JP5722934B2 - Combustion device abnormality detection device - Google Patents

Description

  In the present invention, a heat exchanger heated by a burner is provided in an upper part of a cylinder body forming a combustion chamber of the burner, and is provided in a state of facing the combustion chamber through a temperature measuring opening formed in the cylinder cylinder. The present invention relates to an abnormality detection device for a combustion apparatus provided with combustion chamber temperature detection means and abnormality detection means for detecting combustion abnormality of the burner based on detection information of the combustion chamber temperature detection means.

  The abnormality detection device of the combustion device is used for, for example, a gas instantaneous water heater, and conventionally, for temperature measurement, a combustion chamber temperature detection means constituted by a thermocouple is formed on a cylinder body. A temperature detection value provided in a state of being located at one side portion in a horizontal width direction of the cylinder body in a state of facing the combustion chamber through the opening, and the abnormality detection means is detected by the combustion chamber temperature detection means, specifically, Is configured to detect combustion abnormality of the burner when the detection voltage value of the thermocouple exceeds a preset threshold for determination (see, for example, Patent Document 1).

  Such an abnormality detection device for a combustion apparatus is configured such that the burner causes incomplete combustion and combustion products such as soot that accompany the combustion adhere to and accumulate on the heat exchanger. When the flow of combustion exhaust gas becomes poor, high-temperature combustion exhaust gas flows from the combustion chamber through the temperature measuring opening to the combustion chamber temperature detection means, and a high temperature state is detected. Based on the detection information, the abnormality detecting means can detect a combustion abnormality of the burner.

  In order to explain that combustion products such as soot adhere to and accumulate on the heat exchanger, the burner has a flame hole forming portion in which a large number of flame holes for forming a flame are arranged in a line. And a mixed gas flow path for supplying a mixed gas to each flame hole, and the mixed gas flow path is provided in a pair arranged on the left and right sides in a state of being arranged along the arrangement direction of the flame holes. The mixed gas channel on the left side of the mixed gas channel supplies the mixed gas to the left half of the many flame holes, and the right mixed gas channel on the right side of the many flame holes. The mixed gas is supplied to the flame hole. A large opening is formed in each gas introduction part in the left and right mixed gas flow paths, and a gas nozzle for injecting fuel gas is provided so as to go inward from the opening, and the gas is ejected from the gas nozzle. Fuel gas is blown into the mixed gas flow path forming portion from the introduction portion, and the air (primary air) around the opening is also sucked together by the ejector action accompanying the blowing of the fuel gas. The fuel gas and the primary air are mixed while passing through the mixed gas flow path and supplied to the flame hole.

  In such a burner, a spider web or dust may adhere to the gas introduction part, and the flow of fuel gas or primary air may be hindered. As a result, the flow rate when the fuel gas is ejected is lowered and the ejector action is lowered, so that the intake amount of primary air is reduced, or the amount of air sucked from the opening is reduced. The amount of combustion air relative to the amount of gas is insufficient, and the burner causes incomplete combustion to generate combustion products such as soot. The combustion product flows directly from the generation point by the rising airflow of the combustion exhaust gas and adheres to the heat exchanger.

JP 2000-185851 A

  In the above-described conventional configuration, when a large amount of combustion products adheres to the heat exchanger in the combustion chamber and the exhaust blockage occurs, it is possible to detect such an abnormal state, It was impossible to detect at an early stage that the burner caused incomplete combustion and combustion products such as soot began to adhere to the heat exchanger.

  In other words, in the above-described conventional configuration, the abnormality detection means detects a burner combustion abnormality when the temperature detection value detected by the combustion chamber temperature detection means exceeds a preset threshold for determination. However, the detected temperature value detected by the combustion chamber temperature detecting means, specifically, the detected voltage value is, for example, due to the difference in the burner combustion amount or the usage environment, etc., to the heat exchanger of the combustion products. Even if the adhesion state is the same, different values may be obtained.

  For example, when the burner combustion amount is adjusted to the larger side of the adjustable range, the amount of combustion exhaust gas generated is increased, and even if the combustion product does not adhere to the heat exchanger A slightly higher voltage value may be detected by the combustion chamber temperature detecting means. Also, when the ventilation window provided near the combustion device is closed, exhaust from the combustion chamber is performed well, but when the window is opened to ventilate the room, it is externally passed through the window. Due to the influence of the blown-in air, high-temperature combustion exhaust gas easily flows from the combustion chamber through the temperature measurement opening to the combustion chamber temperature detecting means, and a slightly higher voltage value may be detected.

