Patent Application
20240318868
This application claims the priority benefit of Japan application no. 2023-045393, filed on Mar. 22, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The invention relates to a water heater, such as a hot water supply apparatus.
Patent Document 1 discloses a specific example of a water heater.
The water heater of Patent Document 1 includes a burner unit and a heat exchanger for heating hot water and water. The burner unit includes a burner and a first case (burner body or burner case). The first case is installed to the burner, and fuel gas is supplied into the first case. The heat exchanger includes a second case and a heat transfer tube. Combustion gas generated by the burner travels in the second case. The heat transfer tube is provided in the second case, recovers heat from the combustion gas, and heats hot water and water.
As a means for connecting the first case of the burner unit and the second case of the heat exchanger, a flange part in a frame shape when viewed in a plan view is provided at the upper end of the second case. In addition, a frame-like region corresponding to the flange part is provided at the lower part of the first case. The portions sandwich a sealing member (rubber seal), and are connected with each other by using a fastening member, such as a threaded body.
With such configuration, it is possible to improve the seal performance of the connection position of the first and second cases and prevent the combustion gas from leaking out from the connection position.
However, according to the conventional technique, there is still room for improvement as described in the following.
That is, at the time when the burner is driven for combustion, due to the influence of the combustion gas, the first case of the burner unit may become hot. Conventionally, a fan supplying fuel gas, a valve mechanism for preventing the combustion gas from flowing back, and other devices, for example, are installed to the first case. Therefore, when the first case becomes hot, such devices may suffer from thermal damages.
As a means for prevention, according to the disclosure of Patent Document 2, for example, there is a means for disposing the burner in the second case of the heat exchanger and bringing an outer periphery flange part provided in the burner into contact with the periphery wall part of the second case. According to such means, the heat of the burner is eventually transmitted to the heat transfer tube and escapes via the periphery wall part of the second case from the outer periphery flange part, the temperature of the first case is prevented from rising, and the above issue can be eliminated.
According to such means, the burner provided with the outer periphery flange part is assembled inside the second case of the heat exchanger. Therefore, the overall size may easily increase, and the manufacturing cost may easily increase.
The invention provides a water heater able to improve the seal performance of the connection position between the first case of the burner unit and the second case of the heat exchanger while preventing the overall size from increasing or the configuration from becoming complicated, and suitably preventing the temperature of the first case from increasing.
A water heater according to an aspect of the disclosure provides a water heater. The water heater includes: a burner unit, having a first case and a burner, wherein a fuel gas is supplied into the first case, and the burner is installed to the first case and combusts the fuel gas; a heat exchanger, having a second case and a heat transfer tube, wherein a combustion gas generated by the burner travels in the second case, and the heat transfer tube recovers heat from the combustion gas; and a first connection target part and a second connection target part, being frame-like parts provided at respective opening edge parts of the first case and the second case, and sandwiching a sealing member to face and be connected with each other. An overall shape of the sealing member is in a frame shape corresponding to the first connection target part and the second connection target part, and a concave part that is notched or a hole part that is non-notched is formed at a portion of the sealing member, and a heat transfer convex part is provided in at least one of the first connection target part and the second connection target part, protrudes to enter the concave part or the hole part to be brought into surface contact with an other of the first connection target part and the second connection target part, and generates heat transfer between the first connection target part and the second connection target part.
A water heater according to an aspect of the disclosure provides a water heater. The water heater includes: a burner unit, having a first case and a burner, wherein a fuel gas is supplied into the first case, and the burner is installed to the first case and combusts the fuel gas; a heat exchanger, having a second case and a heat transfer tube, wherein a combustion gas generated by the burner travels in the second case, and the heat transfer tube recovers heat from the combustion gas; and a first connection target part and a second connection target part, being frame-like parts provided at respective opening edge parts of the first case and the second case, and sandwiching a sealing member to face and be connected with each other. An overall shape of the sealing member is in a frame shape corresponding to the first connection target part and the second connection target part, and a concave part that is notched or a hole part that is non-notched is formed at a portion of the sealing member, and a heat transfer convex part is provided in at least one of the first connection target part and the second connection target part, protrudes to enter the concave part or the hole part to be brought into surface contact with an other of the first connection target part and the second connection target part, and generates heat transfer between the first connection target part and the second connection target part.
According to the configuration, effects as follows are attained.
