JP4857803B2 - Hydrogen generator - Google Patents

Description

  The present invention relates to a hydrogen generator for a fuel cell system that provides a configuration for improving the durability of a CO sensor.

Conventionally, this type of CO sensor is provided to detect the CO concentration in an exhaust passage through which combustion exhaust gas from a burner such as a gas water heater flows, and a storage space in which the CO sensor is stored and an internal space of the exhaust passage. A diffusion limiter that allows only a minute amount to pass through the combustion exhaust gas and an opening that supplies the storage space with air and allows the combustion exhaust gas in the storage space to be discharged to the outside. The CO sensor dilutes the combustion exhaust gas with air. Some devices are configured to detect the CO concentration in the generated state. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 08-233261

  However, the conventional configuration aims to stabilize the detection output by reducing the flow rate of the combustion exhaust gas relative to the CO sensor, and to prevent the deterioration of the detection capability by reducing the flow rate of the combustion exhaust gas. Since the CO sensor is configured on the assumption that it is disposed in the combustion exhaust gas such as a gas water heater, it is designed to withstand the temperature of the combustion exhaust gas.

Therefore, if the CO sensor is disposed in the passage through which the combustion exhaust gas of the combustion device for heating the hydrogen generator of the fuel cell system passes, the hydrogen generator is cooled (in the reforming section of the hydrogen generator when the hydrogen generator is stopped). (It is necessary to quench quickly so that carbon does not deposit on the reforming catalyst and deteriorate), and when the post-purge operation necessary is performed, the temperature becomes higher than the combustion exhaust gas of a gas water heater, etc. As a result, the CO sensor is heated by the exhaust air for use, and the components of the CO sensor are deformed by heat, and an accurate detection output cannot be obtained.
The present invention solves the above-mentioned conventional problems, prevents the temperature increase of the CO sensor, prevents deformation and deterioration of the components of the CO sensor, and detects the combustion failure of the combustion device by the CO sensor over a long period of time. An object of the present invention is to provide a hydrogen generator that can perform with high accuracy.

In order to solve the conventional problems, a hydrogen generator according to the present invention includes a reforming unit that generates a product gas containing hydrogen by a reforming reaction of a hydrocarbon-based raw material, and a combustion apparatus provided in the reforming unit. when a CO sensor for component detection of the combustion exhaust gas of the combustion apparatus, when performing the cooling of the combustion apparatus is stopped before Kiaratame transforming portion is provided by at least one of the air supply means and the blower means The hydrogen generator is provided with an air introduction unit for introducing air around the CO sensor and preventing an increase in temperature of the CO sensor.

  As a result, when the post-purge operation necessary for cooling the hydrogen generator is performed, fresh low-temperature air is introduced from the air introduction section around the CO sensor, and the exhaust air that has become hot is Therefore, it is possible to prevent the CO sensor temperature from rising and accurately detect the combustion failure of the heating combustion apparatus using the CO sensor over a long period of time.

  The hydrogen generator of the present invention can accurately detect the CO concentration of the combustion exhaust gas of the combustion apparatus using a CO sensor over a long period of time.

According to a first aspect of the present invention, there is provided a reforming unit that generates a product gas containing hydrogen by a reforming reaction of a hydrocarbon-based raw material, a combustion device provided in the reforming unit, and component detection of combustion exhaust gas of the combustion device a CO sensor for, the combustion apparatus when performing cooling of the stopped previous Kiaratame transforming portion, air that is supplied by at least one of the air supply means and the blower means around the CO sensor, wherein And an air introduction unit for preventing a temperature rise of the CO sensor, so that when the post-purge operation necessary for cooling the hydrogen generator is performed, a fresh low temperature is generated around the CO sensor from the air introduction unit. Exhaust air that has become hot due to the introduction of this air is excluded from the surroundings of the CO sensor, and the temperature rise of the CO sensor can be prevented, and combustion failure detection of the combustion apparatus can be accurately performed over a long period of time.

  In the second invention, in particular, the air introduction unit introduces air from upstream of the CO sensor mounting position in the exhaust duct to prevent the temperature of the CO sensor from rising, so that the combustion exhaust gas reaches the CO sensor. By diluting with air, the temperature of the combustion exhaust gas can be lowered uniformly, and the temperature rise of the CO sensor can be reliably prevented.

In the third aspect of the invention, in particular, the air introduction part enters the insertion passage by introducing air into the insertion passage provided for the CO sensor to face the exhaust duct and preventing the temperature of the CO sensor from rising. By eliminating the high-temperature combustion exhaust gas, it is possible to prevent the temperature of the insertion passage from rising, prevent deterioration of the packing of the CO sensor mounting portion, and maintain the combustion exhaust gas seal over a long period of time.
In the fourth aspect of the invention, in particular, the air introduction unit faces the CO sensor in the exhaust duct, introduces air into a sensor cap provided around the CO sensor to capture a part of the combustion exhaust gas, and the temperature of the CO sensor. By preventing the rise, the CO sensor is directly cooled by a small amount of air, and the temperature rise of the CO sensor is surely prevented, and the exhaust gas in the sensor cap is replaced and the surroundings of the CO sensor are periodically cleaned. Can do.

  In the fifth aspect of the invention, in particular, the air introduction unit introduces air until the temperature detection unit of the reforming unit decreases to a predetermined temperature, thereby applying the existing temperature detection unit and timing of introducing cooling air. Can be easily controlled, and the cost of new parts can be prevented from increasing.

  In the sixth aspect of the invention, in particular, the air introduction unit can introduce air into the existing components of the fuel cell system by introducing the cooling air by the air blowing means of the combustion device. You can prevent up.

  In addition, since the blowing means of the combustion device is used, there is a surplus in the supply capability of the blowing pressure and the blowing amount, and predetermined cooling air can be introduced into the air supply pipe.

  In the seventh aspect of the invention, in particular, since the air introduction unit can maintain a constant amount of air by introducing the cooling air by the independent introduction air blowing means, the introduction air blowing means is simplified by the configuration and the control method. be able to.

  In addition, since dedicated air is supplied to the air introduction section, maintenance can be performed without affecting other parts of the fuel cell system when a failure occurs.

  In the eighth aspect of the invention, in particular, the air introduction unit introduces the cooling air by the selective oxidation air supply means of the selective oxidation unit of the hydrogen generator, thereby introducing air in the existing components of the fuel cell system. Therefore, a new cost increase can be prevented.

  Further, since the introduction of a predetermined amount of air can be maintained at a constant pressure by the selective oxidizing air means, the configuration and the control method can be simplified.

