Patent Application
20190203975
The present invention relates to a heat exchanger and a hot water apparatus.
A heat exchanger in which a plurality of heat transfer plates are accommodated in a case is disclosed, for example, in WO2015/141995 (PTL 1).
In the heat exchanger in the literature above, the plurality of heat transfer plates are sandwiched from the front and the rear between a front member and a rear member of a case divided into two parts. The front member and the rear member of the case are fixed to each other by a screw at a boundary between the front member and the rear member of the case divided into two parts.
PTL 1: WO2015/141995
In the heat exchanger in the literature above, members which form the plurality of heat transfer plates and a member which forms the case are required. Therefore, the number of members disadvantageously increases.
The present invention was made in view of the problem above, and an object thereof is to provide a heat exchanger capable of achieving a reduced number of members and a hot water apparatus including the same.
A heat exchanger according to the present invention includes a heat exchange portion and a case. The heat exchange portion includes a plurality of heat transfer plates layered on one another. The case accommodates the plurality of heat transfer plates of the heat exchange portion. The heat exchange portion includes a front plate portion provided as an outermost layer of the heat exchange portion. The front plate portion of the heat exchange portion forms a part of the case.
According to the heat exchanger in the present invention, the front plate portion of the heat exchange portion forms a part of the case. Therefore, the front plate portion of the heat exchange portion can serve also as the case. Therefore, the number of members can be reduced.
The heat exchanger further includes a pipe joint portion attached to the front plate portion, the pipe joint portion being configured to allow water and/or hot water to flow in and out of the plurality of heat transfer plates. Since the pipe joint portion is attached to the front plate portion, no sealing member such as a gasket is required for sealing a gap between the pipe joint portion and the front plate portion. Since no sealing member such as a gasket is required for sealing a gap between the pipe joint portion and the front plate portion, there is no possibility of leakage of heating gas (combustion gas) through the gap between the pipe joint portion and the front plate portion to the outside of the heat exchanger due to poor sealing. Therefore, sealability can be improved.
In the heat exchanger, the case includes a rear wall portion arranged to sandwich the plurality of heat transfer plates between the rear wall portion and the front plate portion and a pair of sidewall portions which extends from opposing ends of the rear wall portion toward the front plate portion. The pair of sidewall portions is joined to the front plate portion. Therefore, no sealing member such as a gasket is required for sealing a gap between the front plate portion and the pair of sidewall portions. Since no sealing member such as a gasket is required for sealing a gap between the front plate portion and the pair of sidewall portions, there is no possibility of leakage of heating gas (combustion gas) through the gap between the front plate portion and the pair of sidewall portions to the outside of the latent heat recovery heat exchanger due to poor sealing. Since no sealing member such as a gasket is required for sealing a gap between the front plate portion and the pair of sidewall portions, no operation for attaching the sealing member is required. Therefore, assembly of the latent heat recovery heat exchanger is facilitated.
The heat exchanger further includes a flange member arranged at an upper end portion of the case. The flange member includes an extension portion which extends from the upper end portion to the outside of the case and an opening provided on an inner side of the extension portion. The extension portion is provided to surround the opening. Therefore, the sealing member can be placed on the extension portion to surround the opening. Sealing as surrounding the opening can thus be achieved.
In the heat exchanger, the flange member includes a rising coupling portion which rises upward from the extension portion along the opening. The upper end portion of the case is inserted in the opening. The rising coupling portion is joined from an outer side to the upper end portion of the case inserted in the opening. Therefore, the rising coupling portion can readily be welded to the upper end portion of the case.
In the heat exchanger, the rising coupling portion includes a peripheral wall portion which surrounds the opening and a first cut portion provided in an upper edge of the peripheral wall portion. The case includes a second cut portion provided in an upper edge of the upper end portion thereof. The first cut portion is arranged to be superimposed on the second cut portion. Therefore, drainage water can flow to the opening through the first cut portion and the second cut portion. Drainage water can thus readily be discharged.
In the heat exchanger, the opening is quadrangular when the flange member is viewed from above. The first cut portion and the second cut portion are provided in each of four corners of the opening. Therefore, the first cut portion can be made by cutting and erecting four corners of the opening in the flange member. Therefore, the first cut portion can readily be made.
A hot water apparatus according to the present invention includes a combustion apparatus which generates heating gas, a sensible heat recovery heat exchanger which recovers sensible heat of heating gas generated by the combustion apparatus, and the heat exchanger described above as a latent heat recovery heat exchanger which recovers latent heat of heating gas. According to the hot water apparatus in the present invention, a hot water apparatus which can achieve a reduced number of members of the heat exchanger can be provided.
A hot water apparatus according to the present invention includes a combustion apparatus which generates heating gas, a sensible heat recovery heat exchanger which recovers sensible heat of heating gas generated by the combustion apparatus, and the heat exchanger described above as a latent heat recovery heat exchanger which recovers latent heat of heating gas. The sensible heat recovery heat exchanger includes a heat transfer tube for flow of water and/or hot water. The heat transfer tube includes a water entry portion for entry of water and/or hot water thereinto. Any one of the first cut portion and the second cut portion provided in each of four corners of the opening is arranged directly under the water entry portion. According to the hot water apparatus in the present invention, the first cut portion and the second cut portion can be arranged directly under the water entry portion where drainage water is likely.
