DE102017205645A1 - Safety system for a pressure vessel of a motor vehicle - Google Patents

Abstract

The technology disclosed herein relates to a safety system having a thermally activatable safety valve with at least one thermally activatable opening element.

Description

The present invention relates to a safety system for a pressure vessel of a vehicle and to a vehicle having such a safety system. Furthermore, the technology disclosed herein relates to an opening element, e.g. a glass ampule. Furthermore, the technology disclosed herein relates to a method for remote pressure relief of a pressure vessel.

Pressure vessels are used in vehicles for storing fuel, such as hydrogen or natural gas. The fuel is in the vehicle e.g. implemented in a fuel cell or in an internal combustion engine to generate energy for driving the vehicle. Pressure vessels are under a relatively high pressure. In thermal events, such as a vehicle fire, the pressure from the pressure vessel i.d.R. drained controlled. For this purpose, appropriate safety valves are provided. Safety valves with different opening elements are known from the prior art, for example designed as glass ampoules, made of melting material or of shape memory metal.

It is an object of the present invention to provide a safety system for a pressure vessel in a vehicle that is conveniently simple to operate, inexpensive, lightweight and / or space efficient, and preferably allows for safe activation of the safety valve to relieve pressure from the pressure vessel. The object is solved by the features of the independent claim. The dependent claims have preferred embodiments of the invention the subject.

The safety valve has at least one thermally activatable opening element. In the thermal activation, usually at a release temperature of about 110 ° C and more, the opening elements change their shape or are destroyed (= thermal activation). This opens the safety valve. Due to the thermal activation, the opening element can change its shape. Alternatively or additionally, the opening element can be destroyed by thermal activation. The term "opening element" is limited within the scope of the technology disclosed here to the area of the safety valve, which can be changed or destroyed by the thermal activation. In the closed state of the safety valve causes the opening element directly or indirectly, that the safety valve does not release a flow path from the interior of the pressure vessel to the environment. In indirect closing, the opening element holds, for example, a valve body, wherein the valve body in turn closes the safety valve.

The opening element is designed so that it opens at a triggering temperature, for example of 110 ° C. The trip temperature is chosen so that in the case of a thermal event, e.g. a vehicle fire, bursting of the pressure vessel is avoided by thermal structure weakening.

The opening element may be formed, for example, as a glass ampule. Such a glass ampoule is a fluid-filled bursting body. The glass ampoule has a closed fluid volume which is surrounded by a material which is comparatively brittle or fragile even at the triggering temperature (for example glass). The material for the glass ampoule is not limited to "glass", but any material that is sufficiently brittle can be selected. The fluid volume is filled with a fluid which expands comparatively strongly when heated. If the temperature rises to the triggering temperature, the glass ampoule breaks and thus triggers the safety valve (= release of the flow path to the environment).

Alternatively or additionally, a melting solder can be provided. If the temperature in the safety valve rises to the release temperature, the fusible link will soften. The softened solder is deformed by a force directly or indirectly generated by the pressure inside the pressure vessel. This deformation of the melt solder causes a triggering of the safety valve. Furthermore, the opening element may also comprise a shape memory material, in particular a shape memory wire. The shape memory material may in particular be designed to assume a first shape at a temperature below the triggering temperature, which differs from the second shape, which occurs when the triggering temperature is exceeded. Concrete embodiments of a safety valve with a glass ampoule, a fusible link and / or a shape memory material are known in the art. For example, the DE 10 2014 000616 A1 a safety valve with a shape memory material and discussed in the introductory part also solutions with a glass ampoule and a fusible link.

Preferably, the opening element is formed capsule-shaped. It preferably comprises a substantially cylindrical shell region with two i.d.R. arched ends.

The technology disclosed here relates in particular to a thermally activatable opening element for a thermally activatable safety valve, wherein the opening element may comprise on its outer surface or in a wall of the opening element at least one electrical line which can be connected to the electrical circuit. The electrical line may preferably the Do not enclose the opening element on all sides. In particular, the electrical line can be designed and arranged such that the electrical conduction after the thermal activation of the opening element does not completely or at least partially prevent the functional deformation of the opening element.

