JP2002228147A - Catalyst combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst combustion apparatus capable of combustion with high reliability without causing abnormal firing. SOLUTION: There are provided a mixing chamber 3 for mixing a fuel of combustible gas and air supplied respectively from an air supply apparatus 1 and a fuel combustion apparatus 2, a combustion catalyst 4 for rendering the mixed gas mixed in the combustion chamber 3 to an oxidization reaction; and ignition means 5 for igniting the mixed gas supplied to the combustion catalyst 4. Then temperature of the combustion catalyst 4 exceeds a predetermined temperature, the ignition means 5 is prevented from igniting.

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 for oxidizing an air-fuel mixture of a combustible gas and air by a combustion catalyst to perform catalytic combustion.

[0002]

2. Description of the Related Art As a combustion device for supplying high-temperature thermal energy to a reformer for reforming a source fuel into a hydrogen-rich gas in a fuel cell power generation device, a device using the heat generated by a flame has been conventionally known as disclosed in Japanese Patent Application Laid-Open No. H8-208,878. It is widely used in -217401 and the like. However, since these combustion devices generate high-temperature flames, toxic substances are generated in the exhaust gas and thermal efficiency is lowered due to unreacted gas. For this reason, a large number of exhaust gas treatment devices for purifying this exhaust gas to produce clean exhaust gas have been devised and used in the past, but a combustion device using a flame basically uses a clean exhaust gas. Hard to get.

[0003] As one of means for solving these problems in a combustion apparatus using a flame, there is a catalytic combustion apparatus.
The catalytic combustion device uses a combustion catalyst such as platinum or palladium, and oxidizes an air-fuel mixture mixed in a mixing chamber to burn it without flame. As for this catalytic combustion device, many devices have been conventionally provided as shown in International Publication WO98 / 00361.

In this catalytic combustion device, the combustion catalyst cannot perform catalytic combustion of the air-fuel mixture in a steady state unless the temperature exceeds a predetermined temperature. For this reason, usually, when the catalytic combustion device is provided with the ignition means, the mixture is ignited by the ignition means in the mixing chamber below the combustion catalyst and ignited by the ignition means. It is made to warm to more than a predetermined temperature.

[0005]

In the case of a cold start in a state where the catalytic combustion device is cold, it is necessary to operate the ignition means to burn the air-fuel mixture in the mixing chamber with flame.
When the combustion catalyst has a temperature sufficient to cause catalytic combustion, such as when restarting, it is not necessary to cause the air-fuel mixture in the mixing chamber to perform flammable combustion.

However, in the conventional catalytic combustion device, the ignition means is always activated at the time of start-up, so that the air-fuel mixture in the mixing chamber is flammably burnt. Performing such an ignition operation consumes extra time and hinders smooth combustion. In addition, when the temperature of the combustion catalyst is high, the exhaust pressure may increase and the concentration of the mixture in the mixing chamber may increase, and if the ignition means is activated at this time, abnormal ignition may occur in the mixing chamber. It was something.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a catalytic combustion apparatus capable of performing combustion with high reliability without causing abnormal ignition.

[0008]

According to a first aspect of the present invention, there is provided a catalytic combustion device comprising a mixing chamber for mixing air supplied from an air supply device and a fuel supply device with a fuel of a combustible gas. And a combustion catalyst 4 for oxidizing the air-fuel mixture mixed in the mixing chamber 3 to perform catalytic combustion, and an ignition means 5 for igniting the air-fuel mixture supplied to the combustion catalyst 4. When the temperature is equal to or higher than the predetermined temperature, ignition by the ignition means 5 is not performed.

According to a second aspect of the present invention, in the first aspect, a temperature sensor 6 for detecting a temperature of the combustion catalyst 4 and an ignition means when the temperature of the combustion catalyst 4 detected by the temperature sensor 6 is equal to or higher than a predetermined temperature. 5 is provided with control means 7 for controlling so that ignition by 5 is not performed.

A third aspect of the present invention is characterized in that, in the second aspect, the temperature sensor 6 is disposed so as to be embedded in the combustion catalyst 4.

A fourth aspect of the present invention is characterized in that, in the second aspect, the temperature sensor 6 is disposed immediately above the combustion catalyst 4.

