JP7274255B2 - Water heater - Google Patents

Description

The present invention relates to a water heater that produces hot water by burning fuel gas with a burner housed in a combustion can.

Water heaters that generate hot water by burning fuel gas with a burner are widely used. This water heater houses a plurality of burners arranged side by side in one direction inside a case called a combustion can, and also houses a heat exchanger above it. has a structure in which a gas manifold is assembled. The gas manifold is for supplying fuel gas to multiple burners in the combustion can, and multiple gas nozzles are formed in the manifold body. When the manifold cover is attached to the manifold body, a fuel gas passage called a gas distribution passage is formed between the manifold body and the manifold cover. When fuel gas is supplied to the gas distribution passages of the gas manifold, the fuel gas is supplied to each burner from a plurality of gas nozzles formed in the manifold body. The burner burns the fuel gas to generate high-temperature combustion gas, and the heat exchanger exchanges heat between the combustion gas and water to produce hot water.

Also, the water heater is equipped with a spark plug for igniting the burner. When starting hot water supply, fuel gas is supplied to the plurality of burners while sparks are emitted from the ignition plug. Then, the burner near the ignition plug ignites first, the flame is transmitted to the adjacent burner, and the flame is further transmitted to the adjacent burner. Combustion is started.

However, if the ignition of the burners fails for some reason (for example, sparks are not properly emitted from the spark plugs), the fuel gas that has flowed out from all the burners will stay inside the combustion can. Therefore, when sparks are emitted from the spark plug again, a phenomenon (so-called explosive ignition) may occur in which the accumulated fuel gas is ignited explosively. Therefore, an obstacle wall is provided in the gas distribution passage in the gas manifold, and when the supply of fuel gas is started, the gas nozzles on the back side of the obstacle wall lag behind the gas nozzles on the front side of the obstacle wall. A technique for preventing explosion ignition by supplying fuel gas has been proposed (Patent Document 1). In this proposed technique, the gas nozzles on the front side of the obstacle wall start supplying fuel gas to the burner at an earlier timing than the gas nozzles on the back side of the obstacle wall, so the fuel gas is supplied from the gas nozzles on the front side. Ignite the burner. In this way, even if the ignition fails, the burner to which the fuel gas is supplied from the gas nozzle on the far side still does not flow out fuel gas, or only a small amount of fuel gas flows out, so that the burner can be ignited again. It is possible to avoid the occurrence of explosive ignition.

JP 2019-020037 A

However, the proposed technique has a problem that the assembling workability when assembling the manifold cover to the manifold body of the gas manifold is deteriorated. The reason for this is as follows. When assembling the manifold cover to the manifold body, a sealing member is interposed between the manifold body and the manifold cover, and the sealing member is assembled in a compressed state. At this time, if there is an obstruction wall in the gas distribution passage, the seal member is compressed even at the obstruction wall, so the compressed area of the seal member increases, and the reaction force received from the seal member increases. do. As a result, the force required to assemble the manifold cover to the manifold body is increased.

The present invention has been made to solve the above-mentioned problems in the prior art, and while it is possible to avoid the occurrence of explosive ignition, it also reduces the workability when assembling a manifold cover to a manifold body of a gas manifold. To provide a water heater which does not cause a problem.

In order to solve the above problems, the first water heater of the present invention employs the following configuration. i.e.
a combustion can containing a plurality of burners for combusting fuel gas arranged in one direction; A gas manifold formed with gas nozzles, a spark plug for igniting the fuel gas flowing out from the burners, and a combustion gas generated by the combustion of the fuel gas by the plurality of burners and water are heat-exchanged. a heat exchanger for producing hot water;
The plurality of burners include:
an ignited burner ignited by the spark plug;
a flame transfer ignition burner that is ignited by the flames of the adjacent burners being transferred, and
The gas manifold is
a gas distribution passage extending in the direction in which the plurality of burners are arranged and distributing the fuel gas to the plurality of gas nozzles arranged in a row;
a gas supply passage connected to the gas distribution passage for supplying the fuel gas to the gas distribution passage;
The plurality of gas nozzles formed in rows are
an ignition position nozzle array composed of a predetermined plurality of gas nozzles including gas nozzles for supplying the fuel gas to the burner to be ignited;
and a residual nozzle row composed of the gas nozzles remaining after removing the ignition position nozzle row from the plurality of gas nozzles,
The gas supply passage of the gas manifold is connected to the gas distribution passage at a portion where the ignition position nozzle row is formed,
The gas manifold is
a manifold body in which the plurality of gas nozzles are formed;
a manifold cover that is assembled to the manifold body to form the gas distribution passage between itself and the manifold body;
a sealing member that is interposed between the manifold cover and the manifold body to seal the fuel gas in the gas distribution passage at an outer peripheral portion of the gas distribution passage, wherein
At least one of the manifold main body and the manifold cover is formed with a passage groove in which the gas distribution passage is formed by assembling the other manifold main body or the manifold cover,
The fuel gas supplied from the gas supply passage passes through the remaining nozzles between the gas distribution passage in the portion where the ignition position nozzle row exists and the gas distribution passage in the portion where the residual nozzle row exists. a distribution delay wall for delaying the distribution into the rows protruding from the side wall of the channel groove;
The amount of compression of the sealing member is smaller at the portion of the distribution delay wall than at the outer peripheral portion of the gas distribution passage.

