JPH04177004A - Collision combustion device - Google Patents

Abstract

PURPOSE:To greatly reduce the volume of a combustion chamber and achieve a high load combustion by mixing the combustion air and the fuel gas under the turbulence created by the collisions once in a branch combustion chamber and once in the main combustion chamber and burning the mixture rapidly. CONSTITUTION:The combustion air is jetted out from two collision air blow-out holes 22 and 22 which oppose each other vertically and the fuel gas is jetted out from a fuel gas jet hole 25. The combustion air that is jetted out on both sides collide each other in the centers of respective branch combustion chambers 20 and 20 to form a collision space which is in a strong turbulence. The fuel gas that is jetted out mixes with the combustion air in the collision space rapidly and the combustion progresses violently under the turbulence. The combustion, however, does not reach completion in the branch combustion chambers 20 and 20 and the fuel gas which in the process of reaction flows from respective branch combustion chambers 20 and 20 to the main combustion chamber 30 and they collide mutually and they are again disturbed strongly and the combustion gas that is in the middle of reaction and the already burned gas mix rapidly and the combustion is completed by spreading all over the main combustion chamber 30. The gas that has completed the combustion exchanges heat through a heat exchanger 50 in the upper section of the main combustion chamber 30 and then is discharged from an exhaust gas section 40.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an impingement combustion device that collides air flows from both sides and supplies gas fuel to the collision space for combustion.

<Prior art and its problems> Conventionally, Bunsen combustion has been the mainstream in continuous combustors using gas fuel, and premix combustion has been put into practice in some cases. On the other hand, there are almost no practical examples of household combustors using diffusion combustion.

In the Bunsen combustion described above, a high concentration of N is generated in the wake of the high-temperature inner flame.
Since Ox is generated, it is difficult to realize a low NO combustor. Furthermore, since a large space is required for secondary combustion, it is difficult to achieve high-load combustion.

On the other hand, premix combustion with a lean mixture is effective as a means of reducing NO in exhaust gas, but the flame tends to blow out.
The disadvantage is that the amount of combustion is limited. Furthermore, in premixed combustion, the flame stability range is narrow, and in practical combustors, the combustor structure for widening the flame stability range is generally complicated.

In addition, some large commercial combustors use exhaust gas recirculation (E, G), which mixes a portion of the exhaust gas with combustion air.

R) has been attempted to reduce NOx, but the device is complicated and expensive, making it difficult to apply it to household combustors.

Therefore, the present invention eliminates the drawbacks of the above-mentioned prior art and achieves low NOx
The purpose of the present invention is to provide a new impingement combustion device that can realize high-load combustion and is suitable as a continuous combustor for domestic use.

<Means for Solving the Problems> In order to achieve the above object, the impingement combustion device of the present invention has a pair of relatively narrow branch combustion chambers branched in the left and right directions at the lower part of the main combustion chamber, and each of the branch combustion A plurality of pairs of collision air nozzles are provided on the upper and lower walls of the chamber to face each other vertically and eject combustion air, and the end wall of each branch combustion chamber is provided with a pair of collision air nozzles that are horizontal to the collision space of the combustion air. It is characterized by having a plurality of fuel gas ejection holes that eject fuel gas in different directions.

<Operation> Combustion air ejected from the colliding air nozzles that are vertically opposed in each branch combustion chamber collides near the center of the branch combustion chamber, producing strong disturbance. By supplying the fuel gas ejected from the fuel gas nozzle to this collision space, the combustion air and the fuel gas are rapidly mixed in a short period of time, and combustion rapidly progresses. However, since the branch combustion chamber is relatively narrow,
The collision space is also narrow, and combustion is not completed within the branch combustion chamber. This uncombusted combustion gas (in the middle of a reaction) flows from the branch combustion chamber into the main combustion chamber, collides with each other at the confluence point from both branch combustion chambers, and forms a collision space in a strongly disturbed state again. In this collision space, under strong turbulence, the mixture of burnt gas and unburnt gas is promoted, and combustion is completed while rising.

