Abstract:

In order to ensure the normal operation of the refrigeration system with a falling-film evaporator, a liquid ammonia ejection pump is used as the circulating equipment for liquid ammonia in the evaporator. Based on the gas kinetic function method, the performance calculation program of the ejection pump is prepared, the thermal performance of the ejection pump in the refrigeration system is analyzed, and the influence of the operating parameters on the performance of the ejection pump is studied. The results show that, keeping the ejection pressure and outlet pressure unchanged, the higher the working fluid pressure, the larger the entrainment ratio; the lower the working fluid temperature, the smaller the entrainment ratio. Keeping the working pressure and outlet pressure unchanged, the higher the saturated ejection pressure is, the larger the entrainment ratio is, and the closer the value of the ejection pressure is to the value of the outlet pressure, the more significant the change of the entrainment ratio is. The saturated injection liquid ammonia pressure remains unchanged, and the closer the outlet pressure is to the injection liquid ammonia pressure, the more obvious the injection coefficient increases with the increase of the working liquid ammonia pressure.

Key words: ammonia, ejection pump, kinetic theory, thermal performance, entrainment ratio

摘要：

为保证带有降膜蒸发器的制冷系统正常运行，采用液氨喷射泵作为蒸发器中液氨的循环设备。基于动力学理论，编制了喷射泵的性能计算程序，分析了制冷系统中喷射泵的热力学性能，研究了操作参数对喷射泵性能的影响。结果表明，保持引射压力与出口压力不变，工作流体压力越高，喷射系数越大；工作流体温度越低，喷射系数越小。保持工作压力与出口压力不变，饱和引射压力越高，喷射系数越大，引射压力值越接近于出口压力值，喷射系数变化越显著。饱和引射液氨压力不变，出口压力越接近于引射液氨压力，喷射系数随工作液氨压力的升高增加程度越明显。

关键词: 氨, 喷射泵, 动力学理论, 热力学性能, 喷射系数