  In the ninth aspect of the invention, in particular, the air introduction unit can supply the cooling air to the existing components of the fuel cell system by introducing the cooling air of the selective oxidation unit via the air valve. Therefore, a new cost increase can be prevented.

  Further, since the supply of the cooling air is controlled by the temperature of the selective oxidation unit, it can be performed with a simplified configuration of opening and closing the air valve.

  In the tenth aspect of the invention, in particular, the air introduction section introduces the cooling air by the cathode air supply means for supplying air to the cathode of the fuel cell, thereby introducing the cooling air in the existing components of the fuel cell system. Since it can be performed, a new cost increase can be prevented.

  In the eleventh aspect of the invention, in particular, the air introduction unit can introduce the cooling air with the existing components of the fuel cell system by introducing the cooling air with the purge gas replacement air supply means of the fuel cell. Therefore, a new cost increase can be prevented.

  Also, the purge gas replacement air supply means is used only for purging the cathode (air electrode) of the fuel cell and is not active during power generation of the fuel cell, so it can be used effectively to introduce cooling air in the air supply pipe. Can be planned.

  In the twelfth aspect of the invention, in particular, since the hydrogen generator is mounted on the fuel cell system, when the post-purge operation necessary for cooling the hydrogen generator is performed, the air introduction section is provided around the CO sensor. Introducing fresh low-temperature cooling air from the CO sensor to eliminate the high temperature exhaust air from the surroundings of the CO sensor, preventing the CO sensor temperature from rising, and detecting combustion failure in the combustion device for heating with the CO sensor over a long period of time Can be performed with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a hydrogen generator (reforming unit) according to the first embodiment of the present invention.

  In FIG. 1, 1 is a reforming unit that generates hydrogen to be supplied to a fuel cell system using city gas (or LPG or hydrocarbon fuel) as a raw material, and 2 is a treatment in a desulfurization apparatus (not shown). 3 is a raw material gas composed of city gas (or LPG or hydrocarbon fuel) and water vapor, and 3 is a catalyst layer filled with a catalyst mainly composed of nickel or ruthenium. Is subjected to a steam reforming reaction to produce a product gas 4 composed of hydrogen, carbon dioxide and carbon monoxide. Since this generation reaction is an endothermic reaction that occurs at a high temperature of about 700 ° C., the combustion gas is supplied from the combustion device 5 to heat the raw material gas 2 and the catalyst layer 3. A hydrogen generator 6 is configured by the reforming unit (not shown) and the selective oxidation unit (not shown) for removing carbon monoxide from the reforming unit 1 and the product gas 4.

The combustion apparatus 5, city gas 7 (or LPG) offgas 8 discharged from and the fuel cell (unreacted hydrogen gas), or city gas 7 (or LPG) and a mixture of off-gas 8, the distributor as a fuel gas 9 By ejecting from 10 and supplying air 12 from the periphery of the air ejection part 11, a flame 13 is formed and combustion is performed. A plurality of nozzles 14 for ejecting the fuel gas 9 are provided at the tip of the circular distributor 10 in the circumferential direction of the distributor 10 so that the fuel gas 9 is ejected radially. The air ejection part 11 is provided with a plurality of air ejection holes 15 at substantially right angles on the side surfaces of the air ejection part 11. The air ejection part 11 is configured to form a combustion chamber 16 in a cup shape so as to gradually expand in the direction of the outlet of the flame 13 around the distributor 10 and supply combustion air 12 into the combustion chamber 16. .

  The air ejection holes 15 are arranged in a staggered manner in the vertical direction. The nozzle 14 of the distributor 10 is disposed so as to be substantially opposed to the air ejection hole 17 provided at the lowest stage of the air ejection hole 15 of the air ejection section 11. In addition, a plurality of lower air ejection holes 18 are provided at the bottom of the air ejection section 11 so that a part of the air 12 is ejected in a direction parallel to the axial direction of the distributor 10.

  Reference numeral 19 denotes an air chamber that supplies the air 12, and configures a passage so as to surround the periphery of the air ejection portion 11. A blowing means 21 is provided upstream of the air chamber 19 via a blowing duct 20. The blower means 21 is constituted by a blower that supplies air 12, and a turbo fan, a radial fan, or the like that can generate a high pressure is used as the impeller, which is rotated by a motor. The air blower 21 is controlled by the controller 22.

  Reference numeral 23 denotes a combustion cylinder for avoiding the flame 13 generated by the combustion device 5 from directly touching the catalyst container 24 and further defining the flow path of the combustion gas 25. The combustion gas 25 flows along the periphery of the catalyst container 24 and is discharged to the outside of the reformer 1.

  An insertion passage 26 is provided in the center of the distributor 10 so as to penetrate the distributor 10. The insertion passage 26 is configured to be separated from the distributor 10, and the fuel gas 9 does not enter. An ignition electrode 27 is inserted into the insertion passage 26, and is composed of a heat-resistant Kanthal wire or an esit wire. The periphery of the electrode 27 is covered with an insulating insulator 28 for insulation. The insulator 28 is formed of a ceramic material such as heat-resistant alumina or silica, and the surface thereof is coated with a glaze made of a glass component. The tip of the electrode 27 faces the combustion chamber 16 and is positioned so that spark discharges fly to the top plate 29 of the distributor 10.

  Reference numeral 30 denotes flame detection means, which constitutes a frame rod with a heat-resistant Kanthal wire or an sweat wire, and detects the presence or absence of the flame 13. The periphery of the flame detection means 30 is covered with an insulating insulator 31 for insulation. The insulator 31 is formed of a ceramic material such as heat-resistant alumina or silica, and a glaze composed of a glass component is applied to the surface thereof. The tip of the flame detection means 30 faces the combustion chamber 16, bends with a curvature, and is positioned so as to face the flame 13 while having a predetermined gap along the inner wall of the air ejection portion 11. . The flame detection means 30 is mounted by extending the tip of the flame detection means 30 from the space 32 provided by expanding a part of the lower part of the combustion cylinder 23 provided at the upper part of the air ejection part 11, on the inner wall of the air ejection part 11. Along the way. In accordance with an instruction from the control unit 22, an alternating current or direct current voltage is applied to the flame detection means 30 to detect an ionic current in the flame 13. The data of the flame detection means 30 is determined as a voltage value or a current value.

  33 is an exhaust gas passage provided around the catalyst container 24, and an outlet 34 is provided above the reformer 1 so that the combustion gas 25 flows along the catalyst container 24. It is discharged outside as combustion exhaust gas 35. A cylindrical exhaust duct 36 is connected to the outlet 34. The other of the exhaust duct 36 is connected to a heat exchanger (not shown) to recover the heat of the combustion exhaust gas 35 and prevent a decrease in thermal efficiency.