That is, it is configured that the frame-like first connection target part provided in the first case of the burner unit and the frame-like second connection target part provided in the second case of the heat exchanger sandwich the sealing member to face and be connected with each other. Therefore, the seal performance of the connection position of the first and second cases is favorable, and the concern that the combustion gas leaks out from the connection position can be eliminated.
Meanwhile, between the first and second connection target parts, heat can be transferred via the heat transfer convex part. Therefore, when the burner is driven for combustion and the first case receives the heat from the combustion gas, the heat can effectively escape via the heat transfer convex part from the first case toward the second case. Therefore, the temperature of the first case is prevented from increasing, and the concern that the apparatuses disposed to be affiliated with the first case suffer from thermal damages can be eliminated or reduced.
In addition, according to the invention, the notched concave part or the non-notched hole part is formed at the frame-like sealing member, and the heat transfer convex part enters the concave part or the hole part. Therefore, the overall size of the sealing member and the heat transfer convex part does not become bulky, the overall size of the water heater can be reasonably reduced, and the configuration of the water heater can be reasonably simplified.
If, differing from the invention, the heat transfer convex part is simply arranged on the outer side of the sealing member without providing the concave part or the hole part in the sealing member, the total width of these components increases, and, as a result, the first and second connection target parts also become wide. Comparatively, according to the invention, it is possible to properly avoid such issue.
According to an embodiment of the invention, it may also be configured that the heat transfer convex part is in a block shape or a rib shape extending in a same direction as the first connection target part and the second connection target part.
According to the configuration, at the position where the heat transfer convex part is provided, the width of the sealing member is prevented from being excessively narrow, while the size (length) of the heat transfer convex part can increase, and the heat transfer area between the first and second connection target parts can increase.
According to an embodiment of the invention, it may also be configured that the water heater includes: as the heat transfer convex part, multiple heat transfer convex parts arranged at intervals in a direction in which the first connection target part and the second connection target part extend. A fastening part fastening the first connection target part and the second connection target part by using a fastening member is provided at a position between the heat transfer convex parts.
According to the configuration, effects as follows are attained.
That is, at the positions between the heat transfer convex parts, the fastening part fastening the first and second connection target parts is provided. Thus, the fastening force due to the fastening part can be applied to both of the heat transfer convex parts located on the two sides of the fastening part. Accordingly, the heat transfer convex parts are brought into proper surface contact with respect to one of the first and second connection target parts, and it is difficult to generate a large gap therebetween. Therefore, the heat transfer properties between the first and second connection target parts are favorable, and the temperature of the first case can be further prevented from increasing.
According to an embodiment of the invention, it may also be configured that the concave part or the hole part of the sealing member is formed on an outer edge or a portion near the outer edge of the sealing member, and the heat transfer convex part is located at a region near an outer side, which is a side away from the burner, in a region between the first connection target part and the second connection target part, and a portion of the sealing member is present on an inner side of the heat transfer convex part.
According to the configuration, the heat transfer convex part is disposed to be away from the burner. In addition, a portion of the sealing member present on the inner side of the heat transfer convex part exerts an effect of making it difficult for the combustion gas and radiation heat to directly act on the heat transfer convex part from the burner side. Therefore, the heat transfer convex part itself is properly prevented from becoming hot through direct heating. As a result, the heat transfer convex part can effectively function as a portion (cooling function part) for preventing the temperature of the first case from increasing.
According to an embodiment of the invention, it may also be configured that the water heater further includes: an additional hole part, provided at the scaling member; and a guide part for a fastening member, wherein the guide part is protrusively provided at one of the first connection target part and the second connection target part to enter the additional hole part, and the fastening member fastening the first connection target part and the second connection target part is inserted on an inner side. The guide part is in a half-split tubular shape in which a single side portion on a side near the burner is notched.
According to the configuration, in addition to serving as an insertion guide of the fastening member, the guide part can also serve as a spacer that can set the mutual dimension between the first and second connection target parts, the compression margin of the sealing member, etc., to desired dimensions.
Moreover, the guide part is in a half-split tubular shape in which a single side portion that is a side near the burner is notched. Therefore, compared with the case where the guide part is in a tubular shape, for example, which is different from the above, the distance from the burner to the guide part can increase. This indicates that the additional hole part of the sealing member into which the guide part enters is set to be small-sized, and the width of the sealing member close to the burner side with respect to the guide part can increase. Therefore, regarding the periphery part provided with the guide part, it is possible to improve seal properties by using the sealing member.
