JP2011194952A - Tank structure - Google Patents

Abstract

There is provided a tank structure in which the pressure of a fluid filled therein is hardly increased.
A hydrogen tank 10 having a tank body 20 filled with hydrogen and a relief valve 30 provided on the left end side of the tank body 20 and mounted on a fuel cell vehicle 100, and a hydrogen tank And a thermal foam heat insulating layer 51 which is provided on an inner surface 40a (surface on the hydrogen tank 10 side) of the surrounding body 40 and foams when the temperature rises to form a heat insulating layer 52. The hydrogen tank structure 1 is characterized in that a gap S is formed between the previous heat-foamable heat insulating layer 51 and the hydrogen tank 10.
[Selection] Figure 2

Description

  The present invention relates to a tank structure.

In recent years, a fuel cell vehicle equipped with a fuel cell and running on the electric power has been developed. In such a fuel cell vehicle, in addition to the fuel cell, a hydrogen tank (gas tank) that supplies hydrogen (fuel gas) to the fuel cell, a compressor that supplies air, and a refrigerant pump that circulates the refrigerant through the fuel cell Also installed are a PDU (Power Drive Unit) that converts DC power into AC power, a motor for traveling, a drive train that transmits the driving force of the motor to the drive wheels, and the like.
Here, external devices such as a compressor, a refrigerant pump, a PDU, and a drive train generate heat as they operate.

  The hydrogen tank is filled with hydrogen at a high pressure, and a plurality of pressure reducing valves (regulators) are provided in a hydrogen supply channel through which hydrogen supplied from the hydrogen tank to the fuel cell flows. Then, the hydrogen target pressure is set according to the power generation requirement calculated based on the accelerator opening, etc., and the pressure reducing valve is controlled so that the secondary pressure of the pressure reducing valve becomes the calculated target pressure. is doing.

  Although it is different from hydrogen (gas) filled in such a hydrogen tank, fuel vapor is generated due to heat input in the fuel tank in which liquid fuel (gasoline) is stored, and the fuel consumption is not affected. Therefore, a fuel tank structure incorporating a heat dissipation structure has been proposed (see Patent Document 1).

JP 2001-130271 A

However, when a fuel cell vehicle runs under a high-temperature environment in midsummer or when heat is input to the hydrogen tank due to heat generated by an external device such as a compressor as described above, the hydrogen expands, The pressure of will rise.
Thus, when the hydrogen pressure in the hydrogen tank increases, the primary pressure of the pressure reducing valve also increases, and there is a possibility that hydrogen is supplied to the fuel cell at a pressure higher than the target pressure. There is. When hydrogen is supplied at such a high pressure, not only hydrogen is not consumed well in the fuel cell, but also the fuel cell may be deteriorated.

  Here, a method of mounting a wide-range pressure reducing valve with a wide control range is also conceivable, but such a wide-range pressure reducing valve is very expensive, and thus requires a cost.

  Therefore, an object of the present invention is to provide a tank structure in which the pressure of the fluid filled therein is unlikely to increase.

  As means for solving the above problems, the present invention includes a tank body filled with a fluid (hydrogen in the embodiment described later), and a relief valve provided on at least one end side of the tank body. A tank mounted on the vehicle, an enclosure surrounding the tank, and a thermally foamable heat insulating layer provided on the tank side surface of the enclosure and foaming when the temperature rises to form a heat insulating layer. The tank structure is characterized in that a gap is formed between the thermally foamable heat insulating layer before foaming and the tank.

According to such a tank structure, a gap is formed between the heat-foamable heat-insulating layer before foaming and the tank, and no heat-insulating layer is formed on the outer surface of the tank body. The heat resistance of the wall portion of the fluid does not increase, and the fluid and the tank exchange heat well with the outside air existing in the gap.
As a result, even when the temperature of the fluid and the tank increases / decreases as the fluid is filled / released, the fluid and the tank exchange heat with the outside air in the gap, that is, dissipate / absorb heat. Is less likely to rise / fall and is more easily maintained. Therefore, the pressure of the fluid filled in the tank is difficult to increase.

  Further, since the heat insulating layer is not formed on the outer surface of the tank, the wall portion of the tank body becomes thinner and the tank chamber (volume) becomes larger than the tank having the heat insulating layer formed on the surface side.

  In addition, a heat-foaming heat-insulating layer that foams and forms a heat-insulating layer when the temperature rises is provided on the tank-side surface of the enclosure, so that the heat of the external equipment arranged around the tank structure is thermally foamable. When conducted to the heat insulation layer, the heat-foamable heat insulation layer rises in temperature and foams, and a heat insulation layer is formed. If it does so, the heat from an external apparatus will be insulated by the heat insulation layer, and the temperature of the fluid with which the tank was filled will not rise easily, therefore, it will become difficult to raise the pressure of fluid.

