Hydrogen filling system

Abstract

Hydrogen filling system (2, 2a), with: a first container (31) and a second container (32) which are arranged to be filled with hydrogen and are connected to each other; a first hydrogen supply means (10) and a second hydrogen supply means (20) which are configured to supply hydrogen to the first container (31) and the second container (32); and a control device (5) which is configured to control the first hydrogen supply device (10) and the second hydrogen supply device (20), wherein the control device (5) is configured to do the following: Calculating a first hydrogen filling factor, which is a total hydrogen filling factor of the first container (31) and the second container (32), based on a first pressure of hydrogen supplied from the first hydrogen supply medium (10) and a first internal temperature of the first container (31), Calculating a second hydrogen filling factor, which is a total hydrogen filling factor of the first container (31) and the second container (32), based on a second pressure of hydrogen supplied from the second hydrogen supply medium (20) and a second internal temperature of the second container (32), and Stopping the first hydrogen feed (10) and the second hydrogen feed (20) when a higher fill factor of the first hydrogen fill factor and the second hydrogen fill factor reaches a predetermined threshold fill factor.

Description

Background of the invention 1. Field of the invention

[0001] The technology disclosed in the present description relates to a hydrogen filling system. 2. Description of the state of the art

[0002] JP 2010-286 015 A discloses an example of a hydrogen filling system. A hydrogen tank is installed in a fuel cell vehicle. Hydrogen is supplied to the hydrogen tank from a hydrogen feed system. The amount of hydrogen in the hydrogen tank (hydrogen fill factor) is estimated from the temperature and pressure within the hydrogen tank. For the sake of simplicity, the hydrogen tank will subsequently be referred to simply as the "tank".

[0003] DE 11 2009 005 421 T5 and US 2021 / 0 388 947 A1 each disclose a hydrogen filling system according to the preamble of claim 1. Summary of the invention

[0004] Filling multiple interconnected containers with hydrogen increases filling time. This time can be reduced by simultaneously connecting multiple hydrogen feeders to the containers. As described above, the hydrogen filling factor is determined based on the container's internal temperature and pressure. However, when hydrogen is supplied from the hydrogen feeders to a container with a large overall capacity, the pressure within the container varies locally, making it difficult to accurately determine the hydrogen filling factor. This, in turn, complicates the filling process until a suitable hydrogen filling factor is reached.The present invention provides a technology that enables a container to be filled with hydrogen up to a suitable hydrogen filling factor in a hydrogen filling system in which hydrogen is supplied to a container simultaneously from a plurality of hydrogen supply means.

[0005] Specifically, the present invention provides a hydrogen filling system which has the features of claim 1.

[0006] The hydrogen filling system according to the invention can suitably determine the hydrogen filling factor using the first internal temperature, the second internal temperature, the first pressure, and the second pressure. Accordingly, the hydrogen containers can be filled with hydrogen up to a suitable hydrogen filling factor.

[0007] It should be noted that the hydrogen filling factor, obtained from the temperature and pressure, does not depend on the capacity of the container, and that the first and second containers are connected. Accordingly, the expression "hydrogen filling factors of the first container and the second container" can be rephrased as "hydrogen filling factor of the first container" or "hydrogen filling factor of the second container".

[0008] It is desirable that the first and second containers and the first and second hydrogen supply means have the following relationship. The length of a hydrogen supply channel from the first hydrogen supply means to the first container can be shorter than the length of a hydrogen supply channel from the first hydrogen supply means to the second container, and the length of the hydrogen supply channel from the second hydrogen supply means to the second container can be shorter than the length of the hydrogen supply channel from the second hydrogen supply means to the first container. If such a relationship is established, the first container will be primarily filled with hydrogen from the first hydrogen supply means, and the second container will be primarily filled with hydrogen from the second hydrogen supply means.

[0009] The hydrogen filling factors of the first and second connected containers should initially be the same; however, there is a flow channel resistance between the first and second containers, and there are cases where the hydrogen filling factor of the first container and the hydrogen filling factor of the second container differ. Given the above relationship, the first temperature and pressure can appropriately represent the hydrogen filling factor in the first container, and the second temperature and pressure can appropriately represent the hydrogen filling factor in the second container. This allows the hydrogen filling factor of the first and second containers to be appropriately expressed.Overfilling can be prevented by controlling the first and second hydrogen supply methods in accordance with the larger value of the hydrogen filling factors.

