JP2009138904A - Gas tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas tank enabling to release gas from a tank body without using a fusible plug valve, when an atmospheric temperature rises due to the occurrence of a fire, or the like. <P>SOLUTION: The tank body 2 of the gas tank 1 has therein a liner 10 to be filled with hydrogen gas, a reinforcing layer 12 covering the outer peripheral face of the liner 10, and an electric heat wire 14 provided between the liner 10 and the reinforcing layer 12. The melting point of the reinforcing layer 12 is higher than that of the liner 10, and so the liner 10 can be melted by energizing the electric heat wire 14 when detecting the fire of the tank body 2, to release the hydrogen gas to the outside. When using a plurality of heating elements 60a-60f such as nichrome coils instead of the electric heat wire 14, the positions of the heating elements 60a-60f to be energized can be changed depending on a position where a local fire F occurs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas tank for storing a gas such as hydrogen gas.

  2. Description of the Related Art Conventionally, a gas tank that stores compressed gas or the like is known that includes a plug valve that melts and opens a gas passage when the ambient temperature abnormally rises for some reason.

For example, in Patent Document 1, a heat transfer plate having a high thermal conductivity is disposed along the longitudinal direction of the outer periphery of the tank body. With this configuration, even if an abnormal increase in ambient temperature occurs at a location away from the plug valve, heat is transferred from the heat transfer plate to the plug valve to operate the plug valve. In addition, as disclosed in Patent Document 2, in a collision accident not involving a fire, there is also known one that actively heats a fusing valve to release gas to the outside.
JP 2005-315294 A JP 2007-155027 A

In Patent Document 2, the plug valve is operated due to the temperature rise in the event of a fire. However, when a local fire occurs at a location far away from the plug valve, the heat is slowly transmitted to the plug valve. For this reason, there is a possibility that the temperature of the tank body rises and the tank body bursts before the fusing valve operates.
On the other hand, according to patent document 1, the heat of a local fire can be transmitted to a plug valve by a heat transfer plate. However, if a local fire occurs in the vicinity of the plug valve, the gas released by the operation of the plug valve may greatly affect the flame of the fire.

  An object of this invention is to provide the gas tank which can discharge | release an internal gas, when an atmospheric temperature rises by generation | occurrence | production of a fire etc., without using a plug valve.

  In order to achieve the above object, a gas tank of the present invention has a tank body and a control device, and the tank body has a liner filled with gas inside and a reinforcement that has a higher melting point than the liner and covers the outer peripheral surface of the liner. And a heating element provided between the liner and the reinforcing layer, and when the temperature rise around the tank main body is detected, the heating element is energized by the control device.

  According to the present invention, when the heating element is energized, the liner reaches the melting point before the reinforcing layer, and the liner melts. Thereby, the melted portion of the liner serves as a gas release path, and the gas in the liner is released to the outside of the tank body. Therefore, even if the plug valve is not used, when the temperature around the tank body rises due to the occurrence of a fire or the like, the gas in the liner can be released to the outside, and the tank body burst can be suppressed.

  Preferably, the heating element is provided at intervals in a plurality of positions, and the control device may change the position of the heating element to be energized according to the position where the temperature rise is detected. By doing so, the position where the liner is melted can be changed according to the position where the temperature rise is detected. As a result, in the event of a local fire, it becomes possible to release gas at a position far from the location where the fire occurred, and safety can be further enhanced.

  More preferably, the position of the heating element that is energized by the control device may be a position on the opposite side of the temperature increase detection position with respect to the inside of the tank body.

  Preferably, the control device may energize two or more heating elements. For example, when a local fire occurs near the center of the tank body, the heat generators on both ends of the tank body are energized to promote the release of gas and suppress the influence of the released gas on the flame. be able to.

  Preferably, the heating element is in contact with the outer peripheral surface of the liner. By carrying out like this, since the heat | fever of a heat generating body can be directly transmitted by heat transfer to the outer peripheral surface of a liner, a liner can be fuse | melted in a short time.

  According to another preferable aspect of the present invention, the heating element may be a heating wire wound around the outer peripheral surface of the liner. By doing so, the heat of the heating element can be quickly transmitted to the entire periphery of the liner, and the melting of the liner can be promoted.

