Electrical and electronic expansion valves
The electronic expansion valve with electronic control, the stepper motor. The motor moves in and out in small steps. When sleeve attached to the shaft moves up, it provides more accounting slots. It increases the flow of the refrigerant in the evaporator. When he moves down, it covers slots, thus reducing the flow and cooling capacity. One manufacturer uses this type of valve piston packaged chillers from 280 tons of cooling capacity instead of the usual thermostatic expansion valve, usually found on such equipment.
As TXV, this type of valve is used to maintain a constant overheating. Stepper motor controller receives a signal from an electronic control panel, which is attached to an electronic sensor that measures the refrigerant overheating. Because it is controlled independently of pressure, the valve is able to provide a safe launch, safe shutdown, stable performance and high energy efficiency through a full range of operating conditions. As electronic control systems, increasing the popularity, we can expect to see electron-driven valves on more and more systems.