According to an embodiment of the invention, it may also be configured that the burner is installed to the first case by using multiple additional fastening members at a position on the inner side of the first connection target part in the first case, and at least a portion of an inner edge part of the sealing member is configured as an extension part protruding toward an inner side thereof from the first connection target part and the second connection target part and covering at least one of the additional fastening members.
According to the configuration, among the additional fastening members, those covered by the extension part of the sealing member hardly directly receive combustion gas or radiation heat. Therefore, the temperature of the additional fastening member can be prevented from increasing and the increase in temperature of the first case itself that comes along with the increase in temperature of the additional fastening member can be prevented.
The configuration in which the additional fastening member is covered by the sealing member is realized by causing at least a portion of the inner edge part of the scaling member to protrude inwardly from the first and second connection target parts. Therefore, the configuration is reasonable and easy to manufacture.
Other features and advantages of the invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.
In the following, the exemplary embodiments of the invention are described in detail with reference to the drawings.
A water heater WH shown in
The burner unit BU includes a burner 3 and a first case 1 as a burner body case to which the burner 3 is installed. The first case 1 is a cast product, such as an aluminum die-cast. An upwardly convex wall part 12 is provided on the upper surface part of a frame-like base part 11, and a fuel gas supply port 13 is formed on the upwardly convex wall part 12. A chamber 14 open at the lower part in communication with the fuel gas supply port 13 is formed in the first case 1. A first connection target part JI and multiple heat transfer convex parts 15 are provided in the first case 1.
The fan 4 is installed to the upper part of the first case 1, and supplies fuel gas in a mixed gas state in which fuel gas and air are mixed (pre-mixed gas) from the fuel gas supply port 13 to the chamber 14.
The burner 3 includes a porous combustion plate 30 and a burner frame body 31. The combustion plate 30 has multiple ventilation holes 30a (flame holes). The burner frame body 31 supports the combustion plate 30. The burner 3 is installed to the first case 1, so that the combustion plate 30 blocks the lower opening part of the chamber 14. The installation is carried out by installing the burner frame body 31 to the lower surface part of the first case 1 by using multiple screws 88 (equivalent to a specific example of “additional fastening member” in the invention), for example. At the position of installation, a sealing rubber seal 96 with excellent heat resistance is interposed between the burner frame body 31 and the first case 1.
In the chamber 14, the mixed gas travels downward, and passes downward through the ventilation holes 30a of the combustion plate 30 of the burner 3. The mixed gas is ignited by using an ignition plug 86. Accordingly, the front surface side (lower surface side) of the combustion plate 30 becomes a combustion region of the fuel gas. The combustion gas generated through such combustion travels downward, and enters the second case 2 (to be described afterwards) of the heat exchanger HE.
The heat exchanger HE is connected to the lower side of the burner unit BU, recovers heat from the combustion gas generated by the burner 3 and traveling downward, and heats hot water and water. The heat exchanger HE includes multiple body pipes 9A arranged vertically at intervals and a heat transfer tube 9, in addition to the second case 2. The second case 2 is in a tubular shape having a substantially rectangular shape when viewed in a plan view having multiple sidewall parts 2a to 2d surrounding the combustion region on the lower surface side of the burner B and the lower region thereof.
The body pipes 9A are in a substantially C shape when viewed in a plan view that extends in a substantially horizontal direction along the inner surface side of the sidewall parts 2a to 2c, and are connected in series via header flow paths 92a, 92b provided on the sidewall part 2d. Like the heat transfer tube 9, the body pipes 9A are included in the heat transfer tube of the invention. The heat transfer tube 9 is configured so that multiple straight tube parts 90 bonded to multiple fins 97 for heat recovery and extending in the horizontal direction are connected in series via substantially U-shaped bent tubes 91 on the outside of the second case 2.
In the heat exchanger HE, hot water and water are supplied from a water inlet 98 to the body pipe 9A at the uppermost stage. Then, the hot water and water flow to the lower stage side as indicated by arrow signs N1 to N3 of
The first case 1 and the second case 2 are connected by using the first connection target part J1 and a second connection target part J2. The first connection target part J1 and the second connection target part J2 are frame-like when viewed in a plan view (or in a bottom view, the same applies in the following), and sandwich the seal member 5 to face each other and are connected. In the following, the configuration of the portions is described in detail.
