JP4354374B2 - Combustion device - Google Patents

Description

  The present invention provides a combustion in which a fan current is controlled so that a rotation speed of a fan provided in a ventilation system including a burner and supplying combustion air to the burner matches a target rotation speed corresponding to the combustion amount of the burner. Relates to the device.

  In this type of combustion apparatus, the current of the fan motor is controlled so that the rotational speed of the fan supplying combustion air for the burner matches the target rotational speed that causes the burner to burn well. However, when a blockage occurs in the ventilation system provided with the fan, the combustion air supplied to the burner is insufficient even if the fan current is controlled so that the rotational speed of the fan matches the target rotational speed. Combustion is poor. Therefore, the target rotational speed of the fan is increased and corrected to compensate for the combustion air to the burner that has decreased due to the blockage of the ventilation system, based on the fluctuation of the fan rotation speed-fan current characteristic that represents an increase in the degree of blockage of the ventilation system. The Specifically, the fan load decreases as the ventilation system blockage increases, and the fan speed is kept constant but the fan current is reduced. The target rotational speed is corrected to increase.

  However, since there are individual differences in the fans, the fan rotation speed-fan current characteristics are expressed such that the fan current of the fan motor is different even when the fan rotation speed is the same when the ventilation system is not blocked. Variation occurs in the line. The individual value of the fan also affects the correction value for correcting the fan current, and even if the target rotational speed is controlled based on the correction value, the combustion air obtained thereby depends on the degree of blockage of the ventilation system. There is an increased risk of burner burnout failure.

  Therefore, conventionally, a plurality of correction data for the fan current is stored in advance corresponding to individual differences of the fans, and correction data corresponding to the characteristics of the fan being used is selected from the stored correction data. What is selected and adopted is known (see, for example, Patent Document 1). However, since the correction data selection operation is performed manually by the operator, not only the operation is troublesome but also a human selection error may occur. Furthermore, in order to improve the correction accuracy of the fan current, more correction data must be stored in a storage means such as a memory, and there is a disadvantage that the cost increases in order to secure a large storage capacity.

In addition, the fan current is detected every fixed time, and a specific value or the maximum value at the fixed time is set as a reference current value, and the detected current value is compared with the reference current value to obtain a current value. It is known to increase the number of rotations of a fan when it decreases beyond a certain ratio (see, for example, Patent Document 2). However, according to this, since the reference current value becomes a specific value during use, for example, in a situation where the ventilation system gradually narrows due to aging (dust clogging) and the air volume gradually decreases, The current value also decreases, and there is a disadvantage that a desired air volume cannot be obtained accurately.
JP 2003-207127 A Japanese Patent Laid-Open No. 6-3000246

  An object of the present invention is to provide a combustion apparatus that can reduce the adjustment work by an operator and perform high-precision air volume correction according to individual differences of fan motors.

In order to achieve such an object, the present invention provides a fan that is provided in a ventilation system including a burner and forcibly supplies combustion air to the burner, a fan motor that rotationally drives the fan, and a current of the fan motor Current measuring means for detecting the rotational speed of the fan, fan speed of the fan motor so that the rotational speed of the fan matches the target rotational speed corresponding to the burner combustion amount. And a fan control means for controlling the fan control means, wherein the fan control means is a fan rotation determined in advance corresponding to a fan rotation speed-fan current characteristic indicating a lower limit of variation in fan current due to individual fan differences. number - fan current characteristic with respect to the fan said rotational speed detecting means detected detected current by the current measuring means in response to the rotational speed of the fan detected is during operation of the A fan speed as a reference in its rotational speed - the difference between the reference current value based on the fan current characteristics and a first calculating means for calculating the fan current correction value, the fan after the fan current correction value is calculated A fan current which is the difference between the detected current value detected by the current measuring means corresponding to the fan speed detected by the rotational speed detecting means during operation and the fan current correction value calculated by the first calculating means. Second calculation means for calculating a recognition value, and a reference current value based on a fan rotation speed-fan current characteristic serving as a reference in the rotation speed of the fan when the detection current value used for calculating the fan current recognition value is detected and a third arithmetic means for calculating a second calculation unit fan correction value by dividing the calculated fan current recognition value by the reference current value, the fan current correction value, the fan current certification Values, and memory means for respectively storing the fan correction value, characterized in that it comprises a correcting means for correcting the air volume of the fan based on the fan correction value of the storage means.

