JP2016008768A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of eliminating an influence of erroneous determination regarding the length of an air passage in a combustion device.SOLUTION: This specification discloses a combustion device. In the combustion device, a controller can execute processing for determining the length of an air passage based on a detection result by detection means when a fan is operated. In the case where the determination result of the length of the air passage is not retained, the controller is configured so as to execute processing for determining the length of the air passage before the ignition of a burner, and retains the determination result of the length of the air passage acquired in the processing. In the case where the determination result of the length of the air passage is retained, the controller is configured so as to execute the processing for determining the length of the air passage after the extinction of the burner, and in the case where the determination result of the length of the air passage acquired in the processing is different from the retained determination result, it discards the retained determination result.

Description

  The present specification relates to a combustion apparatus.

  Patent Document 1 discloses a burner, a fan for blowing combustion air to the burner, a rotation speed adjusting means for adjusting the rotation speed of the fan, an air supply passage for supplying combustion air to the burner, and combustion exhaust from the burner An exhaust passage that discharges air, detection means for detecting whether or not the magnitude of the index related to the passage resistance of the air passage from the inlet of the supply passage to the outlet of the exhaust passage is within a reference range, and a controller A combustion apparatus is disclosed. In this combustion apparatus, the controller can execute processing for determining the length of the air passage based on the detection result by the detection means when the fan is operated. According to this combustion apparatus, it is possible to appropriately set the combustion specifications such as the rotational speed of the fan during combustion of the burner according to the determined length of the air passage.

JP 2006-64232 A

  In the technique of Patent Document 1, when the length of the air passage is determined, if strong wind is blowing to the inlet of the air supply passage or the outlet of the exhaust passage, the length of the air passage may be erroneously determined. In the technique of Patent Document 1, once the length of the air passage is erroneously determined, the combustion device is used in a state that is not in a normal combustion specification, and there is a possibility that combustion failure or abnormal noise is generated.

  The present specification provides a technique for solving the above problems. The present specification provides a technique capable of eliminating the influence of erroneous determination on the length of the air passage in the combustion apparatus that automatically determines the length of the air passage.

  The present specification includes a burner, a fan for blowing combustion air to the burner, a rotation speed adjusting means for adjusting the rotation speed of the fan, an air supply passage for supplying combustion air to the burner, and combustion exhaust from the burner An exhaust passage that discharges air, detection means for detecting whether or not the magnitude of the index related to the passage resistance of the air passage from the inlet of the supply passage to the outlet of the exhaust passage is within a reference range, and a controller A combustion apparatus is disclosed. The controller can execute processing for determining the length of the air passage based on the detection result by the detection means when the fan is operated. When the determination result of the length of the air passage is not held, the controller executes a process for determining the length of the air passage before ignition of the burner, and the length of the air passage obtained by the processing is determined. The determination result is held. When the determination result of the length of the air passage is held, the controller executes a process for determining the length of the air passage after extinguishing the burner, and the length of the air passage obtained by the processing is determined. When the determination result is different from the held determination result, the held determination result is discarded.

  In the above combustion apparatus, the controller executes a process of determining the length of the air passage before ignition of the burner, and holds the determination result of the length of the air passage. As a result, the controller can appropriately set the combustion specifications such as the rotational speed of the fan during combustion of the burner according to the determined length of the air passage. Further, in the above combustion apparatus, when the determination result of the length of the air passage is already held, the controller performs a process for determining the length of the air passage after the burner is extinguished and is held. Verify the validity of the judgment result. By adopting such a configuration, when a determination result in which the length of the air passage is erroneously determined is held, the influence of the erroneous determination can be eliminated.

  In the above combustion apparatus, the controller detects the detection result when the fan is operated at the first rotational speed and the detection means when the fan is operated at the second rotational speed before the burner is ignited. The first determination process for determining the length of the air passage and the presence / absence of blockage of the air passage based on the detection result of the above, and the fan was operated at the first rotation speed or the second rotation speed before the burner was ignited One of the second determination processes for determining whether or not the air passage is blocked can be selectively executed based on the detection result by the detection means, and the controller rotates the fan to the third rotation after the burner is extinguished. It is possible to further execute a third determination process for determining the length of the air passage based on the detection result of the detection means when operated by the number, and the controller determines the length of the air passage by the past first determination process. Judgment result When the second determination process is held and the third determination process is performed, and the determination result of the length of the air passage by the third determination process is different from the stored determination result, the determination that is retained The result may be discarded and the first determination process may be performed during the subsequent combustion operation.

