JP2002255504A - Burner set for reformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner set for a reformer which keeps an operating state of a fuel cell system constant, keeping a reforming reaction in a reactor by preventing a fluctuation of a fuel supply condition due to a dew formation by using an unreacting exhaust gas from a fuel cell. SOLUTION: The unreacting exhaust gas from the fuel cell is supplied to a branch pipe, and heated with an endothermic member 16. When a combustion air which is supplied to an air preheat chamber 12 passes through a center reducing path 61, a fuel gas is mixed from the lower injection nozzle of the branch pipe, and this is passed through a second baffle plate 7 and a communicating tube 5, and is fired by supplying into a burner port. While heating the air in the air preheat chamber 12 by heat transferring the radiant heat of the flame in a combustion chamber 9 to a burner case and a burner cover, by transferring it from a burner plate 3 to the burner case and each communication tube, mixing chambers 10a, 10b, 11 are heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner device applied to a reformer used in a power generation system using a fuel cell, a cogeneration system, and the like. The present invention relates to a burner device for a reformer used to heat a reforming catalyst in the reformer by burning unreacted hydrogen-rich exhaust gas as a fuel gas.

[0002]

2. Description of the Related Art Conventionally, various fuel cell systems using a fuel cell for power generation and / or waste heat recovery have been proposed. This fuel cell system supplies anode gas containing hydrogen to the anode constituting the fuel cell,
A cathode gas containing oxygen is supplied to the cathode, and hydrogen and oxygen are electrochemically reacted to generate power.

As the anode gas, a hydrogen-rich reformed gas reformed and generated by a reformer is usually used. This reformer includes a reforming catalyst and a burner for heating the reforming catalyst with a combustion gas. In the reformer, a hydrogen-rich reformed gas is generated by a reforming reaction such as a steam reforming reaction using a fuel of a light hydrocarbon such as city gas, LPG or an alcohol such as methanol as a raw material. It has become.

In the above-mentioned burner for a reformer, the hydrogen-rich unreacted exhaust gas (unreacted reformed gas) discharged by the electrochemical reaction in the fuel cell is used as a part or all of the fuel gas. In general, the above-mentioned reforming catalyst is heated by burning the catalyst.

[0005]

However, since the unreacted exhaust gas used as the fuel gas is mainly composed of hydrogen and water vapor that are not used in the electrochemical reaction in the fuel cell, the water vapor concentration is low. High dew point temperature and tens of degrees Celsius
It has a high value. For this reason, if the unreacted exhaust gas is supplied to the burner for the reformer and burned, dew may be formed inside the burner and the fuel gas supply passage to the combustion unit may be blocked.

When the dew condensation occurs and the fuel gas supply passage tends to be blocked, the amount of fuel gas supplied to the combustion unit changes from the set value and the degree of heating of the reforming catalyst varies. become. When the endothermic reaction of the reforming catalyst fluctuates, the reforming reaction in the reformer decreases from the set reaction, and the reformed gas supplied to the fuel cell fluctuates. As a result, it becomes impossible to maintain a constant energy use such as power generation by the fuel cell system.

On the other hand, before introducing the unreacted exhaust gas into the burner, it is conceivable to heat it by a heating means such as an electric heater in advance outside. However, in this case, a new component is required for the heating means. In addition to this, there is a disadvantage that extra energy (electric power or the like) is required to operate the heating means.

The present invention has been made in view of such circumstances, and an object thereof is to use an unreacted exhaust gas from a fuel cell as a fuel gas for heating a catalyst of a reformer. To provide a reformer burner device capable of preventing a change in fuel supply conditions due to the occurrence of dew condensation, maintaining a constant reforming reaction in the reformer, and maintaining a constant operating state of the fuel cell system. It is in.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a reformer that burns hydrogen-rich unreacted exhaust gas discharged from a fuel cell as part or all of a fuel gas. A heat transfer means for heating the fuel gas by transferring the heat of combustion by the flame when the fuel gas is burned to the introduced fuel gas before the combustion, for a reformer burner device to be heated. This is a specific matter (claim 1).

According to the present invention, the heat of combustion of the fuel gas is transferred to the fuel gas introduced before combustion by the heat transfer means, and the fuel gas introduced to the burner device is heated. For this reason, even if the introduced fuel gas contains a large amount of water vapor, the above-mentioned heating makes it possible to prevent the occurrence of dew condensation inside the burner device and to maintain a constant combustion state. become. This makes it possible to maintain the combustion heating of the reforming catalyst of the reformer at a constant level and to maintain the supply of the reformed gas to the fuel cell at a constant level. As a result, it is possible to keep the electrochemical reaction in the fuel cell at a predetermined set state and to keep the energy utilization constant. In addition, since such an effect is obtained by utilizing the combustion heat generated by the burner device itself, energy can be efficiently used without requiring new energy.