That is, as clearly shown in
The first connection target part J1 is in a frame shape provided on the opening edge part on the lower side of the chamber 14 of the first case 1. More specifically, the first connection target part J1 is a frame-shaped portion facing the second connection target part J2 among the base part 11 of the first case 1, and is equivalent to the outer edge part of the base part 11.
The sealing member 5 is a rubber seal having excellent heat resistance, like the sealing rubber seal 96. As clearly shown in
The first connection target part J1 has a pair of straight regions A1 on the front side and the rear side and straight regions A2, A3 on the left and right sides. The same applies to the second connection target part J2. When viewed in a plan view, in a similar manner, multiple notched concave parts 50 are provided at the outer edge part at positions corresponding to the pair of linear regions A1 among the sealing member 5.
Meanwhile, multiple heat transfer convex parts 15 protruding downward are protrusively provided on the first connection target part J1. The heat transfer convex parts 15 are parts that cause heat transfer between the first connection target part J1 and the second connection target part J2, and prevent the temperature of the first case 1 from increasing. The heat transfer convex parts 15 are in a block shape or a rib shape extending in the longitudinal direction of the straight region A1, and tip end surfaces (lower end surfaces) of the heat transfer convex parts 15 are planar. In addition, the heat transfer convex parts 15 enter the notched concave parts 50, and the tip end surfaces of the heat transfer convex parts 15 face and come into contact with the second connection target part J2 (see
In the embodiment, the combustion gas generated when the burner 3 is driven for combustion spreads more easily in the front-rear direction than in the left-right direction of the burner 3, and, among the first connection target part J1, the pair of straight regions A1 are easier to become hot than the straight regions A2, A3. Accordingly, the heat transfer convex parts 15 are provided at the pair of straight regions A1. It goes without saying that the heat transfer convex parts 15 can also be provided in other straight regions A2, A3.
In each of the pair of straight regions A1, the heat transfer convex parts 15 are arranged at appropriate intervals in the longitudinal direction of the straight region A1. Comparatively, at positions between the heat transfer convex parts 15, fastening parts 6a for fastening the first connection target part J1 and the second connection target part J2 by using screws 87 (equivalent to a specific example of “fastening member” of the invention) and positioning pins 61 are provided. In addition, at positions on the left and right sides of the heat transfer convex parts 15, fastening parts 6b having the same configuration as the fastening part 6a are further provided.
The fastening parts 6a, 6b have guide parts 60 for the fastening members. The guide part 60 protrudes downward from the first connection target part J1. The guide part 60 (see also
The positioning pin 61 protrudes downward from the first connection target part J1, and is inserted into a hole part 52 provided separately in the sealing member 5. In
In the following, the effect of the water heater WH is described.
Although the first case 1 of the burner unit BU and the second case 2 of the heat exchanger HE are connected via the first connection target part J1 and the second connection target part J2, the frame-like sealing member 5 is interposed therebetween. Therefore, favorable seal performance is attained, and it is possible to eliminate the concern that the combustion gas leaks out from the connection position of the first connection target part J1 and the second connection target part J2.
Meanwhile, it is possible to transfer heat from the first case 1 to the side of the second case 2 by using the heat transfer convex parts 15. In the second case 2, since the cooling effect exerted by the hot water and water flowing through the body pipe 9A and the heat transfer tube 9 can be expected, such heat transfer is possible. Accordingly, even if the burner 3 is driven for combustion and the first case 1 receives heat from the combustion region of the burner 3, with such heat escaping from the side of the first case 1 to the side of the second case 2, the temperature of the first case 1 can be suppressed from increasing. Therefore, for example, the fan 4 as well as other devices (not shown) installed to the first case 1 can be prevented from suffering from thermal damages.
In the embodiment, the notched concave part 50 is formed at the outer edge part of the sealing member 5, and the heat transfer convex part 15 enters the notched convex part 50. Therefore, compared with the case where the notched convex parts 50 are not provided in the sealing member 5, for example, and only the heat transfer convex parts 15 and the sealing member 5 are provided and arranged, the overall width can be reduced according to the embodiment. This helps reduce the sizes of the first connection target part J1 and the second connection target part J2 and helps reduce the sizes of both of the first case 1 and the second case 2.
In addition, the heat transfer convex parts 15 are in a block shape or a rib shape extending in the longitudinal directions of the straight regions A1 of the first connection target part J1 and the second connection target part J2. Therefore, the size of each of the heat transfer convex parts 15 may be further increased without excessively reducing the width of the sealing member 5 at the positions where the heat transfer convex parts 15. When the size of each of the heat transfer convex parts 15 is increased to increase the heat transfer area between the first connection target part J1 and the second connection target part J2, the temperature of the first case 1 can be further prevented from increasing.
