Measurement Devices and Analysers

NeqSim provides a comprehensive set of measurement devices and process analysers for monitoring fluid properties, compositions, and process conditions.

Overview

Measurement devices in NeqSim fall into several categories:

Fluid Composition Analysers

CombustionEmissionsCalculator

Calculates CO2 emissions from fuel gas combustion based on stream composition.

import neqsim.process.measurementdevice.CombustionEmissionsCalculator;

// Create fuel gas stream
Stream fuelGas = new Stream("Fuel Gas", gas);
fuelGas.setFlowRate(1000.0, "kg/hr");
fuelGas.run();

// Create emissions calculator
CombustionEmissionsCalculator emissionsCalc = 
    new CombustionEmissionsCalculator("CO2 Calculator", fuelGas);

// Get CO2 emissions rate
double co2Emissions = emissionsCalc.getMeasuredValue("kg/hr");
System.out.println("CO2 emissions: " + co2Emissions + " kg/hr");

CO2 Emission Factors (kg CO2 per kg component):

Component Emission Factor
Methane 2.75
Ethane 3.75
Propane 5.50
n-Butane 6.50
n-Pentane 7.50
Hexane 8.50
Nitrogen 0.0
CO2 0.0

NMVOCAnalyser

Calculates the mass flow rate of Non-Methane Volatile Organic Compounds (nmVOCs).

import neqsim.process.measurementdevice.NMVOCAnalyser;

// Create analyser
NMVOCAnalyser nmvocAnalyser = new NMVOCAnalyser("NMVOC Monitor", ventStream);

// Get nmVOC flow rate
double nmvocFlow = nmvocAnalyser.getMeasuredValue("kg/hr");
double nmvocYearly = nmvocAnalyser.getnmVOCFlowRate("tonnes/year");
System.out.println("NMVOC emissions: " + nmvocYearly + " tonnes/year");

Components included in nmVOC calculation:

Dew Point Analysers

HydrocarbonDewPointAnalyser

Calculates the hydrocarbon dew point temperature at a specified pressure.

import neqsim.process.measurementdevice.HydrocarbonDewPointAnalyser;

HydrocarbonDewPointAnalyser hcdp = 
    new HydrocarbonDewPointAnalyser("HC Dew Point", gasStream);
hcdp.setReferencePressure(50.0, "bara");

double dewPointC = hcdp.getMeasuredValue("C");
System.out.println("HC dew point: " + dewPointC + " °C");

WaterDewPointAnalyser

Calculates the water dew point temperature.

import neqsim.process.measurementdevice.WaterDewPointAnalyser;

WaterDewPointAnalyser wdp = 
    new WaterDewPointAnalyser("Water Dew Point", gasStream);
wdp.setReferencePressure(50.0, "bara");

double waterDewPoint = wdp.getMeasuredValue("C");
System.out.println("Water dew point: " + waterDewPoint + " °C");

CricondenbarAnalyser

Calculates the cricondenbar (maximum pressure on phase envelope).

import neqsim.process.measurementdevice.CricondenbarAnalyser;

CricondenbarAnalyser cricondenbar = new CricondenbarAnalyser(gasStream);
double maxPressure = cricondenbar.getMeasuredValue("bara");
System.out.println("Cricondenbar: " + maxPressure + " bara");

HydrateEquilibriumTemperatureAnalyser

Calculates the hydrate equilibrium temperature at the stream pressure.

import neqsim.process.measurementdevice.HydrateEquilibriumTemperatureAnalyser;

HydrateEquilibriumTemperatureAnalyser hydrateAnalyser = 
    new HydrateEquilibriumTemperatureAnalyser(gasStream);
double hydrateTemp = hydrateAnalyser.getMeasuredValue("C");
System.out.println("Hydrate formation temp: " + hydrateTemp + " °C");

Vibration Analysis

FlowInducedVibrationAnalyser

Calculates Flow-Induced Vibration (FIV) risk indicators for pipelines.