In this way, the pressure in the tank body is unlikely to rise, so the regulator that controls the pressure of the fluid from the tank does not need to be in a wide range, and includes a system that includes the regulator and receives the supply of fluid (see below) In the embodiment, the fuel cell system) can be simply and inexpensively configured.
In addition, since the primary pressure of the regulator or the like is unlikely to rise, the pressure of the fluid can be appropriately controlled by the regulator and then supplied to a fluid demanding device (a fuel cell in the embodiment described later) that requires the fluid. .

  In the tank structure, the heat-insulating layer formed by foaming the heat-foamable heat-insulating layer fills the gap.

  According to such a tank structure, in a portion (region) where heat from the external device is likely to enter, that is, in a location where heat from the external device is easily conducted, the heat-foamable heat insulating layer is foamed by this heat and the heat insulating layer is formed. Formed, and the heat insulating layer closes the gap and adheres to the tank. Thereby, the heat from the external device is insulated by the heat insulating layer, and the temperature and pressure of the fluid filled in the tank are unlikely to rise.

  On the other hand, in other places (regions), that is, places where heat from the external device is difficult to conduct, the heat-foamable heat insulating layer does not foam, and a gap remains formed. As a result, while the tank is in close contact with the heat insulating layer on the external device side, the fluid in the tank body can exchange heat with the outside air remaining on the side opposite to the external device. Therefore, even if the fluid is filled / discharged, the heat of the outside of the gap is radiated / absorbed, so that the temperature of the fluid and the tank is hardly increased / decreased.

  The present invention also includes a tank body filled with fluid and a relief valve provided on at least one end side of the tank body, a tank mounted on a vehicle, and an enclosure surrounding the tank And a thermally foamable heat insulating layer that is provided on a surface opposite to the tank of the enclosure and foams when the temperature rises to form a heat insulation layer, and a gap is provided between the enclosure and the tank. Is a tank structure characterized by being formed.

  According to such a tank structure, the fluid and the tank exchange heat with the outside air in the gap, that is, dissipate / absorb heat, so that the temperature of the fluid and the tank is not easily increased / decreased and is easily maintained. Therefore, the pressure of the fluid filled in the tank is difficult to increase.

Further, since the heat insulating layer is not formed on the outer surface of the tank, the wall portion of the tank main body becomes thin and the tank chamber (volume) becomes large.
In addition, a heat-foaming heat insulation layer that foams and forms a heat insulation layer when the temperature rises is provided on the surface of the enclosure opposite to the tank, so that the heat of the external equipment arranged around the tank structure is heated. When conducting to the foamable heat insulating layer, the heat foamable heat insulating layer rises in temperature and foams, forming a heat insulating layer. If it does so, the heat from an external apparatus will be insulated by the heat insulation layer, and the temperature of the fluid with which the tank main body was filled will not rise easily, therefore, it will become difficult to raise the pressure of the fluid.

  Further, in the tank structure, the relief valve is configured to open when the temperature rises, and the heat-foamable heat insulating layer is provided on the relief valve so that heat from the outside is conducted to the relief valve. It is characterized by not being formed around.

  According to such a tank structure, since the heat-foaming heat insulating layer is not formed around the relief valve, heat from the outside is not insulated by the heat-foaming heat insulating layer (heat insulating layer). Conduct quickly to the relief valve. Thereby, the opening timing of the relief valve is not delayed.

  Further, in the tank structure, the enclosure is made of metal.

  According to such a tank structure, since the enclosure is made of metal, the enclosure has a high thermal conductivity. Thereby, the heat from the outside quickly conducts the inside of the enclosure. Therefore, heat from the outside can be quickly conducted to the heat-foamable heat insulating layer.

  Moreover, the said tank structure WHEREIN: The said heat-foamable heat insulation layer is formed corresponding to the position of an external heat source, It is characterized by the above-mentioned.

According to such a tank structure, the heat-foamable heat insulating layer is formed corresponding to the position of the external heat source, that is, corresponding to the region where the heat of the external heat source may be input. Therefore, a heat-foamable heat insulation layer becomes small and is reduced in weight. Thereby, it becomes easy to mount the tank structure on the vehicle.
Note that not only the heat-foamable heat insulating layer but also the surrounding body corresponds to the position of the external heat source, that is, the area surrounding the tank corresponding to the area where the heat of the external heat source may be input. It is preferable to be configured in a similar manner.

  Further, in the tank structure, the enclosure body includes the plurality of panels that constitute the vehicle and are arranged around the tank body.

  According to such a tank structure, an enclosure can be constituted by a plurality of panels arranged around the tank body while constituting the vehicle.

  In the tank structure, the enclosure includes a cover that surrounds the tank.

According to such a tank structure, a surrounding body can be comprised with the cover which surrounds a tank.
If the tank and the cover (enclosure) are configured integrally, the tank structure can be easily handled (assembled, replaced, etc.).

