Patent ID: 12233377

DESCRIPTION OF EMBODIMENTS

Embodiment 1

FIG.1is an example of a configuration diagram showing a configuration of a hydrogen gas supply system of a hydrogen station according to an embodiment 1. InFIG.1, a hydrogen gas supply system500is disposed in a hydrogen station102. The hydrogen gas supply system500includes a hydrogen production apparatus300, a multi-stage accumulator101, a dispenser30(measuring device), a compressor40, an adsorption column70(first adsorption column), an adsorption column control valve system110, an adsorption column75(second adsorption column) and a control circuit100. An example of the hydrogen gas supply apparatus which supplies hydrogen gas to the multi-stage accumulator101and/or the dispenser30is configured by the compressor40, the adsorption column70, the adsorption column control valve system110, the adsorption column75, pipes connecting those, etc. The example ofFIG.1shows an example of the on-site ST, where the hydrogen production apparatus300is disposed in the hydrogen station102. However, it is not limited thereto. A configuration (off-site ST) is also preferable where high purity hydrogen gas produced at another site is carried into the hydrogen station102by a hydrogen trailer, and temporarily accumulated in a curdle or intermediate accumulator (not shown).

The multi-stage accumulator101is composed of a plurality of pressure accumulators10,12, and14. In the example ofFIG.1, the three accumulators10,12, and14configure the multi-stage accumulator101. In the case ofFIG.1, for example, the pressure accumulator10functions as a 1st bank having a low use lower limit pressure. The pressure accumulator12functions as a 2nd bank having an intermediate use lower limit pressure, for example. The pressure accumulator14functions as a 3rd bank having a high use lower limit pressure, for example. However, it is not limited thereto. The pressure accumulators used as the 1st to 3rd banks are interchanged as needed.

Further, inFIG.1, the suction side of the compressor40is connected by a pipe to the discharge side of the hydrogen production apparatus300via a valve328.

The adsorption column70is disposed between the discharge port of the compressor40and the multi-stage accumulator101. In the adsorption column70, an adsorbent (first adsorbent) for adsorbing impurities in the hydrogen gas discharged from the compressor40is arranged. As the adsorbent for the adsorption column70, it is preferable to use the one that has a high adsorption capacity for sulfur and halogen generated from component parts and the like of the compressor40, and, for example, activated carbon is arranged. The adsorbent is not limited to the one formed from one layer, and may be from a plurality of layers of different kinds.

The adsorption column control valve system110is disposed at the gas inlet/outlet port side of the adsorption column70, which is at the discharge side of the compressor40. The adsorption column control valve system110is composed of a plurality of shutoff valves71,72,73and74(a plurality of valves) which can seal the adsorption column70. The shutoff valve71(first valve) is disposed between the discharge port of the compressor40and the gas inlet port of the adsorption column70. The shutoff valve72(second valve) is disposed between the gas outlet port of the adsorption column70and the multi-stage accumulator101. In other words, the discharge side of the compressor40is connected by a pipe76to the gas inlet side of the adsorption column70via the shutoff valve71of the adsorption column control valve system110. The gas outlet side (downstream side) of the adsorption column70is connected by a pipe to the multi-stage accumulator101side and/or the dispenser30side via the shutoff valve72of the adsorption column control valve system110. Further, a return pipe92, which is connected to the suction side of the compressor40, branches between the shutoff valve71and the gas inlet port of the adsorption column70.

In the middle of the return pipe92, the adsorption column75is disposed. In the adsorption column75, an adsorbent (second adsorbent) for adsorbing impurities in the hydrogen gas discharged from the compressor40is arranged. As the adsorbent for the adsorption column75, it is preferable to use the one that has a high adsorption capacity for sulfur and halogen generated from component parts and the like of the compressor40, and, for example, activated carbon is arranged. The adsorbent is not limited to the one formed from one layer, and may be from a plurality of layers of different kinds. Since the adsorption column75is used under a low pressure (e.g., 0.6 MPa), it is formed larger than the adsorption column70. Since the capacity of the adsorption column75is larger than that of the adsorption column70, the adsorbent amount on board of the adsorption column75can be large. Therefore, the impurities discharged from the adsorption column70at every regeneration time can be repeatedly removed by the adsorption column75. The adsorbent of the adsorption column70may be exchanged, without being regenerated, when the adsorption performance is deteriorated. Since the adsorbent amount on board is large, the life can be extended. In the middle of the return pipe92, the shutoff valve74(third valve) of the adsorption column control valve system110is disposed between the gas inlet of the adsorption column70and the gas inlet of the adsorption column75.

