JP2004156895A - Burner, hydrogen generating device and fuel battery power generating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner capable of detecting flame with high accuracy even in combustion of a fuel gas including a small amount of carbon hydride combustible substance. <P>SOLUTION: This burner comprises a fuel distributer 1 having a plurality of fuel injection holes 8 for injecting the fuel gas into a combustion space 3, an air injecting member 2 mounted in a state of surrounding the fuel distributer 1 and having a plurality of air injection holes 9 for injecting the air into the combustion space 3, a temperature detecting member 6 mounted in a state that a temperature detecting point of a tip part is positioned in the air injection hole 9, an air layer is formed with respect to an inner wall of the air injection hole 9, and a main body part is accommodated inside of the air injection member 2, and a flame detecting device 7 connected to the temperature detecting member 6, and detecting a condition of flame on the basis of the temperature information in the combustion space 3 obtained from the temperature detecting member 6. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a burner, and more particularly, to a burner that performs combustion using a fuel gas having a high hydrogen content and a low hydrocarbon-based material content. In particular, hydrogen gas supplied to hydrogen-using equipment such as a fuel cell from a fuel gas mainly containing a hydrocarbon-based substance that is a compound composed of at least carbon and hydrogen, such as natural gas, LPG, gasoline, naphtha, kerosene, and methanol. Or a burner used for burning a fuel gas containing hydrogen as a main component, such as off-gas sent from a fuel cell, and utilizing the heat of combustion for heating or hot water supply. About.

  In a fuel cell power generation system, in a hydrogen generator that generates hydrogen to be supplied to a fuel cell, for example, water is added to a fuel gas mainly containing a hydrocarbon-based substance such as natural gas, LPG, gasoline, naphtha, kerosene, and methanol. Heating is performed at 650 to 700 ° C., whereby the fuel gas is reformed to extract hydrogen (reforming reaction). The reformed gas having a high hydrogen content obtained by the reforming reaction is supplied to the fuel cell and used for power generation. The heating in the reforming reaction is performed using a burner. The burner burns the fuel gas and air to form a flame, thereby generating heat. In the hydrogen generator, heating in the reforming reaction is performed using the heat generated by the burner. As the fuel gas for the burner, for example, off-gas sent from a fuel cell is used for effective use of the supplied gas. The offgas contains a large amount of hydrogen that has not been used in the fuel cell, and thus has a high hydrogen content and high reactivity. For this reason, if a configuration is used in which the off-gas, which is the fuel gas, and the air are supplied to the combustion space in a state of being mixed in advance, there is a risk that the flame may flow backward in the supply system, and there is a problem in safety. Therefore, the burner is configured to separately supply the off gas and the air to the combustion space.

In the burner having the above-described configuration, a flame rod is disposed from the outside of the combustion space to the inside of the combustion space in order to detect ignition misfire, misfire, abnormal combustion, and the like, and to perform combustion safely and efficiently. (For example, see Patent Document 1). In addition, ignition is performed by an igniter installed in the upper space of the combustion space (for example, see Patent Document 2).
JP 2001-201046 A (pages 5-6, FIG. 4) JP-A-7-22043 (page 3, FIG. 1)

In the flame detection method using a flame rod, a voltage is applied between the flame rod and the burner main body that come into contact with the flame formed in the combustion space, and a current generated by ions present in the flame is detected. To perform flame detection. Such a flame detection method using a flame rod is effective when a combustion reaction that forms a flame generates a large amount of ions in the course of the reaction, for example, when burning a fuel gas containing a large amount of a hydrocarbon-based combustible substance. is there. However, when fuel gas having a high hydrogen content and a low hydrocarbon-based combustible material content is burned as described above, ions are not generated in a combustion reaction for forming a flame. For this reason, even if a voltage is applied between the frame rod and the burner body, no current flows, and it is difficult to detect a flame.

On the other hand, in the hydrogen generator, the hydrogen-rich gas mainly composed of H ₂ generated at the time of startup contains a large amount of CO in addition to H ₂ . Such a hydrogen-rich gas containing a large amount of CO (hereinafter referred to as product gas) cannot be supplied to the fuel cell because the CO deteriorates the electrode of the fuel cell. Therefore, the generated gas is also used as the fuel gas of the burner for effective use, like the off-gas. Here, as described above, in the hydrogen generator, the hydrocarbon-based material (such as CH ₄ ) contained in the supplied fuel gas is converted into H ₂ and CO ₂ by a reforming reaction. Is low in unconverted hydrocarbon combustibles. For this reason, in the combustion reaction using such a generated gas as a fuel gas, as in the case of using the off-gas, the generated ions are small. Therefore, when the flame detection method using the flame rod is applied, the current detected when a voltage is applied between the flame rod and the burner main body is small, and therefore, it is possible to detect the flame as in the case of using off-gas. Have difficulty.

  In a burner of a hydrogen generator in a fuel cell power generation system, a current value detected by a flame rod is replaced with a voltage value, and a misfire determination is made based on whether the voltage value is smaller than a threshold voltage for misfire determination. Is If the voltage value falls below the threshold voltage, it is determined that a misfire has occurred and an operation stop operation is performed. Here, as described above, in the burner in which the off gas or the generated gas is supplied as the fuel gas, the amount of ions present in the flame is small, so that the current value detected by the flame rod is small, and thus the current value obtained by the detection is obtained. The applied voltage value becomes smaller. For this reason, if the threshold voltage for misfire determination is set to a high value, the voltage value obtained by the detection falls below the threshold value, and it is determined that a misfire has occurred even though a flame is formed. There is. Therefore, the threshold value needs to be set small, but in this case, there is a possibility that an erroneous determination may be made due to a variation in the value due to noise as a system device member. From the above, when performing combustion using off-gas or generated gas as fuel gas, it is difficult to perform flame detection accurately with the flame detection method using the flame rod.

  Further, in the above-described burner configuration, a space for disposing the frame rod and a space for disposing the discharge electrode for ignition are required near the combustion space. However, when such an installation space is provided, the combustion heat from the burner is transmitted to the space that is not the object to be heated, so that heat is radiated from the installation space. Therefore, the heat transfer efficiency to the hydrogen generator to be heated is reduced. Further, since the device scale of the burner is increased by an amount corresponding to the installation space, the periphery of the burner is narrowed, and the degree of freedom of the configuration around the burner is reduced.

  The present invention has been made to solve these problems, and an object of the present invention is to provide a burner capable of realizing highly accurate flame detection even when burning a fuel gas having a small content of a hydrocarbon-based combustible substance. It is assumed that. Another object of the present invention is to provide a burner that can efficiently heat a heating target by suppressing heat radiation to a target other than the heating target, and is reduced in size to increase the degree of freedom of a surrounding configuration. It is intended to provide.

  In order to solve the above problems, a burner according to the present invention has a fuel distributor that ejects fuel supplied from a fuel supply device, and an air ejection hole that ejects air supplied from an air supply device. Air disposed around the fuel distributor and surrounding the fuel distributor such that air jetted from the air jet holes and fuel jetted from the distributor are burned to form a combustion space forming a flame. A temperature detection member for detecting a temperature of the combustion space, wherein a temperature detection point is located in the air ejection hole or a portion serving as an air flow path of the combustion space, and the temperature detection member. Flame detecting means for detecting the state of the flame in the combustion space based on the temperature detected in Than it is.

