JP2011162818A - Water electrolysis system and method of replacing adsorption device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out an efficient maintenance work by carrying out the replacement work of an adsorption device rapidly and excellently with a simple configuration and process. <P>SOLUTION: A water electrolysis system 10 includes: a water electrolyzer 14; a water adsorption device 20 for adsorbing and removing moisture contained in produced hydrogen thereby obtaining dry hydrogen; a dry hydrogen supply device 24 communicating with the water adsorption device 20 and supplying the dry hydrogen to the outside of the system; a first and second separation part 42a, 42b for replacing the water adsorption device 20; a hydrogen tank 48 only for purge which is provided in a purge gas supply path 46 branched from a dry hydrogen supply path 22 and, when replacing the water adsorption device 20, supplies the dry hydrogen stored therein to a new water adsorption device 20 as a purge gas; and a purge passage 52 which is branched from a hydrogen leading-out path 16 and discharges the purge gas supplied to the water adsorption device 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-pressure water electrolysis device that generates high-pressure hydrogen, an adsorption device that adsorbs and removes moisture contained in the generated hydrogen to obtain dry hydrogen, and a dry hydrogen supply path to the adsorption device. The present invention relates to a water electrolysis system including a dry hydrogen supply device for communicating the dry hydrogen to the outside of the system, and an adsorption device replacement method thereof.

  For example, in a polymer electrolyte fuel cell, a fuel gas (a gas containing mainly hydrogen, such as hydrogen gas) is supplied to the anode side electrode, while an oxidant gas (mainly containing oxygen) is supplied to the cathode side electrode. By supplying a gas (for example, air), direct current electric energy is obtained.

  In general, a water electrolysis apparatus is employed to produce hydrogen gas that is a fuel gas. This water electrolyzer generates hydrogen containing moisture, and it is necessary to remove moisture from the hydrogen in order to obtain dry hydrogen (hereinafter referred to as dry hydrogen).

  For example, as shown in FIG. 5, a high-pressure hydrogen production apparatus disclosed in Patent Document 1 includes an oxygen high-pressure vessel 1, a differential pressure adjusting device 2, a hydrogen high-pressure vessel 3, an electrolytic cell 4, a moisture adsorption cylinder 5, a back pressure valve. 6, a hydrogen cooler 7 and a deoxidizing cylinder 8 are provided.

  The pure water in the oxygen high-pressure vessel 1 is sent to the anode side of the electrolytic cell 4 through a circulation pump, and the pure water is electrolyzed by energizing the electrolytic cell 4 from a power source. Oxygen generated in the electrolysis cell 4 by this electrolysis is sent to the oxygen high-pressure vessel 1 together with the circulating water returning pure water of the circulation pump.

  Hydrogen generated at the cathode of the electrolytic cell 4 is released into the hydrogen high-pressure vessel 3 together with the permeated water. At that time, the pressure in the oxygen high-pressure vessel 1 and the pressure in the hydrogen high-pressure vessel 3 are made equal by the differential pressure adjusting device 2.

  The hydrogen stored in the hydrogen high-pressure vessel 3 is cooled by the hydrogen cooler 7 after the oxygen contained in the hydrogen is removed through the deoxygenation cylinder 8 to condense moisture above the dew point temperature. Further, the dehumidified hydrogen is removed from the moisture adsorption cylinder 5 communicated with the back pressure valve 6 to obtain product hydrogen (dry hydrogen).

JP 2007-100204 A

  In the high-pressure hydrogen production apparatus described above, the adsorbent filled in the moisture adsorption cylinder 5 has a function of physically adsorbing moisture contained in hydrogen, but the adsorption power is reduced by use. Therefore, in order to reliably generate desired dry hydrogen, it is necessary to periodically regenerate the adsorbent and to replace the moisture adsorption cylinder 5 filled with a new adsorbent.

  However, it takes a considerable time to regenerate the adsorbent filled in the moisture adsorption cylinder 5. For this reason, there is a problem that the supply of dry hydrogen is restricted during the regeneration process.

