JPH0442566B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a combustion device that performs high-load combustion by forcibly supplying combustion air with a blower, and is particularly improved to eliminate oscillating combustion associated with operation. This invention relates to a forced air combustion device.

[Prior art] In forced air combustion equipment, due to high-load combustion,
For example, when the exhaust port is made small to prevent internal noise from leaking outside, or when an exhaust pipe is connected to the exhaust port to extend the exhaust, oscillating combustion occurs. We have previously proposed a method for eliminating oscillatory combustion by arranging burners with different amounts of fuel or by using nozzles with different fuel supply amounts for each burner to vary the amount of combustion for each burner.

[Problems to be Solved by the Invention] However, each flame hole has a limit on the flame hole area or length due to the need to prevent backfire. Within these limits, burners with different flame hole areas or lengths must be provided. However, since burners are generally installed in a limited space, there is a problem in that depending on the type of burner, it may be difficult to ensure the overall flame hole area, that is, the amount of combustion.

SUMMARY OF THE INVENTION An object of the present invention is to provide a forced air combustion device that can prevent oscillatory combustion, secure a sufficient flame hole area, and generate a predetermined amount of combustion.

[Means for Solving the Problems] A first aspect of the present invention provides a forced air combustion apparatus in which a plurality of burners having the same shape are installed in a combustor case forming a combustion chamber. A plurality of nozzles that eject the same amount of fuel gas to each of the burners are provided in a fixed arrangement with respect to each primary air suction port of the plurality of burners, and at the position of each primary air suction port of the plurality of burners. A damper having a plurality of corresponding openings exhibiting a smaller area than each of the primary air suction ports is attached to the plurality of burners, and the area of the plurality of openings of the damper is made different among the plurality of burners. Use technical means.

A second aspect of the present invention is a forced air combustion device in which a plurality of burners having the same shape are installed in a combustor case forming a combustion chamber, in which the same amount of fuel is supplied to each of the plurality of burners. A plurality of nozzles for ejecting gas are provided corresponding to each of the primary air suction ports of the plurality of burners, and the arrangement of the plurality of nozzles with respect to each of the primary air suction ports of the plurality of burners is different between the plurality of burners. The technical means of achieving

Here, the plurality of nozzles may be arranged at different positions relative to the primary air suction ports of the plurality of burners, or the plurality of nozzles may be arranged with differences in the ejection direction relative to the primary air suction ports of the plurality of burners. can be granted.

[Operation] In the first aspect of the present invention, since each burner burns approximately the same amount, approximately the same amount of fuel is supplied to each nozzle. When fuel is supplied to the burner, primary air is sucked in by the force of the jet from the nozzle, and primary air is also simultaneously blown in by the blower. This amount of primary air is supplied to each burner in a set amount by an opening provided in a damper attached to the primary air suction port of each burner, corresponding to the primary air suction port of each burner. .

At this time, there is a difference in the amount of primary air supplied to each burner, and since different amounts of air are sucked in, each burner burns at a different air-fuel ratio in its flame hole. do.

Since each burner burns with a different air-fuel ratio during combustion, each burner burns with a different flame propagation speed.

In the second aspect of the present invention, the nozzle provided corresponding to the primary air suction port of each burner has a difference in relative position to the primary air suction port, or a difference in the fuel ejection direction with respect to the primary air suction port. As a result, a difference occurs in the amount of primary air relative to the fuel sucked from the primary air suction port of each burner.

Therefore, each burner burns at a different air-fuel ratio, and the flame propagation velocity is different for each burner.

[Effects of the Invention] In the present invention, since the flame propagation speed differs between burners, the frequency and phase of vibration due to combustion differ depending on the burner. As a result, vibrations due to combustion in each burner do not overlap and resonate, and oscillatory combustion does not occur.

[Example] Next, an example in which the forced air combustion device of the present invention is used in a high-load gas water heater will be described based on the drawings.

