Patent Description:
In recent years, hydrogen fuel has attracted attention as a clean energy source in addition to conventional fuel oils such as gasoline as fuel for automobiles. Along with this, development of a fuel cell vehicle (FCV) using hydrogen fuel as a power source is under way. In order to popularize such a fuel cell vehicle (FCV), it is necessary to spread hydrogen stations that can rapidly fill a FCV with hydrogen fuel. In a hydrogen station, in order to rapidly fill a FCV with hydrogen fuel (hydrogen gas), a multi-stage pressure accumulator including a plurality of pressure accumulators for accumulating hydrogen fuel compressed to a high pressure by the compressor is installed. Then, hydrogen fuel is rapidly charged from the pressure accumulator to the fuel tank by the differential pressure between the pressure in the pressure accumulator and the pressure in the fuel tank of the FCV while keeping the differential pressure large by switching the pressure accumulators to be used (see, for example, Patent Literature <NUM>).

Here, various valves are provided in the dispenser housing that fills the FCV with hydrogen fuel supplied from the multi-stage pressure accumulator. Out of these valves, unlike other ON/OFF valves, a flow rate adjusting valve is often used at an intermediate opening for adjusting the flow rate of fuel gas. Thus, leakage from the shaft seal portion occurs due to deterioration over time. Use or development of a highly accurate flow rate adjusting valve that does not easily cause such a leakage is costly. Therefore, inexpensive and safe hydrogen fuel filling is demanded.

Here, when supplying fuel gas to a large vehicle, there is disclosed a method of using a bypass path in addition to the path through which the fuel gas is supplied to an ordinary vehicle in order to shorten the filling time (see, for example, Patent Literature <NUM>). However, even with this method, the opening of the flow control valve is adjusted, and thus it is not possible to prevent the occurrence of leakage due to the above-described deterioration of the flow control valve over time. Moreover, Patent Literature <NUM> describes a fuel gas charging system comprising several pressure accumulators and two or more adjustment valves for flow rate control as well as a fuel gas charging method.

One aspect of the present invention provides a system and a method capable of hydrogen fuel filling while adjusting the flow rate of supplied hydrogen fuel without using a flow rate adjusting valve.

According to one aspect of the present invention, a hydrogen fuel filling system includes:.

According to further another aspect of the present invention, a hydrogen fuel filling method includes:.

One aspect of the present invention enables hydrogen fuel filling while adjusting the flow rate of supplied hydrogen fuel without using a flow rate adjusting valve. Therefore, inexpensive and safe hydrogen fuel filling becomes possible.

<FIG> is an example of a configuration diagram illustrating a configuration of a hydrogen fuel supply system for a hydrogen station according to embodiment <NUM>. In <FIG>, a hydrogen fuel supply system <NUM> is provided in a hydrogen station <NUM>. The hydrogen fuel supply system <NUM> includes a multi-stage pressure accumulator <NUM>, a dispenser <NUM>, a compressor <NUM>, and a control circuit <NUM>. The multi-stage pressure accumulator <NUM> includes a plurality of pressure accumulators <NUM>, <NUM> and <NUM> having different minimum operating pressures to provide multi stage. In the example of <FIG>, three pressure accumulators <NUM>, <NUM>, and <NUM> constitute the multi-stage pressure accumulator <NUM>. In the example of <FIG>, the pressure accumulator <NUM> acts as a 1st bank having a low minimum operating pressure. The pressure accumulator <NUM> acts as a 2nd bank having an intermediate minimum operating pressure. The pressure accumulator <NUM> acts as a 3rd bank having a high minimum operating pressure. In the hydrogen station <NUM>, a curdle <NUM>, an intermediate pressure accumulator <NUM>, and/or a hydrogen production apparatus <NUM> are additionally provided. In addition, a hydrogen trailer <NUM> filled with hydrogen gas for delivery comes into the hydrogen station <NUM>.

In <FIG>, in the dispenser <NUM> (an example of a filling system), a filter <NUM>, a flow passage 33a (first flow passage), a flow passage 33b (second flow passage), valves 34a and 34b, a shutoff valve <NUM>, a flowmeter <NUM>, a cooler <NUM> (pre-cooler), a shutoff valve <NUM>, a filter <NUM>, an emergency release coupler <NUM>, a thermometer <NUM>, and a control circuit <NUM> are provided, and in the dispenser <NUM>, a nozzle <NUM> extending outside the dispenser <NUM> is further provided. The dispenser <NUM> removes impurities of hydrogen fuel (hydrogen gas) supplied from the multi-stage pressure accumulator <NUM> with the filter <NUM>, passes hydrogen fuel through one or both of the flow passages 33a and 33b, and delivers hydrogen fuel to the cooler <NUM> through the shutoff valve <NUM> and the flowmeter <NUM>. At that time, the flow rate per unit time of hydrogen fuel supplied from the multi-stage pressure accumulator <NUM> is measured by the flowmeter <NUM>. The hydrogen fuel is then cooled to, for example, -<NUM> by the cooler <NUM>. With the cooled hydrogen fuel, a fuel tank <NUM> mounted on an FCV <NUM> is filled through the shutoff valve <NUM>, the filter <NUM>, the emergency release coupler <NUM>, and the nozzle <NUM> using the differential pressure. At that time, the temperature of hydrogen fuel supplied from the dispenser <NUM> is measured by the thermometer <NUM> provided near the outlet of the dispenser <NUM>. The control circuit <NUM> in the dispenser <NUM> controls opening/closing of the valves 34a and 34b, the shutoff valves <NUM> and <NUM>, and a depressurizing valve. In addition, the control circuit <NUM> is connected with the flowmeter <NUM>, the thermometer <NUM>, and a thermometer <NUM> for measuring the outside air temperature. Furthermore, the control circuit <NUM> is configured to be able to communicate with an on-vehicle device <NUM> in the FCV <NUM> (fuel cell vehicle (FCV) using hydrogen fuel as a power source) that has come into the hydrogen station <NUM>. For example, the control circuit <NUM> is configured to be able to communicate wirelessly using infrared rays. In addition, the control circuit <NUM> is connected to the control circuit <NUM> that controls the entire hydrogen fuel supply system <NUM>.

In <FIG>, the suction side of the compressor <NUM> is connected to the curdle <NUM> via a valve <NUM> by a pipe. Similarly, the suction side of the compressor <NUM> is connected to the intermediate pressure accumulator <NUM> via a valve <NUM> by a pipe. Similarly, the suction side of the compressor <NUM> is connected to the filling tank of the hydrogen trailer <NUM> via a valve <NUM> by a pipe. Similarly, the suction side of the compressor <NUM> is connected to the discharge side of the hydrogen production apparatus <NUM> via a valve <NUM> by a pipe.

The discharge side of the compressor <NUM> is connected to the pressure accumulator <NUM> via a valve <NUM> by a pipe. Similarly, the discharge side of the compressor <NUM> is connected to the pressure accumulator <NUM> via a valve <NUM> by a pipe. Similarly, the discharge side of the compressor <NUM> is connected to the pressure accumulator <NUM> via a valve <NUM> by a pipe.

In addition, the pressure accumulator <NUM> is connected to the dispenser <NUM> via a valve <NUM> by a pipe. Further, the pressure accumulator <NUM> is connected to the dispenser <NUM> via a valve <NUM> by a pipe. In addition, the pressure accumulator <NUM> is connected to the dispenser <NUM> via a valve <NUM> by a pipe. In this way, the dispenser <NUM> is commonly connected to the pressure accumulators <NUM>, <NUM>, and <NUM> included in the multi-stage pressure accumulator <NUM>.

The pressure in the curdle <NUM> is measured by a pressure gauge <NUM>. The pressure in the intermediate pressure accumulator <NUM> is measured by a pressure gauge <NUM>. The pressure in the filling tank of the hydrogen trailer <NUM> is measured by a pressure gauge <NUM>. The discharge pressure of the hydrogen production apparatus <NUM> is measured by a pressure gauge <NUM>.

The pressure in the pressure accumulator <NUM> is measured by a pressure gauge <NUM>. The pressure in the pressure accumulator <NUM> is measured by a pressure gauge <NUM>. The pressure in the pressure accumulator <NUM> is measured by a pressure gauge <NUM>.

The hydrogen fuel accumulated under pressure in the tank of the curdle <NUM>, the intermediate pressure accumulator <NUM>, or the hydrogen trailer <NUM> is depressurized to a low pressure (for example, <NUM> MPa) by respective regulators (not illustrated) controlled by the control circuit <NUM>, and supplied to the suction side of the compressor <NUM>. Similarly, hydrogen fuel produced by the hydrogen production apparatus <NUM> is supplied to the suction side of the compressor <NUM> at a low pressure (for example, <NUM> MPa). The compressor <NUM>, under control by the control circuit <NUM>, supplies hydrogen fuel supplied from the curdle <NUM>, the intermediate pressure accumulator <NUM>, the hydrogen trailer <NUM>, or the hydrogen production apparatus <NUM> at a low pressure to each of the pressure accumulators <NUM>, <NUM>, and <NUM> of the multi-stage pressure accumulator <NUM> while compressing the hydrogen fuel. The compressor <NUM> compresses the hydrogen fuel until each of the pressure accumulators <NUM>, <NUM>, and <NUM> of the multi-stage pressure accumulator <NUM> reaches a predetermined high pressure (for example, <NUM> MPa). In other words, the compressor <NUM> compresses the hydrogen fuel until the secondary side pressure POUT on the discharge side reaches a predetermined high pressure (for example, <NUM> MPa). Which of the curdle <NUM>, the intermediate pressure accumulator <NUM>, the hydrogen trailer <NUM>, and the hydrogen production apparatus <NUM> supplies hydrogen fuel to the suction side of the compressor <NUM> can be determined by the control circuit <NUM> controlling opening/closing of the corresponding valves <NUM>, <NUM>, <NUM>, and <NUM> arranged on the respective pipes. Similarly, to which of the pressure accumulators <NUM>, <NUM>, and <NUM> the compressor <NUM> supplies hydrogen fuel can be determined by the control circuit <NUM> controlling opening/closing of the corresponding valves <NUM>, <NUM>, and <NUM> arranged on the respective pipes. Alternatively, the control may be performed such that hydrogen fuel is supplied to two or more pressure accumulators at the same time.

