Class CompressorCurveTemplate

java.lang.Object
neqsim.process.equipment.compressor.CompressorCurveTemplate
All Implemented Interfaces:
Serializable
public class CompressorCurveTemplate extends Object implements Serializable
Template class for storing normalized compressor curve data.

This class stores compressor curves in a normalized (reduced) form that can be scaled to match any compressor's operating conditions using fan laws. The curves are normalized relative to a reference speed, so:

  • Reduced flow = flow / speed
  • Reduced head = head / speed²
  • Efficiency remains unchanged (approximately independent of speed)

12 predefined templates are available in three categories:

Basic Centrifugal (3):

Application-Based (6):

  • PIPELINE - Gas transmission, high capacity, ~85% efficiency
  • EXPORT - Offshore gas export, high pressure, stable operation
  • INJECTION - Gas injection/EOR, very high pressure ratio
  • GAS_LIFT - Artificial lift, wide surge margin, robust design
  • REFRIGERATION - LNG/process cooling, wide operating range
  • BOOSTER - Process plant pressure boosting, balanced design

Compressor Type (4):

Usage Example: 

// Get template by name (flexible naming)
CompressorCurveTemplate template = CompressorCurveTemplate.getTemplate("pipeline");

// Scale to design point
CompressorChartInterface chart = template.scaleToDesignPoint(10000, // designSpeed (RPM)
    5000, // designFlow (m³/hr)
    85.0, // designHead (kJ/kg)
    5 // numberOfSpeeds
);

// Or use with CompressorChartGenerator
CompressorChartGenerator generator = new CompressorChartGenerator(compressor);
CompressorChartInterface chart = generator.generateFromTemplate("EXPORT", 5);

// List available templates
String[] all = CompressorCurveTemplate.getAvailableTemplates();
String[] apps = CompressorCurveTemplate.getTemplatesByCategory("application");
Version:
1.0
Author:
Even Solbraa
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      See Also:

    • name

      private final String name
      Name/identifier for this template.

    • referenceSpeed

      private final double referenceSpeed
      Reference speed used for normalization (RPM).

    • speeds

      private final double[] speeds
      Speed values for each curve (RPM).

    • reducedFlows

      private final double[][] reducedFlows
      Reduced flow values (flow/speed) for each curve. Each row corresponds to a speed.

    • reducedHeads

      private final double[][] reducedHeads
      Reduced head values (head/speed²) for each curve. Each row corresponds to a speed.

    • polytropicEfficiencies

      private final double[][] polytropicEfficiencies
      Polytropic efficiency values (%) for each curve. Each row corresponds to a speed.

    • CENTRIFUGAL_STANDARD

      public static final CompressorCurveTemplate CENTRIFUGAL_STANDARD
      Standard centrifugal compressor template.

      Based on typical multi-stage centrifugal compressor characteristics with:

      • 9 speed curves from ~67% to 100% of max speed
      • 5-7 operating points per curve
      • ~25-30% surge margin
      • Peak efficiency ~78%

    • CENTRIFUGAL_HIGH_FLOW

      public static final CompressorCurveTemplate CENTRIFUGAL_HIGH_FLOW
      High flow centrifugal compressor template.

      Compressor optimized for high volumetric flow with lower head per stage.

    • CENTRIFUGAL_HIGH_HEAD

      public static final CompressorCurveTemplate CENTRIFUGAL_HIGH_HEAD
      High head centrifugal compressor template.

      Compressor optimized for high head with narrower operating range.

    • PIPELINE

      public static final CompressorCurveTemplate PIPELINE
      Pipeline compressor template.

      Designed for natural gas transmission with high capacity, moderate pressure ratio, and wide operating range. Typical for long-distance gas pipelines.

      • High volumetric flow capacity
      • Moderate head (pressure ratio 1.3-1.6 per stage)
      • Wide stable operating range (~40% turndown)
      • Peak efficiency ~82-85%

    • EXPORT

      public static final CompressorCurveTemplate EXPORT
      Export compressor template.

      Designed for offshore gas export with high discharge pressure and stable operation. Optimized for efficiency at design point.

      • High pressure ratio
      • Multiple stages (typically 6-8)
      • Narrow but efficient operating range
      • Peak efficiency ~80%

    • INJECTION

      public static final CompressorCurveTemplate INJECTION
      Injection compressor template.

      Designed for gas injection/reinjection with very high discharge pressure. Used for enhanced oil recovery and reservoir pressure maintenance.

      • Very high pressure ratio (overall 50-200)
      • Lower volumetric capacity
      • Multiple stages with intercooling
      • Peak efficiency ~77%

    • GAS_LIFT

      public static final CompressorCurveTemplate GAS_LIFT
      Gas lift compressor template.

      Designed for artificial lift applications with variable operating conditions. Must handle fluctuating inlet conditions and some liquid carryover.

      • Variable pressure ratio capability
      • Robust design for liquid tolerance
      • Wide surge margin (~35%)
      • Peak efficiency ~75%

    • REFRIGERATION

      public static final CompressorCurveTemplate REFRIGERATION
      Refrigeration compressor template.

