RAILROAD CAR WITH COUNTERMEASURE STRUCTURES THAT MINIMIZE THE LIKELIHOOD OF DEFLAGRATION AND DETONATION HAZARDS FROM GASEOUS HYDROGEN FUEL STORAGE AND SUPPLY COMPONENTS THEREOF

FIELD

This disclosure relates to railroad cars such as fuel tenders with countermeasure structures that minimize the likelihood of deflagration and detonation hazards from gaseous hydrogen fuel storage and supply components thereof.

BACKGROUND

Railroad cars and trains are widely employed to transport a variety of contents. Various conventional trains are powered by one or more locomotives. Many conventional locomotives have one or more diesel combustion engines. Diesel combustion engines release significant amounts of pollutants into the atmosphere. To reduce pollution, certain known locomotives burn a gas vapor instead of diesel fuel. Combustion or conversion of gases is cleaner than combustion of diesel fuel and thus produce less pollutants. There is an increasing interest in the railroad industry to use gas consuming locomotives in part due to their relatively lower emissions and in part due to the relatively lower cost for certain gases.

Various gas consuming locomotives require a separate railroad car (referred to in the railroad industry as a fuel tender) that contains gas storage cylinders and related components that store and supply the gas used by the locomotives. These proposed fuel tenders store the gas in a liquid form or in a pressurized (compressed) gas form. Such proposed fuel tenders need to be connectable to the locomotive to supply the gas from the fuel tender to the locomotive (and its energy conversion systems(s)).

Such gas locomotives and fuel tenders pose certain new sets of challenges for the railroad industry. To provide enough compressed gas to power a locomotive, the gas must be stored in cylinders under high pressure. For example, the high pressures can above 50 psig. These cylinders must be connected to various valves, gauges, regulators, and pipes that communicate the gas from the cylinders. If these cylinders, valves, gauges, regulators, or pipes leak gas, the leaking gas can present a potential ignition hazard.

In a situation where a leak occurs, some leaking gases can mix with air (containing oxygen) in a compartment of the railroad car housing such components and can ignite causing a flame (which is sometimes referred to as a deflagration). The flame can then further propagate super-sonically in the compartment and then cause an explosion (which is sometimes called a detonation).

More specifically, one proposed compressed gas is hydrogen. Gaseous hydrogen has been rising in significance in consideration as a locomotive fuel. Stored hydrogen gas: (1) has a very low viscosity, (2) has a very small kinetic diameter, (3) has a high diffusivity (and specifically three times that of nitrogen in air), (4) does not easily form visible vapor clouds, and (5) is buoyant in air. These characteristics make hydrogen gas more prone to leaking from valves, gauges, regulators, and pipes that communicate the hydrogen gas from cylinders (relative to other gases). In various situations, the detection of leaking hydrogen gas is difficult because hydrogen gas is odorless, needs to be stored without odorants, is colorless, is tasteless, and has a near invisible flame. In various situations, odorants can be used with compressed hydrogen gas, which help is determining leaks but can cause negative effects on fuel cells and do not solve various of the issues described herein.

Another characteristic of hydrogen gas is that, if it presents itself as a homogenous mixture of hydrogen in air, it has very undesirable combustion characteristics. The propensity to ignite and potentially detonate such a homogeneous mixture is very high due to the diffusivity properties. This combustible precondition of a premix gas of hydrogen and air differs from what might occur when a hydrogen gas leak ignites immediately resulting in a localized “torch” effect. If a leak occurs in a closed-in area that preexists as an air-filled space and the leak does not immediately ignite, it can result in the mixing of the hydrogen gas with the air.

FIG. 1 shows an analysis of potential combustion progression of a hydrogen gas in an example compartment of a railroad car such as a fuel tender. Specifically, when a premix occurs, this analysis shows that any ignition of such premix at any point spatially within a premix volume can result in a combustion that progresses in an orderly fashion spherically outwardly from the point of ignition at subsonic flame front speed (which can be considered a deflagration). If allowed to proceed over a critical distance on the order of as an example, fewer than ten feet measured linearly, conditions can exist in the unburnt premix that causes the deflagration (sub-sonic flames) to cease and instead convert into a detonation (super-sonic flames). Such detonation can result in overpressures resulting in damage to surroundings from the overpressure effects directly and indirectly including flying debris subsequent to the overpressure event.

While stopping 100% of all possible leaks of a gas such as hydrogen gas is desirable, in the real-world conditions of railroad cars, preventing all potential leaks is practically impossible. As a result, there is a need for effective railroad cars and specifically fuel tenders that employ suitable countermeasures that reduce the potential escalation of a hydrogen gas/air deflagration event that turns into to a hydrogen gas/air detonation event. In other words, there is a need to provide railroad cars such as fuel tenders that minimize the likelihood of a deflagration turning into a detonation hazard.

BRIEF SUMMARY

Various embodiments of the present disclosure address the above issues by providing railroad cars such as fuel tenders with one or more countermeasure structures that minimize the likelihood of deflagration and detonation hazards related to gaseous hydrogen fuel storage and supply components therein. In various embodiments, the present disclosure provides combinations of different countermeasure structures that minimize the likelihood of deflagration and detonation hazards in one or more of the compartments of such railroad cars.