In the example described above, pressure reduction control is performed on hydrogen fuel such that the pressure PIN of the hydrogen fuel supplied to the suction side of the compressor <NUM> is reduced to a predetermined low pressure (for example, <NUM> MPa), but the invention is not limited to this configuration. A configuration for supplying, to the suction side of the compressor <NUM>, hydrogen fuel accumulated under pressure in the curdle <NUM>, the intermediate pressure accumulator <NUM>, or the hydrogen trailer <NUM> without reducing the pressure of the hydrogen fuel or at a pressure higher than the predetermined low pressure (for example, <NUM> MPa) and then the hydrogen fuel is compressed is possible.

The hydrogen fuel accumulated under pressure in the multi-stage pressure accumulator <NUM> is cooled by the cooler <NUM> in the dispenser <NUM> and is supplied from the dispenser <NUM> to the FCV <NUM> that has come into the hydrogen station <NUM>.

<FIG> is a configuration diagram illustrating an example of the internal configuration of the control circuit in the dispenser according to embodiment <NUM>. In <FIG>, in the control circuit <NUM> in the dispenser <NUM>, a communication control circuit <NUM>, a memory <NUM>, an FCV information receiver <NUM>, a hydrogen temperature receiver <NUM>, an outside air temperature receiver <NUM>, a threshold calculator <NUM>, a threshold setting unit <NUM>, a flow rate receiver <NUM>, determining unit <NUM>, valve controller <NUM>, bank switching controller <NUM>, end pressure information receiver <NUM>, determining unit <NUM>, FCV information relay <NUM>, and storage devices <NUM> and <NUM> such as magnetic disk devices are provided. Each of the components such as the FCV information receiver <NUM>, the hydrogen temperature receiver <NUM>, the outside air temperature receiver <NUM>, the threshold calculator <NUM>, the threshold setting unit <NUM>, the flow rate receiver <NUM>, the determining unit <NUM>, the valve controller <NUM>, the bank switching controller <NUM>, the end pressure information receiver <NUM>, the determining unit <NUM>, and the FCV information relay <NUM> includes a processing circuit, and the processing circuit includes an electric circuit, a computer, a processor, a circuit board, a semiconductor device or the like. Moreover, the components may use a common processing circuit (the same processing circuit). Alternatively, the components may use different processing circuits (separate processing circuits). Input data required and the result of calculation in the FCV information receiver <NUM>, the hydrogen temperature receiver <NUM>, the outside air temperature receiver <NUM>, the threshold calculator <NUM>, the threshold setting unit <NUM>, the flow rate receiver <NUM>, the determining unit <NUM>, the valve controller <NUM>, the bank switching controller <NUM>, the end pressure information receiver <NUM>, the determining unit <NUM>, and the FCV information relay <NUM> are stored in the memory <NUM> each time.

<FIG> is a configuration diagram illustrating an example of the internal configuration of a control circuit that controls the entire hydrogen fuel supply system according to embodiment <NUM>. In <FIG>, in the control circuit <NUM>, a communication control circuit <NUM>, a memory <NUM>, a receiver <NUM>, an end pressure/temperature calculator <NUM>, a transmitter <NUM>, a bank switching command receiver <NUM>, a system controller <NUM>, and a pressure recovery controller <NUM>, a supply controller <NUM>, a bank pressure receiver <NUM>, and storage devices <NUM> and <NUM> such as magnetic disk devices are provided. The pressure recovery controller <NUM> includes a valve controller <NUM> and a compressor controller <NUM>. The supply controller <NUM> includes a dispenser controller <NUM> and a valve controller <NUM>. Each of the components such as the receiver <NUM>, the end pressure/temperature calculator <NUM>, the transmitter <NUM>, the bank switching command receiver <NUM>, the system controller <NUM>, the pressure recovery controller <NUM> (the valve controller <NUM>, the compressor controller <NUM>), the supply controller <NUM> (the dispenser controller <NUM>, the valve controller <NUM>), and the bank pressure receiver <NUM> includes a processing circuit, and the processing circuit includes an electric circuit, a computer, a processor, a circuit board, a semiconductor device or the like. Moreover, the components may use a common processing circuit (the same processing circuit). Alternatively, the components may use different processing circuits (separate processing circuits). Input data required and the result of calculation in the receiver <NUM>, the end pressure/temperature calculator <NUM>, the transmitter <NUM>, the bank switching command receiver <NUM>, the system controller <NUM>, the pressure recovery controller <NUM> (the valve controller <NUM>, the compressor controller <NUM>), the supply controller <NUM> (the dispenser controller <NUM>, the valve controller <NUM>), and the bank pressure receiver <NUM> are stored in the memory <NUM> each time.

In the storage device <NUM>, a conversion table <NUM> indicating correlation between FCV information and the filling information corresponding to the FCV information is stored. The FCV information includes the pressure and temperature of the fuel tank <NUM> mounted on the FCV <NUM>, and the volume of the fuel tank <NUM>, and the filling information includes the remaining amount of hydrogen fuel, the final pressure, and the final temperature to be reached in the fuel tank <NUM>. Furthermore, in the storage device <NUM>, a correction table <NUM> for correcting the result obtained from the conversion table <NUM> is stored.

Here, with hydrogen fuel supplied from the multi-stage pressure accumulator <NUM>, the FCV <NUM> is filled while the flow rate of the hydrogen fuel is adjusted by a dispenser. Therefore, a flow rate adjusting valve has been provided in a conventional dispenser housing. As described above, unlike an ON/OFF valve, such a flow rate adjusting valve is often used at an intermediate opening for adjusting the flow rate of the hydrogen fuel gas. Therefore, leakage from the shaft seal portion occurs due to deterioration over time. Use or development of a highly accurate flow rate adjusting valve that does not easily cause such a leakage is costly. Therefore, inexpensive and safe hydrogen fuel filling is demanded. Therefore, in embodiment <NUM>, in place of a flow rate adjusting valve, a plurality of flow passages A and B is arranged in parallel, and the flow rate of the supplied hydrogen fuel per unit time is adjusted by switching between the flow passages A and B. Hereinafter, when the term "flow rate" is used, it means the flow rate per unit time even if "per unit time" is not stated.

<FIG> is a diagram illustrating an example of a configuration of parallel flow passages according to embodiment <NUM>. <FIG> illustrates a part of the configuration of <FIG>. In the example of <FIG>, the parallel flow passages are configured to allow hydrogen fuel sequentially supplied from the pressure accumulators <NUM>, <NUM>, and <NUM> of the multi-stage pressure accumulator <NUM> to pass through the two flow passages A and B arranged in parallel through the filter <NUM>. In the flow passage A, an orifice 35a is provided in the middle of the flow passage 33a. Furthermore, a valve 34a is provided in the middle of the flow passage 33a, and passage and blocking of the flow passage A are controlled by opening/closing the valve 34a. In the flow passage B, an orifice 35b is provided in the middle of the flow passage 33b. Furthermore, a valve 34b is provided in the middle of the flow passage 33b, and passage and blocking of the flow passage B are controlled by opening/closing the valve 34b. Through the flow passage A (first flow passage), as illustrated in <FIG>, hydrogen fuel supplied from each of the pressure accumulator <NUM>, <NUM>, and <NUM> by switching between the plurality of pressure accumulators <NUM>, <NUM>, and <NUM>, which accumulate hydrogen fuel under pressure, passes. As illustrated in <FIG>, the flow passage B (second flow passage) is arranged in parallel with the flow passage A, and through the flow passage B, hydrogen fuel supplied from each of the pressure accumulators <NUM>, <NUM>, and <NUM> by switching passes. The valves 34a and 34b correspond to a switching valve that selectively switches between the flow passages from one of the two flow passages A and B to the other. The valve controller <NUM> in the control circuit <NUM> controls opening/closing of the switching valve. The valves 34a and 34b are not controlled to be at an intermediate opening but are controlled to be in either of two states, that is, one of full open/full closed state (ON/OFF). The diameters and lengths of the pipes forming the flow passages 33a and, 33b are set to sizes that allow hydrogen fuel to flow sufficiently due to the differential pressure between each of the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM>. The flow passages 33a and 33b are set to have the same pipe diameter and length, for example. In the example of <FIG>, the flowability (conductance) of the two flow passages A and B is adjusted by the size of the passage holes of the orifices 35a and 35b. If the area of the passage hole of an orifice is small (the opening area is small), the flowability can be decreased. Conversely, if the area of the passage hole of an orifice is large (the opening area is large), the flowability can be increased. In the hydrogen station <NUM>, when the FCV <NUM> is filled with hydrogen fuel, the flow rate (filling speed) per unit time is limited. The orifice 35a is sized such that a desired flow rate is achieved in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large. The orifice 35b is sized such that a desired flow rate is achieved even when the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is decreased to some extent. Specifically, in the flow passage B, an orifice having a larger opening size than one in the flow passage A is provided. Accordingly, in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large, the flow rate per unit time is made closer to a desired flow rate by causing the hydrogen fuel to pass through the flow passage A, and when the differential pressure becomes small, the flow passages are switched to the flow passage B provided with the orifice having a larger opening size to facilitate the flow of hydrogen fuel and suppress the decrease in the flow rate per unit time. The configuration of the parallel flow passages according to embodiment <NUM> is not limited to this configuration.

