JP2008185437A - Temperature sensor for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of a generation performance of a fuel cell and to improve detection precision. <P>SOLUTION: A thermocouple temperature sensor 50 is so configured that thermocouple wires 51, 52 are bonded with each other, and the whole part is covered with a cover layer 54. The cover layer 54 is constituted of a first cover layer 54a for covering the outer periphery of the thermocouple wires 51, 52 and a second cover layer 54b for covering the outer periphery of the first cover layer 54a. The first cover layer 54a is made of a polyimide film having insulation property. The first cover layer 54a is constituted so as to maintain a mechanical strength in an extent that it is not damaged even when it is applied with a stress of 3.0 MPa under the operation temperature of the fuel cell 10 in a solid polymer type. The second cover layer 54b is made of a gas impermeable dense member, e.g., a Cr (chrome) film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a temperature sensor for a fuel cell used in a fuel cell.

  Conventionally, a thermocouple type sensor is known as a temperature sensor built in a fuel cell. As a thermocouple type temperature sensor, there is a sheath type sensor in which an inorganic insulator such as magnesia is filled in a sheath which is a heat-resistant alloy and a thermocouple wire is arranged (for example, Patent Documents 1 and 2).

JP 2006-47261 A JP 2006-47220 A

  However, the sheath-type thermocouple temperature sensor has a large outer shape because it includes a sheath, and therefore has the following problems. First of all, if the outer shape is large, the flow of gas to the power generation reaction section of the fuel cell will be hindered and the discharge of generated water will be hindered, which causes the problem of deteriorating the power generation performance of the fuel cell. did. Secondly, when the outer shape is large, the sheath is a metal material, so that the temperature of the peripheral portion thereof is lowered, and the temperature that should be originally obtained cannot be detected with high accuracy.

  The present invention has been made to solve the above-described conventional problems, and has an object to reduce the outer shape to prevent deterioration of the power generation performance of the fuel cell and to improve detection accuracy. .

In order to achieve the above object, a first temperature sensor for a fuel cell of the present invention comprises:
A temperature sensor used in a fuel cell,
A wire constituting the thermocouple;
A first covering layer covering an outer periphery of the strand;
A second coating layer covering the outer periphery of the first coating layer,
The first coating layer has an insulating property and a mechanical strength that does not damage even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell.
The second coating layer is dense and gas-impermeable.

  According to the fuel cell temperature sensor having the above-described configuration, the second coating layer located outside is dense and gas-impermeable, thereby preventing gas from entering. The first covering layer located on the inner side electrically insulates the strands constituting the thermocouple, and has a high strength that does not damage even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell (here In the following, “strength” is mechanical strength, and hereinafter, simply “strength” means mechanical strength). In a conventional sheath-type thermocouple temperature sensor, the inorganic insulator filled between the sheath and the strand is powdery and does not contribute to the strength of the entire sensor. Is maintained. On the other hand, the first temperature sensor for the fuel cell according to the present invention can maintain high strength by the first coating layer as described above, so that the second coating layer corresponding to the sheath has strength. May be low. For this reason, the second coating layer can be made thinner than the sheath of the conventional thermocouple temperature sensor. In other words, the second coating layer can be made thin by providing the first coating layer with a role to bear strength. The first coating layer is conventionally filled with an inorganic insulator, and the thickness does not change so much even if the strength is increased.

  Therefore, in the first temperature sensor for a fuel cell according to the present invention, the second coating layer may be thin, so that the overall outer shape covered with the first coating layer and the second coating layer is small. . As a result, the gas flow to the power generation reaction section of the fuel cell is not inhibited, and the generated water is not inhibited from being discharged, so that deterioration of the power generation performance of the fuel cell can be prevented. Further, when the overall outer diameter is small, the temperature at the peripheral portion is hardly lowered, and therefore the temperature detection accuracy can be improved.

  The first covering layer may be made of resin. Thereby, it is easy to realize insulation. The first coating layer may be a polyimide film. Polyimide is ideal for the first coating layer because it is a material that boasts high heat resistance and is excellent in mechanical strength and electrical insulation.

