JPH03217704A - Combustion method for combustion device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of incomplete combustion by a method wherein on switching to full combustion, total primary air combustion is effected by the whole of a combustion part, and on switching to partial combustion, the ratio between fuel fed to a part of a combustion part and primary air is set to a value lower than 1 and Bunsen combustion wherein combustion air passing the other part of the combustion part is taken in as secondary air is effected. CONSTITUTION:A main solenoid valve 43, a proportional control valve 44, and a second switching valve 48 are actuated and fuel gas is fed in a blower 5 for combustion being fed through a nozzle 49 of a pipe 42. Primary air and fuel gas are mixed together and airfuel mixture flows in a mixing pipe 24 and a combustion case 26. Air-fuel mixture passes through a first combustion plate 23 of a first burner part 21 and the burner port of a second combustion plate 25 of a second burner part 22 for combustion. A first switching valve 46 actuated is and a second switch valve 48 is turned off. Fuel gas is fed through a plurality of nozzles 47 of a gas piping 41 to a plurality of mixing pipes 24. Combustion air is fed in the mixing pipe 24 and the combustion case 26 with the aid of a blower 5 for combustion. Primary air in the mixing pipe 24 is mixed with fuel gas, air-fuel mixture passes the burner port of the first combustion plate 23 and jetted, and secondary air is fed through the burner port of the second combustion plate 25. The ratio between the fuel and the primary air is set to a value lower than 1.0, and Bunsen combustion is made only on the first combustion plate 23.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a combustion method for water heaters, bathtubs, hot water heaters, and other water heaters, a combustion method for stoves and other heating appliances, or a combustion method for gas furnaces, etc. The present invention relates to a combustion method of a combustion device used for a combustion method of a combustion appliance.

[The conventional technology disclosed in Japanese Patent Application Laid-Open No. 62-288449 is to divide a burner that burns fuel into a plurality of all-primary air burner sections, and to carry out combustion in all of these burner sections. A water heater has been proposed that can switch to partial combustion in which combustion is performed in a part of the burner section. In this conventional water heater, combustion is performed by total primary air combustion in both full combustion and partial combustion.

Conventionally, hot water heaters have been known to switch the burner from full combustion to partial combustion when, for example, the exit hot water temperature detected by the exit hot water temperature sensor becomes higher than the set exit water temperature set by the exit hot water temperature setting device and the combustion amount of the burner is greatly reduced. Switching to combustion.

[Problems to be Solved by the Invention]However, in the water heater described above, if the hot water temperature becomes higher than the set hot water temperature during partial combustion, it is necessary to further reduce the combustion amount of the burner; Since the range of the air-fuel ratio for good combustion is very narrow, from 10 to 1.5, it is necessary to perform delicate air-fuel ratio control, which results in complicated air-fuel ratio control. In addition, there was a problem in that the combustion flame was more likely to go out due to wind disturbances and combustion failures were more likely to occur. An object of the present invention is to provide a combustion method for a combustion apparatus that allows simple air-fuel ratio control during partial combustion, and that is less likely to cause combustion flames to disappear or combustion defects to occur due to wind disturbances or the like.

[Means for Solving the Problems] (Claim 1) A combustion method of a combustion apparatus according to the present invention includes a burner which is divided into a plurality of combustion sections and which burns a mixture of combustion air and fuel; switching means for switching between full combustion in which all of the plurality of combustion sections perform combustion and partial combustion in which some of the plurality of combustion sections perform combustion; and supplying combustion air to all of the plurality of combustion sections. In the combustion apparatus, when the switching means switches to the full combustion, all of the plurality of combustion sections perform full primary air combustion, and when the switching means switches to the partial combustion. When
By setting the fuel supplied to only some of the combustion sections among the plurality of combustion sections and the primary air ratio of that section to be smaller than 1.0, combustion that passes through the other combustion sections is achieved. (Claim 2) Further, the air passing through some of the combustion sections of the plurality of combustion sections is adopted. The amount of air passing through other combustion sections is 1/
Good Bunsen combustion can be achieved by reducing the number to 3 or less.

