JP7750168B2 - Hydrogen filling equipment - Google Patents

Description

The technology disclosed in this specification relates to a hydrogen filling device that fills a hydrogen gas tank with hydrogen.

Devices that use hydrogen gas, such as fuel cells, require hydrogen tanks to store the hydrogen. Liquid hydrogen tanks are expensive, and supplying hydrogen gas to devices that use it requires a liquid hydrogen pump and vaporizer in addition to the liquid hydrogen tank, increasing the cost of the entire system. On the other hand, when using a hydrogen gas tank to store hydrogen gas, it takes time to prepare the high-pressure hydrogen gas to supply to the hydrogen gas tank. For example, Patent Document 1 discloses a device for filling a tank with hydrogen gas.

Japanese Patent Application Laid-Open No. 2006-312373

As mentioned above, from a cost perspective, it is desirable for the tank attached to a device that uses hydrogen gas to be a hydrogen gas tank. However, as mentioned above, it takes time to prepare high-pressure hydrogen gas at a hydrogen gas station. This specification provides technology for a device that fills a hydrogen gas tank with hydrogen, eliminating the need to prepare high-pressure hydrogen gas.

This specification discloses a hydrogen filling device that fills hydrogen into a hydrogen gas tank. The hydrogen filling device comprises a liquid hydrogen tank, a storage tank, a liquid hydrogen supply pipe, a first valve, a second valve, a third valve, and a controller. The liquid hydrogen tank stores liquid hydrogen. The storage tank temporarily stores the liquid hydrogen in the liquid hydrogen tank in liquid form. The liquid hydrogen supply pipe flows the liquid hydrogen in the storage tank to the hydrogen gas tank in liquid form. The first valve stops the flow of liquid hydrogen from the liquid hydrogen tank to the storage tank. The second valve discharges gas from the storage tank. The third valve stops the flow of liquid hydrogen from the storage tank to the hydrogen gas tank.

The controller can execute the following three steps. First step: Close the third valve and open the first and second valves to inject liquid hydrogen into the storage tank. Second step: Close the first and second valves when a predetermined amount of liquid hydrogen has accumulated in the storage tank. Third step: Open the third valve when the internal pressure of the storage tank reaches a predetermined hydrogen extrusion pressure and inject liquid hydrogen into the hydrogen gas tank. Here, the hydrogen extrusion pressure is higher than the internal pressure of the hydrogen gas tank. The predetermined amount is the amount of hydrogen equivalent to the difference between the amount of hydrogen when the hydrogen gas tank is fully filled with hydrogen gas and the amount of hydrogen remaining in the hydrogen gas tank before executing the first step.

When the third step is performed, the liquid hydrogen in the storage tank is forced into the hydrogen gas tank due to the internal pressure difference between the storage tank and the hydrogen gas tank. The liquid hydrogen vaporizes inside the hydrogen gas tank. In this way, the hydrogen gas tank is filled with hydrogen gas. The hydrogen filling device disclosed in this specification injects hydrogen in liquid form into the hydrogen gas tank and vaporizes the liquid hydrogen inside the hydrogen gas tank. The hydrogen filling device disclosed in this specification can fill a hydrogen gas tank with hydrogen gas without having to prepare high-pressure liquid hydrogen gas in advance.

One suitable example of a storage tank for temporarily storing liquid hydrogen in its liquid state comprises an outer tank and a hydrogen container. The hydrogen container is supported on the inner surface of the outer tank via a thermal insulator. The hydrogen container has an opening that connects the inside and outside of the hydrogen container, and receives liquid hydrogen supplied from the liquid hydrogen tank.

The hydrogen filling device described above may be equipped with multiple sets of storage tanks and third valves, allowing multiple vehicles to be filled with hydrogen simultaneously.

The hydrogen filling device disclosed in this specification may include an auxiliary tank to which liquid hydrogen from a storage tank is transferred in liquid form, and a gas supply pipe. The gas supply pipe supplies liquid hydrogen vaporized in the auxiliary tank to another hydrogen gas tank. The auxiliary tank includes an outer tank and a hydrogen container placed inside the outer tank. The hydrogen container is supported on the inner surface of the outer tank via a thermal insulator. The hydrogen container has an opening that connects the inside to the outside, and receives liquid hydrogen supplied from the storage tank. The liquid hydrogen in the hydrogen container vaporizes inside the outer tank. Hydrogen gas can then be supplied from this auxiliary tank to another hydrogen gas tank.

A support member that supports a hydrogen container inside the external tank is also one of the technologies disclosed in this specification. The support member comprises an extension mechanism, a ball joint, a universal joint, and an insulating material. One end of the ball joint is fixed to the inner surface of the external tank, and the other end is fixed to one end of the extension mechanism. One end of the universal joint is fixed to the insulating material, and the other end is connected to the other end of the extension mechanism. The insulating material is fixed to the hydrogen container. One end of the support member is fixed to the inner surface of the external tank, while the other end opposite is swingable. This support member allows deformation and shaking of the hydrogen container inside the external tank. Furthermore, the support member can firmly support the hydrogen container even if the external tank is deformed.

