JP4331578B2 - Steam reforming hydrogen production system - Google Patents

Description

  In the present invention, a combustion space is arranged in the center, and the first reformed gas cooling annular flow path and the first catalyst-filled annular flow path are continuously arranged vertically downward so as to surround the periphery concentrically. Further, the second catalyst-filled annular flow path and the third catalyst-filled annular flow path are arranged continuously downward in the vertical direction on the outer side, and the combustion gas flow path through which the combustion gas flows is further disposed on the outer side. In addition, a steam reforming type hydrogen production apparatus in which an evaporator is disposed outside, and a combustion space is disposed in the center, and an annular flow path for cooling the reformed gas is disposed so as to surround the periphery concentrically. Furthermore, the present invention relates to a steam reforming hydrogen production apparatus in which a catalyst-filled annular flow path is further disposed on the outer side, a combustion gas flow path through which combustion gas flows is further disposed on the outer side, and an evaporator is disposed on the outer side.

  In general, the hydrogen supplied to the hydrogen electrode in the fuel cell is formed by, for example, a steam reforming type hydrogen production apparatus that reacts a raw fuel such as natural gas or kerosene with water vapor to generate hydrogen with a catalyst.

  In such a steam reforming type hydrogen production apparatus, a reforming catalyst heating burner is provided at the center of the reforming apparatus, and concentric circles are formed from the inside to the outside so as to surround the reforming catalyst heating burner. Generally, it is composed of a reaction tube having a folded flow path for raw fuel gas reforming that is filled with a reforming catalyst.

  With such a configuration, it is possible to efficiently transmit thermal energy necessary for generating hydrogen from raw fuel gas and water vapor to the reforming catalyst layer.

  On the other hand, the combustion gas that gave thermal energy to the reformed gas and lost its own thermal energy still retains a lot of thermal energy, effectively recovering this exhaust heat energy and reducing the amount of fuel gas For this reason, a steam reforming type hydrogen production apparatus has been devised.

As such a steam reforming type hydrogen production apparatus, a reaction tube having a folded flow path for raw fuel gas reforming that is concentrically filled from the inside to the outside so as to surround the periphery of the burner. Further, there is a steam reforming type hydrogen production apparatus in which a steam necessary for reforming and a preheating pipe for preheating combustion air are arranged (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 02-129001

  By the way, in the steam reforming type hydrogen production apparatus described in Patent Document 1 described above, there is no particular description about the preheating function of the raw fuel gas. However, in configuring the system, it is necessary to incorporate the preheating function in some form. is there.

  Therefore, for example, in the case of using the steam reforming type hydrogen production apparatus described in Patent Document 1 described above in a polymer electrolyte fuel cell system, a method of separately installing a preheating device can be considered. However, in this case, the number of devices constituting the system increases and the size of the entire system becomes a problem.

  In addition, the water vapor required for producing hydrogen by the steam reforming hydrogen production apparatus is conventionally supplied by evaporating an amount of water larger than the required amount of vapor to the evaporator to evaporate the gas-liquid two-phase flow. In the state, it was led to the gas-liquid separator, and after the steam and water were separated and the amount of steam was adjusted, it was mixed with the raw fuel. However, in such a polymer electrolyte fuel cell system, the gas-liquid separator is often large, and the entire system cannot be made compact.

  The present invention has been made in view of the above circumstances, and is a compact steam reforming type hydrogen production united with a raw fuel gas preheating device and an evaporator for generating steam necessary for steam reforming. The object is to obtain a device.