  Further, the tank structure includes a plurality of tanks, and the cover collectively surrounds the plurality of tanks.

  According to such a tank structure, since the cover collectively surrounds the plurality of tanks, the plurality of tanks are grouped together by, for example, a single unit.

  ADVANTAGE OF THE INVENTION According to this invention, the tank structure which cannot raise the pressure of the fluid with which an inside is filled can be provided.

1 is a side view of a fuel cell vehicle according to a first embodiment. It is a sectional side view of the hydrogen tank structure concerning a 1st embodiment, and shows normal time (before foaming). It is a sectional side view of the hydrogen tank structure concerning a 1st embodiment, and shows the time of foaming. It is a sectional side view of the relief valve which concerns on 1st Embodiment, and shows the valve closing state (normal time) of a relief valve. It is a sectional side view of the relief valve concerning a 1st embodiment, and shows the valve opening state (at the time of high temperature) of a relief valve. It is a ring sectional view (X1-X1 line sectional view of Drawing 2) of a hydrogen tank structure concerning a 1st embodiment, and shows normal time (before foaming). It is a ring sectional view (X2-X2 sectional view taken on the line of Drawing 3) of the hydrogen tank structure concerning a 1st embodiment, and shows the time of foaming. It is a sectional side view of the hydrogen tank structure concerning a 2nd embodiment, and shows normal time (before foaming). It is a sectional side view of the hydrogen tank structure concerning a 3rd embodiment, and shows normal time (before foaming). It is a sectional side view of the hydrogen tank structure concerning a 3rd embodiment, and shows the time of foaming. It is a ring sectional view (X3-X3 line sectional view of Drawing 9) of the hydrogen tank structure concerning a 3rd embodiment, and shows normal time (before foaming). It is a ring sectional view (X4-X4 sectional view taken on the line of Drawing 10) of the hydrogen tank structure concerning a 3rd embodiment, and shows the time of foaming. (A), (b) is a top view of the hydrogen tank structure which concerns on a modification. It is a cross-sectional view of a hydrogen tank structure according to a modified example.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

≪Configuration of fuel cell vehicle≫
A fuel cell vehicle 100 (vehicle, moving body) according to the present embodiment includes a fuel cell stack 110 (fuel cell) and a hydrogen tank structure 1 (tank structure, see FIG. 2) including a hydrogen tank 10 (tank). , A pressure reducing valve 121, a compressor 131, and a diluter 132.
Note that specific types of the fuel cell vehicle 100 include, for example, an automobile, a tricycle, a motorcycle, a unicycle, a train, and the like.

  The fuel cell stack 110 is a polymer electrolyte fuel cell (PEFC), and a plurality of single cells formed by sandwiching MEA (Membrane Electrode Assembly) with separators (not shown) are stacked. Has been configured. The MEA includes an electrolyte membrane (solid polymer membrane) and a cathode and an anode that sandwich the membrane. Each separator is formed with an anode flow path 111 (fuel gas flow path) and a cathode flow path 112 (oxidant gas flow path) formed of grooves and through holes.

  The hydrogen tank 10 is a tank filled with hydrogen (fuel gas, fluid) supplied to the anode channel 111. The hydrogen tank 10 is connected to the inlet of the anode flow path 111 through a pipe 121a, a pressure reducing valve 121 (regulator), and a pipe 121b, and the hydrogen in the hydrogen tank 10 passes through the pipe 121a and the anode. It is supplied to the flow path 111.

  That is, the pipe 121a and the pipe 121b constitute a hydrogen supply channel (fuel gas supply channel), and a pressure reducing valve 121 is provided in the hydrogen supply channel. The hydrogen supply flow path is also provided with a normally closed shut-off valve that is controlled to open and close by an ECU (Electronic Control Unit) (not shown). Note that a plurality of pressure reducing valves and shut-off valves are provided in the downstream direction, such as a primary shut-off valve, a primary pressure-reducing valve, a secondary shut-off valve, and a secondary pressure-reducing valve.

  For example, as described in Japanese Patent Application Laid-Open No. 2004-185831 filed by the applicant of the present application, the pressure reducing valve 121 is configured such that the hydrogen pressure in the anode channel 111 and the cathode channel are based on the pilot pressure input from the pipe 121c. It is a primary pressure reducing valve that lowers the hydrogen pressure so that the air pressure at 112 is balanced. The upstream end of the pipe 121c is connected to a pipe 131a through which air flowing toward the cathode channel 112 flows.

  The outlet of the anode channel 111 is connected to the diluter 132 via a pipe 121d. Then, the anode off gas discharged from the anode flow path 111 is discharged to the diluter 132 through the pipe 121d.

