JP3788529B2 - Combustion control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion control device having a function of detecting a shortage of combustion air and causing normal combustion.
[0002]
[Prior art]
Combustion equipment such as a boiler incorporating a combustion control device should be called a daily necessities for the modern society, and is widely used from baths and showers at the time of bathing to hot water supplies such as kitchens and washrooms. The heat source generally uses electricity or gas, and the use of gas is particularly large.
[0003]
When using gas, it is natural to pay attention to gas leakage, but it is necessary to pay sufficient attention to combustion conditions, particularly abnormal combustion due to air shortage. If general combustion control is described, the supply current value to the gas proportional valve that controls the gas amount and the supply voltage (or the number of rotations of the blower) to obtain the predetermined air amount are stored in the microcomputer in advance. It is burning.
[0004]
The relationship between the current and voltage stored in the microcomputer is one-to-one correspondence, and the voltage is automatically determined when the current is determined. If the current is plotted on the horizontal axis, it can be represented by a single straight line or curve. The points on the straight line or the curve satisfy the condition for normal combustion.
[0005]
Further, at present, improvements are made to the above-described technology, and a decrease in the air volume due to fan clogging of the blower or heat exchanger is detected and controlled. Specifically, when the airflow from the blower decreases and the fan load decreases, the current value decreases, and when the current value decreases, the airflow is restored to the original current value to ensure an appropriate airflow. It is doing that.
[0006]
[Problems to be solved by the invention]
However, in the control as described above, the reference current value that flows to the blower during normal combustion must be individually determined in the entire use range of the combustion control device (from minimum combustion to maximum combustion). Takes time. Furthermore, when only one heat exchanger is clogged in a combustor having a plurality of heat exchangers for one blower, the heat exchanger that is not clogged by increasing the air volume will cause abnormal combustion. There is a problem of causing it.
[0007]
An object of the present invention is to provide a combustion control device that can shorten the time to determine a reference current value in view of the above points, prevent abnormal combustion due to air shortage, and accurately determine the state at the time of abnormal combustion. And
[0008]
[Means for Solving the Problems]
(1) The present invention relates to a plurality of burners for burning fuel gas, a flow rate adjusting valve for adjusting the flow rate of the fuel gas, a blower for supplying combustion air to the burner, and a plurality of heats for hot water supply and reheating. An exchanger, drive means for driving the blower at a preset voltage or rotational speed with respect to the amount of fuel gas, current detection means for detecting the current flowing through the blower, and a reference current of the blower for a predetermined combustion time A combustion control device capable of performing automatic pouring, comprising storage means for storing a value, and comparison means for comparing the actual current value of the blower with the reference current value stored by the storage means during the predetermined combustion. For each control device, at the time of automatic pouring, the reference current value is stored and set at least once, the value is fixed as a reference current value, and the comparison means compares the reference current value with the actual current value. Conduct When the actual current value has decreased from the reference current value to a predetermined value or more, the combustion control device reduces the fuel gas amount and drives the blower at a voltage or rotation speed corresponding to the reduced fuel gas amount. .
(2) The present invention is the combustion control device according to item (1), wherein the reference current value at the time of automatic pouring is stored after a predetermined time has elapsed after the start of automatic pouring.
(3) The present invention is the combustion control device that is obtained and stored in the item (1) or the item (2) when the reference current value takes an average value of a plurality of times.
(4) The present invention is the combustion control device according to any one of Items (1) to (3), wherein the reference current value is stored in a state where the blower and the heat exchanger are not clogged.
(5) The present invention is the combustion control device according to any one of items (1) to (4), wherein the reference current value is stored during automatic pouring immediately after the combustion control device is attached.
(6) The present invention is the combustion control device according to any one of the items (1) to (5), wherein the comparison between the reference current value and the actual current value by the comparison means is performed only during automatic pouring.
(7) According to the present invention, in any one of the items (1) to (6), the burner combustion at the time of automatic pouring is forcibly switched to partial combustion having a lower capacity than the maximum combustion amount, and the current after the switching Is a combustion control device that stores the value as a reference current value.