Additional features are described herein, and will be apparent from, the following Detailed Description and the Figures.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a better understanding of the present disclosure, reference is made to example embodiments shown in the following drawings. The components shown in the drawings are not necessarily to scale and various components may be omitted for clarity, and, in certain instances proportions have been exaggerated so as to illustrate various features of the present disclosure.

FIG. 1 shows an example analysis of potential combustion progression of a hydrogen gas in a compartment of a railroad car such as a fuel tender.

FIG. 2 is an exploded perspective view of certain parts of an example fuel tender in which a combination of countermeasure structures of various example embodiments of the present disclosure can be employed.

FIG. 3 is an enlarged fragmentary perspective view of certain parts of the example fuel tender of FIG. 2 showing a compartment in which a combination of countermeasure structures of various example embodiments of the present disclosure can be employed.

FIG. 4 is a perspective view a steel frame cylinder holder rack of the example fuel tender of FIGS. 2 and 3.

FIG. 5A, 5B, and 5C are front, back, and enlarged fragmentary perspective views an example wall filler countermeasure structure of one example embodiment of the present disclosure.

FIG. 6A and 6B are fragmentary perspective and side views of the example compartment of the fuel tender of FIG. 2 and a combination of certain countermeasure structures in that compartment in accordance with one example embodiment of the present disclosure.

FIG. 7 is a fragmentary end view of part of the example fuel tender of FIGS. 2 and 3 and walkway and sub-floor filler countermeasure structures in accordance with one example embodiment of the present disclosure.

FIGS. 8 and 8A are perspective views of roof vent countermeasure structures of one example embodiment of the present disclosure.

FIG. 9 is a chart showing the controlled overpressure at various distances from the fuel tender attendant to a combination of countermeasure structures provided by the present disclosure.

FIG. 10A is a plan view of a panel of various gas carrying and controlling equipment of the example fuel tender of FIGS. 2 and 3.

FIG. 10B is a side view of a combination of countermeasure structures for the panel of the gas carrying and controlling equipment of FIG. 10A in accordance with one example embodiment of the present disclosure.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

While the systems, devices, and methods described herein may be embodied in various forms, the drawings show, and the specification describes certain exemplary and non-limiting embodiments. Not all of the components shown in the drawings and described in the specification may be required, and certain implementations may include additional, different, or fewer components. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of connections of the components may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referred to in the specification reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms that refer to mounting methods, such as mounted, connected, etc., are not intended to be limited to direct mounting methods but should be interpreted broadly to include indirect and operably mounted, connected, and like mounting methods. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the present disclosure and as understood by one of ordinary skill in the art.

Directions and orientations herein refer to the normal orientation of a railroad car in use. Thus, unless the context clearly requires otherwise, the “longitudinal” or “lengthwise” axis or direction is substantially parallel to straight tracks or rails and in the direction of movement of the railroad car on the tracks or rails in either direction. The “transverse” or “lateral” axis or direction is in a horizontal direction substantially perpendicular to the longitudinal axis and the straight tracks or rails. The “leading” end of the railroad car means the first end of the railroad car to encounter a turn on the tracks or rails, and the “trailing” end of the railroad car is opposite of the leading end.

Valves, gauges, regulators, and/or pipes that communicate gas from cylinders are sometimes referred to herein as “gas carrying and controlling equipment.”

Example Countermeasure Structures in Railroad Cars such as Fuel Tenders having Gaseous Hydrogen Fuel Storage and Supply Components

The present disclosure provides various countermeasure structures for gaseous hydrogen fuel storage systems such as but not limited to railroad cars that function as fuel tenders. Railroad cars in the form of fuel tenders are used as a primary example embodiment herein but are not meant to limit the present disclosure.

The railroad cars that function as fuel tenders can include one or more compartments that each house certain components (such as but not limited to gas carrying and controlling equipment) of the fuel tender. For brevity, such railroad cars are not described in detail herein. Example railroad cars that function as fuel tenders are described in U.S. Pat. No. 11,142,224, which is owned by the assignee of the present patent application. FIGS. 2, 3, 4, 6A, 6B, 7, 8, 10A, 10B, and 11 hereof show parts of one such example railroad car that functions as a fuel tender. Various example countermeasure structures described herein are configured to be employed in this example fuel tender or other fuel tenders.

In various embodiments of the present disclosure, the countermeasure structures in the railroad car generally include structural space filler countermeasure structures, and/or venting countermeasure structures in one or more or all of the compartments (that include any gas carrying and controlling equipment) to eliminate or significantly reduce certain spaces in such compartments, and thereby the amount of air in such compartments. This significantly minimizes the likelihood of deflagration and detonation hazards in such compartments.

In various embodiments of the present disclosure, the countermeasure structures in the railroad car include reconfigured compartments (that include gas carrying and controlling equipment) that eliminate or reduce certain spaces and thus the air that fills those spaces in such compartments to minimize the likelihood of deflagration and detonation hazards in such compartment. The minimization of the air in such reconfigured compartments reduces the oxygen in such compartments and thus the possible premix (described above) that can exists in such compartments.

The present disclosure also contemplates that reconfiguring such compartments to eliminate such spaces in such compartments (that include gas carrying and controlling equipment) is not often consistent with the required functions of a fuel tender in railroad operation, including but not limited to human interaction with such gas carrying and controlling equipment for installation, assembly, operation, and/or maintenance.

