JP2001124331A - Combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustor in which a decision can be made whether a burner is in a correct combustion state or not while sustaining a correct decision state over a long term and avoiding disadvantage of cost increase. SOLUTION: A burner 3 comprises a planar member 31 for holding and combusting flame distributed with a plurality of flame holes 30, and a regulation plate 32 for making uniform the conduction of mixture gas over the entire flame hole member 31 distributed with a plurality of holes 33 for passing mixture gas. Based on detection information of a thermocouple S for detecting the temperature of the conduction regulating plate 32, a decision is made whether the burner 3 is in a correct combustion state or not and then combustion state of the burner 3 is controlled correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixture supply means for mixing and supplying a fuel gas and combustion air, a burner for burning the mixture supplied by the mixture supply means, and the burner. Combustion state determining means for determining whether or not the combustion state of the burner is in a proper combustion state; and combustion control means for controlling the burner to a proper state based on the determination information of the combustion state determining means. Is provided, wherein the burner has a plurality of flame holes formed in a dispersed state, a plate-like flame hole forming member for holding and burning a flame, and a plurality of flow holes through which the mixture flows. And a flow rate adjusting member that is formed in a dispersed state and adjusts the flow rate of the air-fuel mixture so that the air-flow rate of the air-fuel mixture is supplied uniformly throughout the flame hole forming member. Related to combustion equipment.

[0002]

2. Description of the Related Art Conventionally, in a combustion apparatus having the above-described configuration, as shown in Japanese Patent Publication No. 3-79611, for example, the temperature of a flame generated by burning an air-fuel mixture with a burner is measured by a thermocouple ( Thermocouple), and based on the detected information, the mixing ratio (air-fuel ratio) of fuel gas and combustion air supplied to the burner as the combustion state of the burner is within the proper range (proper combustion state). ), There is a configuration in which the mixing ratio is controlled to be in an appropriate range. Note that, in the above-described prior art, an all-primary premix burner that burns an air-fuel mixture in which combustion air is mixed with fuel gas in a completely premixed state is used. Since the control configuration as described above has a correlation between the temperature of the flame of the burner and the mixing ratio, the mixing ratio at that time based on the temperature of the flame detected by the thermocouple, that is, This is to determine whether or not the combustion state of the burner is proper.

[0003]

When the burner is an all-primary premixed burner, as in the combustion apparatus having the above-described structure, the mixing ratio between fuel gas and combustion air in the air-fuel mixture is determined. Specifically, the ratio of the combustion air to the fuel gas is set to a relatively low value, that is, the ratio of the air is often set to a low value. It reaches high temperatures of several hundred degrees. However, when the temperature of the flame is directly detected as in the conventional configuration described above, the temperature of the flame of the burner becomes high as described above. There was a problem in terms of durability such as its temperature detection performance (for thermocouples, thermoelectromotive force characteristics etc.) deteriorated early due to corrosion of its surface due to exposure to water. . For example, constantan, chromel, alumel, and the like, which are generally used as materials constituting a thermocouple, have low corrosion resistance when used at the above high temperature.

Incidentally, in order to avoid the disadvantages described above, it is conceivable to constitute the detecting means by using a material having a high heat-resistant temperature. There is a disadvantage that it becomes expensive. For example, it is conceivable that both of a pair of materials constituting a thermocouple as an example of the detecting means are made of a material having a high heat-resistant temperature, but in this case, the detecting means becomes very expensive. Further, one of a pair of materials constituting the thermocouple is formed of a material having a high heat-resistant temperature as described above, and the other is formed of a material having a low heat-resistant temperature. It is also conceivable to adopt a configuration in which the other material having a low heat-resistant temperature is located inside so as to cover the other material having a low heat-resistant temperature so that the other material having a low heat-resistant temperature is not directly exposed to a flame. In addition to the disadvantage that the detection means is expensive, the material located inside is deformed or the thermoelectromotive force characteristic is deteriorated due to aging due to repeated exposure of the heat-sensitive portion to a high-temperature flame. There is a possibility of.

The present invention has been made in view of such a point, and an object of the present invention is to avoid the disadvantage of increasing the cost and to maintain the proper determination state for a long period of time while maintaining the combustion state of the burner. It is an object of the present invention to provide a combustion apparatus that can determine whether or not the fuel cell is in a proper combustion state.

