JP2019138579A - Flame detection device - Google Patents

Abstract

A flame detector capable of appropriately detecting ignition of a burner while suppressing energy consumption for heating a frame rod as much as possible.
A flame detection device 1A maintains a heater 3 for heating a frame rod 2 in a stopped state until the ignition operation of the ignition device 20 in a state where ignition of a burner 10 is not detected reaches a predetermined number of times. When the ignition operation of the ignition device 20 reaches a predetermined number of times, a heater control unit 7c configured to operate the heater 3 at the next ignition operation of the ignition device 20 is provided.
[Selection] Figure 1

Description

  The present invention relates to a flame detection device including a frame rod.

  2. Description of the Related Art Conventionally, a flame detection apparatus that detects a flame (including ignition detection) by detecting a current flowing through a metal frame rod disposed in a flame has been used in various combustion apparatuses. For example, Patent Document 1 describes a device that ignites a burner formed of a ceramic plate by an ignition heater, and detects the ignition / combustion of the burner using a frame rod disposed beside the ignition heater. .

JP-A-10-169976

  Since the frame rod is exposed to a high temperature for flame detection, an oxide film is easily formed on the surface of the frame rod. When the oxide film is formed, especially when the burner is ignited in a low temperature environment, the energization resistance of the frame rod becomes large, and the flame detection sensitivity is lowered. Tends to be difficult.

  On the other hand, it is conventionally known that even if an oxide film is formed on the frame rod to some extent, current flows more easily through the frame rod when the frame rod is heated than at low temperatures.

  Therefore, in order to suppress a decrease in flame detection sensitivity caused by the oxide film, it is conceivable to heat the frame rod with a heater when the burner is ignited. In this case, as can be seen in Patent Document 1, in the case of providing an ignition heater, it is possible to heat the frame rod by the heat of the ignition heater every time the burner is ignited.

  However, in a combustion apparatus that ignites a burner by an ignition device such as an igniter, in order to heat the frame rod at the time of ignition, a heater different from the ignition heater is required. When the rod is heated, the following inconvenience occurs.

  That is, when an oxide film is not formed on the frame rod, or when the oxide film is sufficiently small, even when the burner is ignited in a low temperature environment, the flame detection is properly performed without heating the frame rod. Is possible.

  For this reason, if the flame rod is heated at each ignition in order to suppress a decrease in flame detection sensitivity due to the oxide film, the oxide film is not formed on the frame rod or the oxide film is sufficiently small. In this case, there is a disadvantage that extra energy for heating the frame rod is consumed.

  This invention is made | formed in view of this background, and it aims at providing the flame detection apparatus which can detect ignition of a burner appropriately, suppressing the energy consumption for the heating of a frame rod as much as possible.

In order to achieve such an object, the flame detection device of the present invention includes a frame rod arranged so as to detect a combustion flame of a burner, and a heater for heating the flame rod, and the burner of the burner by an ignition device is provided. A flame detection device configured to detect ignition of the burner based on a detection value of an energization current of the frame rod at the time of ignition,
The ignition device is configured to execute an ignition operation a plurality of times in a state where the ignition of the burner is not detected by the flame detection device when the burner is ignited,
Until the ignition operation of the ignition device in a state where the ignition of the burner is not detected reaches a predetermined number of times, the heater is maintained in a stopped state, and when the ignition operation of the ignition device reaches the predetermined number of times, A heater control unit configured to operate the heater at the time of ignition operation of the ignition device after the next time is provided (first invention). Note that the predetermined number of times may be one time or a plurality of times.

  According to the present invention, when the burner is ignited, the heater is maintained in an operation stopped state until the ignition operation of the ignition device reaches a predetermined number of times. For this reason, if the ignition of the burner is detected by the flame detection device before the ignition operation reaches the predetermined number of times, it is possible to start the burner combustion operation without heating the flame rod by the heater. .

  Here, when the oxide film is not formed on the frame rod, or when the oxide film formed on the frame rod is sufficiently small, the burner is normally operated at the arbitrary number of ignition operations up to the predetermined number of times. When ignited, the flame detection device appropriately detects the ignition of the burner, so that it is not necessary to perform the subsequent ignition operation.

  Accordingly, when the oxide film is not formed on the frame rod or when the oxide film formed on the frame rod is sufficiently small, the frame rod is not usually heated by the heater (that is, the heater rod). The burning operation of the burner can be started (without requiring energy consumption for heat generation).