Thus, various embodiments of the present disclosure provide different combinations of countermeasure structures employed in the fuel tender to a great extent minimize air (and oxygen within air) from existing in the open spaces in such compartment(s) wherein the employ combinations of countermeasure structures fill such spaces. In various embodiments, the countermeasure structures include different combinations of form fitting and space occupying structures that prevent and/or substantially reduce the risk of the existence of premix volumes from ever existing in large enough volumes to represent a risk of deflagration transitioning to detonation (should a leak exist anywhere in a confined space of the compartment) such as described above.

Turning now to FIG. 2, the illustrated example fuel tender railroad car 10 generally includes: (1) a penetration resistant and protective underframe 100 suitably connected to and supported by conventional first and second car trucks 20 and 40; (2) a penetration resistant and protective first end bulkhead 200; (3) a penetration resistant and protective second end bulkhead 300 spaced apart from the first end bulkhead 200; (4) a penetration resistant and protective center bulkhead 400 spaced apart from and between bulkhead 200 and 300; (5) a first cylinder assembly 500 between the bulkheads 200 and 400; (6) a second cylinder assembly 600 between the bulkheads 300 and 400; (7) a penetration resistant and protective first side wall 700; (8) a penetration resistant and protective second side wall 800; (9) a penetration resistant and protective third side wall 900; (10) a penetration resistant and protective fourth side wall 1000; (11) a first roof panel 1100; and (12) a second roof panel 1200. It should be appreciated that these components can be alternatively configured in accordance with the present disclosure.

In this example railroad car 10: (1) the first end bulkhead 200 is suitably connected to the underframe 100; (2) the second end bulkhead 300 is suitably connected to the underframe 100; (3) the center bulkhead 400 is suitably connected to the underframe 100; (4) the first cylinder assembly 500 is suitably connected to the first end bulkhead 200 and the center bulkhead 400 and thus supported by the underframe 100; (5) the second cylinder assembly 600 is suitably connected to the second end bulkhead 300 and the center bulkhead 400 and thus supported by the underframe 100; (6) the first side wall 700 is suitably connected to the first end bulkhead 200, the center bulkhead 400, and the underframe 100; (7) the second side wall 800 is suitably connected to the second end bulkhead 300, the center bulkhead 400, and the underframe 100; (8) the third side wall 900 is suitably connected to the first end bulkhead 200, the center bulkhead 400, and the underframe 100; (9) the fourth side wall 1000 is suitably connected to the second end bulkhead 300, the center bulkhead 400, and the underframe 100; (10) the first roof panel 1100 is suitably connected to the first end bulkhead 200, the center bulkhead 400, the first sidewall 700, and the third sidewall 900 and thus indirectly supported by the underframe 100; and (11) the second roof panel 1200 is suitably connected to the second end bulkhead 300, the center bulkhead 400, the second sidewall 800, and the fourth sidewall 1000 and thus indirectly supported by the underframe 100.

Although not shown in FIG. 2, the example railroad car 10 further includes the pipes that communicate the gas from the cylinders, and the safety critical valves, regulators, other equipment connected to such cylinders and pipes, and other such gas carrying and controlling equipment.

The underframe 100, the first end bulkhead 200, the second end bulkhead 300, the center bulkhead 400, the first side wall 700, the second side wall 800, the third side wall 900, the fourth side wall 1000, the first roof hatch 1100, and the second roof hatch 1200 are individually and in combination configured to protect the cylinders of the cylinder assemblies 500 and 600, as well as the pipes that communicate the gas from the cylinders, the safety critical valves, regulators, other equipment connected to such cylinders and pipes, and other gas carrying and controlling equipment in accidents involving the railroad car 10.

These components individually and in combination are configured to deform, absorb forces, spread out forces, and otherwise protect the cylinders 510 and 610 of the cylinder assemblies 500 and 600, as well as the pipes that communicate the gas from the cylinders, the safety critical valves, regulators, other equipment connected to such cylinders and pipes, and the other gas carrying and controlling equipment in such accidents. These components individually and in combination are thus configured to function as sacrificial components to protect the cylinders of the cylinder assemblies 500 and 600, as well as the pipes that communicate the gas from the cylinders, the safety critical valves, regulators, other equipment connected to such cylinders and pipes, and the other gas carrying and controlling equipment in accidents involving the railroad car 10. These components individually and in combination are also configured to function as a system to protect against the consequences of accidents where part of the railroad car is partially on or partially off the rails in a moving manner (wherein it can engage various objects) or in a stationary manner. These components individually and in combination are configured to satisfy (and in various instances exceed) the requirements set forth in the AAR regulation M-1004 for tenders for alternative fuels.

This example railroad car 10 also includes: (1) a first end mechanical component storage compartment 1300 suitably connected to and supported by the first (or leading) end of the underframe 100; and (2) a second end mechanical and electrical component storage compartment 1400 suitably connected to and supported by the second (or trailing) end of the underframe 100. The first end mechanical component storage compartment 1300 and the second end mechanical and electrical component storage compartment 1400 are each configured to contain various mechanical and/or electrical components employed for the operation of the railroad car 10. This includes various mechanical and electrical components and controls for such components as the pipes that communicate the gas from the cylinders, the safety critical valves, regulators, and other equipment connected to such cylinders and pipes needed for selectively supplying the gas stored in the cylinders 510 and 610 of the cylinder assemblies 500 and 600 to one or more locomotives (not shown).

