Question

An adiabatic capillary tube is used in some refrigeration systems to drop the pressure of the refrigerant from the condenser level to the evaporator level. The R-134a enters the capillary tube as a saturated liquid at 50°C, and leaves at -12°C. Determine the quality of the refrigerant at the inlet of the evaporator.

Answer 1

Answer:

The quality of refrigerant is 0.423

Explanation:

• Adiabatic tubes drop the pressure from condenser level to evaporator level in refrigeration systems.

• The values taken in this problem are from the saturated R-134a table.
• All the calculation is attached in the image. In the problem, hf stands for the enthalpy of saturated liquid while hfg stands for enthalpy of saturated evaporation.
• Both terms have units KJ/kg (kilo joule per kg).