JP2010127374A - Hydrogen storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain an amount of hydrogen filling within hydrogen tanks from being decreased by an increasing internal pressure of the hydrogen tanks. <P>SOLUTION: A hydrogen storage system fills the hydrogen tanks A, B with hydrogen by a controller 7 intermittently repeating hydrogen supply/stop to the inside of the hydrogen tanks A, B in accordance with the internal pressure of the hydrogen tanks A, B. Thereby, the system can restrain the amount of the hydrogen filling within the hydrogen tanks A, B from being decreased by the increasing internal pressure in the hydrogen tanks A, B because the hydrogen supplied to the hydrogen tanks A, B is adsorbed in a hydrogen storage material and then the hydrogen is supplied to the hydrogen tanks A, B again. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydrogen storage system including a hydrogen tank in which a hydrogen storage material is installed.

Conventionally, a hydrogen storage system that detects the internal pressure of a plurality of hydrogen tanks and discharges the hydrogen in the hydrogen tank to the hydrogen consuming device so that the differential pressure between the highest internal pressure and the lowest internal pressure is less than the set value is known. (See Patent Document 1).
JP 2006-269330 A

  Generally, a hydrogen tank equipped with a hydrogen storage material such as a hydrogen storage material or a hydrogen adsorption material generates heat when filled with hydrogen. When the temperature of the hydrogen tank becomes high due to heat generation, the hydrogen storage material cannot store hydrogen, so the internal pressure of the hydrogen tank increases. For this reason, according to the conventional hydrogen storage system described above, the hydrogen filling amount of the hydrogen tank is reduced by filling the hydrogen tank before the hydrogen in the hydrogen tank is sufficiently stored in the hydrogen storage material. There is.

  This invention is made | formed in view of the said subject, The objective is to provide the hydrogen storage system which can suppress that the hydrogen filling amount of a hydrogen tank reduces by the internal pressure of a hydrogen tank rising.

  The hydrogen storage system according to the present invention fills the hydrogen tank with hydrogen by intermittently repeating supply / stop of hydrogen into the hydrogen tank in accordance with the internal pressure of the hydrogen tank.

  According to the hydrogen storage system according to the present invention, the hydrogen supplied to the hydrogen tank waits for the hydrogen storage material to be occluded, and the hydrogen is supplied again to the hydrogen tank, so that the internal pressure of the hydrogen tank increases. Therefore, it is possible to suppress a decrease in the hydrogen filling amount of the hydrogen tank.

  Hereinafter, a hydrogen storage system according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of hydrogen storage system]
As shown in FIG. 1, a hydrogen storage system according to an embodiment of the present invention includes two hydrogen tanks A and B in which hydrogen storage materials are housed, and a fuel cell that consumes hydrogen supplied from the hydrogen tanks A and B. A hydrogen consuming apparatus 2 such as a stack is provided. The solid-line arrows shown in FIG. 1 indicate the refrigerant flow paths, and the refrigerant whose temperature is raised by cooling the hydrogen storage material in the hydrogen tanks A and B is sent from the hydrogen tanks A and B to the radiator 3 and cooled. . The refrigerant cooled by the radiator 3 is sent to the hydrogen consuming device 2 for heat dissipation from the hydrogen consuming device 2 and then supplied again to the hydrogen tanks A and B to cool the hydrogen storage material. An on-off valve 4 and a circulation pump 5 are installed in the refrigerant flow path between the radiator 3 and the hydrogen consuming device 2, and the refrigerant flow rate is controlled by the on-off valve 4 and the circulation pump 5. 1 indicates a hydrogen flow path, and hydrogen supplied from a hydrogen supply source (not shown) is supplied to the hydrogen tanks A and B and the hydrogen consuming apparatus 2 through the hydrogen flow path. Shut valves 6a and 6b for controlling the inflow and outflow of hydrogen from the hydrogen tanks A and B are provided at the connection positions of the hydrogen tanks A and B and the hydrogen flow path.