  The second coating layer may have a mechanical strength lower than that of the first coating layer. The fact that low mechanical strength is sufficient means that the thickness of the second coating layer 54b can be reduced. Therefore, the whole temperature sensor for fuel cells can be made smaller.

  The second coating layer may be a chromium film. Since chromium is chemically stable and excellent in corrosion resistance, it is optimal as the second coating layer when the second coating layer is used as the outer surface. The second coating layer may be a parylene film.

The second temperature sensor for a fuel cell of the present invention comprises:
A temperature sensor used in a fuel cell,
A wire constituting the thermocouple;
A first covering layer covering an outer periphery of the strand;
A second coating layer covering the outer periphery of the first coating layer,
The first covering layer has an insulating property and higher mechanical strength than the second covering layer,
The fuel cell temperature sensor, wherein the second coating layer is dense and gas-impermeable.
It is characterized by that.

  According to the fuel cell temperature sensor having the above-described configuration, the second coating layer located outside is dense and gas-impermeable, thereby preventing gas from entering. The 1st coating layer located inside has the intensity | strength higher than a 2nd coating layer while electrically insulating the strand which comprises a thermocouple. In a conventional sheath-type thermocouple temperature sensor, the inorganic insulator filled between the sheath and the strand is powdery and does not contribute to the strength of the entire sensor. Is maintained. In contrast, the second temperature sensor for the fuel cell of the present invention can maintain high strength by the first coating layer as described above, and the second coating layer corresponding to the sheath has strength. Low. For this reason, the second coating layer can be made thinner than the sheath of the conventional thermocouple temperature sensor. In other words, the second coating layer can be made thin by providing the first coating layer with a role to bear strength. The first coating layer is conventionally filled with an inorganic insulator, and the thickness does not change so much even if the strength is increased.

  Therefore, in the second temperature sensor for the fuel cell of the present invention, similarly to the first temperature sensor for the fuel cell of the present invention, the power generation performance of the fuel cell is prevented from being deteriorated and the detection accuracy is improved. The effect that can be done.

  In the first or second fuel cell temperature sensor described above, the gas diffusion layer is in a fuel cell formed of carbon cloth, and is mounted in a state sandwiched between the gas diffusion layer and the catalyst layer. The outer diameter may be a size of 1/3 or less of the thickness of the gas diffusion layer. Further, in the first or second fuel cell temperature sensor described above, the gas diffusion layer is mounted in a fuel cell in which the gas diffusion layer is formed of carbon paper and is sandwiched between the gas diffusion layer and the catalyst layer. At the same time, the outer diameter may be 1/5 or less of the thickness of the gas diffusion layer.

  According to these configurations, the temperature sensor for the fuel cell is sufficiently buried in the gas diffusion layer and does not interfere with the close contact between the catalyst electrode and the gas diffusion electrode 15b. Therefore, deterioration of the fuel cell performance due to the mounting of the temperature sensor for the fuel cell can be prevented.

  According to this configuration, the fuel cell temperature sensor is sufficiently buried in the gas diffusion layer and does not interfere with the close contact between the catalyst electrode 15a and the gas diffusion electrode 15b. Therefore, deterioration of the fuel cell performance due to the mounting of the temperature sensor for the fuel cell can be prevented.

  Next, the best mode for carrying out the present invention will be described below using examples.

1. Overall configuration of the fuel cell:
FIG. 1 is an explanatory view showing a fuel cell 10 having a temperature sensor for a fuel cell as one embodiment of the present invention in an exploded manner. FIG. 2 is a view taken along line AA in FIG. The fuel cell 10 is a polymer electrolyte fuel cell, and a longitudinal section is shown in FIG. The fuel cell 10 mainly includes a membrane electrode assembly (hereinafter referred to as MEA) 12 in which electrodes 14 and 15 are arranged on both surfaces of a solid polymer electrolyte membrane (hereinafter simply referred to as “electrolyte membrane”) 13. The MEA 12 is provided with a pair of separators 16 and 17 that sandwich the MEA 12 from both sides. The fuel cell 10 is called a single cell, and has an electromotive force of about 0.6 to 0.8V. For this reason, for example, when used as a power supply for a drive motor of a vehicle, a direct current power supply of several hundred volts is obtained by closely stacking a large number of fuel cells 10.

