JPH05172326A - Nozzle drive controller in nozzle moving burner - Google Patents

Abstract

PURPOSE:To provide for a nozzle moving burner a nozzle drive controller which is able to hold always constantly the minimum quantity of fuel consumption regardless of the temperature of the fuel oil. CONSTITUTION:An oil temperature sensor 15 detects the temperature of the fuel oil. A minimum combustion position judgement means 25 judges the position of a nozzle that corresponds to a specified minimum quantity of fuel consumption according to the temperature detected by the oil temperature sensor 15. And, the minimum quantity of fuel consumption is held constant regardless of the temperature of the fuel oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle drive control device for a nozzle moving burner.

[0002]

2. Description of the Related Art Conventionally, in a nozzle moving type burner in which a nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through an opening of an aperture plate to adjust the combustion amount, flame prevention is prevented. Therefore, in order to always secure a certain amount of combustion or more, the stepping motor is controlled so that the nozzle is not separated from the opening of the diaphragm plate by a certain distance or more.

[0003]

However, the amount of combustion changes not only with the amount of fuel oil but also with the temperature of fuel oil.
That is, as shown in FIG. 5, when the nozzle position is fixed,
The higher the temperature of fuel oil, the smaller the amount of combustion. Therefore, in the nozzle drive control device in the conventional nozzle moving type burner, the minimum combustion amount changes depending on the temperature of the fuel oil, and the minimum combustion amount becomes too small to extinguish the flame, or the minimum combustion amount becomes too large, for example, in a water heater. There was a problem that hot water might boil.

An object of the present invention is to provide a nozzle drive control device in a nozzle moving type burner which can always keep the minimum combustion amount constant regardless of the temperature of fuel oil.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a nozzle moving type in which a nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through an opening of an aperture plate to adjust the combustion amount. In the burner, a temperature detection sensor for detecting the temperature of the fuel oil, and a minimum combustion position determination means for determining the position of the nozzle corresponding to a predetermined minimum combustion amount according to the temperature detected by the temperature detection sensor are provided. The feature is that the minimum combustion amount is kept constant regardless of the temperature of the fuel oil.

[0006]

Function: The temperature detection sensor detects the temperature of the fuel oil.
The minimum combustion position determination means determines the position of the nozzle corresponding to a predetermined minimum combustion amount according to the temperature detected by the temperature detection sensor. Then, the minimum combustion amount is kept constant regardless of the temperature of the fuel oil.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings. FIG. 2 is a schematic cross-sectional view of a nozzle moving burner including a nozzle drive control device according to an embodiment of the present invention.
The burner 1 is composed of a nozzle 2 and a diaphragm plate 3. The nozzle 2 is driven back and forth (left and right direction in FIG. 2) by a stepping motor 4 to control the combustion amount. The nozzle 2 communicates with a closed oil sump 6 via an oil conduit 5, and a pump 7 is installed in the oil conduit 5. Fuel oil such as petroleum supplied to the nozzle 2 through the oil conduit 5 by the pump 7 is sprayed from the nozzle 2 and partly blocked by the diaphragm plate 3 and returned to the oil sump 6 through the return pipe 8. .. The oil sump 6 communicates with the space around the nozzle 2 via an air vent pipe 9. That is, since the amount of fuel oil blocked by the throttle plate 3 changes depending on the position of the nozzle 2, the amount of fuel oil passing through the opening 3a of the throttle plate 3 changes, and the combustion amount in the combustion chamber 10 changes. is there. Combustion air is supplied by a blower fan 11 to a combustion chamber 10 in which the fuel oil injected from the nozzle 2 and passed through the opening 3a of the diaphragm plate 3 is burned, and the supply amount of this combustion air is controlled by the air volume control damper 12. Controlled. The air volume control damper 12 is driven by a stepping motor 13. The stepping motors 4 and 13 are connected to a controller 14 having a microcomputer and driven by the controller 14. That is, the controller 14 constitutes a nozzle drive control device for performing feedforward and feedback control of the stepping motor 4. An oil temperature sensor 15 is provided in the oil conduit 5.