  Reference numeral 37 denotes a CO sensor provided in the middle of the exhaust duct 36, which takes a part of the combustion exhaust gas 35 into a detection portion facing the exhaust duct 36 and directly measures the component.

Here, the configuration of the CO sensor 37 will be described with reference to FIGS. FIG. 2 (a) shows C
A circuit diagram of the O sensor is shown. The CO sensor 37 includes a CO detection element 38, a temperature compensation element 39, and two resistance elements 40 and 41 connected to a bridge circuit. The DC power source E is supplied between the connection portion and the connection portion between the temperature compensation element 39 and the resistance element 41, and is heated to a high temperature (about 200 to 400 ° C.) when a current flows. The CO detection element 38 and the temperature compensation element 39 constitute an alumina carrier on a platinum wire. In the CO detection element, the alumina carrier and an oxidation catalyst (for example, platinum or tin oxide) are sintered and contacted with the surface. The unburned gas is burned by the catalytic action. At this time, since the temperature compensation element 39 is made by sintering a mixture of alumina and glass on an alumina carrier so as not to be in contact combustion, there is a difference in element temperature between the CO detection element 38 and the temperature compensation element 39. Since the resistance value of the platinum wire changes depending on the temperature, the difference between the resistance values of the CO detection element 38 and the temperature compensation element 39 increases as the CO concentration in the combustion exhaust gas increases. As a result, the output value V corresponding to the CO concentration in the combustion exhaust gas 35 is output from the connection portion between the CO detection element 38 and the temperature compensation element 39 and the connection portion between the resistance elements 40 and 41 in the bridge circuit.

  FIG. 2B is a partially cutaway perspective view of the CO sensor. The CO sensor houses a CO detection element 38 and a temperature compensation element 39 in a case 42 made of metal (for example, stainless steel). The CO concentration is detected by receiving a part of the combustion exhaust gas 35 flowing in from the intake 43 of the combustion exhaust gas 35 opened in a part of the exhaust gas. A mesh-shaped lid is attached to the intake port 43 to prevent entry of dust, water droplets and the like. The CO detection element 38 and the temperature compensation element 39 are fixed in the case 42 by providing a pedestal 44 made of a heat-resistant resin material (for example, phenol resin), and supporting the platinum wire there. 38 and the temperature compensation element 39 are arranged so as to be exposed in the air. A partition 45 is erected from the pedestal 44 between the CO detection element 38 and the temperature compensation element 39, and the flow under the same conditions of the combustion exhaust gas 35 flows in parallel around the CO detection element 38 and the temperature compensation element 39. I am doing so. The pedestal 44 and the partition 45 are made of a resin material in order to insulate the platinum wire and improve the accuracy of the shape.

  Further, in FIG. 1, the CO sensor 37 instructs to stop the combustion apparatus 5 by stopping the supply of the fuel gas 9 when the CO amount exceeds a predetermined threshold value and it is determined that the combustion state is poor. Yes. When the CO sensor 37 is attached to the exhaust duct 36, a detection portion at the tip thereof is inserted into the exhaust duct 36, and a signal or power connection portion is exposed to the outside to promote heat dissipation and prevent a temperature rise. . The CO sensor 37 is mounted on the exhaust duct 36 by using a packing 46 (for example, heat-resistant Teflon (registered trademark)) between a part of the case 42 of the CO sensor 37 and the outer periphery of the exhaust duct 36. ) And is fixed with a belt (not shown) or the like.

  Reference numeral 47 denotes an air introduction part communicating with the exhaust duct 36 in the middle, and introduces cooling air 49 into the exhaust duct 36 from the blower means 21 via the blower pipe 48. The air introduction portion 47 is provided upstream of the CO sensor 37 mounting portion of the exhaust duct 36 (upstream of the flow of the combustion exhaust gas 35. For example, when the combustion exhaust gas 35 is rising, the air introduction portion 47 is provided below the CO sensor 37. Will be). An on-off valve 50 is provided in the middle of the blow pipe 48, the combustion device 5 is stopped, the on-off valve 50 is opened in accordance with the post-purge operation of the hydrogen generator 6, and the cooling air 49 is introduced into the exhaust duct 36. Then, the hot exhaust air 51 discharged by the post-purge operation is diluted to reduce the temperature to the allowable temperature limit for the CO sensor 37. The on-off valve 50 is constituted by an electric valve or a damper.

52 is a temperature detection unit for detecting the temperature of the catalyst layer 3, and when the hydrogen generator 6 is operating,
The control unit 22 controls the ability of the combustion device 5 so that the temperature of the catalyst layer 3 is kept constant by the temperature detection unit 52. The temperature detection unit 52 is composed of a thermistor and a thermocouple. The temperature detector 52 measures the temperature of a part of the outer wall of the catalyst container 24 of the catalyst layer 3 in order to maintain the sealing property of the catalyst layer 3.

  53 is a heat insulating material provided around the reforming unit 1 in order to reduce the heat radiation of the reforming unit 1 and improve the thermal efficiency. The heat insulating material 53 is made of a heat resistant material such as glass wool or ceramic fiber.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when the hydrogen generator 6 is activated, the air blower 21 is operated by the control unit 22 to blow the combustion air 12. The air 12 passes through the blower duct 20 and flows into the air chamber 19, and is supplied to the combustion chamber 16 from the air ejection holes 15 of the air ejection section 11. Here, when the fuel gas 9 of the city gas 7 (or LPG or hydrocarbon fuel) having a different combustion speed or flow rate is ejected from the nozzle 14 of the distributor 10, the fuel gas 9 ejected radially from the distributor 10 is substantially opposed to the fuel gas 9. The air 12 supplied from the lowermost air ejection hole 17 collides and mixes. At this time, spark discharge is performed by the electrode 27 facing the combustion chamber 16 from the insertion passage 26 provided in the center of the distributor 10 so as to penetrate the distributor 10, and the fuel gas 9 is ignited. Although the fuel gas 9 flows in the direction of the opening of the air ejection part 11, since the shape of the air ejection part 11 is cup-shaped as shown in the figure, the flow path cross-sectional area of the fuel gas 9 continuously increases, As a result, the flow velocity of the fuel gas 9 is reduced, and a partially premixed flame 13 is generated and burned at a place where the flow velocity is equal to or lower than the combustion speed of the city gas 7. This combustion heats the catalyst layer 3 of the reformer 1 to promote the steam reforming reaction and generate the product gas 4.

