Thermodynamics Design of 4-stage Helium compressor

L. Zhou

MMAE, UCF

Overall Design constrains

Compressor inlet and outlet conditions Inlet:

T=58K

P=1.65 bar

Outlet:

T=85K

P=4.79 bar

Compressor power and mass flow rate – Mass flow rate: 4.19 g/s– Shaft Power input: 918 W– RPM: 200 k– Configuration: 4 impellers, co-axial

Compressor configuration

Thermodynamics chart of the compressor

H

S

P1

Pi

P2

Stage1

Stage2

Stage3

Stage4

Intercooler

Aftercooler

Inlet Point

Stage 1 and 2

Stage1– IGV

Inlet: T=58K, P=1.65bar Outlet: T=59K, P=1.63bar

– Impeller Inlet: T=59.3K, P=1. 62bar Outlet: T=63.2K,

P=1.77bar

– Diffuser Outlet: T=68K, P=2.22bar

Stage2– IGV

Inlet: T=67.1K, P=2.24bar Outlet:T=67.6K, P=2.22bar

– Impeller Inlet: T=68K, P=2.22bar Outlet: T=72.3K,

P=2.47bar

– Diffuser Outlet: T=75K, P=2.98bar

Intercooler

Intercooler inlet: 75K Intercooler Outlet: 60K Heat exchanged: 328 W Pressure loss: 3.5%

Stage 3 and 4

Stage3– IGV

Inlet: T=60K, P=2.87bar Outlet: T=60.7K,

P=2.85bar– Impeller

Inlet: T=60.8K, P=2.84bar Outlet: T=66.2K,

P=3.12bar– Diffuser

Outlet: T=73.3K, P=3.84bar

Stage4– IGV

Inlet: T=73.5K, P=3.83bar Outlet:T=73.6K, P=3.83bar

– Impeller Inlet: T=73.6K, P=3.82bar Outlet: T=77.8K,

P=4.15bar

– Diffuser Outlet: T=85K, P=4.92bar

Aftercooler

Intercooler inlet: 85K Intercooler Outlet: 59.5K Heat exchanged: 556.4 W Pressure loss: 4.5%