JP2000018581A - Combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect correctly combustion operation failure. SOLUTION: The present apparatus includes a heat exchanger 2 heated by a burner 3 and provided on an upper portion of a cylindrical trunk 1 that forms a combustion chamber of the burner 3, a first thermocouple 17 for outputting larger electromotive force as temperature of a combustion flame of the burner 3 becomes higher, a second thermocouple 21 for outputting larger electromotive force as ambient temperature in the combustion chamber becomes higher, and control means C for interrupting combustion of the burner 3 when it judges operation failure based upon outputs of the first thermocouple 17 and the second thermocouple 21. Herein, the control means C require detection information of electromotive force by the first thermocouple 17 and detection information of electromotive force by the second thermocouple 21, and judges operation failure based upon those detect ion informations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat exchanger which is heated by a burner, which is provided on an upper part of a cylindrical body forming a combustion chamber of the burner, and the higher the temperature of the combustion flame of the burner, the larger the electromotive force. A first thermocouple that outputs a higher temperature, a second thermocouple that outputs a larger electromotive force as the ambient temperature in the combustion chamber is higher, and an operation abnormality based on the outputs of the first thermocouple and the second thermocouple. When the determination is made, the present invention relates to a combustion device provided with control means for stopping combustion of the burner.

[0002]

2. Description of the Related Art In this type of combustion apparatus, conventionally,
For example, as shown in JP-A-8-61621,
The first thermocouple is arranged so as to directly face the combustion flame of the burner, and the second thermocouple is arranged so as to face the inside from an opening formed in the barrel from the outer surface side of the barrel. I was Then, as shown in a simplified circuit diagram of FIG. 5, the first thermocouple and the second thermocouple are electrically connected in series with electromotive forces having opposite polarities, and both ends thereof are lead wires. And the controller is configured to stop the combustion of the burner when the electromotive force at both ends is equal to or less than a set value.

[0003] In the combustion device having the above-described structure, if the combustion flame of the burner lifts or the combustion flame goes out due to, for example, a shortage of combustion air (lack of oxygen), the electromotive force of the first thermocouple decreases. When the electromotive force at both ends becomes equal to or less than the set value, the combustion of the burner is stopped. Further, if the heat exchanger is clogged due to long-term use, it becomes difficult for the combustion gas to flow to the burner, the ambient temperature in the combustion chamber increases, and the electromotive force of the second thermocouple increases. Then, the electromotive force in the opposite direction of the second thermocouple becomes large,
When the electromotive force at both ends becomes equal to or less than the set value, the combustion of the burner is stopped. In this way, the operation abnormality of the combustion device is properly determined, the combustion of the burner is stopped, and the safety in use is ensured.

[0004]

By the way, in the above-mentioned conventional configuration, the first thermocouple is provided so as to face the vicinity of the burner, so that the generated electromotive force is large. However, the second thermocouple is connected to the first thermocouple. The generated electromotive force is relatively small, and the second thermocouple is provided at a place where the combustion gas of the burner flows, so that the flow of the combustion gas causes, for example, soot or the like on the surface thereof. May adhere. In the case where soot adheres to the surface of the second thermocouple in this way, even if the heat exchanger is clogged as described above and the ambient temperature of the combustion chamber rises, the generated electromotive force is The value becomes smaller than the set value, and there is a possibility that the operation abnormality cannot be properly determined.

The present invention has been made in view of such a point, and an object of the present invention is to provide a combustion apparatus capable of properly detecting a combustion operation abnormality.

[0006]

According to a feature configuration of the present invention, the control means detects the detection information of the electromotive force by the first thermocouple and the detection of the electromotive force by the second thermocouple. Information is obtained for each of them, and the operation abnormality is determined based on the detected information.

Therefore, the control means obtains the detection information of each electromotive force of the first thermocouple and the second thermocouple separately, so that even if there is a difference in the level of the electromotive force generated by each of them, Even if the electromotive force itself detected due to the adhesion of soot becomes small, the ratio of the fluctuation amount due to the change in the temperature of the combustion flame of the burner or the change in the ambient temperature in the combustion chamber to the fluctuation amount of the electromotive force in each thermocouple Is larger than the conventional one.