A vent line90(vent pipe) branches from between the shutoff valve71, which is disposed between the discharge port of the compressor40and the gas inlet port of the adsorption column70, and the gas inlet port of the adsorption column70. In the middle of the vent line90, the shutoff valve73(fourth valve) of the adsorption column control valve system110is disposed.

The downstream side of the adsorption column70is connected by a pipe to the pressure accumulator10via the shutoff valve72and a valve21. Similarly, the downstream side of the adsorption column70is connected by a pipe to the pressure accumulator12via the shutoff valve72and a valve23. Similarly, the downstream side of the adsorption column70is connected by a pipe to the pressure accumulator14via the shutoff valve72and a valve25. Similarly, the downstream side of the adsorption column70is connected by a pipe to the dispenser30via the shutoff valve72and a valve28.

Further, the pressure accumulator10is connected by a pipe to the dispenser30via a valve22. The pressure accumulator12is connected by a pipe to the dispenser30via a valve24. The pressure accumulator14is connected by a pipe to the dispenser30via a valve26.

Further, the discharge pressure of the hydrogen production apparatus300is measured by a manometer318. The pressure in the pressure accumulator10is measured by a manometer11. The pressure in the pressure accumulator12is measured by a manometer13. The pressure in the pressure accumulator14is measured by a manometer15.

In the dispenser30, there are disposed a flow rate adjustment valve29, a flowmeter27, a cooler32(precooler), and a manometer17. The flow rate of the hydrogen gas supplied from the multi-stage accumulator101or the compressor40is measured by the flowmeter27, and adjusted by the flow rate adjustment valve29. Then, the hydrogen gas is cooled to a predetermined temperature (e.g., −40° C.) by the cooler32. Thus, the dispenser30fills a fuel tank202mounted on an FCV200, which is a fuel cell vehicle powered by hydrogen gas, with the cooled hydrogen gas using, for example, a differential pressure. The outlet pressure (outlet pressure for filling fuel) at the outlet for filling hydrogen gas to be filled in the FCV200from the dispenser30is measured by the manometer17. Further, a control circuit34is disposed inside or close to the dispenser30, and configured to be communicable with an on-board device204in the FCV200(fuel cell vehicle powered by hydrogen gas) having arriving at the hydrogen station102. For example, the control circuit34is configured to be radio communicable using infrared rays.

Hydrogen gas serving as a fuel supplied from the dispenser30is injected through the receiving port (receptacle) into the fuel tank202of the FCV200via a fuel passage. The pressure and temperature in the fuel tank202are measured by a manometer206and a thermometer205arranged inside the fuel tank202or at the fuel passage.

The hydrogen gas produced by the hydrogen production apparatus300is supplied in a low-pressure (e.g., 0.6 MPa) state to the suction side of the compressor40. Therefore, the first side pressure PINat the suction side of the compressor40is a low pressure at normal times. Under the control of the control circuit100, the compressor40supplies the hydrogen gas supplied at a low pressure from the hydrogen production apparatus300to the pressure accumulators10,12, and14of the multi-stage accumulator101while compressing it. When the supply amount of hydrogen gas is insufficient in supplying it to the FCV200from the multi-stage accumulator101, or when the multi-stage accumulator101is recovering pressure, the compressor40, under the control of the control circuit100, may directly supply the hydrogen gas, supplied at a low pressure from the hydrogen production apparatus300, to the FCV200while compressing it via the dispenser30.

The compressor40compresses hydrogen gas and supplies it to the pressure accumulator side which accumulates hydrogen gas. Specifically, the compressor40compresses hydrogen gas until the inside of each of the pressure accumulators10,12, and14of the multi-stage accumulator101becomes a predetermined high pressure (e.g., 82 MPa). In other words, the compressor40performs compression until a second side pressure POUTat the discharge side becomes a predetermined high pressure (e.g., 82 MPa or more). Which of the pressure accumulators10,12,14, and the dispenser30is to be a hydrogen gas supply party of the compressor40may be determined by controlling, by the control circuit100, opening/closing of the corresponding valves21,23,25, and28disposed in the respective pipes. Alternatively, it may be controlled to supply the hydrogen gas to two or more pressure accumulators at the same time.

The above-stated example describes the case where the pressure PINfor supplying hydrogen gas to the suction side of the compressor40is reduction-controlled to a predetermined low pressure (e.g., 0.6 MPa). However, it is not limited thereto. Hydrogen gas in a pressure state higher than the predetermined low pressure (e.g., 0.6 MPa) may be supplied to the suction side of the compressor40so as to be compressed. In that case, not a reciprocating compressor which uses the pressure PIN(first side pressure) at the suction side at a fixed pressure (e.g., 0.6 MPa), but a high pressure compressor which can variably change the pressure PIN(first side pressure) at the suction side is employed as the compressor40. For example, it is preferable to use a multi-stage booster type compressor whose pressure PIN(first side pressure) at the suction side is, for example, 20 MPa or less.