[0006]

According to the first aspect of the present invention, a fuel / air mixture supply means for mixing and supplying a fuel gas and combustion air is supplied by the fuel / air mixture supply means. A burner for burning the air-fuel mixture is provided, wherein the burner has a plurality of flame holes formed in a dispersed state, and a plate-shaped flame-hole forming member for holding and burning the flame; A flow rate adjusting member for adjusting the flow rate of the air-fuel mixture such that a plurality of flow holes are formed in a dispersed state and the flow rate of the air-fuel mixture is supplied uniformly over the entire flame hole forming member. Combustion state determining means for determining whether or not the combustion state of the burner is in a proper combustion state, and determining whether the combustion state of the burner is appropriate based on the determination information of the combustion state determination means. Combustion control means to control the state In the combustion device being kicked,
Temperature detection means for detecting the temperature of the flow rate adjusting member is provided, and the combustion state determination means determines whether or not the combustion state of the burner is in a proper combustion state based on the detection information of the temperature detection means. It is configured to determine.

The mixture supplied by the mixture supply means is
By the flow rate adjusting member, the fuel is supplied in a state where the flow rate is made uniform throughout the flame hole forming member, and the flame is burned in a state where the flame is held by the flame hole forming member.
Then, the temperature of the flow rate adjusting member is detected by the temperature detecting means, and the combustion state determining means determines whether the combustion state of the burner is in an appropriate combustion state based on the detection information of the temperature detecting means. It is. In other words, the temperature of the flame hole forming member changes corresponding to the temperature of the flame due to the radiant heat of the flame held by itself, but the flow rate adjusting member forms the flame hole by the radiant heat from the flame hole forming member. It will change according to the temperature of the member. As described above, since the temperature of the flame hole forming member changes in accordance with the temperature of the flame, the temperature of the flow rate adjusting member consequently changes in accordance with the temperature of the flame. Thus, instead of directly detecting the temperature of the flame, the detected temperature is detected by detecting the temperature of the flow rate adjusting member that changes in accordance with the temperature of the flame due to radiant heat from the flame. It can be used as information corresponding to the combustion state of the burner. The temperature of the flow rate adjusting member is sufficiently lower than the temperature of the flame. As the temperature detecting means, there is no need to use a detecting means made of an expensive material having a high heat-resistant temperature, and a low-cost detecting means is used. Can do it, and
There is no disadvantage such as corrosion of the surface due to high temperature, and there is little possibility that the detection performance is deteriorated early.

Although the flow rate adjusting member is heated by the radiant heat as described above, its temperature changes more slowly than the temperature of the flame. In other words, the temperature of the flame is easily changed in response to the short-time dynamic behavior, for example, when the flow of the outside air fluctuates. It is less susceptible to short-term dynamic behavior and will change in response to the constant burning state of the flame.

Therefore, it is possible to determine whether or not the combustion state of the burner is in the proper combustion state while avoiding the disadvantage of increasing the cost and maintaining the proper determination state for a long period of time. The device can be provided.

According to a second aspect of the present invention, in the first aspect, the burner burns an air-fuel mixture obtained by mixing the combustion air with the fuel gas in a completely premixed state. The temperature detecting means is configured to detect a temperature of a portion on the back surface side of the flow rate adjusting member opposite to the plate surface on which the flame hole forming member is located. .

The burner is supplied with the combustion gas in a state where the combustion air is mixed with the fuel gas in a completely premixed state.
The combustion gas is burned. In the all-primary premixing type burner having such a configuration, the mixing ratio of the fuel gas and the combustion air in the combustion gas, specifically, the ratio of the combustion air to the fuel gas is relatively low.
In many cases, the air ratio is set to a low state. In this case, the temperature of the flame reaches a high temperature of several hundred degrees. But,
Since the temperature detecting means is configured to detect the temperature of the back surface side opposite to the plate surface on the side where the flame hole forming member is located in the flow rate adjusting member, the temperature detecting means detects the temperature from the flame hole forming member. Since the temperature on the opposite back side that is not directly heated by the radiant heat is detected, a temperature sufficiently lower than the temperature of the flame or the temperature of the flame hole forming member is detected.