  On the other hand, when exchanging with a new moisture adsorption cylinder 5, there is a possibility that outside air may be mixed into the hydrogen line during the exchanging operation. Accordingly, after the replacement operation of the moisture adsorption cylinder 5, the hydrogen line including the moisture adsorption cylinder 5 needs to be purged with hydrogen, and usually a hydrogen cylinder must be separately prepared. Accordingly, an operation of removing a hydrogen cylinder from the hydrogen line is performed after connecting a hydrogen cylinder to the hydrogen line from the outside, purging with hydrogen in the hydrogen cylinder. For this reason, there is a problem that the entire purge process is complicated and time-consuming.

  The present invention solves this type of problem, and with a simple configuration and process, a water electrolysis system capable of quickly and satisfactorily replacing the adsorption device and performing an efficient maintenance operation, and It is an object of the present invention to provide a method for replacing the adsorption device.

  The present invention is produced by electrolyzing water to produce oxygen and hydrogen having a pressure higher than that of oxygen, and a hydrogen outlet of the high pressure water electrolysis device through a hydrogen lead-out path. An adsorption device that adsorbs and removes moisture contained in the hydrogen to obtain dry hydrogen, and a dry hydrogen outlet that communicates with the dry hydrogen outlet of the adsorption device via a dry hydrogen supply path to supply the dry hydrogen to the outside of the system. The present invention relates to a water electrolysis system including a hydrogen supply device.

  The water electrolysis system is provided upstream and downstream of the adsorption device, and includes a first separation unit and a second separation unit for removing the adsorption device from the hydrogen line, and from the dry hydrogen supply path upstream of the dry hydrogen supply device. A branch purge gas supply path and a purge gas supply path provided in the purge gas supply path store dry hydrogen, and when replacing the adsorption device, store the dry hydrogen to a new adsorption device from the dry hydrogen outlet side. A purge-dedicated hydrogen tank that is supplied as a purge gas, and a purge passage that branches off from a hydrogen lead-out path and discharges the dry hydrogen supplied to the adsorption device as the purge gas from the hydrogen lead-out path.

  The present invention also provides a high-pressure water electrolysis apparatus that electrolyzes water to generate oxygen and hydrogen having a pressure higher than that of the oxygen, and a hydrogen outlet of the high-pressure water electrolysis apparatus communicated with a hydrogen outlet passage An adsorption device for adsorbing and removing moisture contained in the hydrogen that has been removed to obtain dry hydrogen; and a dry hydrogen outlet for communicating with the dry hydrogen outlet of the adsorption device to supply the dry hydrogen to the outside of the system A dry hydrogen supply device, a first separation unit and a second separation unit provided upstream and downstream of the adsorption device for removing the adsorption device from a hydrogen line, and the dry hydrogen upstream of the dry hydrogen supply device A purge gas supply path branched from the supply path and the purge gas supply path are provided to store the dry hydrogen, and to replace the stored dry hydrogen when replacing the adsorption device. A purge-dedicated hydrogen tank that supplies the adsorber as a purge gas from the dry hydrogen outlet side and a branch from the hydrogen lead-out path, and discharges the dry hydrogen supplied to the adsorber as the purge gas from the hydrogen lead-out path The present invention relates to an adsorption device replacement method for a water electrolysis system including a purge flow path.

  In this adsorption device replacement method, the used adsorption device is removed from the water electrolysis system, while a new adsorption device is connected to the water electrolysis system, and the dry hydrogen stored in the purge-dedicated hydrogen tank is renewed. Supplying the adsorber as a purge gas from the dry hydrogen outlet side, and discharging the dry hydrogen led out from the hydrogen inlet of the adsorber to the purge flow path branched from the hydrogen lead-out path; and a high-pressure water electrolyzer And a step of filling the purge-dedicated hydrogen tank with the dry hydrogen derived from the adsorption device.

  According to the present invention, the purge-dedicated hydrogen tank is provided in the purge gas supply path branched from the dry hydrogen supply path. For this reason, when exchanging the adsorption device, dry hydrogen stored in the purge-dedicated hydrogen tank can be used as the purge gas. This dry hydrogen is supplied into the adsorption device from the dry hydrogen outlet side, and then discharged to a purge flow path branched from the hydrogen lead-out path.