  Preferably, a plurality of temperature sensors are provided around the tank body, and the control device may receive a detection signal related to a temperature rise from the temperature sensor and energize the heating element. By doing so, since the temperature sensors are arranged in a multifaceted manner, it is possible to grasp the occurrence of a local fire and the location where it occurs. As a result, the occurrence of a local fire can be detected with certainty, and the release of gas corresponding to the location of the local fire can be made possible.

  Preferably, the control device is located outside the tank body.

  According to the gas tank of the present invention, the internal gas can be released and the burst of the tank main body can be suppressed when the ambient temperature rises without using a plug valve.

  Hereinafter, a gas tank according to an embodiment of the present invention will be described with reference to the accompanying drawings. This gas tank can be mounted in various systems, for example, can be used as a fuel gas tank in a fuel cell system. The fuel gas is a combustible high-pressure gas, such as compressed natural gas or hydrogen gas. In the following description, hydrogen gas will be described as an example of the gas stored in the gas tank.

<First Embodiment>
As shown in FIG. 1, the gas tank 1 includes a tank body 2 for storing hydrogen gas therein, and caps 3 and 3 provided at both ends of the tank body 2. Further, the gas tank 1 includes temperature sensors 4 a to 4 h and a control device 5 outside the tank body 2. The tank body 2 has a sealed cylindrical shape as a whole, and the inside thereof constitutes a storage space 6 for storing hydrogen gas at a pressure higher than normal pressure, for example, 35 MPa or 70 MPa.

  The tank body 2 has, for example, a two-layer structure, and the two layers are an inner resin liner 10 having gas barrier properties and a reinforcing layer 12 positioned on the outer peripheral side of the liner 10. Metal bases 3 and 3 are attached to the mouth portions 15 and 15 formed at both ends of the liner 10 by, for example, insert molding. A valve assembly is attached to the base 3 on the left side of FIG. 1, and hydrogen gas is supplied and discharged between the storage space 6 and an external gas system. A valve may also be attached to the base 3 on the right side of FIG. 1, but here it is configured as a closing plug.

  The liner 10 is obtained by integrating a pair of liner divided bodies 10a and 10b with each other butted together by laser welding or the like. The resin of the liner 10 is not particularly limited as long as it has a melting point lower than that of the resin of the reinforcing layer 12, and examples thereof include a polyethylene resin, a polypropylene resin, and other hard resins. Moreover, the liner 10 can also be comprised as a laminated body which consists of two or more layers combining these resin in two or more layers.

  The reinforcing layer 12 is a layer having higher gas permeability than the liner 10 and covers the outer peripheral surface of the liner 10. The reinforcing layer 12 is made of a fiber reinforced resin layer made of glass fiber or carbon fiber. Here, the reinforcing layer 12 is composed of a CFRP layer formed by reinforcing a matrix resin with carbon fibers, and a resin having a melting point higher than that of the resin of the liner 10, such as an epoxy resin or a modified epoxy resin, is used as the matrix resin. ing. Such a reinforcing layer 12 is formed by, for example, winding a carbon fiber impregnated with a thermosetting epoxy resin around the liner 10 by, for example, a filament winding method and curing the epoxy resin by heating.

  The heating wire 14 is made of a heating element such as a nichrome wire and is provided between the liner 10 and the reinforcing layer 12. Specifically, the heating wire 14 is spirally wound around the outer peripheral surface of the liner 10 and is in contact with the outer peripheral surface of the liner 10. Moreover, the heating wire 14 is wound around the region of the trunk portion having a certain diameter in the region in the longitudinal direction of the liner 10. However, in other embodiments, the heating wire 14 may be wound around both hemispherical wall ends of the liner 10. Further, the winding method is not limited to a spiral shape, and other methods such as a mesh shape may be employed.

  As shown in FIGS. 1 and 2, both ends of the heating wire 14 are connected to the lead wire 16. The lead wire 16 is connected to the battery 18 and the switch 20 through the outer surface of the liner 10 and led out of the tank body 2 from between the caps 3 and 3 and the reinforcing layer 12. When the switch 20 is turned on, electricity is supplied from the battery 18 to the heating wire 14 via the lead wire 16. In response to the supply of electricity, the heating wire 14 generates heat, and the outer surface of the liner 10 is heated by heat transfer.

