引入CO_2混合物以及利用压缩/引射制冷循环,能有效提高其系统循环效率。建立了两相流引射器系统,采用均相流的索科洛夫理论、Eames等理论及热力学方法中两相流引射器模型进行分析,通过与文献中的实验结果对比,确定热力学方法在两相流引射器的设计计算中较为接近实际。基于热力学方法对CO_2/R32(质量比40/60)、CO_2/R41(质量比20/80)两类二元非共沸混合工质压缩/引射制冷循环系统的效率进行分析,发现带引射器比不带引射器时效率分别提高了30%和20%,而且通过引入混合物改善物性后的系统效率可以比纯工质CO_2系统效率提高50%以上,同时证明了CO_2/R32的效果要好于CO_2/R41。
The mixture of CO2 and compression/ejection refrigeration cycle can increase the system efficiency of CO2. This system which was about two phase flow ejector system was established and analyzed by theory of Sokurov, theory of Eames etc. and two phase flow ejector model from thermodynamics method. After comparing with the results in the literature, the thermodynamics method was proved to be more close to the truth in design and calculate method for the ejector of two-phase flow. Thermodynamics method was used for analysing the ejector in compression/ejection refrigeration cycle which working medium were binary non-azeotropic mixed refrigerants CO2/ R32 (mass ratio 40/60 ) and CO2/R41 (mass ratio 20/80 ). The comparisons show that the efficiency of the system with ejector is respectively 30% and 20% higher than the one without ejetor. The system efficiency which is increased by using mixed refrigerants for improving physical properties is more than 50% higher than the one of simple substance CO2 and CO2/R32 is better than CO2/R41.