JP2014074529A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device capable of achieving a proper combustion state immediately after the start of a combustion operation.SOLUTION: When a combustion operation starts, a combustion state is detected and a supply amount of a fuel gas or combustion air is corrected. Also, correction values (supply correction values) are stored for a plurality of times of combustion operations. During a period from the start of the combustion operation to the detection of a combustion state, the supply amount of the fuel gas or the combustion air is corrected based on an estimated correction value determined from a plurality of times of supply correction values. As the estimated correction value is determined from the plurality of times of supply correction values determined based on a detection result of the combustion state, by using the estimated correction value, proper correction is possible even immediately after the start of the combustion operation. Furthermore, as the estimated correction value is determined from the plurality of times of supply correction values, even when the supply correction values vary greatly due to a sudden factor, the influence can be eliminated and a proper combustion state can always be achieved.

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 in the combustion apparatus, it is necessary to mix the fuel gas and the combustion air at an appropriate ratio. Therefore, the combustion apparatus is provided with a thermocouple which is a kind of temperature sensor. The temperature of the flame when the mixed gas burns (combustion state) corresponds to the ratio (air-fuel ratio) of the fuel gas and combustion air mixed so that the temperature of the combustion flame becomes an appropriate temperature. By adjusting the supply amount of combustion air (or one or both of the fuel gases), the mixed gas can be combusted appropriately.

  However, immediately after starting the combustion operation by igniting the mixed gas, the temperature of the flame cannot be accurately detected because the thermocouple is not warmed. Therefore, in order to detect the temperature of the flame as soon as possible after the thermocouple has been warmed up, the thermocouple is ignited from the state where it is completely cooled to room temperature. A technique has been proposed in which flame temperature is detected from the early stage after ignition at the time of reignition, distinguishing from “at the time of reignition” in which ignition is performed from a state that has not yet cooled completely (Patent Document 1). ).

JP-A-8-14552

  However, even with the proposed technique, the flame temperature cannot be detected immediately after the start of the combustion operation, and therefore the supply amount of fuel gas or combustion air cannot be controlled. As a result, there has been a problem that there is a possibility that a combustion failure may occur for a while after starting the combustion operation.

  The present invention has been made in response to the above-described problems in the prior art, and an object thereof is to provide a combustion apparatus capable of realizing an appropriate combustion state immediately after the start of the combustion operation.

In order to solve the above-described problems, the combustion apparatus of the present invention employs the following configuration. That is,
Combustion operation start means for starting combustion operation by igniting a mixed gas obtained by mixing fuel gas and combustion air, combustion state detection means for detecting the combustion state of the mixed gas, and detection result of the combustion state And a supply amount correcting means for correcting a supply amount of at least one of the fuel gas or the combustion air based on
Supply correction value storage means for storing a supply correction value that is a correction value of the supply amount by the supply amount correction means;
During the period from the start of the combustion operation until the combustion state is detected, the supply amount of at least one of the fuel gas or the combustion air is set according to the expected correction value determined based on the supply correction value. Prospect correction means to correct,
Before starting the combustion operation, the expected correction value determining means for determining the expected correction value based on the supply correction value,
The supply correction value storage means stores the supply correction values for a plurality of times retrospectively for a plurality of times of the combustion operation,
The expectation correction value determining means determines the expectation correction value based on the plurality of supply correction values.

  In the combustion apparatus of the present invention, when the combustion operation is started, the supply amount of at least one of the fuel gas and the combustion air is corrected based on the detection result of the combustion state. Also, the supply amount correction value (supply correction value) at this time is stored retrospectively for a plurality of combustion operations. Then, from the start of the combustion operation until the combustion state is detected, the supply amount of at least one of the fuel gas or the combustion air is set based on the expected correction value determined from the supply correction values for a plurality of times. to correct.

  The expected correction value used between the start of the combustion operation and the detection of the combustion state is determined based on the supply correction value at the time of multiple combustion operations, and each supply correction value is It is determined based on the detection result of the combustion state. For this reason, if it correct | amends based on a prospective correction value, the supply amount of at least one of fuel gas or combustion air can be correct | amended appropriately until a combustion state is detected. In addition, the prospective correction value is determined based on the supply correction value at the time of a plurality of combustion operations, so even if the supply correction value at the time of combustion operation greatly fluctuates due to a sudden factor, The influence can be eliminated. As a result, an appropriate combustion state can be realized immediately after the start of the combustion operation.

