JP4250324B2 - Combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas burner provided with a plurality of burner portions arranged side by side, combustion air supply means for supplying combustion air to the plurality of burner portions, and fuel supply for adjusting the supply of fuel gas to the plurality of burner portions Adjusting means, and combustion control means for controlling the operation of the combustion air supply means and the fuel supply adjusting means, and the combustion control means has a plurality of burner sections according to the magnitude of the combustion load. The fuel supply adjusting means is operated so that the fuel gas is supplied only to the burner portion to be burned, so that the number of burner portions to be burned is changed to a plurality of stages of three or more. The present invention relates to a combustion apparatus configured to operate the combustion air supply means so that an appropriate amount of combustion air is supplied to a burner section to be operated.
[0002]
[Prior art]
The combustion apparatus having the above configuration is configured to obtain a large turndown ratio by changing the number of burner portions to be burned among a plurality of burner portions according to the magnitude of the combustion load. In a conventional combustion apparatus, conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 8-285237, even when only a part of the burner portion is burned, the combustion air is supplied to the burner portion to be burned. The configuration is such that an appropriate amount of combustion air is supplied to all the burner portions, and the combustion air is also supplied to the burner portions that stop combustion.
[0003]
That is, combustion air is supplied to a plurality of burner parts by one fan as combustion air supply means, that is, air supplied from one fan is supplied in a state of being divided into a plurality of burner parts. According to the magnitude of the combustion load, the number of burner portions to be burned among the plurality of burner portions is divided into a high-load combustion stage, a low-load combustion stage, and an intermediate load combustion. Combustion is configured to be changed to three stages of large, medium, and small for use, and in each stage, the supply amount of combustion air is adjusted so that the burner portion to be burned is in an appropriate combustion state. It has a configuration.
That is, the relationship of the fan rotation speed as the supply amount of the combustion air with respect to the change of the combustion load is set for each of large, medium, and small stages as shown in FIG. 7, for example. As can be seen from this figure, since the combustion air is also supplied to the burner section that stops combustion, the rotational speed of the fan is high even when the number of burners to burn is small, as in the low-load combustion stage. It was as large as for load combustion. In FIG. 7, the conventional characteristics in the low load combustion (small) stage are indicated by broken lines.
[0004]
[Problems to be solved by the invention]
Therefore, in the above-described conventional configuration, even when only a part of the burner parts is burned, the combustion air is supplied to all the burner parts. Combustion air is supplied. As a result, the combustion air supplied to the burner section whose combustion has been stopped is discharged to the combustion chamber, so that the gas burner as a whole will be supplied with excessive combustion air more than necessary. There is a drawback that the temperature of the combustion exhaust gas is lowered by the flow of the combustion air supplied to the gas and the heat recovery rate is lowered.
[0005]
The present invention pays attention to this point, and its purpose is to obtain a large turndown ratio by changing the number of burner portions to be burned among a plurality of burner portions to a plurality of stages of three or more. In spite of this, it is an object to provide a combustion device that can avoid the disadvantage that the heat recovery rate is greatly reduced without greatly complicating the configuration.
[0006]
[Means for Solving the Problems]
According to claim 1, a gas burner provided with a plurality of burner portions arranged side by side, combustion air supply means for supplying combustion air to the plurality of burner portions, and supply of fuel gas to the plurality of burner portions are adjusted. Fuel supply adjusting means, and combustion control means for controlling the operation of the combustion air supply means and the fuel supply adjusting means. The fuel supply adjusting means is operated so that the fuel gas is supplied only to the burner part to be burned, so that the number of burner parts to be burned in the burner part is changed to a plurality of stages of three or more. In the combustion apparatus configured to operate the combustion air supply means so that an appropriate amount of combustion air is supplied to the burner portion to be burned, the number of burner portions to be burned Among the plurality of stages to be changed, the burner that stops combustion in the state of burning in the stage for low combustion load on the side where the number of burners to be burned out of the stages that burn some of the burner parts A supply suppression means for suppressing the supply of combustion air to the section is provided so as to be switchable between a suppression action state and a suppression release state, and the combustion control means burns out of the plurality of burner sections. The number of burners is switched to the suppression action state and the number of burner parts to be burned is larger than that for the low combustion load stage. It is configured to operate the supply suppression means so as to switch to the suppression release state with the change to the stage for combustion load, and the suppression action state of the supply suppression means and In each of the serial derepression state, is configured to combustion air of the proper amount to the burner unit for burning actuates the combustion air supply means to supply When a change command is issued to change the number of burner sections to be burned to the high combustion load stage according to the magnitude of the combustion load, the burner section for supplying fuel gas by the fuel supply adjusting means A burner that is configured to immediately execute the change operation of the number and to immediately switch from the suppression action state to the suppression release state by the supply suppression unit, and to burn according to the magnitude of the combustion load When a change command for changing the number of parts to the stage for the low combustion load is instructed, the fuel supply adjusting means immediately executes the change operation of the number of burner parts for supplying the fuel gas, and the supply suppression Switching from the suppression release state to the suppression action state by means after a set time delay It is configured.
[0007]
That is, in the case where the number of burner portions to be burned among the plurality of burner portions is changed to a plurality of stages of three or more according to the magnitude of the combustion load, a part of the plurality of stages of the three or more stages When the stage is changed to the stage for low combustion load on the side where the number of burners to be burned is reduced, the supply suppressing means is switched to the suppression action state.
