JP5819795B2 - Combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus for burning a mixed gas generated by mixing fuel gas and combustion air.

  A hot water supply device and a heating device are equipped with a combustion device that burns a mixed gas generated by mixing fuel gas and combustion air. In order to properly burn the mixed gas with the combustion device, it is necessary to mix the fuel gas and the combustion air at an appropriate ratio (air-fuel ratio). Therefore, before shipment of the combustion apparatus, at least when the fuel gas supply amount is a low load with a first supply amount and when the fuel gas supply amount is a high load with a second supply amount (> first supply amount). At two points, an operation (pressure adjustment operation) is performed to adjust the correspondence between the supply amount of the fuel gas and the supply amount of the combustion air so that an appropriate air-fuel ratio can be obtained. When the amount of fuel gas supplied is determined when the combustion apparatus is used, the amount of combustion air supplied relative to the amount of fuel gas supplied is determined as the amount of combustion air supplied at low and high loads (two points). It can be obtained by interpolation from the pressure regulation value.

  Moreover, a combustion apparatus provided with a thermocouple is known as a combustion state detection means for detecting the combustion state of a mixed gas (for example, Patent Document 1). Since the flame temperature (combustion state) when the mixed gas burns corresponds to the air-fuel ratio of the mixed gas, at least one of the fuel gas and the combustion air is set so that the detected value of the thermocouple becomes the reference value. If the supply amount is corrected, the air-fuel ratio of the mixed gas can be controlled more appropriately. Further, by storing the correction amount, in the next combustion, the supply amount of the fuel gas or the combustion air can be corrected from the time of ignition based on the stored correction amount.

JP-A-8-14552

  However, in such a combustion apparatus, even if correction is performed based on the correction amount stored at the time of the previous combustion, an appropriate air-fuel ratio may not be obtained, and as a result, there is a problem that combustion failure or misfire occurs. Such a problem may occur when the supply amount of fuel gas is changed from when the correction amount is stored, and as a cause thereof, if the supply amount of fuel gas changes, the necessary supply of combustion air It is possible that not only the amount has changed, but also the required correction amount has changed, and if the correction was made uniformly based on the stored correction amount, it would be an inappropriate correction depending on the fuel gas supply amount. It may become.

  The present invention has been made in response to the above-described problems in the prior art, and aims to provide a combustion apparatus capable of realizing an appropriate combustion state even when the amount of fuel gas supplied is changed. To do.

In order to solve the above-described problems, the combustion apparatus of the present invention employs the following configuration. That is,
A mixed gas generating means for generating a mixed gas of the fuel gas and the combustion air while controlling a supply amount of the fuel gas and a supply amount of the combustion air;
Combustion operation start means for igniting the mixed gas and starting combustion operation;
Combustion state detection means for detecting the combustion state of the mixed gas;
Correction means for correcting a supply amount of the fuel gas or the combustion air according to the combustion state;
A combustion apparatus comprising: correction coefficient storage means for storing the correction coefficient for the supply amount,
As a correspondence relationship between the supply amount of the fuel gas and the supply amount of the combustion air, the set value of the supply amount of the combustion air when the supply amount of the fuel gas is the first supply amount, and the fuel gas A correspondence storage means for storing a set value of the supply amount of the combustion air when the supply amount is a second supply amount larger than the first supply amount,
The correction coefficient storage means stores the correction coefficient in association with the supply amount of the fuel gas, so that the correction coefficient when the supply amount of the fuel gas is the first supply amount is the first correction coefficient. And storing the correction coefficient when the fuel gas supply amount is the second supply amount as a second correction coefficient,
The mixed gas generation means generates the mixed gas in which the supply amount of the fuel gas or the combustion air is corrected by the correction coefficient corresponding to the supply amount of the fuel gas, and the supply amount of the fuel gas The combustion air supply amount determined according to the correspondence relationship is obtained by interpolating the first correction coefficient at the first supply amount and the second correction coefficient at the second supply amount. The mixed gas is generated by correcting with a correction coefficient .