The electrical line may preferably cover a maximum of 50% or a maximum of 30% or a maximum of 15% of the outer surface of the opening element (6). The opening element may have on the outer surface of the opening element a free surface which is not interrupted by the conduit, wherein the free surface may make up at least 50% or at least 70% or at least 85% of the outer surface of the opening element.

The electrical line can meander-shaped and / or waves (lines) shaped. Furthermore, at least two contact regions for electrical contact with the safety valve can be provided on the opening element.

The technology disclosed herein relates to a thermally activatable safety valve. The thermally activated safety valve, also called pressure relief device or thermal pressure release device or TPRD, is usually provided adjacent to the pressure vessel. In the event of heat (eg due to flames), the TPRD releases the fuel stored in the pressure vessel into the environment. The pressure relief device releases the fuel as soon as the trigger temperature of the TPRD is exceeded (= is activated thermally). It can also be provided trigger lines. Such a system for thermal pressure relief is for example in the DE 10 2011114725 A1 or the EP 1 655 533 B1 shown.

The thermally activatable safety valve may comprise at least one opening element with at least one electrical line, as disclosed herein. The safety valve may have at least two electrical contacts arranged to contact the electrical lead from the opening element.

The thermally activatable safety valve may have at least one heating component. The heating component can be designed to heat at least one thermally activatable opening element, wherein the heating component can be provided in a housing wall or on an inner side of the housing wall of the safety valve.

In particular, the heating component may be a heating coil. In one embodiment, the opening element can be accommodated in the heating coil. Preferably, the heating coil can be designed to be electrically insulating with respect to the housing wall. Preferably, the housing wall is made of a metal material.

The heating component may be formed as a bimetallic element and / or as a shape-memory element. The bimetallic element and / or the shape-memory element can be designed such that the bimetal element and / or the shape-memory element is not contacted by the opening element in a first unheated or non-thermally activated state. In this state, the bimetallic element and / or the Formgedächniselement is spaced from the opening element. Advantageously, it can thus be avoided that vibrations resulting from the driving operation are transmitted to the opening element.

The technology disclosed herein further relates to a safety system for pressure relief of at least one pressure vessel of a motor vehicle. The safety system includes the safety valve disclosed herein, the orifice member disclosed herein, and / or the at least one pressure vessel disclosed herein.

The pressure vessel may be, for example, a cryogenic pressure vessel (= CcH2) or a high-pressure gas vessel (= CGH2). High pressure gas containers are configured to store fuel substantially at ambient temperatures at a nominal operating pressure (also called nominal working pressure or NWP) of about 350 bar (= overpressure to atmospheric pressure), more preferably about 700 barg or more. A cryogenic pressure vessel is suitable to store the fuel at the aforementioned operating pressures even at temperatures well below the operating temperature of the motor vehicle.

The safety valve is expediently arranged on the pressure vessel or connected correspondingly fluid-conducting with the pressure vessel. If there is no thermal event, the safety valve is closed.

The safety system disclosed here may in particular be designed in such a way that the heating component and / or the opening element can be supplied with electrical energy by an internal vehicle energy source and / or by a vehicle-external energy source.

An in-vehicle energy source can be, for example, an electrical energy storage device (eg battery) or a thermoelectric generator. Advantageously, the thermoelectric generator immediately adjacent to the lateral surface be arranged of the pressure vessel. The thermoelectric generator can be designed as the generator described in the German patent application with the application number DE 10 2016 215053.7 (there: thermoelectric generator 110) is disclosed. The content of the German patent application with the application number DE 10 2016 215053.7 is hereby incorporated by reference in this disclosure with respect to the design and arrangement of the thermoelectric generator by reference.

