JPH1183013A - Combustion equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Not only abnormal combustion whose flame shape changes greatly, such as standing flame and misfire, but also abnormal combustion that does not appear in the flame shape can be detected. An object of the present invention is to provide a combustion apparatus having a highly reliable combustion state detecting means which is hardly affected by combustion. SOLUTION: Flame generating means 6 for generating a flame, first electrode means 9 for contacting charged particles generated by the flame,
A voltage applying means for applying a voltage between the flame generating means and the first electrode means, and a potential detecting means for detecting a potential of the charged particles; the potential detecting means and the first electrode means;
A combustion device for detecting a combustion state by detecting a potential difference between the two by the potential detecting means 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device for burning fuel.

[0002]

2. Description of the Related Art A conventional combustion apparatus of this kind is disclosed in
What was described in -235612 was common. As shown in FIG. 13, the combustion device is provided with a burner 1, a flame electrode 2 arranged so as to come into contact with the flame when combustion is normal, and an arrangement so as to come into contact with the flame when combustion is abnormally activated. Frame electrode 3
, An AC power supply 4 and a current detecting means 5.

According to the above construction, when the flame is small immediately after ignition or during abnormal combustion, the flame is applied to the frame electrodes 2 and 3.
However, since a sufficient frame current does not flow through the frame electrodes 2 and 3, an alarm without a flame is issued. During normal combustion, only the flame electrode 2 is positioned in the flame, and the flame does not reach the flame electrode 3. Therefore, the AC voltage causes a current to flow mainly through the frame electrode 2 and indicates a state with a flame. At the time of the flame, the frame electrode 3 also enters the flame, the frame current also flows through the frame electrode 3, and the current caused by the AC voltage is averaged between the frame electrodes 2 and 3, the current flowing through the frame electrode 2 decreases, and the flame It was set to indicate no status and issue an alarm.

[0004]

However, in the above-described conventional combustion apparatus, a necessary condition for judging whether the combustion state is normal or abnormal is a change in the flame shape such as a small flame or a standing flame. When the cause does not greatly change the flame shape, there is a problem that it cannot be detected by the conventional combustion device. In addition, the surface of the frame electrodes 2 and 3 may be affected by deterioration or contamination, and the electrode surface may have an insulating property, and the current value may decrease in spite of normal combustion. In this case, there is a problem that a malfunction may occur as a result. In addition, depending on the configuration of the combustion device, the current value may increase when the combustion is not normal, and it may not be possible to judge an abnormality using only the frame electrode.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a flame generating means for generating a flame, a first electrode means for contacting charged particles generated by the flame, The combustion apparatus includes a voltage applying means for applying a voltage between the first electrode means and a potential detecting means for detecting a potential of the charged particles.

According to the above invention, since the voltage between the flame generating means and the first electrode means is maintained at a constant voltage by the voltage applying means, the charged particles inside the flame are charged with respect to the constant voltage. It has a potential distribution due to particle distribution and the like.

Since the distribution of charged particles in the flame has a correlation with the combustion state, the combustion state can be detected by detecting the potential distribution. Therefore, in the case of abnormal combustion,
Since the distribution and flow of the charged particles change from the normal combustion state and the electric potential distribution of the flame changes, abnormal combustion is detected by detecting the electric potential distribution. Abnormal combustion in this case refers to not only changes in the shape of the flame such as standing flame and misfire as in the past, but also minute combustion conditions such as changes in the distribution of charged particles inside the flame that do not cause a change in the shape of the flame. Can be detected. Also, instead of detecting the current by detecting the current to detect the combustion state, the potential is detected to detect the combustion state. Detection can be performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be carried out by the embodiments described in the claims.
Flame generating means for generating a flame; first electrode means for contacting charged particles generated by the flame; voltage applying means for applying a voltage between the flame generating means and the first electrode means; Is provided, a voltage between the flame generating means (usually a combustion burner) and the first electrode means is maintained at a constant voltage by the voltage applying means. Has a potential distribution due to a charged particle distribution inside the flame with respect to a constant voltage. Since the charged particle distribution inside the flame has a correlation with the combustion state, the combustion state can be detected by detecting the potential distribution. Therefore, in the case of abnormal combustion, the distribution and flow of the charged particles change from the normal combustion state, and the potential distribution of the flame changes. Therefore, the abnormal combustion is detected by detecting the potential distribution. Abnormal combustion in this case refers to not only changes in the shape of the flame such as standing flames and misfires as in the past, but also minute combustion states such as changes in the distribution of charged particles inside the flame that do not cause a change in the flame shape. Changes can be detected. Also, instead of detecting the current by detecting the current to detect the combustion state, the electric potential is detected to detect the combustion state. Detection can be performed.