  Further, in the above-described combustion apparatus of the present invention, when the supply correction value obtained based on the result of detecting the combustion state in the combustion operation is smaller than the expected correction value used at the start of the combustion operation. Alternatively, the supply correction value may be determined as a prospective correction value used at the start of the next combustion operation.

  When maintenance of the combustion apparatus is performed, the combustion apparatus returns to a normal state, so that a correction value (supply correction value) for making the combustion state normal is likely to be small. Therefore, in the combustion operation immediately after the maintenance is performed, the supply correction value in the combustion operation becomes small, while the expected correction value determined based on the supply correction value before the maintenance remains a large value. Yes. From this, when the supply correction value in a certain combustion operation becomes smaller than the expected correction value used at the start of the combustion operation, the supply correction value is used as the expected correction value used at the start of the next combustion operation. The mixed gas can be appropriately burned by immediately reflecting the fact that the maintenance has been performed in the expected correction value.

  In the combustion apparatus of the present invention described above, the expected correction value may be determined from the supply correction values for a plurality of times as follows. First, it is determined whether or not the difference between the maximum value and the minimum value of the supply correction values for a plurality of times is smaller than a predetermined threshold value. If the difference value is smaller than the threshold value, the minimum value of the supply correction value may be determined as the prospective correction value.

  In this way, it is possible to easily determine a prospective correction value from a plurality of supply correction values. In addition, since the expected correction value is always estimated conservatively, the correction from the start of the combustion operation to the detection of the combustion state is not excessive, and the combustion state does not become unstable.

  Further, in the combustion apparatus of the present invention described above, the prospective correction value may be determined as follows. First, it is determined whether or not the difference between the maximum value and the minimum value of the supply correction values for a plurality of times is greater than a predetermined threshold value. If the difference value is larger than the threshold value, the prediction correction value used at the start of the previous combustion operation may be determined as a new prediction correction value.

  While the combustion operation is repeated many times, the supply correction value in a certain combustion operation may change greatly for some unexpected reason. Even in such a case, in the combustion apparatus of the present invention, the difference between the maximum value and the minimum value of the supply correction values for a plurality of times becomes larger than a predetermined threshold value, so the expected correction value used at the start of the previous combustion operation is This is used as a prospective correction value at the start of the next combustion operation. For this reason, even when a combustion operation in which the supply correction value is greatly changed for some unexpected reason occurs, the mixed gas can always be appropriately burned immediately after the start of the combustion operation without being affected by it.

  Further, in the combustion apparatus of the present invention described above, a distinction is made between a low load operation in which the fuel gas supply amount is smaller than a predetermined value and a high load operation in which the fuel gas supply amount is larger than that in the low load operation. The supply amount may be corrected in the state. Then, from the start of the combustion operation to the detection of the combustion state, the expected correction value is determined based on the respective supply correction values during the low load operation and the high load operation, and the supply amount is corrected. Also good.

  In this way, the supply amount can be corrected by distinguishing between the low load operation and the high load operation, so that it is possible to more appropriately correct the supply amount and appropriately burn the mixed gas.

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 operation control process of a present Example. It is explanatory drawing which shows the map in which the fan rotational speed was set with respect to the fuel gas supply amount. It is a flowchart of the pre-activation correction coefficient determination process executed in the operation control process. It is explanatory drawing which illustrated a mode that the correction coefficient RTCIN (0) before activation used at the time of the next combustion operation start was determined based on three correction coefficients RTC (1)-(3) after activation. It is a flowchart of the pre-activity correction coefficient determination process of a 1st modification. It is explanatory drawing which illustrated a mode that the pre-activation correction coefficient determination process of a 1st modification determines the pre-activation correction coefficient RTCIN (0) from three post-activation correction coefficients RTC (1)-(3). It is a flowchart of the pre-activation correction coefficient reading process performed in the combustion apparatus 100 of the 2nd modification. It is a flowchart of the correction coefficient memory | storage process after activation performed with the combustion apparatus 100 of a 2nd modification.