In the first water heater of the present invention, the fuel gas supplied to the gas manifold is distributed from the gas supply passage of the gas manifold through the gas distribution passage to the plurality of gas nozzles, and then to the corresponding burners from the gas nozzles. It is designed to erupt toward the target. A distribution delay wall is provided in the middle of the gas distribution passage, and a plurality of gas nozzles (gas nozzles of the residual nozzle array) formed downstream of the distribution delay wall have gas nozzles formed upstream of the distribution delay wall. The fuel gas from the gas supply passage is distributed later than the plurality of gas nozzles (the gas nozzles in the ignition position nozzle row). The spark plug ignites the burner to which the fuel gas is supplied from the gas nozzles in the ignition position nozzle row. A gas manifold is formed by assembling a manifold cover to a manifold body, and gas distribution passages are formed by assembling at least one of the manifold body and the manifold cover with the other manifold body or the manifold cover. passage grooves are formed. Further, a seal member is interposed between the manifold body and the manifold cover to seal the fuel gas at the outer peripheral portion of the gas distribution passage. The amount of compression of the seal member is smaller at the portion of the distribution delay wall than at the outer peripheral portion of the gas distribution passage.

In this way, when the water heater is ignited, the ignition plug ignites the burner to which the fuel gas is supplied from the gas nozzle upstream of the distribution delay wall (the gas nozzle in the ignition position nozzle row) to start combustion. When the flame spreads to the burners supplied with the fuel gas from the gas nozzles downstream of the distribution delay wall (the gas nozzles of the residual nozzle row), these burners also start combustion. Therefore, even if ignition fails for some reason, the fuel gas has not yet flowed out from the burners corresponding to the gas nozzles downstream of the distribution delay wall, so a large amount of fuel gas remains inside the combustion can. never As a result, when the ignition plug reignites, it is possible to avoid the occurrence of explosive ignition due to the sudden ignition of a large amount of fuel gas stagnating inside the combustion can. In addition, the amount of compression of the seal member interposed between the manifold body and the manifold cover to seal the fuel gas is greater at the distribution delay wall portion than at the outer peripheral portion of the gas distribution passage. quantity is smaller. Therefore, when the manifold cover is assembled to the manifold body with the seal member interposed therebetween, the reaction force due to the compression of the seal member at the portion of the distribution delay wall can be reduced. As a result, it is possible to suppress an increase in the force required to assemble the manifold cover, thereby avoiding deterioration in assembling workability.

Moreover, in order to solve the above-described problems, the second water heater of the present invention employs the following configuration. i.e.
a combustion can containing a plurality of burners for combusting fuel gas arranged in one direction; A gas manifold formed with gas nozzles, a spark plug for igniting the fuel gas flowing out from the burners, and a combustion gas generated by the combustion of the fuel gas by the plurality of burners and water are heat-exchanged. a heat exchanger for producing hot water;
The plurality of burners include:
an ignited burner ignited by the spark plug;
a flame transfer ignition burner that is ignited by the flames of the adjacent burners being transferred, and
The gas manifold is
a gas distribution passage extending in the direction in which the plurality of burners are arranged and distributing the fuel gas to the plurality of gas nozzles arranged in a row;
a gas supply passage connected to the gas distribution passage for supplying the fuel gas to the gas distribution passage;
The plurality of gas nozzles formed in rows are
an ignition position nozzle array composed of a predetermined plurality of gas nozzles including gas nozzles for supplying the fuel gas to the burner to be ignited;
and a residual nozzle row composed of the gas nozzles remaining after removing the ignition position nozzle row from the plurality of gas nozzles,
The gas supply passage of the gas manifold is connected to the gas distribution passage at a portion where the ignition position nozzle row is formed,
The gas manifold is
a manifold body in which the plurality of gas nozzles are formed;
a manifold cover that is assembled to the manifold body to form the gas distribution passage between itself and the manifold body;
a sealing member that is interposed between the manifold cover and the manifold body to seal the fuel gas in the gas distribution passage at an outer peripheral portion of the gas distribution passage, wherein
At least one of the manifold main body and the manifold cover is provided with a passage groove in which the gas distribution passage and the gas supply passage are formed by assembling the other manifold main body or the manifold cover,
Between the passage groove where the gas distribution passage is formed and the passage groove where the gas supply passage is formed, the fuel gas supplied from the gas supply passage passes through the residual nozzle. a distribution delay wall for delaying the distribution into the rows protruding from the side wall of the channel groove;
The amount of compression of the sealing member is smaller in the portion of the distribution delay wall than in the amount of compression in the outer peripheral portions of the gas distribution passage and the gas supply passage. .

