JP5818063B2 - Heat source machine - Google Patents

Description

  The present invention relates to a heat source apparatus having an exhaust part that communicates a combustion chamber containing a combustion burner and the outside, and more particularly to a heat source apparatus that can prevent combustion abnormality due to blockage of the exhaust part.

  2. Description of the Related Art A heat source apparatus that has a combustion chamber that contains a combustion burner and that ignites and burns the burner while supplying combustion air from the outside into the combustion chamber is widely known.

  In such a heat source machine, generally, combustion air is supplied to the combustion chamber in accordance with the amount of combustion of the burner, and combustion gas generated by the combustion of the burner is exhausted to the outside. That is, the heat source unit is formed with an air supply portion and an exhaust portion that communicate with the inside and outside of the housing, and an air flow path is formed from the air supply portion to the exhaust portion through the combustion chamber. While the burner is burning, an air flow is formed from the air supply unit side toward the exhaust unit side.

By the way, when actually operating this kind of heat source machine, it arrange | positions in the state which exposed a part or all of the air supply part (supply cylinder) and the exhaust part (exhaust pipe) outside. Moreover, the operation of the heat source machine may be stopped for a long time. In such a case, the air flow path may be blocked by birds or spiders forming a nest in the air supply / exhaust tube, or by clogging the air supply / exhaust tube with snow, dust, dust, etc. in winter. . If the flow passage cross-sectional area of the air flow passage is blocked by a predetermined amount or more due to some reason described above, there arises a problem that the substantial air flow passing through the combustion chamber is reduced. That is, the combustion air corresponding to the burner combustion amount cannot be supplied to the combustion chamber, and the air-fuel ratio does not become a normal value, so that a combustion failure such as incomplete combustion occurs.
Furthermore, when the combustion operation is performed in a state where the exhaust part is closed, a large amount of combustion gas that has not been exhausted to the outside may remain in the combustion chamber. If the combustion operation is temporarily stopped in this state and then the ignition operation is performed again on the burner, there is a problem that explosion ignition may occur.

As a technique for solving such a problem, there is a technique disclosed in Patent Document 1. In the combustion apparatus disclosed in Patent Document 1, the rotational speed of the blower operated during combustion is set lower than that of a general combustion apparatus. As a result, the amount of air supplied to the combustion chamber is smaller than that of a general combustion apparatus. For this reason, in the combustion device disclosed in Patent Document 1, when a blockage occurs at the air supply port (supply portion) or the exhaust port (exhaust portion), the amount of air supplied to the combustion chamber is further increased than that of a general combustion device. Less. As a result, the burner cannot be burned even when the amount of air supply or exhaust port blocking (blocking rate) is small. In other words, in the combustion device disclosed in Patent Document 1, when the air supply port or the exhaust port is clogged, the burner is not ignited or misfired even when the clogging amount is smaller than that of a general combustion device ( The flame goes out after the burner is ignited).
When the combustion detection means confirms that the burner is misfired or not ignited, the fuel supply to the burner is shut off and the combustion operation of the burner is stopped. That is, in the combustion apparatus disclosed in Patent Document 1, since the fuel supply to the burner is shut off even when the air supply port or the exhaust port is slightly blocked, the air supply port or the exhaust port is blocked. The burner will not burn in a hot state.

Japanese Patent No. 2820896

  By the way, in heavy snow areas where snow falls frequently in winter, the supply / exhaust section is more likely to be blocked due to snow accumulation and freezing than other areas. More specifically, an exhaust part that is often disposed partly or entirely outdoors may be blocked by snow accumulation or freezing at a relatively high frequency.

  Here, in the combustion apparatus disclosed in Patent Document 1, combustion of the burner is stopped even if the exhaust part is only slightly blocked. And if an exhaust part is obstruct | occluded, a combustion apparatus cannot be drive | operated until the cause (for example, snow etc.) of obstruction | occlusion is removed from an exhaust part. Therefore, in situations where exhaust blockages due to snow accumulation or freezing frequently occur, it is necessary to frequently remove snow and the like, which increases the burden on the operation of the combustion device. was there. For this reason, there has been a market desire to prevent the exhaust part from being blocked by snow and freezing. That is, in the conventional heat source machine including the combustion device disclosed in Patent Document 1, it is possible to prevent the burner from being burned in a state where the exhaust part is blocked, but it is possible to prevent the exhaust part from being blocked. could not.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a heat source machine that can prevent the exhaust part from being blocked due to snow accumulation, freezing, or the like.

The invention described in claim 1 for solving the above-described problem is provided with a burner accommodated in the combustion chamber, an exhaust section communicating with the outside and the combustion chamber, a blower, an outside air temperature detecting means, and an exhaust section of the exhaust section. Blockage detection means for detecting a blockage and a control device, and when the outside air temperature means detects a predetermined temperature or lower and the blockage detection means detects a blockage abnormality of the exhaust part, at least a blockage prevention operation is performed. The blockage prevention operation includes an operation accompanied by a combustion operation in which the burner burns, and the blockage prevention operation performs the operation of the blower without burning the burner, and thereafter It is a heat source machine characterized by performing both the combustion operation in which the burner burns and the operation of the blower .

  The heat source apparatus according to the present invention performs a blockage prevention operation in which at least a part of the exhaust section is blocked and the blockage state becomes abnormal when the temperature of the outside air is low, and at least the blower is operated. That is, in a situation where snow accumulation, freezing, etc. are likely to occur, when the blockage ratio of the exhaust part becomes high, air in the combustion chamber having a relatively higher temperature than the outside air can be blown to the exhaust part. As a result, the ice and snow inside the exhaust part can be melted, so that the exhaust part can be prevented from being blocked due to snow accumulation or freezing.