The heating component and / or the opening element can in particular be activatable by an external energy source and / or by a vehicle-external control device. Furthermore, it may be provided that the safety system is set up in such a way that the heating component and / or the opening element can be connected to the vehicle-external energy source and / or to a control unit external to the vehicle. The off-vehicle power source may be any type of electrical power source, such as a battery. The vehicle-external energy source can be set up to supply the heating component and / or the opening element with sufficient energy for the opening element to be thermally activated. The vehicle-external control device can be set up to control the secure actuation of the remote pressure relief device. Suitably, electrical lines can lead to at least one connection for such an energy source or for such a control device. But it can also be provided only an electrical line, for example, if only one pole is needed to control and as another signal, the ground signal or the earth is used. The specific design of the circuit is familiar to a person skilled in the art.

Particularly preferably, at least two electrical connections are provided at different locations of the motor vehicle disclosed here at different locations, to each of which the vehicle-external energy source and / or the vehicle-external control unit can be connected. For example, at least one electrical line, preferably two electrical lines, can lead to each of these connections.

"Spaced apart" in the context of the technology disclosed herein means that the electrical connection points are at least 50 cm apart, preferably at least 1 m or 1.5 m apart. They may be spaced such that the electrical connections are accessible from the outside from different directions and / or from different sides of the vehicle (right side of the vehicle, left side of the vehicle, vehicle floor, vehicle roof, etc.).

Accessible from the outside means in this context that the at least one electrical connection without vehicle-specific special tool and without time-consuming dismantling of other functional components (except covers of the body) from outside the motor vehicle (eg., From the outer skin of the body or from the underbody paneling) accessible is. In this case, the electrical connection can be covered by a flap or cover, which is expediently easy to dismantle.

Preferably, the security system disclosed herein further comprises at least one electrical switch or crash switch or electrical switching device (hereinafter: electrical switch). The electrical switch is open here in the de-energized state. The electrical switch can be arranged and configured such that the electrical switch prevents electrical contact with the heating component and / or the opening element as long as there is no signal indicative of an accident / fire event and / or an external third-party signal from an authenticatable third party. Recognizes a control unit of the motor vehicle or the electrical switching device that the motor vehicle is involved in an accident and / or that a fire event has occurred on the motor vehicle, and / or an authorized third party is authenticated by the control unit (which initiates a closing signal for the electrical switch ), the electrical switch is closed and a power supply to the heating component and / or the opening element allows. The electrical switch is thus a controllable by a control unit of the motor vehicle electrical switch. The devices for detecting a crash in a vehicle are usually present and are also used for triggering other safety systems, for example an airbag. This way, abuse of the system can be avoided.

The electrical switch can also be activated via an external signal (eg rescue workers, maintenance personnel). This means that the electric switch can also be closed by authorized (in particular authenticated) third parties (eg personnel of a service station) without there being a vehicle fire or an accident or a crash signal on the vehicle side. This is particularly advantageous if, for other reasons, a pressure relief should take place, for example because in a vehicle fire or an accident, the control unit has been disabled (eg when parking) and / or the control unit has not detected the fire / accident as such / classified , Also, other reasons are conceivable. Advantageously, the electrical switch can be closed via a wireless or wired communication signal from a vehicle-external device, for example by an e-call System of a service point. In principle, any form of communication is conceivable here.

Preferably, additional security measures can be provided for authenticating the third party closing the electrical switch, for example an encrypted communication protected by a motor vehicle-specific or electronic key. For example, the coding of the vehicle key can be used for this purpose. Particularly advantageous in this embodiment, an internal power source is provided. Alternatively or additionally, however, an external energy source can also be provided.

In particular, a device may be designed to implement the method described in the German patent application with the application number DE 10 2015 223966.7 is disclosed. The in the German patent application with the application number DE 10 2015 223966.7 The disclosed apparatus and the method disclosed therein are hereby incorporated by reference herein. However, the thermal (remote) activation is preferred here by means of the heating component or the opening element disclosed here.

The technology disclosed herein further comprises a motor vehicle, in particular a road vehicle. The motor vehicle includes the safety system disclosed herein and at least one pressure vessel as disclosed herein. The safety system is set up to relieve the pressure of the pressure vessel disclosed herein.