The technology disclosed in this specification may be embodied in a hydrogen filling system that includes the hydrogen filling device and the hydrogen gas tank described above. The hydrogen gas tank comprises an outer tank and a hydrogen container. The hydrogen container is supported on the inner surface of the outer tank via a thermal insulator. The hydrogen container has an opening that connects the inside and outside of the hydrogen container, and receives liquid hydrogen supplied from a storage tank. The liquid hydrogen in the hydrogen container is vaporized inside the outer tank. Such a hydrogen gas tank is suitable for the hydrogen filling device described above.

Details and further improvements to the technology disclosed in this specification are explained in the "Description of Embodiments" below.

1 is a block diagram of a hydrogen filling system including a hydrogen filling device according to a first embodiment. FIG. 10 is a block diagram of a hydrogen filling system including a hydrogen filling device according to a second embodiment. FIG. 1 is a cross-sectional view of an example hydrogen gas tank. FIG. 10 is a cross-sectional view of a modified hydrogen gas tank.

(First embodiment) A hydrogen filling device 100 according to the first embodiment will be described with reference to the drawings. Figure 1 shows a block diagram of the hydrogen filling device 100 and a hydrogen gas tank 200 that receives a supply of hydrogen from the hydrogen filling device 100. The hydrogen gas tank 200 is a tank suitable for the hydrogen filling device 100, and the hydrogen filling device 100 and the hydrogen gas tank 200 together constitute a hydrogen filling system 10.

The hydrogen gas tank 200 is mounted on the fuel cell vehicle 900. The fuel cell vehicle 900 is equipped with a fuel cell stack 901, which operates by receiving a supply of hydrogen gas from the hydrogen gas tank 200.

The hydrogen filling device 100 is equipped with a liquid hydrogen tank 101, a storage tank 110, an auxiliary tank 140, an accumulator tank 146, and an exhaust gas tank 150. The tanks and tanks are connected by pipes with valves.

A large amount of liquid hydrogen is stored in the liquid hydrogen tank 101. The liquid hydrogen tank 101 and the storage tank 110 are connected by a liquid hydrogen pipe 121. The liquid hydrogen pipe 121 sends liquid hydrogen from the liquid hydrogen tank 101 to the storage tank 110. The liquid hydrogen pipe 121 is equipped with a first valve 131. When the first valve 131 is opened, liquid hydrogen flows from the liquid hydrogen tank 101 to the storage tank 110. When the first valve 131 is closed, the flow of liquid hydrogen from the liquid hydrogen tank 101 to the storage tank 110 stops.

The storage tank 110 temporarily stores liquid hydrogen sent from the liquid hydrogen tank 101. The storage tank 110 comprises an outer tank 111 and a hydrogen container 112 placed inside the outer tank 111. The hydrogen container 112 is supported on the inner surface of the outer tank 111 via insulation 113. The hydrogen container 112 is not in contact with anything except the part that is in contact with the insulation 113. The hydrogen container 112 is insulated from the outside. The hydrogen container 112 is a container with an open top, and the inside and outside of the hydrogen container 112 are connected.

Liquid hydrogen supplied through the liquid hydrogen pipe 121 is stored in the hydrogen container 112 in liquid form. Some of the liquid hydrogen stored in the hydrogen container 112 vaporizes and becomes hydrogen gas. The outer tank 111 is designed to withstand a specified upper limit pressure, but since the hydrogen container 112 has an opening, pressure resistance is not required.

An exhaust gas pipe 122 is connected to the outer tank 111 of the storage tank 110. The exhaust gas pipe 122 is connected to the exhaust gas tank 150. A second valve 132 is provided on the exhaust gas pipe 122. When the second valve 132 is opened, the gas inside the storage tank 110 (outer tank 111) is discharged to the exhaust gas tank 150. The main component of the gas discharged from the storage tank 110 (outer tank 111) is hydrogen gas formed by vaporizing liquid hydrogen. Opening the second valve 132 suppresses the increase in internal pressure of the storage tank 110. By suppressing the increase in internal pressure of the storage tank 110, liquid hydrogen can be smoothly supplied from the liquid hydrogen tank 101 to the storage tank 110 at low pressure.