  In the above combustion apparatus, when the controller holds the determination result of the length of the air passage in the first determination process performed before the ignition of the past burner and performs the second determination process, the second after the burner is extinguished. (3) A determination process is performed to verify whether the stored determination result is correct. Even if a strong wind blows on the inlet of the air supply passage or the outlet of the exhaust passage during the first determination process to erroneously determine the length of the air passage, and the controller holds the erroneous determination result, By performing the third determination process, it can be corrected to a subsequent correct determination result. Since the third determination process is performed after the burner is extinguished, the user convenience is not impaired by the waiting time generated by the determination process.

  In the above combustion apparatus, the controller obtains the detection result by the detection means when the fan is operated at the first rotation speed before the burner is fired in the first determination process, and the size of the index is the reference If the air passage is within the range, it is determined that the air passage is short and the air passage is not blocked, and if the size of the index is out of the reference range, the fan is set to a speed higher than the first rotational speed. The detection result obtained by the detection means when operating at a rotational speed of 2 is obtained, and when the size of the index is within the reference range, it is determined that the air passage is long and the air passage is not blocked, When the size of the index is out of the reference range, it is determined that the air passage is blocked, and the controller operates the fan at the second rotation speed before the burner ignition in the second determination process. The detection result by the detection means at the time of When the size of the mark is within the reference range, it is determined that the air passage is not blocked, and when the size of the index is outside the reference range, it is determined that the air passage is blocked, and the controller However, in the third determination process, after the burner is extinguished, the detection result obtained by the detection means when the fan is operated at the third rotational speed is acquired, and the index is within the reference range, the air When it is determined that the passage is short and the size of the index is out of the reference range, the air passage can be determined to be long.

  As an erroneous determination of the length of the air passage, there are many cases where it is erroneously determined that the air passage is long although the air passage is actually short. According to the combustion apparatus described above, even if the controller holds a determination result that is erroneously determined that the air passage is long in the first determination process even though the air passage is actually short, It is possible to discard the erroneously determined determination result by the 3 determination process.

  The combustion apparatus can be configured such that the third rotational speed is higher than the first rotational speed and lower than the second rotational speed.

  Normally, the passage resistance of the air passage is higher when the air supply passage and the exhaust passage are at a high temperature than when the air supply passage and the exhaust passage are kept at room temperature. In the above combustion apparatus, since the first determination process and the second determination process are performed before the burner is ignited, the supply passage and the exhaust passage are kept at room temperature when the first determination process and the second determination process are performed. Yes. In contrast, since the third determination process is performed after the burner is extinguished, when the third determination process is performed, the air supply passage and the exhaust passage are at high temperatures due to the combustion operation. As described above, by setting the third rotational speed, it is possible to suppress the influence of the temperature change of the air supply passage or the exhaust passage on the determination result of the length of the air passage.

  The above combustion apparatus can be configured such that the detection means is a wind pressure switch provided in the air passage.

  According to the combustion apparatus, the detection means can be realized with a simple configuration.

  According to the combustion device disclosed in the present specification, it is possible to eliminate the influence of erroneous determination on the length of the air passage.

It is a figure which shows the schematic structure of the combustion apparatus 2 of an Example. It is a flowchart which shows the example of the control which the controller 26 of the combustion apparatus 2 of an Example performs. It is a flowchart which shows the example of the control which the controller 26 of the combustion apparatus 2 of an Example performs. It is a flowchart which shows the example of another control which the controller 26 of the combustion apparatus 2 of an Example performs. It is a flowchart which shows the example of another control which the controller 26 of the combustion apparatus 2 of an Example performs.

(Example)
A combustion apparatus 2 of this embodiment shown in FIG. 1 houses a combustion chamber 6 inside a housing 4. A burner 8 is accommodated in the combustion chamber 6. Fuel gas is supplied to the burner 8 from a gas supply pipe 10. Air inside the housing 4 is introduced into the combustion chamber 6 by the fan 12. A supply cylinder 14 for supplying air from the outside of the combustion device 2 communicates with the upper portion of the housing 4. An exhaust cylinder 16 that exhausts exhaust gas to the outside of the combustion device 2 communicates with the upper portion of the combustion chamber 6. When the fan 12 is driven in the combustion device 2, air flows into the housing 4 from the outside of the combustion device 2 through the supply cylinder 14. The air that has flowed into the housing 4 is introduced into the combustion chamber 6 and discharged to the outside of the combustion device 2 through the exhaust tube 16. Hereinafter, the flow path through which air flows from the inlet of the supply cylinder 14 to the outlet of the exhaust cylinder 16 is also referred to as an air passage 15 of the combustion device 2.

