跨临界CO2压缩喷射系统稳定性实验研究

为了研究跨临界CO2压缩喷射系统的稳定性,在自行搭建的实验台上进行了改变工作环境参数及调节节流阀开度对系统稳定性影响的实验.通过分析实验工况下工作流体压力、引射流体压力、背压、工作流体流量、引射流体流量、喷射系数和升压比的变化趋势,得出以下系统稳定性规律：当冷却水流量变化或节流阀开度变化时,系统将从一个稳定状态过渡到另一个稳定状态,在过渡阶段系统处于不稳定状态；当节流阀开度接近全开（90%）时,工作流体压力将超过压力极限,工作流体流量将达到压缩机的阻塞工况,系统越来越偏离稳定工况,必须及时关闭系统；当节流阀开度接近全关（5%）时,引射流体流量不断减小,最终减小为零,喷射器不再卷吸引射流体,必须及时关闭系统.

Experimental study of working stability in transcritical CO2 compression-ejection system

Experiments were performed to reveal the influences of operating conditions and throttle opening on working stability of the transcritical CO2 compression ejection system. Through analysis of the trends in primary flow pressure, entrained flow pressure, back pressure, primary flow rate, entrained flow rate, entrainment ratio, and pressure lift, the following characteristics of system stability were determined. Changes in cooling water flow rate or throttle opening can cause the system to transition from one stable state to another. It can behave in an unstable way during the transition. When the throttle is nearly full open (90%), the primary pressure is near the high pressure limit. The primary flow reaches choke condition of the compressor. The system becomes unstable and must be shut down. When the throttle opening is nearly full closed (5%), the flow rate of the entrained fluid decreases until to zero. The ejector no longer entrains this fluid. The system becomes unstable and must be shut down．