  According to this configuration, since the state of the flame is detected by detecting the temperature in the combustion space by the temperature detecting member, the fuel having a low content of the hydrocarbon-based combustible material, which has conventionally been difficult to detect the flame, is used. Also in combustion using gas, flame detection can be performed accurately and accurately regardless of the type of fuel gas.

  The temperature detection member may be arranged such that the temperature detection point is located inside the air ejection hole or near the air ejection hole in the combustion space.

  According to this configuration, since the temperature detection point is located in the air ejection hole or near the air ejection hole in the combustion space, the temperature detection point is not heated to the same temperature as the combustion space. Therefore, the temperature detecting member can detect the temperature within the heat resistance limit, and can prevent deterioration due to heat. Further, since the temperature detection member is disposed with little projection into the combustion space, the temperature in the combustion space can be detected without disturbing the flame formed in the combustion space. Such an effect is particularly remarkably realized in a configuration in which the temperature detection member is arranged such that the temperature detection point is located in the air ejection hole.

  The temperature detection member may be arranged to penetrate the air ejection member.

  It is preferable that the temperature detection point of the temperature detection member is insulated from the inner surface of the air ejection hole.

  According to this configuration, since the temperature detection point of the temperature detection member is disposed insulated from the air ejection hole, it is possible to quickly detect a temperature change in the combustion space without being affected by the air ejection member. It is.

  Preferably, a gap is formed between the temperature detecting member and the inner surface of the air ejection hole, and the width of the gap may be substantially uniform over the outer periphery of the temperature detecting member.

  According to this configuration, the temperature detection member is insulated from the air ejection holes by the air layer existing in the gap. Further, since a flow of the supply air toward the combustion space is formed in the air layer, when a misfire occurs, the temperature detection point of the temperature detection member is rapidly cooled by the flow of the air. Therefore, misfire detection can be performed quickly. In particular, if the width of the air layer is substantially uniform over the entire outer periphery of the temperature detecting member, a uniform flow of supply air is formed in the air layer, so that stable air supply is possible and the combustion state is stabilized.

  The air ejection member has a plurality of the air ejection holes, and in the air ejection hole where the temperature detection member is disposed, a cross-sectional area of the gap between the air ejection hole and the temperature detection member is such that the temperature detection member is disposed. It is preferable that the cross-sectional area of the air ejection hole is not substantially equal.

  According to such a configuration, in the air ejection hole in which the temperature detection member is arranged, it is possible to suppress disturbance of the air ejection state due to the provision of the temperature detection member, and to eject air in the same manner as other air ejection holes. It becomes possible. This makes it possible to form a well-balanced and stable flame.

  The temperature detection member may have the temperature detection point at one end, and a main body may be housed in the air ejection member.

  According to such a configuration, it is not necessary to provide a space for disposing the temperature detecting member, so that an extra installation space is not required. Thereby, it is possible to suppress heat radiation to an extra space, and it is possible to efficiently heat the object to be heated. In addition, the size of the burner can be reduced, and the degree of freedom in the configuration around the burner can be improved.

  The tip of the temperature detection member on the temperature detection point side may be substantially covered with an oxide film.

  In the case where the temperature detecting member whose one end is not previously covered with the oxide film is used, an oxide film is formed along with the combustion, so that the detected temperature changes before and after the oxide film is formed. . On the other hand, if a temperature detecting member whose one end is previously covered with an oxide film is used, the detection temperature does not change before and after the formation of the oxide film, so that the detection accuracy is improved.

  The tip of the temperature detection member on the temperature detection point side may have a substantially hemispherical shape.

  According to such a configuration, a smooth air flow is formed along the outer periphery of the tip, so that the temperature detection member is quickly cooled when the combustion in the burner is stopped. In addition, during combustion, radiant heat is easily received, so that a temperature rise can be easily detected. Therefore, the accuracy of detection is improved.

  The temperature detecting member may be a sheath-shaped thermocouple.

  According to such a configuration, the configuration of the present invention can be easily realized.

  A plurality of the temperature detecting members may be provided, and the temperature detecting members may be provided at different positions so as to detect temperatures in different regions of the combustion space.

  According to this configuration, it is possible to detect the temperatures of the different regions of the combustion space with the plurality of temperature detecting members, and thus it is possible to perform the flame detection more accurately and accurately. Furthermore, particularly, by comparing the flame state in each region of the combustion space, it is possible to detect abnormal combustion quickly and easily and accurately. Therefore, when abnormal combustion occurs, combustion can be stopped immediately, and CO emission and abnormally high temperature can be prevented.

  The combustion space may have a larger sectional area in the flame emission direction.

  According to such a configuration, since combustion is performed in each region of the combustion space according to the amount of combustion, it is possible to stably perform combustion with a wide fuel amount from a low combustion amount to a high combustion amount.

  An electrode housed in the fuel distributor, one end of which protrudes into the combustion space; and an ignition device that is electrically connected to the electrode and applies a voltage to the electrode so as to discharge from the electrode in the combustion space. And a circuit.

  According to such a configuration, it is possible to perform ignition by applying a voltage to the electrode and causing a discharge between the electrode and the fuel distributor or the air ejection member, for example. In such a configuration, since the electrodes are housed in the fuel distributor, no space is required for disposing the ignition means. Since no extra installation space is required, heat radiation to the extra space can be suppressed, and the object to be heated can be efficiently heated. In addition, the size of the burner can be reduced, and the degree of freedom in the configuration around the burner can be improved.

  At the time of ignition, the electrode and the ignition circuit are connected, and after the flame detection means makes an ignition determination based on the temperature information of the combustion space from the temperature detection member, the electrode and the flame detection means Switching means for switching so as to be connected, the flame detection means performs flame detection based on the temperature information from the temperature detection member, and performs flame detection based on an output current from the electrode. Detection may be performed.

  According to this configuration, the flame detection is performed by the conventional electrode in parallel with the flame detection by the temperature detection member, so that the flame detection can be performed more accurately and accurately. Further, in such a configuration, since the electrode serving as the ignition means can be used for flame detection, the configuration is easy and the configuration can be realized without significant change.

  The temperature detection member is disposed at the tip of the electrode protruding into the combustion space so as to perform flame detection in a region different from the region in the combustion space in which flame detection is performed by the temperature detection member. It may be arranged in an area different from the area of the combustion space.

  According to this configuration, it is possible to detect the temperatures of the different regions of the combustion space by the temperature detection member and the electrodes, respectively, so that the flame detection can be performed more accurately and accurately. Furthermore, particularly, by comparing the flame state in each region of the combustion space, it is possible to detect abnormal combustion quickly and easily and accurately. Therefore, when abnormal combustion occurs, combustion can be stopped immediately, and CO emission and abnormally high temperature can be prevented.

  The temperature detection member may detect a flame in an upper region of the combustion space in the flame emission direction, and the electrode may detect a flame of a lower region in the combustion space in the direction.

  According to such a configuration, flame detection can be performed in the upper region and the lower region of the combustion space, so that ignition is detected in the upper region but no ignition is detected in the lower region, and ignition is detected in the upper region. A state in which ignition is not detected but ignition is detected in the lower region can be detected as an abnormal combustion state.

  A hydrogen generator according to the present invention includes a burner having the above-described configuration, and a reformer that generates a reformed gas containing hydrogen by a reforming reaction of a hydrocarbon-based raw material, and includes the reformer using the burner. Is to be heated.

