JPH0517447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in a pulse combustion device used as a heating device for industrial, commercial or domestic water heaters, hot air blowers, and the like.

Conventional configuration and problems Conventionally, pulse combustors have a high flow rate of combustion gas and are pulsating, so they can be used as combustors with high heat exchange efficiency.Furthermore, they do not require a power source except when operating. Therefore, it was promising as a combustor with low running costs. Such a pulse combustor produces loud combustion noise and has a narrow flammable heat output range. Therefore, an attempt was made to reduce combustion noise and widen the variable range of heat output by burning two pulse combustors with low heat output in parallel.

At this time, if the exhaust cushion chamber is shared and the tail pipes of both pulse combustors are connected to the exhaust cushion chamber, the ignition performance will be poor. In particular, it is difficult to ignite one pulse combustor while the other is in operation. In addition, even when both were in combustion, combustion failures frequently occurred and combustion stoppage occurred.

On the other hand, if an exhaust cushion chamber is provided for each pulse combustor, the combustion noise will be a hum because each pulse combustor will have a different pulse combustion frequency due to differences in combustion amount, suction air amount, structural dimensions, etc. It was accompanied by a phenomenon. As a result, the combustion noise was not reduced as much as expected and a harsh sound remained.

Purpose of the Invention The present invention aims to improve the conventional drawbacks, share the exhaust cushion chamber with a simple method, prevent the generation of combustion noise, and improve thermal efficiency, thereby providing a quiet and highly efficient pulse combustion device. With the goal.

Structure of the Invention The present invention doubles the exhaust cushion chamber with a cylindrical partition plate having a bottom, forms an exhaust cushion chamber for each combustor, and also forms a tail pipe outlet and a bottom of the cylindrical partition plate. This pulse combustion device is characterized in that the cylindrical partition plates are separated into each combustor by separately provided partition plates, and the central partition plate is provided with a communication port.

DESCRIPTION OF EMBODIMENTS The figure is a configuration diagram of a pulse combustion apparatus according to an embodiment of the present invention. In the figure, 1 and 2 are pulse combustors. 3 and 4 are combustion chambers, and 5 and 6 are tail pipes that communicate with exhaust cushion chambers 7 and 8.
9 and 10 are gas distributors looking into the combustion chambers 3 and 4; 11 and 12 are air passages leading to the combustion chambers 3 and 4; 13 and 14 are spark plugs;
6 is an air valve, 17 and 18 are gas valves, 19
20 is a partition plate forming the two combustor exhaust cushion chambers 7 and 8; 21 is a communication hole provided in the partition plate 20; 22, 2 is an air cushion chamber;
3 is an exhaust pipe, 24 is combustion air, 25, 26
is fuel gas, 27 and 28 are combustion gases, and 29 is water. Further, 30 is a bottom plate provided with exhaust pipes 22 and 23, which encloses a can body 33 and a gasket 34, and is fixed with bolts 35. The bottom plate 30 of the cylindrical partition plate 31 is fixed with bolts 32. The above configuration constitutes a pulse combustor.

Next, the operation will be explained. Fuel gas 25,2
The gas 6 passes through gas valves 17 and 18 and is supplied to the combustion chambers 3 and 4 from distributors 9 and 10 having a large number of nozzle holes.

Combustion air 24 is supplied from a blower (not shown) and is supplied to the combustion chambers 3 and 4 through the air cushion chamber 19, the air valves 15 and 16, and the air passages 11 and 12. The fuel gas and combustion air supplied to the combustion chambers 3 and 4 are mixed to form an air-fuel mixture, which explodes and burns due to discharge from the spark plugs 13 and 14. Due to the explosion, the pressure inside the combustion chambers 3 and 4 increases, and the air valves 15 and 16 and the gas valve 1
7 and 18 are closed, and the supply of fuel gases 25 and 26 and combustion air 24 is stopped. High temperature combustion gas 2
7 and 28 exchange heat with water 29 while passing through thin tail pipes 5 and 6, and flow into exhaust cushion chambers 7 and 8 while lowering the temperature. This exhaust cushion chamber has a partition plate 2 that divides the chamber.
0 is set. The partition plate 20 and the cylindrical partition plate 31 are fixed to the can body 33 with bolts 32.
The partition plate 20 is provided with a communication hole 21 near the bottom of the cylindrical partition plate 31. Combustion gases 27 and 28 are passed through the exhaust cushion chambers 7 and 8 and the cylindrical partition plate 3.
The gas is discharged through the exhaust pipes 22 and 23 which pass between the two cylindrical portions and are connected to the bottom plate 30.