<FIG> is a diagram illustrating another example of the configuration of the parallel flow passages according to embodiment <NUM>. In the example of <FIG>, similarly to <FIG>, the parallel flow passages are configured to allow the hydrogen fuel sequentially supplied from pressure accumulators <NUM>, <NUM>, and <NUM> of a multi-stage pressure accumulator <NUM> to pass through two flow passages A and B arranged in parallel through a filter <NUM>. In the flow passage A, a valve 34a is provided in the middle of a flow passage 33a, and passage and blocking of the flow passage A are controlled by opening/closing the valve 34a. In the flow passage B, a valve 34b is provided in the middle of a flow passage 33b, and passage and blocking of the flow passage B are controlled by opening/closing the valve 34b. Through the flow passage A (first flow passage), as illustrated in <FIG>, hydrogen fuel supplied from each of the pressure accumulators <NUM>, <NUM>, and <NUM> by switching between the plurality of pressure accumulators <NUM>, <NUM>, and <NUM>, which accumulate hydrogen fuel under pressure, passes. As illustrated in <FIG>, the flow passage B (second flow passage) is arranged in parallel with the flow passage A, and through the flow passage B, hydrogen fuel supplied from each of the pressure accumulators <NUM>, <NUM>, and <NUM> by switching passes. The valves 34a and 34b correspond to a switching valve that selectively switches between the flow passages from one of the two flow passages A and B to the other. The valve controller <NUM> in the control circuit <NUM> controls opening/closing of the switching valve. The valves 34a and 34b are not controlled to be at an intermediate opening but are controlled to be in either of two states, that is, one of full open/full closed state (ON/OFF). In the example of <FIG>, the pipe diameters (or/and lengths) of the flow passages 33a and 33b are made different, and the flowability (conductance) of the two flow passages A and B is adjusted by the size difference. If the pipe diameter is small, the flowability can be decreased. On the contrary, if the pipe diameter is large, the flowability can be increased. Similarly, if the pipe length is long, the flowability can be decreased. If the pipe length is short, the flowability can be increased. The flow passage 33a is sized such that a desired flow rate is achieved in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large. The flow passage 33b is sized such that a desired flow rate is achieved even when the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is decreased to some extent. Specifically, for example, a pipe having a larger diameter than one in the flow passage A is provided in the flow passage B. Accordingly, in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large, the flow rate per unit time is made close to a desired flow rate by passing through the flow passage A. When the pressure becomes small, the flow passages are switched to the flow passage B having a large pipe diameter to facilitate the flow of hydrogen fuel and suppress the decrease in the flow rate per unit time. The configuration of the parallel flow passages according to embodiment <NUM> is not limited to this configuration.

<FIG> is a diagram illustrating another example of the configuration of the parallel flow passages according to embodiment <NUM>. In the example of <FIG>, similarly to <FIG>, the parallel flow passages are configured to allow the hydrogen fuel sequentially supplied from pressure accumulators <NUM>, <NUM>, and <NUM> of a multi-stage pressure accumulator <NUM> to pass through two flow passages A and B arranged in parallel through a filter <NUM>. The flow passage A is formed from a flow passage 33a, and a valve 34a is not provided. Therefore, the flow passage A can be always passed through. In the flow passage B, a valve 34b is provided in the middle of a flow passage 33b, and passage and blocking of the flow passage B are controlled by opening/closing the valve 34b. Through the flow passage A (first flow passage), as illustrated in <FIG>, hydrogen fuel supplied from each of the pressure accumulators <NUM>, <NUM>, and <NUM> by switching between the plurality of pressure accumulators <NUM>, <NUM>, and <NUM>, which accumulate hydrogen fuel under pressure, passes. As illustrated in <FIG>, the flow passage B (second flow passage) is arranged in parallel with the flow passage A, and through the flow passage B, hydrogen fuel supplied from each of the pressure accumulators <NUM>, <NUM>, and <NUM> by switching passes. The valve 34b corresponds to a switching valve that switches between one (flow passage A in this example) and both (flow passages A+B) of the two flow passages A and B. The valve controller <NUM> in the control circuit <NUM> controls opening/closing of the switching valve. The valve 34b is not controlled to be at an intermediate opening but are controlled to be in either of two states, that is, one of full open/full closed state (ON/OFF). In the example of <FIG>, the flowability (conductance) is adjusted by the number of flow passages. The flow passage 33a is sized such that a desired flow rate is achieved in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large. The flow passage 33b is set to have the same size as the flow passage 33a. Accordingly, in a state where the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is large, the flow rate per unit time is made close to a desired flow rate by passing hydrogen fuel through the flow passage A. When the differential pressure becomes small, the flow passages are switched to increase the number of flow passages from one flow passage, which is the flow passage A, to two flow passages further including the flow passage B to double the passage area and facilitate the flow of hydrogen fuel, and then suppress the decrease in the flow rate per unit time. The flow passage 33b is not limited to have the same size as the flow passage 33a but may have any size as long as a desired flow rate can be achieved by both of the flow passages A and B even when the differential pressure between the pressure accumulators <NUM>, <NUM>, and <NUM> and the fuel tank <NUM> of the FCV <NUM> is decreased to some extent. Therefore, the flow passage 33b may be larger or smaller than the flow passage 33a.

As described above, in embodiment <NUM>, the FCV <NUM> is filled with hydrogen fuel while adjusting the flow rate per unit time by using the switchable parallel flow passages A and B instead of a flow rate adjusting valve.

<FIG> is a diagram for describing a filling method when performing differential pressure filling with hydrogen fuel using the multi-stage pressure accumulator according to embodiment <NUM>. In <FIG>, the vertical axis represents pressure and the horizontal axis represents time. When the FCV <NUM> is filled with hydrogen fuel by a differential pressure, the pressure accumulators <NUM>, <NUM>, and <NUM> of the multi-stage pressure accumulator <NUM> typically accumulate the hydrogen fuel at the same pressure P0 (for example, <NUM> MPa) in advance. On the other hand, the fuel tank <NUM> of the FCV <NUM> that has come into the hydrogen station <NUM> is at a pressure Pa. A case where filling of the fuel tank <NUM> of the FCV <NUM> is started from this state will be described. The FCV <NUM> is filled with hydrogen fuel while, in particular, the dispenser <NUM> (hydrogen fuel filling system) adjusts the flow rate per unit time F of the hydrogen fuel by switching the flow passages in the dispenser <NUM> by the switching valve during supply of the hydrogen fuel from the pressure accumulator, to which switching has been made, every time when switching between the plurality of pressure accumulators <NUM>, <NUM>, and <NUM> is made. Here, description will be given using the configuration example of the parallel flow passages illustrated in <FIG> (and <FIG>).

First, filling the fuel tank <NUM> is started from the pressure accumulator <NUM>, which serves as the 1st bank. For the filling, the flow passage A is used in the dispenser <NUM>. The hydrogen fuel accumulated under pressure in the pressure accumulator <NUM> moves toward the fuel tank <NUM> at a desired flow rate per unit time a1 (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank 202a, and the pressure in the fuel tank <NUM> increases gradually as illustrated by the dotted line Pt. Along with the increase, the pressure of the pressure accumulator <NUM> (graph indicated by "1st") gradually decreases. Then, the flow rate per unit time decreases as the differential pressure decreases, and when the flow rate becomes lower than a lower limit threshold Fra1 during the supply by the pressure accumulator <NUM>, the flow passages in the dispenser <NUM> are switched from the flow passage A to the flow passage B. Then, the hydrogen fuel accumulated under pressure in the pressure accumulator <NUM> moves toward the fuel tank <NUM> at a desired flow rate per unit time b1 (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, and the pressure in the fuel tank <NUM> further increases gradually as illustrated by the dotted line Pt. Then, the flow rate per unit time decreases as the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM> decreases, and when the flow rate becomes lower than a lower limit threshold Frb1, which is a time point where the time T1 has elapsed from the start of the filling, the pressure accumulators to be used are switched from the pressure accumulator <NUM> to the pressure accumulator <NUM>, which serves as the 2nd bank. This switching increases the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, so that the filling speed can be kept high. At the same time, flow passages in the dispenser <NUM> are switched from the flow passage B to the flow passage A to return the flow passage to the flow passage A.

Then, the hydrogen fuel accumulated under pressure in the pressure accumulator <NUM>, which serves as the 2nd bank, moves toward the fuel tank <NUM> at a desired flow rate per unit time a2 (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, and the pressure in the fuel tank <NUM> further increases gradually as illustrated by the dotted line Pt. Along with the increase, the pressure of the pressure accumulator <NUM> (graph indicated by "2nd") gradually decreases. Then, the flow rate per unit time decreases as the differential pressure decreases, and when the flow rate becomes lower than a lower limit threshold Fra2 during the supply by the pressure accumulator <NUM>, the flow passages in in the dispenser <NUM> are switched from the flow passage A to the flow passage B. Then, the hydrogen fuel accumulated under pressure in the pressure accumulator <NUM> moves toward the fuel tank <NUM> at a desired flow rate b2 per unit time (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, and the pressure in the fuel tank <NUM> further increases gradually as illustrated by the dotted line Pt. Then, the flow rate per unit time decreases as the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM> decreases, and when the flow rate becomes lower than a lower limit threshold Frb2, which is a time point where the time T2 has elapsed from the start of the filling, the pressure accumulators to be used are switched from the pressure accumulator <NUM> to the pressure accumulator <NUM>, which serves as the 3rd bank. This switching increases the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, so that the filling speed can be kept high. At the same time, flow passages in the dispenser <NUM> are switched from the flow passage B to the flow passage A to return the flow passage to the flow passage A.