According to a second aspect of the present invention, there is provided a flame generating means for generating a flame, a first electrode means and a second electrode means for contacting charged particles generated by the flame,
By providing voltage applying means for applying a voltage between the first electrode means and the second electrode means, and potential detecting means for detecting the potential of the charged particles, the flame generating means is often made of stainless steel or the like. The flame generating means functions as an electrode when the flame generating means is made of a conductive material because the flame generating means may be made of a high heat resistant insulating material such as ceramics. However, when the flame generating means is made of an insulating material, the flame generating means does not function as an electrode. In such a case, by providing the second electrode means that comes into contact with charged particles generated by the flame, the same effect as the invention according to claim 1 can be obtained in which the flame generation means is made of a conductive material.

According to a third aspect of the present invention, the electric potential detecting means for detecting the electric potential of the charged particles is added to the combustion device according to the first or second aspect so that the electric potential can be detected. The means moves arbitrarily in the flame and detects the potential of the charged particles, the internal state of the flame can be detected from the potential distribution of the charged particles in the moving direction, and the normal or abnormal state of the flame is determined from the above-described correlation. . As described above, when the potential distribution of the charged particles is measured, it is possible to determine at which position in the flame the abnormality is on the movement line of the potential detecting means.

Further, by adding a moving means for moving the electric potential detecting means for detecting the electric potential of the charged particles to the combustion apparatus according to the second aspect, the flame generating means is often made of a highly heat-resistant conductive material such as stainless steel. Although it is composed of a material, it may be composed of a highly heat-resistant insulating material such as ceramics. Therefore, when the flame generating means is composed of a conductive material, the flame generating means functions as an electrode. Is made of an insulating material, the flame generating means does not function as an electrode. In such a case, by providing the second electrode means that comes into contact with the charged particles generated by the flame,
The same effect as when the flame generating means is made of a conductive material can be obtained.

According to a fourth aspect of the present invention, there is provided a fuel cell system comprising a potential detecting means for detecting a potential of charged particles installed at a plurality of arbitrarily selected detection points in the flame.
In addition to the above-described combustion apparatus, a two-dimensional or three-dimensional potential distribution of charged particles is continuously detected by a plurality of potential detection means arbitrarily provided in the combustion flame, and the flame is determined from the above-described correlation. A normal or abnormal combustion state can be detected. As described above, when the potential distribution of the charged particles is measured two-dimensionally or three-dimensionally and continuously, the deformation and distortion of the flame shape can be known, and the combustion state can be detected more accurately.

Further, by adding a potential detecting means for detecting the potential of the charged particles provided at a plurality of arbitrarily selected detection points in the flame to the combustion apparatus according to the second aspect, the flame generating means can In many cases, it is made of a high heat-resistant conductive material such as stainless steel, but in some cases, it is made of a high heat-resistant insulating material such as ceramics. Functions as an electrode, but when the flame generating means is made of an insulating material, the flame generating means does not function as an electrode. In such a case, the second contact with the charged particles generated by the flame
By providing the electrode means, the same effect as when the flame generating means is made of a conductive material can be obtained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In each embodiment, the same components are denoted by the same reference numerals, and a description thereof will be partially omitted.

