Patent Description:
<CIT> discloses a safety device for vehicles with engines fueled with compressed gas loaded in at least one cylinder on board the vehicle and where the cylinder is equipped, with a valve housing a plug fuse to open a gas discharge passage. The device includes at least one electric heating means powered by means of an electric circuit normally open, and temperature sensors, placed in at least some zones of the vehicle, each one supplying a signal indicating the temperature in the respective zone of the vehicle and provoking the closing of the electric circuit on the heating element to cause the fusion of the plug fuse so as to open the gas discharge passage when at least one of the signal has reached the preset safety limit. <CIT> discloses a system for discharging fluids from containers.

The present invention provides a system and a method as set out in the claims.

In one aspect, a system includes some number of valves configured to permit fluid flow out of cylinders in response to emergency conditions. For the sake of this disclosure, a system will be considered to have at least two valves configured to cover two vessels separately. A vessel may include multiple individual cylinders so long as the cylinders are in fluid communication through a shared evacuation vent conduit. The first valve is fluidly connected to a first vessel, and the second valve is fluidly connected to a second vessel. The first valve includes a first port, and a second port, and a mechanism that separates communication between the two ports (such as a piston in one example). The first port is in fluid communication with the interior of the first vessel. The second port is in fluid communication with the second valve, and in fluid communication with an atmosphere exterior to the first vessel. In one example, the separating mechanism is a piston with physical movement, though other mechanisms may be used. The piston is disposed within the bore and is movable along the longitudinal axis. A first position of the piston blocks the first port, and a second position of the piston allows fluid communication between the first port and the second port. In one example, the first valve is configured so that fluid pressure from the second valve communicating through the second port urges the piston to the second position.

In another aspect, a method for sympathetic opening for a first valve with fluid pressure from a second valve is described. In a system including the first valve and the second valve, the first valve is fluidly connected to a first vessel, and the second valve is fluidly connected to a second vessel. The first valve can include a body and a piston. The body includes a first port and a second port. The first port is in fluid communication with the first vessel. The second port is in fluid communication with the second valve, and in fluid communication with an atmosphere exterior to the first vessel. A first position of the piston blocks the first port, and a second position of the piston allows fluid communication between the first port and the second port. The method includes urging the piston to the second position when the second valve is open. This movement of the piston can be accomplished by communicating fluid pressure from the second valve through the second port of the first valve, causing mechanical movement of the piston. This movement of the piston may also come from an electric signal being passed to the first valve upon opening of the second, and causing mechanical movement of the piston.

This summary is provided to introduce concepts in simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the disclosed or claimed subject matter and is not intended to describe each disclosed embodiment or every implementation of the disclosed or claimed subject matter. Specifically, features disclosed herein with respect to one embodiment may be equally applicable to another. Further, this summary is not intended to be used as an aid in determining the scope of the claimed subject matter. Many other novel advantages, features, and relationships will become apparent as this description proceeds. The figures and the description that follow more particularly exemplify illustrative embodiments.

The disclosed subject matter will be further explained with reference to the attached figures, wherein like structure or system elements are referred to by like reference numerals throughout the several views. It is contemplated that all descriptions are applicable to like and analogous structures throughout the several embodiments.

While the above-identified figures set forth one or more embodiments of the disclosed subject matter, other embodiments are also contemplated, as noted in the disclosure. In all cases, this disclosure presents the disclosed subject matter by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that fall within the scope of the principles of this disclosure.

The figures may not be drawn to scale. In particular, some features may be enlarged relative to other features for clarity. Moreover, where terms such as above, below, over, under, top, bottom, side, right, left, vertical, horizontal, etc., are used, it is to be understood that they are used only for ease of understanding the description. It is contemplated that structures may be oriented otherwise.

This disclosure describes a more reliable and efficient evacuation system that allows pressure release devices (PRD) in the system to trigger, in addition to their primary response to an emergency condition, as a result of a reaction to complementary PRD's effectively acting in a sympathetic mode to one another.