[When the operation switching means switches to full combustion, fuel is supplied to all of the plurality of combustion sections, and combustion air is supplied to all of the plurality of combustion sections. That is, all primary air combustion is performed in all of the plurality of combustion sections. Therefore, when the burner is switched to full combustion, the burner performs full primary air combustion, so the range of the air-fuel ratio for the good combustion range is narrow, 1.0 to 15, so delicate air-fuel ratio control is performed.

When the switching means switches to partial combustion, fuel is supplied to only some of the plurality of combustion sections, and combustion air is supplied to both some and other of the plurality of combustion sections. At this time, the fuel supplied to a part of the combustion section is set so that the primary air ratio of that part is smaller than 10. By doing so, Bunsen combustion is performed by taking combustion air passing through other combustion sections into some combustion sections as secondary air.

In claim 2, the amount of air passing through some of the combustion sections is 1/3 or less of the amount of air passing through the other combustion sections, so that the combustion of the other sections is reduced. Good Bunsen combustion is achieved by taking in three times or more of the combustion air passing through the combustion section as secondary air for some combustion sections.

Therefore, even if the combustion amount of the burner is further reduced when switching to partial combustion, the air-fuel ratio range within the good combustion range is as wide as 1.θ to 4.0, so careful air-fuel ratio control is required. It disappears. Furthermore, combustion flames are less likely to go out due to disturbances or other winds, and poor combustion is less likely to occur.

[Effects of the Invention] Fine air-fuel ratio control only needs to be performed when switching to full combustion, and when the amount of combustion susceptible to disturbances is small, switching to partial combustion by Bunsen combustion. This is because the range of the air-fuel ratio within the good combustion range is wide, so air-fuel ratio control becomes simple. Therefore, wind resistance can be improved, and incomplete combustion due to extinguishing of the combustion flame or poor combustion can be prevented.

[Example] A combustion method of the combustion apparatus of the present invention will be explained based on an example shown in FIGS. 1 to 3.

1 and 2 show a gas combustion water heater employing the present invention. FIG. 3 shows a combustion plate installed in a gas-fired water heater.

The gas combustion water heater 1 includes a gas burner 2, a water supply pipe 3, a gas supply pipe 4, a combustion blower 5, and a control circuit 6.

The gas burner 2 includes a plurality of first burner sections 21, a second burner section 22, and a combustion case 26.

The first burner section 21 is connected to the other first burner section 21 and the second burner section 21.
It is separated from the burner section 22. These first burner sections 21 are respectively firing the first combustion plate 23 and the mixing tube 24.

The first combustion plate 23 is a part of the plurality of combustion parts of the present invention, and has a plurality of flame ports formed therein. The first combustion plates 23 of this embodiment are distributed at six locations and are provided so that the total flame opening area is 1/3 or less of the second combustion plate 25. In this first combustion plate 23, the air-fuel mixture mixed in the combustion blower 5 during full combustion is combusted in the primary air, and during partial combustion, the air-fuel mixture mixed in the mixing pipe 24 and the surrounding secondary air are combusted. Bunsen combustion with air.

The mixing tube 24 is provided with a throttle 28 at its inlet.

The throttle 28 facilitates mixing of the primary air supplied by the combustion blower 5 and the fuel gas in the mixing pipe 24 during partial combustion. Furthermore, in this embodiment, since the throttle 28 is provided, the amount of air-fuel mixture flowing into the mixing tube 24 is reduced. For this reason, the first combustion plate 23 is formed to have a flame opening area (sparse) commensurate with the amount of air-fuel mixture, thereby making the combustion flame uniform during complete combustion.

The second burner section 22 is separated from the plurality of first burner sections 21 . These second burner parts 22 are connected to the second combustion plate 2
5.

The second combustion plate 25 is another combustion part of the plurality of combustion parts of the present invention, and has a plurality of flame ports formed therein. In this second combustion plate 25, the combustion blower 5
The air-fuel mixture mixed inside is combusted entirely with primary air, and only combustion air is supplied from the combustion blower 5 during partial combustion. In addition,
In this embodiment, a combustion plate 27 in which a first combustion plate 23 and a second combustion plate 25 are integrally formed is used.

