| 论文简介 |
In this paper, a modified dual-evaporator CO2 transcritical refrigeration cycle with two-stage ejector
(MDRC) is proposed. In MDRC, the two-stage ejector are employed to recover the expansion work from
cycle throttling processes and enhance the system performance and obtain dual-temperature refrigeration
simultaneously. The effects of some key parameters on the thermodynamic performance of the
modified cycle are theoretically investigated based on energetic and exergetic analyses. The simulation
results for the modified cycle show that two-stage ejector exhibits more effective system performance
improvement than the single ejector in CO2 dual-temperature refrigeration cycle, and the improvements
of the maximum system COP (coefficient of performance) and system exergy efficiency could reach
37.61% and 31.9% over those of the conventional dual-evaporator cycle under the given operating conditions.
The exergetic analysis for each component at optimum discharge pressure indicates that the gas
cooler, compressor, two-stage ejector and expansion valves contribute main portion to the total system
exergy destruction, and the exergy destruction caused by the two-stage ejector could amount to 16.91%
of the exergy input. The performance characteristics of the proposed cycle show its promise in dualevaporator
refrigeration system. |
(创新港)
