JP2020149815A - Hydrogen energy system - Google Patents

Abstract

To prevent hydrogen from flowing into a water circulation supply path with a simple configuration when a decompressor located in a drainage path of a gas-liquid separator provided in a water electrolyzer fails.SOLUTION: A hydrogen energy system includes a water electrolyzer 1 that generates hydrogen gas by electrolysis of water, a first gas-liquid separator 3 that separates the hydrogen gas discharged from the water electrolyzer 1 into hydrogen and water, a hydrogen utilization device 4 that utilizes the hydrogen discharged from the first gas-liquid separator 3, a second gas-liquid separator 5 that stores the water discharged from the hydrogen utilization device 4 and the water discharged from the first gas-liquid separator 3, a decompressor 12 interposed in a second drainage path 11, an exhaust path 10 that opens the inside of the second gas-liquid separator 5 to the atmosphere, and a water tank 2 that stores the water discharged from the second gas-liquid separator 5 and supplies the stored water to the water electrolyzer 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hydrogen energy system that produces and utilizes hydrogen.

A power generation system that uses natural energy such as solar power generation and wind power generation to generate hydrogen and uses the hydrogen for power generation and heat is drawing attention.

A water electrolysis device that utilizes the electrolysis of water is used to generate hydrogen. Further, hydrogen is used for power generation and heat by using a hydrogen gas turbine, a hydrogen fuel cell, a hydrogen gas combustor, or the like.

Hydrogen is generated and boosted by a water electrolyzer and supplied to the equipment to be used. Further, since hydrogen generated by water electrolysis contains water, it is separated into hydrogen and water as gas components by using a gas-liquid separator. The separated water is appropriately reused for drainage of the device or water electrolysis.

For example, Patent Document 1 proposes a method in which water separated by a gas-liquid separator is returned to a water supply line for supplying water to a hydrogen production apparatus, and hydrogen dissolved together with water is used.

Japanese Unexamined Patent Publication No. 2013-53321

However, in the conventional device described in Patent Document 1 described above, when the decompressor arranged in the drainage path fails, the balance of the pressure loss in the drainage path is lost, and not only water but also hydrogen is transferred to the water supply path and further to oxygen. It will flow into the excess anode. In the conventional device, in order to prevent this, it is necessary to arrange a plurality of decompressors and shutoff valves, which complicates the configuration.

One aspect (aspect) of the present disclosure was devised in view of such circumstances, and when a decompressor arranged in a drainage path of a gas-liquid separator provided in a water electrolyzer fails, hydrogen is generated. It provides a hydrogen energy system that can be prevented from flowing into the water cycle with a simple configuration.

In order to solve the above problems, the hydrogen energy system of one aspect of the present disclosure is from a water electrolyzer that generates hydrogen gas by electrolyzing water and the water electrolyzer connected by a first hydrogen path. A first gas-liquid separator that separates the discharged hydrogen gas into hydrogen and water, and a hydrogen utilization device that uses hydrogen discharged from the first gas-liquid separator connected by a second hydrogen path. A second gas-liquid separator that stores water discharged from the hydrogen utilization device connected by the first drainage path and water discharged from the first gas-liquid separator connected by the second drainage path. A decompressor that is interposed in the second drainage path and decompresses the water discharged to the second gas-liquid separator through the second drainage path, and the atmosphere inside the second gas-liquid separator. The water discharged from the second gas-liquid separator connected by the exhaust path to be opened and the third drainage path is stored, and the stored water is supplied to the water electrolyzer via the water supply path. It is equipped with a water tank.

The hydrogen energy system of one aspect of the present disclosure can prevent hydrogen from flowing into the water circulation path in the event of a failure of the decompressor arranged in the drainage path of the gas-liquid separator provided in the water electrolyzer by a simple configuration. it can.

The figure which shows the structure of the hydrogen energy system of 1st Embodiment The figure which shows the structure of the hydrogen energy system of 2nd Embodiment The figure which shows the structure of the modification 1 of the hydrogen energy system of 1st Embodiment The figure which shows the structure of the modification 2 of the hydrogen energy system of 1st Embodiment

(Knowledge that is the basis of the present invention)
A hydrogen energy system equipped with a water electrolyzer and a hydrogen utilization device and reusing the water separated by the gas-liquid separator for water electrolysis was intensively studied, and the following findings were obtained.