[Control system configuration]
The hydrogen storage system includes a controller 7 that controls the hydrogen filling process into the hydrogen tanks A and B, and a temperature sensor that detects the temperature _{Tw · MHin} of the refrigerant flowing into the hydrogen tank B located upstream of the refrigerant flow path. X1, a temperature sensor X2 for detecting the temperature _{Tw · MHout} of the refrigerant flowing out from the hydrogen tank A located on the downstream side of the refrigerant flow path, and a temperature sensor for detecting the temperature _{Tw · Rin} of the refrigerant flowing into the radiator 3 X3, a temperature sensor X4 for detecting the temperature _{Tw · Rout} of the refrigerant flowing out from the radiator 3, a temperature sensor X5 for detecting the temperature Tw _{· Sin} of the refrigerant flowing into the hydrogen consuming device 2, and the hydrogen consuming device 2 a temperature sensor X6 for detecting the temperature T _{w · Sout} of the refrigerant flowing out, the pressure sensor Y1 for detecting the internal pressure of the hydrogen tank a, for detecting the internal pressure of the hydrogen tank B With a force sensor Y2.

[Hydrogen filling treatment]
In the hydrogen storage system, the controller 7 executes the hydrogen filling process shown below, while suppressing the decrease in the hydrogen filling amount of the hydrogen tanks A and B due to the increase in the internal pressure of the hydrogen tanks A and B. Hydrogen tanks A and B are filled with hydrogen. Hereinafter, the operation of the controller 7 when executing the hydrogen filling process will be described with reference to the flowchart shown in FIG. The flowchart shown in FIG. 2 starts when the hydrogen filling command to the hydrogen tanks A and B is input to the controller 7, and the hydrogen filling process proceeds to step S1. It is assumed that both the shut valves 6a and 6b are closed at the start of the hydrogen filling process.

  In step S1, the controller 7 detects the internal pressures of the hydrogen tanks A and B with reference to the outputs of the pressure sensors Y1 and Y2. Thereby, the process of step S1 is completed and the hydrogen filling process proceeds to the process of step S2.

  In the process of step S2, the controller 7 determines whether or not the internal pressure of the hydrogen tanks A and B detected by the process of step S1 is equal to or lower than the equilibrium pressure (for example, plateau pressure) of the internal hydrogen storage material. . If the result of determination is that the internal pressure is not less than or equal to the equilibrium pressure, the controller 7 advances the hydrogen filling process to the process of step S12. On the other hand, when the internal pressure is equal to or lower than the equilibrium pressure, the controller 7 advances the hydrogen filling process to the process of step S3.

  In the process of step S3, the controller 7 sets the value of the program counter n for counting the number of loops of the hydrogen filling process to 1. Thereby, the process of step S3 is completed and the hydrogen filling process proceeds to the process of step S4.

  In the process of step S4, the controller 7 supplies hydrogen into the hydrogen tank A by opening the shut valve 6a of the hydrogen tank A. Thereby, the process of step S4 is completed, and the hydrogen filling process proceeds to the process of step S5.

In step S5, the controller 7 determines whether or not the internal pressure of the hydrogen tank A has reached the set pressure P _nup (n = 1,..., N) with reference to the output of the pressure sensor Y1. As shown in FIG. 3, the set pressure P _nup is set to a value that asymptotically approaches the internal pressure (for example, 35 MPa) of the hydrogen tank A when the hydrogen tank A is fully filled with hydrogen as the value of n increases. . The controller 7 advances the hydrogen filling process to a process of step S6 in the timing when the inner pressure of the hydrogen tank A reaches the set pressure P _Nup.

  In the process of step S6, the controller 7 shuts off the shut valve 6a of the hydrogen tank A and simultaneously opens the shut valve 6b of the hydrogen tank B, thereby stopping the supply of hydrogen into the hydrogen tank A. At the same time, supply of hydrogen into the hydrogen tank B is started. Thereby, the process of step S6 is completed and the hydrogen filling process proceeds to the process of step S7.