In the combustion apparatus, when the fuel gas supply amount changes, not only the corresponding combustion air supply amount changes, but also the necessary correction (corresponding correction coefficient) may change. Therefore, although the supply amount of the fuel gas is changed, than by correcting the amount of fuel gas supplied or the combustion air by applying the correction coefficient before the change uniformly has poor Ya not an appropriate air-fuel ratio combustion Misfires can occur. On the other hand, in the combustion apparatus of the present invention, the correction coefficient is stored in association with the supply amount of the fuel gas. When the supply amount of the fuel gas is changed, the correction coefficient is changed according to the changed supply amount of the fuel gas. Since the supply amount of the fuel gas or the combustion air is appropriately corrected with the correction coefficient , the mixed gas mixed at an appropriate air-fuel ratio can be appropriately combusted.

Moreover, according to the combustion apparatus of the present invention, if only the first correction coefficient at the first supply amount and the second correction coefficient at the second supply amount are stored, the first supply amount and the second supply amount can be reduced. The correction coefficient corresponding to the fuel gas supply amount in the middle (intermediate region) does not have to be memorized in detail, so the combustion gas supply amount can be changed to an appropriate correction coefficient as the fuel gas supply amount changes. It is possible to easily realize the correction with.

Further, in the above-described combustion apparatus of the present invention, if correction is performed when the supply amount of the fuel gas is larger than the first supply amount and smaller than the second supply amount , the change amount of the correction coefficient is set to the current supply amount. The first correction coefficient and the second correction coefficient may be distributed and stored in accordance with the ratio of the deviation from the amount to the first supply amount and the deviation from the current supply amount to the second supply amount.

The supply amount of the fuel gas is not necessarily set to the first supply amount or the second supply amount. However, if the change amount of the correction coefficient is distributed in this way, even if the combustion operation in which the fuel gas supply amount is set in the intermediate region from the first supply amount to the second supply amount is repeated, the first correction is performed. The memory of the coefficient and the second correction coefficient can be appropriately updated.

  Further, in such a combustion apparatus of the present invention, the amount of fuel gas or combustion air supplied is corrected depending on whether or not the mixed gas is ignited by detecting the presence or absence of the mixed gas when the mixed gas is ignited. Also good.

  In this way, even during ignition, the supply amount of the fuel gas or combustion air can be corrected according to the presence or absence of ignition, so that the mixed gas can be ignited.

It is explanatory drawing which shows the structure of the hot water supply apparatus 1 provided with the combustion apparatus 100 of a present Example. It is a flowchart of the combustion control process of a present Example. It is explanatory drawing which showed notionally the correspondence of fuel gas supply amount and fan rotational speed. It is explanatory drawing which showed notionally the correspondence of the correction coefficient of a fan rotational speed, and fuel gas supply amount. It is a flowchart of the combustion start process performed within a combustion control process. It is a flowchart of the correction coefficient update process performed within a combustion control process. It is explanatory drawing which showed the reason which can burn a mixed gas appropriately by performing a combustion control process.

  FIG. 1 is an explanatory diagram showing a configuration of a hot water supply apparatus 1 equipped with a combustion apparatus 100 of the present embodiment. The hot water supply device 1 includes a housing 10, a combustion device 100 accommodated in the housing 10, a heat exchanger 200 provided above the combustion device 100 in the housing 10, and the like.

  The combustion apparatus 100 mixes a burner 110 that burns a mixed gas of fuel gas and combustion air, a gas passage 112 that supplies fuel gas to the burner 110, and a combustion fan 120 that supplies combustion air to the burner 110. A spark plug 130 that ignites the gas and starts combustion in the burner 110, a thermocouple 140 that detects the combustion state in the burner 110, and the like are provided. A combustion can 20 is provided in the housing 10, and the burner 110, the spark plug 130, and the thermocouple 140 are accommodated in the combustion can 20 together with the heat exchanger 200. The gas passage 112 is provided with an electromagnetic valve 114 that opens and closes the gas passage 112 and a proportional valve 116 that controls the flow rate of the fuel gas passing through the gas passage 112. Furthermore, the combustion apparatus 100 is equipped with a controller 150 that controls combustion, and an electromagnetic valve 114, a proportional valve 116, a combustion fan 120, a spark plug 130, a thermocouple 140, and the like are connected to the controller 150. The controller 150 includes a memory 152 that stores various settings. The spark plug 130 of this embodiment corresponds to “combustion operation start means” of the present invention, and the thermocouple 140 of this embodiment corresponds to “combustion state detection means” of the present invention.