In the conventional example, when the water separated by the gas-liquid separator is reused for water electrolysis in the water electrolysis system, the drainage path becomes a closed circuit, and if the decompressor fails, the pressure loss balance of the drainage path is lost and not only water but also hydrogen. Will flow into the water cycle.

Therefore, the hydrogen energy system of the first aspect of the present disclosure has been devised based on such findings, and is a water electrolyzer that generates hydrogen gas by electrolyzing water and a first hydrogen. The hydrogen gas discharged from the water electrolyzer connected by the path is discharged from the first gas-liquid separator that separates hydrogen and water and the first gas-liquid separator that is connected by the second hydrogen path. The hydrogen utilization device that utilizes the hydrogen, the water discharged from the hydrogen utilization device connected by the first drainage path, and the water discharged from the first gas-liquid separator connected by the second drainage path. A second gas-liquid separator that stores water, a decompressor that depressurizes water that is interposed in the second drainage path and is discharged to the second gas-liquid separator through the second drainage path, and the above. The water discharged from the second gas-liquid separator connected by the exhaust path that opens the inside of the second gas-liquid separator to the atmosphere and the third drainage path is stored, and the stored water is used as the water supply path. It is provided with a water tank that supplies the water electrolyzer to the water electrolyzer.

According to this configuration, if the decompressor fails when draining the first gas-liquid separator, the hydrogen flowing out from the second drainage path due to the imbalance of pressure loss in the second drainage path is the second drainage. Since the flow is discharged to the hydrogen utilization device side in the order of the path and the second gas-liquid separator, the water circulation of the water electrolyzer without newly arranging a pressure reducing valve or a shutoff valve in the second drainage path or the third drainage path. Hydrogen flow to the route can be prevented.

In the hydrogen energy system of the second aspect of the present disclosure, the second gas-liquid separator separates the exhaust gas discharged from the hydrogen utilization device into gas and water via the first drainage path, and the above-mentioned The gas separated by the second gas-liquid separator is exhausted through the exhaust path connected to the second gas-liquid separator.

According to this configuration, if the decompressor fails when draining the first gas-liquid separator, the hydrogen flowing out from the second drainage path due to the imbalance of pressure loss in the second drainage path is the second drainage. It flows in the order of the route and the second gas-liquid separator, and hydrogen is diluted with the exhaust gas (gas with a very low oxygen concentration) of the hydrogen utilization device and discharged.

The hydrogen energy system of the third aspect of the present disclosure discharges the gas contained in the exhaust gas discharged from the hydrogen utilization device through the exhaust path connected to the first drainage path.

According to this configuration, as in the second aspect, if the decompressor fails when draining the first gas-liquid separator, the pressure loss balance of the second drainage path is lost and the second drainage path is released. The outflowing hydrogen flows in the order of the second drainage path, the second gas-liquid separator, and the first drainage path, and the hydrogen is diluted with the exhaust gas (gas having a very low oxygen concentration) of the hydrogen utilization device and discharged.

(Embodiment)
Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Each of the embodiments described below shows an example of each of the above aspects.

Therefore, the numerical values, shapes, materials, components, the arrangement of the components, the connection form, and the like shown below are merely examples, and the present invention is limited to each of the above embodiments unless stated in the claims. It is not something that is done. Further, among the following components, the components not described in the independent claims indicating the highest level concept of this embodiment will be described as arbitrary components. Further, in the drawings, those having the same reference numerals may be omitted from the description. For the sake of clarity, the drawings schematically show each component, and the shape, dimensional ratio, etc. may not be accurately displayed.

(First Embodiment)
[Device configuration]
FIG. 1 is a diagram showing a configuration of a hydrogen energy system according to the first embodiment.

In FIG. 1, the hydrogen energy system 100 of the present embodiment includes a water electrolysis device 1, a water tank 2, a first gas-liquid separator 3, a hydrogen utilization device 4, a second gas-liquid separator 5, and a water circulation path. 6, a first hydrogen path 7, a second hydrogen path 8, a first drainage path 9, an exhaust path 10, a second drainage path 11, a decompressor 12, and a third drainage path 13.

The water electrolyzer 1 electrolyzes water to generate oxygen at the anode and hydrogen at the cathode.

The water tank 2 stores water for the water electrolyzer 1.

The first gas-liquid separator 3 separates hydrogen and water generated by the water electrolyzer.

The hydrogen utilization device 4 utilizes the hydrogen separated by the first gas-liquid separator 3.

The second gas-liquid separator 5 separates the exhaust gas generated from the hydrogen utilization device 4 into gas-liquid.

