JP2016115533A - Fuel battery system, operation method for the same, fuel container and inactive gas discharge method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery system which is suitable for hydrogen leak check of inactive gas, an operation method for the same, a fuel container and an inactive gas discharge method.SOLUTION: A fuel battery system has a pressurization container 10 for pressurizing reaction liquid 11 by pressure of an internal space, a fuel container 50 for housing a solid hydrogen source 1 under an air-tight state with inactive gas, the solid hydrogen source 1 generating hydrogen by reaction with the reaction liquid, a fuel battery 30 for generating power with supplied hydrogen, hydrogen supply pipes 15A and 15B which are connected to the fuel battery and supply hydrogen to an exhaust pipe 16 for exhausting inactive gas and the fuel battery, reaction liquid supply pipes 14A and 14B for supplying reaction liquid from the pressurization container to the fuel container, pressurization pipes 13A and 13B which intercommunicate with the fuel container and are connected to the pressurization container through a check valve 2 for permitting flow-in of hydrogen, a first electromagnetic valve 15S disposed in the hydrogen supply pipe 15A, a second electromagnetic valve 6 connected to the exhaust pipe 16, and a third electromagnetic valve 4 disposed in the reaction liquid supply pipe.SELECTED DRAWING: Figure 8

Description

  The present embodiment relates to a fuel cell system and an operation method thereof, a fuel container, and an inert gas discharge method.

  Conventionally, as a solid hydrogen generation source that supplies water to generate hydrogen gas, a main component is a metal such as iron or aluminum, or a main component is a metal hydride compound such as magnesium hydride or calcium hydride. What to do is known.

  Various fuel cell systems using solid polymer fuel cells that generate electricity by supplying hydrogen generated by reaction with water using calcium hydride or the like as a solid hydrogen generation source have been proposed.

  The fuel cell uses an electrolyte membrane that changes hydrogen into electricity, and a leak check with hydrogen is indispensable in order to perform internal consumption even when no current is taken out.

  Traditionally, leak checking has been carried out by a specialized engineer who takes over the system.

  In a fuel cell system in which a solid hydrogen generation source is packed in a bottle, in order to carry the bottle safely, the bottle is usually filled with an inert gas (such as nitrogen).

Japanese Patent Laid-Open No. 2003-314792 JP 2009-120441 A International Patent Publication No. WO2009 / 122910 International Patent Publication No. WO2006 / 101214

  In a fuel cell system using a solid hydrogen source using a fuel bottle filled with an inert gas, a method for testing a hydrogen leak of the fuel cell system has been an issue.

  In a fuel cell system using a solid hydrogen source, there was no means for measuring hydrogen leakage.

  Moreover, the sequence at the time of starting the fuel cell system using such a solid hydrogen source is not clarified.

  The inventors of the present invention did not need an inert gas to actually start the system, but considered using it for a leak check taking advantage of the fact that it is not consumed by the power generation cell unit.

  The present embodiment provides a fuel cell system in which an inert gas is applied to a hydrogen leak check, an operation method thereof, a fuel container, and an inert gas discharge method.

According to one aspect of the present embodiment, a pressurized container that pressurizes and discharges the reaction liquid by the pressure in the internal space, and a solid hydrogen source that reacts with the reaction liquid supplied from the pressurized container to generate hydrogen. A fuel container that contains an inert gas in an airtight state, an anode to which hydrogen is supplied, a fuel cell that generates power using hydrogen supplied to the anode, and a fuel cell connected to the fuel cell, An exhaust pipe for exhaust, a hydrogen supply pipe connected to the fuel container and supplying hydrogen to the fuel cell, a reaction liquid supply pipe connected to the pressurization container and supplying a reaction liquid to the fuel container, A pressurization pipe connected to the pressurization container via a check valve that communicates with the fuel container and allows the inflow of hydrogen; a first electromagnetic valve disposed in the hydrogen supply pipe;
There is provided a fuel cell system including a second electromagnetic valve connected to the exhaust pipe and a third electromagnetic valve arranged in the reaction liquid supply pipe.

  According to the other aspect of this Embodiment, a fuel container provided with an inert gas and the solid hydrogen source accommodated in the airtight state by the said inert gas is provided.

  According to another aspect of the present embodiment, the first leak check is performed by monitoring the step of mounting the fuel container, the step of turning on the power, the first pressure detector and the second pressure detector. Performing the following steps: opening the first solenoid valve and the second solenoid valve, adjusting the water pressure so that the differential pressure between the water pressure and the hydrogen pressure becomes the first pressure value; Maintaining the open state of the electromagnetic valve, closing the second electromagnetic valve, and performing a second leak check, and the open state of the first electromagnetic valve and the closed state of the second electromagnetic valve Maintaining the third electromagnetic valve and starting the water supply with the third electromagnetic valve open, and waiting for the increase in water pressure, maintaining the first electromagnetic valve open, and opening the third electromagnetic valve, The open / close state of the second solenoid valve is adjusted so that the differential pressure becomes the second pressure value. A step of waiting for an increase in the generated hydrogen concentration, and maintaining the open state of the first electromagnetic valve so that the third electromagnetic valve is open, so that the differential pressure ΔP becomes the third pressure value. And adjusting the open / closed state of the second electromagnetic valve to increase the concentration of the generated hydrogen and then proceeding to a steady operation.