  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 includes a burner 110 that burns a mixed gas of fuel gas and combustion air, a gas passage 112 that supplies fuel gas to the combustion apparatus 100, a combustion fan 120 that supplies combustion air to the burner 110, An ignition plug 130 that ignites the mixed gas and starts combustion in the burner 110, a thermocouple 140 that detects the temperature (combustion state) of the combustion flame in the burner 110, and the like are provided. The gas passage 112 is provided with an electromagnetic valve 114 for opening and closing the gas passage 112 and a proportional valve 116 for controlling the flow rate of the fuel gas passing through the gas passage 112. The electromagnetic valve 114 and the proportional valve 116 are the controller 150. It is connected to the. The controller 150 is also connected with a combustion fan 120, a spark plug 130, a thermocouple 140, and the like. Further, the controller 150 has a built-in memory 152. Further, the burner 110, the spark plug 130, and the thermocouple 140 are accommodated in the combustion can 20 provided in the housing 10 together with the heat exchanger 200. In this embodiment, the spark plug 130 corresponds to “combustion operation start means” in the present invention, and the thermocouple 140 corresponds to “combustion state detection means” in 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. 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 hot water supply apparatus 1 having such a configuration, when water flows through the water pipe 204, combustion of the mixed gas in the burner 110 is started, and the water flowing through the water pipe 204 is heated by the combustion exhaust gas in the heat exchanger 200. , Flows out to the outside as hot water. 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. Therefore, the controller 150 controls the rotational speed of the combustion fan 120 (hereinafter referred to as “fan rotational speed”) based on the temperature (combustion state) of the combustion flame detected by the thermocouple 140, thereby The supply amount is controlled. As described above, the control for starting the combustion operation in the burner 110 and the control for appropriately maintaining the combustion state of the burner 110 after the start of the combustion operation are realized by the controller 150 performing the following operation control. Has been.

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

  When the operation control process is started, first, the fan rotation speed is determined (STEP 100). The fan rotation speed is determined as follows based on the flow rate of water detected by the water flow sensor, the set value of the hot water supply temperature set by the user of the hot water supply apparatus 1, and the like. First, the amount of fuel gas to be burned per unit time (accordingly, the amount of fuel gas supplied to the burner 110) is determined from the flow rate of water and the hot water supply temperature. When the fuel gas supply amount is determined, the necessary combustion air supply amount is determined, so that the fan rotation speed at which the combustion air supply amount is obtained can be determined. In the memory 152 of the controller 150 of the present embodiment, the fan rotation speed with respect to the fuel gas supply amount as shown in FIG. 3 is stored in the form of a map. Therefore, the controller 150 obtains a necessary fuel gas supply amount based on the flow rate of water and the set value of the hot water supply temperature, and then corresponds to the fuel gas supply amount by referring to a map stored in the memory 152. Determine the fan speed.

  Subsequently, the pre-activation correction coefficient RTCIN (1) for correcting the fan rotation speed is read from the memory 152 (STEP 102). Here, the “pre-activation correction coefficient” is the following correction coefficient. As described above with reference to FIG. 1, the hot water supply apparatus 1 of this embodiment includes the thermocouple 140 and corrects the fan rotation speed based on the flame temperature detected by the thermocouple 140. However, since the thermocouple 140 does not output the correct temperature unless the warm-up is completed, the fan rotation speed can be corrected using the thermocouple 140 after the warm-up is completed and the thermocouple 140 is activated. Become. Therefore, it is necessary to correct the fan rotation speed by another method until the thermocouple 140 is activated. The pre-activation correction coefficient is a correction coefficient for correcting the fan rotation speed without using the output of the thermocouple 140 until the thermocouple 140 is activated. On the other hand, the correction coefficient for correcting the fan rotation speed based on the output of the thermocouple 140 after the activation of the thermocouple 140 is referred to as a “post-activation correction coefficient” to distinguish it from the pre-activation correction coefficient. To do. In addition, the pre-activation correction coefficient is determined in advance by a method described later in the hot water supply apparatus 1 of the present embodiment, and is stored in the memory 152 of the controller 150.

  Subsequently, the combustion fan 120 is rotated at the fan rotation speed corrected using the pre-activation correction coefficient RTCIN (1) (STEP 104). Then, combustion air is supplied to the burner 110 at a flow rate corresponding to the fan rotation speed. Then, the solenoid valve 114 and the proportional valve 116 are opened to supply the fuel gas to the burner 110, and the mixed gas is ignited by the spark plug 130 to start the combustion operation in the combustion device 100, and then the timer is started ( (STEP 106). Note that the opening degree of the proportional valve 116 at this time is set to an opening degree corresponding to the fuel gas supply amount obtained when the fan rotational speed is determined in STEP 100.