In the heat source apparatus of the present invention, the blocking prevention operation includes an operation accompanied by a combustion operation in which a burner burns .

  According to such a configuration, the blockage preventing operation is performed while the combustion operation for burning the burner is performed, so that the temperature in the combustion chamber when the blockage preventing operation is performed can be increased. Therefore, even if the temperature in the combustion chamber is low when the blockage preventing operation is started, the blockage preventing operation can be performed by increasing the temperature of the air in the combustion chamber. This makes it possible to blow air with higher temperature to the exhaust part more reliably.

Further heat source apparatus of the present invention, the closure preventing operation was performed the operation of the blower without burning the burner, it intends both rows and operation of the subsequent combustion operation of the burner burns in the blower.

  According to this configuration, after the operation of the blower is performed without burning the burner, the blocking prevention operation is performed in which both the combustion operation in which the burner burns and the operation of the blower are performed. As a result, even if the ice and snow inside the exhaust section cannot be melted only by operating the blower, higher temperature air is blown to the exhaust section by burning the burner and raising the temperature of the combustion chamber. can do. Therefore, the ice and snow inside the exhaust part can be melted more reliably.

According to a second aspect of the present invention, there is provided a burner accommodated in the combustion chamber, an exhaust section communicating with the outside and the combustion chamber, a blower, an outside air temperature detection means, and a blockage detection means for detecting blockage of the exhaust section. And a control device, and when the outside air temperature means detects a predetermined temperature or less and the blockage detection means detects a blockage abnormality of the exhaust part, at least a blockage prevention operation for operating the blower is performed. The combustion operation in which the burner burns and the condition of the blower on condition that a predetermined time or more has elapsed from the end of the previous burner combustion and / or the internal temperature of the combustion chamber has become a predetermined temperature or lower The condition is that the blockage prevention operation is performed together with the operation, and the predetermined time or more has not elapsed since the end of the previous burner combustion and / or the internal temperature of the combustion chamber is higher than the predetermined temperature. To the bar A heat source machine which comprises carrying out the blockage prevention operation for performing the operation of the blower without burning the.

According to the heat source apparatus of the present invention, when a predetermined time or more has elapsed from the end of combustion of the burner and it is predicted that the inside of the combustion chamber is relatively low temperature, or the internal temperature of the combustion chamber becomes a predetermined temperature or less. In this case, a blockage prevention operation is performed in which both the combustion operation in which the burner burns and the operation of the blower are performed. On the other hand, when the predetermined time or more has not elapsed since the end of combustion of the previous burner and the inside of the combustion chamber is predicted to be relatively hot, or the internal temperature of the combustion chamber is lower than the predetermined temperature. When it is large, blockage prevention operation is performed in which the blower is operated without burning the burner.
That is, the blockage prevention operation of the present invention includes the blockage prevention operation in which the blower is operated without burning the burner according to the internal temperature of the combustion chamber, and the blockage prevention operation in which the combustion operation in which the burner burns and the blower are both operated. You can switch between driving. Specifically, when the internal temperature of the combustion chamber is high, the air in the combustion chamber is relatively hot, so the blower is operated without burning the burner to exhaust the hot air in the combustion chamber. Ventilate to the part. On the other hand, when the internal temperature of the combustion chamber is low, the air in the combustion chamber is at a relatively low temperature, so that it is not possible to blow high-temperature air to the exhaust section only by operating the blower. Therefore, both the combustion operation in which the burner burns and the operation of the blower are performed to raise the internal temperature of the combustion chamber to generate high-temperature air in the combustion chamber and to blow the generated high-temperature air to the exhaust section. As described above, by performing the combustion operation only when the temperature in the combustion chamber is low, it is possible to perform the blockage prevention operation with higher energy efficiency compared to the case where the combustion operation and the operation of the blower are always performed together.

The invention according to claim 3, wherein the blower has a fan motor, said blockage detection means and detecting the closed state of the exhaust portion on the basis of the drive current value of the detected fan motor according Item 3. The heat source device according to Item 1 or 2 .

  The heat source device of the present invention may be configured to detect the closed state of the exhaust unit based on the drive current value of the fan motor provided in the blower. In other words, the configuration may be such that the blockage rate of the exhaust part is detected based on the drive current value of the fan motor.

According to a fourth aspect of the present invention, when the blockage detection means detects an increase in the drive current value during or after the blockage prevention operation, the blockage prevention operation is continued until the drive current value reaches a predetermined current value. The heat source device according to claim 3 , wherein the heat source device is a heat source device.

According to this configuration, when an increase in the drive current value is detected by performing the blocking prevention operation, that is, when the blocking ratio of the exhaust unit is reduced by performing the blocking prevention operation, the blocking prevention operation is continuously performed. To do. At this time, the blockage prevention operation is continued until the drive current value reaches a predetermined current value, that is, until the blockage rate of the exhaust portion reaches a predetermined blockage rate. That is, when the blocking prevention operation is performed and the blocking ratio of the exhaust part is reduced, the blocking prevention operation is continued until the predetermined blocking ratio is reached.
More specifically, when the blockage rate of the exhaust unit is reduced by performing the blockage prevention operation, there is a high possibility that the exhaust unit is blocked due to snow accumulation or freezing. Therefore, if the blocking prevention operation is continued in such a case, the blocking ratio of the exhaust part can be reduced with a high probability. At this time, the blockage prevention operation is continued until the blockage rate of the exhaust part reaches a predetermined blockage rate. Thereby, the obstruction | occlusion thing (snow and ice) in an exhaust part does not remain excessively.

