Process Design Guide for NeqSim

Introduction

This guide connects a steady-state flowsheet to preliminary mechanical sizing and reporting. The complete example defines all inputs, runs a separator and compressor, applies project standards, calculates mechanical results, and checks mass balance and output validity. MechanicalDesignGuideDocumentationTest compiles and executes the example directly from this page against the current repository classes.

The synthetic example uses SRK with the classic mixing rule. It demonstrates software behavior and basic physical consistency. Material suitability, code compliance, relief design, layout, and equipment procurement require additional engineering checks and qualified inputs.

Related Documentation

Document	Description
Design Framework	AutoSizeable, process templates, and design optimization
Production Optimization Guide	Production optimization examples
Capacity Constraint Framework	Equipment capacity constraints

Process Design Workflow Overview

1. Define fluid composition, thermodynamic model, units, feeds, and equipment.
2. Run the process and check balances and operating results.
3. Set mechanical inputs and standards, then calculate equipment designs.
4. Check calculation completeness and engineering bounds before reporting results.

Step 1: Define the System

1.1 Create the Fluid System

The complete example uses mole fractions of 0.70 methane, 0.10 ethane, 0.10 propane, 0.05 n-butane, and 0.05 n-pentane. SystemSrkEos constructor inputs are K and bara; 303.15 K corresponds to 30 °C. Use setMixingRule("classic") after adding components.

1.2 Build the Process Flowsheet

Connect a 10,000 kg/hr feed to an HP separator and its gas outlet to a compressor. Set the compressor outlet to 80 bara and its isentropic efficiency to 0.75. Add the feed and equipment to the ProcessSystem in flow order. The example starts with a 1 m separator diameter before calculating a preliminary size.

1.3 Load Project TORG

The example creates a programmatic TechnicalRequirementsDocument so it needs no external project file. Use the real category names returned by StandardType.getDesignStandardCategory(). For external requirements, see TORG Integration: filesystem CSV input takes a Path, and loading a document alone does not activate or apply it.

Step 2: Process Simulation

2.1 Run Base Case Simulation

Call process.run() before mechanical calculations so phase flow and physical properties are available. Retrieve outlet flows with explicit units and compressor duty through getPower("kW"). The example verifies that gas plus liquid mass flow equals feed mass flow, that compressor power is positive and finite, and that outlet pressure equals the target.

2.2 Run Multiple Design Cases

Import DesignCase from neqsim.process.mechanicaldesign. Its load factors are scenario metadata; explicitly change feed/equipment conditions and rerun for each scenario. The Field Development Orchestration example executes normal, maximum, and minimum throughput cases. Adding case labels to an orchestrator alone does not run different operating conditions.

Step 3: Mechanical Design

3.1 Apply Design Standards

Initialize the equipment’s supporting default design inputs before assigning individual standards. Use equipment.getMechanicalDesign().setDesignStandard(StandardType) or a TorgManager; StandardRegistry.applyStandardToEquipment(...) does not exist.

The example chooses ASME_VIII_DIV1, API_12J, and API_617. A registered standard name is not proof of a complete edition-specific calculation. See Mechanical Design Standards for selection support and limitations.

3.2 Run Mechanical Design Calculations

Use setMaxOperationPressure(value, "bara") and setMaxOperationTemperature(value, "C") to define the mechanical operating envelope. setPressureMarginFactor(0.10) is a fractional 10% margin; a TORG pressure safety factor of 1.10 is a multiplier and must not be passed unchanged to this setter.

The current maximum design-pressure getter is getMaxDesignPressure("bara"), and operating temperature is available through getMaxOperationTemperature("C"). There are no generic getDesignPressure() or getDesignTemperature() getters in MechanicalDesign. For separator pressure-vessel sizing, getWallThickness() returns metres, so multiply by 1000 when reporting mm. Total mechanical weight is kg.

The separator pressure-vessel calculation uses the equipment’s current internal diameter. The example first calculates a preliminary diameter, assigns it back to the separator, then runs system design so thickness/weight use that diameter. The pressure margin getter is design metadata; inspect the equipment-specific calculation before assuming every margin or material requirement is automatically enforced.

3.3 Design All Equipment in System

Use SystemMechanicalDesign.calculate(SystemDesignExecutionMode.FAIL_FAST) for this example. It returns a SystemMechanicalDesignResult and throws on a failed equipment calculation. runDesignCalculation() uses best-effort mode; check getLastCalculationResult().isPresent() and the contained result’s isComplete() before accepting its aggregate totals.

See Mechanical Design Database for loading generic design limits. These limits do not automatically replace the explicitly configured operating envelope.

Step 4: Validate and Report

4.1 Validate Design Compliance

DesignValidationResult is in neqsim.process.mechanicaldesign. Add an application check with addError(category, equipmentName, message, remediation) and information with addInfo(equipmentName, message). isValid() only reports whether the collected messages contain an error or critical issue; it is not an independent compliance assessment.