  The MEA 12 is obtained by sandwiching an electrolyte membrane 13 between two electrodes, that is, an anode 14 that is a fuel electrode and a cathode 15 that is an oxygen electrode. In the MEA 12 of this embodiment, the area of the electrolyte membrane 13 is larger than the areas of the anode 14 and the cathode 15. Here, the electrolyte membrane 13 is a membrane made of a solid polymer material having good proton conductivity in a wet state. Specifically, the membrane is made of a fluorine-based resin (such as a Nafion membrane manufactured by DuPont). ) And the like.

  The anode 14 and the cathode 15 are constituted by catalyst electrodes (catalyst layers) 14a and 15a and gas diffusion electrodes (gas diffusion layers) 14b and 15b, respectively. The catalyst electrodes 14a and 15a are located on the side in contact with the electrolyte membrane 13, and are made of conductive carbon black carrying platinum fine particles. On the other hand, the gas diffusion electrodes 14b and 15b are formed of carbon cloth laminated on the catalyst electrodes 14a and 15a and woven with yarns made of carbon fibers. The platinum contained in the catalyst electrodes 14a and 15a has an action of promoting the separation of hydrogen into protons and electrons or promoting the reaction of generating water from oxygen, protons and electrons. If it has, you may use things other than platinum. The gas diffusion electrodes 14b and 15b may be formed of carbon paper or carbon felt made of carbon fiber in addition to carbon cloth, and may have sufficient gas diffusibility and conductivity.

  A plurality of recesses are formed in each of the pair of separators 16 and 17. A flow path for a reaction gas used for an electrochemical reaction is formed between the recess and the MEA 12. That is, an in-cell fuel gas passage 16a through which a fuel gas containing hydrogen passes is formed between the separator 16 on the anode 14 side and the MEA 12. In addition, between the separator 17 on the cathode 15 side and the MEA 12, an in-cell oxidizing gas channel 17a through which an oxidizing gas containing oxygen such as air passes is formed.

2. Configuration of temperature sensor for fuel cell:
A thermocouple temperature sensor 50 as a fuel cell temperature sensor is attached to the fuel cell 10 having such a configuration. The thermocouple type temperature sensor 50 is formed by bonding a pair of strands (hereinafter referred to as “thermocouple strands”) 51 and 52 constituting a thermocouple, and covering the entire U-shape with a coating layer 54. Is. In FIG. 2, 53 is a junction point of the thermocouple wires 51 and 52. The thermocouple wires 51 and 52 are connected to the thermoelectromotive force measurement circuit 57 by conducting wires 56 and 57. The thermoelectromotive force measurement circuit 57 measures a potential difference (thermoelectromotive force) between the thermocouple wires 51 and 52.

  FIG. 3 is a cross-sectional view of the coating layer 54 that covers the thermocouple wires 51 and 52. As shown in the figure, the covering layer 54 includes a first covering layer 54a that covers the outer periphery of the thermocouple wires 51 and 52, and a second covering layer 54b that further covers the outer periphery of the first covering layer 54a. Composed.

  The first coating layer 54a is formed of a polyimide film, has an insulating property, and has a mechanical strength of 200 MPa or more under the operating temperature (-20 to 120 ° C.) of the solid polymer type fuel cell 10. It is the structure to maintain. The mechanical strength of 200 MPa or more is a mechanical strength that does not damage even when subjected to a stress of 200 MPa. Polyimide was used as the first covering layer 54a because it is a material excellent in mechanical strength (200 to 600 MPa) and electrical insulation, as well as having high heat resistance (up to 500 ° C.).

  The second coating layer 54b is formed of a gas impermeable dense member, specifically, a Cr (chromium) film. The polyimide film and the Cr film are coated by a vapor phase growth method.