Combustion air and fuel gas are mixed effectively under two collision disturbances in the branch combustion chamber and the main combustion chamber, so that
The volume of the combustion chamber required for combustion is small, and high-load combustion can be achieved. In addition, since the combustion gases from both branch combustion chambers are collided within the main combustion chamber, the unburnt gas and burnt gas are actively mixed in the collision space, and exhaust gas recirculation (E, G
, R) effect, low NO combustion can be achieved.

<Example> Fig. 1 is a partially sectional perspective view showing an embodiment of the device of the present invention, Fig. 2 is a sectional view of a combustion chamber, Fig. 3 is a view showing another example of the shape of the collision air nozzle, and Fig. 4(A) and 4(B) are diagrams each showing an example of arrangement of collision air ejection holes, and FIG. 5 is a sectional view showing a comparative example with respect to the apparatus of the present invention.

An exhaust section 40 is provided at the top of the combustion can 10, and the interior of the can 10 below is a main combustion chamber 30. Exhaust section 40
A sound deadening material 41 is placed in front of the sound absorbing material 41, and a heat exchanger 50 having a water pipe 51 is placed in front of the sound deadening material 41.

The main combustion chamber 30 is an elongated space having an appropriate width L2 and height H2, and is gradually reduced in size on both the left and right sides towards the bottom, and is branched into a pair of branches in the left and right directions at the bottom. The combustion chamber is set to 20.20. Branch combustion chamber 2
The inner bottom surface of the 0.20 branch part is configured in a chevron shape 21 with a slight upward slope toward the branch line. In addition, the inner wall 3 of the branch part of the branch combustion chamber 20 and 20 at the lower part of the main combustion chamber 30
1.31 is rounded so as not to obstruct the flow of combustion gas, which will be described later. The width between this branch inner wall 31 and 31,
is narrower than the width L2 of the main combustion chamber 30.

The pair of branch combustion chambers 20.20 have a relatively narrow space, and the combustion air is ejected vertically against the upper and lower walls of each branch combustion chamber 20 separated by a relatively short distance H1. A plurality of pairs of air ejection holes 22, 22 are provided along the elongated direction. 23 is a combustion air supply pipe. Furthermore, the end wall 24 of each branch combustion chamber 20 is provided with a fuel gas ejection hole 25 that ejects fuel gas in the horizontal direction. The fuel gas ejected from the fuel gas ejection holes 25 is supplied to the lower part of the collision point P of the combustion air ejected from the pair of air ejection holes 22. 26 is a fuel gas supply pipe.

In the above description, the expression "relatively narrow" in the branch combustion chamber 20 or 20 space means that combustion is not completed within the space. Furthermore, in the above, when the distance H between the upper and lower walls of the branch combustion chamber 20 is "relatively short", it means that the distance H1 is an element constituting the space of the branch combustion chamber 20 that is "relatively narrow"; This means that combustion cannot be completed within the "relatively short" distance H1.

Furthermore, in the width L2 and height H2 of the main combustion chamber 30, "
"Appropriate" means that combustion can be completed in a space having width L2 and height H2.

The shape of the collision air ejection hole 22 may be a round hole shown in FIG. 1, a slit-like hole shown in FIG. 3, or other shapes. Further, the collision air ejection holes 22 may be arranged in a single row as shown in FIG. 1, in two rows as shown in FIGS. 4(^) and (B), or in other plural rows.

Next, the combustion operation and effect of this device will be explained. During operation, combustion air is ejected from the vertically opposed collision air ejection holes 22, 22 at a speed several times the combustion speed, and fuel gas is ejected from the fuel gas ejection holes 25. The combustion air ejected from both sides at approximately the same speed collides at the center of each branch combustion chamber 20, 20, forming a collision space consisting of a strong disturbance state around the air collision point P. The fuel gas ejected horizontally toward the lower part of the air collision point P is rapidly mixed with combustion air in a short time in the collision space. As a result, combustion progresses rapidly under disturbance. However, since the distance H3 between the opposing collision air nozzles 22 is relatively short, the space in the branch combustion chambers 20 is also narrow, and combustion is not completed in each branch combustion chamber 20.