  A plurality (eight) of temperature sensors 4 a to 4 h are provided around the tank body 2. Although the temperature sensors 4 a to 4 h can be provided in contact with the outer surface of the reinforcing layer 12, they are separated from the outer surface of the reinforcing layer 12 here. The arrangement of the temperature sensors 4 a to 4 h is not limited. Here, two temperature sensors 4a, 4d, 4e, and 4h are provided on both end sides (bases 3 and 3 side) of the tank body 2, respectively, and the remaining four pieces are provided with a predetermined interval therebetween. Temperature sensors 4b, 4c, 4f, and 4g are provided.

  The control device 5 is configured as a microcomputer having a CPU, a ROM, and a RAM inside. The control device 5 receives temperature detection signals from the temperature sensors 4a to 4h. When a fire occurs around the tank main body 2 and the temperature (atmosphere temperature) around the tank main body 2 suddenly rises, this is input to the control device 5 by the temperature sensors 4a to 4h. In response to this, the control device 5 turns on the switch 20.

FIG. 3 is a diagram illustrating an example of hydrogen gas release when a local fire occurs.
As shown in FIG. 3, for example, when a local fire F occurs in the vicinity of one of the caps 3, the occurrence of the local fire F (rapid temperature rise) is detected by the temperature sensor 4 d located closest to this. In response to the temperature detection signal from the temperature sensor 4d, the control device 5 turns on the switch 20. Then, the heating wire 14 is energized to generate heat, and the liner 10 and the reinforcing layer 12 are heated. As described above, since the resin of the reinforcing layer 12 has a higher melting point than the resin of the liner 10, the liner 10 reaches the melting point and melts before the reinforcing layer 12.

  3, for example, when the center of the body portion of the liner 10 is melted, hydrogen gas is released from the melted portion 30 to the outside of the liner 10. The released hydrogen gas flows to the outside so as to permeate through the reinforcing layer 12 in the vicinity of the melted portion 30 in the thickness direction, as indicated by an arrow 40 in FIG. Further, since the gap between the liner 10 and the reinforcing layer 12 is generated due to the softening of the liner 10, hydrogen gas is released to the outside through the gap as shown by an arrow 41 in FIG. That is, according to the present embodiment, a leak path for releasing the hydrogen gas in the storage space 6 to the outside is formed by melting the liner 10.

  As described above, according to the gas tank 1 of the present embodiment, hydrogen gas in the tank body 2 is released to the outside when the ambient temperature rises due to the occurrence of a fire or the like without using a plug valve as in the prior art. can do. As a result, an increase in the internal pressure of the tank body 2 can be suppressed, and a burst of the tank body 2 can be suppressed. In particular, in the conventional plug valve system, the arrangement of the plug valve is limited, so that it is difficult to cope with a local fire. However, according to the present embodiment, since the heating wire 14 is provided from one end side to the other end side of the liner 10, even if a local fire occurs at any location from the front end side to the rear end side, the heating wire 14 14, the liner 10 can be melted, and hydrogen gas can be released to the outside in response to a local fire.

Second Embodiment
Next, with reference to FIG. 4, the gas tank 50 according to the second embodiment will be described focusing on the differences. The difference from the first embodiment is that the mode of the heating element is changed and the position of the heating element to be energized is changed in order to change the position where the liner 10 is melted in accordance with the fire occurrence position. In addition, about the structure which is common in 1st Embodiment, the code | symbol same as 1st Embodiment is attached | subjected and the detailed description is abbreviate | omitted.

  The heating elements 60 a to 60 f of the present embodiment are made of, for example, a nichrome coil, and a plurality (here, six) are provided on the outer peripheral surface of the liner 10. Specifically, the heating elements 60 a to 60 f are provided in contact with the outer peripheral surface of the liner 10 and spaced apart from each other. Although the arrangement | positioning is not limited, the heat generating bodies 60a-60f are good to disperse | distribute and provide in each place of the longitudinal direction of the liner 10. FIG. Here, two heating elements 60 a, 60 c, 60 d, and 60 f are provided on both ends of the liner 10, and two heating elements 60 b and 60 e are provided at the joint portion of the liner 10. The number of heating elements may be increased or decreased as appropriate according to the length of the liner 10.

