JPS63271010A - Gas-fired equipment - Google Patents

Abstract

PURPOSE:To reduce the temperature increase at the outer periphery to reduce the heat loss by providing a burning chamber having secondary air supply holes, a mixed gas supply means that supplies the mixed gas and a secondary air chamber that allows the secondary air to be supplied into the burning chamber. CONSTITUTION:When combustion air is supplied from an opening 13 in an air supply space 2 into an outer shell 1, part of the air is introduced into a mixing chamber 6 through primary air holes 11 as primary air, and the remainder flows to a secondary air chamber 5 as secondary air. Fuel gas is supplied to the mixing chamber 6 through a fuel supply pipe 10, and the mixture gas is supplied into the burning chamber 3 through a mixture gas outlet 7. The mixture gas is diffused by a diffuser plate 9 and caused to flow along the inner surface of the cylindrical wall 4 to the downstream side of the burning chamber 3. The secondary air introduced into the secondary air chamber 5 is jetted out of secondary air supply holes 8 in the cylindrical wall 4, and the mixture gas is mixed with said secondary air to become combustible. The gas is ignited and burnt by an ignition device 12. The burning flame 14 is oriented from around the secondary air supply holes 8 to the axis of the burning chamber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to gas combustion devices, and more particularly to devices with improved flame formation conditions.

(Prior Art) An example of a premix type gas combustion device that supplies supplementary air to a combustion zone is shown in Japanese Patent Publication No. 56-20442. In this device, as shown in FIG. 2, an air-fuel mixture is supplied into a burner 23 through a fuel pipe section 21 and a fuel regulating fluid 22, and is ejected from a flame [124] and combusted in a combustion chamber 25. At this time, auxiliary air is supplied from the supply port 26 to the air chamber 27.
The fuel passes through the pipe 28 and the two pipes and is blown out from the outlet 30 into the combustion area in the combustion chamber 25, thereby achieving stable combustion in the burner 23.

(Problem to be Solved by the Invention) However, since the air-fuel mixture is ejected radially from the central axis of the burner 23, the flame 31 is also formed radially outward as shown in FIG. Therefore, there was a problem in that the temperature of the outer circumferential wall of the combustion chamber 25 rose and the heat loss caused by heat radiation therefrom was large. To prevent this, the combustion chamber 2
Cooling devices such as water jackets 1 to 32 should be placed along the outer periphery of the pipe.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a gas combustion device in which the temperature rise in the outer circumference is small and the heat loss is small even without using cooling equipment.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the gas combustion device of the present invention supplies secondary air to the mixture of gas fuel and primary air to combust it. a combustion chamber in which a plurality of secondary air injection holes are provided in the peripheral wall thereof; a mixture supply means for supplying a mixture in the axial direction of the combustion chamber and along the inner side of the peripheral wall; A secondary air chamber is provided on the outer periphery of the combustion chamber and is configured to blow out secondary air into the combustion chamber from the outside of the peripheral wall of the combustion chamber through the secondary air injection hole.

(Function) That is, the present invention supplies an air-fuel mixture to the inside of the peripheral wall of the combustion chamber, and also blows out secondary air from the outside of the peripheral wall toward the central axis l\ of the combustion chamber through the secondary air injection hole. be. With such a configuration, a combustion flame is formed from around the secondary air injection hole in the peripheral wall of the combustion chamber toward the central axis l\ of the combustion chamber. Therefore, the temperature rise of the outer peripheral wall of the combustion device is suppressed to a small level, and heat loss is reduced.

In addition, the secondary air ejection holes are provided in multiple stages from the upstream side to the downstream side of the flow of the air-fuel mixture, and each stage is equipped with a If set, even if unburned substances are generated on the upstream side, they will mix with the secondary air on the downstream side and be completely combusted.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a gas combustion apparatus according to an embodiment of the present invention. A combustion air supply section 2 is provided at one end of the outer cylinder 1, and a cylindrical peripheral wall 4 that partitions and forms a combustion chamber 3 is installed within the outer cylinder 1. A secondary air chamber 5 is formed. A mixing chamber 6 is provided at the end of the combustion chamber 3 on the air supply section 2 side (hereinafter, this will be referred to as the upstream side, and the opposite side will be referred to as the downstream side), and this mixing chamber 6 and the combustion chamber 3 are mixed. It communicates through the air outflow hole 7.