Then, the hydrogen fuel accumulated under pressure in the pressure accumulator <NUM>, which serves as the 3rd bank, moves toward the fuel tank <NUM> at a desired flow rate per unit time a3 (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, and the pressure in the fuel tank <NUM> further increases gradually as illustrated by the dotted line Pt. Along with the increase, the pressure of the pressure accumulator <NUM> (graph indicated by "3rd") gradually decreases. Then, the flow rate per unit time decreases as the differential pressure decreases, and when the flow rate becomes lower than a lower limit threshold Fra3 during the supply by the pressure accumulator <NUM>, the flow passages in the dispenser <NUM> are switched from the flow passage A to the flow passage B. Then, the hydrogen fuel accumulated under pressure in the pressure accumulator <NUM> moves toward the fuel tank <NUM> at a desired flow rate per unit time b3 (filling speed) due to the differential pressure between the pressure accumulator <NUM> and the fuel tank <NUM>, and the pressure in the fuel tank <NUM> further increases gradually as illustrated by the dotted line Pt. Then, the fuel tank <NUM> is filled by the pressure accumulator <NUM>, which serves as the 3rd bank, until the pressure of the fuel tank <NUM> reaches a final pressure PF (for example, <NUM> to <NUM> MPa) that is calculated as described below.

The desired flow rates per unit time a1 to a3 and b1 to b3 at the time of switching the flow passages for the respective banks may be the same or different. Since the conductance of each of the flow passages A and B is constant, the values of the flow rates per unit time change depending on the generated differential pressure. Typically, the values a1, b1, a2, b2, a3, and b3 are gradually smaller in this order.

<FIG> is a flowchart illustrating main steps of a hydrogen fuel filling method according to embodiment <NUM>. In <FIG>, the hydrogen fuel filling method according to embodiment <NUM> performs a series of steps including an FCV information receiving step (S102), a final pressure calculating step (S104), a lower limit flow rate (lower limit threshold Fra1) calculating step (S106), and a flow passage A setting step (S108), a 1st bank setting step (S110), a flow rate determination step (S112), a lower limit flow rate (lower limit threshold Frb1) calculating step (S114), a flow passage B switching step (S116), a flow rate Determination step (S118), a lower limit flow rate (lower limit threshold Fra2) calculating step (S120), a flow passage A switching step (S122), a 2nd bank switching step (S124), a flow rate determination step (S126), a lower limit flow rate (Lower limit threshold Frb2) calculating step (S128), a flow passage B switching step (S130), a flow rate determination step (S132), a lower limit flow rate (lower limit threshold Fra3) calculating step (S134), a flow passage A switching step (S136), a 3rd bank switching step (S138), a flow rate determination step (S140), a lower limit flow rate (lower limit threshold Frb3) calculating step (S142), a flow passage B switching step (S144), and a filling completion determination step (S148).

Here, the flow rate per unit time (g/min) (filling speed) of the hydrogen fuel flowing through the flow passages A and B in the dispenser <NUM> changes depending on the conductance of the flow passages A and B, the pressures of the accumulators <NUM>, <NUM>, and <NUM> (banks), the pressure of the fuel tank <NUM> of the FCV <NUM>, the outside air temperature, and the temperature of supplied hydrogen fuel. Therefore, for each of the flow passages A and B, and for each of the pressure accumulators <NUM>, <NUM>, and <NUM> (bank), a correlation table is created. The correlation table correlates the lower limit threshold of the flow rate per unit time (g/min) (filling speed) and the pressure of the fuel tank <NUM> of the FCV <NUM>, the outside air temperature, and the temperature of supplied hydrogen fuel.

<FIG> is a diagram illustrating an example of the correlation tables in embodiment <NUM>. Part A of <FIG> illustrates an example of the correlation tables of the flow passage A when the 1st bank is used. Part B of <FIG> illustrates an example of the correlation tables of the flow passage B when the 1st bank is used. Furthermore, as illustrated in part C of <FIG>, similarly, the correlation table of the flow passage A when the 2nd bank is used, the correlation table of the flow passage B when the 2nd bank is used, the correlation table of the flow passage A when the 3rd bank is used, and the correlation table of the flow passage B when the 3rd bank is used are created. Correlation tables are created for different ranges of the temperature of supplied hydrogen fuel. For example, three correlation tables may be preferably created for the temperature ranges of supplied hydrogen fuel of -<NUM> to - <NUM>, -<NUM> to -<NUM>, and -<NUM> to -<NUM>. The temperature ranges of supplied hydrogen fuel are not limited to these. Correlation tables may be created for other temperature ranges. Alternatively, a correlation table may be created for each temperature of supplied hydrogen fuel although data amount becomes large.

In the example of part A of <FIG>, the vertical axis of the correlation table defines the outside air temperature (°C), and the horizontal axis defines the pressure (MPa) of the fuel tank <NUM> of the FCV <NUM>, and in the area specified by the outside air temperature (°C) and the pressure of the fuel tank <NUM> of the FCV <NUM> (MPa), the lower limit threshold Fra1 of the flow rate per unit time (g/min) (filling speed) of the flow passage A when the 1st bank is used is defined. In the example of part A of <FIG>, in a case, for example, where the temperature of supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. The higher the outside air temperature and/or the pressure in the fuel tank <NUM> is, the smaller value of the lower limit threshold Fra1 is set to. The same applies to other temperature ranges of supplied hydrogen fuel. In addition, in the example of part A of <FIG>, a case where the pressure of the fuel tank <NUM> of the FCV <NUM> is lower than <NUM> MPa is not illustrated, but the lower limit threshold Fra1 may be defined for a pressure lower than <NUM> MPa.

In the example of part B of <FIG>, the vertical axis of the correlation table defines the outside air temperature (°C), and the horizontal axis defines the pressure (MPa) of the fuel tank <NUM> of the FCV <NUM>, and in the area specified by the outside air temperature (°C) and the pressure of the fuel tank <NUM> of the FCV <NUM> (MPa), the lower limit threshold Frb1 of the flow rate per unit time (g/min) (filling speed) of the flow passage B when the 1st bank is used is defined. When the 1st bank is used with the flow passage B, the flow passage A has already been used. Therefore, the residual pressure in the 1st bank (pressure accumulator <NUM>) has been decreased and the pressure in the fuel tank <NUM> has been contrary increased. Considering this fact, the value is defined. In the example of part B of <FIG>, in a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Frb1 of the flow rate per unit time (filling speed) of the flow passage B when the 1st bank is used is defined as <NUM>/min. Similar to the example of part A of <FIG>, the higher the outside air temperature and/or the pressure in the fuel tank <NUM> is, the smaller value of the lower limit threshold Frb1 is set to. The same applies to other temperature ranges of supplied hydrogen fuel. In addition, in the example of part B of <FIG>, a case where the pressure of the fuel tank <NUM> of the FCV <NUM> is lower than <NUM> MPa is not illustrated, but the lower limit threshold Fra1 may be defined for a pressure lower than <NUM> MPa.

Values different from each other are set to the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used, the lower limit threshold Frb1 of flow rate per unit time (filling speed) of the flow passage B when the 1st bank is used, the lower limit threshold Fra2 of flow rate per unit time (filling speed) of the flow passage A when the 2nd bank is used, the lower limit threshold Frb2 of flow rate per unit time (filling speed) of the flow passage B when the 2nd bank is used, the lower limit threshold Fra3 of flow rate per unit time (filling speed) of the flow passage A when the 3rd bank is used, and the lower limit threshold Frb3 of flow rate per unit time (filling speed) of the flow passage B when the 3rd bank is used. Each value may be determined in advance through an experiment or the like.

Here, the pressure accumulators <NUM>, <NUM>, and <NUM> (banks) accumulate hydrogen fuel at the same pressure P0 (for example, <NUM> MPa) at the start of filling. In other words, when the flow passage A is used, all of the pressures of the pressure accumulators <NUM>, <NUM>, and <NUM> (banks) at the start of use are the same pressure P0 (for example, <NUM> MPa). Conversely, when the flow passage B (or the flow passages A+B) is used, the pressures of the accumulators <NUM>, <NUM>, and <NUM> (banks) at the start of use are the respective lower limit thresholds of the flow rate per unit time (g/min) (filling speed) of the flow passage A when the corresponding banks are used. Therefore, when the lower limit threshold of the flow passage B for each bank under the respective condition is determined, as the pressure of each pressure accumulator <NUM>, <NUM>, and <NUM> (each bank) at the start of use, the pressure after the use of the flow passage A is used.

As described above, the information of each correlation table created in advance is stored in the storage device <NUM>. After each correlation table described above is created, filling of the FCV <NUM> with hydrogen fuel is accepted.