  If a strict discrimination criterion is set by setting a lower voltage value as the discrimination threshold for discriminating an abnormality, the combustion products are generated due to the difference in the external environment as described above. In order to discriminate abnormalities in order to prevent such erroneous detections, there is a possibility that they are frequently erroneously detected even though they are not attached to the heat exchanger. As a discrimination criterion, a relatively loose discrimination criterion was set. Specifically, a relatively high voltage value has been set as the discrimination threshold.

  As a result, a large amount of combustion products such as soot deposits and accumulates on the heat exchanger, and a large amount of high-temperature combustion exhaust flows from the combustion chamber through the temperature measurement opening to the combustion chamber temperature detecting means. If the detected voltage value exceeds the threshold for determination set as a higher voltage value, the abnormal state can be determined, but the burner causes incomplete combustion and combustion products such as soot start to adhere to the heat exchanger. It is difficult to detect such an abnormal state at an early stage.

  The object of the present invention is to detect such an abnormal condition as soon as possible when the burner starts incomplete combustion and combustion products such as soot are attached to the heat exchanger in the combustion chamber. It is in the point which provides the abnormality detection apparatus of the combustion apparatus which becomes possible.

In the abnormality detection device for a combustion apparatus according to the present invention, a heat exchanger heated by a burner is provided at an upper portion of a cylinder body forming a combustion chamber of the burner, and the temperature detection opening is formed through the temperature measurement opening formed in the cylinder cylinder. Combustion chamber temperature detection means provided in a state of facing the combustion chamber, and abnormality detection means for detecting a combustion abnormality of the burner based on detection information of the combustion chamber temperature detection means, The first characteristic configuration is
The burner includes a flame hole forming portion formed in a state where a large number of flame holes for forming a flame are arranged in a line, and a mixing chamber as a mixed gas flow path for supplying a mixed gas to each flame hole. Configured,
A pair of left and right mixing chambers are provided in a state of being aligned along the alignment direction of the flame holes,
Fuel gas and primary air are introduced from the gas introduction portions of the mixing chambers on both the left and right sides to become a mixed gas, and the left mixing chamber on the left and right sides is the left half of the plurality of flame holes. The mixed gas is supplied to the flame holes of the right side, and the mixing chamber on the right side is configured to supply the mixed gas to the flame holes on the right half of the plurality of flame holes,
The combustion chamber temperature detecting means is located at a position corresponding to the left half of the plurality of flame holes and a position corresponding to the right half of the plurality of flame holes. a plurality provided in a state of being distributed at different positions along the width direction of the cylinder barrel,
The abnormality detection unit is configured to determine that the burner is in a combustion abnormality when a relationship between a plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection units deviates from an appropriate setting relationship. And, as the relationship between the plurality of temperature detection values, the difference in the rate of change with time for each of the temperature detection values detected by each of the plurality of combustion chamber temperature detection means is the set appropriate relationship. Is configured to determine that the burner is in a combustion abnormality when the set allowable range is not reached,
The abnormality detection means stores in advance as a reference detection value the temperature detection value of the combustion chamber temperature detection means when the burner is burned at the start of operation after installation, and at the time of subsequent combustion of the burner, The variation range of the temperature detection value of the combustion chamber temperature detection means from the reference detection value is obtained as the rate of change with time.

  In other words, the abnormality detection means includes a plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means provided in a distributed manner in different positions along the lateral width direction of the cylinder body. If the relationship deviates from the setting proper relationship, it is determined that the burner is abnormal in combustion. Here, as the relationship between the plurality of temperature detection values, for example, a difference value between the plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means and a change with time of the plurality of temperature detection values. If there is a difference in the rate, etc., and the difference value of the plurality of temperature detection values is not within the setting allowable range as the setting appropriate relationship, it is determined that the burner is abnormally burned, or the time elapses of the plurality of temperature detection values. For example, there is a configuration in which it is determined that the burner is in an abnormal combustion when the difference in the change rate due to the change is not within the allowable setting range as the appropriate setting relationship.

  Regarding the plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means, even if the change amount of each temperature detection value itself is small, the relationship between the plurality of temperature detection values is as described above. Such a change can be easily detected. In other words, for example, even if the combustion apparatus usage state such as the burner combustion amount or the ventilation window open / close state may change, the plurality of combustion chamber temperature detection means may Since the positions are differently arranged along the width direction, the temperature detection values are always detected under the same conditions. As a result, the occurrence of measurement errors due to the difference in the use state of the combustion apparatus is the same. Therefore, from the relationship between the plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means, for example, one By adhering combustion products at the part, even if only the temperature detection value of any one of the combustion chamber temperature detection means changes slightly, this can be detected with high accuracy.