As a more specific embodiment of the present invention, there is provided a flame hole in which a flame is formed, and a gas supply passage for supplying a fuel gas to the flame hole. One that is arranged so as to be able to directly or indirectly absorb the combustion heat of the flame of the flame hole portion, and is arranged so that the other portion can be transferred to the fuel gas in the gas supply passage. (Claim 2). In this case, a part of the heat transfer means absorbs the heat of combustion when the fuel gas is burned in the flame hole, and the absorbed heat is transferred from the other part of the heat transfer means to the fuel gas in the gas supply passage. , And the fuel gas introduced into the burner device is heated.

As the "heat transfer means" in the second aspect, various specific structures can be employed individually or in combination as described below.

First, as a first specific configuration, the heat transfer means is constituted by a burner case having a gas supply passage formed therein, and a wall portion exposed to a flame injected from a flame hole as the burner case. (Claim 3). In this case, since the wall of the burner case is exposed to the flame, the wall absorbs the radiant heat from the flame, and the absorbed heat is transferred to the gas supply passage through the burner case. Will be. Thus, the fuel gas introduced into the gas supply passage is heated.

In this case, the burner case further includes a burner cover disposed on an outer peripheral side of the burner case and an outer surface of the burner case with an annular space therebetween. The combustion air may be introduced to one side while the other side is communicated with a fuel gas mixing section in the gas supply passage. In other words, this is a case where a premixed combustion system in which combustion air is mixed in advance with fuel gas is employed. In this case, if the combustion air is introduced into the burner case so as to come into contact with the burner case, and the air heated by contacting the burner case is mixed with the fuel gas in the mixing section, the fuel gas is supplied to the gas supply passage. In addition to the heat transfer from the burner case that constitutes the above, the mixing with the heated air ensures more reliable heating.

According to a fourth aspect of the present invention, the burner case is formed of a material having a thermal conductivity higher than or equal to the thermal conductivity of the burner cover. It can be performed more effectively. Further, the burner cover according to claim 4 or 5 has a configuration in which the inner layer facing the annular space is formed of a clad material that is set to a material having a higher thermal conductivity than the outer layer. In this way (claim 6), the heat radiation from the burner cover to the outside can be suppressed, and the combustion heat of the flame can be effectively used for heating the fuel gas.

In a second specific configuration of the heat transfer means according to the second aspect of the present invention, the heat transfer means is constituted by a rod-shaped heat absorbing member, and a flame hole is formed through one end of the rod-shaped heat absorbing member. It is arranged such that it penetrates through the burner plate and protrudes into the combustion chamber, while the other end is brought into contact with the first piping member constituting the gas supply passage (claim 7). In this case, one end of the heat absorbing member absorbs the heat of combustion in the combustion chamber, and the absorbed heat is transmitted from the other end of the heat absorbing member to the first pipe member.
The fuel gas in the pipe member is heated.

Further, as a third specific configuration of the heat transfer means, the heat transfer means is constituted by a second pipe member constituting a gas supply passage, and a part of the second pipe member is provided with a flame hole. The burner plate is disposed in direct or indirect contact with the formed burner plate (claim 8).
In this case, the burner plate is heated by receiving the radiant heat from the flame in the flame hole, and the heat of the burner plate is absorbed by a part of the second pipe member in contact with the burner plate. Will be heated.

[0018]

As described above, according to the burner apparatus for a reformer according to any one of the first to eighth aspects of the present invention, the heat of combustion of the fuel gas is transferred by the heat transfer means. The fuel gas introduced into the fuel cell can be heated.
Even if the fuel gas introduced into the burner device by this heating contains a large amount of water vapor, it is possible to prevent the occurrence of dew condensation inside the burner device and eliminate the possibility of blockage of the passage, and to maintain a certain combustion state. Can be maintained. Thereby, it is possible to prevent the fluctuation of the combustion heating of the reforming catalyst of the reformer and keep it constant. For this reason, the supply of the reformed gas to the fuel cell can be kept constant, and as a result, the operating state of the fuel cell system can be kept at a predetermined set state. In addition, it is possible to save energy and increase the efficiency of heat utilization by utilizing the combustion heat generated by the burner device itself.

In particular, according to the second aspect, a specific structure for heating the fuel gas by transferring the combustion heat absorbed as the heat transfer means to the fuel gas in the gas supply passage is specified. The effect according to item 1 can be obtained more specifically.

According to the third aspect, in the second aspect, the radiant heat from the flame is reliably absorbed by the wall of the burner case, and the absorbed heat is transferred to the fuel gas in the gas supply passage through the burner case. The heat can be reliably transferred. As a result, the fuel gas introduced into the gas supply passage can be reliably heated, and the effect according to claim 1 can be reliably obtained.