  Inside the combustion chamber 6, a heat exchanger 18 is disposed above the burner 8. The heat exchanger 18 is a gas-liquid heat exchanger that exchanges heat between water and combustion gas. A water supply pipe 20 and a hot water discharge pipe 22 communicate with the heat exchanger 18. The water introduced into the water supply pipe 20 passes through the heat exchanger 18 and is sent out to the hot water discharge pipe 22.

  In the combustion device 2, when the fan 12 is driven to burn the burner 8, the water flowing inside the heat exchanger 18 is heated by the combustion gas from the burner 8. The combustion gas that has passed through the heat exchanger 18 is discharged from the exhaust cylinder 16 as combustion exhaust gas.

  The fan 12 is provided with a wind pressure switch 24. The wind pressure switch 24 is turned on when the amount of air introduced into the combustion chamber 6 is greater than or equal to a predetermined amount, and turned off when the amount is less than the predetermined amount. The amount of air introduced into the combustion chamber 6 when the fan 12 is rotated decreases when the passage resistance of the air passage 15 is large, and increases when the passage resistance of the air passage 15 is small. Accordingly, the air volume introduced into the combustion chamber 6 can be treated as an index related to the passage resistance of the air passage 15.

  The controller 26 controls the operation of each component of the combustion device 2.

  The lengths of the supply cylinder 14 and the exhaust cylinder 16 vary depending on the situation of the house where the combustion device 2 is actually installed. In other words, the length of the air passage 15 varies depending on the situation of the house where the combustion device 2 is actually installed. Since the passage resistance of the air passage 15 increases as the air passage 15 becomes longer, the air volume introduced into the combustion chamber 6 when the fan 12 is rotated varies depending on the length of the air passage 15. . Therefore, in order to introduce air into the combustion chamber 6 with an air volume suitable for the combustion of the burner 8 during the combustion operation of the combustion device 2, the length of the air passage 15 is determined and the length of the air passage 15 is determined. Therefore, it is necessary to adjust the rotational speed of the fan 12.

  In the combustion apparatus 2 of the present embodiment, as will be described later, when the fan 12 is rotated at a predetermined rotational speed in the pre-purge operation before burning the burner 8 or the post-purge operation after burning the burner 8. The length of the air passage 15 is determined based on the air volume of the air introduced into the combustion chamber 6. In the combustion apparatus 2 of this embodiment, when the air passage 15 is longer than the reference length, the combustion operation is performed according to the “long specification”, and when the air passage 15 is shorter than the reference length, “short” Combustion operation is performed according to “Specifications”. Specifically, the combustion device 2 sets the rotational speed of the fan 12 during combustion of the burner 8 to a high rotational speed in the combustion operation with the long specification, and the fan during combustion of the burner 8 in the combustion operation with the short specification. A rotational speed of 12 is set to a low rotational speed. The rotational speed of the fan 12 in the long specification and the short specification is stored in the controller 26 in advance.

(Example of control performed by the controller 26)
Hereinafter, processing performed by the controller 26 will be described with reference to FIGS. 2 and 3.

  In step S2, the controller 26 sets the length determination counter to 0. The length determination counter is a counter that indicates the number of times that the air passage 15 is determined to be long during the combustion operation of the combustion device 2.

  In step S4, the controller 26 stands by until there is a combustion start instruction. If there is a combustion start instruction in step S4 (YES), the process proceeds to step S6.

  In step S6, the controller 26 determines whether or not the value of the length determination counter is greater than or equal to a predetermined value. As will be described later, the value of the length determination counter increases every time it is determined that the air passage 15 is long in the pre-purge operation. If the value of the length determination counter is less than the predetermined value (NO in step S6), the process proceeds to step S8.