  The heat exchanger 200 includes a plurality of heat exchange fins 202 through which the combustion exhaust from the burner 110 passes, and a water pipe 204 meandering so as to penetrate the plurality of heat exchange fins 202 many times. Yes. The water flow pipe 204 is provided with a water flow sensor 206 that detects the flow of water inside the water flow pipe 204, and this water flow sensor 206 is connected to the controller 150. In addition, the combustion exhaust gas that has passed through the heat exchanger 200 is discharged to the outside of the housing 10 from an exhaust pipe 300 provided on the upper portion of the combustion can 20.

  In the water heater 1 having such a configuration, when water flows through the water pipe 204, combustion of the mixed gas is started by the burner 110, and the water flowing through the water pipe 204 is heated by the combustion exhaust gas in the heat exchanger 200. After that, it becomes hot water and flows out. At this time, in order for the burner 110 to properly burn the mixed gas, it is necessary to mix the combustion air and the fuel gas at an appropriate ratio (air-fuel ratio). Thus, the control for starting the combustion in the burner 110 and the control for maintaining the combustion state in the burner 110 appropriately are realized by the controller 150 performing the following combustion control processing.

  FIG. 2 is a flowchart showing a combustion control process performed by the controller 150. This process starts when a user of the hot water supply device 1 opens a hot water supply curan (not shown) and water is supplied to the water pipe 204, and the water flow is detected by the water flow sensor 206 provided in the water pipe 204. Is done.

  When the combustion control process is started, first, the supply amount of fuel gas at the start of combustion (at the time of ignition) is determined (STEP 100). The fuel gas supply amount is required per unit time by referring to the flow rate of water detected by the water flow sensor 206, the hot water supply temperature set by operating the setting switch (not shown) by the user of the hot water supply device 1, and the like. Decide according to the amount of heat. Subsequently, the rotation speed of the combustion fan 120 corresponding to the fuel gas supply amount (hereinafter referred to as “fan rotation speed”) is obtained so that the required supply amount of combustion air is obtained with respect to the determined fuel gas supply amount at the time of ignition. And a correction coefficient for adjusting the fan rotation speed is determined (STEP 102). Since the air-fuel ratio of the mixed gas needs to be appropriately controlled as described above, in the combustion apparatus 100 of the present embodiment, the correspondence relationship between the fuel gas supply amount and the fan rotation speed is stored in the memory 152 of the controller 150 in advance. Has been. In addition, when the fan rotation speed is corrected based on the combustion state in the burner 110 as described later, the correction coefficient is stored in the memory 152.

  FIG. 3 is an explanatory diagram conceptually showing the correspondence between the fuel gas supply amount stored in the memory 152 and the fan rotation speed. Before shipment of the hot water supply device 1, at least when the fuel gas supply amount is a low load with the first supply amount QLo and when the fuel gas supply amount is a high load with the second supply amount QHi (> the first supply amount QLo). At two points, the fuel gas supply amount is adjusted with respect to the fan rotation speed (air supply amount) so as to obtain an appropriate air-fuel ratio. This operation is called pressure adjustment operation. The memory 152 stores a set value of the fuel gas supply amount QLo for the fan rotation speed RLo at low load and a set value of the fuel gas supply amount QHi for the fan rotation speed RHi at high load. The memory 152 of this embodiment, which stores the correspondence between the fuel gas supply amount and the fan rotation speed (combustion air supply amount), corresponds to the “correspondence storage means” of the present invention.