According to a fourth aspect of the present invention, in addition to the heating of the fuel gas by the heat transfer from the burner case constituting the gas supply passage according to the third aspect, the air heated by contacting the burner case is supplied to the fuel gas. By mixing with the above, the heating of the fuel gas can be performed more reliably, and the effect according to claim 1 can be more reliably obtained.

According to the fifth aspect, the heat transfer performance of the burner case in the fourth aspect can be higher than that of the burner cover, and the heating of the fuel gas by the heat transfer of the combustion heat can be performed more effectively. it can. According to claim 6,
The heat radiation to the outside from the burner cover according to claim 4 or 5 can be suppressed, and the combustion heat of the flame to be transferred for heating the fuel gas can be efficiently and effectively used.

According to the seventh aspect, in the second aspect, the one end of the rod-shaped heat absorbing member as the heat transfer means surely absorbs the heat of combustion in the combustion chamber, and the absorbed heat is transferred to the other heat absorbing member. Heat can be transferred from the end to the first piping member. As a result, the fuel gas in the first piping member can be reliably heated, and the effect according to claim 1 can be reliably obtained.

Further, according to the present invention, the heat of the burner plate heated by the radiant heat from the flame at the flame hole can be surely absorbed by a part of the second pipe member as the heat transfer means. The heat absorption can heat the internal fuel gas. This also ensures that the effect of claim 1 can be obtained.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows a fuel cell system to which a burner device for a reformer according to an embodiment of the present invention is applied.
This will be briefly described with reference to an example shown in FIG.

The fuel cell system shown in FIG. 1 is a hydrogen-rich reformed gas generated by reforming a predetermined raw fuel gas in a reformer 200 as hydrogen required in a fuel cell 100 such as a polymer electrolyte fuel cell. On the other hand, in the burner device 300 or 300a for heating the reforming catalyst 201 of the reformer 200, the unreacted exhaust gas discharged from the fuel cell 100 is used as part or all of the fuel. It was made.

That is, the fuel cell 100 includes a cathode (air electrode) 101, an anode (hydrogen electrode) 102, and an electrolyte 103.
Then, a hydrogen-rich reformed gas is supplied to each of the anodes 102. In the fuel cell 100, power is generated by an electrochemical reaction between oxygen in the air and hydrogen in the reformed gas based on an electrochemical principle opposite to that of water electrolysis. Then, water generated by this reaction and a reformed gas containing unreacted hydrogen (unreacted exhaust gas) are discharged.

The generation of the hydrogen-rich reformed gas in the reformer 200 is performed as follows. That is, the raw fuel gas (for example, city gas) is supplied to the reformer 200 through the raw fuel gas supply pipe 203 in which the first flow control valve 202 is interposed.
Will be introduced. Before the introduction, the sulfur content in the raw fuel gas is desulfurized by a desulfurizer (not shown).
Steam from a steam supply source is mixed into the raw fuel gas through a steam supply pipe 204. And reformer 2
00, the reforming catalyst 201 is
Alternatively, the fuel is heated by the combustion heat from 300a, and the introduced fuel is steam-reformed based on the endothermic reaction of the reforming catalyst 201 to generate a hydrogen-rich reformed gas. The generated reformed gas is supplied to the anode 102 of the fuel cell 100 after CO (carbon monoxide) in the reformed gas is denatured and removed by the CO processor 205.

On the other hand, the burner device 300 or 300a
Then, combustion air is preliminarily mixed with the unreacted exhaust gas alone or the fuel gas in a state where the raw fuel gas (hereinafter, referred to as a city gas) is mixed with the unreacted exhaust gas. Burned. That is, the unreacted exhaust gas supplied from the fuel cell 100 through the exhaust gas supply pipe 301 and the second flow control valve 302 intervening on the way from the raw fuel gas supply pipe 203 upstream of the first flow control valve 202. The city gas supplied through the branched fuel supply pipe 303 is merged at the junction 305, and the fuel gas composed of only the unreacted exhaust gas or both is introduced into the burner device 300 or 300a. Then, air from the air supply pipe 304 is preliminarily mixed with the introduced fuel gas as described later, and a mixed gas in which the air is preliminarily mixed is burned (premixed combustion). The combustion exhaust gas generated by this combustion is passed through, for example, the inner and outer peripheries of the cylindrical reforming catalyst 201, so that the reforming catalyst 201 is heated.

The burner device 300 or 300a
The amount of city gas supplied to the fuel gas is changed and adjusted by adjusting the opening degree of the second flow control valve 302, whereby the mixing ratio of the city gas (including the state of 0%) in the fuel gas is changed and adjusted. Has become.

<First Embodiment> Next, a burner device 300 according to a first embodiment will be described with reference to FIG.