  Therefore, if the relationship between the plurality of detected temperature values deviates from the setting proper relationship, it is determined that the burner is abnormal in combustion, but a strict determination criterion is set as a criterion for determining the abnormality. Since it is possible to set the setting allowable range as a setting appropriate relationship to a narrow range, in the case where combustion products such as soot are beginning to adhere in a part of the width direction of the combustion chamber, early Such an abnormal state can be detected.

  Therefore, according to the first characteristic configuration, when the burner is incompletely combusted and combustion products such as soot are starting to adhere to the heat exchanger in the combustion chamber, such an abnormality is as early as possible. It has become possible to provide an abnormality detection device for a combustion device that can detect the state.

In addition , when combustion products such as soot have started to adhere only in a partial region in the width direction of the combustion chamber, the amount of combustion product deposited increases as the combustion time of the burner increases, and the degree of blockage decreases. Although the combustion exhaust gas flows through the temperature measurement opening in the combustion chamber temperature detection means arranged corresponding to a part of the region, the temperature detection value rises with time. Will do. On the other hand, since the combustion exhaust gas does not flow in the combustion chamber temperature detection means provided corresponding to other areas where combustion products such as soot are not attached, the temperature detection value does not flow even if time passes. It will not rise. As a result, a difference occurs in the rate of change with time of a plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means.

Therefore, the abnormality detection means determines that a burner combustion abnormality occurs when the difference in the rate of change of the plurality of temperature detection values with the passage of time is not within the set allowable range, that is, exceeds the set allowable range. is there. If the difference in the rate of change of the plurality of temperature detection values with the passage of time is used in this way, the influence of the error due to the individual difference of the plurality of combustion chamber temperature detection means is reduced and the burner combustion is accurately performed. Abnormality can be determined.
Therefore, according to the first characteristic configuration, the abnormality detection device for the combustion apparatus that can detect the abnormal state while reducing the influence due to the error caused by the individual difference among the plurality of combustion chamber temperature detection means. I was able to provide.

Overall configuration of gas instantaneous water heater Exploded perspective view of burner Front view of plate burner Notched front view of plate burner Control block diagram Diagram showing the state of electromotive force generation Diagram showing the state of electromotive force generation Diagram showing the state of electromotive force generation Partial cross section of burner showing experimental contents The figure which shows the generation state of electromotive force of the experimental result Diagram showing the state of electromotive force generation

[First Embodiment]
A case where a first embodiment, which is a reference embodiment of an abnormality detection apparatus for a combustion apparatus according to the present invention, is applied to a gas instantaneous water heater will be described with reference to the drawings.
As shown in FIG. 1, this gas instantaneous water heater includes a cylinder body 1 that forms a combustion chamber R of a gas combustion type burner B, and a fin tube type heat exchanger provided at an upper portion of the cylinder body 1. The heat exchanger 2 is connected to a water supply channel Wi and a hot water supply channel Wo. In the water supply channel Wi, a water supply valve 4, a water governor 5 that adjusts the water supply amount in response to a change in water pressure, and a water supply amount to the heat exchanger 2 and a diversion supply to the hot water supply channel Wo through the bypass channel Wb. A diversion valve 6 for adjusting the ratio of the amount of bypass water to be provided is interposed, and a hot water outlet 8 is connected to the hot water supply passage Wo via a flexible pipe 7. The gas supply path G for supplying the fuel gas to the burner B is only in the state of water flow to the heat exchanger 2 in response to the electromagnetically operated shut-off valve 9 and the interlocking rod 10a linked to the water governor 5. A water pressure responsive valve 10 that opens, a gas governor 11 that keeps the supply pressure of the fuel gas at an appropriate pressure, and an adjustment valve 12 that adjusts the supply amount of the fuel gas are interposed.

The gas instantaneous water heater having such a configuration is configured such that its operation is controlled by the controller C as described below.
That is, when the push button type hot water operation tool 13 is pressed, the operation micro switch 14 is turned ON, and at the same time, the water stop valve 4 is opened in conjunction with the push operation of the hot water operation tool 13 and flows into the water governor 5. The water pressure microswitch 15 is turned on in response to the interlocking rod 10a interlocked with the water governor 5 in the direction of opening the water pressure responsive valve 10 by the water pressure. When the operation micro switch 14 and the water pressure micro switch 15 are turned on, the controller C executes an ignition process by the spark plug 16 and causes the adsorption current to flow through the coil 9a of the shut-off valve 9 to open the shut-off valve 9. Then, the fuel gas is supplied from the gas supply path G to the burner B, and is ignited by the spark plug 16 and burned. During the combustion, combustion air is supplied to the lower part of the cylinder body 1 from the air intake opening, and the exhaust gas from the burner B flows through the cylinder body 1 and is discharged upward from the exhaust port of the opening.

