JP2009009881A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system capable of suppressing the dew condensation in a housing container of a fuel cell by using as little power as possible. <P>SOLUTION: The fuel cell system includes: a fuel cell 10 in which electric power is generated by an electrochemical reaction between hydrogen and oxygen; the housing container 11 in which the fuel cell 10 is housed; a hydrogen tank 13 in which high-pressure hydrogen is filled and which supplies hydrogen to the fuel cell 10; a hydrogen supply passage 14 through which hydrogen supplied from the hydrogen tank 13 to the fuel cell 10 passes; and an expansion means 16 in which hydrogen flown out from the hydrogen tank 13 is decompressed and expanded. In this system, a condensing means 17 for exchanging heat between hydrogen decompressed and expanded by the expansion means 16 and air in the housing container 11 and for condensing the moisture contained in the air, and drainage means 15, 20, 23 in which the moisture condensed by the condensing means 17 is drained outside the housing container 11 are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel cell that generates electricity by an electrochemical reaction between hydrogen and oxygen, and is effective when applied to a moving body such as a vehicle, a ship, and a portable generator.

  Conventionally, a fuel cell is mounted on a moving body while being stored in a storage container. The storage container is sealed with a sealing material or the like in order to prevent foreign substances from entering from the outside. Therefore, when the humidity inside the storage container becomes high due to water vapor that has permeated from the fuel cell, condensation tends to occur inside the storage container due to the temperature difference from the outside, resulting in a decrease in power generation efficiency of the fuel cell and destruction of electronic components. There was a fear.

In order to cope with the above problems, a fuel cell system is known in which a part of a storage container of a fuel cell is formed of a porous body and the inside of the storage container is ventilated by a ventilation device (see, for example, Patent Document 1). ).
JP 2006-49186 A

  However, the configuration of Patent Document 1 requires power for operating the ventilator, which is not desirable from the viewpoint of power saving.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a fuel cell system that can suppress the occurrence of condensation in the storage container of the fuel cell without using power as much as possible.

  In order to achieve the above object, the first feature of the present invention is that a fuel cell (10) for generating electricity by an electrochemical reaction between hydrogen and oxygen, a storage container (11) for storing the fuel cell (10), a high pressure A hydrogen tank (13) that is filled with hydrogen and supplies hydrogen to the fuel cell (10), a hydrogen supply path (14) through which hydrogen supplied from the hydrogen tank (13) to the fuel cell (10) passes, and hydrogen In the supply path (14), the expansion means (16) for expanding the hydrogen flowing out from the hydrogen tank (13), the hydrogen provided in the storage container (11) and expanded by the expansion means (16) and the storage container ( 11) heat exchanging with the air in the interior, condensing means (17) for condensing moisture contained in the air, and exhaust for discharging the moisture condensed by the condensing means (17) to the outside of the storage container (11) Means (15, 20, 23) It is characterized in that it comprises.

  In this way, by utilizing the fact that hydrogen is cooled by adiabatic expansion when the high pressure hydrogen is decompressed and supplied to the fuel cell (10), the air in the storage container (11) can be used without using power. It is possible to condense the moisture contained as steam. Moreover, the condensed water | moisture content is discharged | emitted to the exterior of a storage container (11), and dew condensation can be suppressed inside a storage container (11). Here, the “expansion means” may be one that expands hydrogen by heat insulation or one that expands hydrogen by decompression.

  In addition, a discharge path (15) for discharging the exhaust gas that has not been used for the electrochemical reaction out of at least one of hydrogen and oxygen supplied to the fuel cell (10) to the outside of the storage container (11) is provided. The means has a discharge path (15) and a merging path (20) for merging the moisture condensed by the condensing means (17) to the discharge path (15), and the moisture condensed by the condensing means (17) is removed. It can comprise so that it may discharge | emit to the exterior of a storage container (11) with the said waste gas. Thereby, the water condensed by the condensing means (17) can be discharged to the outside of the storage container (11) from the exhaust gas discharge path (15).

  The discharge means has a drain opening (23) provided in the storage container (11), and the water condensed by the condensation means (17) is stored in the storage container (11) through the drain opening (23). ) Can be configured to discharge outside.