When the combustion gases 27 and 28 pass through the tail pipes 5 and 6, the pressure inside the combustion chambers 3 and 4 becomes negative, the air valves 15 and 16 and the gas valves 17 and 18 are opened, and the combustion air 24 and the fuel gas 25 and 26 are opened. is sucked into the combustion chambers 3 and 4. At that time, the high-temperature combustion gas in the combustion chamber causes the mixture of combustion air and combustion gas to explode. Then, similar explosions are repeated one after another, resulting in a pulse-burning state. When the pulse combustion state is reached, fuel gas 2 is automatically turned off even if the blower is stopped.
5, 26 and combustion air 24 are sucked in.

When two pulse combustors are used for combustion, as described above, it is difficult to match the frequencies of each pulse combustor, resulting in a slight difference in frequency. This difference was the cause of the buzzing phenomenon in the combustion sound. When the exhaust cushion chambers are connected to each other through the communication hole 21 as in the present invention, the pressure of the combustion gases 27 and 28 in the two exhaust cushion chambers 7 and 8, which is stronger, acts on the other exhaust cushion chambers 7 and 8, forcing them to vibrate and synchronize them. Furthermore, it is easier to transmit static pressure when the communication hole 21 is located near the bottom of the cylindrical partition plate 31 because the ejection speed of the combustion gases 27 and 28 ejected from the tail pipes 5 and 6 is faster.
The opening area of 1 is 1/ of the cross-sectional area of tail pipes 5 and 6.
If it is less than 20, the effect of pressure vibration between the exhaust cushion chambers will be small, and if it is more than 1/10, the effect on the other will be too strong during ignition, and if simultaneous ignition is not performed, the combustor will have a delay in ignition. Adversely affects ignition. A large number of communicating holes 21 may be provided, and in that case, the diameter thereof is preferably 3 mm or more to prevent shielding by foreign substances such as dew condensation.

The combustion gases 27 and 28 that have entered the exhaust cushion chambers 7 and 8 are transferred to the exhaust cushion chambers 7 and 8.
The flow flows back to the outlet side of the tail pipes 5 and 6 from the chamber partitioned by the bottom and cylindrical portion of the partition plate 20 and the cylindrical partition plate 31 provided in the can body 33, and the exhaust gas chamber wall surface of the can body 33 and the cylindrical partition. Since the gap between the cylindrical portion of the plate 31 and the exhaust pipes 22 and 23 is narrow so that the exhaust flows uniformly at this time, the wall surface of the exhaust cushion chamber can be effectively used as a heat transfer surface. In addition, the bottom of the cylindrical partition plate 31 allows the combustion gases 27 and 28 to flow through the bottom 30 of the can body 33.
Since the pulsating energy of the combustion gas is relaxed and flows out from the bottom plate and the exhaust pipes 22 and 23 connected thereto, it is effective in reducing noise.

Also, the partition plate 20 of the exhaust cushion chambers 7 and 8
can be installed at appropriate positions depending on the combustion amount of the two combustors. However, the combustion frequency must be set identically in the two combustors.

Note that in the above embodiment, two pulse combustors are used.
Although the case where they are arranged in parallel has been described, there may be two or more, and they may not be arranged in a line but may be arranged in a circle.

Effects of the Invention As explained above, two pulse combustors are combusted in parallel, a common exhaust cushion chamber is used, a partition plate and a cylindrical partition plate are combined on the exhaust cushion chamber to form a compartment, and a cylindrical By providing communication holes near the bottom of the partition plate, the following effects were obtained. Since the pressures of the two pulse combustors are now more susceptible to interaction, they burn more synchronously. Since the combustion gas does not directly hit the bottom plate, the pulsation of the combustion gas does not cause the bottom plate to vibrate, reducing noise. The cylindrical part of the cylindrical partition plate allows the combustion gas to flow uniformly on the wall of the exhaust cushion chamber, making effective use of the heat transfer surface. Since the exhaust cushion chamber is shared and two exhaust cushion chambers are formed by one partition plate, both the configuration and manufacturing are simplified.

[Brief explanation of drawings]

The figure is a sectional view showing the main part of a pulse combustion device according to an embodiment of the present invention. 1, 2... Pulse combustor, 3, 4... Combustion chamber,
5, 6... Tail pipe, 7, 8... Exhaust cushion chamber, 20... Partition plate, 21... Communication hole, 31... Cylindrical partition plate, 33... Can body.

Claims (1)

[Claims] 1 A tail pipe is provided at one end of the combustion chamber, and pulse combustors are arranged in parallel with an air and gas supply path provided at the other end, and a tail pipe is installed in a common cylindrical exhaust cushion chamber for each of the tail pipes. A cylindrical partition plate opening toward the pipe outlet is provided with a gap around the periphery, a partition plate is provided for dividing the cylindrical partition plate with respect to the tail pipe, and the partition plate includes a portion near the bottom of the cylindrical partition plate. A pulse combustion device characterized in that a communication hole is provided in the.