thermal expansion valve is a throttling device commonly used in air conditioning systems, usually composed of a shell, valve core, spring, and temperature sensing components. It achieves cooling and protective effects on the air conditioning system by controlling the flow and pressure of the refrigerant.
The following is some basic information about thermal expansion valves in air conditioning systems:
1. Operational principle
The working principle of a thermal expansion valve is to use temperature sensing elements to sense temperature changes in the refrigeration system and control the refrigerant flow rate by changing the opening of the valve core. When the refrigeration system enters the refrigeration state, the refrigerant enters the low-pressure area through the throttle hole of the thermal expansion valve under high pressure, resulting in a cooling effect.
The functions of thermal expansion valves in air conditioning systems include:
①Control the flow rate of refrigerant: The thermal expansion valve can automatically adjust the opening of the valve core according to the temperature changes in the refrigeration system, thereby controlling the flow rate of refrigerant and achieving the optimal refrigeration effect.
②Energy conservation and emission reduction: The thermal expansion valve can achieve precise control of the flow and pressure of the refrigeration system, thereby improving system energy efficiency, reducing energy consumption and carbon emissions.
③Protecting the compressor: The thermal expansion valve can reduce the flow and pressure of the refrigerant to avoid compressor damage caused by overload or liquid hammer in the air conditioning system.
3. Maintenance and upkeep
To ensure the normal operation of the thermal expansion valve, it should be cleaned and inspected regularly. When cleaning, attention should be paid not to use excessively hot water or chemical solutions to avoid damaging the valve core and temperature sensing components. At the same time, it is necessary to check the valve for leakage, jamming, or blockage, and replace or repair it in a timely manner.
4. The refrigeration system may not necessarily use a thermal expansion valve as a throttling element, but can be replaced by the following parts:
① Capillary tubes and throttling short tubes (CCOT) can be used as throttling components, with low cost and good reliability;
② Electronic expansion valves can be used to make control more precise, but due to the use of sensors, control circuit boards, and actuators with stepper motors, manufacturing is complex and costs increase;
③ The new CO2 system also uses injection pipes as throttling elements.
In summary, the thermal expansion valve plays an important role in the air conditioning system, achieving cooling and protection effects on the air conditioning system by automatically adjusting the flow and pressure of the refrigerant. Its correct maintenance and upkeep can extend its service life, improve the energy efficiency and performance of the air conditioning system.