  The compressor 131 is connected to the inlet of the cathode flow path 112 via the pipe 131a. When the compressor 131 is operated in accordance with a command from the ECU, the compressor 131 takes in and compresses air containing oxygen, and pumps it to the cathode flow path 112. It has become. The compressor 131 is powered by a fuel cell stack 110 or a high voltage battery (not shown).

The compressor 131 is a heat source that generates operating heat when it is operated. In the present embodiment, a case where a part of the operating heat is conducted to the hydrogen tank 10 is illustrated. That is, the compressor 131 is an external device that generates heat when viewed from the hydrogen tank 10. In this example, an external device serving as a heat source is disposed above the hydrogen tank structure 1, and heat from the external device is input from above the hydrogen tank structure 1 (see FIGS. 3 and 7). ).
In addition to the compressor 131, the external devices that generate heat in this manner include various types such as an ECU, a refrigerant pump, a high-pressure battery, a PDU, and a drive train.

The outlet of the cathode channel 112 is connected to the diluter 132 via a pipe 132a. The cathode off-gas discharged from the cathode channel 112 is discharged to the diluter 132 through the pipe 132a.
The pipe 132a is provided with a normally open back pressure valve (not shown) whose opening degree is controlled by the ECU. That is, the ECU calculates the power generation requirement amount, the target air pressure, and the target hydrogen pressure based on the accelerator opening, and controls the opening of the back pressure valve and the rotation speed of the compressor 131 so as to be the target air pressure. It has become.

  The diluter 132 dilutes the hydrogen in the anode off-gas from the pipe 121d with the cathode off-gas from the pipe 132a to reduce the hydrogen concentration, and has a dilution space inside. The diluted gas is discharged out of the vehicle through the pipe 132b.

≪Configuration of hydrogen tank structure≫
Next, a specific configuration of the hydrogen tank structure 1 will be described with reference to FIGS.
As shown in FIGS. 2 to 7, the hydrogen tank structure 1 is provided on a hydrogen tank 10, an enclosure 40 that surrounds the hydrogen tank 10, and an inner surface 40 a (surface on the hydrogen tank 10 side) of the enclosure 40. And a heat-foamable heat-insulating layer 51.

<Hydrogen tank>
The hydrogen tank 10 has a substantially cylindrical outer shape, is mounted horizontally with respect to the fuel cell vehicle 100, and its axial direction is along the vehicle width direction (left-right direction).
The hydrogen tank 10 includes a tank body 20 and a relief valve 30 provided on the left end side (one end side) of the tank body 20.
The hydrogen tank 10 is fixed to a front cross member 41C and a rear cross member 41D described later via a metal belt (not shown).
In addition, the relief valve 30 may be provided on the left end side and the right end side (both ends) of the tank body 20.

<Tank body>
The tank body 20 has a substantially columnar outer shape, and includes a liner 21 and a reinforcing layer 22 that covers the outer peripheral surface of the liner 21 and reinforces the liner 21 as shown in FIGS. It has a heavy structure.
However, the tank body 20 is not limited to a double structure, and may be a single structure composed of only a synthetic resin or metal liner, for example.

  The liner 21 is formed of an aluminum alloy or the like, and is a component that becomes a skeleton of the tank body 20, and has an outer shape that is substantially cylindrical. The inside of the liner 21 is a tank chamber 21a in which hydrogen is filled and stored. Further, a neck portion 21 b into which the relief valve 30 is screwed is formed on the left end side of the liner 21.

  The reinforcing layer 22 is made of, for example, CFRP (Carbon Fiber Reinforced Plastic: carbon) obtained by winding a long carbon fiber impregnated with a thermosetting resin around the liner 21 and then curing the thermosetting resin. Fiber reinforced plastic) layer.

<Relief valve>
The relief valve 30 is a normally closed valve, and when opened, discharges hydrogen in the tank body 20 to the outside, and reduces the pressure in the tank body 20. Further, since the relief valve 30 is disposed on the left end side in the vehicle width direction, even if the fuel cell vehicle 100 is compressed in the front-rear direction due to a collision from the front and rear, the relief valve 30 is not compressed and is protected. It is like that.

The relief valve 30 includes a valve body 31 screwed to the neck portion 21b, a valve body 32 (piston) that moves forward and backward in the valve body 31, and a compression coil that urges the valve body 32 in the valve closing direction (right direction). A spring 33, a cap 34 that keeps the compression coil spring 33 loaded in the valve body 31, and a metal body 35 interposed between the compression coil spring 33 and the cap 34 are provided.
The valve body 31 is normally opened and closed by an ECU (Electronic Control Unit), and is opened when hydrogen is supplied to the fuel cell stack 110 (in-tank solenoid valve). And a normally-closed check valve (both not shown) that opens during hydrogen charging.

  The valve body 31 has a valve seat 31a on which the valve element 32 is seated during normal operation (when the valve is closed), and a first port 31b and a second port 31c, which serve as hydrogen discharge passages when the valve is opened, are provided therein. Is formed.

