High Performance Gas Expansion System for Halon-Free Cargo Hold Fire Suppression System

Project Information

ECOSYSTEM

Grant agreement ID: 864977

DOI

10.3030/864977

Project closed

EC signature date 24 September 2019

Start date 1 October 2019

End date 31 March 2022

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 998 805,00

EU contribution

€ 699 163,51

Coordinated by

COLLINS AEROSPACE IRELAND, LIMITED
Ireland

Periodic Reporting for period 2 - ECOSYSTEM (High Performance Gas Expansion System for Halon-Free Cargo Hold Fire Suppression System)

Reporting period: 2020-10-01 to 2022-03-31

Summary of the context and overall objectives of the project

The ECOSYSTEM project will design, fabricate and demonstrate at TRL 5 a high performance inert gas fire suppression system to be used as a Halon-free cargo hold fire protection. The demonstrator will store the inert gas in lightweight composite pressure vessels. Once the cylinder valves are opened, the high and low discharge of inert gas will be controlled to ensure required flow rates for knock-down and long term suppression of fire. The TRL 5 demonstrator will include safety features to allow the safe operation and will contain all of the necessary instrumentation to characterize the static and transient conditions during its operation.

There are international regulations requiring that Halon 1301 be phased out from new production aircraft by 2040, in accordance with the deadlines laid out in EC Regulation 1005/2009 and subsequent amendments.

The ECOSYSTEM project is organised to achieve the following objectives.

- Develop a set of requirements and KPIs with the TM.
- Develop and assess system architecture options with respect to optimal placement and integration into the demonstrator to ensure high efficiency while meeting the requirements
- Design the system components to meet requirements.
- Perform trade studies to evaluate the various component options for cylinders, pressure regulators, metering units and valves based on weight, volume, safety impact, certification complexity
- Perform a thorough safety/risk analysis at system level. In addition, risk and opportunity analyses, safety assessments and industrialization plans will be generated to support this project
- Model performance of the demonstrator from the pressure vessels to the delivery nozzles using modelling tool such as CFD, thermal analysis and stress analysis
- Characterize system performance by physical measurement at the component and system level at LHO lab and use results to validate the models
- Test prototype at Fraunhofer in an actual cargo hold at and evaluate its performance across a wide range of temperatures and pressures, simulating flight conditions.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Currently cargo compartments of aircraft are protected from fire by Halon, which is extremely damaging to the ozone layer and also a powerful greenhouse gas. The objective of ECOSYSTEM is to design, manufacture and demonstrate a next generation fire suppression system that uses a sustainable and widely available substance: nitrogen gas.

The project includes building and testing the new system to show it is capable of suppressing fire in cargo hold for the duration of the flight or until a safe landing is secured. The team achieved this through development of system architecture options with respect to optimal placement and integration of components into the demonstrator to ensure high efficiency. The best architecture was designed, manufactured and tested for performance and safety at Fraunhofer Institute in an actual cargo hold. In particular:

- Requirements were specified through collaboration with the TM and served as the base input for the demonstrator design.
- Several design tools were used for selection of components and to verify system level performance. The demonstrator design was then completed and followed by a successful Critical Design Review (CDR) with the TM.
- Participants engaged suppliers and discussed specifications, and identified solutions complaint to the requirement. Parts were then purchased, tested and assembled.
- Proof and burst pressure tests on components was performed ensuring safe behaviour of the system. This is then followed by the discharge tests, the purpose of which is to characterize the system behaviour. Such tests was important to select flow regulator set-points and orifice sizes that will deliver the required flow rates. Both HRD and LRD regulators worked as expected in order to get the outlet pressure needed. System characterization showed that the fire suppression Demonstrator functioned correctly.
- The Demonstrator was shipped, installed and operated in Fraunhofer test facility. Interfaces between Demonstrator and test facility were defined and installation work was carried out. A test matrix was developed with 15 test conditions including cold, ambient, and hot conditions. Pressure profiles tested include ground and in-flight phases for empty and loaded conditions. Test campaign was successful showing the demonstrator was capable of meeting all of the requirements from TM. The CFD predictions were compared with the data and good agreement was obtained in terms of oxygen concentration.

The consortium made significant achievements on dissemination and exploitation. COVID-19 had major impact on dissemination activities throughout the project duration. However, this did not prevent partners from disseminating project results at different events such FAA forum 2021. Three patent applications were filled and currently under review by the Patent Office. Additional dissemination events are planned and will take place after the project completion. On exploitation front, the consortium worked closely with the TM and finalized the Industrialization plan taking the Demonstrator to the next level paving the way towards TRL6 and possible flight test.

The project consortium fully achieved all of the project objectives listed above. All of the deliverables and milestones are completed and submitted.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The aviation industry has been working on the challenge of finding a suitable Halon replacement for cargo compartments for the last 20 years or more. A number of fire suppression options have been explored, however, none have been commercialized, or even begun to be commercialized.

The ECOSYSTEM demonstrator is designed within the limits of the distribution system used in existing aircraft. This would open up the possibility of retrofitting older aircraft with inert gas systems to comply with requirements to replace Halon 1301 by the year 2040. The current design of these systems relies heavily on user experience and know how. ECOSYSTEM developed tools and methodologies that ensured optimal design is achieved while also meeting all of the performance and safety requirements.

The consortium partners faced many technical challenges and uncertainty during the execution of the project related to some of the requirements laid down by the TM, which are likely to be mutually exclusive. To achieve the desired result, the demonstrator will have to discharge a large amount of nitrogen gas into the cargo compartment in a short period of time. This will inevitably result in a high mass and volume flow rate and in significant increase in cargo compartment pressure. However, there is a second requirement that only a small pressure rise is allowed in the cargo compartment. Satisfying these criteria is very challenging and required innovation in the design of demonstrator. A second challenge lies in identifying components that can satisfy the temperature requirements, this affects the storage of nitrogen gas, its discharge characteristics and the functional operation of valves regulators, etc. Careful design and selection of the demonstrator components is essential.

The demonstrator was successfully build, characterized and tested in relevant environment achieving TRL5.

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