In the second water heater of the present invention, similarly to the first water heater described above, a distribution delay wall is formed in the gas manifold. It has a function of delaying the timing at which the fuel gas is supplied to the remaining nozzle rows of the gas distribution passages relative to the timing at which the fuel gas is supplied to the rows. Therefore, even if ignition fails for some reason, the fuel gas has not yet flowed out from the burner to which the fuel gas is supplied from the gas nozzles to which the fuel gas is supplied with a delay (that is, the gas nozzles of the remaining gas nozzle row). Or, even if it flows out, it is only a small amount, so a large amount of fuel gas will not stay inside the combustion can. As a result, when the ignition plug reignites, it is possible to avoid the occurrence of explosive ignition due to the sudden ignition of a large amount of fuel gas stagnating inside the combustion can. Further, the amount of compression of the seal member is smaller at the portion of the distribution delay wall than at the outer peripheral portions of the gas distribution passage and the gas supply passage. Therefore, when the manifold cover is assembled to the manifold body, the reaction force caused by compressing the seal member at the distribution delay wall portion can be reduced, so that the workability of assembling the manifold cover can be avoided. becomes possible.

Further, in the above-described first or second water heater of the present invention, the amount of compression of the seal member may be zero at the position of the distribution delay wall.

In this way, when the manifold cover is assembled to the manifold main body, no reaction force is generated at the distribution delay wall portion, so that it is possible to avoid deterioration of workability in assembling the manifold cover.

Further, in the water heater of the present invention described above, a passage groove may be formed in at least the manifold body, and a seal surface against which a seal member is pressed by the manifold cover may be formed on the outer peripheral portion of the passage groove. Then, the end face of the distribution delay wall on the manifold cover side may be formed at a position recessed further into the passage groove than the seal face.

In this way, the amount of compression of the seal member at the distribution delay wall portion can be made smaller than the amount of compression of the seal member at the seal surface, thereby avoiding deterioration in workability of assembling the manifold cover. becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which showed the rough structure of the water heater 1 of a present Example. FIG. 2 is an explanatory diagram showing a rough structure of a gas manifold 10 and a burner 3 mounted on the water heater 1 of this embodiment; 3 is an explanatory diagram showing the shape of gas nozzles 15 formed in a manifold body 11 of the gas manifold 10. FIG. FIG. 4 is an explanatory diagram of the detailed shape of the manifold body 11 of the embodiment; FIG. 3 is an explanatory diagram of the flow of fuel gas inside the gas manifold 10 of the present embodiment; FIG. 5 is an explanatory diagram of the reason why it is possible to avoid the occurrence of explosion ignition in the water heater 1 of the present embodiment; FIG. 4 is an enlarged sectional view showing the positional relationship between the sealing surface 11c of the manifold body 11 and the end surface 16a of the projecting wall 16; FIG. 11 is an explanatory diagram showing a mode in which the end surface 16a of the projecting wall 16 is inclined so that the end surface 16a of the projecting wall 16 and the sealing surface 11c of the manifold body 11 are continuous. FIG. 5 is an explanatory diagram of a manifold body 11, a seal member 13, and a manifold cover 12 of a modification;

FIG. 1 is an explanatory diagram showing the rough structure of the water heater 1 of this embodiment. As shown in the figure, the water heater 1 houses a heat exchanger 5 and a plurality of burners 3, which will be described later, inside a large rectangular combustion can 2, and a gas manifold on the side of the combustion can 2. 10, a spark plug 7 and a flame detector 8 are attached, and a combustion fan 4 is attached below the combustion can 2. When fuel gas is supplied to the gas manifold 10 from a gas pipe (not shown), the fuel gas passes through the inside of the gas manifold 10 and is distributed to the plurality of burners 3 . Further, when the combustion fan 4 is rotated, combustion air required for combustion of the fuel gas is supplied to the inside of the combustion can 2 . Further, the fuel gas can be ignited by shooting a spark from the ignition plug 7, and the flame generated by the ignition of the fuel gas can be detected by the flame detector 8. Therefore, if the flame is not detected by the flame detector 8 in spite of the fact that the spark from the ignition plug 7 is emitted, it is considered that the ignition has failed for some reason, so the spark is emitted from the ignition plug 7 again. Re-ignite by

The high-temperature combustion gas generated by burning the fuel gas in this manner passes through the heat exchanger 5 and is discharged to the outside from the exhaust port 6 provided in the upper portion of the combustion can 2 . The heat exchanger 5 has a structure in which a plurality of metal fins are attached to the outside of a meandering metal pipe, and water flows inside the metal pipe. The high-temperature combustion gas passes through a plurality of metal fins, and at this time, heat is exchanged with water flowing inside the metal pipe to generate hot water.