As a result, a change in the temperature of the combustion flame of the burner and a change in the ambient temperature in the combustion chamber can be properly determined based on the change in the electromotive force generated separately in each of the thermocouples. It became.

According to a second aspect of the present invention, in the first aspect, the control means operates when the absolute value of the output value of the electromotive force of the first thermocouple falls below a burner determination value. It is configured to determine that the burner is causing combustion failure as an abnormality.

When the absolute value of the output value of the electromotive force of the first thermocouple is lower than the discriminating value for the burner, the temperature of the combustion flame of the burner is lower than the set temperature. Since the burner combustion operation is abnormal, such as when a lift has occurred or has gone out, safety can be ensured by stopping the burner combustion in such a case.

According to a third aspect of the present invention, in the first or second aspect, the control means determines that an absolute value of an output value of the electromotive force of the second thermocouple exceeds a determination value for a combustion chamber. It is configured to determine that the operation abnormality is caused by exhaust gas blockage in the combustion chamber.

If the absolute value of the output value of the electromotive force of the second thermocouple exceeds the discrimination value for the combustion chamber, the ambient temperature of the combustion chamber is high, so that the flow of the combustion gas of the burner is not good. Since it can be determined that the exhaust gas is blocked, safety can be ensured by stopping the combustion of the burner in such a case.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the first thermocouple and the second thermocouple are each provided with an electromotive force to the control means. And the control means is configured to separately obtain the detection information of the electromotive force by the first thermocouple and the detection information of the electromotive force by the second thermocouple. Have been.

[0014] Each thermocouple is electrically connected to the control means so that the electromotive force can be individually detected. Therefore, regardless of the ratio of the electromotive force generated by each thermocouple, each thermocouple is connected. By judging each change in the generated electromotive force independently, an abnormal combustion operation can be properly judged.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the first thermocouple and the second thermocouple generate electromotive forces in directions opposite to each other. The two ends are electrically connected to the control means, and the total value of the output of the electromotive force in each thermocouple is inputted to the control means.
An intermediate connection point between the thermocouple and the second thermocouple is electrically connected to the control means so that an output value of an electromotive force of the first thermocouple is input to the control means. It is configured to obtain the output value of the electromotive force of the second thermocouple based on the total value and the output value of the electromotive force of the first thermocouple.

That is, abnormality of the combustion operation of the burner can be determined based on the output value of the electromotive force of the first thermocouple, and the second thermocouple determined based on the total value and the output value of the electromotive force of the first thermocouple. Based on the output values of the pair of electromotive forces, it is possible to determine an exhaust blockage abnormality such as a clogged heat exchanger.

According to a sixth aspect of the present invention, in the fifth aspect, a connection terminal on the first thermocouple side of the first thermocouple and the second thermocouple connected in series is grounded, The electromotive force of the connection terminal on the other end side is connected so as to be input to the control means as the total value, and the control means is configured to perform a control based on the total value and an output value of the electromotive force of the first thermocouple. And a ground short-circuit abnormality of the connection terminal on the other end side is determined.

In other words, what is electrically connected to the control means are both ends of the first thermocouple and the second thermocouple connected in series, and an intermediate connection between the thermocouples. In a case where the connection line for electrically connecting the point and the control means is short-circuited on the way, for example, when the connection line of the connection terminal on the other end side is grounded, the total value becomes almost zero. Since the value is close to an abnormal value, it can be determined that the state is abnormal. If the connection line corresponding to the intermediate connection point is short-circuited to ground, the output value of the electromotive force of the first thermocouple becomes an abnormal value close to zero, so that it can be determined that the state is abnormal.