  On the other hand, if the formation of the oxide film on the frame rod has progressed to some extent, the ignition of the burner may not be detected by the predetermined number of ignition operations. However, in this case, the heater is activated during the subsequent ignition operation, and the frame rod is heated by the heater. When the frame rod is heated, cracks are formed in the oxide film, and it is considered that current can flow through the cracks.

  For this reason, when the burner is ignited by the ignition operation after the next time, it becomes easier for the current to flow through the frame rod. As a result, the ignition of the burner can be properly detected by the flame detection device, and the combustion operation of the burner can be started normally.

  Therefore, according to the flame detection device of the present invention, it is possible to appropriately detect the ignition of the burner while suppressing energy consumption for heating the frame rod as much as possible.

  In the first aspect of the invention, when the ignition of the burner is not detected during the ignition operation of the ignition device in the operation state of the heater, the detected value of the energization current of the frame rod acquired during the ignition operation, and the heater Flame detection failure that determines whether or not a flame detection failure has occurred due to the frame rod, based on a mutual magnitude relationship with the detected value of the energization current of the frame rod obtained during the ignition operation in the operation stop state of It is preferable to further include a determination unit and a response processing unit that executes a corresponding process according to the determination result of the flame detection failure determination unit (second invention).

  Here, in the state where the progress of formation of the oxide film on the frame rod is increased, the burner ignites normally not only when the frame rod is heated but also when the frame rod is heated. Compared to the case where an oxide film is not formed, the current flowing through the frame rod becomes small, and it is likely that the flame detection device cannot detect ignition.

  On the other hand, even when the progress of the formation of the oxide film on the frame rod is increased, the energizing current of the frame rod when the burner is ignited is heated by the heater rather than when the frame rod is not heated by the heater. The case tends to be larger.

  Therefore, in the second invention, the flame detection failure determination unit, when the ignition of the burner is not detected during the ignition operation in the operating state of the heater (that is, during the ignition operation of the number of times larger than the predetermined number), The detected value of the energizing current of the frame rod acquired at the time of the ignition operation and the energization of the frame rod acquired at the time of the ignition operation in the heater stop state (that is, at the ignition operation of the predetermined number of times or less). Based on the mutual magnitude relationship with the detected current value, the presence / absence of occurrence of flame detection failure due to the frame rod is determined. This makes it possible to make the determination appropriately.

  And the said response process part performs the corresponding | compatible process (for example, alerting | reporting process) according to the determination result of a flame detection defect determination part, and when the flame detection defect resulting from a flame rod generate | occur | produces, the response | compatibility suitable for it Processing can be executed. Note that the corresponding process is not limited to the notification process, and may be a predetermined operation control of the combustion equipment.

The figure which shows the principal part structure of a combustion equipment provided with the flame detection apparatus of 1st Embodiment of this invention. The flowchart which shows the action | operation of the ignition device and flame detection apparatus which are shown in FIG. The figure which shows the principal part structure of a combustion equipment provided with the flame detection apparatus of 2nd Embodiment of this invention. The flowchart which shows the action | operation of the ignition device and flame detection apparatus which are shown in FIG.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. Referring to FIG. 1, a flame detection device 1 </ b> A of the present embodiment is provided in a combustion device such as a water heater or a fan heater. The combustion apparatus includes a burner 10 and an ignition device 20 that ignites the burner 10 in addition to the flame detection device 1A.

  The burner 10 is, for example, a gas burner. Fuel gas is supplied from the fuel supply path 11 and fuel air is supplied from a combustion fan (not shown). An electromagnetic valve 12 that opens and closes the fuel supply path 11 and a fuel adjustment valve 13 such as a proportional valve that adjusts the amount of fuel supplied to the burner 10 are interposed in the fuel supply path 11.

  The burner 10 is not limited to a gas burner, and may be a burner that burns liquid fuel such as kerosene.

  The ignition device 20 includes a discharge electrode 21 disposed in the vicinity of the burner 10, an igniter 22 that generates a spark discharge at the discharge electrode 21, and an ignition control unit 23 that executes a control process for igniting the burner 10, Is provided.

  The ignition control unit 23 is configured by an electronic circuit unit including a microcomputer, a memory, an interface circuit, and the like, for example. The ignition control unit 23 controls the operation of the solenoid valve 12, the fuel adjustment valve 13, and the igniter 22 by a function realized by one or both of the installed hardware configuration and program (software configuration). The ignition operation for igniting the burner 10 can be executed.