(8) According to the present invention, in any one of items (1) to (7), the time during which the actual current value flowing through the blower is equal to or less than the reference current value continues for a predetermined time or occurs a predetermined number of times. In this case, it is a combustion control device provided with an abnormal combustion detection means that determines that the combustion is abnormal and stops the combustion.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The automatic pouring in the present invention will be described with reference to FIG. 1. When the user presses the pouring switch of the remote controller 2 and the control device 3 detects the start of automatic pouring, the pouring water electromagnetic valve 8 is opened. In addition, the water amount is controlled by the water amount control valve 6 and the hot water having the temperature set by the user with the remote controller 2 is supplied to the bathtub 21.
[0010]
The combustion control device of the present invention has a plurality of hot water supply burners 25 and 26, and performs burner switching according to the difference in combustion capacity. That is, all burners are burned during maximum combustion, and the burners are partially used (for example, only the hot water supply burner 25 is burned). In general, during automatic pouring, pouring is performed by maximum combustion in order to shorten the pouring time, but a large amount of water suitable for maximum combustion can be obtained in areas where the supply water pressure is low or in low time zones. Therefore, only a part of the burner or the amount of combustion is adjusted and burned to obtain hot water having an appropriate temperature.
[0011]
The reference current value is stored during automatic pouring. In the present invention, as described above, the current change from the reference current value is measured and the decrease in the current value is detected. Therefore, the determination of the reference current value is important. In order to determine the reference current value, it is necessary to continue the combustion under a certain condition for a predetermined time. This is because the current value decreases as the burner temperature rises, and the current value is stabilized. It is indispensable. However, in normal hot water supply, since the user changes the amount of water used as appropriate, it is difficult to continue combustion under certain conditions for a predetermined time. Therefore, it is necessary to store the reference current value at the time of automatic pouring in which the user cannot change the amount of water appropriately.
[0012]
In the present invention, the storage time is shortened by determining the reference current value to be determined over the entire range originally used for the combustion control device only during automatic pouring. In a combustion control device having an automatic pouring function, since automatic pouring is usually performed once a day, it is sometimes necessary to detect a change in current only during automatic pouring. This is because the fan clogging of the blower and the clogging of the heat exchanger proceed gradually, and the clogging does not occur suddenly on the order of several hours. It is not necessary to store the reference current value once, and the same reference current value is used thereafter. Preferably, automatic hot water pouring should be performed and stored immediately after the combustion control device is installed so that there is no possibility of fan clogging of the blower or heat exchanger. When a stable value cannot be measured by a single current value measurement, a stable value can be obtained by taking an average value of a plurality of values.
[0013]
Burner combustion during automatic pouring is ideally performed at maximum combustion as described above, but maximum combustion cannot be performed at locations where the water pressure is low depending on the region and time due to insufficient water volume. Furthermore, even in the summer when the incoming water temperature is high, the temperature reaches the set temperature without maximal combustion, so maximum combustion cannot be performed. In such an area, when the reference current value is determined as described in claim 2 of the present invention, the partial combustion is forcibly switched to a lower combustion capacity than the maximum combustion amount, and the current after the switching is changed to the reference current. Need to remember as. In addition, the predetermined time in the third aspect of the present invention is preferably 2 to 5 minutes. In addition, a number of 3 times or more is preferably used as the predetermined number.
[0014]
The storage of the reference current value according to the present invention will be described with reference to FIGS. 1 and 4. When the automatic pouring switch of the remote controller 2 is pressed and the control device 3 detects the start of automatic pouring, the pouring water electromagnetic valve 8 is opened. At the same time, the water amount control valve 6 is fully opened, and hot water is poured into the bathtub 21 at the temperature set by the remote controller 2. At that time, it is determined whether or not the maximum combustion is possible. If possible, the current value at that time is stored as a reference current value after a lapse of T1. If the maximum combustion is impossible, it is determined that the combustion is less than the maximum combustion, and the current value after the elapse of T1 is stored as the reference current value. Thereafter, the combustion is continued until the automatic pouring is completed, and is terminated.
