JP7283730B2 - Water heater - Google Patents

Description

The present invention relates to a water heater equipped with a fan for supplying combustion air to a burner.

In a water heater, a casing having a burner is accommodated in a housing with an open front, and a chamber having an air intake port is protruded from the upper part of the casing. Water heaters fixed by screwing from are known. For example, in Patent Document 1, a combustion part equipped with a burner is provided below a chamber in which a fan is screwed and fixed, and a sensible heat recovery heat exchanger through which the combustion exhaust of the burner passes and a latent heat recovery heat are provided below it. A reverse combustion type water heater is disclosed in which an exchanger is provided in order from the top.

JP 2018-112321 A

In the case of such a reverse combustion type water heater, immediately after the operation is stopped, the drain stored inside the latent heat recovery heat exchanger evaporates, leaving a high-humidity gas. Since this gas rises in the apparatus with the lapse of time, an opening/closing member serving as a check valve is provided at the communication port (intake port) with the fan in the chamber so as not to flow back to the fan side. The opening/closing member is attached so as to be rotatable in the vertical direction about the upper end of the air intake. When the fan is not driven, the air intake is closed by its own weight. is adopted as the simplest and most effective form.
However, if an opening/closing member that rotates up and down is employed, the opening/closing member that rotates upward may get caught on the upper inner surface of the chamber and may not return to the closed position even if the fan stops.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a hot water heater that can reliably open and close without causing the opening and closing member that prevents backflow of gas to the fan side from being caught when the opening and closing member is opened. .

To achieve the above object, the invention according to claim 1 provides a fan, a chamber into which fuel gas and combustion air are introduced on the downstream side of the fan, a combustion section provided on the lower side of the chamber, A water heater comprising a heat exchange section provided below the combustion section,
The chamber is provided with an introduction portion having an intake port for the gas from the fan and is provided so as to bulge upward. An opening/closing member for opening the intake port by the discharge pressure of the fan in a driven state is provided so as to be rotatable around the upper end thereof, while the upper inner surface of the introduction portion and/or the opening side surface of the opening/closing member has an opening/closing member. A concave-convex portion is formed to regulate the upward rotation position of the member. It is characterized by being formed by a groove between.
According to a second aspect of the present invention, in the structure of claim 1 , the outlet of the intake port that opens to the interior of the introduction portion is an inclined surface extending downward in the gas introduction direction. .

According to the first aspect of the invention, by adopting the concave and convex portion that regulates the upward rotation position of the opening and closing member, the opening and closing member that prevents the backflow of gas to the fan side is prevented from being caught when opened. The opening and closing operation can be reliably performed by Moreover, since the opening/closing member does not open more than necessary, an excessive load is not applied to the supporting portion of the shaft of the opening/closing member.
In particular , since the uneven part is provided on the upper inner surface of the introduction part and is formed by a plurality of ridges extending in the gas introduction direction at the intake port and grooves between the ridges, the air is supplied from the fan into the chamber. A rectification effect of the gas to be drawn is obtained.
According to the second aspect of the invention, in addition to the effect of the first aspect, the outlet of the intake port that opens to the inside of the introduction portion forms an inclined surface extending downward in the gas introduction direction. , the outlet can be reliably closed by the weight of the opening/closing member.

1 is a front view of a water heater with a front cover removed; FIG. 1 is a front view of a water heater with resin sheets, a controller, and a display operation panel omitted; FIG. Fig. 2 is a perspective view of the chamber and fan unit; FIG. 4 is a plan view of the chamber and fan unit; Fig. 3 is a perspective view of the chamber; FIG. 5 is a cross-sectional view along line AA of FIG. 4 (the opening/closing member is in the closed position); FIG. 4 is a perspective view from below of the chamber and fan unit (the opening/closing member is in the closed position); FIG. 5 is a cross-sectional view taken along line AA of FIG. 4 showing the opening/closing member in an open position; FIG. 4 is a perspective view of the chamber and fan unit from below (the opening/closing member is in the open position); It is a perspective view of a fan unit. FIG. 4 is a perspective view showing the initial state when attaching the fan unit to the chamber; FIG. 4 is a front view showing the initial state when attaching the fan unit to the chamber; FIG. 13 is a cross-sectional view taken along line BB of FIG. 12; It is a front view which shows the state which attached the fan unit to the chamber. FIG. 15 is a cross-sectional view taken along line CC of FIG. 14;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a front view showing an example of a water heater, with a front cover removed. FIG. 2 shows a state in which the resin sheet, the controller, and the display operation panel are removed from FIG.
This water heater 1 has a square box-shaped casing 2 with an open front, a burner 4 as a combustion part, and a primary heat exchanger 5 and a secondary heat exchanger 6 as heat exchange parts in order from the top. It is a reverse combustion type that accommodates the provided inner shell 3 . Further, inside the housing 2, there are provided an exhaust part 7 extending backward from the lower part of the inner shell 3 and extending upward, a fan unit 8 connected to the burner 4 on the right side of the inner shell 3, and a fan unit 8. A gas supply unit 10 is connected to the fan unit 8 on the lower side of the , and is supplied with fuel gas from a gas introduction pipe 11 via a gas governor 9 . A controller 12 containing an electric circuit board is installed laterally on the lower right side of the inner barrel 3, and a display operation panel 13 exposed from the front cover is provided at the center of the lower part.

