// Power generation patterns for NeqSim. USE WHEN: modeling gas turbines, steam turbines, HRSG, combined cycle systems, waste heat recovery, or calculating fuel gas consumption and thermal efficiency. Covers GasTurbine, SteamTurbine, HRSG, CombinedCycleSystem classes and heat integration with PinchAnalysis.
| name | neqsim-power-generation |
| description | Power generation patterns for NeqSim. USE WHEN: modeling gas turbines, steam turbines, HRSG, combined cycle systems, waste heat recovery, or calculating fuel gas consumption and thermal efficiency. Covers GasTurbine, SteamTurbine, HRSG, CombinedCycleSystem classes and heat integration with PinchAnalysis. |
| last_verified | 2026-07-04 |
Guide for modeling power generation equipment — gas turbines, steam turbines, heat recovery steam generators (HRSG), and combined cycle systems.
| Class | Package | Purpose |
|---|---|---|
GasTurbine | process.equipment.powergeneration | Gas turbine with compressor, combustor, expander |
SteamTurbine | process.equipment.powergeneration | Steam expansion turbine |
HRSG | process.equipment.powergeneration | Heat recovery steam generator |
CombinedCycleSystem | process.equipment.powergeneration | GT + HRSG + ST integrated system |
PinchAnalysis | process.equipment.heatexchanger.heatintegration | Pinch analysis for heat integration |
HeatStream | process.equipment.heatexchanger.heatintegration | Hot/cold stream for pinch analysis |
// Create fuel gas and air streams
SystemInterface fuelGas = new SystemSrkEos(273.15 + 25, 30.0);
fuelGas.addComponent("methane", 0.90);
fuelGas.addComponent("ethane", 0.06);
fuelGas.addComponent("propane", 0.02);
fuelGas.addComponent("nitrogen", 0.02);
fuelGas.setMixingRule("classic");
Stream fuelStream = new Stream("Fuel Gas", fuelGas);
fuelStream.setFlowRate(5000.0, "kg/hr");
// Air stream (simplified composition)
SystemInterface air = new SystemSrkEos(273.15 + 15, 1.01325);
air.addComponent("nitrogen", 0.79);
air.addComponent("oxygen", 0.21);
air.setMixingRule("classic");
Stream airStream = new Stream("Combustion Air", air);
airStream.setFlowRate(100000.0, "kg/hr");
// Gas turbine
GasTurbine gt = new GasTurbine("GT-001", fuelStream, airStream);
gt.setIsentropicEfficiency(0.88);
gt.setCompressorPressureRatio(18.0);
gt.run();
double power_MW = gt.getPower("MW");
double thermalEff = gt.getThermalEfficiency();
double exhaustT = gt.getExhaustStream().getTemperature() - 273.15;
double fuelRate = gt.getFuelConsumption("kg/hr");
// Steam at high pressure and temperature
SystemInterface steam = new SystemSrkEos(273.15 + 540, 100.0);
steam.addComponent("water", 1.0);
steam.setMixingRule("classic");
Stream steamFeed = new Stream("HP Steam", steam);
steamFeed.setFlowRate(50000.0, "kg/hr");
SteamTurbine st = new SteamTurbine("ST-001", steamFeed);
st.setOutletPressure(0.1); // Condenser pressure in bara
st.setIsentropicEfficiency(0.85);
st.run();
double stPower = st.getPower("MW");
double outletT = st.getOutletStream().getTemperature() - 273.15;
// Recover heat from gas turbine exhaust
HRSG hrsg = new HRSG("HRSG-001", gt.getExhaustStream(), waterFeedStream);
hrsg.run();
Stream steamOut = hrsg.getSteamOutStream();
double steamT = steamOut.getTemperature() - 273.15;
double steamP = steamOut.getPressure();
double stackT = hrsg.getStackTemperature() - 273.15;
// Integrated GT + HRSG + ST