The controller 150 reads the setting values at the time of low load and high load stored in the memory 152, and calculates the fan rotation speed R with respect to the fuel gas supply amount Q determined in STEP 100,
R = RLo + (RHi−RLo) / (QHi−QLo) × (Q−QLo) (1)
Calculate from

FIG. 4 is an explanatory diagram conceptually showing the correspondence between the fan rotation speed correction coefficient and the fuel gas supply amount. In the present embodiment, the correction coefficient of the fan rotation speed is stored in the memory 152 in association with the fuel gas supply amount at two points at the time of low load and high load as in the pressure adjustment work before shipment of the hot water supply device 1. ing. Therefore, the controller 150 reads the correction coefficient CLo corresponding to the fuel gas supply amount QLo at low load and the correction coefficient CHi corresponding to the fuel gas supply amount QHi at high load, and the fuel gas supply determined in STEP 100 The correction coefficient C corresponding to the quantity Q is
C = CLo + (CHi−CLo) / (QHi−QLo) × (Q−QLo) (2)
Calculate from When the fan rotation speed and the correction coefficient for the fuel gas supply amount at the time of ignition are determined in this way, a process (combustion start process) for starting combustion by the burner 110 is executed (STEP 110). The memory 152 of this embodiment stores the compensation factor corresponds to the "correction coefficient storing means" of the present invention. Further, the correction coefficient CLo at the time of low load in the present embodiment corresponds to the “first correction coefficient ” of the present invention, and the correction coefficient CHi at the time of high load of the present embodiment is the “second correction coefficient” of the present invention. It corresponds to " coefficient ".

  FIG. 5 is a flowchart showing the combustion start process. In the combustion start process, first, the rotation of the combustion fan 120 is started (STEP 112). At this time, the rotation speed of the combustion fan 120 is set to the fan rotation speed determined and corrected in STEP 102, and the burner 110 is supplied with combustion air of a supply amount corresponding to the fan rotation speed. Next, the solenoid valve 114 and the proportional valve 116 are opened, and supply of fuel gas to the burner 110 is started (STEP 114). The opening degree of the proportional valve 116 at this time is set to an opening degree corresponding to the fuel gas supply amount determined in STEP 100. Then, in the burner 110, since a mixed gas of fuel gas and combustion air is generated, the mixed gas is ignited using the spark plug 130 (STEP 116). Since the controller 150 controls the fan rotation speed (combustion air supply amount) and the fuel gas supply amount, the controller 150 of this embodiment corresponds to the “mixed gas generation means” of the present invention. ing.

  Subsequently, it is determined whether or not the mixed gas has been ignited (STEP 118). This determination is made based on the output of a frame rod (not shown). When a flame is detected (STEP 118: yes), the combustion start process is terminated and the process returns to the combustion control process of FIG.

  On the other hand, if no flame is detected (STEP 118: no), it is determined whether or not the number of ignition times has reached a predetermined number (for example, 3 times) (STEP 120). If the number of ignitions has not reached the predetermined number (STEP 120: no), correction is performed to decrease the fan rotation speed (STEP 122). When the fan rotation speed is decreased, the fan rotation speed may be decreased by a certain amount or may be decreased by a certain ratio with respect to the current fan rotation speed.

  When the fan rotational speed is decreased, “1” is added to the number of ignitions (STEP 124), and then the process returns to STEP 116, and the mixed gas is ignited again to determine the presence or absence of ignition (STEP 118). If ignition has not occurred (STEP 118: no), the number of ignitions is confirmed (STEP 120), and the fan rotation speed reduction correction and reignition processing are repeated until the number of ignitions reaches a predetermined number.

  The reason why the mixed gas is not ignited is that, for example, the outlet of the exhaust pipe 300 is blocked by an obstacle, the fan rotational speed is corrected excessively, and then the obstacle is removed, so that the supply amount of combustion air is increased. Is considered to be excessive. Accordingly, if ignition does not occur even when ignition is performed, correction is performed to reduce the fan rotation speed. If this is repeated, it approaches the appropriate fan rotation speed (appropriate air-fuel ratio), so that the mixed gas can be ignited. Further, if the correction amount to be reduced at a time is limited and the fan rotation speed is decreased stepwise, it is possible to prevent the combustion air from becoming extremely short and the combustion state at the time of ignition from getting worse.

