KR950011462B1 - Safety combustion control apparatus - Google Patents

Abstract

An electronic safety valve is controlled by an output of a frame rod and an electromotive force of a thermocouple. The device comprises a switch control circuit(607) for switching an electrical energized control state between the first electrical energization control circuit(605) and the second electrical energization control circuit(606). The control circuit(607) controls the safety valve(4) with the first electrical energization control circuit(605) for a predetermined time after igniting operation and the second energization control circuit(606) controls the safety valve(41) after the predetermined time elapses. The device performs a positive shielding of a fuel supply passage if a combustion flame is not detected when a reignition is carried out just after a burner is turned off.

Description

Combustion Safety Control

FIG. 1 is a block diagram showing a combustion control unit of a gas burner.

2 is an electric wiring diagram showing a combustion control unit of a gas burner.

3 is a schematic view showing a gas burner.

4 is a block diagram showing a control device of a gas burner.

5 is a time difference art such as a frame rod and a thermocouple.

* Explanation of symbols for main parts of the drawings

3: gas burner 4: gas pipeline (fuel supply passage)

6: combustion control unit (combustion safety control device)

41: electronic safety valve 605: first energization control means

606: second energization control means 607: switching control means (switching circuit)

619: frame load 640: thermocouple

The present invention relates to a combustion safety control device for controlling an electronic safety valve in accordance with the output of a flame rod disposed near the burner and the electromotive force of the thermocouple.

Conventionally, for example, in a gas combustion device (Japanese Patent Application Laid-Open No. 57-66457), a thermocouple is connected to a coil of an electronic safety valve, and the electronic safety valve is kept open by the electromotive force of the thermocouple and at the same time, While the electromotive force detects the presence of combustion flame by the frame rod for a certain time until the desired electromotive force to keep the safety valve open, it assists maintaining the valve opening of the safety valve by a separate power supply. A combustion safety control device is described.

By the way, in the conventional combustion safety control apparatus, when the gas burner is re-ignitioned immediately after the gas burner is extinguished (hot star art), especially when the electromotive force of the thermocouple is generated while the thermocouple is not cooled, the ignition occurs. If the burner does not produce a combustion flame due to a defect, or if the combustion flame occurs immediately after the combustion flame occurs, the electronic safety valve is kept open by the electromotive force output by the thermocouple even if the frame rod is not output. For this reason, even when combustion is not performed by the gas burner, since the gas supply passage is not interrupted, the live gas flows out and the stability is unstable.

An object of the present invention is to provide a combustion safety control device which reliably shuts off a fuel supply path when a combustion flame is not detected when a burner is re-ignitioned immediately after extinguishing a burner.

The present invention is provided with an electronic safety valve interposed in the fuel supply path for supplying fuel to the burner and the valve is opened when energized, and a frame rod for detecting the presence of a combustion flame generated by the burner, according to the output of the frame rod A second energization control circuit having a first energization control circuit for energizing and controlling the safety valve, a thermocouple for generating electromotive force by a combustion flame of the burner, and a second energization control circuit for energizing and controlling the safety valve in accordance with the electromotive force of the thermocouple; And a switching circuit for controlling the safety valve only by the first energization control circuit until a predetermined time elapses after the ignition operation, and controlling the safety valve only by the second energization control circuit after the predetermined time has elapsed. Technical means were adopted.

Therefore, when the burner is ignited according to the present invention, the electronic safety valve is controlled only by the first energization control circuit until a predetermined time elapses after the ignition operation is performed by the switching circuit. Therefore, the energization of the safety valve and the stop of energization are controlled.

Then, when a predetermined time elapses after the ignition operation, the electronic safety valve is controlled only by the second energization control circuit by the switching circuit, so that the energization of the safety valve and the stop of energization are controlled only by the electromotive force of the thermocouple regardless of the output of the frame rod. . In the case where the re-ignition operation is performed immediately after ignition at the burner, that is, even when the thermocouple is not cooled and the electromotive force is still generated from the thermocouple, the switching circuit is operated as described above until a predetermined time elapses from the ignition operation. The safety valve is controlled only by the first energization control circuit. For this reason, when combustion flame is not detected by the burner by the frame rod, energization to the safety valve is stopped regardless of the electromotive force of the thermocouple, so that the fuel supply path is reliably shut off.