  Therefore, it is not necessary to prepare a separate hydrogen cylinder for the purging process, and it is not necessary to attach or detach the hydrogen cylinder. As a result, the adsorption device replacement operation can be performed quickly and satisfactorily with a simple configuration and process, and an efficient maintenance operation can be performed.

It is a schematic structure explanatory view of a water electrolysis system concerning a 1st embodiment of the present invention. It is a flowchart explaining the adsorption | suction apparatus replacement | exchange method of the said water electrolysis system. It is explanatory drawing of the purge process in the said water electrolysis system. It is a schematic structure explanatory drawing of the water electrolysis system concerning a 2nd embodiment of the present invention. 1 is a schematic explanatory diagram of a high-pressure hydrogen production apparatus disclosed in Patent Document 1. FIG.

  As shown in FIG. 1, the water electrolysis system 10 according to the first embodiment of the present invention is supplied with pure water generated from city water via a pure water supply device 12, and electrolyzes the pure water. By adsorbing water contained in the hydrogen electrolysis device (high-pressure water electrolysis device) 14 for producing oxygen and hydrogen having a pressure higher than that of oxygen, and the high-pressure hydrogen led out from the water electrolysis device 14 to the hydrogen lead-out path 16 The water adsorbing device (adsorbing device) 20 to be removed is communicated with the downstream of the water adsorbing device 20 via a dry hydrogen supply path 22, and the dry hydrogen from which the moisture has been removed is supplied to a system unit, for example, a fuel described later. A dry hydrogen supply device 24 for supplying the battery vehicle 58 and the like, and a controller 25 for controlling the entire system are provided.

  The water electrolysis apparatus 14 has a plurality of water decomposition cells 26 stacked, and end plates 28 a and 28 b are disposed at both ends of the water decomposition cell 26 in the stacking direction. The water electrolysis device 14 is connected to an electrolysis power source 30 that is a DC power source. The anode (anode) of the water electrolysis device 14 is connected to the positive electrode of the electrolysis power supply 30, while the cathode (cathode) is connected to the negative electrode of the electrolysis power supply 30.

  A pipe 32a is connected to the end plate 28a, and pipes 32b and 32c are connected to the end plate 28b. In the pipes 32 a and 32 b, pure water is circulated from the pure water supply device 12 via a water pump 36 disposed in the circulation path 34.

  A hydrogen lead-out path 16 is connected to the pipe 32 c that is a hydrogen discharge port, and the hydrogen lead-out path 16 is connected to the gas-liquid separator 18 via a check valve 38. A pressure regulating valve, for example, a back pressure valve 40 is disposed in the hydrogen lead-out path 16 at a position downstream of the gas-liquid separator 18. The back pressure valve 40 has a function of maintaining hydrogen discharged from the gas-liquid separator 18 at a pressure higher than normal pressure (for example, 35 MPa). Instead of the back pressure valve 40, various valves such as an electromagnetic valve may be used.

  The water adsorbing device 20 includes an adsorption tower (not shown) filled with a moisture adsorbing material that adsorbs water vapor (moisture) contained in hydrogen by a physical adsorption action and releases the moisture to the outside. In the vicinity of the hydrogen inlet 20a and the dry hydrogen outlet 20b of the water adsorption device 20, the hydrogen lead-out path 16 and the dry hydrogen supply path 22 are provided with a first separator 42a and a second separator 42b. By operating the first and second separators 42a and 42b, the water adsorption device 20 is detachable from the hydrogen line of the water electrolysis system 10 (a line including the hydrogen lead-out path 16 and the dry hydrogen supply path 22) and can be exchanged. It becomes.

  In the hydrogen lead-out path 16, a first valve (manual valve or electromagnetic valve) 44a is disposed in the vicinity of the upstream side of the first separation part 42a, while the dry hydrogen supply path 22 is downstream of the second separation part 42b. A second valve (manual valve or electromagnetic valve) 44b is disposed in the vicinity. A purge gas supply path 46 branches into the dry hydrogen supply path 22 upstream of the dry hydrogen supply apparatus 24, specifically, between the second separation unit 42b and the second valve 44b.

