A TUNNEL EMERGENCY LIFE SUPPORT SYSTEM

Abstract

 A tunnel emergency refuge system comprises one or more refuge shelters (6, 7) inside a tunnel (5), and at least one air supply system (1a, 1b) arranged outside the tunnel and fluidly connected to the refuge shelters (6, 7) via one or more air supply lines (8, 8a, 8b). The refuge shelter may be a mobile refuge module (6), which is a stand-alone unit with means enabling movement out of and into the tunnel, and comprising releasable connection means to the air supply lines. The mobile refuge module (6) may be a reinforced freight container, for example an IMO-type container.

Description

Field of the invention

[0001] The invention concerns the field of emergency life support systems in tunnels. In particular, the invention concerns a tunnel emergency refuge system as set out by the preamble of claim 1.

Background of the invention

[0002] Road tunnels and railway tunnels normally provide for efficient and safe transportation, both for the cargo operators and individual motorists. Road tunnels are widely used in the industrialized world, and millions of people daily rely on their safety. A number of European road tunnels are several kilometres long, for example: Lærdal, Norway (24.5 km); St. Gotthard, Switzerland (16.9 km); Arlberg, Austria (14.0 km); Fréjus, France (12.9 km); Mt. Blanc, France (11.6 km); Gudvangen, Norway (11.4 km); Folgefonna, Norway (11.2 km); Jondal, Norway (10.0 km); Oslofjord, Norway (7.4 km).

[0003] While many modem tunnels comprise two tubes, several tunnels have only one tube. The tunnels listed above are all in the latter category, and have bidirectional traffic.

[0004] In the event of a fire, or release of toxic fumes, inside a tunnel, caused for example by a collision between vehicles or by a defective vehicle (e.g. overheated brakes), conditions vital to human survival (e.g. visibility, air (oxygen), temperature) are deteriorating rapidly. Time is of the essence, and lives are often lost in such accidents, before the arrival of rescue personnel and/or due to inadequate or missing life support systems inside the tunnel.

[0005] Several evacuation and refuge device are known, of which JP2002035147 A and WO 2014/016443 A1 describe typical solutions. The prior art systems and devices pertain, however, to tunnels having two tubes, and where escape tunnels are formed at regular intervals, forming cross-connections between the two tubes. If, for example, a fire occurs in one tube, motorists can leave their vehicles and escape on foot to the adjacent tube, via escape tunnels.

[0006] The prior art also includes CN 204754978 U and CA 2630289 A1, which both describe rescue chambers for use in underground mines.

[0007] CN 204754978 U describes a refuge having cooling compression condensing unit and an air supply oxygen system comprising oxygen pressure and setting of control valve, decompression valve, a silencer and filter device for a compressor supply oxygen system, compressor supply oxygen system.

[0008] CA 2630289 describes a modular portable refuge station apparatus comprising an entrance module and a utility module. The modules are lowered individually down a mine shaft or tunnel and transported to a suitable site for assembly. The utility module houses the life support systems for the refuge station, and has a sealed partition wall dividing the module into a front compartment and a rear compartment. Required life support systems are housed in the front compartment which is open to the adjacent occupant module. These systems typically include air conditioning, filtering, CO₂ and CO scrubbing, as well as LED lighting and communications controls, oxygen regulators, and like equipment. The apparatus also provides a dehumidification system whereby condensation is collected in a tray under the air conditioning condenser, and flows through a conduit to the exterior of the refuge station. The conduit includes a P-trap to prevent entry of exterior air.

[0009] Current European directives stipulating minimum safety requirements for road tunnels require that tunnels must have emergency exits that allow users to leave the tunnel without their vehicles and reach a safe place in the event of an accident or fire.

[0010] The reason why emergency shelters without exits to the outside are currently not allowed used is that during some accidents in (Mont Blanc 1999 and St. Gotthard 2001), people evacuated into emergency shelters and died there due to high temperatures and smoke intoxication. These emergency shelters were not designed to withstand the temperatures of a fire burning for more than 2-4 hours and also the fresh air (low pressure) system were exposed to the fire and carried smoke and hot gases into the shelters. It was therefore concluded that it would be impossible or very difficult to provide a safe shelter inside tunnels without exit to the outside that could keep persons safe during a fire that burned for more than 6-10 hours.

[0011] According to the Official Journal of the European Union, L 201/63-64, issued 7.6.2004, examples of such emergency exits are:

• direct exits from the tunnel to the outside;
• cross-connection between tunnel tubes;
• exits to an emergency gallery;
• shelters with an escape route separate from the tunnel tube.