  In the vicinity of the burner B, a burner thermocouple 17 is provided as a combustion flame temperature detecting means. When the burner B is heated by the combustion of the burner B, the burner thermocouple 17 is heated. The adsorption current continues to flow from the controller C to the coil 9a of the shut-off valve 9 due to the electromotive force accompanying the heating of 17 so that the shut-off valve 9 is kept open.

  And the water from the water supply path Wi passes through the water stop valve 4 and the water governor 5 and is diverted by the diversion valve 6, and a part thereof flows into the heat exchanger 2, and the rest passes through the bypass path Wb. The hot water that has flowed into the hot water supply passage Wo and mixed with the hot water from the heat exchanger 2 and has reached an appropriate temperature is discharged from the hot water outlet 8. In this hot water state, when the hot water operation tool 13 is pushed again, the water stop valve 4 is closed in conjunction with the push operation, and the interlocking rod 10a is moved to the water pressure responsive valve along with the stoppage of water flow into the water governor 5. 10 is closed, the water pressure responsive valve 10 is closed, the fuel gas supply to the burner B is cut off, and the combustion is stopped. When the combustion of the burner B is stopped, the electromotive force of the thermocouple 17 for the burner disappears, the controller C stops supplying the adsorption current to the coil 9a of the shut-off valve 9, and the shut-off valve 9 is also closed. Even when a misfire occurs during combustion of the burner B, the electromotive force of the thermocouple 17 for the burner is lost and the shut-off valve 9 is closed, thereby preventing unburned gas from being ejected.

Next, the configuration of the burner B will be described.
This burner B is composed of a flame hole forming portion 21 formed with a large number of flame holes arranged in a line in order to form a flame, and a mixing chamber 20a as a mixed gas channel for supplying a mixed gas to each flame hole. 20b, and the mixing chambers 20a and 20b are provided in a pair of left and right in a state of being aligned along the flame hole alignment direction, and the left mixing chamber 20a of the left and right mixing chambers 20a and 20b is The mixed gas is supplied to the left half of the many flame holes, and the right mixing chamber 20b supplies the mixed gas to the right half of the many flame holes.

  A specific configuration will be described. As shown in FIG. 2, the burner B is constituted by three flat and elongated plate-like burners 18 having the same structure, and each plate-like burner 18 is shown in FIGS. As shown in FIG. 2, on the upper surface, there are provided two flame hole rows 21 as flame hole forming portions formed in a state where a large number of flame holes for forming a flame are arranged in a row, and each flame hole is provided with Mixing chambers 20a and 20b serving as mixed gas flow paths for supplying the mixed gas are provided.

  Further, the pair of left and right mixing chambers 20a and 20b are configured to be separated at the central portion in the left and right direction, and the fuel gas and the gas are introduced from the gas introducing portions 19a and 19b opened in the arc shape of the respective mixing chambers 20a and 20b. The primary air is introduced into the mixed gas, and the mixed gas flowing in from the left gas introducing portion 19a in the flame hole arrangement direction flows through the left mixing chamber 20a and is ejected from the left half of the flame hole array 21 in the arrangement direction. The mixed gas that has been burned and flowed in from the right gas introducing portion 19b flows through the right mixing chamber 20b, and is ejected from the right half of the flame hole array 21 and burned. The mixing chamber 20a and the right mixing chamber 20b are configured so that gas does not flow into each other.

  In other words, a large opening is formed in each of the gas introducing portions 19a and 19b in the left and right mixing chambers 20a and 20b, and a gas nozzle 24 for injecting fuel gas is provided so as to go inward from the opening. Thus, the fuel gas is blown into the mixing chambers 20a and 20b from the gas introducing portions 19a and 19b in a state of being ejected from the gas nozzle 24, and the ejector action accompanying the blowing of the fuel gas causes the gas introducing portions 19a and 19b to Ambient air (primary air) is also sucked together, and fuel gas and primary air are mixed while passing through the mixed gas flow path and supplied to the flame holes.

  As shown in FIGS. 3 and 4, the gas introduction portions 19 a and 19 b are formed with openings having a diameter larger than the outer diameter of the gas nozzle 24, and gradually become smaller in diameter toward the inner depth side from the end portion over a set distance. After that, the inner diameter is gradually increased. In this way, in the portion where the primary air is sucked, the diameter gradually becomes smaller toward the inner depth side, so the ejector action due to the injection of the fuel gas acts effectively, and the inner diameter gradually increases on the inner depth side. Thus, the fuel gas and primary air can be mixed well.