FIG. 1 is a block diagram of a nozzle drive control device according to an embodiment of the present invention. The nozzle drive control device supplies a stepping motor 4 according to an appropriate combustion amount.
A pulse number storage unit 17 that stores in advance the number of pulses per cycle, an appropriate combustion amount calculation unit 18 that calculates an appropriate combustion amount, and a nozzle based on the appropriate combustion amount calculated by this appropriate combustion amount calculation unit 18. The required movement amount calculation means 19 for calculating the required movement amount of 2 and the number of drive pulses per cycle to be supplied to the stepping motor 4 according to the proper combustion amount calculated by the proper combustion amount calculation means 18 The pulse number reading means 20 read from the storage means 17 and the nozzle 2 are moved by the required movement amount calculated by the required movement amount calculation means 19, or the number of pulses read by the pulse number reading means 20 is read by the stepping motor 4. A drive pulse supplying means 21 for supplying the drive pulse to the stepping motor 4 until the drive pulse is supplied; Proper combustion amount difference calculation means 22 for calculating the difference between the present proper combustion amount calculated by the combustion amount calculation means 18 and the previous proper combustion amount, and proper combustion based on the calculation result by the proper combustion amount difference calculation means 22. Quantity calculation means 18
The calculation interval control means 23 for varying the time until the next calculation of the proper combustion amount by the nozzle and the nozzle position storage means 24 for preliminarily storing the relationship between the temperature of the fuel oil and the nozzle position at which a predetermined minimum combustion amount is obtained. And the minimum combustion position for reading the nozzle position from which the minimum combustion amount is obtained according to the detection signal from the oil temperature sensor 15 from the nozzle position storage means 24 and correcting the required movement amount by the required movement amount calculation means 19 as necessary. The determination means 25 is provided. Among these means, the pulse number storage means 17 and the nozzle position storage means 24 are constituted by a part of a storage device (not shown), and the other means are realized by software by the microcomputer of the controller 14. There is. The controller 14 is
Based on input signals from a remote controller (not shown) and various sensors, not only the stepping motor 4 but also the nozzle moving burner or the hot water supply apparatus including the nozzle moving burner is controlled as a whole.

Next, the operation will be described. Pulse number storage means 1
In FIG. 7, the number of drive pulses per cycle supplied to the stepping motor 4 according to the appropriate combustion amount is stored in advance as a table. Further, the nozzle position storage means 24 stores in advance as a table the relationship between the temperature of the fuel oil and the nozzle position at which a predetermined minimum combustion amount is obtained. During the combustion operation, first, the proper combustion amount calculation means 18
Calculates an appropriate combustion amount based on input signals from a remote controller, various sensors, and the like. As a result, the required movement amount calculation means 19 calculates the required movement amount of the nozzle 2 based on the proper combustion amount calculated by the proper combustion amount calculation means 18 and the current position of the nozzle 2, and determines the movement direction. .. On the other hand, the minimum combustion position determination means 25 reads from the nozzle position storage means 24 the nozzle position at which a predetermined minimum combustion amount is obtained, that is, the minimum combustion position, according to the detection signal from the oil temperature sensor 15. As a result, the required movement amount calculation means 19 determines the nozzle position, that is, the target movement position, on the assumption that the nozzle 2 has moved by the previously calculated required movement amount, and the minimum combustion position read by the minimum combustion position determination means 25. In comparison, if the target movement position is farther from the opening 3a of the diaphragm plate 3 than the minimum combustion position, the nozzle 2
The required movement amount is corrected so that moves to the minimum combustion position. Further, the pulse number reading means 20 reads the pulse number of the drive pulse per one cycle supplied to the stepping motor 4 from the pulse number storage means 17 based on the proper combustion amount calculated by the proper combustion amount calculation means 18. As a result, the drive pulse supply means 21 supplies a drive pulse to the stepping motor 4 in accordance with the moving direction calculated by the required movement amount calculation means 19. As a result, the stepping motor 4 is driven, the nozzle 2 moves,
The amount of combustion changes. Then, when the nozzle 2 moves by the required moving amount calculated or corrected by the required moving amount calculating means 19, or the driving pulse is supplied to the stepping motor 4 by the number of pulses read by the pulse number reading means 20. The drive pulse supply means 21 stops the supply of drive pulses to the stepping motor 4. On the other hand, the appropriate combustion amount difference calculation means 22 calculates the difference between the appropriate combustion amount of this time calculated by the appropriate combustion amount calculation means 18 and the previous appropriate combustion amount stored in the storage device (not shown). As a result, the calculation interval control means 23 varies the time until the next calculation of the proper combustion amount by the proper combustion amount calculation means 18, based on the calculation result by the proper combustion amount difference calculation means 22. That is, when the difference between the proper combustion amount of this time and the proper combustion amount of the previous time is small, the time until the calculation of the proper combustion amount of the next time is lengthened.