  In step S8, the controller 26 performs the pre-purge operation by rotating the fan 12 at the first rotational speed. The first rotational speed is such that when the supply cylinder 14 and the exhaust cylinder 16 are kept at room temperature and the air passage 15 is shorter than the reference length, the wind pressure switch 24 is turned on, and the supply cylinder 14 and exhaust cylinder are turned on. The rotation speed of the fan 12 is such that the wind pressure switch 24 is not turned ON when 16 is kept at room temperature and the air passage 15 is longer than the reference length. The first rotation speed is stored in the controller 26 in advance.

  In step S10, the controller 26 determines whether or not the wind pressure switch 24 is turned on. In step S10, if the air passage 15 is short and the air passage 15 is not closed, the wind pressure switch 24 is turned on. When the air passage 15 is long and the air passage 15 is not closed, the wind pressure switch 24 remains OFF. When the air passage 15 is closed, the wind pressure switch 24 remains OFF regardless of the length of the air passage 15. That is, if the wind pressure switch 24 is turned on in step S10, it can be seen that the air passage 15 is short and the air passage 15 is not closed. If the wind pressure switch 24 is turned on in step S10 (in the case of YES), the process proceeds to step S12.

  In step S12, the controller 26 starts controlling the combustion operation with the short specification.

  In step S14, the controller 26 stands by until there is a combustion stop instruction. If there is a combustion stop instruction (YES in step S14), the process proceeds to step S16.

  In step S16, the controller 26 extinguishes the burner 8, stops the fan 12, and stops the combustion operation. After step S16, the process returns to step S4.

  If the wind pressure switch 24 is OFF in step S10 (NO), the process proceeds to step S18. In step S18, the controller 26 performs the pre-purge operation by rotating the fan 12 at the second rotational speed. The second rotational speed is the rotational speed of the fan 12 such that the wind pressure switch 24 is turned on regardless of the length of the air passage 15. The second rotation speed is greater than the first rotation speed. The second rotational speed is stored in the controller 26 in advance.

  In step S20, the controller 26 determines whether or not the wind pressure switch 24 is turned on. In step S20, if the air passage 15 is long and the air passage 15 is not closed, the wind pressure switch 24 is turned on. When the air passage 15 is closed, the wind pressure switch 24 remains OFF regardless of the length of the air passage 15. That is, if the wind pressure switch 24 is turned on in step S20, it can be seen that the air passage 15 is long and the air passage 15 is not closed. If the wind pressure switch 24 is turned on in step S20 (YES), the process proceeds to step S22.

  In step S22, the controller 26 increases the value of the length determination counter by one.

  In step S24, the controller 26 starts controlling the combustion operation with the long specification. After step S24, the process proceeds to step S14.

  If the wind pressure switch 24 is OFF (NO) in step S20, it can be seen that the air passage 15 is closed regardless of the length of the air passage 15. In this case, the process proceeds to step S26, and the controller 26 notifies the user that the supply cylinder 14 or the exhaust pipe 16 is closed, and stops the operation of the combustion device 2.

  In step S6, when the value of the length determination counter is equal to or larger than the predetermined value (in the case of YES), it is already known that the air passage 15 is long in the past operation of the combustion device 2. In this case, the controller 26 holds the past determination result that the air passage 15 is long, and the process proceeds to step S28 in FIG.

  In step S28, the controller 26 rotates the fan 12 at the second rotational speed to perform a pre-purge operation.

  In step S30, the controller 26 determines whether or not the wind pressure switch 24 is turned on. In step S30, when the air passage 15 is not closed, the wind pressure switch 24 is turned on. When the air passage 15 is closed, the wind pressure switch 24 remains OFF. If the wind pressure switch is turned on in step S30 (YES), the process proceeds to step S32.

  In step S32, the controller 26 starts control of the combustion operation with the long specification.

  In step S34, the controller 26 stands by until there is a combustion stop instruction. If there is a combustion stop instruction (YES in step S34), the process proceeds to step S36.

  In step S36, the controller 26 extinguishes the burner 8 and stops the combustion operation.

