脉冲式膨胀机构节流特性的试验研究

Experimental Research on Throttling Characteristics of Impulse Expansion Valve

在制冷陈列柜制冷系统的基础上建立脉冲式膨胀阀制冷系统的性能试验台,通过调节脉冲电子信号,对脉冲膨胀阀进行了节流特性的试验研究。试验得出了脉冲膨胀阀的节流特性规律,指出对脉冲膨胀阀节流特性有影响的因素。研究表明供液系数是影响制冷系统蒸发温度的主要因素,而脉冲频率会影响系统达到稳定的时间以及蒸发温度的波动情况,并对三种节流机构(热力膨胀阀、电子膨胀阀和脉冲膨胀阀)进行了性能对比试验。研究表明使用脉冲膨胀阀的蒸发器蒸发温度变化规律有别于热力膨胀阀和传统的电子膨胀阀。蒸发器入口和出口的温度在开机很短时间内就能达到稳定的蒸发温度,并能稳定在很小的过热度范围内。使用脉冲膨胀阀的制冷系统能很好的实现制冷循环的节流效果,调节脉冲信号可使系统满足工况变化的要求。

The throttling characteristics of impulse expansion valve （IEV） are tested by adjusting impulse electron signals on the experimental apparatus developed by ourselves. The special throttling character of IEV is achieved experimentally and factors influencing the throttling characteristic of IEV are pointed out. The results show that fluid supplying coefficient is the main factor that influences the evaporating temperature of refrigeration system, and impulse frequency affects the time needed by the system to reach steady and the fluctuation of the evaporating temperature. The contrast experimental study on performance of three throttle mechanisms, such as thermostatic expansion valve, electronic expansion valve and impulse expansion valve. The results show that the variation of temperature in the evaporator adopting impulse expansion valve is different from that using thermostatic expansion valve or electronic expansion valve. The inlet and outlet temperature of the evaporator can reach the steady evaporating temperature in a short time and the superheated temperature can be maintained in a small range. The refrigeration system employed IEV can realize much better throttling results and the adjusting impulse electron signal can meet the need of the change of running conditions.