  According to the present invention, when the fan current of the fan motor is controlled by the fan control means, first, the fan current correction value calculated by the first calculation means is stored in the storage means. 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 air volume correction of the fan based on the fan correction value is performed by the correction means. In this way, the fan air volume is corrected based on the values calculated by the respective arithmetic means, so that even if the fan characteristics vary due to individual differences, the air volume correction according to the fan characteristics is automatically performed. Therefore, it is possible to reduce the adjustment work by the operator and to perform highly accurate air volume correction. Further, the reference current value used when calculating the fan current correction value and the fan correction value is determined in accordance with the fan rotation speed-fan current characteristic indicating the lower limit of fan variation. When the fan is a lower limit product (a product that is the lower limit of the variation in fan rotation speed-fan current characteristics), the air volume can be reliably corrected even if the air volume is slightly decreased. Moreover, even when the fan is the upper limit product (the product that is the lower limit of the fan speed-fan current characteristic variation), the fan current is recognized as the lower limit product by the fan current correction value, and the air flow is slightly reduced. Even if it exists, the correction | amendment of an air volume can be performed reliably.

More specifically, in the present invention, the fan control means may be based on a fan rotation speed-fan current characteristic that indicates a lower limit of fan current variation due to individual fan differences . As a result, a slight change in the air volume can be detected and the air volume of the fan can be reliably corrected.

In addition to the above, the fan control means may be configured such that a fan rotation speed that is determined based on a predetermined error below a fan rotation speed-fan current characteristic indicating a lower limit of a fan current variation due to individual fan differences—a fan For example, the current characteristic is used as a reference. According to this, for example, an error associated with a ventilation system other than the fan can be eliminated, and the air volume can be corrected with higher accuracy.

  In the present invention, the fan control means determines the magnitude of the fan current recognition value with respect to the reference current value, and when it is determined that the fan current recognition value is greater than the reference current value, The fan current correction value is obtained through one calculating means, and the fan current correction value of the storage means is updated.

  When the fan current recognition value is larger than the reference current value, it is considered that the fan current correction value is extremely inaccurate for some reason. Therefore, by newly obtaining the fan current correction value and updating the fan current correction value of the storage means, the inaccurate fan current correction value can be corrected, and the accuracy of the airflow correction can be maintained.

  Further, when the fan control unit determines that the fan current recognition value is larger than the reference current value, the fan control unit stores the fan current of the storage unit when the fan current recognition value does not exceed a predetermined upper limit value. It is preferable to update the correction value. For example, when the combustion apparatus of the present invention is adopted in a water heater or the like, when the operation is performed with the front plate of the water heater housing removed during inspection of the water heater or the like, the ventilation system is opened and the fan is opened. The current recognition value may become extremely large. Therefore, by setting an upper limit value of the fan current recognition value that accompanies the opening of the ventilation system in inspection work etc., and not exceeding this upper limit value, by updating the fan current correction value of the storage means, The influence can be eliminated.

  In the present invention, it is preferable that the fan control unit calculates the fan current correction value, the fan current recognition value, and the fan correction value of the storage unit after the combustion operation for a predetermined time. Accordingly, the current can be detected after the current of the fan motor is stabilized, and the fan current correction value, the fan current recognition value, and the fan correction value are accurately calculated to improve the accuracy of the air flow correction. be able to.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a schematic configuration of the combustion apparatus of the present embodiment, FIG. 2 is a diagram for explaining the function of the combustion apparatus of the present embodiment, and FIG. 3 shows the operation of the fan control means in the combustion apparatus of the present embodiment. FIG. 4 is a flowchart showing another example of the operation of the fan control means in the combustion apparatus of the present embodiment.

