JP5018200B2 - Combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus used for combustion at a predetermined air-fuel ratio by supplying combustion air from one air supply source to two combustible parts that can burn independently of each other, and more particularly The present invention relates to a technique for performing control so as to maintain an appropriate combustion state even if the flow path falls into a blocking tendency and the flow path resistance increases.

  Conventionally, the flow path resistance of the exhaust passage of combustion exhaust gas is detected based on the relationship between the fan current value for the fan motor of the blower fan that supplies combustion air in the combustion device and the rotational speed of the fan motor, There is known a method for controlling the rotational speed of a fan motor so that the supply amount of combustion air becomes an optimum amount (see, for example, Patent Document 1 or Patent Document 2). This is because even if the flow resistance of the exhaust passage increases due to repeated combustion operations, the supply amount of combustion air is adjusted and controlled so that a predetermined air-fuel ratio can be secured and an appropriate combustion state can be maintained. To do.

JP 9-329331 A

Japanese Patent Laid-Open No. 10-220741

  By the way, as a combustion device, for example, a combustion section for hot water supply and a heating combustion section for circulating a heating medium such as hot water as a heat source for heating are provided. There is one configured to supply combustion air to one part by one blower fan. In such a configuration, the flow resistance increase characteristic in the exhaust passage is different, so that adjustment control of the air supply amount to the other combustion section under the influence of one flow path resistance increase, that is, the other combustion section There is a possibility of causing an erroneous control in the rotational speed control of the blower fan when the air is burned.

  That is, for example, when only the hot water supply combustion section is operated to burn, only the heating combustion section is operated to be burned, and in any case, when the blower fan is operated, the air from the blower fan is operated. Is supplied to both hot water supply and heating combustion sections, and is affected by the flow path resistance in the exhaust passages of both combustion sections. On the other hand, if there are two combustion parts that can burn independently such as for hot water supply and heating, the deposits depend on the frequency of the combustion operation, the degree of combustion, the size of the cross-sectional area of the air supply, exhaust passage, etc. As a result, the tendency of the increase in flow path resistance is also different between the two combustion sections. In particular, when the hot water combustion section is considerably larger than the heating combustion section, and the flow passage cross-sectional area is considerably large, the influence of the increase in flow path resistance on the hot water combustion section side is dominant. Therefore, it is difficult to sufficiently detect and grasp the increase in flow path resistance on the side of the combustion section for heating by the method of performing self-diagnosis on the degree of increase in flow path resistance based on the fan current value of the blower fan. In such a case, the hot water supply combustion unit side performs self-diagnosis based on the fan fan current value of the blower fan, while the heating combustion unit side performs heating diagnosis side based on the detected temperature value of the combustion flame. It is conceivable to adopt a method for self-diagnosis of the channel resistance.

  However, although the influence of the increase in flow path resistance on the heating side combustion section side is smaller than that on the hot water supply combustion section side, if the increase in flow path resistance occurs on the heating combustion section side, the hot water supply combustion section When the combustion operation is performed, the increase in flow path resistance on the heating combustion unit side may affect the self-diagnosis result based on the fan current value of the blower fan. As a result, there is a risk of erroneous control of the air supply amount based on the rotational speed control of the blower fan.

  Such a problem can occur not only in the heating combustion section, but also in any combustion section other than the hot water supply combustion section, such as a warm-up combustion section.

  The present invention has been made in view of such circumstances, and an object of the present invention is to supply combustion air from one air supply source to two combustion sections capable of independent combustion. It is to be able to perform adjustment control to an appropriate air supply amount even in the combustion apparatus that has been made.

  In order to achieve the above object, according to the present invention, a first combustion section and a second combustion section that can be combusted independently from each other, and one blower that supplies combustion air to both the first combustion section and the second combustion section. Fan, fan operation control means for controlling the fan current value for driving the fan motor so that the rotation speed of the blower fan becomes the target rotation speed, and flame temperature detection means for detecting the combustion flame temperature of the second combustion section The following specific items are provided for a combustion apparatus equipped with: That is, fan correction control means for correcting the rotational speed of the blower fan so as to counter the increase change when a predetermined change in flow path resistance due to the blockage tendency of the supply / exhaust flow path occurs in each combustion section. I will prepare. As the fan correction control means, when an increase in flow resistance in the supply / exhaust flow path of the second combustion section is detected by the flame temperature detection means, the fan current value during the single combustion operation of the first combustion section Is added with a correction value corresponding to an increase in the flow resistance of the second combustion section, and the flow resistance of the supply / exhaust flow resistance in the first combustion section is calculated based on the fan current value after the correction. It is configured to determine whether or not an increase change has occurred (claim 1).