Hereinafter, the combustion safety control device of the present invention will be described based on one embodiment shown in FIGS. FIG. 1 is a block diagram showing a combustion control unit of a gas burner type scrubber, and FIG. 2 is an electrical wiring diagram showing a combustion control unit of a gas burner type scrubber.

As shown in FIG. 3, the gas chlorine type scrubber 1 includes a hot water supply pipe passage 2 for discharging hot water or cold water, a gas pipe passage 4 for supplying fuel gas to the gas burner 3, and a gas flue. The control apparatus 5 of the news feeder 1 is provided.

The hot water supply pipe passage 2 is composed of a water supply pipe 21, a heat absorbing pipe 22, and a hot water supply pipe 23. The water supply pipe 21 is provided with an electronic water shut off valve 24, a water governor valve 25, and a water amount regulating valve 26. The still water valve 24 is opened when energized (on) and closed when energized is stopped (off). The water governor valve 25 keeps the quantity constant. The water quantity control valve 26 controls the degree of opening of the water supply pipe 21 by rotating the hot water adjustment button (not shown) to change the quantity of water.

The endothermic tube 22 is disposed above the gas burner 3, and heats the water by heat-exchanging combustion heat generated in the gas burner 3 with water flowing therein. The tapping pipe 23 is formed of a flexible pipe and discharges hot or cold water from a discharge port. The shower head 27 is coupled to the outer circumference of the discharge port of the tapping tube 23. By switching the switch (not shown in FIG. 3), the shower ed 27 switches the discharge flows discharged from the discharge port of the tapping tube 23 into the discharge flow in the shower state and the discharge flow in the straight state.

The gas pipeline 4 is a fuel supply passage of the present invention, and includes an electronic safety valve 41, a hydraulic pressure response valve 42, a gas burner valve 43, and a gas amount regulating valve 44. When the solenoid coil 40 is energized, the safety valve 41 opens the gas pipeline 4 by opening the valve, and when the energization to the solenoid coil 40 is stopped, the valve is closed to close the gas pipeline 4. The hydraulic pressure regulating valve 42 is formed integrally with the water governor valve 25 so that the valve opens in conjunction with the water flow. The gas burner valve 43 is integrally formed and interlocks to open the valve when water flow is detected. The gas burner 43 keeps the gas pressure at the secondary side constant. The gas amount adjusting valve 44 is connected to a temperature adjusting button, and the amount of gas is changed by controlling the opening degree of the gas pipe 4 by the rotation of the temperature adjusting button.

As shown in FIG. 4, the control device 5 includes a combustion control unit 6, a still water valve control unit 7, a power supply circuit 8, a switching circuit 9, a switching switch 10 and a water flow switch. 11 equipped.

The combustion control unit 6 is a combustion safety control device of the present invention, and includes a safety valve drive circuit 601, an ignition control circuit 602, and a combustion state detection circuit 603.

The safety valve drive circuit 601 is provided with switching circuits 611 and 612, for example. The switching circuit 611 is a circuit for power supply to the safety valve 41, and is composed of, for example, a transistor 613 and resistors 614 and 615.

The switching circuit 611 conducts the solenoid coil 40 of the power supply circuit 8 and the safety valve 41 when the input is at a low level (hereinafter referred to as L level), and supplies power to the solenoid coil 40. To supply. The switching circuit 611 stops supplying power to the solenoid coil 40 of the safety valve 41 when the input is at a high level (hereinafter referred to as H level).

The switching circuit 612 is a circuit for determining the input level of the switching circuit 611. For example, the switching circuit 612 includes a transistor 616 and resistors 617 and 618. When the input is H level, the output is 1 level. When the input is at L level, the output is at H level.

The ignition control furnace 602 controls on / off of the sparker 604, and the sparker 604 ignites a mixture gas of fuel gas and combustion air flowing out from the gas burner 3.

