JP2000297908A - Catalytic combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the decease of thickness and optionality of the shape of a combustion device and to suppress lowering of activity of a catalyst, in a catalyst combustion device to effectively utilize a combustion reaction heat. SOLUTION: This device comprises a combustion chamber 7 having a catalyst body 11 to cause a base material having a plurality of communication holes to support an oxidation catalyst component; and a transmission window or a radiation heat receiving body 9 installed on a combustion chamber wall and made of a heat radiation transmissive material. A heat insulation layer 6 communicated with a flow passage in which air-fuel premixture flows and provided at an internal part with an air-fuel premixture hole 8 is installed on the transmission window of the combustion chamber 7 or a wall positioned facing the radiation heat receiving body 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion device which makes effective use of heat of combustion reaction. Mainly relates to the configuration of the catalytic combustion section.

[0002]

2. Description of the Related Art In a catalytic combustion apparatus using a catalyst having an oxidizing activity with respect to various fuels, a large number of proposals have hitherto been made as constitutions of a catalytic combustion section. Of these, a well-known method is known in which a premixed mixture of fuel and air is supplied to oxidize the catalyst mainly in the vicinity of the upstream surface of the catalyst body and exhaust the combustion exhaust gas through the communication hole of the catalyst body.

[0003]

The above-mentioned conventional catalytic combustion apparatus effectively utilizes radiant heat from the upstream surface of the catalyst body. In addition, since the radiant heat from the downstream surface of the catalyst body and the high-temperature exhaust gas discharged are used for heating the rear surface of the combustion device, it is necessary to separately provide air to lower the temperature of the rear surface of the combustion device. Since it is necessary to install a heat insulating layer or heat insulating material, and the combustion equipment tends to be large,
There is a problem that it is difficult to realize a thin catalytic combustion device. The radiant heat from the downstream surface of the catalyst body is
Eventually, radiation from the outer wall of the combustion device and heat loss due to natural convection are caused, so that there is a problem that radiant heat from the downstream surface cannot be effectively used. Furthermore, the catalytic oxidation reaction is mainly performed near the upstream surface of the catalyst, and the highest temperature region is formed at a position several millimeters downstream from the inlet of the catalyst, but most of the radiant heat from this region However, there is a problem that the radiant heat from the highest temperature region inside the catalyst body cannot be effectively used because the heat is not directly radiated from the opening of the catalyst body.

In the initial stage, the catalytic oxidation reaction mainly occurs near the upstream surface of the catalyst, but the activity gradually decreases from near the upstream surface, and the catalytic oxidation reaction mainly occurs inside the catalyst. When the process is performed, there is a problem that the temperature inside the catalyst body increases, so that the catalyst activity rapidly decreases. In addition, since the temperature of the catalyst body increases and decreases in accordance with the amount of fuel reacting on the surface of the catalyst body, the upper limit of the amount of combustion per unit cross-sectional area with respect to the catalyst body is limited to the amount of the active component carried on the catalyst layer. (For example, platinum group metals). Therefore, there is a problem that it is necessary to increase the cross-sectional area of the catalyst body in order to perform high-load combustion.

An object of the present invention is to solve the problems of such a conventional catalytic combustion device.

[0006]

In order to solve the above-mentioned problems, a first catalytic combustion apparatus of the present invention comprises a combustion chamber provided with a catalyst body and a transmission chamber made of a heat ray permeable material provided on a wall of the combustion chamber. A heat insulating layer having a window or a radiation heat receiving body, communicating with a flow path through which the premixed gas flows, and having a premixed gas communication hole therein is installed on a transmission window of the combustion chamber or a wall facing the radiation heat receiving body. It is characterized by:

[0007] In the second catalytic combustion device of the present invention,
The catalyst body is characterized in that the streamline of the premixed gas flowing out from the premixed gas communication hole and the streamline of the premixed gas flowing into the communication hole of the catalyst body are orthogonal to each other. Further, the invention is characterized in that a plurality of catalysts are arranged in the combustion chamber such that their upstream faces face each other.

In the third catalytic combustion device of the present invention,
The catalyst body has a structure in which a catalyst communication hole layer is stacked and arranged, and has a red-heat emission surface that is not covered by the catalyst communication hole layer adjacent to the upstream entrance, and a transmission window is formed in a combustion chamber wall facing the red-heat emission surface. Alternatively, a radiant heat receiver is provided. Further, the catalyst communication hole layer is characterized in that a flow path parallel to the streamline of the premixed gas flowing into the catalyst body is formed by a laminated arrangement of a flat plate and a corrugated plate.