The burner device 300 includes a substantially cylindrical burner case 2, a thick disk-shaped burner plate 3 having a flame hole 31 formed therein, a bottomed cylindrical burner cover 4,
The first and second disc-shaped first and second communication pipes 5, 5,...
The baffle plates 6 and 7 and the branch pipe 8 are provided as main components, and are burned by a combustion method of premixed combustion and light-and-dark combustion. The “heat transfer means” of the present invention is achieved by the burner case 2, the burner plate 3, the burner cover 4, and the communication pipes 5 individually or cooperatively.
Function as

The burner case 2 has an upper cylinder part 21 and a mounting flange part 22 which are open upward, and are formed in an upper half part.
An outer cylinder part 23 and an inner cylinder part 24 which are smaller in diameter than the upper cylinder part 21 by a predetermined dimension and open downward are formed in a lower half part, and a partition wall part 25 for dividing the upper and lower parts is formed at an intermediate position in the vertical direction. Things. By attaching the mounting flange portion 22 to the reformer 200 together with the burner cover 4 described below, the burner device 300 is fixed to the reformer 200. The burner case 2 is integrally formed of a material having a higher thermal conductivity than the burner cover 4, for example, a high thermal conductive material such as aluminum or copper.

The partition wall 2 is provided inside the upper cylinder 21.
The lower surface of the outer peripheral side of the burner plate 3 is held in contact with the step formed at a position slightly above the burner plate 5, and is partitioned by the upper cylindrical portion 21 protruding above the burner plate 3 and the burner plate 3. Thus, a combustion chamber 9 communicating with the reformer 200 is formed. That is, the upper cylinder portion 21 is exposed to the flame from the flame hole portion 31 and forms a “wall portion” of the burner case 2 that surrounds the combustion chamber 9 and absorbs heat of combustion from the combustion chamber 9. A burner cover 4 is fitted on the outer peripheral surface of the upper cylindrical portion 21 from below with its inner peripheral surface in close contact with the outer cylindrical portion 23.
Is located at a position lower than the lower end position by a predetermined dimension.

The upper and lower dimensions of the inner cylindrical portion 24 are the same as those of the outer cylindrical portion 2.
3, the first baffle plate 6 is fixed to the outer cylindrical portion 23 so as to close the lower end opening thereof.
Further, a second baffle plate 7 is fixed to the inner cylindrical portion 24 so as to partition the outer peripheral space up and down while opening the lower end opening thereof. Then, the branch pipe 8 is moved from the center position of the bottom wall 41 of the burner cover 4 to the first baffle plate 6.
Center throttle passage 61 and center hole 71 of second baffle plate 7
Is fixed in a state of penetrating through. Thereby, the first
The light mixing chamber 10a is formed as an annular space between the flow dividing pipe 8 and the outer cylindrical portion 23 in the upper and lower ranges between the first and second baffle plates 6, 7, and the second light mixing chamber 10b is formed as the second baffle. It is formed as an annular space between the inner and outer cylindrical portions 23 and 24 at the upper position of the plate. The dense mixing chamber 11 is defined by the upper part of the distribution pipe 8 and the partition wall 25 in the inner cylindrical portion 24.

That is, the burner case 2 has a function of forming the mixing chambers 10 a, 10 b, and 11 therein, and also absorbs heat absorbed by the upper cylindrical portion 21 exposed to the combustion chamber 9. It also plays a role as a heat transfer medium for heating by transferring heat to fuel gas in 10a, 10b, 11 and air in an air preheating chamber 12, which will be described later.

An air supply pipe 304 is fixed to the lower outer peripheral surface of the burner cover 4 so as to communicate therewith, and an annular space between the lower inner peripheral surface of the burner cover 4 and the outer cylindrical portion 23; Combustion air is supplied from the air supply pipe 304 to the air preheating chamber 12 formed by the space between the bottom wall portion 41 of the burner cover 4 and the first baffle plate 6 and is filled. .

A junction 305 of the exhaust gas supply pipe 301 and the branch fuel supply pipe 303 is fixed to the bottom wall 41 of the burner cover 4 so as to communicate only with the branch pipe 8. The fuel gas is supplied to the branch pipe 8.

On the other hand, the partition wall 25 of the burner case 2
Each of the through holes is formed at a predetermined position determined in relation to the flame hole portion 31, and a lower end portion of the communication pipe 5 is fixed to each through hole in an internally fitted state, and an upper end portion thereof is connected to the burner plate 3. Is in close contact with the lower surface of the. Each communication pipe 5
Thereby, the second light mixing chamber 10b and a predetermined range of the flame hole 31 communicate with each other.

Next, the above components will be described in more detail with reference to FIGS.

The burner plate 3 is held by being fitted into a step 26 formed on the inner peripheral surface of the upper cylindrical portion 21 from above as shown in FIGS. The step 26 and at least the lower surface of the burner plate 3 are in close contact with each other, and the burner case 2
Heat is transmitted to the The step 2
The heat transfer property may be increased by closely adhering a thin sheet having both heat resistance and heat conductivity such as a graphite sheet between the burner plate 6 and the burner plate 3.

