What is the principle of an electronic expansion valve controller?
2 Answers
The principle of an electronic expansion valve controller is: 1. Electromagnetic expansion valve: It controls the system flow through an electromagnetic coil as the medium. Before the coil is energized, the valve needle remains open. After energization, the opening degree of the valve needle is controlled by the voltage on the electromagnetic coil to regulate the valve's flow. 2. Motorized expansion valve: It is a device driven by a stepper motor, where the logical digital signal provided to the stepper motor controls the internal threaded drive to move the valve needle. Components of an electronic expansion valve: 1. Rotor: Equivalent to the rotor of a synchronous motor, it connects to the valve stem to control the opening size of the valve orifice. 2. Stator: Equivalent to the stator of a synchronous motor; it converts electrical energy into a magnetic field to drive the rotor. 3. Valve needle: Driven by the rotor, its tapered end moves up and down to adjust the flow. 4. Valve body: Made of brass.
The electronic expansion valve controller regulates refrigerant flow by receiving signals from the air conditioning system sensors. Simply put, the AC computer constantly monitors data such as cabin temperature, evaporator temperature, and system pressure. When cooling intensity needs adjustment, the computer sends command signals to the controller. Inside the controller is a precision stepper motor that drives the valve needle up and down to alter the valve opening degree. A larger valve opening allows greater refrigerant flow, while a smaller opening reduces flow. This real-time adjustment enables the AC to precisely maintain set temperatures, unlike old-style expansion valves that were prone to frosting. I particularly appreciate this smart design when driving - the AC saves fuel while maintaining consistent comfort, making long trips exceptionally pleasant.