  In the case of the present invention, it is possible to reliably prevent the occurrence of an erroneous determination regarding the flow path resistance of the first combustion section, and to ensure that an excessive and unnecessary correction is performed on the operating amount of the blower fan based on the erroneous determination. It can be avoided. That is, since the combustion air from the blower fan is supplied not only to the first combustion part but also to the second combustion part during the single combustion of the first combustion part, the flow resistance on the side of the first combustion part is increased and changed. Even if there is no occurrence, if the flow path resistance increases and changes on the second combustion section side, the detected value of the fan current value is changed under the influence. As a result, it is erroneously determined that an increase in flow path resistance has occurred on the first combustion section side, and there is a risk that an excessive correction will be added to the operating amount of the blower fan. As described above, an increase change in the flow path resistance of the second combustion section is detected by a change in the flame temperature of the flame temperature detecting means, and a correction value corresponding to the increase change is obtained as a fan current value during the single combustion operation of the first combustion section. By adding and correcting the detection value, it is possible to remove the influence due to the increase in the flow path resistance of the second combustion section. As a result, it is possible to reliably avoid the possibility of erroneous determination due to the influence due to the increase in flow path resistance of the second combustion section.

  In the first aspect of the present invention, the addition correction for adding a correction value to the detected value of the fan current value at the time of the single combustion operation of the first combustion section is used as an increase change in the channel resistance in the second combustion section. It can be configured to be triggered by the fact that an increase change amount set in advance is reached as an increase change that reduces the fan current value during single combustion. As a result, only when the first combustion section side is affected, correction based on the increase in flow path resistance in the second combustion section can be performed.

  Further, the correction value for the addition correction can be set so that the fan current value after the addition correction corresponds to the fan current value that is fundamentally controlled by the fan operation control means. 3). By doing so, it is possible to reliably control the operation of the blower fan during the single combustion of the first combustion section while reliably preventing erroneous determination due to an increase in flow path resistance on the second combustion section side. obtain.

  In this case, the fan operation control means is configured to control the operation of the blower fan based on the relationship table between the target rotational speed and the control fan current value in a state before the flow path resistance is increased, and the above-described addition correction The correction value to be set can be set in advance on the relationship table in relation to the target rotational speed (claim 4). By doing so, it is possible to simplify and improve the correction control.

  As described above, according to the combustion apparatus of any one of claims 1 to 4, the second combustion section is in spite of no increase in flow path resistance occurring on the first combustion section side. Therefore, it is possible to reliably prevent an erroneous determination that an increase in the flow resistance has occurred in the first combustion section due to an increase in the flow resistance in the air blow fan. It is possible to reliably avoid the excessive and unnecessary correction of the operation amount.

  In particular, according to the second aspect, correction based on the increase in flow path resistance in the second combustion section can be performed only when the first combustion section side is affected.

  According to the third aspect of the present invention, by setting the fan current value after the addition correction to be equivalent to the fan current value that is basically controlled by the fan operation control means, the second combustion section is surely established. The operation control of the blower fan at the time of the single combustion of the first combustion unit can be ensured while preventing erroneous determination due to the increase in the flow path resistance on the side of the first combustion part.

  In this case, according to the fourth aspect, the correction value to be added and corrected on the relationship table between the target rotational speed and the control fan current value is set in advance in relation to the target rotational speed, thereby simplifying the correction control. Efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a combustion apparatus according to an embodiment of the present invention. This combustion apparatus includes a hot water supply combustion unit for realizing a hot water supply function and two heating combustion units for realizing a hot water circulation heating function as two combustion units capable of independent combustion, and from combustion exhaust gas. An example of a latent heat recovery type that achieves high efficiency by performing latent heat recovery is shown. In carrying out the present invention, at least two combustion parts capable of independent combustion can be applied, and those having two combustion parts for hot water supply and bathing. However, it is not necessary to be a latent heat recovery type.