According to a third aspect of the present invention, in the first or second aspect, the temperature detecting means is formed of a thermocouple separate from the flow rate adjusting member, and the flow rate adjusting member is provided. Provided in contact with

As described above, there is no need to use an expensive material having a high heat-resistant temperature as described above, and a low-cost thermocouple can be used. A burner using such a low-cost thermocouple is used. It is possible to properly determine whether or not the combustion state is appropriate.

According to a fourth aspect of the present invention, in the first or second aspect, the temperature detecting means has a thermoelectromotive force characteristic different from a thermoelectromotive force characteristic of a material forming the flow rate adjusting member. A detection member made of a material having the following structure, which is joined to the flow rate adjustment member, and the temperature is detected based on a thermoelectromotive force generated between the detection member and the flow rate adjustment member. Have been.

That is, the thermocouple is formed by joining a pair of thermoelectric materials. The flow rate adjusting member is made of one of the pair of thermoelectric materials, and the detecting member is made of a pair of thermoelectric materials. A thermocouple is formed by utilizing the other thermoelectric material, and the temperature of the flow rate adjusting member is detected based on the thermoelectromotive force generated between the detection member and the flow rate adjusting member. As a result, in a configuration in which a thermocouple separate from the flow rate adjusting member is provided, when the flow rate adjusting member and the separate thermocouple are provided in contact with each other, there is a variation in a joining state between them. This may cause a difference in the heat conduction performance (temperature detection performance), but the flow rate adjusting member itself constitutes a part of the thermocouple. There are advantages that can be done. Moreover,
Since the temperature detection target portion and the thermocouple are the same member, there is an advantage that heat conduction for temperature detection is also efficiently performed and the temperature detection performance is improved.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the flow rate of the air-fuel mixture flowing through the flame hole in the burner is smaller than that in another region. A low flow velocity region is provided, and the temperature detecting means is provided at a position corresponding to the low flow velocity region on the flow rate adjusting member.

In the low-velocity region where the flow rate of the air-fuel mixture flowing through the flame hole is small, the flame approaches the flame-hole forming member as compared with other regions because the air-fuel mixture has a low flow velocity. In the state of burning, the distance between the flame and the flame hole forming member is shortened, the radiant heat from the flame to the flame hole forming member becomes large, and the temperature of the flame hole forming member becomes higher than other regions. Become. Therefore, in the low flow rate region, the temperature change of the flame hole forming member and the temperature change of the flow rate adjusting member with respect to the change in the combustion state of the burner are larger than those in other regions. By detecting the temperature at a location, it is possible to improve the detection accuracy when determining whether or not the combustion state of the burner is in an appropriate combustion state, as compared with a method of measuring a temperature change in another area. Become.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the combustion state determining means determines that the combustion state of the burner is a mixture of the fuel gas and the combustion air. It is configured to determine whether the ratio is at a proper mixing ratio as a proper combustion state, and the combustion control means is configured to control the mixing ratio.

There is a correlation between the temperature of the flame of the burner and the mixing ratio, and the temperature of the flow rate adjusting member corresponds to the temperature of the flame as described above. Based on the detection information, it can be determined whether or not the mixture ratio is at a proper mixture ratio, and by controlling the mixture ratio to be the proper mixture ratio, the burner is brought into a proper combustion state. Can be.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which a combustion device according to the present invention is applied to a hot water supply device will be described with reference to the drawings. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply unit K for heating supplied water to supply hot water to a hot water tap (not shown), a control unit H as control means for controlling the operation of the hot water supply unit K, A remote control operation unit R for instructing the control unit H to send operation information is provided.

The hot water supply unit K includes a heat exchanger 2 for heating water provided in the combustion chamber 1, a gas combustion type all-primary premix burner 3 for heating the heat exchanger 2, and a burner 3. From the upstream side of the combustion air through the ventilation path 7, and,
With the ventilation, each of the fans 4 is provided as an air / fuel mixture supplying means for supplying an air / fuel mixture in which the supplied fuel gas is mixed with the combustion air in a completely premixed state to the burner. Near the burner 3, an igniter 16 for executing an ignition operation for the burner 3 and a frame rod 17 for detecting whether or not the burner 3 is ignited are provided.

