JP2010203704A - Combustion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion device capable of accurately correcting an air volume according to a property of a fan even when fan rotational frequency-current characteristic has variation due to individual difference, in a case when the fan rotational frequency-current characteristic is variable. <P>SOLUTION: When a fan electric current of a fan motor is controlled by a fan control means 32 in a water heater 1, a first fan correction coefficient calculated by an operation processing section 33 is memorized in a storing section 34 first. Then a fan correction coefficient calculated from the first correction coefficient and a second correction coefficient based on output of a flame thermistor 8a by the operation processing section 33 is memorized in the storing section 34. Then the air volume of the fan is corrected on the basis of the fan correction coefficient by a correcting section 35. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a combustion apparatus in which a fan current is controlled so that the rotational speed of a fan that supplies combustion air to a gas burner matches a target rotational speed corresponding to the combustion amount of the gas burner.

  Conventionally, as the above-described combustion apparatus, one provided with the following fan control means for controlling the operation of a fan that supplies combustion air to a gas burner is known (see Patent Document 1).

  The fan control means uses a predetermined fan rotation speed-current characteristic corresponding to the fan current characteristic indicating the lower limit of fan current variation as a reference, and corrects the fan current from the difference between the detected current value and the reference current value. First calculation means for calculating a value, second calculation means for calculating a fan current recognition value that is a difference between the detected current value and the fan current correction value, and a fan correction value based on the fan current recognition value. 3 calculation means, storage means for storing a reference current value, fan current correction value, fan current recognition value, and fan correction value, respectively, and correction means for correcting the fan air volume based on the fan correction value. .

  In this combustion apparatus, when the fan control unit controls the fan current of the fan motor, first, the fan current correction value calculated by the first calculation unit is stored in the storage unit. Next, the fan current recognition value calculated by the second calculation means is stored in the storage means. Subsequently, the fan correction value calculated by the third calculation means is stored in the storage means. Then, the fan air volume correction based on the fan correction value is performed by the correction means.

  Therefore, according to the above combustion apparatus, even if the fan rotation speed-current characteristic varies due to individual differences, the air volume correction is performed according to the characteristics of the fan, and the adjustment work by the operator is reduced and the air volume is highly accurate. Correction can be performed.

JP 2006-094575 A

  In the above combustion apparatus, the fan rotation speed-current characteristic is based on the fan rotation speed-current characteristic determined in advance corresponding to the fan current characteristic indicating the lower limit of the fan current variation. There is a problem that accurate airflow correction cannot be performed when the fan rotation speed-current characteristics fluctuate due to fluctuations with time and the tendency of the motor at high / low rotation.

  The present invention provides a combustion apparatus capable of performing an accurate air flow correction according to the characteristics of the fan even when the fan speed-current characteristics fluctuate due to individual differences when the fan speed-current characteristics fluctuate. With the goal.

  The combustion apparatus of the present invention includes a gas burner, a fan that supplies combustion air to the gas burner, a fan motor that rotationally drives the fan, current detection means that detects a fan current value of the fan motor, A rotation speed detection means for detecting the rotation speed; a flame temperature detection means for detecting a flame temperature of the gas burner; and the fan motor so that the rotation speed of the fan coincides with a target rotation speed corresponding to a combustion amount of the gas burner. Fan control means for controlling the fan current of the fan, wherein the fan control means is based on a predetermined fan rotation speed-current characteristic corresponding to a fan current characteristic indicating a lower limit of variation in the fan current, and A first correction value is calculated based on the detected fan current value detected by the current detecting means and the reference current value based on the fan rotational speed-current characteristic. First calculation means; second calculation means for calculating a fan correction value based on the first correction value and a second correction value based on the output of the flame temperature detection means; the fan current value; the reference current value; The image processing apparatus includes storage means for storing one correction value, the second correction value, and the fan correction value, and correction means for correcting the air volume of the fan based on the fan correction value.

  According to the present invention, when controlling the fan current of the fan motor by the fan control means, first, the first correction value calculated by the first calculation means is stored in the storage means. Then, the fan correction value calculated by the second calculation means based on the first correction value and the second correction value based on the output of the flame temperature detection means is stored in the storage means. Thereafter, the fan air volume correction based on the fan correction value is performed by the correcting means. Accordingly, since the fan correction value is calculated by the first correction value and the second correction value based on the output of the flame temperature detecting means, when the fan rotation speed-current characteristic varies, the fan rotation speed-current characteristic varies depending on individual differences. Even if there is variation, it is possible to correct the airflow accurately according to the characteristics of the fan.

