The gas-liquid separator, also known as the gas-liquid separation tank, is a core protective equipment installed on the low-pressure side of the refrigeration system (between the evaporator and the compressor). Its core responsibility is to completely separate the gaseous and liquid phases in the gas-liquid mixture refrigerant discharged from the evaporator, ensuring that only the gaseous refrigerant enters the compressor, preventing “liquid hammer” faults, and recovering lubricating oil from the refrigerant. It is known as the “safety guard” of the compressor.
The core working principle of the vapor-liquid separator is based on the triple action of “centrifugal force+gravity settling+filter interception” to achieve efficient gas-liquid separation: the gas-liquid mixture refrigerant discharged from the evaporator enters the separator shell through the tangential inlet, and moves at high speed along the cylinder wall in a spiral motion, using centrifugal force to throw the heavier liquid refrigerant and lubricating oil towards the wall, forming a liquid film; The liquid film flows downwards along the wall under the action of gravity and collects in the bottom storage area; Gaseous refrigerant accumulates towards the center under centrifugal force and enters the compressor through the top outlet; At the same time, the filter inside the shell can intercept tiny droplets, further improving the separation efficiency, which can reach over 98%.
According to their structural form and intake method, gas-liquid separators are mainly divided into three types, which are suitable for different system scales:
1. Vertical straight through type: simple structure, compact volume, refrigerant enters vertically from the top, and liquid medium is discharged from the bottom, with moderate separation efficiency (95% -98%), suitable for small refrigeration systems such as household air conditioning, small cold storage, and mobile refrigeration equipment.
2. Horizontal type: The shell is arranged horizontally, and the refrigerant enters from the side in a tangential direction. There is a guide plate inside, which has a large separation area and high separation efficiency (over 98%). It can store more liquid refrigerant and is suitable for large refrigeration systems, such as central air conditioning, large cold chain warehouses, and industrial chillers.
3. Bring back heat function type: Integrating heat exchange pipelines inside or outside the separator, using the heat of gaseous refrigerant to heat the bottom liquid refrigerant, causing partial evaporation of the liquid refrigerant. This not only increases the superheat of the return gas, but also avoids the retention of liquid refrigerant, while improving the cooling efficiency of the system, suitable for low-temperature refrigeration systems (below -18 ℃).
Its core protection mechanism is reflected in two aspects: first, to prevent liquid impact, completely separate liquid refrigerant, and prevent liquid refrigerant from entering the compressor cylinder, causing damage to components such as cylinders and pistons; The second is oil return protection, which collects lubricating oil carried in the refrigerant and returns it to the compressor through the bottom oil return hole to ensure sufficient lubrication and extend the service life of the compressor by more than 30%.