  According to another aspect of the present embodiment, a pressurized container that pressurizes and discharges the reaction liquid by the pressure in the internal space, and solid hydrogen that reacts with the reaction liquid supplied from the pressurized container to generate hydrogen. A fuel container that contains a source in an airtight state with an inert gas, a fuel cell that has an anode to which hydrogen is supplied, and that generates power using the hydrogen supplied to the anode, and is connected to the fuel cell, and the inert gas An exhaust pipe for exhaust, a hydrogen supply pipe connected to the fuel container and supplying hydrogen to the fuel cell, a reaction liquid supply pipe connected to the pressurization container and supplying a reaction liquid to the fuel container, A pressure pipe connected to the pressure container via a check valve that allows hydrogen to flow in, a first solenoid valve disposed in the hydrogen supply pipe, and the exhaust A second solenoid valve connected to the pipe, and the reaction liquid supply pipe A third electromagnetic valve disposed; a hydrogen combustion cell disposed in the exhaust pipe between the fuel cell and the second electromagnetic valve; a hydrogen detection cell; and an output of the hydrogen detection cell. An inert gas discharge method for a fuel cell system, which is connected and has a comparator for comparing with a reference voltage for on / off control of the second solenoid valve, wherein a monitoring voltage of the hydrogen detection cell is larger than the reference voltage. If it is determined that the hydrogen concentration is sufficient, the step of closing the second solenoid valve and stopping the discharge of the inert gas, and the monitoring voltage of the hydrogen detection cell is less than the reference voltage An inert gas discharge method is provided that includes a step of discharging the inert gas.

  According to the present embodiment, it is possible to provide a fuel cell system in which an inert gas is applied to a hydrogen leak check, an operation method thereof, a fuel container, and an inert gas discharge method.

1 is a schematic configuration diagram of a fuel cell system according to a basic technology. The block diagram which shows the structural example of the fuel cell system which concerns on basic technology. In the fuel cell system which concerns on basic technology, the typical block block diagram of a control apparatus. Explanatory drawing which shows typically the chemical reaction of calcium hydride and water. The schematic block diagram which shows the structural example of the fuel cell applied to the fuel cell system which concerns on basic technology. A fuel container applied to the fuel cell system according to the embodiment, wherein (a) a schematic diagram of a configuration in which an inert gas (such as nitrogen) is filled in the fuel container in order to safely transport the fuel container; b) Schematic diagram illustrating a sequence for exhausting an inert gas and filling it with hydrogen gas when starting the fuel cell system according to the embodiment, (c) A state in which the inert gas is exhausted and filled with hydrogen gas The schematic diagram of the structure of the fuel container. 1 is a schematic block configuration diagram of a fuel cell system according to an embodiment. FIG. In the fuel cell system which concerns on embodiment, the detailed block block diagram of the electric power generation part for demonstrating the leak check function of each part at the time of starting. In the fuel cell system which concerns on embodiment, explanatory drawing of the leak check operation | movement of each part at the time of starting. FIG. 10 is a schematic block configuration diagram for explaining a leak check operation in step A in FIG. 9. FIG. 10 is a schematic block configuration diagram for explaining a leak check operation in step B in FIG. 9. In the fuel cell system which concerns on embodiment, the detailed explanatory drawing by the time sequence of the leak check operation | movement of each part at the time of starting. In the fuel cell system according to the embodiment, the time sequence of the on / off operation of the solenoid valves 1 to 3 and the pressure change in the leak check operation of each part at the time of startup. The typical block block diagram of the electric power generation part for demonstrating the inert gas (nitrogen etc.) discharge | emission mechanism in the fuel cell system which concerns on a comparative example. In the fuel cell system which concerns on embodiment, the typical block block diagram of the electric power generation part for demonstrating an inert gas (nitrogen etc.) discharge | emission mechanism. In the fuel cell system according to the embodiment, schematic diagram of a time variation of the monitored voltage V _DET of H ₂ sensing cell due to the on / off operation discharging solenoid valve.

  Next, embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea, and in this embodiment, the material, shape, structure, arrangement, etc. of the component parts are described below. It is not something specific. This embodiment can be modified in various ways within the scope of the claims.

(Fuel cell system)
A schematic configuration of the fuel cell system 20A according to the basic technology is expressed as shown in FIG. Further, a block diagram showing a configuration example of the fuel cell system 20A according to the basic technology is expressed as shown in FIG. In the fuel cell system 20A according to the basic technology, a schematic block configuration of the control device 26 is expressed as shown in FIG. An explanatory diagram schematically showing a chemical reaction between calcium hydride and water is represented as shown in FIG. 4, and is a schematic configuration showing a configuration example of a fuel cell applied to the fuel cell system 20A according to the basic technology. Is expressed as shown in FIG.

  As shown in FIG. 1, the fuel cell system 20A according to the basic technology supplies hydrogen generation means 21 for generating hydrogen by supplying a reaction liquid containing water into a bottle-shaped fuel container 50A, and supplying the generated hydrogen. And a hydrogen supply pipe 15 for supplying the hydrogen generated by the hydrogen generating means 21 to the fuel cell 30.

  A reaction liquid 11 composed of water is stored in a pressurized container 10. The pressurization container 10 is provided with a pressurization device 12 and a pressurization pipe 13 for applying pressure (hydrogen pressure or the like) in the container.

  The pressure in the pressurized container 10 may be equal to or higher than the atmospheric pressure, but it is desirable that the gauge pressure is preferably controlled in a certain range of, for example, about 500 kPa or less, and more preferably in a certain range of 300 kPa or less. Such pressure control can be controlled by pressure setting of a safety valve (not shown) provided in the system.

  Further, a reaction liquid supply pipe 14 is provided for supplying the reaction liquid 11 pushed out by pressurization to the solid hydrogen source 1A.

  The reaction liquid supply pipe 14 is preferably provided with a flow rate limiting unit that limits the flow rate of the reaction liquid. Thereby, the flow volume of the reaction liquid supplied by a pressure difference can be adjusted moderately.

  One end of the reaction liquid supply pipe 14 is extended to above the solid hydrogen source 1A, and the supplied reaction liquid 11a is dropped onto the solid hydrogen source 1A.

  A hydrogen supply pipe 15 that supplies the generated hydrogen to the fuel cell 30 is connected to the fuel container 50A.

  The electricity generated by the fuel cell 30 is supplied to an external load 40 composed of, for example, a smartphone.