  In the figure, reference numeral 2 is a hot water supply circuit for realizing a hot water supply function, 3 is a heating circuit for realizing a hot water circulation heating function, 4 is a can body for heat exchange heating by combustion heat, and 5 is a fuel gas. , A blower fan as an air supply source for supplying combustion air, and a controller for controlling the operation of the hot water supply circuit 2, the heating circuit 3, the fuel supply system 5, the blower fan 6, and the like. It is. The can body 4 includes two portions of a hot water supply can body portion 41 and a heating can body portion 42 which are separated from each other, and both the can body portions 41 and 42 are both upstream (lower end side in FIG. 1). Opened to receive the supply of combustion air from the blower fan 6, the downstream side (upper end side) is joined by the collective exhaust cylinder 43 for discharging the combustion exhaust gas after the recovery of latent heat to the outside, and these upstream and downstream The space is partitioned.

  The hot water supply circuit 2 collects latent heat from combustion exhaust gas, a hot water supply combustion burner 21 as a hot water supply combustion section, a hot water supply primary heat exchanger 22 that heats and heats incoming water by the combustion heat of the combustion burner 21, and combustion exhaust gas. A secondary heat exchanger for hot water supply 23, a water inlet primary heat exchanger 22 and a water inlet passage 24 for allowing tap water to enter the secondary heat exchanger 23, and after being heated by these heat exchangers 22, 23 A hot water outlet 25 for hot water is provided. The hot water supply combustion burner 21, the hot water supply primary heat exchanger 22 and the hot water supply secondary heat exchanger 23 are disposed in the hot water supply can body 41.

  Then, water such as tap water supplied to the water supply connection port 11 of the case 1 of the combustion apparatus is introduced through the inlet channel 24, and this incoming water is first preheated by the secondary heat exchanger 23, and further primary heat exchange for hot water supply. While passing through the vessel 22, the heat exchanged and heated by the combustion heat such as the radiant heat described above, the hot water heated up to a predetermined temperature and discharged into the hot water outlet 25 through the hot water connection port 12 through the hot water supply pipe 13 in the kitchen or bathroom. Hot water is supplied to a predetermined hot water supply location such as a hot water tap 131. In the illustrated example, only one hot-water tap 131 is shown, but there are usually a plurality of hot water taps 131 disposed in a kitchen, a washbasin, a bathroom, and the like.

  The hot water supply control in the hot water supply circuit 2 is performed by the controller 7 based on the input setting of the hot water supply temperature set by the remote controller 71 and the detected values such as the incoming water flow rate, the incoming water temperature and the outgoing hot water temperature. It is executed so that the temperature becomes the set hot water supply temperature.

  The heating circuit 3 includes a heating combustion burner 31 as a heating combustion section, a heating primary heat exchanger 32 that heats and heats circulating hot water using the combustion heat of the combustion burner 31, and recovers latent heat from the combustion exhaust gas. The heating secondary heat exchanger 33 and the heating hot water circulation path 34 passing through the heat exchangers 32 and 33 are configured. The heating combustion burner 31, the heating primary heat exchanger 32, and the heating secondary heat exchanger 33 are disposed in the heating can body portion 42.

  The primary heat exchangers 22 and 32 are composed of, for example, fin-and-tube heat exchangers, and the secondary heat exchangers 23 and 33 are composed of, for example, a multi-plate or multi-tube heat exchanger. Yes. The gaps between the primary heat exchangers 22 and 32 and the secondary heat exchangers 23 and 33 extend between the upstream and downstream sides of the hot water can body 41 and the heating can body 42 to serve as a passage for air and combustion exhaust gas. A supply / exhaust flow path is configured.