  The valve body 32 includes a large-diameter portion 32a on the left side (one end side) and a small-diameter portion 32b extending from the large-diameter portion 32a to the right side (the other end side).

  The small-diameter portion 32b is seated on the valve seat 31a of the valve body 31 at the normal time (when the valve is closed), and shuts off the first port 31b and the second port 31c. Thus, when the 1st port 31b and the 2nd port 31c are interrupted | blocked, the relief valve 30 will be in a valve closing state (refer FIG. 4). In addition, the normal time is a state in which the inside of the tank body 20 is below the rated pressure and the metal body 35 is not melted.

  On the other hand, for example, when the inside of the tank body 20 becomes higher than the rated pressure and the valve body 32 is separated from the valve seat 31a, the first port 31b and the second port 31c communicate with each other. When the first port 31b and the second port 31c communicate with each other in this way, the relief valve 30 is opened (see FIG. 5).

  The metal body 35 is a part for forming a space between the cap 34 and the compression coil spring 33 by melting when the temperature rises and flowing out from the outflow path 34 a formed in the cap 34. . When the space is formed in this way, the valve body 32 slides to the left by the hydrogen pressure in the tank body 20, that is, the small diameter portion 32b is separated from the valve seat 31a, and at the same time, the first port 31b and the second port The port 31c communicates, and hydrogen in the tank body 20 is discharged to the outside through the first port 31b and the second port 31c, so that the pressure decreases.

<Go body>
The surrounding body 40 is a structure that surrounds the hydrogen tank 10, and surrounds the entire hydrogen tank 10 while opening a predetermined gap S between the surrounding body 40 and the hydrogen tank 10.
In addition, the gap S between the enclosure 40 and the hydrogen tank 10 takes into account the thickness before and after foaming of the thermally foamable heat insulating layer 51 formed on the inner surface 40a of the enclosure 40 (thickness increase due to foaming). (1) A gap S is formed between the heat-foamable heat insulating layer 51 and the hydrogen tank 10 at normal time (before foaming), and (2) the heat-insulating layer 52 formed by foaming the heat-foamable heat-insulating layer 51 is provided. Designed to fill the gap S.

  In the first embodiment, such a surrounding body 40 is curved while leaving a predetermined interval (gap S) from the upper outer peripheral surface of the hydrogen tank 10 which is a part of the cross-shaped subframe 41 and the floor panel 42. A curved portion 42a, an under panel 43 covering the lower part of the hydrogen tank 10, a front panel 44, a rear panel 45, a left panel 46, and a right panel 47 are provided. It is a part (panel) constituting the vehicle body of the car 100.

The subframe 41 includes a left frame 41A and a right frame 41B extending in the front-rear direction, and a front cross member 41C and a rear cross member 41D extending in the vehicle width direction.
And the enclosure 40 is comprised by these frames and panels being joined (welding), fastening with a volt | bolt, etc.

Further, these frames and panels are made of metal parts having high thermal conductivity. That is, the enclosure 40 is made of metal and has a high thermal conductivity.
Thereby, the heat from the external device (compressor 131 or the like) is quickly conducted in the enclosure 40 and is conducted quickly to the heat-foamable heat insulating layer 51 formed on the inner surface 40a of the enclosure 40. Therefore, the heat-foamable heat insulating layer 51 is quickly heated and foamed, so that the heat insulating layer 52 is quickly formed.

<Thermal foaming heat insulation layer>
The heat-foamable heat insulating layer 51 is a layer containing a foaming agent such as ammonium polyphosphate as a component. The heat-heatable heat-insulating layer 51 is heated from the outside and rises in temperature. This is a layer that forms a heat insulating layer 52 (foamed layer) in which bubbles are formed (see FIGS. 3 and 7). And when the heat insulation layer 52 is formed in this way, the heat from the outside is insulated by the heat insulation layer 52. Thereby, the temperature of the hydrogen tank 10 (hydrogen) is unlikely to rise, and the pressure of the hydrogen tank 10 is unlikely to rise.

  The foaming temperature at which the heat-foamable heat insulating layer 51 is foamed is appropriately changed by changing the foaming agent that generates gas in accordance with the temperature of the external device such as the compressor 131.

  As described above, the gap S is formed between the heat-foamable heat insulating layer 51 before foaming and the hydrogen tank 10, and air exists in the gap S. That is, the hydrogen tank 10 is configured to exchange heat with the air in the gap S.

As a result, even if the temperature of the hydrogen tank 10 is about to rise due to adiabatic compression of hydrogen during hydrogen filling, the hydrogen tank 10 radiates heat to the air in the gap S, and the amount of temperature rise is reduced.
On the other hand, even if the temperature of the hydrogen tank 10 is about to decrease due to the adiabatic expansion of hydrogen when hydrogen is released, the hydrogen tank 10 absorbs the heat of the air in the gap S, and the amount of temperature decrease is small.