According to the fifth aspect of the present invention, when the blockage detection means detects a decrease in the drive current value, the blockage prevention operation for performing both the combustion operation in which the burner burns and the operation of the blower is performed for a predetermined time. The heat source apparatus according to claim 3 or 4 , wherein combustion of the burner is stopped when the drive current value does not increase by a predetermined amount or more within a predetermined time.

  According to such a configuration, when the blockage detection unit detects a decrease in the drive current value, that is, when the blockage ratio of the exhaust part increases, the blockage prevention operation that performs both the combustion operation in which the burner burns and the operation of the blower is performed. Conduct for a predetermined time. At this time, if the drive current value does not increase by a predetermined amount or more within a predetermined time, combustion of the burner is stopped. More specifically, when the blockage rate of the exhaust part increases, there is a high possibility that snow accumulation in the exhaust part has progressed, and it is necessary to blow snow at a higher temperature to the exhaust part to melt the snow etc. There is. Therefore, the blocking prevention operation for performing both the combustion operation in which the burner burns and the blower operation is performed for a predetermined time. However, if the drive current value does not increase more than a predetermined amount even after the blocking prevention operation is performed for a predetermined time, that is, if the blocking ratio is not reduced by a predetermined amount even if the blocking prevention operation is performed for a predetermined time, The exhaust part may be blocked due to causes other than freezing. Therefore, in that case, combustion of the burner is stopped in order to prevent combustion failure such as incomplete combustion and explosion ignition. As a result, it is possible to reliably prevent the exhaust portion from being blocked due to snow accumulation, freezing, etc., and even if the exhaust portion is blocked due to snow accumulation, freezing, etc., the burner remains closed. It is possible to prevent inconvenience caused by burning.

A sixth aspect of the present invention is the heat source apparatus according to any one of the first to fifth aspects , further comprising a circulation circuit in which the heat medium circulates.

  The heat source machine of the present invention may be a heat source machine having a circulation circuit through which a heat medium circulates.

  The heat source machine of the present invention blows air in the combustion chamber having a relatively high temperature compared to the outside air to the exhaust part when the blockage ratio of the exhaust part becomes high in a situation where snow or freezing is likely to occur. Can do. As a result, the ice and snow inside the exhaust section can be melted, so that the exhaust section can be prevented from being blocked due to snow accumulation, freezing, and the like.

It is an operation principle figure showing a heat source machine concerning an embodiment of the present invention. It is a flowchart which shows the procedure of the obstruction | occlusion prevention control of the heat-source equipment of FIG. In the heat source apparatus of FIG. 1, the exhaust part is completely open, the exhaust part is closed so that the blockage rate of the exhaust part becomes the limit of the burner combustion possible range, and the exhaust part is completely It is explanatory drawing which shows the relationship between the rotation speed of the air blower in the state obstruct | occluded by, and the drive current value of a fan motor.

Embodiments of the present invention will be further described below.
As shown in FIG. 1, the combustion apparatus 1 (heat source machine) of this embodiment is connected to a hot water supply circuit 2 through which hot water flows through a hot water tap or the like (not shown), and hot water or a heat medium connected to an external heating device (not shown). The heating circuit 3 (circulation circuit) through which the water flows is provided, and the hot water or the heat medium flowing through the circuits 2 and 3 can be heated to the target temperature. That is, the combustion apparatus 1 has a hot water supply combustion section 7 and a heating combustion section 8 that can be independently controlled in combustion inside one can body 5 (combustion chamber), and is generated in the hot water combustion section 7. Hot water flowing through the hot water supply circuit 2 can be heated by the combustion gas, and hot water or a heat medium flowing through the heating circuit 3 can be heated by the combustion gas generated in the heating combustion section 8.
In addition, since the circuit structure of the hot water supply circuit 2 and the heating circuit 3 connected to the combustion apparatus 1 of this embodiment is well-known, description is abbreviate | omitted.

  The can body 5 is provided with a hot water supply side heat exchanging portion 11 and a heating side heat exchanging portion 12 therein, and one blower 10 for supplying air is attached to the two combustion portions 7 and 8. It is the structure which was made.

  In addition, a partition plate 14 that divides the gas flow path is provided in the can 5 with reference to the boundary between the hot water combustion unit 7 and the heating combustion unit 8, and the hot water supply side through which air and combustion gas flow is provided. An exhaust passage 16 and a heating side exhaust passage 17 are formed. A hot water supply side heat exchange unit 11 is arranged in the middle of the hot water supply side exhaust flow path 16, and a heating side heat exchange unit 12 is arranged in the middle of the heating side exhaust flow path 17. In addition, the hot water supply side exhaust flow channel 16 and the heating side exhaust flow channel 17 merge on the downstream side in the flow direction of air and combustion gas, and both are continuous with the common exhaust flow channel 18 (exhaust part).

That is, the combustion apparatus 1 of the present embodiment takes in the outside air from the common air supply passage 15 (not shown in FIG. 1 where the connecting portion to the can body 5 is omitted) by operating the blower 10. The can 5 can be supplied. Then, the taken-out outside air is supplied to one or both of the hot water supply combustion section 7 and the heating combustion section 8, and either one or both of the hot water supply side exhaust flow path 16 and the heating side exhaust flow path 17 is allowed to pass through. After that, the common exhaust passage 18 can be exhausted.
Here, the common air supply passage 15 and the common exhaust passage 18 are air supply and exhaust cylinders that are integrally attached to the can 5. And the common air supply flow path 15 and the common exhaust flow path 18 are arranged so that at least a part thereof is exposed to the outdoors. An outside air temperature detecting means 19 is attached to the common supply air flow path 15.