(Embodiment 1) FIG. 1 is a sectional view showing a configuration of a combustion apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 6 denotes a flame generating means, which is generally used when a mixed gas obtained by mixing gaseous fuel with primary air having a theoretical combustion air amount or less in advance is ejected from a plurality of flame holes 7 and burned. An internal flame 8a is formed in the vicinity of the flame hole 7 due to a combustion reaction between the flammable gas and the premixed primary air, and is formed outside the internal flame 8a by a combustion reaction with the surrounding secondary air. A flame 8b is formed. The inner flame 8a looks bright and shining, and the outer flame 8b becomes a nearly transparent combustion flame.
a and the outer flame 8b form the entire flame 8. Charged particles (ions and electrons) are present in the flame 8. One end of the first electrode means 9 is in contact with charged particles generated by the flame 8, and the other end is connected to the flame generating means 6 via the voltage applying means 10.

The flame 8 is composed of an inner flame 8a and an outer flame 8b. Many charged particles are present in the inner flame 8a.
Charged particles are present even at a low density in b.
When the charged particles are negligibly small, for example, when the flame 8 does not exist, that is, when the combustion is stopped, the voltage of 10 to 20 V is applied by the voltage applying means 10 to the first electrode means 9 and the flame generating means 6. , Almost no current flows. However, in the normal combustion state, even when the first electrode means 9 is arranged at a position several mm away from the internal flame 8a, a current of several μA or more flows when the above voltage is applied. This indicates that charged particles are present near the inner flame 8a and also in the outer flame 8b. The current flowing between the electrode means 9 and the flame generating means 6 is detected by, for example, the current detecting means 11 obtained from the voltage between both ends of a resistor having a constant resistance value. Of course, an ammeter may be used instead of the resistor.

The potential detecting means 12 is made of a highly heat-resistant metal body, and one end thereof is arranged at a position where it comes into contact with charged particles. The potential detecting means 12 is a first electrode means 9
Are attached to a fixed base via an insulating ceramic 13a in the same manner as attached to a fixed base (not shown) via an insulating ceramic 13. The non-contact ends of the potential detecting means 12 and the charged particles of the first electrode means 9 are connected via the potential difference detecting means 14. First
When a current flows between the electrode means 9 and the flame generating means 6, there is a potential gradient between the two and the current flows spatially, so that the equipotential surface of the charged particles causes the current flow. Exists perpendicular to the direction. At this time, there is an equipotential surface in contact with the potential detecting means 12. The potential detecting means 12 is conductive, and its potential is the same as that of the contacting equipotential surface. Thereby, the potential difference detecting means 14
Indicates the potential of the charged particles detected by the potential detecting means 12 with respect to the first electrode means 9, the first electrode means 9 and the potential detecting means 1
It is configured to detect as a potential difference between the two.

The potential of the charged particles present in the flame 8 is determined by the state of the charged particles such as temperature and particle density.
The flame 8 that generates the charged particles has such a property that the shape and the internal state vary depending on the air-fuel ratio, the amount of combustion, the property of the combustion space, the property of the flame generating means 6, and the like. At this time, the equipotential surface of the charged particles also changes with the property change of the flame 8, and accordingly, the potential of the charged particles detected by the potential detecting means 12 also changes. In this way, the detection of the potential of the charged particles enables detection of not only normal combustion or abnormal combustion but also a minute combustion state.

When silicon oxide is formed on the end surfaces of the first electrode means 9 and the potential detecting means 12 which come into contact with the charged particles, this silicon oxide is insulative, so that even if it is in a normal combustion state, Also, the current detected by the current detecting means 11 naturally decreases. However, even if the current decreases, it is clear that there is a constant potential gradient corresponding to the current value, and there is also an equipotential surface. That is,
The potential detecting means 12 operates without being affected by the silicon oxide.