Further, in the fourth catalytic combustion device of the present invention, the catalyst body comprises an upstream supporting layer in which the oxidation catalyst component is supported only in the vicinity of the upstream surface, and an oxidation catalyst only in the downstream side of the upstream supporting layer. It is characterized in that a downstream portion carrying layers carrying the components are alternately stacked. In addition, the catalyst body has a configuration in which a catalyst support layer supporting the oxidation catalyst component and an unsupported layer not supporting the oxidation catalyst component are alternately stacked, and the auxiliary catalyst body is disposed downstream of the catalyst body. It is characterized by:

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the practice of the present invention, a catalyst body having a large number of communication holes and having oxidation activity to various fuels,
In addition to heat-resistant heat ray transmitting materials, heat ray reflecting materials, metal catalysts with a large aperture ratio, ignition devices and flow rate control devices, fuel and air mixers, or liquid fuel vaporizers if necessary, temperature A detecting device, a driving device, and the like are required. The catalyst body is a metal or ceramic honeycomb carrier, or a ceramic fiber braided body, a porous sintered body, etc., on which an active component mainly composed of a noble metal such as platinum or palladium is supported. As the heat ray transmitting material, quartz glass or crystallized glass is used. A manual needle valve or an electric solenoid valve is used for controlling the flow rate of air or gaseous fuel, and an electromagnetic pump or the like is used for liquid fuel. Other driving parts are manual lever operation,
An automatic control motor drive or the like is possible, and an electric heater, a discharge igniter, or the like can be used as the ignition device. These are all means conventionally widely used, and other known means are also possible. Here, the description of those details is omitted.

(Embodiment 1) FIG. 1 is a partial sectional configuration view of an embodiment of a catalytic combustion apparatus according to the present invention. In FIG. 1, 1 is a fuel supply unit, 2 is a control valve for controlling the amount of injected fuel, 3 is an air supply fan, 4 is a fuel and air mixing chamber, 5 is a premixed air chamber, and 6 is a ceramic honeycomb. The heat insulating layer 7 is a combustion chamber. Here, the premixed gas chamber 5 and the combustion chamber 7 communicate with each other through a premixed gas communication hole 8. Reference numeral 9 denotes a radiation heat receiving body made of an aluminum plate, and a fin 10 for heat exchange is provided in a part thereof. Also, 11
Is a catalyst body in which a precious metal of white metal is supported on a ceramic honeycomb, 12 is an igniter composed of an electric heater, and 13 is a combustion exhaust gas outlet. Further, reference numeral 14 arranged outside the premixed gas chamber 5 via an air heat insulating layer is a combustion device case.

Next, the operation and characteristics of this embodiment will be described. The amount of fuel supplied from the pipe (here, city gas is used) is controlled by a control valve 2 and mixed with air supplied from an air supply fan 3 in a mixing chamber 4. Supplied to Further, the premixed gas of the fuel and the air supplied to the premixed gas chamber 5 is supplied to the combustion chamber 7 via the premixed gas communication hole 8 arranged in the heat insulating layer 6.

In the initial stage of combustion, the premixed gas that has passed through the communication hole of the catalyst body 11 is ignited by energizing the igniter 12, and flame combustion starts near the downstream of the catalyst body 11. The catalyst body 11 heated by the flame first raises the temperature in the vicinity of the downstream surface and starts catalytic combustion here, and further heats the upstream side by the combustion heat. Transition to catalytic combustion occurs, and the upstream surface of the catalyst body 11 reaches a red-hot state at 800 to 900 ° C. In the steady combustion, the temperature of the upstream surface of the catalyst body 11 is 800 to 900 ° C.
The temperature of the downstream surface is 500 to 700 ° C., although it depends on the thickness of the catalyst body 11 and the like. At this time, 50 to 60% of the reaction heat amount of the fuel is radiated to the upstream side of the catalyst body 11, 21 to 30% is radiated to the downstream side, and the remaining amount is discharged as the heat amount of the combustion exhaust gas. .

Among them, a part of the radiant heat to the upstream side of the catalyst body 11 is directly absorbed by the radiant heat receiver 9 and is diffused by conduction in the radiant heat receiver 9 made of an aluminum plate having a high thermal conductivity. Thereafter, the radiation is radiated from the radiation heat receiving body 9 to the outside. Also,
A part is absorbed in the premixed gas communication hole 8 constituted by the ceramic honeycomb, and then is radiated again to the radiant heat receiver 9 or is used for heating the premixed gas passing through the premixed gas communication hole 8. It is supplied and refluxed to the catalyst body 11. Further, heat rays are also emitted to the opposed catalyst body 11, and about 80% or more is absorbed and used for heating the opposed catalyst body 11. The amount of increase in the amount of radiant heat from the opposed catalyst body 11 that has been heated by such heating is reduced again by the catalyst body 8.
Refluxed.