The first end mechanical component storage compartment 1300 includes various gas pressure reduction apparatus (somewhat shown but not labeled in FIG. 2) configured to receive gas via gas communication pipes from the cylinder 510 and 610 of the cylinder assemblies 500 and 600 at a high pressure and reduce the pressure of gas for supply to one or more locomotives. It should be appreciated that the various other mechanical and electrical components can be positioned in the first end mechanical component storage compartment.

The second end mechanical and electrical component storage compartment 1400 contains suitable control system(s) (somewhat shown but not labeled in FIG. 2) and brake equipment (not shown) for the railroad car 10. It should be appreciated that the various other mechanical components can be positioned in the second end mechanical component storage compartment.

The railroad car of the present disclosure can include various other conventional components of a railroad car that are not shown or described for brevity such as but not limited to: (1) coupler assemblies and equipment (not shown); and (2) braking assemblies and equipment (not shown); etc. Various other mechanical components (other than the components in these two compartments) can be employed for the operation of the railroad car 10, as will be readily understood by one of ordinary skill in the railroad industry. Such conventional assemblies and equipment are not shown or described herein for brevity and that one of ordinary skill in the art would readily understand such additional assemblies and equipment.

The railroad car of the present disclosure such as example railroad car 10 includes a plurality of separate penetration resistant and/or otherwise protective structures that are configured to work independently and work or co-act in combination to protect the individual cylinders 510 and 610 of each of the respective cylinder assemblies 500 and 600, the pipes that communicate the gas from the cylinders, and the safety critical valves, regulators, and other equipment connected to such cylinders and pipes, all from penetrating and other deforming or damaging forces that can occur from accidents in which the railroad car 10 can be involved. These penetration resistant and otherwise protective structures independently and in combination significantly reduce the likelihood that one or more of the cylinders 510 and 610, the pipes that communicate the gas from the cylinders, and the safety critical valves, regulators, and other equipment connected to such cylinders and pipes will be damaged in an accident, and thus significantly reduce the likelihood of a gas release and subsequent ignition hazard from of any of the cylinders 510 and 610 of the respective cylinder assemblies 500 and 600, the pipes that communicate the gas from the cylinders, and/or the safety critical valves, regulators, and other equipment connected to such cylinders and pipes. Certain of these specific penetration resistant and/or otherwise protective structures are described in more detail below with respect to each of the various components.

The first cylinder assembly 500 includes: (1) a plurality of separate elongated cylinders 510 (not individually labeled); (2) a first or outer cylinder holder rack 520; (3) a plurality of first cylinder and rack connectors (not shown); (4) a second or inner cylinder holder rack 540; (5) a plurality of second end cylinder rack connectors (not shown); and (6) a plurality of force spreaders (not shown).

Likewise, the second cylinder assembly 600 includes: (1) a plurality of separate elongated cylinders 610 (not individually labeled); (2) a first or outer cylinder holder rack 620; (3) a plurality of first cylinder and rack connectors (not shown); (4) a second or inner cylinder holder rack 640; (5) a plurality of second end cylinder rack connectors (not shown); and (6) a plurality of force spreaders (not shown).

FIGS. 3, 6A, and 6B show the example center compartment 400 of the fuel tender 10 and certain of the components thereof. This example center compartment 400 has a cubic volume of approximate dimensions of 14′H×10′W×4′L, has an open space large enough to be a risk of a deflagration becoming a detonation if left open, and is substantially filled with different countermeasure structures such as shown in FIG. 6B in accordance with the present disclosure. More specifically, various embodiments of the present disclosure contemplate a series of space occupying and form fitting structures that function as the countermeasure structures, which when applied in combination occupy 90-95% of the cubic volume of the space in this example center compartment 400. It should be appreciated that such center compartments can be larger or smaller (and have different components), which in turn directly affect the optimal minimum percentage of space that must be filled in such compartments to achieve the countermeasure structure benefits. For some compartments, filling as little as 20% of the space can substantially reduced the above described issues for such compartments. Thus, such percentages may vary in accordance with the present disclosure.

In various embodiments, the countermeasure structures for the center compartment 400 generally include one or more relatively large spacer block countermeasure structures 2000 that include a plurality of rectilinear space conforming blocks of closed cell flame retardant foam that when positioned in the compartment 400 occupy the volume between the plane of piping connections from the storage cylinders to the principle structural supports of the cylinders. The present disclosure provides that other materials could be employed for such structures. For example, thermoplastic materials can be employed for such filler countermeasure structures. The present disclosure also provides that the fillers can be hollow or solid for such countermeasure structures. The present disclosure also provides that such fillers for such countermeasure structures 2000 are not inflatable, but in other embodiments, can include inflatable sections.

More specifically, FIG. 4 shows an inner cylinder holder rack 640 that partially supports the cylinders 610 of the example fuel tender 10 of FIGS. 2 and 3. FIGS. 5A, 5B, and 5C show a spacer block countermeasure structure 2000 of one example embodiment of the present disclosure configured to mate with the inner cylinder holder rack 640 shown in FIG. 4 to fill the various spaces defined by the inner cylinder holder rack 640. FIG. 4 illustrates that the inner cylinder holder rack 640 supports the cylinders 610 on one side and forms a plurality of open spaces between the cylinder banks (not labeled) on the other side. This example inner cylinder holder rack 640 is formed from a solid steel somewhat complex shape. The inner cylinder holder rack 640 can form a gap at the top and at the bottom that can be filled in, though not shown, completely separating the compartments. The holes in the center of each cylinder mounting (not labeled) indicate the location of various piping and valves (not shown) that protrude from this end of each cylinder into the empty center compartment 400.