  In the present invention, the flame temperature detection means has an upper limit output value and a lower limit output value as to whether or not to control a fan current of the fan motor, and the fan control means is configured to control the fan according to the second correction value. It is preferable to stop the combustion by stopping the fan when the output of the flame temperature detecting means exceeds the upper limit output value even if the correction for increasing the air volume is repeated a predetermined number of times.

  According to this preferred embodiment, the combustion apparatus can be safely stopped when the fan current cannot be controlled due to a fan failure or the like.

  In the present invention, it is preferable that the fan control means stores the fan correction value even after the combustion is stopped, and corrects the air volume of the fan based on the fan correction value in the next combustion.

  According to this preferable mode, in the next combustion, ignition and combustion from the initial stage of ignition can be made favorable.

  In the present invention, it is preferable that the fan control means calculates the fan correction value based on the second correction value based on the output of the flame temperature detection means in a region after the start of combustion and having a predetermined amount of heat or more.

  According to this preferred embodiment, it is possible to perform highly accurate correction by using a region where the accuracy of the output of the flame temperature detecting means is high.

  In the present invention, it is preferable that the fan control means corrects the air volume of the fan based on the fan correction value even in combustion in a region where the flame temperature detection means does not exist.

  According to this preferred embodiment, it is possible to maintain good combustion in a region where no flame temperature detecting means is present.

It is explanatory drawing which shows schematic structure of the water heater to which the combustion apparatus which concerns on this invention is applied. It is a figure which shows the reference line of the fan rotation speed-current characteristic in the water heater of embodiment. It is a flowchart which shows the action | operation of the fan control means in the water heater of embodiment. It is a figure which shows the output of the flame thermistor in which the fan control means in the water heater of embodiment controls a fan electric current by the output of a flame thermistor. It is a figure which shows the state in which the fan control means in the water heater of embodiment controls a fan electric current by the output of a flame thermistor. It is a figure which shows the correction coefficient of the thermistor used for correction | amendment of the fan control means in the water heater of embodiment.

  The combustion apparatus shown in FIG. 1 is a water heater 1, a gas burner 2, a ventilation system 3 including the gas burner 2, a fan 4 provided in the ventilation system 3 and forcibly supplying combustion air to the gas burner 2, and a water passage 5 and a control unit 7 for controlling the hot water supply operation based on the setting of the hot water supply temperature of the remote controller 6 or the like.

  The gas burner 2 combusts when the gas supplied through the gas passage 8 is ignited by the igniter 10 through the ignition electrode 9, and the state of the combustion flame is detected by the frame rod 11. Further, a flame thermistor (flame temperature detecting means) 8a for measuring the temperature of the combustion flame is provided above the gas burner 2 in a region having a predetermined heat quantity or more. The flame thermistor 8 a outputs a signal corresponding to the combustion temperature of the gas burner 2. The gas passage 8 is provided with an original solenoid valve 12 and a governor proportional solenoid valve 13 in this order from upstream to downstream. The governor proportional solenoid valve 13 is energized and controlled by the control unit 7, exhibits an opening corresponding to the energization amount, and continuously adjusts the amount of gas flowing through the gas passage 8.

  An intake port 15 for sending combustion air to the gas burner 2 is provided below the combustion chamber 14 that houses the gas burner 2, and an exhaust port 16 that discharges combustion exhaust from the gas burner 2 is provided above the combustion chamber 14. It has been. The ventilation system 3 is configured by an air path from the intake port 15 to the exhaust port 16.

  The fan 4 includes a fan motor 17, and the rotation speed and current value of the fan 4 are detected by the rotation speed detection means 18 and the current detection means 19 provided in the control unit 7.

  The water passage 5 is connected upstream with a water supply channel 20 (not shown), upstream with a heat exchange water passage 5a continuous with the water supply passage 20, upstream with the heat exchange water passage 5a, and downstream with a faucet 21. The connected hot water supply path 22 and a bypass path 23 branched from the water supply path 20 and joining the hot water supply path 22 are configured. An electric water amount control device 24 is provided upstream of the branch position between the water supply passage 20 and the bypass passage 23. The electric water amount control device 24 is energized and controlled by the control unit 7, and controls the amount of water flowing through the heat exchange water passage 5 a and the amount of water flowing through the bypass passage 23.