  The first coating layer 54a may be made of other types of resins such as polyacetal, polyethylene, polymethylpentene, polyethylene terephthalate, polycarbonate, parylene, parylene HT, and epoxy-modified silicone instead of the polyimide film. . Moreover, it is not necessary to restrict to resin, and ceramics, such as a zirconia oxide and a ceria oxide, etc. may be sufficient. In short, the first coating layer 54a has an insulating property and is not damaged even when subjected to a stress of 3.0 MPa under the operating temperature (-20 to 120 ° C.) of the solid polymer fuel cell 10. Any material may be used as long as the structure can have the mechanical strength described above. Here, damage refers to breakage, cracks, wear, and the like. In general, in a fuel cell, a relatively high surface pressure of about 1.5 MPa is applied between the separator and the MEA, between the gas diffusion electrode and the catalyst electrode to reduce contact resistance, and the electrolyte membrane swells together. Higher stress is applied due to thermal expansion. Therefore, the first coating layer 54a is configured to have an insulating property and a mechanical strength that does not damage even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell.

  The method of coating the first coating layer 54a on the thermocouple wire 51 is not limited to the vapor phase growth method, and any method may be used as long as it is suitable for each material. It is also possible to use an impregnation method, a spray method, an electrodeposition method of solid phase powder, a hot press of a film, or a combination thereof.

Second cover layer 54b is, instead of the Cr film, TiN (titanium nitride), CrN (chromium nitride), Ti (titanium), SiO ₂ (silicon dioxide), _SI 3 _{N 4} (silicon nitride), _Al 2 O ₃ (alumina oxide) or other metals, metal nitrides or metal oxides. Any metal, metal nitride, or metal oxide may be used as long as it is dense and gas-impermeable. The second coating layer 54b is preferably a layer having excellent adhesion to the first coating layer 54a. The Cr film has excellent adhesion to the polyimide film that is the first coating layer 54a.

  Moreover, it is preferable that the 2nd coating layer 54b is low mechanical strength compared with the mechanical strength of the 1st coating layer 54a. Since the mechanical strength of the Cr film constituting the second coating layer 54b of this example is 10 Mpa or less, and the mechanical strength of the polyimide film constituting the first coating layer 54a is 200 to 600 MPa, The mechanical strength of the second coating layer 54b is lower than that of the first coating layer 54a. Since the second coating layer 54b has a low mechanical strength, the thickness of the second coating layer 54b can be reduced. Note that the method of coating the second coating layer 54b on the first coating layer 54a is not limited to the above vapor phase growth method, and any method may be used as long as it is suitable for each material. An impregnation method from a phase, a spray method, an electrodeposition method of a solid phase powder, a hot press of a film, or a combination thereof may be used.

  As shown in FIGS. 1 and 2, the thermocouple temperature sensor 50 is provided between the catalyst electrode 15 a and the gas diffusion electrode 15 b constituting the cathode 15. Specifically, it is provided between the catalyst electrode 15 a and the gas diffusion electrode 15 b so that the junction 53 of the thermocouple wires 51 and 52 is located near the center in the surface direction of the cathode 15.

  The total diameter D (see FIG. 3, that is, the outer diameter) of the thermocouple wires 51 and 52 covered with the coating layer 54 is the catalyst electrode 15a and the gas diffusion electrode 15b in the region where the thermocouple temperature sensor 50 does not exist. It is preferable that it is a grade which does not obstruct adhesion | attachment between these. This degree depends on the flexibility of the gas diffusion electrode 15b, but when the gas diffusion electrodes 14b and 15b are carbon cloth, the catalyst can be used if the diameter D is 1/3 or less of the thickness of the gas diffusion electrode 15b. The adhesion between the electrode 15a and the gas diffusion electrode 15b is not disturbed. That is, when the entire diameter D of the thermocouple wires 51 and 52 covered with the coating layer 54 is sufficiently smaller than the thickness of the gas diffusion electrode 15b, the thermocouple wires 51 and 52 It is sufficiently buried in the electrode 15b and does not interfere with the close contact between the catalyst electrode 15a and the gas diffusion electrode 15b.

  When the gas diffusion electrodes 14b and 15b are formed of carbon paper, the contact between the catalyst electrode 15a and the gas diffusion electrode 15b can be maintained if the diameter D is equal to or less than 1/5 of the thickness of the gas diffusion electrode 15b. There is no interference. When the close contact between the catalyst electrode 15a and the gas diffusion electrode 15b may be obstructed in a partial region, the relationship between the diameter D and the thickness of the gas diffusion electrode 15b is unnecessary, and the diameter D is It is possible to make it larger than the above relationship.