FIG. 2 is an explanatory diagram showing the shape of a plurality of burners 3 housed inside the combustion can 2 and the internal structure of the gas manifold 10. As shown in FIG. Each burner 3 is formed in a flat and elongated shape, and is mainly formed by combining two sheet metal members facing each other. At one end of the burner 3, two sheet metal members face each other and an opening 3a is formed. A plurality of flame ports 3b are formed by being sintered. Sheet metal members face each other to form a mixing passage 3c between the upper end side where the plurality of flame ports 3b are formed and the opening 3a on the one end side. Inside the combustion can 2, a plurality of such burners 3 are housed in a state of being arranged in one direction. In FIG. 2, for convenience of illustration, some of the burners 3 (the six burners 3 shown on the right side of the drawing) are shown before they are arranged.

The gas manifold 10 includes a die-cast manifold body 11 made of a material such as aluminum and a sheet metal manifold cover 12, which are screwed together with a plurality of mounting screws 14 with a seal member 13 sandwiched therebetween. It has a structure. The manifold body 11 is formed with gas distribution passage grooves 11a extending in the direction in which the plurality of burners 3 are arranged (horizontal direction in FIG. 2). 11b are connected. The gas distribution passage groove 11a and the gas supply passage groove 11b of this embodiment correspond to the "passage groove" of the present invention. Furthermore, a flat sealing surface 11c is formed on the outer peripheral portions of the gas distribution passage groove 11a and the gas supply passage groove 11b.

By assembling the manifold cover 12 to the manifold body 11 with the sealing member 13 interposed therebetween, the gas distribution passage 10a is formed by the gas distribution passage groove 11a and the manifold cover 12, and the gas supply passage groove 11b is formed. and the manifold cover 12 form a gas supply passage 10b. The fuel gas is supplied to the lower part of the gas supply passage 10b from a gas pipe (not shown), and the supplied fuel gas rises up the gas supply passage 10b and reaches the gas distribution passage 10a. It flows within 10a. A plurality of gas nozzles 15 are formed on the manifold body 11 side of the gas distribution passage 10a (that is, the gas distribution passage groove 11a).

FIG. 3 is an explanatory view showing the shape of the gas nozzles 15 projecting from the manifold body 11 when the manifold body 11 of the gas manifold 10 is viewed from the burner 3 side. As shown in the figure, a plurality of gas nozzles 15 protrude in a row on the burner 3 side of the manifold body 11 . These gas nozzles 15 are formed in the same number as the number of burners 3 arranged in one direction at the same intervals as the intervals between the burners 3, and the positions where the respective gas nozzles 15 are formed correspond to each other. This is the position where the opening 3a of the burner 3 opens. The gas nozzle 15 has a roughly conical shape with a flat top, and a nozzle hole 15n penetrating to the gas distribution passage 10a is bored in the center of the flat top. Therefore, the fuel gas that has flowed into the gas distribution passage 10a is ejected from the nozzle hole 15n of the gas nozzle 15 toward the opening 3a of the burner 3. As shown in FIG. The fuel gas ejected from the gas nozzle 15 flows into the opening 3a of the burner 3 while entraining surrounding air.

As described above with reference to FIG. 2, the opening 3a of the burner 3 is connected to the mixing passage 3c, and the fuel gas and air flowing in from the opening 3a mix when passing through the mixing passage 3c. It flows out from a plurality of flame ports 3b formed at the upper end of the burner 3. Furthermore, since an ignition plug 7 is provided above the burners 3 (see FIG. 2), some of the plurality of burners 3 can be ignited by shooting sparks from the ignition plug 7. can. If a part of the burners 3 can be ignited, the flames of the burners 3 successively spread to adjacent burners 3, so that all the burners 3 start combustion. As is clear from the above description, among the plurality of burners 3, there are burners 3 that are ignited by sparks from the spark plug 7 and burners 3 that are ignited by flames of adjacent burners 3 igniting. exists. When it is necessary to distinguish between them, the former burner 3 is referred to as a "burner to be ignited" and the latter burner 3 is referred to as a "fire transfer ignition burner".

Also, even if sparks are emitted from the ignition plug 7, there may be cases where the burner 3 cannot be ignited for some reason. In order to detect such a case, a flame detector 8 is provided to detect flames. If flames are not detected by the flame detector 8, it is determined that the ignition has failed and the ignition is ignited again. Attempt to reignite by shooting a spark from plug 7 . As a result, if the burner 3 can be ignited, the flame of the burner 3 spreads to adjacent burners 3 one after another, so that all the burners 3 can start combustion. However, in a water heater that does not take any special measures, when the ignition plug 7 re-ignites, the fuel gas remaining in the combustion can 2 may ignite explosively, causing explosive ignition. Therefore, in the water heater 1 of this embodiment, the shape of the manifold body 11 is devised to avoid the occurrence of explosive ignition.