The water circulation path 6 connects the water tank 2 and the anode of the water electrolyzer 1 and water circulates in the water circulation path 6.

The first hydrogen path 7 connects the cathode of the water electrolyzer 1 and the first gas-liquid separator 3.

The second hydrogen path 8 connects the first gas-liquid separator 3 and the hydrogen utilization device 4.

The first drainage path 9 connects the hydrogen utilization device 4 and the second gas-liquid separator 5.

The exhaust path 10 is connected to the second gas-liquid separator 5 and exhausts the exhaust gas from the hydrogen utilization device 4.

The second drainage path 11 connects the first gas-liquid separator 3 and the second gas-liquid separator 5.

The decompressor 12 is arranged in the second drainage path 11.

The third drainage path 13 connects the second gas-liquid separator 5 and the water tank 2.

The water electrolyzer 1 will be further described. The water electrolyzer 1 is composed of, for example, a membrane electrode assembly (MEA) in which an electrolyte is sandwiched between an anode and a cathode, and a separator in which a carbon material having a flow path or a metal material such as stainless steel or titanium is processed by sandwiching the MEA. It is provided with a cell laminate. The anode and cathode (electrode) are composed of, for example, a noble metal catalyst such as platinum, but the present invention is not limited thereto.

The water tank 2 will be further described. The water tank 2 is a container for storing water to be supplied to the water electrolyzer 1. The water tank 2 includes a water circulation supply port and a water circulation return port (not shown), and is connected to the water electrolyzer 1 via a water circulation path 6. Although not shown here, water is supplied from the water tank 2 to the anode of the water electrolyzer 1 by a rotary pump or the like. Further, the water tank 2 is connected to the second gas-liquid separator 5 via the third drainage path 13. Although not shown here, the third drainage path 13 may be provided with an on-off valve.

The first gas-liquid separator 3 will be further described. The first gas-liquid separator 3 is a container that takes in hydrogen gas (hydrogen + water) generated by the water electrolyzer 1, separates the hydrogen gas into hydrogen and water, and stores the water in these. The first gas-liquid separator 3 is connected to the cathode outlet of the water electrolyzer 1 via the first hydrogen path 7.

The hydrogen utilization device 4 will be further described. The hydrogen utilization device 4 is a device that reacts hydrogen to extract electricity or heat. The hydrogen utilization device 4 may be, for example, a hydrogen gas turbine, a hydrogen fuel cell, or a hydrogen gas combustor, but is not limited thereto. The pressure of hydrogen supplied from the first gas-liquid separator 3 to the hydrogen utilization device 4 is, for example, 30 MPa to 40 MPa when the type of the hydrogen utilization device 4 is a high pressure type, and when the type of the hydrogen utilization device 4 is a low pressure type. Is 0.6 MPa to 1 MPa. The hydrogen utilization device 4 is connected to the first gas-liquid separator 3 via a second hydrogen path 8. Although not shown here, a hydrogen storage device such as a hydrogen tank or a hydrogen storage alloy may be provided in the second hydrogen path 8. The hydrogen utilization device 4 reacts the hydrogen generated by the water electrolysis device 1 with the air supplied from the outside to extract electricity or heat and supply it as energy to the outside. Exhaust gas containing gas such as nitrogen, oxygen or hydrogen and water is discharged from the hydrogen utilization device 4.

The second gas-liquid separator 5 will be further described. The second gas-liquid separator 5 is a container that takes in the exhaust gas containing water discharged from the hydrogen utilization device 4, separates it into the exhaust gas and water, and stores the separated water. The second gas-liquid separator 5 is connected to the hydrogen utilization device 4 via the first drainage path 9. Further, the exhaust path 10 is connected to the air layer portion above the second gas-liquid separator 5. The exhaust gas of the hydrogen utilization device 4 is discharged to the outside of the hydrogen energy system 100 through the exhaust path 10.

The second drainage path 11 will be further described. The second drainage path 11 connects the first gas-liquid separator 3 and the second gas-liquid separator 5 and includes a decompressor 12 in the path.

The decompressor 12 will be further described. The decompressor 12 is a device capable of reducing the pressure applied to the second drainage path 11 (for example, reducing the pressure to atmospheric pressure) and adjusting the amount of water flowing from the first gas-liquid separator 3 to the second gas-liquid separator 5. Good. Therefore, the pressure reducing device 12 may be, for example, a pressure reducing valve, an orifice, a capillary pipe, or the like, or a combination of these and an on-off valve.