[0010] The first container can be configured with a number of sub-containers, and the first internal temperature can be the highest of the internal temperatures of the sub-containers. Similarly, the second container can be configured with a number of sub-containers, and the second internal temperature can be the highest of the internal temperatures of the sub-containers. This allows the sub-containers to be filled with hydrogen more safely. It should be noted that the term "sub-container" is used for convenience to distinguish them from the "first container" and "second container" mentioned above, and does not limit their capacity or performance.

[0011] Details of the technology disclosed in the present description and further improvements are described below in the “Detailed Description of Embodiments”. Brief description of the drawings

[0012] Features, advantages, and the technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein: Fig. 1 a block diagram of a hydrogen filling system according to a first embodiment; and Fig. 2 is a block diagram of a hydrogen filling system according to a second embodiment. Detailed description of embodiments: First embodiment

[0013] A hydrogen filling system 2 according to a first embodiment is described with reference to Fig. 1 described. Fig. Figure 1 is a block diagram of a hydrogen filling system 2 according to the first embodiment. The hydrogen filling system 2 comprises a first hydrogen supply means 10, a second hydrogen supply means 20, and a fuel cell vehicle 30, which is provided with a first container 31 and a second container 32. Fig. Figure 1 is a top view showing a design of the first hydrogen supply device 10, the second hydrogen supply device 20, and the fuel cell vehicle 30. Fig. 1. Dashed lines represent signal lines.

[0014] The fuel cell vehicle 30 is equipped with a fuel cell 40, an inverter 41, and a motor 42. The first tank 31 and the second tank 32, which store hydrogen, and the fuel cell 40 are connected by a fuel line 37, and hydrogen in the first tank 31 and the second tank 32 is supplied to the fuel cell 40 via the fuel line 37. The fuel line 37 is also connected to a first filling port 35 and a second filling port 36.

[0015] Direct current electrical energy generated by the fuel cell 40 is converted into alternating current electrical energy by the inverter 41. The alternating current electrical energy output from the inverter 41 is supplied to the traction motor 42. An output torque from the motor 42 is transmitted to the rear wheels 44, which are the drive wheels, by means of a differential gear 43.

[0016] The first container 31 is equipped with a temperature sensor 33 for measuring the internal temperature (first internal temperature) of the first container 31, and the second container 32 is equipped with a temperature sensor 34 for measuring the internal temperature of the second container 32 (second internal temperature). Measurement data from the temperature sensors 33 and 34 are sent to a control device (vehicle control device 38) of the fuel cell vehicle 30.

[0017] Fig. Figure 1 shows a state in which the fuel cell vehicle 30 is stopped at a hydrogen station and hydrogen is being supplied to it. The hydrogen station is equipped with two hydrogen supply points (a first hydrogen supply point 10 and a second hydrogen supply point 20). The total tank capacity of the fuel cell vehicle 30 (the combined capacity of the first tank 31 and the second tank 32) is large. The fuel cell vehicle 30 is equipped with two filling ports 35 and 36, so that hydrogen can be supplied simultaneously from the first hydrogen supply point 10 and the second hydrogen supply point 20. The fuel cell vehicle 30 can be filled with hydrogen from the two hydrogen supply points 10 and 20 simultaneously, thereby reducing the hydrogen filling time for the first tank 31 and the second tank 32.

[0018] A nozzle (first nozzle 11) of the first hydrogen supply medium 10 is connected to the first filling opening 35, and a nozzle (second nozzle 21) of the second hydrogen supply medium 20 is connected to the second filling opening 36. The hydrogen from the first hydrogen supply medium 10 is supplied to the first container 31 and the second container 32 through the first nozzle 11, the first filling opening 35, and the fuel line 37. The hydrogen from the second hydrogen supply medium 20 is supplied to the first container 31 and the second container 32 through the second nozzle 21, the second filling opening 36, and the fuel line 37.

[0019] The first hydrogen supply unit 10 is equipped with a pressure sensor 12 for measuring the supply pressure (first pressure) of hydrogen supplied from the first hydrogen supply unit 10, and the second hydrogen supply unit 20 is equipped with a pressure sensor 22 for measuring the supply pressure (second pressure) of hydrogen supplied from the second hydrogen supply unit 20. A station control unit 5 controls the first hydrogen supply unit 10 and the second hydrogen supply unit 20. Measurement data from the pressure sensors 12 and 22 are sent to the station control unit 5.