Since this supply suppression means suppresses the supply of combustion air to the burner section that stops combustion in the state of combustion in the low combustion load stage, combustion is performed in the low combustion load stage. In this state, the combustion air is not supplied to the burner unit that stops the combustion. Since the combustion air supply means operates so that an appropriate amount of combustion air is supplied to the burner portion to be burned, an appropriate amount of combustion air is supplied to the burner portion to be burned. An appropriate combustion state can be maintained even in a state where combustion is performed in the combustion load stage.
As a result, in the combustion state by the stage for such a low combustion load, the temperature of the combustion exhaust gas is lowered by the flow of the combustion air supplied excessively to the burner portion that does not burn, and the heat recovery rate is reduced. The disadvantage can be eliminated.
[0008]
When the number of burner parts to be burned is changed to a high combustion load stage having a larger number of burners than the low combustion load stage, the supply suppressing means is switched to the suppression release state. Even in this stage for high combustion load, the combustion air supply means operates so that an appropriate amount of combustion air is supplied to the burner portion to be burned. Combustion air is supplied, and an appropriate combustion state can be maintained.
[0009]
By the way, the stage for the high combustion load is not only the stage of the maximum number of burners for burning all the burner parts, but the intermediate stage where the number of burners to be burned out of the stages for burning some of the burner parts is increased. In this intermediate stage, a configuration in which the combustion air is not supplied to the burner unit that stops combustion is conceivable.
That is, as another configuration for suppressing excessive supply of combustion air to the entire gas burner and avoiding a decrease in heat recovery rate, the number of burner parts to be burned is set to three or more stages according to the magnitude of the combustion load. When changing to a plurality of stages, as described above separately for each of the plurality of burner sections whose combustion state will change in accordance with the switching of each stage including the intermediate stage as described above. It is the structure of providing a simple supply suppression means.
However, in the case of such a configuration, it is necessary to provide a plurality of supply suppression means having a configuration that can be switched between a suppression action state and a suppression release state, and a configuration for switching the supply state of combustion air is provided. There is a risk that the cost will be significantly increased and the cost will be increased.
[0010]
The applicant has found the following fact through experiments.
In other words, the above-described reduction in the heat recovery rate caused by supplying excessive combustion air to the entire gas burner as described above causes the low combustion load stage, that is, a part of the burner part to burn. In the stage on the intermediate side where the number of burners to be burned increases among the stages in which some burners are burned, which is increased when the stage is changed to the stage on the side where the number of burners to burn is reduced. Found by experiment that it was not so large.
For example, FIG. 8 shows an experimental result of the thermal efficiency of the hot water supply apparatus when the combustion apparatus is applied to a hot water supply apparatus and the number of burner sections to be burned is switched to three stages of large, medium and small. This thermal efficiency corresponds to the heat recovery rate of the combustion device.
In this figure, the measurement result in the conventional configuration in the combustion state corresponding to the stage for the low combustion load is indicated by a broken line (L11), and the intermediate side as described above in the stage for the high combustion load. This stage is indicated by a solid line (L2). Note that the stage of the maximum number of burners is indicated by a solid line (L3). As is clear from this figure, a significant decrease in thermal efficiency appears in the low combustion load stage, and in the intermediate stage as described above of the high combustion load stage, the thermal efficiency is greatly reduced. There is no decline.
Incidentally, the solid line (L1) in the figure shows the measurement result of the thermal efficiency when the supply suppression means is switched to the suppression action state in the low combustion load stage.
[0011]
Accordingly, even in the intermediate stage as described above in the stage for high combustion load, the combustion air is supplied to all the burner parts. The reduction in the heat recovery rate due to such an excessive supply of combustion air is small, and the gas burner as a whole can maintain an almost appropriate combustion state.
[0012]
Thus, according to the configuration of the present invention, the supply suppression means switches to the suppression action state only in the low combustion load stage where the heat recovery rate may be greatly reduced, and the high combustion load stage. Therefore, for example, a complicated configuration such as providing a plurality of supply suppression means as described above is unnecessary, and the burner portion corresponding to the low combustion load stage is not necessary. It is possible to change the supply state of the combustion air with a simple structure as much as possible without causing a significant complication of the structure. Is possible.
[0013]
As a result, it is possible to obtain a large turndown ratio while maintaining an appropriate combustion state by changing the number of burner portions to be burned out of a plurality of burner portions to a plurality of stages of three or more stages. Thus, it has become possible to provide a combustion apparatus that can avoid the disadvantage that the heat recovery rate is greatly reduced without greatly complicating the process.
[0015]
According to claim 1, When the number of burner parts to be burned is changed to the stage for the high combustion load, the combustion load is increased and the combustion amount is increased, so that the necessary combustion amount is output as quickly as possible. In order to achieve this, each of the operation of changing the number of burner parts for supplying fuel gas by the fuel supply adjusting means and the switching from the suppression action state to the suppression release state by the supply suppression means are immediately executed.
[0016]
When the number of burner parts to be burned is changed to the stage for the low combustion load, the operation for changing the number of burner parts for supplying fuel gas by the fuel supply adjusting means is immediately executed. Switching from the suppression release state to the suppression action state by the suppression means is executed after a set time delay.
That is, when the number of burner parts to be burned is changed to a stage for low combustion load on the side where the number of burners to be burned is reduced, the switching from the suppression release state to the suppression action state by the supply suppression unit is immediately performed. If this is done, in the burner section that has been combusting until immediately before the change operation, it takes some time for the fuel gas supplied up to that time to completely burn, so the supply of combustion air is immediately stopped. Then, incomplete combustion may occur. Therefore, such incomplete combustion can be avoided in advance by switching the supply suppression means from the suppression release state to the suppression operation state after delaying the set time. It is doing so. In this way, means suitable for carrying out claim 1 are obtained.