3. Configuration of fuel cell system:
FIG. 4 is a block diagram showing a schematic configuration of a fuel cell system 100 in which the fuel cell 10 to which the above-described thermocouple temperature sensor 50 is mounted is mounted. The fuel cell system 100 is configured for an electric vehicle. As shown in the figure, the fuel cell system 100 includes a fuel cell 10 to which the above-described thermocouple temperature sensor 50 is attached. Further, as a peripheral device of the fuel cell 10, a hydrogen supply device 110, a blower 120, and a cooling device 130 are provided.

  The hydrogen supply device 110 is a device that stores hydrogen therein and supplies hydrogen gas as fuel gas to the anode of the fuel cell 10. For example, the hydrogen supply device 110 may include a hydrogen cylinder or a hydrogen tank having a hydrogen storage alloy inside. Further, the air taken in by the blower 120 is supplied to the cathode of the fuel cell 10 as an oxidizing gas.

  The cooling device 130 includes a cooling water flow path 132 formed so as to pass through the inside of the fuel cell 10, a radiator 134, and a pump 136. By driving the pump 136, the cooling water can be circulated in the cooling water channel 132. In the fuel cell 10, heat is generated with the progress of the electrochemical reaction. Therefore, during power generation, cooling water is circulated in the fuel cell 10, and this cooling water is cooled by the radiator 134, thereby reducing the internal temperature of the fuel cell 10. Keep within the prescribed range.

  In addition to the fuel cell 10, the fuel cell system 100 includes a secondary battery (battery) 140 as an auxiliary power source. The secondary battery 140 is connected in parallel with the fuel cell 10 via the DC / DC converter 150. The inverter 160 generates a three-phase AC power source from these DC power sources, supplies the three-phase AC power source to the vehicle driving motor 170, and controls the rotation speed and torque of the motor 170.

  The fuel cell system 100 includes an electronic control unit 180. The electronic control unit 180 is configured as a logic circuit centered on a microcomputer, and controls the movement of each part of the fuel cell system 100. That is, signals are received from various sensors and switches provided in the electric vehicle, and control signals are output to the hydrogen supply device 110, the blower 120, and the pump 136 to control the operation of the fuel cell 10, or DC / A control signal is output to the DC converter 150 and the inverter 160 to control the operation of the motor 170.

  The electronic control unit 180 is electrically connected to the thermoelectromotive force measurement circuit 57 described above. The electronic control unit 180 takes in the temperature T of the fuel cell 10 measured by the thermoelectromotive force measurement circuit 57, and performs abnormally high temperature prevention control as one of the operation controls of the fuel cell 10. The abnormal high temperature prevention control determines whether or not the temperature T of the captured fuel cell 10 exceeds a predetermined value T0 (for example, 80 ° C.), and when it is determined to exceed, the following (a) to ( By performing at least one of c), the temperature of the fuel cell 10 is reduced.

(A) A process of outputting a control signal to the DC / DC converter 150 to reduce the output torque of the motor 170 is performed. As a result, the load on the fuel cell 10 decreases, and the temperature of the fuel cell 10 decreases.

(B) A control signal is output to the pump 136 provided in the cooling device 130 to perform a process of increasing the flow rate of the cooling water. As a result, the temperature of the fuel cell 10 decreases. Alternatively, the control signal may be output to the radiator 134 included in the cooling device 130 to increase the rotation speed of the cooling fan included in the radiator, thereby increasing the degree of cooling and reducing the temperature of the fuel cell 10.

(C) A process of increasing the supply amount of the hydrogen supply device 110 is performed. Thereby, the sensible heat carried away by gas increases, and the temperature of the fuel cell 10 falls. Alternatively, the control signal may be output to the blower 120 to increase the amount of air supplied to the fuel cell 10.