  The hot water circulation path 34 includes a heating return path 341 that sends low temperature water returned to the expansion tank 35 and stored to the inlet of the heating secondary heat exchanger 33 by the operation of the heating circulation pump 36, and a secondary High temperature water (for example, 80 ° C.) that has been preheated by the latent heat recovery of the combustion exhaust gas in the heat exchanger 33 and then heat exchange heated by the combustion heat of the combustion burner 31 for heating in the primary heat exchanger 32 is supplied to the high temperature forward connection port 14. A high-temperature forward path 342, a low-temperature forward path 343 that branches from the heating return path 341 downstream of the circulation pump 36 and supplies low-temperature water (for example, 60 ° C.) to the low-temperature forward connection port 15, and the high-temperature forward path 342 And a bypass passage 344 for returning the high temperature water to the expansion tank 35 and returning the low temperature return hot water returned from the heating terminals 16 and 17 via the return header 18 to the expansion tank 35. And a road 345.

  An important point in the application of the present invention is the presence of the heating can body portion 42 that can be independently burned apart from the hot water supply can body portion 41, and what is the arrangement and connection structure of the hot water circulation path 34? It doesn't matter. For example, the low-temperature return warm water returned to the return header 18 may be supplied to the secondary heat exchanger 33 first and preheated by recovering the latent heat of the combustion exhaust gas, and then returned to the expansion tank 35. In that case, low temperature water from the expansion tank 35 may be supplied to the primary heat exchanger 32 for heating to heat and heat the high temperature water.

  The heating combustion burner 31 is provided with a burner sensor 37 as a flame temperature detecting means for detecting the temperature of the combustion flame, and the flame temperature detected by the burner sensor 37 is output to the controller 7. ing.

  An exhaust gas drain processing circuit (not shown) is installed in the case 1, and this exhaust gas drain processing circuit is configured so that the combustion exhaust gas in the secondary heat exchanger for hot water supply 23 and the secondary heat exchanger for heating 33 has latent heat. The exhaust gas drain generated by cooling and condensing by heat exchange for recovery is neutralized and then drained.

  The fuel supply system 5 is branched by a fuel gas supply pipe 51, an electromagnetic proportional valve 52 interposed in the fuel gas supply pipe 51, and a fuel gas supply pipe 51 at a downstream position of the electromagnetic proportional valve 52. Branch supply pipes 55 and 56 are provided for supplying fuel gas individually to the hot water combustion burner 21 and a heating combustion burner 31 described later via on-off valves 53 and 54, respectively.

  Further, the can body 4 is provided with one blower fan 6 at the uppermost stream side position of both the can body portions 41, 42, and combustion air taken in by the blower fan 6 flows from the lower end portion of the can body 4. The combustion burners 21 and 31 for hot water supply and heating are operated by combustion by receiving the supplied combustion air supplied to both the can bodies 41 and 42. At this time, based on the predetermined air-fuel ratio and the required combustion amount (required number), the corresponding control values of the fuel gas supply amount and the air supply amount are determined by the controller 7, and the determined fuel is determined. The operation of the electromagnetic proportional valve 52 is controlled so as to be the gas supply amount, while the operation of the blower fan 6 is controlled so as to be the determined air supply amount. Specifically, the basic operation control of the blower fan 6 is to control the rotational speed of the fan motor 61 so that a predetermined air supply amount is obtained. The rotational speed control of the fan motor 61 is controlled by the rotational speed and the fan. This is done by controlling the fan current value so as to achieve a predetermined target rotational speed based on a control table predetermined for the current value. The basic operation control of the blower fan 6 is performed by the fan operation control means 72 (see FIG. 3) described later.

  When the combustion air burner 21 is supplied with combustion air from the blower fan 6 and the combustion operation is performed, for example, the water in the primary heat exchanger 22 is heated by heat exchange with the combustion heat, and the primary heat exchanger is heated. The combustion exhaust gas that has passed through 22 is flowed to the secondary heat exchanger 23 to recover its latent heat, and the combustion exhaust gas that has passed through the secondary heat exchanger 23 passes through a heating secondary heat exchanger 33 described later. The exhaust gas is discharged from the collective exhaust tube 43 together with the combustion exhaust gas after the operation. Similarly, when the heating combustion burner 31 is combusted by receiving supply of combustion air from the blower fan 6, the low-temperature water in the primary heat exchanger 32 is heated by heat exchange with the combustion heat. The combustion exhaust gas that has passed through the primary heat exchanger 32 is caused to flow to the secondary heat exchanger 33 to recover the latent heat, and the combustion exhaust gas that has passed through the secondary heat exchanger 33 is discharged from the collective exhaust tube 43 to the outside. To be released.