  That is, since the hydrogen tank 10 exchanges heat well with the air in the gap S, the temperature of the hydrogen tank 10 is less likely to fluctuate due to the filling / releasing of hydrogen. That is, the temperature of the hydrogen tank 10 does not drop greatly.

However, as shown in FIGS. 2 and 3, the heat-foamable heat insulating layer 51 is not formed on a portion of the inner surface 40 a of the enclosure 40 that faces the relief valve 30. That is, the heat-foamable heat insulating layer 51 is not formed around the relief valve 30.
Thereby, the heat insulation layer 52 is not formed around the relief valve 30. Therefore, the heat from the outside is not insulated by the heat insulation layer 52, but is conducted well to the relief valve 30, and the temperature rises well. Therefore, the opening of the relief valve 30 is not delayed.

  The thickness of the heat insulating layer 52 formed by foaming the heat-foamable heat insulating layer 51 is configured such that the heat insulating layer 52 fills the gap S, that is, the thickness of the heat insulating layer 52 is greater than or equal to the gap S. . The thickness of the heat insulating layer 52 is easily controlled by changing the amount and type of the foaming agent or changing the thickness of the heat-foamable heat insulating layer 51.

  In addition, such a heat-foamable heat insulation layer 51 is formed by apply | coating the well-known heat-foamable heat insulation coating material which uses foaming agents, such as an ammonium polyphosphate, as a component to the inner surface 40a of the enclosure 40, for example. And the thickness of the heat-foamable heat insulation layer 51 is adjusted by changing the application amount and the application frequency.

  Further, the heat-foamable heat insulating layer 51 is not limited to a single layer structure, and may have a multilayer structure including a plurality of foaming agents having different foaming temperatures. Further, an undercoat layer may be interposed between the heat-foamable heat insulating layer 51 and the surrounding body 40, or a topcoat layer may be formed on the heat-foamable heat insulating layer 51.

≪Function and effect of hydrogen tank structure≫
According to such a hydrogen tank structure 1, the following effects are obtained.
Since the gap S is formed between the hydrogen tank 10 and the heat-foamable heat insulating layer 51 at normal time (before foaming), even if the temperature of the hydrogen tank 10 is about to rise / fall due to hydrogen filling / releasing. The hydrogen and hydrogen tank 10 exchanges heat well with the air in the gap S. Thereby, the temperature of hydrogen and the hydrogen tank 10 becomes difficult to rise / fall. That is, the temperature of the hydrogen and the hydrogen tank 10 does not greatly decrease.

Here, the external device serving as the heat source is disposed above the hydrogen tank structure 1 as described above.
Further, when heat from an external device enters the hydrogen tank structure 1 from above, the heat is quickly conducted through the metal enclosure 40 having high thermal conductivity, and promptly reaches the heat-foamable heat insulating layer 51. Conduct. If it does so, the temperature of the substantially upper half of the heat-foamable heat insulation layer 51 will rise rapidly, and if it reaches the foaming temperature corresponding to the kind of foaming agent, it will foam, the heat insulation layer 52 will be formed, and the heat insulation layer 52 will fill the clearance gap S. (See FIGS. 3 and 7). That is, the surface of the heat insulating layer 52 is in close contact with the outer peripheral surface of the hydrogen tank 10.

  Thus, since the heat insulation layer 52 is formed quickly, the heat from the external device is insulated by the heat insulation layer 52. Thereby, the heat from the external device is not conducted to the hydrogen tank 10, the temperature of the hydrogen and the hydrogen tank 10 is unlikely to rise, and the hydrogen pressure is also unlikely to rise.

  On the other hand, since heat from an external device is difficult to conduct in the lower half of the hydrogen tank structure 1, the lower half of the thermally foamable heat insulating layer 51 does not foam, and the heat insulating layer 52 does not fill the gap S. That is, the gap S remains as it is in the lower half of the hydrogen tank structure 1, and the hydrogen and the hydrogen tank 10 exchange heat with the air in the gap S even after the upper part of the hydrogen tank 10 and the heat insulating layer 52 are in close contact with each other. It is possible. As a result, even if hydrogen is charged / released, the heat in the gap S is dissipated / heat absorbed, so that the hydrogen pressure is unlikely to rise.

  In addition, when an external device that generates heat is disposed on the left side of the hydrogen tank 10 and the heat of the external device enters the left side of the hydrogen tank 10, it surrounds the left relief valve 30, that is, faces the relief valve 30. Since the thermally foamable heat insulating layer 51 does not exist on the inner surface 40a of the surrounding body 40, the heat insulating layer 52 is not formed.