  According to this configuration, since the burner having the above configuration is used, even when a gas containing a small amount of a hydrocarbon-based flammable substance is used as the fuel gas for the burner, flame detection can be performed accurately and accurately. It is possible to do. Therefore, in the hydrogen generator having such a configuration, it is possible to form a flame safely while performing flame detection regardless of the type of fuel gas.

  A fuel cell power generation system according to the present invention includes a hydrogen generator having the above configuration, and a gas containing hydrogen as a main component obtained from the hydrogen generator being supplied to a fuel electrode side and an oxidant gas being supplied to an oxidant electrode side. And a fuel cell that is supplied to the power generator to generate power.

According to this configuration, since the above-described effect is obtained in the hydrogen generator, it is possible to perform heating during the reforming reaction by burning off gas or product gas containing hydrogen as a main component with a burner as a fuel gas. Therefore, it is possible to realize a system with high power generation efficiency and low environmental load.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to implement | achieve accurate flame detection in the combustion which uses the gas with a small content of hydrocarbon type combustible substance, for example, the gas of hydrogen main component as a fuel gas. Further, by making the combustion space in the shape of an inverted truncated cone expanding in the flame emission direction, it is possible to realize a wide range of combustion from a low combustion amount to a high combustion amount. In addition, by installing an electrode as an ignition device in the fuel distributor and installing a temperature detection member in the air outlet, there is no need to install an electrode or flame detection member outside the combustion space, so heating is not required. In addition to suppressing heat radiation to the target, the burner can be reduced in size, and the degree of freedom in the configuration around the burner can be improved. In addition, the electrode is used as a discharge part at the time of ignition, and after ignition is confirmed by the temperature detection member, the electrode is used as a flame detection member for detecting a current in the flame as in the related art, so that more accurate detection is possible. This is to perform a simple flame detection. In addition, abnormal combustion can be detected by detecting the flame state in a plurality of different areas in the combustion space. In the case of abnormal combustion, combustion is stopped immediately to prevent CO emission and abnormal high temperature. Can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a cross-sectional view schematically illustrating a configuration of a burner according to Embodiment 1 of the present invention. 2 and 3 are diagrams for explaining the arrangement of the temperature detecting member of FIG. 1 in detail. FIG. 2 is a partially enlarged sectional view, and FIG. 3 is a partially enlarged plan view.

  As shown in FIG. 1, the burner includes a fuel distributor 1 having a plurality of fuel ejection holes 8, an air ejection member 2 having a plurality of air ejection holes 9, and a temperature housed and arranged in the air ejection member 2. And a detection member 6. The space defined by the inner wall 2B of the air ejection member 2 is a combustion space (combustion chamber) 3, and the temperature detection member 6 detects the temperature of the combustion space 3.

  The air ejection member 2 has a cylindrical shape with both ends opened, and the inside of the cylinder is hollow in the following shape. That is, the inner peripheral wall 2B of the air ejection member 2 is inclined, so that the cylindrical inner hole becomes an inverted truncated cone-shaped space whose cross-sectional area increases toward the upper end opening (flame discharge outlet). ing. That is, the inner peripheral wall 2B has a cup shape. The cup-shaped space which is an inner hole of the air ejection member 2 becomes a combustion space 3 in which a flame is formed and combustion is performed. In the air ejection member 2, the cylindrical peripheral wall is formed to be hollow. That is, in the peripheral wall portion, an internal space 20 is formed between the outer peripheral wall 2A, the inner peripheral wall 2B, the upper end wall 2C, and the lower end wall 2D, and the internal space 20 surrounds the combustion space 3 in the circumferential direction. It has a configuration. The internal space 20 of the air ejection member 2 communicates with the combustion space 3 through a plurality of air ejection holes 9 provided in the circumferential direction and the vertical direction of the inner peripheral wall 2B. Further, the internal space 20 has an air supply port 31 provided in the outer peripheral wall 2A, and the air supply device 5 provided outside is connected to the air supply port 31. The air supply device 5 includes a blower (not shown) such as a pump or a fan, and supplies combustion air to the air ejection member 2 while adjusting the flow rate. As a method of adjusting the supply flow rate of the air, a method of controlling and adjusting the operation of the blower, or, in a supply system, a flow rate adjustment member such as a valve is disposed downstream of the blower, and There is a method of performing adjustment by controlling.

  The air ejection member 2 is made of, for example, metal. Since such an air ejection member 2 has a large volume, it has a larger heat capacity than a temperature detection member 6 described later. As shown in FIG. 2, circular air ejection holes 9 (9A, 9B) having a predetermined diameter are formed at predetermined intervals in an inner peripheral wall 2B forming the combustion space 3. Here, the air ejection hole 9 is composed of one air ejection hole 9A having a diameter D1 of 2.0 mm and a number of air ejection holes 9B having a diameter D2 of 1.2 mm. The temperature detecting member 6 is provided in the air ejection hole 9A. The temperature detecting member 6 has a configuration in which a temperature detecting point (not shown) provided at the tip slightly projects into the combustion space 3, faces the combustion space 3, and is located in the flow of air. I have. The main body of the temperature detecting member 6 is disposed so as to protrude outside through the internal space 20 of the air ejection member 2 and the through hole 32 provided in the lower end wall 2D. The temperature detecting member 6 is supported by a support member (not shown), and a space between the through hole 32 of the air ejection member 2 and the temperature detecting member 6 is sealed by a seal member (not shown) so that air does not leak. ing. Here, a sheath-shaped thermocouple having a diameter of 1.6 mm is used as the temperature detecting member 6, and a tip portion including a temperature detecting point (not shown) is covered with the oxide film 16. By being covered with the oxide film in this manner, it is possible to accurately detect the temperature in the combustion space 3 as described later. The temperature detection member 6 is arranged so as not to directly contact the inner surface of the air ejection hole 9A, and has a gap between the temperature detection member 6 and the inner surface of the air ejection hole 9A. As shown in FIG. 3, here, for example, the temperature detecting member 6 is concentrically arranged in the circular air ejection hole 9 </ b> A, and thereby the width of the annular air layer 17 formed on the outer periphery of the temperature detecting member 6. L (that is, the distance between the inner surface of the air ejection hole 9A and the outer peripheral surface of the temperature detecting member 6) is substantially uniform over the entire outer periphery of the temperature detecting member 6. With such a configuration, as described later, in the air ejection hole 9A in which the temperature detecting member 6 is disposed, the cross-sectional area of a portion serving as an air flow path (that is, the air layer 17) is different from that of the other air ejection holes 9B. This is almost the same as the case, and an air flow path having a uniform width L is formed on the outer periphery of the temperature detecting member 6. Although a thermocouple is used as the temperature detecting member 6 here, a thermistor or the like may be used instead of the thermocouple. The temperature detecting member 6 is connected to a flame detecting device 7 provided outside the burner.

  A tubular fuel distributor 3 having a closed end is fitted to a lower portion of the combustion space 3 having a smaller cross-sectional area than an upper portion (a flame discharge outlet side). The fuel distributor 3 is disposed such that a distal end provided with a plurality of fuel ejection holes 8 in a circumferential direction projects to a center portion of the combustion space 3 having a circular cross section, and a base end is disposed outside. Connected to the fuel gas supply device 4. The fuel gas supply device 4 supplies a fuel gas including a combustible gas to the fuel distributor 1 while adjusting the flow rate, and includes a blower (not shown) such as a pump and a fan. As a method of adjusting the supply flow rate of the fuel gas, a method of adjusting the operation by controlling the operation of the blower, or, in a supply system, a flow rate adjustment member such as a valve is provided downstream of the blower. And a method of performing adjustment.