In the process of step S7, the controller 7 determines whether or not the internal pressure of the hydrogen tank B has reached the set pressure P _nup used in the process of step S5 with reference to the output of the pressure sensor Y2. In the present embodiment, the set pressure P _nup used for the hydrogen tank B is the same as the set pressure P _nup used for the hydrogen tank A. However, as shown in FIG. The set pressure P _nup may be different from the set pressure P _nup used for the hydrogen tank A. Further, as shown in FIG. 4, in the first (n = 1) hydrogen filling process, hydrogen is preferentially set in one hydrogen tank (in this case, hydrogen tank A) with a set pressure (30 [MPa in the example shown in FIG. 4). ]), Or as shown in FIG. 5, in the first (n = 1) hydrogen filling process, both hydrogen tanks are filled with hydrogen simultaneously at a set pressure (in the example shown in FIG. 5, 30 [ MPa]). The controller 7 advances the hydrogen filling process to a process of step S8 at a timing the internal pressure reaches the set pressure P _Nup.

  In the process of step S8, the controller 7 stops the supply of hydrogen into the hydrogen tank B by shutting off the shut valve 6b of the hydrogen tank B. Thereby, the process of step S8 is completed, and the hydrogen filling process proceeds to the process of step S9.

  In the process of step S9, the controller 7 determines whether or not the value of the program counter n is a predetermined value N. As a result of determination, when the value of the program counter n is a predetermined value N, the controller 7 determines that the internal pressures of the hydrogen tanks A and B when the hydrogen tanks A and B are fully filled with hydrogen It is determined that the value is close to, and the hydrogen filling process proceeds to the process of step S12. On the other hand, if the value of the program counter n is not the predetermined value N, the controller 7 determines that the hydrogen tanks A and B are not yet sufficiently filled with hydrogen, and advances the hydrogen filling process to the process of step S10. .

In the process of step S10, the controller 7 refers to the outputs of the pressure sensors Y1 and Y2, and the hydrogen storage material in the hydrogen tanks A and B stores hydrogen, so that the internal pressure of the hydrogen tanks A and B is set to the set pressure P _nup. It is determined whether or not a lower set pressure _P.sub.ndown (n = 1,..., N) has been reached. Note As with set pressure P _Ndown also set pressure P _Nup, asymptotic near the inner pressure of the hydrogen tank A when the hydrogen is fully filled hydrogen tank A with increasing values of n, as shown in FIG. 3 (e.g. 35 MPa) Is set to a value. In this embodiment, the hydrogen tank A and the hydrogen tank B have the same set pressure _Pndown . However, as shown in FIG. 3, the hydrogen tank A and the hydrogen tank B may have different set pressures _Pndown. . _Further , the determination as to whether the internal pressure of the hydrogen tank A has reached the set pressure _Pndown is completed during the processes of steps S7 to _S9 , and the determination as to whether the internal pressure of the hydrogen tank B has reached the set pressure _Pndown. May be completed at a timing before executing the process of step S6. The controller 7 is hydrogen tank A, a timing hydrogen filling process the internal pressure reaches the set pressure P _Ndown of B advances to the processing in step S11. When the internal pressure of the hydrogen tank A reaches the set pressure P _down before the internal pressure of the hydrogen tank B, the controller 7 advances the hydrogen filling process to the process of step S11 to supply hydrogen into the hydrogen tank A. It is desirable to start.

  In the process of step S11, the controller 7 increments the value of the program counter n by one. Thereby, the process of step S11 is completed and the hydrogen filling process returns to the process of step S4.

  In the process of step S12, the controller 7 supplies hydrogen into the hydrogen tanks A and B by opening the shut valves 6a and 6b of the hydrogen tanks A and B. At this time, when the temperature in the hydrogen tanks A and B rises as the hydrogen is filled, and as a result, the equilibrium pressure of the hydrogen storage material increases and the pressure in the hydrogen tanks A and B suddenly rises. The controller 7 may return the hydrogen filling process to the process of step S4. Thereby, the process of step S12 is completed and the hydrogen filling process proceeds to the process of step S13.

  In the process of step S13, the controller 7 refers to the outputs of the pressure sensors Y1 and Y2, and the internal pressure of the hydrogen tanks A and B is a predetermined hydrogen filling automatic stop pressure (A / S pressure, for example, when hydrogen is fully filled. It is determined whether or not the internal pressure of the hydrogen tank is reached. Then, the hydrogen filling process proceeds to the process of step S14 at the timing when the internal pressure of the hydrogen tanks A and B reaches the predetermined hydrogen filling automatic stop pressure.