  In step S38, the controller 26 rotates the fan 12 at the third rotational speed to perform a post-purge operation. In the third rotation speed, when the supply cylinder 14 and the exhaust cylinder 16 are at a high temperature and the air passage 15 is shorter than the reference length, the wind pressure switch 24 is turned on, and the supply cylinder 14 and the exhaust cylinder 16 are turned on. Is the rotation speed of the fan 12 so that the wind pressure switch 24 is not turned on when the air passage 15 is longer than the reference length. Normally, when the supply cylinder 14 and the exhaust cylinder 16 are heated to a high temperature by the combustion operation of the combustion device 2, the passage resistance of the air passage 15 becomes larger than when the supply cylinder 14 and the exhaust cylinder 16 are kept at room temperature. . Therefore, the third rotation speed is larger than the first rotation speed. Further, the third rotational speed is smaller than the second rotational speed. The third rotation speed is stored in advance in the controller 26.

  In step S40, the controller 26 determines whether or not the wind pressure switch 24 is turned on. If the past determination result regarding the length of the air passage 15 held by the controller 26 at the time of step S40 is correct (that is, if the air passage 15 is long), the wind pressure switch 24 remains OFF in step S40. , Never turn on. If the past determination result regarding the length of the air passage 15 held by the controller 26 is incorrect (that is, if the air passage 15 is short), the wind pressure switch 24 is turned on in step S40. Therefore, when the wind pressure switch 24 is turned ON in step S40 (in the case of YES), the process proceeds to step S2, and the controller 26 resets the length determination counter to zero. If the wind pressure switch 24 is turned off in step S40 (NO), the process proceeds to step S4, and the controller 26 maintains the value of the length determination counter as it is.

  If the wind pressure switch 24 is OFF (NO) in step S30, it can be seen that the air passage 15 is closed. In this case, the process proceeds to step S42, and the controller 26 notifies the user that the supply cylinder 14 or the exhaust pipe 16 is closed, and stops the operation of the combustion device 2.

  As described above, when the air passage 15 is short, the combustion apparatus 2 according to the present embodiment has the short air passage 15 and the air only by the pre-purge operation at the first rotation speed in steps S8 and S10. It can be confirmed that the passage 15 is not blocked. The time required for determining the length of the air passage 15 and whether or not the air passage 15 is blocked can be shortened.

  Further, when the air passage 15 is long, the combustion apparatus 2 of the present embodiment performs the pre-purge operation at the first rotation speed at steps S8 and S10, and then at the second rotation speed at steps S18 and S20. By performing the pre-purge operation, it is confirmed that the air passage 15 is long and that the air passage 15 is not blocked. If the number of times that the air passage 15 is determined to be long after the combustion device 2 has been operated several times becomes equal to or greater than the predetermined number of times, the controller 26 holds the determination result thereafter, and in steps S28 and S30, It is confirmed only that the air passage 15 is not blocked by the pre-purge operation at the rotational speed of 2. With such a configuration, it is possible to shorten the time required for determining the length of the air passage 15 and whether or not the air passage 15 is blocked.

  When the length of the air passage 15 is determined, if strong wind is blowing on the inlet of the supply cylinder 14 or the outlet of the exhaust cylinder 16, the length of the air passage 15 may be erroneously determined. If such erroneous determination continues, the controller 26 may hold a determination result that is erroneously determined that the air passage 15 is long. Therefore, in the combustion apparatus 2 of the present embodiment, after the controller 26 holds the determination result that the air passage 15 is long, the controller 26 performs the post-purge operation at the third rotational speed in steps S38 and S40. It is verified whether or not the determination result that the air passage 15 is long is correct. If the determination result is incorrect, the held determination result is discarded. By adopting such a configuration, even if the determination result that the air passage 15 has erroneously determined is held, it can be corrected to a subsequent correct determination result.

  In the above embodiment, the configuration in which the controller 26 holds the determination result that the air passage 15 is long when the value of the length determination counter becomes equal to or larger than the predetermined value in step S6 has been described. The controller 26 may hold the determination result based on the determination criterion. For example, in step S <b> 6, the controller 26 may hold a determination result that the air passage 15 is long when the ratio of the length determination number to the total number of determinations is equal to or greater than a predetermined value. Alternatively, the controller 26 may hold the determination result that the air passage 15 is long when the determination result that the air passage 15 is long continues continuously a predetermined number of times.

(An example of another control performed by the controller 26)
Hereinafter, processing performed by the controller 26 will be described with reference to FIGS. 4 and 5.

  In step S52, the controller 26 sets the short determination counter to 0. The short determination counter is a counter that indicates the number of times that the air passage 15 is determined to be short during the combustion operation of the combustion device 2.

  In step S54, the controller 26 stands by until there is a combustion start instruction. If there is a combustion start instruction in step S54 (YES), the process proceeds to step S56.

