JPS6021296B2 - combustor - Google Patents

Description

Detailed Description of the Invention The present invention relates to combustion noise in a combustor, and when a specific abnormal combustion state is reached due to fluctuations in external conditions for combustion, flame vibrations are caused to resonate in a burner case or a heat exchanger. The purpose of this is to generate combustion sound and achieve an abnormality detection effect.

Generally, normal combustion is maintained in a combustor by a balance between the amount of fuel supplied and the amount of combustion air.

However, the air-fuel ratio can easily deteriorate due to deficiencies in the air supply or exhaust means, abnormalities such as headwinds, or if liquid fuel is used, due to stagnation, etc., resulting in abnormal combustion. At this time, a significant amount of soot is generated and the amount of carbon monoxide and unburned gas in the exhaust gas increases, but in conventional combustors, this can be confirmed visually through the heat exchanger or a window installed on the side wall of the combustion chamber. This can easily be overlooked and cause abnormal combustion to continue. As a result, the combustor body may be rapidly contaminated by soot accumulation, the burner or its vicinity may be damaged due to overheating, and furthermore, there may be a risk of flame or explosion.
In addition, in a combustor that connects a chimney above the heat exchanger and uses the draft force of the chimney to supply air, abnormalities may occur if the chimney height is insufficient during installation and the specified draft force cannot be obtained. There were cases where the fuel was used with abnormal combustion from the beginning without being aware of the condition, leading to the results described above.

Therefore, in order to eliminate the above-mentioned drawbacks, the combustor of the present invention has an abnormality alarm function that causes the burner case and heat exchanger to resonate specific flame vibrations that occur when the balance between air and fuel is disrupted to generate combustion noise. An embodiment of the oil combustor will be described below with reference to the accompanying drawings.

In FIG. 1, 1 is a combustor main body, which has a burner 2 inside, and the outside of the burner 2 is covered with a burner case 3.

A heat exchanger 4 is installed above the burner 2.
A chimney 5 is connected to the top. Air holes 6a and 6b are provided in the upper and lower parts of the side wall of the burner 2, respectively, and the air sent from the air supply pipe 7 is guided to the burner case 3 and the air holes 6a
, 6b. On the other hand, fuel oil is supplied to burner 2 from oil pipe 8.
It is supplied to the bottom, sucked up to the tip of the vaporizing wick 9, vaporized, and burned with blue flame near the upper air hole 6b. 10 is a glass window provided in front of the heat exchanger 4, 11 is an ignition heater, 12
is a fan for indoor air circulation.

In the above configuration, the fuel vaporization amount (proportional to the calorific value) is controlled by the amount of supplied air, especially the air supplied from the lower air hole 6a, and changes as shown in curves A to B in FIG. When the amount of air is further reduced beyond point B, the flame formed near the upper air hole 6b changes from a blue flame to a yellow combustion accompanied by a bottom flame, causing a rapid increase in heat radiation to the vaporizing wick 9.

For this reason, the change in the amount of vaporization is dominated by the thermal influence, and as the amount of air decreases, the amount of vaporization conversely increases, resulting in the characteristics shown by curves B to C. At this time, the excess air coefficient ranges from around 2 to 1.
4 to 1.6, resulting in high-density laminar flow combustion near the upper air hole 6b. Here, when the diameter of the upper air hole 6b is set to 1.2 ribs, flame vibrations of 880 to 960 Hz are emitted at the combustion castle between points B and C.

At this time, the natural frequency of the burner case 3 and heat exchanger 4 is set to 9.
If you set it around 00Hz, the air hole 6b of burner 2
Vibrations generated in the vicinity alternately resonate with the burner case 3 and the heat exchanger 4, and are gradually amplified, resulting in the generation of loud noise. In this way, if the normal usage range is set to the area shown by curves A and B, when the burning state enters an abnormal state with yellow fire and soot shown by curves B and C due to headwinds, etc., the above-mentioned resonance will occur. It emits an audible alarm and can immediately detect abnormalities.

In addition, even if the chimney 5 does not reach the specified height and the draft force is insufficient, that is, there is insufficient air, it will fall within the range of curves B and C and can be easily detected by issuing an alarm. You can check the presence or absence of

As described above, the combustor of the present invention resonates and amplifies the flame vibrations that occur in a specific combustion state in the burner case or heat exchanger, and generates a sound that detects an abnormal state, and can be used in an abnormal state. This provides an effective means to notify of contamination of equipment, danger of explosion or fire, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an oil combustor according to an embodiment of the present invention, and FIG. 2 shows its combustion characteristics. 11... Burner body, 2... Burner, 3
・・・・・・．・Burner case, 4...Heat exchanger, 5.
...Chimney, 6a...Lower air hole, 6b...
...Top air hole, 9...Vaporization, Figure 2, Figure 1

Claims (1)

[Claims] 1. A burner having a large number of air holes in a side wall, a burner case that covers the outside of the burner and guides air to the upper air holes;
and a heat exchanger installed above the burner, and the burner burns with blue flame, and the flame oscillates when the flame in the burner is in a combustion state in which the air excess coefficient is too low, accompanied by the generation of yellow flame. A combustor characterized in that the natural vibration frequency of at least one of the heat exchanger and the burner case is equal to or an integral multiple of the frequency. 2. The combustor according to claim 1, wherein the natural vibration frequency of at least one of the heat exchanger and the burner case is set within a range of 880 to 960 Hz.