The hydrogen gas accumulated in the multi-stage accumulator101is cooled by the cooler32in the dispenser30, and supplied from the dispenser30to the FCV200arriving at the hydrogen station102.

FIG.2is a configuration diagram showing an example of an internal structure of the control circuit100according to the embodiment 1. The control circuit100functions as a control apparatus. InFIG.2, in the control circuit100, there are disposed a communication control circuit50, a memory51, a receiving unit52, an end pressure calculation unit54, a flow planning unit56, a system control unit58, a pressure recovery control unit61, a supply control unit63, a pressure receiving unit66, an HPU control unit67, and storage devices80,82, and84, such as magnetic disk drives. The pressure recovery control unit61includes a valve control unit60and a compressor control unit62. The supply control unit63includes a dispenser control unit64and a valve control unit65. Each of the “units” such as the receiving unit52, the end pressure calculation unit54, the flow planning unit56, the system control unit58, the pressure recovery control unit61(the valve control unit60, the compressor control unit62), the supply control unit63(the dispenser control unit64, the valve control unit65), the pressure receiving unit66, and the HPU control unit67includes processing circuitry. The processing circuitry includes an electric circuit, a computer, a processor, a circuit board, a semiconductor device, or the like. As the processing circuitry, for example, a CPU (Central Processing Unit), an FPGA (Field-Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit) may be used. Further, for each unit, common processing circuitry (same processing circuitry) may be used. Alternatively, different processing circuitry (separate processing circuitry) may be used. Input data required in the receiving unit52, the end pressure calculation unit54, the flow planning unit56, the system control unit58, the pressure recovery control unit61(the valve control unit60, the compressor control unit62), the supply control unit63(the dispenser control unit64, the valve control unit65), the pressure receiving unit66, and the HPU control unit67, or calculated results are stored in the memory51each time.

In the storage device80, there is stored a conversion table81which shows correlation among FCV information, such as the pressure, temperature, and volume of the fuel tank202mounted on the FCV200, a remaining hydrogen gas amount calculated based on the FCV information, and filling information, such as a final pressure and a final temperature to be filled in the fuel tank202. Moreover, in the storage device80, a correction table83for correcting results obtained from the conversion table81is stored.

In the hydrogen gas supply system500, when the compressor40compresses the hydrogen gas having been refined to high purity by the hydrogen production apparatus300, even if impurities such as sulfur and halogen generated from component parts and the like of the compressor40are mixed in the hydrogen gas, the impurities can be removed by the adsorption column70disposed at the downstream side of the compressor40, and in addition to this, it is possible, using the adsorption column control valve system110, the return pipe92, and the adsorption column75, to efficiently use the hydrogen gas remaining in the adsorption column70while inhibiting the impurities having been adsorbed by the adsorbent in the adsorption column70from desorbing and diffusing to the compressor40side (first side), (that is, inhibiting the quality of hydrogen gas to be supplied to the FCV, etc. from becoming out of specification (e.g., ISO standards). That is, the hydrogen gas supply system500can inhibit the quality of hydrogen gas to be supplied to the FCV, etc. from becoming out of specification (e.g., ISO standards) while avoiding wasting hydrogen gas.

FIG.3is a configuration diagram showing an example of an internal structure of a compressor and an example of a structure of an adsorption column control valve system according to the embodiment 1. InFIG.3, descriptions of the structure from the hydrogen production apparatus300to the suction port of the compressor40, and the structure from the shutoff valve72to the multi-stage accumulator101(and dispenser30) are omitted. The example ofFIG.3shows, as the compressor40, a multi-stage compressor equipped with a five-stage compression mechanism. A cooler for cooling compressed hydrogen gas is individually disposed between each stage of the compression mechanism in the compressor40. Moreover, a snapper is disposed at the suction side of the first stage of the compression mechanism. The snapper functions as an accumulation tank (buffer) for mitigating pulsation of the hydrogen gas supplied from the hydrogen production apparatus300. Further, an orifice91(throttling mechanism) is disposed in the middle of the vent line90(vent pipe). A rapid pressure change due to opening of the vent line90can be reduced by the orifice91. Further, the return pipe92is connected to, for example, a snapper as the suction side of the compressor40. An orifice93(throttling mechanism) is arranged in the middle of the return pipe92. A rapid pressure change in the case of flowing hydrogen gas to the return pipe92can be reduced by the orifice93. Depending on the structure of the compressor40, there may be a case where impurities, such as sulfur components, are generated in the cylinder in which a moving part, such as a piston, for driving each compression mechanism is arranged. Then, as shown in the example ofFIG.3, a cylinder leak line may be connected to the return pipe92between the gas inlet of the adsorption column75, and the shutoff valve74in order to release the pressure in the cylinder and to adsorb/remove impurities, generated in the cylinder, by the adsorption column75. Further, in the compressor40, a decompression pipe42, which connects the discharge side of the last stage compression mechanism and the snapper at the suction side of the first stage compression mechanism of the compressor40, is connected via a flow rate adjustment valve41.