FIG. 1 shows a first embodiment of a high-load gas water heater with a reduced external size.

Water heater body 2 housed in water heater case 1
is composed of a supply section 10, a combustion section 20, and a burner section 30 that burns fuel and air from the supply section 10 in the combustion section 20.

The supply unit 10 includes a blower duct 12 equipped with a blower 11 and a fuel supply pipe 13 provided within the blower duct 12 .

The blower 11 is provided in communication with a blower duct 12 , takes in outside air from an air intake port (not shown) provided in the water heater case 1 , and supplies primary air and secondary air for combustion via the blower duct 12 . It is supplied to the burner section 30. A fuel supply pipe 13 is provided within the ventilation duct 12 . The fuel supply pipe 13 forms a manifold that branches fuel gas to be supplied, and is connected to a fuel supply section (not shown), and branches the fuel gas supplied from the fuel supply section to the burner section 30 for supply. Fuel gas supplied from the fuel supply pipe 13 is sucked in by the blower 11, mixed with air supplied through the blower duct 12, and sent to the burner section 30.

The combustion part 20 is a part where fuel gas is combusted, and a combustion chamber 22 is formed by a combustion duct 21. The combustion chamber 22 is provided with a heat exchanger 23 for supplying hot water. The heat exchanger 23 is a metal pipe connected to a water supply section (not shown), and uses the heat generated when the fuel gas is combusted by the burner section 30 to heat the water passing through the pipe and turn it into hot water. It is something. Above the combustion duct 21 forming the combustion chamber 22, there is an exhaust pipe 24 for discharging the burned combustion exhaust gas to the outside of the combustion duct 21.
is provided.

The burner section 30 constitutes the main part of the present invention,
As shown in FIGS. 2 and 3, the burner unit 30 of this embodiment includes a plurality of burners 40, a flame holding plate 50 and a burner bottom plate 60 that accommodate the plurality of burners 40 therein and form a burner case, and a burner bottom plate 60 that accommodates the plurality of burners 40 therein. The burner damper 70 is provided to set the amount of air supplied by the supply section 10 to the burner damper 40, and an ignition device 31 and a flame rod 32 are connected to a control device (not shown).

The ignition device 31 is a spark-type igniter, and when operated by an operation section (not shown), it can generate a spark between it and the burner 40 to ignite the igniter. The flame rod 32 uses an ignition sensor to confirm the ignition of the burner 40, and sends a signal to the control device to detect the ignition state.

The burner 40 is formed by folding a metal plate press-worked into a symmetrical shape along the center line of symmetry, and is adhered with high rigidity by welding.
An inlet 41 through which fuel gas and primary air supplied from the supply section 10 are introduced is provided at the bottom, and a burner head 43 consisting of a number of elongated flame holes 42 is provided at the top. The fuel gas and primary air introduced from the inlet 41, which is the primary air suction port of the present invention, are branched into two on the way to the burner head 43, and are split into two at the numerous flame holes 4 of the burner head 43.
It passes through an inlet passage 44 which is formed in communication again along 2 and is guided to the burner head 43. Introductory path 4
A wide fin-like part 45 is provided around the burner 4, and this fin-like part 45, together with the fin-like part 45 of the adjacent burner 40, forms a passage in order to stably guide the secondary air supplied from the supply part 10. Form. A protrusion 46 is formed on the bottom side of the fin-like portion 45 to stabilize the burner 40 when the burner portion 30 is assembled.