The three plate-like burners 18 having such a configuration are provided side by side with a predetermined interval and fixedly held by a burner holder 22 made of three members, so that the flame hole array 21 of each plate-like burner 18 is a cylinder. It arrange | positions so that the horizontal width direction of the trunk | drum 1 may be met.
Then, by assembling the manifold 23 connected to the gas supply path G using the burner holder 22, a total of six gas nozzles 24 attached to the manifold 23 face each other adjacent to the gas introduction portions 19a and 19b. When the fuel gas is blown from each gas nozzle 24, the surrounding air is also sucked together by the ejector action at that time.
Thereafter, the fuel gas and air are mixed in each of the mixing chambers 20a and 20b, and the mixed gas supplied from the three gas introduction portions 19a on the left side is the left half in the flame hole row 21 of the three plate burners 18. The mixed gas supplied from the three gas inlets 19b on the right side is jetted from the right half in the flame hole row 21 of the three plate-like burners 18 and burned.

Next, the combustion stop control that is executed when a combustion abnormality or the like of the burner B occurs will be described.
First, the amount of primary combustion air sucked from the gas introduction portions 19a and 19b is abnormally reduced, the oxygen concentration in the primary combustion air is lowered, the combustion flame becomes longer, or the combustion flame is unexpected. A burner thermocouple 17 is provided for detecting a combustion abnormality of the burner B, such as falling off in the heat exchanger 2, and for detecting abnormality such as adhesion of combustion products such as soot to the heat exchanger 2. A pair of combustion chamber thermocouples 25a and 25b serving as combustion chamber temperature detecting means are provided in a state of being distributed and arranged at different positions along the lateral width direction on the front surface side of the outer peripheral portion of the cylinder body 1. As shown in FIG. 1, the heat sensitive part is attached to the cylinder 1 so as to face the temperature measurement opening 1 a formed on the front surface of the cylinder 1.

  Explaining that the combustion product such as soot adheres, one of the left and right gas inlets 19a, 19b provided at both ends of the flame hole array in the arrangement direction and a mixture communicating therewith Spider webs or dust may adhere to the chambers 20a and 20b. As a result, the flow rate of the fuel gas to be blown down or the amount of primary air to be sucked in decreases, resulting in insufficient combustion air, resulting in incomplete combustion in the flame hole row portion connected to the mixing chambers 20a and 20b. is there. If it does so, combustion products, such as soot, will generate | occur | produce, the combustion products will flow upwards, and will adhere to the heat exchanger 2. FIG.

  Furthermore, a temperature fuse 26 for a cylinder body that blows when the temperature in the vicinity of the outer periphery of the cylinder body 1 becomes abnormally high, and a temperature for the vicinity of the nozzle that melts when the temperature near the gas nozzle 24 becomes abnormally high. A fuse 27 is also provided. The cylinder barrel temperature fuse 26 is disposed in the vicinity of the back surface of the outer peripheral portion of the cylinder barrel 1, and the nozzle vicinity temperature fuse 27 is disposed in the vicinity of the lower portion of the gas nozzle 24.

  As shown in FIG. 5, the burner thermocouple 17 and the pair of combustion chamber thermocouples 25a and 25b are electrically connected to input terminals of the controller C, respectively, and are connected to the thermocouples 17 and 25a. , 25b are input to the controller C.

The controller C also functions as an abnormality detection means for detecting the combustion abnormality of the burner B, and is based on the detection information of the electromotive force by the above-described burner thermocouple 17 and combustion chamber thermocouples 25a and 25b. It is configured to detect a combustion abnormality.
That is, if the amount of primary air for combustion sucked from the gas introduction portions 19a and 19b is abnormally decreased or the oxygen concentration in the primary air for combustion is abnormally reduced, the burner B causes incomplete combustion and combustion. When the flame becomes long or the combustion flame disappears unexpectedly, as shown in FIG. 6, the electromotive force V1 of the burner thermocouple 17 for detecting the combustion flame temperature decreases. Therefore, when the electromotive force V1 of the burner thermocouple 17 falls below a preset abnormality detection value Vst1 for burner, the controller C determines that it is in an abnormal state and closes the shut-off valve 9 to close the burner. The fuel gas supply to B is turned off, and the combustion of the burner B is stopped.