Since charged particles are flowing inside the flame,
The potential difference detected by the potential difference detecting means 14 indicates fluctuation. In this case, it is preferable that the potential difference detecting means 14 has, for example, a parallel connection circuit of a 1 MΩ resistor and a capacitor of several μF in parallel with a voltmeter. This is because a DC component can be easily taken out by bypassing the fluctuation of the potential difference with a capacitor.

1, the voltage applying means 10 is a DC power supply, and in many cases, the voltage between the first electrode means 9 and the flame generating means 6 is kept at 24V.
In the following embodiments, the first electrode means 9 is used unless otherwise specified.
And the voltage between the flame generating means 6 is 24V. The current detecting means 11 is a 10 kΩ resistor, and the potential difference detecting means 14 is 1
The configuration was such that a parallel connection circuit of a resistor of MΩ and a capacitor of several μF and a voltmeter were connected in parallel. A high heat-resistant stainless steel wire (about 2 m in diameter) as the first electrode means 9 and the potential detecting means 12
m) was used. The flame generating means 6 is a burner made of high heat-resistant stainless steel mounted on a household oil fan heater.

The oil is forcibly burned by the combustion device shown in FIG.
The potential difference V obtained by the potential difference detecting means 14_frIn Figure 2
Indicated. FIG. 2 shows a normal combustion amount of about 2500 kcal / h.
Horizontal direction (A-A 'direction) inside the flame 8 during combustion
5 is a potential difference distribution curve of FIG. The horizontal axis of FIG.
(B-B 'plane) to the tip of the end of the potential detecting means 12
Separation L. In the first embodiment, the charged particles of the potential detecting means 12
The height of the end in contact with the tip of the end of the potential detecting means 12
From the plane A to the plane A-A '. In FIG. 2, H = 28 m
The results measured at m and 32 mm are shown. H = 32mm
Then, the potential difference becomes a high value within L = 10 mm near the flame hole.
And decreased with increasing distance from the flame hole, especially when L was 10 mm
Above this, it drops rapidly. And L is about 2
At about 0mm, the potential difference becomes almost 0V and charged particles
Suggests the existence limit of When H = 28 mm, L is 6
Potential difference V at ~ 7 mm_frIndicates the peak value
Shows a substantially constant value when L is within about 10 mm.
As L gets away from 8, suddenly when L becomes 10mm or more
It is lower. And L becomes about 20mm
And the potential difference becomes almost 0V, suggesting the existence limit of charged particles
I do. At this time, the potential difference V _frHowever, the position of almost 0V is visually
Coincides with the outermost surface of the flame 8.

FIG. 3 shows a combustion amount of about 2500 k as in FIG.
It is a potential difference distribution curve which shows the dependence of the potential difference V _{fr on} the primary air amount at cal / h. In FIG. 3, the horizontal axis represents the distance L from the outer surface (BB ′ plane) of the flame hole 7 to the tip of the end of the potential detecting means 12, and at each primary air ratio PA (ratio between the primary air and the theoretical air amount). The relationship between the potential difference V _fr and L is shown. H = 28 mm. FIG. 4 is a potential difference-PA curve showing the correlation between the potential difference V _fr and the primary air ratio PA when L is about 6 mm. FIG. 4 shows the potential difference V _fr and P
It shows a strong positive correlation of A. In a normal combustion state in which the combustion amount is constant, the value of the potential difference V _fr is substantially constant. Therefore, if the correlation in FIG. 4 is used, it is possible to detect abnormal combustion due to primary air fluctuation.

