基于CFD模拟的喷射泵操作参数对泵抽气性能的影响

通过CFD方法讨论了不同操作参数对喷射泵内部流体的流动特性及泵抽气性能的影响.随着工作蒸汽压力的增加，在壅塞位置处，被抽气体过流面积变化减小，马赫数、引射系数升高，喷射泵的抽气性能增强.当工作蒸汽压力过高时，由于膨胀核的增大，被抽气体的过流面积减小，引射系数显著下降.随着引射蒸汽压力的增加，壅塞和激波向下游移动，泵抽气性能增强.此外，引射系数随着背压的增加而减小，当背压过高时，返流现象明显，泵的抽气性能急剧下降直至失效.研究结果表明，操作参数的选择不仅能提高喷射泵的抽气效率和极限排气能力，也极大地提高了喷射制冷系统的制冷效率，降低了能源的消耗.

Influence of Operating Parameters on the Ejector Performance Based on CFD Simulation

The influences of the different operating parameters on flow characteristic of internal flow field and the ejector performance are discussed by CFD method. With the increase of the primary fluid pressure， the flow area of the secondary fluid pressure decreases at the choking position， however， the Mach number and the entrainment ratio both gradually increased， and the pumping performance is enhanced. When the pressure is too high， the flow region of the secondary fluid is compressed due to the increase of the expansion core and the entrainment ratio decreases obviously. With the increasing of the primary fluid pressure， the choking position and the shock wave moves downstream. The pumping performance of the ejector is strengthened. The entrainment ratio decreases with the increase of the back pressure. When the back pressure is too high， the reflux phenomenon is obvious and the pumping performance decreases sharply until it loses efficiency. The results indicated that the reasonable selection of the operating parameters can not only improve the pumping efficiency and exhaust capacity of the ejector， but also greatly improve the refrigeration efficiency of jet refrigeration system and reduce the energy consumption.