  On the other hand, if the number of ignition times reaches a predetermined number (STEP 120: yes), it is determined that some abnormality (fuel gas shortage, etc.) has occurred, and the solenoid valve 114 and the proportional valve 116 are closed to supply fuel to the burner 110. The supply of gas is stopped and the rotation of the combustion fan 120 is stopped (STEP 126). Subsequently, when an abnormality is notified by displaying an error on a display unit (not shown) (STEP 128), the combustion start process is terminated without returning to the combustion control process of FIG.

  In the combustion control process of FIG. 2, when returning from the combustion start process of FIG. 5 in a state where the mixed gas is ignited (STEP 118: yes in FIG. 5), it is determined whether or not a predetermined time has passed (STEP 130). As described above with reference to FIG. 1, the combustion apparatus 100 includes the thermocouple 140 that detects the combustion state of the burner 110, and corrects the fan rotation speed based on the detected value of the thermocouple 140. However, immediately after the gas mixture is ignited and combustion is started, since the thermocouple 140 is not warmed, a large error is likely to occur in the detection value of the thermocouple 140 based on the flame temperature. Therefore, a predetermined time (warm-up time) from the start of combustion in the burner 110 until the thermocouple 140 is warmed is provided, and when the warm-up time has not elapsed (STEP 130: no), the warm-up time elapses. It will be in a standby state as it is.

  Thereafter, when the warm-up time has elapsed (STEP 130: yes), it is determined whether or not the detected value of the thermocouple 140 is the reference value (within the reference range) (STEP 132). If the detection value of the thermocouple 140 is out of the reference value (STEP 132: no), the fan rotation speed is corrected so that the detection value of the thermocouple 140 becomes the reference value (STEP 134). For example, when the detection value of the thermocouple 140 is higher than the reference value, it is considered that the combustion air is less than the appropriate air-fuel ratio, so that correction for increasing the fan rotation speed is performed. On the other hand, when the detected value of the thermocouple 140 is lower than the reference value, it is considered that there is more combustion air with respect to the fuel gas than the appropriate air-fuel ratio, and thus correction for reducing the fan rotation speed is performed.

  When correcting the fan rotation speed, the fan rotation speed may be corrected (increased or decreased) by a certain amount regardless of the distance between the detection value of the thermocouple 140 and the reference value. You may correct only the magnitude | size according to. Further, since the controller 150 corrects the fan rotation speed, the controller 150 of this embodiment corresponds to the “correction unit” of the present invention.

  If the fan rotation speed is corrected, a process (correction coefficient update process) for updating the fan rotation speed correction coefficient stored in the memory 152 is subsequently executed (STEP 140). On the other hand, when the detection value of the thermocouple 140 is the reference value in the determination of STEP 132 (STEP 132: yes), it is considered that the air-fuel ratio of the mixed gas is appropriate, so there is no need to correct the fan rotation speed. The processing of STEP134 and STEP140 is omitted.

  FIG. 6 is a flowchart showing the correction coefficient update process. In the correction coefficient update process, first, a correction coefficient corresponding to the fan rotation speed corrected in STEP 134 is calculated (STEP 142). The calculation of the correction coefficient is performed as follows. First, the fan rotational speed with respect to the current fuel gas supply amount is obtained from the above equation (1) using the set values (see FIG. 3) at the time of low load and high load stored in the memory 152. Then, the correction coefficient is calculated by dividing the fan rotation speed corrected in STEP 134 by the fan rotation speed obtained from the equation (1).

  Subsequently, it is determined whether or not the current fuel gas supply amount is the second supply amount QHi at the time of high load (STEP 144). As a result, when it is the second supply amount QHi at the time of high load (STEP 144: yes), the correction coefficient CHi at the time of high load stored in the memory 152 is updated to the value of the correction coefficient calculated at STEP 142 ( (STEP146). Thereafter, the correction coefficient update process is terminated, and the process returns to the combustion control process of FIG.