  The controller (25) for adjusting the amount of hydrogen expansion by the expansion means (16) and the condensation amount detection means (24) for detecting the amount of moisture condensed by the condensation means (17) are provided. ) Can be configured to control the expansion amount of hydrogen by the expansion means (16) based on the condensation amount detected by the condensation amount detection means (24). Thereby, the amount of condensed water which generate | occur | produces in a condensation part (17) can be kept appropriately. When the condensation amount detected by the condensation amount detection means (24) is small, the control unit (25) controls the expansion means (16) to increase the hydrogen expansion amount by the expansion means (16) and detect the condensation amount. If the amount of condensation detected by the means (24) is large, the amount of hydrogen expansion by the expansion means (16) may be reduced.

  Further, the storage container (11) is provided with a water storage part (19) for storing the water condensed by the condensing means (17), and the discharge means (15, 20, 23) are provided in the water storage part (19). It can comprise so that the water | moisture content stored may be discharged | emitted to the exterior of a storage container (11). Thereby, the condensed water which generate | occur | produced in the condensation part (17) can be temporarily stored by the water storage part (19).

  Further, the condensation amount detection means can be a moisture amount detection means (23) for detecting the amount of moisture stored in the water reservoir (19). In this case, the “moisture amount measuring means” can detect the water level of the water storage section, and specifically, can be configured as a water level detecting means using a float or an optical water level detecting means. it can.

  The condensation amount detection means may be a humidity sensor (24) that detects the humidity in the storage container (11). In this case, the “humidity sensor” can be composed of a hygrometer or a dew point meter, and the hygrometer can be either an absolute hygrometer or a relative hygrometer.

  Moreover, the water storage part (19) can receive the water | moisture content which fell from the condensing means (17) by making it arrange | position below the condensing means (17) perpendicular | vertical direction.

  Further, the water reservoir (19) can be configured integrally with the condensing means (17).

  The condensing means comprises a heat transfer part (18, 22) for exchanging heat between the hydrogen expanded by the expansion means (16) and the air in the storage container (11) from a porous body. It is possible to prevent water adhering to (18, 22) from scattering. In this case, the “porous body” can be made of a foam metal, and at least one of copper and aluminum can be suitably used.

  Moreover, it can prevent that the water | moisture content stored by the water storage part (19) scatters by providing a porous body (21) in a water storage part (19). In this case, the “porous body” can be made of a foam metal, and at least one of copper, aluminum, and stainless steel can be suitably used.

  In addition, the fuel cell (10) is used as a driving source for moving the moving body, and the storage container (11) can be configured to be mounted on the moving body. In this case, the discharge means (15, 20, 23) causes the moisture condensed in the condensing part (17) due to the pressure difference between the inside and outside of the storage container (11) generated when the moving body moves to the outside of the storage container (11). It can be configured to be discharged.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing a fuel cell system according to the present embodiment, and this fuel cell system is applied to an electric vehicle as a moving body, for example.

  As shown in FIG. 1, the fuel cell system of this embodiment includes a fuel cell 10 that generates electric power by utilizing an electrochemical reaction between hydrogen and oxygen. The fuel cell 10 supplies electric power to an electric load (not shown) or an electric device such as a secondary battery. In the case of an electric vehicle, an electric motor as a vehicle driving source corresponds to an electric load. In the present embodiment, a solid polymer electrolyte fuel cell is used as the fuel cell 10, and a plurality of fuel cells serving as basic units are stacked and electrically connected in series. In the fuel cell 10, the following electrochemical reaction between hydrogen and oxygen occurs to generate electric energy.

(Negative electrode side) H ₂ → 2H ⁺ + 2e ⁻
(Positive _{^{side) 2H + + 1 / 2O 2}} + 2e - → H 2 O
The fuel cell 10 is stored in a storage container 11. An opening 12 for ventilation is formed in the storage container 11. The storage container 11 only needs to have a strength capable of fixing the fuel cell 10, and any material such as a metal material, a non-ferrous metal material, and a non-metal material can be used. In addition, the shape of the storage container 11 is not limited to a rectangular parallelepiped, and may be a special shape such as a cone or a hexagonal column as long as it can store the fuel cell 10. Furthermore, the shape of the opening part 12 of the storage container 11 is not specifically limited, It can be set as circular, an ellipse, a rectangle, a square, a rhombus, a triangle, and other geometric shapes.