CombinedCycleSystem ccgt = new CombinedCycleSystem("CCGT");
ccgt.setGasTurbine(gt);
ccgt.setHRSG(hrsg);
ccgt.setSteamTurbine(st);
ccgt.run();
double totalPower = ccgt.getTotalPower("MW");
double combinedEfficiency = ccgt.getCombinedEfficiency();
// Typical: 55-62% for modern CCGT
// Identify minimum utility requirements for a process
PinchAnalysis pinch = new PinchAnalysis("Plant Heat Integration");
// Add hot streams (need cooling)
pinch.addHotStream(new HeatStream("Reactor effluent", 250.0, 60.0, 5000.0));
pinch.addHotStream(new HeatStream("Column overhead", 120.0, 40.0, 3000.0));
pinch.addHotStream(new HeatStream("Product cooler", 80.0, 30.0, 1500.0));
// Add cold streams (need heating)
pinch.addColdStream(new HeatStream("Feed preheater", 25.0, 180.0, 4500.0));
pinch.addColdStream(new HeatStream("Reboiler", 150.0, 160.0, 2000.0));
// Set minimum approach temperature
pinch.setMinApproachTemperature(10.0); // degrees C
pinch.run();
double minHotUtility = pinch.getMinHotUtility(); // kW
double minColdUtility = pinch.getMinColdUtility(); // kW
double pinchTemp = pinch.getPinchTemperature(); // °C
// Fuel gas composition determines CO2 emissions
// CH4 + 2O2 -> CO2 + 2H2O
// C2H6 + 3.5O2 -> 2CO2 + 3H2O
// C3H8 + 5O2 -> 3CO2 + 4H2O
// Approximate: 2.75 kg CO2 per kg natural gas (varies with composition)
double fuelRate_kg_hr = gt.getFuelConsumption("kg/hr");
double co2Factor = 2.75; // kg CO2 / kg fuel (adjust for actual composition)
double co2_tonnes_yr = fuelRate_kg_hr * co2Factor * 8760 / 1e6;
For late-life or turndown studies where the question is "which turbines, how
many, and at what load?" — use the catalog-driven classes under
neqsim.process.equipment.powergeneration.gasturbine. These integrate directly
with ProcessSystem and link to Compressor.getPower() via the
PowerDemandConsumer interface.
| Class | Purpose |
|---|---|
GasTurbineCatalog | Loads the bundled gas_turbine_catalog.csv (14 aero + industrial models: LM2500, LM2500PLUS_G4, LM6000PF/PG, RB211_6562, Trent 60, SGT-700/750, Centaur 50, Taurus 60/70, Mars 100, Titan 130/250) |
GasTurbineSpec | Immutable rating point (rated MW, ISO heat rate, exhaust flow/T, NOx, mass) |
GasTurbinePerformanceMap | Part-load + ambient correction (aero vs industrial polynomials, min-load fraction) |
GasTurbineDegradation | Recoverable + non-recoverable fouling vs fired hours, water-wash and overhaul reset |
GasTurbineEmissions | Full-carbon-balance CO2, NOx, methane slip from fuel composition |
CO2TaxSchedule | Loads co2_tax_norway.csv (2020–2040 NOK/tonne, CO2 tax + EU ETS), linear interpolation |
GasTurbineUnit | TwoPortEquipment — runs inside a ProcessSystem, accepts fuel Stream, aggregates Compressor shaft load via addPowerConsumer |
TurbineDispatchOptimizer | Picks the cheapest feasible on/off combination (brute-force ≤8 units, merit-order above) with N+1 reserve |
LateLifeRetrofitStudy | Year-by-year NPV / CO2-avoided / payback for baseline vs retrofit fleet over a declining demand profile |
GasTurbineSpec spec = GasTurbineCatalog.get("LM2500");
GasTurbineUnit gt = new GasTurbineUnit("GT-A", fuelStream, spec);
gt.setAmbientTemperatureK(273.15 + 30.0); // hot day derate
gt.setDemandedPower(15.0e6); // 15 MW shaft
gt.run(UUID.randomUUID());
double avail_MW = gt.getAvailablePowerW() / 1.0e6;
double load = gt.getLoadFraction();
double co2_tph = gt.getCO2EmissionKgPerS() * 3.6;