In the present invention, a combustion space is arranged in the center, and the first reformed gas cooling annular flow path and the first catalyst-filled annular flow path are continuously arranged vertically downward so as to surround the periphery concentrically. And the second catalyst-filled annular flow path and the third catalyst-filled annular flow path are continuously arranged vertically downward on the outer side, and the combustion gas flow path through which the combustion gas flows is further disposed on the outer side. Further, in the steam reforming type hydrogen production apparatus in which an evaporator is further arranged outside, a raw fuel preheating annular passage disposed on the second catalyst-filled annular passage, and a preheating annular passage thereof And a second reformed gas cooling annular flow path disposed adjacent to the inside of the first reformed gas cooling annular flow path and in a vertical direction of the first reformed gas cooling annular flow path, and the first reformed gas cooling annular flow. Combustion is performed between the passage and the combustion space and in the second reformed gas cooling annular flow passage and the combustion space. And a heat insulating material disposed respectively between the outer shrink burner, fuel annular channel for the preheater original, the second catalyst packed annular flow path, the third catalyst packed annular flow passage, the The first catalyst-filled annular channel, the first reformed gas cooling annular channel, and the second reformed gas cooling annular channel are flowed in this order.

  In addition, a combustion space is arranged in the center, a reformed gas cooling annular flow path is arranged so as to surround the circumference concentrically, a catalyst-filled annular flow path is arranged on the outer side, and combustion is performed on the outer side. In a steam reforming type hydrogen production apparatus in which a combustion gas flow path through which a gas flows is arranged and an evaporator is further arranged outside of the combustion gas flow path, the evaporator is installed in an annular flow path through which the combustion gas flows and inside the annular flow path. And a spiral tube.

  In addition, a combustion space is arranged in the center, a reformed gas cooling annular flow path is arranged so as to surround the circumference concentrically, a catalyst-filled annular flow path is arranged on the outer side, and combustion is performed on the outer side. A steam reforming type hydrogen production apparatus in which a combustion gas flow path through which a gas flows is disposed and an evaporator is disposed outside thereof, and a heat insulating material provided between the combustion gas flow path and the evaporator It is.

  In addition, a combustion space is arranged in the center, a reformed gas cooling annular flow path is arranged so as to surround the circumference concentrically, a catalyst-filled annular flow path is arranged on the outer side, and combustion is performed on the outer side. In a steam reforming type hydrogen production apparatus in which a combustion gas flow path through which a gas flows is disposed and an evaporator is disposed outside the combustion gas flow path, the evaporator includes an annular flow path that is filled with water and an inside of the annular flow path And a spiral pipe flow path through which the combustion gas flows.

  In addition, a combustion space is arranged in the center, a reformed gas cooling annular flow path is arranged so as to surround the circumference concentrically, a catalyst-filled annular flow path is arranged on the outer side, and combustion is performed on the outer side. In a steam reforming hydrogen production apparatus in which a combustion gas flow path through which a gas flows is disposed and an evaporator is disposed outside the combustion gas flow path, the evaporator includes an annular flow path filled with water and an inner side of the annular flow path. It is constituted by a combustion gas annular flow path which is laid adjacently and through which the combustion gas flows.

  According to the present invention, since the preheating annular flow path having a low temperature is arranged outside the second reformed gas cooling annular flow path having a high temperature, it is possible to reduce heat radiation to the outside. Get.

  Also, the second reformed gas cooling annular channel is installed adjacent to the combustion burner close to the temperature level at which the reformed gas is desired to be cooled, so that it is less susceptible to internal heating and is effectively reformed. The effect that the gas can be cooled to a predetermined temperature is obtained.

  In addition, since the heat insulating material is installed between the combustion space and the first reformed gas cooling annular flow path, it flows into the first reformed gas cooling annular flow path from the combustion space, and the reformed gas There is also an effect that it is possible to reduce the amount of heat energy that causes the function of lowering the temperature to be hindered.

  Further, by installing the spiral tube in the combustion gas flow path, the evaporator can be provided integrally in the apparatus housing, and the apparatus can be reduced in size.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a polymer electrolyte fuel cell system according to an embodiment of the present invention.

  In the figure, the raw fuel is obtained by burning the fuel for combustion and hydrogen not used in the polymer electrolyte fuel cell described later, after being mixed with the steam discharged from the gas-liquid separator 1. The reformed gas is heated to become a hydrogen-rich (high-concentration hydrogen) reformed gas, which is sent to a CO remover 4 including a known shift reactor, partial oxidation reactor, and the like. Further, the combustion exhaust gas discharged from the steam reforming hydrogen production apparatus 3 is sent to the steam generator 5.

