JPH0626624A - Method and apparatus for promoting combustion in combustion device - Google Patents

Abstract

PURPOSE:To prevent heat from escaping toward a burner pipe wall and to enable a blow-off limited flow rate to be expanded by a method wherein an annular flame holding unit arranged at an inner circumferential surface of an air fuel mixing unit is made of heat generating member or a flame holding unit heating means is provided. CONSTITUTION:An inner circumferential surface of an air fuel mixing unit 4 is provided with an annular rim-shaped flame holding unit 10. As the combustion air is injected from air injection holes 3 and fuel gas is injected from a fuel gas supplying passage 8, a negative pressure region is generated near a side surface of a combustion gas nozzle of the flame holding unit 10, thereby its lift is restricted. In this case, the flame holding unit 10 is comprised of a ring-like ceramic heater 10' and this heater is electrically energized to increase a temperature of the flame holding unit 10. The flame holding unit may be heated with a suitable heating means separately arranged from the flame holding unit 10. In this way, heating amount released from the combustion gas to the pipe wall is reduced and further heat is supplied to gas from the burner pipe, so that combustion speed can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for promoting combustion in a combustor such as a burner or an internal combustion engine and a combustor used directly for carrying out the method.

[0002]

2. Description of the Related Art The amount of heat generated in a combustor such as a burner or an internal combustion engine is determined by the amount of supplied fuel / oxidant, and its upper limit (generated heat amount) is dependent on the blow-off limit amount. If the blow-off limit amount is expanded, the heat generation amount that can be generated in the combustor of the same shape can be increased (combustion load factor can be improved). Therefore, in order to expand the flame holding ability, a rim type flame holder or the like has been conventionally used, such as a high-speed burner described in Japanese Utility Model Laid-Open No. 62-81822.

[0003]

On the other hand, in a state where the flame is held near the outlet of the burner or the like, if the amount of heat transferred to the burner pipe wall is large, the combustion speed becomes small. In the state where the combustion is maintained, the amount of heat generated is the heat supply to the surrounding gas bodies (fuel, oxidant and atmosphere) and the escape of heat to the burner. This latter heat release to the burner (mainly to the burner tube wall) is quite large, which hinders the increase of the combustion speed and hinders the expansion of the blowout limit amount. Simply install a flame stabilizer. This problem cannot be solved only by suppressing the lift by creating a negative pressure region near the side surface of the combustion gas nozzle. The present invention has been made in view of the above problems of the prior art, the purpose of which is to prevent the escape of heat to the burner pipe wall,
This is to increase the amount of heat that can be generated by further increasing the flame holding capacity and expanding the blowout limit flow rate.

[0004]

To achieve the above object, in the combustion promoting method of the present invention, the flame holding portion is heated to a high temperature during combustion, and the combustor therefor is an air / fuel mixer ( The annular flame stabilizer provided on the inner peripheral surface of the burner tube is constituted by a heating element, or a flame stabilizer heating means for heating the flame stabilizer is provided.

[0005]

In the combustion promoting method and the combustor configured as described above, the amount of heat escaping from the combustion gas to the pipe wall decreases due to the temperature rise of the burner pipe wall of the flame holding part, and further, the heat from the burner pipe to the gas is reduced. Are supplied to increase the burning rate.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, A is a combustor, in this case a gas burner, which is formed into a substantially conical shape in a cylindrical burner casing 2 having a combustion gas ejection nozzle 1 formed at its tip, and a large number of air ejection holes 3 formed on the entire peripheral wall thereof. The air / fuel mixer 4 which is dispersively opened is installed with its large-diameter side opening facing the combustion gas ejection nozzle 1 side.

A combustion air supply passage 6 is formed between the burner casing 2 and the air / gas mixer 4 to open an air inlet 5 to the burner casing 2, and the air supplied from the air inlet 5 is supplied to the combustion air supply passage 6. Air from the air ejection hole 3
It is designed to jet into the gas mixer 4. Further, the combustion air supply passage 6 has a jet passage 7 that opens in an annular shape along the outer circumference of the large-diameter side opening of the air / fuel mixer 4, and one of the air supplied from the air inlet 5 is provided. The portion is arranged to be along the inner peripheral surface of the burner casing 2 and is ejected toward the combustion gas nozzle ejection 1 side.

