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The Function and Working Principle of Solenoid Valve

Jan. 13, 2021

1.The composition of the solenoid valve

The Solenoid Valve is a valve that controls the automatic on and off of refrigerant in the refrigeration system. Solenoid valves can be divided into direct acting and indirect acting. Solenoid valves used in commercial refrigeration equipment are generally direct acting.

The solenoid valve is composed of a valve body and a solenoid head, which are generally direct-acting. The so-called direct opening and closing solenoid valve is to use the armature in the solenoid to directly control the opening and closing of the valve hole. The aperture is generally 6- Between 22mm.

2. The function and working principle of solenoid valve

The role of solenoid valve:

The refrigeration system is divided into high pressure and low pressure, liquid and gas. In order to prevent the high-pressure liquid refrigerant from impacting the compressor after the compressor is stopped, solenoid valves are used for protection. When the compressor is started, the system pressure is in a balanced state so there is no impact At this time, the solenoid valve is powered on to turn on the compressor to start, and the refrigerant circulates for cooling.

When the compressor is shut down or the Explosion-Proof Solenoid Valve is quickly cut off after the stop, the refrigerant on the high-pressure side will not return to the compressor in the opposite direction, but will pass through the compressor in the direction of circulation. Slowly the entire refrigeration system has Slowly restore balance with the stop pressure of the compressor.

working principle:

When the refrigeration equipment is started, the solenoid coil generates electromagnetic force to open the valve. When the coil in the solenoid head is energized, the coil and the armature generate an inductive magnetic field. The armature drives the valve needle to move up, the valve hole is opened, and the fluid flows normally. When the set temperature is reached, when the coil in the solenoid is de-energized, the magnetic field disappears, the armature falls by rain and spring force, the valve needle closes the valve hole, and the fluid stops flowing.

Solenoid Valve

Solenoid Valve

3.The selection of solenoid valve

Generally, the solenoid valve with the appropriate port size should be selected according to the flow rate of the system, and the working voltage, applicable ambient temperature, working pressure and other parameter requirements should also be considered. When installing the solenoid valve, the valve body of the solenoid valve should be perpendicular to the pipeline to ensure that the solenoid valve core can move up and down easily.

In order to ensure the tightness when the solenoid valve is closed, it is required that the flow direction of the medium in the system should be consistent with the nominal direction on the solenoid valve body. In addition, in order to prevent the solenoid valve core hole from being dirty, it is recommended that the front end of the solenoid valve Install the filter, and the solenoid valve body should be fixed on the unit or bracket to avoid vibration and cause system leakage.

4.Common faults of solenoid valves

1. The power supply wiring is bad, just need to re-wire or connect the plug-in;

2. The unstable voltage of the power supply requires timely adjustment of the voltage to restore the rated value;

3. Impurities in the system cause the main spool of the solenoid valve or the moving iron spool to be stuck. The impurities in the system must be cleaned in time and the solenoid valve must be replaced;

4. The quality of the solenoid valve itself or the working life is too long, it needs to be replaced;

5. The main valve core or the seal of the moving iron core is damaged and cannot be closed;

6. The solenoid valve spring fails, and the spring must be replaced in time;

If you have more questions, please feel free to contact the Solenoid Valve Supplier

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