The security system disclosed herein may include at least one delay device. The deceleration device can be provided on the vehicle side. Alternatively or additionally, the deceleration device can also be provided on the vehicle-external energy source or on the vehicle-external control. The delay device is set up to delay the operation of the heating component and / or the opening element in time. The technical implementation of such a delay device is familiar to the expert. In control engineering, the term "idle timer" is used for this purpose. The delay device disclosed herein may delay the thermal actuation of the orifice member for at least 30 seconds, at least 2 minutes, or at least 2 minutes, or at least 5 minutes. Thus, security forces can advantageously bring before the triggering of the opening element to safety. Advantageously, therefore, do not have long electrical conductors are laid to trigger from a safe distance. Preferably, the delay device can be designed so that the delay time can be set. As with a self-timer of a camera can thus be set when the remote pressure relief should take place.

In other words, the technology disclosed herein relates to a glass ampule having corrugated or meandering conduits on its outer surface. In particular, such a glass ampoule does not have any conductor winding which holds any glass fragments after the glass ampule has burst. The splinters are able to move freely and the deformation of the glass ampoule is less affected. Thus, the triggering behavior can be improved.

The bimetallic strip can be heated electrically, for example. The bimetallic strip may be formed such that the bimetallic strip changes its shape such that it rests against the glass ampoule at a temperature of about 110 ° C. The bimetallic strip then transfers the heat to the glass ampoule by means of heat conduction. Overall, the response of the safety valve can be improved in such an embodiment. On the one hand, heat can be transmitted to the glass ampoule by heat conduction comparatively well, and on the other hand, the bimetallic strip does not transmit mechanical forces and moments (e.g., vibration) to the glass ampoule during normal vehicle operation. The disclosed technology goes hand in hand with a better triggering behavior, with a better tripping behavior, with less influence on the system, because the glass bulb is not in direct contact with the tripping device and is therefore not affected in its behavior (in case of an external fire) or lifetime.

The electrical control can be done via a safety switch that releases the control of the heating component and / or the opening element only when the vehicle control has detected an accident or fire. Alternatively or additionally, third parties (normally rescue workers) can release the heating component and / or the opening element, for example by the electric switch disclosed here or by the disclosure of the German patent application with the application number incorporated herein by reference DE 10 2015 223966 ,

The proposed remote pressure relief can be integrated into existing and secured TPRD systems with significantly less effort, without changing the design and function of the TPRD systems. Thus, already proven TPRD systems can continue to be used, which can now also be operated remotely, in particular from outside the motor vehicle. In addition, the system disclosed here usually comparatively cheap, easy and with little space requirement can be realized.

• 1 schematisch einen Schaltkreis des hier offenbarten Sicherheitssystems 1 eines Kraftfahrzeugs 2 mit dem Sicherheitsventil 5;
• 2 schematisch eine Querschnittszeichnung eines Sicherheitsventils 5 mit einer Heizkomponente 20 und einem Öffnungselement 6;
• 3 schematisch ein Öffnungselement 6; und
• 4 schematisch ein weiteres Öffnungselement 6.

Further details, features and advantages of the technology disclosed herein will become apparent from the following description and the figures. Show it:

• 1 schematically a circuit of the disclosed here safety system 1 of a motor vehicle 2 with the safety valve 5;
• 2 schematically a cross-sectional drawing of a safety valve 5 with a heating component 20 and an opening element 6;
• 3 schematically an opening element 6; and
• 4 schematically another opening element. 6

