JPS58158406A - Pulsation combustion unit - Google Patents

Abstract

PURPOSE:To reduce a low frequency sound by a method wherein a discharging gas chamber communicating with a combustion chamber of a pulsation combustion unit and a gas feeding chamber communicating with an upstream of the combustion chamber are defined to form a connection chamber, and a sound from the discharging side and a sound from the gas feeding side are struck to each other under their inverse phases. CONSTITUTION:A pulsation combustion unit is operated such that an ignition plug 4 and a combustion starting blower 5 are operated when started, the mixture of gas and air fed into the combustion chamber 11 is exploded and combustioned. Once a self- activating cycle is completed, a negative pressure in the combustion chamber 1 causes the combustion air to be automatically sucked into the combustion chamber 1 along with the gas. Further, a connecting chamber 7 to which the gas discharging pipe 2 and one end of the gas feeding pipe 6 are connected is arranged, and each of the pipes 2, 6 is opened to the gas discharging chamber 10 and the gas feeding chamber 9 partitioned by the barrier wall 8 in the chamber 7. Each of the chambers 9, 10 is opened to a gas feeding port 11 and a gas discharging port 13. Thereby, a sound can be muffled by striking under an inverse phase a discharging sound and a gas feeding sound via barrier wall 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse combustor. A zero-pulse combustor inherently has high-load combustion characteristics and excellent heat transfer characteristics. Otherwise, combustion air is automatically sucked and ignites spontaneously, so there are many advantages such as reducing the cost required to drive spark plugs and blowers. However, due to the excessive noise generated during combustion, it has not been commercialized much despite the many advantages mentioned above. Conventionally, a muffler was attached to the combustor as a means of muffling noise, but mufflers are used to reduce low-frequency sounds. There were problems such as an increase in the size of the structure. In addition, as a means to suppress this low frequency component, we installed two combustors,
Measures have been considered to cancel the noise by using a phase difference on the air supply side, but with these measures, the configuration of the combustion device would be complicated if the combustor as a whole were to satisfy the noise reduction effect. In particular, with the two-combustion chamber configuration, cost reduction cannot be achieved, and this has been a difficult point for commercialization.

SUMMARY OF THE INVENTION In view of the conventional problems, the present invention provides a low-noise, low-cost pulse combustor.

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a first embodiment of the pulse combustor of the present invention. As shown in the figure, the pulse combustor includes a combustion chamber 1, an exhaust pipe 2, a pulp device 3, a spark plug 4, a combustion starting blower 5 , an air supply vibro, and a connection chamber 7.

Furthermore, this connection chamber 7 is constructed with a barrier 8 having a function of blocking only the flow of fluid and transmitting sound into the air supply chamber 9.
The air supply chamber 9 is partitioned into an exhaust chamber 10, and the air supply chamber 9 is also provided with an exhaust port 13 and an exhaust pipe connection hole 14.

Further, an air supply vibro is connected to the air supply pipe connection hole 12, and an exhaust pipe 2 is connected to the exhaust pipe connection hole 14. The structure is such that

Next, the operation of the pulse combustor will be explained. When starting, it is necessary to move the spark plug 4 and combustion starting blower 5, but once a self-excitation cycle is formed, negative pressure is generated in the combustion chamber 1, and the air supply port 11 and Combustion air is drawn into the combustion chamber 1 through the air chamber 9, the air supply vibro, and the pulp device 3, and combustion continues by spontaneous ignition. After the explosion, the combustion gas passes through the exhaust pipe 2, enters the exhaust chamber 1o, collides with the barrier 8 that partitions the connection chamber 7, and is exhausted to the outside through the exhaust port 13. The above is the flow of fluid during combustion.Based on this, we will next explain the sound waves.

First, after the explosion, the sound waves pass from the combustion chamber 1 through the exhaust pipe 2 and enter the exhaust chamber 1o in the same way as the combustion gas.

Also, on the air supply side, the sound waves pass through the pulp device 3 and the air supply vibro, and enter the air supply chamber 9. Then, the sound from the exhaust side and the sound from the air supply side pass through the barrier 8 in the connection chamber 7,
They collide with opposite phases and cancel each other out. At this time, sound from the exhaust side passes through the barrier 8, but the flow of combustion gas is blocked by the barrier 8, so even in the process of automatically sucking combustion air, the combustion gas will not disturb the pulse combustion. This also ensures combustion stability. In addition, the lengths of the air supply vibro and exhaust pipe 2 are determined so that the sound from the air supply side and the sound from the exhaust side are in opposite phases within the connection chamber 7, and the tips of both are also Although it may be in contact with the inner wall of the connecting chamber 7, it is more effective to have both ends projecting into the connecting chamber 7, and a good noise reduction effect can be obtained.