As the FCV information receiving step (S102), the FCV information receiver <NUM> receives FCV information about the fuel tank <NUM> (hydrogen storage vessel) mounted on the FCV <NUM> from the on-vehicle device <NUM> mounted on the FCV <NUM> (fuel cell vehicle (FCV)) that uses hydrogen fuel as a power source. Specifically, the following operation is performed. When the FCV <NUM> comes into the hydrogen station <NUM>, and the nozzle <NUM> of the dispenser <NUM> is fixed to the receptacle of the fuel tank <NUM> of the FCV <NUM> by a user or an operator of the hydrogen station <NUM>, communication between the on-vehicle device <NUM> and the communication control circuit <NUM> is established. Upon establishment of the communication, the on-vehicle device <NUM> outputs (transmits) FCV information including the current pressure and temperature of the fuel tank <NUM> and the volume of the fuel tank <NUM> in real time. The FCV information receiver <NUM> receives the FCV information via the communication control circuit <NUM>. The received FCV information is then output to the threshold calculator <NUM> and stored in the storage device <NUM> in correlation with the reception time information. The received FCV information is also output by the FCV information relay <NUM> to the control circuit <NUM> via the communication control circuit <NUM>. In the control circuit <NUM>, the receiver <NUM> receives the FCV information via the communication control circuit <NUM>. The FCV information is monitored constantly or at predetermined sampling intervals while the communication between the on-vehicle device <NUM> and the control circuit <NUM> (communication control circuit <NUM>) is established. The received FCV information is stored in the storage device <NUM> together with the reception time information. The control circuit <NUM> also receives the outside air temperature measured by the thermometer <NUM>. The outside air temperature may be received via the control circuit <NUM> or directly from the thermometer <NUM>. Alternatively, the outside air temperature may be measured by another thermometer (not illustrated) in the control circuit <NUM>.

Furthermore, upon establishment of the communication between the on-vehicle device <NUM> and the control circuit <NUM> (communication control circuit <NUM>), the supply controller <NUM> controls the dispenser <NUM> and the valve (for example, the valve <NUM>) to control the initial pressure and the supplied hydrogen temperature. Specifically, the dispenser controller <NUM> controls the valve controller <NUM> in the dispenser <NUM> such that the shutoff valves <NUM> and <NUM> are open only for a moment. The valve controller <NUM> opens the valve <NUM> only for a moment in synchronization with the operation of the shutoff valves <NUM> and <NUM>. As a result, hydrogen fuel flows to the FCV <NUM> side only for a moment. At that time, the thermometer <NUM> measures the temperature of the supplied hydrogen fuel. In addition, a pressure gauge (not illustrated) measures the initial pressure of the supplied hydrogen fuel. The measured temperature of the supplied hydrogen fuel is received by the hydrogen temperature receiver <NUM>. Further, the thermometer <NUM> measures the outside air temperature, and the measured outside air temperature is received by the outside air temperature receiver <NUM>. The temperature of the supplied hydrogen fuel and the outside air temperature are monitored constantly or at predetermined sampling intervals while the communication between the on-vehicle device <NUM> and the control circuit <NUM> (communication control circuit <NUM>) is established. The received temperature of the supplied hydrogen fuel and the outside air temperature are stored in the storage device <NUM> in correlation with the reception time information.

As the final pressure calculating step (S104), the end pressure/temperature calculator <NUM> reads the conversion table <NUM> from the storage device <NUM>, and calculates and predicts the final pressure PF and the final temperature corresponding to the received pressure and temperature of the fuel tank <NUM> at the initial reception, the volume of the fuel tank <NUM>, and the outside air temperature. In addition, the end pressure/temperature calculator <NUM> reads the correction table <NUM> from the storage device <NUM> and corrects the numerical value obtained referring to the conversion table <NUM>. If an error is large in the result obtained only by using the data of the conversion table <NUM>, the correction table <NUM> may be provided based on the result obtained by an experiment, a simulation, or the like. The calculated final pressure PF and final temperature are output by the transmitter <NUM> to the control circuit <NUM> in the dispenser <NUM> via the communication control circuit <NUM>. In the control circuit <NUM> of the dispenser <NUM>, the end pressure information receiver <NUM> receives the final pressure PF and final temperature information transmitted from the control circuit <NUM> via the communication control circuit <NUM>.

As the lower limit flow rate (lower limit threshold Fra1) calculating step (S106), the control circuit <NUM> variably calculates and sets the lower limit threshold Fra1 with reference to the correlation table (table information) stored in the storage device <NUM>. To the control circuit <NUM>, specific information is input, and the control circuit <NUM> variably sets the lower limit threshold according to the value defined in the specific information. At least one of the pressure information of the fuel tank <NUM> mounted on the FCV <NUM>, the hydrogen fuel temperature information, and the outside air temperature information is used as the specific information. For example, table information defining the pressure of the fuel tank <NUM> and the outside air temperature in association is used. In other words, to the control circuit <NUM>, pressure information of the fuel tank <NUM> mounted on the FCV <NUM> is input, and the control circuit <NUM> variably sets the lower limit threshold according to the pressure value defined in the pressure information. In addition, to the control circuit <NUM>, the temperature of the hydrogen fuel is input, and the control circuit <NUM> variably sets the lower limit threshold according to the temperature of the hydrogen fuel. Furthermore, to the control circuit <NUM>, the outside air temperature is input, and the control circuit <NUM> variably sets the lower limit threshold according to the outside air temperature. Specifically, the threshold calculator <NUM> reads information of the temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage A and the 1st bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Fra1 corresponding to the current pressure of the fuel tank <NUM> and the outside air temperature defined in the FCV information. The calculated lower limit threshold Fra1 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets the lower limit threshold Fra1 stored in the storage device <NUM> as a determination threshold.

As the flow passage A setting step (S108), the valve controller <NUM> controls the valve 34a to open it and the valve 34b to close it, so that the flow passage A becomes a hydrogen fuel flow passage in the dispenser <NUM>.

As the 1st bank setting step (S110), the supply unit <NUM> uses the dispenser <NUM> to fill the fuel tank <NUM> with hydrogen fuel from the pressure accumulator <NUM>, which serves as the 1st bank of the multi-stage pressure accumulator <NUM> (start filling). The supply unit <NUM> includes, for example, the multi-stage pressure accumulator <NUM>, the valves <NUM>, <NUM>, and <NUM>, and the dispenser <NUM> related to the filling operation. Specifically, the supply unit <NUM> operates as follows. Under the control of the system controller <NUM>, the supply controller <NUM> controls the supply unit <NUM> such that the supply unit <NUM> supplies hydrogen fuel from the pressure accumulator <NUM> to the fuel tank <NUM> of the FCV <NUM>. Specifically, the system controller <NUM> controls the dispenser controller <NUM> and the valve controller <NUM>. The dispenser controller <NUM> communicates with the control circuit <NUM> of the dispenser <NUM> via the communication control circuit <NUM> to control the operation of the dispenser <NUM>. Specifically, the valve controller <NUM> opens the shutoff valves <NUM> and <NUM> in the dispenser <NUM>. The valve controller <NUM> then outputs a control signal to the valves <NUM>, <NUM>, and <NUM> via the communication control circuit <NUM> to control opening/closing of each valve. Specifically, the valve controller <NUM> opens the valve <NUM> and keeps the valves <NUM> and <NUM> closed. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage A.

During the supply of the hydrogen fuel, the flowmeter <NUM> in the dispenser <NUM> measures the flow rate per unit time F (g/min) of the supplied hydrogen fuel constantly or at predetermined sampling intervals. The measured flow rate per unit time F is received by the flow rate receiver <NUM> via the communication control circuit <NUM>. The received flow rate per unit time F is output to the determining unit <NUM>.

As the flow rate determination step (S112), the determining unit <NUM> determines whether the received flow rate per unit time F becomes lower than the set lower limit threshold Fra1. When the flow rate per unit time F becomes lower than the lower limit threshold Fra1, the process proceeds to the next step. When the flow rate per unit time F is not lower than the lower limit threshold Fra1, the flow rate determination step (S112) is repeated until the flow rate per unit time F becomes lower than the lower limit threshold Fra1.

As the lower limit flow rate (lower limit threshold Frb1) calculating step (S114), the control circuit <NUM> variably calculates and sets the lower limit threshold Frb1 with reference to the correlation table (table information) stored in the storage device <NUM>. Specifically, the threshold calculator <NUM> reads information of the latest temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage B and the 1st bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Frb1 corresponding to the current pressure of the fuel tank <NUM> and the latest outside air temperature defined in the FCV information. The calculated lower limit threshold Frb1 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets (updates) the lower limit threshold Frb1 stored in the storage device <NUM> as a determination threshold.

As the flow passage B switching step (S116), the control circuit <NUM> switches the flow passages by the switching valve when the measured flow rate F becomes lower than the lower limit threshold Fra1. In the example of <FIG> and <FIG>, the two valves 34a and 34b correspond to the switching valve. In the example of <FIG>, the valve 34b corresponds to the switching valve. Specifically, the valve controller <NUM> controls the valve 34a to close it and the valve 34b to open it, so that hydrogen fuel flow passages in the dispenser <NUM> are switched from the flow passage A (is set) to the flow passage B. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage B. In other words, hydrogen filling of the fuel tank <NUM> from the pressure accumulator <NUM> is continued.

As described above, the FCV <NUM> is filled with hydrogen fuel while the flow passages are switched by the switching valves (valves 34a and 34b) during the supply from the pressure accumulator <NUM>. The FCV <NUM> is filled with hydrogen fuel while adjusting the flow rate per unit time F of the hydrogen fuel by switching the flow passages.

As the flow rate determination step (S118), the determining unit <NUM> determines whether the received flow rate per unit time F becomes lower than the set lower limit threshold Frb1. When the flow rate per unit time F becomes lower than the lower limit threshold Frb1, the process proceeds to the next step. When the flow rate per unit time F is not lower than the lower limit threshold Frb1, the flow rate determination step (S118) is repeated until the flow rate per unit time F becomes lower than the lower limit threshold Frb1.