FIG. 4 is an explanatory diagram showing the detailed shape of the manifold body 11 of this embodiment. As shown in the figure, the manifold body 11 of this embodiment is formed with gas distribution passage grooves 11a extending in the left-right direction in the drawing, and gas supply passage grooves 11b connected across the gas distribution passage grooves 11a. It is A flat seal surface 11c is formed on the outer peripheral portion of the gas distribution passage groove 11a and the gas supply passage groove 11b. A plurality of gas nozzles 15 are formed. A projecting wall 16 is formed from the side wall of the gas distribution passage groove 11a so as to narrow the width of the groove. The projecting walls 16 are formed at two locations, so that the gas distribution passage groove 11 a is divided into three regions by the two projecting walls 16 . The gas supply passage groove 11b is connected to the central gas distribution passage groove 11a among the three divided gas distribution passage grooves 11a. Further, as the gas distribution passage groove 11a is divided into three regions, the plurality of gas nozzles 15 formed in the gas distribution passage groove 11a are also divided into three groups. Hereinafter, among the plurality of gas nozzles 15, the gas nozzle 15 formed in the central gas distribution passage groove 11a (sandwiched between the two projecting walls 16) will be referred to as a "confluence portion gas nozzle 15f". The gas nozzle 15 formed in the gas distribution passage groove 11a on the far side is sometimes referred to as "the far side gas nozzle 15s".

The projecting wall 16 of this embodiment corresponds to the "distribution delay wall" of the present invention. Further, the nozzle row formed by the confluence gas nozzles 15f corresponds to the "ignition position nozzle row" of the present invention, and the nozzle row formed by the back side gas nozzles 15s corresponds to the "residual nozzle row" of the present invention. . In the above-described embodiment, the manifold main body 11 is formed with the gas distribution passage grooves 11a and the gas supply passage grooves 11b. 10b are integrated into the gas manifold 10, but the gas distribution passage 10a and the gas supply passage 10b may be formed separately. For example, the gas distribution passage 10a is formed in the gas manifold 10 by attaching the manifold cover 12 to the manifold body 11 in which the gas distribution passage groove 11a is formed but the gas supply passage groove 11b is not formed, The gas manifold 10 may be formed by connecting a gas supply passage 10b formed of a pipe member or the like to the gas distribution passage 10a.

FIG. 5 is an explanatory view conceptually showing the flow of fuel gas supplied from the gas supply passage 10b to the gas distribution passage 10a. 5, illustration of the manifold cover 12 and the seal member 13 is omitted. The thick dashed arrows shown in the figure represent the flow of the fuel gas. As shown in the figure, the fuel gas flows into the gas supply passage 10b from a gas inlet 11d opening downward in the gas supply passage 10b, passes through the gas supply passage 10b, and joins the gas distribution passage 10a. After joining the gas distribution passage 10a, the gas is divided into left and right and flows through the gas distribution passage 10a. Therefore, the fuel gas flows around the protruding wall 16, and the gas nozzle 15 (that is, the gas nozzle 15s on the far side) on the far side of the protruding wall 16 is equipped with the gas nozzle 15 (the gas nozzle on the front side of the protruding wall 16). That is, the fuel gas is supplied later than the confluence gas nozzle 15f). By doing so, it is possible to avoid the occurrence of explosive ignition for the following reasons.

FIG. 6 is an explanatory diagram showing how the water heater 1 of this embodiment starts combustion. When igniting the burner 3, the combustion fan 4 is rotated to supply combustion air into the combustion can 2, and furthermore, the ignition plug 7 is attached to the inlet of the gas manifold 10 in a state in which sparks are emitted. By opening the gas control valve 9, the supply of fuel gas is started. In FIG. 6(a), the hatched portion represents the area where the fuel gas exists.

The fuel gas spreads in the gas distribution passage 10a, but since the gas manifold 10 of this embodiment is provided with the protruding wall 16 in the gas distributing passage 10a, the fuel is Gas distribution is delayed. Therefore, the fuel gas is discharged from the gas nozzles 15 existing between the left and right projecting walls 16 (that is, the confluence gas nozzles 15f) before the gas nozzles 15 that exist on the back side of the projecting walls 16 (that is, the back-side gas nozzles 15s). After being ejected and supplied to the corresponding burner 3, it flows out from the burner 3. In FIG. 6(b), the portion where the fuel gas ejected from the confluence gas nozzle 15f exists is indicated by hatching.

The burners 3 to which the fuel gas is supplied from the confluence gas nozzle 15f also include burners 3f to be ignited by the spark plugs 7. As shown in FIG. Therefore, the ignited burner 3f can be ignited by shooting a spark from the ignition plug 7. FIG. The flame transfer ignition burner 3s can be ignited from the ignited burner 3f, and the flame can be transferred to the flame transfer ignition burner 3s to which the fuel gas is supplied from the confluence gas nozzle 15f. As a result, as shown in FIG. 6(c), first, the burner 3 to which the fuel gas is supplied from the confluence gas nozzle 15f starts combustion. The burners 3 to which the fuel gas is supplied from the confluence gas nozzle 15f include the burners 3 whose flame detectors 8 detect flames. Therefore, when combustion starts in the burner 3 to which the fuel gas is supplied from the confluence gas nozzle 15f, the flame detector 8 detects the flame. Hereinafter, the burner 3 to which the fuel gas is supplied from the confluence gas nozzle 15f is simply referred to as the ``confluence burner 3'', and the burner 3 to which the fuel gas is supplied from the rear gas nozzle 15s is referred to as It may simply be referred to as "back side burner 3".