[0017]
Claim 2 According to the claim 1 Each of the plurality of burner portions includes a primary air intake port that takes in primary air to be supplied to a flame port that forms a flame as the combustion air, and secondary air that is to be supplied to the flame port. A primary air intake port corresponding to a burner unit that stops combustion in a state where the supply suppression means combusts in the stage for low combustion load; The secondary air intake is shielded to suppress the intake of combustion air, and the primary air intake and the secondary air intake are opened to allow the intake of combustion air. A shielding member that can be switched over between a release position and a moving operation means for moving the shielding member between the operating position and the release position. Thus, it is configured to switch to the suppression action state by moving the shielding member to the action position, and to switch to the suppression release state by moving the shielding member to the release state. It is characterized by.
[0018]
The plurality of burner parts take in primary air to be supplied to the flame port from the primary air intake port, and take in secondary air to be supplied to the flame port from the secondary air intake port. Combustion air composed of primary air and secondary air is mixed and combusted to form a flame. In the suppression operation state, the supply suppression means moves the shielding member to the operating position by the movement operation means. The supply of combustion air is suppressed by blocking the primary air intake port and the secondary air intake port. Therefore, in the burner section that stops combustion, supply is suppressed for both primary air and secondary air, so compared to those that suppress supply of either primary air or secondary air. Therefore, the supply of combustion air can be reliably suppressed, and the excess supply amount of combustion air as the whole gas burner can be reduced, and means suitable for implementing claim 1 or 2 are provided. can get.
[0019]
Claim 3 According to the claim 1 In this case, the gas burner, as the plurality of burner portions, burns a rich combustion burner portion with a small air mixing ratio and a light combustion burner portion with which a light mixture with a high air mixing ratio is burned. In a state where they are alternately arranged, and the rich combustion burner section should be supplied to a rich flame outlet that burns the rich mixture to form a flame. The combustion air is configured to include a thick air intake port for taking in the combustion air, and the light combustion burner portion is to be supplied to a light flame inlet that burns the light air-fuel mixture to form a flame. The concentrated air intake port of the rich combustion burner section that stops combustion in a state where the supply suppression means combusts in the stage for low combustion load, And for the low combustion load An action position for blocking the intake of the combustion air by blocking the intake air for the pale combustion of the burner section for burning the light, which stops the combustion in the stage where the combustion is performed in the stage, and the intake of the concentrated air; and A shielding member that can be switched over between a release position that allows the intake of combustion air by opening each of the light air inlets, and a movement operation that moves the shielding member between the action position and the release position. And the movement operation means switches the shielding member to the action position to switch to the suppression action state, and moves the shielding member to the release state to perform the suppression. It is characterized by being configured to switch to a release state.
[0020]
The above-described rich and light combustion type gas burner burns a rich mixed gas that has a small air mixing ratio and can be stably burned at the rich flame opening, and the flame holding action of the rich mixed gas by the combustion flame allows for light use. A light air-fuel mixture having a large air mixing ratio at the flame mouth is continuously burned stably, and the combustion apparatus as a whole is allowed to perform stable combustion while suppressing generation of NOx as much as possible. In such a lean burn type gas burner, the combustion air to be supplied to the rich flame port is taken from the rich air intake port, and an air-fuel mixture in which the fuel gas and the combustion air are mixed is used. A flame is formed by burning in the air, and the combustion air to be supplied to the light flame inlet is taken in from the light air inlet, and the mixture of fuel gas and combustion air is mixed with the light flame. Although the flame is formed by burning at the mouth, the supply suppression means is for the rich combustion that stops the combustion by moving the shielding member to the operation position by the movement operation means in the suppression action state. The supply of combustion air is suppressed by shielding the air intake port for the enrichment in the burner and the air intake port for the light in the burner for light combustion that stops combustion.
Therefore, in the burner unit that stops combustion, not only the combustion air for the rich combustion burner unit but also the combustion air for the light combustion burner unit are both supplied, so that the combustion for the gas burner as a whole can be surely performed. The excess supply of air can be reduced, and a suitable means for carrying out claim 1 or 2 is obtained.
[0021]
Claim 4 According to the claim 3 In the above, the supply suppression means causes the combustion among the burner portions that stop combustion when the number of burner portions to be burned is changed to the low combustion load stage and switched to the suppression action state. It is configured to allow supply of combustion air to the light combustion burner portion adjacent to the burner portion.
[0022]
As described above, in the lean burn gas burner as described above, the lean mixture having a large air mixing ratio in the burner burner portion is stably maintained by the flame holding action of the burner portion of the rich burner portion. Combustion and a large amount of combustion air in the burner section for light combustion is also supplied to the burner section for rich combustion so that the burner for rich combustion also performs stable combustion so that the entire combustion apparatus generates NOx as much as possible. Since stable combustion is performed while suppressing, the burner portion is burned in a state where the burner portion for light combustion is positioned between the burner portions for rich combustion, so the number of burner portions to be burned is In the case of changing to the stage for low combustion load, the burner portion for rich combustion is located at the end portion in the arrangement direction of the burner portions to be burned.
Of the burner parts that stop the combustion, the burner part adjacent to the rich burner part located at this end is the burner for light combustion, and it is assumed that no combustion air is supplied to the burner for light combustion. The burner part for rich combustion located at the end is only supplied with combustion air only from the burner for light combustion located on the opposite side of the line-up direction. There is a risk of causing.