FIG.4is a flowchart showing main steps of an example of a hydrogen gas supply method according to the embodiment 1. InFIG.4, the hydrogen gas supply method of the embodiment 1 executes a series of steps: an FCV filling step102, a pressure accumulation step (S104), an adsorption column decompression/regeneration step (S121), a compressor suspension and HPU idling operation step (S122), an in-compressor decompression step (S124), and a purge control step (S128). The pressure accumulation step (S104) executes a series of steps as internal steps: a compressor operation and HPU rated operation step (S106), a valve control step (S108), an adsorption step (S110), and a determination step (S112). The hydrogen purge control step (S128) does not need to be executed each time. For example, with respect to the cycle of the respective steps inFIG.4, the hydrogen purge step (S128) may be executed once for several cycles. Needless to say, it may be carried out each time.

In the FCV filling step102, hydrogen gas is supplied to the FCV200, and the fuel tank202in the FCV200is filled with the hydrogen gas. Specifically, as an example, it operates as follows: Here, description is started from a state where hydrogen gas of a specified pressure (e.g., 82 MPa) is accumulated in the multi-stage compressor101.

When the FCV200arrives at the hydrogen station102, a worker of the hydrogen station102or a user of the FCV200connects (fits) a nozzle44of the dispenser30to the receiving port (receptacle) of the fuel tank202of the FCV200, and fixes the nozzle44. When the FCV200arrives at the hydrogen station102, and the user or a worker of the hydrogen station102connects and fixes the nozzle44of the dispenser30to the receiving port (receptacle) of the fuel tank202of the FCV200, a communication between the on-board device204and the control circuit34(repeater) is established.

Next, when the communication between the on-board device204and the control circuit34is established, FCV information such as the present pressure and temperature of the fuel tank202, and the volume of the fuel tank202is output (transmitted) in real time from the on-board device204. The FCV information is relayed by the control circuit34and transmitted to the control circuit100. In the control circuit100, the receiving unit52receives the FCV information via the communication control circuit50. While the communication between the on-board device204and the control circuit34is established, the FCV information is monitored at all times or at predetermined sampling intervals (e.g., 10 msec to several seconds). The received FCV information is stored in the storage device80together with receiving time information.

The end pressure calculation unit54reads the conversion table81from the storage device80, and calculates and estimates a final pressure PF corresponding to a received pressure Pa and temperature Ti of the fuel tank202at the initial reception time, a volume V of the fuel tank202, and an outside air temperature T′. Moreover, the end pressure calculation unit54reads the correction table83from the storage device80, and corrects a numerical value obtained from the conversion table81as necessary. If there is a large error in an obtained result based on only data of the conversion table81, the correction table83may be provided on the basis of a result obtained by an experiment, a simulation or the like. The calculated final pressure PF is output to the system control unit58.

Next, the flow planning unit56creates, using the multi-stage accumulator101, a filling control flow plan for performing differential pressure supplying (filling) of hydrogen gas to the fuel tank202of the FCV200. The flow planning unit56creates a plan of a filling control flow which includes a selection of the accumulator (selecting from the pressure accumulators10,12, and14) and a switching timing of the multi-stage accumulator101in order to make the pressure in the fuel tank202be the final pressure PF. Control data of the created filling control flow plan is temporarily stored in the storage device82. When planning the filling control flow, the flow planning unit56sets a pressure increase rate depending on the outside temperature, and calculates a filling speed corresponding to the pressure increase rate. Further, after in the middle of filling, in order to inhibit a rapid temperature increase, the flow planning unit56calculates a filling speed corresponding to the pressure increase rate depending on an outside temperature. The pressure increase rate determined depending on an outside temperature is beforehand included in the data of the conversion table81. The filling control flow is planned on these conditions, and a time t (end time1) (reaching time) from starting filling to reaching the final pressure PF is obtained.