In various embodiments, the countermeasure structure(s) for the inner cylinder holder rack 640 of FIG. 4 include(s) one or more wall structures comprising space occupying foam blocks secured to a sheet metal backing (applied to form a second contacting wall of space occupying material). FIG. 5A, 5B, and 5C show various views of such an example wall filler countermeasure structure 2000 of one example embodiment of the present disclosure.

The wall filler countermeasure structure 2000 includes a backing wall 2010 and a plurality of filler blocks 2100 connected to and extending from the backing wall 2010. The backing wall 2010 can include one or more layers and in this illustrated example embodiment includes four suitably attached layers 2012, 2014, 2016, and 2018 of a metal material that provide suitable strength for the backing wall 2010 while still providing a suitable amount of flexibility for the backing wall 2010. Such flexibility can be important during the installation process. The plurality of filler blocks 2100 in this illustrated example embodiment include individual filler blocks 2160a, 2160b, 2160c, 2160d, 2160e, 2160f, 2160g, 2160h, 2160i, 2160j, 2160k, 2160l, 2160m, and 2160n that are respectively sized, shaped, spaced-apart, positioned, and otherwise configured to respectively be positioned in the spaces (not labeled) formed by the inner cylinder holder rack 640. The individual filler blocks 2160a to 2160n are each suitably connected to the backing wall 2010. The individual filler blocks 2160a to 2160n are each made from a suitable foam or other flexible and/or compressible material that enables the filler blocks 2160a to 2160n to fill the spaces of the inner cylinder holder rack 640. The backing wall 2010 and the filler blocks 2100 thus provide a layered structure that is configured to mate with and fit the shape of the inner cylinder holder rack 640. The layers thereof suitably fill the spaces between the cylinder mounting surfaces (not labeled) and the equipment (such as the piping which is not shown) connected thereto. In various embodiments, the backing wall 2010 and the filler blocks 2100 can meet at the plane of piping connections of the cylinders to occupy and displace air that can exist in this subsection of the cubic volume of the center compartment 400. In various embodiments, the backing wall 2010 and the filler blocks 2100 can be made from one or more other suitable materials including fire retardant materials. In various embodiments, the backing wall 2010 and the filler blocks 2100 can be made from a layered foam rubber structure.

In various embodiments, the fuel tender 10 can include a layer of tubing (not shown) that branches off the main pipe from the center of the cylinder holder rack 640. That tubing can be nestled into one or more of the conforming foam rubber blocks of the countermeasure structure 2000 to reduce the possible free air space. In various embodiments, the tubing can also be covered with another layer (not shown) of foam rubber countermeasure structures (not shown) that fill the space between the tubing and the main piping and valves. In various embodiments, a final layer (not shown) with a protective metal cover (not shown) can cover the main piping and further reduce the free air space.

In various embodiments, the countermeasure structure 2000 thus includes a plurality of small block structures that fill the sub-spaces of the center compartment 400 (such as those spaces that are exceedingly complex in shape). The present disclosure contemplates that these interstitial spaces that would otherwise be occupied by air are filled with these small block structures of similar foam material packed into the voids at a ratio, for example, of twice as many free cubic inches of small foam shapes as the calculated open volume. These filling countermeasure structures ensure the filling of the relevant spaces with foam material effecting the displacement of air from those areas. In various embodiments, the present disclosure also provides that these small block countermeasure structures can be of different shapes (such as cubic, spherical, etc.), and in some cases different combinations of different shapes can be employed for a dense packing factor (and subsequent displacement of empty volumes).

In various embodiments, the countermeasure structures include an identical or similar wall filler countermeasure structure 2000 for the cylinder holder rack 540 such as shown in FIG. 6B. Such wall filler countermeasure structure 2000 will face in an opposite direction as the wall filler countermeasure structure 2000 for the cylinder holder rack 640. Such opposing countermeasure structures 2000 thus define a space between the respective backing walls 2010 of each such countermeasure structure 2000 that will face each other such as shown in FIG. 6B. The present disclosure contemplates that such space between such countermeasure structures can be filled with one or more additional countermeasure structures 2000 such as but not limited to the additional countermeasure structure shown in FIG. 6B and described below. For example, in various embodiments, a relatively large dunnage bag countermeasure structure 2500 can be employed to fill the space between the opposing countermeasure structures 2000. In various embodiments, the opposing countermeasure structures 2000 include backing walls 2010 (described above) that have smooth metal outer surfaces that reduce the potential snags and tears of the large dunnage bag countermeasure structure 2500 that fills the space between the cylinder assemblies 500 and 600.

In various embodiments, one or more active air connections (not shown) can be provided to supply air to the inflatable dunnage bags to mitigate against small leaks in the dunnage bags. In various embodiments, the air can be obtained from the compressed air system on the railroad car.

FIG. 6A shows the empty compartment 400 and FIG. 6B shows an expandable dunnage bag countermeasure structure 2500 that is employed to fill the space between the relatively smooth walls (which have a low likelihood of puncturing such bags) of the countermeasure structures 2000 (also shown in FIGS. 5A, 5B, and 5C). This example embodiment uses one or more inflatable dunnage bag countermeasure structures 2500 to fill the space between the two backing walls of the countermeasure structures 2000 in the longitudinal direction, between two roll-up doors (not shown) of the compartment 400 in the lateral direction, and vertically between a walkway grate (not shown) and a ceiling grate (not shown) of the compartment 400. It should be appreciated that these two grates (that define multiple spaces) are configured to not trap migrating hydrogen as its natural buoyancy pushes it up towards the roof vents.