      Designed for process cooling and LNG applications with refrigerants. Optimized for wide operating range and varying loads.

      • Wide operating range for varying cooling loads
      • Adapted for high molecular weight refrigerants
      • Good part-load efficiency
      • Peak efficiency ~78%

    • BOOSTER

      public static final CompressorCurveTemplate BOOSTER
      Booster compressor template.

      Designed for moderate pressure boosting in process plants. General-purpose design with good balance of capacity and head.

      • Moderate pressure ratio (2-4)
      • Medium capacity
      • Balanced operating range
      • Peak efficiency ~76%

    • SINGLE_STAGE

      public static final CompressorCurveTemplate SINGLE_STAGE
      Single-stage centrifugal compressor template.

      Simple single impeller design for low pressure ratio applications. Common for utilities, blowers, and simple compression duty.

      • Low pressure ratio (1.5-2.5 per stage)
      • Simple, cost-effective design
      • Wide flow range
      • Peak efficiency ~75%

    • MULTISTAGE_INLINE

      public static final CompressorCurveTemplate MULTISTAGE_INLINE
      Multistage inline (barrel) compressor template.

      Multiple stages in series within a barrel casing for high pressure applications. Standard design for oil and gas industry.

      • High pressure ratio (5-15 overall)
      • 4-8 stages typical
      • Compact design, good for high pressure
      • Peak efficiency ~78%

    • INTEGRALLY_GEARED

      public static final CompressorCurveTemplate INTEGRALLY_GEARED
      Integrally geared compressor template.

      Multiple pinions with impellers driven by a bull gear. Flexible staging for air separation and process applications.

      • Flexible pressure ratio per stage
      • Good for air separation, process air
      • High efficiency through optimized staging
      • Peak efficiency ~82%

    • OVERHUNG

      public static final CompressorCurveTemplate OVERHUNG
      Overhung impeller compressor template.

      Cantilever design with impeller mounted on extended shaft. Simple maintenance access, common for smaller applications.

      • Low to medium pressure
      • Simple maintenance
      • Cost-effective for smaller duties
      • Peak efficiency ~74%

  • Constructor Details

    • CompressorCurveTemplate

      public CompressorCurveTemplate(String name, double referenceSpeed, double[] speeds, double[][] flows, double[][] heads, double[][] efficiencies)
      Constructor for CompressorCurveTemplate.
      Parameters:
      name - Template name/identifier
      referenceSpeed - Reference speed used for normalization (RPM)
      speeds - Speed values for each curve (RPM)
      flows - Flow values for each curve (m³/hr). Will be normalized internally.
      heads - Head values for each curve (kJ/kg). Will be normalized internally.
      efficiencies - Polytropic efficiency values (%) for each curve

  • Method Details

    • getName

      public String getName()
      Get the template name.
      Returns:
      the template name

    • getReferenceSpeed

      public double getReferenceSpeed()
      Get the reference speed used for normalization.
      Returns:
      reference speed in RPM

    • getNumberOfSpeedCurves

      public int getNumberOfSpeedCurves()
      Get the number of speed curves in this template.
      Returns:
      number of speed curves

    • getSpeedRatios

      public double[] getSpeedRatios()
      Get the speed ratios (speed/referenceSpeed) for all curves.
      Returns:
      array of speed ratios

    • scaleToDesignPoint

      public CompressorChartInterface scaleToDesignPoint(double designSpeed, double designFlow, double designHead, int numberOfSpeeds)
      Scale this template to match a specific compressor operating point.

      The scaling uses fan laws to generate curves that pass through the specified design point (designFlow, designHead) at the design speed. Uses interpolate and extrapolate chart type by default.

      Parameters:
      designSpeed - Design speed in RPM
      designFlow - Design flow rate in m³/hr
      designHead - Design polytropic head in kJ/kg
      numberOfSpeeds - Number of speed curves to generate (uses evenly spaced speeds from template range)
      Returns:
      A new CompressorChart with scaled curves

    • scaleToDesignPoint

      public CompressorChartInterface scaleToDesignPoint(double designSpeed, double designFlow, double designHead, int numberOfSpeeds, String chartType)
      Scale this template to match a specific compressor operating point with specified chart type.

      The scaling uses fan laws to generate curves that pass through the specified design point (designFlow, designHead) at the design speed.

      Parameters:
      designSpeed - Design speed in RPM
      designFlow - Design flow rate in m³/hr
      designHead - Design polytropic head in kJ/kg
      numberOfSpeeds - Number of speed curves to generate
      chartType - Chart type: "simple", "interpolate", or "interpolate and extrapolate"
      Returns:
      A new CompressorChartInterface with scaled curves

    • createChart

      static CompressorChartInterface createChart(String chartType)
      Create a chart instance of the specified type.

      This method is package-private to allow reuse by CompressorChartGenerator.

      Parameters:
      chartType - The chart type: "simple", "fan law", "interpolate", or "interpolate and extrapolate"
      Returns:
      A new chart instance

    • repeatEfficiency

      private static double[][] repeatEfficiency(int numSpeeds, double[] efficiencyProfile)
      Create efficiency array with same values for all speeds.