  Thereafter, it is determined whether or not the time measured by the timer has reached the activation time of the thermocouple 140 (time required for completion of warm-up) (STEP 108). If the activation time has not been reached (STEP 108: no), the same As it repeats the determination, it enters a standby state. Then, when the activation time has elapsed (STEP 108: yes), it is considered that the thermocouple 140 has been warmed up and a correct output can be obtained, so that the flame temperature (combustion state) detected by the thermocouple 140 is reached. Based on this, the fan rotation speed is corrected (STEP 110). For example, when the flame temperature detected by the thermocouple 140 is higher than a predetermined target range, the ratio of the combustion air to the fuel gas is considered to be smaller than the target value, so that the fan rotation speed is increased. Conversely, when the flame temperature detected by the thermocouple 140 is lower than the predetermined target range, the ratio of the combustion air to the fuel gas is considered to be larger than the target value, so that the fan rotation speed is decreased.

  In correcting the fan rotation speed, the fan rotation speed may be corrected by a certain amount regardless of how far the flame temperature detected by the thermocouple 140 is separated from the target range. You may correct | amend only the magnitude | size according to the gap with respect to a target range. Further, in this embodiment, in order to set the ratio of the combustion air to the fuel gas as the target value, the supply amount of the combustion air is changed by changing the fan rotation speed. The supply amount of the fuel gas may be changed by changing. In this embodiment, since the controller 150 corrects the fan rotation speed, the controller 150 corresponds to the “supply amount correcting means” in the present invention.

  Subsequently, it is determined whether or not the combustion operation of the combustion apparatus 100 is to be terminated (STEP 112). When it is determined that the combustion operation is not to be terminated (STEP 112: no), the process returns to STEP 110 again and the thermocouple 140 is output. Continue to correct the fan speed based on. Such processing is repeated while the combustion apparatus 100 is in a combustion operation. If it is determined that the combustion operation in the combustion apparatus 100 is to be ended (STEP 112: yes), a correction coefficient corresponding to the fan rotation speed at the end of the operation is stored in the memory 152 as a post-activation correction coefficient RTC (1) (STEP 114). ). The correction coefficient at this time is calculated as follows. First, the fuel gas supply amount at the end of the operation is detected, and the fan speed is acquired by referring to the map of FIG. Then, the correction coefficient is calculated by dividing the fan rotation speed at the end of the operation by the fan rotation speed obtained from the map of FIG.

  When the correction coefficient calculated in this way is stored as the post-activation correction coefficient RTC (1) (STEP 114), in preparation for the start of the next combustion operation, the pre-activation correction coefficient is determined by a method described later (STEP 200), and then, FIG. The operation control process is terminated. In this embodiment, the post-activation correction coefficient corresponds to the “supply correction value” in the present invention, and the memory 152 that stores the post-activation correction coefficient corresponds to the “supply correction value storage unit” in the present invention. The pre-activation correction coefficient corresponds to the “expected correction value” in the present invention, and the controller 150 that corrects the fan rotation speed based on the pre-activation correction coefficient corresponds to the “expected correction means” in the present invention. Further, as will be described below, the controller 150 determines the pre-activity correction coefficient, and thus corresponds to the “probability correction value determining means” in the present invention.

  FIG. 4 shows a flowchart of the pre-activity correction coefficient determination process for determining the pre-activity correction coefficient. In the pre-activation correction coefficient determination process, first, post-activation correction coefficients RTC (1) to (3) are read from the memory 152 of the controller 150 (STEP 202). Here, the post-activation correction coefficient RTC (1) is a correction coefficient stored in the memory 152 at the end of this combustion operation (see STEP 114 in FIG. 3). The post-activation correction coefficient RTC (2) is a correction coefficient stored in the memory 152 at the end of the previous combustion operation. Further, the post-activation correction coefficient RTC (3) is a correction coefficient stored in the memory 152 at the end of the previous combustion operation. Note that, here, it is assumed that there are three post-activation correction coefficients, but at least two post-activation correction coefficients RTC may be read.

  Next, it is determined whether or not the read post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1) (see STEP 102 in FIG. 2) used at the start of the current combustion operation (STEP 204). . As a result, when the post-activation correction coefficient RTC (1) is not smaller than the pre-activation correction coefficient RTCIN (1) (STEP 204: no), the read after-activation correction coefficient RTC (1) to (3) A difference value between the maximum value and the minimum value is calculated (STEP 206), and it is determined whether or not the difference value is smaller than a predetermined threshold value (STEP 208). As a result, when the difference value is equal to or smaller than the predetermined threshold (STEP 208: yes), the minimum value among the post-activation correction coefficients RTC (1) to (3) is used for the pre-activation correction used in the next combustion operation. The coefficient RTCIN (0) is stored in the memory 152 (STEP 210). Here, the minimum value of the post-activation correction coefficient RTC (1) to (3) is stored as the pre-activation correction coefficient RTCIN (0), but the average value of the post-activation correction coefficient RTC (1) to (3) is The pre-activation correction coefficient RTCIN (0) may be used. Alternatively, since it is assumed here that the difference between the maximum value and the minimum value of the post-activation correction coefficients RTC (1) to (3) is small, the post-activation correction coefficients RTC (1) to (3) The maximum value may be the pre-activation correction coefficient RTCIN (0).