4). Effect:
According to the thermocouple temperature sensor 50 of the present embodiment configured as described above, the second coating layer 54b located outside is dense and gas-impermeable, thereby preventing gas intrusion. For this reason, the thermocouple temperature sensor 50 is highly resistant to gas, moisture, and acid. On the other hand, the first covering layer 54a located on the inner side electrically insulates the thermocouple wires 51 and 52 and is not damaged even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell 10. Maintain mechanical strength. In a conventional sheath-type thermocouple temperature sensor, the inorganic insulator filled between the sheath and the strand is powdery and does not contribute to the strength of the entire sensor. Is maintained. On the other hand, since the thermocouple temperature sensor 50 can maintain high strength by the first coating layer 54a as described above, the second coating layer 54b corresponding to the sheath has low strength. Also good. For this reason, the 2nd coating layer 54b can be made thin compared with the sheath of the conventional thermocouple type temperature sensor.

  Therefore, in the thermocouple temperature sensor 50 of the present embodiment, since the second coating layer 54b may be thin, the entire outer shape covered with the first coating layer 54a and the second coating layer 54b is small. It becomes. As a result, the gas flow to the power generation reaction section of the fuel cell 10 is not inhibited, and the generated water is not inhibited from being discharged, so that the power generation performance of the fuel cell 10 can be prevented from deteriorating. Further, when the overall outer diameter is small, the temperature at the peripheral portion is hardly lowered, and therefore the temperature detection accuracy can be improved.

  Further, in the fuel cell system 100 including the fuel cell 10 equipped with the thermocouple temperature sensor 50 of the present embodiment, the temperature of the fuel cell 10 can be detected with high accuracy. Moreover, it can be performed with good responsiveness. As a result, it is possible to improve the power generation efficiency and the durability of the fuel cell.

5. Other embodiments:
The present invention is not limited to the above-described embodiments and modifications thereof, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) First modification:
In the above-described embodiments and modifications thereof, the second coating layer 54b is made of metal, metal nitride, or metal oxide, but can be replaced with resin.

  FIG. 5 is a cross-sectional view of a thermocouple temperature sensor 250 as a first modification. As shown in the figure, the thermocouple temperature sensor 250 includes thermocouple wires 251 and 252, and the thermocouple wires 251 and 252 are covered with a coating layer 254. The thermocouple wires 251 and 252 are the same as the thermocouple wires 51 and 52 of the first embodiment. The coating layer 254 includes a first coating layer 254a that covers the outer periphery of the thermocouple wires 251 and 252 and a second coating layer 254b that further covers the outer periphery of the first coating layer 254a. The first coating layer 254a is the same polyimide film as in the first embodiment.

  The second coating layer 254b is a parylene film. The parylene film is a coating film formed of a paraxylylene-based resin, and is excellent in gas impermeability, electrical insulation, and heat resistance. Therefore, the parylene film was used as the second coating layer 254b. According to the first modified example having such a configuration, the outer shape can be made small as in the above-described embodiment, thereby preventing the power generation performance of the fuel cell 10 from deteriorating and improving the temperature detection accuracy. can do. Note that the second coating layer 254b may be an epoxy film, a silicone film, or the like instead of the valylene film. Any resin film may be used as long as it is dense and impermeable to gas.

(2) Second modification:
In the above embodiment, the first coating layer 54a maintains a mechanical strength that does not cause damage even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell, and then the second coating layer 54b. Had a lower mechanical strength than the mechanical strength of the first coating layer 54a, but instead, the first coating layer was a machine that was below 3.0 MPa at the operating temperature of the fuel cell. The second coating layer may have a mechanical strength lower than that of the first coating layer, although the strength is high. That is, the first coating layer has a configuration that is not limited to the numerical value of the mechanical strength of the first coating layer as long as it has an insulating property and has a mechanical strength higher than that of the second coating layer. Can do. Also with this configuration, the mechanical strength of the second coating layer can be lowered as in the first embodiment, so that the second coating layer can be made thinner than the conventional one. Therefore, the second modification also has the effect of preventing the power generation performance of the fuel cell from being deteriorated and improving the detection accuracy, as in the above-described embodiment.