  A combustion apparatus 1 shown in FIG. 1 is a hot water heater, and includes a burner 2, a ventilation system 3 including the burner 2, a fan 4 provided in the ventilation system 3 for forcibly supplying combustion air to the 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 burner 2 burns 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. 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 burner 2 is provided at the lower portion of the combustion chamber 14 that houses the burner 2, and an exhaust port 16 for discharging combustion exhaust from the burner 2 is provided at the upper portion of 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 of the fan 4 are measured by the rotation speed detection means 18 and the current measurement means 19 provided in the control unit 7.

  The water flow channel 5 includes a water supply channel 20 connected to a water supply (not shown) upstream, a heat exchange water flow channel 5a continuous to the water supply channel 20 upstream, and a heat exchanger water flow channel 5a upstream to the faucet 21 downstream. 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 amount sensor 25 and a water supply thermistor 26 in order from upstream to downstream. The water amount 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 burner 2 through the fins 28 of the heat exchanger 27 provided above the burner 2 in the combustion chamber 14, and becomes 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 burner 2 and fan control means 32 that controls the supply of combustion air to the burner 2 by the fan 4.

  The combustion control means 31 sets the target combustion amount of the burner 2 based on the hot water supply temperature set by the remote controller 6 and controls the combustion amount of the burner 2 so as to coincide with 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 of the fan motor 17 is adjusted so that the rotational speed of the fan 4 measured by the rotational speed detection means 18 matches the target rotational speed. Control the current. More specifically, the fan control unit 32 includes an arithmetic processing unit 33 (first arithmetic unit, second arithmetic unit, third arithmetic unit), a storage unit 34 (storage unit), and a correction unit 35 (correction unit). And. As will be described later, the arithmetic processing unit 33 has a function of calculating a fan current correction constant (fan current correction value), a fan current recognition value, and a fan correction coefficient (fan correction value).

The storage unit 34 stores a fan current correction constant, a fan current recognition value, and a fan correction coefficient. Further, as shown in FIG. 2, a reference line L (solid line) of fan rotation speed-fan 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-fan 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-fan current characteristic line Ls (one-dot chain line) indicating the lower limit of the variation of the fan. Errors due to variations other than current (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 should match the fan rotation speed-fan current characteristic line Ls indicating the lower limit of fan variation. You can also. The correction unit 35 corrects the target rotational speed of the fan 4 based on the fan current correction constant 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 burner 2 starts burning. At this time, the target combustion amount of the 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 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 burner 2 by controlling the energization amount of the governor proportional solenoid valve 13 according to the fan rotation 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 burner 2, and the burner 2 starts burning. Then, the water flowing through the heat exchange water passage 5 a by the combustion exhaust of the 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 burner 2 so that the hot water supply temperature measured by the hot water supply thermistor 30 matches the set value.

  Here, the operation of the fan control means 32 will be described in detail based on the flowchart of FIG. As shown in FIG. 3, first, when the fan current correction constant is cleared in STEP1, the fan current correction constant is set to 0 as in STEP2. The fan current correction constant is cleared by the operator operating a clear switch (not shown). When the fan motor 17 is repaired or replaced, or the heat exchanger 27 is cleaned, the fan current correction constant is cleared. Is cleared. Next, in STEP 3, the ignition signal is turned ON, and the burner 2 is ignited by the igniter 10 through the ignition electrode 9. On the other hand, if the fan current correction constant is not cleared in STEP 1, the fan current correction constant stored in the storage unit 34 in STEP 4 is adopted.

  Subsequently, in STEP 5, the fan rotational speed is corrected by the correction unit 35 using the fan correction coefficient stored in advance in the storage unit 34, and the combustion operation of the burner 2 is performed. Note that the correction rotation speed at this time is calculated from the set rotation speed and the fan correction coefficient (set rotation speed × fan correction coefficient). Then, the combustion operation of the burner 2 by STEP 5 is continued for 10 minutes by STEP 6, and proceeds to STEP 7 after 10 minutes. In this manner, the heat of the fan motor 17 rises and the fan current becomes relatively stable after a predetermined time (in this embodiment, 10 minutes) after the start of combustion of the burner 2.