[0023]
Therefore, when the number of burner parts to be burned is changed to the low combustion load stage and switched to the restraining action state, the supply suppressing means is adjacent to the burner part to be burned out of the burner parts for stopping the combustion. Since the combustion air is allowed to be supplied to the light combustion burner portion, the combustion air is also supplied to the rich combustion burner portion located at the end as described above. Supply is sufficiently carried out to maintain an appropriate combustion state, and means suitable for carrying out claim 4 can be obtained.
[0024]
Claim 5 According to claims 1 to 4 In any one of the above, when the combustion control means changes the number of burner portions to be burned to the stage for the low combustion load, the burner portion located at the center in the arrangement direction of the plurality of burner portions It is comprised so that it may burn.
[0025]
For example, when heating an object to be heated such as a heat exchanger for hot water supply by a gas burner, the gas burner and the object to be heated are usually efficiently heated when all of a plurality of burner parts are burned. In order to be heated, it is considered that the center part in the arrangement direction of the burner parts is often arranged so as to correspond to the center part of the object to be heated. Since it is the structure which burns the burner part located in the center part of the arrangement direction among burner parts, even when it is a case where it burns in the stage for such a low combustion load, it is in the center part of the arrangement direction. By burning the burner part located, it becomes possible to heat the object to be heated with the combustion efficiency being as good as possible. 4 Provides a suitable means to implement any of
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a combustion apparatus according to the present invention will be described with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of a combustion apparatus according to the present invention will be described. This combustion apparatus is provided with a gas burner G provided with a plurality of burner portions arranged side by side. The gas burner G includes a burner unit 3 for burning a rich mixture having a low air mixing ratio and a burner unit 10 for burning a light mixture having a high air mixing ratio as the plurality of burner units. Are composed of a light and dark combustion type gas burner provided in a state in which they are alternately arranged.
That is, as shown in FIGS. 1 to 3, the light and dark combustion type gas burner G is provided with a combustion chamber case 2 having a substantially rectangular tube shape inside a burner case 1 having a substantially rectangular tube shape. A large number of flat burner portions 3 for flat combustion are arranged in parallel at a predetermined interval. Below the burner case 1, a fan 4 is provided as combustion air supply means for supplying combustion air and cooling air. A discharge port 4 a of the fan 4 is opened at the bottom of the burner case 1. Thus, an air chamber 6 is formed between the bottom portion of the burner case 1 and the air conditioning plate 5 made of a porous plate that forms the bottom portion of the combustion chamber case 2. Further, a cylindrical air flow passage 50 for cooling air circulation for cooling the burner case 1 is formed in a gap portion between the burner case 1 and the combustion chamber case 2.
[0027]
The rich combustion burner unit 3 includes a flat rich flame port 7 that discharges a rich mixture having a small primary air mixing ratio upward, a thick mixing chamber 8 that communicates with the rich flame port 7, The mixing chamber 8 is provided with a concentration inlet 9 as a concentration air intake for introducing a fuel gas for generating a rich mixture and combustion air. The rich combustion burner section 3 is formed of a single metal plate, and the plate is bent and bonded together at the thickening flame port 7 so that the thickening mixing chamber 8 and the thickening burner 3 are used. An introduction port 9 is formed, and below the concentration mixing chamber 8, a light gas conduction path 11 of a light combustion burner section 10 to be described later, and a fuel gas and combustion air in the light gas conduction path 11. The light introduction port 12 as a light air intake port having a cross-sectional ellipse shape is formed integrally with the same plate-like body, and the periphery is joined by spot welding.
[0028]
The flat dense burner portions 3 formed in this way are stored in parallel in the combustion chamber case 2 at a predetermined interval, so that a flat space is provided between the adjacent rich combustion burner portions 3. This interval space is used for forming the burner portion 10 for light combustion. Specifically, between the rich flame ports 7 of the rich combustion burner unit 3, a pale flame port 13 that discharges a pale mixture having a high primary air mixing ratio upward is provided. A lower space communicating with 13 is configured as a light mixing chamber 14, and the air-fuel mixture is ejected into the light mixing chamber 14 from a plurality of outlets 15 formed in the light gas conduction path 11. In addition, a plurality of rectifying plates 16 fixed to the rich combustion burner portion 3 are configured to be positioned in the light flame ports 13.
[0029]
A gas header 17 is disposed in front of the thick inlet 9 of the rich burner 3 and the light inlet 12 of the light burner 10. As shown in FIG. A gas supply path, which will be described later, is connected in communication, and a large number of gas nozzles for concentration 21 and a large number of gas nozzles for light 22 are attached to the gas header 17.
[0030]
The concentration gas nozzle 21 faces each concentration introduction port 9, and a part of the cooling air flowing between the burner case 1 and the combustion chamber case 2 by blowing the fuel gas from the concentration gas nozzle 21. Are sucked into the thickening inlet 9 at a predetermined rate by the ejector action, mixed in the process of passing through the thickening mixing chamber 8 to generate a thick air-fuel mixture, and this rich air-fuel mixture is discharged from the thickening flame opening 7.
