SECOND LAW OF THERMODYNAMICS ThermodynamicsWp actual= (Hout - Hin)actual(1-32)actual= (hout - hin)actual(1-33)wpmPump efficiency, , is defined as the ratio of the work required by the pump if it were an idealh ppump wp, idealto the actual work required by the pump wp, actual.(1-34)h pWp, idealWp, actualExample:A pump operating at 75% efficiency has an inlet specific enthalpy of 200 Btu/lbm. Theexit specific enthalpy of the ideal pump is 600 Btu/lbm. What is the exit specificenthalpy of the actual pump?Solution:Using Equation 1-34:h pwp, idealwp, actualwp, actualwp, idealh p(houthin)actual(houthin)idealh phout, actual(houthin)idealh phin, actualhout, actual(600 Btu/lbm200 Btu/lbm).75200 Btu/lbmhout, actual= 533.3 Btu/lbm + 200 Btu/lbmhout, actual= 733.3 Btu/lbmHT-01 Page 82 Rev. 0
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