CO2 initially at T1 = 300 K and p1 = 100 kPa is compressed in a piston cylinder

Question

CO2 initially at T1 = 300 K and p1 = 100 kPa is compressed in a piston cylinder arrangement with an initial volume V, = 100 liters. The ambient surroundings arc at 300 K. The piston is used to compress the CO2 to a volume of 5 liters. For each of the following two processes, calculate the work W1-2. the final p1, the heal transferred to the surroundings Q1-7 and the total entropy generation Assume CO2 is an ideal gas with a constant Cv =0.71 KJ/kg*K. A slow compression with adequate heat loss to maintain the temperature at 300 K. (0.5 pts.) A more rapid process w here pv1,2 constant. (0.5 pts )

Explanation / Answer

given PV1.2=const

so P1V11.2=P2V21.2 (STANDARD FORMULA) GIVEN P1=100KPA,V1=100 LIT,V2-5 LIT

SO P2=P1(V1/V2)1.2

P2=100*(100/5)1.2 = 3641 KPA IS THE FINAL PRESSURE............

and work done W=P1V1-P2V2/(1.2-1)

=100*100-5*3641/0.2=41 KJ IS THE WORK DONE................

NOW T2 IS T1V11.2-1=T2V21.2-1  (STANDARD FORMULA)

SO T2=T1(V1/V2)1.2-1 = 10923.3 K

INTERNAL ENERGY=Cv*(T2-T1) FOR UNIT MASS

SO =0.71*(10923.3-300)=7542 KJ

SO HEAT TRANSFERED TO SURRONDING IS Q=U+W=7542+41=7583 KJ...........

ENTROPY GENRATED IN SYSTEM =Q*(T1-T2)/T1T2=24.58 KJ/KG

dude...due to lengthy calculations there might be asnwer wrong...but however formuals and concept is right

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.