The example verifies mass balance, compressor pressure/power, positive finite diameter, thickness and weight, and complete equipment calculations. It also compares the explicitly assigned corrosion allowance with the requirement. These are software/consistency checks, not a substitute for an independent sizing benchmark.

4.2 Generate Design Report

Use SystemMechanicalDesign.generateSummaryReport() for equipment totals and the validation container’s getSummary() for the checks performed by the application. Clearly distinguish calculated dimensions, configured operating limits, and selected standards in reports.

Using the Field Development Orchestrator

The constructor is FieldDevelopmentDesignOrchestrator(process, projectId). Use getValidationResult() after runCompleteDesignWorkflow(); validateDesign() is private. The orchestrator guide describes active TORG handling, per-case execution, and the need to inspect mechanical calculation completeness separately.

Design Phases and Accuracy

Phase	Current planning range	Full-design validation flag
SCREENING	±40-50%	No
CONCEPT_SELECT	±25-35%	No
PRE_FEED	±20-30%	No
FEED	±15-20%	Yes
DETAIL_DESIGN	±10-15%	Yes
AS_BUILT	±5%	No

These are DesignPhase metadata, not verified uncertainty intervals. Selecting a phase does not alter the thermodynamic model or automatically improve the mechanical correlations.

Supported Design Standards

Use the Mechanical Design Standards guide to distinguish standard metadata, mapped implementations, strict selection, and calculation support. A standard appearing in StandardType does not establish that every equipment type or clause is implemented.

Data Sources

Configure data sources on each MechanicalDesign using setDesignDataSource(...) or setDesignDataSources(...). StandardBasedCsvDataSource takes a filesystem Path or a classpath-resource String. StandardRegistry.registerDataSource(...) is not available. See Mechanical Design Database for executable CSV examples.

Complete Example

The example logs summaries at INFO level; enable INFO output in your Log4j2 configuration to see them. Its result checks run regardless of the logging level.

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import neqsim.process.equipment.ProcessEquipmentInterface;
import neqsim.process.equipment.compressor.Compressor;
import neqsim.process.equipment.separator.Separator;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.mechanicaldesign.DesignValidationResult;
import neqsim.process.mechanicaldesign.MechanicalDesign;
import neqsim.process.mechanicaldesign.SystemDesignExecutionMode;
import neqsim.process.mechanicaldesign.SystemMechanicalDesign;
import neqsim.process.mechanicaldesign.SystemMechanicalDesignResult;
import neqsim.process.mechanicaldesign.designstandards.StandardType;
import neqsim.process.mechanicaldesign.torg.TechnicalRequirementsDocument;
import neqsim.process.mechanicaldesign.torg.TorgManager;
import neqsim.process.processmodel.ProcessSystem;
import neqsim.thermo.system.SystemSrkEos;

public class ProcessDesignExample {
  private static final Logger logger = LogManager.getLogger(ProcessDesignExample.class);

  public static void main(String[] args) {
    SystemSrkEos fluid = new SystemSrkEos(303.15, 50.0);
    fluid.addComponent("methane", 0.70);
    fluid.addComponent("ethane", 0.10);
    fluid.addComponent("propane", 0.10);
    fluid.addComponent("n-butane", 0.05);
    fluid.addComponent("n-pentane", 0.05);
    fluid.setMixingRule("classic");
    Stream feed = new Stream("Feed", fluid);
    feed.setFlowRate(10000.0, "kg/hr");
    Separator separator = new Separator("HP Separator", feed);
    separator.setInternalDiameter(1.0);
    Compressor compressor = new Compressor("Export Compressor", separator.getGasOutStream());
    compressor.setOutletPressure(80.0, "bara");
    compressor.setIsentropicEfficiency(0.75);
    ProcessSystem process = new ProcessSystem();
    process.add(feed);
    process.add(separator);
    process.add(compressor);
    process.run();

    double gasKgPerHour = separator.getGasOutStream().getFlowRate("kg/hr");
    double liquidKgPerHour = separator.getLiquidOutStream().getFlowRate("kg/hr");
    double powerKw = compressor.getPower("kW");
    DesignValidationResult validation = new DesignValidationResult();
    if (!Double.isFinite(gasKgPerHour) || !Double.isFinite(liquidKgPerHour)
        || gasKgPerHour <= 0.0 || liquidKgPerHour < 0.0
        || Math.abs(gasKgPerHour + liquidKgPerHour - feed.getFlowRate("kg/hr")) > 1.0e-5
        || !Double.isFinite(powerKw) || powerKw <= 0.0
        || Math.abs(compressor.getOutletStream().getPressure("bara") - 80.0) > 1.0e-9) {
      validation.addError("Process", "Flowsheet", "Invalid mass balance, power, or outlet pressure",
          "Review feed conditions and equipment configuration");
    }