  In the fuel cell system, a hydrogen tank 13 for supplying hydrogen to the fuel cell 10, a hydrogen supply path 14 through which hydrogen supplied to the fuel cell 10 passes, and an electrochemical reaction in the fuel cell 10 were not used. A hydrogen discharge path 15 for discharging hydrogen exhaust gas to the outside is provided. Although not shown, the fuel cell system includes an air supply device for supplying air (oxygen) to the air electrode (positive electrode) side of the fuel cell 10 and air supplied from the air supply device. An air supply path that passes therethrough and an air discharge path for discharging air exhaust gas that has not been used for the electrochemical reaction in the fuel cell 10 to the outside are provided.

  The hydrogen tank 13 is filled with high-pressure hydrogen and is disposed outside the storage container 11. The hydrogen supply path 14 is provided with an expansion valve 16 as expansion means for expanding high-pressure hydrogen supplied from the hydrogen tank 13. As the expansion valve 16, either an adiabatic expander using heat insulation or a decompression expander using reduced pressure may be used. The hydrogen supplied from the hydrogen tank 13 is decompressed and expanded by the expansion valve 16 and then supplied to the hydrogen electrode (negative electrode) side of the fuel cell 10 through the hydrogen supply path 14.

  A condensing unit 17 is provided downstream of the expansion valve 16 in the hydrogen flow direction in the hydrogen supply path 14. The condensing unit 17 is disposed inside the storage container 11, and heat exchange is performed between hydrogen that has been adiabatically expanded by the expansion valve 16 to be low-temperature and low-pressure and the air in the storage container 11, and the air in the storage container 11. It is comprised as a condensation means to condense the water | moisture content contained in water vapor.

  FIG. 2 is a perspective view of the condensing unit 17. As shown in FIG. 2, the condensing unit 17 includes a plurality of heat transfer units 18 configured as fins in the hydrogen supply path 14 and is configured as a fin tube heat exchanger. The hydrogen supply path 14 is configured as a pipe made of, for example, SUS. The heat transfer part 18 is comprised from the metal plate comprised from a metal with high heat conductivity like copper or aluminum.

  Returning to FIG. 1, in the storage container 11, a water storage unit 19 for storing the water condensed in the condensing unit 17 is provided. The water reservoir 19 is configured as a container having an upper opening, and is disposed below the condenser 17 in the vertical direction. In the water storage unit 19, the condensed water generated by the condensing unit 17 falls and gathers. If the condensation part 17 is a position which can condense the condensed water produced | generated by the condensation part 17 inside the storage container 11, the installation position will not receive a restriction | limiting at all. Furthermore, the water storage unit 19 is fixed to the storage container 11, and any fixing method may be used as long as it is a method that does not easily separate, such as welding means having a predetermined mechanical strength, such as welding, brazing, bonding, screws, and rivets. May be used.

  The lower end of the water reservoir 19 is connected to the hydrogen discharge path 15 via the junction 20. The merge part 20 is configured as a pipe, and the water stored in the water storage part 19 is supplied to the hydrogen discharge path 15 via the merge part 20 and discharged to the outside together with the hydrogen exhaust gas. The junction 20 and the hydrogen discharge path 15 correspond to the discharge means of the present invention.

  Further, the merging section 20 may be connected to an air discharge path (not shown) so that the water storage section 19 is discharged to the outside together with the air exhaust gas. In this case, the merging section 20 may be merged with at least one of the hydrogen discharge path 15 or the air discharge path (not shown).

  Here, how to obtain the heat transfer area necessary for condensing moisture contained in the air as steam by the condensing unit 17 will be described. The following explanation is based on the phenomenon that condensation occurs due to the contact of the saturated vapor with a lower temperature part. Further, the condensation in the condensing unit 17 causes the entire cooling surface (heat transfer unit 18) of the condensing unit 17 to be condensed water. It is assumed that is a so-called film-like condensation that flows down in a film form.

The amount of heat Q taken away by condensation in the condensing unit 17 can be expressed by Equation 1 by applying heat exchange in convection heat transfer. In Formula 1, heat exchange in convection heat transfer is applied, but even when heat conduction or heat radiation is applied, the heat transfer area A can be similarly obtained.
(Equation 1)
Q = h × A × ΔT × t
Here, Q: amount of heat taken away by condensation [J / sec], h: film heat transfer coefficient [J / m ² · sec · ° C.], A: heat transfer area [m ² ], ΔT: temperature difference [° C. ], T: Elapsed time [sec].