FIG. 5 shows a combustion amount of about 2500 k as in FIG.
potential shows the dependence of the secondary air amount of the potential difference V _fr in cal / h is the distribution curve. In FIG. 5, the horizontal axis represents the distance L from the outer surface (BB ′ surface) of the flame hole 7 to the tip of the end of the potential detecting means 12. H = 32 mm. In FIG. 5, when L is within 10 mm, there is a clear difference in the potential difference distribution with and without secondary air. In particular, when the position of the potential detecting means 9 is fixedly arranged between L and 5 mm, it is possible to sufficiently detect normal combustion and abnormal combustion due to insufficient secondary air. According to visual observation, no significant change such as an extreme change in the shape of the flame 8 at this time was observed. Therefore, according to the present embodiment, it is possible to detect even an abnormality in the combustion state that does not appear in the flame shape. In the above-described current detection by the frame electrode of the conventional example, it is difficult to detect an abnormality due to a shortage of secondary air that does not significantly change the shape of the flame 8. Various measures have been taken to avoid the difficulty of detection.
This also shows the effectiveness of the present invention.

(Embodiment 2) FIG. 6 is a sectional view showing a configuration of a combustion apparatus according to Embodiment 2 of the present invention. When the flame generating means 6 is made of a heat-resistant conductive material such as stainless steel, the flame generating means itself can function as an electrode for collecting charged particles such as ions and electrons. However, when the flame generating means 6 is made of a heat-resistant insulating material such as ceramics, the flame generating means 6 does not work as an electrode. In such a case, as shown in FIG. 6, it is desirable to arrange the second electrode means 15 at a position where it comes into contact with charged particles generated by the flame 8. This is because the second electrode means 15 functions as an electrode for collecting charged particles such as ions and electrons. More preferably, it is desirable to dispose the second electrode means 15 near the flame generating means 6. Since the flame generating means 6 is provided with a plurality of flame holes 7, this arrangement allows the second electrode means 15 to reliably contact one inner flame 8a or a plurality of inner flames 8a. Since many charged particles are present in the inner flame 8a, their incidence on the second electrode means 15 is facilitated. Therefore, a potential difference V _fr equivalent to the case where the flame generating means 6 is made of a conductive material can be detected. It is apparent that the second electrode means 15 is porous as long as it does not hinder the flow of fuel or combustion gas, for example, is preferably a wire mesh.

(Embodiment 3) FIG. 7 is a sectional view showing the structure of a combustion apparatus according to Embodiment 3 of the present invention. The third embodiment is different from the first or second embodiment in that the potential detecting unit 12 can be moved by the moving unit 16. (In the case of the first embodiment or the second embodiment, the potential detecting unit 1
2 was fixed in a predetermined position. ) Transportation means 16
Moves the potential detecting means 12 in the direction of AA 'in FIG. The moving distance was set to a distance slightly beyond the outermost edge of the flame 8 from the closest distance at which the potential detecting means 12 did not contact the flame generating means 6. As can be seen from FIG.
It is preferably about 30 mm to 30 mm. Thereby, the potential difference distribution in the AA ′ direction of the flame 8 can be easily obtained. The potential difference distribution is the same as in FIGS. 2, 3 and 4, but in Example 1.
And A- in comparison with the detection at the fixed point performed in Example 2.
Combustion detection having a one-dimensional spread in the A 'direction can be performed.
Therefore, a change in the peak position of the potential difference, a change in the potential near the peak position, or the extent of the flame spread indicates that
It can be seen which part in the A 'direction is abnormal.

The moving means 16 sets the potential detecting means 12 to A-
A 'direction, BB' direction or AA 'direction, B- direction
It may be configured to move in a direction perpendicular to the direction B ′. In this case, the obtained potential difference distribution is different from that in FIG.
A similar concept may be used for detecting the combustion state.

