Ulvac CRYO-U Series, Instruction Manual

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Principle of Refrigerator Operation
E-4 ULVAC CRYOGENICS INCORPORATED
1st Displacer
Regenerator
2nd Displacer
Regenerator
1st Seal
1st
LOAD
2nd Seal
2nd
LOAD
Expansion chamber
1st
Expansion chamber
2nd
Figure E-3 Two-stage
Refrigerator
Compressor
Low pressure
High pressure
Valve
close
Room temp.
a
b
Open
Regenerator
Cylinder
Displacer
Expansion chamber (low temp.)
1 cycle
c
d
High pressure
Low pressure
Seal
Low pressure
High pressure
Low pressure
High pressure
P
H
d
c
B
C
b
A
D
a
P
L
V
P-V diagram
W=
∮
PdV
=(P
H
－
P
L
)V
Figure E-2 Principle of
G-M Cycle Operation
P
re
s
su
re
o
f E
x
p
a
ns
io
n C
h
am
be
r
Volume of Expansion Chamber