  In this ignition operation, the ignition control unit 23 controls the electromagnetic valve 12 and the fuel adjustment valve 13 so as to supply a certain amount of fuel to the burner 10 and also operates the igniter 22 to spark discharge the discharge electrode 21. Is generated. As a result, the burner 10 is ignited.

  1 A of flame detection apparatuses of this embodiment are related with the flame rod 2 arrange | positioned so that the combustion flame (it shows with a dashed-two dotted line) which generate | occur | produces in the burner 10, the heater 3 which heats this flame rod 2, and flame detection And a flame detection processing unit 7 for executing the processing. The heater 3 is a rod-shaped electric heater, and protrudes together with the frame rod 2 from a base portion 4 made of an insulating material such as glass so as to be arranged adjacent to the frame rod 2. The frame rod 2 and the heater 3 are each connected to the flame detection processing unit 7 via a conductive wire 5.

  The flame detection processing unit 7 is configured by an electronic circuit unit including a microcomputer, a memory, an interface circuit, and the like, for example. And the flame detection process part 7 provided the alternating voltage of a fixed voltage between the burner 10 to the flame | frame rod 2 as a function implement | achieved by one or both of the mounted hardware configuration and the program (software configuration). A function as a current detector 7a for detecting the current flowing through the frame rod 2 in a state, a function as an ignition detector 7b for detecting the ignition of the burner 10 based on the detected value of the current, and the operation of the heater 3 A function as a heater control unit 7c that performs control (energization control) is included.

  In addition, the flame detection processing unit 7 can acquire information on the ignition operation (for example, information on whether or not the ignition operation is being executed, the number of executions of the ignition operation, etc.) from the ignition control unit 23, and Information such as whether or not ignition is detected can be given to the ignition control unit 23.

  Supplementally, all or part of the function of the flame detection processing unit 7 and all or part of the function of the ignition control unit 23 may be realized by a common electronic circuit unit. Moreover, the electronic circuit unit which has the function of one or both of the flame detection process part 7 and the ignition control part 23 may include the function to perform operation control of the whole combustion equipment.

  Next, the operation of the flame detection device 1A and the ignition device 20 of this embodiment will be described with reference to the flowchart of FIG.

  When a start request for the combustion operation of the burner 10 is generated, an initial check is performed in STEP 1 by an operation control unit (not shown) of the combustion equipment. In this initial check, it is checked whether or not a predetermined electronic device or power source of the combustion device is normal. Note that if an abnormality is detected in the initial check, the operation of the combustion equipment is stopped.

  Next, in STEP 2, the ignition operation (first ignition operation) of the ignition device 20 is performed by the control process of the ignition control unit 23. During execution of this ignition operation, in STEP 3, while the current detection unit 7 a of the flame detection processing unit 7 detects the current of the frame rod 2, the ignition detection of the burner 10 based on the detected value of the current (ignition is performed). Is detected) by the ignition detection unit 7b. In this case, the ignition detection unit 7b detects whether or not the burner 10 has ignited depending on whether or not the detected value of the current of the frame rod 2 has increased to a current value equal to or greater than a predetermined value (for example, 1 μA).

  In STEP 3, when the ignition of the burner 10 is detected within a predetermined time (for example, within 4 seconds) after the ignition operation is started, the determination result in STEP 3 is affirmative. In this case, in STEP 4, the ignition operation by the ignition control unit 23 is stopped. More specifically, the operation of the igniter 22 is stopped.

  And in STEP5, control of the combustion operation of the burner 10 is started by the operation control part.

  On the other hand, if the ignition of the burner 10 is not detected within a predetermined time after the start of the ignition operation in STEP 3, the determination result in STEP 3 is negative. In this case, in STEP 6, the ignition operation by the ignition control unit 23 is stopped. More specifically, the operation of the igniter 22 is stopped, and the solenoid valve 12 is controlled to close (fuel supply to the burner 10 is shut off).

  Further, in STEP 7, the heater control unit 7c of the flame detection processing unit 7 controls the heater 3 to be in an ON state (a state in which heat is generated by energization). Thereby, the heater 3 generates heat, and the frame rod 2 is heated by the heat.

