Question

A simple saturated refrigeration cycle that uses R-12 has an evaporating temp of −50C and a condensing temp of 400C. Determine the refrigerating effect per kg,

Answer 1

The refrigerating effect per kg can be determined using the enthalpy of vaporization and the enthalpy of compression.

Step-by-step explanation:

The refrigerating effect per kg can be determined using the formula:

refrigerating effect per kg = enthalpy of vaporization - enthalpy of compression

The enthalpy of vaporization can be calculated using the Clausius-Clapeyron equation:

ln(P2/P1) = ΔH_vap/R*(1/T1 - 1/T2)

Where P1 and T1 are the pressure and temperature at the evaporator, P2 and T2 are the pressure and temperature at the condenser, R is the specific gas constant, and ΔH_vap is the enthalpy of vaporization. Once the enthalpy of vaporization is known, it can be subtracted from the enthalpy of compression to determine the refrigerating effect per kg.