What state is the refrigerant in when it enters the metering device?

The correct state of the refrigerant when it enters the metering device is commonly a saturated liquid at a low temperature and low pressure. This is critical for the refrigeration cycle to function effectively.

The metering device is responsible for controlling the flow of refrigerant into the evaporator. If the refrigerant enters in the wrong state, it can lead to inefficient or ineffective operation of the system. When it is a saturated liquid, this means that it is at its boiling point and is ready to absorb heat as it enters the evaporator, where it will change into a vapor and provide cooling.

The other choices describe states that are not conducive for the effective operation of the refrigerant in the metering device. A superheated state indicates that the refrigerant is at a higher temperature and pressure than necessary, which can lead to reduced efficiency. A sub-cooled state might suggest that it is overly cooled and not in the ideal condition to absorb heat. Finally, a supercooled state at a very low temperature indicates that the refrigerant is far too cold and pressurized incorrectly for proper evaporation and heat absorption in the subsequent phase of the refrigeration cycle.

Overall, the saturated liquid state with low temperature and low pressure ensures that the refrigerant can efficiently perform