  On the other hand, when the difference between the maximum value and the minimum value of the post-activation correction coefficients RTC (1) to (3) is larger than a predetermined threshold (STEP 208: no), the post-activation correction coefficient RTC An average value RTC (Ave) of (1) to (3) is calculated and stored in the memory 152 as a pre-activation correction coefficient RTCIN (0) used at the start of the next combustion operation (STEP 212). When the difference between the maximum value and the minimum value of the post-activation correction coefficients RTC (1) to (3) is larger than a predetermined threshold (STEP 208: no), the pre-activation correction coefficient RTCIN (0 ) Will be described later.

  The processing for determining the pre-activation correction coefficient RTCIN (0) when the post-activation correction coefficient RTC (1) is not smaller than the pre-activation correction coefficient RTCIN (1) has been described above. On the other hand, when the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1) (STEP 204: yes), the post-activation correction coefficient RTC (1) is changed to the pre-activation correction coefficient RTCIN (0). ) Is stored in the memory 152 (STEP 214). This reason (the reason why the post-activation correction coefficient RTC (1) is used as the pre-activation correction coefficient RTCIN (0) when the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1)) will also be described later. To do.

  Subsequently, it is determined whether or not the pre-activation correction coefficient RTCIN (0) for starting the next combustion operation is smaller than 1.0 (STPE 216), and if smaller than 1.0 (STEP 216: yes). Then, after changing the pre-activation correction coefficient RTCIN (0) to 1.0 (STEP 218), the pre-activation correction coefficient determination process of FIG. 4 is terminated, and the operation control process of FIG. 2 is resumed. On the other hand, when the pre-activation correction coefficient RTCIN (0) is larger than 1.0 (STEP 216: no), the pre-activation correction coefficient determination process is performed without changing the pre-activation correction coefficient RTCIN (0). To return to the operation control process of FIG.

  FIG. 5 illustrates a state in which the pre-activation correction coefficient RTCIN (0) is determined based on the three post-activation correction coefficients RTC (1) to (3). The circles shown in the figure represent the post-activation correction coefficient RTC, and the asterisk in the figure represents the pre-activation correction coefficient RTCIN.

  For example, as illustrated in FIG. 5A, it is assumed that the post-activation correction coefficients RTC (1) to (3) at the time of the three combustion operations from this time to the previous time are substantially the same value. As described above, if the post-activation correction coefficient RTC determined based on the output of the thermocouple 140 takes approximately the same value in the past multiple combustion operations (three times in this embodiment), the next combustion is performed. The post-activation correction coefficient RTC determined based on the output of the thermocouple 140 during operation is expected to be substantially the same value. If so, it is considered that the mixed gas can be combusted appropriately by correcting the fan rotation speed using the correction coefficient even before the thermocouple 140 is activated. Therefore, in the pre-activation correction coefficient determination process of the present embodiment, the difference value between the maximum value and the minimum value of the three post-activation correction coefficients RTC (1) to (3) is calculated, and the difference value is a predetermined threshold value. Is smaller than the minimum value of the three post-activation correction coefficients RTC (1) to (3), the pre-activation correction coefficient RTCIN (0) for starting the next combustion operation (STEPs 206 to 210 in FIG. 4). reference).

  In this way, the fan rotation speed is corrected based on the pre-activation correction coefficient RTCIN (0) until the thermocouple 140 is activated during the next combustion operation, so that the mixed gas is supplied immediately after the start of the combustion operation. Can be burned properly. The minimum value of the three post-activation correction coefficients RTC (1) to (3) is set as the next pre-activation correction coefficient RTCIN (0), and the pre-activation correction coefficient RTCIN (0) is smaller than “1.0”. (See STEP 218). For this reason, the fan rotational speed is corrected most conservatively. As a result, the combustion operation can always be performed on the safe side until the thermocouple 140 is activated.

