JPH04177006A - Collision combustion device - Google Patents

Abstract

PURPOSE:To realize a high load combustion in a small combustion chamber by achieving a rapid mixture of the air and combustion gas under a strong turbulence in the lower combustion chamber and an effective mixture of the unburned gas and burned gas also in the upper combustion chamber. CONSTITUTION:The combustion air is jetted out of air blow-out ports 22 and 22 that are mutually opposed and the fuel gas is jetted out of a fuel gas blow-out port. The combustion air that is jetted out of both sides collides in the center of a lower combustion chamber 20 and forms a collision space that is in a violently turbulent state. And, the fuel gas that is blown out is mixed with the combustion air rapidly in the collision space and the combustion proceeds rapidly under the turbulence. But the combustion is not completed in the lower combustion chamber 20, but the fuel gas that is in the middle of reaction enters the upper combustion chamber 30 and it is again disturbed strongly by a baffle board 31. By this turbulence the combustion gas in the middle of reaction and already burned gas are mixed and they spread all over the upper combustion chamber 30 and complete their combustion. After the gas that completes combustion exchanges heat by a heat exchanger 33 in the upper section of the combustion chamber 30, it is discharged from an exhaust section 40.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an impingement combustion device that collides with airflow from both sides and supplies gaseous fuel to the collision space to perform 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 O, is generated, it is difficult to realize a low NoX 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 NOx in exhaust gas, but flames tend to blow out easily.
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 to widen the flame stability range is generally complex.

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 N low, but the device is complicated and expensive, making it difficult to apply to household combustors.

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

<Means for Solving the Problems> In order to achieve the above object, the impingement combustion device of the present invention includes a plurality of pairs of impingement air nozzles provided horizontally opposite each other at a relatively short distance; A lower combustion chamber is provided with a plurality of fuel gas injection holes that eject gas fuel vertically from below toward a collision point of air ejected from a pair of collision air injection holes, and a lower combustion chamber that is continuous above the lower combustion chamber. The combustion chamber is characterized in that it has an upper combustion chamber that is enlarged in size, and that a baffle plate is provided in the upper combustion chamber to disturb the upward flow from the lower combustion chamber.

<Operation> The air ejected from the opposing collision air nozzles collides in the lower combustion chamber, producing strong disturbance. Fuel gas is ejected from below into this collision space and ignited, so that air and gaseous fuel are mixed in a very short time, and combustion rapidly progresses under strong disturbance. Since the distance between the opposing collision air nozzles is relatively short, the collision space is also narrow.
Combustion is not completed within the lower combustion chamber. The combustion gas in the middle of this reaction (combustion) becomes an upward flow and enters the upper combustion chamber, where it is again strongly disturbed by the baffle plate. This disturbance promotes the mixing of burnt gas and unburnt gas, and the gas spreads into the upper combustion chamber to complete combustion.

Air and fuel gas are mixed effectively in the lower combustion chamber,
In addition, the gases in the middle of combustion are mixed effectively in the upper combustion chamber, so the volume of the combustion chamber required for combustion is small.
High-load combustion can be achieved.

In addition, the baffle plate in the upper combustion chamber actively mixes and burns the burnt gas and unburnt gas, so exhaust gas recirculation (E,
G, R) effects can lower NoX.

<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. FIGS. 4(8) and 4(B) are diagrams each showing an example of the arrangement of the collision air nozzles, and FIG. 5 is a sectional view showing an example of the collision air nozzles, which is not very preferable.

A lower combustion chamber 20 is provided in the lower part of the combustion can body 10, an upper combustion chamber 30 is provided in the middle part of the combustion can body 10, and an exhaust part 40 is provided in the upper part.

a lower combustion chamber 20 provided at the lower part of the combustion can body 10;
consists of a long and narrow space in the horizontal direction, with two walls facing each other across a relatively short distance,
21 are provided with a plurality of pairs of impingement air outlets 22, 22, each horizontally opposed. 23 and 23 are combustion air supply pipes, respectively.

Further, a plurality of fuel gas injection holes 25 are provided in the bottom wall 24 of the lower combustion chamber 20 and open vertically toward the air collision point 27 of the air ejected from each of the collision air injection holes 22.22 pairs. ing. 26 is a fuel gas supply pipe. Note that in the above, a relatively short distance means that the collision space including the air collision point 27 configured within that distance is relatively narrow.
This means that the combustion of the supplied fuel gas is not completed in the collision space.