A liquid hydrogen supply pipe 123 is connected to the bottom of the hydrogen container 112. The liquid hydrogen supply pipe 123 is connected to the hydrogen gas tank 200 of the fuel cell vehicle 900. More specifically, a hydrogen supply nozzle 139 is provided at the tip of the liquid hydrogen supply pipe 123, and the hydrogen supply nozzle 139 is connected to a hydrogen supply port 902 provided in the body of the fuel cell vehicle 900. Inside the body of the fuel cell vehicle 900, a first pipe 211 of the hydrogen gas tank 200 is connected to the hydrogen supply port 902. Liquid hydrogen in the storage tank 110 is sent from the hydrogen container 112 to the hydrogen gas tank 200 via the liquid hydrogen supply pipe 123 and the first pipe 211.

The liquid hydrogen supply pipe 123 is equipped with a third valve 133. When the third valve 133 is closed, the flow of liquid hydrogen from the storage tank 110 to the hydrogen gas tank 200 stops.

The first valve 131, second valve 132, and third valve 133 are controlled by the controller 190. By controlling the valves 131, 132, and 133, the controller 190 supplies liquid hydrogen from the liquid hydrogen tank 101 to the hydrogen gas tank 200 of the fuel cell vehicle 900. The liquid hydrogen in the liquid hydrogen tank 101 vaporizes in the hydrogen gas tank 200, and the hydrogen gas tank 200 is eventually filled with hydrogen gas.

The hydrogen filling process performed by the controller 190 will now be described. The controller 190 can perform the following three steps:

(First step) The controller 190 closes the third valve 133 and opens the first valve 131 and the second valve 132. When the first valve 131 is opened, liquid hydrogen is sent from the liquid hydrogen tank 101 to the storage tank 110. The liquid hydrogen is sent from the liquid hydrogen tank 101 to the storage tank 110 through the liquid hydrogen pipe 121. One end of the liquid hydrogen pipe 121 is located above the opening of the hydrogen container 112 inside the storage tank 110.

As mentioned earlier, liquid hydrogen accumulates in the hydrogen container 112 inside the outer tank 111 of the storage tank 110. The hydrogen remains liquid in the hydrogen container 112, but some of the liquid hydrogen vaporizes to form hydrogen gas. Because the top of the hydrogen container 112 is open, the hydrogen gas spreads inside the outer tank 111. Because the controller 190 opens the second valve 132, the hydrogen gas in the outer tank 111 is sent to the exhaust gas tank 150 through the exhaust gas pipe 122. Note that prior to the first step, the internal pressure of the exhaust gas tank 150 is set to atmospheric pressure.

(Second step) The controller 190 closes the first valve 131 and the second valve 132 when a predetermined amount of liquid hydrogen has accumulated in the storage tank 110. The supply of liquid hydrogen from the liquid hydrogen tank 101 stops, and the discharge of hydrogen gas from the storage tank 110 also stops. Some of the liquid hydrogen in the hydrogen container 112 vaporizes. As the liquid hydrogen vaporizes, the temperature inside the external tank 111 drops and the pressure increases. When the liquid hydrogen and hydrogen gas inside the external tank 111 reach thermal equilibrium, the vaporization of the liquid hydrogen stops. In this embodiment, the pressure of the hydrogen gas at this time is referred to as the hydrogen extrusion pressure.

(Third step) When the internal pressure of the storage tank 110 reaches the hydrogen extrusion pressure, the controller 190 opens the third valve 133 of the liquid hydrogen supply pipe 123. As mentioned above, one end of the liquid hydrogen supply pipe 123 is connected to the bottom of the hydrogen container 112. The hydrogen extrusion pressure is adjusted to be higher than the internal pressure of the hydrogen gas tank 200. When the third valve 133 is opened, the liquid hydrogen in the hydrogen container 112 is extruded into the hydrogen gas tank 200 through the liquid hydrogen supply pipe 123 due to the internal pressure difference between the storage tank 110 and the hydrogen gas tank 200. At this time, the hydrogen is transferred from the storage tank 110 to the hydrogen gas tank 200 while some of it vaporizes and remains liquid.

The amount of liquid hydrogen sent from the liquid hydrogen tank 101 to the storage tank 110 in the second step (the aforementioned "predetermined amount") will be explained. Prior to executing the first step, the controller 190 calculates the amount of hydrogen to be filled into the hydrogen gas tank 200. The amount of hydrogen to be filled into the hydrogen gas tank 200 (the aforementioned "predetermined amount") corresponds to the difference between the amount of hydrogen when the hydrogen gas tank 200 is fully filled with hydrogen gas and the amount of hydrogen remaining in the hydrogen gas tank 200 before executing the first step. Prior to executing the first step, the controller 190 communicates with the controller of the fuel cell vehicle 900 to obtain information on the amount of hydrogen when the hydrogen gas tank 200 is fully filled and the current amount of hydrogen remaining. Alternatively, the controller 190 obtains information from the controller of the fuel cell vehicle 900 on the amount of hydrogen when the hydrogen gas tank 200 is fully filled and the current internal pressure and internal temperature of the hydrogen gas tank 200. The controller 190 estimates the amount of hydrogen remaining in the hydrogen gas tank 200 from the current internal pressure and temperature of the hydrogen gas tank 200. The controller 190 subtracts the current amount of remaining hydrogen from the amount of hydrogen that will be present when the hydrogen gas tank 200 is fully filled, and determines a predetermined amount, i.e., the amount of hydrogen to be sent to the hydrogen gas tank 200 during this filling.