The burner cover 4 is constituted by a clad material in which a plurality of layers of different materials are laminated, and the clad material is formed by an inner layer 43 facing the air preheating chamber 12 and an outer layer 4.
It is formed of a material having better heat conductivity than 2. For example, in the example of the two-layer clad material shown in FIG. 3, steel is set as the material of the outer layer 42, and copper having good heat conductivity is set as the material of the inner layer 43. Thus, the combustion chamber 9
Heat is efficiently transmitted to the air preheating chamber 12 side through the burner case 2 and the inner layer 43 in a state where the heat absorption from the outside is suppressed to the outside and the air can be preheated.

The flame holes 31 formed in the burner plate 3 are composed of a large number of small-diameter flame holes penetrating vertically and arranged in a predetermined range as shown in FIGS. . That is, the flame hole 31 (see FIG. 4)
Is formed by continuously arranging a plurality of (eight in the example in the figure) unit flame holes 32 in which a large number of small-diameter flame holes are arranged in a donut annular range. The inner diameter of each communication pipe 5 is set to a size corresponding to the intermediate diameter of the inner and outer circumferences of the unit flame holes 32, and the communication pipes 5 are individually brought into close contact with the lower surface of each unit flame hole 32. Touched. Thus, the light mixed gas is supplied from the second light mixing chamber 10 b to each of the small-diameter flame holes only in the inner peripheral range of each unit flame hole portion 32 through each communication pipe 5. In FIG. 4, reference numeral 13 denotes flame temperature detecting means for detecting the temperature of the combustion flame from the flame hole 31. In the example of FIG. 4, a thermocouple enclosed in a sheath is used as the flame temperature detecting means. An ignition device (not shown) is provided at a position above the flame hole 31 of the burner plate 3.

The burner plate 3 and the burner case 2
A first partition plate 14 is fixed at an intermediate position in the vertical direction between the partition wall portion 25 and the partition wall portion 25, and the space between the burner plate 3 and the partition wall portion 25 is vertically partitioned by the first partition plate 14. ing. A plurality of ejection holes 141, 141,... Are formed in the first partition plate 14 at predetermined intervals so as to surround the communication tubes 5 at positions on the outer peripheral side of the communication tubes 5. Concentrated mixing chamber 1 with hole 141
The concentrated mixed gas supplied from 1 through the center hole 27 is ejected upward toward the small-diameter flame holes in the outer peripheral area of each unit flame hole portion 32. The rich mixing chamber 11
Are divided into upper and lower spaces by a second partition plate 14, and the upper and lower spaces are defined by the small holes 151, 1 of the second partition plate 15.
, Are communicated with each other.

The central throttle passage 61 of the first baffle plate 6
Is formed in an upwardly funnel shape by bending and raising the edge of the through hole in the center upward. The first discharge hole 81 of the branch pipe 8 faces the middle position in the vertical direction of the center throttle passage 61. , 81, ... are opened laterally. Also,
The upper end of the distribution pipe 8 enters the lower space of the concentrated mixing chamber 11 with the top surface closed, and faces the annular gap between the upper end of the distribution pipe 8 and the inner cylindrical portion 24. 8 are open laterally.

As shown in FIGS. 3 and 5, the second baffle plate 7 has a center hole 71 formed at the center thereof, and a plurality of cut-and-raised passages 72, at the outer peripheral side facing the second light mixing chamber 10b. 72 are formed. Each of the cut-and-raised passages 72 (see also FIG. 6) is opened on one side in the circumferential direction, so that the light mixed gas from the first light mixing chamber 10a is swirled to the second light mixing chamber 10b. So as to make the mixture flow even more evenly.

The first and second light mixing chambers 10a, 10a,
The “mixing section” of the present invention by the 10b and the rich mixing chamber 11
And the above-described mixing chambers 10a, 10b, and 11 defined by the flow dividing pipe 8 and the burner case 2.
The "gas supply passage" of the present invention is constituted by the communication pipes 5 as "second piping members".

In FIG. 3, 28a is a spacer ring for fixing the position of the first partition plate 14, 28b is a spacer ring for fixing the position of the second partition plate 15, 28c
And 28d are spacer rings for holding the second baffle plate 7 therebetween to fix the position.

The combustion operation of the burner device 300 having the above configuration will be described with reference to FIGS. First, fuel gas is supplied from the junction 305 to the distribution pipe 8, while combustion air is supplied from the air supply pipe 304 to the air preheating chamber 1.
2 is supplied. The air in the air preheating chamber 12 passes through the central throttle passage 61 of the first baffle plate 6 and the first light mixing chamber 10
flows into a. At the time of this inflow, the air is
From 2, it passes through the central throttle passage 61 having a passage cross-sectional area smaller than that, and flows again into the wide first light mixing chamber 10 a. Therefore, when passing through the center throttle passage 61, the fuel gas is ejected from the first ejection holes 81 of the branch pipe 8 in a direction orthogonal to the flow with respect to the flow of the air in the state where the circulation speed is high. In addition to being mixed with the air, the fuel gas and the air flow in a turbulent state into the first light mixing chamber 10a, so that the fuel gas and the air are further mixed to approach uniform mixing. .