Similarly, the light gas nozzles 22 face the light introduction ports 12, and when a fuel gas is blown from the light gas nozzles 22, a part of the cooling air is also used at a predetermined rate by the ejector action. The air is sucked into the introduction port 12, mixed in advance in the process of passing through the light gas conduction path 11, and the air-fuel mixture is ejected from the ejection port 15 of the light gas conduction path 11 into the light mixing chamber 14. In the light mixing chamber 14, the air-fuel mixture from the jet outlet 15 and the combustion air supplied from the air chamber 6 through the air conditioning plate 5 are mixed to generate a light air-fuel mixture. Is discharged from the light flame outlet 13. That is, the light introduction port 12 and the air conditioning plate 5 function as a light air intake port.
The light mixture thus generated is discharged from the light flame port 13 and burned, and the rich gas mixture is discharged from the gas flame port 7 adjacent to the light flame port 13 and burned. Light and dark combustion will be executed.
[0031]
The combustion apparatus includes a gas supply adjustment unit as a fuel supply adjustment unit that adjusts the supply of fuel gas to the plurality of burner units 3 and 10, a fan 4 as a combustion air supply unit, and the gas supply adjustment. And a control unit H as a combustion control means for controlling the operation of the unit, and the control unit H sets the number of burner units to be burned among the plurality of burner units according to the magnitude of the combustion load in three stages. The gas supply adjustment unit is operated so that the fuel gas is supplied only to the burner unit to be burned, and an appropriate amount of combustion air is supplied to the burner unit to be burned, so that the combustion is performed in the above-described multiple stages. The fan 4 is configured to operate as described above.
[0032]
More specifically, the gas header 17 is divided into three regions by a partition wall 23 as shown in FIG. That is, the rich gas nozzles 21 corresponding to the five rich combustion burner portions 3 located on the center side in the arrangement direction of the plurality of burner portions 3 and 10, and the four light combustion burner portions 10 also located on the central side. The first region R1 including the light gas nozzle 22 corresponding to the first region R1, a pair of the concentration gas nozzle 21 and the light gas nozzle 22 located on the left side of the first region R1 in FIG. 5, and the first region R1 A second region R2 including two sets of the gas nozzles 21 and the light gas nozzles 22 located on the right side, the two leftmost gas nozzles 21 and the light gas nozzles 22 and the rightmost set of one set. These are three regions including the third region R3 including the thickening gas nozzle 21 and the light gas nozzle 22.
The three regions R1, R2, and R3 are connected to the three first branch supply channels 18, the second branch supply channel 19, and the third branch supply channel 20 that are branched from the gas supply channel 26, respectively. Each branch supply path 18, 19, 20 is provided with a first switching solenoid valve V1, a second switching solenoid valve V2, and a third switching solenoid valve V3. Further, these branch supply paths 18, 19 are provided. , 20 is provided with an electromagnetic proportional valve 27 and a safety valve 28 for adjusting the total amount of fuel gas to be supplied. These switching electromagnetic valves V1, V2, V3, the electromagnetic proportional valve 27, and the safety valve 28 constitute the gas supply adjusting unit, and the control unit H controls the operation of the gas supply adjusting unit.
[0033]
Therefore, by opening all of the switching solenoid valves V1, V2, V3, the electromagnetic proportional valve 27, and the safety valve 28, the fuel gas is supplied to all the rich burner units 3 and the light burner units 10, and all the burners are supplied. When the third switching solenoid valve V3 is closed from this state, the eight combustion burner portions 3 on the center side in the arrangement direction and the seven on the center side in the arrangement direction are placed. The fuel gas is supplied to the light combustion burner unit 10 and burns (middle). Then, when the second switching solenoid valve V2 is closed from that state, the fuel gas is supplied to the five dense combustion burner portions 3 on the center side in the arrangement direction and the four light combustion burner portions 10 on the center side in the arrangement direction. Is supplied and burned (small).
That is, the number of burner sections to be burned can be changed to three stages of large, medium and small.
[0034]
Then, among the plurality of stages for changing the number of burner parts to be burned, combustion is stopped in the stage for low combustion load on the side where the number of burners to be burned is reduced, that is, in the “small” state. A supply suppression means Y for suppressing the supply of combustion air to the burner portion is provided to be switchable between a suppression action state and a suppression release state, and the control portion H burns out of the plurality of burner portions. For the high combustion load, the number of burners is switched to the suppression action state and the number of burner parts to be burned is larger than the low combustion load stage. In other words, the supply suppression means Y is operated so as to switch to the suppression release state as it is changed to the “medium” or “large” state.
[0035]
And in each of the suppression action state of the supply suppression means Y and the suppression cancellation | release state, it is comprised so that the rotational speed of the fan 4 may be changed and controlled so that an appropriate amount of combustion air may be supplied to the burner part to burn. . In other words, as described above, the number of burner sections to be burned is changed to three stages of large, medium and small according to the combustion load. On the other hand, the total amount of fuel gas to be supplied is adjusted by the electromagnetic proportional valve 27, and the rotation speed of the fan 4 is adjusted so that the supply amount of combustion air is in an appropriate state according to the combustion load. (See FIG. 7).
[0036]
The supply suppression means Y is a state in which combustion is performed in the rich combustion inlet 9 of the rich combustion burner unit 3 that stops combustion in the state of combustion in the low combustion load stage, and in the low combustion load stage. In which the air for intake of the burner unit 10 for stopping the combustion is stopped, that is, the inlet 12 for light and the air conditioning plate 5 are respectively shielded to suppress the intake of combustion air, and the introduction of concentrated A shielding member 30 that can be switched over between a release position that allows the intake of combustion air by opening the mouth, the light introduction port 12 and the air conditioning plate 5, and the shielding member 30 between the action position and the release position. The moving operation means 31 is operated to move the shielding member 30 to the operation position, and the shielding member 30 is switched to the restraining action state and the shielding member 30 is released. And it is configured to switch the derepression state thereby moving operation.
