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Data Description
| Data | Unit | Description | ||
| Set | Item | Type | Native | |
| Equipment Properties | CompressionType | The type of the compression . | ||
| Option | The input specification used (DischargePressure, PressureRatio or CompressionRatio) | |||
| DischargePressure | Pressure | psia | Outlet pressure of the flow. Default is 0 psig. | |
| PressureRatio | The outlet pressure divided to the inlet pressure (p2/p1). | |||
| CompressionRatio | The ratio between the input volume flow and the discharge volume flow (V1/V2). | |||
| Efficiency | Fraction Or Percent |
Fraction | The efficiency of the compressor . | |
| Calculated Properties | TheoreticalPower | Work | hp | The head power of the compressor. |
| ActualPower | Work | hp | Head power divided to the efficiency. | |
| Gamma | Adiabatic coefficient, Cp/Cv. | |||
Equipment Properties
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Example of using equipment
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Method&Equations
The compressor can simulate three compression types: isothermal (when a complete cooling is assumed during the compression), adiabatic (when no heat is transfered to the environment) or polytropic (characterizing the real compressors when part of the accumulated heat due to the compression is released).
As with the similar equipment used for liquids, pump, friction can be lumped into the work therm by sing an efficiency but unlike pumps, the gases cannot be treated as incompressible, so a differential equation is required:
The compression is a change in terms of the thermodynamic properties of the flow from the innitial state to the final state, beeing governed by the law:
The exponent n gives the compression type:
n=1 -> isothermal compression
n= k=Cp/Cv=Gamma -> isentropic (adiabatic)
n # 1, n# k -> polytropic
The power heads can be calculated using the equation:
where n takes the the value of the corresponding compression type (1,k,n).
The ratio of the head work to the actual work is the compression efficiency.
The discharge temperature for the adiabatic and polytropic compression might be calculated using the equation:
Taking into account the compressor efficiency, the performance losses are related with :