(Embodiment 4) FIG. 8 is a sectional view showing a configuration of a combustion apparatus according to Embodiment 4 of the present invention. When the flame generating means 6 is made of a heat-resistant conductive material such as stainless steel, the flame generating means itself can function as an electrode for collecting charged particles such as ions and electrons. However, when the flame generating means 6 is made of a heat-resistant insulating material such as ceramics, the flame generating means 6 does not work as an electrode. In such a case, as shown in FIG. 8, it is desirable to arrange the second electrode means 15 at a position where it comes into contact with charged particles generated by the flame 8. This is because the second electrode means 15 functions as an electrode for collecting charged particles such as ions and electrons. More preferably, it is desirable to dispose the second electrode means 15 near the flame generating means 6. Since the flame generating means 6 is provided with a plurality of flame holes 7, this arrangement allows the second electrode means 15 to reliably contact one inner flame 8a or a plurality of inner flames 8a. Since many charged particles are present in the inner flame 8a, their incidence on the second electrode means 15 is facilitated. Therefore, a potential difference V _fr equivalent to the case where the flame generating means 6 is made of a conductive material can be detected. It is apparent that the second electrode means 15 is porous as long as it does not hinder the flow of fuel or combustion gas, for example, is preferably a wire mesh. The operation and operation of the moving means 16 are the same as those in the third embodiment, and the description is omitted.

(Embodiment 5) FIG. 9 is a plan view showing a configuration of a combustion apparatus according to Embodiment 5 of the present invention. The fifth embodiment is different from the first embodiment or the second, third, and fourth embodiments in that a plurality of detection points C, in which the plurality of potential detection units 12 a, 12 b, 12 c, and 12 d are arbitrarily selected in the flame 8, D, E, F
(In FIG. 9, there are four points C, D, E, and F, but this is not a limitation.) The position of the detected point can be represented by L and H as in the third embodiment. Each of the potential detecting means 12a, 12b, 12c, 12
One end of d is connected to the first terminal via the respective potential difference detecting means 14a, 14b, 14c, and 14d as in the first embodiment.
It is connected to one end of the electrode means 9. Further, each of the potential detecting means 12a, 12b, 12c, 12d is connected to each of the insulating ceramics 13a, 13b, 13c, 1c.
It is attached to a fixed base (not shown) via 3d. If L and H are arbitrarily determined, the potential of the charged particle becomes 2
It can be continuously measured and detected as a three-dimensional or three-dimensional distribution. Therefore, as compared with the above-described first to fourth embodiments, the combustion state can be detected more three-dimensionally and continuously in time.

FIG. 10 shows a combustion amount of about 2500 kcal / h.
At the detected points C, D, E, F in the normal combustion of
It is a difference distribution figure. Four potential detecting means 12a, 12b,
The arrangement of 12c and 12d is centered on the flame generating means 6.
And two adjacent potential detecting means 12 and flame generating means 6
(For example, C-flame generating means 6-D) is substantially
90 °. Note that C 'and D' in FIG.
, E ′ and F ′ are detected points C, D, E, F and
The detected position between the endflames 8a adjacent in the clockwise direction in FIG.
Position. For L and H, four potential detection
Each of the delivery means 12a, 12b, 12c, and 12d has L =
6 mm and H = 28 mm. From FIG. 10, the potential difference V_fr
It can be seen that the closer to the position of the internal flame 8a is, the larger it is. Toes
Potential difference V _frJudging from the fact that it is a star-shaped flame shape
Recognize. Here, for example, some empty space near the point D
When an abnormal change in the fuel ratio or an abnormal change in the combustion environment occurs,
Changes occur in the distribution and flow of charged particles near point D,
The equipotential surface in the vicinity fluctuates. Therefore, the potential detection
Potential difference detected at stages 12a, 12b, 12c, 12d
Is most variable at the point D detected by the potential detecting means 12b.
Will be transformed. Depending on the degree of abnormality, shadows other than point D
It is affected, but it is point D that is significantly affected. This
By detecting changes in the potential distribution such as
It is possible to detect a three-dimensional combustion state that is not found in Examples 1 to 4.
You.