  Here, a more specific configuration of the fuel cell system 20 will be described with reference to the block diagram of FIG.

As shown in FIG. 2, the fuel cell system 20 </ b> A according to the basic technology includes a power generation unit 25 and a power supply circuit 28 that performs DC / DC conversion of a DC voltage supplied by a DC current I _fc output from the power generation unit 25. A lithium ion battery (LIB) 29 that absorbs the excess or deficiency of the power generation amount of the power generation unit 25, and a CPU 27 for controlling the power supply circuit 28 and the LIB 29 based on the water pressure, hydrogen pressure, etc. in the power generation unit 25 The control apparatus 26 provided with.

  A pressurization pipe (hydrogen pipe) 13 connected to the fuel cell (fuel cell) 30 is connected to the pressurization container 10 so that the inside of the pressurization container 10 is pressurized with hydrogen.

The power supply circuit 28 includes a DC / DC converter 35 to which a DC current I _fc output from the fuel cell (fuel cell) 30 is supplied, and a diode 36 that prevents a reverse current flow from the outside.

  The LIB 29 includes a LIB cell 29a.

Further, CPU 27, when the current Iout output from the DC / DC converter 35 is higher than the determined load current I _load to the external load demand charges the surplus current to the LIB cell 29a, current I _out the load current When the _load is less than I _load , control is performed so as to supply a deficient current (I _lib ) from the LIB cell 29a.

  As described above, according to the fuel cell system 20A according to the basic technology, it is possible to stably supply a current that satisfies a request in response to an external load request from various devices or the like.

  As shown in FIG. 3, the control device 26 includes a CPU 27 and a display device 46, a temperature sensor 48, a pressure sensor 54, a voltage monitor 56, and a valve sensor 52 connected to the CPU 27. The CPU 27 is connected to the power generation unit 25, the power supply circuit 28, and the LIB 29, and can control each unit.

Here, the chemical reaction between calcium hydride (CaH ₂ ) constituting the solid hydrogen source 1A and water (H ₂ O) constituting the reaction liquid 11 is expressed as shown in FIG.

The chemical reaction formula at this time is expressed as CaH ₂ + 2H ₂ O → Ca (OH) ₂ + 2H ₂ .

  The pressurization container 10 may have a structure that pressurizes and discharges the reaction liquid 11 accommodated therein, and even in a form in which the reaction liquid 11 is directly accommodated in the sealed container, the pressure reaction container 11 is interposed via another container provided inside. The form which accommodates the reaction liquid 11 may be sufficient. The reaction solution 11 may be anything that reacts with the solid hydrogen source 1A to generate hydrogen, and neutral water, an aqueous acid solution, an aqueous alkaline solution, or the like is used.

  The pressure in the pressurized container 10 may be not less than the atmospheric pressure, but the gauge pressure is preferably controlled within a certain range of 500 kPa or less, more preferably 300 kPa or less.

  As the solid hydrogen source 1A, it is possible to use a hydrogen-generating substance such as particles alone (use it without embedding the resin), but from the viewpoint of controlling the reaction rate with the reaction solution, It is preferable that the material contains a particulate hydrogen generating substance. In that case, as the resin to be used, those other than the water-soluble resin are preferable from the viewpoint of appropriately adjusting the reaction.

  As the solid hydrogen source 1A, a metal hydride such as calcium hydride, lithium hydride, potassium hydride, lithium aluminum hydride, sodium aluminum hydride, or magnesium hydride, a metal such as aluminum, iron, magnesium, calcium, Examples thereof include metal hydride complex compounds such as borohydride compounds. Of these, metal hydrides are preferable, and calcium hydride is particularly preferable. A plurality of metal hydride compounds, metals, and metal hydride complex compounds can be used in combination, or they can be used in combination.

That is, as the solid hydrogen source 1A, one containing granular calcium hydride (CaH ₂ ) in the resin base material excluding the water-soluble resin is particularly preferable. In this solid hydrogen source 1A, the granular calcium hydride is dispersed or embedded in the resin matrix, thereby suppressing the reactivity of the calcium hydride and improving the handleability during the reaction with water. Is done. In addition, by using calcium hydride as a hydrogen generating substance, the reactivity with water and the like is increased, and the volume expansion coefficient of the reaction product (calcium hydroxide) generated when reacting with water and the like is increased. The action of collapsing the resin base material is increased, and the reaction with water and the like easily proceeds to the inside naturally.

  The content of the solid hydrogen source 1A is preferably 60% by weight or more in the solid hydrogen source 1A, but from the viewpoint of collapsing the resin base material during the reaction while maintaining the shape retention, It is preferable that it is 60 to 90 weight%, and 70 to 85 weight% is more preferable.

  The average particle size of the granular solid hydrogen source 1A is preferably 1 to 100 μm, more preferably 6 to 30 μm, and still more preferably 8 to 10 μm from the viewpoint of appropriately controlling dispersibility in the resin and reaction.

  When another hydrogen generating substance is added to calcium hydride, the content of the hydrogen generating substance is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, and 0 to 5% by weight in the hydrogen generating agent. Is more preferable.

  As the resin, a resin other than the water-soluble resin is preferably used, and examples thereof include a thermosetting resin, a thermoplastic resin, and a heat resistant resin, and a thermosetting resin is preferable. By using a thermosetting resin, the resin base material generally tends to be brittle, the resin base material collapses more easily during the reaction, and the reaction easily proceeds naturally.

  Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylic resin, fluororesin, polyester, and polyamide. Examples of the heat resistant resin include aromatic polyimide, polyamide, and polyester.

  Examples of the thermosetting resin include epoxy resins, unsaturated polyester resins, phenol resins, amino resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. Especially, an epoxy resin is preferable from a viewpoint that the resin base material has moderate disintegration during the hydrogen generation reaction. When the thermosetting resin is cured, a curing agent, a curing accelerator, or the like is appropriately used as necessary.