  Next, the operation of the above-described burner during combustion will be described.

  As shown by arrows in FIG. 1, fuel gas is supplied from the fuel gas supply device 4 to the fuel distributor 1. Further, the fuel gas is ejected from the fuel distributor 1 to the combustion space 3 through the fuel ejection holes 8. Here, the fuel gas supplied from the fuel gas supply device 4 is a combustible gas containing hydrogen as a main component. As such a fuel gas, for example, as described in a fifth embodiment (FIG. 8) described later, a generated gas generated at the time of starting the hydrogen generator of the fuel cell power generation system may be used. Battery off-gas may be used.

  On the other hand, air is supplied from the air supply device 5 to the air ejection member 2. As shown by arrows in the drawing, air is introduced into the internal space 20 of the air ejection member 2, and is further ejected into the combustion space 3 through the air ejection holes 9. At this time, since the cross-sectional areas of the air passages are substantially equal between the air ejection holes 9A and the air ejection holes 9B, the flow rates of the air ejected from both are substantially equal. Therefore, the disturbance of the air ejection state due to the arrangement of the temperature detection member 6 in the air ejection hole 9A can be minimized, and the disturbance of the combustion state can be suppressed. In the air ejection hole 9A, an air passage having a uniform width L is formed on the outer periphery of the temperature detection member 6 as described above. Air is spouted evenly. Therefore, disturbance of the air ejection state is further suppressed, and disturbance of the combustion state can be further suppressed.

  The fuel gas and the air thus supplied to the combustion space 3 are mixed in the combustion space 3. Then, ignition is performed by an ignition device (not shown) such as a pilot flame or a heater, and the fuel gas and the air are reacted and burned in the combustion space 3 to form a flame 10. Here, as described above, since the air is supplied from the air ejection holes 9A and 9B at a substantially equal flow rate, it is possible to form a stable and well-balanced flame 10. Then, as indicated by the arrow in the figure, the heat released from the formed flame is transmitted to the object to be heated to perform heating. If the fuel gas and the air are separately supplied and mixed in the combustion space 3 as described above, the conventional configuration in which the combustible fuel gas and the air are mixed in advance and supplied to the combustion space 3 for combustion. As described above, since there is no fear that the flame flows backward in the supply system, the combustion can be performed more safely.

  Here, at the time of the combustion, the state of the flame is detected using the temperature detection member 6 in order to grasp ignition, misfire, and abnormal combustion. Hereinafter, a method of detecting a flame will be described.

  When the flame 10 is formed in the combustion space 3, the temperature in the combustion space 3 that has been at a normal temperature until then rises, and the temperature detected by the temperature detection member 6 rises. Here, the temperature detection member 6 has a temperature detection point (not shown) at the tip located in the air ejection hole 9 </ b> A of the air ejection member 2, and the main body is housed in the internal space 20 of the air ejection member 2. Therefore, the temperature detecting member 6 is not directly exposed to the flame in the combustion space 3. For this reason, the temperature detecting member 6 does not become high in temperature (about 1000 ° C.) in the same manner as the temperature of the combustion space 3 at the time of combustion. Is prevented. Further, since the temperature detecting member 6 projects only a little into the combustion space 3, it is possible to detect the temperature of the combustion space 3 without disturbing the flame formed in the combustion space 3.

  On the other hand, since the temperature detection point (not shown) at the tip of the temperature detection member 6 faces the combustion space 3, it is possible to quickly and accurately detect the temperature in the combustion space 3. Here, the temperature detection member 6 does not directly contact the inner surface of the air ejection hole 9 </ b> A at the tip where the temperature detection point is provided, but has an air layer 17 formed therearound and is insulated from the air ejection member 2. . For this reason, it is possible to detect the temperature change of the combustion space 3 without being affected by the temperature change of the inner peripheral wall 2B of the air ejection member 2. That is, since the temperature of the temperature detecting point of the temperature detecting member 6 rises faster than the temperature of the inner peripheral wall 2B of the air ejection member 2 having a large heat capacity, the ignition can be quickly and accurately detected. .

  The temperature information of the combustion space 3 detected by the temperature detecting member 6 is transmitted to the flame detecting device 7 as an electric signal. The flame detection device 7 determines whether or not the flame 10 has been formed (ignited) in the combustion space 3 based on the transmitted electric signal based on a temperature change in the combustion space 3. As a method of determining ignition, for example, a method of determining whether the detected temperature of the combustion space 3 is higher than a predetermined temperature may be used, or the rate of temperature rise per unit time may be a predetermined temperature. A method of determining whether or not the speed is higher than the ascending speed may be used.

  On the other hand, if a misfire occurs for some reason, the temperature of the combustion space 3 which has been in a high temperature state rapidly drops. Accordingly, the temperature detected by the temperature detecting member 6 also decreases. The temperature information of the combustion space 3 detected in this manner is transmitted to the flame detection device 7 in the same manner as described above. The flame detection device 7 determines whether or not the flame 10 in the combustion space 3 has misfired based on the temperature change of the combustion space 3 based on the transmitted electric signal. As a method for determining misfire, for example, a method for determining whether or not the detected temperature of the combustion space 3 is lower than a predetermined temperature may be used, or the rate of temperature decrease per unit time may be a predetermined temperature. A method of determining whether or not the speed is greater than the decreasing speed may be used. Here, as described above, since a gap is formed between the temperature detection point of the temperature detection member 6 and the inner surface of the air ejection hole 9A and the air layer 17 exists, the temperature detection member 6 The temperature quickly drops with the misfire without being affected by the air ejection member 2. In particular, a flow toward the combustion space 3 is usually formed in the air layer 17 between the inner surface of the air ejection hole 9A and the supply of air, and the temperature detecting member 6 causes the flow in the air to flow. positioned. Therefore, the temperature of the temperature detecting member 6 is rapidly cooled by the flow of the air, and if the heating is not performed due to misfire, the temperature of the temperature detecting member 6 drops rapidly at the temperature detecting point. Therefore, after a misfire, misfire detection can be performed in a short time.

  According to the above-described flame detection method, the flame 10 can be detected by a temperature change in the combustion space 3 irrespective of the current value at the time of combustion as in the related art. In the combustion using a fuel gas which is difficult to detect by the flame detection method described above, that is, a fuel gas having a small content of a hydrocarbon-based combustible substance, the flame state can be detected accurately and accurately.

  Here, as described above, since the tip of the temperature detection member 6 on the temperature detection point (not shown) side is covered with the oxide film 16, a temperature detection member on which an oxide film is not formed in advance is used. In comparison with the case where the temperature is higher, the temperature in the combustion space 3 can be detected with higher accuracy for the following reasons. That is, if a temperature detecting member not previously covered with an oxide film is used, the tip of the temperature detecting member is oxidized with the combustion in the combustion space 3 and an oxide film is eventually formed. There is a change in the temperature detected by the temperature detecting member before and after the formation of. On the other hand, if the oxide film 16 is previously formed on the tip of the temperature detecting member 6 as in the present embodiment, it is possible to prevent such a change in the detected temperature. Therefore, flame detection can be performed with higher accuracy.