  During power generation of the fuel cell system, off-gas 8 (unreacted hydrogen gas) discharged as the remainder of the product gas 4 supplied from the hydrogen generator 6 to the fuel cell (not shown) is used as the fuel gas 9. The catalyst layer 3 of the reformer 1 is heated to promote the steam reforming reaction.

  At this time, the CO concentration in the combustion exhaust gas 35 is continuously measured by the CO sensor 37, and the state of the flame 13 is evaluated. For example, when the air blower 21 is exhausted or the supply air is blocked, the flame 13 becomes short of air and generates CO, and the CO sensor 37 detects the signal and sends the signal to the controller 22. The control unit 22 determines that the combustion state of the combustion device 5 is defective when the signal exceeds a predetermined value (for example, a threshold signal corresponding to the maximum amount of CO emission defined by JIS or the like), and the combustion device 5 is instructed to stop. In addition, the control unit 22 instructs the hydrogen generator 6 and the fuel cell system to perform a stop operation. Further, even if the flame 13 becomes excessive in air due to a decrease in the supply amount due to a decrease in temperature or a supply failure of the fuel gas 9, the signal of the CO sensor 37 is similarly evaluated to determine the combustion state. Like to do. The flame detection means 30 measures the ionic current of the flame 13 and determines whether a predetermined data signal is obtained by the control unit 22 as a voltage value or a current value. If there is an abnormality, the combustion apparatus 5 is stopped. We are trying to ensure safety.

  When the hydrogen generator 6 is stopped, the combustion device 5 is stopped and the hydrogen generator 6 performs a post-purge operation. At this time, the opening / closing valve 50 provided in the middle of the blower pipe 48 is opened by the support of the control unit 22, a part of the air 12 is introduced from the blower duct 20 into the blower pipe 48, and the cooling air 49 is supplied from the air introduction part 47. Is supplied to the exhaust duct 36, and the hot exhaust air 51 discharged by the post-purge operation is diluted, and the temperature of the exhaust air 51 is lowered to the allowable temperature limit for the CO sensor 37. The controller 22 evaluates the temperature of the temperature detector 52 and introduces air until the temperature of the catalyst layer 3 of the hydrogen generator 6 is lowered to a predetermined temperature (for example, the temperature at which the carbon deposition of the catalyst layer 3 does not occur). Cooling air 49 is introduced from the portion 47 to prevent the temperature of the CO sensor 37 from rising.

  As described above, in the present embodiment, when the post-purge operation necessary for cooling the hydrogen generator 6 is performed, fresh low-temperature cooling air 49 is supplied from the air introduction unit 47 around the CO sensor 37. Since the exhaust air 51 that has been introduced and becomes hot is excluded from the surroundings of the CO sensor 37, the temperature of the CO sensor 37 is prevented from increasing, the deterioration of the CO sensor is prevented, and the combustion device 5 using the CO sensor 37 over a long period of time It is possible to accurately detect the combustion failure.

  Further, since the cooling air 49 is distributed from the air 12 when the post-purge operation is performed, the cooling air 49 can be increased by fully utilizing the capacity of the blower, and the temperature rise of the CO sensor 37 can be prevented.

  In addition, an on-off valve 50 is provided in the middle of the blow pipe 48, and the blow pipe 48 is closed except for the post-purge operation. Therefore, the combustion exhaust gas 35 during the operation of the combustion device 5 is prevented from flowing back to the blow pipe 48 and burned A decrease in the CO concentration detection accuracy of the exhaust gas 35 can be prevented.

  Further, since the temperature rise of the CO sensor 37 can be prevented, the components of the CO sensor 37 (for example, the pedestal 44 and the partition portion 45) are made of a resin material, and the insulation of the platinum wire and the improvement of the shape accuracy can be realized. Since the CO sensor 37 used for a gas water heater or the like can be used, the cost increase of developing the CO sensor 37 for the hydrogen generator 6 can be prevented.

  In addition, since the CO sensor 37 employs a contact combustion type, the hydrogen component in the combustion exhaust gas 35 is also sensitive, so the combustion state of the off gas 8 changes and a large amount of hydrogen in the fuel gas 9 is present. Even if it slips, it determines with the combustion failure of the combustion apparatus 5, and safety | security can be ensured.

  Further, since the flame detection means 30 determines the presence or absence of the flame 13, misfire due to a sudden change in the combustion state can be evaluated, and the time delay of the measurement of the CO sensor 37 is complemented to cope with a sudden change in the combustion state. be able to.

  In addition, a CO sensor 37 that detects a component of the flue gas 35 of the combustion device 5 and a control unit 22 that stops the combustion device 5 when the combustion state of the combustion device 5 can be determined to be defective from the signal of the CO sensor 37 are provided. Therefore, when the flame 13 becomes defective due to fluctuations in the combustion air 12 or the fuel gas 9, the CO sensor 37 can directly determine the components of the combustion exhaust gas 35 so that the poor combustion state can be determined. The combustion apparatus 5 can be stopped with high accuracy, and the safety of the hydrogen generator 6 (fuel cell system) can be ensured.

  Further, since the distributor 10 for injecting the fuel gas 9 in the peripheral direction and the air injection portion 11 for injecting the air 12 from the periphery toward the center so as to surround the distributor 10 are provided, the mixing of the fuel gas 9 and the air 12 is performed. The flame 13 can be shortened and the hydrogen generator 6 can be downsized.

  Further, since the nozzle 14 and the lowermost air ejection hole 17 are arranged substantially opposite to promote the mixing of the fuel gas 9 and the air 12, in this part, the hydrogen that is easy to burn and the combustion speed is high is the air. Mixing sufficiently, the flame 13 always maintains a stable state, and the characteristics of the combustion exhaust gas 35 can be improved.

  Further, since the air 12 is ejected from the position intersecting the fuel gas 9 from below through the lower air ejection hole 18, the mixing of the fuel gas 9 and the air 12 can be further improved. This air 12 not only improves the gas mixing, but also maintains the flame 13 even when the flow rate of the air 12 is relatively excessively supplied with respect to the flow rate of the combustion gas 9, thereby stabilizing the combustion. It has a great effect on conversion.

  Further, since the city gas 7 (or LPG or hydrocarbon fuel) or the different offgas 8 fuel returning from the fuel cell can be ejected from the nozzle 14 of the distributor 10, the configuration is simplified and the cost can be reduced.

  Further, since the city gas 7 (or LPG or hydrocarbon fuel) or the off gas 8 is always ejected from the distributor 10, the distributor 10 is cooled and is not overheated by the flame 13, and can be used for a long period of time.

