Application of vortex control to a transcritical R744 ejector cycle.

This paper presents results of a novel expansion device refrigerant flow control mechanism called vortex control. The key advantage of this control mechanism is being far less vulnerable to clogging than conventional expansion devices since the flow control is achieved without having to adjust the cross-sectional flow area in order to achieve the desired modulation effect. Vortex flow control is seen as particularly promising when applied to transcriticalR744 ejectors, where flow control of the motive nozzle is known to substantially impact ejector and cycle efficiencies. Vortex control can potentially offer the advantage that overall ejector efficiency is less impacted than designs where a needle is used to modulate the motive nozzle flow. The effects of operating conditions were investigated experimentally. It is shown that vortex flow control appears to be feasible for two-phase ejectors using R744 and similar flow modulation ranges as with needle control were achieved.

本文介绍了一种名为涡流控制（vortex control）的新型膨胀装置制冷剂流量控制机制的研究结果。该控制机制的核心优势在于，与传统膨胀装置相比，其抗堵塞能力显著更强——因为无需调整流动截面积即可实现预期的调节效果，从而达成流量控制。涡流控制应用于跨临界R744喷射器时前景尤为广阔，因为在这类喷射器中，动力喷嘴的流量控制对喷射器效率及循环效率均有显著影响。相较于采用针阀调节动力喷嘴流量的设计，涡流控制有望带来整体喷射器效率受影响程度更低的优势。研究人员通过实验探究了运行条件的影响。结果表明，涡流控制应用于R744两相喷射器具有可行性，且实现了与针阀控制相当的流量调节范围。