JPH01217111A - Burner - Google Patents

Abstract

PURPOSE:To prevent the resonant sound generated by vibrating combustion by providing pressure vibration generating means which is connected to the inside of a combustion section for communication and generates a pressure vibration in the combustion section. CONSTITUTION:Pressure vibration generating means consists of a box body 16, ceramics plate 18 equipped with an electrode 17, and quartz oscillator 27. With the use of a hot water maker 1 the fuel gas which is jetted into a scroll casing 19 from a gas injection nozzle 21 through a gas supply piping 22 and the air which is sucked-in from a centrifugal blower 4 are mixed in a mixing chamber 9 and they are sent to a burner 7 to burn. When a vibrating combustion occurs in a hot water maker 1 as described above, the quartz oscillator 27 in an electronic control circuit 6 is controlled and the ceramics plate 18 in the box body 16 is vibrated to generate a pressure vibration in the mixing chamber 9 and combustion chamber 8 which communicate with the inside of the box body 16 and the flame is vibrated forcibly to change the flame shape. As a result the response characteristics of the flame which are closely related to the generation of vibrating combustion change, and it becomes possible to prevent a resonant sound.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a combustion device that forcibly supplies combustion air to a combustion chamber to carry out high-load combustion, and in particular prevents the generation of resonance noise that occurs during combustion. Regarding combustion equipment.

[Prior art and its problems] For example, in a combustion device such as a household instantaneous water heater, a mixture of air and fuel gas is forcibly supplied to a combustion section by a blower to perform high-load combustion.

In combustion devices that perform such high-load combustion, vibrational energy within the combustion section is amplified due to the interaction between pressure fluctuations in the gas flow path system including the combustion section and the response characteristics of the flame, which is a combustion reaction. There is a problem in that so-called oscillatory combustion, in which combustion occurs while resonating with one of the modes of the natural vibrations of the combustion engine, is likely to occur, resulting in the generation of resonance noise.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a combustion device that prevents the generation of resonance noise due to oscillatory combustion.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a combustion section that burns fuel, a blower that supplies combustion air into the combustion section, and a blower that is provided in communication with the inside of the combustion section. The technical means is to include a pressure vibration generating means for generating pressure vibrations in the combustion section.

[Operation and Effects of the Invention] The present invention having the above-mentioned configuration has the following effects:
Pressure oscillations are generated within the combustion section to force the flame to vibrate, changing the shape of the flame and changing the response characteristics of the flame.

This is intended to prevent the occurrence of oscillatory combustion by changing the shape of the flame, since oscillatory combustion is deeply related to the response characteristics of the flame.

Therefore, by the action described above, it is possible to obtain a flame shape different from the flame shape when oscillating combustion occurs, and it is possible to prevent the occurrence of oscillatory combustion and the generation of resonance sound.

[Example] Next, an example of the combustion apparatus of the present invention will be described based on the drawings.

FIG. 1 shows a schematic sectional view of an instantaneous gas water heater to which the combustion device of the present invention is applied.

This instantaneous gas water heater 1 includes a combustion case 3 that forms a combustion section and a heat exchange section, a centrifugal blower 4 that supplies combustion air to the combustion section, and a centrifugal blower 4 that supplies fuel gas to the combustion section. and an electronic control circuit 6 that controls the combustion state in the combustion section.

The combustion section for burning fuel includes a combustion chamber 8 equipped with a combustion plate type gas burner (hereinafter abbreviated as "burner") 7 formed by forming a large number of ejection holes 7a in a ceramic plate, and an upstream part of the combustion chamber 8. It consists of a mixing chamber 9 for combustion air and fuel gas, which is formed at the lower side of Figure 1. The burner 7 has a ceramic refractory frame 1 fitted around the outer periphery of the burner 1.
0 and is fixed within the combustion case 3 by a frame-shaped fixture 11.

The heat exchange section formed approximately in the center of the combustion case 3 has a heat exchange pipe 12 connected at one end to a water supply pipe (not shown) and at the other end to a hot water supply pipe (not shown) to improve heat exchange efficiency. It is composed of a plate fin group 13 that increases the height. This heat exchange section heats the water supplied to the heat exchange vibe 12 from the water supply pipe by exchanging heat with the combustion gas in the combustion chamber 8, and then flows out to the hot water supply pipe.

An exhaust port 14 is formed in the upper part of the combustion case 3 (upper side in FIG. 1) to exhaust the combustion gas burned in the burner 7.
It is connected to an exhaust pipe (not shown) that communicates with the outside of the main body case 2 .

The combustion case 3 described above is configured as an exhaust pan 3a in which an exhaust port 14 is formed, a combustion case main body 3b forming a combustion chamber 8 and a heat exchange section, and a burner case 3C forming a mixing chamber 9. There is.