  In STEP 7, the arithmetic processing unit 33 newly calculates a fan correction coefficient (updated fan correction coefficient), and the correction unit 35 corrects the fan rotational speed using the updated fan correction coefficient, so that the burner 2 performs the combustion operation. Is called. The arithmetic processing unit 33 first calculates a fan current recognition value from the difference between the actual fan current value measured by the current measuring means 19 and the fan current correction current (actual fan current value−fan current correction current). Next, an updated fan correction coefficient is calculated (reference current value / fan current recognition value) based on the reference current value and the fan current recognition value shown in FIG. The fan current recognition value calculated here is stored in the storage unit 34. In STEP 7, since the updated fan correction coefficient is calculated after 10 minutes from the start of combustion of the burner 2 in STEP 6, the current of the fan motor 17 is relatively stable, and the updated fan correction coefficient is calculated with high accuracy. Further, as shown in FIG. 2, the reference current value used for calculating the updated fan correction coefficient is near the lower side of the fan rotation speed-fan current characteristic line Ls (one-dot chain line) indicating the lower limit of the variation of the fan 4. Since the reference line L (solid line) is set along the line, when the current of the fan 4 being used is the lower limit product, even if the dust volume adheres to the ventilation system 3 and the air volume slightly decreases, the air volume is reliably corrected. Even when the current of the fan 4 being used is the upper limit product, it is recognized as the lower limit product by the fan current recognition value, and even if the air flow is slightly reduced, the air volume is surely corrected. be able to.

  Subsequently, when the combustion stop signal of the burner 2 is turned on (at the end of the combustion operation) in STEP 8, the process proceeds to STEP 9. In STEP 9, when the fan current recognition value in the storage unit 34 is smaller than the predetermined upper limit value, the process proceeds to STEP 10, and when the fan current recognition value is larger than the predetermined upper limit value, the process proceeds to STEP 11. When the fan current recognition value is larger than the predetermined upper limit value, for example, although not shown, it is conceivable that the operation is performed with the front plate of the water heater housing removed during the inspection work. Therefore, the process proceeds to STEP11, and the previous fan correction coefficient is stored in the storage unit 34, and the process proceeds to STEP14 and the combustion is stopped.

  In STEP 10, when the fan current recognition value of the storage unit 34 is larger than the reference current value, the process proceeds to STEP 12, and when the fan current recognition value is smaller than the reference current value, the process proceeds to STEP 13. That is, when the fan current recognition value is smaller than the reference current value in STEP 10, it is considered that an extremely inaccurate fan current recognition value is calculated for some reason. Therefore, the process proceeds to STEP 13 and the fan current correction constant in the storage unit 34 is not updated, and at the same time, the fan correction coefficient in the storage unit 34 is updated with the updated fan correction coefficient calculated in STEP 7. In STEP 10, when the fan current recognition value of the storage unit 34 is larger than the reference current value, for example, the fan current correction constant may be an abnormal numerical value. Therefore, in STEP 12, the arithmetic processing unit 33 calculates a new fan current correction constant from the actual fan current value and the reference current value (actual fan current value−reference current value), and updates the fan current correction constant in the storage unit 34. Then, the fan correction coefficient is reset (fan correction coefficient = 1). As a result, the fan current correction constant is set to a normal value, and the correction accuracy is maintained. And after passing through STEP12 or STEP13, the combustion of the burner 2 is stopped by STEP14.

  Next, another example of the operation of the fan control means 32 will be described based on the flowchart of FIG. In FIG. 4, STEP1 to STEP6 are the same as STEP1 to STEP6 in FIG. 4, when the combustion stop signal of the burner 2 is turned ON (at the end of the combustion operation) in STEP 7 through STEP 6, the process proceeds to STEP 8 and combustion of the burner 2 is stopped. Next, after STEP 9, after purge is started.

  During this after purge, the process proceeds to STEP 10 first. When the fan current recognition value in the storage unit 34 is smaller than the predetermined upper limit value, the process proceeds to STEP 11. When the fan current recognition value is larger than the predetermined upper limit value, STEP 12 is performed. Proceed to In STEP 12, the previous fan correction coefficient is stored, and the process proceeds to STEP 14 to complete the after purge.