Next, the amount of heat Q ′ necessary for condensation can be expressed by Equation 2.
(Equation 2)
Q ′ = q × L
Here, Q ′ is the amount of heat necessary for condensation [J], q is the condensation latent heat of water [J / g], and L is the amount of moisture in the effective space [g].

  From the above, the heat transfer area A can be obtained from the equation when the amount of heat Q taken away by condensation is equal to the amount of heat Q ′ necessary for condensation, that is, Q = Q ′.

Equation 3 is obtained from Equation 1 and Equation 2.
(Equation 3)
h × A × ΔT × t = q × L
Equation 4 is obtained by transforming Equation 3.
(Equation 4)
A = (q × L) / (h × ΔT × t)
Hereinafter, specific numerical values are applied to Equation 4 to determine the heat transfer area A of the condensing unit 17.

First, the film-film heat transfer coefficient h is set to h = 5.000 J / m ² · sec · ° C. in the case of film-like condensation, which is described as a representative value in academic books. Next, assuming that the normal temperature is 30 ° C., the hydrogen before passing through the expansion valve 16 is 30 ° C., and the hydrogen after passing through the expansion valve 16 is 0 ° C., the temperature difference ΔT = 30 ° C. The elapsed time t is the time required to collect the water in the liquid state generated in the condensing unit 17 in the water storage unit 19, and here, t = 600 sec. The water condensation latent heat q is a value q = 2.400 J / g described in the literature.

Furthermore, when it is assumed that the target space in the present embodiment is an atmospheric pressure and is filled with air having a saturated vapor pressure, the water content L in the effective space can be expressed by Equation 5.
(Equation 5)
L = R × V
Here, R: Saturated water vapor amount [g / m ³ ], V: Effective space volume [m ³ ].

When the atmosphere in the effective space is a normal operating temperature of the fuel cell of 80 ° C., the saturated water vapor amount R of air is R = 364.5 g / m ³ under the atmospheric pressure at the temperature of 80 ° C. Further, the effective space volume V, the volume piping the fuel cell 10 and not shown, from the container 11, the sensor, which minus the volume of incidental equipment such as valves, and V = 0.005 m ^3.

When these specific numerical values are used to determine the heat transfer area A, A = 48.6 mm ² is obtained. The heat transfer area A is defined as follows. When the condensing part 17 is a heat exchanger having a large number of heat receiving / dissipating parts and the hydrogen supply path 10 is a pipe having a diameter of 5 mm, the condensing part 17 has fins (heat transfer part having an outer diameter of 6 mm). This can be realized by providing three 18) and six heat receiving / dissipating surfaces. Thereby, the condensation part 17 can be arrange | positioned inside the storage container 11, without sacrificing another structure. In addition, the thickness per fin as the heat receiving / dissipating part in the condensing unit 17 and the arrangement interval of the fins can be freely set as long as the heat transfer area A is satisfied and the other configurations are not sacrificed. it can.

  Next, the operation of the fuel cell system configured as described above will be described. First, air supply is started from an air supply device (not shown), hydrogen supply is started from the hydrogen tank 13, and the fuel cell 10 starts power generation. In the condensing unit 17, heat exchange is performed between the low-temperature and low-pressure hydrogen adiabatically expanded by the expansion valve 16 and the air in the storage container 11.

  In the condensing unit 17, the air contained in the air is condensed by cooling the air with low-temperature hydrogen, and water droplets adhere to the surface of the heat transfer unit 18. The condensed water generated in the condensing unit 17 falls downward and is stored in the water storage unit 19. And the water | moisture content stored by the water storage part 19 is supplied to the hydrogen discharge path 15 via the junction part 20, and is discharged | emitted outside with hydrogen waste gas.

  As described above, when the high pressure hydrogen is decompressed and supplied to the fuel cell 10, it is used as steam in the air in the storage container 11 without using power by utilizing the fact that the hydrogen becomes low temperature due to adiabatic expansion. The contained water can be condensed. Further, by discharging the condensed moisture to the outside of the storage container 11, it is possible to suppress the occurrence of dew condensation inside the storage container 11.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  FIG. 3 is a conceptual diagram of the fuel cell system of the present embodiment. As shown in FIG. 3, the water reservoir 19 of the present embodiment is provided with a porous body 21. As the porous body 21 provided in the water storage unit 19, a foam metal made of, for example, copper, aluminum, stainless steel, or the like can be used.

