JPH031585B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a domestic hot water heater using an all-primary premixing method, in which the entire amount of air required for combustion is supplied to the burner to supply fuel gas. Adopting an all-primary premixing system in which air is mixed with the fuel gas before supplying it, the air mixture is forcibly controlled by a centrifugal blower to achieve a smaller size and shorter flame.Furthermore, the heat resistance of the burner itself has been improved. Moreover, the present invention relates to an all-primary premixing type domestic water heater that is capable of increasing heat exchange capacity by obtaining a large amount of heat with a small installation area.

(Prior Art) Conventionally, combustion methods using gas as fuel can be broadly classified into a diffusion combustion method and a premix combustion method.

Among the diffusion combustion type devices, there is a so-called Bunsen burner, which is commonly used in home water heaters.

This Bunsen burner uses some combustion air,
For example, approximately half of the required amount of fuel gas is mixed in beforehand when supplying fuel gas to the burner, but since this is not enough air for combustion, the remaining combustion air is used as secondary air near the flame nozzle. This system takes in sufficient air to completely burn the fuel gas.

In addition, the premix combustion method, for example,
There is a gas instantaneous water heater proposed in Publication No. 60-146250.

When supplying fuel gas to the burner, this gas instantaneous water heater has a blower outlet near the supply nozzle of the gas supply pipe, which forcibly sends in combustion air to provide all necessary combustion air. This is an all-primary premixing system in which air is taken in during gas supply and sent to the flame port through a narrow mixer.

In addition, regardless of whether the diffusion combustion method or the premix combustion method is used, in the conventional case, the area around the flame nozzle becomes high in temperature due to the heat of the flame, so the flame nozzle itself must be made to have excellent heat resistance, and the flame In order to prevent heating of the so-called inner shell, which covers the space above the inner shell, a structure is adopted in which water pipes of a heat exchanger are arranged around the inner shell to cool it.

On the other hand, Japanese Utility Model Publication No. 56-50254 proposes a gas burner that generates a large amount of heat considering its installation area.

This gas burner has a semicircular belt-like flat plate with a large number of convex-shaped protrusions smaller than the width of the flat plate formed adjacent to each other such that the protrusions in the protrusions are positioned toward the inside of the semicircular belt-like flat plate. This is alternately combined with flat plates of the same shape that do not have the convex portions to form a flame generation part inside the semicircle, and a water cooling pipe is passed through each of these flat plates to prevent overheating. It is designed to be cooled to

(Problems to be solved by the invention) <Problems with the conventional technology> However, in the case of the diffusion combustion method, when the interval between the flame ports is narrowed, a portion where the flames overlap occurs, and there is no combustion in that portion. If the air is not used properly, incomplete combustion will occur, resulting in a very long flame. Therefore, the flame ports must be arranged at a certain distance from each other, so in order to ensure a certain amount of discharged gas to obtain a specified amount of heat, it is necessary to set the flame ports to a size below a certain limit. It is not possible to aim for Therefore, it has been almost impossible to make the device compact and generate a large amount of heat.

In addition, in this method, since the secondary air is dominated by diffusion, it is inevitable that the flame will become longer to some extent during the combustion stage, and this will not lead to a shorter flame.
Therefore, it is necessary to maintain a certain distance between the flame port and the heat exchanger, which is equal to or longer than the length of the flame.
This space had to be reserved as an essential space, which posed a major obstacle to miniaturization.

On the other hand, in the case of a premix combustion method, especially the type of gas instantaneous water heater mentioned above, the distance from the mixer to the flame opening is short, and the blower's air outlet is located near the supply nozzle of the gas supply pipe. Because of this, the combustion air and combustion gas are not sufficiently mixed at the distance from the supply nozzle to the flame nozzle, and in order to achieve good mixing, the mixer part must be made large. .

In reality, if we look at the conditions inside the mixer, the fuel gas from the supply nozzle flows straight toward the flame nozzle, so it is not sufficiently mixed with the combustion air. The fuel gas that reaches the part is supplied without being sufficiently mixed with combustion air. As a result, it is very difficult to achieve complete combustion under stable conditions, and as mentioned above, there is also the problem that the size of the mixer section increases.

In addition, regardless of whether the diffusion combustion method or the premix combustion method is used, in the conventional case, an inner shell is required, and the water pipes of the heat exchanger are arranged around it, so the width (thickness) of the inner shell is It also had the disadvantage of increasing the size of the entire system.

