Final Report Summary - VULCAN (An innovative, fully automated, intelligent vehicle fire and smoke detection and extinguishing system for buses/coaches.)
The Vulcan project addresses the global concern associated with bus and coach fires. By using the automatic fire detection and suppression system (AFDSS) developed in that project bus operating companies can offer more safe service to their clients. At the same time it can reduce the risk of financial losses caused by physical damage to the vehicles and their productivity. The use of Vulcan system also helps to save from insurance costs and claims. These benefits are realized by some novel features compared to existing vehicle fire suppression systems. Early detection of fire and evaluation of its extent in Vulcan AFDSS is achieved by the help of the smoke detector. A robust aspirating smoke detector is connected to the engine compartment. If there is smoke generated before or at the outbreak of fire smoke detector gives alarm to Vulcan control system that then gives appropriate response. Additional heat detector gives alarm when the temperature at the engine compartment exceeds 180 oC. If the vehicle driver is present then the extinguishing system will be released by the driver. In case the driver is not present, the release of extinguishing agent is done automatically.
The fire extinguishing system of the Vulcan AFDSS comprising piping, nozzles and agent tank has optimized design that ensures more safe operating conditions and savings in terms of system dimensions. The most important breakthrough was made in nozzle design. The nozzles developed during the Vulcan project enable to produce a combination of positive properties of mist and spray of extinguishing agent rather than spraying alone that has been used by Dafo Brand earlier. New nozzles can create an extinguishant mist at pressure values (20 to 25 bar) that are feasible to use in vehicle fire suppression systems.
The agent tank developed during the Vulcan project is easily scalable for different vehicles with different sizes of engine compartments.
Intelligent control system of the Vulcan enables to detect fires automatically in their early stage and either giving a visual and audible alarm to the driver who then initiates the extinguishing process. In case the vehicle stands unattended the Vulcan system functions can detect fire and activate the extinguishing process during 72 h without extra power supply. These features significantly reduce the chances of operator error, eliminate delays in responding to fire and, therefore, reduce property damages.
Successful completion of Vulcan project has created new business opportunities to participating SMEs either in a form of system provider, component provider or end-user.
Project Context and Objectives:
Bus and coach fires are a global concern. According to reported bus fire statistics, around 1% of all buses are involved in some form of fire incident each year. Most buses that experience engine bay type fires are either severely or totally burnt out costing the European community huge financial and property losses, and posing great danger to the safety of the travelling public. Such fires result in considerable financial losses from physical damage to the coach, applicable insurance deductibles, lost property of the passengers and lost productivity of the bus itself.
Due to that the professional sector of bus and coach operators and legislators has become increasingly concerned with the fire risks of coaches and buses and many of these have actively encouraged the installation of automatic fire detection and suppression systems (AFDSS). Insurance companies have addressed this topic by making it a requirement for mass transit vehicles such as passenger buses to have fire detection and suppression systems.
The main objective of VULCAN project was to develop a new innovative fixed installation vehicle fire and smoke detection and suppression system for buses/coaches capable of automatically and intelligently giving a proportional response to a fire problem. The system will be able to predict the outbreak of fire and evaluate the size of the potential fire and issue out a graduated response that leads to the lowest consequential damage.
This main objective was achieved by realizing three technological objectives. First, smoke detection system was added for predicting outbreak of fire. The main requirements for smoke detection were response time of less than 20 s and robustness to resist contamination by dust particles, diesel, and hydraulic oils. Second development area dealt with the optimization of fire suppression part of the system including the design of agent tank, nozzles and piping system. The aim was to fabricate a cheap and lightweight agent tank that would enable to reduce fuel consumption of the vehicle from weight saving and would also enable miniaturization of the system. The latter aim was also behind finding an optimal configuration of nozzles and fittings that would enable to minimise the number and size of nozzles while maximising extinguishing performance and minimising the space requirement of the system. Finally, the control system was developed including intelligent fire detection and decision making algorithms as well as connectivity to vehicle CAN bus control system. The aim was to develop intelligent response system algorithms to give graduated response to fire according to its characteristics.
In order to achieve the main project results several scientific and technological objectives had to be achieved first.
For early detection of fire a smoke detector was used as a novel part of AFDSS. For reliable operation performance smoke sensor had to be protected from harsh environment (contamination by different particles and diesel and hydraulic oils) present in vehicles and more specifically in engine compartment. For that a protective housing and a filter system was designed. Testing of the integrated system proved the protective housing and used filters to keep away all contamination and ensure reliable operation of the smoke sensor. Another investigation area for smoke sensor was its response to outbreak of fire. For that smoke detection profiles for different materials (e.g. cooling liquid, hydraulic oil, rubber, etc.) potentially present in an engine compartment were recorded. The recordings showed that smoke level rise is detected in most cases presiding ignition by some time delay. The shortest detected time delay between smoke detection and the outbreak of fire for appropriate material was around 20 s. This information was used for creating Vulcan system control algorithms.
In terms of the development of the fire extinguishing part of the system the main attention was on investigating the possibility to create a mist from the extinguishing agent under normal operating pressure, optimizing both the droplet size of the mist as well as the spray pattern and velocity of the directional spray and also suggest the suitable proportions between mist and spray in the nozzle. The optimal results were achieved for a mist nozzle that is used in a cluster configuration of several smaller nozzles. The optimal working pressure of the nozzles is in the range of 20 – 25 bars. Optimized piping system was designed and produced according to determined working pressure and other initial requirements concerning, for example, overall robustness and reliability of the distribution system as well as the attachment to the vehicle construction. Piping used for Vulcan AFDSS is made of commercially available stainless steel hydraulic tubes connected by threaded high pressure rings. Standard fitting types are used for pipe connections. Nozzles layout was determined based on a series of additional simulations using extinguishing agent properties and expected fire scenario on engine model. General piping system design can be easily adapted to any different engine compartment layout by changing the pipe length and total number of particular fitting type specified in general design.