What has flowed into the first light mixing chamber 10a is a light mixed gas.
1 flows into the rich mixing chamber 11, while the other part passes through the cut-and-raised passages 72, 72,.
It flows into the light mixing chamber 10b. Each cut-and-raised passage 72
The gas passes through and the swirl flow turns the light mixed gas.
Assured uniform mixing of air and fuel gas. Then, the uniformly mixed light mixed gas is supplied from each communication pipe 5 to a large number of small-diameter flame holes in the inner peripheral range of each unit flame hole portion 32, and burns as a light flame on the upper surface of the burner plate 3. Is done.

On the other hand, with respect to the light mixed gas flowing from the center hole 71 into the annular gap of the rich mixing chamber 11, the fuel gas is further injected from each second injection hole 82 of the branch pipe 8 in a direction orthogonal to the flow. And mixed to form a rich mixed gas. At this time, since the downstream side of the lower space of the rich mixing chamber 11 is narrowed by the second partition plate 15 to only the small holes 151, the fuel gas is sufficiently mixed. When the rich mixed gas passes through the small holes 151 of the second partition plate 15 and flows into the upper space of the rich mixing chamber 11, the mixing is made uniform. Then, the concentrated mixed gas is supplied from the center hole 27 through the ejection holes 141 of the first partition plate 14 to a plurality of small-diameter flame holes in the outer peripheral side of the unit flame hole portions 32. Burns as a rich flame.

When the fuel cell 100 is started, only the city gas is supplied to the burner device 300, and the burner device 300 is operated by using the city gas as a fuel gas.

In the above-described mixed-concentration combustion, the branch pipe 8
WI (Wobbe Index) and the supply pressure (primary pressure in the distribution pipe 8 upstream of each of the ejection holes 81 and 82) when the fuel gas supplied to the fuel cell is city gas and unreacted exhaust gas. Even in the case of a mixture of two kinds of gases which are greatly different from each other, the secondary pressure of each of the first ejection holes 81 (the pressure of the air flowing through the center throttle passage 61 downstream of the first ejection holes 81) and the 2 Secondary pressure of the ejection hole 82 (the center hole 71
And the pressure of the light mixed gas flowing into the rich mixing chamber 11). For this reason, the rich mixed gas generated by mixing the light mixed gas generated by mixing with the fuel gas ejected from each of the first jet holes 81 and the fuel gas jetted from each of the second jet holes 82. Each fuel gas concentration (mixing ratio) with the gas can be maintained substantially constant.

On the other hand, the upper cylindrical portion 21 and the burner plate 3 of the burner case 2 are heated by receiving the radiant heat from each of the above-mentioned dense and light combustion flames. The heat absorbed by the upper cylinder portion 21 is transmitted through the burner case 2 itself to the lower half outer cylinder portion 23 and the like, and is also transmitted to the burner cover 4 to the lower air preheating chamber 12 side. It is. At the same time, the heat of the burner plate 3 is transferred to the burner case 2 via the step portion 26 and also to each communication pipe 5. Then, the heat transfer heats the mixing section including the first and second light mixing chambers 10a and 10b and the rich mixing chamber 11, while the air in the air preheating chamber 12 is preheated (for example, about 100 ° C.). ). For this reason,
The fuel gas introduced through the branch pipe 8 is first heated by being mixed with the preheated air, and then heated in the mixing chambers 10a, 10b, 11 and the communication pipes 5.

Thus, even if unreacted exhaust gas containing a large amount of water vapor and having a high dew point is used as the fuel gas, it is possible to reliably prevent the occurrence of dew condensation, and to avoid the possibility of the passage being blocked due to the dew condensation. Can be. As a result, the reforming reaction in the reformer 200 can be maintained at the set state, and the electrochemical reaction in the fuel cell 100 can be reliably maintained in the set state.

Further, since the heat of the burner plate 3 is consumed for heating the fuel gas and the combustion air as described above, overheating of the burner plate 3 is prevented and unreacted exhaust gas is used. This can prevent the occurrence of flashback.

<Second Embodiment> FIGS. 7 and 8 show a burner device 300a according to a second embodiment of the present invention. The burner device 300a differs from the burner device 300 of the first embodiment only in that a heat absorbing member 16 is further added as one of the heat transfer means, and the other points are the burner device 300 of the first embodiment (FIG. 2 and FIG. 3).
Therefore, the same components are denoted by the same reference numerals as in the first embodiment, and detailed description thereof will be omitted.