The structure of the hydrogen gas tank 200 will now be described. The hydrogen gas tank 200 comprises an outer tank 201 and a hydrogen container 202 disposed inside the outer tank 201. The hydrogen container 202 is supported on the inner surface of the outer tank 201 via a heat insulating material 203. The hydrogen container 202 is in contact with the heat insulating material 203. The hydrogen container 202 is insulated from the outside. The hydrogen container 202 is a container with an open top, and liquid hydrogen supplied through the liquid hydrogen supply pipe 123 and the liquid hydrogen pipe 121 is stored in the hydrogen container 202. The outer tank 201 has a pressure-resistant structure that can withstand a predetermined upper limit pressure, but the hydrogen container 202 does not require a pressure-resistant structure because it has an opening.

The internal pressure of the outer tank 201 before liquid hydrogen is supplied varies depending on the amount of liquid hydrogen remaining in the tank. The liquid hydrogen contained in the hydrogen container 202 vaporizes, filling the outer tank 201 with hydrogen gas. All liquid hydrogen injected into the hydrogen gas tank 200 vaporizes.

In the hydrogen filling system 10 of the embodiment, hydrogen is injected in liquid form from the hydrogen filling device 100 into the hydrogen gas tank 200, the liquid hydrogen is vaporized inside the hydrogen gas tank 200, and the hydrogen gas tank 200 is filled with hydrogen gas. This filling method is achieved in the following two steps. Injection step: Liquid hydrogen is injected into the hydrogen gas tank 200. Vaporization step: Liquid hydrogen is vaporized inside the hydrogen gas tank 200. With this method, there is no need for the hydrogen filling device 100 to prepare a large amount of high-pressure hydrogen gas. In other words, the hydrogen filling device 100 can fill the hydrogen gas tank 200 with hydrogen gas without preparing a large amount of high-pressure hydrogen gas.

The fuel cell vehicle 900 is equipped with a fuel cell stack 901 that runs on hydrogen gas, and hydrogen gas from the hydrogen gas tank 200 (external tank 201) is sent to the fuel cell stack 901 via the second pipe 212.

The following describes other equipment provided in the hydrogen filling device 100. The storage tank 110 and auxiliary tank 140 are connected by a liquid hydrogen pipe 124. The liquid hydrogen pipe 124 is equipped with a fourth valve 134. When the controller 190 opens the fourth valve 134, the liquid hydrogen in the storage tank 110 flows into the auxiliary tank 140 in liquid form.

The auxiliary tank 140 comprises an outer tank 141 and a hydrogen container 142. The hydrogen container 142 is disposed inside the outer tank 141. The hydrogen container 142 is supported on the inner surface of the outer tank 141 via insulation 143. The hydrogen container 142 is in contact with the insulation 143. The hydrogen container 142 is insulated from the outside. The hydrogen container 142 is a container with an open top, and liquid hydrogen transferred from the storage tank 110 via the liquid hydrogen pipe 124 is stored in the hydrogen container 142. The outer tank 141 has a pressure-resistant structure that can withstand a predetermined upper limit pressure, while the hydrogen container 142 does not require a pressure-resistant structure because it has an opening. The liquid hydrogen stored in the hydrogen container 142 vaporizes, and the outer tank 141 is filled with high-pressure hydrogen gas. In other words, the auxiliary tank 140 has the same structure as the hydrogen gas tank 200. For example, as shown in FIG. 1, hydrogen gas can be filled from the auxiliary tank 140 into the hydrogen gas tank 911 of another fuel cell vehicle 910. In this case, the amount of liquid hydrogen injected into the auxiliary tank 140 corresponds to the difference between the amount of hydrogen when the hydrogen gas tank 911 is fully filled before filling and the amount of hydrogen remaining in the hydrogen gas tank 911 before filling. All of the liquid hydrogen injected into the auxiliary tank 140 vaporizes, and the auxiliary tank 140 becomes filled with hydrogen gas.

A hydrogen gas supply pipe 144 is connected to the auxiliary tank 140, and the hydrogen gas supply pipe 144 is equipped with a valve 145. The hydrogen gas supply pipe 144 can be connected to a regular hydrogen gas tank 911. The regular hydrogen gas tank 911 is mounted on, for example, a fuel cell vehicle 910. After the auxiliary tank 140 is filled with hydrogen gas, opening the valve 145 supplies high-pressure hydrogen gas from the auxiliary tank 140 to the regular hydrogen gas tank 911. In other words, the auxiliary tank 140 of the hydrogen filling device 100 can supply high-pressure hydrogen gas to the regular hydrogen gas tank 911.