The flame stabilizing plate 50 has a U-shaped cross section and accommodates a plurality of burners 40 therein. A burner head 43 of each burner 40 is provided on the top surface 51 of the flame stabilizing plate 50.
A burner head fitting opening 52 for exposing the burner head to the outside of the flame holding plate 50, and a burner head fitting opening 52 for exposing secondary air to the outside of the flame holding plate 50, and
Secondary air supply ports 53 for supplying air to the air are alternately arranged in parallel at regular intervals. The burner head fitting port 52 is formed to match the shape of the burner head 43 in order to stabilize the burner head 43 in the direction in which the burner head fitting port 52 and the secondary air supply port 53 are arranged.
The same number of burners 40 are provided. The secondary air supply port 53 is provided to reliably supply secondary air to each flame hole 42 of the burner head 43, and is a long and narrow slit divided into two in the direction in which the numerous flame holes 42 are provided. It is formed into a shape and is provided between each burner head fitting opening 52 and on the outside of each of the burner head fitting openings 52 at both ends. Below the two side surfaces 54 of the flame stabilizing plate 50, stepped portions 55 slightly protruding outward are provided, and near the boundary 56 between the stepped portions 55 and the side surfaces 54, the burners 40 are arranged side by side. burner 4 along the direction
The same number of burner fixing holes 57 as zero are provided. These banner fixing holes 57 are provided to fit the protrusions 46 provided in each burner 40, and the protrusions 46 fitted in the burner fixing holes 57 are connected to the burner fixing holes 57. This makes it stable with respect to the direction in which the burners 40 are arranged side by side, and
Side surface 54 serving as one end of burner fixing hole 57
Movement in the direction of the top surface 51 is restricted and stabilized by the engaging portion.

The burner bottom plate 60 is made of metal in the shape of a flat box, and in the longitudinal direction of which each burner 40 is arranged side by side is an inlet 4.
A burner connection port 61 that fits into the burner head 43 connects secondary air to both sides of the burner connection port 61.
A secondary air inlet 62 for supplying air to the burner 40 is provided corresponding to each burner 40, respectively. The burner connection port 61 is provided with a fitting protrusion 63,
The inlet 41 of the burner 40 is fitted to the outside thereof, and the burner 40 is stabilized.

In the burner section 30, the burner 40 is fitted into the burner head fitting opening 52 and the fixing hole 57 of the flame stabilizing plate 50, and the burner 40 is fitted into the inlet 41 of the burner 40 and the burner bottom plate 60.
After the burner connection port 61 is fitted through the fitting protrusion 63, it passes through the mounting hole 58 provided in the flame holding plate 50 and is fixed to the screw hole 64 of the burner bottom plate 60 with a screw 65. .

Inside the burner bottom plate 60 is the supply section 10 described above.
A fuel supply pipe 13 and a burner damper 70 shown in FIGS. 4 and 5 are provided.

The burner damper 70 was originally provided to be able to change the amount of primary air to the burner 40 in accordance with the type of gas, but here it is devised to eliminate oscillating combustion, and is the primary air setting means of the present invention. . The burner damper 70 is provided with a plurality of through holes 71 as shown in FIG. 4, and the through holes 71 correspond to the burner connection ports 61 of the burner bottom plate 60, respectively. The through hole 71 has a large diameter port 71a and a small diameter port 7.
There are two diameters of different sizes of 1b, and the through hole 7
1, different amounts of primary air are supplied to the inlet ports 41 fitted with the respective burner connection ports 61. Further, the burner damper 70 is further provided with a fuel supply pipe 13 of the supply section 10 at a distance from the burner damper 70, as shown in FIG.
The fuel supply pipe 13 is provided with an inlet 41 of each burner 40 via each through-hole 71 of the burner damper 70.
A nozzle 14 is provided at a position corresponding to.
This nozzle 14 injects the same amount of fuel gas into each burner 40.
When the same amount of fuel gas is supplied from the nozzle 14 to the inlet 41, the diameter of each through-hole 71 of the burner damper 70 is increased by the suction force generated when ejecting from the nozzle 14 and the blower 11. An amount of secondary air corresponding to the amount of secondary air is simultaneously sucked and supplied to the inlet 41.