The 1 schematically shows a circuit in which the technology disclosed here is realized. Dashed marked is the motor vehicle 2 , The connection is easily accessible to the outside 8th intended. The connection 8th For example, it may be provided behind a flap of the body shell or on the underbody panel. The connection 8th is designed such that an external energy source 3 easily connectable. Here is shown only one connection 8th , The motor vehicle preferably comprises 2 at least two connections 8th in different places of the motor vehicle 2 are arranged accessible from the outside. Advantageously, regardless of the vehicle situation after an accident, the external energy source 3 be connected. About electrical power lines 7 is the external source of energy 3 connected to the heating component 20. The heating component 20 is here on or in a safety valve 5 or on or in an opening element 6 arranged (not shown, cf. 2 ). The electric power lines 7 , the external energy source 3 and the heating component 20 form here an electrical circuit, in which here additionally designed as a crash switch electrical switch 9 is provided. The electric switch 9 is open when de-energized. If an accident or a vehicle fire is detected by a control unit (not shown), then the control unit causes the electrical switch 9 is closed. Alternatively or additionally, security personnel could remotely activate the heating component 20. Thus, with connected external power source 3 only one current will flow if there is an accident or vehicle fire. This measure can help to reduce the likelihood of improper pressure relief. Further, the system disclosed herein may include a delay device 12 include. The delay device 12 is set up, even with a closed electrical switch 9 and connected external power source 3 to prevent the flow of current directly after the formation of the closed circuit initially for a certain time. Here is the delay device 12 drawn as a separate component. Likewise, the delay device could 12 also be integrated into another component (eg heating component, control unit, etc.). Thus, the rescuers usually have enough time to go outside the danger zone after they have the external energy source 3 to the connection 8th of the motor vehicle 2 have connected. Such a delay device 12 but must not be provided. It is also possible to use the external energy source 3 by means of long electrical power lines to the connection 8th connect, wherein the line length is suitably chosen so that the external energy source is located outside the danger area. At the external energy source 3 Then, an external control or an external switch can be provided, via which the circuit is closed. Now is the circuit closed and now flows after a certain delay by the delay device 12 an electric current, the heating component heats the opening element 6 the safety valve 5 and optionally other areas of the safety valve 5 , Shown here is an external energy source 3 , Of course, however, alternatively or additionally, an in-vehicle energy source can be provided.

The 2 shows a schematic cross-sectional view of a safety valve 5 attached to a pressure vessel 4 is provided. Through an inlet 51 the fuel, here hydrogen, can enter the safety valve 5 flow. A piston 54 including seal 53 prevents the escape of fuel through the blow-off line 52 , The piston 54 is here by the opening element 6 held in its first fuel passage blocking position. The opening element 6 is claimed here on pressure. About the piston 54 becomes a force exerted by the pressure chamber internal pressure piston force on the opening element 6 transfer. The counterpressure element 55 is here with the case 56 the safety valve 5 via connecting rods 57 connected. The counterpressure element 55 brings the counterforce to the piston force. The counterpressure element 55 and the connecting rods 57 are designed such that heated air of the environment can easily flow into the valve chamber 58 to the opening element 6 in case of fire immediately adjacent to the safety valve 5 thermally activate. If a fire event now takes place at another location of the motor vehicle or if an accident has occurred, the heating component 20 can be energized. The heating component 20 heats the fluid in the fluid space 11 and optionally other sections of the safety valve 5 , such as the counter-pressure element 55 , the connecting rods 57 and/ or sections of the housing 56 , Exceeds the temperature in the fluid space 11 the triggering temperature, it breaks like a glass ampule 10 formed opening element 6 , Consequently, it acts on the piston 54 only the piston force applied by the pressure vessel internal pressure. The piston 54 shifts so in the axial direction of the safety valve 5 to the counter-pressure element 55 out. Through this axial movement of the fuel through the blow-off line 52 escape and the pressure vessel 4 is depressurized.

The heating element 20 extends through the wall of the glass ampoule here 10 , Likewise, the heating component 20 could also be provided on the outer surface of the glass ampoule. Alternatively or additionally, the heating component 20 could also be in an insert on the inside of the housing 56 (shown here dotted) be provided or in the connecting rods. The heating component 20 could be in the housing 56 again meandering or spiraling.

3 shows an embodiment of the opening element 6 in which the electrical line 61 the heating component 20 meandering on one side of the opening element 6 runs. The 4 shows a further embodiment in which the electrical line 61 undulating on one side of the opening element 6 runs. Preferably runs as it were on the opposite other sides of the in the 3 and 4 shown
opening elements 6 no electrical line 61 the heating component 20.