  The content of the resin is preferably less than 40% by weight, but is preferably 5 to 35% by weight in the hydrogen generator from the viewpoint of collapsing the resin base material during the reaction while maintaining the shape retention. -30% by weight is more preferred.

  The solid hydrogen source 1A used may contain other components such as a catalyst and a filler as optional components other than the above components. As the catalyst, an alkali compound such as sodium hydroxide, potassium hydroxide and calcium hydroxide is also effective in addition to the metal catalyst for the hydrogen generator.

  Next, a schematic configuration of the fuel cell 30 will be described with reference to FIG.

  The mechanism of a fuel cell is to generate electricity directly by electrochemically reacting the generated hydrogen with oxygen in the air.

  The fuel cell 30 utilizes the principle of obtaining water and electric power through a chemical reaction between hydrogen and oxygen. Here, hydrogen is used as an input material and oxygen is used as an oxidizing agent.

  The fuel cell 30 includes a fuel electrode (anode) 33, an air electrode (cathode) 31, and an electrolyte membrane (ion exchange resin membrane or the like) 32.

  One set of fuel electrode 33, air electrode 31, and electrolyte membrane 32 constitute one power generation cell (single cell). As shown in FIG. 5, the power generation cell has a sandwich structure in which an electrolyte membrane 32 is sandwiched between an air electrode 31 and a fuel electrode 33. Actually, a plurality of such power generation cells are connected in series and parallel to form the fuel cell 30.

  The fuel electrode 33 is composed of, for example, an anode catalyst formed of platinum or the like and a porous conductive support layer for supporting the anode catalyst, and the air electrode 31 is composed of, for example, a cathode catalyst and a porous conductive support layer. .

Hydrogen (H ₂ ) generated by the solid hydrogen source 1A is supplied to the fuel electrode (anode) 33 of the fuel cell 30 configured as described above, and hydrogen releases electrons (e ⁻ ) in the anode catalyst. It becomes hydrogen ion (proton: H ⁺ ).

The electrons (e ⁻ ) move to the air electrode (cathode) 31 via a load (for example, various electric circuits) 40.

On the other hand, hydrogen ions (H ⁺ ) move in the electrolyte membrane 32 toward the air electrode (cathode) 31, and oxygen (O ₂ ) and electrons moving through the load 40 (air) at the air electrode (cathode) 31. e ⁻ ) and reduced to water (H ₂ O).

  Such a reaction at each electrode is represented by the following chemical formula.

Reaction at the fuel electrode 33: H ₂ → 2H ⁺ + 2e ⁻
Reaction at the air electrode 31: 2H ⁺ + (1/2) O ₂ + 2e ⁻ → H ₂ O
Overall reaction: H ₂ + (1/2) O ₂ → H ₂ O
By such a reaction, the fuel cell 30 can output electricity using hydrogen (H ₂ ) generated from the solid hydrogen source 1A as a fuel.

(Fuel container)
The relationship between the fuel bottle, inert gas, and hydrogen gas is shown below.

  A configuration of a fuel container 50 applied to the fuel cell system 20 according to the embodiment, in which the fuel container 50 is filled with an inert gas (such as nitrogen) in order to safely transport the fuel container 50, is schematically illustrated. FIG. 6A is a schematic diagram illustrating a sequence of exhausting an inert gas (such as nitrogen) and filling it with hydrogen gas when starting the fuel cell system according to the embodiment. The configuration of the fuel container 50 that is represented as shown in FIG. 6B and is filled with hydrogen gas by exhausting an inert gas (such as nitrogen) is schematically shown in FIG. 6C. Is done. The inert gas filled in the fuel container 50 is normally replaced with hydrogen at startup.

  In the fuel cell system 20 according to the embodiment, a leak check of the system can be performed using the inert gas at this time.

  The configuration of the fuel cell system 20 according to the embodiment is the same as the configuration of the fuel cell system 20A according to the basic technology shown in FIGS.

  The fuel cell system 20 according to the embodiment provides a leak check method for each part at startup in a fuel cell system using a solid hydrogen source. This is particularly useful when an inert cell (such as nitrogen) is placed in the fuel container 50 filled with fuel or the pressurized container 10 filled with water to ensure safety.

  In order to transport the fuel container 50 safely, the fuel container 50 is filled with an inert gas (such as nitrogen), but when starting up using such a fuel container 50, the inert gas is discarded and hydrogen gas is used. It is necessary to satisfy. Further, the inert gas itself is a hindrance that does not contribute to power generation, but it can be used to test the leakage of the fuel cell system by taking advantage of the characteristic that it is not consumed by the fuel cell.

  In the fuel cell system 20 according to the embodiment, the system is checked for leaks using the inert gas in the fuel container 50.

  In the fuel cell system 20 according to the embodiment, since the leak check can be performed every time the system is started, the safety of the system can be improved.

(Block configuration of fuel cell system)
In the fuel cell system 20 according to the embodiment, a schematic block configuration for explaining a leak check function of each part at the time of start-up is expressed as shown in FIG.

As shown in FIG. 7, the fuel cell system 20 according to the embodiment reacts with a pressurized container 10 that pressurizes and discharges the reaction liquid by the pressure in the internal space, and the reaction liquid supplied from the pressurized container 10. A fuel container 50 that contains the solid hydrogen source 1 that generates hydrogen in an airtight state, an anode to which hydrogen is supplied, and a fuel cell 30 that generates power using the hydrogen supplied to the anode; The hydrogen supply pipes 15A and 15B for supplying hydrogen to the fuel cell 30 and one end of the pressure vessel 10 are connected to the pressure vessel 10 and the other end is inserted into the solid hydrogen source 1 to supply the reaction liquid. And the pressure pipes 13A and 13B connected to the pressure vessel 10 through the check valve 2 that communicates with the fuel vessel 50 and allows the inflow of hydrogen, and the pressure vessel 10A. First pressure to detect the water pressure P _H2O A force detector 13P and a second pressure detector 15P that is disposed in the hydrogen supply pipe 15A and detects the hydrogen pressure _PH2 of the fuel container 50 are provided.