Regarding the operation of the nozzle drive control device,
A more specific description will be given with reference to the flowcharts of FIGS. 3 and 4. First, the proper combustion amount calculation means 18 calculates the proper combustion amount (step S1). Next, the appropriate combustion amount difference calculating means 22 calculates the difference between the appropriate combustion amount calculated by the appropriate combustion amount calculating means 18 in step S1 and the previous appropriate combustion amount stored in the storage device, and the difference is calculated. It is determined whether or not the value is equal to or smaller than the predetermined value A (step S2). If the difference is less than or equal to the predetermined value A, the calculation interval control means 23 starts the timer t ₂ (step S3). Next, the required movement amount calculating means 19 calculates the required movement amount and direction of the nozzle 2 based on the proper combustion amount calculated by the proper combustion amount calculating means 18 in step S1 and the current position of the nozzle 2 (step). S4). Next, the minimum combustion position determination means 25 reads the temperature of the fuel oil from the oil temperature sensor 15 (step S5), and reads the minimum combustion position from the nozzle position storage means 24 according to the temperature of the fuel oil (step S6). Next, the required movement amount calculation means 19 performs step S
The nozzle position, that is, the target moving position when it is assumed that the nozzle 2 has moved by the required moving amount calculated in 14 is compared with the minimum combustion position read by the nozzle position storage means 24 in step S6 (step S7), and the target When the movement position is farther from the opening 3a of the diaphragm plate 3 than the minimum combustion position, the required movement amount is corrected so that the nozzle 2 moves to the minimum combustion position (step S8). Next, the pulse number reading means 2
0 reads out the pulse number of the driving pulse per one cycle supplied to the stepping motor 4 from the pulse number storage means 17 based on the proper combustion amount calculated by the proper combustion amount calculation means 18 in step S1 (step S9). .. Next, the drive pulse supply means 19 applies a drive pulse of a predetermined pulse width to each coil of the stepping motor 4 in a predetermined cycle based on the moving direction of the nozzle 2 calculated by the required movement amount calculation means 18 in step S4. It is sequentially and cyclically supplied (step S10), and it is judged whether or not the supply of the drive pulses of the number of pulses read in step S9 is completed (step S11). If the supply is not completed, the nozzle 2 is operated in step S4. It is determined whether or not the calculation or the required movement amount corrected in step S8 has moved (step S1
2) If it is moving, a stop voltage is applied to the coil of the stepping motor 4 (step S13). As a result, the position of the nozzle 2 changes, the amount of fuel oil passing through the opening 3a of the diaphragm plate 3 changes, and the amount of combustion changes. Next, the calculation interval control means 23 determines whether or not the timer t ₂ started in step S3 has timed out (step S14), and if timed up, step S1.
The appropriate combustion amount calculated by the appropriate combustion amount calculating means 18 is stored in the storage device (step S15), and step S15
Return to 1. If it is determined in step S14 that the timer t ₂ has not expired, step S14
Return to. If it is determined in step S12 that the nozzle 2 has not moved by the required movement amount calculated in step S4 or corrected in step S8, the process returns to step S11. If it is determined in step S11 that the supply of the driving pulses of the number of pulses read in step S9 is completed, the process proceeds to step S13. If it is determined in step S7 that the target moving position is not farther than the minimum combustion position from the opening 3a of the diaphragm plate 3, the process proceeds to step S9. Also if it is determined that the difference from the proper combustion amount and the previous proper combustion amount of time in step S2 is not less than a predetermined value A, calculating the interval control unit 23, a timer is started t ₁ (step S16), and the step S4 move on. When the timer t ₁ is started in step S16, it is determined in step S14 whether or not the timer t ₁ is up. The timer t ₁ has a shorter time than the timer t ₂ .