[0037]
As shown in FIGS. 1, 2, and 6, the shielding member 30 has a shape obtained by bending a plate material into a substantially L shape, and in the “small” state, the rich combustion burner that stops combustion. A vertical surface portion 30a that shields the thickening inlet 9 of the portion 3 and the light inlet 12 of the light combustion burner portion 10 that stops combustion, and the air conditioning plate 5 of the light combustion burner portion that stops combustion. The vertical surface portion 30a is formed with an insertion hole 30a1 that allows the supply of combustion air to the burner portion to be burned in the “small” state, and the horizontal surface portion 30b. Is configured to shield only a portion with respect to the burner portion that stops combustion.
[0038]
Next, the configuration of the moving operation means 31 will be described.
As shown in FIG. 2 and FIG. 6, the shielding member 30 is moved upward by a screw feed mechanism driven by one electric motor 36, and the corresponding thickening inlet 9 and The light introduction port 12 is shielded and provided so as to be slidable in the vertical direction over an action position where the corresponding air conditioning plate is shielded by the horizontal surface portion 30b and a release position where the part moves downward and opens the respective parts. ing.
In other words, the shielding member 30 is supported so as to be movable in the vertical direction while guiding the four corners of the horizontal surface portion 30b by the guide rods 32 while keeping the horizontal position from shifting. The internal thread portion 33 formed on the shaft is screwed into a pair of screw shafts 34 and 34 that are rotatable about an axis along the vertical direction and whose vertical movement is restricted, and is driven by an electric motor 36. The horizontal drive shaft 35 and the screw shafts 34, 34 are interlocked and connected by bevel gear mechanisms 37, 37, and the screw shafts 34, 34 are rotated in the same direction and at the same rotational speed, whereby the shielding member 30. Can be slid in the vertical direction. In addition, a limit switch 39 for detecting that the shielding member 30 has been raised to the operating position and a limit switch 40 for detecting that the shielding member 30 has been lowered to the release position are provided. After driving the motor 36, when any of the limit switches 39, 40 is turned on, the driving of the electric motor 36 is stopped.
[0039]
Then, the control unit H changes the number of burner units to be burned to the stage for the high combustion load, that is, the “medium” or “large” state according to the magnitude of the combustion load. When the change command is instructed, the gas supply adjusting unit immediately executes the change operation of the number of burner units that supply the fuel gas, and immediately switches from the suppression operation state to the suppression release state by the supply suppression means Y. It is configured to let you. When a change command is issued to change the number of burner sections to be burned to the low combustion load stage, that is, the “small” state according to the magnitude of the combustion load, the gas supply adjustment section The operation of changing the number of burner parts for supplying the fuel gas is immediately executed, and the switching from the suppression release state to the suppression operation state by the supply suppression means Y is executed after a set time delay.
In other words, the switching operation by the gas supply adjusting unit is always performed quickly, and the rotational speed of the electric motor 36 is driven at a high speed so that the operation of moving the shielding member 30 from the operating position to the release position by the electric motor 36 is performed quickly. When the movement operation from the release position to the action position is performed, the switching operation of the shielding member 30 is executed with a delay for a set time for completely burning the fuel gas supplied into the mixing chamber. Thus, incomplete combustion can be avoided.
[0040]
And the said shielding member 30 is a burner part to burn among the burner parts which stop combustion, when the number of the burner parts to burn is changed into the stage for low combustion loads, and it is switched to the suppression effect | action state. It is comprised so that supply of combustion air may be permitted with respect to the adjacent burner part 10 for light combustion. That is, since the fuel gas is not supplied to the burner unit 10 for light combustion indicated by symbol A in FIGS. 3 and 4, the combustion is stopped, but the supply of combustion air is allowed. Will be. If it does in this way, the incomplete combustion resulting from the shortage of the combustion air in the burner part 3 for rich combustion located in an edge part will be avoided, and an appropriate combustion state will be maintained.
Even when all the burner parts are burned, the rich combustion burner part 3 is positioned at the extreme end. However, the rich burner part 3 at the extreme end is described above. By supplying combustion air through such an air flow passage 50, an appropriate combustion state is maintained.
[0041]
Accordingly, as described above, in the stage for the low combustion load on the side where the number of burners to be burned is reduced, that is, in the “small” state, the supply suppression means Y is used for combustion with respect to the burner portion whose combustion is to be stopped. Since the supply of air is suppressed, the excess supply amount of combustion air as a whole gas burner can be reduced. As shown in FIG. 7, in the case of the conventional configuration in which the supply suppression means Y is not provided (shown in the figure). Compared to the state indicated by the broken line), in the “small” state, the rotation speed by the fan 4 can be reduced to obtain an appropriate combustion state, and the power cost can be reduced.
Moreover, as is clear from the experimental data by the applicant in FIG. 8, the thermal efficiency can be improved by the above configuration as compared with the thermal efficiency (indicated by the broken line L11) in the case of the conventional configuration in which the supply suppression means Y is not provided. It was. Note that this thermal efficiency experimental data corresponds to the characteristic line L1 corresponding to the “small” state and the “medium” state when the combustion device is applied to a hot water supply device that heats the heat exchanger for hot water supply. A characteristic line L2 and a characteristic line L3 corresponding to the “large” state are shown, which are measured as thermal efficiency data and correspond to the heat recovery rate of the combustion apparatus.