  A purge-dedicated hydrogen tank 48 is connected to the purge gas supply path 46 for supplying the stored dry hydrogen as a purge gas from the dry hydrogen outlet 20b side to the new adsorption device 20 when the adsorption device 20 is replaced. A flow rate adjusting throttle valve 50 and a third valve (solenoid valve) 44c are disposed in the purge gas supply path 46 from the purge dedicated hydrogen tank 48 side.

  In the hydrogen lead-out path 16, a purge flow path 52 branches from between the first separator 42a and the first valve 44a. The purge passage 52 is provided with a fourth valve (electromagnetic valve) 44d.

  The dry hydrogen supply path 22 is connected to a hydrogen tank 54 constituting the dry hydrogen supply device 24. The hydrogen tank 54 is provided with an on-off valve 56 and can be connected to a fuel tank (not shown) of the fuel cell vehicle 58. The hydrogen tank 54 may be provided as necessary, and the hydrogen tank 54 may be deleted and hydrogen gas may be directly supplied from the dry hydrogen supply path 22 to the fuel cell vehicle 58.

  The operation of the water electrolysis system 10 configured as described above will be described below.

  First, pure water generated from city water is supplied to the water electrolysis device 14 via the pure water supply device 12. In the water electrolysis apparatus 14, when energized from the electrolysis power supply 30, pure water is electrolyzed and hydrogen is generated.

  Hydrogen generated in the water electrolysis device 14 is sent to the gas-liquid separator 18 through the hydrogen lead-out path 16. In the gas-liquid separator 18, water vapor contained in hydrogen is separated from the hydrogen. The hydrogen from which the water vapor has been removed becomes high-pressure hydrogen via the back pressure valve 40 and is then sent to the hydrogen inlet 20 a of the water adsorption device 20.

  In the water adsorption device 20, water vapor contained in hydrogen is adsorbed to obtain dry hydrogen (dry hydrogen). Further, dry hydrogen is led out from the dry hydrogen outlet 20 b of the water adsorption device 20 to the dry hydrogen supply path 22. This dry hydrogen is sent to the dry hydrogen supply device 24 and stored in the hydrogen tank 54. The dry hydrogen stored in the hydrogen tank 54 is filled into the fuel cell vehicle 58 under the opening action of the on-off valve 56 as necessary.

  Next, the adsorption device replacement method of the water electrolysis system 10 according to the first embodiment will be described below along the flowchart shown in FIG.

  When it is determined that the water adsorption device 20 needs to be replaced from the usage time or the like (YES in step S1), the process proceeds to step S2 and the operation of the water electrolysis device 14 is stopped. Furthermore, it progresses to step S3, and after the 1st and 2nd valve | bulb 44a, 44b is obstruct | occluded, the 1st and 2nd isolation | separation part 42a, 42b is isolate | separated and the water adsorption apparatus 20 after use is removed from the water electrolysis system 10. Meanwhile, a new water adsorption device 20 is attached to the water electrolysis system 10 (step S4).

  After the new water adsorption device 20 is connected to the hydrogen line, the process proceeds to step S5, and the fourth valve 44d is opened. When the third valve 44c is opened (step S6), the high-pressure dry hydrogen filled in the purge-dedicated hydrogen tank 48 is led to the dry hydrogen supply path 22 through the purge gas supply path 46.

  This dry hydrogen is introduced into the water adsorbing device 20 from the dry hydrogen outlet 20b of the water adsorbing device 20, and is replaced with nitrogen gas or the like in the water adsorbing device 20 as a purge gas. This purge gas is purged outside the system from the hydrogen inlet 20a of the water adsorption device 20 via the purge flow path 52 (see FIG. 3).

  Further, in step S7, it is determined whether or not the purge process of the new water adsorption device 20 has been completed. The end of the purge process of the water adsorbing device 20 can be determined based on, for example, the elapsed time after opening the third valve 44c, the detection result by a hydrogen concentration meter (not shown), or the like.

