JPH0439565B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is a method for burning kerosene by taking in room air,
This invention relates to a combustion device that performs heating by emitting combustion gas into a room.

BACKGROUND TECHNOLOGY In general, this type of combustion appliance is as shown in Fig. 5.
A burner 3, a hot air fan 4 and its motor 5, and a controller 6 that controls all of these are installed inside the space surrounded by the exterior 1 and the stand 2, and the indoor air A is combusted by the blower motor. The configuration is such that the mixture is mixed with gas B and discharged from the louver 7 as warm air C at an appropriate temperature for use in heating the room.

As shown in Fig. 6, the burner 3 includes a vaporizer cylinder 8 for vaporizing kerosene for combustion, an electromagnetic pump 9 for supplying a fixed amount of kerosene, a burner motor unit 10 for sending combustion air, and an ignition electrode for igniting the vaporized kerosene. 1
1. A flame rod 12 and the like for monitoring the state of the combustion flame D are provided. The circuit of the electromagnetic pump 9 is as shown in Fig. 7, and includes a diode 13, resistors 14,
5. The capacitor 16 and the zener diode 17 are configured so that DC 140V and 12V are generated at points C and d. A first thyristor 19 is connected to the coil 18 of the electromagnetic pump 9, and a second thyristor 21 is connected to the resistor 20, and these connection points are referred to as points e and f. A capacitor 21 and a resistor 22 are connected between points e and f, and a trigger element 23, a gate point g of the thyristor 21, and a resistor 24 are connected between points f and b. On the other hand, the transistor 26 of the photocoupler 25 receives a signal from the controller 6 between the gate h of the first thyristor 19 and the point d.
are connected through a resistor 27. In addition, other resistance 2
9. Connect the capacitor 30 and diodes 28 and 31 as shown in FIG.

In this circuit, a direct current is always applied to the thyristors 19 and 21 due to the direct current generated from the alternating current terminals a and b. During normal operation, a voltage is applied to the gate point g through the resistor 20 → point f → trigger element 23, so the thyristor 21 is in the ON state. However, the thyristor 19 is turned off because there is no signal from the controller 6. Therefore, the point e side is positive, f
The dot side has negative polarity and the capacitor 21 is charged. In this state, when a signal from the controller 6 enters the light emitting diode 28 in the form of a pulse signal, the transistor 26 turns on and hits the gate h, so the thyristor 19 turns on. In this state, the voltage at point e suddenly drops and the charge in the capacitor 21 is discharged in the circuit of resistor 22 → point e → thyristor 19 → point b → thyristor 21 → point f, so the thyristor 21 is instantly A reverse voltage is applied to the switch, causing it to turn off. This time point f is positive,
The capacitor 21 starts to be charged when the point e is negative, and the charging voltage of the capacitor 21 increases until the voltage of the trigger element 23 reaches the trigger voltage, and when the trigger is finally triggered, the thyristor 21 is turned on again. Therefore, this time, the charge of the capacitor 21 changes from point f to thyristor 21 to thyristor 19.
→Point e→A reverse voltage is applied to the thyristor 19 in the loop of the resistor 22, causing it to turn off. By repeating this, the electromagnetic pump 9 is operated, and kerosene is supplied to the vaporizer tube 8 to be vaporized and burned. The controller 6 controls the on-off interval of the thyristor 19 to vary the combustion state from strong to weak.

Problems to be Solved by the Invention However, in the circuit of this combustion device, the thyristors 19 and 21, the trigger element 23, the resistor 20,
If the characteristics of the capacitor 21 or the like change even slightly, the amount of fuel discharged from the pump 9 will change significantly.