  The signal is detected by the CO sensor 37 and sent to the control unit 22, and the control unit 22 sets a predetermined value (for example, a threshold value based on a signal corresponding to the maximum discharge amount of CO defined by JIS or the like). When exceeding, the combustion state of the combustion device 5 is determined to be defective and an instruction to stop the combustion device 5 is issued. However, the control unit 22 sets the signal of the CO sensor 37 to a value lower than a predetermined value, and the blowing unit 21. (For example, even if the CO value is lower than a predetermined value, the air 12 is increased to reduce the CO concentration, and this operation is repeated each time the CO concentration increases) If the CO sensor 37 exceeds the predetermined value at the time, the combustion device 5 may be stopped.

(Embodiment 2)
FIG. 3 is a cross-sectional view showing the hydrogen generator 6 in the second embodiment of the present invention.

  In FIG. 3, the air introduction part 47 introduces cooling air 49 from upstream of the CO sensor 37 mounting position in the exhaust duct 36 to prevent the temperature of the CO sensor 37 from rising.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the hydrogen generator 6 performs the post-purge operation, the on-off valve 50 provided in the middle of the blower pipe 48 is opened, and a part of the air 12 is introduced into the blower pipe 48 from the blower duct 20. Then, the cooling air 49 is introduced from upstream of the CO sensor 37 mounting position in the exhaust duct 36, and the exhaust air 51 flows into the CO sensor 37 after the temperature of the exhaust air 51 is decreased upstream of the CO sensor 37. Thus, the temperature rise of the CO sensor 37 is prevented.

  As described above, in the present embodiment, before the exhaust air 51 reaches the CO sensor 37, the exhaust air 51 is diluted with the cooling air 49 to uniformly lower the temperature of the exhaust air 51, thereby reliably increasing the temperature of the CO sensor 37. It is possible to prevent the deterioration of the CO sensor 37 and maintain the accuracy of CO concentration detection over a long period of time.

Moreover, since the air introduction part 47 is a simple structure which connects the ventilation duct 48 to the exhaust duct 36, it can also suppress a cost increase low.
In FIG. 3, the air introduction part 47 introduces the cooling air 49 until the temperature detection part 52 of the reforming part 1 falls to a predetermined temperature.
About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. The controller 22 stops the combustion device 5 and opens the on-off valve 50 provided in the middle of the blower pipe 48 before starting the post-purge operation of the hydrogen generator 6 to distribute a part of the air 12 from the blower duct 20. Then, the cooling air 49 is introduced into the exhaust duct 36. At this time, the temperature detection unit 52 of the catalyst layer 3 provided in the reformer 1 monitors the temperature of the catalyst layer 3 during the post purge, and the catalyst layer 3 has a predetermined temperature (when the hydrogen generator 6 is stopped) If the catalyst layer is left at a high temperature, carbon is deposited on the catalyst layer 3 and the catalyst deteriorates. Therefore, the post-purge operation is continued until it is necessary to rapidly cool to about 100 to 150 ° C. The hot exhaust air 51 discharged to 36 is diluted with cooling air 49 introduced from the air introduction portion 47 and cooled to prevent the temperature of the CO sensor 37 from rising.
As described above, in the present embodiment, the air introduction unit 47 introduces the cooling air 49 until the temperature detection unit 52 of the reforming unit 1 is lowered to a predetermined temperature, and therefore discharges it to the exhaust duct 36. The temperature of the exhaust air 51 can be reliably lowered, the temperature increase of the CO sensor 37 can be prevented, the deterioration of the CO sensor 37 can be prevented, and the accuracy of CO concentration detection can be maintained over a long period of time.
In addition, it is possible to easily control the timing of introducing the cooling air 49 by applying the existing temperature detection unit 52, and it is possible to prevent the cost increase factor of adding a new temperature detection component.
In FIG. 3, the air introduction unit 47 introduces the cooling air 49 by the blowing means 21 of the combustion device 5. The air introduction part 47 branches from the middle of the blower duct 20 that supplies the combustion air 12 to the combustion device 5 using the blower 21 via the blower pipe 48 and is connected to the exhaust duct 36.
About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

When the combustion device 5 is stopped and the hydrogen generator 6 performs the post-purge operation, the on-off valve 50 provided in the middle of the blower pipe 48 is opened, and a part of the air 12 is introduced into the blower pipe 48 from the blower duct 20. Then, cooling air 49 is introduced into the exhaust duct 36 through the blower pipe 48 to prevent the temperature of the CO sensor 37 from rising. At this time, the air blowing means 21 is controlled by the control unit 22 so as to send the cooling air 49 in addition to the air 12 necessary for the post-purge operation of the hydrogen generator 6.
As described above, in the present embodiment, the air introduction unit 47 introduces the cooling air 49 by the air blowing means 21 of the combustion device 5, so that the air blowing means 21 is an existing component of the fuel cell system. Since the cooling air 49 can be supplied, the structure is simple and a new cost increase can be prevented.

  Further, since the blowing means 21 of the combustion device 5 is used, there is a surplus in the ability of blowing pressure and blowing volume, and the predetermined cooling air 49 can be introduced into the air introduction portion 47. In addition, the thing of the shape of FIG. 1 has the same effect by the same effect | action.

(Embodiment 3)
FIG. 4 is a partial cross-sectional view showing the periphery of the CO sensor of the hydrogen generator 6 in the third embodiment of the present invention.

  In FIG. 4, the air introduction unit 47 introduces cooling air 49 into an insertion passage 54 provided to allow the CO sensor 37 to face the exhaust duct 36, thereby preventing the temperature of the CO sensor 37 from rising. The CO sensor 37 is attached to the attachment portion 55 of the insertion passage 54 by fixing the CO sensor 37 with a screw or the like via a packing 56 (for example, using a heat-resistant resin such as Teflon (registered trademark)). I have to. The insertion passage 54 is provided to improve the assemblability when the CO sensor 37 is mounted.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the hydrogen generator 6 performs the post-purge operation, the on-off valve 50 provided in the middle of the blower pipe 48 is opened, and a part of the air 12 is introduced into the blower pipe 48 from the blower duct 20. Then, the cooling air 49 is introduced into the insertion passage 54 provided in the exhaust duct 36 through the blower pipe 48, and the high temperature exhaust air 51 entering the insertion passage 54 is excluded, thereby the CO sensor in the insertion passage 54. The temperature rise of 37 is prevented.

  As described above, in the present embodiment, since the high-temperature exhaust air 51 that enters the insertion passage 54 is excluded, the temperature increase of the CO sensor 37 in the insertion passage 54 is prevented, and the deterioration of the CO sensor 37 is prevented. And the accuracy of CO concentration detection can be maintained over a long period of time.

