2200LZJE-HO-C6-N_2013.12.
Chapter 2 Configuration and Specifications of Compressor
Compound 2-stage Screw Compressor 2016**C
2.5
Mechanisms
2-12
(A) Properly adapted Vi to load condition
Both the required compression ratio and Vi are low. Both the required compression ratio and Vi are high.
(B) Improperly adapted Vi to load condition
Vi is too low compared to the required compression ratio. Vi is too high compared to the required compression ratio.
Figure 2-12 Relationship between Volume ratio (Vi) and Operation Conditions
Suction
Suction
Compression
Change in volu
me enclosed
by
tooth
pr
ofiles
Internal pressure
Internal pressure
Low Vi conditions
High Vi conditions
Rotor rotation angle
Rotor rotation angle
Suction port closed
Suction port closed
Discharge
port
opened
Discharge port opened
Change in volu
me enclosed
by
tooth
pr
ofiles
Change in volu
me enclosed
by
tooth
pr
ofiles
Suction
Suction
Compression
Discharge
Compression
Discharge
Suction port closed
Suction port closed
Discharge
port
opened
Discharge port opened
Internal pressure
Internal pressure
Operation under
low Vi and high
compression ratio
Operation under
high Vi and low
compression ratio
Rotor rotation angle
Rotor rotation angle
Change in volu
me enclosed
by tooth profiles
Compression
Discharge
Discharge