The notched convex parts 50 are formed at the outer edge part of the sealing member 5, and the heat transfer convex parts 15 are located at regions near the outer side, which is a side away from the burner 3, in the region between the first connection target part J1 and the second connection target part J2. In addition, a portion of the sealing member 5 is present on the inner side of the heat transfer convex part. Such portion also exerts an effect of blocking the combustion gas traveling from the side of the burner 3 or radiation heat from reaching the heat transfer convex part 15. As a result, the heat transfer convex part 15 itself is appropriately prevented from directly receiving heat and becoming hot, and the heat transfer convex part 15 can effectively function as a portion for preventing the temperature of the first case 1 from increasing.
Although the first connection target part J1 and the second connection target part J2 are fastened to each other by the fastening parts 6a, 6b, the fastening part 6a is located between multiple (two) heat transfer convex parts 15. Therefore, the fastening force of the fastening part 6a is applied to both of the heat transfer convex parts 15, and the tip end surfaces thereof can be reliably brought into surface contact with the second connection target part J2. In addition, the fastening parts 6b are provided on the left and right sides of the heat transfer convex parts 15. Therefore, it is possible to more appropriately bring the heat transfer convex parts 15 into surface contact with the second connection target part J2.
As described above, the guide part 60 into which the screw 87 is inserted serves as a spacer for defining the fastening margin (equivalent to the compression margin of the scaling member 5) at the time of fastening the screw 87, and the guide part 60 is in a half-split tubular shape as shown in
More specifically,
Comparatively, as shown in
In the embodiment shown in
According to the embodiment, it is difficult for the screws 88 for installing the burner 3 to directly receive the combustion gas or radiation heat. Therefore, the temperature of the screws 88 is prevented from increasing, and the increase in the temperature of the first case 1 that comes together with the increase in the temperature of the screws 88 can be prevented. The configuration in which the extension parts 55 are provided in the sealing member 5 is simple, and the number of components does not increase. Therefore, the manufacturing cost can be prevented from increasing.
Also, differing from the embodiment, it is also possible to provide the extension part 55 only at one position, for example, and cover only some of the screws 88.
In the embodiment shown in
As shown in the embodiment, in the invention, it is possible to provide the non-notched hole parts 50A in place of providing the notched convex parts 50 in the sealing member 5. In such case as well, the same effect as the above embodiment is expected.
The invention is not limited to the above embodiment. The specific configuration of the respective parts of the water heater according to the invention can be designed and modified in various ways within the claimed scope of the invention.
In the embodiment, the heat transfer convex parts 15 are provided at the first connection target part J1. However, in place thereof or in addition thereto, it is also possible to configure the heat transfer convex parts 15 at the second connection target part J2.
The heat transfer convex part 15 may be configured as a stepped part, for example, and it is possible to set the specific shape thereof in various shapes other than a block shape or a rib shape extending in a predetermined direction. The specific number or the specific position of the heat transfer convex part can be changed in various ways.
It suffices as long as the first connection target part and the second connection target part of the invention are frame-like parts provided at the respective opening edge parts of the first case of the burner unit and the second case of the heat exchanger and parts that sandwich the sealing member to face and be connected with each other, and it is not required for the first connection target part and the second connection target part to be configured as flange parts. As the fastening member fastening the first connection target part and the second connection target part, threaded members other than screws may also be used.
The specific material of the sealing member is not particularly limited, either. Although the sealing member is in a frame shape (loop shape), as described above, a component in which multiple components are connected in a frame shape may also be adopted.
Although the water heater WH of the embodiment is of a reverse combustion type in which the fuel gas or the combustion gas travels downward. The invention is not limited thereto. For example, an apparatus may also be arranged upside down with respect to the above embodiment, and a forward combustion type in which the fuel gas travels upward from the burner unit toward the heat exchanger can be arranged. The specific configuration of the heat exchanger or each part of the burner unit forming the water heater is not limited to the contents of the above embodiment.
In addition to a hot water supply apparatus capable of general hot water supply, bath hot water supply, or room-heating hot water supply, the concept of the water heater according to the invention also covers other apparatuses having a hot water generating function.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-045393 | Mar 2023 | JP | national |