The fuel gases undergoing reaction flow from each branch combustion chamber 20 to the main combustion chamber 30, collide with each other at the flow confluence, and form a strongly disturbed collision space there again. Due to this disturbance, the combustion gas in the middle of the reaction and the burnt gas quickly mix and spread throughout the main combustion chamber 30, completing combustion. The gas that has been completely combusted is transferred to the heat exchanger 5 at the upper part of the main combustion chamber 30.
0 and then exhausted from the exhaust section 40.

The inner bottom surface of the branch part where the left and right branch combustion chambers 20.20 branch is shaped like a chevron 21 toward the central branch line. It is smoothly transported to the center of the chamber 30 and collides stably. When the chevron-shaped portion 21 is horizontal or convex downward, combustion noise due to unnecessary turbulence of combustion gas is large.

In addition, in the case where the lower combustion chamber 27 is not paired with the upper combustion chamber 33 as in the comparative example shown in FIG. Since the collision disturbance state caused by the gas occurs only once in the lower combustion chamber 27, the flame becomes unstable under lean mixture conditions and a large amount of unburnt gas is emitted, but in the present invention, the collision occurs only twice. The flame remains stable until it approaches the flammability limit.

Further, in the above configuration of the present invention, all the collision air jet holes 22
With more combustion air being blown out, one branch combustion chamber 2
Even when fuel gas is supplied only from the fuel gas nozzle 25 of 0, stable combustion is possible, and the fuel can be further reduced than the lean limit when using the fuel gas nozzles 25 and 25 on both sides. , input aperture ratio (T, D, R)
can be made larger.

In addition, in the embodiment, a collision diffusion combustor is used that supplies fuel gas to a collision space made of combustion air, but it is also possible to use a premix collision combustor that mixes fuel gas with collision air in advance.

<Effects> The present invention has the above configuration and operation, and according to the collision combustion apparatus according to claim 1, combustion air and fuel gas are subjected to collision disturbance twice in the branch combustion chamber and the main combustion chamber. , can be mixed effectively and combusted rapidly, so the volume of the combustion chamber can be significantly reduced and high-load combustion can be achieved. In addition, since the combustion gases from both branch combustion chambers collide and are disturbed within the main combustion chamber, the mixing of unburned gas and burnt gas also occurs actively, resulting in a reduction in exhaust gas recirculation (E, G, R) effect. Nox combustion can be achieved.

Diffusion combustors generally have a small combustion chamber load, but with the device of the present invention, even a diffusion combustor can achieve a high load of about 3 x 107 kcal/m"h for a household combustor. Also, NOx emissions can be reduced. The amount is 2 at an excess air ratio of 1.2.
5ppm, which is less than the 174
O, can be realized.

[Brief explanation of drawings]

Fig. 1 is a partially sectional perspective view showing an embodiment of the device of the present invention, Fig. 2 is a sectional view of the combustion chamber, Fig. 3 is a view showing another example of the shape of the collision air nozzle, and Fig. 4 (A ) and (B) are diagrams each showing an example of arrangement of collision air ejection holes, and FIG. 5 is a sectional view showing a comparative example with respect to the apparatus of the present invention. 10; Combustion can body 20: Branch combustion chamber 22: Collision air nozzle 24: End wall 25: Fuel gas nozzle 30: Main combustion chamber

Claims (1)

[Claims] (1) The lower part of the main combustion chamber is formed into a pair of relatively narrow branch combustion chambers branched in the left and right directions, and combustion air is ejected vertically against the upper and lower walls of each branch combustion chamber. A plurality of pairs of air ejection holes are provided, and a plurality of fuel gas ejection holes are provided on the end wall of each branch combustion chamber for ejecting fuel gas in a horizontal direction with respect to the combustion air collision space. Impingement combustion device.