import neqsim.process.measurementdevice.FlowInducedVibrationAnalyser;

// Create pipeline
PipeBeggsAndBrills pipeline = new PipeBeggsAndBrills("Export", feed);
pipeline.setLength(5000.0);
pipeline.setDiameter(0.3048);  // 12 inch
pipeline.setThickness(0.0127); // 0.5 inch
pipeline.run();

// Create FIV analyser
FlowInducedVibrationAnalyser fivAnalyser = 
    new FlowInducedVibrationAnalyser("FIV Monitor", pipeline);
fivAnalyser.setSupportArrangement("Stiff");
fivAnalyser.setSupportDistance(3.0);  // meters

// Get FIV metrics
fivAnalyser.setMethod("LOF");  // Likelihood of Failure
double lof = fivAnalyser.getMeasuredValue("");
System.out.println("Likelihood of Failure: " + lof);

fivAnalyser.setMethod("FRMS");  // Fatigue Root Mean Square
double frms = fivAnalyser.getMeasuredValue("");
System.out.println("F-RMS: " + frms);

Support Arrangements:

Analysis Methods:

Process Monitors

PressureTransmitter

Monitors pressure at a measurement point.

import neqsim.process.measurementdevice.PressureTransmitter;

PressureTransmitter pt = new PressureTransmitter(separator);
pt.setUnit("bara");
double pressure = pt.getMeasuredValue();

TemperatureTransmitter

Monitors temperature at a measurement point.

import neqsim.process.measurementdevice.TemperatureTransmitter;

TemperatureTransmitter tt = new TemperatureTransmitter(heatExchanger);
tt.setUnit("C");
double temperature = tt.getMeasuredValue();

LevelTransmitter

Monitors liquid level in vessels.

import neqsim.process.measurementdevice.LevelTransmitter;

LevelTransmitter lt = new LevelTransmitter(separator);
lt.setUnit("%");
double level = lt.getMeasuredValue();

VolumeFlowTransmitter

Monitors volumetric flow rate.

import neqsim.process.measurementdevice.VolumeFlowTransmitter;

VolumeFlowTransmitter vft = new VolumeFlowTransmitter(stream);
vft.setUnit("m3/hr");
double volumeFlow = vft.getMeasuredValue();

Safety Devices

GasDetector

Simulates gas detection for safety systems.

import neqsim.process.measurementdevice.GasDetector;

GasDetector gasDetector = new GasDetector("Gas Detector 1", stream);
gasDetector.setDetectionLimit(20.0);  // % LEL
boolean gasDetected = gasDetector.isTriggered();

FireDetector

Simulates fire detection for safety systems.

import neqsim.process.measurementdevice.FireDetector;

FireDetector fireDetector = new FireDetector("Fire Detector 1");
fireDetector.setTemperatureThreshold(65.0);  // °C
boolean fireDetected = fireDetector.isTriggered();

Quality Analysers

MolarMassAnalyser

Calculates the molar mass of a stream.

import neqsim.process.measurementdevice.MolarMassAnalyser;

MolarMassAnalyser mma = new MolarMassAnalyser(gasStream);
double molarMass = mma.getMeasuredValue("kg/mol");
System.out.println("Molar mass: " + molarMass * 1000 + " g/mol");

WaterContentAnalyser

Measures water content in gas streams.

import neqsim.process.measurementdevice.WaterContentAnalyser;

WaterContentAnalyser wca = new WaterContentAnalyser(gasStream);
double waterContent = wca.getMeasuredValue("ppm");
System.out.println("Water content: " + waterContent + " ppm");

pHProbe

Measures pH of aqueous streams.

import neqsim.process.measurementdevice.pHProbe;

pHProbe ph = new pHProbe(aqueousStream);
double phValue = ph.getMeasuredValue("");
System.out.println("pH: " + phValue);