  The flow of the combustion exhaust gas discharged from the collective exhaust cylinder 43 through the hot water supply can body 41 and the heating can body 42 is brought about based on the supply pressure of air from the most upstream blower fan 6. Yes, when the gaps between the primary heat exchangers 22 and 32 and the secondary heat exchangers 23 and 33 in the can bodies 41 and 42 and the flow paths of the combustion gas and the combustion exhaust gas become narrow due to the accumulation of deposits, etc. The flow resistance increases, and the fan current value tends to decrease even if an attempt is made to maintain the blower fan 6 at the same rotational speed in response to the increase of the flow resistance. Therefore, by observing the relationship between the rotational speed detection value of the blower fan 6 and the fan current value, it is possible to perform a self-diagnosis process on the degree of increase / decrease change in the channel resistance.

  The supply / exhaust volume through which combustion air and combustion exhaust gas flow is set to be considerably larger in the hot water supply can body portion 41 than in the heating can body portion 42. For this reason, even if the blower fan 6 is operated to burn only the heating combustion burner 31, a considerable portion of the air supply amount from the blower fan 6 is a hot water supply can body 41. The increase in flow path resistance on the hot water supply can body portion 41 side has a dominant influence on the rotation of the blower fan 6. For this reason, in the fan correction control means 73 to be described later, the self-diagnosis regarding the flow path resistance on the hot water supply can body 41 side (hereinafter simply referred to as “hot water supply side”) This is done by looking at the relationship with the detected value of the fan current value at that time.

  On the other hand, an increase in flow path resistance on the heating can body portion 42 side (hereinafter simply referred to as “heating side”) does not appear so greatly as the rotation of the blower fan 6 as described above. Based on the flame temperature detected by the burner sensor 37, the degree of increase in flow path resistance on the heating side is self-diagnosed. That is, if the air supply amount decreases due to an increase in flow path resistance on the heating side, the air-fuel ratio changes to the fuel rich side and the tip of the combustion flame is deflated, and the flame temperature detected by the burner sensor 37 is also It will change to the high temperature side. For example, as shown in FIG. 2, when the temperature at the front end side of the combustion flame 8 is detected by the burner sensor 37, if the flow path resistance increases, the combustion flame 8 is sequentially changed as indicated by 8a, 8b, 8c. It changes and the detection temperature of the burner sensor 37 changes to a higher temperature side. For this reason, it is possible to perform a self-diagnosis process on the degree of increase in flow path resistance by looking at the high temperature side change of the temperature value detected by the burner sensor 37.

  As shown in FIG. 3, the controller 7 performs fan operation control means 72 that performs the above-described basic operation control of the blower fan 6 based on the set air-fuel ratio and the required number, and basic operation control by the fan operation control means 72. Fan correction control means 73 for correcting the control amount based on the self-diagnosis relating to the flow path resistance described above, and a relationship table 74 registered in advance are provided. The fan correction control means 73 performs hot water combustion by self-diagnosis based on the rotation speed of the blower fan 6 detected by the rotation speed detection means 62 and the fan current value detected by the fan current value detection means 63 on the hot water supply side. While correcting the basic operation control amount of the blower fan 6 when the burner 21 is burned, the heating combustion burner 31 is burned by self-diagnosis based on the flame temperature detected by the burner sensor 37 on the heating side. In this case, the basic operation control amount of the blower fan 6 is corrected. As a result, the combustion state of the combustion burners 21 and 31 is maintained at a predetermined air-fuel ratio even if the flow path resistance increases and changes.