  The porous body 21 can retain moisture by capillary force. For this reason, even when an external factor, for example, vibration or impact associated with traveling of the vehicle acts on the storage container 11, the water stored in the water storage unit 17 is not scattered outside the water storage unit 19. For this reason, it is possible to prevent moisture from adhering to the electronic components and the like in the storage container 11. In addition, the porous body 21 can be comprised from 2 or more types of materials, or can employ | adopt 2 or more types of porosity. Thus, by mixing different materials and porosities, moisture can be held more reliably, and the effect of preventing moisture from being scattered can be improved.

(Third embodiment)
Next, a third embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  FIG. 4 is a perspective view of the condensing unit 17 of the present embodiment. As shown in FIG. 4, the condensing unit 17 of the present embodiment is configured by providing a cylindrical heat transfer unit 22 in the hydrogen supply path 14. The heat transfer unit 22 is configured as a cylindrical member having a diameter larger than that of the hydrogen supply path 14, and the inner wall surface of the heat transfer unit 22 and the outer wall surface of the hydrogen supply path 14 are in contact with each other. The heat transfer unit 22 is configured as a porous body. In the present embodiment, a foam metal made of a material excellent in receiving and radiating heat, such as copper or aluminum, is used as the heat transfer section 22. When the heat transfer section 22 is installed in the hydrogen supply path 14, any joining means having a predetermined mechanical strength, such as welding, brazing, bonding, screws, rivets, etc., which is not easily separated can be used. May be.

Here, the volume in the case where the heat transfer area A of the condensing unit 17 obtained in the first embodiment is realized by the heat transfer unit 22 made of a porous body is obtained. Assuming that the porous body is formed of a foam metal, and applying the specific surface area of the foam metal described in the academic book = 10.000 m ² / m ³ , the heat transfer area A determined in the first embodiment is 48.6 mm. the volume Va of the porous body needs to be ² becomes Va = 4.86mm ^3. This volume Va can be realized by assuming that the hydrogen supply path 14 is a pipe having a diameter of 5 mm, and that the heat transfer section 22 is a cylindrical foam metal member having a thickness of 0.2 mm and a length of 2 mm. Thereby, the condensation part 17 can be arrange | positioned inside the storage container 11, without sacrificing another structure.

  Also with the above configuration, the same effect as the condensing unit 17 of the first embodiment can be obtained.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  FIG. 5 is a conceptual diagram of the fuel cell system of the present embodiment. As shown in FIG. 5, in this embodiment, the water storage part 19 is provided directly under the condensation part 17, and the water storage part 19 and the condensation part 17 are comprised integrally. When integrating the water storage unit 19 with the condensing unit 17, the water storage unit 17 may be held by a holding member provided in the hydrogen supply path 14, or a water storage unit 17 may be formed by a component that forms part of the condensing unit 17. May be held. The joining means for integrating the water storage unit 19 and the condensing unit 17 has any mechanical strength such as welding, brazing, adhesion, screw, rivet, and any method that does not easily separate is used. May be.

  Also with the above configuration, the same effect as in the first embodiment can be obtained.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  FIG. 6 is a conceptual diagram of the fuel cell system of the present embodiment. As shown in FIG. 6, in this embodiment, a drainage opening 23 is provided in the vicinity of the water reservoir 19 in the storage container 11. The water reservoir 19 and the drain opening 23 are in communication with each other, and the water stored in the water reservoir 19 is discharged from the drain opening 23. The drain opening 23 corresponds to the discharge means of the present invention.

  Here, the storage container 11 of the present embodiment is mounted on a mobile body (electric vehicle), and the interior of the storage container 11 becomes lower than the outside due to the traveling of the mobile body. For this reason, the water stored in the water storage unit 19 can be discharged to the outside of the storage container 11 through the drainage opening 23 using the pressure difference between the inside and the outside of the storage container 11 as the mobile body travels. it can.

  Also with the above configuration, the same effect as in the first embodiment can be obtained.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  FIG. 7 is a conceptual diagram of the fuel cell system of the present embodiment. As shown in FIG. 7, in this embodiment, a water amount detection sensor 24 is provided inside the storage container 11. The water amount detection sensor 24 detects the amount of water stored in the water storage unit 19, and is configured as a water level sensor that detects the water level in the present embodiment. As the water amount detection sensor 24, a water level sensor using an float or an optical water level sensor can be used. The water amount detection sensor 24 corresponds to the condensation amount detection means of the present invention.