As a result, even if the decompressor 12 fails, the pressure loss balance of the second drainage path 11 is lost, and hydrogen flows from the first gas-liquid separator 3 through the second drainage path 11, the second gas-liquid separator Hydrogen is discharged to the outside from the exhaust path 10 via the 5. Therefore, it is not necessary to newly provide a pressure reducing valve, a shutoff valve, or the like, and the hydrogen energy system can have a simple configuration. Further, by passing through the exhaust path 10 via the second gas-liquid separator 5, the gas in the upper layer of the second gas-liquid separator 5 is consumed by combustion or power generation, and the oxygen concentration is very low. Can be diluted and exhausted with.

(Second Embodiment)
[Device configuration]
FIG. 2 is a diagram showing the configuration of the hydrogen energy system of the second embodiment.

The hydrogen energy system 100A shown in FIG. 2 includes a water electrolyzer 1, a water tank 2, a first gas-liquid separator 3, a hydrogen utilization device 4, a second gas-liquid separator 5, a water circulation path 6, and the like. The first hydrogen path 7, the second hydrogen path 8, the first drainage path 9, the exhaust path 10, the second drainage path 11 connecting the first gas-liquid separator 3 and the second gas-liquid separator 5, A decompressor 12 and a third drainage path 13 are provided.

The exhaust path 10 is connected to the first drainage path 9 and exhausts the exhaust gas from the hydrogen utilization device 4. Since other configurations are the same as those of the first embodiment, the description thereof will be omitted.

As described above, in the hydrogen energy system 100A of the second embodiment, the exhaust path 10 is connected to the first drainage path 9 instead of the second gas-liquid separator 5 with respect to the hydrogen energy system 100 of the first embodiment. It is a configuration.

Therefore, as in the first embodiment, even if the decompressor 12 fails, the pressure loss balance of the second drainage path 11 is lost, and hydrogen flows from the first gas-liquid separator 3 through the second drainage path 11, the second drainage path 11 is second. Since hydrogen is discharged to the outside through the gas-liquid separator 5, the first drainage path 9, and the exhaust path 10, it is not necessary to newly provide a pressure reducing valve, a shutoff valve, or the like. Therefore, as in the first embodiment, the hydrogen energy system 100 can have a simple configuration. Further, hydrogen can be diluted with a gas having a very low oxygen concentration and exhausted by passing through the second gas-liquid separator 5 and the exhaust path 10.

(Modification example 1)
[Device configuration]
FIG. 3 is a diagram showing a configuration of an example of a modification 1 of the hydrogen energy system of the first embodiment.

The hydrogen energy system 100B of the first modification of the first embodiment has a configuration in which a ventilator 14 for internal ventilation is added to the hydrogen energy system 100 of the first embodiment near the outlet of the exhaust path 10. Since the other configurations are the same as the configurations of the hydrogen energy system 100 of the first embodiment, the description thereof will be omitted.

The ventilator 14 may be any device capable of ventilating the inside of the hydrogen energy system 100B, and may be composed of, for example, an axial fan, but is not limited thereto.

With such a configuration, even if the decompressor 12 fails, the pressure loss balance of the second drainage path 11 is lost, and hydrogen flows from the first gas-liquid separator 3 through the second drainage path 11, this hydrogen is released. , It can be diluted with exhaust gas having a low oxygen concentration through the second gas-liquid separator 5 and the exhaust path 10. Then, by operating the ventilator 14, the diluted hydrogen can be reduced to a lower concentration and discharged to the outside of the hydrogen energy system 100B.

(Modification 2)
[Device configuration]
FIG. 4 is a diagram showing a configuration of a modification 2 of the hydrogen energy system of the first embodiment.

In the hydrogen energy system 100C of the second modification of the first embodiment, the hydrogen utilization device 4 using hydrogen is a fuel cell, and the hydrogen discharge path 15 and the hydrogen circulation path are different from the hydrogen energy system 100 of the first embodiment. 16 and a purge valve 17 are added.

The hydrogen circulation path 15 connects the hydrogen utilization device 4 and the second gas-liquid separator 5.

The hydrogen circulation path 16 connects the second hydrogen path 8 and the hydrogen discharge path 15.

The purge valve 17 is arranged in the hydrogen discharge path 15.

