JP2005172106A - Storing method and apparatus for hydrogen gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storing method and an apparatus for hydrogen gas capable of storing high density hydrogen in a safe and easy to handle state while keeping evaporation loss small. <P>SOLUTION: Hydrogen gas is stored in the hydrogen container at an air pressure larger than atmospheric pressure by introducing hydrogen gas into the hydrogen gas container 3 made of fiber reinforced plastics, dipping the container for hydrogen gas in cryogenic refrigerant 11 consists of liquid nitrogen or inert gas and cooling inside the hydrogen gas container 3 at a temperature equal to or less than inversion temperature of hydrogen. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydrogen gas storage method and apparatus for filling and storing hydrogen gas in a container at high density for use in a fuel cell vehicle or the like.

In recent years, the environmental destruction caused by oil has advanced and global warming has been rapidly progressing. Carbon dioxide, nitrogen oxides, hydrocarbons, and sulfur oxides emitted from automobiles that run on gasoline are adversely affecting human health. Therefore, in order to improve the problems of resources and the environment, development of a fuel cell vehicle that exhausts only water by using oxygen and hydrogen that exist infinitely on the earth as fuel is under way. Improvements to liquid hydrogen tanks and hydrogen gas tanks for fuel cell vehicles are also underway (see Patent Document 1 below), and fuel cell vehicles can run about 400 km with a single liquid hydrogen charge and about 300 km with a hydrogen gas charge. Has reached.
JP 2002-181295 A

When liquid hydrogen is used as the fuel, the travel distance is longer than that of hydrogen gas. However, when the vehicle is stopped for a long time, the liquid hydrogen evaporates little by little due to heat penetration from the container, and the remaining amount decreases.
Since liquid hydrogen exists only at a temperature of −253 ° C. or less at atmospheric pressure, in order to maintain this state, radiant heat is prevented by placing it in a special container for cryogenic storage with a multilayer insulation layer in a vacuum insulation tank. There must be. However, even in this dedicated container, the liquid hydrogen in the container gradually evaporates due to heat conduction from the support fitting and the liquid hydrogen outlet. A certain automobile manufacturer has a loss of 4 to 6% per day from a container storing liquid hydrogen of a fuel cell vehicle, and the fuel loss increases as the vehicle is left for a long time. When driving a car, it is thought that there is no fuel already, and maintenance of liquid hydrogen becomes a problem.

  In the method of filling with hydrogen gas, if a high pressure gas container of about 150 liters is filled at 35 MPa, the vehicle can travel about 200 km, but the traveling distance is only 1/3 compared to the same type gasoline car. In order to solve this problem, it is conceivable to increase the tank capacity, but there is no room for adding a cylindrical tank in a limited space of an automobile. There is a method of arranging hydrogen tanks on the roof like a bus, but the overall volume becomes large.

In addition, there is a method of increasing the absolute pressure of hydrogen gas by increasing the filling pressure of the high-pressure gas container. Originally, hydrogen molecules with a small molecular diameter are easy to permeate the materials that make up the container, and the higher the pressure, the more important it is to develop a container with less leakage. Since the high-pressure gas has a large energy when the container breaks and is dangerous, the thickness of the container must be made thick and sturdy in consideration of safety, and tends to increase as a result. In addition, the compressor used at the hydrogen station (the place where hydrogen produced at the factory is stored and supplied to the fuel cell vehicle is equivalent to the current gas station) must also be of an ultra-high pressure specification. There are many.
SUMMARY OF THE INVENTION An object of the present invention is to provide a hydrogen gas storage method and apparatus capable of storing high-density hydrogen in a safe and easy-to-handle manner with low evaporation loss.

  According to the first aspect of the present invention, hydrogen gas is introduced into a hydrogen gas container made of fiber reinforced plastics, the hydrogen gas container is immersed in a cryogenic refrigerant, and the temperature in the hydrogen gas container is equal to or lower than the reverse temperature of hydrogen. Then, the hydrogen gas is stored at a pressure higher than atmospheric pressure in the hydrogen gas container.

  According to a second aspect of the present invention, there is provided a refrigerant container for storing a cryogenic refrigerant and a fiber-reinforced plastics, and a heat conducting member is provided therein, and is immersed in the refrigerant to store hydrogen gas having an inversion temperature or lower and an atmospheric pressure or higher. It is set as the structure provided with a hydrogen gas container.