Another component of the fire extinguishing system under development during the Vulcan project was the agent tank with the aim of achieving lightweight design that could easily be assembled into the vehicle. This work resulted in a scalable design, which makes overall cost of the agent tank lowered while there is no need to make any machining of these components other than just cutting to the needed length. The dimensional requirements of the agent tank were also met. Developed agent tank is based on a piston-cylinder concept: self-leading piston sliding along cylinder wall and piston supported by piston central leading bar/pipe. In this solution, cylinder and piston leading bar/pipe can be found as standard products off the shelf but in the higher tolerances class defined by appropriate regulations. Such a solution makes overall cost lowered while there is no need to make any machining of these components than just cutting to the needed length. Changing the length results in change of tank volume making the tank volume to be easily scalable from 5 to 15 litres. The agent tank is fixed to vehicle structure with just 2 screws and fixing clamps.
In terms of control system development two iterations of hardware were developed with interfaces to different sensors, ways of communication (e.g. USB, BlueTooth, CAN bus), and other external devices (e.g. alarm light and horn). Vulcan control unit is designed to function both in a situation where the vehicle’s ignition is on (considered as the status where the driver is present), but also while it is turned off. While the ignition it turned off and the bus is standing in a depot, for example, Vulcan AFDSS operates on a built in back-up battery which ensures extinguishing system release in case of a power failure within 72 h. Application software development of the Vulcan control system mainly included implementing AFDSS control actions in different alarm and state situations. Based on the study on response to different sensors (aspirating smoke detector and heat detector) available in the control system intelligent fire detection and system response algorithms were developed and implemented in control system application software. In the case of fire the smoke detector and/or heat detector achieves its maximum level it gives signal to the control unit that then either gives an alarm (in case the driver is present) or automatically releases the extinguishing system (in case the driver is not present). If the driver is present, the release of extinguishing system has to be performed manually. Additionally a service interface software tool was also developed for setting up the system after installation and for maintenance purposes. Service interface tool includes an activity log, where different events (e.g. smoke or heat detector alarm states, sensor faults, release activation) and system states can be viewed against date and time.
Vulcan control system has also a CAN bus interface which can submit status and alarm messages to vehicle CAN bus and is able to receive messages. For each vehicle manufacturer further integration is necessary to adjust the system to their specific proprietary CAN bus solution.
In system integration phase the whole AFDSS comprising fire extinguishing, detection and control systems was integrated and tested. During testing phase the system was validated against initial requirements. Fire events ranging from slightly complicated to challenging were generated. Test showed that Vulcan system enables to detect fire in a timely manner (reaction time below 20 s) and the fire can be extinguished in an early phase when the air flow in the engine compartment is rather low. However, with further optimization of the operating parameters (mainly pressure) of the release system the Vulcan AFDSS would be able to reliably suppress also fires when the air flow through the engine compartment is medium or high.
Now that Vulcan project has finished it can be said that most of its objectives where achieved that allows Dafo to offer an AFDSS with the feature of early detection of fire thanks to smoke detector added to the control system. CAN bus readiness developed during the project helps to seamlessly integrate the AFDSS with the other relevant control units of the vehicle. Bluetooth functionality added to the control unit hardware creates a point to easily access control system log data including information obtained from different sensors of the system. This feature is especially useful for system installation, maintenance, but also further development purposes. In general Vulcan control system will contribute to significant reduction of the chances of operator error, eliminate delays in responding to fire and reduce property damages.
Improvements made in agent tank, nozzle and piping design ensure achievement of lower operating pressure, savings in space and more adjustable design. This enables to offer more flexible AFDSS solutions to end-users, save energy consumption and build systems that are safer to the users. For end-users the use of Vulcan AFDSS also enables to reduce the risk of financial losses caused by physical damage to the vehicles and their productivity. It also helps to save from insurance costs and claims.
The use of Vulcan AFDSS is not limited only to busses. The other significant target market would be heavy duty vehicles. For example, Volvo as an end-user of the system is very interested in installing the Vulcan system on their wheel loaders.
Vulcan consortium has introduced this new system to wider audience using different channels. Project partners have attended several trade fairs in the field of fir safety in transportation (e.g. Fire in Vehicles 2014, Bus World 2015, Interschutz 2015) and introduced possibilities of Vulcan AFDSS to wider audience in a form of oral presentations and individual conversations with the visitors of the fair. Presentations were supported by the use of different visual aids like posters and leaflets that were distributed to any interested parties. Already in the early phase of the project a Vulcan logo was created and has now been used in all dissemination materials. The use of professionally designed logo has enabled to brand the Vulcan process and prototype so that the product has already obtained name recognition amongst vehicle fire and smoke detection and extinguishing suppliers as well as end customers and other public. A project video was also created that gives overview of the general concept of the project, technical solution of the Vulcan AFDSS, and introduces project partners. The video has also been shown on fairs and is freely available on Vulcan website (http://projectvulcan.eu/ ). The results of Vulcan project were also disseminated in a form of an article published in BrandPosten (an SP Fire Research Newsletter).
List of Websites:
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Phone: +46 8 506 405 50
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