  Next, in STEPs 8 to 10, an initial check, ignition operation (second ignition operation), and ignition detection are performed as in STEPs 1 to 3. In this case, since the frame rod 2 is heated by the heater 3, even if the formation of an oxide film on the frame rod 2 is somewhat advanced, the combustion flame of the burner 10 acts on the frame rod 2. It becomes a state in which current easily flows through the frame rod 2.

  If the ignition of the burner 10 is detected within a predetermined time after the start of the ignition operation in STEP 9, the determination result in STEP 10 becomes affirmative. In this case, as in the case where ignition of the burner 10 is detected in STEP 3, the ignition operation is stopped in STEP 4 (operation of the igniter 22 is stopped). Control is started. In this case, the operation (energization) of the heater 3 is stopped at or after the start of the control of the combustion operation of the burner 10.

  On the other hand, if ignition of the burner 10 is not detected within a predetermined time after the start of the ignition operation in STEP 9, the determination result in STEP 10 is negative. In this case, in STEP 11, the ignition operation by the ignition control unit 23 is stopped. More specifically, the operation of the igniter 22 is stopped, and the solenoid valve 12 is controlled to close (fuel supply to the burner 10 is shut off).

  Next, in STEP 12, the ignition control unit 23 (or the flame detection processing unit 7) determines whether the number of ignition operations, which is the number of executions of the ignition operation from STEP 2 to the present, is less than a predetermined upper limit number Nmax (for example, 3 times). Judge whether or not. When the number of ignition operations <Nmax (when the determination result of STEP 12 is affirmative), the processing from STEP 8 described above is executed again. In this case, the ON state of the heater 3 by the heater control unit 7c is continued.

  Further, when the number of ignition operations is equal to or greater than Nmax (when the determination result in STEP 12 is negative), in STEP 13, the operation of the combustion device (including the operation of the heater 3) is stopped by the operation control unit. In this case, an error notification that the burner 10 cannot be normally ignited can be output via a display (not shown).

  According to the first embodiment, during the first ignition operation, no heat is generated by energizing the heater 3, and during the second and subsequent ignition operations, heat is generated due to the energization of the heater 3 (and consequently the frame rod 2 is heated). Is called.

  Here, an oxide film is not formed on the frame rod 2 or the formation thereof is sufficiently small (a state where a sufficient current can flow through the frame rod 2 when a combustion flame acts on the frame rod 2). Then, in the first ignition operation, the ignition of the burner 10 is detected, and the determination result in STEP 3 becomes affirmative. Therefore, the combustion operation of the burner 10 is started without generating heat by energizing the heater 3 (without consuming energy by the heater 3). For this reason, energy consumption for heating the frame rod 2 can be reduced.

  On the other hand, if the ignition of the burner 10 is not detected during the first ignition operation, the ignition operation is performed in a state in which heat is generated by energization of the heater 3 (and consequently the frame rod 2 is heated). Even if the formation of the oxide film on the frame rod 2 has progressed somewhat, if the burner 10 ignites normally, a sufficient current flows through the frame rod 2 and consequently the ignition of the burner 10 can be properly detected. . As a result, the normal combustion operation of the burner 10 can be performed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the present embodiment differs from the first embodiment in part of the configuration and processing, and thus the description of the same matters as in the first embodiment is omitted.

  Referring to FIG. 3, the flame detection processing unit 7 of the flame detection device 1B of the present embodiment has functions as a current detection unit 7a, an ignition detection unit 7b, and a heater control unit 7c as in the first embodiment. In addition, when the ignition of the burner 10 is not detected, the function as the flame detection failure determination unit 7d for determining whether or not the formation of the oxide film on the frame rod 2 is in an excessively advanced state, A response processing unit 7e that executes a corresponding process according to the determination result of the flame detection failure determination unit 7d.

  Moreover, the flame detection processing unit 7 can control the display of the display 30 as a notification output unit provided in the combustion device. In the present embodiment, configurations other than those described above are the same as those in the first embodiment.

  Next, the operation of the flame detection device 1B and the ignition device 20 of the present embodiment will be described with reference to the flowchart of FIG.

  When a start request for the combustion operation of the burner 10 is generated, the processing shown in the flowchart of FIG. 4 is executed. In this case, the processing of STEPs 21 to 25 is the same as STEPs 1 to 5 in the first embodiment.

  When the ignition of the burner 10 is not detected in STEP 23 (when the determination result in STEP 23 is negative), next, in STEP 26, the ignition operation by the ignition control unit 23 (first ignition operation) is performed as in STEP 6 above. In addition to being stopped, the flame detection processing unit 7 further stores and holds the current value Ia detected by the current detection unit 7a during the first ignition operation.