[0012] Compliance with these directives has proven to be costly, highly complex, or in some cases, even impossible. This is particularly the case for long tunnels having only one tube, and even more so for undersea single-tube tunnels.

[0013] It is therefore a need for an improved tunnel emergency life support and evacuation system.

Summary of the invention

[0014] The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

[0015] It is thus provided a tunnel emergency refuge system, comprising one or more enclosed refuge shelters inside a tunnel, and at least one air supply system configured for compressing air, characterized in that the air supply system is arranged outside the tunnel and fluidly connected to the refuge shelters via one or more air supply lines, and the wherein the air supply system comprises an air supply unit and a pressure control unit. Having the air supply system outside the tunnel, allows for easy access to equipment for testing, maintenance and refurbishment.

[0016] In one embodiment, the air supply system comprises an air bottle cascade. In one embodiment, the air supply unit comprises an emergency power generator and air filling equipment.

[0017] In one embodiment, a first air supply system is arranged outside a first tunnel opening and second air supply system is arranged outside a second tunnel opening. Lines of communication, power and high pressure air extend into each refuge shelter. These dual connections provide redundancy and flexibility. There lines are made so that they easily may be disconnected and changed out in case of damage or any upgrade.

[0018] The refuge shelter may be thermally insulated and sealed to prevent ingress of gases from inside the tunnel, and may also comprise an air lock. The shelters are insulated with a combination of internal and external insulation to protect both the structure and give an acceptable temperature inside the refuge during fires generating between 30 MW and 300MW, and peak temperatures of approximately 1400 °C.

[0019] In one embodiment, the refuge shelter is a refuge compartment built on site inside the tunnel, as a free-standing structure, or a compartment partly or entirely formed in the matter in which the tunnel is formed.

[0020] In one embodiment, the refuge shelter is a mobile refuge module, which is a stand-alone unit with means enabling movement out of and into the tunnel, and comprising releasable connection means to the air supply lines. The mobile refuge module may be a reinforced freight container, for example an IMO-type container.

[0021] In one embodiment, the air supply system is configured for compressing air to a pressure up to 300 bar. This enables the supply to one or more emergency rooms inside the tunnel (road tunnel or railway tunnel) of stored breathing air, breathing air compressors, or a combination of the two, to provide breathing air and pressurization to the refuge shelters.

[0022] The invented system provides a flexible and reliable refuge system, providing a safe shelter for motorists in the tunnel. The refuge compartments and mobile refuge modules are receiving a direct and continuous supply of fresh breathing air from the compressors in the air supply system outside the tunnel, for a virtually unlimited period of time. The invention is particularly useful in undersea, single-tube, tunnels where evacuation shafts cannot be constructed. The use of compressors ensures a reliable supply of compressed fresh air, which is more advantageous than a conventional, low-pressure, ventilation system in the hostile environment caused by a tunnel fire. The invention allows for supplying all shelters with breathing air for 2 to 4 hours, using the stored high pressure air in the bottle cascade. After a designated time, and when most of the emergency shelters have been evacuated by safety personnel, the shelters that are still needed (e.g. close to the fire or accident, or upstream the fire or accident) may be pressurized for an unlimited time to assure a safe refuge until the fire is put out.

Brief description of the drawings

[0023] These and other characteristics of the invention will become clear from the following description of preferential forms of embodiment, given as a non-restrictive examples, with reference to the attached schematic drawings, wherein:

Figure 1 is a perspective-sectional view, illustrating an embodiment of the invented system installed in a tunnel through a terrain formation;

Figure 2 is a perspective-sectional view, illustrating an embodiment of the invented system installed in a tunnel through a terrain formation and partly below water;

Figure 3 corresponds to figure 2, but illustrates an alternative embodiment of the invented system;

Figure 4 is a diagram illustrating principles of the invented system;

Figure 5 is a perspective view, illustrating an embodiment of the invented system; and

Figures 6 and 7 are enlarged pictures of certain sections of figure 5.

Detailed description of preferential embodiments

[0024] The following description may use terms such as "horizontal", "vertical", "lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

[0025] Figure 1 shows an embodiment of the invented system installed in, and in a connection with, a tunnel 5 through a terrain formation G, such as a hill, mountain or other physical structure. Located in the vicinity each tunnel opening 5a, 5b, and outside the tunnel, are air supply systems 1a,b. For the purpose of this description, "outside the tunnel" shall mean a location not covered by the terrain formation.