(Embodiment 6) FIG. 11 shows Embodiment 6 of the present invention.
It is a top view which shows the structure of the combustion apparatus of FIG. Flame generating means 6
Is made of a heat-resistant conductive material such as stainless steel, it can itself act as an electrode for collecting charged particles such as ions and electrons. However, when the flame generating means 6 is made of a heat-resistant insulating material such as ceramics, the flame generating means 6 does not work as an electrode. In such a case, as shown in FIG. 11, it is desirable to arrange the second electrode means 15 at a position where it comes into contact with charged particles generated by the flame 8. This is because the second electrode means 15 functions as an electrode for collecting charged particles such as ions and electrons. More preferably, it is desirable to dispose the second electrode means 15 near the flame generating means 6. Since the flame generating means 6 is provided with a plurality of flame holes 7, this arrangement allows the second electrode means 15 to reliably contact one inner flame 8a or a plurality of inner flames 8a. Since many charged particles are present in the inner flame 8a, their incidence on the second electrode means 15 is facilitated. Therefore, a potential difference V _fr equivalent to the case where the flame generating means 6 is made of a conductive material can be detected. It is apparent that the second electrode means 15 is porous as long as it does not hinder the flow of fuel or combustion gas, for example, is preferably a wire mesh. Note that the potential detecting means 12a, 12b, 12c, 12d provided at the detected points C, D, E, F
The operation and operation of this embodiment are the same as those of the fifth embodiment, and the description is omitted.

(Embodiment 7) Next, a commercially available petroleum fan heater was used, and necessary components were added so that the combustion section would have the same configuration as that of Embodiment 1 to obtain a combustion apparatus. Although the flame generating means differs from the above-described flame generating means 6 in the structure such as the flame hole 7, the detection of the potential difference V _fr is basically the same as in the above-described embodiment.

FIG. 12 shows that the combustion amount was about 25 in the seventh embodiment.
FIG. 5 illustrates potential differences V _fr detected in various combustion states described later at 00 kcal / h. The positions of the potential detecting means 7 were L = 6 mm and H = 28 mm. FIG.
The horizontal axis of 2 represents various combustion states as follows.
(A) is normal combustion, (b) is a partial blockage of an outlet, (c) is a blockage of a secondary air hole, and (d) is a portion of a wall of a combustion chamber surrounding a flame generating means having a diameter of about one. This is a state in which a 10 mm hole has been formed. In a commercially available combustion device, combustion detection by current can be performed in the same manner as in the conventional example. However, it is difficult to detect the above-mentioned abnormalities (c) and (d) only by the behavior of the electric current. Required a simple configuration. However, as can be seen from FIG. 12, the potential difference V _fr clearly indicates the difference between normal combustion and abnormal combustion or an abnormal combustion environment, and according to the present embodiment, abnormality detection can be performed relatively easily with a simple configuration. It becomes possible.

In the seventh embodiment, the configuration of the first embodiment is added to a commercially available petroleum fan heater. However, as described above, by adding the configurations of the third and fifth embodiments, the configuration is further increased. It is clear that detailed combustion detection is possible.

[0036]

As is apparent from the above description, claim 1
According to the described invention, at the detected point inside the flame, the potential of the charged particles generated by the flame is detected as a potential difference from the first electrode means using the potential detection means, and the change in the potential difference is used to determine the combustion state. Is to be detected. The potential difference shows a value different from the potential difference in the normal combustion state when the primary air or the secondary air has an abnormal change (including a change in the air-fuel ratio). Therefore, unlike the conventional example, it is possible to detect not only when the flame becomes small due to an abnormality immediately after ignition or during combustion, or when the flame rises, but also a slight change that does not appear in the flame shape at the time of combustion. is there. In addition, since the potential of the charged particles is detected instead of the current detection as in the related art, even if silicon oxide or the like adheres to and contaminates the surfaces of the potential detection means and the first electrode means, the combustion state is not affected. Detection is possible. Therefore, it is possible to perform highly reliable combustion detection with a simple configuration and, at the same time, detect a slight change in the combustion state, thereby enabling combustion control at an early stage of the abnormality.

According to the second aspect of the present invention, even when the flame generating means is made of an insulating material and does not function as an electrode, the second electrode means having conductivity is provided in the flame near the flame hole of the flame generating means. In this configuration, a voltage is applied between the first electrode means and the first electrode means. Even if the flame generating means is made of an insulating material, the effect is the same as that of the invention according to claim 1 with a simple structure. The effect of can be obtained.