Further, the fuel gas is supplied to the gas nozzle 15 (that is, the depth side gas nozzle 15s) located on the depth side of the projecting wall 16 with a delay from the confluence portion gas nozzle 15f. Therefore, even if combustion is started by the burner 3 in the confluence portion (the burner 3 to which the fuel gas is supplied from the confluence portion gas nozzle 15f), the burner 3 on the back side (the burner 3 to which the fuel gas is supplied from the back side gas nozzle 15s) ) does not spread immediately (see FIG. 6(c)). However, the fuel gas supplied from the back gas nozzle 15s eventually flows out from the burner 3 on the back side, and the flame spreads to the fuel gas. Combustion will start at 3.

Further, since the fuel gas flows out from the burner 3 on the far side later than the burner 3 at the confluence, the burner 3 at the confluence cannot be ignited even if the spark is emitted from the spark plug 7. , the fuel gas has not yet flowed out from the burner 3 on the far side, or if it has flowed out, it is only a small amount. Therefore, when the ignition plug 7 sparks again, the amount of the fuel gas present in the combustion can 2 is suppressed, so the fuel gas is ignited without explosive ignition and the water heater 1 starts burning. becomes possible.

However, when the projecting wall 16 is formed in the gas distribution passage 10a of the gas manifold 10, there is a problem that the assembling workability when assembling the manifold cover 12 to the manifold body 11 is deteriorated. The reason for this is as follows. As described above with reference to FIG. 2, the manifold cover 12 is attached to the manifold body 11 with the seal member 13 interposed therebetween. The seal member 13 is strongly compressed by the manifold cover 12 at the seal surface 11c portion of the manifold body 11, thereby sealing the fuel gas in the gas distribution passage 10a from leaking to the outside. Here, if the protruding wall 16 protrudes in the gas distribution passage 10a, the sealing member 13 is compressed not only at the sealing surface 11c but also at the protruding wall 16, and the sealing member 13 is compressed. compression area increases. As a result, it is necessary to assemble the manifold cover 12 to the manifold main body 11 with a greater force in order to secure the sealing pressure on the sealing surface 11c, resulting in a decrease in assembling workability.

Therefore, in the water heater 1 of the present embodiment, the end surface 16a of the projecting wall 16 formed in the gas distribution passage groove 11a of the manifold body 11 faces the sealing surface 11c of the manifold body 11, and the groove bottom of the gas distribution passage groove 11a. It is formed in a state of being retracted to the side. FIG. 7(a) is a cross-sectional view of the manifold body 11 cut at the position of the projecting wall 16 (the position of the AA cross section in FIG. 5). As shown, the protruding wall 16 protrudes from the side wall 11e of the gas distribution passage groove 11a, and the end surface 16a of the protruding wall 16 is located at a distance dh from the sealing surface 11c of the manifold body 11. It is recessed to the groove bottom side of the distribution passage groove 11a. 7(b), when the manifold cover 12 and the seal member 13 are assembled to the manifold main body 11 with the mounting screws 14, the amount of compression of the seal member 13 at the seal surface 11c is reduced. , the amount of compression at the end surface 16a of the projecting wall 16 can be reduced. Further, if the distance dh by which the end face 16a of the projecting wall 16 is retracted with respect to the sealing surface 11c is set equal to or greater than the amount of compression of the sealing member 13 at the sealing surface 11c, the end face 16a of the projecting wall 16 The amount of compression can also be zero. If the amount of compression of the seal member 13 is reduced, the reaction force received from the seal member 13 when the manifold cover 12 is assembled is also reduced (when the amount of compression is zero, the reaction force is also zero). It is possible to avoid deterioration of workability when assembling 12 .

In the example shown in FIG. 7, the end face 16a of the projecting wall 16 is formed at a position one step lower than the sealing face 11c of the manifold body 11. As shown in FIG. Accordingly, there is a step at the portion where the end surface 16a of the projecting wall 16 and the sealing surface 11c of the manifold body 11 are connected. However, as illustrated in FIG. 8, the end surface 16a of the projecting wall 16 may be formed obliquely so as to continue from the sealing surface 11c of the manifold body 11. As shown in FIG. Even in this case, the amount of compression of the seal member 13 at the end surface 16a of the protruding wall 16 is reduced, so that the reaction force to the manifold cover 12 can be suppressed. It is possible to avoid.

In the above-described embodiment, the protruding wall 16 is assumed to protrude into the gas distribution passage 10a (see FIG. 4, for example). However, the protruding wall 16 does not necessarily have to protrude into the gas distribution passage 10a. For example, when the gas supply passage 10b merges obliquely with the gas distribution passage 10a, the projecting wall 16 may be provided at the point where the gas supply passage 10b and the gas distribution passage 10a merge.