Each GasTurbineUnit aggregates the live shaft demand from any number of
Compressor objects in the same flowsheet — the dispatcher reads it on every
run():
ProcessSystem plant = new ProcessSystem();
plant.add(exportCompressor); // existing Compressor
plant.add(injectionCompressor);
GasTurbineUnit gt = new GasTurbineUnit("GT-A", fuelStream,
GasTurbineCatalog.get("LM2500"));
gt.addPowerConsumer(exportCompressor);
gt.addPowerConsumer(injectionCompressor);
plant.add(gt);
plant.run(); // gt sums Compressor.getPower() automatically
List<GasTurbineUnit> fleet = Arrays.asList(gt1, gt2, gt3); // each is a GasTurbineUnit
TurbineDispatchOptimizer disp = new TurbineDispatchOptimizer(
/*fuelPriceNOKPerKg*/ 4.5,
/*co2CostNOKPerTonne*/ 1500.0);
disp.setRequireNplusOne(true);
TurbineDispatchOptimizer.DispatchResult r = disp.dispatch(fleet, 18.0e6);
if (r.feasible) {
System.out.println(r.summary()); // running units, load, NOK/hr
}
double[] demandMW = new double[15];
for (int i = 0; i < 15; i++) demandMW[i] = Math.max(8.0, 20.0 - i * 0.8);
LateLifeRetrofitStudy study = new LateLifeRetrofitStudy(
baselineFleet, // e.g. 2x LM6000PF
retrofitFleet, // e.g. 2x SGT-700
demandMW,
/*startYear*/ 2026,
CO2TaxSchedule.loadDefault(),
/*fuelPriceNOKPerKg*/ 4.5);
study.setRetrofitCapexMNOK(800.0);
study.setDiscountRate(0.08);
study.setAnnualOperatingHours(8000);
LateLifeRetrofitStudy.RetrofitResult res = study.run();
System.out.println("NPV (MNOK): " + res.npvMNOK);
System.out.println("CO2 avoided (t): " + res.totalCO2AvoidedTonne);
System.out.println("Payback (yr): " + res.simplePaybackYear);
GasTurbineUse legacy GasTurbine | Use GasTurbineUnit + catalog |
|---|---|
| You model the GT thermodynamically (compressor + combustor + expander) and care about exhaust composition into an HRSG | You are doing right-sizing, dispatch, retrofit, or fleet-level CO2/NPV studies and want vendor rating points, part-load + ambient correction, degradation, and N+1 |
Combined-cycle integration where exhaust gas feeds an HRSG | Late-life turndown, replacing oversized turbines, CO2-tax sensitivity |
To evaluate a bottoming cycle on top of a GasTurbineUnit retrofit fleet, feed
the synthesised exhaust into the legacy HRSG + SteamTurbine. Use the
per-unit exhaust mass flow and temperature from GasTurbineSpec (corrected by
GasTurbinePerformanceMap if needed) to build an exhaust Stream, then size
the bottoming cycle and add its power output to the retrofit LateLifeRetrofitStudy
result as an annual energy credit (extra MWh × fuel-equivalent × CO2 factor).
The 20-year rightsizing notebook (see below) demonstrates this pattern in
section 10.
Instead of a synthetic linear decline, drive the compressor shaft load from a
physics-based reservoir + flow line model. A simple gas-law material balance on
the reservoir gives (P_res, T_res) each year; a PipeBeggsAndBrills riser
plus flow line gives arrival pressure at the platform; the export compressor
suction pressure then sets shaft demand which the GasTurbineUnit /
TurbineDispatchOptimizer resolves. This couples the late-life study to real
field decline (recovery factor, reservoir size uncertainty) and is the right
pattern when CO2 tax and turbine count must be evaluated against an uncertain
production profile rather than a stipulated demand curve. Section 11 of the
20-year rightsizing notebook implements this end-to-end.