[0012]

Embodiments of the present invention will be described below.

FIG. 1 shows an embodiment of the present invention, in which a catalytic combustor 1 is formed in a bottomed cylindrical shape whose lower surface is closed.
1 is formed, and the lower part of the catalytic combustor 11 is a mixing chamber 3.
The catalyst combustor 11 is filled with a combustion catalyst 4 such as platinum or palladium above the mixing chamber 3. An air supply pipe 12 is connected to the mixing chamber 3 of the catalytic combustor 11, and a fuel supply pipe 13 is connected to the air supply pipe 12.

The air supply pipe 12 is provided with an air supply device 1 formed by a fan or the like.
Through the mixing chamber 3 of the catalytic combustor 11. This air refers to all gases containing oxygen and capable of promoting an oxidation reaction. Also, the fuel supply pipe 13
Is connected to a fuel supply device 2. The fuel supply device 2 is provided with a tank for storing flammable gas fuel and a needle valve, and supplies a predetermined amount of flammable gas fuel by opening the needle valve. The flammable gas is a gaseous gas such as methane gas, propane gas or butane gas, or a gas obtained by vaporizing a fuel such as a liquid. The combustible gas fuel is supplied from the fuel supply pipe 13 to the air supply pipe 12, and the fuel is supplied to the mixing chamber 3 of the catalytic combustor 11 through the air supply pipe 12 together with the air.

A temperature sensor 6 is provided for the combustion catalyst 4 filled in the upper part of the catalytic combustor 11. This temperature sensor 6
For example, an R-type thermocouple can be used, and is disposed so as to be embedded in the center of the combustion catalyst 4. At the inlet from the air supply pipe 12 to the mixing chamber 3, an ignition means 5 formed by a spark plug or the like for performing ignition by spark is provided.

The temperature sensor 6, the ignition means 5,
Each of the air supply device 1 and the fuel supply device 2 is a CP.
It is electrically connected to control means 7 formed by U or the like. Here, the temperature data of the combustion catalyst 4 detected by the temperature sensor 6 is inputted to the control means 7, and whether or not the temperature of the combustion catalyst 4 is equal to or higher than a predetermined minimum temperature required for catalytic combustion. If the temperature is equal to or higher than the predetermined temperature, the control means 7 controls the ignition means 5 so as not to operate the ignition means 5. The predetermined temperature is set in the control means 7, but the predetermined temperature may be set slightly higher than the minimum temperature required for catalytic combustion.

In starting the catalytic combustion device formed as described above, when the starting operation is performed, the fan of the air supply device 1 is operated by the command from the control means 7 to supply air through the air supply pipe 12. Catalytic combustor 1
The fuel is supplied to the mixing chamber 3 and the needle valve of the fuel supply device 2 is opened to supply the fuel of the combustible gas from the fuel supply pipe 13 to the mixing chamber 3 to mix the air and the fuel in the mixing chamber 3. At this time, the temperature data of the combustion catalyst 4 detected by the temperature sensor 6 is input to the control means 7, and if the temperature data is lower than the set temperature, for example, 450 ° C., the ignition means 5 is controlled by the control means 7. Then, the air-fuel mixture in the mixing chamber 3 is ignited and burns with flame. By burning the air-fuel mixture in the mixing chamber 3 below the combustion catalyst 4, the heat generated at that time preheats the combustion catalyst 4 to a temperature at which catalytic combustion can be performed, and shifts to catalytic combustion.

When the temperature of the combustion catalyst 4 is a temperature at which catalytic combustion is possible, such as in the case of restarting, the temperature data inputted from the temperature sensor 6 to the control means 7 is set to a set temperature, for example, 450 ° C. or more. Therefore, the ignition means 5 is controlled so as not to perform the ignition operation. Therefore, the air-fuel mixture in which the fuel and the air are mixed in the mixing chamber 3 is directly supplied to the combustion catalyst 4 and catalytically burned.