  Further, during the combustion operation, when a sudden factor such as the outlet of the exhaust pipe 300 being blocked by some obstacle occurs, as illustrated in FIG. 5B, after the activation during the combustion operation. The correction coefficient RTC (1) increases greatly. In such a case, in the pre-activation correction coefficient determination process of the present embodiment, the difference value between the maximum value and the minimum value of the three post-activation correction coefficients RTC (1) to (3) is less than a predetermined threshold value. It is determined that it is large (STEP 208: no in FIG. 4). In this case, the average value RTC (Ave) of the last three post-activation correction coefficients RTC (1) to (3) including the current combustion operation is the pre-activation correction coefficient for the next combustion operation. RTCIN (0) is obtained (STEP 212). For this reason, even if a sudden factor occurs during the combustion operation, the mixed gas can be appropriately burned immediately after the start of the combustion operation without being greatly affected by the sudden factor. Of course, when the state in which the exhaust tube 300 is blocked for some reason continues, the state described above with reference to FIG. It becomes possible to burn the mixed gas appropriately immediately after the start of operation. Instead of the average value RTC (Ave), the minimum value RTC (Min) of the last three post-activation correction coefficients RTC (1) to (3) is used as the pre-activation correction coefficient RTCIN ( 0).

  Further, when the heat exchange fin 202 of the heat exchanger 200 is cleaned, the passage resistance of the combustion exhaust gas suddenly decreases, and the post-activation correction coefficient RTC (1) suddenly decreases as shown in FIG. 5C. Is determined that the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1) (STEP 204: yes), and the rapidly decreased post-activation correction coefficient RTC (1) starts the next combustion operation. The pre-activity correction coefficient RTCIN (0) at the time is obtained (STEP 214). For this reason, when the heat exchange fins 202 of the heat exchanger 200 are cleaned, the influence is immediately reflected in the pre-activation correction coefficient RTCIN (0) at the start of the next combustion operation, and the combustion operation starts. It becomes possible to burn the mixed gas appropriately immediately after.

  In the above-described embodiment, when the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1) (STEP 204: yes), the post-activation correction coefficient RTC (1) is always set. The pre-activation correction coefficient RTCIN (1) is described as (STEP 214). However, to the extent that the post-activation correction coefficient RTC (1) is slightly smaller than the pre-activation correction coefficient RTCIN (1), the post-activation correction coefficient RTC (1) need not necessarily be the pre-activation correction coefficient RTCIN (1). There is no. Further, in the above-described embodiment, when the difference between the maximum value and the minimum value of the correction coefficients RTC (1) to (3) for the past three times is larger than the threshold value (STEP 208: no), these RTCs The average value RTC (Ave) of (1) to (3) has been described as being used as the next pre-activity correction coefficient RTCIN (0). However, when the difference between the maximum value and the minimum value of RTC (1) to RTC (3) is larger than the threshold value, the average value RTC (Ave) is not necessarily used as RTCIN (0). Below, such a 1st modification is demonstrated easily.

  FIG. 6 shows a flowchart of the pre-activation correction coefficient determination process of the first modification. This process is a process executed instead of the pre-activity correction coefficient determination process (STEP 200) described above with reference to FIG. Also in the pre-activation correction coefficient determination process (STEP 250) of the first modification, first, post-activation correction coefficients RTC (1) to (3) are read from the memory 152 of the controller 150 (STEP 252).

  Next, a difference value between the maximum value and the minimum value among the post-activation correction coefficients RTC (1) to (3) is calculated (STEP 254), and the difference value is equal to or less than a predetermined threshold value. (STEP256: yes), the minimum value among the post-activation correction coefficients RTC (1) to (3) is stored in the memory 152 as the pre-activation correction coefficient RTCIN (0) used during the next combustion operation (STEP258). On the other hand, when the difference value is larger than the predetermined threshold (STEP 256: no), the post-activation correction coefficient RTC (1) at the time of the current combustion operation is the pre-activation value used at the start of the current combustion operation. It is determined whether or not it is smaller than the correction coefficient RTCIN (1) (STEP 260). As a result, when the post-activation correction coefficient RTC (1) is not smaller than the pre-activation correction coefficient RTCIN (1) (STEP 260: no), the pre-activation correction coefficient RTCIN (1) is used at the start of the next combustion operation. The pre-correction coefficient RTCIN (0) is stored in the memory 152 (STEP 262). On the other hand, when the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1) (STEP 260: yes), the post-activation correction coefficient RTC (1) is used at the start of the next combustion operation. The coefficient RTCIN (0) is stored in the memory 152 (STEP 264).