  The water supply path 20 is provided with a water flow amount sensor 25 and a water supply thermistor 26 in order from upstream to downstream. The flowing water sensor 25 outputs a signal corresponding to the flowing water amount, and the water supply thermistor 26 outputs a signal corresponding to the water supply temperature. In the heat exchange water passage 5a, water is heated by the combustion exhaust of the gas burner 2 through the fins 28 of the heat exchanger 27 provided above the gas burner 2 in the combustion chamber 14 to become warm water. A hot water temperature thermistor 29 that outputs a signal corresponding to the hot water temperature is provided downstream of the heat exchanger 27 in the heat exchange water passage 5a. The hot water supply passage 22 is provided with a hot water supply temperature thermistor 30 that outputs a signal corresponding to the hot water supply temperature downstream from the joining position with the bypass passage 23.

  The control unit 7 includes combustion control means 31 that controls the amount of combustion of the gas burner 2 and fan control means 32 that controls the amount of air supplied to the gas burner 2 by the fan 4.

  The combustion control means 31 sets the target combustion amount of the gas burner 2 based on the hot water supply temperature set by the remote controller 6, and controls the combustion amount of the gas burner 2 so as to match the target combustion amount.

  The fan control means 32 sets the target rotational speed of the fan 4 according to the target combustion amount, and the fan motor 17 has a fan speed so that the rotational speed of the fan 4 detected by the rotational speed detection means 18 matches the target rotational speed. Control the current. More specifically, the fan control unit 32 includes a calculation processing unit 33 (first calculation unit, second calculation unit), a storage unit 34 (storage unit), and a correction unit 35 (correction unit). . As will be described later, the arithmetic processing unit 33 has a function of calculating a first correction coefficient (first correction value) and a fan correction coefficient (fan correction value).

  The storage unit 34 stores a fan current detection value, a first correction coefficient, a second correction coefficient (second correction value), and a fan correction coefficient. Further, as shown in FIG. 2, a reference line L (solid line) of fan rotation speed-current characteristics is stored in the storage unit 34 in advance. The reference line L is determined in advance corresponding to the fan rotation speed-current characteristic indicating the lower limit of fan variation. In the present embodiment, the reference line L is set along the lower side of the fan rotational speed-current characteristic line Ls (one-dot chain line) indicating the lower limit of the variation of the fan. Errors due to variations other than (for example, variations in the ventilation system 3 and the like) are eliminated. If sufficient accuracy is obtained for the ventilation system 3 and the like, the influence of the error becomes extremely small. Therefore, the reference line L may be matched with the fan rotation speed-current characteristic line Ls indicating the lower limit of fan variation. it can. The correction unit 35 corrects the target rotational speed of the fan 4 based on the fan correction coefficient stored in the storage unit 34.

  Next, the function of the combustion apparatus having the above configuration will be described. First, when the faucet 21 is opened, water flows into the water passage 5 and when the amount of flowing water measured by the flowing water amount sensor 25 exceeds a predetermined amount, the gas burner 2 starts combustion. At this time, the target combustion amount of the gas burner 2 is set by the combustion control means 31 in order to supply hot water at the hot water temperature set by the remote controller 6. Further, the fan control means 32 sets the target rotational speed of the fan 4 in accordance with the target combustion amount of the gas burner 2 and then controls the fan rotational speed to coincide with the target rotational speed. Further, the combustion control means 31 controls the gas supply amount from the gas passage 8 to the gas burner 2 by controlling the energization amount of the governor proportional solenoid valve 13 in accordance with the fan speed controlled by the fan control means 32. Thus, the combustion air is first supplied by the fan 4, the ignition electrode 9 is then operated by the igniter 10, the gas is supplied to the gas burner 2, and the gas burner 2 starts to burn. Then, the water flowing through the heat exchange water passage 5 a by the combustion exhaust of the gas burner 2 is heated through the heat exchanger 27 to become hot water, and is supplied to the outside through the hot water supply passage 22. At this time, the combustion control means 31 appropriately changes the target combustion amount of the gas burner 2 so that the hot water supply temperature measured by the hot water supply thermistor 30 matches the set value.

  Next, the operation of the fan control means 32 will be described in detail based on the flowchart of FIG. First, in STEP 1, the ignition signal is turned ON, and the gas burner 2 is ignited by the igniter 10 through the ignition electrode 9.

  Next, in STEP 2, the fan rotation speed is corrected by using the first correction coefficient Rfc and the second correction coefficient Rth stored in advance in the storage unit 34 by the correction unit 35, and the combustion operation of the gas burner 2 is performed. The correction rotation speed at this time is calculated from the set rotation speed and the fan correction coefficient (first correction coefficient × second correction coefficient).