According to the third aspect of the present invention, since the potential detecting means can be moved by the moving means, the change in the peak position of the potential difference and the change in the vicinity of the peak position can be compared with the detection at the fixed point. It is possible to detect a change in potential or the degree of spread of the flame, and it is possible to detect which part of the flame is abnormal. Further, optimal combustion control for the abnormality at that time can be performed. Further, since the potential of the charged particles is detected instead of the current as in the conventional example, highly reliable combustion can be detected without being affected by surface contamination by silicon oxide or the like.

Further, even when the flame generating means 6 is made of an insulating material and does not function as an electrode, the second electrode means having conductivity is provided in the flame near the flame hole of the flame generating means, so that the first means is provided. This is a configuration in which a voltage is applied to the electrode means, and even if the flame generating means is made of an insulating material, the same effect as the above effect can be obtained with a simple structure.

According to the fourth aspect of the present invention, since the potential detecting means is arranged at a plurality of arbitrarily selected detection points in the flame, the potential of the charged particles is continuously represented as a two-dimensional or three-dimensional distribution. And even if there is a local abnormality in the flame, the abnormality can be detected. Further, optimal combustion control for the abnormality at that time can be performed. Further, since the current is detected by the current as in the conventional example, the potential of the charged particles is detected, so that highly reliable combustion can be detected without being affected by surface contamination by silicon oxide or the like.

Further, even when the flame generating means is made of an insulating material and does not function as an electrode, the second electrode means having conductivity is provided in the flame near the flame hole of the flame generating means, so that the first electrode means is provided. And the flame generating means made of an insulating material can provide the same effect as the above effect with a simple structure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a combustion apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a potential difference distribution curve of a flame in the combustion device.

FIG. 3 is a diagram showing a potential difference distribution curve showing dependence of a flame on a primary air amount in the combustion device.

FIG. 4 is a diagram showing a potential difference-PA curve of a flame in the combustion device.

FIG. 5 is a diagram showing a potential difference distribution curve showing the dependence of the flame on the amount of secondary air in the combustion device.

FIG. 6 is a sectional view of a combustion device according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a combustion device according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a combustion device according to a fourth embodiment of the present invention.

FIG. 9 is a plan view of a combustion device according to a fifth embodiment of the present invention.

FIG. 10 is a diagram showing a potential difference distribution by the combustion apparatus.

FIG. 11 is a plan view of a combustion apparatus according to Embodiment 6 of the present invention.

FIG. 12 is a diagram showing potential differences in various combustion states in the combustion apparatus according to the seventh embodiment of the present invention.

FIG. 13 is a configuration diagram of a conventional combustion device.

[Explanation of symbols]

 Reference Signs List 6 flame generating means 8 flame 9 first electrode means 10 voltage applying means 12 potential detecting means 12a potential detecting means at point C 12b potential detecting means at point D 12c potential detecting means at point E 12d potential detecting means at point F 14 potential difference detection Means 15 Second electrode means 16 Moving means

Claims (4)

[Claims] 1. Flame generating means for generating a flame, first electrode means for contacting charged particles generated by the flame,
A combustion apparatus comprising: voltage applying means for applying a voltage between the flame generating means and the first electrode means; and potential detecting means for detecting a potential of the charged particles. 2. A flame generating means for generating a flame, a first electrode means and a second electrode means in contact with charged particles generated by the flame, and between the first electrode means and the second electrode means. A combustion apparatus comprising: voltage applying means for applying a voltage; and potential detecting means for detecting a potential of the charged particles. 3. The combustion device according to claim 1, further comprising a moving unit that makes it possible to move a potential detecting unit that detects a potential of the charged particles. 4. The combustion apparatus according to claim 1, further comprising potential detection means for detecting the potential of charged particles installed at a plurality of arbitrarily selected detection points in the flame.