JP2000018511A - Catalyst carrier for catalytic combustion type heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a manufacturing coat by integrally forming a catalyst carrier and a heat-exchanger as temperature is maintained at a value necessary to catalytic combustion and to improve the efficiency of heat-exchange with a heating medium through integral formation thereof. SOLUTION: In this catalyst carrier of a catalytic combustion type heater, thin corrugated sheets 39 made of a metal and plates are alternately laminated together to mold a core 43 through which an air-fuel mixture A/F of fuel and air for combustion flows down. Further, pipes 31 and 33 for heat-exchange through which a heating medium W flows down are integrally joined together at a part situated downstream from the core 43. A heat transfer suppression area 47 wherein the sectional area of the core 43 in a direction orthogonal to the flow-down direction of the air-fuel mixture A/F is decreased is formed at the core 43 situated upper stream from the pipes 31 and 33 for heat- exchanger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst carrier for a catalytic combustion heater used in a vehicle heating system.

[0002]

2. Description of the Related Art In recent years, a so-called "catalytic combustion heater" is used in which a mixture of fuel and combustion air is combusted by a catalyst, and a heat medium is heated by combustion heat generated by the catalytic combustion to heat air supplied to a vehicle interior. Of Japanese Patent Application Laid-Open No. 4-314613
And Japanese Patent Application Laid-Open No. 9-118125.

FIG. 8 shows a catalytic combustion type heater disclosed in Japanese Patent Application Laid-Open No. 4-314613. In the figure, reference numeral 1 denotes a cylindrical casing, in which a catalyst carrier (a particulate catalyst) in which a catalyst such as platinum is carried. (Carrier) 3 is mounted. Then, the fuel F and the combustion air A from the fuel tank and the blower 7 are mixed by the carburetor 5 mounted on the upstream side of the catalyst carrier 3 so that the mixture A / F is burned by the catalyst. Has become. Then, in order to activate the catalyst, the combustion air A is previously heated by the heating element 9 mounted in the casing 1.

In the casing 1, a heating medium (water) W
A heat exchanger 15 provided with an inlet pipe 11 and an outlet pipe 13 through which the heat medium W is introduced is provided downstream of the catalyst carrier 3. The pipe 13 is led to a heater core. Then, the heating medium W, which has been heat-exchanged with the supply air to the vehicle interior by the heater core,
Is configured to be introduced again from the inlet pipe 11 to the heat exchanger 15, and the burned mixture A / F
Is exhausted from the exhaust holes 21 and 23 provided in the casing 1 and the protective cover 19 covering the casing 1. However, since the combustion of the air-fuel mixture A / F proceeds at a low temperature by using a catalyst, the catalytic combustion type heater 17 It is attracting attention as a clean heat source that emits almost no nitric oxide, carbon monoxide, or noncombustible fuel.

[0005]

However, in the conventional structure in which the catalyst carrier and the heat exchanger are separately provided in the casing as described above, the catalyst carrier and the heat exchanger are manufactured in separate processes, and these are manufactured. Since it has to be assembled in the casing, there are drawbacks that the production is troublesome and the cost is high.

On the other hand, by integrating the catalyst carrier and the heat exchanger, the production cost can be reduced and the productivity can be improved. However, when these are integrated, the temperature required for catalytic combustion decreases. Problems occur. That is, in general, the oxidation reaction of the catalyst does not proceed below 200 ° C.
Although a temperature of 00 ° C. or higher is required, the water (antifreeze; LLC) usually used as the heat medium W is kept at a temperature of about 100 ° C. in order to prevent thermal deterioration.

[0007] Therefore, if the pipe of the heat exchanger through which the heat medium kept at a low temperature flows and the catalyst carrier are integrated, the temperature of the catalyst carrier drops due to heat conduction to the pipe, and incomplete combustion occurs. It has been pointed out that there is a danger of such a situation. The present invention has been devised in view of such circumstances, and by improving the catalyst carrier used in the catalytic combustion heater as described above, while maintaining the temperature required for catalytic combustion, the catalyst carrier and the heat exchanger are combined. An object of the present invention is to provide a catalyst carrier of a catalytic combustion type heater in which the manufacturing cost is reduced by integrating them, and the efficiency of heat exchange with a heat medium is improved by integrating them.

[0008]

In order to achieve the above object, a catalyst carrier of a catalytic combustion type heater according to the first aspect of the present invention comprises a thin metal corrugated plate and a flat plate which are alternately laminated to produce a fuel and a fuel. While forming a core through which a mixture of air for use flows down, a heat exchange pipe through which a heat medium flows down is integrally joined to a downstream portion of the core, and a core upstream of the heat exchange pipe, It is characterized in that a heat transfer suppression area for a heat exchange pipe is provided in which a cross-sectional area of a core in a direction orthogonal to a flowing direction of the air-fuel mixture is reduced.

