JP6173161B2 - Combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus such as a water heater or an indoor heater, and more particularly to a combustion apparatus having a function of prohibiting combustion of a burner according to the CO concentration in the combustion exhaust gas of the burner.

  In combustion devices such as water heaters and hot water heaters, a CO sensor that detects the CO concentration in the combustion exhaust discharged from the burner is provided in the exhaust passage, and the CO concentration detected by the CO sensor becomes higher than the standard. For example, those configured to automatically stop combustion of the burner are known (see, for example, Patent Documents 1 to 3).

  As a burner used in this type of combustion apparatus, a burner having a single flame hole such as a Bunsen burner has been used. However, in order to reduce the environmental load such as NOx, the gas concentration is lower than the stoichiometric air-fuel ratio. A so-called concentration burner has been used which has a pale flame hole for ejecting a low pale mixed gas and a rich flame hole for ejecting a rich mixed gas having a higher gas concentration than the pale mixed gas outside the pale flame hole.

JP 2005-147498 A JP 2008-249296 A JP-A-7-180834

  Incidentally, as shown in FIG. 4, in the combustion apparatus using the Bunsen burner, if the amount of air supplied into the combustion chamber decreases due to the blockage of the exhaust passage or the like, and the gas concentration in the burner increases, However, if the air concentration is excessively supplied into the combustion chamber and the gas concentration becomes low, the CO concentration in the combustion exhaust gas does not increase. However, in the combustion apparatus using the above-described concentration burner, not only when the gas concentration becomes high, but also when the gas concentration becomes low due to excessive supply of air into the combustion chamber, The formed flare flame is lifted and further spreads to the outside where the rich flame is present, so that the temperature of the upper area of the flare flame is lowered and the CO concentration in the combustion exhaust gas may be increased.

  Therefore, for example, in the case of supplying combustion air to the combustion chamber via the air supply pipe, such as a forced air supply / exhaust type water heater, the lid of the device housing is opened when performing trial operation and maintenance during construction. If the air flows into the combustion chamber also from the open portion, the gas concentration of the burner becomes low, and the CO concentration increases even when no blockage occurs. In addition, if the purge process of the newly installed gas pipe is insufficient at the time of construction and air remains in the gas pipe, the gas concentration similarly decreases and the CO concentration temporarily increases. Therefore, as described above, in a combustion apparatus that prohibits combustion of a burner as the CO concentration in combustion exhaust gas increases, the operation is unintentionally interrupted and the usability is poor.

  The present invention has been made in view of the above problems, and has an object of having a concentration burner in which the CO concentration in the combustion exhaust gas increases as the amount of air supplied into the combustion chamber increases, In a combustion apparatus having a function of prohibiting combustion of a burner according to the CO concentration, it is intended to improve safety and usability when performing trial operation and maintenance during construction.

  The present invention includes an apparatus housing having an openable / closable lid, a burner having a rich flame hole and a light flame hole, a CO sensor for detecting the CO concentration in the combustion exhaust of the burner, and the CO concentration higher than a reference. A combustion apparatus having a combustion prohibiting function execution unit for prohibiting combustion of the burner when the engine has been stopped and maintaining the burner in a combustion prohibited state until a predetermined release instruction is issued, wherein the combustion prohibiting function is effectively By disabling the normal mode and the combustion prohibition function, the amount of air flowing into the device casing when the lid is opened increases, and the CO concentration in the combustion exhaust from the pale flame hole is higher than the standard. A mode switching unit is provided that can selectively switch between an inspection mode that does not prohibit burner combustion even when the temperature is high.

  In the case of a combustion device using a light and dark burner, not only when the air supplied to the combustion chamber decreases and the gas concentration increases, but also when the gas concentration becomes low due to excessive supply of air into the combustion chamber However, there is a risk of increasing the CO concentration in the combustion exhaust gas. However, in this case, when the normal mode is selected and the combustion prohibition function is enabled, if the CO concentration in the burner combustion exhaust gas becomes higher than the reference value, the burner combustion is prohibited. Is selected and the combustion prohibiting function is disabled, the burner combustion is not prohibited even if the CO concentration in the combustion exhaust of the burner is higher than the reference value. Thereby, when performing a trial run and maintenance at the time of construction, it is possible to prevent the combustion of the burner from being unintentionally prohibited.

