Final answer:
The refrigerant must leave the cylinder as a liquid to maintain composition and ensure efficient heat transfer in a refrigeration cycle. It goes through phase changes in the evaporator and condenser to absorb and release heat effectively.
Step-by-step explanation:
When working with blended refrigerants, the refrigerant must leave the cylinder as a liquid to ensure proper composition of the refrigerant mixture as it enters the HVAC system. In refrigeration cycles, phase changes are essential for efficient heat transfer. The liquid refrigerant flows through an expansion valve to the evaporator coils, where it evaporates by absorbing heat and cooling the surrounding area. This vapor is then compressed, raising its temperature and pressure, and it condenses back to a liquid in the condenser, releasing the absorbed heat to the outside environment. To maintain efficiency and performance, it is crucial that the refrigerant maintains its blended composition, which is achieved by dispensing it as a liquid. Withdrawal as a gas could lead to fractionation, where the mixture composition could change, impairing the system's efficiency and possibly causing damage or reduced cooling effectiveness.