The burner 4 is of the all-primary-air type in which a mixture of fuel gas and all the combustion air necessary for combustion is burned. It has a casing 14, and the upper surface of the upper casing 14 is closed by a chamber 15 that projects upward and to which the fan unit 8 is connected. A flame hole plate (not shown) in which a plurality of flame holes are formed is provided on the lower surface of the upper casing 14, and the air-fuel mixture can be combusted on the surface (lower surface) of the flame hole plate.
As shown in FIGS. 3 and 4, the chamber 15 includes an upper plate portion 16 which is square in plan view and screwed to the upper casing 14 from above, and an introduction portion 17 which bulges upward from the upper plate portion 16 . and are integrally formed. A plurality of heat radiation ribs 18, 18 . . .

The introduction part 17 is formed so as to extend in the front-rear direction, and on the front side of the right side thereof, as shown in FIG. 5, a horizontally long rectangular opening 19 is formed. is provided. The intake port 20 has a short tubular shape with a flange 21 provided at the right end, and a rectifying rib 22 having a cross shape when viewed from the side and a cylindrical shape at the center is provided inside.
The intake port 20 is held in a state of protruding into the introduction portion 17 by engaging the flange 21 with the inner side of the inner rib 23 protruding outside the opening 19 and fitting it into the opening 19 from the right side. . The left end portion of the intake port 20 protruding into the introduction portion 17 forms an inclined outlet 24 that protrudes leftward as it goes downward.
An outer rib 25 projecting to the right side of the inner rib 23 is provided outside the inner rib 23 on the front side of the right side surface of the introduction portion 17 , and a packing 26 is fitted between the inner rib 23 and the outer rib 25 . ing.

An opening/closing member 27 is provided inside the intake port 20 . As shown in FIGS. 6 and 7, the opening/closing member 27 is a rectangular plate capable of closing the outlet 24 of the intake port 20. The shaft portion 28 provided at the upper end is provided at the left end of the upper surface of the intake port 20. By being engaged with the hook 29 , it is attached so as to be rotatable in the vertical direction around the shaft portion 28 . However, when the fan unit 8 is not driven, the outlet 24 is maintained in the closed position by its own weight. This prevents the gas in the inner barrel 3 from flowing back to the fan unit 8 side through the intake port 20 .
When the air-fuel mixture is discharged from the fan unit 8, the opening/closing member 27 rotates upward and moves to the open position to open the outlet 24, as shown in FIGS. A concave-convex portion 30 is formed by alternately forming ridges 31 and grooves 32 extending in the left-right direction in the front-rear direction. The projection 31 is formed with a height such that the lower surface is slightly above the hook 29, and when the opening/closing member 27 rotates above the hook 29, it abuts against the projection 31 and further rotation is restricted. It has become.

In the introduction part 17 of the chamber 15, behind the opening 19, as shown in FIG. A frame 33 is integrally formed. On the other hand, on the front side of the opening 19 and on the front surface of the introduction portion 17, an inner fixing surface 34 is provided as a first fixing surface portion facing the front, with screw holes 35, 35 formed in the upper and lower portions. The hinge frame 33 and the inner fixing surface 34 form an intake side fixing portion.

The fan unit 8 accommodates a fan 41, which is a centrifugal fan, in a fan case 40 that is circular in plan view, and has a fan motor 42 that rotates the fan 41 at the center of the upper side of the fan case 40. As shown in FIG. A suction port 43 connected to the gas supply unit 10 is formed in the center of the lower surface of the fan case 40 .
Further, as shown in FIG. 10, the fan case 40 is provided with a discharge port 44 protruding in the tangential direction. The discharge port 44 has a short cylindrical shape that opens in a horizontally long rectangular shape, and an outer flange 45 having the same outer shape as the outer rib 25 provided at the opening 19 of the chamber 15 is provided at the projecting end. A fitting portion 46 that fits inside the outer rib 25 and contacts the inner rib 23 protrudes around the discharge port 44 on the left side surface of the outer flange 45 .