The fuel cell which is the hydrogen utilization device 4 will be further described. Fuel cells generate electricity using hydrogen gas and oxidant gas (eg, air). Specifically, a fuel cell generates electricity by electrochemically reacting hydrogen and oxygen. For example, it includes a membrane electrode assembly (MEA) in which an electrolyte is sandwiched between an anode and a cathode, and a cell laminate composed of a separator having a flow path sandwiched between carbon materials or a metal material such as stainless steel or titanium. .. The anode and cathode (electrode) are composed of, for example, a noble metal catalyst such as platinum, but the present invention is not limited thereto.

To further explain the hydrogen discharge path 15, the hydrogen discharge path 15 is a path for discharging hydrogen that has not been consumed by the fuel cell.

The hydrogen circulation path 16 will be further described. The hydrogen circulation path 16 is a path for connecting the hydrogen discharge path 15 and the second hydrogen path 8 and reusing the hydrogen discharged from the fuel cell in the fuel cell. The hydrogen circulation path 16 may be provided with a booster pump (for example, a diaphragm pump). By providing the hydrogen circulation path 16, the hydrogen utilization efficiency of the fuel cell, which is the hydrogen utilization device 4, can be improved.

The purge valve 17 may be an on-off valve capable of flowing and shutting off hydrogen flowing through the hydrogen discharge path 15. For example, it may be a direct acting solenoid valve. By opening the purge valve 17, it is possible to eliminate the decrease in hydrogen concentration that occurs in the closed circuit configuration for hydrogen reuse (the circuit configuration when the purge valve 17 is closed).

As described above, even when the hydrogen utilization device 4 becomes a fuel cell and there are a plurality of discharge paths from the hydrogen utilization device 4, the same effect as that of the first embodiment can be obtained. That is, even if the decompressor 12 fails, the pressure loss balance of the second drainage path 11 is lost, and hydrogen flows from the first gas-liquid separator 3 through the second drainage path 11, the second gas-liquid separator 5 Hydrogen is discharged to the outside through the exhaust path 10. Therefore, it is not necessary to newly provide a pressure reducing valve, a shutoff valve, or the like, and the hydrogen energy system 100C can have a simple configuration.

The hydrogen energy systems 100, 100A, 100B, and 100C of the first embodiment, the second embodiment, the first modification, and the second modification may be combined with each other as long as they do not cause a contradiction.

From the above description, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as an example only and is provided for the purpose of teaching those skilled in the art the best way to carry out the present disclosure. The details of its structure and / or function can be substantially modified without departing from the spirit of the present disclosure.

The hydrogen energy system of one aspect of the present disclosure includes a water electrolyzer and a hydrogen utilization device that utilizes water generated by the water electrolysis apparatus, and hydrogen energy that reuses water separated by a gas-liquid separator for water electrolysis. Available for system.

1 Water electrolyzer 2 Water tank 3 1st gas-liquid separator 4 Hydrogen utilization device 5 2nd gas-liquid separator 6 Water circulation path 7 1st hydrogen path 8 2nd hydrogen path 9 1st drainage path 10 Exhaust path 11 2nd drainage Route 12 Decompressor 13 Third drainage route 14 Ventilator 15 Hydrogen discharge route 16 Hydrogen circulation route 17 Purge valve 100, 100A, 100B, 100C Hydrogen energy system

Claims (3)

A water electrolyzer that produces hydrogen gas by electrolyzing water,
A first gas-liquid separator that separates hydrogen gas discharged from the water electrolyzer connected by the first hydrogen path into hydrogen and water.
A hydrogen utilization device that utilizes hydrogen discharged from the first gas-liquid separator connected by a second hydrogen path, and a hydrogen utilization device.
A second gas-liquid separator that stores water discharged from the hydrogen utilization device connected by the first drainage path and water discharged from the first gas-liquid separator connected by the second drainage path. When,
A decompressor that is interposed in the second drainage path and decompresses the water discharged to the second gas-liquid separator through the second drainage path.
An exhaust path that opens the inside of the second gas-liquid separator to the atmosphere,
It is provided with a water tank for storing the water discharged from the second gas-liquid separator connected by the third drainage path and supplying the stored water to the water electrolyzer via the water supply path. ,
Hydrogen energy system. The second gas-liquid separator separates the exhaust gas discharged from the hydrogen utilization device into gas and water via the first drainage path.
The gas separated by the second gas-liquid separator is exhausted through the exhaust path connected to the second gas-liquid separator.
The hydrogen energy system according to claim 1. The gas contained in the exhaust gas discharged from the hydrogen utilization device is discharged through the exhaust path connected to the first drainage path.
The hydrogen energy system according to claim 1.

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