Incidentally, as a characteristic configuration of claim 4, for example,
Although the configuration shown in FIG. 4 is conceivable, in such a configuration, the abnormality of the combustion operation can be properly determined. However, for example, point P3 in FIG. 4 (for detecting the electromotive force of the second thermocouple) When the terminal is short-circuited to the ground, if the above-mentioned soot is attached, such an abnormal state may not be detected effectively.

However, according to the characteristic structure of the present invention, such disadvantages can be solved and the abnormality of the combustion operation can be properly determined, while the wiring between each thermocouple and the control means can be properly determined. It has become possible to provide a combustion device capable of appropriately detecting a ground short-circuit abnormality or the like.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where a combustion device according to the present invention is applied to a water heater will be described below with reference to the drawings. First, the overall configuration of the hot water supply device will be described with reference to FIG. A fin tube type heat exchanger for water heating 2 is provided at the upper end inside the cylinder 1, a burner 3 for heating the heat exchanger 2 is provided below the cylinder 1, and the burner 3 is provided inside the cylinder 1. A combustion chamber R is formed. Water supply channel W to heat exchanger 2
i, a water shutoff valve 4, a water governor 5 for adjusting a water supply amount in response to a change in water pressure, and a diverter valve 6 are provided. A hot water outlet Wo from the heat exchanger 2 is connected to a flexible pipe 7 And is connected to the tapping tool 8 via. The gas supply path G to the burner 3 is connected to the water governor 5 via the shut-off valve 9 and the interlocking rod 10a in response to a water pressure responsive valve 10 that opens only in a water supply state, and in response to a change in the original pressure of the fuel gas supply. A gas governor 11 for maintaining the fuel gas supply pressure to the burner 3 at an appropriate pressure, and an adjustment valve 12 for adjusting the fuel gas supply amount are provided. The shunt valve 6
The amount of water supplied to the heat exchanger 2 and the amount of bypass water to be separately supplied from the water supply channel Wi to the hot water channel Wo via the bypass channel Wb are adjusted. Further, a controller C is provided as a control means including a microcomputer for performing various controls of the hot water supply device.

Next, the control operation of the controller C at the time of tapping and stopping water will be described. When the tapping-type tapping operation tool 13 is pressed to tap the tap, the operation microswitch 14 is pressed.
Is turned on, and at the same time, the water shutoff valve 4 is opened in conjunction with the pushing operation of the tapping operation tool 13, water enters the water governor 5, and the interlocking rod 10 a opens the water pressure responsive valve 10 by the water pressure. In response, the hydraulic micro switch 15 is turned on. When the operation microswitch 14 and the hydraulic microswitch 15 are turned on, the controller C causes the spark plug 16 to spark and causes an adsorption current to flow through the coil 9a of the shutoff valve 9, so that the shutoff valve 9 is opened. Therefore, the fuel gas is
Shut-off valve 9, water pressure responsive valve 10 opened by interlocking rod 10 a responsive to water pressure, gas governor 11, and regulating valve 1
2 and is supplied to the burner 3 and ignited by the spark of the spark plug 16 and burned. The first thermocouple 17 is provided in contact with the combustion flame of the burner 3, and is attracted from the controller C to the coil 9 a of the shut-off valve 9 by the electromotive force of the first thermocouple 17 heated by the combustion flame of the burner 3. The current continues to flow, and the opening of the shutoff valve 9 continues. on the other hand,
The water flows to the heat exchanger 2 through the water stop valve 4, the water governor 5, and the flow dividing valve 6, and at the same time, flows to the hot water path Wo through the bypass path Wb. Then, the hot water from the heat exchanger 2 and the water from the bypass passage Wb are mixed, and the hot water at an appropriate temperature is discharged from the tapping tool 8.

When the tapping operation tool 13 is pressed in the tapping state to stop water, the water stop valve 4 is closed and water supply is stopped in conjunction with the pushing operation, so that the water governor 5 has no water pressure difference. The interlocking rod 10a responds in a direction to close the hydraulic pressure responsive valve 10, the hydraulic pressure responsive valve 10 is closed, the fuel gas supply to the burner 3 is cut off, and the combustion of the burner 3 is stopped. With the pushing operation of the tapping operation tool 13 in the tapping state described above,
Operation micro switch 14 and hydraulic micro switch 1
When the switch 5 is turned off, the controller C stops flowing the adsorption current to the coil 9a, so that the shut-off valve 9 is closed.