FIG. 9 is an explanatory view of a modified example in which a projecting wall 16 is provided at a location where the gas supply passage 10b and the gas distribution passage 10a meet. FIG. 9(a) illustrates a modified manifold body 11, FIG. 9(b) illustrates a modified sealing member 13, and FIG. 9(c) illustrates a modified manifold cover 12. ing. As shown in FIG. 9(a), the manifold body 11 is formed with gas distribution passage grooves 11a in the horizontal direction in the drawing, and a plurality of gas nozzles 15 are formed in the gas distribution passage grooves 11a. there is In the example shown in FIG. 9A, the gas nozzles 15 are formed in two rows, but the two rows are not necessarily required, and one row may be used.

The gas supply passage groove 11b is connected to the gas distribution passage groove 11a obliquely from below (from the lower left to the upper right in the drawing). A protruding wall 16 is provided on the side wall 11e where the gas supply passage groove 11b and the gas distribution passage groove 11a meet. In the drawing, the end face 16a of the protruding wall 16 is indicated with diagonal lines. Furthermore, a seal surface 11c is formed on the outer peripheral portions of the gas distribution passage groove 11a and the gas supply passage groove 11b.

The manifold cover 12 illustrated in FIG. 9C is assembled to the manifold main body 11 of such a modified example with the seal member 13 illustrated in FIG. 9B sandwiched therebetween. Then, the gas distribution passage 10a is formed in the portion of the gas distribution passage groove 11a, and the gas supply passage 10b is formed in the portion of the gas supply passage groove 11b. Even in the water heater 1 of such a modified example, it is possible to prevent the occurrence of explosion ignition for the following reasons.

First, as shown in FIG. 9A, the gas supply passage 10b joins the gas distribution passage 10a obliquely upward to the right. Therefore, the fuel gas that has flowed into the gas distribution passage 10a flows more easily in the right direction than in the left direction in the gas distribution passage 10a. Further, a protruding wall 16 protrudes from the side wall 11e on the left side of the portion where the gas supply passage 10b joins the gas distribution passage 10a. Therefore, in order for the fuel gas that has flowed into the gas distribution passage 10a to flow leftward in the gas distribution passage 10a, it is necessary not only to bypass the projecting wall 16 but also to change the flow direction at an acute angle. As a result, the fuel gas is rapidly supplied to the portion where the gas supply passage 10b joins the gas distribution passage 10a and to the gas nozzle 15 formed on the right side of the junction. The gas is supplied to the gas nozzle 15 on the left side later than the part where it merges with 10a. That is, in the gas manifold 10 of the modified example, the gas nozzles 15 formed at the portion where the gas supply passages 10b join the gas distribution passages 10a and the gas nozzles 15 formed at the right side of the joining portion are the same as those of the present embodiment described above. The gas nozzle 15 corresponding to the confluence portion gas nozzle 15f and formed on the left side of the portion where the gas supply passage 10b merges with the gas distribution passage 10a corresponds to the back side gas nozzle 15s of this embodiment described above. (See FIG. 9(a)). Therefore, it is possible to prevent the occurrence of explosion ignition by a mechanism similar to that of the water heater 1 of the present embodiment described above.

Also in the manifold body 11 of such a modified example, the end surface 16a of the projecting wall 16 shaded in FIG. It is formed in a recessed state. Alternatively, as shown in FIG. 8, the end surface 16a of the projecting wall 16 is formed obliquely from the sealing surface 11c. In this way, the amount of compression of the seal member 13 at the end surface 16a of the projecting wall 16 is smaller than the amount of compression of the seal member 13 at the seal surface 11c, so that the reaction force to the manifold cover 12 can be suppressed. As a result, it becomes possible to avoid deterioration of the assembling workability of the manifold cover 12 .

Although the water heater 1 of the present embodiment and modified examples has been described above, the present invention is not limited to the above-described embodiments and modified examples, and can be implemented in various forms without departing from the gist thereof. is.

For example, in the embodiment and modification described above, the gas distribution passage groove 11a and the gas supply passage groove 11b are formed on the manifold main body 11 side. However, the gas distribution passage groove 11a and the gas supply passage groove 11b may be formed on the manifold cover 12 side.

DESCRIPTION OF SYMBOLS 1... Water heater, 2... Combustion can, 3... Burner, 3a... Opening,
3b...flame mouth, 3c...mixing passage, 3f...ignited burner,
3s...Fire transfer ignition burner, 4...Combustion fan, 5...Heat exchanger,
6... exhaust port, 7... spark plug, 8... flame detector, 9... gas control valve,
DESCRIPTION OF SYMBOLS 10... Gas manifold, 10a... Gas distribution passage, 10b... Gas supply passage,
11... Manifold body, 11a... Gas distribution passage groove, 11b... Gas supply passage groove,
11c...seal surface, 11d...gas inlet, 11e...side wall,
12... Manifold cover, 13... Seal member, 14... Mounting screw,
15 gas nozzle 15f confluence gas nozzle 15n nozzle hole
15s... Deep side gas nozzle, 16... Protruding wall, 16a... End face.