The disclosed concept relates to a system of pressure relief device or pressure release device (PRD) actuators or valves that can vent a pressure vessel as a result of over-heating of that particular pressure vessel, as well as in a sympathetic mode in which multiple connected pressure vessels are simultaneously vented in response to the over-heating of any one of the pressure vessels that are connected in the system.

An individual pressure vessel has a high pressure live port in selective communication with a vent port. In an exemplary embodiment, a trigger element of the PRD is located along an outside surface of the pressure vessel. For the purpose of example only, the trigger elements of the PRDs represented in the figures include a shape memory alloy (SMA). The focus of this disclosure is in the sympathetic triggering of PRDs and not in the specific design of the trigger element. In an example in which the trigger element is a SMA wire, if the temperature in the vicinity of any pressure vessel increases past its transition temperature, the trigger element allows shifting of the piston of a pressure relief actuator (to the right as illustrated in <FIG>), thereby opening communication between the high pressure live port and the vent line. Thus, in one mode, the PRD is actuated by a trigger mechanism such as a heat-activated solenoid, shape memory alloy wire, or fusible element.

In an exemplary embodiment, the vent lines of the multiple pressure vessels of the system are connected so that increased pressure in the vent line (caused by the venting of high-pressure contents of one pressure vessel) can also push the piston of other system-connected PRDs to the right, thereby venting all other connected pressure vessels in the system. Accordingly, a second mechanism for actuation is through sympathetic back pressure activation of all the PRDs connected to the pressure vessels in the system, in response to activation of any one of the PRDs due to high heat. While a particular actuation mechanism of the exemplary PRD is described, it is contemplated that the teachings of sympathetic back pressure activation described herein can also be applied to other actuators that have different mechanisms than those specifically described.

<FIG> is a schematic view of a cross section of an exemplary pressure release device or pressure relief device (PRD) that can be used in a system as disclosed. While the illustrated exemplary PRD <NUM> is heat-activated, it is contemplated that the described system can be used with PRDs that are actuated by other means including, for example, electrically activated solenoids and valves responsive to manual and automatic actuation in response to triggers including temperature, pressure, chemical concentration, and other conditions and operations.

As shown in <FIG>, in an exemplary embodiment, PRD valve <NUM> includes a body <NUM> having a bore or cavity <NUM> therein. Bore <NUM> has a longitudinal axis <NUM> along which piston or shuttle <NUM> is slideably moveable. Bore <NUM> is in fluid communication with high pressure port <NUM> and vent port <NUM>. In <FIG>, PRD <NUM> is shown in a closed configuration, wherein shuttle <NUM> closes communication between high pressure port <NUM> and vent port <NUM>. High pressure port <NUM> is configured for fluid communication with a source of pressurized fluid <NUM> (shown in <FIG>), such as a pressure vessel or pressure cylinder, for example. Vent port <NUM> is configured for communication with an atmosphere outside the system, as well as with other valves <NUM> in the system <NUM>.

To open PRD <NUM>, shuttle <NUM> is moved to the right in the drawing <FIG>, in direction <NUM>, through primary and secondary mechanisms in an exemplary embodiment. The primary mechanism is the use of a trigger element; shown by example as a SMA wire <NUM>. The primary mechanism is not limited to a SMA design, but is any trigger element that can displace the piston through temperature input. In an exemplary embodiment, as shown in the system diagrams of <FIG>, SMA element 28a is positioned along pressure vessel 30a. In an exemplary embodiment, SMA element 28a is positioned along the pressure vessel 30a in a controlled path by use of channels, tubes, pulleys, other means, or a combination thereof and then anchored near its end <NUM>. If SMA <NUM> is exposed to a temperature greater than its transition temperature, it shortens, thereby pulling shuttle <NUM> in direction <NUM>. Thus, in system <NUM>, if any pressure vessel 30a or 30b is exposed to a temperature higher than the transition temperature of SMA <NUM>, it is expected that the high temperature will shorten the corresponding SMA 28a or 28b to an extent that pulls shuttle <NUM> to an open configuration of PRD 10a or 10b.