According to a third aspect of the present invention, the heat conducting member is a wire or a net.
According to a fourth aspect of the present invention, a path for introducing hydrogen gas to be stored in the hydrogen gas container is provided with a heat exchanger provided with an adsorbent and immersed in the refrigerant.

  ADVANTAGE OF THE INVENTION According to this invention, the storage method and apparatus of the hydrogen gas which can store a high density hydrogen in a safe state which is easy to handle and with a small evaporation loss can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the hydrogen gas storage device according to the embodiment of the present invention includes a hydrogen gas container 3 supported by a support member 2 in a refrigerant container 1 that is thermally insulated by vacuum. The refrigerant container 1 includes a vacuum tank 4 and a refrigerant tank 5, and the side walls and the bottom are vacuum insulated by a multilayer heat insulating material 6. A liquid nitrogen supply valve 8, a safety valve 9, and a hydrogen gas sensor 10 are attached to a lid 7 attached by a flange. The liquid nitrogen 11 which is a cryogenic refrigerant | coolant is stored.

The hydrogen gas container 3 is made of CFRP (carbon fiber reinforced plastics), has a liner 13 made of aluminum on its inner surface as a heat conducting member, and is filled with a metal mesh 14 made of stainless steel. The inlet 15 of the hydrogen gas container 3 is connected to a heat exchanger 17 serving as an impurity trap having activated carbon 16 as an adsorbent. The heat exchanger 17 includes a hydrogen gas supply valve 18, a pressure gauge 19, and a discharge valve. A hydrogen gas introduction pipe 21 having 20 is inserted from the outside of the refrigerant container 1. Reference numeral 36 denotes a through hole provided in Experiment 6 to be described later.
In order to examine the operational effects of the hydrogen gas storage device of the present embodiment having the above-described configuration, the following experiments 1 to 6 were performed.

  First, as experiment 1, as shown in FIG. 2, first, a hydrogen gas container 3 made of CFRP having an inner volume of 4.5 liters, an outer diameter of 140 mm, and a length of 500 mm was prepared. Hydrogen gas adjusted by a pressure regulator was introduced into the hydrogen gas container 3 so as to maintain a pressure of 0.1 MPa as a gauge pressure. Temperature sensors were arranged at positions A, B, C, and D inside and outside the hydrogen gas container 3 and immersed in the refrigerant container 1 containing liquid nitrogen 11. Then, the temperature distribution in the hydrogen gas container 3 and the elapsed time for cooling were examined.

  The measurement result of the temperature distribution is shown by x in FIG. FIG. 4 shows that the temperature distribution in the hydrogen gas container 3 is higher than the temperature of the liquid nitrogen 11. This is because the hydrogen gas container 3 is made of CFRP made of plastics (resin) having poor heat conduction, and therefore heat transfer due to convection and radiation of hydrogen gas is slow and the temperature in the hydrogen gas container 3 is quite liquid nitrogen 11. This is probably because the temperature is difficult to reach.

  Next, as shown in FIG. 3, the hydrogen gas container 3 is provided with a heat transfer plate 25 having a diameter of 50 mm, a diameter of 10 mm, a diameter of 10 mm, so that heat conduction occurs from outside the hydrogen gas container 3 into the hydrogen gas container 3. A copper cooling pipe 26 having an inner diameter of 4 mm was inserted. The introduced hydrogen gas pressure is 0.1 MPa, the same as the previous time.

  The temperature distribution in the hydrogen gas container 3 and the cooling time when the hydrogen gas container 3 was immersed in the liquid nitrogen 11 were examined. The position of the temperature sensor is the same as described above. The result is indicated by symbol ◯ in FIG. Further, the cooling time characteristic of the location B is shown in FIG. From FIG. 5, it can be seen that the time to reach the temperature of the liquid nitrogen that is the refrigerant is faster with the cooling pipe 26 than without the cooling pipe 26.

