喷嘴临界截面直径对喷射器性能影响的实验研究

Experimental Study on the Influence of Nozzle Critical Section Diameter on Ejector Performance

中文关键词: 二氧化碳  喷嘴临界截面直径  喷射器  喷射系数  实验研究

英文关键词: CO2  nozzle critical section diameter  ejector  ejection coefficient  experimental study

中文摘要:

      依据索科洛夫等学者提出的经验公式对喷射器进行优化设计,搭建了用于测量喷射器性能的实验台,以CO2为工质,分别研究当工作流体压力在8.0~9.6MPa、引射流体压力在2.4~2.8MPa以及工作流体温度在70~90℃时,喷嘴临界截面直径对喷射系数的变化规律。实验结果表明：当喷射器背压为3.9MPa、工作流体温度为90℃、引射流体压力为2.4MPa、工作流体压力在8.0~9.6MPa时,喷射器的喷射系数随喷嘴临界截面直径的增大而减小；当喷射器背压为3.9MPa、工作流体温度为90℃、工作流体压力为10.0MPa、引射流体压力在2.4~2.8MPa时,喷射器的喷射系数也随喷嘴临界截面直径的增大而减小；且喷射系数理论值与实验值吻合度较好,误差在±3.75%范围内。当喷射器工作流体压力为10.0MPa、引射流体压力为2.7MPa、喷射器背压为3.9MPa、工作流体温度在70~90℃时,喷射系数随着喷嘴临界截面直径的增大而逐渐减小。另外，在保持喷射器的基本工作参数不变时，工作流体压力及引射流体压力的提高对喷射器喷射系数均有提升作用。

英文摘要:

      According to the empirical formula proposed by Sokolov and other scholars, the ejector was optimized and a test bench for measuring the performance of the ejector was built.Taking CO2 as the working fluid, the change of the critical section diameter of the nozzle to the ejection coefficient was studied when the working fluid pressure varies from 8.0 to 9.6 MPa, the ejector fluid pressure varies from 2.4 to 2.8 MPa, and the working fluid temperature varies from 70 to 90℃. The experimental results show that when the ejector back pressure is 3.9MPa, the working fluid temperature is 90℃, the ejector fluid pressure is 2.4MPa, and the working fluid pressure is in the range of 8.0~9.6MPa, the ejection coefficient falls with the critical section of the nozzle rise. And the same trend is obtained when the ejector back pressure is 3.9MPa, the working fluid temperature is 90℃, the working fluid pressure is 10.0 MPa, and the ejector fluid pressure is in the range of 2.4 to 2.8 MPa. The theoretical value of the ejection coefficient agrees well with the experimental value, and the error is within the range of ±3.75%. When the ejector working fluid pressure is 10.0MPa, the ejector fluid pressure is 2.7 MPa, the ejector back pressure is 3.9 MPa, and the working fluid temperature is in the range of 70-90℃, the ejection coefficient increases with the critical section diameter of the nozzle slowing shrieking.In additon, when the basic working parameters of the ejector are kept unchanged, the increase of the working fluid pressure and the ejector fluid pressure can improve the ejection coefficient of the ejector.