A small hole 15 is formed in the wall forming the mixing chamber 9 of the burner case 3C, as shown in FIG.
An airtight box body 16 communicating with the burner case 5 is attached to the outside of the burner case 3C.

A ceramic plate 18 serving as a vibrating body having electrodes 11 provided on its surface is housed within the box body 16.

The centrifugal blower 4 includes a scroll casing 19 and a fan 2
0 and a fan motor (not shown), and the discharge port 18a of the scroll casing 19 is connected to the central opening of the burner case 3C forming the mixing chamber 9.

The gas supply path 5 includes a gas supply pipe 22 having a gas injection nozzle 21 for injecting fuel gas into the scroll casing 19, a flow control valve 23 provided in the gas supply pipe 22 for adjusting the flow rate of the fuel gas, and It is comprised of a safety valve 24 that automatically cuts off the supply of fuel gas in the event of a gas leak.

The electronic control circuit 6 includes a spark electrode 25, which is an ignition device that causes sparks to fly on the top surface of the burner 7 during ignition, a thermocouple 26, which is a combustion sensor that detects the oxygen concentration (air-fuel ratio) of the combustion flame, and a flow rate control system described in 1. Valve 23 and safety valve 24
, the electronic control circuit 6 drives and controls the fan motor of the centrifugal blower 4, etc.
A crystal oscillator 27 is electrically connected to the electrode 17 of the ceramic plate 18 to control the vibration of the ceramic plate 18.

Note that the pressure vibration generating means of the present invention includes a box body 16, an electrode 1
Ceramic plate 18 with 7 and crystal oscillator 27
It consists of

Next, the operation of this embodiment will be explained.

When the water heater 1 is used, the fuel gas injected into the scroll casing 19 from the gas injection nozzle 21 via the gas supply pipe 22 and the air sucked by the centrifugal blower @4 are mixed in the mixing chamber 9. After that, it is sent to burner 7 and burned.

In a combustion apparatus that performs such high-load combustion, oscillatory combustion is likely to occur, and resonance sound is generated because any one mode of the acoustic natural vibration of the combustion chamber 8 resonates.

When oscillating combustion occurs in the water heater 1 of this embodiment,
The crystal oscillator 27 of the electronic control circuit 6 is controlled to vibrate the ceramic plate 18 inside the box body 16. As a result, the box body 16
Pressure vibrations are generated in the mixing chamber 9 and the combustion chamber 8 that communicate with the inside, and the flame that is the combustion reaction of the burner 7 is forcibly vibrated to change the shape of the flame.

As a result, the response characteristics of the flame, which are closely related to the occurrence of oscillatory combustion, change, making it possible to prevent the occurrence of oscillatory combustion and, therefore, to prevent resonance noise.

As described above, in the present invention, the occurrence of oscillatory combustion is prevented by housing and providing the ceramic plate 18 that vibrates under the control of the crystal oscillator 27 in the box body 16 provided in communication with the combustion chamber 8. This can eliminate resonance noise and contribute to realizing quiet operation of the water heater 1.

(Modified Example) In the above-described embodiment, the box body 16 that houses the ceramic plate 18 that is the vibrating body is provided at a location communicating with the mixing chamber 9 in the burner case 3C, but there is no need to limit it in this way. For example, the box body 16 may be installed outside the combustion case 3 forming the combustion chamber 8 and communicated with the combustion chamber 8. The ceramic plate 18 may be provided directly in the combustion chamber 8 or in the mixing chamber 9 communicating with the combustion chamber 8 without using the combustion chamber 8.

Although the ceramic plate 18 vibrating under the control of the crystal oscillator 27 is housed in the box 16 as the pressure vibration generating means, a speaker may also be used.

Although the ceramic plate 18 is used as the vibrating body, other vibrating bodies such as a crystal plate may be used.

Although the case where the combustion device of the present invention is applied to an instantaneous gas water heater is illustrated, it may be applied to other combustion devices such as a combustion type heating device.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a W4 gas water heater to which the combustion device of the present invention is applied. In the diagram 4... Centrifugal blower (combustion section) 8... Combustion chamber (combustion section) 9... Mixing chamber (combustion section) 16...
Box body (pressure vibration generating means) 18...Ceramic plate (pressure vibration generating means) 27...Crystal oscillator (pressure vibration generating means)

Claims (1)

[Claims] 1) A combustion section that burns fuel, a blower that supplies combustion air into the combustion section, and a pressure device that is provided in communication with the combustion section and that generates pressure vibrations within the combustion section. A combustion device comprising vibration generating means.