  Further, as shown in FIG. 7, the fuel cell system 20 according to the embodiment is connected to a DC / DC converter 35 to which a DC current Ifc output from the fuel cell 30 is supplied, and the DC / DC converter 35. You may provide the diode 36 which blocks the backflow of the electric current from the outside.

  Further, as shown in FIG. 7, the fuel cell system 20 according to the embodiment may include a power storage unit capable of supplementing the output to the outside when the output from the fuel cell 30 fluctuates. .

  Here, the power storage means may include a LIB 29.

Although omitted in FIG. 7, the DC / DC converter 35 is controlled based on the water pressure P _H2O and the hydrogen pressure P _H2 detected by the first pressure detector 13P and the second pressure detector 15P. A control device (26: FIG. 2) may be provided.

  The reaction liquid supply pipes 14A and 14B may include an electromagnetic valve 4 that controls the flow rate of water.

  The hydrogen supply pipe 15A may include a regulator 15R that controls the flow rate of hydrogen. The hydrogen supply pipe 15B may be provided with a regulator 13R that controls the flow rate of hydrogen.

(Block configuration of power generation unit)
Further, in the fuel cell system according to the embodiment, a detailed block configuration of the power generation unit 25 for explaining a leak check function of each unit at the time of start-up is expressed as shown in FIG.

  In the fuel cell system 20 according to the embodiment, a detailed block configuration of the power generation unit 25 for explaining a leak check function of each unit at the time of startup is expressed as shown in FIG. 8 shows a range where the power generation unit 25 shown in FIG. 8 can perform a leak check.

  As shown in FIG. 8, the power generation unit 25 of the fuel cell system 20 according to the embodiment includes a pressurized container 10, a fuel container 50 to which a reaction liquid is supplied from the pressurized container 10, and a fuel to which hydrogen is supplied. A battery 30; an inert gas exhaust pipe 16 connected to the fuel cell 30; hydrogen supply pipes 15A and 15B connected to the fuel container 50 for supplying hydrogen to the fuel cell 30; The pressure supply pipes 13A and 14B connected to the pressure vessel 10 through the reaction solution supply pipes 14A and 14B for supplying the reaction solution to the container 50 and the check valve 2 communicating with the fuel container 50 and allowing the inflow of hydrogen. 13B, the first electromagnetic valve 15S arranged in the hydrogen supply pipe 15A, the second electromagnetic valve 6 for exhaust connected to the fuel cell 30, and the third electromagnetic valve arranged in the reaction liquid supply pipes 14A and 14B. The electromagnetic valve 4 is provided.

  Further, a hydrogen combustion cell 42 and a hydrogen detection cell 44 may be disposed between the fuel cell 30 and the second electromagnetic valve 6.

  Further, the hydrogen combustion cell 42 and the hydrogen detection cell 44 may have the same configuration as the fuel cell constituting the fuel cell 30.

  The hydrogen supply pipe 15A may include a regulator 15R that controls the flow rate of hydrogen. The hydrogen supply pipe 15B may include a regulator 13R that controls the flow rate of hydrogen. Moreover, as a setting pressure of the secondary side of the regulator 15R, 100-200 kPa (especially 120 kPa) is mentioned, for example. Examples of the set pressure of the regulator 13R include 10 to 100 kPa (particularly 30 kPa).

The pressurizing pipe 13A may include a first pressure detector 13P that detects the water pressure _PH2O . The hydrogen supply pipe 15A may be provided with a second pressure detector 15P for detecting the hydrogen pressure P _H2.

  As the pressure detectors 13P and 15P, a pressure sensor that measures the gas pressure with a pressure-sensitive element via a diaphragm (stainless diaphragm, silicon diaphragm, etc.), converts the pressure into an electric signal, and the like can be used. Typical pressure sensors include semiconductor piezoresistive diffusion pressure sensors, capacitance pressure sensors, and the like.

  In the fuel cell system according to the embodiment, an ammonia remover may be provided in the hydrogen supply pipes 15A and 15B in order to remove ammonia as an impurity from the generated hydrogen. Specifically, a sheet-like ammonia removing agent filled in a container can be used. Such an ammonia removing agent is commercially available in the form of a sheet, but it is also possible to use one in which a granular adsorbent or the like is contained in a breathable bag.

(Power generation cell stack)
In the case where the hydrogen combustion cell 42 and the hydrogen detection cell 44 are formed of fuel cells, the power generation cell stack 100 has a 4 × 12 cell + 2 cell configuration, and the number of cells may be increased. It is not necessary to form a special cell as the hydrogen detection cell 44.

(Leak check method)
(Comparative example)
In the fuel cell system according to the comparative example, since the fuel container 50 is initially filled with hydrogen, the operation of the system is started without performing a leak check. The operation at the time of startup of the fuel cell system according to the comparative example is as follows. That is, the fuel container 50 filled with hydrogen at a hydrogen pressure P _H2 (for example, about 100 kPa) and the pressurized container 10 filled with water are connected to the fuel cell system, and the first electromagnetic valve 15S is opened. As a result, the water pressure becomes 100 kPa, and the power generation cell stack is filled with hydrogen, so that power generation starts. When power generation is started, the pressure in the fuel container 50 starts to decrease, so the third electromagnetic valve 4 is opened, and water supply is started using the differential pressure between the pressurized container 10 and the fuel container 50. Thus, in the fuel cell system according to the comparative example, since the fuel container 50 is initially filled with hydrogen, the operation of the system starts without performing a leak check.

  In the fuel cell system 20 according to the embodiment, the start-up sequence was changed by sealing the fuel container 50 that had been sealed in the fuel cell system 20 with nitrogen as an inert gas.

