The electronic expansion valve is a commonly used control element in refrigeration and air conditioning systems to regulate the flow and pressure of refrigerant. This article will introduce the control principle and fault judgment method of electronic expansion valve in detail.
First, the control principle of the electronic expansion valve.
The electronic expansion valve is a type of needle valve driven by a stepper motor with adjustable opening, and its working principle is mainly based on the differential pressure and thermal properties of the refrigerant. In a refrigeration system, the refrigerant expands due to changes in temperature and pressure as it passes through an electronic expansion valve at high pressure, which regulates the flow and pressure of the refrigerant.
The control principle of the electronic expansion valve is mainly based on the pressure and temperature changes of the refrigeration system, detects the status of the system through sensors, and transmits the signal to the controller. According to the received signal, the controller controls the rotation of the stepper motor through the drive circuit, so as to adjust the opening degree of the electronic expansion valve. By adjusting the opening degree, the flow and pressure of the refrigerant can be controlled to achieve the desired cooling effect of the system.
Second, the fault judgment of the electronic expansion valve.
During use, the electronic expansion valve may have some faults, which will affect the normal operation of the refrigeration system. Therefore, it is very important to master the fault judgment method of electronic expansion valves.
1.The opening degree is abnormal.
Abnormal opening of the electronic expansion valve can be caused by a faulty stepper motor, a faulty sensor, or a faulty controller. If you find that the opening degree is abnormal, you should first check whether the relevant parts are working properly. If the part is normal, it may be that there is an abnormality in the control program and the control program needs to be readjusted or upgraded.
2.Fluorine leakage.
Fluorine leakage is one of the common failures of electronic expansion valves, mainly caused by aging or damaged seals, loose or damaged valve cores, etc. If fluorine leakage is found, the relevant parts should be repaired or replaced in time. During the repair process, attention should be paid to cleaning and replacing the sealing ring to ensure that the sealing effect is good.
3.Noise and vibration.
During use, if there is noise and vibration in the electronic expansion valve, it may be caused by loose components, faulty motors, or improper installation of pipes, etc. The installation of all relevant components should be checked to ensure that it is secure and reliable, and that the motor is working properly. If an abnormality is found, the relevant parts should be repaired or replaced in time.
4.Unable to adjust properly.
If you find that the electronic expansion valve does not adjust properly, it may be due to a faulty sensor, faulty controller, or poor wiring connection. All relevant parts should be checked to ensure that the wiring is well connected, and that the sensors and controllers are working properly. If an abnormality is found, the relevant parts should be repaired or replaced in time.
III. Conclusion. As an important control element in the refrigeration and air conditioning system, the working state of the electronic expansion valve directly affects the refrigeration effect and the stability of the system. Therefore, it is very important to understand the control principle and fault judgment method of the electronic expansion valve to maintain the normal operation of the refrigeration system. In actual use, the working status of the electronic expansion valve should be checked regularly, and the fault problem should be found and solved in time to ensure the stability and reliability of the system. At the same time, for professional maintenance personnel, they should continue to learn new technologies and new knowledge to improve their skill level in order to better maintain and manage the refrigeration and air conditioning system.