Furthermore, the gas burner disclosed in Publication of Utility Model Publication No. 56-50254 has a semicircular shape, so the fire generating area is large compared to the installation area, so the amount of heat generated is reduced due to the large number of flame openings. is large, and has excellent heat resistance because the water cooling pipe is passed through it. However, as mentioned above, the structure is complicated because it combines two types of flat plates and has water cooling pipes passing through it.
There were drawbacks that led to increased costs.

<Technical Issues> In view of the above-mentioned problems, the present invention dramatically improves the mixing of fuel gas and combustion air, thereby enabling complete combustion in a stable state and shortening the time. We aim to reduce the flame size and size, and also improve the heat resistance of the burner itself, and
It was created with the aim of increasing the heat exchange capacity by obtaining a large amount of heat with a small installation area, and also simplifying the structure so that it can be provided at a low cost.

[Structure of the Invention] (Means for Solving the Problems) This invention comprises a plurality of gas supply nozzles disposed upstream of an air intake portion of a centrifugal blower, and a plurality of gas supply nozzles disposed upstream of an air intake portion of a centrifugal blower; a concave flame outlet plate for gas combustion, in which the porous plate is curved to have a substantially U-shaped cross section, and the curved outside of the plate is directed toward the air outlet; placed between
A gas burner is formed with a distribution mixer section that appropriately disperses the air and fuel gas sent out from the air outlet while stirring and sends the mixed gas to the concave plate, and a water pipe is provided with a large number of fins in the shape of a brim. The heat exchangers arranged side by side are disposed opposite to the curved inner side of the concave gas combustion nozzle plate, and the portion of the fin facing the concave gas combustion nozzle plate is formed into a substantially U-shape of the concave plate. The above-mentioned problem is solved by correspondingly having a notch in a substantially inverted U shape and directly connecting the substantially U-shaped open end surface of the concave flame port plate for gas combustion to the fins to enable heat transfer.

(Function) A plurality of gas supply nozzles placed upstream of the air intake part of the centrifugal blower, and a concave gas combustion nozzle made of a porous plate placed beside the air outlet of the centrifugal blower. , a distribution mixer section disposed between the blower outlet and the concave gas combustion outlet plate, which appropriately disperses the air and fuel gas sent out from the blower outlet while stirring, and sends the mixed gas to the concave plate; A gas burner is formed by forming a gas burner, and at the blowing outlet, fuel gas and combustion air are sufficiently mixed and sent out due to the turbulence of the airflow during blowing by the impeller of the centrifugal blower, and the air for combustion is evenly distributed. At the same time, the mixed gas of fuel gas and combustion air is uniformly sent to all the holes of the concave flame port plate for gas combustion while being further mixed by the mixer section. Then, a concave burner outlet plate for gas combustion is formed by curving a porous plate into a substantially U-shaped cross section, and the outside of the curve is directed toward the air outlet to increase the area of the burner outlet surface to increase the calorie content. generate.

On the other hand, a heat exchanger in which a large number of fins are arranged side by side in a brim shape on a water pipe is disposed facing the curved inner side of the concave gas combustion port plate, and facing the concave gas combustion port plate of the fins. The part is cut out in an approximately inverted U-shape corresponding to the approximately U-shape of this concave plate to prevent the flame from directly welding to the fins, thereby eliminating burnout of the fins. By directly connecting the substantially U-shaped open end surface of the fin to the fin for heat transfer, the heat of the concave flame outlet plate for gas combustion can be dissipated to the fin.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

That is, reference numeral B shown in the figure is a domestic water heater, which is composed of a gas burner 1 and a heat exchanger 20.

The gas burner 1 includes a centrifugal blower 2,
It consists of a plurality of gas supply nozzles 3, a distribution mixer section 4, and a gas combustion outlet concave plate 5.

As shown in FIGS. 2 and 3, the centrifugal blower 2 includes a motor 6 disposed approximately in the center, rotates around the motor 6 itself by the driving force of this motor 6, and rotates in the direction of rotation. The impeller 7 is made of curved blades, and the rotating side surface of the impeller 7 surrounding these forms an air intake 8 as an air intake part, and the air outlet 9 is formed in the tangential direction to the rotation of the impeller 7. The casing 10 is arranged in a substantially snail shape, and the casing 10 is arranged in the form of a snail.