  The fuel cell uses an electrolyte membrane that changes hydrogen into electricity, and a leak check with hydrogen is indispensable in order to perform internal consumption even when no current is taken out. In the fuel cell system 20 according to the embodiment, nitrogen is sealed in a fuel container 50 filled with fuel, and a leak check is performed using this nitrogen.

  In the leak check method of the fuel cell system 20 according to the embodiment, an inert gas (nitrogen gas) in the fuel container 50 is poured into the entire piping of the fuel cell system 20 at the initial stage of startup, and then each valve is closed. Measuring the pressure, and measuring the pressure again after a predetermined time and checking the difference.

(Operation method at startup)
In the fuel cell system according to the embodiment, the operation method at the time of start-up including the leak check is expressed as shown in FIG. In FIG. 9, “-” indicates that the previous state is maintained.

Further, in the fuel cell system 20 according to the embodiment, the time sequence at startup corresponding to FIG. 9 is expressed as shown in FIGS. 10 and 11. FIG. 10 shows the time change of the water pressure P _H2O and the hydrogen pressure P _H2 corresponding to the operation step and the time change of the monitoring voltage V _DET2 in the hydrogen detection cell 44. FIG. 10 also schematically shows a decrease in the nitrogen gas concentration and an increase in the hydrogen gas concentration as the inert gas corresponding to the operation step, and the open / close states of the first to third solenoid valves. Further, FIG. 11 shows ON / OFF pulse operation timings of the first to third solenoid valves at the time of activation, and temporal changes in the water pressure P _H2O and the hydrogen pressure P _H2 .

As shown in FIGS. 9 to 11, the operation method of the fuel cell system 20 according to the embodiment includes a step 1 for mounting the fuel container 50, a step 2 for pressing and holding the switch button to turn on the power, The first pressure detector 13P that detects P _H2O and the second pressure detector 15P that detects the hydrogen pressure P _H2 are monitored to perform a leak check, and the first solenoid valve 15S and the second solenoid valve 15S Step 3 of adjusting the water pressure P _H2O so that the differential pressure ΔP = P _H2O −P _H2 is 15 kPa, and maintaining the open state of the first electromagnetic valve 15S The electromagnetic valve 6 is closed, step B for performing a leak check, the open state of the first electromagnetic valve 15S and the closed state of the second electromagnetic valve 6 are maintained, and the third electromagnetic valve 4 is opened. Start water supply and wait for the water pressure P _H2O to rise Step 4 and the first solenoid valve 15S are kept open, the third solenoid valve 4 is opened, and the second solenoid valve 6 is set so that the differential pressure ΔP = P _H2O −P _H2 becomes 15 kPa. Adjusting the open / close state and waiting for an increase in the generated hydrogen concentration, maintaining the open state of the first solenoid valve 15S, and opening the third solenoid valve 4, the differential pressure ΔP = P _H2O -P _H2 is to adjust the opening and closing state of the second solenoid valve 6 to be within 30 kPa, after which the concentration of hydrogen generated was increased, and a step 6 to shift to the steady operation. In the above, in step 2 to step 6 and step A ·, the long-pressed state of the switch button is maintained.

In step 5, the second electromagnetic valve 6 adjusts the open / close state so that the differential pressure ΔP = P _H2O −P _H2 becomes 15 kPa, and in step 6, the differential pressure ΔP = P _H2O −P _H2 becomes 30 kPa. The open / close state is adjusted as follows. In particular, in step 6, the state of the end cell of the fuel cell may be monitored to adjust the open / close state.

(Leak check operation)
-Step A-
A block configuration for explaining the leak check operation in step A is expressed as shown in FIG. The dotted line indicates the range where the leak check can be performed. In step A, the power generation unit 25 of the fuel cell system 20 performs a leak check on the connection state of the fuel container 50.

That is, as shown in FIG. 12, after the fuel container 50 is mounted and the power is turned on, the first pressure detector 13P and the second pressure detector 15P are monitored, and the fuel container 50 and the third electromagnetic wave are monitored. The leak check of the connection state of the valve 4, the fuel container 50, the second pressure detector 15P, and the first electromagnetic valve 15S can be performed with an inert gas.
-Step B-
A block configuration for explaining the leak check operation in step B is represented as shown in FIG. The dotted line indicates the range where the leak check can be performed. In step B, the airtightness of the entire system of the power generation unit 25 of the fuel cell system 20 is checked.

That is, as shown in FIG. 13, after the leak check in step A, the first solenoid valve 15S and the second solenoid valve 6 are opened so that the differential pressure ΔP = P _H2O −P _H2 becomes 15 kPa. After adjusting the water pressure P _H2O , the second solenoid valve 6 is closed, and the first pressure detector 13P and the second pressure detector 15P are monitored to inactivate the leak check of the entire power generation unit 25 system. It can be implemented with gas.

  In the fuel cell system according to the embodiment, the safety during transportation (delivery) can be ensured by changing the sealed gas in the fuel container 50 from hydrogen to nitrogen. In addition, it is possible to perform a leak check with nitrogen, and to detect a malfunction in the fuel cell system 20 immediately after startup.

  In the fuel cell system according to the embodiment, a leak check mechanism in the system using the solid hydrogen source can be provided.

  In the fuel cell system according to the embodiment, it is possible to check the leak of the fuel cell system 20 every time it is started, and the safety can be improved.

  The fuel cell system leak check method according to the embodiment is useful in a fuel cell system using a fuel container in which a solid hydrogen source is put in a container and sealed with an inert gas.

(Inert gas discharge mechanism)
In the fuel cell system 20 according to the embodiment, it is necessary to discharge the inert gas (mainly nitrogen) remaining in the fuel cell system 20.

  In the fuel cell system according to the comparative example, a schematic block configuration of the power generation unit 25A for explaining an inert gas (such as nitrogen) discharge mechanism is expressed as shown in FIG.