Thus, in various embodiments, the countermeasure structures include one or more expandable structures that fill parts of the cubic space of the center compartment 400. Such expandable countermeasure structures can be for example, one or more air bags (such as inflatable dunnage bag 2500 that can be inserted into relatively small spaces and substantially expanded using an inflator) or other expandable structures.

It should also be appreciated that the compartment 400 can include moveable doors (such as the roll-up doors mentioned above) or removable doors that enable access to the compartment 400 and that the countermeasure structure 2000 and 2500 can also be installed in a removable manner to enable service of the compartment 400 and equipment therein.

In various embodiments, the countermeasure structures include one or more sections of sprayed foam that fill the cubic space of the center compartment or other compartments. The sprayed foam can be non-expandable, expandable, or self-expanding. In various embodiments, the countermeasure structures can include other expandable materials such as air or liquid activated expandable materials. In various such embodiments, the liquid can be any suitable liquid such as but not limited to solvents.

FIG. 7 shows certain walkway and sub-floor filler countermeasure structures 3000 that can be employed to fill walkway and sub-floor related spaces in accordance with various embodiments of the present disclosure. This example railroad car 10 has a walkway grate (not labeled) at a door level that facilitates service access. In this example, there is approximately four feet from the walkway grate to the actual floor of the fuel tender 10. There are several valves, manifolds, piping, and pipe flanges in that space near the floor. These items can eventually need service, so the small foam rubber cubes or spheres or other shaped countermeasure structures 3000 are packed into this area to conform to the complex shapes. When packed into the space, these countermeasure structures 3000 squeeze out the free air in these spaces. These small countermeasure structures 3000 (such as packing foam rubber pieces) are removable, for instance, with a vacuum (not shown) configured for that purpose.

In various embodiments, the small countermeasure structures 3000 are small foam structures that can be compressed and held in compressed states by one or more layers of heavier foam rubber sheets (not shown), one or more dunnage bags (not shown), and/or one or more of the heavy floor grates (not shown).

In various embodiments, the countermeasure structures includes combinations of subfloor foam balls (as well as the above described panels and dunnage bag) that displace a substantial percentages of the respective spaces such as 80% to 95%. It should be appreciated that for certain of the spaces a lower % displacement can be applicable.

The present disclosure provides that that filling the spaces of the compartment having the gas carrying and controlling equipment to at least 80 to 95% (with a plurality of countermeasure structures such as a plurality of different countermeasure structures) will reduce the potential combustion of the remaining small potential premix volumes to a small fraction of the critical potential flame front progression length. For example, in the case of a 90% plus filling of the open spaces in a compartment, and hence the prevention of the existence of a premix volume of significant size, the expected maximum potential over pressure event is far below the level that could result in damage to equipment or personnel.

In various embodiments, the present disclosure provides that one or more or all of the countermeasure structures are configured to be removed for servicing of the respective compartments. In various embodiments, the countermeasure structures can be removed manually, via one or more tools (such as but not limited to vacuum suction tools in the case of small countermeasure structures), or via deflation (of the dunnage bag countermeasure structures).

In various embodiments, the present disclosure also provide that the countermeasure structures include one or more roof mounted air exhaust vents that provide a rapid path of natural buoyant escape for any gas that through permeation or interstitial migration might accumulate in any unvented buoyant space in a compartment. For example, FIGS. 8 and 8A show the compartment 1300 including a roof structure 1302 and roof vent countermeasure structures 1320a, 1320b, 1320c, 1320d, 1320e, 1320f, 1320g, and 1320h of one example embodiment of the present disclosure. The roof vent countermeasure structures 1320a, 1320b, 1320c, 1320d, 1320e, 1320f, 1320g, and 1320h are placed in conjunction with appropriate components to eliminate pockets of hydrogen from forming as any leaked hydrogen “floats” toward the top of the respective compartment of the railroad car 10. The roof vent countermeasure structures 1320a, 1320b, 1320c, 1320d, 1320e, 1320f, 1320g, and 1320h are of sufficient size to remain open in various weather conditions and in various embodiments are each protected with a small porosity screen (not shown).

The roof vent countermeasure structures 1320a, 1320b, 1320c, 1320d, 1320e, 1320f, 1320g, and 1320h are configured to be resistant to all types of weather conditions yet remain open for the venting of free hydrogen. Each roof vent countermeasure structure includes a relatively large center hole surrounded by an oversize very fine mesh screen, all covered by a hood. Rain and wind must go up and over an internal baffle to get to the large hole access to the inside of the tender. Blowing snow is blocked by the fine mesh screen and wind tends to clear the screen. Side vents, primarily for fresh air intake, are louvered panels backed with the same fine mesh screen.

In various embodiments, the countermeasure structures in the fuel tender include one or more other ventilation systems (not shown) that prevent ice and snow buildup, to enable hydrogen to escape from the fuel tender.

In various embodiments, the underneath side of the roof structure 1100, 1200, and/or 1302 is/are sprayed with a countermeasure structure including an expanding foam to form a smooth surface with no hidden pockets for accumulation of such gases in such roof structure.