  The outside air temperature detection means 19 is a known thermistor and can acquire the ambient temperature of the place (space) where the combustion apparatus 1 is installed.

  Each of the hot water supply combustion section 7 and the heating combustion section 8 includes a plurality of burners 21 that burn fuel gas and an ignition device 22, and the burner sensor 23 is provided only in the heating combustion section 8. Yes. The burner sensor 23 is a thermocouple, and a tip is arranged near the flame hole of the burner 21 so that the temperature of the inner flame of the flame can be detected.

  The hot water combustion section 7 and the heating combustion section 8 are each provided with a plurality of electromagnetic valves 25 capable of restricting and blocking the supply of the fuel gas to the burner 21, and the flow direction of the fuel gas from the electromagnetic valve 25. A gas proportional valve 26 capable of adjusting the flow rate of the fuel gas is provided on the upstream side. The plurality of solenoid valves 25 and the gas proportional valve 26 are arranged in series in the flow path through which the fuel gas flows.

  The hot water supply side heat exchange unit 11 and the heating side heat exchange unit 12 are both primary heat exchangers 11a and 12a that mainly recover sensible heat of the combustion gas, and secondary heat exchangers that mainly recover the latent heat of the combustion gas. 11b and 12b. The primary heat exchangers 11a and 12a are located upstream of the secondary heat exchangers 11b and 12b in the flow direction of the combustion gas, and are connected in series with each other.

  The blower 10 includes a fan motor (not shown), a rotation speed detection means (not shown) that detects the rotation speed of the fan motor, and a current detection means (not shown) that detects the current value of the motor. Yes. The fan motor of this embodiment is a DC motor driven by a direct current, and the rotation speed detection means is a Hall element that detects a magnetic field generated by a rotating magnet built in the motor, and the current detection means. Is a current sensor equipped with a Hall element.

  Moreover, the combustion apparatus 1 of this embodiment is provided with the control apparatus 30, and operation | movement of each apparatus is controlled by the control apparatus 30. FIG.

  Specifically, the control device 30 can acquire signals from various temperature sensors (outside air temperature detection means 19, burner sensor 23) provided in the combustion apparatus 1, current detection means, rotation speed detection means, and the like of the blower 10. It has become. As a result, the control device 30 detects the presence or absence of flames in the burner 21, the amount of combustion of a plurality or individual burners 21, the internal temperature of the can 5, the ambient temperature of the place where the combustion device 1 is installed, Information such as the driving current value of the fan motor and the rotation speed of the fan motor during operation can be acquired. And the control apparatus 30 is provided with memory | storage means, such as EEPROM which is not shown in figure, can memorize | store the acquired information, and can control each part of the combustion apparatus 1 based on the acquired information.

  Furthermore, the control device 30 is connected to the fan motor of the blower 10 and can vary the rotation speed of the fan motor of the blower 10.

  The control device 30 is connected to the burner 21, various control valves such as an electromagnetic valve 25 and a gas proportional valve 26 provided in a gas supply path for supplying fuel gas to the burner 21, and the ignition device 22. As a result, a combustion start operation, a combustion stop operation, and an operation for increasing or decreasing the combustion amount can be performed on the burner 21.

Then, the operation | movement in the combustion apparatus 1 of this embodiment is demonstrated.
Combustion device 1 includes a single hot water supply operation for performing only a hot water supply operation, a single heating operation for heating only hot water or a heat medium supplied to an external heating device, and a combined hot water supply and heating operation for performing both hot water supply operation and heating operation simultaneously. It is set as the structure which can implement three driving | operation consisting of.

  The hot water supply single operation is an operation in which hot water supplied to the hot water supply circuit 2 is heated from a water supply source (not shown) and hot water supplied from a hot water tap such as a currant or shower is supplied. More specifically, when hot water is supplied to a hot water supply circuit 2 from a water supply source (not shown), a pre-purge is performed in which the blower 10 blows air for a certain period of time. When the pre-purge ends, the blower 10 is controlled to a target rotational speed based on the combustion amount. At the same time, fuel gas is supplied to the hot water supply combustion section 7, and ignition by the ignition device 22 is performed on the burner 21 of the hot water combustion section 7 so that the combustion operation of the hot water supply combustion section 7 is performed. Is done. The hot water flowing through the hot water supply side heat exchange unit 11 is heated by the combustion gas generated by this. The hot water heated by the hot water supply side heat exchanging section 11 is mixed with hot water supplied from a water supply source (not shown) on the downstream side, adjusted to an appropriate temperature, and discharged from the hot water tap.

  The heating single operation is an operation in which hot water or a heat medium (hereinafter referred to as hot water) supplied to an external heating device is heated without heating hot water for hot water supply. More specifically, when an external heating device is operated, the heating circulation pump 32 in the heating circuit 3 is driven, and hot water introduced into the combustion device 1 by a sensor provided on the heating circuit 3. Temperature is detected. Then, the information is transmitted to the control device 30, and the combustion operation in the heating combustion unit 8 is started based on the preset target temperature and the current hot water temperature. The combustion operation in the heating combustion section 8 and the hot water heating method in the heating side heat exchange section 12 are the same as the combustion operation in the hot water combustion section 7 and the hot water heating method in the hot water supply heat exchange section 11. Therefore, a duplicate description is omitted. Moreover, as a heating apparatus, there exist some which require high temperature (for example, 80 degree Celsius) hot water, such as a fan convector, and those which require relatively low temperature (for example, 60 degree Celsius) hot water, such as a floor heating appliance. Further, in this heating independent operation, a combustion operation for performing combustion in the burner 21 and a combustion stop operation for temporarily stopping combustion in the burner 21 may be intermittently performed.