  In STEP 11, the process proceeds to STEP 13 when the fan current recognition value in the storage unit 34 is larger than the reference current value, and proceeds to STEP 14 when the fan current recognition value is smaller than the reference current value. In STEP 14, the arithmetic processing unit 33 calculates a fan current recognition value and a new fan correction coefficient (updated fan correction coefficient), and the updated fan correction coefficient is stored in the storage unit 34. By calculating the fan correction coefficient during the after purge, it is possible to accurately calculate the fan correction coefficient with less influence of the error than in the case where the fan rotation speed is excessively low as during combustion. In STEP 13, the arithmetic processing unit 33 calculates a new fan current correction constant from the actual fan current value and the reference current value (actual fan current value−reference current value), and sets the fan current correction constant in the storage unit 34. Update and reset the fan correction coefficient (fan correction coefficient = 1). After step 13 or step 14, the after purge is completed in step 15.

Explanatory drawing which shows schematic structure of the combustion apparatus of embodiment of this invention. The diagram explaining the function of the combustion apparatus of this embodiment. The flowchart which shows the action | operation of the fan control means in the combustion apparatus of this embodiment. The flowchart which shows the other example of the action | operation of the fan control means in the combustion apparatus of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Combustion device, 2 ... Burner, 3 ... Ventilation system, 4 ... Fan, 17 ... Fan motor, 18 ... Rotation speed detection means, 19 ... Current measurement means, 32 ... Fan control means, 33 ... Arithmetic processing part (1st Calculation means, second calculation means, third calculation means) 34... Storage section (storage means), 35... Correction section (correction means).

Claims (6)

A fan that is provided in a ventilation system including a burner and forcibly supplies combustion air to the burner, a fan motor that rotationally drives the fan, current measuring means that detects a current of the fan motor, and rotation of the fan A combustion apparatus comprising: a rotation number detection means for detecting a number; and a fan control means for controlling a fan current of a fan motor so that the rotation speed of the fan coincides with a target rotation speed corresponding to a combustion amount of the burner. In
The fan control means, a fan rotation speed indicating the lower limit of the variation in the fan current caused by the individual difference of the fan - fan speed predetermined corresponding to the fan current characteristics - relative to the fan current characteristics, wherein during operation of the fan rotational speed detecting means in response to the rotational speed of the fan detected by the current detection current value detected by the measuring means and fan speed as a reference in its rotational speed - the difference between the reference current value based on the fan current characteristics First current calculation means for calculating a fan current correction value , and detected by the current measurement means corresponding to the number of rotations of the fan detected by the rotation speed detection means during operation of the fan after the fan current correction value is calculated a second calculating means for calculating the fan current recognition value is the difference between the fan current correction value calculated by been detected current value and the first calculating means, the fan current Detection current value used for the calculation of識値becomes a reference in the rotation speed of the fan when the detected fan rotation speed - is calculated a reference current value based on the fan current characteristics by the second computing means fan current recognition value A third calculation unit that calculates the fan correction value by dividing the reference current value, the fan current correction value, the fan current recognition value, and the fan correction value, and A combustion apparatus comprising: correction means for correcting the air volume of the fan based on the fan correction value. 2. The combustion apparatus according to claim 1, wherein the fan control means is based on a fan rotation speed-fan current characteristic indicating a lower limit of fan current variation due to individual fan differences . The fan control means is based on a fan rotation speed-fan current characteristic determined based on a predetermined error below a fan rotation speed-fan current characteristic indicating a lower limit of fan current variation due to individual fan differences. The combustion apparatus according to claim 1.   The fan control means determines the magnitude of the fan current recognition value with respect to the reference current value. When it is determined that the fan current recognition value is larger than the reference current value, the fan control means passes through the first calculation means. The combustion apparatus according to any one of claims 1 to 3, wherein the fan current correction value is obtained and the fan current correction value of the storage means is updated.   When the fan control means determines that the fan current recognition value is larger than the reference current value, and the fan current recognition value does not exceed a predetermined upper limit value, the fan current correction value of the storage means The combustion apparatus according to claim 4, wherein the combustion apparatus is updated.   6. The fan control unit according to claim 1, wherein the fan control unit calculates the fan current correction value, the fan current recognition value, and the fan correction value of the storage unit after the combustion operation for a predetermined time. Combustion device according to item.

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