Using the Compressor Device in PIPE-FLO Advantage 17

Using the Compressor Device in PIPE-FLO® Advantage 17

Introduction

The new Compressor device is used to size or evaluate the performance of a gas compressor in systems modeled in PIPE-FLO Advantage 17. Compressors without performance curve data are considered to be in a "sizing" mode and can be set to define the operational flow rate, inlet pressure, outlet pressure, differential pressure, or a pressure ratio requirement that must be achieved by the compressor. Performance curve data is entered as pressure ratio and efficiency vs. flow rate at a given test speed. Performance data also allows the compressor to be set to a fixed operating speed and the speed, efficiency, and input power is calculated.


Design Data for a Compressor


  • Name (required): unique identifier, default set by Auto-Naming
  • Design Status: Will change from Undesigned to Sizing to Designed when the sufficient operational and design data is entered, respectively.
  • Elevation (required): where the blower is in relation to the reference zero elevation datum of the system. 
  • Compressor Curve (optional): enter the Compressor Curve performance data for additional calculations such as speed, input power, and efficiency. The data table allows for copying the data from an external source and pasting it into the table.
  • Operation (required): the Operation allows for modeling multiple process control scenarios by setting the Flow Rate, Discharge Pressure, Suction Pressure, Differential Pressure, Pressure Ratio, and Temperature Control. The Compressor can be placed in Temperature Control mode by selecting the Blower as a Flow Control Device at a Heat Transfer Device. The Fixed Speed mode can only be used if the Blower Curve data is entered.   
  • Polytropic Exponent Method (required, default to Calculate n):  select the method used to calculate or enter the Polytropic Exponent used to define the thermodynamic compression process. The default selection is "Calculate" to use the assigned Fluid Zone temperatures at the inlet and outlet. "Use Specific Heat Ratio" sets the polytropic exponent equal to the inlet Fluid Zone's specific heat ratio. A warning will be thrown if the assigned outlet Fluid Zone temperature is not within the Fluid Zone Tolerance of the calculated Polytropic Outlet Temperature. 

Calculated Results for a Compressor 

  • Flow Rate
  • Corrected Flow Rate
  • Adiabatic Head
  • Polytropic Head
  • Differential Total Pressure
  • Differential Static Pressure
  • Pressure Ratio
  • Inlet Total Pressure
  • Inlet Static Pressure
  • Outlet Total Pressure
  • Outlet Static Pressure
  • Isentropic Outlet Temperature
  • Polytropic Outlet Temperature
  • Polytropic Exponent
  • Speed
  • Corrected Speed
  • Input Power
  • Adiabatic Output Power 
  • Polytropic Output Power
  • Efficiency
  • Isentropic Output Power
  • Polytropic Output Power
  • % Deviation

Compressor Calculations

Compressors can be modeled along with Compressible Pipe devices to be included in the compressible fluid flow analysis, or they can be modeled with incompressible Pipe devices. The isentropic, adiabatic, and polytropic relationships are used to define the thermodynamic path of compression. See the program Help File for equations used for the Compressor.

Compressor Applications