The air intake port 8 is provided upstream of the air intake portion, and in the illustrated example, there are five circular air intake ports 8, for example, the impeller 7 of the casing 10.
The rotating side surfaces are appropriately arranged in the circumferential direction. Note that the shape, arrangement, etc. of the air intake port 8 are not limited as long as it is provided upstream of the air intake portion.

In this way, the centrifugal blower 2 and the gas supply nozzle 3
By forming the
is a type that rotates with direct current, and even if sparks occur during rotation, fuel gas will never enter the motor 6 as long as the impeller 7 is rotating, and there is no fear of ignition. In addition, in the case of a DC type motor, since dust and the like are extremely disliked, the motor itself is sealed, so it can be said that there is no chance of a spark igniting the mixed gas containing the fuel gas. Furthermore, in the case of a type of motor that rotates on alternating current, sparks are rarely generated unless there is a malfunction, and even if the motor case is provided with ventilation holes (not shown) to prevent overheating, Since ventilation holes are provided only between the impeller and the outside (atmosphere), while the impeller 7 is rotating, there is a negative pressure behind the impeller 7, so the mixed gas motor There was no intrusion into any parts, and there was no ignition caused by sparks.

The air intake port 8 has a plurality of gas supply nozzles 3 formed by branching from the gas supply pipe 11, and five gas supply nozzles 3 are formed at the tip thereof.
They are inserted one by one. This gas supply nozzle 3
As shown in FIG. 4, an appropriate number of small nozzle holes 12 are bored on the circumferential surface of the tip portion, and as shown in FIG. It is formed so that In this way, by opening the small nozzle hole 12 in the gas supply nozzle 3, the combustion air and fuel gas can be mixed even better.

On the other hand, the concave flame outlet plate 5 for gas combustion is arranged above the air outlet 9 of the centrifugal blower 2, and has a plate thickness of 2 mm to 5 mm.
Small flame opening holes 13 are bored at small intervals in a rectangular metal plate, and the metal plate is curved into a substantially U-shape, with the curved outer surface 5a facing the side of the air outlet 9. has been done. Flange-like open end flanges 5c are formed laterally at both open ends of the concave flame port plate 5 for gas combustion, and the cross-sectional shape is an inverted hat shape. The thickness of the concave flame outlet plate 5 for gas combustion may be set to a length that allows the flame outlet small holes 13 to be cooled by the gas passing through the small holes 13 themselves. In other words, even if you do not use a thick plate of about 2 mm to 5 mm, for example, although not shown in the drawing, you can use a flame outlet made by applying a drawing process called burring to a thin plate and having a cylinder perpendicular to the thin plate. The cylinder may be formed into a small hole 13, and the length of the cylinder may be appropriately increased to enable cooling with gas, and the shape is not limited to this.

By forming the concave flame port plate 5 for gas combustion in this way, it is possible to install a greater number of flame ports than if the flame ports were simply arranged flat if the installation area was the same. As a result, the amount of fuel gas discharged increases accordingly, making it possible to obtain a gas burner with greater thermal power in the same area.

Then, the air outlet 9 and the concave flame outlet plate 5 for gas combustion.
The combustion air and fuel gas sent out from the air outlet 9 are mixed and dispersed as appropriate between the
A distribution mixer section 4 that uniformly sends the mixed gas to all the small holes 13 of the concave flame port plate 5 for gas combustion.
are arranged.

This distribution mixer section 4 is made up of a suitable number of dispersion plates 14 made of porous plates having a large number of small dispersion holes 15. In order to send the gas, the area from the air outlet 9 to the concave flame port plate 5 for gas combustion is disposed within the sealed outer wall 16. In this case, the number of dispersion plates 14 may be any number, but even if there is only one dispersion plate 14, the above-mentioned mixing and dispersion can be carried out sufficiently by appropriately changing the position, density, etc. of the small dispersion holes 15. In other words,
The structure of the distribution mixer section 4 is not limited to that described above as long as it is small.