  Specifically, the correction control by the fan correction control means 73 is divided into control during the learning period (step S1) and control after the learning period has elapsed (step S2) as shown in FIG. This learning period is an initial setting period in which it is considered that a situation in which the flow resistance increases due to the blockage tendency based on the use over time after the combustion apparatus is newly installed does not occur. This is a period for correcting the variation in the mounting position of each component of the combustion apparatus, the variation derived from the equipment, etc. and resetting it to the normal control state. That is, during this learning period, when it is determined by the self-diagnosis that the flow resistance is increased, except for those based on sudden or temporary causes such as inflow of back wind from the collective exhaust pipe 43, For example, it is determined not to be based on the blockage tendency due to the above, but due to variations in the mounting position of the burner sensor 37, sensor variations such as the rotational speed detection means 62 or the fan current value detection means 63, and variations in reading, etc. However, corrections are made to correct these variations. Specifically, the relationship between the actually detected values of the rotational speed of the blower fan 6 and the fan current value is a control relationship (FF line in the relationship table 74 of FIG. 5) set in advance as the relationship table 74. The correction processing for converting and setting the reading value (detection value) of the fan current value is performed so that

  In the control after the learning period (step S2), if it is determined as a result of self-diagnosis that the flow path resistance has increased, the passage of combustion air or combustion exhaust gas tends to be blocked. Thus, it is determined that the flow path resistance is truly increased, and the fan current value is corrected so that a predetermined air supply amount is supplied against the increase. At this time, if the amount of increase in flow path resistance on the heating side is equal to or greater than a predetermined value, the influence on the self-diagnosis on the hot water supply side due to the increase in flow path resistance on the heating side is eliminated when the hot water combustion burner 21 is in a combustion operation. In order to properly perform the self-diagnosis on the hot water supply side, the reading value at the time of measuring the fan current value is corrected by adding a predetermined amount, and the self-diagnosis on the hot water supply side is performed using the fan current value of this additional correction value. I am doing so.

More specifically, in the control during the learning period (step S1), the hot water supply side takes in the fan current value and the rotational speed under the control of the basic control unit of the blower fan 6 during the combustion operation of the hot water supply combustion burner 21, and both Is corrected to be on the FF line of FIG. 5 in the relationship table 74. If there is no variation such as device reading variation, the above FF line rotates with a fan current value set in advance so that if a certain fan current value is passed, the rotation speed is based on a predetermined feedforward control (FF control). It is a relationship with numbers. When the control during the learning period (step S1) is completed, on the hot water supply side, the flow resistance is continuously increased due to the occurrence of deposits and the like that block the flow path, and the air flow is temporarily or suddenly increased. As long as there is no increase in flow path resistance including an increase in flow path resistance, the relationship between the fan current value and the rotational speed is a relationship defined by the FF line in FIG. If speed is a N ₁ in FIG. 5, for example, fan current value at that time becomes A _1.

  On the other hand, on the heating side, the flame temperature is detected from the burner sensor 37 during the combustion operation of the heating combustion burner 31, and the rotational speed of the blower fan 6 is adjusted so that the flame temperature falls within a predetermined temperature range (for example, a range less than 650 ° C.). Increase correction. Specifically, if the name detection flame temperature by the burner sensor 37 is, for example, 300 ° C. to less than 650 ° C., it is normal and is not corrected, but if it exceeds 650 ° C., the air is blown so that it falls within the range of 650 ° C. The rotational speed of the fan 6 is increased. When such rotation speed increase correction is executed, an increase correction counter is integrated for one time. The rotation speed increase correction is canceled and reset when the combustion operation is stopped. The correction is made in consideration of the temporary and sudden flow resistance increase such as inflow of the reverse wind, and this is called normal correction. When the rotation speed increase correction is executed again even when the heating combustion burner 31 is combusted, the increase correction counter is accumulated once more, and these are repeated to set the count value of the increase correction counter to a predetermined value. When the upper limit value (for example, 10 times) is reached, a rotational speed increase correction of a predetermined unit correction amount (for example, 1%) is added. This rotational speed increase correction is not canceled even if the combustion operation of that time is stopped, and in the next combustion operation, the blower fan 6 starts to operate with the rotational speed increase correction taken into account from the beginning. In this sense, this rotational speed increase correction is called initial correction. Further, even if the blower fan 6 is operated in a state where the initial correction for one time (1%) is taken into consideration from the initial stage of the combustion operation, if the increase correction counter is counted again to the upper limit value, the initial value for one more time is added. Correction is applied, and this repetition is executed until the maximum initial correction amount α% (for example, 4%) is reached. As described above, mainly the variation in the mounting position of the burner sensor 37 and other variations are removed.