  When the hydrogen purge process of the new water adsorption device 20 is completed (YES in step S7), the process proceeds to step S8, and after the fourth valve 44d is closed, the third valve 44c is closed (step S9). And after the 1st valve | bulb 44a is open | released (step S10), it progresses to step S11 and the driving | operation of the water electrolysis apparatus 14 is restarted. At this time, the third valve 44c is opened with the second valve 44b closed (step S12).

  For this reason, the hydrogen produced by the water electrolysis device 14 is adsorbed with water vapor by the water adsorption device 20, and is filled as dry hydrogen into the purge-dedicated hydrogen tank 48 through the purge gas supply path 46. When dry hydrogen is charged to the purge-dedicated hydrogen tank 48 to a predetermined pressure (YES in step S13), the process proceeds to step S14, and the third valve 44c is closed.

  Next, the process proceeds to step S15, and the second valve 44b is opened so that the dry hydrogen discharged from the water adsorption device 20 to the dry hydrogen supply path 22 is filled in the hydrogen tank 54 constituting the dry hydrogen supply device 24. Is done. Furthermore, said process is performed until water electrolysis processing is complete | finished (step S16).

  In this case, in the first embodiment, the purge gas supply path 46 branches from the dry hydrogen supply path 22 connected to the dry hydrogen outlet 20b of the water adsorption device 20, and the purge gas supply path 46 includes a purge dedicated hydrogen tank. 48 is provided. The purge-dedicated hydrogen tank 48 is filled with hydrogen generated in advance by the water electrolysis device 14 after being converted to dry hydrogen through the water adsorption device 20.

  Therefore, when replacing the water adsorbing device 20 with a new water adsorbing device 20, dry hydrogen stored in the purge-dedicated hydrogen tank 48 can be used as the purge gas. That is, the dry hydrogen in the purge-dedicated hydrogen tank 48 is supplied into the water adsorption device 20 from the dry hydrogen outlet 20b and then discharged to the purge flow path 52 branched from the hydrogen lead-out path 16 (see FIG. 3). .

  For this reason, it is not necessary to separately prepare a hydrogen cylinder for the purge process of the new water adsorption device 20, and the attaching / detaching action of the hydrogen cylinder becomes unnecessary. Moreover, the dry hydrogen stored in the hydrogen tank 54 can be filled in the fuel cell vehicle 58 while the new water adsorbing device 20 is being purged, so that the hydrogen supply process is efficient and satisfactory. It becomes feasible.

  As a result, the water adsorption device 20 can be replaced quickly and satisfactorily with a simple configuration and process, and the first and second separation portions 42a and 42b are automatically and reliably purged with hydrogen gas. It will be. For this reason, the effect that an efficient maintenance work can be performed is acquired.

  Furthermore, at the time of the hydrogen purge process, after the water adsorption device 20 is replaced, first, the fourth valve 44d is opened, and then the third valve 44c is opened (see Steps S5 and S6). . When the third valve 44c is opened earlier than the fourth valve 44d, the high-pressure dry hydrogen filled in the purge-dedicated hydrogen tank 48 is introduced into the water adsorbing device 20, and the inside of the water adsorbing device 20 is rapidly increased. This is because there is a risk of boosting the pressure.

  Furthermore, after completion of the hydrogen purge process, after the fourth valve 44d is closed, the third valve 44c is closed (see step S8 and step S9). On the contrary, when the third valve 44c is first closed, the inside of the water adsorption device 20 is depressurized to substantially atmospheric pressure, and this water adsorption device 20 is newly started when water electrolysis treatment is started. This is because it takes time to boost the inside.

  FIG. 4 is a schematic configuration explanatory view of a water electrolysis system 60 according to the second embodiment of the present invention.

  In addition, the same reference number is attached | subjected to the component same as the water electrolysis system 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The water electrolysis system 60 includes a pressure detection sensor 62 for detecting the pressure of the purge-dedicated hydrogen tank 48. For this reason, in the second embodiment, it is determined whether or not the hydrogen purge process of the new water adsorption device 20 has been completed (step S7), and the pressure drop in the purge-dedicated hydrogen tank 48 detected by the pressure detection sensor 62 is determined. Can be detected from. This is because the flow rate of the dry hydrogen discharged as the purge gas can be calculated from the pressure drop value of the dry hydrogen in the purge dedicated hydrogen tank 48. Thereby, in 2nd Embodiment, the effect similar to said 1st Embodiment is acquired.