    for (ProcessEquipmentInterface equipment : process.getUnitOperations()) {
      equipment.getMechanicalDesign().setCompanySpecificDesignStandards("default");
    }
    TechnicalRequirementsDocument torg = TechnicalRequirementsDocument.builder()
        .projectId("DOCS-001").projectName("Synthetic process design")
        .addStandard(StandardType.ASME_VIII_DIV1.getDesignStandardCategory(), StandardType.ASME_VIII_DIV1)
        .addStandard(StandardType.API_12J.getDesignStandardCategory(), StandardType.API_12J)
        .addStandard(StandardType.API_617.getDesignStandardCategory(), StandardType.API_617)
        .safetyFactors(new TechnicalRequirementsDocument.SafetyFactors(1.10, 25.0, 3.0, 0.125, 1.0))
        .build();
    TorgManager manager = new TorgManager();
    manager.apply(torg, process);
    MechanicalDesign separatorDesign = separator.getMechanicalDesign();
    separatorDesign.setMaxOperationPressure(50.0, "bara");
    separatorDesign.setMaxOperationTemperature(30.0, "C");
    separatorDesign.setPressureMarginFactor(torg.getSafetyFactors().getPressureSafetyFactor() - 1.0);
    compressor.getMechanicalDesign().setMaxOperationPressure(80.0, "bara");
    compressor.getMechanicalDesign().setMaxOperationTemperature(
        compressor.getOutletStream().getTemperature("C"), "C");
    separatorDesign.calcDesign();
    separator.setInternalDiameter(separatorDesign.getInnerDiameter());

    SystemMechanicalDesign systemDesign = new SystemMechanicalDesign(process);
    SystemMechanicalDesignResult calculation = systemDesign.calculate(SystemDesignExecutionMode.FAIL_FAST);
    double wallThicknessMm = separatorDesign.getWallThickness() * 1000.0;
    if (!calculation.isComplete() || !Double.isFinite(systemDesign.getTotalWeight())
        || systemDesign.getTotalWeight() <= 0.0 || !Double.isFinite(separatorDesign.getInnerDiameter())
        || separatorDesign.getInnerDiameter() <= 0.0 || !Double.isFinite(wallThicknessMm)
        || wallThicknessMm <= 0.0
        || separatorDesign.getCorrosionAllowance() < torg.getSafetyFactors().getCorrosionAllowance()) {
      validation.addError("Mechanical", separator.getName(), "Incomplete or invalid design results",
          "Inspect equipment outcomes, standards, dimensions, and material inputs");
    }
    if (!validation.isValid()) {
      throw new IllegalStateException(validation.getMessages().toString());
    }
    validation.addInfo("Flowsheet", "Documented execution and physical consistency checks passed");
    logger.info("Gas={} kg/hr; liquid={} kg/hr; compressor={} kW", gasKgPerHour, liquidKgPerHour, powerKw);
    logger.info("Separator diameter={} m; wall={} mm; maximum design-pressure metadata={} bara",
        separatorDesign.getInnerDiameter(), wallThicknessMm, separatorDesign.getMaxDesignPressure("bara"));
    logger.info("{}", validation.getSummary());
    logger.info("{}", systemDesign.generateSummaryReport());
  }
}

For these inputs, gas and liquid outlet mass flows must sum to 10,000 kg/hr and the compressor outlet pressure must be 80 bara. The explicitly configured maximum separator operating pressure is 50 bara; the 10% margin makes its maximum design-pressure metadata 55 bara. Mechanical results are preliminary estimates from the selected implementations.

Related Documentation

Document	Description
Mechanical Design Standards	Standards selection and implementation coverage
Mechanical Design Database	Supported data-source APIs, formats, and units
TORG Integration	Requirements, activation, application, and limitations
Field Development Orchestration	Explicit operating cases and workflow reports

Quick Reference

Key Classes

Class	Purpose
ProcessSystem	Flowsheet and simulation
MechanicalDesign	Equipment design inputs and outputs
SystemMechanicalDesign	Equipment calculations and aggregate report
SystemMechanicalDesignResult	Completion and per-equipment outcomes
StandardType, StandardRegistry	Standards metadata and implementation selection
TechnicalRequirementsDocument, TorgManager	Project requirements and supported application
FieldDevelopmentDesignOrchestrator	Base-case workflow coordination
DesignPhase, DesignCase, DesignValidationResult	Phase/case metadata and validation messages

Key Packages

Package	Contents
neqsim.process.processmodel	ProcessSystem
neqsim.process.equipment	Equipment interfaces and subpackages
neqsim.process.mechanicaldesign	Mechanical design, orchestration, phases/cases, validation
neqsim.process.mechanicaldesign.designstandards	Standards framework
neqsim.process.mechanicaldesign.torg	TORG framework
neqsim.process.mechanicaldesign.data	Design-limit data sources