  Thereby, the heat input to the left side portion of the enclosure 40 is conducted well to the relief valve 30 without being insulated by the heat insulation layer 52 after being conducted through the enclosure 40. Therefore, the temperature of the relief valve 30 rises quickly, and when the metal body 35 melts, the relief valve 30 opens (see FIG. 5). Then, hydrogen in the tank chamber 21a is released to the outside, and the pressure in the hydrogen tank 10 decreases.

In this way, the hydrogen pressure in the hydrogen tank 10 is unlikely to increase, so the primary pressure of the pressure reducing valve 121 shown in FIG. 1 does not increase under the influence of the operating heat of the compressor 131 or the like.
Therefore, it is not necessary to provide the wide-range pressure reducing valve 121 having a wide control range, and the fuel cell vehicle 100 can be manufactured at low cost. The pressure reducing valve 121 can reduce and adjust hydrogen to an appropriate pressure, hydrogen is supplied to the anode flow path 111 at an appropriate pressure, and deterioration of the fuel cell stack 110 due to hydrogen supply at an unexpectedly high pressure. Is also prevented. In addition, the passage of hydrogen through the fuel cell stack 110 is reduced, and the fuel consumption of the fuel cell stack 110, that is, the consumption efficiency of hydrogen is increased.

<< First Embodiment-Modification >>
The first embodiment of the present invention has been described above, but the present invention is not limited to this, and can be appropriately combined with the embodiments described later, or can be modified as follows.

  In the first embodiment described above, the configuration in which the heat-foamable heat insulating layer 51 is not formed around the relief valve 30, that is, the portion facing the relief valve 30 in the inner surface 40 a of the enclosure 40 is exemplified. A configuration in which the heat-foamable heat insulating layer 51 is formed around the valve 30, that is, the entire inner surface 40 a may also be used.

  In the first embodiment described above, the configuration in which the hydrogen tank 10 is mounted on the moving body is exemplified, but other than this, for example, a stationary hydrogen tank 10 may be used.

  In the first embodiment described above, the configuration in which the tank is a hydrogen tank that supplies hydrogen to the fuel cell stack 110 is exemplified. However, for example, a natural gas tank that supplies natural gas to a CNG (Compressed Natural Gas) engine may be used. .

In the first embodiment described above, the configuration in which the tank body 20 is filled with flammable hydrogen is illustrated, but the configuration is not limited to the flammable gas, and for example, a configuration in which oxygen, nitrogen, argon, or the like is filled may be used. .
The filling target is not limited to gas, and may be a tank in which liquid (fluid) such as liquid hydrogen or LPG (Liquefied Petroleum Gas) is filled and stored.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to FIG. Only parts different from the first embodiment will be described.
The hydrogen tank structure 2 according to the second embodiment further includes a thermally foamable heat insulating layer 53 provided on the outer surface 40b of the enclosure 40 (the surface opposite to the hydrogen tank 10). Thereby, when the heat of the external device is input, a heat insulating layer is also formed on the outer surface 40b side of the enclosure 40.
In addition, the heat-foamable heat insulation layer 53 is not formed around the relief valve 30 as in the first embodiment.

«Third embodiment»
Next, a third embodiment of the present invention will be described with reference to FIGS. Only parts different from the first embodiment will be described.
The hydrogen tank structure 3 according to the third embodiment includes a tank cover 61 (enclosure) surrounding the hydrogen tank 10 and a thermal foaming property provided on the entire inner surface 61a (surface on the hydrogen tank 10 side) of the tank cover 61. And a heat insulating layer 71.
The relative position between the tank cover 61 and the hydrogen tank 10 is held by, for example, a spacer (not shown).
In addition to this, the outer surface 61b of the tank cover 61 (the surface opposite to the hydrogen tank 10) may be provided with the heat-foaming heat insulating layer 71, or the heat-foaming heat insulating layer 71 may be provided only on the outer surface 61b. It may be configured.

The tank cover 61 has a substantially bottomed cylindrical body that is open on the relief valve 30 side and has a bottom on the right side. The tank cover 61 surrounds the portion other than the relief valve 30 of the hydrogen tank 10, that is, the tank body 20 of the hydrogen tank 10. Thereby, heat from the outside is quickly conducted to the relief valve 30.
In addition, the tank cover 61 including the relief valve 30 may surround the entire hydrogen tank 10.

  The tank cover 61 is made of a metal having a high thermal conductivity, like the enclosure 40 according to the first embodiment. Thereby, the heat from the outside is conducted well in the tank cover 61 and quickly conducted to the heat-foamable heat insulating layer 71.

  A gap S is formed between the heat-foamable heat insulating layer 71 at normal time (before foaming) and the tank body 20 as in the first embodiment (see FIGS. 9 and 11). As a result, even if hydrogen is charged / released, the hydrogen and hydrogen tank 10 is satisfactorily exchanged with the air in the gap S, and the temperature of the hydrogen and hydrogen tank 10 is less likely to change. Therefore, the pressure of the hydrogen tank 10 is difficult to increase.