The combustion state detection circuit 603 includes a first energization control circuit 605, a second energization control circuit 606, and a switching control circuit 607 as shown in FIGS. 1 and 2.

The first energization control circuit 605 has a frame rod 619, an oscillation circuit 620, a flame detection circuit 621, and a switching circuit 622. The frame rod 619 is made of a heat-resistant metal and is directly inserted into the combustion flame to detect the presence of the combustion flame by rectifying the combustion flame. The oscillation circuit 620 is composed of, for example, coils 623 and 624, a resistor 625, a diode 626, and a transistor 627. When power is supplied, the output repeats the H level and the L level.

The flame detection circuit 621 includes, for example, a coil 628, a zener diode 629, capacitors 630 and 631, resistors 632, 633, 634, and a FET 635. In the flame detection circuit 621, when a combustion flame is formed and a current flows from the frame rod 619 to the gas burner 3 side, the potential of the drain of the FET 635 becomes L level, and a combustion flame is generated. Otherwise, the potential of the drain becomes H level. In addition, the coil 628 is coupled to the coils 623 and 624 of the oscillation circuit 620 to form a transformer, and boosts the voltage to 150-200V.

The switching circuit 622 consists of, for example, an inverter 636, a transistor 637, and resistors 638 and 639, and the potential of the collector of the transistor 637 becomes level when the input is L level and the input is H level. L level.

The second energization control circuit 606 is composed of a thermocouple 640, for example, a comparator 641 and resistors 642, 643, and 644. The thermocouple 640 is a thermal couple made of different types of metal wires, and generates thermal power by the combustion flame to detect whether the gas burner 3 is abnormally burned due to the oxygen depletion state of the combustion flame.

The comparator 641 outputs L when the output voltage of the thermocouple 640 is lower than the set value determined by the resistors 642 and 643 (for example, 5 mV-7 mV), and the thermocouple 640 output voltage. When it rises above this set value, the output becomes H level. In addition, the output voltage of the thermocouple 640 generally takes 3A-5 seconds to rise to the set value after the ignition operation.

The switching control circuit 607 is a switching circuit of the present invention and includes, for example, a timer circuit 645, a switching circuit 646, an electrolytic capacitor 647, and diodes 648 and 649. The timer circuit 645 outputs L level until a predetermined time (for example, 20 seconds) elapses after the ignition operation is performed, and the output becomes H level after a predetermined time elapses.

The switching circuit 646 is a circuit for supplying power to the first energization control circuit 605 and includes, for example, a transistor 605 and resistors 651 and 652. This switching circuit 646 supplies power to the first energization control circuit 605 when the input is at the L level. In addition, the switching circuit 646 stops supplying power to the first energization control circuit 605 when the input is at the H level. That is, the first energization control circuit 605 operates as long as a predetermined time elapses after the ignition operation is performed, and consumes electric power. The electrolytic capacitor 647 stabilizes the input voltage of the first energization control circuit 605.

The index valve control unit 7 is an index for controlling the index valve 24 according to the output of the output holding circuit 72 and the output holding circuit 72 for holding the output of the infrared sensor 71 which is a reflective photoelectric switch. The valve drive circuit 73 is incorporated.

The infrared sensor 71 is composed of a light emitting element 74 such as a photo diode that emits infrared rays, and a light receiving element 75 such as a photo transistor that detects infrared rays reflected from a target object such as a user's hand.

When the light receiving element 75 detects infrared rays, the output holding circuit 72 outputs a high level (H level). When the light receiving element 75 detects infrared rays again, the output becomes a low level (L level).

The still water valve driving circuit 73 turns on the still water valve 24 when the input is at the H level, and opens the valve, and closes the valve by turning off the still water valve 24 when the input is at the L level.

The power supply circuit 8 is, for example, a battery of 3V is used, the water flow switch 11 to be described later that the water flows, and the electric power is only when the tang mode is selected and the switching switch 10 is turned on Electric power can be supplied to the valve 41, the safety valve driving circuit 601, the first energization control circuit 605, the second energization control circuit 606, and the switching control circuit 607.