  In the process of step S14, the controller 7 stops the supply of hydrogen to the hydrogen tanks A and B by shutting off the shut valves 6a and 6b of the hydrogen tanks A and B. Thereby, the process of step S14 is completed and a series of hydrogen filling processes are complete | finished.

  As is apparent from the above description, in the hydrogen storage system according to the embodiment of the present invention, the controller 7 intermittently supplies / stops hydrogen into the hydrogen tanks A and B according to the internal pressure of the hydrogen tanks A and B. The hydrogen tanks A and B are filled with hydrogen by repeating the process repeatedly. Specifically, the controller 7 stops supplying hydrogen after supplying hydrogen to the hydrogen tanks A and B to a predetermined pressure, and the hydrogen storage material stores the hydrogen so that the internal pressure of the hydrogen tanks A and B becomes the predetermined pressure. Then, hydrogen is supplied again at a stage where the pressure decreases. According to such a configuration, hydrogen is supplied again into the hydrogen tanks A and B after the hydrogen supplied into the hydrogen tanks A and B is occluded by the hydrogen storage material. , B can be prevented from decreasing the hydrogen filling amount of the hydrogen tanks A, B due to the increase in the internal pressure of B.

  In the hydrogen storage system according to the embodiment of the present invention, while the controller 7 stops supplying hydrogen to the hydrogen tank A (or hydrogen tank B), the hydrogen is stored in the hydrogen tank B (or hydrogen tank A). To supply hydrogen continuously. And according to such a structure, even if it is a case where the apparatus which automatically stops supply of hydrogen according to a pressure or the supply amount of hydrogen is provided in the hydrogen supply apparatus, the hydrogen supply apparatus is continuously hydrogenated. Therefore, hydrogen can be charged quickly.

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by description and drawing which make a part of indication of this invention by this embodiment. For example, in the present embodiment, the controller 7 intermittently repeats the supply / stop of hydrogen into the hydrogen tanks A and B according to the internal pressure of the hydrogen tanks A and B. Has a correlation with the temperature in the hydrogen tanks A and B. Therefore, a temperature sensor is provided in the hydrogen tanks A and B, and the hydrogen tanks A and B according to the temperatures in the hydrogen tanks A and B detected by the temperature sensor. The supply / stop of hydrogen may be repeated intermittently. In this embodiment, the number of hydrogen tanks is two, that is, hydrogen tank A and hydrogen tank B, but the present invention is not limited to this embodiment, and hydrogen storage having three or more hydrogen tanks. It can also be applied to the system. As described above, other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

It is a schematic diagram which shows the structure of the hydrogen storage system used as embodiment of this invention. It is a flowchart figure which shows the flow of the hydrogen storage process used as embodiment of this invention. It is a figure which shows the internal pressure change of the hydrogen tank accompanying filling with hydrogen. It is a figure which shows an example of the internal pressure change of the hydrogen tank accompanying opening and closing of a shut valve. It is a figure which shows the other example of the internal pressure change of the hydrogen tank accompanying opening and closing of a shut valve.

Explanation of symbols

2: Hydrogen consuming device 3: Radiator 4: Open / close valve 5: Circulation pumps 6a, 6b: Shut valves A, B: Hydrogen tanks X1-X6: Temperature sensors Y1, Y2: Pressure sensors

Claims (2)

A hydrogen tank equipped with hydrogen storage materials;
A detection unit for detecting an internal pressure or an internal temperature of the hydrogen tank;
A control unit that controls supply / stop of hydrogen into the hydrogen tank based on a detection result of the detection unit;
The control unit fills the hydrogen tank with hydrogen by intermittently repeating supply / stop of hydrogen into the hydrogen tank in accordance with an internal pressure or an internal temperature of the hydrogen tank. . The hydrogen storage system according to claim 1,
A plurality of the hydrogen tanks are provided, and the control unit supplies hydrogen to at least one of the other hydrogen tanks while hydrogen supply to at least one of the plurality of hydrogen tanks is stopped. A hydrogen storage system characterized by supplying.

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