Homework Assignment 10
Due Thursday April 28 by 2:00
You may skip 10.22 parts b and e and 10.23 part e
Answers: 10.22
a) 44%
10.23 a) 39%
Most of you probably solved these by hand. My solution is done using EES, but the method is the
same. I have indicated any differences in solution process between EES and a hand solution in the
parentheses {}.
{problem 10.22 ideal Rankine cycle}
{knowns}
Plow=4
Phigh=12000
Qdotin=50000
h1=enthalpy(steam, x=0, P=Plow)
{use hf at Plow if doing this by hand}
h2=h1+wpump
wpump=v1*(PhighPlow)
v1=volume(steam, x=0, P=Plow)
{use vf at Plow if doing this by hand}
h3=enthalpy(steam, P=Phigh, x=1)
s3=entropy(steam, P=Phigh, x=1)
h4=enthalpy(steam, P=Plow, s=s3)
{if doing by hand solve for x using s=sf+xsfg and then find h4
using that x}
wnet=wturbinewpump
wturbine=h3h4
qin=h3h2
thermaleff=wnet/qin
power=mdot*wnet
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentQdotin=mdot*qin
{this solves for mdot}
Variables in Main
h1=121.4
h2=133.4
h3=2684
h4=1653
mdot=19.6 kg/s
Phigh=12000
Plow=4
power=19981 kW
Qdotin=50000
qin=2551
s3=5.492
thermaleff=0.3996
v1=0.001004
wnet=1019
wpump=12.05
{problem 10.23 ideal Rankine cycle}
{knowns}
Plow=4
Phigh=12000
Qdotin=50000
h1=enthalpy(steam, x=0, P=Plow)
{use hf at Plow if doing this by hand}
h2=h1+wpump
wpump=v1*(PhighPlow)/0.90 {note pump efficiency added}
v1=volume(steam, x=0, P=Plow)
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '12
 Okamoto
 Heat Transfer, Feedwater heater, 0.05 kg, 10 pts

Click to edit the document details