A hydrogen gas pipe 151 is connected to the outer tank 141 of the auxiliary tank 140. The hydrogen gas pipe 151 is connected to the exhaust gas tank 150. The hydrogen gas pipe 151 is equipped with a pump 152 and a valve 153. As mentioned above, hydrogen gas is stored in the exhaust gas tank 150. When the internal pressure of the auxiliary tank 140 (external tank 141) drops, the controller 190 opens the valve 153 and drives the pump 152 to send hydrogen gas from the exhaust gas tank 150 to the auxiliary tank 140 (external tank 141). By driving the pump 152, pressurized hydrogen gas is supplied to the outer tank 141, and the internal pressure of the outer tank 141 also increases.

The hydrogen gas pipe 151 is also connected to the pressure accumulator tank 146. A valve 154 is provided in the hydrogen gas pipe 151 to stop the supply of hydrogen gas from the exhaust gas tank 150 to the pressure accumulator tank 146. The controller 190 opens the valve 154 and drives the pump 152 to send the hydrogen gas from the exhaust gas tank 150 to the pressure accumulator tank 146. As the pump 152 operates, the hydrogen gas in the exhaust gas tank 150 is pressurized and sent to the pressure accumulator tank 146. By opening the valve 154 and driving the pump 152, the pressure accumulator tank 146 is filled with high-pressure hydrogen gas.

A hydrogen gas supply pipe 147 is also connected to the pressure accumulator tank 146, and the hydrogen gas supply pipe 147 is equipped with a valve 148. A regular hydrogen gas tank 921 can also be connected to the hydrogen gas supply pipe 147. The regular hydrogen gas tank 921 is mounted on the fuel cell vehicle 920. When the controller 190 opens the valve 148, high-pressure hydrogen gas is supplied from the pressure accumulator tank 146 to the regular hydrogen gas tank 921.

To maintain the internal pressure of the exhaust gas tank 150 below a predetermined target upper limit pressure, the controller 190 opens the valve 154, drives the pump 152, and transfers the hydrogen gas in the exhaust gas tank 150 to the pressure accumulator tank 146 when the internal pressure of the exhaust gas tank 150 approaches the target upper limit pressure.

The exhaust gas tank 150 and liquid hydrogen tank 101 are connected by a hydrogen pipe 155, which is equipped with a valve 157. When the pressure in the liquid hydrogen tank 101 exceeds a predetermined threshold pressure, the controller 190 opens the valve 157, allowing evaporated hydrogen to flow into the exhaust gas tank 150.

The storage tank 110 comprises an outer tank 111 and a hydrogen container 112 placed inside the outer tank 111. The hydrogen container 112 has an opening at the top, connecting the inside and outside of the hydrogen container 112. The hydrogen container 112 is supported on the inner surface of the outer tank 111 by heat insulating material 113. A liquid hydrogen supply pipe 123 that sends liquid hydrogen to the hydrogen gas tank 200 is connected to the bottom of the hydrogen container 112. The liquid hydrogen in the liquid hydrogen tank 101 is temporarily stored in liquid form in the storage tank 110, and then sent to the hydrogen gas tank 200. This storage tank 110 is suitable for temporarily storing liquid hydrogen in liquid form.

(Second embodiment) Figure 2 shows a hydrogen filling device 100a of the second embodiment. The hydrogen filling device 100a and a hydrogen gas tank 200 constitute a hydrogen filling system 10a. The hydrogen gas tank 200 in Figure 2 is the same as the hydrogen gas tank 200 in Figure 1.

The hydrogen filling device 100a of the second embodiment has three sets of storage tanks 110 and third valves 133. The hydrogen filling device 100 has a set of storage tank 110a and third valve 133a, a set of storage tank 110b and third valve 133b, and a set of storage tank 110c and third valve 133c. The three sets of storage tanks 110 and third valves 133 are connected in parallel. Hereinafter, the three storage tanks 110a, 110b, and 110c will be referred to as storage tanks 110 when not distinguishing between them. The three third valves 133a, 133b, and 133c will be referred to as third valves 133 when not distinguishing between them.

The hydrogen filling device 100a is equipped with three hydrogen supply nozzles 139a, 139b, and 139c that supply hydrogen to fuel cell vehicles. It also has auxiliary valves 133d and 133e. By connecting each of the hydrogen supply nozzles 139a-139c to a hydrogen gas tank of a fuel cell vehicle, hydrogen can be supplied to three hydrogen gas tanks simultaneously.