On the other hand, about 50% of the radiant heat to the downstream side of the catalyst body 11 is directly absorbed by the radiant heat receiver 9 and diffused through the radiant heat receiver 9 made of an aluminum plate having a high thermal conductivity. Thereafter, the radiation is radiated from the radiation heat receiving body 9 to the outside. Also,
Heat rays are also emitted to the wall of the combustion chamber 7 on the heat insulating layer 6 side. Part of this radiant heat is reflected by the wall of the combustion chamber 7 on the heat insulating layer 6 side, and then absorbed by the radiation heat receiving body 9, and part of the radiant heat passes through the heat insulating layer 6 to the premixed gas chamber 5 side However, since the heat insulating layer 6 is formed of a ceramic honeycomb of a poor heat conductor, the amount of conduction is very small. Therefore, the temperature of the wall of the premixed gas chamber 5 is 100
It is kept below ℃. Further, the temperature of the combustion device case 14 arranged via the premixed gas chamber 5 and the air insulation layer is 60 ° C.
It is kept below ℃.

Further, the flue gas having the same temperature as the temperature of the downstream surface of the catalyst body 11 exchanges heat with the radiation heat receiving body 9 mainly at the fins 10 for heat exchange, and
After the temperature has dropped to 250 ° C., it is discharged from the flue gas discharge port 13. At this time, the amount of heat held by the recovered combustion exhaust gas is diffused by conduction in the radiation heat receiving body 9 made of an aluminum plate having a high thermal conductivity, and then radiated from the radiation heat receiving body 9 to the outside.

By applying a configuration in which both the upstream and downstream surfaces of the catalyst body 11 are exposed to the radiation heat receiving body 9 as described above, contact oxidation is performed near the upstream surface of the catalyst body 11 and the upstream surface of the catalyst body 11 is exposed. In addition to effectively utilizing the radiant heat from the upstream surface of the catalyst body 11 as well as using the radiant heat from the catalytic converter 11, it is possible to use 50% or more of the radiant heat from the downstream surface. Therefore, it is possible to provide a catalytic combustion device having extremely high heat utilization efficiency. Further, in addition to such an arrangement of the catalyst body 11, a heat insulating layer 6 made of a ceramic honeycomb of a poor heat conductor is provided on the combustion device case 14 side of the combustion chamber 7, so that the heat transfer to the combustion device case 14 is achieved. Because it is possible to significantly reduce the amount of heat, without installing a thick heat insulating material or air heat insulation layer,
Only 5 to 10 between the premixed gas chamber 5 and the combustion device case 14
By installing an air heat insulation layer of about mm, the temperature of the combustion device case 14 can be suppressed. For this reason,
A very compact and thin catalytic combustion device can be realized. Furthermore, by arranging the upstream surfaces of the plurality of catalyst bodies 11 to face each other, a part of the mutual radiant heat is received to support the catalytic combustion (maintain the temperature of the catalyst bodies 11). It is possible to provide a catalytic combustion device excellent in combustion stability even under load.

In this embodiment, the catalyst 11
As the ceramic honeycomb carrier, a ceramic fiber braided body, a porous sintered body, a honeycomb-shaped carrier made of a metal substrate, a braided body made of a metal fiber, a punched metal or a lath having a large porosity. A net or the like may be used, and the same effect as described above can be obtained. The heat insulating layer 6 is made of a ceramic honeycomb. However, if the heat insulating layer 6 is a thermally non-conductive substrate having premixed gas communication holes 8 in part, a heat insulating material made of glass (ceramic) fiber is used. And the same effect as described above can be obtained. Further, although the heat insulating chamber 6 is provided outside the combustion chamber 7, it may be provided inside the combustion chamber 7, and the same effect as described above can be obtained. Furthermore, although the radiation heat receiving body 9 made of an aluminum plate is provided, a heat ray transmitting material such as quartz glass or crystallized glass may be provided, or a heat medium flow path may be provided on the surface of the radiation heat receiving body 9. In each case, the same effect as above can be obtained.