Along with the created filling control flow, the fuel tank202mounted on the FCV200powered by hydrogen gas is filled with hydrogen gas from the dispenser30(measuring device). Specifically, it operates as follows:

FIG.5is a diagram illustrating a filling method in a case of performing differential pressure filling of hydrogen fuel by using a multi-stage accumulator according to the embodiment 1. InFIG.5, the ordinate axis indicates a pressure and the abscissa axis indicates a time. When performing differential pressure filling of hydrogen fuel to the FCV200, the pressures in the accumulators10,12, and14of the multi-stage accumulator101are generally accumulated in advance at the same pressure P0(e.g., 82 MPa). On the other hand, the fuel tank202of the FCV200arriving at the hydrogen station102has a pressure Pa. It will be described where filling the fuel tank202of the FCV200starts from the state described above.

First, filling the fuel tank202starts from the 1st bank, for example, the pressure accumulator10. Specifically, it operates as follows: Under the control of the system control unit58, the supply control unit63controls the supply unit106to supply the hydrogen fuel from the pressure accumulator10into the fuel tank202of the FCV200. Specifically, the system control unit58controls the dispenser control unit64and the valve control unit65. The dispenser control unit64communicates with the control circuit34of the dispenser30via the communication control circuit50, and controls the operation of the dispenser30. Specifically, first, the control circuit43adjusts the opening degree of the flow rate adjustment valve29in the dispenser30so that the filling speed may be a calculated filling speed M. Then, the valve control unit65outputs control signals to the valves22,24, and26via the communication control circuit50, and controls opening/closing of each valve. Specifically, the valve22is opened, and the valves24and26are kept in a state of closed. Thereby, the hydrogen fuel is supplied from the pressure accumulator10to the fuel tank202. By the differential pressure between the pressure accumulator10and the fuel tank202, the hydrogen fuel accumulated in the pressure accumulator10moves toward the fuel tank202side at an adjusted filling speed, and the pressure in the fuel tank202gradually increases as shown by a dotted line Pt. Along with this, the pressure (the graph indicated by “1st”) of the pressure accumulator10gradually decreases. Then, at the time of reaching the use lower limit pressure of the 1st bank, which indicates that a time T1has elapsed since starting of filling, the accumulator to be used is switched from the pressure accumulator10to the 2nd bank, for example, the pressure accumulator12. Specifically, the valve control unit65outputs a control signal to the valves22,24, and26via the communication control circuit50, and controls opening/closing of each valve. Specifically, the valve22is closed, the valve24is opened, and the valve26is kept in a state of closed. Thereby, since the differential pressure between the pressure accumulator12and the fuel tank202is large, the state in which the filling speed is high can be maintained.

Then, by the differential pressure between the 2nd bank, for example, the pressure accumulator12and the fuel tank202, the hydrogen fuel accumulated in the pressure accumulator12moves toward the fuel tank202side at a filling speed similarly adjusted, and the pressure in the fuel tank202gradually increases as indicated by the dotted line Pt. Along with this, the pressure (the graph indicated by “2nd”) of the pressure accumulator12gradually decreases. Then, at the time of reaching the use lower limit pressure of the 2nd bank, which indicates that a time T2has elapsed since starting of filling, the accumulator to be used is switched from the pressure accumulator12to the 3rd bank, for example, the pressure accumulator14. Specifically, the valve control unit65outputs control signals to the valves22,24, and26via the communication control circuit50, and controls opening/closing of each valve. Specifically, the valve24is closed, the valve26is opened, and the valve22is kept in a state of closed. Thereby, since the differential pressure between the pressure accumulator14and the fuel tank202is large, the state in which the filling speed is high can be maintained.

Then, by the differential pressure between the 3rd bank, for example, the pressure accumulator14and the fuel tank202, the hydrogen fuel accumulated in the pressure accumulator14moves toward the fuel tank202side at an adjusted filling speed, and the pressure in the fuel tank202gradually increases as shown by the dotted line Pt.

Along with this, the pressure (the graph indicated by “3rd”) in the pressure accumulator14gradually decreases. Then, by the accumulator14serving as the 3rd bank, the filling is performed until the pressure in the fuel tank202reaches a calculated final pressure PF (e.g., 65 to 81 MPa).