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, or in two rows as shown in FIGS. 4(A) and 4(B), or in other plural rows.

The upper combustion chamber 30 gradually and continuously expands from the vicinity of the air collision point 27 of the lower combustion chamber 20 to a width L.
It is composed of a relatively large space with 2 spaces. A baffle plate 31 is provided in the upper combustion chamber 30 above the air collision point 27. The baffle plate 31 is made of a heat-resistant material or water-cooled metal. Note that in the above, a relatively wide space refers to a space that allows combustion to be completed within that space.

A heat exchanger 33 with a water pipe 32 arranged above the combustion chamber 30
will be provided. Further, a sound deadening material 41 is arranged in the exhaust section 40.

Next, the combustion operation and effect of this device will be explained. During operation, combustion air is ejected from the opposing impingement 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 the lower combustion chamber 20, forming a collision space consisting of a strong disturbance state around the air collision point 27.

The fuel gas ejected toward the air collision point 27 is rapidly mixed with combustion air in the collision space in a short period of time. As a result, combustion progresses rapidly under disturbance. However, since the distance L1 between the opposing collision air nozzles 22 is relatively short, the collision space is also narrow, and combustion is not completed in the lower combustion chamber 20. The fuel gas in the middle of the reaction is transferred to the lower combustion chamber 2.
0 and enters the upper combustion chamber 30, where the flow is again blocked by the baffle plate 31 and is strongly disturbed. Due to this disturbance, the combustion gas in the middle of reaction from below and the burnt gas whose combustion has been completed in the upper combustion chamber 30 quickly mix and spread throughout the upper combustion chamber 30 to complete combustion. After the combustion has been completed, the gas is heat exchanged in the upper part of the upper combustion chamber 30 by the heat exchanger 33, and then is discharged from the exhaust section 40.

It is preferable that the shape of the baffle plate 31 is concave on the lower side. Because the lower side is concave, the lower combustion chamber 2
This is because the upward flow from 0 hits the baffle plate 31 and produces a downward flow, which mixes with the burnt gas and has a large disturbance effect. Note that without the baffle plate 31, the upward flow from the lower combustion chamber 20 would quickly pass through the center of the upper combustion chamber 30, and combustion would not be completed successfully.

Further, collision air nozzle 2 provided in the lower combustion chamber 20
2 preferably does not protrude inward from the wall 21. By doing so, the flame is stably held in the space near the air collision point 27 without being held in the collision air outlet 22. In the configuration in which the collision air nozzle 28 protrudes into the lower combustion chamber as shown in FIG. 5, the protruding portion is heated, resulting in poor durability. Also, a protruding collision air outlet 28
The flame is more likely to be retained in the area, reducing the effect of turbulence.

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 impingement combustion apparatus according to claim 1, rapid mixing of air and fuel gas under strong disturbance in the lower combustion chamber and upper combustion are achieved. Since it is possible to achieve effective mixing of unburned gas and burnt gas using the baffle plate in the room, a large output can be produced with a small combustion chamber as a whole, and high-load combustion can be achieved.

Furthermore, since effective mixed combustion of unburned gas and burnt gas can be achieved in the combustion chamber, NO and t1 degrees can be sufficiently reduced without using any special external additional equipment.

Diffusion combustors generally have a small combustion chamber load, but in the device of the present invention, even a diffusion combustor can achieve a high load of about 2 x 10'kcal/m'h as a household combustor. Also, the amount of NO emissions is 2 at an excess air ratio of 1.2.
5ppm, which is less than 1/4 of that of a conventional general Bunsen combustor, and it is possible to achieve low N without using an expensive exhaust gas recirculation device.
oX 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 jet holes, and FIG. 5 is a sectional view showing an example of a less preferred collision air jet hole. 10: Combustion can body 20: Lower combustion chamber 22: Collision air nozzle 25: Fuel gas nozzle 27: Air collision point 30: Upper combustion chamber 31: Baffle plate

Claims (1)

[Claims] (1) A plurality of pairs of collision air nozzles provided horizontally opposite each other at a relatively short distance, and vertical direction from below toward the collision point of the air ejected from the pairs of collision air nozzles. It has a lower combustion chamber provided with a plurality of fuel gas injection holes for ejecting gas fuel in the direction, and an upper combustion chamber that is continuously expanded above the lower combustion chamber, and inside the upper combustion chamber. An impingement combustion device characterized in that a baffle plate is provided to disturb the upward flow from the lower combustion chamber.