[0020] While hydrogen is being supplied to the first tank 31 and the second tank 32 of the fuel cell vehicle 30, the station control device 5 and the vehicle control device 38 can communicate with each other. When it detects that the first nozzle 11 is connected to the first filling port 35 and the second nozzle 21 is connected to the second filling port 36, the station control device 5 notifies the vehicle control device 38 of the start of hydrogen supply and also starts a supply of hydrogen from the first hydrogen supply device 10 and the second hydrogen supply device 20.

[0021] It is generally known that the hydrogen filling factor in a container is expressed as a function of the container's internal pressure and temperature. It is important to note that the hydrogen filling factor represents the ratio of the amount of hydrogen currently in the container to the amount of hydrogen it would hold when completely filled. The hydrogen filling factor, derived from the container's internal pressure and temperature, is independent of the container's capacity. An expression for calculating the hydrogen filling factor from the container's internal pressure and temperature is described in the literature (SAE J2601, Fueling Protocols for Light Duty Gaseous Hydrogen, https: / / www.sae.org / standards / content / j2601_201407 / ).

[0022] The fuel cell vehicle 30 is equipped with two hydrogen tanks and is filled with hydrogen through two points (the first filling port 35 and the second filling port 36). Furthermore, there is also a flow channel resistance on the fuel line 37, which connects the first tank 31 and the second tank 32. Accordingly, the temperature and pressure in the tanks can vary depending on the position within them. The hydrogen filling system 2 can accurately determine the hydrogen filling factor based on the temperature and pressure in the tank at various positions and can fill the tank with hydrogen up to a suitable hydrogen filling factor.

[0023] The station control device 5 controls the first hydrogen supply device 10 and the second hydrogen supply device 20. The hydrogen supply process carried out by the station control device 5 is described.

[0024] The station control device 5 receives data regarding the first internal temperature and the second internal temperature from the vehicle control device 38. The station control device 5 finds exactly one total hydrogen filling factor of the first container 31 and the second container 32 (a hydrogen filling factor with respect to the total capacity from the capacity of the first container 31 and the capacity of the second container 32), based on the first internal temperature, the second internal temperature, the first pressure and the second pressure.

[0025] As in Fig. As shown in Figure 1, the first container 31 and the first filling port 35 are located on the left side of the vehicle, as is the first hydrogen supply point 10. The second container 32 and the second filling port 36 are located on the right side of the vehicle, and the second hydrogen supply point 20 is also located on the right side of the vehicle. The first container 31, the second container 32, the first filling port 35, and the second filling port 36 are connected by the fuel line 37. The hydrogen supply channel from the first hydrogen supply point 10 to the first container 31 is shorter than the hydrogen supply channel from the first hydrogen supply point 10 to the second container 32.By shortening the hydrogen supply channel, the pressure drop between the pressure sensor and the container is reduced, an error in the calculated fill factor is minimized, and the fill rate (fill quantity per unit of time) can be increased compared to a case with only one supply medium. Furthermore, the hydrogen supply channel from the second hydrogen supply medium 20 to the second container 32 is shorter than the hydrogen supply channel from the second hydrogen supply medium 20 to the first container 31. As described above, the first container 31 and the second container 32 are connected by the fuel line 37, which is narrow. Accordingly, the first container 31 is primarily filled with hydrogen from the first hydrogen supply medium 10, and the second container 32 is primarily filled with hydrogen from the second hydrogen supply medium 20.

[0026] From the above relationship, it follows that the hydrogen supply pressure (first pressure) of the first hydrogen supply medium 10 is close to the internal pressure of the first container 31, and the hydrogen supply pressure (second pressure) of the second hydrogen supply medium 20 is close to the internal pressure of the second container 32. The station control medium 5 calculates the first hydrogen filling factor based on the first pressure and the first internal temperature, and calculates the second hydrogen filling factor based on the second pressure and the second internal temperature. The first container 31 and the second container 32 are connected by the fuel line 37, and accordingly, it would naturally be assumed that the first hydrogen filling factor and the second hydrogen filling factor would be the same. However, if the internal temperature and pressure vary locally, there are cases in which the first hydrogen filling factor and the second hydrogen filling factor differ.The station control device 5 stops the first hydrogen supply device 10 and the second hydrogen supply device 20 when the higher hydrogen fill factor of the first hydrogen fill factor and the second hydrogen fill factor reaches a predetermined threshold fill factor. Because the station control device 5 decides to stop the hydrogen supply based on the higher hydrogen fill factor of the first hydrogen fill factor and the second hydrogen fill factor, overfilling of the hydrogen tank is prevented, and the safety of the first tank 31 and the second tank 32 being filled with hydrogen is improved. The threshold fill factor is set, for example, at 90%.