Furthermore, by connecting a hydrogen gas tank to the hydrogen supply nozzle 139a and opening the third valve 133b and auxiliary valve 133d, hydrogen can be supplied from the storage tank 110b to the hydrogen gas tank. Furthermore, by connecting a hydrogen gas tank to the hydrogen supply nozzle 139a and opening the third valve 133c and auxiliary valves 133d and 133e, hydrogen can be supplied from the storage tank 110c to the hydrogen gas tank. In this way, hydrogen can be supplied from any of the three storage tanks 110a-110c to a hydrogen gas tank connected to any of the three hydrogen supply nozzles 139a-139c.

The controller 190 performs the first and second steps described above on the three sets of storage tanks 110. That is, after the first and second steps are performed, liquid hydrogen accumulates in one of the hydrogen containers 112 in the storage tank 110. The storage tank 110 (external tank 111) is equipped with a pressure sensor (not shown), allowing the controller 190 to know the internal pressure of the storage tank 110 (external tank 111). In the third step, the controller 190 opens the third valve 133 for the storage tank 110.

Liquid hydrogen is pushed from storage tank 110a to hydrogen gas tank 200. As the amount of liquid hydrogen in storage tank 110a decreases, the internal pressure of storage tank 110a decreases. As the internal pressure of storage tank 110a decreases, the third valve 133a of storage tank 110a is closed and the internal pressure of the hydrogen gas tank 200 rises. The required pressure is calculated from the pressure and temperature, and the internal pressure of storage tank 110b is raised to a pressure at which the tank can be filled. After the pressure has risen to the required pressure, controller 190 opens the third valve 133b of storage tank 110b. Liquid hydrogen is sent to the hydrogen gas tank 200 from storage tank 110b instead of storage tank 110a. In this way, liquid hydrogen can be quickly injected into the hydrogen gas tank 200.

The controller 190 calculates the filling amount when communicating with the fuel cell vehicle, and if the first storage tank 110a is insufficient, it executes the first and second steps in a storage tank that corresponds to the calculated amount. This internal pressure is always filled with a set pressure difference and is executed at the minimum internal pressure at that time. For example, a tank with a residual pressure of 10 MPa does not need to be filled to 70 MPa, so filling is performed at a lower pressure such as 30 MPa or 40 MPa. As the tank internal pressure increases, the storage tanks are switched from low pressure to high pressure.

In Figure 2, the auxiliary tank 140 and pressure accumulator tank 146 from Figure 1 are not shown, but the hydrogen filling device 100a of the second embodiment may also be equipped with the auxiliary tank 140 and pressure accumulator tank 146, similar to the hydrogen filling device 100 of the first embodiment.

A preferred structure for the hydrogen gas tank 200 will now be described. Figure 3 shows a schematic cross-sectional view of the hydrogen gas tank 200. As previously mentioned, the hydrogen gas tank 200 comprises an outer tank 201 and a hydrogen container 202 disposed within the outer tank 201. The hydrogen container 202 is supported on the inner surface of the outer tank 201 via a heat insulating material 203. The hydrogen container 202 has an opening 204 at its top, which connects the inside and outside of the hydrogen container 202.

The hydrogen gas tank 200 is equipped with a first pipe 211 that guides liquid hydrogen to the hydrogen container 202, and a second pipe 212 that guides hydrogen gas in the external tank 201 to the outside. The first pipe 211 and second pipe 212 penetrate the wall of the external tank 201. As mentioned above, the first pipe 211 is connected to the liquid hydrogen supply pipe 123 of the hydrogen filling device 100 (100a). The second pipe 212 is connected to the fuel cell stack 901 of the fuel cell vehicle 900 (see Figure 1). Although not shown, each of the first pipe 211 and second pipe 212 is equipped with a valve that stops the flow of fluid.

One end of the hydrogen container 202 is supported on the inner surface of the outer tank 201 via a support member 300. An insulating material 203 is provided at the tip of the support member 300, and the insulating material 203 is fixed to the hydrogen container 202.

An enlarged view of the dashed line area in Figure 3 (enlarged view of the support member 300) is shown at the bottom of Figure 3. The support member 300 includes a ball joint 310, a slide rod 320, a universal joint 330, and a heat insulator 203. The slide rod 320 can also be referred to as an extension/retraction mechanism.

The X direction of the coordinate system in the figure corresponds to the longitudinal direction of the support member 300, and the Y and Z directions are perpendicular to the X direction (longitudinal direction). The ball joint 310 is composed of an outer cup 311 and an inner ball 312. The inner ball 312 is fitted into the outer cup 311. The inner ball 312 can rotate around each of three axes (X-axis, Y-axis, and Z-axis) relative to the outer cup 311. The outer cup 311 is fixed to the inner surface of the outer tank 201, and the inner ball 312 is fixed to the slide rod 320. In other words, one end of the ball joint 310 is fixed to the inner surface of the outer tank 201, and the other end is fixed to one end of the slide rod 320 (one end of the extension mechanism). The ball joint 310 allows rotation of the slide rod 320 around each of the three axes relative to the outer tank 201.