The combustion case 26 is supplied with the air-fuel mixture mixed within the combustion blower 5 during full combustion, and is supplied with the air-fuel mixture mixed within the combustion blower 5 during partial combustion.
Only combustion air is supplied from the

The water supply pipe 3 has a water supply pipe 31, a heat exchanger 32, and a hot water supply pipe 33.

The water supply pipe 31 is a pipe that supplies water to the heat exchanger 32.

The heat exchanger 32 includes a first combustion plate 23 of the first burner section 21 and a second combustion plate 25 of the second burner section 22 of the gas burner 2.
The flame generated and the combustion heat held by the combustion gas heat the water flowing inside.

The hot water supply pipe 33 is a pipe that supplies hot water from downstream of the heat exchanger 32 to the kitchen, washroom, bath, or the like.

The gas supply pipe 4 is a pipe that guides fuel gas from the gas pipe to the gas burner 2, and is connected to the first gas pipe 41 on the gas burner 2 side.
and a second gas pipe 42.

This gas supply pipe 4 is provided with a main solenoid valve 43 and a proportional control valve 44 . The main solenoid valve 43 opens when energized and supplies fuel gas to the gas burner 2 . The proportional control valve 44 adjusts the amount of fuel gas passing therethrough by controlling the degree of opening of the gas supply pipe 4 according to the amount of energization.

Further, the first gas pipe 41 is provided with an electromagnetic first switching valve 46 that opens when energized, and a nozzle 47 is provided at the tip of the first gas pipe 41 in correspondence with each of the first combustion plates 23. ing. Further, the second gas pipe 42 is provided with an electromagnetic second switching valve 48 that opens when energized, and one nozzle 49 at the tip faces the intake port of the combustion blower 5. has been done.

The first switching valve 46 is a switching means that is opened during partial combustion, and supplies fuel gas only to the first combustion plate 23 of the first burner section 21 of the gas burner 2 . The plurality of nozzles 47 are
During partial combustion, the fuel gas flowing through the first gas pipe 41 is supplied into the mixing pipe 24 of each first burner section 21 .

The second switching valve 48 is a switching means that is opened during full combustion, and is opened when the first combustion plate 2 of the first burner section 21 of the gas burner 2
3 and the second combustion plate 25 of the second burner section 22 with fuel gas. One nozzle 49 supplies the fuel gas flowing in the second gas pipe 42 into the combustion blower 5 during full combustion.

Note that when the first switching valve 46 is open, the second switching valve 48 is closed and Bunsen combustion is performed in the first burner section 21, and when the second switching valve 48 is open, Bunsen combustion is performed. is the first
The switching valve 46 is closed, and the first burner section 21 and the second burner section 22 perform all primary air combustion.

The combustion blower 5 is a blowing means, and when energized during full combustion, it supplies the mixture into the mixing tube 24 and the combustion case 26, and when energized during partial combustion, it supplies only combustion air to the mixing tube 24 and the combustion case. It is supplied into the case 26.

The control circuit 6 controls the igniter (not shown) and the main solenoid valve 43 in response to signals from an operation switch (not shown), a hot water temperature sensor (not shown), a hot water temperature setting device (not shown), etc. , the proportional control valve 44, the first switching valve 46, the second switching valve 48, and the combustion blower 5 are energized and controlled.

The combustion method of the gas combustion water heater 1 of this embodiment will be explained based on FIGS. 1 and 2.

■． When the main solenoid valve 43, the proportional control valve 44, and the second switching valve 48 are energized during full combustion, fuel gas is supplied into the combustion blower 5 from one nozzle 49 of the second gas pipe 42.

By energizing the combustion blower 5, combustion air (
While the primary air) and fuel gas are forcibly mixed in the combustion blower 5, the plurality of mixing pipes 24 and the combustion case 26
flow inside.

The air-fuel mixture that has flowed into the mixing tube 24 and the combustion case 26 flows through the flame port of the first combustion plate 23 of the first burner section 21 and the second
It passes through the flame port of the second combustion plate 25 of the burner section 22 and is ejected. At this time, when the igniter is activated, the first combustion plate 23
Then, combustion is started at the second combustion plate 25.