[0015]
The comparison between the reference current value and the actual current value will be described with reference to FIGS. 1 and 3. When the automatic pouring switch of the remote controller 2 is pressed and the control device 3 detects the start of automatic pouring, the pouring water electromagnetic valve 8 Is opened at the same time as the water amount control valve 6 is fully opened, and hot water is poured into the bathtub 21 at the temperature set by the remote controller 2. At that time, it is determined whether or not the maximum combustion is possible. If possible, the reference current value is compared with the actual current value after the time T1 has elapsed. On the other hand, when the maximum combustion is impossible, it is determined that the combustion is forcibly less than the maximum combustion, and the reference current value is compared with the actual current value after the time T1 has elapsed. As a result of the comparison, when it is confirmed that the current decreases by I1 amperes, the combustion capacity is lowered and the automatic pouring is continued. Note that the reduction width from the reference current value is preferably 80 milliamperes or more in consideration of the error of the blower itself and the combustion state. The automatic pouring stops combustion when the number of current reductions (the number of abnormal combustions) is N1 or more or when the integration of current reduction times (accumulation time for abnormal combustion) exceeds T10 hours.
[0016]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a combustion control device of the present invention, and FIG. 2 is a block diagram of the combustion control device. The flow of water in the water heater 1 which is a combustion control device is divided into two directions after passing through the water amount sensor 4 for detecting the amount of water supplied from the water supplied from the water supply port, and one side to the heat exchanger 5 and the other side. To the outlet of the heat exchanger 5. At the outlet of the heat exchanger 5, hot water that has passed through the heat exchanger 5 and water that has not passed are mixed, and after passing through the water amount control valve 6 and the hot water supply thermistor 7 for detecting hot water temperature, pass through the hot water supply pipe 24 and from the hot water tap 20. The hot water is discharged or passed through the hot water electromagnetic valve 8 and supplied to the bathtub 21. The water heater 1 also has a flow for remedy in addition to the water flow described above, and the water flowing from the bathtub 21 via the bathtub return pipe 23 is a bath thermistor 11 for detecting hot water temperature and a circulating water flow detection. The pump 9 is reached via the flow switch 10. The water that has flowed out of the pump 9 is heated by the reheating heat exchanger 19 and then returned to the bathtub 21 by the pouring line 22.
[0017]
When the hot-water tap 20 is in an open state, the control device 3 detects the signal of the water amount sensor 4 by the water amount detection unit 28, drives the blower 18 by the blower drive unit 34, and enters the combustion chamber in which the heat exchanger 5 is arranged. Supply combustion air. When the blower 18 is driven, the safety solenoid valve 13 connected to the gas pipe, the hot water solenoid valve 15 for supplying gas to the hot water burner 26, and the hot water switching solenoid valve 16 for supplying gas to the hot water burner 25 are opened. . The proportional solenoid valve 14 installed between the safety solenoid valve 13 and the hot water solenoid valve 15 is driven by the proportional solenoid valve drive unit 35 and changes the amount of combustion by adjusting the gas amount. When gas is supplied to the hot water supply burners 25 and 26, the ignition device drive unit 38 drives the ignition device 12 to ignite. Therefore, the control device 3 detects the signal of the hot water supply thermistor 7 with the hot water temperature detection unit 29, adjusts the valve opening of the proportional solenoid valve 14 so as to reach the temperature set by the remote controller 2, and the valve opening. Air-fuel ratio control is performed by sending a blower drive voltage commensurate with (gas supply amount) to the blower.
[0018]
If the set water temperature cannot be obtained even after the maximum combustion, the water control valve 6 is driven by the water control valve drive unit 36 to reduce the amount of hot water supply to obtain hot water at the set temperature. Conversely, when the set temperature cannot be obtained even with the minimum combustion, the hot water supply switching electromagnetic valve 16 is closed by the electromagnetic valve drive unit 37.
[0019]
As described above, the combustion control device that once memorizes the reference current value compares the current value each time automatic hot water is supplied. When the difference between the reference current value and the actual current value exceeds 100 milliamperes, abnormal combustion is assumed, the abnormal combustion frequency (N1) is set to 3 times, and the accumulated time of abnormal combustion (T10) is set to 3 minutes. As a result of clogging the fan, the warning lamp flashes on the temperature display on the remote control 2 and the buzzer sounds at the same time when the automatic pouring switch is pressed, and the combustion capacity is reduced (specifically, No. 16 to No. 6). The combustion was stopped when the same operation was repeated three times. As described above, in the present invention, it is not necessary to store the reference current value over the entire use range of the combustion control device, so that the storage time can be shortened. Furthermore, since the actual current value is not reduced, the reference current value is not restored, so that even if only one of the plurality of heat exchangers is clogged, other heat exchangers will not be abnormally burned.