The switching circuit 9 is composed of one transistor and is connected in series between the combustion control unit 6 and the power supply circuit 8. This switching circuit 9 is turned on when the input is at H level and turned off when the input is at L level.

The switching switch 10 is a switch for switching the hot water and the water mode, and is connected in series between the combustion control unit 6 and the switching circuit 9. The changeover switch 10 is turned on when the hot mout is selected by the user (contact is closed), and turned off (opened when the male mode is selected).

The water flow switch 11 is connected in series between the combustion control unit 6 and the switching switch 10. This water flow switch 11 is a switch in which the hydraulic pressure actuating valve 42 detects water flow and is interlocked when the valve is opened, and is turned off when the valve is closed.

The operation of the combustion control unit 6 of this gas combustion type water purifier will be described based on FIGS. 1 to 5.

When the water flow switch 11 is turned on and the changeover switch 10 is turned on together (bath mode selection), the safety valve 41 forcibly keeps the valve open for a short time. For this reason, the combustion gas is supplied to the gas burner 3 through the gas pipeline 4 and ignited, and combustion starts in the gas burner 3 as shown in FIG.

When combustion is started in the gas burner 3, the output of the timer furnace 645 of the switching control circuit 607 may pass for a predetermined time tl (for example, 20 seconds) as shown in FIG. L level until As described above, when the output of the timer circuit 645 is at the L level, the input of the transistor 650 of the switching circuit 646 is at the L level, and thus the transistor 650 is turned on. For this reason, since electric power is supplied from the power supply circuit 8 to the 1st electricity supply control circuit 605, the 1st electricity supply control circuit 605 will start operation | movement at the same time as a combustion start.

Here, when the combustion flame generated by the gas burner 3 is detected by the frame rod 619, a current flows from the frame rod 619 in the direction of the combustion flame so that the gate of the FET 635 becomes a negative potential. In other words, the flame detection circuit 621 determines that the frame rod 619 has detected a combustion flame.

When the gate of the FET 635 becomes negative, the potential of the drain of the FET 635 becomes H level. Therefore, the input of the inverter 636 becomes H level, and an L level signal is output from the inverter 636. do. For this reason, since the potential of the base of the transistor 637 of the switching circuit 622 becomes L level, the transistor 637 is turned on.

Therefore, since the output of the switching circuit 622 becomes H level, the transistor 616 of the switching circuit 612 is turned on and the transistor 613 of the switching circuit 611 is turned on for the safety valve driving circuit 601. . Therefore, since power is supplied from the power supply circuit 8 to the solenoid coil 40 of the safety valve 41, combustion of the gas burner 3 is continued.

On the other hand, since the second energization control circuit 606 is always supplied with power from the power supply circuit 8, when the gas burner 3 is normally burned after the ignition operation, it is as shown in FIG. Similarly, the output voltage of the thermocouple 640 rises above the set value. Then, the output of the comparator 641 is at the H level, but the output of the H level of the comparator 641 is output while the output of the timer circuit 645 is at the L level, that is, until a predetermined time has elapsed after the ignition operation. The timer circuit 645 is sucked through the 648. For this reason, the output of the second energization control circuit 606 is not transmitted to the safety valve 41 until a predetermined time elapses after the ignition operation. Therefore, only the output of the frame rod 619 is used to control the safety valve 41. Opening and closing are controlled.

When a predetermined time has elapsed after the ignition operation, the output of the timer circuit 645 becomes H level as shown in Fig. 5B. For this reason, since the potential of the base of the transistor 650 of the switching circuit 646 becomes H level, the transistor 650 is turned off. For this reason, since supply of electric power is stopped from the power supply circuit 8 to the 1st electricity supply control circuit 605, the 1st electricity supply control circuit 605 stops operation | movement. That is, the frame rod 619 is forcibly turned off as shown in FIG. 5C, so that power consumption of the first energization control circuit 605 including the frame rod 619 is lost.

Therefore, when the normal combustion of the gas burner 3 is detected by the thermocouple 640, the output of the H level of the comparator 641 is sent to the safety valve drive circuit 601 through the diode 649. At this time, after a predetermined time has elapsed, power is not supplied to the first energization control circuit 605 so that the opening and closing of the safety valve 41 are controlled only by the electromotive force of the thermocouple 640.