(Embodiment 2) A second embodiment of the present invention will be described. In the present embodiment, the basic configuration is the same as that of the first embodiment. However, the catalyst body has a stack of the catalyst communication hole layers, and a red-hot radiating surface not covered by the adjacent catalyst communication hole layer is arranged near the upstream entrance. The configuration is different from that of the first embodiment in that a transmission window made of a heat ray permeable material is provided on the combustion chamber wall facing the red heat radiation surface. Therefore,
The description will focus on this difference.

FIG. 2 is a sectional view of a main part of the present embodiment.
In FIG. 2, the catalyst body 11 is configured by laminating a plurality of catalyst communication hole layers 15 each composed of a flat plate made of a metal base material and a corrugated plate in which an upstream entrance is sequentially arranged on the downstream side. Reference numeral 16 denotes a red heat radiating surface which is not covered by the adjacent catalyst communication hole layer, and reference numeral 17 denotes a transmission window made of a heat ray transmission material provided on a part of the combustion chamber 7 wall facing the side wall of the catalyst communication hole layer 15.

Next, the operation and characteristics of this embodiment will be described. When a premixed mixture of fuel and air is supplied from the upstream inlets of the plurality of catalyst communication hole layers 15 of the catalyst body 11, a catalytic oxidation reaction is mainly performed near the upstream inlet and side walls of the catalyst communication hole layers 15. As shown in FIG. 3, when the catalyst body 11 has an upstream surface in the same plane, heat radiation from the vicinity of the upstream surface is more easily performed than the inside due to the form of the catalyst body 11. The temperature distribution has a maximum temperature region at a position several millimeters downstream from the upstream surface of the catalyst body 11 due to the balance between the heat radiation amount and the heat radiation mainly to the upstream side. In particular, when the catalytic oxidation reaction is performed on the further downstream side with the decrease in the catalytic activity from near the upstream surface of the catalyst body 11, a further high-temperature region is formed inside the catalyst body 11, This leads to an accelerated decrease in catalytic activity. On the other hand, in the case where the catalyst body 11 is provided with a red heat radiating surface 16 not covered by the adjacent catalyst communication hole layer 15 near the upstream inlet, the catalyst communication hole layer 15
Most of the heat of reaction in the catalyst body 11 is radiated from the red-hot radiation surface 16, and the balance of the reaction amount and the radiation amount causes the catalyst 11
In the case where the catalyst activity is reduced from the vicinity of the upstream surface, a local high-temperature region inside the catalyst body 11 is not easily formed. For this reason, the temperature of the red-light emitting surface 16 facing the transmission window 17 is substantially uniform within the range of 800 to 900 ° C., and the catalyst 1
No local high-temperature region is observed as in the case where the oxidation catalyst component is supported on the whole (FIG. 3). About 10% of the heat rays radiated from the red heat radiation surface 16 are reflected by the transmission window 17 and returned to the catalyst 11. After about 55% is once absorbed by the transmission window 17, secondary radiation is performed from the transmission window 17 which has reached 500 to 600 ° C. In addition, about 35%
Are transmitted through the transmission window 17 and directly emitted to the outside of the catalytic combustion device.

The catalyst body 11 having the red heat radiating surface 16 not covered by the adjacent catalyst communication hole layer 15 near the upstream inlet is used, and the heat ray is transmitted to the wall of the combustion chamber 7 facing the red heat radiating surface 16. Window 1 made of conductive material
By installing 7, it becomes possible to directly use the radiant heat rays from the main reaction area. For this reason, it becomes possible to provide a catalytic combustion device having high utilization efficiency of radiant heat. In addition, the balance between the amount of reaction and the amount of heat radiation from the red-light radiating surface 16 allows the temperature of the side wall of the catalyst communication hole layer 15 facing the transmission window 17 to be made substantially uniform, so that the catalyst activity decreases. It becomes possible to suppress. For this reason, even in a large-sized catalytic combustion system that performs maintenance such as replacement of the catalyst body 11, the frequency of replacement can be reduced by suppressing the rate of decrease in catalytic activity, and the amount of noble metal used is significantly reduced. It is possible to realize a catalytic combustion device that is excellent in economic efficiency. Further, it is possible to provide a catalytic combustion device having a wide application range, which can be applied to a device requiring a guaranteed catalyst life of tens of thousands of hours or more, such as a household combustion device.