  This temperature distribution shows the effect of heat conduction by the cooling pipe 26 provided with the heat transfer board 25 and cooling by radiation and convection from the cooling pipe 26 cooled by the heat conduction, so that the temperature in the hydrogen gas container 3 is further increased. This shows that the temperature of the liquid nitrogen 11 is approaching, and the effect of the inserted cooling pipe 26 appears.

  Next, as Experiment 2, as shown in FIG. 6, the heat exchanger 17 was connected to a CFRP hydrogen gas container 3 having an inner volume of 4.5 liters, an outer diameter of 140 mm, and a length of 500 mm into which the cooling pipe 26 was inserted. The gas container 3 was filled with hydrogen gas having a gauge pressure of 0.1 MPa. Next, after the hydrogen gas container 3 was placed, liquid nitrogen 11 was gently poured into the vacuum-insulated refrigerant container 1. After the heat exchanger 17 and the hydrogen gas container 3 were completely immersed in the liquid nitrogen 11, the injection of liquid nitrogen was stopped. Next, 10 MPa of hydrogen gas was supplied while adjusting the valves 30 and 31 connected to the heat exchanger 17. After about 34 minutes, the supply pressure and the pressure in the hydrogen gas container 3 became the same and became in an equilibrium state.

At this time, the temperatures indicated by the temperature sensors arranged at positions A, B, C, and D of the container 3 are as follows: A is −191 ° C., B is −196 ° C., C is −192 ° C., and D is liquid nitrogen temperature. It was 196 degreeC. The density of hydrogen under this condition is about 33 kg / cm ³ from the temperature and pressure, and it is estimated that hydrogen is in a supercritical state. In order to reproduce the density in this state only with a hydrogen gas pressure of 0 ° C., it must be about 50 MPa. It is necessary to develop a new ultrahigh pressure vessel that meets this requirement. Thus, high-density hydrogen can be stored by maintaining the hydrogen gas container 3 with the cooling pipe 26 inserted therein at a relatively low pressure and a very low temperature.

Next, as Experiment 3, after preparing the experiment under the same conditions as in Experiment 2, the supply pressure was adjusted to 5 MPa and hydrogen gas was introduced into the hydrogen gas container 3. After about 20 minutes, the internal pressure of the hydrogen gas container 3 became the same as the supply pressure, and an equilibrium state was reached. The temperatures indicated by the temperature sensors arranged at positions A, B, C, and D of the hydrogen gas container 3 are as follows: A is −192 ° C., B is −196 ° C., C is −193 ° C., and D is liquid nitrogen temperature. It was 196 degreeC. The density of hydrogen under these conditions is about 16 kg / cm ³ from the temperature and pressure. In order to reproduce the density in this state only with a hydrogen gas pressure of 0 ° C., the hydrogen gas container 3 must be about 20 MPa (200 kg / cm ² ). Thus, by cooling to a very low temperature, hydrogen gas having a high density can be easily stored at a relatively low pressure.

  Next, as Experiment 4, as shown in FIG. 7, a hydrogen gas container 3 made of CFRP (4.5 liters, outer diameter 140 mm, length 500 mm) equipped with a cooling pipe 26 is prepared. Furthermore, a CFRP take-out container 32 having the same internal volume was connected. A heat exchanger 17 is connected to the hydrogen gas container 3 on the hydrogen gas supply side.

  In order to prevent the hydrogen gas container 3 and the extraction container 32 from becoming negative pressure when immersed in the liquid nitrogen 11, hydrogen gas of 0.1 MPa previously adjusted by the pressure regulator 29 was introduced into the containers 3 and 32. In the hydrogen gas container 3, temperature sensors were arranged at positions A, B, C, and D. Further, the hydrogen gas container 3 and the heat exchanger 17 were disposed in the vacuum insulated refrigerant container 1. Thereafter, liquid nitrogen 11 was poured into the refrigerant container 1 little by little so that the hydrogen gas container 3 was not subjected to a rapid temperature change. After the hydrogen gas container 3 was completely immersed in the liquid nitrogen 11, the supply of liquid nitrogen was stopped.