Note that since the mixing tube 24 is provided with the throttle 28, the amount of air-fuel mixture in the first combustion plate 23 is reduced. For this reason,
If the flaming sun ratio of the first combustion plate 23 and the flaming sun ratio of the second combustion plate 25 are approximately the same, the combustion flame generated on the first combustion plate 23 will be low. Therefore, by making the flame daily ratio of the first combustion plate 23 sparser than that of the second combustion plate 25 so that the flame opening area corresponds to the amount of air-fuel mixture supplied to the first combustion plate 23. , the heights of the combustion flames of the first combustion plate 23 and the second combustion plate 25 are made uniform.

Then, the heat exchanger 32 is connected to the water pipe through the water supply pipe 31.
The water supplied to the first combustion plate 23 and the second combustion plate 2
It is heated by the flame generated in step 5 and the combustion heat held by the combustion gas. Then, the heated hot water is transferred to the hot water supply pipe 33
It is supplied to the kitchen, washroom, bath, etc. through the pipe.

By the way, during full combustion, the rotation speed, that is, the amount of air supplied to the first burner section 21 and the second burner section 22, is changed by controlling the amount of electricity supplied to the combustion blower 5 by the control circuit 6. By controlling the amount of electricity supplied to the proportional control valve 44 and changing the amount of gas to be supplied in accordance with the amount of air blown by the combustion blower 5, the air-fuel ratio is controlled to be the optimum air-fuel ratio for the good combustion range. . Therefore, stable combustion is performed on the first combustion plate 23 and the second combustion plate 25.

Further, for example, when the outlet hot water temperature detected by the outlet hot water temperature sensor becomes higher than the set outlet hot water temperature set by the outlet hot water temperature setting device, the combustion amount of the gas burner 2 is throttled by the control circuit 6. In this way, even when reducing the combustion amount of the gas burner 2, the amount of electricity supplied to the combustion blower 5 and the proportional control valve 44 is controlled so that the first combustion plate 23 and the second combustion plate 25 perform stable combustion. The amount of air and gas is reduced. Then, when reducing the combustion amount further than a predetermined combustion amount, the gas burner 2 is switched from full combustion to partial combustion.

■． During partial combustion, the first switching valve 46 is energized and the second switching valve 48 is de-energized. Therefore, one nozzle 49 of the second gas pipe 42
The supply of fuel gas into the combustion blower 5 is stopped, and the supply of fuel gas from the plurality of nozzles 47 of the first gas pipe 41 to the plurality of first gas pipes 41 is stopped.
Fuel gas is supplied only into the mixing tube 24 of the burner section 21 . Therefore, the second combustion plate 25 extinguishes the fire.

Then, combustion air is supplied by the combustion blower 5 into the plurality of mixing pipes 24 and the combustion case 26.

The combustion air (primary air) that has flowed into the mixing tube 24 is
It is mixed with fuel gas ejected from the plurality of nozzles 41 of the gas pipe 41. This air-fuel mixture passes through the flame port of the first combustion plate 23 of the first burner section 21 and is ejected. Furthermore, the second
Only the combustion air supplied from the combustion blower 5 is ejected from the flame port of the second combustion plate 25 to the first combustion plate 23 as secondary air.

Note that the fuel supplied only to the first combustion plate 23 of the first burner section 21 and the primary air ratio of that portion are set to be smaller than 1.0. Furthermore, the amount of primary air supplied to the first combustion plate 23 is reduced to 173 or less compared to the amount of secondary air supplied to the second combustion plate 25. For this reason,
By taking in from around the first combustion plate 23 an amount of secondary air that is three times or more the amount of primary air that has flowed into the combustion case 26 and passed through the flame port of the second combustion plate 25. ,
Bunsen combustion is performed only on the first combustion plate 23.

By the way, for example, when the outlet hot water temperature detected by the outlet hot water temperature sensor becomes higher than the set outlet hot water temperature set by the outlet hot water temperature setting device and the combustion amount of the gas burner 2 is further reduced, the air-fuel ratio in the good combustion range due to Bunsen combustion The width of is 1,
Since the range is wide from 0 to 4.0, the amount of electricity supplied to the combustion blower 5 and the proportional control valve 44 can be controlled to increase the amount of air blown and the amount of gas, without having to perform detailed air-fuel ratio control as in full primary air combustion. You can narrow it down.