The heat exchanger 2 is connected to a water supply channel 5 to which water is supplied from, for example, a household water supply, and a water supply channel 6 for discharging hot and cold water.
A water flow rate sensor 8 for detecting a water flow rate to the heat exchanger 2 and an input water temperature thermistor 9 for detecting a temperature of water supplied through the water inlet channel 5 are provided. The tapping path 6 is provided with a tapping temperature thermistor 10 for detecting the temperature of tap water from a tap tap (not shown).

The fuel supply path 11 for supplying the fuel gas to the ventilation path 7 is connected to the ventilation path 7 so that a suction force acts by the ventilation of the fan 4. In other words, the larger the amount of ventilation of the fan 4, the greater the amount of fuel gas supplied to the ventilation path 7. In the fuel supply path 11, an electromagnetically operated safety valve 12 and a main valve 13 for interrupting the supply of fuel from the upstream side in the fuel supply direction, and the fuel supply pressure downstream of the installation location is maintained at atmospheric pressure. Each of the zero governors 14 is provided as pressure adjusting means. A movable damper 24 as suction resistance changing means is provided downstream of the zero governor 14 in the fuel supply direction and opens and closes a suction unit 25 that sucks combustion air into the ventilation passage 7. Is adapted to adjust the amount of combustion air to the ventilation passage 7 by changing the passage resistance. In addition, a gas hole 26 connected to the fuel supply path 11 and sucking the fuel gas is provided in the ventilation path 7.

Referring to the zero governor 14, as shown in FIG. 2, a valve body 14a for adjusting the opening degree of the gas passage, a diaphragm 14b for receiving a pressure difference between the atmospheric pressure Pt and the zero governor outlet pressure P2, and a valve body 14a. And a spring 14c supporting the diaphragm 14b and the spring 1
It comprises an adjusting mechanism 14d for adjusting 4c. For example, when the zero governor inlet pressure P1 fluctuates upward, the zero governor outlet pressure P2 also fluctuates upward along with the pressure fluctuation. However, the valve body 14a moves along with the zero governor outlet pressure P2 pressure fluctuation. Moves downward to cause the zero governor outlet pressure P2 to fluctuate downward, thereby adjusting the zero governor outlet pressure P2 to the atmospheric pressure Pt. Further, when the atmospheric pressure Pt fluctuates upward, the valve body 14a moves upward in accordance with the pressure fluctuation, and the zero governor outlet pressure P2 is adjusted to the atmospheric pressure Pt fluctuating upward. In this way, even when the primary fuel supply pressure P1 to the zero governor 14 and the atmospheric pressure Pt fluctuate, the zero governor outlet pressure P2 remains at the atmospheric pressure P2.
It is adjusted to be t.

The remote control operation unit R includes an operation switch 18 for instructing start / stop of the operation of the hot water supply unit K, a temperature setting switch 20 capable of changing and setting a target hot water supply temperature, and a display for displaying a tapping temperature and a target hot water supply temperature. The fuel cell system includes a unit 21, an operation lamp 22 for displaying an operation state, a combustion lamp 23 for indicating that the burner 3 is in a combustion state, and the like.

Next, the configuration of the burner 3 will be described. The burner 3 is provided with a flame hole forming member 31 in which a plurality of flame holes 30 are formed. As described above, the air-fuel mixture obtained by mixing the combustion air with the fuel gas in a completely premixed state is supplied to the fan 4.
, And is constituted by an all-primary premixed burner that burns a combustion gas that is passed through the flame hole 30. As shown in FIG. 3, the burner 3 is located near the upstream side of the flame hole forming member 31 in the direction of flow of the combustion gas, and the flow rate of the air-fuel mixture over the entire flame hole forming member is controlled. A flow rate adjusting plate 32 is provided as an example of a flow rate adjusting member that adjusts the flow rate of the air-fuel mixture so as to be supplied uniformly.