  On the other hand, when the current fuel gas supply amount is not the second supply amount QHi at the time of high load (STEP 144: no), it is next determined whether or not it is the first supply amount QLo at the time of low load. (STEP 148). As a result, when it is the first supply amount QLo at low load (STEP 148: yes), the low load correction coefficient CLo stored in the memory 152 is updated to the correction coefficient value calculated at STEP 142 ( (STEP 150). Thereafter, the correction coefficient update process is terminated, and the process returns to the combustion control process of FIG.

On the other hand, when the current fuel gas supply amount is not the first supply amount QLo at the time of low load (STEP 148: no), the change amount of the correction coefficient is determined based on the current fuel gas supply amount at the time of high load and low load. The time is distributed (STEP 152). This distribution is performed as follows. First, using the correction coefficient CLo at low load and the correction coefficient CHi at high load (see FIG. 4) stored in the memory 152, the correction coefficient corresponding to the current fuel gas supply amount from the above equation (2). Ask for. Then, the amount of change in the correction coefficient is calculated by subtracting this correction coefficient from the correction coefficient calculated in STEP 142. After calculating the change amount ΔCi of the correction coefficient in this way, based on the current fuel gas supply amount Q, the change amount ΔCHi of the correction coefficient distributed at high load is
ΔCHi = ΔC × (Q−QLo) / (QHi−QLo) (3)
Calculate from Also, the amount of change ΔCLo of the correction coefficient distributed at low load is
ΔCLo = ΔC × (QHi−Q) / (QHi−QLo) (4)
Calculate from

  Subsequently, in accordance with the distribution determined in STEP 152, the correction coefficients for high load and low load stored in the memory 152 are updated (STEP 154). That is, the correction coefficient change amount ΔCHi distributed at high load in STEP 152 is added to and stored in the correction coefficient CHi at high load stored in the memory 152, and at the low load stored in the memory 152. The correction coefficient change amount ΔCLo distributed at low load in STEP 152 is added to and stored in the correction coefficient CLo.

  When the hot water supply device 1 is used, the fuel gas supply amount is not necessarily set to the first supply amount QLo at low load or the second supply amount QHi at high load. Therefore, if the change amount of the correction coefficient is distributed between the high load time and the low load time based on the current fuel gas supply amount, the fuel gas supply amount is larger than the first supply amount QLo and larger than the second supply amount. Even when the combustion operation set in the small intermediate region is repeated, the storage of the correction coefficient at the time of high load and low load can be appropriately updated. When the correction coefficients at the time of high load and low load are thus updated, the correction coefficient update process is terminated and the process returns to the combustion control process of FIG.

  In the combustion control process of FIG. 2, if the correction coefficient update process of STEP 140 (FIG. 6) returns, or if the detected value of the thermocouple 140 is the reference value and the processes of STEP 134 and STEP 140 are omitted in STEP 132, the process continues. Then, it is determined whether or not the fuel gas supply amount has been changed (STEP 160). This determination is made by detecting changes in the flow rate of water detected by the water flow sensor 206 and the hot water supply temperature set by the user of the hot water supply device 1. The fuel gas supply amount is changed accordingly.

  When the fuel gas supply amount is changed (STEP 160: yes), the fan rotation speed and the correction coefficient corresponding to the changed fuel gas supply amount are determined (STEP 162). The processing of STEP 162 is basically the same as the processing of STEP 102 for determining the fan rotation speed and the correction coefficient corresponding to the fuel gas supply amount at the time of ignition. That is, the changed fan rotation speed is calculated from the equation (1) using the set values at low load and high load stored in the memory 152. Further, the corrected correction coefficient is calculated from the equation (2) using the low load and high load correction coefficients stored in the memory 152. Subsequently, the rotational speed of the combustion fan 120 is changed to the fan rotational speed determined and corrected in STEP 162 (STEP 164).

  On the other hand, when the fuel gas supply amount is not changed (STEP 160: no), there is no need to change the fan rotation speed, so the processing of STEP 162 and STEP 164 is omitted, and then the combustion in the burner 110 is stopped. (STEP 166). In the hot water supply apparatus 1 of the present embodiment, when the user closes the hot water supply curan, the water flow sensor 206 does not detect the flow of water. Therefore, the determination in STEP 166 is whether or not the water flow sensor 206 detects the water flow. Based on.