In the present embodiment, the catalyst communication hole layer 1
As 5, a honeycomb-shaped carrier in which flat plates and corrugated plates made of a metal substrate are alternately laminated is used, but a ceramic honeycomb carrier, a braided body of ceramic fibers, a porous sintered body, a braided body made of metal fibers, and the like are used. May be used, and the same effect as described above can be obtained. The heat insulating layer 6 is made of a ceramic honeycomb. However, if the heat insulating layer 6 is a thermally non-conductive substrate having premixed gas communication holes 8 in part, a heat insulating material made of glass (ceramic) fiber is used. And the same effect as described above can be obtained. Further, although the heat insulation chamber 6 is provided inside the combustion chamber 7, it may be provided outside the combustion chamber 7, and the same effect as described above can be obtained.
In addition, a transmission window 17 made of a heat ray transmitting material is installed, but a radiation heat receiving body made of a base material such as an aluminum plate having a high thermal conductivity is installed, or a heat medium flow path is attached to the surface of the radiation heat receiving body. In any case, the same effects as described above can be obtained. Further, although the catalyst communication hole layer 15 is constituted by a single channel layer, the catalyst communication hole layer 15 may be constituted by a multiple channel layer, and the same effect as described above can be obtained. Is the one with the greatest effect.

(Embodiment 3) A third embodiment of the present invention will be described. In this embodiment, the basic configuration is the same as that of the first embodiment, except that the upstream catalyst layer is supported only in the vicinity of the upstream surface, and the oxidation catalyst component is provided only downstream of the upstream catalyst layer. Is different in that a catalyst body having a configuration in which downstream-portion-bearing layers carrying the same are alternately stacked is used. Therefore, the description will focus on this difference.

FIG. 4 is a sectional view of a main part of this embodiment.
In FIG. 4, the catalyst body 11 has a configuration in which flat plates made of a metal base material and corrugated plates are alternately laminated, and 18 is an upstream supporting layer in which an oxidation catalyst component is supported only near the upstream surface.
Is a downstream supporting layer in which the oxidation catalyst component is supported only on the downstream side of the upstream supporting layer.

Next, the operation and characteristics of this embodiment will be described. When the premixed fuel and air are supplied from the upstream inlet of the catalyst body 11, the upstream support layer 18 is mainly near the upstream surface of the catalyst body 11, and the downstream support layer 19 is mainly near the front end of the catalyst support area. A catalytic oxidation reaction is carried out. In the case where the oxidation catalyst component is carried on the entire catalyst body 11, heat radiation from the vicinity of the upstream surface is more easily performed than the inside of the catalyst body 11. The temperature distribution having the highest temperature region at a position several millimeters downstream from the upstream surface of the catalyst body 11 is obtained by the balance with the amount of heat radiation by radiation (FIG. 3). In particular, when the catalytic oxidation reaction is performed on the further downstream side with the decrease in the catalytic activity from near the upstream surface of the catalyst body 11, a further high-temperature region is formed inside the catalyst body 11, This leads to an accelerated decrease in catalytic activity. On the other hand, when the upstream supporting layers 18 and the downstream supporting layers 19 are alternately arranged,
Part of the reaction heat in the upstream support layer 18 is recovered by the premixed gas flowing in the adjacent downstream support layer 19, and the catalyst body is balanced by the balance between the reaction amount and the heat recovery amount in the premixed gas. Even when the catalyst activity decreases from near the upstream surface of the catalyst 11, a local high-temperature region inside the catalyst body 11 is not easily formed. The heat recovered into the pre-mixed gas is returned to the reaction region of the downstream supporting layer 19. Similarly, a part of the reaction heat in the downstream support layer 19 is recovered by the combustion exhaust gas flowing in the adjacent upstream support layer 18, and the balance between the reaction amount and the heat recovery amount in the premixed gas is obtained. Even when the catalyst activity decreases from near the tip of the catalyst supporting region of the catalyst body 11, a local high-temperature region inside the catalyst body 11 is hardly formed. For this reason, as shown in FIG. 5, although the temperature distribution inside the catalyst body 11 becomes slightly high on the downstream side, a local high temperature as in the case where the oxidation catalyst component is carried on the entire catalyst body 11 (FIG. 3). No area is observed.

By using the catalyst body 11 in which the upstream supporting layers 18 and the downstream supporting layers 19 are alternately stacked as described above, a part of the heat of reaction is reduced by the premixed gas flowing through the adjacent flow path, or Since the heat is recovered by the combustion exhaust gas, it is possible to suppress the progress of the decrease in the catalytic activity without forming a local high-temperature region inside the catalyst body 11. For this reason, even in a large-sized catalytic combustion system that performs maintenance such as replacement of the catalyst body 11, the frequency of replacement can be reduced by suppressing the rate of decrease in catalytic activity, and the amount of noble metal used is significantly reduced. It is possible to realize a catalytic combustion device that is excellent in economic efficiency. Further, it is possible to provide a catalytic combustion device having a wide application range, which can be applied to a device requiring a guaranteed catalyst life of tens of thousands of hours or more, such as a household combustion device.