  The hot water supply / heating combined operation is an operation in which the operation of a single hot water supply operation for heating hot water for hot water supply and the operation in a single heating operation for heating hot water supplied to a heating device are controlled simultaneously. In addition, since each operation | movement of the combustion apparatus 1 in a hot water supply / heating combined use operation can apply the above-mentioned description, description is abbreviate | omitted.

  Here, as described above, a part of the common exhaust passage 18 is exposed to the outdoors. For this reason, when the combustion apparatus 1 is used in a cold region, there is a concern that the snow or the like blown into the common exhaust passage 18 may be clogged due to snow accumulation or freezing. Therefore, in the combustion apparatus 1 of the present embodiment, blockage prevention control is performed in order to prevent a large blockage in the common exhaust passage 18 due to snow accumulation or freezing. The blockage prevention control, which is a characteristic operation of the present embodiment, will be described in detail below.

  In the blockage prevention control of the present embodiment, in a situation where the common exhaust flow path 18 is predicted to be blocked due to snow accumulation or freezing, high temperature air (or combustion gas) inside the can 5 is discharged to the common exhaust flow path. By blowing to 18, snow or the like blown into the common exhaust flow path 18 before the common exhaust flow path 18 is completely closed can be melted. This will be described in detail with reference to FIG.

  In the blockage prevention control of the present embodiment, when the outside air temperature Tx detected by the outside air temperature detecting means 19 becomes equal to or lower than the specified temperature Ty (Yes in Step 1), the process proceeds to Step 2. Then, whether the specified time t1 has elapsed since the combustion of the burner 21 in the hot water combustion unit 7 and the heating combustion unit 8 has ended, or the specified time t1 has elapsed since the scavenging operation in the previous blockage prevention control. It is determined whether or not.

  Then, the time elapsed since the combustion operation of the burner 21 in the combustion section 7 for hot water supply was completed, the time elapsed after the combustion operation of the burner 21 in the heating combustion section 8 was completed, and the blockage prevention control was performed previously. When all of the elapsed time since the scavenging operation is equal to or longer than the specified time t1 (Yes in Step 2), the process proceeds to Step 3 to perform the scavenging operation in which the blower 10 is operated at the rotation speed Nx. .

  That is, in the blockage prevention control according to the present embodiment, the outside air temperature is low (Yes in Step 1), and the specified time t1 has elapsed from the state where the common exhaust flow path 18 is not blocked by snow or freezing (Yes in Step 2). The scavenging operation is carried out on the condition (step 3). More specifically, when the outside air temperature is high, there is a high possibility that the blockage of the common exhaust flow path 18 (hereinafter referred to as ice / snow blockage) due to snow accumulation or freezing has not occurred. Further, when the combustion operation is performed by the burner 21, there is a high possibility that no ice / snow blockage has occurred. In addition, when the blockage prevention control is performed, there is a high possibility that the ice / snow blockage is resolved. That is, in the blockage prevention control of the present embodiment, it is determined that the ice / snow is not blocked when the outside air temperature is high, or when the combustion operation or the blockage prevention control is performed. Further, it is determined that the ice / snow blockage does not occur during the specified time t1 from the state where the ice / snow blockage is not performed. On the other hand, when the outside air temperature is low and the specified time t1 has elapsed since the ice / snow is not blocked, there is a possibility that the ice / snow is blocked. In this case, the process proceeds to step 3 and the scavenging operation is performed.

  When the scavenging operation is completed, the routine proceeds to step 4, where the driving current value Ix1 during the scavenging operation in step 3 and the driving current of the fan motor when the blower 10 is operated at the rotation speed Nx during the previous combustion operation. The value Iy is compared.

  More specifically, the drive current value Iy to be compared with the drive current value Ix1 during the scavenging operation is previously subjected to the combustion operation in one or both of the hot water supply combustion section 7 and the heating combustion section 8. In this case, the driving current value of the fan motor when the blower 10 is operated together with the combustion operation in the burner 21 is obtained. That is, in the present embodiment, when the combustion operation is performed in the combustion units 7 and 8, the control device 30 can store the rotational speed and drive current value of the fan motor during the combustion operation. At this time, when the rotational speed of the blower 10 during the combustion operation is changed due to an increase or decrease in the amount of combustion in the combustion units 7 and 8, a drive current value corresponding to the changed rotational speed can be stored. . In other words, the combustion apparatus 1 can store a drive current value corresponding to the number of rotations of the fan motor during the combustion operation.

  Further, the drive current value Iy to be compared is the drive current value of the fan motor when the blower 10 is operated at the same rotational speed Nx as the scavenging operation in Step 3. That is, the drive current value Iy is the drive current value of the fan motor when the blower 10 is operated at the rotational speed Nx during the combustion operation in the burner 21. Here, as described above, there is a high possibility that ice / snow blockage does not occur during the combustion operation. The drive current value of the fan motor increases when the blockage rate (flow channel resistance) of the common exhaust flow path 18 decreases and the blockage rate (flow path resistance) increases when the rotation speed is the same. Descend. That is, in the combustion apparatus 1 of the present embodiment, the current drive current value Ix1 is compared with the drive current value Iy at the same rotation speed Nx in a state where no ice / snow blockage occurs (step 4), thereby The common exhaust flow path 18 is closed (flow resistance increase / decrease change degree) is detected (blockage detecting means).