On the other hand, the heat exchanger 20 is formed by arranging a large number of rectangular fins 22 in a flange-like manner on a water pipe 21, and the heat exchanger 20 is arranged to face the curved inner surface 5b of the concave flame port plate 5 for gas combustion. There is. Then, the portion of the fin 22 facing the concave gas combustion nozzle plate 5 is cut out in a substantially inverted U shape corresponding to the substantially U shape of the face plate 5 to form a cutout portion 23 . The uncut portion of the facing portions is defined as a connecting portion 24, and this connecting portion 24 and the upper surface of the open end flange 5c are directly connected to enable heat transfer. In this case, direct connection that allows heat transfer means that the connecting portion 24 and the open end flange 5c may be simply directly connected, or the fin 22 and the concave gas combustion nozzle plate 5 may be connected through a material with good heat transfer. may be concatenated. In other words, the main point is to release the heat of the concave gas combustion outlet plate 5 to the fins 22 to prevent the concave gas combustion outlet plate 5 from overheating.
Any connection state may be used as long as the heat can be used for heating water through heat exchange.

By forming the heat exchanger 20 in this way, and by curving the concave flame port plate 5 for gas combustion into a substantially U-shape, the flame 17 is directed to the open end of the concave flame plate 5 for gas combustion. Since the fins 22 are directly connected to the open end flange 5c, the flame 17 will not come into contact with the connected portion and cause burnout. Because the flame 17 from the concave gas combustion outlet plate 5 missed the position where the heating power was greatest, the fin 2
The burnout caused by No. 2 is completely eliminated.

[Effect of the invention] This invention configured as described above has a centrifugal blower 2.
A plurality of gas supply nozzles 3 are arranged on the upstream side of the air intake part, and the air outlet 9 of the centrifugal blower 2 is arranged on the side, and the porous plate is curved to have a substantially U-shaped cross section. A gas combustion flame outlet concave plate 5 with the curved outer side facing the air outlet 9, and a gas combustion flame outlet concave plate 5 disposed between the air outlet 9 and the gas combustion flame outlet concave plate 5, the air outlet 9
The air and fuel gas sent out from the concave plate 5 are appropriately dispersed while being stirred, and the mixed gas is then
By forming the gas burner 1 which consists of a distribution mixer part 4 which supplies gas to the air, since it is a centrifugal blower 2, there is a gas supply nozzle 3 upstream of the air intake part.
Even if the motor 6 is arranged, there is no fear that the fuel gas will be ignited by sparks generated during the rotation of the motor 6. Moreover, by providing the gas supply nozzle 3 upstream of the air intake part, all the air and fuel gas necessary for combustion are removed by the impeller 7 while the fuel gas reaches the air outlet 9. Stirred and mixed, air outlet 9
By the time the fuel has reached this point, the gas mixture has been sufficiently mixed and a stable fuel state can be obtained thereafter. Furthermore, in this case, since a plurality of gas supply nozzles 3 are provided, the fuel gas is supplied in a more dispersed manner, and mixing is performed more reliably.

Next to the air outlet 9 of the centrifugal blower 2,
A gas combustion outlet concave plate 5 formed of a porous plate is arranged, and the air outlet 9 and the gas combustion outlet concave plate 5 are arranged.
A distribution mixer section 4 is provided between the air outlet 9 and the combustion gas, which mixes and disperses the air and combustion gas as appropriate, and sends the mixed gas to the concave plate 5.
Since the gas mixture completely mixed as described above is further mixed and dispersed by the distribution mixer section 4, the small flame openings 1 of the concave flame opening plate 5 for gas combustion are mixed and dispersed.
Since it can be sent uniformly to 3, the concave flame outlet plate 5 for gas combustion
The flame 18 from
The flame becomes short as shown in the figure. As a result, the distance between the heat exchanger 17 and the concave flame port plate 5 for gas combustion can be extremely small, and the space for the flame, which was conventionally indispensable, can be extremely reduced. Moreover, since the mixed gas itself is completely mixed, no air is required on the surface of the concave flame port plate 5 for gas combustion. It is possible to arrange many flame ports in a small area without any problems, and it is possible to form a small and large-capacity burner.
Furthermore, since the mixed gas is almost completely mixed in advance, it is sufficient to shorten the distance through which the mixed gas passes through the distribution mixer section 4.
This allows for miniaturization in all aspects.

In addition, since the concave gas combustion outlet plate 5 is formed by curving a porous plate with a substantially U-shaped cross section, the flame outlets can be simply arranged flat if the installation area is the same. Compared to this, it is possible to install a larger number of flame ports, which increases the amount of fuel gas discharged, making it possible to obtain a gas burner with greater thermal power in the same area.