As the lower limit flow rate (lower limit threshold Fra2) calculating step (S120), the control circuit <NUM> variably calculates and sets the lower limit threshold Fra2 with reference to the correlation table (table information) stored in the storage device <NUM>. Specifically, the threshold calculator <NUM> reads information of the latest temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage A and the 2nd bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Fra2 corresponding to the current pressure of the fuel tank <NUM> and the latest outside air temperature defined in the FCV information. The calculated lower limit threshold Fra2 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets (updates) the lower limit threshold Fra2 stored in the storage device <NUM> as a determination threshold. In addition, the bank switching controller <NUM> transmits, via the communication control circuit <NUM>, a bank switching command instructing bank switching to the 2nd bank to the control circuit <NUM>.

As the flow passage A switching step (S122), the control circuit <NUM> controls switching of the flow passages by the switching valve when the measured flow rate F becomes lower than the lower limit threshold Frb1. In the examples of <FIG> and <FIG>, the two valves 34a and 34b correspond to the switching valve. In the example of <FIG>, the valve 34b corresponds to the switching valve. Specifically, the valve controller <NUM> controls the valve 34a to open it and the valve 34b to close it, so that hydrogen fuel flow passages in the dispenser <NUM> are switched from the flow passage B (is set) to the flow passage A.

As the 2nd bank switching step (S124), the bank switching command receiver <NUM> receives a bank switching command from the dispenser <NUM> via the communication control circuit <NUM>. Upon receiving the bank switching command, the supply unit <NUM> uses the dispenser <NUM> to fill the fuel tank <NUM> with hydrogen fuel from the pressure accumulator <NUM>, which serves as the 2nd bank of the multi-stage pressure accumulator <NUM> (start filling). Specifically, the supply unit <NUM> operates as follows. To the system controller <NUM>, the bank switching command is input, and the system controller <NUM> controls the supply controller <NUM>. Under the control of the system controller <NUM>, the supply controller <NUM> controls the supply unit <NUM> such that the supply unit <NUM> supplies hydrogen fuel from the pressure accumulator <NUM> to the fuel tank <NUM> of the FCV <NUM>. Specifically, the system controller <NUM> controls the valve controller <NUM>. The valve controller <NUM> outputs a control signal to the valves <NUM>, <NUM>, and <NUM> via the communication control circuit <NUM> to control opening/closing of each valve. Specifically, the valve controller <NUM> opens the valve <NUM> and closes the valves <NUM> and <NUM>. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage A.

As the flow rate determination step (S126), the determining unit <NUM> determines whether the received flow rate per unit time F becomes lower than the set lower limit threshold Fra2. When the flow rate per unit time F becomes lower than the lower limit threshold Fra2, the process proceeds to the next step. When the flow rate per unit time F is not lower than the lower limit threshold Fra2, the flow rate determination step (S126) is repeated until the flow rate per unit time F becomes lower than the lower limit threshold Fra2.

As the lower limit flow rate (lower limit threshold Frb2) calculating step (S128), the control circuit <NUM> variably calculates and sets the lower limit threshold Frb2 with reference to the correlation table (table information) stored in the storage device <NUM>. Specifically, the threshold calculator <NUM> reads information of the latest temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage B and the 2nd bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Frb2 corresponding to the current pressure of the fuel tank <NUM> and the latest outside air temperature defined in the FCV information. The calculated lower limit threshold Frb2 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets (updates) the lower limit threshold Frb2 stored in the storage device <NUM> as a determination threshold.

As the flow passage B switching step (S130), the control circuit <NUM> controls switching of the flow passages by the switching valve when the measured flow rate F becomes lower than the lower limit threshold Fra2. Specifically, the valve controller <NUM> controls the valve 34a to close it and the valve 34b to open it, so that hydrogen fuel flow passages in the dispenser <NUM> are switched from the flow passage A (is set) to the flow passage B. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage B. In other words, hydrogen filling of the fuel tank <NUM> from the pressure accumulator <NUM> is continued.

As the flow rate determination step (S132), the determining unit <NUM> determines whether the received flow rate per unit time F becomes lower than the set lower limit threshold Frb2. When the flow rate per unit time F becomes lower than the lower limit threshold Frb2, the process proceeds to the next step. When the flow rate per unit time F is not lower than the lower limit threshold Frb2, the flow rate determination step (S132) is repeated until the flow rate per unit time F becomes lower than the lower limit threshold Frb2.

As the lower limit flow rate (lower limit threshold Fra3) calculating step (S134), the control circuit <NUM> variably calculates and sets the lower limit threshold Fra3 with reference to the correlation table (table information) stored in the storage device <NUM>. Specifically, the threshold calculator <NUM> reads information of the latest temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage A and the 3rd bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Fra3 corresponding to the current pressure of the fuel tank <NUM> and the latest outside air temperature defined in the FCV information. The calculated lower limit threshold Fra3 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets (updates) the lower limit threshold Fra3 stored in the storage device <NUM> as a determination threshold. In addition, the bank switching controller <NUM> transmits, via the communication control circuit <NUM>, a bank switching command instructing bank switching to the 3rd bank to the control circuit <NUM>.

As the flow passage A switching step (S136), the control circuit <NUM> controls switching of the flow passages by the switching valve when the measured flow rate F becomes lower than the lower limit threshold Frb2. Specifically, the valve controller <NUM> controls the valve 34a to open it and the valve 34b to close it, so that hydrogen fuel flow passages in the dispenser <NUM> are switched from the flow passage B (is set) to the flow passage A.

As the 3rd bank switching step (S138), the bank switching command receiver <NUM> receives a bank switching command from the dispenser <NUM> via the communication control circuit <NUM>. Upon receiving the bank switching command, the supply unit <NUM> uses the dispenser <NUM> to fill the fuel tank <NUM> with hydrogen fuel from the pressure accumulator <NUM>, which serves as the 3rd bank of the multi-stage pressure accumulator <NUM> (start filling). Specifically, the supply unit <NUM> operates as follows. To the system controller <NUM>, the bank switching command is input, and the system controller <NUM> controls the supply controller <NUM>. Under the control of the system controller <NUM>, the supply controller <NUM> controls the supply unit <NUM> such that the supply unit <NUM> supplies hydrogen fuel from the pressure accumulator <NUM> to the fuel tank <NUM> of the FCV <NUM>. Specifically, the system controller <NUM> controls the valve controller <NUM>. The valve controller <NUM> outputs a control signal to the valves <NUM>, <NUM>, and <NUM> via the communication control circuit <NUM> to control opening/closing of each valve. Specifically, the valve controller <NUM> opens the valve <NUM> and closes the valves <NUM> and <NUM>. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage A.

As the flow rate determination step (S140), the determining unit <NUM> determines whether the received flow rate per unit time F becomes lower than the set lower limit threshold Fra3. When the flow rate per unit time F becomes lower than the lower limit threshold Fra3, the process proceeds to the next step. When the flow rate per unit time F is not lower than the lower limit threshold Fra3, the flow rate determination step (S140) is repeated until the flow rate per unit time F becomes lower than the lower limit threshold Fra3.

As the lower limit flow rate (lower limit threshold Frb3) calculating step (S142), the control circuit <NUM> variably calculates and sets the lower limit threshold Frb3 with reference to the correlation table (table information) stored in the storage device <NUM>. Specifically, the threshold calculator <NUM> reads information of the latest temperature of the supplied hydrogen fuel and the outside air temperature, which is stored in the storage device <NUM>, also reads the correlation table for the flow passage B and the 3rd bank corresponding to the temperature of supplied hydrogen fuel, and calculates the lower limit threshold Frb3 corresponding to the current pressure of the fuel tank <NUM> and the latest outside air temperature defined in the FCV information. The calculated lower limit threshold Frb3 (threshold data) is temporarily stored in the storage device <NUM>. In addition, the threshold setting unit <NUM> sets (updates) the lower limit threshold Frb3 stored in the storage device <NUM> as a determination threshold.

As the flow passage B switching step (S144), the control circuit <NUM> controls switching of the flow passages by the switching valve when the measured flow rate F becomes lower than the lower limit threshold Fra3. Specifically, the valve controller <NUM> controls the valve 34a to close it and the valve 34b to open it, so that hydrogen fuel flow passages in the dispenser <NUM> are switched from the flow passage A (is set) to the flow passage B. Accordingly, hydrogen fuel is supplied from the pressure accumulator <NUM> to the fuel tank <NUM> through the flow passage B. In other words, hydrogen filling of the fuel tank <NUM> from the pressure accumulator <NUM> is continued.

As the filling completion determination step (S148), the determining unit <NUM> determines whether the filling is completed. Specifically, the determining unit <NUM> determines whether the current pressure of the fuel tank <NUM> defined in the FCV information has reached the received final pressure PF. When the current pressure of the fuel tank <NUM> defined in the FCV information has not reached the received final pressure PF, the filling completion determination step (S148) is repeated until the final pressure PF is reached. The filling is finished when the current pressure of the fuel tank <NUM> defined in the FCV information has reached the received final pressure PF. Specifically, the valve controller <NUM> closes the shutoff valves <NUM> and <NUM> to block the flow passages. In addition, the valve controller <NUM> closes the valve <NUM>.