As described above, filling the fuel tank202with the hydrogen gas is performed in order from the 1st bank. The above example describes the case where the pressure P1of the fuel tank202of the FCV200arriving at the hydrogen station102is sufficiently lower than the level of the use lower limit pressure of the pressure accumulator10serving as a preset low pressure bank. As an example, the case is described where it is sufficiently low such as ½ or less of the one at the full filling (filling up) time. In such a case, in order to rapidly charge the pressure to the fuel tank202of the FCV200to be the final pressure PF, the three accumulators10,12, and14, for example, are required. However, the pressure in the fuel tank202of the FCV200arriving at the hydrogen station102is not limited to being sufficiently low. When the pressure in the fuel tank202is higher than, for example, ½ of the one at the full filling (filling up) time, two accumulators10and12, for example, may be sufficient. Further, when the pressure in the fuel tank202is high, one accumulator10, for example, may be sufficient. In any case, the accumulator to be used is switched between the pressure accumulators10,12, and14.

When filling (supplying) of the hydrogen gas into the fuel tank202of the FCV200is completed, the nozzle44of the dispenser30is removed from the receiving port (receptacle) of the fuel tank202of the FCV200, and after paying a fee corresponding to the filling amount, for example, the user leaves the hydrogen station102.

In the pressure accumulation step (S104), the compressor40compresses hydrogen gas and supplies it to the pressure accumulator side which accumulates the hydrogen gas. Specifically, it operates as follows:

In the compressor operation and HPU rated operation step (S106), the multi-stage accumulator101starts filling hydrogen to the FCV200. When the pressure in any of the accumulators in the multi-stage accumulators101decreases, and/or when the filling amount of the hydrogen supply from the multi-stage accumulator101to the FCV200is insufficient, the hydrogen production apparatus300shifts from an idling operation to a rated operation (e.g., 100% load operation) under the control of the HPU control unit67, and increases the amount of hydrogen gas produced. In that case, the valve control circuit60makes an open valve319close, and the valve328open. Then, under the control of the compressor control unit62, the compressor40starts the operation, and compresses and discharges the low-pressure hydrogen gas supplied from the hydrogen production apparatus300.

In the valve control step (S108), the valve control circuit60controls the adsorption column control valve system110so that compressed hydrogen gas may be supplied to the pressure accumulator side.

FIG.6is a diagram illustrating operations of the adsorption column control valve system at the time of the pressure accumulation step according to the embodiment 1. InFIG.6, the valve control circuit60controls the shutoff valves73and74to be closed, and the shutoff valves71and72to be opened from closed.

In the adsorption step (S110), using the adsorption column70with an adsorbent arranged, impurities in the hydrogen gas discharged from the compressor40are adsorbed onto the adsorbent in the adsorption column70. Then, the hydrogen gas of high purity because of the impurities having been adsorbed is supplied to the multi-stage accumulator101side from the gas outlet of the adsorption column70.

Further, the valve control unit60opens, for example, the valve25from the state where the valves21,22,23,24,25,26, and28are closed.

Then, hydrogen gas, which has been compressed from a low pressure (e.g., 0.6 MPa) by the operation of the compressor40and whose impurities have been adsorbed by the adsorbent in the adsorption column70, is charged into the accumulator14until the pressure in the accumulator14reaches a predetermined pressure P0(e.g., 82 MPa). By this, the pressure in the accumulator14is accumulated (recovered).

Next, the valve control unit60closes the valve25, and instead opens the valve23.

Then, similarly, hydrogen gas is charged into the accumulator12until the pressure in the accumulator12reaches a predetermined pressure P0(e.g., 82 MPa), thereby accumulating (recovering) the pressure in the accumulator12.

Next, the valve control unit60closes the valve23, and instead opens the valve21.

Then, similarly, hydrogen gas is charged into the accumulator10until the pressure in the accumulator10reaches a predetermined pressure P0(e.g., 82 MPa), thereby accumulating (recovering) the pressure in the accumulator10.

In the determination step (S112), the system control unit58determines whether the pressures of all the accumulators10,12, and14of the multi-stage accumulator101have been accumulated to a predetermined pressure P0(e.g., 82 MPa). If not having been accumulated up to the predetermined pressure P0(e.g., 82 MPa) yet, the pressure accumulation is continued. When having been accumulated up to the predetermined pressure P0(e.g., 82 MPa), it proceeds to the next step. Although the case where pressure accumulation is continued until the pressures of all the accumulators10,12, and14of the multi-stage accumulator101have been sufficiently accumulated is described here as an example, it is not limited thereto. The pressure accumulation step (S104) may be ended at the stage where pressure accumulation of any one of the accumulators10,12, and14has been sufficiently performed.

By the process described above, the pressures of the accumulators10,12, and14can be accumulated up to the predetermined pressure P0(e.g., 82 MPa). Thereby, preparation for differential pressure filling to the FCV200by the multi-stage accumulator101is performed.

In the adsorption column decompression/regeneration step (S121), in the state where the adsorption column70is blocked from the compressor40by the shutoff valve71, the inside of the adsorption column70is depressurized from a high pressure to a low pressure by flowing the compressed hydrogen gas in the adsorption column70into the return pipe92by opening the shutoff valve74. Further, impurities desorbed from the adsorbent in the adsorption column70are adsorbed by the adsorbent in the adsorption column75by flowing the compressed hydrogen gas in the adsorption column70into the return pipe92by opening the shutoff valve74.

FIG.7is a diagram illustrating an example of operations of an adsorption column control valve system at the time of the adsorption column decompression/regeneration step according to the embodiment 1. InFIG.7, the valve control unit60closes the shutoff valves71and72, and opens the shutoff valve74from the state where the shutoff valves71and72are open and the shutoff valves73and74are closed. Thereby, the compressor40and the adsorption column70are shut off by the shutoff valve71. Then, the high-pressure hydrogen gas remaining in the adsorption column70is returned to the suction side of the compressor40through the return pipe92. At this time, since the orifice93is disposed in the return pipe92, a rapid pressure change can be inhibited, thereby inhibiting damage to component parts of the adsorption column70, etc., or breakage, etc. of the adsorbent such as activated carbon. Further, pressure increase at the gas inlet side of the adsorption column75can be inhibited, and the adsorption column75can be used at a greatly lower pressure than the working pressure of the adsorption column70. Because the pressure inside the adsorption column70is depressurized, adsorbed impurities desorb from the adsorbent. Then, the impurities diffuse to the return pipe92along the flow of the internal hydrogen gas. If this goes on, it ends in that the impurities removed purposely will be returned to the suction side of the compressor40. Therefore, according to the embodiment 1, the impurities desorbed from the adsorbent in the adsorption column70are adsorbed by the adsorbent in the adsorption column75. Thereby, the adsorbent of the adsorption column70can be regenerated (refreshed). Accordingly, even when the adsorption column70is miniaturized and the on-board amount of the adsorbent is small, the adsorption performance of the adsorbent can be extended. Simultaneously, the impurities in the hydrogen gas in the adsorption column70are adsorbed by the adsorbent in the adsorption column75, and therefore, the hydrogen gas becoming of high purity is returned to the suction side of the compressor40so as to be reused.

FIG.8is a diagram illustrating another example of operations of an adsorption column control valve system at the time of an adsorption column decompression/regeneration step according to the embodiment 1. InFIG.8, the valve control unit60may close the shutoff valves71and72and open the shutoff valves73and74from the state where the shutoff valves71and72are open and the shutoff valves73and74are closed. Thereby, the hydrogen gas in the adsorption column70is discharged further to the vent line90in addition to being discharged to the return pipe92. Therefore, the inside of the adsorption column70is depressurized from a high pressure to a low pressure, and the impurities desorbed from the adsorbent in the adsorption column70are discharged to the vent line90. It may be appropriately set whether or not to use the vent line90in addition to the return pipe92. Although the amount of hydrogen gas to be reused decreases by using the vent line90, the time needed to depressurize the inside of the adsorption column70can be reduced.

Alternatively, as it is not limited to the case where the shutoff valves73and74are opened simultaneously, a time difference may be set between operations of opening the shutoff valves73and74. It is no problem whichever of them is opened first.

In the compressor suspension and HPU idling operation step (S122), the hydrogen production apparatus300shifts from a rated operation (e.g., 100% load operation) to an idling operation (e.g., 30% load operation) under the control of the HPU control unit67, thereby reducing the amount of hydrogen gas produced. The valve control circuit60controls the open valve319to be open from closed, and the valve328to be closed from open, thereby stopping supplying hydrogen gas to the compressor40. A small amount of hydrogen gas produced by the idling operation is discharged to the air because the open valve319has become open. Then, under the control of the compressor control unit62, the operation of the compressor40is suspended (stopped). Therefore, while the operation of the compressor40is completely stopped, the shutoff valves71and72are controlled to be closed.

In the in-compressor decompression step (S124), under the control of the compressor control unit62, while the flow rate adjustment valve41adjusts the flow rate at a predetermined opening degree, the pressure inside the compressor40is depressurized down to the pressure at the suction side of the compressor40via the decompression pipe42.

Here, even when the discharge side of the compressor40is depressurized, since the discharge port of the compressor40and the gas inlet port of the adsorption column70are shut off by the shutoff valve71, it is possible to prevent or inhibit impurities desorbed from the adsorbent in the adsorption column70from diffusing toward the compressor40side (first side).