Claims (4)

a combustion can containing a plurality of burners for combusting fuel gas arranged in one direction; A gas manifold formed with gas nozzles, a spark plug for igniting the fuel gas flowing out from the burners, and a combustion gas generated by the combustion of the fuel gas by the plurality of burners and water are heat-exchanged. a heat exchanger for producing hot water;
The plurality of burners include:
an ignited burner ignited by the spark plug;
a flame transfer ignition burner that is ignited by the flames of the adjacent burners being transferred, and
The gas manifold is
a gas distribution passage extending in the direction in which the plurality of burners are arranged and distributing the fuel gas to the plurality of gas nozzles arranged in a row;
a gas supply passage connected to the gas distribution passage for supplying the fuel gas to the gas distribution passage;
The plurality of gas nozzles formed in rows are
an ignition position nozzle array composed of a predetermined plurality of gas nozzles including gas nozzles for supplying the fuel gas to the burner to be ignited;
and a residual nozzle row composed of the gas nozzles remaining after removing the ignition position nozzle row from the plurality of gas nozzles,
The gas supply passage of the gas manifold is connected to the gas distribution passage at a portion where the ignition position nozzle row is formed,
The gas manifold is
a manifold body in which the plurality of gas nozzles are formed;
a manifold cover that is assembled to the manifold body to form the gas distribution passage between itself and the manifold body;
a sealing member that is interposed between the manifold cover and the manifold body to seal the fuel gas in the gas distribution passage at an outer peripheral portion of the gas distribution passage, wherein
At least one of the manifold main body and the manifold cover is formed with a passage groove in which the gas distribution passage is formed by assembling the other manifold main body or the manifold cover,
The fuel gas supplied from the gas supply passage passes through the remaining nozzles between the gas distribution passage in the portion where the ignition position nozzle row exists and the gas distribution passage in the portion where the residual nozzle row exists. a distribution delay wall for delaying the distribution into the rows protruding from the side wall of the channel groove;
A water heater, wherein the amount of compression of the seal member is smaller at the portion of the distribution delay wall than at the outer peripheral portion of the gas distribution passage. a combustion can containing a plurality of burners for combusting fuel gas arranged in one direction; A gas manifold formed with gas nozzles, a spark plug for igniting the fuel gas flowing out from the burners, and a combustion gas generated by the combustion of the fuel gas by the plurality of burners and water are heat-exchanged. a heat exchanger for producing hot water;
The plurality of burners include:
an ignited burner ignited by the spark plug;
a flame transfer ignition burner that is ignited by the flames of the adjacent burners being transferred, and
The gas manifold is
a gas distribution passage extending in the direction in which the plurality of burners are arranged and distributing the fuel gas to the plurality of gas nozzles arranged in a row;
a gas supply passage connected to the gas distribution passage for supplying the fuel gas to the gas distribution passage;
The plurality of gas nozzles formed in rows are
an ignition position nozzle array composed of a predetermined plurality of gas nozzles including gas nozzles for supplying the fuel gas to the burner to be ignited;
and a residual nozzle row composed of the gas nozzles remaining after removing the ignition position nozzle row from the plurality of gas nozzles,
The gas supply passage of the gas manifold is connected to the gas distribution passage at a portion where the ignition position nozzle row is formed,
The gas manifold is
a manifold body in which the plurality of gas nozzles are formed;
a manifold cover that is assembled to the manifold body to form the gas distribution passage between itself and the manifold body;
a sealing member that is interposed between the manifold cover and the manifold body to seal the fuel gas in the gas distribution passage at an outer peripheral portion of the gas distribution passage, wherein
At least one of the manifold main body and the manifold cover is provided with a passage groove in which the gas distribution passage and the gas supply passage are formed by assembling the other manifold main body or the manifold cover,
The fuel gas supplied from the gas supply passage passes through the residual nozzle between the passage groove in the portion where the gas distribution passage is formed and the passage groove in the portion where the gas supply passage is formed. a distribution delay wall for delaying the distribution into the rows protruding from the side wall of the channel groove;
The amount of compression of the sealing member is smaller in the portion of the distribution delay wall than in the amount of compression in the outer peripheral portions of the gas distribution passage and the gas supply passage. Water heater. In the water heater according to claim 1 or claim 2,
The seal member is interposed between the manifold cover and the manifold body even at the position of the distribution delay wall, but the compression amount is zero at the position of the distribution delay wall. Water heater. In the water heater according to any one of claims 1 to 3,
The passage groove is formed at least in the manifold body,
A sealing surface against which the sealing member is pressed by the manifold cover is formed on an outer peripheral portion of the passage groove formed in the manifold body,
A water heater, wherein an end surface of the distribution delay wall on the side of the manifold cover is formed at a position on a deeper side of the passage groove than the seal surface.

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