  A pressure gauge 33 and a gas discharge valve 34 were attached to an extraction container 32 provided outside the refrigerant container 1 and connected to the hydrogen gas container 3. The supply pressure was set to 5 MPa, and introduction of hydrogen gas into the hydrogen gas container 3 was started. About 51 minutes after the start of the introduction, the pressures of the hydrogen gas container 3 and the extraction container 32 became 5 MPa, which was almost the same as the supply pressure, and reached an equilibrium state. The temperature in the hydrogen gas container 3 was −191 ° C. for A, −196 ° C. for B, −191 ° C. for C, and −196 ° C. for D. The temperature of E in the take-out container 32 was about 28 ° C. When the discharge valve 34 was opened, the release of hydrogen gas was confirmed. With such a configuration, the cryogenic high pressure hydrogen gas stored in the hydrogen gas container can be taken out at normal temperature and pressure.

  Next, as Experiment 5, the storage device shown in FIG. That is, a metal mesh (length) of 50 mesh (number of 50 holes per inch) of stainless steel in a CFRP hydrogen gas container 3 having an inner volume of 4.5 liters (outer diameter 140 mm, length 500 mm). 300 mm and a width of about 360 mm) were introduced by rolling them one by one from the inlet of the hydrogen gas container 3 to form a seven-layer metal mesh 14 layer.

  The introduced wire mesh 14 is made of stainless steel and has elasticity. In the hydrogen gas container 3, the wire mesh inserted first is in contact with the aluminum liner 13 and is continuously in contact with the other wire mesh. A heat exchanger 17 also serving as an impurity trap containing activated carbon 16 was connected to the hydrogen gas container 3. First, the hydrogen gas container 3 was filled with hydrogen gas. Hydrogen gas was introduced and evacuated several times to obtain a high purity hydrogen gas state. Next, the hydrogen gas container 3 was placed in the refrigerant container 1, and the multilayer heat insulating material 6 was evacuated for 8 hours to provide a vacuum heat insulating function. Next, the supply pressure of hydrogen gas was set to 0.15 MPa, and liquid nitrogen 11 was gently injected.

  When the hydrogen gas container 3 was completely immersed in the liquid nitrogen 11, the hydrogen gas supply pressure was set to 1.0 MPa and the hydrogen gas container 3 was supplied. After holding for 30 seconds, the pressurization and holding were repeated every 1.0 MPa and the hydrogen gas supply was stopped at 5.0 MPa. The time during which the supply pressure and the hydrogen gas container pressure were in an equilibrium state was shorter than that of the previous experiment 2 and was 7 minutes 30 seconds. At this time, the temperature sensor at the center F of the hydrogen gas container 3 was -190 ° C. In this way, by introducing a multi-layered metal mesh 14 into the hydrogen gas container 3 and introducing the hydrogen gas heat exchanged with the liquid nitrogen 11, a high pressure state can be obtained at a very low temperature in a relatively short time.

  Next, as an experiment 6, an experiment was performed that simulated that the hydrogen gas leaked from the crack after entering the hydrogen gas container 3 in the storage device of FIG. First, a through-hole 36 having a diameter of 0.1 mm was formed in the hydrogen gas container 3, and then the apparatus was configured in the same configuration as shown in Experiment 5. After setting the hydrogen gas to 0.09 MPa, liquid nitrogen 11 was injected. After immersion, the liquid nitrogen supply valve 8 was closed. After 18 seconds, the hydrogen gas sensor 10 detected hydrogen gas. Considering that the hydrogen gas density is low, the installation part of the hydrogen gas sensor 10 is formed with a protrusion on the lid 7 of the refrigerant container 1 so that light hydrogen gas is easily collected. In this way, when the hydrogen gas container 3 is immersed in the liquid nitrogen 11 and the hydrogen gas container 3 is cracked for some reason, the refrigerant container 1 remains as a small bubble without diffusing in the liquid nitrogen 11. As a result, the leakage of hydrogen gas can be detected quickly.

  In the hydrogen gas storage device of the present embodiment as described above, the hydrogen gas container 3 filled with hydrogen gas is a liquid having a temperature equal to or lower than the reverse temperature of hydrogen (−80 ° C.) before filling with hydrogen gas. It cools with cryogenic refrigerants or cryogenic refrigerators, such as nitrogen (boiling point -196 degreeC), liquefied argon (boiling point -195.8 degreeC), and liquefied neon (boiling point -246 degreeC). However, since the hydrogen gas container 3 is made of fiber reinforced plastics (FRP) and has poor heat conduction, it takes time to cool down to the temperature of the cryogenic refrigerant. Furthermore, the thermal conductivity of hydrogen is smaller in the cryogenic state than in the greenhouse state (for example, 189 mW / m · K at a temperature of 300 K and 87.3 mW / m · K at 80 K under a constant pressure of 10 MPa). There is a problem.