  Further, by cooling the entire insertion passage 54, it is possible to prevent deterioration of the packing 56 of the attachment portion 55 of the CO sensor 37, and to maintain the seal of the combustion exhaust gas 35 for a long period of time.

(Embodiment 4)
FIG. 5 is a partial cross-sectional view showing the periphery of the CO sensor of the hydrogen generator 6 according to the fourth embodiment of the present invention.

  In FIG. 5, the air introduction unit 47 faces the CO sensor 37 to the exhaust duct 36, introduces cooling air into a sensor cap 57 provided around the CO sensor 37 in order to capture a part of the combustion exhaust gas 35, and The temperature rise of the sensor 37 is prevented. The sensor cap 57 is provided to suppress the flow rate when a part of the combustion exhaust gas 35 is taken into the CO sensor 37 and form a uniform flow. The sensor cap 57 is fixed to the insertion passage 54 with the CO sensor 37 through the packing 56 by close tightening.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the hydrogen generator 6 performs the post-purge operation, the on-off valve 50 provided in the middle of the blower pipe 48 is opened, and a part of the air 12 is introduced into the blower pipe 48 from the blower duct 20. Then, the cooling air 49 is introduced into the sensor cap 57 provided in the insertion passage 54 through the blower pipe 48, and the high-temperature exhaust air 51 entering the sensor cap 57 is excluded, so that the inside of the sensor cap 57 The temperature rise of the CO sensor 37 is prevented.

  As described above, in the present embodiment, since the cooling air 49 is introduced into the sensor cap 57, the CO sensor 37 is directly cooled by the cooling air 49 in a short time, and the temperature rise of the CO sensor 37 is surely prevented. can do.

In addition, since the combustion exhaust gas 35 remaining in the sensor cap 57 after the combustion device 5 in the sensor cap 57 is stopped is replaced with the cooling air 49, the surroundings of the CO sensor 37 are periodically cleaned, and variations in CO concentration detection are detected. Can be reduced.
(Embodiment 5)
FIG. 6 is a cross-sectional view of the hydrogen generator 6 in the fifth embodiment of the present invention.

  In FIG. 6, the air introduction unit 47 introduces cooling air 49 by an independent introduction air blowing means 58. The introduction air blowing means 58 is constituted by a blower that introduces cooling air 49, and a turbo fan, a radial fan, or the like that can generate a high pressure is used as an impeller, which is rotated by a motor. The control unit 22 controls the introduction air blowing means 58.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

When the combustion apparatus 5 is stopped and the post-purge operation of the hydrogen generator 6 is performed, the cooling air 49 is blown by the introduction air blowing means 58 along with the supply of the post-purge air 12 by the blowing means 21. The air is introduced from the air introduction portion 47 into the exhaust duct 36 via 48.
The controller 22 keeps the introduction air supply means 58 in a constant state with simple control such as turning on and off.

  As described above, in the present embodiment, the air introduction unit 47 can maintain a constant amount of air by introducing the cooling air 49 by the independent introduction air blowing unit 45, so that the introduction air blowing unit 58 is provided. It can be simplified by the configuration and the control method.

  In addition, since the cooling air 49 is independently introduced into the air introduction unit 47, replacement maintenance or the like can be performed without affecting other parts of the fuel cell system when a failure occurs.

  In addition, although the introduction air supply means 58 is comprised with an air blower, it is also possible to use the pump and booster which can take out a high voltage | pressure.

  In addition, when the combustion apparatus 5 is operating, it is also possible to provide an opening / closing valve 50 in the middle of the blow pipe 48 and close the blow pipe 48 so that the combustion exhaust gas 35 does not flow backward in the blow pipe 48.

When the combustion device is in operation, the introduction air blowing means 58 is operated so that the combustion exhaust gas 35 does not flow back into the blower pipe 48, and a constant cooling air 49 is always introduced from the blow pipe 48 into the exhaust duct 36. It is also possible.
(Embodiment 6)
FIG. 7 is a system diagram of the hydrogen generator in the sixth embodiment of the present invention.

In FIG. 7, the air introduction unit 47 introduces the cooling air 49 by the selective oxidation air supply means 60 of the selective oxidation unit 59 of the hydrogen generator 6. The hydrogen generator 6 includes a reforming unit 61 and a selective oxidation unit 59 for removing carbon monoxide from the reforming unit 1 and the product gas 4. The selective oxidation air supply means 60 supplies selective oxidation air 62 to the selective oxidation unit 59 to remove CO (oxidizes carbon monoxide to reduce its concentration) in the product gas 4. .
The selective oxidation unit 59 and the selective oxidation air supply means 60 communicate with each other through a selective oxidation air supply pipe 63.

  A selective oxidation air valve 64 is provided in the middle of the selective oxidation air supply pipe 63. The selective oxidation air valve 64 is constituted by an electric valve or a damper. A blowing pipe 48 is branched from a selective oxidizing air supply pipe 63 in the middle of the selective oxidizing air valve 64 and the selective oxidizing air supply means 60, and is connected to an air introduction part 47. With this configuration, the cooling air 49 is sent from the selective oxidation supply means 60 to the air introduction unit 47. The selective oxidation supply means 60 is configured by a pump, a booster, a blower or the like that can take supply pressure to supply the selective oxidation air 62.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion apparatus 5 is stopped and the post purge operation of the hydrogen generator 6 is performed, the selective oxidation supply means 60 is instructed by the control unit 22 in accordance with the supply of the post purge air 12 by the blower means 21. Cooling air 49 is introduced into the exhaust duct 36 from the air introduction part 47 through the selective oxidizing air supply pipe 63 and the blower pipe 48 and mixed with the exhaust air 51. At this time, the on-off valve 50 provided in the middle of the blower pipe 48 is opened. In addition, the selective oxidation air valve 64 is closed so that the cooling air 49 does not flow backward to the selective oxidation unit 59.

  When the combustion device 5 is operating, the selective oxidation air valve 64 is opened to supply the selective oxidation air 62 to the selective oxidation unit 59. At this time, the on-off valve 50 provided in the middle of the blower pipe 48 is closed so that the combustion exhaust gas 35 does not flow backward to the blower pipe 48. Thereafter, the selective oxidizing air supply means 60 supplies the selective oxidizing air 62 while power generation is performed by the fuel cell system.

  As described above, in the present embodiment, the air introduction unit 47 introduces the cooling air 49 by the selective oxidation air supply means 60 of the selective oxidation unit 59 of the hydrogen generator 6, so that the existing fuel cell system is installed. Since it is possible to introduce air with these components, it is possible to prevent a new cost increase.

