Environmental Control Library - Overview
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The Environmental Control Library (ECL) is a Modelica model library for analyzing and designing aircraft environmental control systems. It contains components like heat exchangers, compressors, turbines, and pipes that can be connected to model complete environmental control systems. ECL supports modeling systems with bidirectional flow and accounts for variations in ambient conditions. Recent improvements include restructuring the library for easier navigation and updating documentation. ECL can be used to simulate systems through a full flight envelope and is also suitable for real-time simulation in flight simulators. Example applications include modeling ram air cooling systems.
Environmental Control Library - Overview
- 1. An overview ENVIRONMENTAL CONTROL LIBRARY 7 September 2017 © Modelon
- 2. AGENDA • What is Environment Control Library (ECL)? • History • Key features • ECL and other Modelon Libraries • Library contents • Recent improvements • Application examples • Contact 7 September 2017 © Modelon
- 3. WHAT IS ENVIRONMENT CONTROL LIBRARY (ECL)? • A Modelica model library for aircraft environmental control systems analysis and design • Designed to study energy consumption and thermal conditions that affect the level of comfort for passengers and crew • Performance aspects driven by large variations in ambient conditions (humidity, temperature) ECL models account for these effects through first principles and fully support bidirectional flow. 7 September 2017 © Modelon
- 4. ECL HISTORY • Developed internally at Modelon since a number of years together with a European airframer • Publically available with version 3.1 (September 2015) • A package hardened through industrial program deployment. 47 September 2017 © Modelon
- 5. KEY FEATURES (1) • Flexible composition of user-defined system architectures for efficient model management • Real-time capable high performance models enabling Hardware-In-the-Loop (HIL) applications • Full support for bidirectional flow for analysis of all modes of operation on ground and in flight 57 September 2017 © Modelon
- 6. KEY FEATURES (2) • Efficient representation of moist air enabling robust and fast simulation of large-scale systems • Online visualization of simulation results for intuitive understanding of the system behavior • Configurable model fidelity for faster simulation and right complexity level • Easy integration with other libraries 67 September 2017 © Modelon
- 7. CONNECTIONS WITH OTHER MODELON LIBRARIES RELEVANT FOR COOLING SYSTEMS • Air cycle refrigeration systems turbofan system bootstrap system reversed bootstrap system ram powered reverse bootstrap • Vapor cycle refrigeration systems • Liquid cooled systems • Environmental Control Library • Fuel System Library • Vapor Cycle Library • Liquid Cooling Library • Heat Exchanger Library 7 • acceleration forces • positioning in 3D space • air/fuel mixed and unmixed • moist air • turbines, • fans • compressors • ejector 7 September 2017 © Modelon
- 8. IMPROVEMENTS • Previous version of Environmental Control System Library 3.3 • Library restructured for easier navigation • Documentation has been substantially updated • Fixed bugs 87 September 2017 © Modelon
- 9. RECENT IMPROVEMENTS • Current version of Environmental Control System Library 3.3.1 • Updated to latest changes in Modelon Base library 97 September 2017 © Modelon
- 10. • An efficient and numerically robust framework suitable for large-scale complex systems. • Library includes: heat exchangers compressors turbines pumps volumes valves cabin pipes ECL CONTENTS 107 September 2017 © Modelon
- 11. • Model that lets you choose between purely static mass and energy balances and one with (optional) dynamic volume included • Heat transfer: external only exposes volume temperature to port, internal resistance defined by constant coefficient PIPES
- 12. • Dynamic energy and mass balances • Volume without hydraulics resistance • Spray volume with additional water spray inlet • Static water separator model VOLUMES
- 13. TURBINE AND COMPRESSOR • Table based components • Characteristic maps to be provided as tables • Draft physical components based on Hans’ ideas.
- 14. • Table based component with water condensation • Basic NTU-version (dry conditions only) HEAT EXCHANGERS
- 15. • Ejector with three ports Motive flow inlet port Suction port Discharge port • Check valve • Control valve (Kv-value parameterization) PUMPS AND VALVES
- 16. • Single port sensors: p, T • Two port flow sensors: m_flow, V_flow • System settings and boundary conditions System settings (altitude, Mach number, etc.) SENSORS AND FLUIDS
- 17. • Pressure source/sink, • Multiple pressure source/sink • Mass flow source/sink • Options: set parameters, signal inputs, use atmosphere information from system component BOUNDARY CONDITIONS
- 18. COVERED COOLING SYSTEMS • Air cycle refrigeration systems Bootstrap system Reversed bootstrap system Ram powered reverse bootstrap • Vapor cycle refrigeration systems • Liquid cooled systems 18 C919, air cycle machine Source: wikipedia 7 September 2017 © Modelon
- 19. ECL LIBRARY APPLICATIONS • Offline simulation of complete ECL-system through complete flight envelope and all operating conditions Large systems Includes controls, sequential and feedback • Real time simulation of the same system models Some simplifications, but same overall model (real time capability achieved through model configuration selection) To be included in special flight simulator hardware 197 September 2017 © Modelon
- 20. A RAM COOLING SYSTEM 20 Main Heat exchanger Fan Ram air Exhaust air Preliminary Heat exchanger 7 September 2017 © Modelon
- 21. A RAM COOLING SYSTEM ECL 3.3 Ram air 21 Quasi-steady-state components: • System (1) • Turbines (2) • Compressors (3) • Heat exchangers (4) • Flow resistances (5) • Sinks/sources (6) Mass and energy storage: • Dynamic volumes (incl. e.g. moisture condensation) (7) (1) (2) (3) (4) (5) (7) (6) Hot air (4)(6) (6) 7 September 2017 © Modelon
- 22. • More example models • Improvements based on customer requests FUTURE DEVELOPMENT
- 23. For more information, please contact: sales@modelon.com www.modelon.com CONTACT INFORMATION 237 September 2017 © Modelon