  In step S56, the controller 26 determines whether or not the value of the short determination counter is greater than or equal to a predetermined value. As will be described later, the value of the short determination counter increases every time it is determined that the air passage 15 is short in the pre-purge operation. If the value of the short determination counter is less than the predetermined value (NO in step S56), the process proceeds to step S58.

  In step S58, the controller 26 rotates the fan 12 at the second rotational speed and performs a pre-purge operation.

  In step S60, the controller 26 determines whether or not the wind pressure switch 24 is turned on. If the air passage 15 is not closed in step S60, the wind pressure switch 24 is turned on regardless of the length of the air passage 15. When the air passage 15 is closed, the wind pressure switch 24 remains OFF regardless of the length of the air passage 15. That is, if the wind pressure switch 24 is turned on in step S60, it can be seen that the air passage 15 is not blocked. If the wind pressure switch 24 is turned ON in step S60 (YES), the process proceeds to step S62.

  In step S62, the controller 26 performs the pre-purge operation by rotating the fan 12 at the first rotational speed.

  In step S64, the controller 26 determines whether or not the wind pressure switch 24 is turned on. It has already been found that the air passage 15 is not blocked at the time when the process of step S64 is performed. In step S64, if the air passage 15 is short, the wind pressure switch 24 is turned on. When the air passage 15 is long, the wind pressure switch 24 is turned off. If the wind pressure switch 24 is turned on in step S64 (in the case of YES), the process proceeds to step S66.

  In step S66, the controller 26 increases the value of the short determination counter by one.

  In step S68, the controller 26 starts control of the combustion operation with the short specification.

  In step S70, the controller 26 stands by until there is a combustion stop instruction. If there is a combustion stop instruction (YES in step S70), the process proceeds to step S72.

  In step S72, the controller 26 extinguishes the burner 8, stops the fan 12, and stops the combustion operation. After step S72, the process returns to step S54.

  If the wind pressure switch 24 is OFF in step S64 (NO), the process proceeds to step S74.

  In step S74, the controller 26 starts control of the combustion operation with the long specification. After step S74, the process proceeds to step S70.

  If the wind pressure switch 24 is OFF (NO) in step S60, it can be seen that the air passage 15 is closed regardless of the length of the air passage 15. In this case, the process proceeds to step S76, and the controller 26 notifies the user that the supply cylinder 14 or the exhaust cylinder 16 is closed, and stops the operation of the combustion device 2.

  In step S56, when the value of the short determination counter is equal to or larger than the predetermined value (in the case of YES), it is already known that the air passage 15 is short in the past operation of the combustion device 2. In this case, the controller 26 holds the past determination result that the air passage 15 is short, and the process proceeds to step S78 in FIG.

  In step S78, the controller 26 rotates the fan 12 at the first rotational speed to perform a pre-purge operation.

  In step S80, the controller 26 determines whether or not the wind pressure switch 24 is turned on. If the air passage 15 is not closed in step S80, the wind pressure switch 24 is turned on. When the air passage 15 is closed, the wind pressure switch 24 remains OFF. If the wind pressure switch is turned on in step S80 (YES), the process proceeds to step S82.

  In step S82, the controller 26 starts control of the combustion operation with the short specification.

  In step S84, the controller 26 stands by until there is a combustion stop instruction. If there is a combustion stop instruction (YES in step S84), the process proceeds to step S86.

  In step S86, the controller 26 extinguishes the burner 8 and stops the combustion operation. After step S86, the process returns to step S54.

  If the wind pressure switch 24 is OFF (NO) in step S80, it can be seen that the air passage 15 is closed. In this case, the process proceeds to step S88, and the controller 26 notifies the user that the supply cylinder 14 or the exhaust cylinder 16 is closed, and stops the operation of the combustion device 2.

  As described above, the combustion apparatus 2 of the present embodiment confirms that the air passage 15 is not blocked by the pre-purge operation at the second rotational speed in steps S58 and S60, and in steps S62 and S64. The length of the air passage 15 is determined by the pre-purge operation at the first rotational speed. If the number of times that the air passage 15 is determined to be short after the combustion device 2 has been operated several times becomes equal to or greater than the predetermined number of times, the controller 26 holds the determination result thereafter, and in steps S78 and S80, Only pre-purge at a rotational speed of 1 confirms that the air passage 15 is not blocked. With such a configuration, it is possible to shorten the time required for determining the length of the air passage 15 and whether or not the air passage 15 is blocked.