  When initial correction exceeding the maximum initial correction amount α% is required, that is, when the combustion operation is performed with the initial correction of α% taken into account, increase correction is required until the increase correction counter is counted to the upper limit value. In this case, the same increase correction as before is added, but it is treated as a normal correction, and if the combustion is stopped, the increase correction exceeding the α% is canceled.

  Next, in the control after the learning period has elapsed (step S2), when the hot water supply combustion burner 21 is combusted, self-diagnosis on the hot water supply side is performed based on the reading of the fan current value of the blower fan 6, while heating When the combustion burner 31 is burned, the heating side self-diagnosis is performed based on the flame temperature detected by the burner sensor 37. Then, if it is determined that the flow path resistance is increased based on the self-diagnosis result, it is determined that a tendency of clogging due to deposits or the like has actually occurred, and the increase correction is performed.

That is, on the hot water supply side, the reading value of the fan current value of the blower fan 6 during the combustion operation of the hot water supply combustion burner 21 is the fan current value (on the FF line in FIG. 5) corresponding to the target rotational speed by the basic control unit at that time. If the current falls below the fan current value), it is determined that the flow path resistance has increased and the target rotational speed is increased by a predetermined amount when the reduction exceeds the dead zone line of FIG. 5 and enters the lower side. to correct. 5, fan current value if the target rotational speed, for example, N ₁ in the absence increased flow resistance (occurrence of clogging tendency) is the place to be A _1, the results of flow path resistance is increased, the fan current value There becomes lower than B _1, it performs an increase correction of the rotational speed. That is, the dead zone line in FIG. 5 is set in advance as a criterion for determining whether or not to perform increase correction. If the actual flow path resistance increase (degree of blockage tendency) on the heating side reaches a set amount as will be described later, the increase in flow path resistance on the heating side affects the self-diagnosis on the hot water supply side. Judgment is made and the hot water supply side self-diagnosis is performed by substituting the reading value of the fan current value used for the self-diagnosis with the reading value after adding the actual reading value by a predetermined value and correcting it.

On the other hand, on the heating side, a self-diagnosis based on the detected flame temperature of the burner sensor 37 is performed every time the combustion burner 31 for heating is burned, and the detected flame temperature is controlled in the same manner as in the control during the learning period (step S1). Is within a range showing an increase in flow path resistance (range of 650 ° C. or higher), normal correction is executed. In addition, every time the normal correction is executed, the count value of the increase correction counter is newly counted, and each time the count value reaches the upper limit value, an initial correction of unit correction (one time; for example, 1%) is added. If the integrated initial correction amount obtained by adding the initial correction amount during the learning period of step S1 to (α + β)% with respect to the initial correction after the learning period has elapsed, the supply / exhaust volume reaches the hot water supply can body 41. Although it is smaller than that, there is a risk of causing a misdiagnosis on the hot water supply side due to an increase in flow path resistance on the heating side, so that the integrated initial correction amount on the heating side has reached (α + β)% Is used as a trigger to add a predetermined value to the reading of the fan current value used for self-diagnosis on the hot water supply side to avoid the occurrence of erroneous diagnosis. The additional correction amount is the current value of the difference between the FF line and the correction line in FIG. For example, if the target rotational speed is N ₁ , the difference current value between the fan current value A ₁ of the FF line and the fan current value C ₁ of the correction line with respect to the actual reading value of the fan current value at that time ( A self-diagnosis is performed on the hot water supply side using the added current value to which A ₁ -C ₁ ) is added. In other words, plus the current value is lower than the current value B ₁ of the dead band line, it is determined that the flow resistance increases occurs rotational speed increase correction of the blower fan 6 during combustion operation of the hot water supply side in the hot water supply side To do. The above correction line indicates that the rotation speed and fan current of the blower fan 6 are generated even when the blower fan 6 is operated by previously producing a can body 4 having a predetermined blockage tendency by experiment. An additional correction amount is obtained such that the relationship with the value is output in a relationship equivalent to that of the FF line, and is set based on this. The integrated initial correction amount (α + β)% is the “preset increase change amount” in the claims.