  In the CO remover 4, carbon monoxide, which is an impurity, is removed from the reformed gas discharged from the steam reforming hydrogen production apparatus 3, and then sent to the solid polymer fuel cell 6, where the solid polymer The fuel cell 6 generates power using the hydrogen gas received from the CO remover 4 and air, and the electric power obtained thereby is output. The anode exhaust gas (surplus hydrogen) of the polymer electrolyte fuel cell 6 is sent to the steam reforming hydrogen production apparatus 3 and combusted together with the combustion fuel.

  On the other hand, the combustion exhaust gas exiting the steam reforming hydrogen production apparatus 3 is transferred to the water by the evaporator 5 and then discarded outside the system. In addition, the vapor generated in the evaporator 5 is sent to the gas-liquid separator 1 in a gas-liquid two-phase state, and is separated into water vapor and water by the gas-liquid separator 1, and the water vapor passes through a path where it is mixed with the raw fuel. Sent out.

  Here, the shift reactor used for the CO remover 4 reacts carbon monoxide contained in the hydrogen-rich reformed gas after leaving the steam reforming hydrogen production apparatus 3 with steam, It has the function of converting to hydrogen and reducing the carbon monoxide concentration.

  Although the operating temperature of this shift reactor varies depending on the catalyst used, it is usually about 150 ° C to 300 ° C, and the hydrogen-rich reformed gas of 600 ° C to 700 ° C needs to lower the temperature. The steam reforming type hydrogen production apparatus has a folded flow path, and is devised to reduce the temperature itself while recovering heat in the reforming catalyst.

  FIG. 2 shows an example of a steam reforming hydrogen production apparatus according to an embodiment of the present invention. This steam reforming type hydrogen production apparatus has a cylindrical shape as a whole, and each component is roughly formed in a ring arranged concentrically.

  This steam reforming type hydrogen production apparatus is housed in a substantially cylindrical casing 10 made of a heat retaining material, and includes a preheating annular channel 11 through which a mixture of raw fuel gas and steam flows, and a raw material connected to the lower part thereof. A catalyst-filled annular flow path 12 filled with catalyst particles for converting fuel gas into hydrogen, a catalyst-filled annular flow path 13 connected to the lower portion of the catalyst-filled annular flow path 12, and a catalyst-filled annular flow path 13 are folded back. The catalyst-filled annular flow path 15 connected via the section 14, the reformed gas cooling annular passage 16 connected to the upper part of the catalyst-filled annular flow path 15, and the reformed gas cooling annular flow path 16 And a reformed gas cooling annular flow path 17 connected thereto.

  Further, the inner surface of the preheating annular channel 11 and the outer surface of the reformed gas cooling annular channel 17, the inner surface of the catalyst-filled annular channel 12 and the outer surface of the reformed gas cooling annular channel 16, and the catalyst-filled annular flow The inner surface of the channel 13 and the outer surface of the catalyst-filled annular channel 14 are installed adjacent to each other with a partition wall therebetween.

  Further, a combustion burner 18 disposed inside the reformed gas cooling channel 17, a combustion gas space 20 adjacent to the reformed gas cooling annular channel 16 and the heat insulating material 19, and a catalyst-filled annular channel. 15 adjacent to the partition wall, and adjacent to the radiant heat transfer section 21 through which the gas combusted in the combustion space 20 flows, the catalyst-filled annular channel 12 and the catalyst-filled annular channel 13 with a partition wall therebetween. A combustion gas passage 22 through which the combustion gas that has passed through the radiant heat transfer section 21 flows is provided.

An annular passage 24 through which the adjacent combustion gas flows is provided outside the combustion gas passage 22 via a heat insulating material 23. Inside the annular passage 24, water or water and steam are contained inside. A spiral tube 25 constituting the water vapor generator 5 that flows in a phase flow is laid. The discharge port 26 is for discharging the combustion gas that heated the spiral tube 25.