  Further, when the burner B causes incomplete combustion and combustion products such as soot in the combustion exhaust gas adhere to and accumulate on the heat exchanger 2, high-temperature exhaust gas flows out from the temperature measurement opening 1a, as shown in FIG. Thus, the electromotive forces V2a and V2b of the thermocouples 25a and 25b for the combustion chamber are increased. Therefore, when any one of the electromotive forces V2a and V2b exceeds the combustion chamber abnormality detection value Vst2, the controller C determines that the state is abnormal and closes the shut-off valve 9 to stop the combustion of the burner B. It is configured to let you. In the state where the burner B is normally burned, the electromotive forces V2a and V2b of the thermocouples 25a and 25b for the combustion chamber are about 10 mV, and the combustion chamber abnormality detection value Vst2 is the carbon monoxide concentration (hereinafter referred to as “carbon monoxide concentration”). A voltage value (for example, 18.5 mV) corresponding to a state where the CO concentration is about several hundred ppm (for example, 300 ppm) is set.

In this gas instantaneous water heater, in addition to the threshold value determination for the electromotive force of each thermocouple as described above, the burner B causes incomplete combustion and combustion products such as soot adhere to the heat exchanger 2. It has a configuration for detecting an abnormality that can detect as soon as possible.
That is, when the relationship between the pair of temperature detection values detected by the left and right combustion chamber thermocouples 25a and 25b deviates from the appropriate setting relationship, the controller C determines that the burner B is in a combustion abnormality. It is configured as follows. Specifically, when the controller C determines that the difference value of the electromotive force between the left and right combustion chamber thermocouples 25a and 25b as a relationship between the pair of temperature detection values is not within the setting allowable range as the setting appropriate relationship, That is, when the differential value of the electromotive force exceeds the set allowable value ΔVst that is the upper limit of the set allowable range, it is determined that the burner B is in a combustion abnormality. Therefore, in this embodiment, the setting allowable range corresponds to a range in which the difference value of electromotive force is equal to or less than the setting allowable value ΔVst.

  In other words, incomplete combustion occurs in a part of the burner B due to a spider web extending to one of the pair of left and right gas introduction portions 19a and 19b and the mixing chambers 20a and 20b. When combustion products such as soot start to adhere, the combustion exhaust gas flows through the temperature measuring opening 1a to the thermocouple 25a (or 25b) for the combustion chamber corresponding to the region to which the combustion product adheres, and the temperature Although the detection value increases, the combustion exhaust gas does not flow to the combustion chamber thermocouple 25b (or 25a) corresponding to the region where combustion products such as soot are not attached, so that the temperature detection value does not increase. Become.

  Therefore, when the difference value between the electromotive forces of the left and right combustion chamber thermocouples 25a and 25b exceeds the set allowable value ΔVst (for example, 2 mV), the controller C assumes that the burner B has caused a combustion abnormality. It discriminate | determines and it is comprised so that the cutoff valve 9 may be closed and combustion of the burner B may be stopped. In this way, a small value (2 mV) is set as the setting allowable value ΔVst for the difference value between the electromotive forces of the thermocouples 25a and 25b for the left and right combustion chambers, so that the criterion for discrimination becomes stricter. As shown in FIG. 8, the process after the occurrence of an abnormality as compared with the case where an abnormal state is determined by individual threshold determination for the electromotive forces of the left and right combustion chamber thermocouples 25 a and 25 b (see FIG. 7). An abnormal state can be determined at an early stage where the time is short.

  As described above, a small value is set as the set allowable value ΔVst. However, if the initial value of the temperature detection value is different due to individual differences between the left and right combustion chamber thermocouples 25a and 25b, it is accurate. Since the determination cannot be made, the controller C burns the burner B at the start of operation after the instantaneous gas water heater is installed, that is, in a state where combustion products such as soot are not adhered, for a set time ( The electromotive force of each of the left and right combustion chamber thermocouples 25a and 25b at the time when a few seconds have passed is stored in advance as an initial value, and the detected value thereafter is corrected by the initial value. Therefore, it is possible to determine a combustion abnormality accurately and early.

  Further, when the ambient temperature in the cylinder body 1 becomes abnormally high, the cylinder body temperature fuse 26 is blown, and when the temperature near the gas nozzle 24 becomes abnormally high, the nozzle vicinity temperature fuse 27 is blown. When the cylinder barrel temperature fuse 26 is blown or the nozzle vicinity temperature fuse 27 is blown, the controller C closes the shutoff valve 9 to stop the combustion of the burner B.