  Further, in the above configuration, since the combustion space 3 has a cup shape, that is, an inverted truncated cone shape having a larger cross section toward the upper portion (flame discharge outlet), the combustion space 3 is balanced in accordance with the combustion amount within a wide combustion amount range. A well stable flame 10 can be formed. Specifically, when the supply flow rate of the mixed gas of the fuel gas and the air as the combustion source is small and the combustion amount is low, the flow velocity and the combustion speed of the mixed gas are balanced in the region of the combustion space 3 having a small cross-sectional area. I do. That is, since the size of the flame is determined by the balance between the flow rate of the mixed gas as the combustion source and the combustion speed (reaction speed of the combustion reaction), when the combustion amount is low, the combustion speed is constant. In this case, the flame 10A is formed around the lower part of the fuel space 3 where the mixed gas supply flow rate becomes equal to the mixed gas flow rate equal to the combustion velocity. On the other hand, when the flow rate of the mixed gas is large and the amount of combustion is large, the flow rate of the mixed gas and the combustion speed are balanced in the region of the combustion space 3 having a large cross-sectional area. Therefore, in this case, a flame 10B is formed above the combustion space 3. Thus, by making the combustion space 3 cup-shaped, stable combustion can be realized in a wide combustion amount range. The air ejection member 2 having such a cup-shaped combustion space 3 can be formed as a single component by pressing or drawing, so that the processing surface is also easy. Here, the hottest part at the boundary between the part where combustion is performed and the part where combustion is not performed is defined as a flame. That is, the flame refers to the outermost contour portion of the formed flame.

  Further, since the temperature detecting member 6 is disposed so as to be housed in the air ejection member 2, a space for installing the temperature detecting member as in the conventional case using a frame rod or the like as the temperature detecting member becomes unnecessary. . Therefore, it is not necessary to provide an extra installation space around the burner, and it is possible to efficiently heat the object to be heated by suppressing unnecessary heat radiation from the space. In addition, the size of the burner can be reduced by the amount that no extra installation space is required, and the degree of freedom of the configuration around the burner can be greatly improved.

  The hole diameters of the air ejection holes 9A and 9B, the diameter of the temperature detection member 6, and the shapes thereof are merely examples, and are not limited thereto. Further, in the air ejection holes 9A and 9B, the cross-sectional areas of the air flow paths do not necessarily have to be equal as described above, and if the air layer 17 is formed around the temperature detecting member 6, The cross sections of the air flow paths in the air ejection holes 9A and 9B may be different from each other. Further, the width L of the air layer 17 may not be uniform. Further, as a modified example of the present embodiment, the combustion space 3 formed by being surrounded by the air ejection member 2 is not a cup shape as shown in FIG. 1 but a column shape having a uniform cross-sectional area. You may.

  FIG. 4 is a partially enlarged cross-sectional view schematically showing a configuration of a characteristic portion in a modification of the first embodiment. As shown in FIG. 4, the burner of this example has the same configuration as the burner of FIG. 1, but differs from the burner of FIG.

That is, in the burner of the present example, the tip of the temperature detection member 6 arranged in the air ejection hole 9A on the temperature detection point (not shown) side has a hemispherical shape. A tip having such a shape is more susceptible to radiant heat than a tip having a corner, and thus a temperature rise accompanying combustion can be detected with high accuracy. Also, at the tip of such a shape, a smooth air flow is formed along the smooth surface of the hemisphere, so that it is easy to cool, and the temperature drops rapidly when a misfire occurs. Therefore, misfire can be detected with high accuracy. From the above, according to the configuration of the present example, the above-described effects are more effectively achieved.
(Embodiment 2)
FIG. 5 is a cross-sectional view schematically illustrating a configuration of a burner according to the second embodiment of the present invention. The burner of the present embodiment has the same configuration as that of the first embodiment, but differs from the first embodiment in that a plurality of temperature detecting members are disposed at different positions in the combustion space.

  That is, in the present embodiment, in addition to the temperature detecting member 6 provided in the same manner as in the first embodiment, the temperature detecting member 60 is further arranged so as to be located below the temperature detecting member 6. . The temperature detecting member 60 is connected to the flame detecting device 7, and the temperature information of the lower region of the combustion space 3 obtained by the temperature detecting member 60 is transmitted to the flame detecting device 7 as an electric signal. Here, similarly to the temperature detecting member 6, the temperature detecting member 60 has a configuration in which the tip on the temperature detecting point (not shown) side is covered with the oxide film 16. Further, similarly to the temperature detection member 6, a temperature detection point (not shown) is located in the air ejection hole 9 so as to be positioned in the flow of air, and is disposed on the outer periphery of the temperature detection member 60. An air layer having a uniform width is formed. Therefore, according to the temperature detecting member 60, similarly to the temperature detecting member 6, it is possible to accurately and accurately detect the temperature of the lower region of the combustion space 3. Further, here, similarly to the first embodiment, the temperature in the upper region of the combustion space 3 can be detected accurately and accurately by the temperature detection member 6. As described above, by detecting the temperatures of the different regions of the combustion space 3, that is, the upper region and the lower region, and comparing the ignition states in the respective regions, particularly, abnormal combustion can be easily and accurately detected. Becomes possible. When it is determined that the combustion is abnormal, for example, the supply of the fuel gas from the fuel gas supply device 4 is stopped to stop the combustion. Thereby, it is possible to prevent the emission of CO due to abnormal combustion and the deterioration of equipment including the burner due to high temperature. Hereinafter, a method for detecting abnormal combustion will be described in detail.

  First, when the combustion is performed normally and the flame 11C is formed, the temperature of the combustion space 3 becomes substantially uniform, so the temperature detection provided at the upper part of the combustion space 3 (near the exit of the combustion space 3). The temperature detected by the member 6 and the temperature detected by the temperature detecting member 60 provided in the lower part (near the fuel distributor 1) of the combustion space 3 become substantially equal, and the flame detector 7 has the upper and lower parts of the combustion space 3 It is determined that it is in the ignition state. Therefore, in this case, it can be confirmed that the combustion is normally performed in the combustion space 3.

  On the other hand, for example, when the combustion amount becomes excessively large for some reason or when the air supply amount decreases and the flame tends to be lifted, an abnormal combustion state occurs, and the flame 11B having the upper portion of the combustion space 3 as a base is formed. It is formed. When such a flame 11B is formed, the upper portion of the combustion space 3 is significantly heated to a higher temperature than usual. Therefore, the temperature detected by the temperature detecting member 6 provided in the upper part of the combustion space 3 increases. On the other hand, in this case, no flame exists at the lower part of the combustion space 3. Therefore, the temperature detected by the temperature detection member 60 provided in the lower part of the combustion space 3 becomes low. When the temperature information of the upper part of the combustion space 3 obtained from the temperature detecting member 6 and the temperature information of the lower part of the combustion space 3 obtained from the temperature detecting member 60 are transmitted to the flame detecting device 7, the flame The detection device 7 determines a flame state based on each information. In this case, based on the information from the temperature detecting member 6, since the detected temperature in the upper part of the combustion space 3 is higher than a predetermined value, it is determined that the upper part of the combustion space 3 is in the ignition state. On the other hand, based on the information from the temperature detecting member 60, since the detected temperature in the lower part of the combustion space 3 is smaller than the predetermined value, it is determined that the lower part of the combustion space 3 is in a misfire state. As a result, it can be confirmed that the flame 11B is abnormal.