As shown in FIG. 5, the flame hole forming member 31 is formed in a plate shape in which a plurality of flame holes 30 are formed in a dispersed state. The flame F is formed on the plate surface located at the position (1), and is heated to a high temperature by the radiant heat from the flame F. Therefore, it is made of a metal material made of an alloy having a high heat-resistant temperature. The flame hole forming member 31 has a thin plate structure with a plate thickness of about 0.5 to 0.6 mm.

As shown in FIG. 6, the flow rate adjusting plate 32 is formed in a plate shape in which a plurality of flow holes 33 through which the air-fuel mixture flows are formed in a distributed manner. The flow rate adjusting plate 32 does not reach a high temperature unlike the flame hole forming member 31, but is made of a metal material having excellent corrosion resistance, for example, stainless steel. still,
The flow rate adjusting plate 32 has a thickness of 0.5 to 0.6.
It has a thin plate structure of about mm. This flow adjustment plate 32
The air-fuel mixture supplied by the fan 4 is formed so that the distribution of the air-fuel mixture distribution becomes substantially uniform over the entire area of the plate surface of the flame-hole forming member 31, i.e., the flame-forming region. It has a function to adjust. However, as shown in FIGS. 5 and 6, in the flame formation region formed by the flame hole forming member 31, the low flow velocity region Q <b> 1 in which the flow rate of the combustion gas flowing through the flame hole 30 is smaller than in other regions. Is formed in the flow rate adjusting plate 32, a small flow rate area Q2 in which the size of the flow hole 33 is smaller than that of other areas. The gap between the flame hole forming member 31 and the flow rate adjusting plate 32 is set to about 0.5 to 1.5 mm.

Further, a thermocouple S is provided as temperature detecting means for detecting a temperature at a position of the flow rate adjusting plate 32 corresponding to the low flow velocity region Q1. Specifically, the thermocouple S uses a configuration in which a pair of thermoelectric materials are integrally joined in advance, and as shown in FIG. 5 and FIG. A tip for temperature detection is provided at a location (temperature detection target location X) on the back side opposite to the plate surface on which the flame hole forming member is located and corresponding to the small flow rate region Q2. It is provided in a state of being brought into contact. The thermocouple S outputs a thermoelectromotive force corresponding to the temperature of the temperature detection target location X, and the output is input to the control unit H.

The control section H is provided with a microcomputer, and changes and adjusts the combustion amount of the burner 3 so that the hot water temperature becomes the target hot water supply temperature based on an operation command of the remote control operating section R during hot water supply. And determining whether or not the mixing ratio between the fuel gas of the combustion air and the combustion air is within an appropriate range based on the detection information of the thermocouple S. If is not within the proper range, control is performed so as to change and adjust the mixture ratio so as to be within the proper range. Therefore, a combustion control means 100 for controlling the combustion state of the burner 3 using the control section H and a combustion state determination means 101 for determining whether or not the combustion state of the burner 3 is in an appropriate combustion state are constituted. Will be.

From the graph shown by the solid line in FIG. 7, the temperature of the flow rate adjusting plate 32 measured at the temperature detection target location X and the mixing ratio of the fuel gas supplied to the burner 3 and the combustion air are shown. Shows the relationship with the ratio of the actually supplied combustion air to the theoretical amount of fuel gas (hereinafter referred to as air ratio). As described above, there is a specific change characteristic between the temperature and the air ratio, and the air ratio at that time can be determined by detecting the temperature. In the drawing, a graph shown by a broken line shows a relationship between the temperature of the flow rate adjusting plate 32 and the air ratio measured in a region other than the small flow region Q2, that is, in a region where the flow velocity is high. . As is apparent from this characteristic, the small flow rate region Q2 has a larger amount of change in temperature with respect to the change in the air ratio than the other regions. As compared with the case of measurement, a change in the output with respect to a change in the combustion state of the burner increases, and a high S / N ratio can be obtained, so that the detection accuracy is improved.