Further, the rear end of the outer flange 45 is provided with a hinge piece 47 as a second hinge portion that can be inserted into and locked to the hinge frame 33 of the chamber 15, and the front end of the outer flange 45 is bent leftward. An outer fixing piece 48 is formed as a second fixing surface portion that contacts the inner fixing surface 34 of the introduction portion 17 from the front. Through holes 49 , 49 corresponding to the screw holes 35 , 35 are formed above and below the outer fixing piece 48 .

Therefore, when attaching the fan unit 8 to the chamber 15, first, the fan case 40 is held in an oblique posture with respect to the opening 19 of the introduction portion 17 so that the front end of the outer flange 45 is farther from the opening 19 than the rear end. As shown in FIGS. 11 to 13, the hinge piece 47 of the outer flange 45 is first inserted into the hinge frame 33 provided in the introduction portion 17 and locked. Next, the fan case 40 is rotated counterclockwise in plan view about the hinge piece 47 while being locked to the hinge frame 33 , so that the outer fixed piece 48 of the outer flange 45 covers the front surface of the introduction portion 17 . Then, as shown in FIGS. 14 and 15 , the fitting portion 46 is fitted inside the outer rib 25 so that the discharge port 44 communicates with the intake port 20 . In this state, the attachment of the fan unit 8 is completed by screwing the screws 50, 50 into the screw holes 35, 35 of the introduction portion 17 via the through holes 49, 49 of the outer fixing piece 48, respectively. Since the fan unit 8 is attached by screwing from the front in this manner, the attachment work can be performed easily.

On the other hand, to take out the fan unit 8, the screws 50, 50 are first loosened and removed from the front to release the connection of the outer fixing piece 48 to the inner fixing surface 34, in reverse order to the above procedure. Next, the fan unit 8 is rotated clockwise about the hinge piece 47 in a plan view to the state shown in FIGS. Then, by moving the fan unit 8 forward as it is and extracting the hinge piece 47 from the hinge frame 33 , the fan unit 8 can be taken out forward from the housing 2 .

As shown in FIG. 2, the primary heat exchanger 5 has a plurality of fins arranged side by side at predetermined intervals in the left-right direction in the lower part of a square cylindrical inner casing 60 to which the burner 4 is attached. A plurality of heat transfer tubes passing through are arranged. A connection pipe 61 with the secondary heat exchanger 6 is connected to the inlet end of the heat transfer tube provided at the lower right side of the middle casing 60, and the outlet end of the heat transfer tube provided at the upper part is A hot water outlet pipe 62 is connected. Around the outer circumference of the upper side of the middle casing 60, a band-shaped resin sheet 63 (FIG. 1) is wound around which substantially the entire surface is covered with a meandering conductive pattern.
The secondary heat exchanger 6 includes a plurality of uneven heat transfer plates arranged side by side at predetermined intervals in the front-rear direction in a square cylindrical lower casing 64 that communicates with the middle casing 60 . An internal flow path is formed continuously between the lower casing 64, and an inlet provided at the front lower part of the lower casing 64 and an outlet provided at the front upper part are connected to the internal flow path. A water supply pipe 65 is connected to the inlet, and a connecting pipe 61 is connected to the outlet.

The exhaust part 7 includes a drain receiver 66 attached to the lower surface of the lower casing 64 of the secondary heat exchanger 6 and an exhaust duct 67 erected behind the drain receiver 66 . A bottom portion of the drain receiver 66 is connected to a neutralizer 69 via a drain discharge pipe 68 .
The exhaust duct 67 is made of a synthetic resin and has a horizontally elongated prismatic shape, and an upper cover 70 having a cylindrical exhaust tube portion 71 protruding from the upper surface of the housing 2 is joined to the opening at the upper end of the exhaust duct 67 . .