[0027] In the hydrogen filling system 2 according to the first embodiment, all of the interconnected hydrogen containers (the first container 31 and the second container 32) can be filled with hydrogen up to a suitable hydrogen filling factor.

[0028] Fig. Figure 2 is a block diagram of a hydrogen filling system 2a according to a second embodiment. The hydrogen filling system 2a is equipped with a fuel cell vehicle 30, the first hydrogen supply means 10 and the second hydrogen supply means 20.

[0029] The fuel cell vehicle 30a is equipped with four tanks (one sub-tank 31a No. 1a, one sub-tank 31b No. 1b, one sub-tank 32a No. 2a, and one sub-tank 32b No. 2b). The four sub-tanks 31a, 31b, 32a, and 32b are connected by the fuel line 37. Sub-tank 31a No. 1a and sub-tank 31b No. 1b are closer to the first filling opening 35 than sub-tank 32a No. 2a and sub-tank 32b No. 2b, and sub-tank 32a No. 2a and sub-tank 32b No. 2b are closer to the second filling opening 36 than sub-tank 31a No. 1a and sub-tank 31b No. 1b. It should be noted that the term ‘sub-container’ is an expression used to distinguish it from the ‘first container 31’ and the ‘second container 32’ described above for practical reasons and does not limit its capacity or performance.

[0030] The first hydrogen supply channel 10 is connected to the first filling opening 35, and the second hydrogen supply channel 20 is connected to the second filling opening 36. The length of a hydrogen supply channel from the first hydrogen supply channel 10 to the lower container 31a No. 1a and the lower container 31b No. 1b is shorter than a hydrogen supply channel from the first hydrogen supply channel 10 to the lower container 32a No. 2a and the lower container 32b No. 2b. The length of a hydrogen supply channel from the second hydrogen supply channel 20 to the lower container 32a No. 2a and the lower container 32b No. 2b is shorter than the hydrogen supply channel from the second hydrogen supply channel 20 to the lower container 31a No. 1a and the lower container 31b No. 1b. Accordingly, the lower container 31a No. 1a and the lower container 31b No. 1b are primarily filled with hydrogen from the first hydrogen supply medium 10, and the lower container 32a No. 2a and the lower container 32b No.2b primarily filled with hydrogen from the second hydrogen supply medium 20.

[0031] Sub-container 31a No. 1a and sub-container 31b No. 1b are grouped as the first container 31, and sub-container 32a No. 2a and sub-container 32b No. 2b are grouped as the second container 32. In other words, sub-container 31a No. 1a and sub-container 31b No. 1b can be treated as a first container 31, and sub-container 32a No. 2a and sub-container 32b No. 2b can be treated as a second container 32.

[0032] The lower container 31a No. 1a is equipped with a temperature sensor 33a for measuring its internal temperature, and the lower container 31b No. 1b is equipped with a temperature sensor 33b for measuring its internal temperature. The lower container 32a No. 2a is equipped with a temperature sensor 34a for measuring its internal temperature, and the lower container 32b No. 2b is equipped with a temperature sensor 34b for measuring its internal temperature.

[0033] Measurement data from temperature sensors 33a, 33b, 34a, and 34b are sent to the station control unit 5 via the vehicle control unit 38. The station control unit 5 calculates a first hydrogen filling factor based on the higher of the internal temperatures of the lower reservoir 31a No. 1a and the lower reservoir 31b No. 1b, which are grouped as the first reservoir 31, and the first pressure (hydrogen supply pressure of the first hydrogen supply unit 10). The station control unit 5 calculates a second hydrogen filling factor based on the higher of the internal temperatures of the lower reservoir 32a No. 2a and the lower reservoir 32b No. 2b, which are grouped as the second reservoir 32, and the second pressure (hydrogen supply pressure of the second hydrogen supply unit 20).The station control device 5 stops the first hydrogen supply device 10 and the second hydrogen supply device 20 when the higher hydrogen filling factor of the first hydrogen filling factor and the second hydrogen filling factor reaches a threshold filling factor. The hydrogen filling system 2a according to the second embodiment can also fill all the connected containers 31a, 31b, 32a and 32b with hydrogen up to a suitable hydrogen filling factor.

