蒸发器出口状态热式测量的实验研究

根据热式感应原理,专门设计热式感应传感器,用于测量蒸汽压缩制冷循环中干式蒸发器出口的气液两相流动状态;热式感应传感器的测量数据与蒸发器出口流型、过热度等参数的综合比较分析表明:热式感应传感器可以辨识出蒸发器出口过热蒸汽、雾状流和二者交替三种流动状态.同时,实验数据表明蒸发器出口处于过热蒸汽、雾状流二者交替的过渡区时其换热效率最佳,因此热式感应传感器可以用于作为膨胀阀-干式蒸发器调节回路的反馈信号.应用热式感应传感器对蒸发器出口状态的随机性和周期性波动的测量证明:热式感应传感器动态性能良好,可以实时反映蒸发器出口状态变化.

EXPERIMENTAL STUDY ON THE FLOW STATE AT EVAPORATOR EXIT WITH A THERMAL SENSOR

A delicate thermal sensor is especially designed to measure a two-phase flow at dry evaporator's outlet in a refrigeration cycle and relationship between the temperature differences with a thermal sensor.The presence of a two-phase flow pattern and superheat at dry evaporator's outlet indicates that the thermal sensor can tell one from another between superheat vapor,fog,and mixture-vapor,and that the dry evaporator achieves its max heat exchange mass when mixture-vapor appears here.Meanwhile,the fact that thermal sensor has detected random and periodic fluctuation proves that it can inform real-time state at evaporator's outlet.