Next, with reference to FIG. 1, a description will be given of the structure of the safety means that is executed when a combustion abnormality occurs in the burner 3 or when the temperature inside the hot water supply device rises abnormally.
The above-described first thermocouple 17 that outputs an electromotive force according to the temperature of the combustion flame of the burner 3 and the second thermocouple that outputs an electromotive force having a polarity opposite to that of the first thermocouple 17 according to the temperature of the combustion chamber R. (2) Nozzle-side temperature fuse 1 that blows when the temperature near the thermocouple 21 and the gas nozzle 18 becomes abnormally high.
9, and a cylinder body temperature fuse 20 that is blown when the temperature near the outer periphery of the cylinder body 1 becomes abnormally high.

The first thermocouple 17 uses a metal thermocouple mounting plate so that the heat-sensitive portion is located inside the combustion flame in a normal combustion state, and the plus side thereof is electrically connected to the thermocouple mounting plate. It is provided to be connected. The second thermocouple 21 is
The heat sensing portion is provided so as to face a temperature measurement opening 1 a formed in the cylinder body 1.

The thermal fuse 19 for the vicinity of the nozzle and the thermal fuse 20 for the cylinder body have the same configuration. Although not shown, a fuse element having lead wires connected to both ends thereof is placed in a tube having flexibility and heat resistance. At the same time, and two places on the outer periphery of the tube are bound by a binder and fixed in the tube. The temperature fuse 19 for the vicinity of the nozzle is connected to the gas nozzle 18 corresponding to the burner 3.
The fuse 20 for the cylinder body is arranged in the vicinity of the rear side of the outer peripheral portion of the cylinder body 1 (the wall side when the water heater is installed on the wall). .

The first thermocouple 17, the second thermocouple 21, and each of the thermal fuses 19 and 20 are electrically connected to a controller C via a lead wire, respectively. 17 and the second thermocouple 21 are connected such that electromotive forces of opposite polarities are input to the controller C. That is, as shown in FIG. 2, the minus terminal of the first thermocouple 17 and the minus terminal of the second thermocouple 21 are connected,
As described above, the positive terminal of the first thermocouple 17 is connected to the thermocouple mounting plate to be electrically grounded and the lead wire 22 is connected.
Is connected to the input terminal a of the controller C through
The plus terminal of the second thermocouple 21 is connected to the input terminal b of the controller C via the lead wire 23. An intermediate connection point between the first thermocouple 17 and the second thermocouple 21 is connected to an input terminal c of the controller C via a lead wire 24. Therefore, the first thermocouple 17 and the second thermocouple 21
Are connected in series in a state where they generate electromotive forces in opposite directions, and both ends thereof are electrically connected to the controller C so that the total value of the output of the electromotive force in each thermocouple is It is configured to be input between the input terminals a and b. Also, the output value of the electromotive force of the first thermocouple 17 is configured to be input to the input terminal c of the controller C.

Then, the controller C controls the first thermocouple 1
7, and the second thermocouple 21
The detection information of the electromotive force is obtained for each, and the operation abnormality is determined based on the detection information. In other words, the controller C calculates the total value input between the input terminals a and b and the output value of the electromotive force of the first thermocouple 17 input to the input terminal c.
The output value of the electromotive force of the second thermocouple 21 is calculated by calculation, and when the electromotive force of the first thermocouple 17 and the electromotive force of the second thermocouple 21 that are separately calculated decrease, When it is determined that the operation is abnormal as described later, the flow of the adsorption current to the coil 9a of the shut-off valve 9 is stopped, the shut-off valve 9 is closed, and the combustion of the burner 3 is stopped. is there.