  In STEP 3, it is determined whether or not the combustion temperature of the gas burner 2 detected by the flame thermistor 8 a is higher than the combustion temperature of the target combustion amount set by the combustion control means 31 for 20 seconds or more. . Specifically, it is determined whether the combustion temperature of the gas burner 2 detected by the flame thermistor 8a exceeds the upper limit output value (corrected UP determination temperature) shown in FIG.

  Thereafter, when the determination in STEP 3 is NO, in STEP 4, the state where the combustion temperature of the gas burner 2 detected by the flame thermistor 8 a is lower than the combustion temperature of the target combustion amount set by the combustion control means 31 is 10. It is determined whether or not more than a second has elapsed. Specifically, it is determined whether or not 10 seconds or more have passed since the combustion temperature of the gas burner 2 detected by the flame thermistor 8a has dropped from the lower limit output value (corrected DOWN determination temperature) shown in FIG.

  On the other hand, if the determination in STEP 3 is YES, in STEP 5, it is determined whether or not the value of the correction counter, which is about the second correction coefficient Rth shown in FIG. If the value of the correction counter is not 5, in STEP 6, 1 is added to the correction counter. On the other hand, when the value of the correction counter is 5, in STEP 7, the combustion operation of the water heater 1 is stopped. If the determination in STEP 4 is YES, in STEP 8, 1 is subtracted from the correction counter. The initial value of the second correction coefficient Rth is 1 for the correction counter.

  In this embodiment, in STEP5, it is determined whether or not the value of the correction counter is 5. If the value of the correction counter is 5, the combustion operation of the water heater 1 is stopped in STEP7. Specifically, as shown in FIG. 6, the fan control means 32 performs a predetermined number of corrections (in the illustrated case, two times) to increase the air volume of the fan 4 by the second correction coefficient based on the output of the flame thermistor 8a. Even if it repeats, when the output of the flame thermistor 8a exceeds an upper limit output value, the combustion which stops the fan 4 is stopped.

  Next, when the determination in STEP 4 is NO, in STEP 9, it is determined whether or not the first correction coefficient Rfc has been updated.

  If the determination in STEP 9 is NO, in STEP 10, the gas burner 2 is burned and operated with a fan correction coefficient of Rfc × Rth.

  Thereafter, in STEP 11, the updated fan correction coefficient Rfc × Rth is calculated by the arithmetic processing unit 33, and the fan rotation speed is corrected by using the updated fan correction coefficient by the correction unit 35, and the combustion operation of the gas burner 2 is performed. The arithmetic processing unit 33 calculates the first fan correction coefficient based on the fan current detection value detected by the current detection means 19 and the reference current value shown in FIG. Then, the calculated first fan correction coefficient is stored in the storage unit 34.

  The fan control means 32 stores the fan correction coefficient in the storage unit 34 even after the combustion is stopped, and corrects the air volume of the fan 4 based on the fan correction coefficient stored in the storage unit 34 in the next combustion. .

  Further, the fan control means 32 calculates a fan correction coefficient by a second correction coefficient based on the output of the flame thermistor 8a that measures the temperature of the combustion flame in the region above the predetermined heat quantity above the gas burner 2.

  Further, the fan control means 32 corrects the air volume of the fan 4 based on the fan correction coefficient stored in the storage unit 34 even in the combustion operation in the region where the flame thermistor 8a does not exist.

  Next, in STEP 12, it is determined whether or not the combustion stop signal of the gas burner 2 is ON (combustion operation end). If the determination in STEP 12 is NO, the process returns to STEP 3. On the other hand, when the determination in STEP 12 is YES, in STEP 13, the updated fan correction coefficient is stored. Then, the fan current control by the fan control means 32 is terminated.

  According to the present embodiment, when the fan control unit 32 controls the fan current of the fan motor, first, the first fan correction coefficient calculated by the arithmetic processing unit 33 is stored in the storage unit 34. Next, the fan correction coefficient calculated by the arithmetic processing unit 33 using the first correction coefficient and the second correction coefficient based on the output of the flame thermistor 8 a is stored in the storage unit 34. Then, the fan air volume correction based on the fan correction coefficient is performed by the correction unit 35. Accordingly, since the fan correction coefficient is calculated by the first correction coefficient and the second correction coefficient based on the output of the flame temperature detecting means, when the fan rotation speed-current characteristic varies, the fan rotation speed-current characteristic varies due to individual differences. Even if there is, there is an accurate air flow correction according to the characteristics of the fan.