The invention according to claim 2 is the invention according to claim 1.
In the catalyst carrier according to the present invention, the heat transfer suppression region is constituted by a corrugated plate and a number of small holes provided in a flat plate. The heat transfer suppression region is characterized by comprising at least a louver formed in the corrugated plate by a large number of cuts perpendicular to the flowing direction of the air-fuel mixture.

According to a fourth aspect of the present invention, there is provided the catalyst carrier according to any one of the first to third aspects, wherein the mixture flowing down to the downstream portion of the core to which the heat exchange pipe is joined is provided. A heat transfer enhancement area for enhancing heat transfer of air is provided.
The invention according to claim 4 is characterized in that, in the catalyst carrier according to claim 4, the heat transfer enhancement region is formed of a louver formed at least in the corrugated plate by a number of cuts perpendicular to the flowing direction of the air-fuel mixture.

(Function) According to the catalyst carrier according to each of the claims, since the heat transfer suppression region is provided in the core on the upstream side of the heat exchange pipe, the core upstream side which has become high in temperature due to the combustion of the air-fuel mixture. Is difficult to transfer to the heat exchange pipe, and as a result, the combustion temperature of the catalyst does not suddenly decrease due to heat conduction to the heat exchange pipe.

According to the fourth and fifth aspects of the present invention, the heat transfer enhancement region is provided downstream of the core on which the heat exchange pipe is mounted, so that the heat transfer enhancement region flows down the heat transfer enhancement region. Since the combustion heat of the catalytic combustion of the air-fuel mixture is transferred to the downstream part of the core and the heat exchange pipe, the combustion heat is actively recovered by the heat medium flowing down the heat exchange pipe. .

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a catalytic combustion type heater using a catalyst carrier according to one embodiment of the first to fifth aspects. In FIG. 1, reference numeral 25 denotes a box-shaped casing having diffusers 27 and 29 attached to both ends. Inside, a pair of heat exchange pipes 3 through which the heat medium (water) W flows down
A rectangular parallelepiped catalyst carrier 35 in which 1, 33 are assembled vertically
Is installed.

The catalytic combustion heater 37 according to the present embodiment also burns a mixture A / F of fuel and combustion air from a fuel tank and a blower (not shown) with a catalyst carried on a catalyst carrier 35, The heat medium W flowing down the heat exchange pipes 31 and 33 is heated by the combustion heat generated by the catalytic combustion, and the burned air-fuel mixture A / F is exhausted to the outside.

In this embodiment, the combustion air is preheated by an initial igniter (not shown) in order to activate the catalyst. Thus, the catalyst carrier 35 shown in FIG.
As shown in FIG. 3, a core 43 formed by alternately laminating thin corrugated plates 39 and flat plates 41 made of ferritic stainless steel, and two pairs of stainless steel heat exchange molded into a flat cross-sectional shape. The heat exchange pipes 31 and 33 of each pair are disposed downstream of the core 43 (the mixture A / F flowing down) so as to be orthogonal to the flow of the mixture A / F. In parallel between the flat plates 41 on the downstream side of
It is brazed integrally with the core 43.

In this embodiment, a platinum catalyst is carried on the corrugated plate 39 and the flat plate 41 on the upstream side of the core 43 in order to effectively use the catalyst. That is, when the upstream side and the downstream side of the core 43 are compared, the upstream side has a higher combustion temperature than the downstream side of the core 43 and has excellent catalytic activity, and the mixture A / F flowing down the downstream side has a higher combustion temperature. In most cases, the combustion proceeds on the upstream side and is almost completely decomposed into water, carbon dioxide, and the like. Therefore, there is no merit in carrying the catalyst on the downstream side.

Therefore, in the present embodiment, the catalyst is set to be completely used for completely combusting the air-fuel mixture A / F, and is carried on the upstream side of the core 43, so that the catalyst is effectively used. As shown in FIGS. 1 to 3, the core 43 (corrugated plate 39 and flat plate 41) on the upstream side of the heat exchange pipe 31 is provided with a heat transfer suppression region 47 including a number of small holes 45. By providing such a large number of small holes 45 in the core 43, the cross-sectional area of the core 43 in a direction orthogonal to the flowing direction of the air-fuel mixture A / F is reduced, so that the heat exchange pipes 31, 33 Since the heat transfer area is reduced, the heat exchange pipes 31, 33
Is suppressed, and the temperature of catalytic combustion upstream of the core 43 does not suddenly decrease.