On the other hand, a heat exchanger 20 in which a large number of fins 22 are arranged side by side in a brim shape on a water pipe 21 is disposed facing the inside of the curve of the concave flame port plate 5 for gas combustion.
The portion facing the gas combustion nozzle concave plate 5 is cut out in an approximately inverted U shape corresponding to the approximately U shape of this concave plate 5, and the gas combustion nozzle concave plate 5 is opened in an approximately U shape. By directly connecting the end face and the fins 22 for heat transfer, the flame 17 in the gas combustion concave flame port plate 5 is directed inward and laterally as it goes toward the open end of the gas combustion flame concave plate 5. Even if the fins 22 are directly connected to this open end surface, the flame 17 will not melt and burn out the connected portion. Moreover, as mentioned above, since the structure is very compact and does not require an inner shell, there is no need to arrange water pipes around the inner shell as in the conventional case, and the fin 22 has a recessed flame opening for gas combustion. Since the face plate 5 is directly connected and formed to allow heat to escape, heating of the concave flame port plate 5 for gas combustion is prevented, and a product with excellent heat resistance and miniaturization can be obtained. Also, if you think about it the other way around, this structure can also be seen as the placement of a heat exchanger inside the inner shell, but it is much smaller than the conventional inner shell, and moreover, the fins 22 are As a result, the inner shell itself is reinforced, and no resonance noise is generated.

As explained above, according to the present invention, by dramatically improving the mixing of fuel gas and combustion air, complete combustion can be achieved in a stable state, resulting in shorter flame length and smaller size. Moreover, the heat resistance of the burner itself has been improved, the heat exchange capacity has been increased by making it possible to obtain a large amount of heat with a small installation area, and the structure has been simplified, so that it can be provided at a low cost. Compared to conventional home water heaters, this system offers a variety of effects that are far superior to other conventional home water heaters.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
The figure is a partially cutaway perspective view, Figure 2 is a front sectional view, Figure 3 is a side sectional view, Figure 4 is an enlarged sectional view of the gas supply nozzle, and Figure 5 shows the state of gas ejection in Figure 4. It is a sectional view taken along the line V-V. B...Home water heater, 1...Gas burner,
2...Centrifugal blower, 3...Gas supply nozzle, 4
...Distribution mixer section, 5... Gas combustion outlet concave plate, 5a... Curved outer surface, 5b... Curved inner surface,
5c...Open end flange, 6...Motor, 7...
...Impeller, 8...Air intake, 9...Blower outlet,
10...Casing, 11...Gas supply pipe, 12
... Nozzle small hole, 13 ... Burner mouth small hole, 14 ... Dispersion plate, 15 ... Dispersion small hole, 16 ... Outer wall, 17 ...
...Flame, 20...Heat exchanger, 21...Water pipe, 22
...Fin, 23...Notch, 24...Connection.

Claims (1)

[Claims] 1. A plurality of gas supply nozzles arranged on the upstream side of the air intake part of the centrifugal blower, and a plurality of gas supply nozzles arranged on the side of the air outlet of the centrifugal blower, and a porous plate having a substantially U-shaped cross section. a gas combustion flame outlet concave plate which is curved in a shape such that the curved outer side thereof faces the side of the air outlet, and a gas combustion flame outlet concave plate which is arranged between the air outlet and the gas combustion flame outlet concave plate, and the air is sent out from the air outlet. A gas burner is formed of a distributing mixer section that appropriately disperses and fuel gas while stirring and sends the mixed gas to the concave plate, and a heat exchanger that has a water pipe with a large number of fins arranged side by side in a brim shape. , disposed opposite to the curved inner side of the concave gas combustion nozzle plate, the portion of the fin facing the concave gas nozzle plate having an approximately inverted U shape corresponding to the approximately U shape of the concave plate. 1. A domestic water heater of an all-primary premixing type, characterized in that a substantially U-shaped open end face of a concave flame outlet plate for gas combustion is directly connected to a fin for heat transfer. 2. A centrifugal blower consists of a Sirotskov fan, which has a motor placed approximately in the center, an impeller that rotates around the motor due to the driving force of the motor, and an air intake part placed along the rotating side of the impeller. A domestic hot water supply device using an all-primary premixing method of the domestic hot water supply device according to claim 1. 3. The all-primary premixing type domestic water heater according to claim 1 or 2, wherein the distribution mixer section is formed of a porous plate.