Compressor Power Calculator
Calculate the theoretical power required for adiabatic (isentropic) compression of an ideal gas.
Actual Shaft Power
183.16 kW
Actual Shaft Power vs Mass Flow Rate (m)
Formula
## Adiabatic Compressor Power The isentropic (ideal adiabatic) compression process provides the theoretical minimum power needed. Real compressors require more power due to irreversibilities. ### Formula **W_ideal = m × Cp × T1 × (PR^((gamma-1)/gamma) - 1)** **W_actual = W_ideal / eta_isentropic** **T2 = T1 × (1 + (PR^((gamma-1)/gamma) - 1) / eta)** where PR is the pressure ratio, gamma is the specific heat ratio, and eta is the isentropic efficiency.
Exemplo Resolvido
Compressing 1 kg/s of air from 300 K with pressure ratio 4, gamma=1.4, eta=80%.
- 01(gamma-1)/gamma = 0.4/1.4 = 0.2857
- 02PR^0.2857 = 4^0.2857 = 1.486
- 03Ideal power = 1 × 1.005 × 300 × (1.486 - 1) = 301.5 × 0.486 = 146.5 kW
- 04Actual power = 146.5 / 0.80 = 183.2 kW
- 05T2 = 300 × (1 + 0.486/0.80) = 300 × 1.608 = 482.3 K
Perguntas Frequentes
What is typical isentropic efficiency?
Centrifugal compressors: 75-85%, axial compressors: 85-92%, reciprocating compressors: 70-85%, screw compressors: 70-80%. Larger, more advanced machines tend toward the higher end.
Why is discharge temperature important?
High discharge temperatures can damage seals and lubricants, cause thermal expansion issues, and limit the pressure ratio per stage. Air compressors are often limited to about 200°C discharge, requiring intercooling for high pressure ratios.
When is multi-stage compression needed?
For pressure ratios above about 3-4 per stage (depending on gas and machine type), intercooling between stages reduces power consumption and limits discharge temperature. The ideal approach uses equal pressure ratios per stage.
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