  More specifically, the current value Ia is, for example, a current detection value at the end of the first ignition operation, a current detection value at a predetermined time point during the first ignition operation, or the first time Is the maximum value of the current detection value during the ignition operation.

  Next, in STEP 27, similarly to STEP 7, the heater control unit 7c of the flame detection processing unit 7 controls the heater 3 to be in an ON state (a state in which heat is generated by energization).

  Next, in STEPs 28 to 30, an initial check, ignition operation (second ignition operation), and ignition detection are performed as in STEPs 8 to 10.

  When the ignition of the burner 10 is detected in STEP 30 (when the determination result in STEP 30 is affirmative), as in the first embodiment, the ignition is the same as when the ignition of the burner 10 is detected in STEP 23. In STEP 24, the ignition operation is stopped (the operation of the igniter 22 is stopped). In STEP 25, control of the combustion operation of the burner 10 is started. In this case, the operation (energization) of the heater 3 is stopped at or after the start of the control of the combustion operation of the burner 10.

  On the other hand, when the ignition of the burner 10 is not detected in STEP 30 (when the determination result in STEP 30 is negative), the ignition operation by the ignition control unit 23 is stopped in STEP 31 as in STEP 11. Further, the flame detection processing unit 7 stores and holds the current value Ib detected by the current detection unit 7a during the ignition operation in STEP 29 (during the previous ignition operation).

  The current value Ib is acquired in the same manner as the current value Ia in STEP 26. For example, a current detection value at the end of the ignition operation in STEP 29 or a predetermined value during the ignition operation in STEP 29 This is the current detection value at a predetermined time point or the maximum value of the current detection value during the ignition operation in STEP29.

  Next, in STEP 32, the current value Ib in STEP 31 (current value Ib in the ignition operation when the heater 3 is ON) is changed to the current value Ia in STEP 26 (current value Ia in the ignition operation when the heater 3 is OFF). Is determined by the flame detection failure determination unit 7d of the flame detection processing unit 7. More specifically, in STEP 32, it is determined whether Ia + α ≦ Ib (whether Ib is greater than Ia by a predetermined value α (α> 0) or larger). In STEP 32, for example, it may be determined whether the ratio Ia / Ib between Ia and Ib is equal to or less than a predetermined value β (0 <β <1).

  Here, when the formation of an oxide film on the frame rod 2 has progressed to some extent, the energizing current of the frame rod 2 when the burner 10 ignites normally is the case where the frame rod 2 is not heated by the heater 3. Rather than when heated by the heater 3. This is considered to be because when the frame rod 2 is heated, cracks are formed in the oxide film, and current can flow through the cracks.

  Therefore, if the determination result in STEP 32 is affirmative, the burner 10 is normally ignited during the ignition operation in STEP 22 and in the ignition operation in STEP 29, but an oxide film is formed on the frame rod 2. Since the degree of progress of the flame is increasing (because the current of the frame rod 2 is difficult to flow), there is a high possibility that a flame detection failure in which ignition cannot be normally detected has occurred.

  Therefore, if the determination result in STEP 32 is affirmative, in STEP 34, the operation control unit stops the operation of the combustion device (including the operation of the heater 3), and the response processing unit 7e of the flame detection processing unit 7 is stopped. However, the display unit 30 is notified of an error indicating that an abnormality caused by the frame rod 2 (more specifically, an abnormality of flame detection failure caused by an oxide film formed on the frame rod 2) has occurred.

  On the other hand, if the determination result in STEP 32 is negative, in STEP 33, the ignition control unit 23 (or the flame detection processing unit 7) has a predetermined number of ignition operations from STEP 22 to the present time, as in STEP 12. It is determined whether or not it is less than the upper limit number Nmax. When the number of ignition operations <Nmax (when the determination result in STEP33 is affirmative), the process in STEP28 is executed again. In this case, the ON state of the heater 3 by the heater control unit 7c is continued.

  Further, when the number of ignition operations is equal to or greater than Nmax (when the STEP33 determination result is negative), in STEP35, the operation control unit stops the operation of the combustion device (including the operation of the heater 3), and The display device 30 is notified of an error that an ignition failure has occurred due to the influence of wind or the like.