  The present invention also provides an apparatus housing having an openable / closable lid, a burner having a rich flame hole and a light flame hole, a CO sensor for detecting the CO concentration in the combustion exhaust of the burner, and the CO concentration as a reference A combustion prohibiting function execution unit for prohibiting combustion of the burner when the number of times of higher CO concentration abnormality reaches a predetermined number, and maintaining the burner in a combustion prohibited state until a predetermined release instruction is given In the combustion apparatus, the normal mode for counting the number of times the CO concentration has become abnormal and the count of the number of times the CO concentration has become abnormal are not performed, so that the lid is opened and flows into the device housing Provided with a mode switching unit capable of selectively switching between an inspection mode in which combustion of the burner is not prohibited even when the amount of air increases and the CO concentration in the combustion exhaust gas from the pale flame hole becomes higher than the reference It is a thing.

  In the case of a combustion device using a light and dark burner, not only when the air supplied to the combustion chamber decreases and the gas concentration increases, but also when the gas concentration becomes low due to excessive supply of air into the combustion chamber However, there is a risk of increasing the CO concentration in the combustion exhaust gas. However, in this case, when the normal mode is selected, if the number of times the CO concentration in the burner combustion exhaust gas becomes higher than the reference value (the number of times the CO concentration becomes abnormal) reaches a predetermined number, the burner combustion However, when the inspection mode is selected, the number of times the CO concentration has become abnormal is not counted. Therefore, even if the CO concentration in the combustion exhaust of the burner is higher than the reference value, the burner combustion is not performed. Not prohibited. Thereby, when performing a trial run and maintenance at the time of construction, it is possible to prevent the combustion of the burner from being unintentionally prohibited.

In the combustion apparatus, the switching between the normal mode and the inspection mode can be executed only when the lid is opened.
In this case, since the mode cannot be switched unless the cover of the device casing is opened, the burner combustion prohibition function is disabled during normal operation other than trial operation or maintenance. Can be prevented.

Further, the present invention is configured such that in the above-described combustion apparatus, outdoor air is taken into the apparatus housing from the supply pipe, and discharged from the exhaust pipe to the outside through the combustion chamber together with the combustion exhaust of the burner.
In this case, during the normal operation, the combustion air of the burner is taken into the device casing from the supply pipe, but when the lid is opened for trial operation and maintenance, a large amount of air is also released from the open part. Flows into the apparatus casing, and the increase in the CO concentration in the combustion exhaust of the burner appears significantly. Therefore, the mode switching function is more useful.

  As described above, according to the present invention, if the normal mode is selected, combustion of the burner can be prohibited according to the CO concentration in the combustion exhaust. On the other hand, if the inspection mode is selected, When performing maintenance, it is possible to prevent unintentional combustion of the burner, thereby improving safety and usability.

FIG. 1 is a schematic configuration diagram of a combustion apparatus according to an embodiment of the present invention. FIG. 2 is an operation flowchart showing the mode switching control of the combustion apparatus according to the embodiment of the present invention. FIG. 3 is an operation flowchart showing the mode switching control of the combustion apparatus according to another embodiment of the present invention. FIG. 4 is a graph showing the relationship between the CO concentration in the combustion exhaust and the air-fuel ratio in the Bunsen burner and the rich flame burner.

Next, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 1, the combustion apparatus 1 according to the present embodiment takes outdoor air from an air supply pipe 101 into an apparatus housing 10 by an air supply / exhaust fan 11, and further combusts with combustion exhaust discharged from a burner 12. This is a so-called forced supply / exhaust hot water heater configured to be led into the chamber 100 and discharged from the exhaust pipe 102 to the outside through the arrangement portion of the heat exchanger 13 again. Although not shown, a maintenance lid (hereinafter referred to as “front plate”) that can be opened and closed is provided on the front surface of the apparatus housing 10.