[0042]
[Second Embodiment]
Next, a second embodiment of the present invention will be described.
In this embodiment, the gas burner is applied to an ordinary Bunsen burner instead of the light and dark combustion gas burner as in the first embodiment. That is, in the ordinary Bunsen burner, as shown in FIG. 9, each of the plurality of burner portions has a primary air intake port 40 for taking in primary air to be supplied to the flame port 39 forming a flame as the combustion air, A secondary air intake port 41 for taking in secondary air to be supplied to the flame mouth as the combustion air is provided, and a gas nozzle similar to the gas nozzle of the first embodiment is provided in the primary air intake port 40. The primary air is taken in by the ejector action by the ejection of the gas from the gas nozzle. Moreover, the secondary air taken in from the secondary air intake port 41 is supplied to the flame port 39 through the space between each burner part.
[0043]
And like the shielding member 30 in the said embodiment, the said primary air intake 40 corresponding to the burner part which stops combustion in the state burned in the stage for the said low combustion load, and the said secondary air intake 41 are provided. Switching between an operation position that shields each of them and suppresses the intake of combustion air and a release position that opens the primary air intake port 40 and the secondary air intake port 41 to allow the intake of combustion air. A free shielding member 42 is provided, and the shielding member 42 is moved and operated between the action position and the release position by a movement operation means similar to the movement operation means 31 in the above embodiment. .
Note that the configuration for switching to the operating position in accordance with the change to the low combustion load stage is the same as in the first embodiment.
[0044]
[Third Embodiment]
Next, a third embodiment of the present invention will be described.
In this embodiment, the vertical surface portion and the horizontal surface portion of the shielding member 30 in the first embodiment are divided and moved separately, and the other configurations are the same as those in the first embodiment.
More specifically, as shown in FIG. 11, the divided horizontal surface portion 50 is configured to be slid up and down by a screw feed type moving operation means having an electric motor 36 similar to that of the first embodiment. . The divided vertical surface portion 51 is configured as follows. That is, as shown in FIG. 10, an insertion hole 52 through which the gas nozzle for concentration 21 and the gas nozzle for light 22 are inserted is formed in the vertical surface portion 51 of the single plate configuration. The screw feed type moving operation means having the same electric motor 36 moves to the release position that moves to the gas header 17 side, and moves to the concentration introduction port 9 or the light introduction port 12 side. In addition, a movement operation is performed to a position where the combustion air is prevented from being introduced from the light introduction port 12 to switch between a suppression action state and a suppression release state.
At this time, the vertical surface portion 51 cannot completely block the concentration inlet 9 and the light inlet 12, but can suppress the introduction of combustion air, and supply excess air. It becomes possible to suppress.
[0045]
[Another embodiment]
Hereinafter, other embodiments other than the above embodiment will be listed.
[0047]
( 1 ) The supply suppression means is not limited to a configuration in which the combustion air intake portion to the burner portion where combustion is to be stopped is completely shut off, but a large amount is suppressed and a slight supply is allowed. The configuration may be various, and the configuration can be variously changed.
For example, as shown in the third embodiment, instead of a configuration in which the divided horizontal surface portion 50 and the vertical surface portion 51 as described above are provided, and they are moved and operated by the moving operation means, respectively. Alternatively, only one of the horizontal plane part 50 and the vertical plane part 51 may be provided, and the movement operation means may be switched between the suppression action state and the suppression release state.
[0048]
( 2 In the first embodiment, when the number of burner parts to be burned is changed to the low combustion load stage, the burner parts located in the center part in the arrangement direction among the plurality of burner parts are burned. Although comprised as mentioned above, you may make it burn not only such a structure but the burner part located in the edge part side of a row direction.
[0049]
( 3 In each of the above embodiments, as the supply suppression means, the supply of air is suppressed by shielding the place where the combustion air is taken into the gas burner, but instead of such a configuration, for example, for combustion It may be configured to suppress air circulation at the air outlet, that is, at the flame outlet.
[0050]
( 4 ) In each of the above embodiments, the configuration in which the number of burner portions to be burned among the plurality of burner portions is changed to three stages of large, medium, and small, but is not limited to three stages in this way and is not limited to three stages. Any configuration may be used as long as the number of steps is four, five, or more.
The stage for the low combustion load on the side where the number of burners to be burned is not limited to the stage having the smallest number of burners among the plurality of stages, for example, one stage having the smallest number of burners to burn. In order to increase the number of burners in order from 2 to 3, in order to change to 2, 3, 4, and 5 stages, the 1st stage and 2nd stage on the side where the burner number decreases is the stage for low combustion load. Alternatively, various combinations such as one stage, two stages, and three stages for low combustion load may be used as low combustion load stages. Thus, when setting the stage for low combustion loads, it is good to set the stage for which the heat recovery rate as a combustion apparatus becomes below a preset value as a stage for low combustion loads.
[0051]
( 5 The above-described combustion apparatus is not limited to heating a heat exchanger for hot water supply, but can be implemented in various usage forms such as a combustion apparatus used as a heating apparatus, and its application is not limited. .
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a combustion apparatus according to a first embodiment.
FIG. 2 is a partially cutaway perspective view of the combustion apparatus of the first embodiment.
FIG. 3 is a longitudinal front view of the combustion apparatus of the first embodiment.
FIG. 4 is a diagram showing a combustion state of a gas burner at a low combustion load stage according to the first embodiment.
FIG. 5 is a schematic configuration diagram showing a fuel supply state of the combustion apparatus of the first embodiment.