  The heating element 60a and the heating element 60d are opposed to each other with the inside of the tank body 2 interposed therebetween. Similarly, the heating element 60b and the heating element 60e face each other, and the heating element 60c and the heating element 60f face each other. The heating element 60a and the heating element 60f are arranged so as to be point-symmetric with respect to the center of the tank body 2. In this regard, the heating element 60c and the heating element 60d have the same arrangement relationship. The heating elements 60a to 60f are connected to lead wires (not shown) and are configured to be individually energized. With this configuration, the heating elements 60a to 60f can individually generate heat.

  The temperature sensors 70a to 70f are made of, for example, thermocouples, and are provided outside the reinforcing layer 12 at positions corresponding to the heating elements 60a to 60f. Here, the temperature sensors 70a to 70f are in contact with the outer peripheral surface of the reinforcing layer 12, but may of course be provided in a non-contact manner. The temperature sensors 70 a to 70 f are connected to the control device 5 and input the detection result of the atmospheric temperature to the control device 5. The control device 5 selects the heating elements 60a to 60f to be energized according to the positions of the temperature sensors 70a to 70f that have detected the local fire.

  For example, when a local fire F occurs in the vicinity of the temperature sensor 70d, and this is detected by the temperature sensor 70d, the control device 5 energizes only the heating element 60c located farthest from the temperature sensor 70d. To do. As a result, the portion of the liner 10 in the vicinity of the heating element 60c is actively heated and melted, and hydrogen gas is released from the melted portion to the outside of the liner 10.

  As described above, according to the gas tank 50 of the present embodiment, in addition to the operational effects exhibited by the gas tank 1 of the first embodiment, when the local fire F occurs, hydrogen gas can be released at the position farthest from the location of occurrence. it can. Thereby, it can fully suppress that the hydrogen gas after discharge | releases influences the local fire F, and can improve safety | security further.

  Here, when a local fire occurs, two or more heating elements may be energized depending on the location of the local fire. For example, when a local fire occurs near the center of the tank body 2 and this is detected by the temperature sensor 70b, the control device 5 may energize the heating elements 60d and 60f on both ends of the tank body 2. . By doing so, the release of hydrogen gas can be promoted at a position away from the local fire.

  In addition, the control apparatus 5 is good to have memorize | stored the map in ROM about the correspondence of the location and the energization location of a local fire. In the present embodiment, when the temperature sensor 70a detects a local fire, the heating element 60f is energized. When the temperature sensor 70c detects a local fire, the heating element 60d is energized, and the temperature sensor 70d detects a local fire. When the temperature sensor 70e detects a local fire, the heating element 60a and 60c are energized. When the temperature sensor 70f detects a local fire, the heating element 60a is energized.

It is a sectional side view showing the gas tank concerning a 1st embodiment. It is a side view which shows a liner and a heat generating body except the reinforcement layer of the gas tank which concerns on 1st Embodiment. It is a figure which shows an example of gas discharge when a local fire generate | occur | produces around the gas tank which concerns on 1st Embodiment. It is a side view which shows the gas tank which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Gas tank, 2 ... Tank main body, 4a-4h ... Temperature sensor, 5 ... Control apparatus, 10 ... Liner, 12 ... Reinforcement layer, 14 ... Heating wire (heating element), 50 ... Gas tank, 60a-60f ... Heating element, 70a-70f ... temperature sensor, F ... local fire

Claims (8)

A tank body having a liner filled with gas, a reinforcing layer having a melting point higher than that of the liner and covering the outer peripheral surface of the liner, and a heating element provided between the liner and the reinforcing layer When,
A gas tank comprising: a control device that energizes the heating element when a temperature rise around the tank body is detected. The heating element is provided at a plurality of positions at intervals,
The gas tank according to claim 1, wherein the control device changes a position of a heating element to be energized according to a position where the temperature rise is detected.   The gas tank according to claim 2, wherein a position of the heating element energized by the control device is a position on a side opposite to the temperature rise detection position across the tank body.   The gas tank according to claim 2 or 3, wherein the control device energizes two or more heating elements.   The gas tank according to any one of claims 1 to 4, wherein the heating element is in contact with an outer peripheral surface of the liner.   The gas tank according to any one of claims 1 to 4, wherein the heating element is a heating wire wound around an outer peripheral surface of the liner. A plurality of temperature sensors are provided around the tank body,
The gas tank according to claim 1, wherein the control device receives a detection signal related to the temperature rise from the temperature sensor and energizes the heating element.   The gas tank according to claim 1, wherein the control device is located outside the tank main body.

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