  One end of the air supply pipe 101 is connected to the apparatus housing 10 and the other end is opened to the outside of the room. The exhaust pipe 102 has one end connected to the upper portion of the combustion chamber 100 and the other end open to the outside of the chamber.

  The combustion chamber 100 is defined with a predetermined space inside the apparatus housing 10. The air outlet of the supply / exhaust fan 11 is connected to the lower part of the combustion chamber 100, and the internal space of the combustion chamber 100 is connected to the internal space of the apparatus housing 10 through the intake port of the supply / exhaust fan 11. . Therefore, when the air supply / exhaust fan 11 is operated, outdoor air is taken into the apparatus housing 10 from the air supply pipe 101 and further exhausted through the internal space of the combustion chamber 100 from the exhaust pipe 102 to the outside.

  The air supply / exhaust fan 11 includes a fan motor 110 that is driven in response to an instruction from a control circuit 20 incorporated in the apparatus housing 10, and the rotation speed of the fan motor 110 is adjusted to adjust the burner 12. Air supply is increased or decreased. Although not shown, the fan motor 110 is provided with a rotation speed sensor that detects the rotation speed of the fan motor 110 and outputs it to the control circuit 20. The rotation speed of the supply / exhaust fan 11 corresponds to the rotation speed of the fan motor 110.

  The burner 12 has a plurality of flame holes 120 through which the gas supplied from the gas pipe 31 is ejected into the combustion chamber 100, and is incorporated at a position below the combustion chamber 100. In the vicinity of the flame hole 120, a spark discharge is generated by applying a high voltage from an igniter (not shown), and a spark plug 14 that ignites the gas ejected from the flame hole 120, and the presence or absence of a combustion flame in the flame hole 120 is detected. A frame rod 15 is adjacently installed. Although not shown in the drawing, the flame hole 120 has a pale flame hole for ejecting upward a light mixed gas having a gas concentration lower than the stoichiometric air-fuel ratio, and a dense mixed gas having a gas concentration higher than that of the light mixed gas. It is composed of dense flame holes that are ejected upward from both sides.

  The gas pipe 31 is provided with an original gas solenoid valve 21 capable of shutting off the supply of gas to the burner 12 and a gas proportional valve 22 for adjusting the amount of gas supplied to the burner 12. The amount of combustion of the burner 12 is increased or decreased by adjusting the opening of the gas proportional valve 22 with the electromagnetic valve 21 opened.

  The heat exchanger 13 has one end connected to the water supply pipe 32 and the other end connected to the tapping pipe 33, and a plurality of endothermic fins 132 arranged side by side so as to intersect the endothermic pipe 131. And is incorporated at an upper position in the combustion chamber 100. Accordingly, the water supplied from the water supply pipe 32 to the heat exchanger 13 is heated in the heat absorption pipe 131 by heat exchange with the combustion exhaust discharged from the burner 12 and led to the hot water discharge pipe 33. And it mixes with the water supplied to the hot water supply pipe 33 via the bypass pipe 34 from the water supply pipe 32, is adjusted to preset temperature, and is supplied to hot water utilization destinations, such as a hot water tap and a bathtub.

  The water supply pipe 32 is provided with a water amount sensor 23 for detecting the flow rate of water supplied to the heat exchanger 12 and a water amount adjustment valve 24 for adjusting the amount of water supplied to the heat exchanger 13. . In addition, a bypass valve 25 for adjusting the amount of water supplied from the water supply pipe 32 to the hot water supply pipe 33 is provided at a connection portion between the water supply pipe 32 and the bypass pipe 34. Further, the hot water supply pipe 33 is provided with a hot water temperature sensor 26 for detecting the temperature of the mixed water of the hot water supplied from the heat exchanger 13 and the water supplied from the bypass pipe 34. By adjusting the opening of the water amount adjustment valve 24 and the bypass valve 25 according to the detected temperature, the temperature of the hot water to the hot water usage destination is adjusted.