In step 4, when the drive current value Ix1 during the scavenging operation is not lower than the drive current value Iy at the same rotational speed Nx during the previous combustion operation by a predetermined ratio (D%) or more, that is, the following formula (1 ):
Ix1 ≦ (1-0.01 * D) * Iy (1)
If the above relationship is not satisfied (No in step 4), it is determined that the common exhaust flow path 18 is sufficiently open, and the blocking prevention operation is not performed.

  On the other hand, when the drive current value Ix1 during the scavenging operation is lower than the drive current value Iy at the same rotation speed Nx during the previous combustion operation by a predetermined ratio (D%) or more in step 4, that is, the above formula When the relationship of (1) is satisfied (Yes in Step 4), it is determined that a blockage abnormality may have occurred in the common exhaust flow path 18, and the process proceeds to Step 5, where the common exhaust flow The blockage status of the road 18 is confirmed.

  Specifically, in step 5, it is determined whether or not the drive current value Ix1 during the scavenging operation exceeds the reference drive current value Iz. Here, the reference drive current value Iz is a fan motor when the blower 10 is operated at the rotational speed Nx under the condition that the blockage rate of the common exhaust passage 18 is a predetermined value X (for example, 90%). Drive current value. And the blockage rate X (for example, 90%) of the common exhaust flow path 18 at this time is an upper limit value of the blockage rate at which the burner 21 can burn. This will be described in detail below.

  For example, it is assumed that the common exhaust flow path 18 is gradually closed due to snow or the like blowing into the common exhaust flow path 18 and being accumulated. At this time, from the state where the common exhaust flow path 18 is completely opened (state where the blockage rate is 0%) to the state where the common exhaust flow path 18 is completely closed (state where the blockage rate is 100%). The occlusion rate gradually increases. Here, even if the blockage rate increases and the air supply amount to the burner 21 decreases, if the blockage rate does not exceed a certain value (for example, 90%), combustion operation with the burner 21 is possible. It has become. That is, even if the air supply amount decreases, as long as the air supply amount to the burner 21 does not fall below a certain amount, although the air-fuel ratio changes to the fuel rich side, the combustion operation in the burner 21 can be continued. ing. On the other hand, when the blockage rate exceeds a certain value (for example, 90%) and the air supply amount to the burner 21 falls below a certain amount, misfire or misfire occurs in the burner 21 due to insufficient air amount. The combustion operation with the burner 21 cannot be performed. In other words, if the blockage rate of the common exhaust flow path 18 is within a predetermined range (for example, 0% to 90%), the combustion operation with the burner 21 is possible.

  Here, as described above, the drive current value Iz used as a reference when checking the blockage state in the present embodiment is the same as the rotation speed Nx of the blower 10 in the scavenging operation in the state of the blockage rate X (for example, 90%). This is the drive current value Iz when operating with. And the above-mentioned blockage rate X (for example, 90%) is the same as the upper limit value (for example, 90%) of the range of the blockage rate in which the combustion operation with this burner 21 is possible. From this, this drive current value Iz is the same as the drive current value Iz when supplying the lowest amount of air supply that can be performed by the burner 21 when the blower 10 is operated at the rotational speed Nx. Become. In other words, when the blower 10 is operated at the rotation speed Nx, the lower limit value of the drive current value of the blower 10 at which the combustion operation with the burner 21 can be performed.

  In step 5, it is determined whether or not the drive current value Ix1 during the scavenging operation exceeds the reference drive current value Iz. That is, it is determined whether or not the drive current value Ix1 of the blower 10 during the scavenging operation is a drive current value at which the burner 21 can perform the combustion operation.

  At this time, when the drive current value Ix1 during the scavenging operation exceeds the reference drive current value Iz (Yes in Step 5), the process proceeds to Step 6 and the blockage preventing operation is performed. On the other hand, when the drive current value Ix1 during the scavenging operation is equal to or less than the reference drive current value Iz (in the case of No in step 5), the combustion operation with the burner 21 is already blocked. It judges that it is a thing, and transfers to step 9. Then, in step 9, the blockage abnormality is notified, stored, transmitted to another device (not shown), and the blockage prevention control is terminated.

Steps 4 and 5 will now be described more specifically with reference to FIGS.
Assume that the rotational current Nx is 3000 rpm and the fan motor drive current value Iy is 600 mA when the blower 10 is operated at 3000 rpm in a state where the common exhaust passage 18 is completely opened. Further, it is assumed that the fan motor drive current value Iz is 400 mA when the blower 10 is operated at 3000 rpm in a state in which the common exhaust flow path 18 is closed by the closing rate X (for example, 90%). Further, it is assumed that the predetermined ratio D is 20% and the drive current value Ix1 during the scavenging operation is 470 mA.

  In this case, the drive current value Ix1 (470 mA) during the scavenging operation is lower than the drive current value Iy (600 mA) of the fan motor in a fully opened state by D% (20%) or more (decreased by 120 mA or more). Therefore, it is determined that there is a possibility that a blockage abnormality has occurred in the common exhaust flow path 18 (Yes in step 4). In addition, since the drive current value Ix1 (470 mA) during the scavenging operation is equal to or greater than the drive current value Iz (400 mA) of the fan motor in a state where the common exhaust passage 18 is closed by the closing rate X (for example, 90%), It is determined that the drive current value is feasible (Yes in step 5).