[0034] Points to be considered regarding the hydrogen filling system described in the embodiments are outlined. The hydrogen filling system according to the embodiments uses the pressure of hydrogen supplied by the hydrogen supply medium (hydrogen supply pressure) as an approximation of the internal pressure of the containers. In the hydrogen filling system according to the embodiments, if two hydrogen supply media are used simultaneously, the hydrogen filling factor of the containers can be determined in a suitable manner using the hydrogen supply pressure of each hydrogen supply medium.

[0035] The technology described in the embodiments can also be applied when containers are simultaneously filled with hydrogen via three or more hydrogen supply methods. In this case, the hydrogen filling factor of the containers is determined based on the hydrogen supply pressure from each of the three or more hydrogen supply methods. When the highest hydrogen filling factor among a variety of determined hydrogen filling factors reaches the threshold filling factor, all hydrogen supply methods are stopped. Thus, the containers can be filled with hydrogen up to a suitable hydrogen filling factor.

[0036] If the connected containers are filled with hydrogen simultaneously, each container is preferably equipped with a temperature sensor. The temperature sensors are preferably installed near the container inlets. A container group with a short hydrogen supply channel to the first hydrogen supply medium constitutes the first container group, and a container group with a short hydrogen supply channel to the second hydrogen supply medium constitutes the second container group. For example, consider a vehicle with filling ports on the right and left sides, where the container group on the left side constitutes the first container group and the container group on the right side constitutes the second container group.The first container group and the second container group are connected to each other, wherein the first container group is primarily filled with hydrogen from the first hydrogen supply medium which is connected to the filling opening on the left side, and wherein the second container group is primarily filled with hydrogen from the second hydrogen supply medium which is connected to the filling opening on the right side.

[0037] The station control system determines the first hydrogen filling factor from the highest temperature reading from the temperature sensors of the first tank group and the hydrogen supply pressure of the first hydrogen supply. The station control system determines the second hydrogen filling factor from the highest temperature reading from the temperature sensors of the second tank group and the hydrogen supply pressure of the second hydrogen supply. The station control system stops all hydrogen supply when the combined hydrogen filling factor of the first and second hydrogen filling factors reaches the threshold filling factor.

[0038] The technology disclosed in the present description can be an arrangement that supplies hydrogen to a container that is different from a hydrogen container installed in a fuel cell vehicle.

[0039] The hydrogen filling process is preferably based on regulations established by the Society of Automotive Engineers (SAE), however, the technology disclosed in this description is not limited to the SAE regulations.

Claims

[1] Hydrogen filling system (2, 2a), with: a first container (31) and a second container (32) which are arranged to be filled with hydrogen and are connected to each other; a first hydrogen supply means (10) and a second hydrogen supply means (20) which are configured to supply hydrogen to the first container (31) and the second container (32); and a control device (5) which is configured to control the first hydrogen supply device (10) and the second hydrogen supply device (20), wherein the control device (5) is configured to do the following: Calculating a first hydrogen filling factor, which is a total hydrogen filling factor of the first container (31) and the second container (32), based on a first pressure of hydrogen supplied from the first hydrogen supply medium (10) and a first internal temperature of the first container (31), Calculating a second hydrogen filling factor, which is a total hydrogen filling factor of the first container (31) and the second container (32), based on a second pressure of hydrogen supplied from the second hydrogen supply medium (20) and a second internal temperature of the second container (32), and Stopping the first hydrogen feed (10) and the second hydrogen feed (20) when a higher fill factor of the first hydrogen fill factor and the second hydrogen fill factor reaches a predetermined threshold fill factor. [2] Hydrogen filling system according to claim 1, wherein: a length of a hydrogen supply channel from the first hydrogen supply medium (10) to the first container (31) is shorter than a length of a hydrogen supply channel from the first hydrogen supply medium (10) to the second container (32); and a length of a hydrogen supply channel from the second hydrogen supply medium (20) to the second container (32) is shorter than a length of a hydrogen supply channel from the second hydrogen supply medium (20) to the first container (31). [3] Hydrogen filling system according to claim 1 or 2, wherein the first container (31) is arranged from a plurality of sub-containers (31a, 31b), and the first internal temperature is the highest internal temperature of the internal temperatures of the sub-containers (31a, 31b).

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