  A CO sensor 27 that detects the CO concentration in the combustion exhaust discharged from the burner 12 and guided into the exhaust pipe 102 is provided in the exhaust pipe 102 in the vicinity of the connecting portion with the combustion chamber 100.

  The fan motor 110, the rotation speed sensor, the spark plug 14, the frame rod 15, the original gas solenoid valve 21, the gas proportional valve 22, the water amount sensor 23, the water amount adjustment valve 24, the bypass valve 25, the hot water temperature sensor 26, and the CO sensor 27 is connected to the control circuit 20 through electrical wiring (not shown). Further, an operation terminal 4 for remotely operating the combustion apparatus 1 is connected to the control circuit 20 by electrical wiring or wirelessly.

  The control circuit 20 performs an operation determination unit that determines whether or not the detected water amount of the water amount sensor 23 has reached the minimum working water amount, a supply / exhaust execution unit that operates and stops the supply / exhaust fan 11, and ignition and extinguishing of the burner 12. Point fire extinguishing unit to be performed, combustion amount adjusting unit for adjusting the combustion amount of the burner 12 according to the temperature detected by the hot water temperature sensor 26, and supply / exhaust amount adjustment for adjusting the rotational speed of the fan motor 110 according to the combustion amount of the burner 12 Circuit configuration.

  Further, the control circuit 20 prohibits combustion of the burner 12 when it is determined that the exhaust pipe 102 is in a closed state, a blockage determination unit that determines the closed state of the exhaust pipe 102 based on the energization current of the fan motor 110. An execution unit for the blockage point fire limit function, a CO concentration determination unit that determines whether the CO concentration detected by the CO sensor 27 is abnormal in CO concentration higher than the reference concentration, and whether the CO concentration has increased to a predetermined concentration, CO concentration A fan rotation speed correction unit that corrects the rotation speed of the fan motor 110 according to the above, an execution unit for an automatic fire extinguishing function that automatically stops combustion of the burner 12 when it is determined that the CO concentration is abnormal, and a CO that is determined to be abnormal in CO concentration An abnormality counting unit that counts the number of abnormalities, an abnormal number determination unit that determines whether or not the number of CO abnormalities has reached a predetermined number, and a burner 1 when the number of CO abnormalities reaches a predetermined number A combustion prohibiting function execution unit that prohibits combustion of the gas, an abnormality notification unit that notifies the operation terminal 4 that the exhaust pipe 102 is in a closed state, or that the combustion of the burner 12 has been automatically stopped, and a combustion prohibiting function are enabled. A mode switching unit that can selectively switch between the normal mode and the inspection mode that disables the combustion prohibition function, and a mode that automatically enables the combustion prohibition function when the combustion prohibition function is disabled for a predetermined time. It has a circuit configuration such as an execution unit for an automatic return function.

  In addition, the control circuit 20 is provided with a changeover switch 41 as a changeover instruction unit for manually switching the mode and a release switch 42 as a release instruction unit for manually releasing the combustion prohibited state of the burner 12. It has been. The changeover switch 41 and the release switch 42 are incorporated in a position that can be operated only inside the apparatus housing 10 and with the front plate opened.

  As shown in FIG. 2, when an instruction to start operation is given at the operation terminal 4, the control circuit 20 monitors whether or not the detected water amount of the water amount sensor 23 is equal to or greater than the minimum operating water amount as an instruction to start hot water supply. To start. When the detected water amount of the water amount sensor 23 reaches the minimum operating water amount, the air supply / exhaust fan 11 is operated at a preset blockage detection rotation speed, and the energization current (fan current) of the fan motor 110 at that time is the reference current. It is determined whether it is lower (ST1 to ST2).

  As a result, if the fan current is lower than the reference current, the sound output unit and the display unit (not shown) of the operation terminal 4 are informed that the exhaust pipe 102 is closed, and combustion of the burner 12 is prohibited. Then, after waiting for an instruction to cancel combustion inhibition by the release switch 42 inside the apparatus housing 10, the step ST1 is performed again (ST3 to ST5).