Multi-Phase Measurement

MultiPhaseMeter

Simulates multi-phase flow meter measurements.

import neqsim.process.measurementdevice.MultiPhaseMeter;

MultiPhaseMeter mpm = new MultiPhaseMeter("MPFM-1", multiphaseStream);

double gasFlow = mpm.getGasFlowRate("Sm3/hr");
double oilFlow = mpm.getOilFlowRate("m3/hr");
double waterFlow = mpm.getWaterFlowRate("m3/hr");
double waterCut = mpm.getWaterCut();
double gor = mpm.getGOR("Sm3/Sm3");

Compressor Monitoring

CompressorMonitor

Monitors compressor performance parameters.

import neqsim.process.measurementdevice.CompressorMonitor;

CompressorMonitor cm = new CompressorMonitor(compressor);

double polyEff = cm.getPolytropicEfficiency();
double isenEff = cm.getIsentropicEfficiency();
double head = cm.getPolytropicHead("kJ/kg");
double power = cm.getPower("kW");
double surgeMargin = cm.getSurgeMargin();

Well Allocation

WellAllocator

Allocates production to individual wells based on test data.

import neqsim.process.measurementdevice.WellAllocator;

WellAllocator allocator = new WellAllocator("Allocation System");
allocator.addWellTest("Well-A", oilRate, gasRate, waterRate);
allocator.addWellTest("Well-B", oilRate2, gasRate2, waterRate2);
allocator.allocateProduction(totalOil, totalGas, totalWater);

double wellAOil = allocator.getAllocatedOil("Well-A");

Python Usage

from jpype import JClass

# Import measurement devices
CombustionEmissionsCalculator = JClass('neqsim.process.measurementdevice.CombustionEmissionsCalculator')
FlowInducedVibrationAnalyser = JClass('neqsim.process.measurementdevice.FlowInducedVibrationAnalyser')
NMVOCAnalyser = JClass('neqsim.process.measurementdevice.NMVOCAnalyser')

# Emissions calculation
emissions_calc = CombustionEmissionsCalculator("CO2", fuel_stream)
co2_rate = emissions_calc.getMeasuredValue("kg/hr")
print(f"CO2 emissions: {co2_rate} kg/hr")

# nmVOC analysis
nmvoc = NMVOCAnalyser("NMVOC", vent_stream)
nmvoc_rate = nmvoc.getMeasuredValue("tonnes/year")
print(f"NMVOC: {nmvoc_rate} tonnes/year")

# FIV analysis
fiv = FlowInducedVibrationAnalyser("FIV", pipeline)
fiv.setMethod("LOF")
lof = fiv.getMeasuredValue("")
print(f"LOF: {lof}")

API Reference

MeasurementDeviceBaseClass

Base class for all measurement devices.

Method Returns Description
getMeasuredValue() double Get measurement in default unit
getMeasuredValue(unit) double Get measurement in specified unit
setUnit(unit) void Set default measurement unit
getUnit() String Get current measurement unit
displayResult() void Display measurement result

StreamMeasurementDeviceBaseClass

Base class for stream-based measurement devices.

Method Returns Description
setStream(stream) void Set the stream to measure
getStream() StreamInterface Get the measured stream

CombustionEmissionsCalculator

Method Returns Description
getMeasuredValue(unit) double Get CO2 emissions rate
setComponents() void Update component list from stream

FlowInducedVibrationAnalyser

Method Parameters Description
setMethod(method) "LOF" or "FRMS" Set analysis method
setSupportArrangement(type) "Stiff", "Medium stiff", "Medium", "Flexible" Set pipe support type
setSupportDistance(distance) meters Set support spacing
setSegment(segment) segment number Analyse specific pipe segment

NMVOCAnalyser

Method Returns Description
getMeasuredValue(unit) double Get nmVOC flow rate
getnmVOCFlowRate(unit) double Get nmVOC flow rate

See Also