  Moreover, the expansion valve 16 of this embodiment is comprised so that an opening degree can be adjusted. By adjusting the opening of the expansion valve 16, the amount of hydrogen expansion can be adjusted, the amount of air cooled in the condensing unit 17 can be adjusted, and the amount of condensed water generated in the condensing unit 17 can be adjusted. The expansion valve 16 of the present embodiment is configured to adjust the amount of hydrogen expansion between a first predetermined value and a second predetermined value that is smaller than the first predetermined value. Here, the “hydrogen expansion amount” is a pressure regulation value by the expansion valve 16 and is equal to the valve opening.

  The fuel cell system is provided with a control unit (ECU) 25 that performs various controls. The control unit 25 includes a well-known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The control unit 25 receives a detection signal from the water amount detection sensor 24 and outputs a control signal to the expansion valve 16 and the like. The amount of water stored in the storage unit 19 is the amount of condensed water generated by the condensing unit 17 in the storage container 11, and the control unit 25 expands the amount of hydrogen by the expansion valve 16 based on the detection value of the water amount detection sensor 24. Control.

  Next, a method for controlling the expansion valve 16 by the fuel cell system of the present embodiment will be described. FIG. 8 shows the relationship between the amount of water generated in the condensing unit 17 and the amount of hydrogen expansion by the expansion valve 16. In FIG. 8, the upper part shows a temporal change in the amount of water generated in the condensing unit 17, and the lower part shows a temporal change in the amount of hydrogen expanded by the expansion valve 16.

  As shown in FIG. 8, when the detected value of the moisture amount detection sensor 23 reaches a predetermined upper limit value, the control unit 25 reduces the hydrogen expansion amount by the expansion valve 16 from the first predetermined value to the second predetermined value. Let Thereby, the moisture content produced | generated by the condensation part 17 falls. Next, when the detected value of the moisture amount detection sensor 23 reaches a predetermined lower limit value, the control unit 25 increases the hydrogen expansion amount by the expansion valve 16 from the second predetermined value to the first predetermined value. Thereby, the moisture content produced | generated by the condensation part 17 increases.

  As described above, when the amount of water generated in the condensing unit 17 reaches the upper limit value, the amount of water generated in the condensing unit 17 can be suppressed by reducing the amount of hydrogen expansion by the expansion valve 16, and the condensing unit 17. In the case where the amount of water generated in the above reaches the lower limit, the amount of water generated in the condensing unit 17 can be increased by increasing the amount of hydrogen expansion by the expansion valve 16. As a result, the amount of condensed water generated in the condensing unit 17 can be appropriately maintained, condensation can be prevented from occurring in the storage container 11 due to insufficient cooling in the condensing unit 17, and further, the water storage unit can be stored due to excessive cooling in the condensing unit 17. It is possible to avoid the water overflowing from 19 to the electronic components in the storage container 11.

  In the present embodiment, the water amount detection sensor 23 is configured to detect the water amount of the water storage unit 19. However, the present invention is not limited thereto, and a humidity sensor that detects the humidity in the storage container 11 may be used. As the humidity sensor, an absolute hygrometer, a relative hygrometer, or a dew point meter can be used.

(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described. Only the parts different from the sixth embodiment will be described below.

  FIG. 9 shows the relationship between the amount of water generated in the condensing unit 17 of this embodiment and the amount of hydrogen expansion by the expansion valve 16. As shown in FIG. 9, in this embodiment, the amount of hydrogen expansion by the expansion valve 16 is decreased from the first predetermined value to the second predetermined value at a constant rate of change to the second predetermined value and the first predetermined value. Increasing at a constant rate of change.

  Even with such a configuration, the same effect as in the sixth embodiment can be obtained. In the example shown in FIG. 9, the hydrogen expansion amount by the expansion valve 16 is changed at a constant rate of change. However, it is not always necessary to have a constant rate of change, such as sine, cosine, arc, etc. The rate of change may be a curve, or may be a rate of change that combines a constant value in a staircase pattern.