  On the other hand, if the fan current of the fan motor 110 is greater than or equal to the reference current as a result of the blockage determination in ST2, the exhaust pipe 102 is in a normal state where the exhaust pipe 102 is not blocked. Is adjusted to the set rotational speed at the time of ignition and spark discharge is performed from the spark plug 14, and the original gas solenoid valve 21 is opened to start supplying gas to the burner 12. Thereby, the burner 12 is ignited. When the burner 12 is ignited, the opening of the gas proportional valve 22 is adjusted according to the temperature detected by the hot water temperature sensor 26, the amount of combustion of the burner 12 is adjusted, and the rotational speed detected by a rotational speed sensor (not shown). Is adjusted to match the target rotational speed corresponding to the combustion amount of the burner 12. Thereby, supply of combustion exhaust from the burner 12 into the combustion chamber 100 is started (ST6).

  When combustion of the burner 12 is started, if the operation of switching to the inspection mode is not performed by the changeover switch 41 inside the apparatus housing 10, that is, the “normal mode” is selected, and the combustion prohibiting function of the burner 12 is activated. If it is valid, as an abnormal determination of the CO concentration in the combustion exhaust, it is determined whether or not the CO concentration detected by the CO sensor 27 is higher than the reference concentration and whether or not the CO concentration has reached a predetermined concentration. (ST7 to ST8).

  As a result, if the CO concentration is equal to or lower than the reference concentration and does not reach the predetermined concentration, whether or not the detected water amount of the water amount sensor 23 is less than the minimum working water amount is monitored as an instruction to stop the hot water supply. When the detected water amount becomes less than the minimum working water amount, the original gas solenoid valve 21 is closed, the burner 12 is extinguished, and the operation is terminated (ST9 to ST12).

  On the other hand, as a result of the determination of the CO concentration abnormality in ST8, if the CO concentration is equal to or lower than the reference concentration but has increased to a predetermined concentration (Yes in step ST10), the rotational speed of the fan motor 110 is increased and the burner is increased. The number of fan rotations to increase the amount of air supplied to 12 is corrected (ST13).

  If the CO concentration abnormality determination in ST8 is higher than the reference concentration (Yes in step ST9), the number of abnormalities of CO stored in the memory as being abnormal in CO concentration (in the initial operation start state, “ “0”) is added with “1”. If the number of CO abnormalities at this time does not reach the predetermined number N (here, “3”), the voice output unit (not shown) of the operation terminal 4 indicates that the combustion of the burner 12 is automatically stopped due to the CO concentration abnormality. In addition, the information is displayed from the display unit, the original gas solenoid valve 21 is closed, the burner 12 is automatically extinguished, and the process returns to step ST1 again (ST14 to ST15).

  When the number of CO abnormalities reaches the predetermined number N as a result of the repetition of steps ST1 to ST15 (Yes in step ST14), the operation terminal 4 indicates that the combustion of the burner 12 has been automatically stopped due to equipment abnormality. The sound output unit and the display unit are informed, the original gas solenoid valve 21 is closed, the burner 12 is automatically extinguished, and the combustion of the burner 12 is prohibited until the cancel switch 42 instructs to cancel the combustion prohibition. When the cancel switch 42 is instructed to cancel the combustion prohibition, the number of CO abnormalities is reset to “0”, and the process returns to the step ST1 (ST16, ST5).

  By the way, when the front plate of the apparatus housing 10 is opened in order to perform trial operation and maintenance at the time of construction, and the changeover switch 41 is operated to switch to the inspection mode, that is, the “inspection mode” is selected, and the burner 12 is selected. When the combustion prohibiting function is disabled (Yes in step ST7), the determination of the hot water supply stop instruction in ST11 is performed without performing the determination of abnormal CO concentration in ST8. That is, when the combustion prohibiting function of the burner 12 is disabled, even if the CO concentration increases, the fan rotation speed is not corrected, and the burner 12 is not automatically extinguished or prohibited from burning.