  As described above, in the self-diagnosis relating to the increase in flow path resistance during the combustion operation of the hot water supply combustion burner 21, the fan current value of the blower fan 6 may be reduced due to the occurrence of the blockage tendency on the heating side. If the decrease in current value is lower than the dead zone line, even if the increase in flow resistance does not occur to the extent that the hot water supply actually requires correction, the increase in rotation speed is corrected based on the increase in flow resistance. Therefore, it is possible to prevent the possibility of such a misdiagnosis from occurring.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Various other embodiments are included. That is, in the above-described embodiment, the learning period and the control divided after the learning period have been performed. However, the present invention is not limited to this, and if the variation such as the mounting position variation of the burner sensor 37 is negligible, the learning period The inside control may be omitted. In this case, if the initial correction amount on the heating side reaches a predetermined amount, the current value after correcting the actual fan current value by a predetermined additional amount during the combustion operation of the hot water combustion burner 21 is corrected. It may be used to perform a self-diagnosis on the hot water supply side.

  It should be noted that the degree of increase in the channel resistance can be grasped according to the initial correction amount of the initial correction described in the above embodiment. That is, assuming that the basic control amount is 100% as the initial correction and is increased by 1% from 101 to 110%, the current initial correction amount between 101 to 110% and the increase degree of the channel resistance ( In other words, the relative relationship with the blockage degree or the blockage rate of the flow path can be determined by conducting an experiment or the like in advance. For example, a table preliminarily defining the relationship between the initial correction amount and the blockage rate of the supply / exhaust passage such that the initial correction amount of 101 to 110% corresponds to the blockage rate of 60 to 80% is set, and this table is used. For example, it is possible to grasp what the current blocking rate is using the initial correction amount as a parameter.

It is a schematic diagram which shows embodiment of this invention. It is explanatory drawing which shows the relationship between a combustion flame and a burner sensor position. It is a block diagram of the controller which concerns on control of a ventilation fan. It is a flowchart which shows the correction control content in a fan correction control means. It is a related figure which shows the relationship between the rotation speed of a ventilation fan, and a fan electric current value.

Explanation of symbols

6 Blower fan 21 Hot water combustion burner (first combustion part)
31 Combustion burner for heating (second combustion part)
37 Burner sensor (flame temperature detection means)
61 Fan motor 62 of blower fan Rotational speed detection means 63 Fan current value detection means 72 Fan operation control means 73 Fan correction control means 74 Relationship table

Claims (4)

A first combustion section and a second combustion section that can be combusted independently of each other, a single blower fan that supplies combustion air to the first and second combustion sections, and the rotational speed of the blower fan is a target rotation. A combustion apparatus comprising fan operation control means for controlling a fan current value for driving a fan motor so as to be a number, and flame temperature detection means for detecting a combustion flame temperature of the second combustion section,
Fan correction control means is provided for correcting the rotational speed of the blower fan so as to counter the increased change of the predetermined flow path resistance caused by the blockage tendency of the supply / exhaust flow path in each combustion section. And
The fan correction control means detects the fan current value during the single combustion operation of the first combustion section when the flame temperature detection means detects an increase in flow resistance in the supply / exhaust flow path of the second combustion section. The correction value corresponding to the increase change of the flow path resistance on the second combustion section side is added to the value, and the increase change of the flow resistance of the supply / exhaust gas in the first combustion section based on the fan current value after the addition correction A combustion apparatus configured to determine whether or not a fuel has occurred. The combustion device according to claim 1,
The addition correction for adding a correction value to the detected value of the fan current value during the single combustion operation of the first combustion section is an increase change in the flow path resistance in the second combustion section during the single combustion of the first combustion section. A combustion apparatus configured to be triggered by the fact that a preset increase change amount has been reached as an increase change that reduces the fan current value. The combustion apparatus according to claim 1 or 2, wherein
The combustion apparatus, wherein the correction value to be corrected for addition is set so that the fan current value after the correction for addition corresponds to a fan current value for which basic operation control is performed by the fan operation control means. The combustion apparatus according to claim 3, wherein
The fan operation control means is configured to perform operation control of the blower fan based on a relationship table between the target rotational speed and the control fan current value in a state before the flow path resistance is increased,
The combustion apparatus, wherein the correction value for correcting the addition is preset on the relation table in relation to the target rotational speed.

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