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

Periodic Reporting for period 1 - ECOSYSTEM (High Performance Gas Expansion System for Halon-Free Cargo Hold Fire Suppression System)

Reporting period: 2019-10-01 to 2020-09-30

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. ECOSYSTEM demonstrator will reached TRL 5, therefore the objective is bringing a product to market in 5 years or less after project end. Industrial project partners have the means, capability and motivation to further develop and productize this Halon-free fire protection system in its European engineering and manufacturing centres.

The ECOSYSTEM project is organised to achieve the following objectives and the progress towards meeting these objectives is described.

Objective 1: Develop a set of requirements and Key Performance Indicators (KPIs) with the topic manager and partners.
Objective 2: Develop and assess system architecture options with respect to optimal placement and integration of the sub-components into the demonstrator to ensure high efficiency while meeting the requirements and KPIs.
Objective 3: Design the system components to meet the KPIs and requirements.
Objective 4: 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 etc.
Objective 5: 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.
Objective 6: Model the performance of the demonstrator from the pressure vessels to the delivery nozzles using modelling tool such as CFD, thermal analysis and stress analysis. The models will be validated using testing data.
Objective 7: Characterize the system performance by physical measurement at the component and system level (pressure and mass flow rate as a function of time) at L’Hotellier lab and use the results to validate the models.
Objective 8: Test the fabricated prototype at the Fraunhofer Institute (Holzkirchen) in an actual cargo hold at and evaluate its performance across a wide range of temperatures and pressures, simulating flight conditions.
The project partners were engaged with the Topic Manager (TM) from day 1 of the project execution and developed a set of requirements and Key Performance Indicators (KPIs) for the demonstrator performance and safety aspects. The final set of requirements for the components and system are specified and are documented in deliverable D2.1. Following the requirement specification, the project partners focused their effort on the demonstrator design. Numerical analysis of different fidelity levels was performed by UTRC, including 0D, 1D and CFD, to select demonstrator components and complete the system design. The analysis was used to verify that the demonstrator meets all of the performance and safety requirements from the TM. GEC-P completed the stress analysis confirming that selected components and system are able to withstand extreme temperatures and service pressures set by the TM. Results of this analysis were also used by L’Hotellier, Kidde and B/E Aerospace to finalize the components selection and to complete the integrated design of the demonstrator.

The CDR was held with the TM on November 19, 2019 and was approved on November 26, 2019. Final demonstrator design is documented in D2.2.

Now that the design is final, the consortium partners are progressing with the manufacturing of the demonstrator and completed the preliminary safety and reliability assessment (D3.1) and drafted the first industrialization plan (D6.1).
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 to automate the design and ensure 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.

ECOSYSTEM will deliver a TRL5 demonstrator fire suppression system, based on inert gas , to be used as a Halon-free cargo hold fire protection.