  When the combustion amount becomes too small or the air supply amount increases for some reason, an abnormal combustion state occurs, and a small flame 11A is formed in the lower part of the combustion space 3. When such a flame 11A is formed, the lower portion of the combustion space 3 is significantly heated to a higher temperature than usual. For this reason, the temperature detected by the temperature detecting member 60 provided below the combustion space 3 increases. On the other hand, no flame is formed in the upper part of the combustion space 3, so that the temperature detected by the temperature detecting member 6 provided in the upper part of the combustion space 3 becomes low. Based on the temperature information on the upper part of the combustion space 3 obtained from the temperature detecting member 6 and the temperature information on the lower part of the combustion space 3 obtained from the temperature detecting member 60 in this way, the flame detecting device 7 The state of the flame 11A is detected. In this case, based on the information from the temperature detecting member 6, since the detected temperature in the upper part of the combustion space 3 is lower than a predetermined value, it is determined that the upper part of the combustion space 3 is in a misfire state. On the other hand, based on the information from the temperature detecting member 60, since the detected temperature in the lower part of the combustion space 3 is higher than the predetermined value, it is determined that the lower part of the combustion space 3 is in the ignition state. As a result, it can be confirmed that the flame 11A is abnormal.

In addition, the number of the temperature detecting members when the plurality of temperature detecting members are provided and the arrangement position in the combustion space 3 are not limited to the above, and may have other configurations.
(Embodiment 3)
FIG. 6 is a sectional view schematically showing a configuration of a burner according to the third embodiment of the present invention. The burner of the present embodiment has the same configuration as that of the first embodiment, but differs from the first embodiment in that an electrode 12 serving as ignition means is provided in the fuel distributor 1.

  That is, in the present embodiment, the electrode 12 is provided at the center of the inner hole of the tubular fuel distributor 1 having a double structure. The electrode 12 is supported by a support member 15 fitted into the inner hole of the combustion distributor 1, and the tip of the electrode 12 projects into the combustion space 3. The support member 15 is made of, for example, ceramic having heat resistance and insulating properties. The protruding tip of the electrode 12 is bent toward the inner wall of the air ejection member 2 so as to draw an arc. The base end of the electrode 12 penetrates the bottom wall of the fuel distributor 1 and protrudes to the outside, and is electrically connected to an ignition circuit 13 provided outside. The gap between the electrode 12 and the support member 15 and the gap between the inner peripheral wall of the fuel distributor 1 and the support member are filled with a seal member (not shown).

  In the above configuration, at the time of ignition, air is ejected from the air ejection holes 9 of the air ejection member 2 into the combustion space 3, and fuel gas is ejected from the fuel ejection holes 8 of the fuel distributor 1 into the combustion space 3. At this time, since the fuel distributor 1 has a double structure, the electrode 12 and the support member 15 disposed in the fuel distributor 1 supply the fuel gas from the fuel gas supply device 4 to the distributor 1 and supply the fuel to the distributor 1. It does not prevent fuel gas ejection from the ejection holes 8. When the fuel gas and the air are supplied to the combustion space 3 and mixed, a voltage is applied from the ignition circuit 13 to the electrode 12. As a result, discharge occurs between the electrode 12 and the inner wall of the air ejection member 2, and as a result, ignition occurs. Then, combustion is performed in the combustion space 3 to form a flame. At this time, as in the first embodiment, the temperature in the combustion space 3 is detected by the temperature detecting member 6 and the flame state is detected by the flame detecting device 7.

  In the configuration according to the present embodiment, the same effects as those described above in the first embodiment are obtained, and further, the following effects are obtained. That is, in the present embodiment, since the electrode 12 serving as the ignition means is housed and disposed in the fuel distributor 1, the electrode 12 for setting the ignition means is provided around the burner such as above the combustion space 3 as in the related art. There is no need to secure space. Therefore, it is possible to suppress heat radiation from the installation space that occurs when an extra installation space is provided, and thus it is possible to efficiently heat the object to be heated. In addition, the size of the burner can be further reduced by the amount that does not require an extra installation space, so that the degree of freedom of the configuration around the burner can be further improved.

In the above description, a case has been described in which the discharge is performed between the electrode 12 and the inner wall of the air ejection member 2 to ignite, but the discharge may be performed between the electrode 12 and the fuel distributor 1 to perform the ignition. . In this case, it is preferable that the tip of the electrode 12 projecting into the combustion space 3 be bent toward the fuel distributor 1 so that electric discharge easily occurs between the electrode 12 and the fuel distributor 1. Note that the shape of the electrode 12 is not limited to the above, and may not necessarily be bent.
(Embodiment 4)
FIG. 7 is a sectional view schematically showing a configuration of a burner according to the fourth embodiment of the present invention. As shown in FIG. 7, the burner of the present embodiment has the same configuration as the burner of the third embodiment, but differs from the third embodiment in the following points. That is, in the present embodiment, the ignition circuit 13 and the flame detection device 7 are connected to the electrode 12 in parallel via the switch 14. In such a configuration, switching is performed to connect the electrode 12 and the ignition circuit 13 at the time of ignition as described below, and after ignition is detected, switching is performed so that the electrode 12 and the flame detection device 7 are connected. .

  That is, at the time of ignition, the changeover switch 14 is switched so that the electrode 12 and the ignition circuit 13 are connected, and ignition is performed as in the third embodiment. On the other hand, when the flame is formed by the ignition, the flame detection device 7 detects the ignition based on the temperature information of the combustion space 3 from the temperature detection member 6. Then, the changeover switch 14 performs switching so as to connect the electrode 12 and the flame detection device 7. Thereby, simultaneously with the flame detection method using the temperature detection member 6, the flame detection device 7 can perform the flame detection based on the conventional flame detection method, that is, based on the output current detected from the electrode 12. Thereby, since flame detection can be performed by two methods using the temperature detection member 6 and the electrode 12, more accurate flame detection can be realized.

  Here, the flame state of the upper part of the combustion space 3 is detected by the temperature detection member 6, and the electrode 12 whose tip is disposed below the temperature detection member 6 in the combustion space 3 is used. It is possible to detect the state of the flame below. Then, by detecting the flame state in a plurality of different regions in the combustion space 3 as described above, it becomes possible to detect the abnormal combustion state, as in the second embodiment.

  First, when the combustion is performed normally and the flame 11C is formed, the combustion is performed based on the temperature detected by the temperature detection member 6 provided above the combustion space 3 (near the exit of the combustion space 3). The flame detecting member 7 determines that the upper part of the space 3 is in the ignition state. Further, in parallel with the detection by the temperature detection member 6, the output current from the electrode 12 disposed below the space 3 (near the fuel distributor 1) is detected, and the current value is converted into a voltage value. Then, an ignition determination is made based on whether or not the obtained voltage value is larger than the threshold voltage. In this case, since a flame is formed in the lower part of the combustion space 3, the output current increases, and the detected voltage value becomes higher than the threshold voltage. Therefore, the flame detection device 7 determines that the lower part of the combustion space 3 is in the ignition state. Since the upper and lower portions of the combustion space 3 are determined to be in the ignited state, normal combustion is confirmed.