Further, since the selective air supply means 60 can maintain the introduction of a predetermined amount of air at a constant pressure, the configuration and the control method can be simplified.
(Embodiment 7)
FIG. 8 is a system diagram of the hydrogen generator in the seventh embodiment of the present invention.

  In FIG. 8, the air introduction unit 47 introduces the cooling air 66 of the selective oxidation unit 59 through the air valve 65. The air valve 65 is configured by an electric valve or a damper. The introduction air blowing means 67 supplies the cooling air 66 of the selective oxidation unit 59 via the air valve 65. A cooling air supply pipe 68 is branched in the middle of a blow pipe 48 that communicates the introduction air blowing means 67 and the air introduction section 47. An opening / closing valve 50 is provided in the air supply pipe 48 between the point where the cooling air supply pipe 68 is branched and the air introduction part 47. The other of the cooling air supply pipes 68 communicates with a cooling air passage 69 provided around the selective oxidation unit 59. An air valve 65 is provided in the cooling air supply pipe 69 between the cooling air passage 69 and the blower pipe 48. In addition, in order to keep the temperature of the selective oxidation unit 59 within a predetermined temperature range, the control unit 22 controls the supply of the cooling air 66 by opening and closing the air valve 65. The introduction air blowing means 67 is constituted by a pump, a booster, a blower or the like that can take supply pressure to supply the cooling air 66. Reference numeral 70 denotes a temperature detection unit of the selective oxidation unit 59, which is a thermocouple or a thermistor.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the post-purge operation of the hydrogen generator 6 is performed, the on-off valve 50 is opened according to the instruction of the control unit 22 in accordance with the supply of the post-purge air 12 by the blower 21. Then, the cooling air 49 is introduced from the air introduction part 47 into the exhaust duct 36 by the introduction air blowing means 67 via the blow pipe 48 and mixed with the exhaust air 51. At this time, the air valve 65 is closed so that the cooling air 49 does not flow out into the cooling air passage 69 of the selective oxidation unit 59.

  When the combustion apparatus 5 is in operation, the control unit 22 measures the temperature of the selective oxidation unit 59 by the temperature detection unit 70, and when the temperature exceeds a predetermined range, the air valve 65 is opened and the cooling unit 5 is used for cooling. Air 66 is supplied to the cooling air passage 69. Thereafter, the cooling air 66 is supplied by the introduction air blowing means 67 while power generation is performed by the fuel cell system. Further, the cooling air 66 keeps the temperature of the selective oxidation unit 59 within a certain range by repeatedly closing the air valve 65 and opening and closing the air valve 65 when the temperature of the selective oxidation unit 59 decreases. I am doing so.

As described above, in the present embodiment, the air introduction unit 47 introduces the cooling air 49 by the introduction air blowing means 67 that supplies the cooling air 53 of the selective oxidation unit 59, whereby the fuel cell. Since existing components of the system can be used and shared, new cost increases can be prevented.

Further, the introduced air feed wind means 67, during operation of the combustion apparatus 5 is capable of easy control of supplying a constant air since the only supply of the cooling air 66 of the selective oxidizing unit 59, air inlet The cooling air 49 can be easily introduced into the portion 47.

  In FIG. 9, the air introduction part 47 introduces the cooling air 49 by the cathode air supply means 73 for supplying the cathode air 72 to the cathode 71 of the fuel cell. The cathode air supply means 73 is constituted by a blower, and uses a turbo fan, a radial fan, or the like that can generate a high pressure as an impeller, and rotates it with a motor. The control unit 22 controls the cathode air supply means 73. The cathode air supply means 73 communicates with the inlet 75 of the cathode 71 via the cathode air supply pipe 74. The blower pipe 48 is branched from the middle of the cathode air supply pipe 74, and a part of the cathode air 72 is introduced into the exhaust duct 36 from the air introduction part 47 as cooling air 49 and mixed with the exhaust air 51. The air on / off valve 76 is provided except that an air on / off valve 76 is provided in the middle of the cathode air supply pipe 74 between the branched portion of the blower pipe 48 and the inlet 75 of the cathode 71 and the cathode 71 requires the cathode air 72. Is closed so that the cooling air 49 does not flow backward to the cathode 71. An open / close valve 50 is provided between the point where the air supply pipe 74 branches from the cathode air supply pipe 74 and the air introduction part 47. While the combustion apparatus 5 is operating, the open / close valve 50 is closed and the cathode air 72 is The air inlet 47 is prevented from flowing out.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the post-purge operation of the hydrogen generator 6 is performed, the on-off valve 50 is opened according to the instruction of the control unit 22 in accordance with the supply of the post-purge air 12 by the blower 21. The cathode air supply means 73 introduces dilution air 49 into the exhaust duct 36 from the air introduction portion 47 via the air blowing pipe 48 and mixes it with the exhaust air 51. In the controller 22, when supplying the cathode air 72 to the cathode 57, the air opening / closing valve 76 is opened. When the cathode air 72 is not necessary for the cathode 71, the air on-off valve 76 is closed. When the combustion apparatus 5 is operating, the cathode air 72 is continuously supplied by the cathode air supply means 73, and at this time, the on-off valve 50 of the blower pipe 48 is closed.

As described above, in the present embodiment, the air introduction unit 47 can introduce the cooling air 49 by the cathode air supply means 73 that is an existing component of the fuel cell system, and thus has a simple configuration. This can prevent a new cost increase.
(Embodiment 9)
FIG. 10 is a system diagram of a hydrogen generator according to the ninth embodiment of the present invention.

In FIG. 10, the air introduction part 47 introduces the cooling air 49 by the replacement air supply means 78 of the purge gas 77 of the fuel cell. The replacement air supply means 78 is constituted by a pump, a booster, a blower or the like that can take supply pressure to push the purge gas 77 with the replacement air 79. The replacement air supply means 78 communicates with the inlet 75 of the cathode 71 through a replacement air supply pipe 80 that branches from the middle of the cathode air supply pipe 74. Thereby, the purge gas 77 in the cathode 71 is pushed out by the replacement air 79 supplied to the replacement air supply means 78, and the cathode 71 is filled with the replacement air 79. A replacement air valve 81 is provided in the middle of the replacement air supply pipe 80, and is opened during the discharge process of the purge gas 77 of the cathode 71 performed before or after the power generation of the fuel cell system. At other times, the replacement air valve 81 is closed. The blower pipe 48 is branched from a replacement air supply pipe 80 between the replacement air valve 81 and the replacement air supply means 78, and a part of the replacement air 79 is introduced into the exhaust duct 36 from the air introduction part 47 as cooling air 49. Thus, the temperature of the exhaust air 51 is lowered by mixing with the exhaust air 51. An on-off valve 50 is provided between a point where the blower pipe 48 branches from the replacement air supply pipe 80 and the air introduction part 47. The on-off valve 50 and the replacement air valve 81 are constituted by electric valves and dampers.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the post-purge operation of the hydrogen generator 6 is performed, the on / off valve of the blower pipe 47 is instructed by the control unit 22 in accordance with the supply of the post-purge air 12 by the blower 21. 50 is opened, and the cooling air 49 is introduced into the exhaust duct 36 from the air introduction part 47 through the blower pipe 47 by the replacement air supply means 78 and mixed with the exhaust air 51.

