heat transfer. The simulation results also show that the inner surface temperature of the walls in the radiant cooling room is much lower than that in non-cooling room in the day with the maximum cooling load, which reduces the indoor operation temperature largely, and improves the thermal comfort. Finally, according to the analysis of indoor temperature of the rooms with different operation schedules of cooling system, it can be derived that the indoor mean temperature changes with the working time of radiant cooling system, and the operation schedule can be adjusted in practice according to the actual indoor temperature to achieve the integration of energy efficiency and thermal comfort.展开更多
基金Project(12C0379)supported by the Scientific Research Fund of Hunan Province,ChinaProject(13QDZ04)supported by the Scientific Research Foundation for Doctors of Xiangtan University,China
文摘A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the power and refrigeration cycle, respectively. A performance comparison and analysis for the combined system was presented. The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1% in thermal efficiency and 6.7% in exergy efficiency than that of basic ORC-VCRC. Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system. Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure, respectively. However, superheated temperature at expander inlet has little impact on the two indicators. It can achieve higher overall COP, net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC.
基金Project(2010DFA72740) supported by the International Science & Technology Cooperation Program of China
文摘A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by TRNSYS. The comparative analysis of the characteristics of attenuation and delay proves that the operation of radiant cooling system increases the degree of temperature attenuation of the room and reduces the inner surface temperature of the wall significantly, but has little effect on the attenuation coefficient and delay time of wall heat transfer. The simulation results also show that the inner surface temperature of the walls in the radiant cooling room is much lower than that in non-cooling room in the day with the maximum cooling load, which reduces the indoor operation temperature largely, and improves the thermal comfort. Finally, according to the analysis of indoor temperature of the rooms with different operation schedules of cooling system, it can be derived that the indoor mean temperature changes with the working time of radiant cooling system, and the operation schedule can be adjusted in practice according to the actual indoor temperature to achieve the integration of energy efficiency and thermal comfort.