Here, the FCV <NUM> that comes into the hydrogen station <NUM> is not limited to have the fuel tank <NUM> having a sufficiently low pressure. When the pressure of the fuel tank <NUM> is higher than, for example, a half of the pressure of the fuel tank <NUM> when it is full, for example, the two pressure accumulators <NUM> and <NUM> may be sufficient. When the pressure of the fuel tank <NUM> is higher, for example, the one pressure accumulator <NUM> may be sufficient. In any case, the pressure accumulators to be used are switched in the order of the pressure accumulators <NUM>, <NUM>, and <NUM>. The pressure of the fuel tank <NUM> is monitored, as part of the FCV information, constantly or at predetermined sampling intervals while the communication between the on-vehicle device <NUM> and the control circuit <NUM> (communication control circuit <NUM>) is established. The determining unit <NUM> then determines whether the current pressure of the fuel tank <NUM> defined in the FCV information has reached the final pressure PF. When the current pressure of the fuel tank <NUM> reaches the final pressure PF, the filling is finished.

As described above, the hydrogen fuel filling method according to embodiment <NUM> includes a step of filling the FCV <NUM> that uses hydrogen fuel as the power source with hydrogen fuel supplied from the pressure accumulator, which accumulate hydrogen fuel under pressure, through the flow passage A, a step of switching between the plurality of pressure accumulators, a step of switching the flow passages of the hydrogen fuel from the flow passage A to the flow passage B arranged in parallel with the flow passage A, or switching the flow passages of the hydrogen fuel from the flow passage A to both of the flow passages A and B during the supply from the pressure accumulator, and a step of filling the FCV <NUM> with hydrogen fuel from the pressure accumulator through the flow passage to which switching has been made, wherein the fuel cell vehicle is filled with hydrogen fuel without using a flow rate adjusting valve in both of a case that the hydrogen fuel passing through the first flow passage and a case that the hydrogen fuel passing through the second flow passage.

Further, as described above, the hydrogen fuel filling method according to embodiment <NUM> includes a step of, when the multi-stage pressure accumulator <NUM> is used, filling the FCV <NUM> with hydrogen fuel while adjusting the flow rate per unit time of the hydrogen fuel supplied from the pressure accumulator <NUM> out of the plurality of accumulators <NUM>, <NUM>, and <NUM>, which accumulate the hydrogen fuel under pressure, by switching the flow passages of the hydrogen fuel supplied from the pressure accumulator <NUM> selectively from the flow passage A to the flow passage B arranged in parallel with the flow passage A or from the flow passage A to both of the flow passages A and B during the supply, and subsequently to the filling with hydrogen fuel supplied from the pressure accumulator <NUM>, a step of filling the FCV <NUM> with hydrogen fuel supplied from the pressure accumulator <NUM> while adjusting the flow rate per unit time F of the hydrogen fuel supplied from the pressure accumulator <NUM> by switching the flow passages of the hydrogen fuel supplied from the pressure accumulator <NUM>, to which switching has been made from the pressure accumulator <NUM>, selectively from the flow passage A to the flow passage B arranged in parallel with the flow passage A, or from the flow passage A to both of the flow passages A and B during the supply. Similarly, subsequently to the filling of the FCV <NUM> with hydrogen fuel supplied from the pressure accumulator <NUM>, a step of filling the FCV <NUM> with hydrogen fuel supplied from the pressure accumulator <NUM> is included.

By the processes described above, the filling (supply) the fuel tank <NUM> of the FCV <NUM> with hydrogen fuel is finished. The nozzle <NUM> of the dispenser <NUM> is disconnected from the receiving port (receptacle) of the fuel tank <NUM> of the FCV <NUM>, and a user pays a fee, for example, corresponding to the supplied amount and leaves the hydrogen station <NUM>.

On the other hand, such filling reduces the amount of hydrogen fuel and reduces the pressure in each pressure accumulator <NUM>, <NUM>, and <NUM>. Therefore, the bank pressure receiver <NUM> receives the pressures in the pressure accumulators <NUM>, <NUM>, and <NUM> from the respective pressure gauges <NUM>, <NUM>, and <NUM> via the communication control circuit <NUM> constantly or at predetermined sampling periods, and stores the pressures in the storage device <NUM>.

Since the pressure in each of the pressure accumulators <NUM>, <NUM>, and <NUM> is lowered due to the filling of the fuel tank <NUM> of the FCV <NUM>, a pressure recovery mechanism <NUM> recovers the pressure in each of the pressure accumulators <NUM>, <NUM>, and <NUM>. The compressor <NUM>, the valves <NUM>, <NUM>, and <NUM>, the valves <NUM>, <NUM>, <NUM>, and <NUM>, and the like are included in the pressure recovery mechanism <NUM>. First, the system controller <NUM> selects a hydrogen fuel supply source connected to the suction side of the compressor <NUM> from the curdle <NUM>, the intermediate pressure accumulator <NUM>, the hydrogen trailer <NUM>, or the hydrogen production apparatus <NUM>. Then, under the control of the system controller <NUM>, the pressure recovery controller <NUM> controls the pressure recovery mechanism <NUM> to recover the pressure of each of the pressure accumulators <NUM>, <NUM>, and <NUM>. Specifically, first, the valve controller <NUM>, controls one valve (valve <NUM>, <NUM>, <NUM>, or <NUM>) corresponding to a supply source of hydrogen fuel selected from the curdle <NUM>, the intermediate pressure accumulator <NUM>, the hydrogen trailer <NUM>, or the hydrogen production apparatus <NUM> to change the state of the valve from an open state to a closed state under the control of the system controller <NUM>. As a result, low-pressure hydrogen fuel is supplied to the suction side of the compressor <NUM>.

The pressure of the pressure accumulator as each bank used for filling the fuel tank <NUM> of the FCV <NUM> may also be recovered during the filling. However, since there is not enough time to recover the pressure to the specified pressure, the pressure needs to be recovered after the filling. Since the banks are switched in the order of the 1st bank, the 2nd bank, and the 3rd bank, first, the pressure in the pressure accumulator <NUM>, which serves as the 1st bank, is recovered. The valve controller <NUM> opens the valve <NUM> from the state where the valves <NUM>, <NUM> and <NUM> are closed.

Then, the compressor controller <NUM> drives the compressor <NUM> to deliver low-pressure (for example, <NUM> MPa) hydrogen fuel while compressing it and fill the pressure accumulator <NUM> with hydrogen fuel until the pressure in the pressure accumulator <NUM> reaches a predetermined pressure P0 (for example, <NUM> MPa) so as to recover the pressure in the pressure accumulator <NUM>.

Next, the valve controller <NUM> closes the valve <NUM> and opens the valve <NUM> instead.

By the processes described above, the hydrogen fuel can be similarly supplied when the next FCV <NUM> comes into the hydrogen station <NUM>.

Here, in the above-described example, the case where the flow passages are switched using the lower limit thresholds of the flow rate F has been described, but other configurations may be possible.

<FIG> is a diagram illustrating still another example of the correlation tables in embodiment <NUM>. <FIG> illustrates an example of the correlation tables of the flow passage A when the 1st bank is used. Furthermore, the correlation table of the flow passage B when the 1st bank is used, the correlation table of the flow passage A when the 2nd bank is used, the correlation table of the flow passage B when the 2nd bank is used, the correlation table of the flow passage A when the 3rd bank is used, and the correlation table of the flow passage B when the 3rd bank is used are created for each range of the temperature of supplied hydrogen fuel. In each correlation table, instead of the lower limit threshold of the flow rate per unit time, an upper limit threshold t of hydrogen fuel supply time in one flow passage using one bank may be preferably defined. For each flow passage using each bank, the time from the start of supply to the time when the lower limit threshold of the flow rate per unit time (filling speed) is reached may be calculated, and the time may be defined as the upper limit threshold. Other than this point, the correlation tables are similar to those illustrated in part A of <FIG>.

In the example of <FIG>, the vertical axis of the correlation table defines the outside air temperature (°C), and the horizontal axis defines the pressure (MPa) of the fuel tank <NUM> of the FCV <NUM>, and in the area specified by the outside air temperature (°C) and the pressure of the fuel tank <NUM> of the FCV <NUM> (MPa), the upper limit threshold of supply time t (sec) of the flow passage A when the 1st bank is used is defined. In the example of <FIG>, in a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the upper limit threshold t0010 of the supply time of the flow passage A when the 1st bank is used is defined. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the upper limit threshold t4010 of the supply time of the flow passage A when the 1st bank is used is defined. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the upper limit threshold t0080 of the supply time of the flow passage A when the 1st bank is used is defined. In a case, for example, where the temperature of the supplied hydrogen fuel is within the range of -<NUM> to -<NUM>, the outside air temperature is <NUM>, and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the upper limit threshold t4080 of the supply time of the flow passage A when the 1st bank is used is defined.

Then, the control circuit <NUM> controls switching of the flow passages by the switching valve when the time during which hydrogen fuel passes through one or both of the flow passages A and B reaches the upper limit threshold. To the control circuit <NUM>, specific information is input, and the control circuit <NUM> variably sets the upper limit threshold according to the value defined in the specific information. As described above, at least one of the pressure information of the fuel tank <NUM> mounted on the FCV <NUM>, the hydrogen fuel temperature information, and the outside air temperature information is used as the specific information. For example, table information defining the pressure of the fuel tank <NUM> and the outside air temperature in association is used.

A similar filling method can be implemented by replacing the above-mentioned lower limit flow rate with the upper limit time and replacing the lower limit threshold of the flow rate per unit time (filling speed) with the upper limit threshold of the supply time.

Note that, in the above-described example, the case where different correlation tables are created for banks from the 1st bank to the 3rd bank when the lower limit thresholds of the flow rate F illustrated in parts A to C of <FIG> are used has been described, but other configurations may be possible. As simpler correlation tables, a correlation table of the flow passage A common to banks and a correlation table of the flow passage B common to banks may be created for each temperature range of supplied hydrogen fuel. Furthermore, the case where a correlation table is created for each temperature range of supplied hydrogen fuel has been described, but other configurations may be possible. As even simpler correlation tables, a correlation table of the flow passage A and a correlation table of the flow passage B common to temperature ranges of hydrogen fuel and common to banks may be created.