  Although not shown, when the combustion prohibiting function of the burner 12 is invalidated (Yes in step ST7), monitoring of the elapsed time from the time when the combustion prohibiting function is set invalid is started. When the elapsed time reaches a predetermined time (for example, 20 minutes), the combustion inhibition function is effectively restored.

  As described above, in the case of the combustion apparatus using the light and dark burner, not only when the air supplied into the combustion chamber 100 decreases and the gas concentration increases, but the air is supplied excessively into the combustion chamber 100. Even when the gas concentration is low, there is a risk of increasing the CO concentration in the combustion exhaust. However, according to the above embodiment, the normal mode is selected and the combustion prohibition function is enabled. If the CO concentration in the combustion exhaust of the burner 12 becomes higher than the reference value, the combustion of the burner 12 is prohibited. On the other hand, when the inspection mode is selected and the combustion prohibiting function is disabled, even if the CO concentration in the combustion exhaust of the burner 12 is higher than the reference value, the combustion of the burner 12 is not prohibited. Thereby, when performing a trial run and maintenance at the time of construction, it is possible to prevent the combustion of the burner from being unintentionally prohibited. Therefore, safety is high and usability is also good.

  In particular, in this case, the changeover switch 41 and the release switch 42 are incorporated in the apparatus housing 10, and the mode switching and the combustion prohibited state are canceled unless the front plate of the apparatus housing 10 is opened. Therefore, it is possible to prevent the burn-in prohibition function of the burner 12 from being invalidated even during a normal operation that is not a trial operation or maintenance. Further, when the burner 12 is in a combustion prohibited state during operation, it is possible to prevent the combustion prohibited state from being easily released. Therefore, safety is higher.

  By the way, in the case of the combustion apparatus having the above-described fan rotational speed correction function, whether the rotational speed adjustment operation of the air supply / exhaust fan 11 is during an abnormality in accordance with the increase in CO concentration, or the combustion amount of the burner 12 It is difficult to specify whether it is the normal time according to the change. For this reason, when an abnormality is determined during operation and inspection and repair are performed, the cause of the abnormal operation may not be completely removed, and the abnormality may be determined immediately after the operation is resumed. However, in this case, when the inspection mode is selected, even if the CO concentration in the combustion exhaust of the burner 12 rises above a predetermined value, the amount of air supplied into the apparatus housing 10 is not increased. It is possible to reliably detect an abnormality caused by the rise, and it is possible to further suppress an increase in the CO concentration in the combustion exhaust gas. Therefore, safety is much higher.

  In this case, if the predetermined time has elapsed after the burn-in prohibition function of the burner 12 is set to be invalid, the burn-in prohibition function is automatically returned to the valid state. It can be prevented, and there is no need to manually return the combustion prohibition function from invalid to valid. Therefore, safety is higher and usability is better.

  Furthermore, the combustion apparatus 1 is configured to take outdoor air from the supply pipe 101 into the apparatus housing 10 and discharge the outdoor air from the exhaust pipe 102 through the combustion chamber 100 together with the combustion exhaust of the burner 12. When the front plate of the apparatus housing 10 is opened, more air flows into the combustion chamber 100, and the increase in the CO concentration in the combustion exhaust of the burner 12 appears significantly. Therefore, the mode switching function is more useful.

  In the above-described embodiment, when the inspection mode is selected, combustion of the burner 12 is prohibited regardless of the CO concentration in the combustion exhaust gas by not performing the determination of abnormal CO concentration (step ST8) itself. However, when the inspection mode is selected, even if the CO concentration in the combustion exhaust gas is higher than the reference concentration, the combustion of the burner 12 is not prohibited by not counting the number of abnormal CO emissions. It may be configured as described above.