Further, a large number of secondary air ejection holes 8 are provided in multiple stages in the peripheral wall 4 from the upstream side to the downstream side, and the sum of the frontage areas of the ejection holes 8 in each stage increases as it goes downstream. is set to .

A conical diffuser plate 9 is provided coaxially with the combustion chamber 3 on the upstream side of the combustion chamber 3, and the diffuser plate 9 and the mixing chamber 6 constitute an air-fuel mixture supply means. Further, a fuel supply pipe 10 is connected to the mixing chamber 6, and a primary air hole 11 is provided on the side thereof.

In addition, in the figure, 12 is an ignition device provided facing into the combustion chamber 3.

Next, the operation of this embodiment will be explained.

First, when combustion air is supplied into the gas chamber 1 from the jet port 13 of the air supply section 2, a part of it is introduced into the mixing chamber 6 through the primary air hole 11 as primary air, and the rest is It flows into the secondary air chamber 5 as secondary air. At this time, gas fuel is supplied into the mixing chamber 6 via the fuel supply pipe 10, and the gas fuel and primary air are mixed here, and the mixture is formed as an air-fuel mixture from the air-fuel mixture outlet hole 7 into the combustion chamber. Inside is supplied. The air-fuel mixture thus supplied is uniformly diffused by the diffusion plate 9 and then flows toward the downstream side of the combustion chamber 3 along the inside of the peripheral wall 4.

At this time, the secondary air introduced into the secondary air chamber 5 is
The secondary air is ejected into the combustion chamber 3 from the secondary air ejection hole 8 . As a result, the air-fuel mixture mixes with this secondary air, becomes in a flammable range, and is ignited by the ignition device 12 to combust. In this way, a combustion flame 14 is formed from around the secondary air nozzle 8 toward the central axis of the combustion chamber 3.

Note that the total area between the secondary air nozzles 8 at each stage is set to increase toward the downstream side of the combustion chamber 3, and the area near the upstream diffusion plate 9 is Even if combustion substances are generated, as they flow downstream, they are further mixed with secondary air and are completely combusted.

[Effects of the Invention] As explained above, according to the present invention, the following excellent effects are exhibited.

(1) Since the combustion flame is formed from the peripheral wall of the combustion chamber toward the central axis of the combustion chamber, the temperature rise at the outer periphery of the device, which consists of external stations, etc., is suppressed to a small level, and a reduction in heat loss can be achieved. At the same time, the length of the combustion flame can be shortened.

(2) Combustion flame is transmitted through multiple flame ports (secondary air ejection holes)
Since the flame temperature per flame port is reduced, NOx can be reduced.

(3) By providing secondary air blow-off holes in multiple stages,
The amount of combustion can be easily adjusted.

(/I) Furthermore, by increasing the sum of the frontage areas of the secondary air nozzles at each stage toward the downstream side of the combustion chamber, unburned substances are completely combusted, and the COi can be reduced by 19 degrees.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a gas combustion apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. In the figure, 3 is a combustion chamber, 4 is a peripheral wall, 5 is a secondary air chamber, 6 is a mixing chamber, 8 is a secondary air outlet, and 9 is a diffusion plate.

Claims (2)

[Claims] (1) A gas combustion device that supplies secondary air to a mixture of gas fuel and primary air to combust it, including a combustion chamber in which a plurality of secondary air injection holes are provided in the peripheral wall of the combustion chamber, and the combustion chamber. an air-fuel mixture supply means for supplying the air-fuel mixture in the axial direction and along the inner side of the circumferential wall of the combustion chamber; A gas combustion device characterized by comprising a secondary air chamber for blowing out secondary air indoors. (2) The secondary air ejection holes are provided in multiple stages from the upstream side to the downstream side of the flow of the air-fuel mixture, and the total opening area of each stage increases as it goes toward the downstream side. A gas combustion device according to claim 1.