Two-Stage Refrigerator - Ulvac CRYOPUMP CRYO-U Series Instruction Manual

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