  Therefore, in the present embodiment configured as described above, the raw fuel of approximately 100 ° C. to 150 ° C. receives the thermal energy from the reforming gas cooling annular flow channel 17 in the preheating annular flow channel 11, For example, it is preheated to about 400 ° C.

  The preheated gas then flows into the catalyst-filled annular channel 12 and receives thermal energy transmitted from the reformed gas cooling annular channel 16 through the partition wall and thermal energy transmitted from the combustion gas channel 22 through the partition wall, For example, the temperature is raised to about 500 ° C., and a steam reforming reaction is caused, so that a part of the raw fuel is reformed into hydrogen, carbon monoxide, and carbon dioxide to become a mixed gas having a high hydrogen concentration.

  In this way, the fuel partially reformed to a gas having a high hydrogen concentration then flows into the catalyst-filled annular flow path 13 and receives the thermal energy from the combustion gas flow path 22 to receive the same steam reforming. It undergoes a quality reaction and is reformed into a gas mixture with a higher hydrogen concentration. At this time, the temperature is further increased to about 600 ° C., for example.

  Next, the mixed gas having an increased hydrogen concentration flows into the catalyst-filled flow path 15, receives thermal energy from the radiant heat transfer section 21, causes a similar steam reforming reaction, and has a predetermined hydrogen concentration. It is reformed to a mixed gas. At this time, the temperature of the mixed gas is increased to, for example, about 700 ° C.

Then, the high hydrogen concentration mixed gas exiting the catalyst-filled annular flow path 15 flows into the reformed gas cooling annular flow path 16 and gives thermal energy to the catalyst-filled annular flow path 12 to, for example, about 450 ° C. The temperature drops. At this time, the mixed gas having a high hydrogen concentration that passes through the first reformed gas cooling annular flow path 16 is heated from the combustion space 20, but since the heat insulating material 19 is interposed, the reformed gas is reformed from the combustion space 20. The amount of heat transferred to the gas cooling annular channel 16 can be reduced.

  The mixed gas that has exited the reformed gas cooling annular flow path 16 enters the reformed gas cooling annular flow path 17 and gives thermal energy to the preheating annular flow path 11, and the temperature drops to, for example, 280 ° C.

On the other hand, the fuel and air for combustion after passing through the burner 18 burn in the combustion space 20 to form a flame, become a combustion gas of about 1200 ° C. to 1300 ° C., flow to the radiant heat transfer section 21, and flow into the catalyst-filled annular flow path. The thermal energy is applied to 15 to lower the temperature, for example, reaches a temperature of about 800 ° C. and flows into the combustion gas passage 22.

  The combustion gas supplies thermal energy to the catalyst-filled annular flow path 13 and the catalyst-filled annular flow path 12 while flowing through the combustion gas flow path 22, and the temperature is lowered to 400 ° C to 500 ° C.

  Thereafter, the combustion gas flows into the annular flow path 24, gives thermal energy to the spiral tube 25, is cooled to about 100 ° C., and is discharged to the outside through the discharge port. Further, the moisture flowing into the spiral tube 15 receives heat from the annular channel 24, and all or a part thereof evaporates to become steam.

  Thus, in this embodiment, the preheating annular channel 11 and the reformed gas cooling channel 17 are disposed adjacent to each other, so that the raw fuel gas is heated to the minimum temperature at which the steam reforming reaction occurs. The function of increasing the temperature and the function of cooling the reformed gas can be performed at the same time, and heat radiation to the outside can be reduced.

  Further, the reformed gas cooling annular flow path 17 is installed adjacent to the combustion burner 18 close to the temperature level at which the reformed gas is desired to be cooled, so that the reformed gas is effectively prevented from being heated from the inside. Can be cooled to a predetermined temperature.

  Further, since the reformed gas cooling annular channel 16 and the catalyst-filled annular channel 12 are disposed adjacent to each other, the function of supplying heat necessary for the steam reforming reaction to the raw fuel gas, and the steam reforming reaction The function of lowering the temperature of the reformed gas that has been raised to cause the failure can be performed at the same time.