In the water heater 1 configured as described above, when water is passed through the appliance, the controller 12 drives the fan motor 42 to rotate the fan 41 at a rotation speed corresponding to the amount of combustion requested by a remote controller or the like. . Then, the fan unit 8 draws in air proportional to the rotation speed of the fan 41 . At the same time, fuel gas is supplied from the gas introduction pipe 11, and after being pressure-regulated by the gas governor 9, it is mixed with air in the gas supply unit 10 via a venturi provided on the suction side of the fan unit 8 to generate a mixture. be done. The generated air-fuel mixture is discharged from the discharge port 44 of the fan case 40 to the intake port 20 of the chamber 15 of the burner 4, pushes up the opening/closing member 27, is supplied from the outlet 24 into the upper casing 14, and is supplied to the flame hole plate. The fuel is ejected from each flame hole, ignited by an ignition electrode (not shown), and burned.
At this time, the upwardly rotated opening/closing member 27 comes into contact with the ridges 31 of the concave/convex portion 30 formed on the upper inner surface of the introduction portion 17 and is restricted from further rotation. There is no possibility that it will be caught on the upper inner surface of the introduction part 17 and will not return. Moreover, the possibility that an excessive load is applied to the hook 29 is eliminated. Furthermore, since part of the air-fuel mixture that has entered the introduction portion 17 flows along the ridges 31 of the concave-convex portion 30, the air-fuel mixture can be rectified.

Combustion exhaust gas from the burner 4 passes between the fins in the inner casing 60 of the primary heat exchanger 5, exchanges heat with water flowing in the heat transfer tubes, and recovers sensible heat. After that, by passing between the heat transfer plates in the lower casing 64 of the secondary heat exchanger 6, heat is exchanged with water flowing through the internal flow paths of the heat transfer plates, and latent heat is recovered. Hot water at the set temperature is thus discharged from the hot water discharge pipe 62 .
On the other hand, the combustion exhaust that has passed through the lower casing 64 enters the drain receiver 66 of the exhaust portion 7, moves to the rear portion of the drain receiver 66, rises in the exhaust duct 67, and is discharged to the outside from the exhaust cylinder portion 71. be. The drain generated in the secondary heat exchanger 6 drops into the drain receiver 66 and is discharged to the outside of the equipment via the drain discharge pipe 68 and the neutralizer 69 .

Immediately after the operation is stopped, high-humidity gas remains in the secondary heat exchanger 6 due to the evaporation of the drain, and this gas rises in the inner shell 3 with the passage of time, It reaches into the chamber 15 of the burner 4 . However, since the outlet 24 of the intake port 20 is blocked by the opening/closing member 27 , the rising gas is prevented from flowing back through the intake port 20 to the fan unit 8 .

(Effects of invention related to fixing structure between chamber and fan unit)
According to the water heater 1 of the above configuration, the intake-side fixing portion is the hinge frame 33 (first hinge portion) provided on the rear side of the intake port 20, and the inner side of the hinge frame 33 (first hinge portion) provided on the front side of the intake port 20 and facing the front. A fixing surface 34 (first fixing surface portion) is provided, and a discharge-side fixing portion is provided on the rear side of the discharge port 44 and engages with the hinge frame 33 so as to be rotatable about a vertical axis. A hinge piece 47 (second hinge portion) and an outer fixed piece 48 (second fixed portion) provided forward of the outlet 44 and overlapping the inner fixed surface 34 from the front while the inlet 20 and the outlet 44 are in communication. The outer fixed piece is engaged with the hinge frame 33 and the hinge piece 47, the fan unit 8 rotates about the axis, and the intake port 20 and the discharge port 44 communicate with each other. 48 is screwed to the inner fixing surface 34 from the front.
As a result, the fan unit 8 can be fixed to the chamber 15 by screwing from the front, and the fan unit 8 can be taken out by removing the screws from the front. Therefore, not only the fan unit 8 can be attached during manufacturing, but also the fan unit 8 can be attached and detached during maintenance with good workability.

In particular, here, the second hinge portion is the hinge piece 47 projecting rearward, and the first hinge portion is the hinge frame 33 into which the hinge piece 47 is inserted. can be done smoothly.

In the above embodiment, the first hinge portion is a hinge frame with an opening at the center, but it may be a recess instead of an opening, or a plurality of openings and recesses may be provided. It does not have to be L-shaped in plan view.
Also, the second hinge portion can be appropriately changed, such as forming a plurality of hinge pieces or providing a shaft portion at the tip, in accordance with the shape of the first hinge portion.
Furthermore, in the above embodiment, the first hinge portion is the hinge frame and the second hinge portion is the hinge piece, but conversely, the first hinge portion may be the hinge piece and the second hinge portion may be the hinge frame.
Also, the first fixing surface portion and the second fixing surface portion may be screwed at three or more locations. The arrangement of the chamber and the fan unit may be reversed left to right.