In this embodiment, each through hole 71 of the burner damper 70
As shown in FIG. 4, there are large diameter openings 71a at both ends.
are arranged, and small diameter openings 71b are arranged alternately toward the center, and a large number of large diameter openings 71a are again arranged in the center. This is because there tends to be a shortage of air in the center compared to the ends, so in order to compensate for the lack of air, a large amount of primary air is supplied in advance, making sure that sufficient air is supplied here. Therefore, the burner section 30 of this embodiment can generate a sufficient amount of heat. Also, by providing large diameter openings 71a at both ends, the frame rod 32
Flame detection at the ignition device 31 and ignition at the ignition device 31 are effectively performed. That is, on the flame rod 32 side, a large amount of primary air is provided so that the flame can change quickly in the event of an abnormality, allowing for faster flame detection, and on the ignition device 31 side, it is made easier to ignite.

In this embodiment, since combustion air is forcibly sent by the blower 11, the burner 40 is in the combustion chamber 22.
The flame is short, making it a relatively small, high-load combustor.

The high-load gas water heater of this embodiment having the above configuration operates as follows.

When the combustion device is operated by an operating means (not shown), the blower 11 of the supply section 10 is operated, air is supplied from the blower duct 12, and fuel gas is supplied from the fuel supply pipe 13 to each nozzle 14. The air and fuel gas are mixed and passed from the inlet 41 of each burner 40 through the inlet passage 44 and ejected from the flame hole 42 of the burner head 43. Further, from the secondary air inlet 62 of the burner bottom plate 60, the fin-shaped portion 4 of each burner 40 is connected.
Air is supplied to the burner head 43 through the secondary air supply port 53 of the flame stabilizing plate 50. The air-fuel mixture ejected from the flame hole 42 of the burner head 43 is ignited by the ignition device 31. At this time, the same amount of fuel gas is supplied to the inlet 41 of each burner 40, but different amounts of primary air are supplied depending on the diameter of each through-hole 71 of the burner damper 70. As a result, in each burner 40, the fuel gas mixed with the amount of air corresponding to the diameter of the through hole 71 is guided to the burner head 43, and the air-fuel mixture with a different air-fuel ratio is combusted for each burner 40. Become. Due to the different air/fuel ratios in the burner head 43, the flame propagation speed in each burner is different. Therefore,
Since the frequency of vibration caused by combustion is affected by this flame propagation speed, the frequency and phase of vibration in each burner 40 differ depending on the burner, and this means that the burner section 30 as a whole works to cancel out the vibration. . In this way, by varying the amount of primary air taken in from the inlet 41 by the burner damper 70, oscillatory combustion does not occur in the burner section 30 as a whole. Since the burner 40 whose primary air amount is limited by the burner damper 70 can be completely burned by the secondary air supplied from the primary air supply port 53, the burner 40 can only be used for fuel gas supplied from the nozzle 14. It is possible to secure a combustion amount corresponding to the amount of combustion, and it is possible to generate a sufficient amount of heat as a combustion device.

As described above, in the forced air combustion apparatus of the present invention, oscillatory combustion can be eliminated by varying the amount of primary air supplied to each burner.

In this embodiment, the burner damper has two types of diameters, but it is not necessarily necessary to use two types of diameters, and more types may be used. The arrangement is not limited to the arrangement shown in FIG. 4, but other arrangements may be used depending on the shape and size of the burner section 30 used to eliminate oscillatory combustion.

FIG. 7 shows a second embodiment.

In this embodiment, a burner damper is not provided, but a difference is made in the relative position between the inlet 41 of the burner 40 and the nozzle 14. As a means of making a difference in the relative position, the nozzle attachment part of the fuel supply pipe 13 is lengthened. Part 1
Fuel supply pipe 13 with two types: 3a and short part 13b
are using. Therefore, the amount of primary air sucked into the inlet 41 when fuel gas is ejected from each nozzle 14 is determined by the suction force generated by the ejection of the nozzle 14 fixed to the long part 13a and the amount fixed to the short part 13b. Since the suction force generated by the ejection from the nozzle 14 is different, the inlet 41 and the short portion 13 correspond to the long portion 13a.
It is different from the introduction port 41 corresponding to b. Therefore, since each burner 40 burns at a different air-fuel ratio, oscillatory combustion can be eliminated in the burner section 30 as a whole.