Next, a second embodiment of the pulse combustor of the present invention will be explained using FIG. 2. First, as for the configuration, the combustion chamber 1, exhaust pipe 2, pulp device 3, spark plug 4, combustion starting blower 6, and air supply vibro are located near the tip of the first exhaust pipe 2.
The exhaust side branch part 15 is also placed near the tip of the air supply vibro.
．． An air supply side branch 16 is provided, the two branches are connected by a pipe, and a barrier is installed at both ends of the connecting pipe 17 that blocks only the flow of fluid and allows sound to pass through, and an exhaust side barrier 18 is provided. , is provided as the air supply side barrier 19. Regarding the sound waves, after the explosion, the sound waves pass from the combustion chamber 1 through the exhaust pipe 2 to the exhaust side, and at the exhaust side branch part 16, the sound waves pass through the exhaust side barrier 1 at the exhaust side branch part 16.
8 and enters the connecting vibe 17. On the other hand, on the air supply side, the sound waves pass through the air supply vibro of the pulp apparatus 3, pass through the air supply side barrier 19 at the air supply side branch part 16, and enter the connection pipe 17. And the sound from the exhaust side and the air supply side -
The sounds collide with each other in opposite phases within the connecting pipe 17 and cancel each other out. The length of this connecting pipe 17 is determined so that the sound from the exhaust side and the sound from the air supply side are canceled out in opposite phases.

Also, at this time, the flow of combustion gas passes through the exhaust pipe 2,
Because it is blocked by the exhaust side barrier 18, it does not flow through the connecting pipe 17 to the air supply side, and even in the process of automatically sucking combustion air, the combustion air is blocked by the air supply side barrier 19, so it does not flow to the air supply side through the connection pipe 17. There is no flow into the pipe 17, thus ensuring combustion stability.

Furthermore, a third embodiment of the pulse combustor of the present invention will be explained using FIG. First, the configuration of the combustion chamber 1, exhaust pipe 2, pulp device 3, spark plug 4, combustion starting blower 5, and air supply vibro is the same as in the second embodiment, but in the third embodiment, the exhaust pipe 2 At the downstream position, Helmholtz type resonance 2. A buffer chamber that does not change the frequency characteristics of the combustion sound based on is provided as an exhaust side buffer chamber 2o, and an exhaust side branch section 16 is provided downstream of the exhaust side buffer chamber 20. Similarly, an air supply side buffer chamber 21 is provided at an upstream position of the air supply vibro, and an air supply side branch section 16 is provided upstream of the air supply side buffer chamber 21. These two branch parts are connected by a pipe, and the above-mentioned barriers are provided at both ends of the connecting pipe 17. Although it has conventionally been done to provide a buffer chamber to stabilize the Helmholtz resonance frequency, the present invention connects pipes downstream and upstream of the buffer chamber to achieve the same noise reduction effect as in the second embodiment. However, it also makes the combustion sound wave more regular and effectively counter-phases it, thereby canceling out low-frequency sounds.

As described above, the present invention makes it possible to collide sound from the exhaust side and sound from the intake side in opposite phases, thereby reducing low-frequency sounds without deteriorating combustion characteristics. It is. Because Luss combustion originally has a frequency based on Helmholtz resonance, suppressing low-frequency sounds is an important point in noise reduction. The feature is that low-frequency sound reduction can be achieved without increasing the size of the structure. In addition, in order to achieve a satisfactory noise reduction effect with conventional means of canceling out sound by installing two combustors or using a phase difference only on the exhaust side and only on the intake side, it is necessary to avoid the complexity of the combustion device. However, in the pulse combustor of the present invention, the intake and exhaust nozzles, which are essential for combustion, also serve as noise reduction parts, so the device configuration is simple and costs can be reduced.
0 that can contribute to commercialization

[Brief explanation of the drawing]

1, 2, and 3 are sectional views of a pulse combustor according to an embodiment of the present invention, respectively. 1... Combustion chamber, 2-... Exhaust nozzle,
3 @... Fist pulp device, 4... Ignition pudugu, 5... Start blower for combustion, 6... Air supply nokubu, 7... ... Connection room, 8 ... Barrier, 9 ... Air supply room, 1o ... Exhaust room, 11. ... Air supply port, 12 ... Air supply pipe connection hole, 13 ... Exhaust port, 14 ...
・Exhaust pipe connection hole, 16... Exhaust side branch part,
16...Air supply side branch, 17...Connection (eve), 18...Exhaust side barrier, 19...
...Air supply side barrier, 20...Exhaust side buffer chamber, 21
...Air supply side buffer chamber.

Claims (1)

[Claims] 1. A combustion chamber, and an exhaust pipe connected to the combustion chamber;
It has a valve device located upstream of the combustion chamber and an air supply pipe, has a connecting chamber, and partitions this connecting chamber into an air supply chamber and an exhaust chamber with a barrier that blocks only the flow of fluid and allows sound to pass through. , an air supply port and an air supply pipe connection hole are provided in the air supply chamber, an exhaust port and an exhaust pipe connection hole are provided in the exhaust chamber, and the tip of the air supply pipe and the tip of the exhaust pipe are connected to the connection hole of the air supply chamber. and a pulse combustor connected to the connection hole of the exhaust chamber and facing each other with the barrier in between. 2. a combustion chamber, and an exhaust pipe connected to the combustion chamber;
It has a valve device located upstream of the combustion chamber and an air supply pipe, and a branch part is provided near the tip of each of the exhaust pipe and the air supply pipe, and these two branch parts are connected by a pipe. Block only the flow of fluid at both ends of the pipe,
A pulse combustor with a barrier that allows sound to pass through. . 3. A buffer chamber is provided at a downstream position of the exhaust pipe, an exhaust side branch part is provided downstream of the buffer chamber, a buffer chamber is further provided at an upstream position of the air supply pipe, and an air supply side branch part is provided upstream of the buffer chamber,
The pulse combustor according to claim 2, wherein these two branch parts are connected by a pipe.