  On the other hand, for example, when the combustion amount becomes excessively large for some reason or when the air supply amount decreases and the flame tends to be lifted, abnormal combustion occurs and a flame 11B based on the upper part of the combustion space 3 is formed. Is done. When such a flame 11B is formed, the upper portion of the combustion space 3 is significantly heated to a higher temperature than usual. For this reason, the temperature detected by the temperature detection member 6 provided in the upper part of the combustion space 3 becomes high, and based on this, the flame detection device 7 determines that the upper part of the combustion space 3 is in an ignition state. On the other hand, in this case, since no flame exists at the lower part of the combustion space 3, the output current from the electrode 12 arranged at the lower part of the combustion space 3 is not detected. The value becomes smaller than the threshold voltage. Therefore, the flame detection device 7 determines that the lower part of the combustion space 3 is in a misfire state. Then, an abnormal combustion state can be confirmed from the ignition determination results of the upper and lower portions of the combustion space 3 obtained in this manner.

  When the combustion amount becomes too small or the air supply amount increases for some reason, an abnormal combustion state occurs, and a small flame 11A is formed in the lower part of the combustion space 3. When such a flame 11A is formed, an output current from the electrode 12 is detected in the lower part of the combustion space 3 because a flame exists. In this case, the voltage value obtained by converting the detected current value becomes larger than the threshold voltage, and therefore, the flame detection device 7 determines that the lower part of the combustion space 3 is in the ignition state. On the other hand, no flame is formed in the upper part of the combustion space 3, so that the temperature detected by the temperature detecting member 6 provided in the upper part of the combustion space 3 becomes low. The flame detector 7 determines that the upper part of the combustion space 3 is in a misfire state based on the temperature information. Then, an abnormal combustion state can be confirmed from the ignition determination results of the upper and lower portions of the combustion space 3 obtained in this manner.

  In the above first to fourth embodiments, the case where the temperature detection points of the temperature detection member are arranged in the air ejection holes has been described, but the arrangement positions of the temperature detection points are not limited to this. For example, if a temperature detecting member made of a material having extremely high heat resistance is used, the temperature detecting member may be arranged so as to extend from the air ejection hole to the combustion space. That is, if the temperature detecting member is insulated from the surrounding burner constituent members and is arranged so as to be exposed to the air flow ejected from the air ejection holes, the temperature sensing member is arranged in a configuration other than the above-described first to fourth embodiments. There may be. In an arrangement in which the temperature detection point of the temperature detection member is too far into the air ejection hole or in an arrangement in which the temperature detection point is located in the space between the outer wall and the inner wall of the air ejection member, the temperature of the combustion space can be accurately determined. It cannot be detected accurately and quickly. For this reason, the temperature detection point of the temperature detection member needs to be arranged at a position corresponding to the temperature change of the combustion space promptly, specifically, at least a position facing the combustion space.

Further, in the above-described second to fourth embodiments, the case has been described where the tip of the temperature detection member on the temperature detection point side has a corner, but as in the modification of the first embodiment, the temperature detection member has The tip may be hemispherical.
(Embodiment 5)
FIG. 8 is a schematic diagram showing a configuration of a fuel cell power generation system having a hydrogen generator including a burner according to the present invention. As shown in FIG. 8, the fuel cell power generation system 100 has a fuel cell 53 and a hydrogen generator 52 as main components. The fuel cell 53 has a conventional structure.

The hydrogen generator 52 has a burner 50, a reformer 51, and a CO converter 54. As the burner 50, the burner described in the first to fourth embodiments is used. As the reformer 51 and the CO converter 54, those having a conventional structure are used. In the reformer 51, CH ₄ as a fuel gas is supplied, and a reforming reaction represented by a reaction formula in the drawing is performed. Since the reforming reaction needs to be performed at a high temperature of 650 to 700 ° C., the reformer 51 is heated by the burner 50 in the hydrogen generator 52. The reformed gas generated in the reformer 51 by the reforming reaction is further supplied to the CO converter 54. In the CO converter 54, CO is removed from the reformed gas by the reaction represented by the reaction formula in the figure. As described above, the reformer 51 and the CO shifter 54 generate a hydrogen-rich gas containing H ₂ as a main component, and the hydrogen-rich gas is further supplied to the fuel cell 53 as a fuel gas. Here, in the hydrogen generator 52, when the apparatus is started, a hydrogen-rich gas (product gas) containing a large amount of CO is generated. Since CO deteriorates the electrodes of the fuel cell 53, the generated gas cannot be used in the fuel cell 53. For this reason, the generated gas is supplied to the burner 50 of the hydrogen generator 52 as a fuel gas. Here, the generated gas contains a large amount of CO as described above, but the operation of the reformer 51 is performed so that the conversion rate of CH ₄ to H ₂ and CO ₂ in the reforming reaction is increased. because it is controlled, the ratio of the unconverted hydrocarbon combustible materials contained in the product gas is low, the product gas has a high content of H _2.

In the fuel cell 53 supplied with the hydrogen-rich gas obtained by the hydrogen generator 52, a reaction represented by a reaction formula in the figure is performed using the hydrogen-rich gas and oxygen in the air. Thereby, power generation is performed. Electric energy obtained from the fuel cell 53 is used for various purposes. On the other hand, of the hydrogen-rich gas supplied to the fuel cell 53, off-gas containing H ₂ not used for the reaction is supplied to the burner 50 of the hydrogen generator 52 and used as a fuel gas for the burner 50.

  Hereinafter, the flame detection operation of the hydrogen generator 52 in the fuel cell power generation system 100 (FIG. 8) including the hydrogen generator 52 having the burner 50 according to the fourth embodiment of FIG. 7 will be described with reference to FIG. explain.

  FIG. 9 is a diagram showing operation data of the hydrogen generator 52 in the fuel cell power generation system 100 according to the present embodiment. As shown in FIG. 9, a graph A in the figure shows a temporal change in the temperature of the reformer 51 of the hydrogen generator 52, and a graph B shows the temperature of the combustion space 3 detected by the temperature detecting member 6. , And the graph C shows the temporal change of the voltage value converted from the output current value from the electrode 12 (FIG. 7).

  As shown in the graph A, when the fuel cell power generation system 100 is started and the burner 50 is ignited, the temperature of the reformer 51 starts to increase after a lapse of a predetermined time from the ignition because the heat capacity is large. Then, after a lapse of more than ten minutes, the reformer 51 reaches a predetermined temperature (about 650 to 700 ° C.) and is kept at that temperature.

  On the other hand, as shown in the graph B, when the burner 50 is ignited, a temperature change in the combustion space 3 is detected by the temperature detecting member 6, and the detected temperature gradually increases immediately after a voltage value of the electrode 12 described later increases. When the temperature reaches a predetermined temperature after a lapse of time, the detected temperature becomes constant.

  Further, as shown in the graph C, at the time of ignition, a generated gas (or off-gas) having a high hydrocarbon-based combustible substance content is supplied to the burner 50, so that the converted voltage of the output current value from the electrode 12 is converted. The value rises instantly. Incidentally, as described above, since this voltage value is affected by the composition of the generated gas, it changes as follows with the elapse of the operation time. That is, until the reformer 51 reaches the predetermined temperature, the conversion rate in the reforming reaction gradually increases, and accordingly, the hydrogen concentration in the product gas obtained from the reformer 51 gradually increases. However, since the content of the hydrocarbon-based combustible substance in the product gas gradually decreases, the voltage value of the electrode 12 decreases even when the temperature of the reformer 51 increases. When the temperature of the reformer 51 becomes constant at the predetermined temperature, the voltage value also becomes constant at the lower limit. In this case, when the conversion rate in the reformer 51 is increased in order to generate a large amount of hydrogen in the hydrogen generator 52, the voltage value is further reduced.