Therefore, air-fuel ratio control becomes easy during partial combustion.
Furthermore, during partial combustion, the range of the air-fuel ratio in the good combustion range is wide, from 1.0 to 4.0, as described above, so that the combustion flame is less likely to disappear due to wind such as disturbance. Therefore, wind resistance is improved and incomplete combustion can be prevented.

Furthermore, since the gas burner 2 functions as a Bunsen burner during partial combustion, the dew point temperature of the steam in the heat exchanger 32 can be lowered.

Therefore, generation of drain in the heat exchanger 32 can be prevented.

(Modified example) In this embodiment, the present invention is set based on the area ratio of the air passages to the first burner section and the second burner section, but it is possible to provide a plurality of combustion blowers to supply air to the burner section that performs partial combustion. The primary air ratio between the fuel and the primary air in that area may be set to be less than 1.0. Furthermore, the amount of air supplied to the burner section undergoing partial combustion may be reduced to 1/3 or less of the amount of air supplied to the burner section during extinguishing. In this case, there are multiple supply paths for combustion air to the combustion plate. Moreover, the diameter of the flame port of the combustion plate of the first burner may be made smaller than the diameter of the flame port of the combustion plate of the second burner.

In this embodiment, two electromagnetic valves are used as switching means for switching between full combustion and partial combustion, but one three-way valve may be used as the switching means. Also, three or more switching valves may be used.

In this embodiment, the first combustion plate and the second combustion plate are integrally formed, but the first combustion plate and the second combustion plate may be formed separately.

In this embodiment, a plurality of first burner sections are provided, but one first burner section may be provided.

In this embodiment, one second burner section is provided, but two or more second burner sections may be provided.

In this embodiment, the present invention was adopted as a combustion method for water heaters such as water heaters and bath pots, but the present invention may also be adopted as a combustion method for hot water heaters and other hot water appliances, and the present invention may also be adopted as a combustion method for hot water heaters and other hot water appliances. It may be used as a combustion method for
It may also be adopted as a combustion method for combustion appliances such as gas smokers.

In this embodiment, gaseous fuel such as fuel gas is used as the fuel, but liquid fuel such as petroleum may also be used.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention. Figure 1 is a cross-sectional view showing total primary air combustion in a gas combustion water heater, Figure 2 is a cross-sectional view showing Bunsen combustion in a gas combustion water heater,
FIG. 3 is a plan view showing the first combustion plate and the second combustion plate incorporated in the gas combustion type water heater. In the figure 1... Gas combustion type water heater (combustion device) 2... Gas burner 5... Combustion blower (air blowing means) 23...
・First combustion plate (some combustion parts among multiple combustion parts) 2
5... Second combustion plate (other combustion part of the plurality of combustion parts) 46... First solenoid valve (switching means) 48... Second
Solenoid valve (switching means)

Claims (1)

[Scope of Claims] 1) A burner that is divided into a plurality of combustion sections and performs combustion of a mixture of combustion air and fuel; a total combustion system in which all of the plurality of combustion sections perform combustion; A combustion apparatus comprising a switching means for switching between partial combustion and partial combustion in which some of the combustion sections perform combustion, and a blowing means for supplying combustion air to all of the plurality of combustion sections, wherein the switching means causes the When switched to full combustion, all primary air combustion is performed in all of the plurality of combustion sections, and when switched to partial combustion by the switching means,
By setting the fuel supplied to only some of the combustion sections among the plurality of combustion sections and the primary air ratio of that section to be smaller than 1.0, combustion that passes through the other combustion sections is achieved. A combustion method for a combustion apparatus, characterized in that Bunsen combustion is performed in which air is introduced as secondary air into the part of the combustion section. 2) When switching to the partial combustion, the amount of air passing through some of the plurality of combustion sections is reduced to 1/3 or less of the amount of air passing through other combustion sections. A combustion method for a combustion device according to claim 1, characterized in that: