JP5378624B1 - High pressure hydrogen production system and method for operating high pressure hydrogen production system - Google Patents

Abstract

The number of pressure accumulators is reduced.
A high-pressure hydrogen production system 110 includes a hydrogen production apparatus 210 that produces hydrogen, a first compressor (low-pressure compressor 230) that pressurizes hydrogen produced by the hydrogen production apparatus, and a first compressor. When the pressure of the first pressure accumulator (low pressure accumulator 240) and the second pressure accumulator (variable pressure accumulator 270) storing the hydrogen boosted by the first pressure accumulator exceeds the first threshold, Hydrogen produced by the hydrogen production apparatus is started when the stop process for controlling the production apparatus to stop the production of hydrogen by the hydrogen production apparatus is started and the pressure of the first pressure accumulator becomes equal to or higher than the second threshold value which is larger than the first threshold value. And the control part 290 which makes the 2nd pressure accumulator store the hydrogen pressure | voltage-risen by the 1st compressor is provided.
[Selection] Figure 1

Description

  The present invention relates to a high-pressure hydrogen production system that produces high-pressure hydrogen and supplies it to a supplier such as a fuel cell vehicle, and an operation method of the high-pressure hydrogen production system.

  In recent years, vehicles equipped with fuel cells (FCV: Fuel Cell Vehicle, hereinafter referred to as “fuel cell vehicles”) have been developed. Since the fuel cell vehicle uses a fuel cell that generates electric power by chemically reacting hydrogen and oxygen (air) as a power source, it is necessary to supply hydrogen to the fuel cell vehicle. That is, gasoline for a gasoline vehicle powered by a gasoline engine corresponds to hydrogen for a fuel cell vehicle. Therefore, the fuel cell vehicle supplies hydrogen at the hydrogen station for the fuel cell vehicle, which corresponds to a gasoline station for the gasoline vehicle, and the supplied hydrogen is stored in a hydrogen tank provided in the fuel cell vehicle. It will be.

  The hydrogen station includes a hydrogen production apparatus (for example, Patent Document 1) and a pressure accumulator that stores hydrogen produced by the hydrogen production apparatus, and hydrogen stored in the pressure accumulator is supplied to the fuel cell vehicle. Will be.

JP 2011-132103 A

  In the hydrogen station, the pressure accumulator is provided to absorb the fluctuation (load fluctuation) of the hydrogen consumption (the amount of hydrogen supplied to the fuel cell vehicle). In order to reduce the cost required for the accumulator Therefore, development of a technology for reducing the number of pressure accumulators is desired.

  An object of the present invention is to provide a high-pressure hydrogen production system capable of reducing the number of pressure accumulators and a method for operating the high-pressure hydrogen production system.

  In order to solve the above problems, a high-pressure hydrogen production system according to the present invention includes a hydrogen production apparatus that produces hydrogen, a first compressor that pressurizes hydrogen produced by the hydrogen production apparatus, and the first compression. A first pressure accumulator and a second pressure accumulator for storing hydrogen boosted by the machine, and the hydrogen production apparatus by controlling the hydrogen production apparatus when the pressure of the first pressure accumulator exceeds a first threshold value. When the pressure of the first pressure accumulator becomes equal to or higher than a second threshold value that is greater than the first threshold value, hydrogen produced by the hydrogen production apparatus is And a controller that stores the hydrogen boosted by the compressor in the second pressure accumulator.

  Further, when the pressure of the first pressure accumulator becomes less than the second threshold value, the control unit boosts the hydrogen stored in the second pressure accumulator by the first compressor, and When the pressure in the first pressure accumulator is less than the first threshold value, the hydrogen production device is controlled to start the production of hydrogen by the hydrogen production device. Hydrogen produced by the hydrogen production apparatus may be boosted by the first compressor and stored in the first pressure accumulator.

  The controller is selected from a group of a load keeping process, a stop process, and a start process for keeping the current load of the hydrogen production device when the pressure of the first accumulator reaches the first threshold value. One process may be performed.

  Moreover, it is good also as providing further the 2nd compressor which pressurizes the hydrogen stored by the said 1st pressure accumulator, and the 3rd pressure accumulator which stores the hydrogen pressure | voltage-risen by the said 2nd compressor. .

  In order to solve the above problems, an operation method of a high-pressure hydrogen production system according to the present invention includes a hydrogen production apparatus that produces hydrogen, a first compressor that pressurizes hydrogen produced by the hydrogen production apparatus, An operation method of a high-pressure hydrogen production system including a first pressure accumulator and a second pressure accumulator for storing hydrogen boosted by one compressor, wherein the pressure of the first pressure accumulator is a first threshold value. When the pressure of the first pressure accumulator is determined to exceed the first threshold value, a stop process for stopping the hydrogen production by the hydrogen production device is started, and the first pressure accumulation is determined. It is determined whether or not the pressure of the vessel has become a second threshold value that is greater than or equal to the first threshold value, and if it is determined that the pressure of the first pressure accumulator has become the second threshold value or more, it is produced by the hydrogen production device. The first pressure Hydrogen boosted by machine, characterized in that stored in the second accumulator.

  When it is determined that the pressure of the first pressure accumulator is less than the second threshold value, the hydrogen stored in the second pressure accumulator is boosted by the first compressor, and the first pressure accumulator Storing in the pressure accumulator, determining whether the pressure of the first pressure accumulator is less than the first threshold, and determining that the pressure of the first pressure accumulator is less than the first threshold; A start process for starting hydrogen production by a hydrogen production apparatus may be performed, and the hydrogen produced by the hydrogen production apparatus may be boosted by the first compressor and stored in the first pressure accumulator. .

  Further, when it is determined whether or not the pressure of the first pressure accumulator has reached the first threshold value, and it is determined that the pressure of the first pressure accumulator has reached the first threshold value, One process selected from the group of the load keep process for keeping the load, the stop process, and the start process may be performed.

  According to the present invention, the number of pressure accumulators can be reduced.

It is a figure for demonstrating the hydrogen station concerning embodiment. It is a figure for demonstrating the high pressure hydrogen production system of a comparative example. It is a figure for demonstrating the hydrogen production amount in the period when a stop process is performed, and the period when a start process is performed at the time of an output 100% operation | movement in a hydrogen production apparatus. It is a figure for demonstrating the operation processing of the high pressure hydrogen production system at the time of normal operation and a start process. It is a figure for demonstrating the operation processing of the high pressure hydrogen production system at the time of a stop process. It is a flowchart for demonstrating the flow of control of a hydrogen production apparatus. It is a flowchart for demonstrating the flow of control of a low pressure compressor. It is a flowchart for demonstrating the flow of control of a valve | bulb.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Hydrogen station 100)
FIG. 1 is a diagram for explaining a hydrogen station 100 according to the present embodiment. As shown in FIG. 1, the hydrogen station 100 includes a high-pressure hydrogen production system 110, a precooler 120, and a dispenser 130. In FIG. 1, the hydrogen flow is indicated by a solid line, and the signal flow is indicated by a dashed arrow.

(High pressure hydrogen production system 110)
The high-pressure hydrogen production system 110 includes a hydrogen production apparatus 210, a suction tank 220, a low-pressure compressor 230 (first compressor), a low-pressure accumulator 240 (first accumulator), and a high-pressure compressor 250 (first 2 compressor), high pressure accumulator 260 (third accumulator), variable pressure accumulator 270 (second accumulator), pressure measuring unit 280, control unit 290, valves V1, V2, V3 and the pressure reducing valve V4 are comprised.

  The hydrogen production apparatus 210 includes, for example, a steam reforming vessel that generates a mixed gas containing hydrogen by catalytic reaction of fossil fuel such as city gas and liquefied petroleum gas (LPG) with water vapor, and in the mixed gas. It includes a shift reaction vessel that generates hydrogen by reacting carbon monoxide with water vapor, a hydrogen separation membrane that purifies hydrogen from a mixed gas containing hydrogen, and a pressure swing adsorption device (PSA) High-purity hydrogen is produced from fossil fuels such as city gas and liquefied petroleum gas. The pressure of hydrogen produced by the hydrogen production apparatus 210 is, for example, 0.7 MPa.

  The suction tank 220 is provided between the hydrogen production device 210 and the low-pressure compressor 230 and functions as a cushion tank.

  The low-pressure compressor 230 pressurizes the hydrogen (0.7 MPa) produced by the hydrogen production apparatus 210 and compresses it to 33 MPa to 40 MPa, for example.

  The low pressure accumulator 240 stores hydrogen (33 MPa to 40 MPa) boosted by the low pressure compressor 230.

  The high pressure compressor 250 increases the pressure of hydrogen (33 MPa to 40 MPa) stored in the low pressure accumulator 240 and compresses it to 82 MPa, for example.

  The high pressure accumulator 260 stores hydrogen (82 MPa) boosted by the high pressure compressor 250.

  The variable pressure accumulator 270 is boosted by the low-pressure compressor 230 when a stop process that is performed when stopping the hydrogen production by the hydrogen production apparatus 210 is executed in accordance with a control command of the control unit 290 described later. The generated hydrogen is stored. Further, when the pressure of the low pressure accumulator 240 decreases, hydrogen is discharged from the variable pressure accumulator 270. In the present embodiment, the upper limit pressure (maximum allowable pressure) of the variable pressure accumulator 270 is substantially equal to the upper limit pressure of the low pressure accumulator 240, for example, 40 MPa.

  The pressure measuring unit 280 measures the pressure of the low pressure accumulator 240 and the pressure of the suction tank 220.

  The control unit 290 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit), reads programs and parameters for operating the CPU itself from the ROM, and cooperates with the RAM as a work area and other electronic circuits. To manage and control the entire high-pressure hydrogen production system 110.

  In the present embodiment, the control unit 290 controls the low pressure compressor 230 and the high pressure compressor 250. More specifically, the control unit 290 determines the compression capacity of the low-pressure compressor 230 so that the pressure at the inlet of the low-pressure compressor 230 (here, the pressure of the suction tank 220) becomes a target value Psuc (for example, 0.55 MPa). Control or stop. Further, the control unit 290 controls or stops the compression capacity of the high-pressure compressor 250 so that the pressure of the high-pressure accumulator 260 becomes a predetermined value (for example, 82 MPa).

  The control unit 290 also performs drive control of the hydrogen production apparatus 210 and opening / closing control of the valves V1, V2, and V3. The valve V1 is provided in a pipe connecting the downstream of the low-pressure compressor 230 and the variable pressure accumulator 270, and the valve V2 is provided in a pipe connecting the variable pressure accumulator 270 and the suction tank 220. V <b> 3 is provided on the downstream side of the connection point between the pipe connecting the low pressure compressor 230 and the low pressure accumulator 240 to the pipe connecting the downstream of the low pressure compressor 230 and the variable pressure accumulator 270. The valves V1, V2, and V3 are constituted by on-off valves.

  The piping connecting the valve V2 and the suction tank 220 is provided with a pressure reducing valve V4. The pressure reducing valve V4 may be provided in a pipe connecting the variable pressure accumulator 270 and the valve V2. The set pressure of the pressure reducing valve V4 is higher than the target value Psuc of the suction tank 220, for example, 0.6 MPa. The drive control of the hydrogen production apparatus 210 and the opening / closing control of the valves V1, V2, and V3 will be described in detail in the operation process of the high-pressure hydrogen production system 110 described later.

  Then, the hydrogen stored in the high pressure accumulator 260 is cooled by the precooler 120 (for example, −40 ° C.) and filled into a hydrogen tank provided in the fuel cell vehicle via a filling control valve of the dispenser 130. Is done. Here, since hydrogen is heated by adiabatic compression when hydrogen is filled from the high pressure accumulator 260 into the hydrogen tank of the fuel cell vehicle, the precooler 120 is prevented from reaching the heat resistant temperature of the hydrogen tank. Is provided.

(Pressure design of low pressure compressor 230 and high pressure compressor 250)
Next, the pressure design of the low pressure compressor 230 and the high pressure compressor 250 will be described. Since the pressure of a hydrogen tank of a fuel cell vehicle is 70 MPa as a world standard, in order to fill the hydrogen tank with a differential pressure, the hydrogen pressure of the supply source exceeds 70 MPa (for example, 82 MPa). It is necessary to. However, since the pressure of the hydrogen produced by the hydrogen production apparatus 210 is as low as 0.7 MPa, the hydrogen produced by the hydrogen production apparatus 210 cannot be supplied to the fuel cell vehicle as it is. Therefore, the high-pressure hydrogen production system 110 of the present embodiment boosts the hydrogen produced by the hydrogen production apparatus 210 to 82 MPa.

  Specifically, first, the pressure of the last-stage high-pressure accumulator 260 in the high-pressure hydrogen production system 110 is designed to 82 MPa, that is, the outlet pressure of the high-pressure compressor 250 is designed to 82 MPa. Therefore, a high-pressure compressor 250 capable of increasing the pressure of hydrogen to 82 MPa may be employed. However, depending on the performance of the high-pressure compressor 250, it is necessary to increase the pressure at the inlet to 33 MPa to 40 MPa. Therefore, in the high-pressure hydrogen production system 110 according to the present embodiment, the low-pressure compressor 230 and the low-pressure accumulator 240 are provided, and the low-pressure compressor 230 converts hydrogen (0.7 MPa) produced by the hydrogen production apparatus 210 to 33 MPa to The pressure is increased to 40 MPa and stored in the low pressure accumulator 240, and the high pressure compressor 250 increases the pressure of 33 MPa to 40 MPa hydrogen stored in the low pressure accumulator 240 to 82 MPa.

(Effect of variable pressure accumulator 270)
Next, the effect of the variable pressure accumulator 270 in the high pressure hydrogen production system 110 will be described. Here, first, the design of the number of low pressure accumulators in the comparative example will be described, and then the effect of the variable pressure accumulator 270 in the high pressure hydrogen production system 110 will be described.

  FIG. 2 is a diagram for explaining a high-pressure hydrogen production system 10 of a comparative example. In addition, about the structure of the high pressure hydrogen production system 10, Comprising: The structure substantially equal to the structure of the high pressure hydrogen production system 110 mentioned above attaches | subjects the same code | symbol, and abbreviate | omits description.

  As shown in FIG. 2, the high pressure hydrogen production system 10 includes a hydrogen production apparatus 210, a suction tank 220, a low pressure compressor 230, a low pressure accumulator 12, a high pressure compressor 250, a high pressure accumulator 260, a pressure A measurement unit 280 and a control unit 290 are included. That is, compared with the high pressure hydrogen production system 110, the high pressure hydrogen production system 10 is not provided with the variable pressure accumulator 270, the valves V1, V2, V3, and the pressure reducing valve V4. Is different from the low pressure accumulator 240. Hereinafter, the design of the number of low-pressure accumulators 12 will be described.

  The hydrogen production apparatus 210 performs not only the normal operation but also a stop process that is performed when the operation is stopped (a process from when the operation stop instruction is input until the hydrogen production apparatus 210 is stopped), and Hydrogen is also produced during a period in which processing (start processing) is performed from the start of operation until the normal operation is reached.

  FIG. 3 shows a period during which the stop process is performed (hereinafter referred to as “stop process period”) and a period during which the start process is performed (hereinafter referred to as “start”) when the hydrogen production apparatus 210 is operated at 100% output. It is a figure for demonstrating the production amount of hydrogen of "processing period". FIG. 3 (a) is a diagram for explaining the hydrogen production amount at the time of 100% output operation, and FIG. 3 (b) is a diagram for explaining the hydrogen production amount during the stop processing period. FIG. 3C is a diagram for explaining the amount of hydrogen produced in the start processing period.

When the hydrogen production apparatus 210 is operating at an output of 100%, for example, it is assumed that hydrogen is produced at 300 m ³ / h. In this case, as shown in FIG. 3A, the hydrogen production apparatus 210 always produces hydrogen at 300 m ³ / h when operating at an output of 100%.

Here, the average filling amount of hydrogen into the fuel cell vehicle (the average amount of hydrogen that can be filled by the hydrogen production apparatus 210) will be described. The average filling amount of hydrogen into the fuel cell vehicle (m ³ / h) It depends on the hydrogen production capacity (m ³ / h) by the production apparatus 210. That is, the hydrogen station 100 according to the present embodiment can supply hydrogen to the fuel cell vehicle at 300 m ³ / h.

  However, since the fuel cell vehicle does not necessarily visit the hydrogen station 100 on average, it is necessary to adjust the amount of hydrogen produced by the hydrogen production apparatus 210.

  More specifically, in a period when the number of fuel cell vehicles visiting the hydrogen station 100 is small, that is, in a period in which the amount of hydrogen supplied to the fuel cell vehicle is less than the amount of hydrogen produced by the hydrogen production device 210, When 210 is operated at an output of 100%, hydrogen cannot be stored in the low pressure accumulator 12 or the high pressure accumulator 260. Therefore, when the hydrogen stored in the low pressure accumulator 12 or the high pressure accumulator 260 reaches a predetermined amount, the control unit 290 controls the hydrogen production apparatus 210 to perform a stop process. In addition, since the high pressure accumulator 260 is more expensive than the low pressure accumulator 12, the capacity of the low pressure accumulator 12 is generally larger than that of the high pressure accumulator 260. Therefore, when the hydrogen stored in the low pressure accumulator 12 exceeds a predetermined amount (predetermined pressure, for example, 37 MPa), the control unit 290 controls the hydrogen production apparatus 210 to perform the stop process.

When starting the stop process, as shown in FIG. 3B, the hydrogen production apparatus 210 gradually decreases the production rate of hydrogen from 300 m ³ / h, and finally sets it to 90 m ³ / h, for example. It will shift to the stop state. The hydrogen production apparatus 210 always produces hydrogen (90 m ³ / h) at an output of 30% even in a stopped state (idling state), and in the stopped state, the hydrogen production apparatus 210 itself produced it. Hydrogen is burned and consumed. That is, when the hydrogen production apparatus 210 is stopped, there is no apparent hydrogen output (zero), but in reality, hydrogen is produced at 90 m ³ / h. Here, it is assumed that the stop process requires one hour.

  Thus, hydrogen is produced even during the stop processing period (from the start of the stop processing until reaching the stop state), so the capacity of the low pressure accumulator 12 (the number of low pressure accumulators 12) is stopped. The capacity is determined in consideration of the amount of hydrogen produced during the treatment period.

More specifically, the number X of low-pressure accumulators 12 necessary for storing the amount of hydrogen produced during the stop processing period can be calculated based on the following formula (1).
X = A / {(Pmax−Pth1) × 10 × D / z} (1)
Here, A is the amount of hydrogen (m ³ ) produced during the stop process period, Pmax is the upper limit pressure (MPa) of the low pressure accumulator 12, and Pth1 is the pressure (MPa) of the low pressure accumulator 12 that triggers the start of the stop process. ), D is the capacity (m ³ ) of the low pressure accumulator 12 per unit, and z is the compression coefficient of hydrogen.

In the example shown in FIG. 3B, the amount of hydrogen A produced in the stop processing period (indicated by hatching in FIG. 3B) is (300 m ³ / h + 90 m ³ / h) / 2 × 1h = 195 m ³ It becomes. Further, the upper limit pressure Pmax of the low pressure accumulator 12 is 40 MPa, the pressure Pth1 of the low pressure accumulator 12 serving as a trigger for starting the stop process is 37 MPa, the capacity D is 0.3 m ³ / piece, and the hydrogen compression coefficient z is 1.2. If the number X of the low-pressure accumulators 12 necessary for storing the amount of hydrogen produced during the stop processing period is calculated using Equation (1), the result is 26.0.

  On the other hand, after the hydrogen production apparatus 210 has been stopped, a large number of fuel cell vehicles have come to the hydrogen station 100, and the hydrogen stored in the low pressure accumulator 12 has decreased, and the hydrogen stored in the low pressure accumulator 12 has been reduced. When the amount falls below a predetermined amount (a predetermined pressure, for example, 37 MPa), the control unit 290 controls the hydrogen production apparatus 210 to perform a start process.

As described above, the hydrogen production apparatus 210 constantly produces hydrogen (90 m ³ / h) at an output of 30% even in a stopped state (idling state). Therefore, when the start process is started from the stop state of the hydrogen production apparatus 210, the combustion of hydrogen in the hydrogen production apparatus 210 itself is stopped, and the output of hydrogen is immediately started at 90 m ³ / h.

When starting the start process, as shown in FIG. 3C, the hydrogen production apparatus 210 gradually increases the production rate of hydrogen from 90 m ³ / h, and finally outputs 300 m ³ / h as 100%. It will shift to driving. Here, it is assumed that the start process takes one hour. In this way, hydrogen is produced in the start processing period (from the start processing is started until operation reaches 100% output), but compared to operation with 100% output, production per unit time. When the hydrogen supply at the maximum supply capacity (300 m ³ / h) in the hydrogen station 100 is necessary because the amount is small, all the hydrogen produced by the hydrogen production device 210 during the start process is supplied to the fuel cell vehicle. However, hydrogen corresponding to the maximum supply capacity cannot be supplied.

Therefore, in order to stably supply hydrogen to the fuel cell vehicle, the low pressure accumulator 12 always stores the difference between the amount of hydrogen produced in the start processing period and the amount of hydrogen supplied to the fuel cell vehicle. It is necessary to keep it. The number Y of low-pressure accumulators 12 for storing such differences can be calculated using the following equation (2).
Y = B / {(Pth2−Pmin) × 10 × D / z} (2)
Here, B is the difference (m ³ ) between the amount of hydrogen produced during the start processing period and the amount of hydrogen supplied to the fuel cell vehicle, and Pmin is the lower limit pressure (MPa) of the low pressure accumulator 12, that is, the high pressure compressor The lower limit value of the pressure at the inlet of 250, Pth2 is the pressure (MPa) of the low pressure accumulator 12 serving as a trigger for starting execution of the start process, D is the capacity (m ³ ) of the low pressure accumulator 12 per unit, and z is The compression coefficient of hydrogen is shown.

In the example shown in FIG. 3C, the difference B between the amount of hydrogen produced during the start processing period and the maximum expected amount of hydrogen supplied to the fuel cell vehicle (indicated by hatching in FIG. 3C). ) Is {300 m ³ / h− (300 m ³ / h + 90 m ³ / h) / 2} × 1h = 105 m ³ . Further, the lower limit Pmin of the pressure at the inlet of the high pressure compressor 250 is 33 MPa, the pressure Pth2 of the low pressure accumulator 12 serving as a trigger for starting execution of the start process is 37 MPa substantially equal to Pth1, and the capacity D is 0.3 m ^3. When the compression coefficient z of hydrogen is 1.2 and the number Y of low-pressure accumulators 12 necessary for storing the amount of hydrogen deficient in the start processing period is calculated using Equation (2), 10. There will be five.

  Considering the above results, the number of the low pressure accumulators 12 is the number of X and Y so that hydrogen can be stored in the low pressure accumulator 12 even during the stop processing period or the start processing period. The larger one (here, X, ie 26) is set.

  Further, if the above Pth1 and Pth2 are set so that X = Y, the number of low-pressure accumulators 12 can be reduced. Since Pth1 = Pth2 as described above, in the example of FIGS. 3B and 3C, Pth1 = Pth2 = 35.45 MPa, and the number of low-pressure accumulators 12 is 17.2.

  Thus, the number of low-pressure accumulators 12 is 26.0 or 17.2 (18). In order to reduce the cost required for the low-pressure accumulator 12, the number of low-pressure accumulators 12 is There is a need for a reduction in.

  Therefore, the high-pressure hydrogen production system 110 according to this embodiment includes a variable pressure accumulator 270. As described above, the variable pressure accumulator 270 stores the hydrogen boosted by the low-pressure compressor 230 when the stop process is performed according to the control command of the control unit 290. In addition, during the stop process and in the stop state, the control unit 290 discharges the hydrogen stored in the variable pressure accumulator 270 and increases the pressure by the low pressure compressor 230. Hereinafter, the operation process of the high pressure hydrogen production system 110 by the control unit 290 will be described in detail.

(Operation processing of the high-pressure hydrogen production system 110 during normal operation)
FIG. 4 is a diagram for explaining an operation process of the high-pressure hydrogen production system 110 during the normal operation and the start process. In FIG. 4, the flow of hydrogen is indicated by solid arrows. As shown in FIG. 4, during the normal operation, the control unit 290 maintains the valve V1 in the closed state, maintains the valves V2 and V3 in the open state, and causes the hydrogen production apparatus 210 to perform the normal operation to perform low pressure compression. The machine 230 and the high-pressure compressor 250 are driven.

  Then, the hydrogen produced by the hydrogen production apparatus 210 is boosted by the low pressure compressor 230, stored in the low pressure accumulator 240, boosted by the high pressure compressor 250, and stored in the high pressure accumulator 260.

(Operation processing of the high-pressure hydrogen production system 110 when performing the stop processing)
FIG. 5 is a diagram for explaining an operation process of the high-pressure hydrogen production system 110 during the stop process. In FIG. 5, the flow of hydrogen is indicated by solid arrows. When the high-pressure hydrogen production system 110 is in normal operation and the pressure of the low-pressure accumulator 240 measured by the pressure measurement unit 280 exceeds a first threshold (for example, 37 MPa), the control unit 290 controls the hydrogen production apparatus 210. To start the stop process.

  When the pressure of the low pressure accumulator 240 measured by the pressure measuring unit 280 becomes equal to or higher than a second threshold value (for example, 40 MPa) greater than the first threshold value, the control unit 290, as shown in FIG. , V3 is closed, and the valve V1 is opened to discharge the hydrogen produced by the hydrogen production apparatus 210 to the low-pressure compressor 230. The hydrogen is boosted by the low-pressure compressor 230 and stored in the variable pressure accumulator 270.

  When the pressure of the low pressure accumulator 240 becomes less than the second threshold value during the stop process, the control unit 290 closes the valve V1, opens the valves V2 and V3, and opens the variable pressure accumulator 270 as shown in FIG. Hydrogen is discharged to the low-pressure compressor 230, boosted by the low-pressure compressor 230, and stored in the low-pressure accumulator 240. On the other hand, when the pressure of the low pressure accumulator 240 measured by the pressure measuring unit 280 becomes equal to or higher than the second threshold value, the control unit 290 closes the valves V2 and V3 and opens the valve V1 (see FIG. 5A).

  When the stop process of the hydrogen production apparatus 210 is completed, the hydrogen production apparatus 210 is stopped.

  When the pressure of the low pressure accumulator 240 becomes less than the second threshold value in the stopped state, as shown in FIG. 5C, the control unit 290 closes the valve V1, opens the valves V2 and V3, and starts from the variable pressure accumulator 270. Hydrogen is discharged to the low-pressure compressor 230, boosted by the low-pressure compressor 230, and stored in the low-pressure accumulator 240. On the other hand, when the pressure of the low pressure accumulator 240 measured by the pressure measuring unit 280 becomes equal to or higher than the second threshold, the control unit 290 closes the valves V2 and V3 and opens the valve V1.

(Operation processing of the high-pressure hydrogen production system 110 when performing the start processing)
The stop process is performed, and the high pressure hydrogen production system 110 is stopped. During this time, hydrogen is supplied to the fuel cell vehicle, and the pressure of the low pressure accumulator 240 measured by the pressure measuring unit 280 is set to the first threshold value ( When the pressure is less than 37 MPa, for example, the hydrogen production device 210 is controlled to perform a start process, the hydrogen produced by the hydrogen production device 210 is discharged to the low-pressure compressor 230, the pressure is increased by the low-pressure compressor 230, It is stored in the low pressure accumulator 240 (see FIG. 4).

  As described above, according to the high-pressure hydrogen production system 110 according to the present embodiment, the number of low-pressure accumulators 240 is the number necessary for storing the amount of hydrogen deficient in the start processing period (for example, 11). As a matter of course, the excess in the stop processing period is stored in the variable pressure accumulator 270.

  Further, before performing the start process, first, hydrogen stored in the variable pressure accumulator 270 is discharged, and when the pressure of the low pressure accumulator 240 becomes less than the first threshold, the start process is started. Before performing the starting process, the pressure stored in the variable pressure accumulator 270 can be reduced to the target value Psuc by discharging the hydrogen stored in the variable pressure accumulator 270. That is, the lower limit pressure of the variable pressure accumulator 270 can be set to the target value Psuc.

  Here, since the low-pressure compressor 230 pressurizes the hydrogen in the suction tank 220, the target value Psuc of the suction tank 220 controlled by the low-pressure compressor 230 is determined based on the lower limit value of the inlet pressure of the low-pressure compressor 230. The Rukoto.

  On the other hand, since the high pressure compressor 250 boosts the hydrogen stored in the low pressure accumulator 240, the lower limit pressure of the low pressure accumulator 240 is determined based on the lower limit value of the pressure at the inlet of the high pressure compressor 250. .

  Since the lower limit value of the pressure at the inlet of the low pressure compressor 230 is smaller than the lower limit value of the pressure at the inlet of the high pressure compressor 250, the lower limit pressure of the variable pressure accumulator 270 is made smaller than that of the low pressure accumulator 240. Can do. The amount of hydrogen that can be stored in the pressure accumulator depends on the difference between the upper limit pressure and the lower limit pressure when the capacities are equal. Therefore, the variable pressure accumulator 270 can store a larger amount of hydrogen than the low pressure accumulator 240.

  That is, when filling hydrogen during the stop process, the initial pressure (lower limit pressure) of the variable pressure accumulator 270 is smaller than the lower limit pressure of the low pressure accumulator 240, so that the low pressure is already high as in the comparative example. It is possible to store a larger amount of hydrogen in the variable pressure accumulator 270 than in the accumulator 12. Therefore, with the configuration including the variable pressure accumulator 270, it is possible to store hydrogen generated during the stop processing period with a smaller capacity (number) than the low pressure accumulator 12 of the comparative example. Therefore, the cost required for the pressure accumulator can be reduced, and the cost of the hydrogen station 100 can be reduced. Moreover, since the number of pressure accumulators can be reduced, the site area of the hydrogen station 100 can be reduced.

(Number of low pressure accumulator 240 and variable pressure accumulator 270 in high pressure hydrogen production system 110)
Next, the number of low pressure accumulators 240 and variable pressure accumulators 270 in the high pressure hydrogen production system 110 will be described.

  As described above, when the start process is performed, at least 10.5 (11) low-pressure accumulators 240 are required. Therefore, the number of low-pressure accumulators 240 is eleven.

Then, assuming that the number of low pressure accumulators 240 is 11, the number of variable pressure accumulators 270 necessary for storing the amount of hydrogen produced during the stop processing period is calculated. More specifically, first, the hydrogen amount Lh (m ³ ) that can be stored by the eleven low-pressure accumulators 240 is calculated based on the following formula (3).
Lh = {(Pmax−Pth1) × 10 × D / z} × C (3)
Here, Pmax is the upper limit pressure (MPa) of the low pressure accumulator 240, Pth1 is the pressure (MPa) of the low pressure accumulator 240 that serves as a trigger for starting the stop process, and D is the capacity of the low pressure accumulator 240 per unit (m ³ ), C is the number of low-pressure accumulators 240 (here, 11), and z is the compression coefficient of hydrogen.

The upper limit pressure Pmax of the low pressure accumulator 240 is 40 MPa, the pressure Pth1 of the low pressure accumulator 240 serving as a trigger for starting the stop process is 37 MPa, the capacity D is 0.3 m ³ / piece, the hydrogen compression coefficient z is 1.2, When the amount of hydrogen Lh (m ³ ) that can be stored by the eleven low-pressure accumulators 240 is calculated using Expression (3), it is 82.5 m ³ .

Then, when the storage amount of hydrogen produced in the stop process period and (195m ^3), the difference (112.5m ³⁾ amount of hydrogen Lh (82.5m ³⁾ the variable pressure accumulator 270, which stores such difference Therefore, the number M of variable pressure accumulators 270 can be calculated using the following equation (4).
M = E / {(Qmax−Qmin) × 10 × F / z} Expression (4)
Here, E is the amount of hydrogen produced in the stop process period and ^{(m 3),} the difference ^(m 3) of hydrogen quantity Lh ^{(m 3),} Qmax is the upper limit pressure of the variable pressure accumulator 270 (MPa), Qmin Is the lower limit pressure (MPa) of the variable pressure accumulator 270, F is the capacity (m ³ ) of one variable pressure accumulator 270, and z is the compression coefficient of hydrogen.

The difference E between the amount of hydrogen (m ³ ) produced during the stop processing period and the amount of hydrogen Lh (m ³ ) is 112.5 m ³ , the upper limit pressure Qmax of the variable pressure accumulator 270 is 40 MPa, and the lower limit of the variable pressure accumulator 270 Variable pressure accumulation required to store the difference E using equation (4), with the pressure Qmin being Psuc (0.55 MPa), the capacity F being 0.3 m ³ / piece, the hydrogen compression coefficient being 1.2 When the number M of the containers 270 is calculated, it is about 1.1 (two).

  As described above, according to the hydrogen station 100 according to the present embodiment, the number of accumulators arranged upstream of the high-pressure compressor 250 can be 13 (11 + 2). Thereby, compared with the pressure accumulator of a comparative example, it becomes possible to reduce a pressure accumulator by half or 5 pieces from a comparative example.

  Further, in the hydrogen station 100, the decompression pressure of the decompression valve V4 may be set to a pressure higher than the target value Psuc of the suction tank 220. As a result, when the pressure of the low pressure accumulator 240 becomes less than the second threshold in the stopped state, the hydrogen pressure of the variable pressure accumulator 270 is discharged until the target value Psuc is reached. When shifting to normal operation and performing stop processing, the hydrogen storage amount of the variable pressure accumulator 270 can be ensured as designed.

(Operation method of high-pressure hydrogen production system 110)
Subsequently, an operation method of the high-pressure hydrogen production system 110 will be described. FIG. 6 is a flowchart for explaining the control flow of the hydrogen production apparatus 210, FIG. 7 is a flowchart for explaining the control flow of the low-pressure compressor 230, and FIG. 8 shows the valves V1 and V2. , V3 is a flowchart for explaining the flow of control.

(Drive control of hydrogen production apparatus 210)
As shown in FIG. 6, first, the control unit 290 determines whether or not the pressure of the low pressure accumulator 240 is equal to the first threshold (S310). If it is determined that the pressure of the low pressure accumulator 240 is equal to the first threshold (YES in S310), the control unit 290 keeps (maintains) the current load of the hydrogen production apparatus 210 (S312).

  On the other hand, when the pressure of the low pressure accumulator 240 is not equal to the first threshold value (NO in S310), the control unit 290 determines whether or not the pressure of the low pressure accumulator 240 is higher than the first threshold value (S314). ). When it is determined that the pressure of the low pressure accumulator 240 is higher than the first threshold (YES in S314), a stop process (load down) for stopping the hydrogen production by the hydrogen production apparatus 210 is started (S316). On the other hand, if it is determined that the pressure of the low pressure accumulator 240 is not a pressure that exceeds the first threshold value, that is, is less than the first threshold value (NO in S314), a start process (load-up) for starting hydrogen production by the hydrogen production device 210 ) Is started (S318).

(Drive control of low-pressure compressor 230)
As shown in FIG. 7, first, the control unit 290 determines whether or not the pressure in the suction tank 220 is equal to the target value Psuc (S410). If it is determined that the pressure in suction tank 220 is equal to target value Psuc (YES in S410), control unit 290 loads (suction / discharge amount) and keeps low-pressure compressor 230 (S412).

  On the other hand, when the pressure in suction tank 220 is not equal to target value Psuc (NO in S410), control unit 290 determines whether or not the pressure in suction tank 220 is higher than target value Psuc (S414). If it is determined that the pressure in the suction tank 220 is higher than the target value Psuc (YES in S414), the low-pressure compressor 230 is loaded (S416). On the other hand, when it is determined that the pressure in the suction tank 220 is not higher than the target value Psuc, that is, lower than the target value Psuc (NO in S414), the low-pressure compressor 230 is loaded down (S418).

(Open / close control of valves V1, V2, and V3)
As shown in FIG. 8, first, the control unit 290 determines whether or not the pressure of the low pressure accumulator 240 is equal to or higher than the second threshold (S510). When it is determined that the pressure of the low pressure accumulator 240 has become equal to or higher than the second threshold (YES in S510), the control unit 290 opens the valve V1 and closes the valves V2 and V3 (S512). On the other hand, if it is determined that the pressure of the low pressure accumulator 240 has become less than the second threshold (NO in S510), the valve V1 is closed and the valves V2 and V3 are opened (S514).

  As described above, according to the high-pressure hydrogen production system 110 and the operation method of the high-pressure hydrogen production system 110 according to the present embodiment, the number of pressure accumulators can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the hydrogen production apparatus 210 configured to include a hydrogen separation membrane and PSA has been described as an example. However, the hydrogen production technology of the hydrogen production apparatus 210 is not limited, and various existing technologies can be used.

  In the above embodiment, the first threshold value is set to 37 MPa. However, if the first threshold value is determined based on the lower limit value (allowable lower limit value) of the inlet pressure of the high-pressure compressor 250, the numerical value is limited. Absent.

  Moreover, in the said embodiment, although the 2nd threshold value was demonstrated as 40 Mpa, if a 2nd threshold value is determined based on the upper limit of the pressure | voltage resistance of the low voltage | pressure accumulator 240, there will be no limitation in a numerical value. For example, when the upper limit value of the pressure resistance of the low pressure accumulator 240 is 40 MPa, the second threshold value may be 39.5 MPa.

  In the above embodiment, the configuration in which the high-pressure hydrogen production system 110 includes the low-pressure compressor 230 and the high-pressure compressor 250 has been described. However, depending on the performance of the high-pressure compressor, a single compressor may be used (for example, a high-pressure compressor capable of increasing the pressure to 82 MPa even when the inlet pressure is the delivery pressure of the hydrogen production apparatus 210). In this case, the high-pressure hydrogen production system includes a hydrogen production apparatus 210, a suction tank 220, a high-pressure compressor capable of increasing pressure to 82 MPa even at the delivery pressure of the hydrogen production apparatus 210, a high-pressure accumulator 260, and a variable-pressure accumulator. The number of pressure accumulators can be reduced by employing a configuration including 270, pressure measuring unit 280, control unit 290, valves V1, V2, and V3, and pressure reducing valve V4.

  In the above-described embodiment, the pressure reducing valve V4 may be a spring pressure reducing valve that keeps the downstream pressure mechanically constant, or may be an electronic control valve that keeps the downstream pressure constant.

  In the above embodiment, when the pressure of the low-pressure compressor 230 reaches the first threshold value, the control unit 290 performs a load keeping process for keeping the current load of the hydrogen production apparatus 210. When the pressure of the machine 230 reaches the first threshold, the controller 290 may perform a stop process or a start process.

  INDUSTRIAL APPLICABILITY The present invention can be used for a high-pressure hydrogen production system that produces hydrogen and supplies it to a supplier such as a fuel cell vehicle, and a method for operating the high-pressure hydrogen production system.

110 High Pressure Hydrogen Production System 210 Hydrogen Production Equipment 230 Low Pressure Compressor (First Compressor)
240 Low pressure accumulator (first accumulator)
250 High-pressure compressor (second compressor)
260 High pressure accumulator (third accumulator)
270 Variable pressure accumulator (second accumulator)
290 control unit

Claims (7)

A hydrogen production device for producing hydrogen;
A first compressor that pressurizes the hydrogen produced by the hydrogen production device;
A first pressure accumulator and a second pressure accumulator for storing hydrogen boosted by the first compressor;
When the pressure of the first pressure accumulator exceeds the first threshold value, the hydrogen production apparatus is controlled to start a stop process for stopping the production of hydrogen by the hydrogen production apparatus, and the pressure of the first pressure accumulator is increased. A control unit that stores the hydrogen produced by the hydrogen production apparatus and the pressure increased by the first compressor in the second pressure accumulator when the second threshold value is greater than the first threshold value;
A high-pressure hydrogen production system comprising:   When the pressure of the first pressure accumulator becomes less than the second threshold value, the control unit boosts the hydrogen stored in the second pressure accumulator by the first compressor, and When the pressure is stored in the pressure accumulator and the pressure of the first pressure accumulator becomes less than the first threshold, the hydrogen production apparatus is controlled to perform a start process for starting production of hydrogen by the hydrogen production apparatus, 2. The high-pressure hydrogen production system according to claim 1, wherein the hydrogen produced by the production apparatus is pressurized by the first compressor and stored in the first pressure accumulator.   When the pressure of the first pressure accumulator reaches the first threshold value, the control unit is selected from a group of a load keeping process for keeping the current load of the hydrogen production apparatus, the stop process, and the start process. The high-pressure hydrogen production system according to claim 2, wherein the high-pressure hydrogen production system according to claim 2 is performed. A second compressor for boosting hydrogen stored in the first pressure accumulator;
A third pressure accumulator for storing hydrogen boosted by the second compressor;
The high pressure hydrogen production system according to any one of claims 1 to 3, further comprising: A hydrogen production apparatus that produces hydrogen, a first compressor that pressurizes hydrogen produced by the hydrogen production apparatus, a first pressure accumulator that stores hydrogen boosted by the first compressor, and a second pressure accumulator A high pressure hydrogen production system comprising a pressure accumulator of
Determining whether the pressure of the first pressure accumulator has exceeded a first threshold;
When it is determined that the pressure of the first pressure accumulator has exceeded the first threshold, a stop process for stopping the production of hydrogen by the hydrogen production apparatus is started,
Determining whether the pressure of the first pressure accumulator is equal to or greater than a second threshold value greater than the first threshold value;
When it is determined that the pressure of the first pressure accumulator is equal to or higher than the second threshold value, hydrogen produced by the hydrogen production apparatus and pressurized by the first compressor is converted into the second pressure accumulator. A method of operating a high-pressure hydrogen production system, characterized by storing in When it is determined that the pressure of the first pressure accumulator has become less than the second threshold value, the hydrogen stored in the second pressure accumulator is boosted by the first compressor, and the first pressure accumulator is Stored in
Determining whether the pressure of the first pressure accumulator is less than the first threshold;
When it is determined that the pressure of the first pressure accumulator has become less than the first threshold, a start process for starting production of hydrogen by the hydrogen production apparatus is performed,
6. The method of operating a high-pressure hydrogen production system according to claim 5, wherein the hydrogen produced by the hydrogen production apparatus is boosted by the first compressor and stored in the first pressure accumulator. Determining whether the pressure of the first pressure accumulator has reached the first threshold;
When it is determined that the pressure of the first pressure accumulator has reached the first threshold value, one process selected from the group of a load keeping process for keeping the current load of the hydrogen production apparatus, the stop process, and the start process The method for operating the high-pressure hydrogen production system according to claim 6, wherein:

Images