  Further, since the heat insulating material 19 is installed between the combustion space 20 and the reformed gas cooling annular flow path 16, it flows into the reformed gas cooling annular flow path 16 from the combustion space 20, and the reformed gas temperature. It is possible to reduce the amount of thermal energy that causes the hindrance to the function of lowering.

  Further, the annular flow path 24 and the spiral pipe flow path 25 installed in the annular flow path 24 convert the combustion exhaust gas having a temperature of about 400 ° C. to 500 ° C. into water inside the spiral pipe 15 or a mixture of water and steam. Thermal energy can be transmitted, and a function as an evaporator can be achieved by an apparatus integrated with the reformer, and a small steam reforming hydrogen production apparatus can be provided by integrating the evaporator. For example, when hydrogen is supplied to a fuel cell with a power generation output of 1 Kw class, the size of the casing 10 is 200 to 250 (mm) in diameter and about 350 to 400 (mm) in height. be able to.

  Further, since the heat insulating material 23 is installed between the annular flow path 24 and the combustion gas flow path 22, the combustion gas flow path is connected to a portion having the function of an evaporator constituted by the spiral pipe 25 and the annular flow path 24. Thus, the amount of heat energy directly transmitted from 12 can be reduced, and steam can be generated without hindering heat transfer from the combustion gas passage 22 to the catalyst-filled annular passage 12.

  FIG. 3 shows an example of a steam reforming hydrogen production apparatus according to another embodiment of the present invention. In the figure, the same or corresponding parts as those in FIG.

  In the present embodiment, an annular channel 26 that can pool water inside and adjacent to the outside of the combustion gas channel 22 via a heat insulating material 23 ′, and laid inside the annular channel 26. Is provided with a spiral tube 27 through which the combustion gas after passing through the combustion gas flow path 22 flows.

  Therefore, the preheating annular flow passage 11 and the reformed gas cooling annular flow passage 17 constitute a fuel preheating structure, and the annular flow passage 26 and the spiral tube 27 laid inside thereof constitute an evaporator. Therefore, in the polymer electrolyte fuel cell system shown in FIG. 1, the steam reforming hydrogen production apparatus 3 can have the functions of the preheater 1, the evaporator 5, and the steam / water separator 1. The entire system can be made compact.

  FIG. 4 shows an example of a steam reforming hydrogen production apparatus according to still another embodiment of the present invention. In the figure, the same parts as those in FIG. 3 and the corresponding parts are denoted by the same reference numerals, and the description thereof is omitted.

  This embodiment has a structure in which the embodiment shown in FIG. 3 is installed upside down.

  Therefore, since the combustion gas flows from the bottom to the top in the spiral tube 27, the water can be heated with the high-temperature gas even when the water level of the pooled water in the annular flow path 26 is lowered. The heat of can be used for effective evaporation.

  FIG. 5 shows an example of a steam reforming hydrogen production apparatus according to still another embodiment of the present invention. In the figure, the same or corresponding parts as those in FIG.

  In the present embodiment, an annular channel 31 for pooling water is disposed adjacent to a combustion gas annular channel 32 through which combustion gas flows, and the annular channel 31 and the combustion gas annular channel 32 constitute an evaporator. is doing.

  Even with such a configuration, heat from the combustion exhaust gas flowing through the combustion gas annular passage 32 and having a temperature of about 400 ° C. to 500 ° C. is heated to water pooled in the annular passage 31 or a mixture of water and steam. Energy can be transmitted, and a function as an evaporator can be achieved by an apparatus integrated with the reformer. Thus, a small steam reforming type hydrogen production apparatus can be provided by integrating the evaporator.