  At this time, as shown in FIG. 3, the drive current value Ix1 during the scavenging operation is equal to the drive current value Iy of the fan motor in a state where the blockage rate is 0% (a state where the common exhaust passage 18 is completely opened). The value is between the drive current values Iz of the fan motor in the state of the blockage rate X (for example, 90%). That is, the curve L1 showing the relationship between the fan speed and the drive current value in the state where the blockage rate is 0%, and the curve L2 showing the relationship between the fan speed and the drive current value in the state where the blockage rate is X (for example, 90%). Located in the range between. Here, the drive current value Ix1 during the scavenging operation varies in a range between the curve L1 and the curve L3 indicating the relationship between the fan rotation speed and the drive current value in a state where the blockage rate is 100%. The range between the curves L1 and L2 is a range in which the burner 21 can burn, and the range between the curves L2 and L3 is a range in which the burner 21 cannot burn. That is, when the answer is Yes in Step 5, the drive current value Ix1 during the scavenging operation is located in a range between the curves L1 and L2, and when the answer is No in Step 5, the drive current value Ix1 during the scavenging operation. Is located in a range between the curve L2 and the curve L3. As a matter of course, the same applies to the case where the rotational speed of the fan changes from 3000 rpm.

  In other words, the common exhaust passage 18 is blocked by a certain amount or more (in the case of Yes in step 4), and the closing rate of the common exhaust passage 18 is within a range in which the combustion operation with the burner 21 is possible, and is excessively blocked. On condition that there is nothing (in the case of Yes in Step 5), the process proceeds to Step 6 to perform the blocking prevention operation.

  In the blocking prevention operation of the present embodiment, the burner 21 is burned in one or both of the hot water supply combustion section 7 and the heating combustion section 8, and the blower 10 is operated. As a result, high-temperature air in the can 5 is blown to the common exhaust passage 18 to melt snow and the like in the common exhaust passage 18.

  Then, during the blocking prevention operation, an operation of acquiring the drive current value Ix2 is performed at regular time intervals (or always). Then, the acquired drive current value and a reference drive current value (for example, the drive current value Ix1 before the start of the blocking prevention operation or the previous drive current value Ix2 acquired when the operation of the previous step 7 was performed) and Compare. And it is discriminate | determined whether the drive current value Ix2 after implementing the acquired obstruction | occlusion prevention driving | operation increased from the drive current value before implementation of the obstruction | occlusion prevention driving | operation (step 7).

  At this time, if the drive current value does not increase even when the blocking prevention operation is performed (No in Step 7), that is, the blocking abnormality of the common exhaust passage 18 is improved even if the blocking prevention operation is performed. If not, it is determined that the blockage abnormality of the common exhaust flow path 18 is not caused by snow accumulation, freezing, or the like, and the process proceeds to step 9. Then, in step 9, the blockage abnormality is notified, stored, transmitted to another device (not shown), and the blockage prevention control is terminated.

  On the other hand, when the drive current value is increased by performing the blockage prevention operation (Yes in step 7), that is, when the blockage abnormality of the common exhaust passage 18 is improved by performing the blockage prevention operation. Then, it is determined that snow cover, freezing, etc. are melted and the blockage abnormality of the common exhaust passage 18 is improved, and the routine proceeds to step 8.

  In step 8, the drive current value Ix2 acquired after the blockage preventing operation is performed is driven when the common exhaust passage 18 is driven at the same rotation speed in a state where the common exhaust passage 18 is not blocked (a state where the blockage rate is 0%). It is determined whether or not the current value Iy has been reached. Then, when the drive current value Ix2 acquired after the blockage prevention operation is performed is the same as the drive current value Iy in a state where the blockage prevention operation is not performed (Yes in Step 8), that is, the blockage is performed after the blockage prevention operation is performed. If no abnormality is detected, it is determined that the blockage abnormality of the common exhaust passage 18 due to snow accumulation, freezing, or the like has been resolved, and the blockage prevention control is terminated.

  On the other hand, when the drive current value Ix2 after execution of the blocking prevention operation is not the same as the drive current value Iy in the non-blocked state (No in step 8), the operations of step 6 and step 7 are performed. repeat. Above, description of the obstruction | occlusion prevention control of this embodiment is complete | finished.

  In the above-described embodiment, the heat source unit 1 including the can 5 (combustion chamber) in which the combustion units 7 and 8 including the burner 21 and the ignition device 22 and the heat exchange units 11 and 12 are integrated has been described. However, the heat source apparatus of the present invention is not limited to this. For example, a structure (combustion chamber) containing at least a combustion part including a burner and a case containing a heat exchange part may be provided separately, and a part of each case may be continuous.

  Further, in the above-described embodiment, a so-called single-can two-water combustion apparatus provided with two combustion sections and two heat exchange sections has been described. However, the heat source apparatus of the present invention is not limited to this. For example, the hot water supply apparatus provided with the combustion part and the heat exchange part 1 each may be sufficient. In addition, as in a so-called two-can two-water combustion apparatus, combustion is provided with a plurality of combustion gas passages through which combustion gas generated in the combustion section flows, and each combustion gas passage is provided in a separate can body. It may be a device.

  The heat source apparatus of the present invention may be a so-called FF type hot air heating apparatus. That is, the heat source machine of the present invention may be a heat source machine that does not have a heat exchange unit. The heat source device of the present invention may be a heat source device in which the heat source device main body is arranged outdoors. The heat source device main body is arranged in the room, and air is supplied or exhausted from outside through an air supply / exhaust cylinder or the like. It may be a heat source machine. Therefore, the supply / exhaust tube may be configured to be provided inside the housing of the heat source device main body, or may be configured to be continuous with the housing of the heat source device main body and extend outward.