On the other hand, in the downstream part of the core 43 to which the heat exchange pipes 31 and 33 are joined, in order to positively recover the heat from the high-temperature mixture A / F flowing down in the core 43 to the heat medium W. A louver 49 formed by a large number of cuts perpendicular to the flowing direction of the air-fuel mixture A / F is provided on the corrugated plate 39 and the flat plate 41 to form a heat transfer enhancement region 51, which flows down the heat transfer enhancement region 51. The combustion heat of the catalytic combustion of the air-fuel mixture A / F is transmitted to the downstream portion of the core 43 and the heat exchange pipes 31, 33, and the combustion heat is transmitted to the heat medium W flowing down the heat exchange pipes 31, 33. They can be actively collected.

Although not shown, the louver 49 may be provided by processing the corrugated plate 39 or the flat plate 41 in advance by a conventionally known method. As shown in FIG. 1, the heat exchange pipes 31 and 33 penetrate the casing 25, respectively, and the heat medium tanks 5 mounted on the left and right sides of the casing 25.
3,55. The inside of one heat medium tank 53 is partitioned by one partition plate 57, and the catalyst carrier 3 is separated.
Upper and lower two heat exchange pipes 33 arranged downstream of
Are formed, and an outlet-side tank portion 53b is formed in which the other heat exchange pipe 31 is opened. The introduction pipe 59 and the exit pipe 61 are connected to the introduction tank section 53a and the exit tank section 53b, respectively. The heat medium W is introduced from the introduction pipe 59 by the pump 63 into the introduction tank section 53a. It has become.

The heat medium W introduced into the introduction-side tank 53a flows down the heat exchange pipe 33, the heat medium tank 55, and the heat exchange pipe 31 as shown in FIG. After being heated and sent to the heater core from the outlet tank portion 53b and the outlet pipe 61 to exchange heat with the supply air to the vehicle interior, it is again introduced into the catalytic combustion heater 37 via the introduction pipe 59. ing.

Since the catalytic combustion heater 37 using the catalyst carrier 35 according to the present embodiment is configured as described above,
A mixture of fuel and combustion air A / F is burned with a catalyst,
When the heat medium W is introduced into the catalytic combustion heater 37 from the introduction pipe 59, the heat medium W is heated by the combustion heat of the catalytic combustion while flowing down the heat exchange pipe 33, the heat medium tank 55, and the heat exchange pipe 31. However, since the heat transfer suppression region 47 is provided in the core 43 on the upstream side of the heat exchange pipe 31, the heat of the corrugated plate 39 and the flat plate 41 which have become high due to the combustion of the air-fuel mixture A / F is generated by the heat. It is difficult to conduct to the exchange pipes 31.33, and as a result, the temperature on the upstream side of the catalyst carrier 35 (cell 43) on which the catalyst is supported does not drop sharply.

In the downstream of the core 43 on which the heat exchange pipes 31 and 33 are mounted, there is provided a heat transfer enhancement area 51 comprising a large number of louvers 49 orthogonal to the flow direction of the air-fuel mixture A / F. Therefore, as shown in FIG.
The combustion heat of the catalytic combustion of the air-fuel mixture A / F flowing down to 1 is transferred to the downstream portion of the core 43 and the heat exchange pipes 31 and 33, and the heat medium W flowing down in the heat exchange pipes 31 and 33.
Thus, the combustion heat is positively recovered.

As described above, in the present embodiment, the catalyst carrier 35
Heat exchange pipes 31, 3 as heat exchangers
3, the manufacturing cost can be reduced in manufacturing the catalytic combustion heater 37 as compared with the conventional example shown in FIG. Further, in the present embodiment, when integrating the heat exchange pipes 31 and 33 into the core 43, they are attached to the downstream part of the core 43 and are transferred to the core 43 on the upstream side of the heat exchange pipe 31. 47, and a heat transfer enhancement area 51 composed of a large number of louvers 49 downstream of the core 43 to which the heat exchange pipes 31 and 33 are attached.
, Good heat exchange with the heat medium W was possible while maintaining the temperature required for catalytic combustion.

This embodiment has an advantage that the catalyst can be effectively used because the entire amount of the catalyst necessary for completely combusting the air-fuel mixture A / F is supported on the upstream side of the core 43.
In providing the heat transfer suppression region 47 in the core 43, FIG.
As shown in FIG.
The small holes 45 may be provided on the entire surface of the flat plate or the flat plate, and instead of such small holes 45, a large number of slits or fine holes are provided on the corrugated plate or the flat plate in a direction perpendicular to the heat transfer direction, Mixture A
The heat transfer suppression region may be formed by reducing the cross-sectional area of the core 43 in a direction orthogonal to the flow direction of / F.