In this embodiment, a honeycomb-shaped carrier in which flat plates and corrugated plates made of a metal base material are alternately laminated is used as the catalyst body 11, but a ceramic honeycomb carrier, a braided ceramic fiber, A porous sintered body, a braided body made of a metal fiber, or the like may be used, and the same effects as described above can be obtained. Further, the oxidation catalyst component is supported on the upstream support layer 18 from the inlet on the upstream surface of the catalyst body 11, but an unsupported portion may be provided near the upstream inlet, and the upstream support layer 18 flows through the upstream support layer 18. If the catalyst surface area is sufficient for the premixed gas amount, the same effect as described above can be obtained. Further, the catalyst 11
Although the oxidation catalyst component is supported from immediately downstream of the upstream portion supporting layer 18 to the downstream surface outlet, an interval may be provided from the upstream portion supporting layer 18 or an unsupported portion may be provided near the downstream outlet. If the catalyst has a sufficient surface area for the amount of premixed gas flowing through the support layer 19, the same effect as described above can be obtained. Further, although the upstream portion supporting layer 18 and the downstream portion supporting layer 19 are constituted by a single channel layer and arranged alternately, they may be constituted by a multiple channel layer, and the same effect as described above can be obtained. Although there is a single channel layer, the greatest effect can be obtained.

(Embodiment 4) A fourth embodiment of the present invention will be described. This embodiment has the same basic configuration as that of the third embodiment, except that a catalyst support layer supporting an oxidation catalyst component and a non-support layer not supporting an oxidation catalyst component are alternately stacked. And that an auxiliary catalyst is disposed downstream of the catalyst. Therefore, the description will focus on this difference.

FIG. 6 is a sectional view of a main part of the present embodiment.
In FIG. 6, a catalyst body 11 and a second catalyst body 19 have a configuration in which flat plates and corrugated plates made of a metal base material are alternately laminated, and a reference numeral 21 denotes a catalyst support layer on which an oxidation catalyst component is supported.
Reference numeral 2 denotes an unsupported layer that does not support the oxidation catalyst component. Reference numeral 23 denotes an auxiliary catalyst.

Next, the operation and characteristics of this embodiment will be described. When a premixture of fuel and air is supplied from the upstream inlet of the catalyst body 11, a catalytic oxidation reaction is mainly performed in the catalyst supporting layer 21 near the upstream inlet. Catalyst support layer 21
A part of the reaction heat is recovered by the premixed gas flowing in the adjacent unsupported layer 22 and is returned to the second catalyst body 20. In addition, the catalyst 1
In step 1, unreacted fuel, air and combustion exhaust gas are supplied according to the ratio of the catalyst support layer 21 and the unsupported layer 22 arbitrarily set, and the catalytic oxidation reaction is similarly performed mainly in the vicinity of the upstream inlet of the catalyst support layer 21. Is performed. A part of the reaction heat in the catalyst supporting layer 21 is recovered by the pre-mixed gas flowing in the adjacent unsupported layer 22 and is returned to the auxiliary catalyst body 23 to be heated. In addition, the catalyst support layer 21 arbitrarily set in the second catalyst body 20 discharged from this
The unreacted fuel corresponding to the ratio of the unsupported layer 22 and the unsupported layer 22 reaches a complete reaction in the auxiliary catalyst body 23. However, the catalyst body 11
When the temperature is higher than 1000 ° C., a flame is formed in the flow path of the unsupported layer 22 or in the downstream surface, and the flame can be flame assisted by catalytic combustion.

As described above, the catalyst supporting layer 21 and the non-supporting layer 22
By using the catalyst body 11 having a configuration in which
It is possible to improve the upper limit of the combustion load per unit cross-sectional area with respect to the catalyst body regulated by the heat-resistant limit temperature of the active component supported on the catalyst layer. For this reason, since the installation space for the catalyst body can be significantly reduced, a very compact and thin catalytic combustion device can be realized. Further, by arbitrarily setting the installation ratio of the catalyst supporting layer 21 and the non-supporting layer 22, a catalytic combustion device as a heating heat source capable of uniform heating over a wide range, such as a far-infrared radiation panel, is provided. Can be done.