That is, if the amount of primary air for combustion sucked from the receiving port 32 becomes abnormally small, or if the oxygen concentration in the primary air for combustion becomes abnormally low, the burner 3 causes incomplete combustion and burns. The flame gets longer. If the burner 3 causes such incomplete combustion as an operation abnormality to prolong the combustion flame or unexpectedly extinguish the combustion flame, the electromotive force V1 of the first thermocouple 17 decreases. As shown in FIG. 3A, when the electromotive force V1 decreases and falls below the burner determination value Vs1, the controller C closes the shut-off valve 9 and cuts off the supply of the fuel gas to the burner 3. Thus, the combustion of the burner 3 is stopped.

Further, when combustion products and dust in the combustion gas adhere to the heat exchanger 2 and the combustion gas passage of the heat exchanger 2 becomes narrow, the amount of the combustion gas remaining in the combustion chamber R increases. hand,
The ambient temperature in the combustion chamber R increases. As the ambient temperature in the combustion chamber R becomes higher due to such exhaust blockage, FIG.
As shown in (b), the electromotive force V2 of the second thermocouple 21 increases, but when the ambient temperature in the combustion chamber R becomes abnormally high, the electromotive force V2 decreases the combustion chamber determination level Vs2. If it exceeds, the controller C closes the shutoff valve 9 and stops the combustion of the burner 3 in the same manner.

Therefore, the controller C operates the first thermocouple 1
7, the absolute value of the output value of the electromotive force is the burner determination value V.
If it is less than s1, it is determined that the burner 3 has caused combustion failure as an operation abnormality. If the absolute value of the output value of the electromotive force in the second thermocouple 21 exceeds the combustion chamber determination value Vs2, it is determined that the operation is abnormal. It is determined that the exhaust gas is blocked in the combustion chamber R.

The ambient temperature in the combustion chamber R rises abnormally due to the adhesion of combustion products and dust in the combustion gas to the heat exchanger 2, causing the temperature near the outer periphery of the cylinder 1 to rise. When the temperature becomes abnormally high, the temperature fuse 20 for the cylinder body is blown. or,
A spider web or dust accumulates in the receiving port 32 of the burner 3, and a part of the fuel gas ejected from the gas nozzle 18 leaks out of the receiving port 32, and the leaked gas is discharged from the burner 3. When the temperature in the vicinity of the gas nozzle 18 becomes abnormally high due to the ignition and burning of the combustion flame, the nozzle-use temperature fuse 19 is blown. When the temperature fuse 20 for the cylinder body is blown or the temperature fuse 19 for the vicinity of the nozzle is blown in this way, the controller C closes the shut-off valve 9 to stop the combustion of the burner 3. ing.

In this way, when an operation abnormality occurs, the combustion of the burner 3 is stopped to improve the safety in use.

With the above-described configuration, for example, when the lead wire 23 in FIG. 2 contacts the case in the middle of the wiring (point P1 on the circuit) and short-circuits to ground, the total value Vt becomes substantially zero. Therefore, combustion of the burner 3 is immediately stopped. The lead wire 24 shown in FIG.
In the case where the grounding short-circuit occurs due to contact with the case in the middle of wiring (point P2 on the circuit), the output value of the electromotive force of the first thermocouple 17 becomes almost zero. Combustion will be stopped. In this manner, the combustion of the burner 3 is stopped by effectively determining the ground short-circuit abnormality of the lead wire or the like.

[Another Embodiment] (1) In the above embodiment, the first thermocouple 17 and the second thermocouple 21 are connected in series, and both ends thereof and an intermediate connection point are connected to the controller C ( Control means), and the total value of the output of the electromotive force in each thermocouple,
Although the output value of the electromotive force of the first thermocouple 17 is input, instead of such a configuration, for example, as shown in FIG. 4, the first thermocouple 17 and the second thermocouple 21 are connected to a controller. C (control means) are electrically connected in parallel so that each of them can independently detect an electromotive force, and the controller C detects detection information of the electromotive force by the first thermocouple 17, and
The detection information of the electromotive force by the second thermocouple 21 may be obtained separately for each.