As shown in FIG. 6 or FIG.
May be provided with louvers 65 and 67 of various shapes formed by a large number of cuts perpendicular to the flowing direction of the air-fuel mixture A / F to provide a heat transfer suppression region. As in the above-described embodiment, the intended purpose can be achieved. Further, instead of the small holes 45 in the embodiment of FIG. 1, a louver 49 may be provided from the upstream side to the downstream side of the core 43. According to such an embodiment, the upstream side of the heat exchange pipe 31 The louver 49 functions as a heat transfer suppression area, and the louver 4 on the downstream side of the core 43 to which the heat exchange pipes 31 and 33 are attached.
9 functions as a heat transfer enhancement region.

According to this embodiment, the corrugated plate 39
It is not necessary to provide the small holes 45 and the louvers 49 in the flat plate 41 and the louvers 49, respectively, and only the louvers 49 need to be provided in the corrugated plate 39 or the flat plate 41. Therefore, there is an advantage that the manufacturing of the core 43 becomes easy.

[0027]

As described above, in manufacturing the catalytic combustion heater, the use of the catalyst carrier according to the claims makes it possible to integrally join the catalyst carrier and the heat exchange pipe as the heat exchanger. The production cost can be reduced as compared with the conventional example in which the catalyst carrier and the heat exchanger are separately provided.

Further, in the invention according to each claim, in integrating the heat exchange pipes, these are mounted on the downstream portion of the core of the catalyst carrier, and the heat transfer suppression region is transferred to the core upstream of the heat exchange pipe. The heat of the upstream portion of the core, which became high in temperature due to the combustion of the air-fuel mixture, was not easily conducted to the heat exchange pipe, and as a result, the temperature required for catalytic combustion could be maintained. According to the fourth and fifth aspects of the present invention, the heat transfer enhancement area is provided downstream of the core on which the heat exchange pipe is mounted, so that the heat medium flowing down the heat exchange pipe is subjected to the combustion heat. Was positively recovered, and good heat exchange with the heat medium became possible.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a catalytic combustion heater using a catalyst carrier according to an embodiment of the present invention.

FIG. 2 is an overall perspective view of a catalyst carrier according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a schematic sectional view of the catalyst carrier shown in FIG.

FIG. 5 is a perspective view of a corrugated sheet showing a modification of the heat transfer suppression region.

FIG. 6 is a cross-sectional view of a main part of a corrugated sheet showing a modification of the heat transfer suppression region.

FIG. 7 is a cross-sectional view of a main part of a corrugated sheet showing a modification of the heat transfer suppression region.

FIG. 8 is a sectional view of a conventional catalytic combustion heater.

[Explanation of symbols]

 Reference Signs List 25 casing 31, 33 heat exchange pipe 35 catalyst carrier 37 catalytic combustion heater 39 corrugated plate 41 flat plate 43 core 45 small hole 47 heat transfer suppression area 49, 67, 69 louver 51 heat transfer enhancement area 53, 55 heat medium tank A / F mixture W heat medium

Claims (5)

[Claims] 1. A thin metal corrugated plate (39) and a flat plate (4).
1) are alternately stacked to form a mixture (A) of fuel and combustion air.
/ F), and a heat exchange pipe (31, 33) through which the heat medium (W) flows down is integrally joined to a downstream portion of the core (43), and The core (4) on the upstream side of the heat exchange pipes (31, 33)
3) a heat transfer suppression area (47) to the heat exchange pipes (31, 33), which has a reduced cross-sectional area of the core (43) in a direction orthogonal to the downflow direction of the air-fuel mixture (A / F). A catalyst carrier for a catalytic combustion heater, comprising: 2. The catalytic combustion heater according to claim 1, wherein the heat transfer suppression zone (47) comprises a number of small holes (45) provided in the corrugated plate (39) and the flat plate (41). Catalyst carrier. 3. The heat transfer suppression area (47) is formed of a louver formed by a large number of cuts in the corrugated plate (39) at least in a direction perpendicular to the flowing direction of the air-fuel mixture (A / F). Item 3. A catalyst carrier for the catalytic combustion heater according to Item 1. 4. An air-fuel mixture (A / F) flowing downstream of a core (43) to which heat exchange pipes (31, 33) are joined.
The catalyst carrier for a catalytic combustion heater according to any one of claims 1 to 3, further comprising a heat transfer enhancement region (51) for increasing the heat transfer of the catalyst. 5. The heat transfer enhancement area (51) comprises a louver (49) formed at least in the corrugated plate (39) by a number of cuts perpendicular to the flowing direction of the air-fuel mixture (A / F). A catalyst carrier for a catalytic combustion heater according to claim 4.