[0020]
【The invention's effect】
According to the present invention, it is possible to shorten the time until the determination of the reference current value, detect abnormal combustion due to air shortage, and accurately determine the state at the time of abnormal combustion. In addition, by forcing the memory of the reference current value to be less than the maximum combustion, abnormal combustion can be reliably captured even when used in a low water pressure area.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a combustion control device showing an embodiment of the present invention.
FIG. 2 is a block diagram of a combustion control device of the present invention.
FIG. 3 is a flowchart for comparing the reference current value and the actual current value according to the present invention.
FIG. 4 is a flowchart illustrating reference current value storage according to the present invention.
[Explanation of symbols]
1. Water heater 2. Remote control Control device 4. 4. Water volume sensor 5. Hot water supply heat exchanger 6. Water volume control valve Hot water thermistor 8. 8. Hot water solenoid valve Pump 10. Flow switch 11. Bath thermistor 12. Ignition device 13. Safety solenoid valve 14. Proportional solenoid valve 15. Hot water solenoid valve 16. Hot water switching solenoid valve 17. Bath solenoid valve 18. Blower 19. Memorial heat exchanger 20. Hot water tap 21. Bathtub 22. Pouring line piping 23. Bath return piping 24. Hot water supply piping 25. Hot water burner 26. Hot water heater 27 Memorial Burner 28. Water amount detection unit 29. Hot water temperature detection unit 30. Control unit 31. Storage unit 32. Comparison unit 33. Current value detection unit 34. Blower drive unit 35. Proportional solenoid valve drive unit 36. Water amount control valve drive unit 37. Solenoid valve drive unit 38. Ignition drive unit

Claims (8)

A plurality of burners for burning fuel gas;
A flow control valve for adjusting the flow rate of the fuel gas;
A blower for supplying combustion air to the burner;
Multiple heat exchangers for hot water supply and memorial service,
Drive means for driving the blower at a preset voltage or rotational speed with respect to the amount of fuel gas;
Current detection means for detecting the current flowing through the blower;
Storage means for storing a reference current value of the blower for a predetermined combustion time;
Comparing means for comparing the actual current value of the blower with the reference current value stored by the storage means during the predetermined combustion,
In the combustion control device that can perform automatic pouring,
For each combustion control device,
Set the reference current value at least once during automatic pouring,
The value is fixed as a reference current value thereafter,
The comparison means compares the reference current value with the actual current value, and when the actual current value is reduced to a predetermined value or more from the reference current value, the fuel gas amount is reduced and the reduced fuel gas amount is dealt with. the voltage or combustion control device Ru drives the blower at a rotation speed. The combustion control device according to claim 1, wherein the reference current value at the time of automatic pouring is stored after a predetermined time has elapsed after the start of automatic pouring. The combustion control device according to claim 1 or 2, wherein the reference current value is obtained and stored by taking an average value a plurality of times. 4. The combustion control device according to claim 1, wherein the reference current value is stored in a state where the blower and the heat exchanger are not clogged. 5. The combustion control device according to claim 1, wherein the reference current value is stored during automatic pouring immediately after the combustion control device is attached. 6. The combustion control device according to claim 1, wherein the comparison between the reference current value and the actual current value by the comparison unit is performed only during automatic pouring. In any of claims 1 to 4, the burner combustion during automatic pouring, to the low partial combustion capable than the maximum combustion amount forcibly switched, you store current after the switching as a reference current value retardant Firing control device. 7. The combustion according to claim 1, wherein when the time during which the actual current value flowing through the blower is equal to or less than the reference current value continues for a predetermined time or occurs a predetermined number of times, abnormal combustion is determined. combustion controller having abnormal combustion detection means for stopping.

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