Hereinafter, experimental results by the applicant will be described.
This experimental result will be explained. As shown in FIG. 9, the flow path is narrowed in the right gas introduction part 19b of the pair of left and right gas introduction parts 19a and 19b instead of an external object such as a spider web. Detection of the electromotive forces V2a, V2b of the thermocouples 25a, 25b for the left and right combustion chambers over time by burning the burner B in a state where the closing pseudo body gt (shaded portion in the figure) is mounted Values were measured sequentially. In addition, the concentration of CO contained in the combustion exhaust gas was sequentially measured.

A line L1 in FIG. 10 indicates a detection value of the electromotive force V2b of the thermocouple 25b for the right combustion chamber, and a line L2 indicates a detection value of the electromotive force V2a of the thermocouple 25a for the left combustion chamber. A line L3 indicates the detected value of the CO concentration.
According to this experimental result, the electromotive force V2b of the right-side combustion chamber thermocouple 25b that is assumed to generate combustion products such as soot is the combustion chamber abnormality detection value Vst2 (for example, 18 .5 mV) was exceeded when the burn time of burner B was about 6 hours.
On the other hand, the difference between the electromotive force V2b of the right combustion chamber thermocouple 25b and the electromotive force V2a of the left combustion chamber thermocouple 25a exceeds the set allowable value ΔVst (2 mV). The burn time of burner B was about 3 hours.
In this way, it was confirmed that it was possible to detect as early as possible that the burner B caused incomplete combustion and combustion products such as soot began to adhere to the heat exchanger 2.

  By the way, as shown in FIG. 10, when the combustion time reaches about 3 hours, the left and right combustion chamber thermocouples exceed the set allowable value ΔVst even though the CO concentration is about the same as the initial value. It can be seen that a difference is starting to occur in the detection value of the electromotive force V2 of 25b. The reason for this will be described below along with the progress of the experiment.

  That is, when the plugging pseudo body gt is mounted as described above, the burner B is incompletely burned and combustion products such as soot are generated, but the generation of carbon monoxide is about 100 ppm to hundreds of ppm. Such a combustion state continues immediately after ignition. Thereafter, combustion products such as soot are deposited and deposited on the heat exchanger 2 by continuing combustion of the burner B. However, in a state where the amount of deposited deposition of combustion products on the heat exchanger 2 is small, carbon monoxide The CO concentration was almost the same as the initial value without substantially affecting the generation. That is, it is considered that there is no influence to the extent that the supply of combustion air is insufficient in a state where the amount of deposition of accumulated combustion products on the heat exchanger 2 is small. As the burner B continues to burn and the amount of combustion products deposited on the heat exchanger 2 increases, the difference between the electromotive forces V2a and V2b of the left and right combustion chamber thermocouples 25a and 25b increases. As a result, it was confirmed that the CO concentration started to increase.

  By the way, the state in which combustion products such as soot are attached in a partial region in the lateral width direction in the combustion chamber R as described above is the width direction of the combustion chamber R in the flame hole row 21 of the burner B. In order to detect incomplete combustion in some of the laterally extending flame holes of the burner B, it is considered that this is caused by incomplete combustion occurring in some of the flame holes. Although it is conceivable to provide a plurality of burner thermocouples 17 that directly detect the temperature of the combustion flame of burner B, it is possible to accurately detect incomplete combustion in the plurality of flame holes formed in burner B. Therefore, it is necessary to provide a large number of thermocouples 17 for the burner, which increases the number of thermocouples, increases the number of parts, and greatly complicates the structure.

  On the other hand, in the combustion chamber R in which the combustion exhaust gas of the burner B flows, the combustion products such as soot that are generated by the incomplete combustion of the burner B are caused by the lateral width as the combustion exhaust gas flows. Since the incomplete combustion of the burner B is narrow, the deposits of combustion products such as soot are generated in a state of spreading over a relatively wide area. The thermocouples 25a and 25b for the combustion chamber can be used to accurately detect the incomplete combustion of the burner B without increasing the number of the thermocouples 25a and 25b and making the structure greatly complicated. It is possible to detect that the combustion products are starting to adhere.

[Second Embodiment]
Hereinafter, a second embodiment which is an embodiment of the present invention will be described.
In the second embodiment, the manner of abnormality determination by the controller is different, but the other configuration is the same as that of the first embodiment, so only the different configuration will be described and the description of the same configuration will be omitted.

  In other words, in this embodiment, the controller C serving as the abnormality detecting means has the time of the plurality of temperature detection values as the relationship between the plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection means. When the difference in change rate with the passage of time is not within the setting allowable range as the setting appropriate relationship, it is determined that the burner is in a combustion abnormality.