  As a result, when the combustion in the burner 110 is not stopped (STEP 166: no), the process returns to STEP 132 to correct the fan rotation speed based on the detected value of the thermocouple 140 or to change the fuel gas supply amount. Accordingly, the process of changing the fan rotation speed is repeated. On the other hand, when the combustion in the burner 110 is stopped (STEP 166: yes), the combustion control process of FIG. 2 is terminated.

  FIG. 7 is an explanatory diagram showing the reason why the mixed gas can be combusted appropriately by executing the above-described combustion control process. As described above, the pressure adjustment work is performed before the hot water supply device 1 is shipped, and the set value of the fuel gas supply amount with respect to the fan rotation speed at the time of low load and high load is stored. Further, the fan rotation speed is corrected based on the detection value of the thermocouple 140 so that the air / fuel ratio becomes more appropriate. For example, it is assumed that the fan rotational speed when the fuel gas supply amount is the second supply amount QHi at the time of high load is corrected. In the conventional combustion apparatus 100, as shown in FIG. 7A, correction is performed by uniformly applying the correction amount (correction coefficient). Therefore, the first supply amount when the fuel gas supply amount is low is low. Even if it is changed to QLo, the fan rotation speed is corrected with the correction coefficient at the time of high load. However, the correction amount actually required (corresponding correction coefficient) may vary depending on the fuel gas supply amount as shown by the thick broken line in FIG. 7B. In this case, FIG. Even if the fan rotation speed with respect to the first supply amount QLo at the time of low load is corrected by the correction coefficient at the time of high load as in (), an appropriate air-fuel ratio cannot be obtained.

  On the other hand, in the combustion apparatus 100 of the present embodiment, the correction when the fuel gas supply amount is the second supply amount QHi at the time of high load and the correction factor when the fuel gas supply amount is the first supply amount QLo at the time of low load. As shown in FIG. 7B, the fan rotation speed with respect to the first supply amount QLo at the time of low load is appropriately corrected using the correction coefficient CLo at the time of low load. Therefore, the mixed gas can be burned at an appropriate air-fuel ratio.

  When the fuel gas supply amount is between the first supply amount QLo at low load and the second supply amount QHi at high load (intermediate region), the stored correction coefficient CLo at low load is stored. And a correction coefficient CHi at the time of high load, a corresponding correction coefficient is obtained by interpolation calculation. For this reason, as long as only the correction coefficient at the time of low load and high load is stored, it is not necessary to memorize the correction coefficient corresponding to the fuel gas supply amount in the intermediate region. Thus, it is possible to easily correct the fan rotation speed appropriately with the correction coefficient.

  Although the combustion apparatus 100 of the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, in the above-described embodiment, in order to obtain an appropriate air-fuel ratio, the fan rotation speed (combustion air supply amount) is corrected. However, instead of the fan rotation speed, the opening degree of the proportional valve 116 is changed. (Supply amount of fuel gas) may be corrected.

  In addition, in the above-described embodiment, apart from the correspondence (see FIG. 3) between the fuel gas supply amount and the fan rotation speed at the time of low load and high load adjusted by the pressure adjustment work before shipment of the hot water supply device 1. The correction coefficient (see FIG. 4) at the time of low load and high load was stored in the memory 152. However, when the fan rotation speed is corrected based on the detection value of the thermocouple 140, the correction coefficient is not stored (updated), but the setting value itself of the fan rotation speed stored in the memory 152 is updated. You may do it. In this way, it is possible to immediately obtain the corrected fan rotation speed using the low load and high load set values stored in the memory 152.

  In the above-described embodiment, correction coefficients are stored for two points at low load and high load. However, the correction coefficients are not limited to two, and correction coefficients are set at three or more points with different fuel gas supply amounts. You may remember it. If the number of correction coefficients stored in this way is increased, the fan rotation speed can be finely adjusted in accordance with the fuel gas supply amount to increase the correction accuracy.

