Problem 6.10 – Adiabatic Efficiency of a CO2 (R744) Compressor

Recall Chapter 4d in which we evaluated a heat pump system using Carbon Dioxide refrigerant (R744) as shown:

This is a practical system with data adapted from a previous Visteon Corp. automobile a/c design, thus the compressor does not follow an isentropic process. In this exercise you should do the following:

• Plot the compressor process (1)-(2) on the enthalpy-entropy ( h-s ) diagram provided below. Plot also the isentropic compressor process and (using the Property Tables) determine the compressor isentropic efficiency η _C . Recall that the compressor isentropic efficiency η _C is defined as the isentropic work done on the compressor divided by the actual work done. Indicate both the isentropic work done and the actual work done on the h-s diagram. [ η _C =74% ]