1 is a block diagram showing a polymer electrolyte fuel cell system according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The schematic sectional drawing which showed an example of the steam reforming type hydrogen production apparatus concerning one Example of this invention. The schematic sectional drawing which showed an example of the steam reforming type | mold hydrogen production apparatus concerning the other Example of this invention. The schematic sectional drawing which showed an example of the steam reforming type | mold hydrogen production apparatus concerning further another Example of this invention. The schematic sectional drawing which showed an example of the steam reforming type | mold hydrogen production apparatus concerning further another Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Preheating annular flow path 12 Catalyst filling annular flow path 13 Catalyst filling annular flow path 14 Turn-up part 15 Catalyst filling annular flow path 16 Reforming gas cooling annular flow path 17 Reforming gas cooling annular flow path 18 Combustion burner 19 Thermal insulation material 20 Combustion space 21 Radiation heat transfer section 22 Combustion gas flow path 23 Thermal insulation materials 24, 26, 31 Annular flow path 25, 17 Spiral tube 32 Combustion gas annular flow path

Claims (7)

A combustion space is disposed in the center, and the first reformed gas cooling annular flow path and the first catalyst-filled annular flow path are continuously disposed vertically downward so as to surround the periphery concentrically; A second catalyst-filled annular flow path and a third catalyst-filled annular flow path are continuously arranged vertically downward on the outside, and a combustion gas flow path through which combustion gas flows is further arranged on the outside. In the steam reforming type hydrogen production apparatus in which the evaporator is arranged,
An annular flow path for preheating raw fuel disposed on the second catalyst-filled annular flow path;
A second reformed gas cooling annular channel disposed adjacent to the inner side of the preheating annular channel and disposed in a vertical direction of the first reformed gas cooling annular channel;
Between the first reformed gas cooling annular flow path and the combustion space, and between the second reformed gas cooling annular flow path and the outside of the combustion burner that performs combustion in the combustion space, respectively. With the heat insulating material arranged ,
Raw fuel is converted into the preheating annular passage, the second catalyst filling annular passage, the third catalyst filling annular passage, the first catalyst filling annular passage, and the first reformed gas cooling annular. A steam reforming type hydrogen production apparatus, characterized by flowing in the order of a flow path and the second flow path for cooling the second reformed gas. 2. The steam reforming hydrogen production apparatus according to claim 1 , wherein a heat insulating material is provided between the combustion gas flow path and the evaporator. The evaporator includes an annular flow path of flow of the combustion gas, steam reforming hydrogen generator according to claim 1, characterized in that it is constituted by a spiral tube that is placed inside the annular channel. 2. The steam reforming type according to claim 1 , wherein the evaporator is constituted by an annular flow path filled with water and a spiral tube flow path through which combustion gas is laid in the annular flow path. Hydrogen production equipment. The evaporator includes an annular flow passage which the water is filled, according to claim 1, wherein the formed by the combustion gas annular channel in which the combustion gas is laid adjacent to the inside of the annular channel flows steam reforming hydrogen production apparatus. The steam reforming type hydrogen production apparatus according to any one of claims 1 to 5 and the hydrogen-rich reformed gas generated by the steam reforming type hydrogen production apparatus are input and included in the reformed gas. A CO remover that removes carbon monoxide, which is an impurity, and a solid polymer fuel cell that generates power using hydrogen gas and air received from the CO remover and outputs the power. A polymer electrolyte fuel cell system. 6. A preheater that mixes and preheats steam and raw fuel, and a hydrogen-rich reformed gas is generated from a mixture of steam and raw fuel preheated by the preheater. The steam reforming type hydrogen production apparatus and the hydrogen-rich reformed gas produced by the steam reforming type hydrogen production apparatus are input, and CO removal is performed to remove carbon monoxide, which is an impurity contained in the reformed gas. , A solid polymer fuel cell that generates electric power using hydrogen gas and air received from the CO remover and outputs the electric power, and combustion exhaust gas discharged from the steam reforming hydrogen production apparatus A solid polymer type comprising: an evaporator for generating water; and a gas-liquid separator for separating water vapor flowing from the evaporator into gas and liquid and sending the water vapor to the preheater to be mixed with raw fuel Fuel cell system

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