  When the length of the air passage 15 is determined, even if strong wind is blowing to the inlet of the supply cylinder 14 or the outlet of the exhaust pipe 16, it is erroneously determined to be short although the air passage 15 is actually long. There is no end. For this reason, in the above control, after the controller 26 holds the determination result that the air passage 15 is short, the determination result by the post-purge operation is not verified. Unlike this, it may be configured to verify the determination result by the post-purge operation. In this case, the controller 26 executes processing similar to steps S38 and S40 in FIG. 3 after step S86 in FIG. If the wind pressure switch 24 is turned on when the fan 12 is rotated at the third rotational speed, the determination result that the air passage 15 is short is correct, so the process returns to step S54 in FIG. If is OFF, the determination result held that the air passage 15 is short is incorrect, and the process returns to step S52 of FIG.

  As described above, the combustion apparatus 2 of the present embodiment includes the burner 8, the fan 12 that blows combustion air to the burner 8, the rotation speed adjusting means (controller 26) that adjusts the rotation speed of the fan 12, and the burner. An air supply passage (supply cylinder 14) for supplying combustion air to 8; an exhaust passage (exhaust cylinder 16) for discharging combustion exhaust from the burner 8; and an air passage from the inlet of the supply passage to the outlet of the exhaust passage It is detected whether or not the size of the index related to the passage resistance of 15 (the amount of air introduced into the combustion chamber 6 when the fan 12 is rotated) falls within the reference range (becomes the reference value or more). Detection means (wind pressure switch 24) and a controller 26 are provided. The controller 26 can execute processing for determining the length of the air passage 15 based on the detection result by the detection means when the fan 12 is operated (processing of steps S8, S10, S18, and S20 in FIG. 2). , Processing in steps S38 and S40 in FIG. 3). When the determination result of the length of the air passage 15 is not held, the controller 26 executes a process for determining the length of the air passage 15 before ignition of the burner 8, and the air obtained by the processing It is configured to hold the determination result of the length of the passage (processing of steps S6, S8, S10, S18, S20, and S22 in FIG. 2). When the determination result of the length of the air passage 15 is held, the controller 26 executes processing for determining the length of the air passage 15 after the burner 8 is extinguished, and the air passage obtained by the processing is performed. If the determination result of 15 length is different from the stored determination result, the stored determination result is discarded (processing of steps S2, S6, S38, and S40 in FIG. 2).

  In particular, in the combustion apparatus 2 of the present embodiment, the controller 26 detects the detection result by the detection means when the fan 12 is operated at the first rotation speed before the burner 8 is ignited, and the fan 12 in the second rotation. First determination processing for determining the length of the air passage 15 and the presence or absence of blockage of the air passage 15 based on the detection result of the detection means when operated by the number (processing of steps S8, S10, S18, S20 in FIG. 2) ), And before the ignition of the burner 8, based on the detection result by the detection means when the fan 12 is operated at the first rotation speed or the second rotation speed, the presence or absence of blockage of the air passage 15 is determined. 2 determination processing (steps S28 and S30 in FIG. 3) can be selectively executed. The controller 26 performs a third determination process for determining the length of the air passage 15 based on the detection result by the detection means when the fan 12 is operated at the third rotation speed after the burner 8 is extinguished (FIG. 3). Steps S38 and S40) can be further executed. When the controller 26 holds the determination result of the length of the air passage 15 in the past first determination process and performs the second determination process, the controller 26 performs the third determination process, and performs the third determination process. If the length determination result is different from the held determination result (determination in step S40 in FIG. 3), the held determination result is discarded, and the first determination process is performed during the subsequent combustion operation. It is configured.

