Lämpölaajenemisventtiili

Lämpölaajenemisventtiili, often abbreviated as TEV or EXV (expansion valve), is a key component in refrigeration and air conditioning systems. Its primary function is to control the flow of refrigerant into the evaporator, ensuring optimal system performance and efficiency. The valve operates based on the temperature of the refrigerant vapor leaving the evaporator.

A common type of TEV utilizes a sensing bulb filled with a volatile fluid. This bulb is attached to the suction line of the evaporator. As the temperature of the refrigerant vapor increases, the fluid in the bulb expands, which in turn actuates a diaphragm or bellows mechanism within the valve. This mechanism opens the valve further, allowing more refrigerant to flow into the evaporator. Conversely, if the evaporator temperature decreases, the fluid contracts, causing the valve to close or restrict the refrigerant flow.

The correct operation of the TEV is crucial for maintaining the desired superheat at the evaporator outlet. Superheat refers to the temperature of the refrigerant vapor above its saturation temperature. Too little superheat can lead to liquid refrigerant entering the compressor, potentially causing damage, while too much superheat indicates insufficient refrigerant flow and reduced cooling capacity. TEVs are therefore essential for protecting the compressor and maximizing the efficiency of the refrigeration cycle. They are widely used in various applications, from domestic refrigerators to large industrial cooling systems.