The secondary mechanism is what is termed as the sympathetic trigger. It takes place in response to the triggering of any PRD in the system, rather than in response to direct heat exposure. As a first example, when an individual PRD <NUM> is triggered, it is contemplated that in system <NUM>, the opening of fluid communication between a high pressure port <NUM> connected to a particular pressure vessel <NUM> and its associated vent port <NUM> will pressurize fluid lines in communication with other connected PRDs <NUM>, so that a PRD <NUM> is also actuated by pressurized fluid flowing through vent port <NUM> in direction <NUM> (labeled in <FIG>). Thus, in a sympathetic actuation mode, pressurized fluid flowing from a different pressure vessel <NUM>, in direction <NUM>, will serve to push shuttle <NUM> to the right in direction <NUM>, thereby opening a vent path between high pressure port <NUM> and vent port <NUM>. After opening the vent path, pressurized fluid can flow in direction <NUM> (labeled in <FIG>).

Alternatively or additionally, the sympathetic trigger may be handled electrically through the actuation of a solenoid <NUM>, to push shuttle <NUM> in direction <NUM>. Such a solenoid <NUM> in an exemplary embodiment is activated by communication with an associated controller attached to one or more sensors monitoring the system for a primary trigger, such as increased temperature, pressure, chemical concentration, or other sensed conditions. If the sensors associated with solenoid <NUM> sense a primary trigger, solenoid <NUM> activates and thereby pushes shuttle <NUM> to the right in direction <NUM>, to an extent sufficient to open a fluid communication path between high pressure port <NUM> and vent port <NUM>, as shown in <FIG>. However, it is contemplated that other mechanisms for opening PRD <NUM> can be utilized, including other mechanisms that may be actuated by other mechanical and/or electrical means.

As shown in <FIG>, evacuation of pressurized fluid from a connected cylinder or pressure vessel is accomplished by a flow of the pressurized fluid through from the pressure vessel through high pressure port <NUM> and out vent port <NUM> in direction <NUM>. While particular structures and functions of components in PRD <NUM> are illustrated in an exemplary embodiment, it is contemplated that system <NUM> can be used with PRDs of other structures and configurations.

<FIG> is a schematic view of an exemplary system <NUM>, having two sets, designated "a" and "b," of a pressurized fluid source <NUM>, pressure vessel <NUM>, trigger element <NUM>, PRD <NUM>, and associated conduits and connectors. While two respective sets of these elements are described, it is contemplated that many more analogous sets can be used in a similar system. When referring to an element in general in this disclosure, and not to a particular element of a particular set, we will use the numerical designation for a particular element, without the "a" or "b. " Moreover, while particular configurations and connections of elements are illustrated in the exemplary system, it is contemplated that the elements may be arranged differently, and the teachings of the system can be applied to systems using more or fewer elements, including components not described. Additionally, a system may combine elements, such as using a single pressurized fluid source <NUM> for both pressure vessels 30a, 30b, for example.

In <FIG>, pressurized conduits are represented by short dashed lines, and non-pressurized conduits are represented by solid lines. Line <NUM> connects pressurized fluid source <NUM> to its respective pressure vessel <NUM>. Note that in <FIG>, in routine use of system <NUM>, a pressurized conduit <NUM> communicates high-pressure fluid from pressurized fluid source <NUM> to pressure vessel <NUM>. The high-pressure fluid communicates through pressurized conduit <NUM> to PRD <NUM>. In normal operation, PRD <NUM> is closed, as shown in <FIG>, so that there is no fluid communication between high pressure port <NUM> and vent port <NUM>. Accordingly, vent conduit <NUM> is not pressurized, as depicted by the solid line.