  Specifically, as shown in FIG. 3, when combustion of the burner 12 is started (ST6), the above-described CO concentration abnormality determination in ST8 is performed. When the CO concentration is higher than the reference concentration (Yes in step ST9), the “normal mode” is selected by the changeover switch 41, and the combustion prohibiting function of the burner 12 is valid (No in step ST21). The determination of the number of CO abnormalities in ST14 described above is performed. On the other hand, if the “inspection mode” is selected by the changeover switch 41 and the burn-in prohibition function of the burner 12 is invalid (Yes in step ST21), the determination of the CO abnormality frequency is not performed without determining the number of CO abnormalities. And automatic fire extinguishing of the burner 12 is performed. Thereby, the effect similar to the said embodiment is exhibited.

  In the above-described embodiment, when the CO concentration in the combustion exhaust of the burner 12 becomes higher than the reference concentration in the state where the normal mode is selected, the CO concentration abnormality is notified and the burner 12 is automatically extinguished. However, when the CO concentration in the combustion exhaust of the burner 12 is higher than the reference concentration in the state where the normal mode is selected, only the CO concentration abnormality is notified, and then the hot water supply stop instruction is given. The burner 12 may be configured to extinguish the fire.

  The CO sensor 27 is provided in the exhaust pipe 102 at a position in the vicinity of the connecting portion with the combustion chamber 100. However, if the CO concentration in the combustion exhaust discharged from the burner 12 can be accurately detected, the combustion chamber 100 is provided. It may be provided inside, or may be provided at a position further downstream than the connecting portion of the exhaust pipe 102.

  The present invention is not limited to the forced supply / exhaust type (FF type) combustion apparatus such as the combustion apparatus 1 described above, and indoor air is taken into the apparatus casing 10 from an air supply port opened in the apparatus casing 10. The present invention can also be applied to a forced exhaust type (FE type) combustion apparatus configured to discharge from the exhaust pipe 102 through the combustion chamber 100 together with the combustion exhaust of the burner 21. Moreover, this invention is applicable not only to a water heater, but to combustion apparatuses, such as a hot water supply heating source and a bath water heater.

DESCRIPTION OF SYMBOLS 1 Combustor 10 Apparatus housing 11 Supply / exhaust fan 12 Burner 13 Heat exchanger 20 Control circuit 27 CO sensor

Claims (4)

An apparatus housing having an openable / closable lid, a burner having a rich flame hole and a light flame hole, a CO sensor for detecting the CO concentration in the combustion exhaust of the burner, and when the CO concentration becomes higher than a reference A combustion apparatus comprising a combustion prohibiting function execution unit for prohibiting combustion of the burner and maintaining the burner in a combustion prohibited state until a predetermined release instruction is issued;
By disabling the combustion prohibition function and the normal mode for enabling the combustion prohibition function, the amount of air that flows into the device casing when the lid is opened increases, and combustion exhaust from the pale flame hole A combustion apparatus comprising a mode switching unit capable of selectively switching between an inspection mode in which burner combustion is not prohibited even when the concentration of CO in the interior becomes higher than a reference. An apparatus housing having an openable / closable lid, a burner having a rich flame hole and a light flame hole, a CO sensor for detecting the CO concentration in the combustion exhaust of the burner, and a CO concentration abnormality whose CO concentration is higher than a reference A combustion apparatus having a combustion prohibiting function execution unit for prohibiting combustion of the burner when the number of times reached reaches a predetermined number of times, and maintaining the burner in a combustion prohibited state until a predetermined release instruction is issued,
The normal mode for counting the number of times that the CO concentration has become abnormal and the count of the number of times that the CO concentration has become abnormal are not performed, thereby increasing the amount of air that flows into the device housing when the lid is opened. A combustion apparatus comprising a mode switching unit capable of selectively switching between an inspection mode in which combustion of the burner is not prohibited even if the CO concentration in the combustion exhaust gas from the pale flame hole becomes higher than a reference. The combustion apparatus according to claim 1 or 2,
A combustion apparatus configured to be able to perform switching between a normal mode and an inspection mode only when the lid is opened. The combustion apparatus according to any one of claims 1 to 3,
A combustion apparatus configured to take outdoor air from an air supply pipe into an apparatus housing and discharge the air from the exhaust pipe through the combustion chamber together with the combustion exhaust of the burner.

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