(2) In the above embodiment, the temperature fuse 19 for the vicinity of the nozzle, the temperature fuse 20 for the cylinder body, and the like are provided to further improve the safety in use. You may.

(3) In the above embodiment, the case where the specific configuration of the combustion device to which the present invention is applied is a hot water supply device is illustrated, but the specific configuration of the combustion device can be variously changed.
For example, a heating device may be used.

[Brief description of the drawings]

FIG. 1 is a block diagram of a hot water supply apparatus to which the present invention is applied.

FIG. 2 is a control block diagram.

FIG. 3 is a diagram showing an electromotive force generation state;

FIG. 4 is a control block diagram showing a connection state of a thermocouple of another embodiment.

FIG. 5 is a control block diagram showing a connection state of a conventional thermocouple.

[Explanation of symbols]

 Reference Signs List 1 cylinder body 2 heat exchanger 3 burner 17 first thermocouple 21 second thermocouple C control means R combustion chamber Vs1 discriminant value for burner Vs2 discriminant value for combustion chamber

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiko Yagi 1-1-52, Oka, Minami-ku, Osaka-shi, Osaka F-term in Harman Co., Ltd. (Reference) 3K003 RA01 SA01 SA03 SA08 SB08 SC04 3K005 TA03 TB07 TC04 UA11 VA04 VA05

Claims (6)

[Claims] 1. A first thermoelectric device, wherein a heat exchanger heated by a burner is provided on an upper part of a cylinder body forming a combustion chamber of the burner, and outputs a higher electromotive force as a temperature of a combustion flame of the burner is higher. When the operation abnormality is determined based on the pair, the second thermocouple that outputs a larger electromotive force as the ambient temperature in the combustion chamber is higher, and the output of the first thermocouple and the second thermocouple, A control unit for stopping combustion, wherein the control unit outputs detection information of electromotive force by the first thermocouple and detection information of electromotive force by the second thermocouple, respectively. In search of each,
A combustion device configured to determine the operation abnormality based on the detection information; 2. When the absolute value of the output value of the electromotive force of the first thermocouple is smaller than a burner determination value, the control means determines that the burner is causing combustion failure as the operation abnormality. Claim 1 configured to
A combustion device as described. 3. The control means according to claim 1, wherein, when the absolute value of the output value of the electromotive force of the second thermocouple exceeds the discrimination value for the combustion chamber, the control means causes an exhaust blockage in the combustion chamber as the operation abnormality. The combustion device according to claim 1, wherein the combustion device is configured to determine the combustion condition. 4. The first thermocouple and the second thermocouple,
The control unit is electrically connected to each of the control units so that the electromotive force can be detected separately. The control unit detects the electromotive force detection information by the first thermocouple and the electromotive force detection information by the second thermocouple. The combustion device according to any one of claims 1 to 3, wherein the detection information of the electric power is obtained separately for each. 5. The first thermocouple and the second thermocouple,
They are connected in series in a state of generating electromotive force in opposite directions, and both ends thereof are electrically connected to the control means, and the total value of the output of the electromotive force in each thermocouple is input to the control means. And an intermediate connection point between the first thermocouple and the second thermocouple is electrically connected to the control means, and an output value of an electromotive force of the first thermocouple is transmitted to the control means. The control means is configured to obtain an output value of the electromotive force of the second thermocouple based on the total value and an output value of the electromotive force of the first thermocouple. The combustion device according to any one of claims 1 to 3, wherein: 6. The first thermocouple and the second thermocouple connected in series.
In the thermocouple, the connection terminal on the first thermocouple side is grounded and connected so that the electromotive force of the connection terminal on the other end is input to the control means as the total value. The combustion device according to claim 5, wherein the combustion device is configured to determine a ground short-circuit abnormality of the connection terminal on the other end side based on a value and an output value of an electromotive force of the first thermocouple.