As described above, the minimum combustion position determination means 25
However, the nozzle position where the minimum combustion amount is obtained according to the detection signal from the oil temperature sensor 15, that is, the minimum combustion position is read from the nozzle position storage means 24, and the required movement amount calculation means 19 calculates the required movement amount previously calculated. The nozzle position on the assumption that the nozzle 2 has moved only, that is, the target moving position, is compared with the minimum combustion position read by the minimum combustion position judging means 25, and the target moving position is the opening of the diaphragm plate 3 more than the minimum combustion position. When it is far from 3a, the required movement amount is corrected so that the nozzle 2 moves to the minimum combustion position, so that the minimum combustion amount can always be kept constant regardless of the temperature of the fuel oil. Therefore, even if the fuel oil is at a high temperature, the combustion amount does not become smaller than the predetermined minimum combustion amount, so that it is possible to prevent flame quenching well, and even if the fuel oil is at a low temperature, the combustion amount at the minimum combustion is the predetermined minimum Since it does not become larger than the amount, it is possible to favorably prevent boiling of hot water in the water heater.

When the change in the proper combustion amount is small as in this embodiment, the proper combustion amount calculation cycle is changed from T ₁ to T _2.
If the length of the stepping motor 4 is increased, the ratio of the drive time to the stop time of the stepping motor 4 is reduced, and burnout due to overheating of the coil of the stepping motor 4 can be favorably prevented.

In the above embodiment, the nozzle position storage means 24 stores in advance a table of the relationship between the temperature of the fuel oil and the nozzle position at which a predetermined minimum combustion amount is obtained.
The minimum combustion position determination means 25 is configured to read the minimum combustion position from the nozzle position storage means 24 in accordance with the detection signal from the oil temperature sensor 15. However, the nozzle that obtains the temperature of the fuel oil and a predetermined minimum combustion amount. The relationship with the position is stored in advance in a storage device as a mathematical expression, and the minimum combustion position determination means 25 is configured to calculate the minimum combustion position according to the detection signal from the oil temperature sensor 15 using the mathematical expression. Good.

Further, the actual control method of the combustion operation is not limited to the above-mentioned embodiment except the control of the minimum combustion position, and any method can be adopted.

[0015]

According to the present invention, which has the above-mentioned structure, the nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through the aperture of the diaphragm plate to adjust the combustion amount. In the burner, a temperature detection sensor for detecting the temperature of the fuel oil and a minimum combustion position determination means for determining the position of the nozzle corresponding to a predetermined minimum combustion amount according to the temperature detected by the temperature detection sensor are provided. Since the amount of combustion is kept constant regardless of the temperature of the fuel oil, the minimum amount of combustion can be kept constant regardless of the temperature of the fuel oil. Even if the fuel oil is at a low temperature, the combustion amount at the time of the minimum combustion does not become larger than the minimum combustion amount and the boiling water of the water heater can be prevented. It is possible to prevent the good.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a nozzle drive control device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a nozzle moving burner including a nozzle drive control device according to an embodiment of the present invention.

FIG. 3 is a first half portion of a flowchart for explaining the operation of the nozzle drive control device in the embodiment of the present invention.

FIG. 4 is a second half of a flowchart for explaining the operation of the nozzle drive control device in the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a relationship between a temperature of fuel oil and a combustion amount when a nozzle position is fixed.

[Explanation of symbols]

 2 nozzle 3 diaphragm plate 3a opening 4 stepping motor 15 oil temperature sensor 25 minimum combustion position determination means

Claims (1)

[Claims] 1. A nozzle moving burner for adjusting a combustion amount by changing an amount of fuel oil passing through an opening of an aperture plate by moving a nozzle for spraying fuel oil by a stepping motor, and a temperature of the fuel oil. And a minimum combustion position determination means for determining the position of the nozzle corresponding to a predetermined minimum combustion amount according to the temperature detected by the temperature detection sensor, and the minimum combustion amount is determined by the temperature of the fuel oil. A nozzle drive control device for a nozzle moving type burner, which is configured to be held constant regardless of the above.