The control operation of the control unit H will be described in detail. The control unit H starts the combustion of the burner 3 as the flow of water to the heat exchanger 2 is started. Control is performed so as to stop the combustion of the burner 3 as the flow of water is stopped, and when the flow of water to the heat exchanger 2 is detected, the fan 4 is controlled so that the outlet temperature becomes the target hot water supply temperature. The processing for adjusting the ventilation amount is executed. Specifically, after the operation state is set in accordance with the ON operation of the operation switch 18, the flow rate detected by the flow rate sensor 8 in response to the opening operation of the hot water tap (not shown) exceeds the set flow rate. And the ventilation operation by the fan 4 is started, and the safety valve 1
2 and the main valve 13 are opened to adjust the number of revolutions of the fan 4 so that the amount of gas for ignition is adjusted, the igniter 14 performs the ignition operation of the burner 3, and the flame rod 17 confirms the ignition of the burner 3. . afterwards,
To set the hot water temperature to the target hot water supply temperature based on the detection information of each of the incoming water temperature thermistor 9, the hot water temperature thermistor 10, and the flow rate sensor 8 and the information on the target hot water temperature set by the temperature setting switch 20. Feed-forward control is performed to adjust the amount of air flow through the fan 4 so that the amount of gas required for the hot water is adjusted to the required amount.
Feedback control is performed to finely adjust the air flow rate of the fan 4 in accordance with the deviation between the detected temperature and the target hot water supply temperature. In this way, the water from the water inlet channel 5 is heated by the heat exchanger 2, and hot water at the target hot water supply temperature is discharged from a hot water tap (not shown).

When the combustion amount of the burner 3 is controlled so that the hot water temperature becomes the target hot water supply temperature, the temperature of the flame hole forming member 31 is determined based on the detection information of the thermocouple S. When the mixing ratio (air ratio) at that time deviates from the appropriate range, the movable damper 24 is adjusted to control the mixing ratio so as to be in the appropriate range.

The control operation of the control section H will be described with reference to the flowchart of FIG. First, in a state where the operation switch 18 of the remote control operation unit R is turned on and the hot water supply device is set to the operation state, the water flow rate detected by the water flow rate sensor 8 with the opening operation of the hot water tap (not shown). When the water flow exceeds the set water amount, the ignition process of the burner 3 is performed (steps 1 to 3). In other words, when the combustion of the burner 3 is stopped, the ventilation operation by the fan 4 is started, and the safety valve 12 and the main valve 13 are opened to adjust the rotation speed of the fan 4 so that the amount of the ignition gas is obtained. At the same time, the ignition of the burner 3 is performed by the igniter 16, and the ignition of the burner 3 is confirmed by the frame rod 17.

After that, based on the detection information of each of the incoming water temperature thermistor 9, the outgoing water temperature thermistor 10, and the flow rate sensor 8, and the information on the target hot water supply temperature set by the temperature setting switch 20, the outlet water temperature is set to the target. The amount of air flow through the fan 4 so that the amount of gas required to reach the hot water
Specifically, the number of rotations of the fan is adjusted (step 4).

Then, based on the detection value output from the thermocouple S, the mixing ratio of the fuel gas and the combustion air in the ventilation passage 7, specifically, the air ratio as described above is set in an appropriate range (for example, 1). (Range: 3 to 1.4) is determined (step 5). If it is not within the proper range, the movable damper 24 is operated to change and adjust the suction amount of the combustion air into the ventilation passage 7 so as to be within the proper range (step 6). In this way, the mixing ratio between the fuel gas and the combustion air in the ventilation passage 7 is adjusted to be within an appropriate range.

In this type of all-primary premix burner, the air ratio is often set to a relatively low value, and the temperature of the flame F reaches a high temperature of several thousand degrees. That is, in the plate surface A on the flame forming side of the flame hole forming member 31 in FIG. 4, the temperature may become high as described above due to the radiant heat from the flame F. In B, the radiant heat from the flame F is not directly transmitted, and even if the heat of the plate surface A on the flame forming side is transmitted through the inside of the flame hole forming member 31, the temperature is lower than that of the plate surface A on the flame forming side. are doing. Further, the plate surface C of the flow rate adjusting plate 32 on the side where the flame hole forming member 31 is located is heated by the radiant heat from the plate surface B on the back surface side of the flame hole forming member 31, so that the flow rate adjusting member 32 is heated. In the plate surface D on the back surface opposite to the plate surface C on the side where the flame hole forming member is located in the plate 32, the heat on the plate surface C is transmitted through the inside of the flow rate adjusting plate 32 and the temperature rises. Moreover, the temperature of the plate surface A on the flame forming side of the flame hole forming member 31 is the highest temperature closest to the temperature of the flame, and thereafter the temperature decreases in the order of the plate surface B, the plate surface C, and the plate surface D. However, the temperature at each location will change corresponding to the temperature of the flame. That is, the flow rate adjusting plate 3
The temperature of the plate surface D on the back side in FIG. 2 changes according to the temperature of the flame, but is low as shown in FIG.