In the present embodiment, a honeycomb-shaped carrier in which flat and corrugated plates made of a metal base material are alternately laminated is used as the catalyst body 11 and the second catalyst body 20.
A ceramic honeycomb carrier, a braided body of ceramic fibers, a porous sintered body, a braided body made of metal fibers, or the like may be used, and the same effects as described above can be obtained. Further, the catalyst supporting layer 21 in the catalyst body 11 and the second catalyst body 20
The installation ratio of the unsupported layer 22 and the installation number of the catalyst bodies can be arbitrarily set, and the same effects as described above can be obtained by optimizing according to the application. Further, although the catalyst supporting layers 21 and the non-supporting layers 22 are constituted by a single channel layer and are arranged alternately, the catalyst supporting layers 21 and the unsupported layers 22 may be constituted by a multiple channel layer, and the same effects as above can be obtained. In this case, the greatest effect can be obtained when a single channel layer is used. Furthermore, although the radiation heat receiver 9 made of an aluminum plate is provided, a heat medium flow path may be provided on the surface of the radiation heat receiver 9, and the same effect as described above can be obtained in any case.

Although the present invention has been described above with reference to an example in which the present invention is applied to a catalytic combustion apparatus for gaseous fuel supplied from a fuel tank, the present invention is not limited to this.
That is, the following cases are also included in the present invention.

As a fuel type, a liquefied gas fuel filled in a fuel container such as butane gas or a case where a liquid fuel such as kerosene is used can be applied. A high-pressure liquefied gas fuel such as butane gas may not be provided with an air supply means such as a blower fan, but may be provided with a means such as a nozzle and a throat for sucking and introducing air by using a fuel gas ejection pressure. . When a liquid fuel is used, a means for vaporizing the liquid fuel upstream of the fuel / air mixer is added.

As the catalyst body, a honeycomb-shaped carrier made of ceramic honeycomb or metal is used, but the material and the shape are not limited as long as the catalyst body has a large number of communication holes through which a premixed gas can flow. For example, a sintered body of ceramic or metal, a metal nonwoven fabric, a braided body of ceramic or metal fiber, and the like can be used, and the shape of the material is not limited to a flat plate, but may be a curved shape, a tubular shape, a corrugated shape, or the like. And can be set arbitrarily according to the application. The active component is generally a precious metal such as platinum, palladium, or rhodium, but may be a mixture of these metals, another metal or an oxide thereof, or a mixed composition thereof, and may be a fuel. It is possible to select an active ingredient according to species and use conditions.

Although a direct ignition system downstream of the catalyst body using an electric heater is used as an ignition means, a piezoelectric ignition device is used as an igniter for starting flame combustion. It is an effective means to make it happen.

[0038]

As described above, in the catalytic combustion apparatus according to the present invention, by adopting a configuration in which both the upstream and downstream surfaces of the catalytic body are exposed to the radiant heat receiving body, the upstream surface of the catalytic body is exposed. In addition to being able to effectively use the radiant heat from the fuel cell, it is also possible to use 50% or more of the radiant heat from the downstream surface, so that it is possible to provide a catalytic combustion device with extremely high heat utilization efficiency. Further, in addition to such an arrangement of the catalyst body, by providing a heat insulating layer composed of a poor thermal conductor, it is possible to greatly suppress the amount of heat transferred to the combustion device case. The temperature of the combustion device case can be suppressed without providing a material or an air insulation layer. Therefore, a very compact and thin catalytic combustion device can be realized. Furthermore, by arranging the upstream surfaces of a plurality of catalyst bodies facing each other,
Since the catalytic combustion is assisted by receiving a part of the mutual radiant heat, it is possible to provide a catalytic combustion device having excellent combustion stability even under a particularly low combustion load.

In addition, a catalyzer having a red heat radiating surface which is not covered by the adjacent catalyst communication hole layer near the upstream inlet is used, and a transmission window made of a heat ray permeable material is provided on a combustion chamber wall facing the red heat radiating surface. Is installed, it is possible to directly use the radiant heat rays from the main reaction area. For this reason, it becomes possible to provide a catalytic combustion device having high utilization efficiency of radiant heat.