  Specifically, the controller C has the left and right combustion chambers when the burner B is burned at the start of operation after the instantaneous gas water heater is installed, that is, when combustion products such as soot are not attached. The electromotive force of each of the thermocouples 25a and 25b for use is stored in advance as reference detection values (V0a and V0b) (see FIG. 11), and the set unit time with the passage of time during the subsequent burner B combustion The electromotive forces of the left and right combustion chamber thermocouples 25a and 25b are detected for each time, and the fluctuation ranges ΔV2a and ΔV2b (corresponding to the rate of change with time) from the reference detection values are obtained. The difference between the fluctuation ranges of the thermocouples 25a and 25b is calculated sequentially.

  Then, the controller C determines that the variation range difference (ΔV2a−ΔV2b) as the rate of change with time of the temperature detection value is not within the setting allowable range, that is, the variation range difference (ΔV2a−ΔV2b) is determined in advance. If the set allowable value ΔVst is exceeded, it is determined that the combustion of the burner B is abnormal (see FIG. 11), the shutoff valve 9 is closed, and the combustion of the burner B is stopped. Therefore, in this embodiment, the allowable setting range corresponds to a range in which the difference (ΔV2a−ΔV2b) in the fluctuation range is equal to or less than the allowable setting value ΔVst.

  If comprised in this way, even if there exists a detection error resulting from the individual difference of the thermocouples 25a and 25b for right and left combustion chambers, it becomes possible to accurately detect whether or not it is an abnormal state. .

[Another embodiment]
Hereinafter, another embodiment will be described.

  The combustion chamber temperature detecting means is not limited to a configuration in which two combustion chamber temperature detecting means are provided, one on each of the left and right sides. Also good.

  The thermocouple as the combustion chamber temperature detecting means is not limited to a plurality of thermocouples arranged in a distributed manner in the width direction of the cylinder on the front surface of the cylinder body. It may be provided in a state of being distributed and arranged at different positions along the width direction of the cylinder, and in the width direction on the surface along the front-rear direction of the outer peripheral surface of the cylinder body, instead of the front surface and the back surface of the cylinder cylinder A plurality may be provided in a state of being distributed and arranged at different positions.

  The combustion apparatus is not limited to a gas instantaneous water heater, but can be applied to various combustion apparatuses such as a gas stove.

1 Cylinder 1a Opening for temperature measurement 2 Heat exchanger 25a, 25b Combustion chamber temperature detection means B Burner C Abnormality detection means R Combustion chamber ΔVst Setting allowable value

Claims (1)

A combustion chamber temperature provided in a state where a heat exchanger heated by a burner is provided at an upper part of a cylinder body forming a combustion chamber of the burner and faces the combustion chamber through a temperature measuring opening formed in the cylinder cylinder An abnormality detection device for a combustion apparatus provided with detection means and abnormality detection means for detecting combustion abnormality of the burner based on detection information of the combustion chamber temperature detection means,
The burner includes a flame hole forming portion formed in a state where a large number of flame holes for forming a flame are arranged in a line, and a mixing chamber as a mixed gas flow path for supplying a mixed gas to each flame hole. Configured,
A pair of left and right mixing chambers are provided in a state of being aligned along the alignment direction of the flame holes,
Fuel gas and primary air are introduced from the gas introduction portions of the mixing chambers on both the left and right sides to become a mixed gas, and the left mixing chamber on the left and right sides is the left half of the plurality of flame holes. The mixed gas is supplied to the flame holes of the right side, and the mixing chamber on the right side is configured to supply the mixed gas to the flame holes on the right half of the plurality of flame holes,
The combustion chamber temperature detecting means is located at a position corresponding to the left half of the plurality of flame holes and a position corresponding to the right half of the plurality of flame holes. a plurality provided in a state of being distributed at different positions along the width direction of the cylinder barrel,
The abnormality detection unit is configured to determine that the burner is in a combustion abnormality when a relationship between a plurality of temperature detection values detected by each of the plurality of combustion chamber temperature detection units deviates from an appropriate setting relationship. And, as the relationship between the plurality of temperature detection values, the difference in the rate of change with time for each of the temperature detection values detected by each of the plurality of combustion chamber temperature detection means is the set appropriate relationship. Is configured to determine that the burner is in a combustion abnormality when the set allowable range is not reached,
The abnormality detection means stores in advance as a reference detection value the temperature detection value of the combustion chamber temperature detection means when the burner is burned at the start of operation after installation, and at the time of subsequent combustion of the burner, An abnormality detection device for a combustion device configured to obtain a fluctuation range of the temperature detection value of the combustion chamber temperature detection means from the reference detection value as the rate of change with time.

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