(Effects of invention related to opening/closing member and concave/convex portion in chamber)
According to the water heater 1 of the above configuration, the chamber 15 is provided with the introduction portion 17 having the air-fuel mixture intake port 20 bulging upward, and the fan 41 is provided at the air intake port 20 in the chamber 15. An opening/closing member 27 is provided rotatably around its upper end, which closes the intake port 20 by its own weight when it is not driven, and opens the intake port 20 by the discharge pressure of the fan 41 when the fan 41 is driven. An uneven portion 30 is formed on the upper inner surface of the introduction portion 17 to restrict the upward rotation position of the opening/closing member 27, so that when the opening/closing member 27 is opened, the backflow of gas to the fan 41 side is prevented. The opening and closing operation can be reliably performed without the occurrence of catching. Moreover, since the opening/closing member 27 is not opened more than necessary, the hook 29 is not subjected to excessive load.

In particular, here, the uneven portion 30 is formed by a plurality of ridges 31 extending in the air-fuel mixture introduction direction at the intake port 20 and grooves 32 between the ridges 31, so that the air is supplied from the fan 41 into the chamber 15. A straightening action of the air-fuel mixture is obtained.
In addition, since the outlet 24 of the intake port 20 that opens to the inside of the introduction portion 17 has an inclined surface extending in the direction of introduction of the air-fuel mixture as it goes downward, the outlet 24 is reliably blocked by the weight of the opening/closing member 27. can do

In addition, the number and shape (height, width, etc.) of the ridges of the uneven part are not limited to the above form, and can be changed as appropriate. You may make it into a grid|lattice form.
The opening/closing member may also be changed in its overall shape, hinge shape, etc. as appropriate. For example, the opening/closing member may be formed so as to be thicker as it goes downward by eliminating the inclination of the outlet of the intake port.
Further, in the above embodiment, the upper inner surface of the introduction portion is provided with uneven portions, but the opening-side surface of the opening/closing member is provided with uneven portions, and when opened, the rotation position of the opening/closing member is restricted by contact with the upper inner surface. can also It is also possible to provide uneven portions on both the opening/closing member and the upper inner surface of the introduction portion so that the opening/closing member can be regulated in rotational position by mutual abutment.

In addition, common to each invention, each form of the burner, the primary heat exchanger, the secondary heat exchanger, the arrangement of the fan unit, the arrangement of the controller, etc. can be changed as appropriate. A water heater without a secondary heat exchanger may also be used.
In addition, the fan unit is of a premix type that supplies a mixture of fuel gas and combustion air to the chamber. Each invention is applicable even to a water heater that mixes with fuel gas on the downstream side and introduces it into the chamber.

DESCRIPTION OF SYMBOLS 1... Water heater, 2... Housing, 3... Inner body, 4... Burner, 5... Primary heat exchanger, 6... Secondary heat exchanger, 7... Exhaust part, 8... Fan Unit 10 Gas supply unit 12 Controller 14 Upper casing 15 Chamber 16 Upper plate 17 Inlet 19 Opening 20 Suction port 24 Exit 27 Opening/closing member 30 Uneven portion 31 Projection 33 Hinge frame 34 Screw hole 40 Fan case 41 Fan 42 Fan motor , 44... Discharge port, 45... Outer flange, 47... Locking piece, 48... Coupling piece, 49... Through hole, 50... Screw, 60... Middle casing, 61... Connecting pipe, 62 .. hot water discharge pipe, 64.. lower casing, 65.. water supply pipe.

Claims (2)

with a fan
a chamber into which fuel gas and combustion air are introduced downstream of the fan;
a combustion section provided on the underside of the chamber;
A water heater comprising a heat exchange section provided below the combustion section,
The chamber is provided with an introduction portion having an intake port for the gas from the fan and is provided so as to bulge upward. is provided rotatably about an upper end thereof, for closing the air intake port and opening the air intake port by the discharge pressure of the fan when the fan is driven;
An upper inner surface of the introduction portion and/or an opening-side surface of the opening/closing member is formed with an uneven portion that regulates an upward rotational position of the opening/closing member,
The uneven portion is provided on the upper inner surface of the introduction portion and is formed by a plurality of ridges extending in the gas introduction direction at the intake port and grooves between the ridges. water heater. 2. The water heater according to claim 1 , wherein an outlet of said intake port that opens into said introduction portion forms an inclined surface extending downwardly in the direction of introduction of said gas.

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