Therefore, drainage water can efficiently be discharged.
As described above, according to the present invention, a heat exchanger which can achieve a reduced number of members and a hot water apparatus including the same can be provided.
An embodiment of the present invention will be described below with reference to the drawings.
A construction of a hot water apparatus in one embodiment of the present invention will initially be described.
Referring to
Fan assembly 32 is configured to send mixture gas of fuel gas and air taken in from the outside of housing 50 to combustion apparatus 30. Fan assembly 32 includes a fan case, an impeller arranged in the fan case, and a drive source (such as a motor) for rotating the impeller.
Fuel gas flows to venturi 34 through gas valve 36 and orifice 35. Gas valve 36 is configured to control a flow rate of fuel gas. Air taken in from the outside of housing 50 flows to venturi 34.
Fuel gas and air are mixed in venturi 34. Venturi 34 is configured to increase a flow velocity of mixture gas by reducing the flow of mixture gas of fuel gas and air.
Mixture gas which has passed through venturi 34 is sent by fan assembly 32 to combustion apparatus 30 through chamber 31.
Combustion apparatus 30 is configured to generate heating gas (combustion gas). Combustion apparatus 30 is configured to supply combustion gas to sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10.
Combustion apparatus 30 is an inverse combustion type apparatus which supplies combustion gas downward. Mixture gas issued from combustion apparatus 30 is ignited by an igniter 30a and becomes combustion gas.
Combustion gas sequentially passes through sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10. Thereafter, combustion gas is discharged to the outside of housing 50 through duct 33. Therefore, combustion gas flows downward from above through the inside of sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10, changes its direction in duct 33, and flows upward from below.
Each of sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10 is configured to exchange heat with combustion gas supplied by combustion apparatus 30. Sensible heat recovery heat exchanger 20 is attached under combustion apparatus 30 and latent heat recovery heat exchanger 10 is attached under sensible heat recovery heat exchanger 20.
Sensible heat recovery heat exchanger 20 is a heat exchanger for recovering sensible heat of combustion gas. Sensible heat recovery heat exchanger 20 recovers sensible heat of heating gas (combustion gas) generated by combustion apparatus 30. Latent heat recovery heat exchanger 10 is a heat exchanger for recovering latent heat of combustion gas. Latent heat recovery heat exchanger 10 recovers latent heat of heating gas (combustion gas). Water vapor of combustion gas is condensed in latent heat recovery heat exchanger 10 and condensed water (drainage water) is produced. Drainage water is drained to the outside of housing 50 through a part of duct 33.
When a temperature of incoming water and/or hot water is low also in sensible heat recovery heat exchanger 20 or when an amount of heating by combustion apparatus 30 is small, drainage water is produced also in sensible heat recovery heat exchanger 20. Drainage water is drained to the outside of housing 50 through a part of duct 33 via latent heat recovery heat exchanger 10.
Sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10 are connected to each other through pipe 40. A part of pipe 40 on a water entry side relative to latent heat recovery heat exchanger 10 and a part of pipe 40 on a hot water exit side relative to sensible heat recovery heat exchanger 20 are bypassed by bypass pipe 41.
The part of pipe 40 on the hot water exit side relative to sensible heat recovery heat exchanger 20 and bypass pipe 41 are connected to each other by three-way valve 42. Three-way valve 42 is constructed to be able to switch between a flow path from sensible heat recovery heat exchanger 20 to a hot water outlet of pipe 40 and a flow path from sensible heat recovery heat exchanger 20 to bypass pipe 41.
Liquid to liquid heat exchanger 43 is connected to bypass pipe 41. Hydronic pipe 44 connected to a hydronic terminal is inserted in liquid to liquid heat exchanger 43. Warm water warmed as a result of passage through sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10 flows in liquid to liquid heat exchanger 43. As warm water which flows in liquid to liquid heat exchanger 43 flows outside hydronic pipe 44, heat can be exchanged between warm water which flows in liquid to liquid heat exchanger 43 and warm water which flows in hydronic pipe 44.
Water supplied to hot water apparatus 100 becomes hot as a result of heat exchange with combustion gas in sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10. Hot water can thus be supplied by hot water apparatus 100.
Warm water which returns from the hydronic terminal passes through hydronic pipe 44 to be warmed as a result of heat exchange with warm water warmed by sensible heat recovery heat exchanger 20 and latent heat recovery heat exchanger 10 in liquid to liquid heat exchanger 43 and thereafter it is supplied again to the hydronic terminal. Warm water can thus be supplied to the hydronic terminal by hot water apparatus 100.
A plate type heat exchanger in the present embodiment is applied to latent heat recovery heat exchanger 10 of hot water apparatus 100.