For example, when the withstand voltage of the thyristor 19 becomes lower than the voltage at point c, the thyristor 19 turns on automatically even without a trigger signal, and the number of pulses becomes extremely large. Furthermore, if the value of the resistor 20 becomes large for some reason, the current supply to the capacitor 21 is delayed and the turn-on of the thyristor 21 is delayed, which lengthens the ON time of the thyristor 19, resulting in a large amount of oil being supplied. That is, the amount of kerosene supplied increases both when the pulse width increases and when the pulse number increases. Therefore, since the rotational speed of the burner motor 10 does not change, the length of the flame within the burner increases, and in some cases, the flame may blow out from the louver 7 shown in FIG. 5. In addition, there are cases where the oil decreases, which is detected by the flame rod 12. However, if there are many flames, there will be a lot of flame, so the flame rod will not detect abnormalities and may become dangerous as mentioned above. I was in a state where I was only looking forward to improvement. FIG. 8 is a diagram showing such a state. The solid line in the figure is the pulse waveform applied to the pump coil 18 under normal conditions. That is, the pulse width is υ ₁ and the pulse interval (frequency) is t ₁ . If the thyristor 19 has a low breakdown voltage and turns on only when the c-point voltage is high in the shaped waveform, the thyristor 19 will oscillate at the same frequency as the power supply frequency, and the pulse interval will decrease as indicated by the dotted line _t2 in the figure. Furthermore, when the resistance 20 becomes larger, the width increases as shown by the dashed dotted line υ ₂ in FIG.

The present invention was made in view of these points.
The purpose is to improve safety.

Means for Solving the Problems In order to achieve the above object, the present invention includes a combustion control section A that controls combustion as shown in FIG. 1, and a pulse signal is generated based on the output from this combustion control section A. A pulse generator B, a pump drive circuit C that drives an electromagnetic pump based on pulse signals from the pulse generator B, and pulses from the pulse generator B and pump drive circuit C are monitored to determine whether there is an abnormality. The configuration includes an abnormality determination section D that determines the.

Effects With the above configuration, the present invention detects abnormal oscillation or expansion of pulse width due to component failure, noise, etc. and stops combustion. There is no flame coming out from the
It can be used with confidence.

Embodiment An embodiment of the present invention will be described below based on the drawings. FIG. 2 shows the pump drive circuit C shown in FIG. 1.
This shows the combustion control section A and the abnormality determination section D. Here, the combustion control section A and the abnormality determination section D are constituted by a microcomputer E, and are connected to an AC power source via a DC converter 33.
Further, the pump drive circuit C has a series circuit of a resistor 34 and a light emitting diode 36 of a photocoupler 35 connected in parallel to the conventional pump coil 18 shown in FIG.
The transistor 37 of the photocoupler 35 is connected to the microcomputer E (AD). The reference numeral 39 indicates all load groups such as fan motors, and the other components are the same as the conventional example shown in FIG. 7, so a description thereof will be omitted.

In the above configuration, the operation of the pump drive circuit C is the same as the conventional example shown in FIG.
Since the diode 36 of the photocoupler 35 is connected in parallel with the phototransistor 37, when a pulse is applied to the pump coil 18, the phototransistor 37 is
It is in the ON state, and its pulse signal is sent to the abnormality determination section D of the microcomputer E. Here, as shown in Fig. 3, the pulse interval during normal operation is T ₁ ,
The pulse width is V ₁ and is shown by a solid line. Of these, _T1 varies depending on the amount of combustion, and follows the instruction issued from the combustion control section A in the microcomputer E. Further, the pulse width V ₁ differs like V ₂ due to circuit variations and the like. Therefore, the third
As shown in the figure, in anticipation of this variation, etc., the interval T ₂ until the next pulse arrives is set in advance as follows.

T ₂ ≦T ₁ −T ₂ The above V ₂ is determined by adjusting with the resistor 20 to absorb variations in the pump oscillation circuit C and variations in the pump mechanism, and varies from pump to pump. Therefore, the maximum width is set as the limit and this is defined as _V2 .

Next, the operation of the microcomputer 32 in determining the pulse signal of the output transistor 37 of the pulse detection photocoupler 35 to the pump coil 18 will be explained using FIG.