In various embodiments, the present disclosure also contemplates countermeasure structures for one or more other compartments on the fuel tender 10 in which the primary gas control and pressure reduction equipment is housed and protected from the elements. In this case, the reduction of potential volume of premix is first provided by effectively boxing the pressure reduction equipment in an enclosure such as enclosure 5000 shown in FIGS. 10A and 10B that is not gas permeable and that is resistant to fire. For example, the enclosure 5000 can be a metal such as a steel enclosure. The enclosure 5000 is as close to formfitting as practical for fitting the irregular equipment of the pressure reduction equipment into a rectilinear enclosure. The enclosure 5000 is a small fraction of the cubic volume of the compartment in which it is positioned. The enclosure 5000 is filled and baffled by foam countermeasure structures 6000 (that can be similar to those used in the center compartment as described above). The combination of the enclosure 5000 and space filling countermeasure structures 6000 eliminates the condition of a potential premix volume of critical size from existing as well as a reduction in linear distance for the sub-sonic to super-sonic flame front to develop. In various embodiments, the enclosure 5000 includes aggressive venting (not shown) through the use of a plurality of roof and wall intake and exhaust vents (not shown) and the natural convection incident to the presence of those vents and the natural high level of buoyancy of H2 gas in air.

FIG. 9 shows the controlled overpressure at various distances from the fuel tender attendant to a combination of countermeasure structures provided by the present disclosure. The three lines on the chart show the pressure of detonation analytical results with no countermeasures, countermeasures configured to reduce the volume by 90%, and countermeasures configured to reduce the volume by 95%. The left end of the chart shows the reduction of pressure in the compartment. The rest of the chart shows the pressure at various distances. The example is at 33 feet (10 meters) from the railroad card tender. The chart shows the reduction for a 90% countermeasure filled volume compartment detonation is 50%. The chart shown that for a 95% countermeasure filled volume, there is a little more reduction. Maximum pressure is expressed in “barg,” which means bars gauge or multiples of atmospheric pressure as might be measured on a gauge with respect to normal atmospheric pressure. The “psig” is a conversion of the maximum pressure of the detonation expressed in pounds per square inch as measured by a gauge.

FIGS. 10A and 10B show such example equipment and the pressure reduction system countermeasure structures 6000 for such equipment in accordance with one example embodiment of the present disclosure. In this embodiment, the pressure reduction system is built on a flat panel 5100 of steel and mounted in an upright position. The enclosure 5000 includes an open back steel box that mounts tightly to the equipment plate. Access and ventilation are provided at the bottom of the cabinet with cut-outs for the piping and tubing. The equipment is dominated by a large valve 5500 roughly centered on the plate. The cabinet covers that valve, and the empty space left above and below the valve 5500 is filled with foam rubber sheets. Small foam rubber cubes, balls, or otherwise shaped countermeasure structures 6000 are used to conform around most of the panel mounted equipment, valves, pressure regulators, piping, tubing, etc. The space for free air is greatly reduced and thus the risks of detonation are reduced in turn as well. If a hydrogen leak were to develop, the buoyant hydrogen can migrate up to the roof of the cabinet where the vents that allow it to escape the cabinet into the much larger, well-ventilated compartment. The larger compartment also has roof vents (such as described above) that are configured to let rising hydrogen escape the compartment into the larger atmosphere whilst preventing obstruction from outside weather elements including rain, ice, and snow.

The present disclosure further provides various additional countermeasure structures (not shown) for the fuel tender that can be employed in combination with any of the above countermeasure structures.

In various embodiments, the countermeasure structures in the fuel tender include one or more turbulence inducement structures (not shown) that reduce the possibility of a premix. In various such embodiments, these countermeasure structures include straight and/or angled slits (not shown) to direct air during movement.

In various embodiments, the countermeasure structures in the fuel tender include the application of intumescent paint or materials (not shown) that in the case of a fire further displace the air space and thus minimize the effects of a second combustion event and detonation risk after extinguishing of the first fire.

In various embodiments, the countermeasure structures in the fuel tender include the application of endothermic materials (not shown) to further reduce the intensity of fire, onto the structure or the cylinders, absorbing the thermal energy of a fire.

In various embodiments, the countermeasure structures in the fuel tender include surface coatings (not shown) with reactive materials such as aluminum hydroxide that release water upon heating, and in this case via dehydration, in turn leaving a residual alumina coating that forms a protective layer against further fire and flames.

In various embodiments, the countermeasure structures in the fuel tender include adding one or more protective layers (not shown) of fire-retardant material such as polybenzimidazole to prevent melting in the case of a fire, retaining the mechanical form of other surfaces.

In various embodiments, the countermeasure structures in the fuel tender include the installation of burst disks (not shown) in exhaust piping to prevent diffusion ignition of trapped air from, among other things, hydraulic hammer effects of the high-pressure fluid expansion at remarkably high velocities.

In various embodiments, the countermeasure structures in the fuel tender include mechanical dilution mechanisms (not shown) such as fans or other air movement devices.

In various embodiments, the countermeasure structures in the fuel tender include small open spaces (not shown) near the roof to passively direct the buoyant hydrogen out of the fuel tender.

In various embodiments, the various countermeasure structures in the fuel tender include countermeasure structures (not shown) that work when the fuel tender is inverted or not in an upright position (such as but not limited to drains in the bottom that double as liquid drains when upright and gas exhaust when upside down).