  Further, the outside air temperature detecting means of the heat source machine of the present invention may be provided either inside or outside the housing of the heat source machine body. The outdoor ambient temperature or a temperature equivalent to it (for example, when the main body of a heat source is installed in a building constructed separately from a house such as a barn) may be provided at a position where it can be detected. . In the case where it is provided inside the housing, the blower is operated and the outside air temperature is detected after the outside air is taken into the housing.

  In the above-described embodiment, the blocking prevention operation in which both the combustion operation by the burner 21 and the operation of the blower are performed, but the blocking prevention operation of the present invention is not limited to this. For example, the internal temperature of the combustion chamber (can 5) may be acquired by a predetermined sensor such as a burner sensor 23 (thermocouple), and different blockage prevention operations may be performed according to the acquired temperature. Specifically, when the internal temperature of the combustion chamber is high, a blocking prevention operation (hereinafter referred to as a first blocking prevention operation) in which the blower is operated without burning the burner is performed, and the internal temperature of the combustion chamber is low. In this case, a configuration may be employed in which a blocking prevention operation (hereinafter referred to as a second blocking prevention operation) in which both the combustion operation by the burner and the operation of the blower are performed is performed.

  Furthermore, the second blocking prevention operation may be performed at the start of the blocking prevention operation, and the first blocking prevention operation may be performed after a predetermined time has elapsed from the start of the blocking prevention operation. That is, until the internal temperature of the combustion chamber rises, the second blockage prevention operation involving combustion of the burner is performed, and when the internal temperature of the combustion chamber sufficiently rises due to combustion of the burner, the first blockage prevention operation is performed. It may be configured to switch.

  On the other hand, the first blocking prevention operation may be performed at the start of the blocking prevention operation, and the second blocking prevention operation may be performed after a predetermined time has elapsed from the start of the blocking prevention operation. That is, if the drive current value does not increase even if the first blockage prevention operation without burning the burner is performed and the improvement of the blockage is not recognized, the configuration is switched to the second blockage prevention operation with the burner combustion operation. There may be.

  That is, the blockage prevention operation of the present invention includes the blockage prevention operation with the burner combustion operation and the burner without burning depending on conditions such as the internal temperature of the combustion chamber, the blockage state of the supply / exhaust cylinder, the outside air temperature, and the like. It is possible to switch between the blocking prevention operation for operating the blower.

  In the above-described embodiment, the blockage detection unit that detects the blockage state of the common exhaust flow path 18 by comparing the drive current values of the fan motor has been described. However, the blockage detection unit employed in the heat source apparatus of the present invention is the same. It is not limited to. For example, a configuration in which the blockage state of the common exhaust flow path 18 is detected by a wind pressure switch, a wind pressure sensor, or the like may be used. That is, the blockage detection means employed in the heat source apparatus of the present invention only needs to be able to detect the blockage state of the common exhaust flow path 18.

1 Combustion device (heat source machine)
3 Heating circuit (circulation circuit)
5 Can body (combustion chamber)
10 Blower 18 Common exhaust flow path (exhaust section)
19 Outside air temperature detection means 21 Burner 30 Control device

Claims (6)

A burner housed in the combustion chamber, an exhaust section communicating with the outside and the combustion chamber, a blower, an outside air temperature detection means, a blockage detection means for detecting blockage of the exhaust section, and a control device, When the outside air temperature means detects a predetermined temperature or less and the blockage detection means detects a blockage abnormality of the exhaust part, at least a blockage prevention operation for operating the blower is performed.
The blocking prevention operation includes an operation accompanied by a combustion operation in which a burner burns,
In the blockage prevention operation, the blower is operated without burning the burner, and then the combustion operation in which the burner burns and the operation of the blower are performed together . A burner housed in the combustion chamber, an exhaust section communicating with the outside and the combustion chamber, a blower, an outside air temperature detection means, a blockage detection means for detecting blockage of the exhaust section, and a control device, When the outside air temperature means detects a predetermined temperature or less and the blockage detection means detects a blockage abnormality of the exhaust part, at least a blockage prevention operation for operating the blower is performed.
Combustion operation in which the burner burns and operation of the blower on condition that a predetermined time or more has elapsed from the end of the previous burner combustion and / or the internal temperature of the combustion chamber has become a predetermined temperature or less. To implement a blockage prevention operation
The blower is operated without burning the burner on the condition that the predetermined time or more has not elapsed since the end of the previous burner combustion and / or the internal temperature of the combustion chamber is higher than the predetermined temperature. A heat source machine characterized by performing an obstruction prevention operation. The blower includes a fan motor,
3. The heat source apparatus according to claim 1, wherein the blockage detection unit detects a blockage state of the exhaust part based on the detected drive current value of the fan motor. After Ongoing or implementation of the closure preventive operation, if the blockage detection means detects an increase in drive current value, according to claim 3 in which the driving current value is equal to or to continue the closure preventive operation up to a predetermined current value The heat source machine described in 1. When the blockage detection means detects a decrease in the drive current value, the blockage prevention operation is performed for a predetermined time in which both the combustion operation in which the burner burns and the operation of the blower are performed, and the drive current value falls within the predetermined time. The heat source apparatus according to claim 3 or 4 , wherein combustion of the burner is stopped when it does not rise above a predetermined amount . The heat source apparatus according to any one of claims 1 to 5, further comprising a circulation circuit through which the heat medium circulates.

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