  Further, in the above-described embodiment, in the combustion start process of FIG. 5, when the mixed gas is not ignited even when ignited, correction (STEP 122) is performed to decrease the fan rotation speed. Therefore, along with this decrease correction, the correction coefficient changing process of FIG. 6 may be executed to update the correction coefficients stored at high load and low load stored in the memory 152. In this way, it is possible to reflect the details of correction at the time of ignition in the correction after ignition.

DESCRIPTION OF SYMBOLS 1 ... Hot-water supply apparatus, 10 ... Housing, 20 ... Combustion can,
100 ... Combustion device, 110 ... Burner, 112 ... Gas passage,
114 ... Solenoid valve, 116 ... Proportional valve, 120 ... Combustion fan,
130 ... Spark plug, 140 ... Thermocouple, 150 ... Controller,
152 ... Memory, 200 ... Heat exchanger, 202 ... Heat exchange fin,
204 ... Water pipe, 206 ... Water flow sensor 300 ... Exhaust pipe

Claims (4)

A mixed gas generating means for generating a mixed gas of the fuel gas and the combustion air while controlling a supply amount of the fuel gas and a supply amount of the combustion air;
Combustion operation start means for igniting the mixed gas and starting combustion operation;
Combustion state detection means for detecting the combustion state of the mixed gas;
Correction means for correcting a supply amount of the fuel gas or the combustion air according to the combustion state;
A combustion apparatus comprising: correction coefficient storage means for storing the correction coefficient for the supply amount,
As a correspondence relationship between the supply amount of the fuel gas and the supply amount of the combustion air, the set value of the supply amount of the combustion air when the supply amount of the fuel gas is the first supply amount, and the fuel gas A correspondence storage means for storing a set value of the supply amount of the combustion air when the supply amount is a second supply amount larger than the first supply amount,
The correction coefficient storage means stores the correction coefficient in association with the supply amount of the fuel gas, so that the correction coefficient when the supply amount of the fuel gas is the first supply amount is the first correction coefficient. And storing the correction coefficient when the fuel gas supply amount is the second supply amount as a second correction coefficient,
The mixed gas generation means generates the mixed gas in which the supply amount of the fuel gas or the combustion air is corrected by the correction coefficient corresponding to the supply amount of the fuel gas, and the supply amount of the fuel gas The combustion air supply amount determined according to the correspondence relationship is obtained by interpolating the first correction coefficient at the first supply amount and the second correction coefficient at the second supply amount. A combustion apparatus that generates the mixed gas by correcting with a correction coefficient . The combustion apparatus according to claim 1, wherein
The correction coefficient storage means determines the amount of change in the correction coefficient when the supply amount of the fuel gas is larger than the first supply amount and smaller than the second supply amount from the supply amount to the first supply amount. The combustion apparatus is distributed and stored in the first correction coefficient and the second correction coefficient in accordance with a ratio of the deviation up to and the deviation from the supply amount to the second supply amount . The combustion apparatus according to claim 1 or 2,
The combustion state detection means detects the presence or absence of ignition of the mixed gas at the time of ignition of the mixed gas,
The said correction | amendment means correct | amends the supply amount of the said fuel gas or the said combustion air according to the presence or absence of the ignition of the said mixed gas, The combustion apparatus characterized by the above-mentioned . A mixed gas generating means for generating a mixed gas of the fuel gas and the combustion air while controlling a supply amount of the fuel gas and a supply amount of the combustion air;
Combustion operation start means for igniting the mixed gas and starting combustion operation;
Combustion state detection means for detecting the combustion state of the mixed gas;
Correction means for correcting a supply amount of the fuel gas or the combustion air according to the combustion state;
Correction coefficient storage means for storing the correction coefficient of the supply amount;
A combustion apparatus comprising:
The combustion state detection means detects the presence or absence of ignition of the mixed gas at the time of ignition of the mixed gas,
The correction means corrects the supply amount of the fuel gas or the combustion air according to whether or not the mixed gas is ignited ,
The correction coefficient storage means stores the correction coefficient in association with the supply amount of the fuel gas,
The combustion apparatus characterized in that the mixed gas generating means generates the mixed gas in which the supply amount of the fuel gas or the combustion air is corrected by the correction coefficient corresponding to the supply amount of the fuel gas .

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