      Helper method to reduce repetition in template definitions where efficiency curves are identical across speeds.

      Parameters:
      numSpeeds - Number of speed curves
      efficiencyProfile - Single efficiency profile to repeat
      Returns:
      2D array with repeated efficiency profiles

    • findClosestSpeedIndex

      private int findClosestSpeedIndex(double targetRatio)
      Find the index of the template curve closest to the specified speed ratio.
      Parameters:
      targetRatio - Target speed ratio (speed/designSpeed)
      Returns:
      Index of the closest template curve

    • createCentrifugalStandardTemplate

      private static CompressorCurveTemplate createCentrifugalStandardTemplate()
      Create the standard centrifugal compressor template.
      Returns:
      the template

    • createCentrifugalHighFlowTemplate

      private static CompressorCurveTemplate createCentrifugalHighFlowTemplate()
      Create the high flow centrifugal compressor template.
      Returns:
      the template

    • createCentrifugalHighHeadTemplate

      private static CompressorCurveTemplate createCentrifugalHighHeadTemplate()
      Create the high head centrifugal compressor template.
      Returns:
      the template

    • createPipelineTemplate

      private static CompressorCurveTemplate createPipelineTemplate()
      Create the pipeline compressor template.
      Returns:
      the template

    • createExportTemplate

      private static CompressorCurveTemplate createExportTemplate()
      Create the export compressor template.
      Returns:
      the template

    • createInjectionTemplate

      private static CompressorCurveTemplate createInjectionTemplate()
      Create the injection compressor template.
      Returns:
      the template

    • createGasLiftTemplate

      private static CompressorCurveTemplate createGasLiftTemplate()
      Create the gas lift compressor template.
      Returns:
      the template

    • createRefrigerationTemplate

      private static CompressorCurveTemplate createRefrigerationTemplate()
      Create the refrigeration compressor template.
      Returns:
      the template

    • createBoosterTemplate

      private static CompressorCurveTemplate createBoosterTemplate()
      Create the booster compressor template.
      Returns:
      the template

    • createSingleStageTemplate

      private static CompressorCurveTemplate createSingleStageTemplate()
      Create the single-stage compressor template.
      Returns:
      the template

    • createMultistageInlineTemplate

      private static CompressorCurveTemplate createMultistageInlineTemplate()
      Create the multistage inline (barrel) compressor template.
      Returns:
      the template

    • createIntegrallyGearedTemplate

      private static CompressorCurveTemplate createIntegrallyGearedTemplate()
      Create the integrally geared compressor template.
      Returns:
      the template

    • createOverhungTemplate

      private static CompressorCurveTemplate createOverhungTemplate()
      Create the overhung impeller compressor template.
      Returns:
      the template

    • getTemplate

      public static CompressorCurveTemplate getTemplate(String templateName)
      Get a template by name.

      Supports various naming conventions - spaces, hyphens, and underscores are interchangeable. The search is case-insensitive.

      Parameters:
      templateName - Name of the template (e.g., "CENTRIFUGAL_STANDARD", "pipeline", "gas-lift")
      Returns:
      The matching template, or CENTRIFUGAL_STANDARD if not found

    • getAvailableTemplates

      public static String[] getAvailableTemplates()
      Get all available template names.
      Returns:
      Array of template names

    • getTemplatesByCategory

      public static String[] getTemplatesByCategory(String category)
      Get templates by category.
      Parameters:
      category - The category: "basic", "application", or "type"
      Returns:
      Array of template names in that category

    • getOriginalChart

      public CompressorChartInterface getOriginalChart()
      Get the original (unscaled) compressor chart from this template.

      This method returns a chart with the exact curve data stored in the template, without any scaling. Useful for recreating the original reference curves.

      Returns:
      A new CompressorChartInterface with the original template curves

    • getOriginalChart

      public CompressorChartInterface getOriginalChart(String chartType)
      Get the original (unscaled) compressor chart from this template with specified chart type.
      Parameters:
      chartType - Chart type: "simple", "interpolate", or "interpolate and extrapolate"
      Returns:
      A new CompressorChartInterface with the original template curves

    • getSpeeds

      public double[] getSpeeds()
      Get the original speeds from the template.
      Returns:
      Array of speed values in RPM

    • scaleToSpeed

      public CompressorChartInterface scaleToSpeed(double targetReferenceSpeed)
      Scale the template curves to match a target speed, preserving the relative curve shapes.

      This scales all curves proportionally so that the reference speed maps to the target speed. Uses fan laws: flow scales with speed, head scales with speed².

      Parameters:
      targetReferenceSpeed - The target speed that corresponds to the template's reference speed
      Returns:
      A new CompressorChartInterface with scaled curves

    • scaleToSpeed

      public CompressorChartInterface scaleToSpeed(double targetReferenceSpeed, String chartType)
      Scale the template curves to match a target speed with specified chart type.
      Parameters:
      targetReferenceSpeed - The target speed that corresponds to the template's reference speed
      chartType - Chart type: "simple", "interpolate", or "interpolate and extrapolate"
      Returns:
      A new CompressorChartInterface with scaled curves