FIG. 2 shows another example of the embodiment of the present invention. In this example, the temperature sensor 6 is disposed immediately above the combustion catalyst 4, for example, at a position 10 mm above. Other configurations are the same as those in FIG. There is a correlation between the temperature of the combustion catalyst 4 and the temperature around it, and particularly, the correlation between the temperature of the combustion catalyst 4 and the temperature immediately above it is high. By measuring, the temperature of the combustion catalyst 4 can be detected from the correlation. When the temperature sensor 6 is embedded in the combustion catalyst 4 as in the embodiment of FIG. 1 described above, the temperature of the combustion catalyst 4 can be accurately measured. The high temperature at the time of combustion acts on the temperature sensor 6 as it is. On the other hand, by disposing the temperature sensor 6 directly above the combustion catalyst 4 as in the embodiment of FIG.
And the high temperature during the catalytic combustion does not act on the temperature sensor 6 as it is, and an inexpensive temperature sensor 6 such as a K-type thermocouple can be used. . For example, temperature sensor 6
Is lower than 350 ° C., it is determined that the temperature of the combustion catalyst 4 is lower than the temperature required for catalytic combustion, and the ignition means 5 is controlled to perform ignition operation. When the temperature is 350 ° C. or higher, the temperature of the combustion catalyst 4 is determined to be a temperature at which catalytic combustion is possible, and the ignition means 5 is controlled so as not to perform the ignition operation.

[0020]

As described above, the catalytic combustion device according to the first aspect of the present invention comprises a mixing chamber for mixing air supplied from the air supply device and the fuel supplied from the fuel supply device with a fuel of a combustible gas. A combustion catalyst for oxidizing the air-fuel mixture and igniting the air-fuel mixture supplied to the combustion catalyst; and igniting the air-fuel mixture supplied to the combustion catalyst. Since the ignition is not performed, it is possible to prevent the ignition means from being ignited when the temperature of the combustion catalyst is at a temperature at which the catalyst can be catalyzed. In addition, it is possible to improve the reliability by preventing abnormal ignition of the air-fuel mixture.

According to a second aspect of the present invention, there is provided a temperature sensor for detecting the temperature of the combustion catalyst, and a control for controlling the ignition by the ignition means when the temperature of the combustion catalyst detected by the temperature sensor is higher than a predetermined temperature. Since the means is provided, the ignition control by the ignition means can be reliably performed by the detection of the temperature of the combustion catalyst by the temperature sensor and the control by the control means based on the detected temperature.

According to the third aspect of the present invention, since the temperature sensor is disposed so as to be embedded in the combustion catalyst, the temperature of the combustion catalyst can be accurately detected by the temperature sensor.

According to the fourth aspect of the present invention, since the temperature sensor is disposed immediately above the combustion catalyst, the temperature sensor can be easily mounted, and the high temperature during combustion of the catalyst acts on the temperature sensor as it is. This makes it possible to use an inexpensive temperature sensor.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing another example of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air supply device 2 Fuel supply device 3 Mixing chamber 4 Combustion catalyst 5 Ignition means 6 Temperature sensor 7 Control means

Continued on the front page (72) Inventor Hitoshi Kudo 1048 Kazuma Kadoma, Osaka Prefecture F-term in Matsushita Electric Works, Ltd. (reference) 3K005 AB02 AC06 BA08 CA06 EA02 3K017 BA02 BA05 BB01 BB06 BC10 BD01 BF03 BH02 3K065 TA13 TB11 TD05 TH01 TK04 TN01

Claims (4)

[Claims] 1. A mixing chamber for mixing air supplied from an air supply device and a fuel supply device with a fuel of a combustible gas, and a combustion in which the air-fuel mixture mixed in the mixing chamber is oxidized and catalytically burned. A catalytic combustion apparatus comprising: a catalyst; and ignition means for igniting an air-fuel mixture supplied to the combustion catalyst, wherein ignition is not performed by the ignition means when the temperature of the combustion catalyst is equal to or higher than a predetermined temperature. 2. A fuel cell system comprising: a temperature sensor for detecting a temperature of a combustion catalyst; and control means for controlling ignition by an ignition means when the temperature of the combustion catalyst detected by the temperature sensor is equal to or higher than a predetermined temperature. The catalytic combustion device according to claim 1, wherein: 3. The catalytic combustion device according to claim 2, wherein the temperature sensor is disposed so as to be embedded in the combustion catalyst. 4. The catalytic combustion device according to claim 2, wherein the temperature sensor is disposed immediately above the combustion catalyst.