[0026] Each air supply system 1a,b is connected to enclosed refuge compartments 7 inside the tunnel via air supply lines 8, in a manner which will be described below. Figure 2 shows the same embodiment as in figure 1, but installed in relation to a tunnel 5 which partly also extends under a body of water W. It should be understood that the refuge compartment 7 is an enclosed room, with thermal insulation and thus providing a safe refuge for travellers in the event of a fire inside the tunnel. The refuge compartments 7 may be purpose-built shelters of e.g. reinforced concrete, or may be shelters formed in pockets (niches) in the tunnel walls. The internal surfaces (walls, floor, ceiling) are sealed with an impervious membrane, to prevent ingress of toxic and/or hot gases and fumes. Insulated fire doors, in combination with an air-lock, are provided. Breathable, fresh, air from outside the tunnel is supplied into the refuge compartment 7 via the air supply lines 8. The air supply lines 8 are pipes provided with thermal insulation in order to withstand the extreme heat generated by a fire inside the tunnel. Alternatively, the air supply lines may be embedded inside, or placed behind, concrete walls or in culverts below the roadway. Each refuge compartment 7 is ventilated by extract fire dampers and safety valves, in a manner known in the art.

[0027] Figure 3 shows another embodiment of the invented system, installed in relation to a tunnel 5 which in the illustrated embodiment extends under a body of water W and through a terrain formation G (The embodiment illustrated in figure 3 shall not be limited to such tunnel configuration). In this embodiment, the stationary refuge compartments 7 described above with reference to figures 1 and 2 are replaced by mobile refuge modules 6. The internal surfaces (walls, floor, ceiling) of the modules are sealed with an impervious membrane, to prevent ingress of toxic and/or hot gases and fumes. Insulated fire doors, in combination with an air-lock, are provided.

[0028] The mobile refuge modules 6, which preferably are constructed from a durable and heat-resistant material (e.g. steel) may be transported into the tunnel and placed in purpose-built pockets (niches) in the tunnel wall, or in the main tunnel bore, alongside the roadway (dimensions permitting). Therefore, for the purpose of this description of the invention, the term "mobile refuge module" shall mean a module which is movable and not an integral part of the tunnel. Breathable, fresh, air from outside the tunnel 5 is supplied into each mobile refuge module 6 by the air supply systems 1a,b, via the air supply lines 8. The air supply lines 8 are pipes provided with thermal insulation in order to withstand the extreme heat generated by a fire inside the tunnel. Alternatively, the air supply lines may be embedded inside, or placed behind, concrete walls or in culverts below the roadway. The air supply lines 8 are dimensioned in a manner well known in the art.

[0029] Figure 4 is a schematic illustration of an embodiment of the invented system. Air supply systems 1a,b are arranged outside the tunnel 5. Each air supply system 1a,b comprises in the illustrated embodiment an air supply unit 2a,b, an air bottle cascade 3a,b (optional), and a pressure control unit 4a,b. The air supply unit 2a,b comprises (not shown) an air inlet, air compressor, and power and control systems to operate the air supply system. This equipment is well known in the art. The air compressor enables the air supply unit to deliver fresh air from outside the tunnel, to the refuge compartments 7 and/or mobile refuge modules 6 for a virtually unlimited period of time. In the embodiment in which the bottle cascade is used, the bottles may be maintained in a full condition when the system is in a stand-by mode. Having two air supply systems outside the tunnel, preferably one at either end (in the vicinity of each tunnel opening), as illustrated in the figures, provides a redundancy if one air supply system should fail or must be shut down.

[0030] Each air supply unit 2a,b may also comprise an emergency power generator and air filling equipment (for e.g. fire fighters). Air supply lines 8a,b extend from each air supply system 1a,b (in the illustrated embodiment located in the vicinity of respective tunnel openings 5a,b) and into mobile refuge modules 6 inside the tunnel 5. Reference numbers 8a', 8b' indicate bypass lines from the air supply unit to the pressure control unit, as the air bottle cascades 3a,b are optional. Inside the tunnel, the air supply lines are connected to each mobile refuge module 6 (as indicted by the arrows in figure 4). Although not illustrated, it should be understood that power, control, and sensor cables may run from the air supply systems 1a,b outside the tunnel, to each mobile refuge module 6 inside the tunnel.