(3) Third modification:
Further, the present invention may be applied to a fuel cell of a different type from the above-described embodiments and modifications. For example, it can be applied to a direct methanol fuel cell. Alternatively, it may be a fuel cell having an electrolyte membrane other than a solid polymer, for example, a molten carbonate fuel cell, a phosphoric acid fuel cell, and the like, and the same effect can be obtained by applying the present invention. That is, the first coating layer has a mechanical strength of 3.0 MPa or more under the operating temperature of each fuel cell type, that is, a mechanical strength that does not damage even when subjected to a stress of 3.0 MPa. It is good.

It is explanatory drawing which decomposes | disassembles and represents the fuel cell 10 provided with the thermocouple type temperature sensor 50 as one Example of this invention. It is an AA arrow line view of FIG. It is sectional drawing of the coating layer 54 which coat | covers the thermocouple strand 51,52. 1 is a block diagram showing a schematic configuration of a fuel cell system 100 equipped with a fuel cell 10 equipped with a thermocouple temperature sensor 50. FIG. It is sectional drawing of the thermocouple type temperature sensor 250 as a 1st modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 13 ... Electrolyte membrane 14 ... Anode 14a ... Catalyst electrode 14b ... Gas diffusion electrode 15 ... Cathode 15a ... Catalyst electrode 15b ... Gas diffusion electrode 16. .. Separator 16a ... Fuel gas flow path in single cell 17 ... Separator 17a ... Oxidation gas flow path in single cell 50 ... Thermocouple temperature sensor 51, 52 ... Thermocouple wire 53 ... Junction 54 ... Coating layer 54a ... First coating layer 54b ... Second coating layer 56 ... Conducting wire 57 ... Thermionic force measuring circuit 100 ... Fuel cell system 110 ... Hydrogen supply device 120 ... Blower 130 ... Cooling device 132 ... Cooling water flow path 134 ... Radiator 136 ... Pump 160 ... Inverter 170 ... Motor 180 ... Electronic Control unit 250 ... thermocouple temperature sensor 251,252 ... thermocouple wire 254 ... covering layer 254a ... first covering layer 254b ... second covered Covering layer

Claims (9)

A temperature sensor used in a fuel cell,
A wire constituting the thermocouple;
A first covering layer covering an outer periphery of the strand;
A second coating layer covering the outer periphery of the first coating layer,
The first coating layer has an insulating property and a mechanical strength that does not damage even when subjected to a stress of 3.0 MPa under the operating temperature of the fuel cell.
The fuel cell temperature sensor, wherein the second coating layer is dense and gas-impermeable.   The temperature sensor for a fuel cell according to claim 1, wherein the first covering layer is made of resin.   The temperature sensor for a fuel cell according to claim 1, wherein the first coating layer is a polyimide film.   The temperature sensor for a fuel cell according to any one of claims 1 to 3, wherein the second coating layer has a mechanical strength lower than that of the first coating layer.   The temperature sensor for a fuel cell according to any one of claims 1 to 3, wherein the second coating layer is a chromium film.   The temperature sensor for a fuel cell according to any one of claims 1 to 3, wherein the second coating layer is a parylene film. A temperature sensor used in a fuel cell,
A wire constituting the thermocouple;
A first covering layer covering an outer periphery of the strand;
A second coating layer covering the outer periphery of the first coating layer,
The first covering layer has an insulating property and higher mechanical strength than the second covering layer,
The fuel cell temperature sensor, wherein the second coating layer is dense and gas-impermeable. A temperature sensor for a fuel cell according to any one of claims 1 to 7,
In the fuel cell in which the gas diffusion layer is formed of carbon cloth, it is mounted in a state sandwiched between the gas diffusion layer and the catalyst layer,
A temperature sensor for a fuel cell, wherein an outer diameter is not more than 1/3 of a thickness of the gas diffusion layer. A temperature sensor for a fuel cell according to any one of claims 1 to 7,
In the fuel cell in which the gas diffusion layer is formed of carbon paper, the gas diffusion layer is mounted in a state sandwiched between the gas diffusion layer and the catalyst layer,
A temperature sensor for a fuel cell, wherein the outer diameter is 1/5 or less of the thickness of the gas diffusion layer.

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