  In particular, in the combustion apparatus 2 of the present embodiment, the controller 26 obtains the detection result by the detection means when the fan 12 is first operated at the first rotation speed before the burner 8 is ignited in the first determination process. If the size of the index falls within the reference range, it is determined that the air passage 15 is short and the air passage 15 is not blocked (the processing in steps S8 and S10 in FIG. 2), and the size of the index. Is out of the reference range, the detection result by the detecting means when the fan 12 is operated at the second rotational speed higher than the first rotational speed is acquired, and the size of the index is within the reference range. If it is determined that the air passage 15 is long and the air passage 15 is not blocked (steps S18 and S20 in FIG. 2), and the index size is out of the reference range, It is determined that the passage 15 is blocked. In the second determination process, the controller 26 obtains the detection result by the detection means when the fan 12 is operated at the second rotational speed before the burner 8 is ignited, and the index size is within the reference range. If it is, it is determined that the air passage 15 is not closed (steps S28 and S30 in FIG. 3), and the air passage is closed when the index size is out of the reference range. judge. Further, in the third determination process, the controller 26 acquires a detection result by the detection means when the fan 12 is operated at the third rotation speed after the burner 8 is extinguished, and the size of the index is within the reference range. If so, it is determined that the air passage 15 is short (the processing in steps S38 and S40 in FIG. 3), and if the index size is out of the reference range, it is determined that the air passage is long.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2 Combustor 4 Housing 6 Combustion chamber 8 Burner 10 Gas supply pipe 12 Fan 14 Cylinder 15 Air passage 16 Exhaust cylinder 18 Heat exchanger 20 Water supply pipe 22 Hot water pipe 24 Wind pressure switch 26 Controller

Claims (5)

With a burner,
A fan for blowing combustion air to the burner;
A rotational speed adjusting means for adjusting the rotational speed of the fan;
An air supply passage for supplying combustion air to the burner;
An exhaust passage for exhausting combustion exhaust from the burner;
Detecting means for detecting whether or not the magnitude of the index related to the passage resistance of the air passage from the inlet of the supply passage to the outlet of the exhaust passage is within a reference range;
A combustion device comprising a controller,
The controller can execute a process of determining the length of the air passage based on the detection result by the detection means when the fan is operated,
When the determination result of the length of the air passage is not held, the controller executes a process for determining the length of the air passage before ignition of the burner, and the length of the air passage obtained by the processing is determined. It is configured to hold the judgment result of
When the determination result of the length of the air passage is held, the controller executes a process for determining the length of the air passage after extinguishing the burner, and the length of the air passage obtained by the processing is determined. A combustion apparatus configured to discard a held determination result when the determination result is different from the held determination result. Based on the detection result by the detection means when the fan is operated at the first rotation speed and the detection result by the detection means when the fan is operated at the second rotation speed before ignition of the burner. First detection processing for determining the length of the air passage and the presence or absence of blockage of the air passage, and detection by the detection means when the fan is operated at the first rotational speed or the second rotational speed before the burner is ignited Based on the result, it is possible to selectively execute one of the second determination processes for determining whether or not the air passage is blocked,
The controller can further execute a third determination process for determining the length of the air passage based on the detection result by the detection means when the fan is operated at the third rotation speed after the burner is extinguished,
The controller performs the third determination process when the second determination process is performed while holding the determination result of the length of the air passage by the first determination process in the past, and the length of the air passage by the third determination process is determined. The combustion apparatus according to claim 1, wherein when the determination result is different from the held determination result, the held determination result is discarded, and the first determination process is performed during the subsequent combustion operation. In the first determination process, the controller first obtains a detection result by the detection means when the fan is operated at the first rotation speed before the burner is ignited, and the index size is within the reference range. Determines that the air passage is short and the air passage is not blocked, and if the index is out of the reference range, the fan is operated at a second rotational speed higher than the first rotational speed. When the detection result by the detection means is acquired and the size of the index falls within the reference range, it is determined that the air passage is long and the air passage is not blocked, and the size of the index is the reference If it is out of range, determine that the air passage is blocked,
In the second determination process, the controller obtains a detection result by the detection means when the fan is operated at the second rotation speed before the burner is ignited, and when the magnitude of the index falls within the reference range Determining that the air passage is not blocked, and determining that the air passage is blocked when the size of the indicator is outside the reference range,
In the third determination process, after the burner is extinguished, the controller acquires a detection result by the detection unit when the fan is operated at the third rotation speed, and when the size of the index falls within the reference range, The combustion apparatus according to claim 2, wherein it is determined that the air passage is short, and the air passage is determined to be long when the size of the index is out of the reference range.   The combustion apparatus according to claim 2 or 3, wherein the third rotational speed is higher than the first rotational speed and lower than the second rotational speed.   The combustion apparatus according to any one of claims 1 to 4, wherein the detection means is a wind pressure switch provided in the air passage.

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