In addition, as shown in FIG. 5 (a), the thermocouple 640 is not cooled and is still not comparable when the reignition operation is performed immediately after the combustion in the gas burner 3, for example, after t2 = 10 seconds. There is a case where the output of 641 is H level. Even in such a case, the output of the timer circuit 645 becomes one level as shown in Fig. 5B until the predetermined time elapses after the ignition operation. For this reason, as described above, since the output of the comparator 641 is attracted to the timer circuit 645, the output of the second energizing circuit 606 is not applied to the safety valve 41.

Therefore, when the combustion flame is not detected in the gas burner 3 due to the ignition failure, there is no rectifying action of the combustion flame by the frame rod 619. Therefore, from the drain of the FET 635 of the flame detection circuit 621. The potential of the L level is output. For this reason, since the transistor 637 is turned off, the input of the transistor 616 becomes L level, and both the transistors 613 and 616 are turned off. Therefore, since the supply of electric power from the power supply circuit 8 to the solenoid coil 40 of the safety valve 41 is stopped, the safety valve 41 is closed. Since the gas pipeline 4 is reliably shut off after this time, the live gas is not discharged from the gas burner 3.

As described above, when the combustion control unit 6 of the gas combustion type water purifier 1 is re-ignited immediately after the gas burner 3 is extinguished, the gas line 4 is irrelevant regardless of the output of the thermocouple 640. Can be reliably blocked. As a result, since the safety can be improved, it is possible to provide the combustion control unit 6 of the highly reliable gas-fired gas stove 1.

Since the ignition is detected by the frame rod 619 until a predetermined time elapses after the ignition operation, the ignition is detected faster than the case where only the thermocouple 640 is attached. Therefore, the time for forcibly opening and holding the safety valve 41 can be shortened, and the release of the live gas from the gas burner 3 even when the ignition is wrong is avoided.

Since the supply of power to the first energization control circuit 605 is stopped after a predetermined time has elapsed since the ignition operation, when the battery is used in the power supply circuit 8, for example, the battery consumption can be reduced. .

After the predetermined time has elapsed since the ignition operation, the restraint valve 41 is energized and controlled according to the output of the thermocouple 640, so that abnormal combustion such as oxygen deficiency can be detected.

[Modification]

The first energization control circuit, the second energization control circuit, and the switching circuit may be composed of one or two or more microcomputers. The switching circuit may be configured with a timer circuit and a ring race position. The first energization control circuit, the second energization control circuit or the switching circuit can be variously changed within the scope of the present invention.

In the present embodiment, the infrared sensor 71 is provided as a device for outputting the valve core signal to the water stop valve 24, but other output devices such as a touch switch may be provided.

The present invention may be used for a combustion safety control device for a combustion device such as a water heater, a heater, or a furnace for burning liquid fuel.

According to the present invention, when the combustion flame is not detected by the frame rod when the burner is re-ignitioned immediately after extinguishing the burner, the fuel supply path can be reliably shut off regardless of the electromotive force of the thermocouple, thereby improving safety. Therefore, a highly reliable combustion safety control apparatus can be provided.

Claims (1)

(a) an electronic safety valve (41) installed in the fuel supply path (4) for supplying fuel to the burner (3) and opening the valve when energized; and (b) oil of the combustion flame generated from the burner (3). A first conduction control circuit 605 having energization control of the safety valve 41 according to an output of the frame rod 619, and (c) the burner 3. A second energization control circuit 606 having a thermocouple 640 for generating electromotive force by a combustion flame of (), and energizing and controlling the safety valve 41 according to the electromotive force of the thermocouple 640, and (d) ignition. Until the predetermined time elapses from the operation, the safety valve 41 is energized by only the first energization control circuit 605 regardless of the electromotive force generated in the thermocouple 640 of the second energization control circuit 606. After the predetermined time has elapsed, the frame load 619 of the first energization control circuit 605 detects the result. And a switching circuit (607) for controlling the safety valve (41) by the second energization control circuit (606) only, with or without combustion flame.