Quoted: "Carbon Dioxide enters an adiabatic compressor at 100 kPa and 300 K at a rate of 2.2 kg/s and exits at 600 kPa and 450 K. Neglecting the kinetic energy changes, determine the isentropic efficiency of the compressor."
I can't figure out the h terms becuase my book's table doesn't go down to 200 kPa.
Any help is appreciated.
Thanks
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Look at the stuff below and see whether any of it looks like stuff in your textbook and/or class notes. There are a bunch of assumptions that have to be made in solving a problem like this, and your prof may have given you some clues.
adiabatic efficiency of compressor that operates between entrance (station 1) and exit (station 2) is given by the following formula:
Eff = (h2s-h1)/(h2-h1) (where h2s is the enthalpy that would result from an isentropic process that had the same pressure ratio)
Assuming a perfect gas and constant specific heats, for an isentropic process: (p2/p1) = (T2/T1)^(gamma/gamma-1), where gamma is the ratio of specific heats
gamma for CO2 is 1.293759 (according to this website:
LINK(Does your textbook or class notes indicate the gamma for CO2?)
Using algebra, solve for T2, which would be the temperature at the exit in an isentropic process. Coincidentally, I get 450 degrees, which means the effiicency of the compressor is 100% (because the isentropic temperature and actual temperature are the same, the isentropic enthalpy and the actual enthalpy are therefore the same).
edited to fix the formula