It is a conceptual diagram of the fuel cell system of 1st Embodiment. It is a perspective view of the condensation part of a 1st embodiment. It is a conceptual diagram of the fuel cell system of 2nd Embodiment. It is a perspective view of the condensation part of a 3rd embodiment. It is a conceptual diagram of the fuel cell system of 4th Embodiment. It is a conceptual diagram of the fuel cell system of 5th Embodiment. It is a conceptual diagram of the fuel cell system of 6th Embodiment. It is a figure which shows the relationship between the amount of water | moisture content generated in the condensation part in 6th Embodiment, and the expansion amount of hydrogen by an expansion valve. It is a figure which shows the relationship between the moisture content which generate | occur | produced in the condensation part in 7th Embodiment, and the expansion amount of hydrogen by an expansion valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Storage container, 12 ... Opening part, 13 ... Hydrogen tank, 14 ... Hydrogen supply path, 15 ... Hydrogen discharge path, 16 ... Expansion valve, 17 ... Condensing part, 18 ... Heat-transfer part, 19 ... Water storage part, 20 ... confluence part, 21 ... porous body, 22 ... heat transfer part, 23 ... drainage opening, 24 ... water quantity detection sensor.

Claims (14)

A fuel cell (10) for generating electricity by an electrochemical reaction between hydrogen and oxygen;
A storage container (11) for storing the fuel cell (10);
A hydrogen tank (13) filled with high-pressure hydrogen and supplying hydrogen to the fuel cell (10);
A hydrogen supply path (14) through which hydrogen supplied from the hydrogen tank (13) to the fuel cell (10) passes;
Expansion means (16) for expanding hydrogen flowing out of the hydrogen tank (13) in the hydrogen supply path (14);
Condensing means (condenser means) provided in the storage container (11) for exchanging heat between the hydrogen expanded by the expansion means (16) and the air in the storage container (11) to condense moisture contained in the air. 17)
A fuel cell system comprising: discharge means (15, 20, 23) for discharging the moisture condensed by the condensation means (17) to the outside of the storage container (11). A discharge path (15) for discharging the exhaust gas not used in the electrochemical reaction out of at least one of hydrogen and oxygen supplied to the fuel cell (10) to the outside of the storage container (11);
The discharge means includes the discharge path (15) and a merging path (20) for merging the moisture condensed in the condensation means (17) to the discharge path (15). The fuel cell system according to claim 1, wherein the water condensed in () is discharged together with the exhaust gas to the outside of the storage container (11). The discharge means has a drain opening (23) provided in the storage container (11), and the water condensed by the condensation means (17) is stored in the drain via the drain opening (23). The fuel cell system according to claim 1, wherein the fuel cell system is discharged to the outside of the container (11). A controller (25) for adjusting the amount of hydrogen expansion by the expansion means (16);
A condensation amount detection means (24) for detecting the amount of moisture condensed by the condensation means (17),
The control unit (25) controls the expansion amount of hydrogen by the expansion means (16) based on the condensation amount detected by the condensation amount detection means (24). The fuel cell system according to claim 1. A water storage part (19) that is provided in the storage container (11) and stores water condensed by the condensing means (17);
The discharge means (16, 20, 23) is configured to discharge moisture stored in the water storage section (19) to the outside of the storage container (11).
The fuel cell system according to claim 4, wherein the condensation amount detection means is a moisture amount detection means (23) for detecting the amount of water stored in the water storage section (19). A water storage part (19) provided in the storage container (11) for storing the water condensed by the condensing means (17);
The said discharge | emission means (15, 20, 23) discharges | emits the water currently stored by the said water storage part (19) to the exterior of the said storage container (11), The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The fuel cell system described in 1. The fuel cell system according to claim 6, wherein the condensation amount detection means is a humidity sensor (24) for detecting humidity in the storage container (11). The fuel cell system according to any one of claims 5 to 7, wherein the water reservoir (19) is disposed vertically below the condensing means (17). The fuel cell system according to claim 8, wherein the water reservoir (19) is configured integrally with the condensing means (17). In the condensing means, the heat transfer section (18, 22) for exchanging heat between the hydrogen expanded by the expansion means (16) and the air in the storage container (11) is composed of a porous body. A fuel cell system according to any one of claims 1 to 9. The fuel cell system according to claim 10, wherein the porous body is made of a foam metal. The fuel cell system according to any one of claims 1 to 11, wherein a porous body (21) is provided in the water reservoir (19). The fuel cell (10) is used as a driving source for moving a moving body, and the storage container (11) is mounted on the moving body. The fuel cell system according to one. The discharging means (15, 20, 23) is configured to store moisture condensed in the condensing unit (17) due to a pressure difference between the inside and outside of the storage container (11) generated when the movable body moves. The fuel cell system according to claim 13, wherein the fuel cell system is discharged outside.

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