  The subsequent processing is the same as the pre-activity correction coefficient determination processing (STEP 200) described above. That is, it is determined whether or not the pre-activation correction coefficient RTCIN (0) is smaller than 1.0 (STPE 266). If it is smaller than 1.0 (STEP 266: yes), the pre-activation correction coefficient RTCIN (0) is determined. Is changed to 1.0 (STEP 268). On the other hand, when the pre-activation correction coefficient RTCIN (0) is larger than 1.0 (STEP 266: no), the pre-activation correction coefficient determination process is performed without changing the pre-activation correction coefficient RTCIN (0). Exit.

  FIG. 7 illustrates a state in which the pre-activation correction coefficient determination process of the first modification determines the pre-activation correction coefficient RTCIN (0) from the three post-activation correction coefficients RTC (1) to (3). For example, as illustrated in FIG. 7A, when the difference between the maximum value and the minimum value of the post-activation correction coefficients RTC (1) to (3) is smaller than a predetermined threshold value, As in the correction coefficient determination process (STEP 200), the minimum value of the post-activation correction coefficients RTC (1) to (3) is set as the next pre-activation correction coefficient RTCIN (0) (see STEPs 254 to 258 in FIG. 6).

  Further, as illustrated in FIG. 7B, the post-activation correction coefficient RTC (1) is greatly increased due to some sudden factor, or conversely, the post-activation correction coefficient RTC (1) is largely decreased. In such a case, it is determined that the difference between the maximum value and the minimum value of the three post-activation correction coefficients RTC (1) to (3) is larger than a predetermined threshold (STEP 256: no in FIG. 6). If the post-activation correction coefficient RTC (1) suddenly increases as shown in FIG. 7B, it is determined that the post-activation correction coefficient RTC (1) is larger than the pre-activation correction coefficient RTCIN (1). As a result (STEP 260: no), the pre-activation correction coefficient RTCIN (1) during the current combustion operation becomes the pre-activation correction coefficient RTCIN (0) during the next combustion operation (STEP 262). For this reason, even if a sudden factor occurs during the combustion operation, the mixed gas can be appropriately burned immediately after the start of the combustion operation without being affected by the sudden factor.

  Further, when the post-activation correction coefficient RTC (1) suddenly decreases as shown in FIG. 7C, it is determined that the post-activation correction coefficient RTC (1) is smaller than the pre-activation correction coefficient RTCIN (1). (STEP260: yes), the sharply reduced post-activation correction coefficient RTC (1) becomes the pre-activation correction coefficient RTCIN (0) at the start of the next combustion operation (STEP 264). For this reason, when the heat exchange fins 202 of the heat exchanger 200 are cleaned, the influence is immediately reflected in the pre-activation correction coefficient RTCIN (0) at the start of the next combustion operation, and the combustion operation starts. It becomes possible to burn the mixed gas appropriately immediately after.

  In the above-described embodiment or the first modification, the fan rotation speed is determined according to the amount of fuel gas supplied (see FIG. 3), but the fan rotation speed correction coefficient (that is, the pre-activation correction coefficient RTCIN and The post-activation correction coefficient RTC) has been described as a simple coefficient that does not depend on the amount of fuel gas supplied. However, the fan rotation speed correction coefficient (that is, the pre-activation correction coefficient RTCIN and the post-activation correction coefficient RTC) is also determined in accordance with the fact that the fan rotation speed to be corrected is determined according to the fuel gas supply amount. It may be determined according to the gas supply amount.

  FIG. 8 is a flowchart of the pre-activation correction coefficient reading process performed by the combustion apparatus 100 of the second modification. This process is a process executed instead of STEP 102 after the fan rotation speed is determined (STEP 100) in the operation control process described above with reference to FIG. When the pre-activation correction coefficient reading process (STEP 300) is started, first, it is determined whether or not the operation state of the combustion apparatus 100 is a high load operation state (STEP 302). This determination is made based on the fuel gas supply amount obtained to determine the fan rotation speed. That is, when the fuel gas supply amount is larger than the predetermined amount, it is determined as a high load operation state, and when it is less than the predetermined amount, it is determined as a low load operation state.

  As a result, when it is determined that the operation is a high load operation (STEP 302: yes), the pre-activation correction coefficient for high load is read from the memory 152 of the controller 150 (STEP 304). On the other hand, when it is determined that the operation is not a high load (STEP 302: no), a pre-activation correction coefficient for low load is read (STEP 306). The pre-activation correction coefficient for high load and low load is determined by a method described later and stored in the memory 152 in advance. When the pre-activation correction coefficient for high load or low load is read (STEP 304 and STEP 306), the pre-activation correction coefficient reading process of FIG. 8 is terminated and the operation control process of FIG. 2 is resumed.