  Therefore, a cooling pipe 26 made of metal is inserted as a heat conducting member so as to communicate from the outside to the inside of the hydrogen gas container 3 to increase the cooling efficiency of the hydrogen gas. Further, the inner surface of the hydrogen gas container 3 is lined with a material having good thermal conductivity such as aluminum, copper, and stainless steel, and one end of the lining material (liner) is connected to the outside of the container 3 to facilitate heat conduction of the refrigerant. By doing so, the cooling effect in the hydrogen gas container 3 is increased. However, if the inner diameter of the cooling pipe 26 is made small so as to produce a throttling effect when hydrogen gas is injected, there is a drawback that it takes too long to fill the hydrogen gas. As a countermeasure, instead of increasing the diameter of the hydrogen gas container 3, the container 3 is randomly filled with a wire mesh 14 or a wire having good thermal conductivity such as stainless steel, copper, or aluminum as a heat conductive member. When cooled in a 4.2K refrigerator, liquid helium, or the like under such conditions, the charged hydrogen becomes solid in the vicinity of the mesh of the metal mesh 14, and it is in a high density state without any particular pressure. Stored. The density can be maintained even if an adsorbent such as activated carbon or carbon nanotube is added to the hydrogen gas container 3.

There are four advantages of cooling the hydrogen gas container 3 made of FRP with a refrigerant such as liquid nitrogen. The first point is an effect of preventing leakage of hydrogen gas having a small molecular diameter and low viscosity from FRP. That is, for example, when FRP is cooled with liquid nitrogen, nitrogen molecules and water molecules of impurities enter the gaps between the fiber network and the resin that is easily formed after molding, thereby closing the meshes and gaps and suppressing the permeation (leakage) of hydrogen molecules. In addition, it also has the effect of blocking leakage from cracks that tend to occur during use with a cryogenic refrigerant. That is, aluminum or chromium molybdenum steel, which is a metal material constituting the liner 13 of the hydrogen gas container 3, is often manufactured by a die press or a welded structure, and residual stress is likely to occur. The hydrogen gas container 3 that repeatedly fills and discharges hydrogen gas at a high pressure of 35 MPa (350 kg / cm ² ) accumulates metal fatigue due to repeated stress. Furthermore, there is internal corrosion that is likely to occur due to impurities in hydrogen gas. The possibility of leakage of hydrogen gas from cracks that may occur in combination of these can be reduced.

  The second point is advantageous in that if hydrogen gas leaks from the cracked portion of the hydrogen gas container 3 into the refrigerant, the gas can be easily detected. The density of the hydrogen gas is lighter than the liquid nitrogen of the cryogenic refrigerant and tends to accumulate in the upper layer portion of the refrigerant container 1. By installing the hydrogen gas sensor 10 there, the hydrogen gas having a low density does not diffuse in the refrigerant and rises in the form of bubbles, so that leakage can be detected quickly.

  Third, by covering the hydrogen gas container 3 with an inert cryogenic refrigerant such as liquid argon, liquid neon, or liquid nitrogen, safety can be maintained even when hydrogen is released due to an accident. In other words, hydrogen gas must be released urgently for the purpose of preventing container destruction in the event of an accident, but if hydrogen gas is released into the refrigerant in this state, the inert gas refrigerant is released while mixing with the hydrogen gas. Therefore, safety is maintained because it deviates from the three conditions for combustion (the combustible gas is in the combustion-supporting gas and is set to the ignition temperature).