The above-described control operations such as the adjustment of the amount of ventilation are executed until the amount of water passing through the heat exchanger 2 becomes less than the set amount or the operation switch 18 is turned off. That is, when the amount of water flowing into the heat exchanger 2 becomes less than the set amount or the operation switch 18 is turned off, if the burner 3 is burning, the safety valve 12 and the main valve 13 are closed, and the fan A burner combustion stop process for stopping the ventilation of the burner 3 to stop the ventilation of the burner 3 (steps 7, 8, 9).

The numerical values indicating the respective plate thicknesses and the gaps between the flame hole forming member 31 and the flow rate adjusting plate 32 are examples, and are not limited to the numerical values as described above.
It may be implemented with a different plate thickness or gap.

[Another Embodiment] Another embodiment will be described below.

(1) In the above embodiment, a thermocouple constructed in such a manner that a pair of thermoelectric materials are integrally joined in advance is used as the thermocouple as the temperature detecting means. The present invention is not limited to such a configuration, and may be configured as follows. As shown in FIG. 9, an L-shaped plate 35 as an example of a detection member made of a material having a thermoelectromotive force characteristic different from the thermoelectromotive force characteristics of the material constituting the flow rate adjusting plate 32 is passed through the flow rate adjusting plate 32. The heat generation generated between the L-shaped plate member 35 and the flow rate adjustment plate 32 by joining to the plate surface D on the back surface opposite to the plate surface C on the side where the flame hole forming member is located in the adjustment plate 32. It may be configured to detect the temperature based on the electric power. The L-shaped plate 35 is formed by bending a thin plate into a substantially L-shape to form one surface with the flame hole forming member 31.
Is connected by spot welding to a portion indicated by a black dot in FIG. As a material of each member, the flow regulating plate 32 is made of stainless steel having excellent corrosion resistance, and the L-shaped plate 35 is made of a general-purpose thermocouple material such as constantan. Therefore, in a state where the flame hole forming member 31 and the L-shaped plate member 35 respectively correspond to a pair of thermoelectric materials, a thermocouple S is formed, and the temperature is determined based on the thermoelectromotive force generated between them. Is detected. The detection member is not limited to the configuration in which the plate is bent into an L shape, and may have any shape. Further, the detection member is not limited to the configuration joined to the plate surface D, and may be joined to the plate surface C.

(2) In the above embodiment, the burner
A low-velocity region where the flow velocity of the combustion gas flowing through the flame hole is smaller than that of the other region is provided, and the temperature detecting means is a different portion from the flame forming portion of the flame hole forming member 31. In addition, the configuration is such that the temperature at a location corresponding to the low flow velocity region is detected. However, the temperature detection unit is not limited to such a configuration, and the temperature may be detected in a region other than the low flow velocity region as described above. It may be configured to detect. In this case, the burner may not be provided with the low flow velocity region.

(3) In the above embodiment, when the mixing ratio is changed and adjusted, the movable damper is operated to change and adjust the suction amount of the combustion air into the ventilation passage 7. Not limited to this, for example, a fuel adjustment valve that can change and adjust the fuel supply amount is provided at a position downstream of the zero governor 14 in the fuel supply direction in the fuel supply path 11,
A configuration may be employed in which the fuel adjustment valve is adjusted to change and adjust the mixing ratio.

Further, when the mixing ratio is changed and adjusted, the mixing ratio between the fuel gas and the combustion air is not limited to the configuration in which either the combustion air supply amount or the fuel supply amount is adjusted. As described above, both the fuel supply amount and the combustion air supply amount may be adjusted.

(4) In the above embodiment, the fuel supply path 11
Although a zero governor is provided as a pressure adjusting means in this embodiment, the present invention is not limited to the zero governor, and may be a general gas governor such as a proportional valve with a governor.