  FIG. 9 is a flowchart of post-activation correction coefficient storage processing performed in the combustion apparatus 100 of the second modification. This process is a process executed instead of STEP 114 when it is determined that the combustion operation is ended in the operation control process of FIG. 2 (STEP 112: yes). When the post-activation correction coefficient storage process (STEP 400) is started, it is determined whether or not the operation state of the combustion apparatus 100 is a high load operation state (STEP 402). This determination is made by comparing the fuel gas supply amount before the end of the combustion operation with a predetermined amount.

  As a result, when the fuel gas supply amount is larger than the predetermined amount, it is determined that the operation is a high load operation (STEP 402: yes), and the fan rotation speed correction coefficient at the end of the combustion operation is determined as the activity for the high load operation. The post correction coefficient is stored in the memory 152 of the controller 150 (STEP 404). On the other hand, when the fuel gas supply amount is smaller than the predetermined amount, it is determined that the operation is a low load operation (STEP 402: no), and the correction coefficient of the fan rotation speed at the end of the combustion operation is used for the low load operation. Is stored in the memory 152 of the controller 150 (STEP 406). When the post-activation correction coefficient for high load or low load is stored in this way (STEP 404, STEP 406), the post-activation correction coefficient storage process of FIG. 9 is terminated and the operation control process of FIG. 2 is resumed.

  Then, when the combustion apparatus 100 of the second modification returns from the post-activation correction coefficient storage process, the pre-activation correction coefficient determination process is started (see STEP 200 in FIG. 2). The contents of the pre-activation correction coefficient determination process are the same as the pre-activation correction coefficient determination process of the present embodiment described above with reference to FIGS. 4 and 5, but the post-activation correction is performed in the combustion apparatus 100 of the second modification. Two types of correction coefficients for high load and low load are stored as coefficients. Correspondingly, two types of pre-activation correction coefficients for high load and low load are determined as the pre-activation correction coefficient. The pre-activity correction coefficient for high load or low load read in the pre-activity correction coefficient reading process of FIG. 8 is determined in this way.

  In the combustion apparatus 100 according to the modified example described above, the fan rotation speed can be corrected according to the load by distinguishing between the case of high load operation and the case of low load operation. The ratio with air can be adjusted more finely, and the mixed gas can be burned more appropriately. For this reason, it becomes possible to burn the mixed gas more appropriately even after the start of the combustion operation until the thermocouple 140 is activated.

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

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, 300 ... Exhaust pipe

Claims (5)

Combustion operation start means for starting combustion operation by igniting a mixed gas obtained by mixing fuel gas and combustion air, combustion state detection means for detecting the combustion state of the mixed gas, and detection result of the combustion state And a supply amount correcting means for correcting a supply amount of at least one of the fuel gas or the combustion air based on
Supply correction value storage means for storing a supply correction value that is a correction value of the supply amount by the supply amount correction means;
During the period from the start of the combustion operation until the combustion state is detected, the supply amount of at least one of the fuel gas or the combustion air is set according to the expected correction value determined based on the supply correction value. Prospect correction means to correct,
Before starting the combustion operation, the expected correction value determining means for determining the expected correction value based on the supply correction value,
The supply correction value storage means stores the supply correction values for a plurality of times retrospectively for a plurality of times of the combustion operation,
The expectation correction value determining means determines the expectation correction value based on the plurality of supply correction values. The combustion apparatus according to claim 1, wherein
When the supply correction value based on the detection result of the combustion state in the combustion operation is smaller than the prediction correction value used at the start of the combustion operation, the expectation correction value determination means A combustion apparatus, wherein a correction value is determined as the prospective correction value. The combustion apparatus according to claim 1 or 2,
When the difference between the maximum value and the minimum value of the supply correction values for the plurality of times is smaller than a predetermined threshold value, the expectation correction value determination unit determines the minimum value of the supply correction value as the expectation correction value. A combustion apparatus characterized by: The combustion apparatus according to any one of claims 1 to 3,
When the difference between the maximum value and the minimum value of the plurality of supply correction values for a plurality of times is greater than a predetermined threshold value, the expectation correction value determination unit determines the expectation correction value used at the start of the previous combustion operation. The combustion apparatus is determined as a new prospective correction value. The combustion apparatus according to any one of claims 1 to 4,
The supply amount correction means, the supply correction value storage means, the expectation correction means, and the expectation correction value determination means are configured so that the supply amount of the fuel gas is smaller than a predetermined value during low load operation and during the low load operation. A combustion apparatus that performs each operation while distinguishing from a high-load operation in which the supply amount of the fuel gas is larger than that.

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