NeqSim Wiki

Welcome to the NeqSim documentation. This comprehensive wiki provides guides, tutorials, and reference materials for using the library and contributing to development.

About NeqSim

NeqSim (Non-Equilibrium Simulator) is a Java library for estimating fluid properties and process design. The library contains models for:

Development was initiated at the Norwegian University of Science and Technology (NTNU). NeqSim is part of the NeqSim project.

Quick Start

import neqsim.thermo.system.SystemSrkEos;
import neqsim.thermodynamicoperations.ThermodynamicOperations;

// Create a fluid
SystemSrkEos fluid = new SystemSrkEos(298.15, 10.0);  // T(K), P(bara)
fluid.addComponent("methane", 0.9);
fluid.addComponent("ethane", 0.07);
fluid.addComponent("propane", 0.03);
fluid.setMixingRule("classic");

// Run flash calculation
ThermodynamicOperations ops = new ThermodynamicOperations(fluid);
ops.TPflash();

// Get results
System.out.println("Z-factor: " + fluid.getZ());
System.out.println("Density: " + fluid.getDensity("kg/m3") + " kg/m3");

🚀 Getting Started

Guide Description
Getting Started Installation, first calculations, and basic concepts
Usage Examples Comprehensive code examples
FAQ Frequently asked questions
GitHub Guide Complete documentation index

🧪 Thermodynamics & Phase Behavior

Guide Description
Thermodynamics Guide Equations of state, flash calculations, mixing rules
Fluid Characterization Plus fractions, pseudo-components, TBP modeling
Flash Equations & Tests Flash calculations validated by tests
Property Flash Workflows PH, PS, UV flash calculations

⚙️ Process Simulation

Guide Description
Process Simulation Guide Building flowsheets, running simulations
Advanced Process Simulation Recycles, adjusters, complex systems
Logical Unit Operations Controllers, splitters, recycles
Transient Simulation Guide Dynamic process modeling
Process Control Framework PID controllers, automation
Bottleneck Analysis Capacity constraints, production optimization

🔧 Equipment Models

Equipment Documentation
Distillation Column Sequential, damped, inside-out solvers
Gibbs Reactor Chemical equilibrium reactor
Flow Meter Models Orifice, venturi, ultrasonic meters
Air Cooler Air-cooled heat exchanger
Heat Exchanger Design Mechanical design methods
Water Cooler Water-cooled systems
Steam Heater Steam heating systems
Battery Storage Energy storage unit
Solar Panel Solar power generation

📊 PVT & Reservoir

Guide Description
PVT Simulation Workflows CVD, CCE, DL simulations
Black-Oil Flash Playbook Black-oil modeling techniques
Humid Air Mathematics Psychrometric calculations

📏 Standards & Quality

Guide Description
Gas Quality Standards ISO 6976, GPA standards

🔌 Integration & Tools

Guide Description
Java from Colab Running NeqSim in Google Colab
JUnit Test Overview Test suite structure

Installation

Maven:

<dependency>
    <groupId>com.equinor.neqsim</groupId>
    <artifactId>neqsim</artifactId>
    <version>3.0.0</version>
</dependency>

Download: GitHub Releases

Resources