What condition does superheating refer to in the refrigeration cycle?

Superheating refers to the condition in which a refrigerant is heated beyond its boiling point while remaining in a gaseous state. This occurs in the refrigeration cycle after the refrigerant has evaporated in the evaporator coil and is now in vapor form. At this stage, the refrigerant must be heated further to ensure that it is fully in vapor form before it enters the compressor.

This process is crucial because if the refrigerant enters the compressor in a mixed state of liquid and gas, it can lead to compressor damage due to liquid slugging. By ensuring that the refrigerant is superheated, it guarantees that only vapor reaches the compressor, allowing for efficient operation and protecting the system.

The other conditions mentioned do not align with the definition of superheating, as they refer to various states of refrigerants that do not involve exceeding the boiling point in the gaseous phase.