Neqsim Power Generation

1. Gas Turbine

// 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");

2. Steam Turbine

// 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;

3. Heat Recovery Steam Generator (HRSG)

// 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;

4. Combined Cycle System

// 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

5. Heat Integration (Pinch Analysis)

// 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

6. Emissions from Power Generation

// 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;

Applicable Standards

Common Pitfalls