In various embodiments, the various countermeasure structures in the fuel tender include countermeasure structures (not shown) that preferential leak paths to direct leaks towards external vents.

In various embodiments, the various countermeasure structures in the fuel tender include countermeasure structures (not shown) that segregate or seal compartments with each having individual vents, to prevent leaks from penetrating such compartments.

In various embodiments, the various countermeasure structures in the fuel tender include countermeasure structures (not shown) that include additional fire-reacting components such as intumescent paint.

In various embodiments, the various countermeasure structures in the fuel tender include countermeasure structures (not shown) that include double-walled with inert annulus or remote-ventilated annulus to direct leaks away from the compartment.

In various embodiments, the countermeasure structures in the fuel tender include various combinations of two or more or all of the above countermeasure structures for one or more of the compartments of the fuel tender.

It should be appreciated from that above that various embodiments of the present disclosure provide a railroad car that functions as a fuel tender, wherein the railroad car includes: (1) a compartment partially defined by spaced-apart cylinder assemblies, each cylinder assembly including a plurality of cylinders; and (2) a plurality of different countermeasure structures in the compartment, wherein the different countermeasure structures occupy at a percentage that is part of the cubic volume of empty space in the compartment. In various such embodiments, the compartment is partially defined by spaced-apart first and second cylinder holder racks of the cylinder assemblies, and wherein the plurality of countermeasure structures include a first wall filler countermeasure structure mated with the first cylinder holder rack and a second wall filler countermeasure structure mated with the second cylinder holder rack. In various such embodiments, the compartment is partially defined by spaced-apart first and second cylinder holder racks of the cylinder assemblies, and wherein the plurality of countermeasure structures include a first wall filler countermeasure structure mated with the first cylinder holder rack, a second wall filler countermeasure structure mated with the second cylinder holder rack, and an inflatable dunnage bag positioned between the first wall filler countermeasure structure and the second wall filler countermeasure structure. In various such embodiments, one of the countermeasure structures is inflatable and one of the countermeasure structures is not inflatable. In various such embodiments, one of the countermeasure structures is inflatable, one of the countermeasure structures is not inflatable, and one of the countermeasure structures includes foam rubber cubes or spheres. In various such embodiments, one of the countermeasure structures includes a plurality of space-apart compressible blocks. In various such embodiments, the plurality of different countermeasure structures in the compartment are configured to result in a reduction of possible flame path length in deflagration to prevent or minimize detonation. In various such embodiments, the percentage is at least twenty percent. In various such embodiments, the percentage is equal to or above ninety percent.

It should be further appreciated from that above that various embodiments of the present disclosure provide a railroad car that functions as a fuel tender, wherein the railroad car includes: (1) a compartment partially defined by spaced-apart cylinder assemblies, each cylinder assembly including a plurality of cylinders; and (2) a plurality of different countermeasure structures in the compartment, and wherein the different countermeasure structures include: (a) a plurality of first countermeasure structures in the compartment, and (b) a second countermeasure structure in the compartment, wherein the first and second countermeasure structures are different countermeasure structures, wherein the plurality of different countermeasure structures occupy a percentage that is part of the cubic volume of empty space in the compartment. In various such embodiments, each of the plurality of first countermeasure structures includes a backing wall and a plurality of filler blocks connected to and extending from the backing wall. In various such embodiments, the second countermeasure structure includes an inflatable dunnage bag. In various such embodiments, the second countermeasure structure includes an inflatable dunnage bag positioned between the plurality of first countermeasure structures. In various such embodiments, the second countermeasure structure includes an inflatable dunnage bag. In various such embodiments, the railroad car includes active air supplier for the inflatable dunnage bag, wherein the active air supplier is connected to an air supply of the railroad car. In various such embodiments, the first countermeasure structures each have a smooth inner surface engagable by the inflatable dunnage bag. In various such embodiments, the plurality of different countermeasure structures in the compartment are configured to result in a reduction of possible flame path length in deflagration to prevent or minimize detonation. In various such embodiments, the percentage is at least twenty percent. In various such embodiments, the percentage is equal to or above ninety percent.

It should be further appreciated from that above that various embodiments of the present disclosure provide a railroad car that functions as a fuel tender, wherein the railroad car includes: (1) a compartment partially defined by spaced-apart first and second cylinder holder racks; (2) a first wall filler countermeasure structure mated with the first cylinder holder rack; and (3) a second wall filler countermeasure structure mated with the second cylinder holder rack. In various such embodiments, the railroad car includes an inflatable dunnage bag positioned between the first wall filler countermeasure structure and the second wall filler countermeasure structure. In various such embodiments, the first wall filler countermeasure structure has a smooth inner surface engagable by the inflatable dunnage bag, and the second wall filler countermeasure structure has a smooth inner surface engagable by the inflatable dunnage bag. In various such embodiments, the first wall filler countermeasure structure and the second wall filler countermeasure structure in the compartment are configured to result in a reduction of possible flame path length in deflagration to prevent or minimize detonation.

Various other changes and modifications to the present embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

RAILROAD CAR WITH COUNTERMEASURE STRUCTURES THAT MINIMIZE THE LIKELIHOOD OF DEFLAGRATION AND DETONATION HAZARDS FROM GASEOUS HYDROGEN FUEL STORAGE AND SUPPLY COMPONENTS THEREOF

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