DESCRIPTION OF SYMBOLS 10, 60 ... Water electrolysis system 12 ... Pure water supply apparatus 14 ... Water electrolysis apparatus 16 ... Hydrogen lead-out path 20 ... Water adsorption apparatus 20a ... Hydrogen inlet 20b ... Dry hydrogen outlet 22 ... Dry hydrogen supply path 24 ... Dry hydrogen supply apparatus 25 ... Controller 38 ... Check valve 40 ... Back pressure valves 42a and 42b ... Separating parts 44a to 44d ... Valve 46 ... Purge gas supply path 48 ... Purge dedicated hydrogen tank 52 ... Purge flow path 54 ... Hydrogen tank 56 ... On-off valve 58 ... Fuel cell Vehicle 62 ... Pressure detection sensor

Claims (2)

A high pressure water electrolyzer that electrolyzes water to produce oxygen and hydrogen at a higher pressure than the oxygen;
An adsorber that communicates with a hydrogen outlet of the high-pressure water electrolysis apparatus via a hydrogen lead-out path to adsorb and remove moisture contained in the generated hydrogen to obtain dry hydrogen;
A dry hydrogen supply device that communicates with a dry hydrogen outlet of the adsorption device via a dry hydrogen supply path to supply the dry hydrogen to the outside of the system;
A water electrolysis system comprising:
A first separation unit and a second separation unit provided upstream and downstream of the adsorption device, for removing the adsorption device from the hydrogen line;
A purge gas supply path branched from the dry hydrogen supply path upstream of the dry hydrogen supply device;
A purge provided in the purge gas supply passage for storing the dry hydrogen and supplying the stored dry hydrogen as a purge gas from the dry hydrogen outlet side to the new adsorption device when the adsorption device is replaced. A dedicated hydrogen tank,
A purge flow path that branches off from the hydrogen lead-out path and discharges the dry hydrogen supplied to the adsorption device as the purge gas from the hydrogen lead-out path;
A water electrolysis system comprising: A high pressure water electrolyzer that electrolyzes water to produce oxygen and hydrogen at a higher pressure than the oxygen;
An adsorber that communicates with a hydrogen outlet of the high-pressure water electrolysis apparatus via a hydrogen lead-out path to adsorb and remove moisture contained in the generated hydrogen to obtain dry hydrogen;
A dry hydrogen supply device that communicates with a dry hydrogen outlet of the adsorption device via a dry hydrogen supply path to supply the dry hydrogen to the outside of the system;
A first separation unit and a second separation unit provided upstream and downstream of the adsorption device, for removing the adsorption device from the hydrogen line;
A purge gas supply path branched from the dry hydrogen supply path upstream of the dry hydrogen supply device;
Dedicated to purging, provided in the purge gas supply path, for storing the dry hydrogen and supplying the stored dry hydrogen to the new adsorption device as a purge gas from the dry hydrogen outlet side when the adsorption device is replaced. A hydrogen tank,
A purge flow path that branches off from the hydrogen lead-out path and discharges the dry hydrogen supplied to the adsorption device as the purge gas from the hydrogen lead-out path;
An adsorption device replacement method for a water electrolysis system comprising:
Removing the adsorber after use from the water electrolysis system, while connecting a new adsorber to the water electrolysis system;
The dry hydrogen stored in the purge-dedicated hydrogen tank is supplied to the new adsorption device as the purge gas from the dry hydrogen outlet side, and the dry hydrogen derived from the hydrogen inlet of the adsorption device is Discharging to the purge flow path branched from the hydrogen outlet path;
A step of operating the high-pressure water electrolysis apparatus and filling the dry hydrogen tank derived from the adsorption apparatus into the purge-dedicated hydrogen tank;
An adsorption device replacement method for a water electrolysis system, comprising:

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