  Note that the error notification in STEPs 34 and 35 is not limited to visual notification, but may be audio notification by voice or the like, or both visual notification and audio notification. May be.

  In this embodiment, as in the first embodiment, no heat is generated by energization of the heater 3 during the first ignition operation, and heat generation due to the energization of the heater 3 (and hence the frame rod) during the second and subsequent ignition operations. 2). Therefore, the same effect as that of the first embodiment can be obtained.

  In addition, in the present embodiment, when the ignition of the burner 10 is not detected even if the ignition operation is performed twice or more, the frame at the time of the ignition operation in the OFF state of the heater 3 (at the time of the first ignition operation). By determining the mutual magnitude relationship between the current value Ia of the rod 2 and the current value Ib of the frame rod 2 during the ignition operation in the ON state of the heater 3 (during the second and subsequent ignition operations), the frame rod 2 (The abnormality of the flame detection failure due to the state in which the progress of the formation of the oxide film on the frame rod 2 is increased) can be detected, and an error notification to that effect can be performed. As a result, measures, such as replacement | exchange of the frame rod 2, can be taken appropriately.

  In each of the embodiments described above, the upper limit number Nmax of the number of ignition operations is set to 3, but it may be 2 times or 4 times or more. When Nmax = 2, the determination process in STEP 12 in FIG. 2 or the determination process in STEP 33 in FIG. 3 may be omitted.

  In each of the above embodiments, when ignition is not detected during the first ignition operation, the heater 3 is turned on (operating state) during the second and subsequent ignition operations so that the frame rod 2 is heated. (The predetermined number of times in the present invention is one). However, for example, until the ignition operation of a predetermined number of times of 2 or more (for example, the second time), the heater 3 is turned off (operation stop state), and the ignition operation after the predetermined number of times + 1 (for example, after the third time) Sometimes, the heater 3 may be turned on.

  In this case, the current value Ia used in the process of the flame detection failure determination unit 7d (the determination process in STEP 32) is a current value acquired during the ignition operation for any one number of times from the first time to the predetermined number of times. However, it may be an average value or a maximum value of current values acquired at the time of each ignition operation from the first time to a predetermined number of times.

  In the second embodiment, the process of storing the current value Ib in STEP 31 and the process of comparing the current values Ia and Ib in STEP 32 are, for example, the burner 10 in the first ignition operation that matches the upper limit number Nmax. It may be executed only when no ignition is detected.

  Alternatively, for example, when the ignition of the burner 10 is not detected during each ignition operation up to the number of times that matches the upper limit number Nmax, the current acquired during each ignition operation after the second time when the frame rod 2 is heated by the heater 3 Using the average value or the maximum value of the value Ib and the current value Ia gained during the first ignition operation without operating the heater 3, the process of the flame detection failure determination unit 7d (the determination process of STEP 32) is performed. May be.

  In each of the above embodiments, the frame rod 2 and the heater 3 are provided separately. For example, the heater 3 is assembled to the frame rod 2 in a state of being electrically insulated from the energizing portion of the frame rod 2. Also good.

  DESCRIPTION OF SYMBOLS 1A, 1B ... Flame detection apparatus, 2 ... Frame rod, 3 ... Heater, 7c ... Heater control part, 7d ... Flame detection defect judgment part, 7e ... Response processing part.

Claims (2)

A flame rod arranged so as to detect the combustion flame of the burner; and a heater for heating the flame rod, and when the burner is ignited by an ignition device, A flame detection device configured to detect ignition of a burner,
The ignition device is configured to execute an ignition operation a plurality of times in a state where the ignition of the burner is not detected by the flame detection device when the burner is ignited,
Until the ignition operation of the ignition device in a state where the ignition of the burner is not detected reaches a predetermined number of times, the heater is maintained in a stopped state, and when the ignition operation of the ignition device reaches the predetermined number of times, A flame detection device comprising: a heater control unit configured to operate the heater during the ignition operation of the ignition device after the next time. The flame detection device according to claim 1,
If ignition of the burner is not detected during the ignition operation of the ignition device in the heater operating state, the detected value of the energization current of the frame rod acquired during the ignition operation, and the heater in the operation stop state A flame detection failure determination unit that determines whether or not a flame detection failure has occurred due to the frame rod, based on a mutual magnitude relationship with a detected value of the energization current of the frame rod acquired during an ignition operation; A flame detection apparatus, further comprising: a response processing unit that executes a corresponding process according to a determination result of the detection failure determination unit.