Another way to differentiate the relative positions is to make the nozzle attachment portions of the fuel supply pipes 13 the same and change the lengths of the nozzles 14 to be attached.

FIG. 8 shows a third embodiment.

Here, as a means of differentiating the amount of primary air to the inlet 41, the ejection angle is made different so that the ejection direction of the fuel gas from the nozzle 14 attached to the fuel supply pipe 13 is different for each nozzle. As a result,
As in the second embodiment, since the suction force due to the ejection of fuel gas differs for each nozzle 14, combustion occurs at a different air-fuel ratio for each burner 40, and therefore oscillatory combustion can be eliminated. In this case, it is not possible to set a very large angle, so it is best to keep it at about 5° to 10°.

In the second and third embodiments described above, a burner damper may be provided to limit the amount of primary air to the inlet 41 to some extent.

In addition, if burner management is not complicated, you can change the shape of the burner throat to change the amount of primary air sucked in, or change the shape of the burner to make it more in line with the inlet. The ratio may be changed to provide a difference in the amount of primary air sucked.

Further, the amount of primary air may be made different for each burner group. Furthermore, it is preferable to supply a burner with a reduced amount of primary air with a larger amount of secondary air than other burners, for example by changing the size of the secondary air supply port 53.

[Brief explanation of the drawing]

Figures 1 to 6 show the first embodiment, Figure 1 is a partial cross-sectional side view of the water heater, Figure 2 is a perspective view of the burner section, and Figure 3 is an exploded perspective view of the burner section. , FIG. 4 and FIG. 5 are a plan view and a side view showing the burner damper, FIG. 6 is a schematic sectional view showing the arrangement of the burner and nozzle, and FIG. 7 is a diagram showing the arrangement of the burner and nozzle of the second embodiment. FIG. 8 is a schematic cross-sectional view showing the arrangement of the burner and nozzle of the third embodiment. In the figure, 13... Fuel supply pipe, 14... Nozzle (multiple nozzles), 21... Combustion duct (combustor case), 22... Combustion chamber, 30... Burner section (forced air combustion device) , 40... Burner (plural burners), 41... Inlet port (primary air suction port), 7
0... Burner damper (damper), 71... Through hole (multiple openings).

Claims (1)

[Scope of Claims] 1. In a forced air combustion device in which a plurality of burners having the same shape are installed in a combustor case forming a combustion chamber, the same amount of fuel gas is supplied to each of the plurality of burners. A plurality of nozzles ejecting the air are provided in a fixed arrangement with respect to each of the primary air suction ports of the plurality of burners, and the area is smaller than each of the primary air suction ports corresponding to the position of each of the primary air suction ports of the plurality of burners. A forced air combustion device characterized in that a damper having a plurality of openings exhibiting the above is attached to the plurality of burners, and the area of the plurality of openings of the damper is made different among the plurality of burners. 2. In a forced air combustion device in which a plurality of burners having the same shape are installed together in a combustor case forming a combustion chamber, a plurality of nozzles eject the same amount of fuel gas to each of the plurality of burners. is provided corresponding to each primary air suction port of the plurality of burners, and the arrangement of the plurality of nozzles with respect to each primary air suction port of the plurality of burners is different among the plurality of burners. Forced air combustion equipment. 3. The forced air combustion apparatus according to claim 2, wherein the plurality of nozzles are arranged at different positions relative to the primary air suction ports of the plurality of burners. 4. The forced air combustion apparatus according to claim 2, wherein the plurality of nozzles have different jetting directions relative to the primary air suction ports of the plurality of burners.