This paper presents an experimental study of the influence of a variable geometry ejector (VGE) design on the performance of a small-scale, 1.5 kW nominal capacity solar heat driven ejector air-conditioning system under real-life working conditions. Under variable operating conditions (e.g. solar radiation, ambient temperature) fixed geometry ejector performs poorly, therefore the objective of the present work was to prove the benefit of the VGE concept. In the experimentally tested VGE the area ratio through a movable spindle (SP) and the nozzle exit position (NXP) can be adjusted in order to respond to the operating conditions. The results showed very stable operation of the cooling cycle during the experiments. Both NXP, SP had considerable influences on the cooling cycle performance. An optimal NXP was identified, which did not change with various operating conditions. Similarly, SP also showed an optimum; however, the optimum point depended strongly on the operating conditions. The results clearly indicated the benefit of using the VGE design over the fixed geometry. COP improvement was as high as 24% with a maximum of 0.29 corresponding to a cooling capacity of 1.6 kW when compared to a fixed geometry ejector. The study also confirmed the importance of using a variable-speed pump in the ejector cycle.

本文介绍了在实际工作条件下可变几何形状喷射器（VGE）设计对小型1.5 kW标称容量太阳能热驱动喷射器空调系统性能的影响的实验研究。在可变的工作条件下（例如太阳辐射，环境温度），固定式几何喷射器的性能较差，因此，本工作的目的是证明VGE概念的益处。在经过实验测试的VGE中，可以调整通过可移动主轴（SP）的面积比和喷嘴出口位置（NXP），以响应工作条件。结果表明，在实验过程中冷却循环的运行非常稳定。恩智浦，SP都对冷却循环性能产生很大影响。确定了最佳的恩智浦，不会随各种运行条件而变化。同样，SP也显示出最佳状态。但是，最佳点在很大程度上取决于操作条件。结果清楚表明，使用VGE设计优于固定几何。与固定几何形状的喷射器相比，COP改进高达24％，最大值为0.29，对应的冷却能力为1.6 kW。该研究还证实了在喷射器循环中使用变速泵的重要性。与固定几何形状的喷射器相比为6 kW。该研究还证实了在喷射器循环中使用变速泵的重要性。与固定几何形状的喷射器相比为6 kW。研究还证实了在喷射器循环中使用变速泵的重要性。