  From the above, in the hydrogen generator 52, at the time of ignition and for a predetermined period thereafter, detection can be performed by the conventional flame detection method based on the voltage value of the electrode 12, and particularly, the response to ignition is excellent. Therefore, at the time of ignition, it is possible to perform detection with higher accuracy than the detection by the temperature detection member 6. However, when the temperature of the reformer 51 rises and the conversion rate in the reforming reaction increases, the electrode 12 In the detection method using, it is easily affected by noise, which makes detection difficult. Therefore, in this case, the flame is detected using the electrode 12 at the time of ignition, and thereafter, particularly, the gas having a high conversion rate in the reformer 51 and a small content of the hydrocarbon-based flammable substance is supplied to the burner 50. In the supplied combustion state, the temperature detection member 6 performs flame detection. Thus, the formation of a flame can be detected instantaneously at the time of ignition, and the flame state can be accurately detected in combustion in which a gas containing a small amount of a hydrocarbon-based combustible substance is supplied as a fuel gas.

  Thus, according to such a configuration, it is possible to perform flame detection with high accuracy in the gas hydrogen generator 52 regardless of the composition of the fuel gas supplied to the burner during the operation of the fuel cell power generation system 100. Therefore, it is possible to burn off gas or generated gas as fuel gas in the burner 50, and as a result, using off gas or generated gas as fuel, high power generation efficiency and small load on the environment, and safety It is possible to realize a high power generation system.

  In the present embodiment, the case where the burner according to the present invention is used for heating the hydrogen generator of the fuel cell power generation system has been described, but the burner according to the present invention is configured by at least carbon and hydrogen. The present invention can also be used as a burner that uses a gas containing a small amount of a combustible substance containing a compound composed of a compound to be used as a fuel gas, for example, a burner for heating a hot water supply member.

  The burner according to the present invention, the hydrogen generator including the burner, and the fuel cell power generation system are useful, for example, as a fuel cell system used in a cogeneration system.

FIG. 2 is a cross-sectional view schematically illustrating a configuration of a burner according to the first embodiment of the present invention. FIG. 2 is a schematic partial enlarged cross-sectional view illustrating an arrangement of a temperature detection member in FIG. 1. FIG. 3 is a schematic partial enlarged plan view showing an arrangement of a temperature detecting member in FIG. 2. FIG. 5 is a cross-sectional view schematically illustrating a configuration of a burner according to a modification of the first embodiment of the present invention. FIG. 7 is a cross-sectional view schematically illustrating a configuration of a burner according to a second embodiment of the present invention. FIG. 13 is a cross-sectional view schematically illustrating a configuration of a burner according to a third embodiment of the present invention. FIG. 13 is a cross-sectional view schematically illustrating a configuration of a burner according to a fourth embodiment of the present invention. FIG. 14 is a schematic configuration diagram of a fuel cell power generation system according to Embodiment 5 of the present invention. FIG. 14 is a diagram showing operation data of the hydrogen generator of the fuel cell power generation system according to Embodiment 5.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Fuel distributor 2 Air ejection part 3 Combustion space 4 Fuel gas supply device 5 Air supply device 6 Temperature detection member 7 Flame detection device 8 Fuel gas ejection hole 9 Air ejection hole 12 Electrode 13 Ignition circuit 14 Changeover switch 15 Support member

Claims (18)

A fuel distributor for ejecting fuel supplied from a fuel supply device, and an air ejection hole for ejecting air supplied from an air supply device, the fuel ejection device including the fuel distributor and ejecting from the air ejection hole around the fuel distributor. A burner comprising: an air ejecting member arranged so as to surround the distributor so that air to be emitted and fuel ejected from the distributor are burned to form a combustion space in which a flame is formed.
A temperature detection point is located in the air ejection hole or in a portion that becomes a flow path of air in the combustion space, and a temperature detection member that detects a temperature of the combustion space,
And a flame detecting means for detecting a state of the flame in the combustion space based on the temperature detected by the temperature detecting member.   2. The burner according to claim 1, wherein the temperature detection member is arranged such that the temperature detection point is located inside the air ejection hole or near the air ejection hole in the combustion space.   The burner according to claim 1, wherein the temperature detection member is arranged to penetrate the air ejection member.   The burner according to claim 1, wherein the temperature detection point of the temperature detection member and an inner surface of the air ejection hole are insulated.   The burner according to claim 4, wherein a gap is formed between the temperature detecting member and the inner surface of the air ejection hole, and the width of the gap is substantially uniform over the outer periphery of the temperature detecting member.   The air ejection member has a plurality of the air ejection holes, and in the air ejection hole where the temperature detection member is disposed, a cross-sectional area of the gap between the air ejection hole and the temperature detection member is such that the temperature detection member is disposed. 5. The burner according to claim 4, wherein the cross-sectional area of the air ejection hole is not substantially equal to the cross-sectional area.   The burner according to claim 1, wherein the temperature detection member has the temperature detection point at one end, and a main body is housed in the air ejection member.   The burner according to claim 7, wherein a tip of the temperature detection member on the temperature detection point side is substantially covered with an oxide film.   The burner according to claim 7, wherein a tip of the temperature detection member on the temperature detection point side has a substantially hemispherical shape.   The burner according to claim 1, wherein the temperature detecting member is a sheath-shaped thermocouple.   The burner according to claim 1, wherein a plurality of the temperature detecting members are provided, and the temperature detecting members are arranged at different positions so as to detect temperatures in different regions of the combustion space.   The burner according to claim 1, wherein a cross-sectional area of the combustion space increases in a flame emission direction.   An electrode housed in the fuel distributor, one end of which protrudes into the combustion space; and an ignition device that is electrically connected to the electrode and applies a voltage to the electrode so as to discharge from the electrode in the combustion space. The burner according to claim 1, further comprising a circuit.   At the time of ignition, the electrode and the ignition circuit are connected, and after the flame detection means makes an ignition determination based on the temperature information of the combustion space from the temperature detection member, the electrode and the flame detection means Switching means for switching so as to be connected, the flame detection means performs flame detection based on the temperature information from the temperature detection member, and performs flame detection based on an output current from the electrode. 14. The burner according to claim 13, which performs detection.   The temperature detection member is disposed at the tip of the electrode protruding into the combustion space so as to perform flame detection in a region different from the region in the combustion space in which flame detection is performed by the temperature detection member. 15. The burner according to claim 14, wherein the burner is arranged in a region different from the region of the combustion space.   16. The burner according to claim 15, wherein the temperature detection member detects a flame in an upper region of the combustion space in a flame emission direction, and the electrode detects a flame of a lower region in the combustion space in the direction.   A burner according to claim 1, further comprising a reformer configured to generate a reformed gas containing hydrogen by a reforming reaction of a raw material containing a compound composed of at least carbon and hydrogen, wherein the reformer is used by using the burner. To heat the hydrogen generator.   18. The fuel according to claim 17, wherein a gas mainly composed of hydrogen obtained from the hydrogen generator is supplied to the fuel electrode side and an oxidant gas is supplied to the oxidant electrode side to generate power. A fuel cell power generation system including a battery.

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