See examples/notebooks/gas_turbine_rightsizing_20yr.ipynb
for a complete 20-year late-life right-sizing study: catalog + site correction,
degradation, dispatch with N+1, LateLifeRetrofitStudy with CO2TaxSchedule,
HRSG + steam-turbine combined-cycle extension, and reservoir-driven demand.
| Standard | Scope |
|---|---|
| ISO 2314 | Gas turbine acceptance tests |
| IEC 60034 | Rotating electrical machines |
| API 616 | Gas turbines for petroleum industry |
| API 611/612 | Steam turbines |
| ASME PTC 22 | Gas turbine power performance |
| ASME PTC 6 | Steam turbine performance |
| Pitfall | Solution |
|---|---|
| Unrealistic efficiency (>45% simple cycle) | Typical: 30-40% simple cycle, 55-62% combined cycle |
| Missing air stream for gas turbine | GT requires both fuel and combustion air |
| Steam below saturation in turbine outlet | Check for wet steam — may need superheat or extraction |
| Pinch analysis with wrong units | HeatStream uses °C for temperature, kW for duty |
Dynamic simulation guidance for NeqSim. USE WHEN: running transient simulations, modeling startup/shutdown, tuning PID controllers, analyzing pressure/level dynamics, performing blowdown/depressurization, or setting up measurement devices and control loops. Covers runTransient, DynamicProcessHelper, controller tuning, and dynamic equipment configuration.
Hydrogen production routes (SMR/ATR/POX, blue-H2 WGS/capture/compression chains, electrolysis, ammonia cracking) with NeqSim. USE WHEN: modeling fired SMR reformers, ATR and POX syngas generators, water-gas shift, pressure-swing adsorption (PSA), CO2 capture/compression/export placeholders, H2 drying/compression/export, water electrolyzers (PEM/Alkaline/SOEC/AEM), stack I-V curves, hydrogen plant cost estimation, para/ortho hydrogen conversion, catalyst deactivation, or blue/green H2 flowsheets. Covers ReformerFurnace, CatalyticTubeReformer, WaterGasShiftReactor, ComponentCaptureUnit, BlueHydrogenPlantBuilder, AutothermalReformer, PartialOxidationReactor, PSACascade, Electrolyzer, ParaOrthoH2Correction, CatalystDeactivationKinetics, and cost estimates.
Distillation column design rules for NeqSim. USE WHEN: setting up distillation columns, troubleshooting convergence, selecting internals (trays/packing), sizing columns, or analyzing column performance. Covers DistillationColumn setup, solver selection, feed tray optimization, reflux ratio, and internals selection per industry standards.
Structured inventory of NeqSim's capabilities by engineering discipline. USE WHEN: checking what NeqSim can do, planning implementations, assessing gaps for engineering tasks, or routing work to the right agent. Covers thermodynamics, process equipment, PVT, standards, mechanical design, flow assurance, safety, and economics.
Process controllability and operability — operating envelope mapping, turndown analysis, startup/shutdown sequencing, control valve sizing per ISA-75 (Fl, Fp, choked flow), rangeability, hunting/loop tuning, recycle stability. USE WHEN: a task involves operability assessment, turndown studies, control valve sizing, startup/shutdown procedures, or 'will this design operate?' questions. Complements neqsim-dynamic-simulation (transient solver) with steady-state operability framing.
Emergency depressurization (blowdown) per API 521 §5.20 and minimum design metal temperature (MDMT) assessment per ASME UCS-66 / API 579 / EN 13445 — VU-flash transient inventory model, time-to-target-pressure, low-temperature embrittlement screening, and integration with PSV/flare loads. USE WHEN: a task requires sizing a blowdown valve, generating a P-vs-time curve for a vessel under fire / depressurization, checking MDMT against blowdown end-temperature, providing source terms for relief and flare networks, or distinguishing blowdown from trapped-liquid fire rupture screening. Anchors on neqsim.process.safety.depressurization.DepressurizationSimulator and neqsim.process.safety.mdmt.MDMTCalculator.