First, when the pump drive circuit C starts operating and the first pulse is input, the pulse width V is checked. Then, do nothing in particular until this pulse width V becomes V≧V ₂ ...(1). In addition to the above condition (1), the basic interval T until the next pulse arrives.
Perform a comparison with T ₂ . That is, it is monitored whether T≦T ₂ (2). And this T
As long as the pulse is shorter than T ₂ , that is, conditions (2) and any of the above conditions (1) are satisfied, pulses existing during this period are counted and integrated. Then, count T ₂ itself, and if the number of T ₂ that satisfies condition (1) or (2) is less than 10, clear the previous work and start checking the pulse again. Repeat the action, but the number of times T ₂ is
After 10 times have elapsed, count the number of pulses so far and stop the combustion if this pulse has elapsed, for example, 5 times or more. If it is less than 4 times, change the pulse width so far.
Clear all T ₂ counts and continue burning. Then, clear the number of pulses and T ₂ so far and make everything work from the beginning.

Here, 10 times or 5 times is an assumption, but in reality, the level is determined by the degree of flame emission.

To detect pulses within this normal pulse interval T ₁ , it is possible to detect them once within T ₁ and stop combustion if there is even one abnormality, but in reality, pulses due to noise etc. However, at this level, there is no need to stop combustion as the flame will not reach the point where it is exhausted. Therefore, it is effective to continue for about 10 cycles and then judge whether or not there is an abnormality.

Furthermore, since the pulse width V ₂ can also be detected compared to the specified pulse width V ₁ , it has become possible to detect abnormal pulse widths as well.

Effects of the Invention As is clear from the description of the embodiments above, according to the present invention, the amount of oil supplied increases due to, for example, a voltage failure in the thyristors 19 and 21, a failure in the resistors 20 and 22, the capacitor 21, and the trigger element 23. It is also possible to prevent this in advance and prevent flames from forming in the exhaust section.

Furthermore, as in the present invention, a method to prevent flame blow-out may be to install a temperature-sensitive element such as a thermistor or thermostat in the exhaust port or louver and stop the operation due to the temperature rise, but in either case, the operation may be delayed. In contrast, in the present invention,
Detection is possible on the ms order, ensuring extremely high safety.

Note that even if the pulse interval becomes narrow for some reason, for example, 3 out of 10 detections will be T ₁ −V ₂
If it is configured to detect when it enters between the two, it can be detected.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a combustion device according to an embodiment of the present invention, Fig. 2 is a circuit diagram of the main parts, Fig. 3 is an explanatory diagram of the same pulse waveform, and Fig. 4 is a flowchart for explaining the same operation. , FIG. 5 is a cross-sectional view of the hot air fan according to the present invention, and FIG. 6 is a structural explanatory diagram of the burner portion thereof.
FIG. 7 is a circuit diagram showing a conventional example, and FIG. 8 is an explanatory diagram of its pulse waveform. A... Combustion control section, B... Pulse generation section, C...
...Pump drive circuit, D...Pulse abnormality determination section, 1
8...Electromagnetic pump.

Claims (1)

[Claims] 1. A combustion control section, a pulse generation section that generates pulses based on the output from the combustion control section, and a pump drive circuit that drives an electromagnetic pump based on the pulses from the pulse generation section. , the pulses from the pump drive circuit and the pulse generator are monitored, and the pulses are not measured for a period slightly longer than the time the pulses are being applied to the electromagnetic pump, and thereafter until the next pulse is applied. A combustion device comprising a pulse abnormality determination unit that measures the pulse abnormality and stops combustion when the abnormality count obtained by repeating this measurement several times exceeds a certain value. 2. The combustion device according to claim 1, wherein the abnormality measured by the abnormality determining section is either the pulse width V ₂ or the interval T ₂ until the next pulse is applied, or both.