In addition, by using a catalyst body in which the upstream supporting layer and the downstream supporting layer are alternately stacked, a local high temperature region is not formed inside the catalyst body, and the catalyst activity decreases. Can be suppressed. For this reason,
Even in large-scale catalytic combustion systems that perform maintenance such as catalyst replacement, the frequency of replacement can be reduced by suppressing the rate of decrease in catalyst activity, and the amount of precious metals used is greatly reduced, which is economical. It is possible to realize a catalytic combustion device. Further, it is possible to provide a catalytic combustion device having a wide application range, which can be applied to a device requiring a guaranteed catalyst life of tens of thousands of hours or more, such as a household combustion device.

Furthermore, by using a catalyst body having a structure in which a catalyst-supporting layer and an unsupported layer are stacked, the combustion per unit cross-sectional area of the catalyst body controlled by the heat-resistant limit temperature of the active component supported on the catalyst layer can be achieved. It is possible to improve the upper limit of the load. For this reason, since the installation space for the catalyst body can be significantly reduced, a very compact and thin catalytic combustion device can be realized. Further, by arbitrarily setting the proportion of the catalyst-supporting layer and the non-supporting layer, it is possible to provide a catalytic combustion device as a heating heat source capable of performing uniform heating over a wide range.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional configuration diagram of a combustion apparatus as a first embodiment of the present invention.

FIG. 2 is a cross-sectional configuration diagram of a main part of a combustion device according to a second embodiment of the present invention.

FIG. 3 is a temperature distribution diagram inside a catalyst body as a conventional catalytic combustion device.

FIG. 4 is a cross-sectional configuration diagram of a main part of a combustion device according to a third embodiment of the present invention.

FIG. 5 is a temperature distribution diagram inside a catalyst body according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional configuration diagram of a main part of a combustion apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel supply part 2 Control valve 3 Air supply fan 4 Mixing chamber 5 Premixed gas chamber 6 Heat insulation layer 7 Combustion chamber 8 Premixed air communication hole 9 Radiation heat receiving body 10 Fin 11 Catalyst body 12 Ignition device 13 Combustion exhaust gas outlet 14 Combustion Device case 15 Catalyst communication hole layer 16 Red heat emission surface 17 Transmission window 18 Upstream portion support layer 19 Downstream portion support layer 20 Second catalyst body 21 Catalyst support layer 22 Unsupported layer 23 Auxiliary catalyst body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuo Fujita 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Terms (reference) 3K017 BA01 BB06 BB07 BB08 BB09 BC07 BC09 BC10 BD01 BG03 BH02 3K065 TA12 TB08 TC05 TD04 TD05 TK04 TK06 TK09

Claims (7)

[Claims] 1. A combustion chamber provided with a catalyst in which an oxidation catalyst component is supported on a base material having a plurality of communication holes, and a transmission window or a radiation heat receiver made of a heat ray permeable material provided on the combustion chamber wall. In addition to the above, a heat insulating layer which communicates with a flow path through which the premixed gas flows and has a premixed gas communication hole therein is provided on a wall facing the transmission window or the radiation heat receiving body of the combustion chamber. And a catalytic combustion device. 2. The catalyst body is disposed such that a streamline of the premixed gas flowing out of the premixed gas communication hole and a streamline of the premixed gas flowing into the communication hole of the catalyst body are orthogonal to each other. The catalytic combustion device according to claim 1, wherein 3. The catalytic combustion apparatus according to claim 1, wherein a plurality of the catalyst bodies are arranged in the combustion chamber such that their upstream surfaces face each other. 4. The catalyst body has a structure in which a catalyst communication hole layer is disposed in a stacked manner and has a red-heat radiating surface which is not covered by the catalyst communication hole layer adjacent to an upstream entrance of the catalyst communication hole layer. 3. The catalytic combustion device according to claim 1, wherein the transmission window or the radiation heat receiving body is provided on a wall of the combustion chamber facing the red heat radiation surface. 5. The catalyst communication hole layer according to claim 1, wherein a flow path parallel to a streamline of a premixed gas flowing into the catalyst body is formed by laminating a flat plate and a corrugated plate. 4
A catalytic combustion device according to any of the preceding claims. 6. The catalyst body comprises: an upstream supporting layer in which an oxidation catalyst component is supported only in the vicinity of an upstream surface; and a downstream supporting layer in which an oxidation catalyst component is supported only downstream of the upstream supporting layer. A catalytic combustion device having a configuration in which layers are alternately stacked. 7. The catalyst body has a structure in which a catalyst support layer supporting an oxidation catalyst component and an unsupported layer not supporting an oxidation catalyst component are alternately stacked, and an auxiliary catalyst supporting the oxidation catalyst component is provided. A catalytic combustion device, wherein a medium is arranged in a combustion chamber downstream of the catalyst body.