The heat absorbing member 16 has a rod shape having a heat absorbing head 161 whose diameter is increased in the circumferential direction, a shaft portion 162, and a joint portion 163 having a threaded portion. Aluminum or the like). The heat-absorbing member 16 includes the center hole 33 of the burner plate 3, the first partition plate 14, and the partition wall 25.
The joint portion 163 is screwed into the top wall portion 83 of the branch pipe 8 'as a "first piping member" by passing through the center hole 27 of the second partition plate 15' and the center hole 152 of the second partition plate 15 '. It is joined by. As a result, the heat absorbing head 161 is exposed above the burner plate 3, and can absorb combustion heat from the flame in the combustion chamber 9.

As shown in FIG. 9, the heat absorbing head 161 is formed with a concave groove for engaging a fastening tool for the above-mentioned screw fastening. In the illustrated example, a straight concave groove is shown so that the tip of a (-) driver can be engaged, but a (+) shape may be used. Further, the shape may be a polygonal shape such as a hexagonal shape such as a hexagonal bolt head. The heat absorbing member 16 is screwed into the branch pipe 8 ′, so that the burner plate 3 can be more firmly fixed in addition to fixing the heat absorbing member 16.

When the heat absorbing head 161 is screwed and fastened, the heat absorbing head 17 is inserted between the heat absorbing head 161 and the burner plate 3 with the heat resistant packing 17 interposed therebetween. Gas leakage is prevented, and excessive generation of stress on the burner plate 3 due to thermal expansion or absorption of dimensional errors in manufacturing is prevented.

In the case of the second embodiment, the heating of the fuel gas is performed in addition to the same heating as that of the first embodiment via the burner case 2, the communication pipes 5 and the burner cover 4. Heating of the fuel gas on the upstream side as compared with the case of the first embodiment can also be performed.

That is, the flame hole 31 of the burner plate 3
The radiant heat of the flame from the heat absorbing head 1 of the heat absorbing member 16
61 directly absorbs heat, and the absorbed heat is transferred to the branch pipe 8 via the shaft 162 and the joint 163. As a result, the branch pipe 8 'itself is heated, and the fuel gas in the branch pipe 8', which is the most upstream among the fuel gases introduced into the burner device 300a, can be heated. In addition, by radiating heat from the shaft portion 162, it becomes possible to further promote heating of a rich mixed gas having a high fuel gas concentration.

As described above, in the second embodiment, the occurrence of dew condensation when using unreacted exhaust gas containing a large amount of water vapor as a fuel gas and having a high dew point can be more reliably prevented than in the first embodiment. It is possible to completely avoid the possibility of the passage being blocked due to dew condensation. As a result, the reforming reaction in the reformer 200 can be reliably maintained at the set state, and the electrochemical reaction in the fuel cell 100 can be reliably maintained at the set state.

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the second embodiment, and includes various other embodiments. That is, in the second embodiment, one end of the heat absorbing member 16 is screwed into the top wall portion 83 of the flow dividing pipe 8 'in a penetrating state as the joining portion 163, but the present invention is not limited to this. Good. Even in this case, the heat absorbed by the heat absorbing head 161 can be transferred to the branch pipe 8 'to heat the fuel gas.

In the second embodiment, the heat absorbing member 16
The junction 163 which is one end is the top wall 8 of the branch pipe 8 '.
3 is shown, but the present invention is not limited to this, and a configuration may be adopted in which a heat-dissipating member is provided as a heat-absorbing member, one end of which penetrates the internal space of the flow dividing tube 8 'and radiates heat. In this case, for example, as shown in FIG.
6 'may be configured. In this case, the heat radiating portion 164 is inserted into the diverting tube 8 ′ from a screw hole formed through the top wall portion 83 of the diverting tube 8 ′, and the joining portion 163 is screwed into the screw hole to form the heat absorbing member 16. 'May be fixed. By doing so, the heat absorbing head 16
1 is transferred to the shunt tube 8 'via the shaft portion 162 and the joint portion 163, and is also transferred to the radiator 164, and the heat is transferred from the peripheral surface of the radiator 164 to the shunt tube 8'. The heat is radiated to the fuel gas itself. Therefore, the fuel gas introduced into the burner device 300a can be heated at the most upstream side, and the occurrence of dew condensation in the burner device 300a can be more reliably prevented. The extension length of the heat radiating portion 164 may be set, for example, in a range up to a boundary position between the branch pipe 8 'and the merging portion 305, in addition to the example illustrated in FIG.

In the first and second embodiments, the reformer 2
Although the burner devices 300 and 300 'are attached upward to the lower part of 00, the invention is not limited thereto, and the burners may be attached sideways or downward.

In the first and second embodiments, in addition to the premixed combustion system in which the fuel gas and the air are mixed in advance,
Although the mixing degree of the fuel gas and the air is divided into two types of concentration and mixed to realize the concentration combustion method, the present invention is not limited to this. Only the combustion method may be realized. Also in this case, it is possible to similarly prevent the occurrence of dew condensation in the burner device based on the heating of the fuel gas before combustion described above.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a fuel cell system to which an embodiment of the present invention is applied.