Similarly, the case where different correlation tables are created for banks from the 1st bank to the 3rd bank when the upper limit thresholds of the supply time illustrated in <FIG> are used has been described, but other configurations may be possible. As simpler correlation tables, a correlation table of the flow passage A common to banks and a correlation table of the flow passage B common to banks may be created for each temperature range of supplied hydrogen fuel. Furthermore, the case where a correlation table is created for each temperature range of supplied hydrogen fuel has been described, but other configurations may be possible. As even simpler correlation tables, a correlation table of the flow passage A and a correlation table of the flow passage B common to temperature ranges of hydrogen fuel and common to banks may be created.

As described above, according to embodiment <NUM>, filling with hydrogen fuel while adjusting the flow rate of the supplied hydrogen fuel is possible without using a flow rate adjusting valve by providing the switchable parallel flow passages. Therefore, inexpensive and safe hydrogen fuel filling becomes possible.

In embodiment <NUM>, the case where the correlation tables defining the temperature of supplied hydrogen fuel, the outside air temperature, and the lower limit threshold of the flow rate corresponding to the pressure of the fuel tank <NUM> of the FCV <NUM> are used has been described, but other correlation tables may be possible. In embodiment <NUM>, a case where a correlation table simpler than that in embodiment <NUM> is used will be described. A configuration of a hydrogen fuel supply system of a hydrogen station according to embodiment <NUM> is similar to that illustrated in <FIG>. A flowchart illustrating main steps of a hydrogen fuel filling method according to embodiment <NUM> is similar to that illustrated in <FIG>. Embodiment <NUM> is similar to embodiment <NUM> except for the description about the correlation table.

<FIG> is a diagram illustrating an example of correlation tables in embodiment <NUM>. Part A' of <FIG> illustrates an example of correlation tables of the flow passage A when the 1st bank is used. Part B' of <FIG> illustrates an example of correlation tables of the flow passage B when the 1st bank is used. Furthermore, as illustrated in part C' of <FIG>, similarly, a correlation table of the flow passage A when the 2nd bank is used, a correlation table of the flow passage B when the 2nd bank is used, a correlation table of the flow passage A when the 3rd bank is used, and a correlation table of the flow passage B when the 3rd bank is used are created. Correlation tables are created for different ranges of the temperature of supplied hydrogen fuel. For example, three correlation tables may be preferably created for the temperature ranges of supplied hydrogen fuel of -<NUM> to - <NUM>, -<NUM> to -<NUM>, and -<NUM> to -<NUM>. The temperature ranges of supplied hydrogen fuel are not limited to these. Correlation tables may be created for other temperature ranges. Alternatively, a correlation table may be created for each temperature of supplied hydrogen fuel although data amount becomes large.

In the example of part A' of <FIG>, as a correlation table, the lower limit threshold Fra1 of the flow rate per unit time (g/min) (filling speed) of the flow passage A when the 1st bank is used corresponding to the pressure (MPa) of the fuel tank <NUM> of the FCV <NUM> is defined. In the example of part A' of <FIG>, in a case, for example, where the temperature of supplied hydrogen fuel is within the range of -<NUM> to -<NUM> and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. In a case, for example, where the temperature of supplied hydrogen fuel is within the range of -<NUM> to -<NUM> and the pressure of the fuel tank <NUM> of the FCV <NUM> is <NUM> MPa, the lower limit threshold Fra1 of the flow rate per unit time (filling speed) of the flow passage A when the 1st bank is used is defined as <NUM>/min. The higher the pressure in the fuel tank <NUM> is, the smaller value of the lower limit threshold Fra1 is set to. The same applies to other temperature ranges of supplied hydrogen fuel.

In the example of part B' of <FIG>, as a correlation table, the lower limit threshold Frb1 of the flow rate per unit time (g/min) (filling speed) of the flow passage B when the 1st bank is used corresponding to the pressure (MPa) of the fuel tank <NUM> of the FCV <NUM> is defined. When the 1st bank is used with the flow passage B, the flow passage A has already been used. Therefore, the residual pressure in the 1st bank (pressure accumulator <NUM>) has been decreased and the pressure in the fuel tank <NUM> has been contrary increased. Similar to the example of part A' of <FIG>, the higher the pressure in the fuel tank <NUM> is, the smaller value of the lower limit threshold Frb1 is set to. The same applies to other temperature ranges of supplied hydrogen fuel.

Note that, also in embodiment <NUM>, similar to embodiment <NUM>, a case where different correlation tables are created for banks from the 1st bank to the 3rd bank when the lower limit threshold of the flow rate F is used has been described, but other configurations may be possible. As simpler correlation tables, a correlation table of the flow passage A common to banks and a correlation table of the flow passage B common to banks may be created for each temperature range of supplied hydrogen fuel. Furthermore, the case where a correlation table is created for each temperature range of supplied hydrogen fuel has been described, but other configurations may be possible. As even simpler correlation tables, a correlation table of the flow passage A and a correlation table of the flow passage B common to temperature ranges of hydrogen fuel and common to banks may be created.

In addition, similar to the case described with reference to <FIG>, in each correlation table illustrated in parts A' to C' of <FIG>, instead of the lower limit threshold of the flow rate per unit time, an upper limit threshold t of the hydrogen fuel supply time in one flow passage using one bank may be preferably defined. Furthermore, the case where different correlation tables are created for banks from the 1st bank to the 3rd bank when the upper limit thresholds of the supply time are used instead of the lower limit threshold of the flow rate per unit time has been described, but other configurations may be possible. As simpler correlation tables, a correlation table of the flow passage A common to banks and a correlation table of the flow passage B common to banks may be created for each temperature range of supplied hydrogen fuel. Furthermore, the case where a correlation table is created for each temperature range of supplied hydrogen fuel has been described, but other configurations may be possible. As even simpler correlation tables, a correlation table of the flow passage A and a correlation table of the flow passage B common to temperature ranges of hydrogen fuel and common to banks may be created.

Here, in each of the above-described embodiments, the case where at least the correlation tables defining the lower limit threshold of the flow rate (or the upper limit threshold of the supply time) corresponding to the pressure of the fuel tank <NUM> of the FCV <NUM> are used has been described, but other configurations may be possible. Regardless of other conditions, a constant lower limit threshold of the flow rate (or upper limit threshold of the supply time) may be set for the flow passage A and a constant lower flow rate threshold (or upper feed time threshold) may be set for the flow passage B.

The embodiments have been described with reference to the specific examples. However, the present invention is not limited to these specific examples. For example, in the above-described examples, the cases where determination is made based on only one of the lower limit threshold of the flow rate and the upper limit threshold of the supply time to switch the flow passages, but the present invention is not limited to this configuration. A case where the flow passages are switched when it is determined that both the lower limit threshold of the flow rate and the upper limit threshold of the supply time are satisfied is also preferable. Alternatively, a case where the flow passages are switched when it is determined that one of the lower limit threshold of the flow rate or the upper limit threshold of the supply time is satisfied is also preferable.

Further, in the above-described examples, the case where the multi-stage pressure accumulator <NUM> including the three pressure accumulators <NUM>, <NUM>, and <NUM> is used to fill one FCV with hydrogen fuel has been described, but the present invention is not limited to this configuration. Depending on the volumes and the like of the pressure accumulators <NUM>, <NUM>, and <NUM>, more pressure accumulators may be used for filling one FCV. Alternatively, there may be a case where two pressure accumulators are enough for filing one FCV.

In the above-described examples, the case where one dispenser <NUM> is provided and the case where one nozzle <NUM> is provided for the one dispenser <NUM> have been described, but the present invention is not limited to this configuration. The number of dispensers <NUM> may be two or more. Similarly, the number of nozzles <NUM> provided for one dispenser <NUM> may be two or more.

In addition, although description has not been provided for parts of the device configuration, the control method, and the like that are not directly necessary for the description of the present invention, required device configuration and control method can be appropriately selected and used.

Claim 1:
A hydrogen fuel filling system (<NUM>) comprising:
a first flow passage (33a) through which hydrogen fuel supplied from a pressure accumulator (<NUM>) that accumulates hydrogen fuel under pressure passes, the pressure accumulator (<NUM>) including a plurality of pressure accumulators (<NUM>, <NUM>, and <NUM>) accumulating hydrogen fuel under pressure;
a second flow passage (33b) through which hydrogen fuel supplied from the pressure accumulator (<NUM>) passes, and which is arranged in parallel with the first flow passage (33a);
a switching valve (34a and 34b) that switches flow passages selectively from one of the first (33a) and second flow passages (33b) to another, or that switches flow passages between one and both of the first (33a) and second flow passages (33b); and
a control circuit (<NUM>) that controls opening/closing of the switching valve (34a and 34b), wherein
switching is made between the plurality of pressure accumulators (<NUM>, <NUM>, and <NUM>),
a fuel cell vehicle (<NUM>) using hydrogen fuel as a power source is filled with hydrogen fuel while switching the flow passages by the switching valve (34a and 34b) during supply of hydrogen fuel from the pressure accumulator to which switching has been made every time when switching between the plurality of pressure accumulators (<NUM>, <NUM>, and <NUM>) is made, and
the fuel cell vehicle (<NUM>) is filled with hydrogen fuel without using a flow rate adjusting valve in both of a case that the hydrogen fuel passing through the first flow passage (33a) and a case that the hydrogen fuel passing through the second flow passage (33b).