[0031] It should be understood that the air supply systems 1a,b may supply several mobile refuge modules 6 in the tunnel (illustrated by dotted lines in figure 4). It should also be understood that set-up shown in figure 4 is equally applicable to the embodiment described above with reference to the stationary refuge compartments 7

[0032] In case of an accident and fire occurring at a location A in the tunnel, motorists could seek refuge in the mobile refuge modules 6 and the air supply systems 1a,b would be activated. The air bottles in the cascades 3a,b may supply air instantaneously, while the compressors are starting up. Then, as the compressors come into operation, fresh air from outside the tunnel is drawn into the air supply units 2a,b (indicated by "L" in figure 4). The air is pressurized by one or more compressors (for example up to 300 bar) and fed via the supply lines 8a', 8b' to respective pressure control units 4a,b and then into the tunnel. Pressurized air may also be diverted to the air bottle cascades 3a,b (control valves not shown), in order to re-fill the bottles.

[0033] As an example, the system operating pressure may be in the region of 300 bar (e.g. to fill the bottles), while the pressure control unit may limit the pressure in the air supply lines to the refuge shelters to e.g. 50 bar. Breathable, fresh, air is thus supplied into each mobile refuge module 6 at an appropriate pressure
Although the invention shall not be limited to two air supply systems 1a,b, as illustrated - and may in fact work with only one air supply system - the dual (or multiple) configuration, including the location of the different air supply systems 1a,b at opposite tunnel openings 5a,b, provides valuable redundancy and flexibility during operation.

[0034] Figures 5, 6 and 7 provide a further illustration of the invented system. In this variant, three mobile refuge modules 6 are interconnected via an air supply line 8 inside the tunnel 5. Although not illustrated, it should be understood that power, control, and sensor cables may run from the air supply systems 1a,b outside the tunnel, to each mobile refuge module 6 in the tunnel. Each mobile refuge module may be fitted with seats 9 and other amenities and utilities, such as first-aid equipment, water, etc. Each refuge compartment 7 is ventilated by extract fire dampers and safety valves, in a manner known in the art.

[0035] In one embodiment, the mobile refuge module 6 is a reinforced freight container, for example a 20' to 40' freight container, accommodating approximately 20 to 50 persons, depending on the internal layout.

[0036] Each mobile refuge module comprises an air-lock 10 with fireproof and thermally insulated doors (not shown). Each mobile refuge module 6 comprises passive fire protection, for example in the form of external and internal insulation (e.g. mineral wool) and/or sprayed thermal insulation. All doors are sealable to prevent ingress of fire gases or other fumes.

[0037] The system is configured to maintain an over-pressure, in the region of e.g. 50 Pa. Fire dampers close automatically in the event of a fire (sensor controlled).

[0038] An advantage with the mobile refuge modules is that they may be removed from the tunnel for upgrades, repairs and refurbishment. Rescue personnel may also perform rescue drills on mobile refuge modules outside the tunnel, thereby not disrupting traffic through the tunnel.

[0039] Although the invention has been described with reference to road tunnels, it should be understood that it also applies to other tunnels, for example railway tunnels.

Claims

1. A tunnel emergency refuge system, comprising one or more enclosed refuge shelters (6, 7) inside a tunnel (5), and at least one air supply system (1a, 1b) configured for compressing air, characterized in that the air supply system is arranged outside the tunnel and fluidly connected to the refuge shelters (6, 7) via one or more air supply lines (8, 8a, 8b), and wherein the air supply system (1a) comprises an air supply unit (2a) and a pressure control unit (4a).

2. The system of claim 1, wherein the air supply system (1a) comprises an air bottle cascade (3a).

3. The system of claim 1 or claim 2, wherein the air supply unit (2a) comprises an emergency power generator and air filling equipment.

4. The system of any one of claims 1-3, wherein a first air supply system (1a) is arranged outside a first tunnel opening (5a) and second air supply system (1b) is arranged outside a second tunnel opening (5b).

5. The system of any one of claims 1-4, wherein the refuge shelter (6, 7) is thermally insulated and sealed to prevent ingress of gases from inside the tunnel, and comprises an air lock (10).

6. The system of any one of claims 1-5, wherein the refuge shelter is a refuge compartment (7) built on site inside the tunnel, as a free-standing structure, or a compartment partly or entirely formed in the matter (G) in which the tunnel is formed.

7. The system of any one of claims 1-5, wherein the refuge shelter is a mobile refuge module (6), which is a stand-alone unit with means enabling movement out of and into the tunnel, and comprising releasable connection means to the air supply lines.

8. The system of claim 7, wherein the mobile refuge module (6) is a reinforced freight container, for example an IMO-type container.

9. The system of any one of claims 1-8, wherein the air supply system (1a, 1b) is configured for compressing air to a pressure up to 300 bar.

10. The system of any one of claims 1-9, wherein the tunnel (5) is a road tunnel or a railway tunnel.

Drawing