Pressure Monitoring in ESD Blowdown System

Overview

The ESD blowdown system now includes comprehensive pressure monitoring during transient calculations to verify that the separator pressure is properly released via the blowdown valve.

Key Features

1. Continuous Pressure Monitoring

The system tracks separator pressure at every time step:

2. Pressure Relief Verification

Automated checks verify:

Usage Examples

Example 1: Basic Pressure Monitoring (ESDBlowdownSystemExample.java)

// Track pressure during blowdown
double initialPressure = separator.getGasOutStream().getPressure("bara");
double minPressure = initialPressure;
double maxPressure = initialPressure;

for (double time = 0.0; time <= totalTime; time += timeStep) {
    // Run equipment in transient mode
    separator.run();
    bdValve.runTransient(timeStep, uuid);
    // ... other equipment
    
    // Monitor separator pressure
    double currentPressure = separator.getGasOutStream().getPressure("bara");
    minPressure = Math.min(minPressure, currentPressure);
    maxPressure = Math.max(maxPressure, currentPressure);
    
    System.out.printf("Time: %.1fs, Pressure: %.2f bara%n", time, currentPressure);
}

// Verify pressure relief
System.out.printf("Pressure drop: %.2f bar (%.1f%% reduction)%n", 
    initialPressure - finalPressure, 
    100.0 * (initialPressure - finalPressure) / initialPressure);

Example 2: Pressure Buildup and Relief Test

The new test testPressureReliefViaBlowdown() demonstrates:

Scenario:

  1. Normal Operation (0-5s) - Separator at 60 bara, outlet valve 50% open
  2. Outlet Blockage (5-10s) - Outlet valve closes to 5%, pressure rises
  3. ESD Activation (10s) - Push button activates blowdown valve
  4. Depressurization (10-30s) - Pressure drops as gas flows to flare

Output:

═══ PRESSURE PROFILE ═══
Initial pressure: 60.00 bara
Maximum pressure reached: 65.23 bara
Pressure at ESD activation: 65.23 bara
Final pressure: 52.18 bara
Pressure rise before ESD: 5.23 bar (8.7% increase)
Pressure drop after ESD: 13.05 bar (20.0% reduction)

✓ Pressure buildup detected: 60.00 bara → 65.23 bara
✓ ESD successfully activated at 65.23 bara
✓ Pressure relieved to 52.18 bara (20.0% reduction)

Monitoring Points

Separator Pressure

double sepPressure = separator.getPressure("bara");
// or
double sepPressure = separator.getGasOutStream().getPressure("bara");

Blowdown Flow Rate

double bdFlow = blowdownStream.getFlowRate("kg/hr");

Valve Opening

double opening = bdValve.getPercentValveOpening(); // 0-100%
boolean isOpen = bdValve.getPercentValveOpening() > 90.0;

Flare Load

double heatRelease = flare.getHeatDuty("MW");
double totalGas = flare.getCumulativeGasBurned("kg");

Transient Calculation Pattern

// Initialize tracking variables
double initialPressure = separator.getPressure("bara");
double maxPressure = initialPressure;
double finalPressure = initialPressure;

// Time loop
double timeStep = 0.5; // seconds
for (double time = 0.0; time <= simulationTime; time += timeStep) {
    
    // 1. Update process conditions (if needed)
    if (time >= eventTime) {
        esdButton.push(); // Trigger ESD
        splitter.setSplitFactors(new double[] {0.0, 1.0});
    }
    
    // 2. Run all equipment
    feedStream.run();
    separator.run();
    // ... other steady-state equipment
    
    // 3. Run transient equipment
    bdValve.runTransient(timeStep, UUID.randomUUID());
    
    // ... more equipment
    
    flare.run();
    flare.updateCumulative(timeStep); // Track cumulative values
    
    // 4. Monitor and record
    double currentPressure = separator.getPressure("bara");
    maxPressure = Math.max(maxPressure, currentPressure);
    finalPressure = currentPressure;
    
    // 5. Output (optional)
    System.out.printf("t=%.1fs: P=%.2f bara, BD=%.1f%%, Flow=%.1f kg/hr%n",
        time, currentPressure, bdValve.getPercentValveOpening(), 
        blowdownStream.getFlowRate("kg/hr"));
}

// 6. Verify results
if (finalPressure < initialPressure) {
    System.out.println("✓ Pressure successfully relieved");
}

Verification Checks

Automated Assertions

// Pressure should decrease after blowdown
assertTrue(finalPressure < pressureAtEsdActivation, 
    "Pressure should decrease after ESD activation");

// Valve should be activated
assertTrue(bdValve.isActivated(), "BD valve should be activated");

// Gas should flow to flare
assertTrue(flare.getCumulativeGasBurned("kg") > 0, 
    "Gas should flow to flare");

// Valve should be fully open
assertTrue(bdValve.getPercentValveOpening() > 90.0, 
    "BD valve should be nearly fully open");

Console Output Verification

The system provides detailed output showing:

Running the Examples

Run the basic example with pressure monitoring:

mvn exec:java -Dexec.mainClass="neqsim.process.util.example.ESDBlowdownSystemExample"

Run the comprehensive test suite:

# Run all blowdown tests
mvn test -Dtest=BlowdownValveESDSystemTest

# Run specific pressure relief test
mvn test -Dtest=BlowdownValveESDSystemTest#testPressureReliefViaBlowdown

Expected Results

When the blowdown system is working correctly, you should observe:

  1. Pressure Decrease - Separator pressure drops after ESD activation
  2. Valve Opening - BD valve gradually opens to 100% over configured time
  3. Gas Flow - Significant flow rate through blowdown valve to flare
  4. Heat Release - Flare shows increasing heat duty as gas combusts
  5. Cumulative Tracking - Total gas burned and emissions tracked

Typical Values

Troubleshooting

If pressure is not relieved:

  1. Check BD valve is activated: bdValve.isActivated()
  2. Verify valve opening: bdValve.getPercentValveOpening()
  3. Check flow to blowdown: blowdownStream.getFlowRate("kg/hr")
  4. Verify splitter redirects flow: splitter.setSplitFactors(...)
  5. Check orifice pressure drop: bdOrifice.getOutletPressure()

Integration with Process Systems

The pressure monitoring integrates with:

Summary

The enhanced ESD blowdown system provides:

This ensures that the blowdown valve correctly relieves pressure when activated, protecting equipment from overpressure conditions.