In the fuel cell system according to the comparative example, a constant resistance (for example, 400 mΩ) is connected to the H ₂ detection cell 44 as shown in FIG. 15, and the value of the monitoring voltage (specified voltage) V _DET is, for example, If it is 250 mV or more, it is judged that the hydrogen concentration is sufficient, and the discharge of the inert gas is stopped, and if it is 200 mV, the operation of discharging the inert gas is performed. In such control, the voltage cannot be sufficiently increased due to long-term storage / environmental temperature of the H ₂ detection cell 44, resulting in a problem. Further, in the fuel cell system according to the comparative example, the system operation cannot be performed unless the H ₂ detection cell 44 is sufficiently activated before the fuel cell system is used and the specified voltage is reached during the operation. Also, it is unclear whether what can operate only at an environmental temperature of 26 ° C. can operate at a low temperature (1-5 ° C.) at which the voltage decreases.

In the fuel cell system 20 according to the embodiment, the exhaust voltage of the inert gas (mainly nitrogen) remaining in the fuel cell system 20 is monitored by the monitoring voltage V _{DET of the} H ₂ detection cell 44 that monitors the hydrogen concentration. Is controlled by.

In the fuel cell system 20 according to the embodiment, by constantly updated set of monitored voltage V _DET of H ₂ detection cell 44 during operation, the discharge of the inert gas regardless of the state of the H ₂ detection cell 44 Is possible.

In the fuel cell system 20 according to the embodiment, even the H ₂ detection cell 44 after long-term storage can be operated in a low temperature environment.

  In the fuel cell system according to the embodiment, a schematic block configuration of the power generation unit 25 for explaining an inert gas (nitrogen etc.) discharge mechanism is expressed as shown in FIG.

In the fuel cell system according to the embodiment, as shown in FIG. 15, the output of the H ₂ detection cell 44 is connected to the comparator 80 of the reference voltage V _ref , and the monitoring voltage V _{DET of the} H ₂ detection cell 44 is connected. The output is compared with the reference voltage V _ref and the output voltage V _out is obtained from the comparator 80.

In the fuel cell system according to the embodiment, for example, if the value of the reference voltage Vref is set to 10 mV and the value of the monitoring voltage V _DET of the H ₂ detection cell 44 is, for example, 20 mV or more, the hydrogen concentration is sufficient. It is judged that there is, the solenoid valve 6 for discharge is closed, the discharge of the inert gas is stopped, and if it is 10 mV, the inert gas is discharged. In such control, the voltage can be sufficiently increased by long-term storage / environment temperature of the H ₂ detection cell 44.

In the fuel cell system 20 according to the embodiment, the time change characteristic of the monitoring voltage V _DET of the H ₂ detection cell 44 accompanying the on / off operation of the exhaust solenoid valve 6 is schematically as shown in FIG. expressed.

When the fuel cell system 20 according to the embodiment, which sets the initial monitoring voltage V _DET of H ₂ detection cell 44 to 10mV a noise level above the voltage reached the voltage above 20 mV, H ₂ It is determined that hydrogen has reached the detection cell 44.

  When the voltage rises, the solenoid valve 6 to be exhausted is closed (closed). However, since the rise in voltage overshoots, if the maximum value of this voltage is 4a (V), the voltage drops to the exhaust voltage a (V). Sometimes the exhaust solenoid valve 6 is opened, and when the voltage rises to the exhaust stop voltage 2a (V), the exhaust solenoid valve 6 is closed. Using this maximum value, the set voltage is updated during operation from the specified value. That is, as shown in FIG. 16, this voltage is updated during system operation.

  As described above, according to the present embodiment, it is possible to provide a fuel cell system in which an inert gas is applied to a hydrogen leak check, an operation method thereof, a fuel container, and an inert gas discharge method.

[Other embodiments]
As described above, the embodiments have been described. However, it should be understood that the descriptions and drawings forming a part of this disclosure are illustrative and do not limit the embodiments. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  As described above, this embodiment includes various embodiments not described here.

  The fuel cell system according to the present embodiment can be applied to all fuel cell systems such as a hydrogen generation system using a solid hydrogen source and a portable power generator.

1, 1A ... Solid hydrogen source (calcium hydride)
2 ... Check valve 4, 6, 15S ... Solenoid valve 10 ... Pressurization vessel 11, 11a ... Reaction liquid 12 ... Pressurization device 13, 13A, 13B ... Pressurization piping (hydrogen piping)
13P, 15P ... Pressure detectors 13R, 15R ... Regulators 14, 14A, 14B ... Reaction liquid supply pipe (water pipe)
15, 15A, 15B ... hydrogen supply pipe 16 ... exhaust pipe 20 ... power generation device 21 ... hydrogen generation means 25, 25A ... power generation unit 26 ... control device 27 ... CPU
28 ... Power circuit 29 ... Lithium ion battery (LIB)
29a ... Lithium ion battery cell (LIB cell)
DESCRIPTION OF SYMBOLS 30 ... Fuel cell 31 ... Air electrode 32 ... Electrolyte membrane 33 ... Fuel electrode 35 ... DC / DC converter 36 ... Diode 40 ... External load 42 ... Hydrogen combustion cell 44 ... Hydrogen detection cell 46 ... Display device 48 ... Temperature sensor 50 50A ... Fuel container 52 ... Solenoid valve opening / closing sensor 54 ... Pressure sensor 56 ... Voltage monitor 80 ... Comparator 100 ... Power generation cell stack

Claims (22)