  In the control unit 22, the replacement air valve 81 is opened and the replacement air 79 is supplied to the cathode 51 during the discharge process of the purge gas 77 of the cathode 57 before or after the power generation of the fuel cell system. At other times, the replacement air valve 81 is closed, and when the post-purge operation is performed while the combustion apparatus 5 is stopped, the cooling air 49 is continuously supplied from the replacement air supply means 78 to the exhaust duct 36. To be introduced to.

  As described above, in the present embodiment, the air introduction unit 47 introduces the cooling air 49 by the replacement air supply means 78 of the purge gas 77 of the cathode 71, so that the replacement is an existing component of the fuel cell system. By sharing the air supply means 78, a new cost increase can be prevented.

Further, the replacement air supply means 78 is used only for the discharge process of the purge gas 77 of the cathode 71 of the fuel cell and is not activated during the power generation of the fuel cell, so that the cooling air 49 is introduced from the air introduction part 47. Therefore, it can be used effectively.
(Embodiment 10)
FIG. 11 is an overall configuration diagram showing a fuel cell system according to a tenth embodiment of the present invention.
In FIG. 11, when the air introduction part 47 is communicated with the exhaust duct 36 and the post-purge operation necessary for cooling the hydrogen generator 6 is performed, a fresh low temperature is generated around the CO sensor 37 from the air introduction part 47. The hydrogen generator 6 for introducing the cooling air 49 is mounted on the fuel cell system 82. The fuel cell system 82 includes a polymer electrolyte fuel cell 83, a hot water supply device (not shown), and the like.

  About the hydrogen generator 6 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the combustion device 5 is stopped and the post-purge operation of the hydrogen generator 6 is performed, the on / off valve of the blower pipe 47 is instructed by the control unit 22 in accordance with the supply of the post-purge air 12 by the blower 21. 50 is opened and cooling air 49 is introduced into the exhaust duct 36 from the air introduction part 47 and mixed with the exhaust air 51 to reduce the temperature of the exhaust air 51 that has become hot and prevent the temperature of the CO sensor 37 from rising. is doing.

  As described above, in the present embodiment, the temperature increase of the CO sensor 37 is prevented, and deterioration of the CO sensor 37 due to the high-temperature exhaust air 51 during the post-purge operation of the hydrogen generator 6 is prevented. Combustion failure detection of the combustion device 5 can be accurately performed over a period.

  Further, since the combustion failure of the combustion device 5 can be determined by the CO sensor 37, the generation of CO from the fuel cell system 82 can be prevented and safety can be ensured.

  As described above, the hydrogen generator according to the present invention introduces fresh low-temperature air from the air introduction part around the CO sensor at the time of post-purge to prevent the temperature of the CO sensor from rising, thereby detecting a combustion failure over a long period of time. Therefore, it can be applied to a heat source of a water heater or a heater.

Configuration diagram of a hydrogen generator in Embodiment 1 of the present invention (A) Circuit diagram of the CO sensor in the hydrogen generator of the present invention (b) Same as above, partially cut away perspective view of the CO sensor Sectional block diagram of the hydrogen generator in Embodiment 2 of the present invention Partial configuration diagram of a hydrogen generator in Embodiment 3 of the present invention Partial configuration diagram of a hydrogen generator in Embodiment 4 of the present invention Sectional block diagram of the hydrogen generator in Embodiment 5 of the present invention System diagram of hydrogen generator in Embodiment 6 of the present invention System diagram of hydrogen generator in Embodiment 7 of the present invention System diagram of hydrogen generator in Embodiment 8 of the present invention System diagram of hydrogen generator in Embodiment 9 of the present invention Configuration diagram of fuel cell system in Embodiment 10 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reformation part 4 Product gas 5 Combustion device 6 Hydrogen generator 35 Combustion exhaust gas 37 CO sensor 47 Air introduction part 48 Blower pipe 49 Cooling air 51 Exhaust air

Claims (11)

A reforming section that generates a product gas containing hydrogen by a reforming reaction of a hydrocarbon-based raw material;
A combustion device provided in the reforming unit, a CO sensor for detecting a component of combustion exhaust gas of the combustion device,
It said combustion device when performing the cooling of the stop before Kiaratame transforming portion, air that is supplied by at least one of the air supply means and the blower means around the CO sensor, temperature increase of the CO sensor an air introducing portion for preventing,
A hydrogen generator. 2. The hydrogen generator according to claim 1, wherein the air introduction unit introduces cooling air from upstream of the CO sensor mounting position in the exhaust duct to prevent a temperature increase of the CO sensor. 3. The hydrogen generator according to claim 1, wherein the air introduction unit introduces cooling air into an insertion passage provided to allow the CO sensor to face the exhaust duct to prevent a temperature increase of the CO sensor. 2. The air introduction unit faces a CO sensor in an exhaust duct, introduces cooling air into a sensor cap provided around the CO sensor in order to take in a part of combustion exhaust gas, and prevents an increase in temperature of the CO sensor. The hydrogen generator according to any one of -3. The hydrogen generator according to any one of claims 1 to 4, wherein the air introduction unit introduces cooling air until the temperature detection unit of the reforming unit decreases to a predetermined temperature. The hydrogen generator according to any one of claims 1 to 5, wherein the air introduction unit introduces cooling air by a blower of the combustion device. The hydrogen generator according to any one of claims 1 to 6, wherein the air introduction section introduces cooling air by an independent introduction air blowing means. The hydrogen generator according to any one of claims 1 to 7, wherein the air introduction unit introduces cooling air by a selective oxidation air supply means of a selective oxidation unit of the hydrogen generator. The hydrogen generator according to claim 1, wherein the air introduction unit introduces cooling air for the selective oxidation unit via an air valve. The hydrogen generator according to any one of claims 1 to 9, wherein the air introduction unit introduces cooling air by a cathode air supply unit that supplies air to a cathode of the fuel cell. The hydrogen generator according to any one of claims 1 to 10, wherein the air introduction unit introduces cooling air by means of a replacement air supply unit for purge gas of the fuel cell.

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