  The flame thermistor 8a has an upper limit output value and a lower limit output value for determining whether or not to control the fan current of the fan motor 17, and the fan control means 32 uses a second fan correction coefficient based on the output of the flame thermistor 8a. Even if correction for increasing the air volume of the fan 4 is repeated a predetermined number of times, the combustion of the fan 4 is stopped when the output of the flame thermistor 8a exceeds the upper limit output value, so that the fan current cannot be controlled due to a failure of the fan 4 or the like. When it becomes, it can stop the water heater 1 safely.

  Further, the fan control means 32 stores the fan correction coefficient even after the combustion is stopped, and corrects the air volume of the fan 4 based on the fan correction coefficient in the next combustion. Combustion from the beginning of ignition can be improved.

  Further, since the fan control means 32 calculates the fan correction coefficient by the second correction coefficient based on the output of the flame thermistor 8a in the area after the start of combustion and exceeding a predetermined amount of heat, the area where the accuracy of the output of the flame thermistor 8a is high. It is possible to correct with high accuracy by using.

  Further, since the fan control means 32 corrects the air volume of the fan 4 on the basis of the fan correction coefficient even in the combustion in the region where the flame thermistor 8a does not exist, the combustion in the region where the flame thermistor 8a does not exist can be maintained well. .

  DESCRIPTION OF SYMBOLS 1 ... Hot water heater, 2 ... Gas burner, 3 ... Ventilation system, 4 ... Fan, 5 ... Water passage, 5a ... Heat exchange water passage, 6 ... Remote control, 7 ... Control unit, 8 ... Gas passage, 8a ... Flame thermistor, 9 ... Ignition electrode, 10 ... Ignator, 11 ... Frame rod, 12 ... Original solenoid valve, 13 ... Governor proportional solenoid valve, 14 ... Combustion chamber, 15 ... Inlet, 16 ... Exhaust, 17 ... Fan motor, 18 ... Rotation speed Detection means, 19 ... Current detection means, 20 ... Water supply path, 21 ... Faucet, 22 ... Hot water supply path, 23 ... Bypass path, 24 ... Electric water amount control device, 25 ... Flow rate sensor, 26 ... Water supply thermistor, 27 ... Heat exchange 28 ... fins, 29 ... hot water temperature thermistor, 30 ... hot water temperature thermistor, 31 ... combustion control means, 32 ... fan control means, 33 ... arithmetic processing unit (first arithmetic means, second arithmetic means), 34 ... memory Part (storage means) 35 ... correcting section (correction means), L, Ls ... fan speed - current characteristic line.

Claims (5)

With a gas burner,
A fan for supplying combustion air to the gas burner;
A fan motor that rotationally drives the fan;
Current detecting means for detecting a fan current value of the fan motor;
A rotational speed detection means for detecting the rotational speed of the fan;
Flame temperature detecting means for detecting the flame temperature of the gas burner;
Fan control means for controlling the fan current of the fan motor so that the rotational speed of the fan matches a target rotational speed corresponding to the combustion amount of the gas burner,
The fan control means includes
Based on a predetermined fan rotation speed-current characteristic corresponding to the fan current characteristic indicating the lower limit of the variation of the fan current,
First calculation means for calculating a first correction value based on a fan current detection value detected by the current detection means and a reference current value based on the fan rotation speed-current characteristic;
Second calculating means for calculating a fan correction value by a second correction value based on the first correction value and the output of the flame temperature detecting means;
Storage means for storing the fan current detection value, the reference current value, the first correction value, the second correction value, and the fan correction value;
And a correction unit that corrects the air volume of the fan based on the fan correction value. The combustion apparatus according to claim 1, wherein
The flame temperature detection means has an upper limit output value and a lower limit output value whether or not to control the fan current of the fan motor,
The fan control means stops the combustion that stops the fan when the output of the flame temperature detection means exceeds the upper limit output value even if the correction for increasing the air volume of the fan by the second correction value is repeated a predetermined number of times. Combustion device characterized by that. The fuel device according to claim 1 or 2,
The fan control means stores the fan correction value even after the combustion is stopped, and corrects the air volume of the fan based on the fan correction value in the next combustion. The combustion apparatus according to any one of claims 1 to 3,
The said fan control means calculates the said fan correction value by the said 2nd correction value based on the output of the said flame temperature detection means in the area | region more than predetermined heat amount after the combustion start, The combustion apparatus characterized by the above-mentioned. The combustion apparatus according to any one of claims 1 to 4,
The combustion apparatus according to claim 1, wherein the fan control unit corrects the air volume of the fan based on the fan correction value even in combustion in a region where the flame temperature detection unit does not exist.

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