Within the scope of the technology disclosed here, the singular number (eg "opening element", "heating component", "safety valve") is used in a somewhat simplifying manner, as it were with its plural (ie "at least one opening element", "at least one heating component", at least one safety valve) should be or should be disclosed with and whose plural was not explicitly repeated solely for the sake of legibility.

In the context of the technology disclosed here, "external to the vehicle" means that the object designated as vehicle-external is not arranged in the motor vehicle or is not permanently connected to the motor vehicle during its intended use. Rather, it is a mobile component or component installed at a location other than the motor vehicle. However, an article external to the vehicle can be connected to the motor vehicle for the intended use, for example, for the duration of use.

LIST OF REFERENCE NUMBERS

1

security system

2

vehicle

3

external electrical energy source

4

pressure vessel

5

safety valve

51

inlet

52

blow-off line

53

poetry

54

piston

55

Counterpressure element

56

casing

57

connecting rod

6

opening element

61

electrical line

7

electrical power lines

8th

electrical connection

9

crash switch

10

glass ampoule

11

fluid space

12

delay means

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014000616 A1 [0007]
• DE 102011114725 A1 [0012]
• EP 1655533 B1 [0012]
• DE 102016215053 [0021]
• DE 102015223966 [0029, 0034]

Claims (10)

Thermally activatable opening element (6) for a thermally activatable safety valve (5) of a pressure vessel, wherein the opening element (6) on its outer surface or in a wall of the opening element (6) comprises at least one electrical line (61) connectable to an electrical circuit is, wherein the electrical line (61) does not surround the opening element (6) on all sides; and / or wherein the electrical line (61) is designed and arranged such that the electrical line (61) after the thermal activation of the opening element (6) does not at least partially prevent the functional deformation of the opening element (6). Opening element (6) after Claim 1 or 2 in that the electrical line (61) covers a maximum of 50% or a maximum of 30% or a maximum of 15% of the outer surface of the opening element (6). The orifice member (6) of any one of the preceding claims, wherein the outer surface of the orifice member (6) has a flank not interrupted by the conduit (61), the flank being at least 50% or at least 70% or at least 85% of the outer surface of the Opening element (6) makes. Opening element (6) according to one of the preceding claims, wherein the electrical line (61) runs meandering and / or undulating. A thermally activated safety valve (5) for a pressure vessel having at least one opening element (6) according to one of the preceding claims, comprising at least two electrical contacts which are adapted to contact the electrical line (61) from the opening element. A thermally activatable safety valve (5) for a pressure vessel having at least one heating component (20), wherein the heating component (20) is designed to heat at least one thermally activatable opening element (6), wherein the heating component (20) in a housing wall (561) and / or on an inner side of the housing wall (561) of the safety valve (5) is provided. A thermally activated safety valve (5) for a pressure vessel having at least one heating component (20), wherein the heating component (20) is designed to heat at least one thermally activatable opening element (6), wherein the heating component (20) comprises a bimetallic element (20) and / or a Formgedächniselement (20), wherein the bimetallic element (20) and / or Formgedächniselement (20) is formed such that it does not contact the opening element (6) in a first state, and that in a second state, the opening element (6 ) contacted. Opening element (6) according to one of the previous Claims 1 to 4 or safety valve according to one of the Claims 5 to 7 wherein the thermally activatable opening element (6) comprises a fusible link, a glass ampule (10) and / or a shape memory material. Safety system (1) for pressure relief of at least one pressure vessel (4) of a motor vehicle (2), comprising at least one opening element (6) according to one of the preceding Claims 1 to 4 or at least one safety valve according to one of Claims 5 to 7 , Security system (1) after Claim 9 , further comprising at least one electrical switch (9), which is designed to interrupt the power supply to the heating component (20) as long as there is no accident event and / or no vehicle fire and / or external third party signal.

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