FIG. 2 is an explanatory longitudinal sectional view showing the first embodiment.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a partially cutaway plan view of FIG. 2;

FIG. 5 is a plan view of a second baffle plate.

FIG. 6 is an enlarged sectional view taken along line AA of FIG. 5;

FIG. 7 is a diagram corresponding to FIG. 2, showing a second embodiment.

FIG. 8 is a partially enlarged view of FIG. 7;

FIG. 9 is a partially cutaway plan view of FIG. 7;

FIG. 10 is a diagram corresponding to FIG. 8, showing another embodiment of the second embodiment.

[Explanation of symbols]

 Reference Signs List 2 burner case (heat transfer means) 3 burner plate 4 burner cover 5 communication pipe (heat transfer means, second pipe member) 8 branch pipe (first pipe member) 9 combustion chamber 10a first light mixing chamber (mixing section) 10b Second light mixing chamber (mixing section) 11 Rich mixing chamber (mixing section) 12 Air preheating chamber (annular space) 16, 16 'Heat absorbing member 21 Upper cylinder section (wall of burner case) 32 Flame hole section 100 Fuel cell 200 Reformer 300, 300a Burner device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01M 8/06 H01M 8/06 GB (72) Inventor Akira Fujio 2-5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Akira Morimoto, Inventor 93, Edocho, Chuo-ku, Kobe, Hyogo Prefecture Inside Noritz (72) Inventor Hideo Ueda 93, Edocho, Chuo-ku, Kobe, Hyogo Stock Association In Noritz, Inc. (72) Inventor Masaya Yoshimura 93, Edocho, Chuo-ku, Kobe, Hyogo Prefecture Incorporated Noritsu (72) Inventor Takeshi Wakata 93, Edocho, Chuo-ku, Kobe, Hyogo Pref. Inventor Hirokazu Owatari 93, Edocho, Chuo-ku, Kobe City, Hyogo Prefecture Inside Noritz Co., Ltd. (72) Inventor Koji Kishio 93, Edocho, Chuo-ku, Kobe City, Hyogo Prefecture Co., Ltd. Ritsu in the F-term (reference) 3K017 DC02 DC04 3K068 AA02 AA03 AA05 AB05 AB21 AB36 4G040 EA02 EA03 EA06 EB03 EB44 EB46 4G140 EA02 EA03 EA06 EB03 EB44 EB46 5H027 AA02 BA01 BA09 BA19

Claims (8)

[Claims] 1. A reformer burner device for heating a reformer by burning hydrogen-rich unreacted exhaust gas discharged from a fuel cell as a part or all of a fuel gas, wherein the fuel gas is burned. A burner device for a reformer, comprising: heat transfer means for heating the fuel gas by transferring the heat of combustion by the flame at the time of the combustion to the fuel gas before combustion. 2. The burner device for a reformer according to claim 1, further comprising: a flame hole in which a flame is formed; and a gas supply passage for supplying a fuel gas to the flame hole. The means is arranged so that a part thereof can directly or indirectly absorb the heat of combustion with respect to the flame of the flame hole, while the other part can transfer heat to the fuel gas in the gas supply passage. The burner device for the reformer, which is provided in the company. 3. The burner device for a reformer according to claim 2, further comprising a burner case having a gas supply passage formed therein as the heat transfer means, and the burner case is injected from a flame hole. A burner device for a reformer, comprising a wall exposed to a flame. 4. The burner device for a reformer according to claim 3, further comprising: a burner cover disposed on an outer peripheral side of the burner case and an outer surface of the burner case with an annular space therebetween. A burner device for a reformer, wherein combustion air is introduced into one side of the annular space, and the other side is communicated with a mixing portion with fuel gas in a gas supply passage. 5. The burner device for a reformer according to claim 4, wherein the burner case is formed of a material having a heat conductivity higher than or equal to the heat conductivity of the burner cover.
Burner device for reformer. 6. The reformer burner device according to claim 4, wherein the burner cover is made of a plurality of layers, and the inner layer facing the annular space has a higher thermal conductivity than the outer layer. A burner device for a reformer, which is formed of a clad material set in (1). 7. The burner device for a reformer according to claim 2, further comprising a rod-shaped heat absorbing member as a heat transfer means, wherein the rod-shaped heat absorbing member has a burner plate having a flame hole formed at one end thereof. And the other end of the burner device is disposed so as to protrude into the combustion chamber while being in contact with the first pipe member constituting the gas supply passage. 8. The burner device for a reformer according to claim 2, further comprising a second pipe member constituting a gas supply passage as a heat transfer means, wherein a part of the second pipe member is a flame hole. A burner device for a reformer, which is disposed in direct or indirect contact with a burner plate on which a portion is formed.