(5) In the above embodiment, the burner is
Combustion air has been exemplified by an all-primary premix burner that burns a combustion gas mixed with a fuel gas in a completely premixed state, but the invention is not limited to such a configuration. Alternatively, the burner may be configured to take in primary air and secondary air, and the type of burner is not limited.

(6) In the above embodiment, the case where the flame hole 30 formed in the flame hole forming member 31 and the passage hole 33 formed in the flow rate adjusting plate 32 are formed in a circular shape is exemplified. The present invention is not limited to a circular shape, and may be implemented in various forms such as a square hole.

(7) In the above embodiment, an example is shown in which the combustion device according to the present invention is applied to a hot water supply device, but it is also applicable to various other devices such as a heating device.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a water heater.

FIG. 2 is a schematic configuration diagram of a zero governor.

FIG. 3 is a cutaway side view showing a schematic configuration of a burner.

FIG. 4 is a cross-sectional view of a burner showing a temperature measurement point.

FIG. 5 is a plan view showing a flame hole forming member.

FIG. 6 is a plan view showing a flow rate adjusting plate;

FIG. 7 is a graph showing the relationship between the temperature of the flame hole forming member and the air ratio.

FIG. 8 is a flowchart showing a control operation.

FIG. 9 is a vertical sectional side view of a burner showing a temperature measurement point in another embodiment.

[Explanation of symbols]

 Reference Signs List 3 burner 31 flame hole forming member 32 flow rate adjusting plate (flow rate adjusting member) 35 L-shaped plate (detection member) 100 combustion control means 101 combustion state determination means S temperature detection means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K005 AA06 AB01 AC06 BA05 BA06 CA06 DA01 DA05 EA02 EB05 TA01 TB03 TC04 UA01 UA11 3K017 AA01 AB07 AB08 AD09

Claims (6)

[Claims] An air-fuel supply means for mixing and supplying a fuel gas and combustion air, a burner for burning the air-fuel mixture supplied by the air-fuel mixture supply means, and a combustion state of the burner which is appropriate for combustion Combustion state determination means for determining whether or not the state is, based on the determination information of the combustion state determination means,
Combustion control means for controlling a combustion state of the burner to be in an appropriate state is provided, wherein the burner has a plurality of flame holes formed in a dispersed state, and has a plate-like flame hole for holding and burning a flame. The forming member and the plurality of through-holes through which the air-fuel mixture flows are formed in a dispersed state, and the mixing is performed such that the flow rate of the air-fuel mixture is supplied uniformly over the entire flame hole forming member. A combustion flow rate adjusting member configured to adjust the flow of air, wherein a temperature detection unit that detects a temperature of the flow rate adjustment member is provided; A combustion device configured to determine whether a combustion state of the burner is in a proper combustion state based on detection information of a temperature detection unit. 2. The burner is composed of an all-primary premix burner that burns an air-fuel mixture in which the combustion air is mixed with the fuel gas in a completely premixed state. The combustion device according to claim 1, wherein a temperature of a rear surface side of the flow rate adjusting member opposite to a plate surface on which the flame hole forming member is located is detected. 3. The combustion apparatus according to claim 1, wherein the temperature detecting means is constituted by a thermocouple separate from the flow rate adjusting member, and is provided in contact with the flow rate adjusting member. . 4. The temperature detecting means joins a detecting member made of a material having a thermoelectromotive force characteristic different from that of a material constituting the flow rate adjusting member to the flow rate adjusting member. The combustion device according to claim 1, wherein the temperature is detected based on a thermoelectromotive force generated between the detection member and the flow rate adjusting member. 5. The burner is provided with a low flow velocity region in which a flow velocity of the air-fuel mixture flowing through the flame hole is smaller than another region, and wherein the temperature detecting means is provided in the flow rate adjusting member. Claim 1 which is provided in a place corresponding to a low flow velocity region.
5. The combustion device according to any one of 4. 6. The combustion state determining means determines whether or not a mixture ratio of the fuel gas and the combustion air is a proper mixture ratio as a proper combustion state as a combustion state of the burner. The combustion device according to any one of claims 1 to 5, wherein the combustion control means is configured to control the mixture ratio.