In the purge control step (S128), after a predetermined time has elapsed since the shutoff valve73was opened, the control apparatus100controls to close the shutoff valve74, open the shutoff valve71, and supply the hydrogen gas supplied from the hydrogen production apparatus300through the compressor40being stopped to the adsorption column70. Specifically, in the state where the compressor40is stopped (suspended) and the inside of the adsorption column70has been depressurized to a low pressure, the hydrogen gas supplied from the hydrogen production apparatus300through the compressor40being stopped is introduced as a purge gas to the adsorption column70. The “predetermined time” here is equivalent to a time assumed to be a period in which, for example, the pressure of a sealed space (space closed by the shutoff valves71,72,73, and74) becomes equal to or less than the supply pressure from the hydrogen producing device300. The gas volume for a sealed space and the time for discharging the gas volume can be calculated based on the pipe diameter, the pipe length, the volume of the adsorption column70, the pressure at the time of sealing, etc.

FIG.9is a diagram illustrating operations of an adsorption column control valve system at the time of the hydrogen purge control step according to the embodiment 1. In the hydrogen production apparatus300under an idling operation, high-purity hydrogen gas is continued to be produced although the production amount is small. Conventionally, the hydrogen gas produced by the hydrogen production apparatus300under an idling operation is not supplied to the compressor40, but is discharged from the vent line via the open valve319. Then, in the example ofFIG.9, the valve control unit60controls to open the shutoff valves71and73, close the shutoff valves72and74, close the open valve319, and open the valve328. By this, the hydrogen gas produced by the hydrogen production apparatus300under an idling operation is supplied into the adsorption column70through the compressor40being stopped, and is discharged from the vent line90. By using this hydrogen gas as a purge gas to be introduced into the adsorption column70, regeneration of the adsorbent can be accelerated. It is assumed that impurities such as sulfur and halogen are generated due to sliding of the piston ring and the like which is generated by driving a piston during the operation of the compressor40, for example. Accordingly, it is assumed that impurities such as sulfur and halogen are not generated while the compressor40is suspended (stopped), and therefore, hydrogen gas maintaining high purity can be used as a purge gas. Further, by using the hydrogen gas produced by the hydrogen production apparatus300under the idling operation as a purge gas, hydrogen gas conventionally discarded can be utilized.

When the next FCV200arrives at the hydrogen station102, it returns to the FCV filling step (102), and each step from the FCV filling step (102) to the in-compressor decompression step (S124) (or the purge control step (S128)) is repeated.

As described above, according to the embodiment 1, it is possible to efficiently use hydrogen gas remaining in the adsorption column70while inhibiting impurities of the hydrogen gas, adsorbed by an adsorbent disposed at the downstream side of the compressor40, from diffusing to the compressor40side. Further, the adsorbent in the adsorption column70can be regenerated, and the adsorption performance of the adsorbent in the adsorption column70can be extended. Therefore, it is also possible to further miniaturize the adsorption column70.

Embodiments have been explained referring to specific examples described above. However, the present invention is not limited to these specific examples. For example, the present invention can also be applied to a hydrogen production apparatus by electrolysis.

Further, while the apparatus configuration, control method, and the like not directly necessary for explaining the present invention are not described, necessary apparatus configuration and control method can be appropriately selected and used.

In addition, all operation methods and control devices of a hydrogen production apparatus that include elements of the present invention and that can be appropriately modified by those skilled in the art are included within the scope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention relates to a hydrogen gas supply apparatus and a hydrogen gas supply method, and can be applied to, for example, a hydrogen gas supply apparatus and hydrogen gas supply method arranged at a hydrogen station.

REFERENCE SIGNS LIST

10,12,14Accumulator,11,13,15,17,318Manometer21,22,23,24,25,26,28,328Valve27Flowmeter29Flow rate adjustment valve30Dispenser31Sensor32Cooler34Control circuit40Compressor41Flow rate adjustment valve42Decompression pipe44Nozzle50Communication control circuit51Memory52Receiving unit54End pressure calculation unit56Flow planning unit58System control unit60,65Valve control unit61Pressure recovery control unit62Compressor control unit63Supply control unit64Dispenser control unit66Pressure receiving unit67HPU control unit70,75Adsorption column71,72,73,74Shutoff valve76Pipe80,82,84Storage device81Conversion table83Correction table90Vent line92Return pipe91,93Orifice100Control circuit101Multi-stage accumulator102Hydrogen station106Supply unit110Adsorption column control valve system200FCV202Fuel tank204On-board device205Thermometer206Manometer300Hydrogen production apparatus319Open valve500Hydrogen gas supply system