Abstract: The system of screw chiller will easily occur exhaust temperature protection under the condition of low load and high pressure drop. Adding liquid injection in the general refrigeration can effectively improve it. What’s more, it can also ensure the system steadily running. But he volume of liquid injection should be under control in the system. And it can be achieved by throttle orifice and throttle capillary vessel. In this paper, we can provide a simple calculation method of throttle component.

Key words: Screw type chiller, Motor efficiency, Spray, Throttle mechanism