A pressurized container that pressurizes and discharges the reaction liquid by the pressure in the internal space;
A fuel container that contains a solid hydrogen source that reacts with the reaction solution supplied from the pressurized container to generate hydrogen in an airtight state with an inert gas;
A fuel cell having an anode to which hydrogen is supplied, and generating power with the hydrogen supplied to the anode;
An exhaust pipe connected to the fuel cell for exhausting the inert gas;
A hydrogen supply pipe connected to the fuel container and supplying hydrogen to the fuel cell;
A reaction liquid supply pipe connected to the pressure vessel and supplying a reaction liquid to the fuel container;
A pressurized pipe connected to the pressurized container via a check valve communicating with the fuel container and allowing inflow of hydrogen;
A first solenoid valve disposed in the hydrogen supply pipe;
A second solenoid valve connected to the exhaust pipe;
A fuel cell system comprising: a third electromagnetic valve disposed in the reaction liquid supply pipe.   The fuel cell system according to claim 1, wherein the hydrogen supply pipe includes a first regulator that controls a flow rate of hydrogen.   The fuel cell system according to claim 1, wherein the hydrogen supply pipe includes a second regulator that controls a flow rate of hydrogen.   The fuel cell system according to any one of claims 1 to 3, wherein the pressurization pipe includes a first pressure detector that detects water pressure.   The fuel cell system according to claim 1, wherein the hydrogen supply pipe includes a second pressure detector that detects a hydrogen pressure. A DC / DC converter to which a DC current output from the fuel cell is supplied;
6. The fuel cell system according to claim 1, further comprising: a diode connected to the DC / DC converter and preventing reverse current flow from the outside.   The fuel cell system according to any one of claims 1 to 6, further comprising power storage means capable of supplementing the output to the outside when the output from the fuel cell fluctuates.   The fuel cell system according to claim 7, wherein the power storage unit includes a lithium ion battery.   The fuel cell system according to claim 1, wherein the inert gas includes nitrogen gas.   The fuel cell system according to any one of claims 1 to 9, wherein the solid hydrogen source includes calcium hydride, and the reaction solution includes water.   The hydrogen combustion cell and hydrogen detection cell which are arrange | positioned at the said exhaust pipe between the said fuel cell and the said 2nd solenoid valve are provided, The hydrogen detection cell is provided. Fuel cell system.   The fuel cell according to claim 11, further comprising a comparator connected to an output of the hydrogen detection cell and compared with a reference voltage for on / off control of the second solenoid valve for exhausting the inert gas. system.   The fuel cell system according to claim 12, wherein the hydrogen combustion cell and the hydrogen detection cell have a configuration equivalent to a fuel cell constituting the fuel cell.   At the initial stage of start-up, the inert gas in the fuel container is poured into the entire pipe, and then the first to third solenoid valves are closed to measure the water pressure and the hydrogen pressure. The fuel cell system according to claim 13, wherein a leak check is performed by measuring the hydrogen pressure and the hydrogen pressure and checking a difference between the two. With inert gas,
And a solid hydrogen source stored in an airtight state with the inert gas.   The fuel container according to claim 15, wherein the inert gas includes nitrogen gas.   The fuel container according to claim 15 or 16, wherein the solid hydrogen source comprises calcium hydride. Installing a fuel container;
Turning on the power;
Monitoring the first pressure detector and the second pressure detector to perform a first leak check;
Opening the first solenoid valve and the second solenoid valve, and adjusting the water pressure so that the differential pressure between the water pressure and the hydrogen pressure becomes the first pressure value;
Maintaining the open state of the first solenoid valve, closing the second solenoid valve, and performing a second leak check;
Maintaining the open state of the first electromagnetic valve and the closed state of the second electromagnetic valve, starting the water supply with the third electromagnetic valve open, and waiting for the increase in water pressure;
Maintaining the open state of the first solenoid valve, opening the third solenoid valve, adjusting the open / close state of the second solenoid valve so that the differential pressure becomes a second pressure value; A step of waiting for an increase in the generated hydrogen concentration;
Maintaining the open state of the first solenoid valve, opening the third solenoid valve, and adjusting the open / close state of the second solenoid valve so that the differential pressure ΔP becomes a third pressure value. And a step of shifting to a steady operation after the concentration of the generated hydrogen increases, and a method of operating the fuel cell system.   In the step of performing the first leak check, the first pressure detector and the second pressure detector are monitored, and in the power generation unit of the fuel cell system, the leak check of the connection state of the fuel container is performed as an inert gas. The operation method of the fuel cell system according to claim 18, wherein   In the step of performing the second leak check, the first pressure detector and the second pressure detector are monitored, and the leak check of the entire power generation unit of the fuel cell system is performed with an inert gas. The operation method of the fuel cell system according to claim 18. Fuel that contains a pressurized container that pressurizes and discharges the reaction liquid by the pressure in the internal space, and a solid hydrogen source that generates hydrogen by reacting with the reaction liquid supplied from the pressurized container in an airtight state by an inert gas. A fuel cell that has a container and an anode to which hydrogen is supplied and that generates power using the hydrogen supplied to the anode; an exhaust pipe connected to the fuel cell for exhausting the inert gas; and the fuel container A hydrogen supply pipe connected to supply hydrogen to the fuel cell; a reaction liquid supply pipe connected to the pressurized container for supplying a reaction liquid to the fuel container; and communicated with the fuel container; A pressurization pipe connected to the pressurization vessel via an allowable check valve, a first solenoid valve disposed in the hydrogen supply pipe, a second solenoid valve connected to the exhaust pipe, A third solenoid valve disposed in the reaction solution supply pipe; A hydrogen combustion cell and a hydrogen detection cell disposed in the exhaust pipe between the fuel cell and the second electromagnetic valve; and an output of the hydrogen detection cell; An inert gas discharge method for a fuel cell system comprising a comparator for comparison with a reference voltage for control,
Determining that the hydrogen concentration is sufficient if the monitoring voltage of the hydrogen detection cell is greater than the reference voltage, closing the second solenoid valve, and stopping discharging the inert gas;
And a step of discharging the inert gas if the monitoring voltage of the hydrogen detection cell is equal to or lower than the reference voltage.   The inert gas discharge method according to claim 21, wherein the reference voltage can be updated at any time as the monitoring voltage changes with time.

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