On the other hand, a fuel gas supply passage 8 is connected to the small diameter side opening of the air / fuel mixer 4 so that the fuel gas supplied from the fuel inlet 9 is blown into the air / fuel mixer 4. There is. Further, an annular rim-shaped flame stabilizer 10 is attached to the inner peripheral surface of the air / fuel mixer 4, so that combustion air is ejected from the air ejection holes 3 and fuel gas is ejected from the fuel gas supply passage 8. The lift is suppressed by generating a negative pressure region near the side surface of the combustion gas nozzle of the flame stabilizer 10 with the ejection.

Reference numeral 11 denotes a pilot burner, which is provided in the fuel gas supply passage 8 so that its flame port 12 is located near the small diameter side opening of the air / fuel mixer 4 and faces the combustion gas injection nozzle 1. It is provided in.

The structure described above is based on the above-mentioned actual construction 62-.
The structure is already known as a gas burner described in Japanese Patent No. 81822, but in the present embodiment, the annular rim type flame stabilizer 10 is constituted by a ring-shaped ceramic heater 10 'in the gas burner having such a structure. By energizing the heater 10 ', the flame stabilizer 10 can be heated. The ceramic heater 10 ′ constituting the flame stabilizer 10 has its terminal 13 penetrating the air / fuel mixer 4 and the burner casing 2 and extended to the outside of the casing 2, and is held and fixed to the casing via the holding insulating portion 14. .

Thus, having such a structure, 80,000 Kcal /
The gas burner of the present invention in which the flame stabilizer 10 of the burner for time is composed of a ring-shaped ceramic heater 10 'is different from the conventional gas burner which is the same in shape and has a structure in which the flame stabilizer 10 cannot be heated. When comparing the combustion of Example), the combustion of the comparative example exceeds 140,000 Kcal / hour if the rated value exceeds 80,000 Kcal / hour.
Lift occurred in time, and blown off at 160,000 Kcal / hour, but in the system of the present invention, stable combustion was obtained even at 250,000 Kcal / hour by heating the flame stabilizer to 1200 ° C.

In the embodiment described above, the flame stabilizer is made of a ceramic heater to raise the temperature of the flame holding portion. However, the flame stabilizer is not limited to the ceramic heater but may be made of another suitable heating element such as a nichrome wire heater. Alternatively, the flame stabilizer may be heated by a suitable heating means provided separately from the flame stabilizer. Also, in a burner of a type that does not include a rim-type flame stabilizer, the same effect can be obtained by heating the flame-holding part by some method.

Since the present invention is configured as described above, it has the following effects. (1). The increase in the temperature of the burner tube wall in the flame-holding section reduces the amount of heat that escapes from the combustion gas to the tube wall, and the heat is supplied to the gas from the burner tube, which can increase the combustion speed and increase the flow rate. But it won't blow away. Therefore,
With the same combustor, a combustor with a larger calorific value can be obtained. (2). The combustion range (air / fuel mixture ratio) is expanded. In particular, the expansion of the lean region brings about purification of combustion exhaust gas (low NOX, low CO, etc.).

[Brief description of drawings]

FIG. 1 is a combustor (gas burner) showing an embodiment of the present invention.
Sectional view of.

FIG. 2 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

 A Combustor 4 Air / fuel mixer 10 Flame stabilizer (flame holding part) 10 'Heating element

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Mitsuaki Tamura 1-17-1 Chiyo, Hakata-ku, Fukuoka-shi, Fukuoka Within Seibu Gas Co., Ltd. (72) Hidenobu Matsushita 1-1-17 Chiyo, Hakata-ku, Fukuoka-shi, Fukuoka No. 1 West Gas Co., Ltd. (72) Inventor Akito Kumamoto 1-17-1 Chiyo, Hakata-ku, Fukuoka City Fukuoka Prefecture

Claims (2)

[Claims] 1. A method of promoting combustion in a combustor, which comprises raising the temperature of a flame holding portion to a high temperature during combustion. 2. An annular flame stabilizer provided on the inner peripheral surface of the air / fuel mixer of the combustor is composed of a heating element, or a flame stabilizer heating means for heating the flame stabilizer is provided. Characterized combustor.