Conduit <NUM> connects each pressure release device <NUM> to its respective pressure vessel <NUM>, such as at high-pressure port <NUM> of PRD <NUM>. <FIG> depicts system <NUM> in a normal operation state, wherein pressure vessel <NUM> contains fluid at an elevated pressure compared to an atmospheric pressure, such pressurized fluid being supplied from pressurized fluid source <NUM>. High pressure port <NUM> of each PRD <NUM> is closed by shuttle <NUM> (as in <FIG>). Accordingly, while conduit <NUM> between PRD <NUM> and pressure vessel <NUM> is pressurized by fluid from the connected pressure vessel <NUM>, conduit <NUM> connected to vent port <NUM> is not thereby pressurized. Conduit <NUM> branches off at tee connection <NUM> into trigger conduit <NUM> and vent conduit <NUM>. Each vent conduit <NUM> terminates in vent <NUM>, which can be an outlet to the atmosphere.

In the operation of system <NUM>, PRD 10a associated with pressure vessel 30a, may open by the primary activation of <NUM>) the trigger element <NUM> due to elevated temperatures above a desired temperature in the vicinity of pressure vessel 30a; and/or <NUM>) activation of a solenoid <NUM> due to elevated temperatures at connected sensors. Additionally PRD 10a may open by the secondary sympathetic actuation as explained below. A threshold temperature over which PRD <NUM> opens may be calibrated by the selection of control parameters for solenoid <NUM>, and/or dimensions and materials of SMA element <NUM>, and/or calibration of a pressure force required in direction <NUM> to move shuttle <NUM>, for example. Moreover, while PRDs as described respond to a threshold temperature, it is contemplated that the system can also be triggered in response to other environmental conditions, including but not limited to pressure or the sensed concentration of certain air components.

In an exemplary embodiment where pressure is used as the secondary sympathetic trigger, each tee connector <NUM> is configured to preferentially direct pressurized fluid flow preferentially through trigger conduit <NUM> rather than to vent conduit <NUM>. Thus, as shown in <FIG>, if either PRD <NUM> is activated so that fluid communication is allowed between high pressure port <NUM> and vent port <NUM>, such flow pressurizes conduit <NUM> connected to vent port <NUM>. This pressurized fluid flows through tee connector <NUM> to then pressurize trigger conduit <NUM>, as shown in <FIG>. Such fluid pressure in trigger conduit <NUM> then enters vent port <NUM> of all other connected PRDs <NUM> in system <NUM>, to open those other PRDs <NUM> by fluid pressure pushing on shuttles <NUM> in direction <NUM>, as shown in <FIG>. Thus, all PRDs <NUM> in system <NUM> will be opened automatically in a sympathetic mode upon the triggering of at least one PRD <NUM>. Each PRD <NUM> will open according to one or more of the primary and secondary mechanisms discussed above; namely, first, displacement of shuttle <NUM> by the actuation of a trigger element <NUM> or activation of the solenoid <NUM> from connected sensors such as temperature sensors; second, displacement of shuttle <NUM> in direction <NUM> due to sympathetic back pressure actuation through vent port <NUM> from the venting of other pressure vessels <NUM> in the connected system <NUM> or sympathetic solenoid activation.

As shown in <FIG>, after all connected PRDs <NUM> in system <NUM> have been opened, excess pressurized fluid from pressure vessel <NUM> and/or pressurized fluid sources <NUM> is directed by tee connection <NUM> to vent lines <NUM>, to ultimately exhaust to the atmosphere (or a suitable exhaust receiving chamber) at vent <NUM>. While conduit 44a is illustrated as connecting vent port <NUM> and tee connector <NUM>, it is contemplated that in a different embodiment, a split for trigger conduit <NUM> and vent conduit <NUM> can be plumbed or built directly into PRD <NUM>.

The disclosed system <NUM> provides for automatic, sympathetic activation of all PRDs <NUM> in the system <NUM>, in response to the opening of any one of the connected PRDs <NUM>. Such a design reduces the time needed for individual mechanical triggering of PRDs in a system. Moreover, a vent flow rate of the system can be increased by having all connected PRDs <NUM> open nearly simultaneously. Thus, system <NUM> is simpler and more reliable in emergency situations than systems that merely use the primary mechanisms.

