Page 454 - Advanced thermodynamics for engineers

444 CHAPTER 18 LIQUEFACTION OF GASES

m = 1- y
p , T , h 2
2
2

m = 1
p , T , h
1 1 1
Throttle

Receiver

Liquid yield
y
p L,T , h L
L
FIGURE P18.2
Final stage of liquefaction plant.

Calculate the pressure for maximum yield at a temperature of 120 K.

" ! #
r ffiffiffiffiffiffiffiffiffiffi! r ffiffiffiffiffiffiffiffiffiffi
a <bT i <bT i
p ¼ 2 1 3 1 ; 62:8 bar
b 2a 2a
P18.3 The equation of state for a certain gas is

<T k
v m ¼ þ
p <T
where k is a constant. Show that the variation of temperature with pressure for an isenthalpic
process from 1 to 2 is given by

2 2 4k
T T ¼ p 1 p 2
1
2
c p <