  The fourth point is removal of impurities in the hydrogen gas by cooling the cryogenic refrigerant. For example, by cooling the hydrogen gas container 3 with liquid nitrogen, impurities in hydrogen having a temperature equal to or higher than the boiling temperature of liquid nitrogen are trapped. The purity of the hydrogen gas before cooling is controlled to 99.99% or more, but not a little air is mixed in the holding joint of the detachable joint in the filling operation. Further, the substance adsorbed on the introduction pipe or the inner wall of the container is carried to the heat exchanger 17 cooled by the refrigerant using hydrogen gas as a carrier, and impurities are trapped. As a result, the purity of the hydrogen gas in the hydrogen gas container 3 is increased, and high purity hydrogen gas can be stored and supplied. From this point of view, the trap combined heat exchanger 17 is effective. Further, by placing an adsorbent such as activated carbon 16 or molecular sieve whose adsorption performance is improved at a low temperature in the heat exchanger 17, it is possible to easily manage the removal and discharge of impurities, the exchange of the adsorbent, and the like.

  The hydrogen gas storage device of this embodiment is filled with high-pressure hydrogen gas in a state where the hydrogen gas container 3 is cooled. However, if hydrogen gas having a temperature higher than the reverse temperature is injected into the cooled hydrogen gas container 3, the cooling effect is lost. Therefore, the hydrogen gas to be filled is also used with the cryogenic refrigerant or cryogenic refrigerator used for cooling the hydrogen gas container 3. Cool to below.

  As a method of maintaining the gas state under a cryogenic high pressure, the hydrogen gas container 3 is cooled with a cryogenic refrigerant such as liquid nitrogen, liquid argon, liquid neon or the like and maintained in a high pressure state. At present, it is desirable to use liquid nitrogen that is rich in resources, has large latent heat, is widely used as an industrial product, and is cheaper than other cryogenic refrigerants. There is also a method of directly cooling the heat transfer plate 25 attached to the hydrogen gas container 3 with a refrigerator, but this method requires electric power for operating the refrigerator or water cooling equipment for cooling the refrigerator itself. At present, a method using a refrigerant is preferable because it is necessary.

Setting the hydrogen gas to an extremely low temperature state means that the hydrogen gas has a higher density than the density of the hydrogen gas at room temperature. For example, under a pressure of 20 MPa, the density at a temperature of 273.15 K is 15.69 kg / m ³ , whereas when cooled to 90 K, the density increases approximately three times to 43.65 kg / m ³ . It is effective to fill the hydrogen gas container 3 with a high density. Under the condition that the temperature of the hydrogen gas to be filled and the temperature in the hydrogen gas container 3 to be filled are both cooled with a very small temperature difference, the hydrogen gas container 3 is efficiently filled with the hydrogen gas having a low temperature and a high density. The

  When filling under conditions of low temperature and high pressure near the critical point of hydrogen gas, hydrogen in a supercritical state composed of high density gas can be effectively stored. The supercritical state in hydrogen means a state in which the temperature and pressure at or near the critical point of hydrogen (temperature 33K, pressure 1.3 MPa) are maintained, and it is neither liquid (pseudo liquid state) nor gas (pseudo). Gas state). By changing the temperature and pressure in the cryogenic region near the critical point, it is possible to freely control the state above the density of the liquid or gas.

  The hydrogen gas storage device of this embodiment is also provided with an extraction container 32 for extracting hydrogen stored in the hydrogen gas container 3 at a high pressure and a very low temperature in a room temperature state. The take-out container 32 is not cooled, but is connected to the hydrogen gas container 3 stored at a high pressure and a very low temperature by a pipe, and only the pressure is balanced to be the same pressure. According to this configuration, the high-density cryogenic high-temperature hydrogen gas can be taken out as room-temperature and low-density hydrogen gas and supplied to the fuel cell at a reaction ratio at an appropriate concentration with oxygen. Alternatively, hydrogen having an appropriate temperature density may be provided by appropriately cooling or heating the extraction container 32.

  As described above, the hydrogen stored in the present embodiment is in a high density state but is not a liquid, so that there is little loss due to evaporation. Since the refrigerant for cooling the hydrogen also uses cryogenic liquid nitrogen, liquefied neon, liquefied argon, or the like, it can be stored for a long time in a high vacuum heat insulating container and can maintain a high density state.