The slide rod 320 is composed of a cylindrical outer rod 321 and a rod-shaped inner rod 322. The inner rod 322 is fitted into the outer rod 321, and the inner rod 322 extends and retracts in the X direction relative to the outer rod 321. The outer rod 321 is fixed to the inner ball 312 of the ball joint 310, and the inner rod 322 is fixed to the first yoke 331 of the universal joint 330. The slide rod 320 allows the universal joint 330 to extend and retract relative to the inner ball 312 of the ball joint 310.

The universal joint 330 has a structure in which a first yoke 331 and a second yoke 332 are connected to a cross shaft 333. As indicated by arrows A and B in FIG. 3, the second yoke 332 can rotate relative to the first yoke 331 around an axis parallel to the Y axis and an axis parallel to the Z axis. The first yoke 331 is fixed to the inner rod 322 of the slide rod 320, and the second yoke 332 is fixed to the heat insulating material 203. In other words, one end of the universal joint 330 is fixed to the heat insulating material 203, and the other end is connected to the other end of the slide rod 320. The universal joint 330 allows rotation of the heat insulating material 203 relative to the inner rod 322 of the slide rod 320 about two axes (the Y axis and the Z axis).

The other end of the support member 300, which faces the hydrogen container 202, can move/rotate freely relative to the one end facing the external tank 201. In other words, the other end of the support member 300 has six degrees of freedom relative to the one end (movement along the X, Y, and Z axes and rotation around each axis). The support member 300 allows deformation and shaking of the hydrogen container 202 inside the external tank 201. Furthermore, the support member 300 can firmly support the hydrogen container 202 even if the external tank 201 deforms. The hydrogen container 202 is insulated from the external tank 201 (and from the outside).

Figure 4 shows a cross-sectional view of a modified hydrogen gas tank 200a. The hydrogen gas tank 200a differs from the hydrogen gas tank 200 in Figure 3 in that it is equipped with a check valve 205 at the opening 204. Other than the check valve 205, the structure of the hydrogen gas tank 200a in Figure 4 is the same as the structure of the hydrogen gas tank 200 in Figure 3.

Check valve 205 allows gas to flow from the inside to the outside of hydrogen container 202, and blocks gas flow in the opposite direction (from the outside to the inside of hydrogen container 202). Check valve 205 may be a flexible metal plate that adheres to the edge of opening 204 on the outside of hydrogen container 202. A portion of the flexible metal plate is fixed to the outside of hydrogen container 202. The other portion of the flexible metal plate only contacts the edge of opening 204 of hydrogen container 202. When the pressure inside hydrogen container 202 becomes higher than the pressure outside, check valve 205 (flexible metal plate) rolls away from hydrogen container 202, allowing gas to flow from the inside to the outside of hydrogen container 202. When the pressure outside hydrogen container 202 is higher than the pressure inside, check valve 205 (flexible metal plate) adheres to the edge of opening 204 around the entire periphery. Therefore, gas cannot flow from the outside to the inside of hydrogen container 202.

The hydrogen gas tank 200/200a is a tank suitable for vaporizing liquid hydrogen injected into the hydrogen container 202 and filling the outer tank 201 with hydrogen gas. The hydrogen gas tank 200/200a is suitable for use in pairs with the hydrogen filling device 100/100a of the embodiment.

In the storage tank 110, the hydrogen container 112 may be supported on the inner surface of the outer tank 111 by the support member 300 shown in Figure 3. In the auxiliary tank 140, the hydrogen container 142 may be supported on the inner surface of the outer tank 141 by the support member 300.

It is also preferable to provide a heater in the storage tank 110. The heater heats the liquid hydrogen. After executing the second step and before executing the third step, the controller 190 activates the heater to heat the liquid hydrogen. The heat from the heater promotes the vaporization of the liquid hydrogen. This shortens the time it takes for the pressure inside the outer tank 111 to reach the desired pressure.

After performing the third step, the controller 190 may close the third valve 133 and open the second valve 132 again to discharge the remaining gas in the storage tank 110 into the exhaust gas tank 150.

Features of the hydrogen tank disclosed in this specification are listed below. One embodiment of the hydrogen tank disclosed in this specification comprises an outer tank, a hydrogen container, a support member, a first pipe, and a second pipe. The hydrogen container is a container placed inside the outer tank and has an opening that connects the inside and outside of the container. The support member supports the hydrogen container against the inner surface of the outer tank. The first pipe conducts liquid hydrogen from outside the outer tank to the hydrogen container. The second pipe conducts hydrogen gas inside the outer tank to the outside of the outer tank. The support member comprises an expansion mechanism, a ball joint, and a universal joint. One end of the ball joint is fixed to the inner surface of the outer tank, and the other end is fixed to one end of the expansion mechanism. One end of the universal joint is fixed to the insulation, and the other end is connected to the other end of the expansion mechanism. The insulation is fixed to the hydrogen container.