In an exemplary embodiment using pressure imbalance as the secondary trigger, PRD <NUM> is designed so that a relatively small pressure imbalance (i.e., a differential between atmospheric pressure and a pressure of fluid flowing in direction <NUM> of vent port <NUM>) would be required to move shuttle <NUM> to the open position shown in <FIG>.

An exemplary, non-limiting embodiment of system <NUM> includes first valve 10a and second valve 10b. The first valve 10a is fluidly connected to a first vessel 30a and the second valve 10b fluidly connected to a second vessel 30b. First valve 10a includes body <NUM> and piston <NUM>. Body <NUM> includes bore <NUM> having longitudinal axis <NUM>, first port <NUM> and second port <NUM>. First port <NUM> is in fluid communication with bore <NUM> and an interior of the first vessel 30a. Second port <NUM> is in fluid communication with bore <NUM>, in fluid communication with the second valve 10b, and in fluid communication with an atmosphere <NUM> exterior to the first vessel 30a. Piston <NUM> is disposed within bore <NUM> and is movable along longitudinal axis <NUM>. A first position of the piston <NUM> blocks the first port <NUM>, as shown in <FIG>. A second position of the piston <NUM> allows fluid communication between the first port <NUM> and the second port <NUM>, as shown in <FIG>. First valve 10a is configured so that fluid pressure from the second valve 10b communicating through the second port <NUM> urges the piston <NUM> to the second position.

In an exemplary embodiment, a trigger element <NUM> has a first end connected to piston <NUM>. The fusible element <NUM> has a first position, wherein piston <NUM> is in its first position (closed), shown in <FIG>. Exposure of the trigger element <NUM> to a threshold condition causes the trigger element <NUM> to urge the piston <NUM> to the second position (open), shown in <FIG>. In an exemplary embodiment, the trigger element <NUM> is a shape memory alloy element, and the threshold condition is a temperature at or exceeding its transformation temperature. As shown in <FIG>, at least a portion of the trigger element 28a is positioned along the first vessel 30a. In an exemplary embodiment, system <NUM> further includes solenoid <NUM>, which is configured to push piston <NUM> from the first position (shown in <FIG>) to the second position (shown in <FIG>) in direction <NUM>. This solenoid can be used for primary or secondary triggering.

In an exemplary embodiment, system <NUM> includes trigger conduit <NUM> through which the fluid pressure from the second valve 10b is communicated to the second port 22a of first valve 10a. In an exemplary embodiment, system <NUM> includes vent conduit <NUM> and connector 46a between second port 22a, trigger conduit <NUM>, and vent conduit <NUM>. Connector 46a opens fluid communication between the trigger conduit <NUM> and the second port 22a until a threshold pressure level in trigger conduit <NUM> is reached, causing a secondary sympathetic trigger. Connector 46a opens fluid communication between trigger conduit <NUM> and vent conduit <NUM> when the threshold pressure level in trigger conduit <NUM> is exceeded. In an exemplary embodiment, connector 46a also opens fluid communication between second port 22a and vent conduit <NUM> when the threshold pressure level in trigger conduit <NUM> is exceeded.

Claim 1:
A system (<NUM>) comprising:
a first valve (10a) fluidly connected to a first pressure vessel (30a); and
a second valve (10b) fluidly connected to a second pressure vessel (30b); wherein a trigger conduit (<NUM>) is fluidly connecting the first valve (10a) and
the second valve (10b), wherein the trigger conduit (<NUM>) is configured to:
accept fluid from opening of one of the first valve (10a) or the second valve (10b) by activation of a trigger element (<NUM>) that is at least one of a shape memory alloy element or a heat-activated solenoid (<NUM>); and
communicate pressure of the fluid to open the other of first valve (10a) or the second valve (10b); and
the system comprising a vent conduit (<NUM>) fluidly connected to at least one of the first (10a) and second (10b) valves and an atmosphere exterior to the first pressure vessel (30a).