  The heat insulation layer 72 formed by foaming the heat-foamable heat insulation layer 71 is designed to fill the gap S and be in close contact with the tank body 20 (see FIGS. 10 and 12). That is, the size of the gap S, the thickness of the thermally foamable heat insulating layer 71, and the degree of foaming (type of foaming agent) are designed so that the heat insulating layer 72 fills the gap S.

<< Modification of Third Embodiment >>
The third embodiment of the present invention has been described above, but can be changed as follows, for example.
In the third embodiment described above, the tank cover 61 in which the heat-foamable heat insulating layer 71 is formed on the inner surface 61a exemplifies a configuration that surrounds the entire tank body 20, but the position of an external heat source (such as the compressor 131) is exemplified. Corresponding to the above, the tank body 20 may be partially surrounded.

  For example, as shown in FIG. 13A, when the compressor 131 (heat source) is disposed in front of the hydrogen tank 10, only the trunk portion of the tank body 20 that may be heated by the compressor 131 is covered with the tank cover. A configuration surrounded by 61 may be adopted. The thermally foamable heat insulating layer 71 formed on the inner surface 61 a of the tank cover 61 is also disposed corresponding to the position of the compressor 131.

  Further, as shown in FIG. 13B, when the compressor 131 (heat source) is arranged on the right side of the hydrogen tank 10, only the right side portion of the tank body 20 that may be heated by the compressor 131 is removed from the tank. It is good also as a structure enclosed with the cover 61. FIG. The thermally foamable heat insulating layer 71 formed on the inner surface 61 a of the tank cover 61 is also disposed corresponding to the position of the compressor 131.

  Thus, the tank cover 61 and the heat-foamable heat insulating layer 71 are formed and arranged so as to surround only the portion of the tank body 20 that may be heated, corresponding to the position of the compressor 131 that is an external heat source. Therefore, the tank cover 61 and the heat-foamable heat insulating layer 71 become smaller and lighter.

In the above-described third embodiment, the configuration in which the tank cover 61 surrounds one hydrogen tank 10 has been illustrated. However, for example, as shown in FIG. 14, two hydrogen tanks 10 are provided in the fuel cell vehicle 100. When mounted, the tank cover 61 may be configured to collectively surround the two hydrogen tanks 10.
According to such a configuration, the work time required for mounting the tank cover 61 is shortened, the mass and the manufacturing cost are reduced by reducing the total amount of the tank cover 61, and further, the function as a unitary object surrounded by one unit. Benefits such as ease of warranty.

1, 2, 3 Hydrogen tank structure (tank structure)
DESCRIPTION OF SYMBOLS 10 Hydrogen tank 20 Tank main body 30 Relief valve 40 Enclosure 40a, 61a Inner surface (surface on the hydrogen tank side)
40b, 61b External surface (surface opposite to the hydrogen tank)
51, 53, 71 Heat-foaming heat insulation layer 52, 72 Heat insulation layer 61 Tank cover (enclosure)
100 Fuel cell vehicle (vehicle)
110 Fuel cell stack (fuel cell)
121 Pressure reducing valve 131 Compressor (heat source)
S clearance

Claims (9)

A tank body filled with fluid, and a relief valve provided on at least one end side of the tank body, and a tank mounted on a vehicle;
A go body surrounding the tank;
A heat-foamable heat-insulating layer that is provided on the tank-side surface of the enclosure and foams to form a heat-insulating layer when the temperature rises;
With
A gap is formed between the heat-foamable heat insulating layer before foaming and the tank. The tank structure according to claim 1, wherein the heat insulation layer formed by foaming the heat-foamable heat insulation layer fills the gap. A tank body filled with fluid, and a relief valve provided on at least one end side of the tank body, and a tank mounted on a vehicle;
A go body surrounding the tank;
A heat-foamable heat-insulating layer that is provided on the surface of the enclosure opposite to the tank and foams to form a heat-insulating layer when the temperature rises;
With
A gap structure is formed between the surrounding body and the tank. The relief valve is configured to open when the temperature rises,
The heat-foamable heat insulating layer is not formed around the relief valve so that heat from outside is conducted to the relief valve. The tank structure described in 1. The tank structure according to any one of claims 1 to 4, wherein the surrounding body is made of metal. The tank structure according to any one of claims 1 to 5, wherein the thermally foamable heat insulating layer is formed corresponding to a position of an external heat source. The tank according to any one of claims 1 to 6, wherein the enclosure includes the vehicle and a plurality of panels arranged around the tank main body. Structure. The tank structure according to any one of claims 1 to 6, wherein the surrounding body includes a cover that surrounds the tank. Comprising a plurality of said tanks;
The tank structure according to claim 8, wherein the cover collectively surrounds the plurality of tanks.

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