By using the hydrogen tank disclosed in this specification, hydrogen can be placed in the tank's hydrogen container as a liquid. The liquid hydrogen placed in the hydrogen container vaporizes and spreads throughout the outer tank. Unlike conventional tanks, which are filled with hydrogen as a gas, hydrogen can be easily filled.

The support member has one end fixed to the inner surface of the outer tank and the other end on the opposite side that can swing. This support member allows the hydrogen container to deform and swing inside the outer tank. Furthermore, the support member can firmly support the hydrogen container even if the outer tank deforms.

It is preferable that the opening of the hydrogen container be equipped with a check valve that allows gas to flow from the inside to the outside of the hydrogen container and blocks gas flow in the opposite direction.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of those objectives is itself technically useful.

10, 10a: Hydrogen filling system 100, 100a: Hydrogen filling device 101: Liquid hydrogen tank 110, 110a-110c: Storage tank 111, 141, 201: Outer tank 112, 142, 202: Hydrogen container 113, 143, 203: Heat insulating material 121, 124: Liquid hydrogen pipe 122: Exhaust gas pipe 123: Liquid hydrogen supply pipe 131, 132, 133, 133a-133c, 134, 145, 148, 153, 154, 157: Valve 140: Auxiliary tank 139, 139a-139c: Hydrogen supply nozzle 144: Hydrogen gas supply pipe 146: Accumulator tank 147: Hydrogen gas supply pipe 150: Exhaust gas tank 151: Hydrogen gas pipe 152: Pump 155: Hydrogen pipe 190: Controller 200, 200a: Hydrogen gas tank 204: Opening 205: Check valve 211: First pipe 212: Second pipe 300: Support member 310: Ball joint 311: Outer cup 312: Inner ball 320: Slide rod 321: Outer rod 322: Inner rod 330: Universal joint 331: First yoke 332: Second yoke 333: Cross shaft 900: Fuel cell vehicle 901: Fuel cell stack 902: Hydrogen supply port 910, 920: Fuel cell vehicle 911, 921: Hydrogen gas tank

Claims (2)

A hydrogen filling device that fills hydrogen into a hydrogen gas tank.
A liquid hydrogen tank that stores liquid hydrogen;
a storage tank for temporarily storing the liquid hydrogen in the liquid hydrogen tank in a liquid state;
a liquid hydrogen supply pipe that allows the liquid hydrogen in the storage tank to flow into the hydrogen gas tank in liquid form;
a first valve that stops the flow of the liquid hydrogen from the liquid hydrogen tank to the storage tank;
a second valve for discharging gas from the storage tank;
a third valve that stops the flow of the liquid hydrogen from the storage tank to the hydrogen gas tank;
an auxiliary tank into which the liquid hydrogen in the storage tank is transferred in liquid form;
a gas supply pipe for supplying the liquid hydrogen vaporized in the auxiliary tank to another hydrogen gas tank;
A controller;
It is equipped with
The auxiliary tank is
The outer tank and
a hydrogen container supported on the inner surface of the outer tank via a thermal insulator, the hydrogen container having an opening communicating the inside and outside of the hydrogen container, and configured to receive the liquid hydrogen supplied from the storage tank;
It is equipped with
The controller
a first step of injecting the liquid hydrogen into the storage tank by closing the third valve and opening the first valve and the second valve;
a second step of closing the first valve and the second valve when a predetermined amount of liquid hydrogen has accumulated in the storage tank;
a third step of opening the third valve to inject the liquid hydrogen into the hydrogen gas tank when the internal pressure of the storage tank reaches a predetermined hydrogen extrusion pressure;
Run
the hydrogen extrusion pressure is higher than the internal pressure of the hydrogen gas tank,
A hydrogen filling device, wherein the predetermined amount is an amount of hydrogen equivalent to the difference between the amount of hydrogen when the hydrogen gas tank is fully filled with hydrogen gas and the amount of hydrogen remaining in the hydrogen gas tank before the first step is performed. the auxiliary tank includes a support member that supports the hydrogen container against the inner surface;
The support member is
An extension mechanism;
a ball joint having one end fixed to the inner surface and the other end fixed to one end of the telescopic mechanism;
a universal joint having one end fixed to the heat insulating material and the other end connected to the other end of the extension mechanism;
It is equipped with
The heat insulating material is fixed to the hydrogen container.
The hydrogen filling device according to claim 1 .