  As described above, in this embodiment, the hydrogen gas container 3 provided with the heat transfer plate 25, or the inside of the hydrogen gas container 3 is filled with a wire or wire mesh 14 made of aluminum, copper, stainless steel, etc., and the liquid nitrogen 11, Cooling with a cryogenic refrigerant such as liquid argon, the temperature of the hydrogen gas filled in the hydrogen gas container 3 is made substantially the same as the temperature of the refrigerant, and maintained at a high pressure state above atmospheric pressure. Store hydrogen.

  Further, the hydrogen gas container 3 is immersed in the liquid nitrogen 11 that is a refrigerant and released into the refrigerant in the event of an emergency occurrence of hydrogen, so that the safety can be maintained because the hydrogen gas container 3 is mixed with the inert refrigerant and released. An emergency hydrogen gas leak from the hydrogen gas container 3 is detected by a hydrogen gas sensor 10 installed at the upper part of the refrigerant container 1. Cooling the CFRP-made hydrogen gas container 3 with a refrigerant allows the refrigerant molecules and impurity water molecules to enter the gaps between the fiber network and the resin that is easily formed after molding, so that even hydrogen molecules with a small molecular diameter are filled. There is an effect of reducing the permeation and leakage.

  By filling hydrogen gas container 3 cooled by a cryogenic refrigerant with hydrogen at a relatively low pressure of, for example, 10 MPa to 5 MPa, the conventional method (filling at a high pressure of 35 MPa at normal temperature to ensure an absolute amount) is achieved. It can easily store high density hydrogen.

Sectional drawing which shows the storage apparatus of the hydrogen gas of the Example of this invention. The figure which shows the apparatus structure of the experiment 1 which verifies the effect of the storage apparatus of the hydrogen gas of the Example of this invention. The figure which shows the other apparatus structure of Experiment 2 which verifies the effect of the storage apparatus of the hydrogen gas of the Example of this invention. 3 is a graph showing the results obtained by the experiment 1; 3 is a graph showing the results obtained by the experiment 1; The figure which shows the apparatus structure of Experiment 2 and 3 which verifies the effect of the storage apparatus of the hydrogen gas of the Example of this invention. The figure which shows the apparatus structure of the experiment 4 which verifies the effect of the storage apparatus of the hydrogen gas of the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigerant container, 2 ... Hydrogen gas container support member, 3 ... Hydrogen gas container, 4 ... Vacuum tank, 5 ... Refrigerant tank, 6 ... Multilayer heat insulating material, 7 ... Cover, 8 ... Liquid nitrogen supply valve, 9 ... Safety valve, DESCRIPTION OF SYMBOLS 10 ... Hydrogen gas sensor, 11 ... Liquid nitrogen, 13 ... Liner, 14 ... Wire mesh, 15 ... Hydrogen gas container inlet, 16 ... Activated carbon, 17 ... Heat exchanger, 18 ... Hydrogen gas supply valve, 19 ... Pressure gauge, 20 ... Discharge Valve, 21 ... Hydrogen gas introduction pipe, 25 ... Heat transfer panel, 26 ... Cooling pipe, 27 ... Cooling gas discharge port, 28 ... Pressure gauge, 29 ... Pressure regulator, 30, 31 ... Valve, 32 ... Extraction container, 33 ... pressure gauge, 34 ... gas discharge valve, 35 ... emergency discharge valve, 36 ... through hole, A, B, C, D, E, F ... temperature sensor installation location, H ... hydrogen gas introduction path.

Claims (4)

  Hydrogen gas is introduced into a hydrogen gas container made of fiber reinforced plastics, the hydrogen gas container is immersed in a cryogenic refrigerant, and the hydrogen gas container is cooled to a temperature equal to or lower than the reversal temperature of hydrogen. A hydrogen gas storage method characterized by storing hydrogen gas at atmospheric pressure or higher in a container.   A refrigerant container for storing a cryogenic refrigerant, and a hydrogen gas container made of fiber reinforced plastics, provided with a heat conducting member therein, and immersed in the refrigerant to store hydrogen gas having an inversion temperature or lower and an atmospheric pressure or higher. A hydrogen gas storage device.   3. The hydrogen gas storage device according to claim 2, wherein the heat conducting member is a wire or a net. 3. The hydrogen gas storage device according to claim 2, further comprising a heat exchanger provided with an adsorbent and immersed in the refrigerant in a path for introducing hydrogen gas to be stored in the hydrogen gas container.

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