FIG. 6 is a diagram showing a configuration of supply suppression means of the first embodiment.
FIG. 7 is a graph showing the relationship between fan rotation speed and combustion load in the first embodiment.
FIG. 8 is a graph showing the relationship between thermal efficiency and combustion load in the first embodiment.
FIG. 9 is a longitudinal front view of a combustion apparatus according to a second embodiment.
FIG. 10 is a diagram showing a configuration of supply suppression means of the third embodiment.
FIG. 11 is a diagram showing a configuration of supply suppression means of the third embodiment.
[Explanation of symbols]
3, 10 Burner
4 Combustion air supply means
30, 42 Shielding member
31 Moving operation means
39
40 Primary air intake
41 Secondary air intake
G Gas burner
H Combustion control means
Y Supply suppression means

Claims (5)

A gas burner with a plurality of burner portions arranged side by side;
Combustion air supply means for supplying combustion air to the plurality of burner parts;
Fuel supply adjusting means for adjusting supply of fuel gas to the plurality of burner parts;
Combustion control means for controlling the operation of the combustion air supply means and the fuel supply adjustment means,
The burner unit that burns so that the combustion control means burns in a form in which the number of burner units to be burned among the plurality of burner units is changed to a plurality of stages of three or more according to the magnitude of the combustion load. The fuel supply adjusting means is operated so that the fuel gas is supplied only to the fuel gas, and the combustion air supply means is operated so that an appropriate amount of combustion air is supplied to the burner unit to be burned. A combustion device comprising:
Among the plurality of stages for changing the number of burner parts to be burned, in the state of burning in the stage for low combustion load on the side where the number of burners to be burned out of the stages for burning some burner parts, Supply suppression means for suppressing the supply of combustion air to the burner section that stops combustion is provided to be switchable between a suppression action state and a suppression release state,
The combustion control means comprises:
As the number of burner portions to be burned among the plurality of burner portions is changed to the stage for low combustion load, the state is switched to the suppression action state, and the number of burner portions to be burned is changed to the low combustion load. The supply suppression means is configured to operate so as to switch to the suppression release state in accordance with the change to the high combustion load stage having a larger number of burners than the stage for combustion.
In each of the suppression action state and the suppression release state of the supply suppression unit, the combustion air supply unit is configured to operate so that an appropriate amount of combustion air is supplied to the burner unit to be burned ,
When a change command is issued to change the number of burner parts to be burned to the high combustion load stage according to the magnitude of the combustion load, the number of burner parts that supply fuel gas by the fuel supply adjusting means Is immediately executed, and the switching from the suppression action state by the supply suppression means to the suppression release state is immediately executed,
When a change command for changing the number of burner portions to be burned to the low combustion load stage is commanded according to the magnitude of the combustion load, the number of burner portions for supplying fuel gas by the fuel supply adjusting means The combustion apparatus is configured to immediately execute the change operation and to perform the switching from the suppression release state to the suppression operation state by the supply suppression unit with a set time delay . Each of the plurality of burner portions includes a primary air intake port that takes in primary air to be supplied to a flame port that forms a flame as the combustion air, and secondary air that is to be supplied to the flame port as the combustion air. With a secondary air intake for taking in,
The supply suppression means is
An action position for suppressing the intake of combustion air by shielding the primary air intake and the secondary air intake corresponding to the burner section that stops combustion in the state where combustion is performed in the low combustion load stage. A shielding member that can be switched over between a release position that allows the intake of combustion air by opening the primary air intake and the secondary air intake, respectively,
A moving operation means for moving the shielding member between the operating position and the release position;
The moving operation means is configured to switch to the suppression action state by moving the shielding member to the action position, and to switch to the suppression release state by moving the shielding member to the release state. combustion apparatus of which claim 1 is. The gas burner is
As the plurality of burner parts, a rich combustion burner part that burns a rich air-fuel mixture with a low air mixing ratio and a light combustion burner part that burns a light air-fuel mixture with a large air mixing ratio are alternately arranged. Consists of light and dark combustion gas burners prepared in line,
The rich combustion burner unit is configured to include a thick air intake port for taking in the combustion air to be supplied to a rich flame port that forms a flame by burning the rich air-fuel mixture,
The light combustion burner unit is configured to include a light air intake port for taking in the combustion air to be supplied to a light flame port that forms a flame by burning the light air-fuel mixture,
The supply suppression means is
Combustion is stopped in the state in which combustion is performed in the stage for low combustion load, and in the state in which combustion is performed in the stage for low combustion load, and in the state for combustion in the stage for low combustion load. The operation position for blocking the intake of combustion air by blocking the intake air for light of the burner portion for light combustion, the intake air for concentration, and the intake air for light are opened. A switching member that is switchable between a release position that allows intake of combustion air,
A moving operation means for moving the shielding member between the operating position and the release position;
The moving operation means is configured to switch to the suppression action state by moving the shielding member to the action position, and to switch to the suppression release state by moving the shielding member to the release state. combustion apparatus of which claim 1 is. The supply suppression means is
When the number of burner parts to be burned is changed to the low combustion load stage and switched to the suppression action state, the light combustion adjacent to the burner part to be burned out of the burner parts for stopping combustion The combustion apparatus according to claim 3 , wherein the combustion burner is configured to allow supply of combustion air to the burner unit . The combustion control means comprises:
The burner part located in the center part of the line-up direction among the plurality of burner parts is burned when the number of burner parts to be burned is changed to the stage for the low combustion load. The combustion apparatus of any one of 1-4 .

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