A construction of a heat exchanger set in the present embodiment will now be described with reference to
Sensible heat recovery heat exchanger (primary heat exchanger) 20 mainly includes a case 21, a header 22, and a heat transfer tube 23. Case 21 includes a first sidewall 21a to a fourth sidewall 21d. First sidewall 21a to fourth sidewall 21d are connected in the order of first sidewall 21a to fourth sidewall 21d. Case 21 forms a frame which opens upward and downward. Combustion gas is fed through the upper opening and combustion gas is exhausted through the lower opening. First sidewall 21a and third sidewall 21c face each other and second sidewall 21b and fourth sidewall 21d face each other.
Header 22 is provided on an outer surface of first sidewall 21a. A pipe joint 24a on the water entry side and a pipe joint 24b on the hot water exit side are attached to header 22 provided on the outer surface of first sidewall 21a. Not-shown header 22 is provided also on an outer surface of third sidewall 21c.
Header 22 provided on the outer surface of first sidewall 21a and header 22 provided on the outer surface of third sidewall 21c are connected to each other through a plurality of heat transfer tubes 23. The plurality of heat transfer tubes 23 are provided in a region surrounded by first sidewall 21a to fourth sidewall 21d as well as in second sidewall 21b and fourth sidewall 21d. Heat transfer tube 23 has a water entry portion for entry of water and/or hot water in heat transfer tube 23. The water entry portion is a portion where water and/or hot water enters heat transfer tube 23 first.
Water and/or hot water introduced from pipe joint 24a on the water entry side reaches header 22 provided on the outer surface of third sidewall 21c through not-shown heat transfer tube 23 from header 22 provided on the outer surface of first sidewall 21a. Water and/or hot water which has reached header 22 provided on the outer surface of third sidewall 21c reaches header 22 provided on the outer surface of first sidewall 21a through an adjacent heat transfer tube 23 connected to header 22. Water and/or hot water which has reached header 22 provided on the outer surface of first sidewall 21a reaches header 22 provided on the outer surface of third sidewall 21c through an adjacent heat transfer tube 23 connected to the header.
Water and/or hot water further goes back and forth between header 22 provided on the outer surface of first sidewall 21a and header 22 provided on the outer surface of second sidewall 21b through heat transfer tube 23. Finally, water and/or hot water exits from pipe joint 24b on the hot water exit side. Thus, water and/or hot water which flows in from pipe joint 24a on the water entry side flows out of pipe joint 24b on the hot water exit side through header 22 provided on the outer surface of first sidewall 21a, heat transfer tube 23, and header 22 provided on the outer surface of third sidewall 21c.
Referring to
Referring to
Front plate portion 11a is provided as an outermost layer of heat exchange portion 11. Front plate portion 11a is brazed to a front surface of heat transfer plate 11b arranged in the forefront among the plurality of heat transfer plates 11b. Front plate portion 11a is greater in thickness than heat transfer plate 11b. Front plate portion 11a can thus reinforce heat transfer plate 11b.
Rear plate portion 11c is provided as an outermost layer of heat exchange portion 11 on a side opposite to front plate portion 11a with respect to the plurality of heat transfer plates 11b. Rear plate portion 11c is brazed to a rear surface of heat transfer plate 11b arranged rearmost among the plurality of heat transfer plates 11b. Rear plate portion 11c is greater in thickness than heat transfer plate 11b. Rear plate portion 11c can thus reinforce heat transfer plate 11b.
Referring to
Front plate portion 11a is joined to heat transfer plate 11b arranged at one end (a first end) in the direction of layering of the plurality of heat transfer plates 11b and rear plate portion 11c is joined to heat transfer plate 11b arranged at the other end (a second end) in the direction of layering of the plurality of heat transfer plates 11b.
Adjacent heat transfer plates 11b of the plurality of heat transfer plates 11b are brazed to each other. A gap between a pair of adjacent heat transfer plates 11b of the plurality of heat transfer plates 11b defines a flow path through which water and/or hot water passes.
A space between the pair of adjacent heat transfer plates 11b of the plurality of heat transfer plates 11b defines a flow path through which combustion gas flows. Each of a space between a pair of heat transfer plates 11b and front plate portion 11a and a space between a pair of heat transfer plates 11b and rear plate portion 11c also defines a flow path through which combustion gas passes. Heat can thus be exchanged between water and/or hot water which passes through latent heat recovery heat exchanger (secondary heat exchanger) 10 and combustion gas.
Heat transfer plate 11b has, for example, a substantially rectangular outer geometry in a plan view. Heat transfer plate 11b is formed, for example, by pressing one flat plate. Heat transfer plate 11b has flow path projections and recesses formed in pressing. The flow path projections and recesses of heat transfer plate 11b have a plurality of flow path projections and a plurality of flow path recesses. As the plurality of heat transfer plates 11b are layered on one another, the plurality of flow path projections and the plurality of flow path recesses define flow paths for passage of water and/or hot water between a pair of heat transfer plates 11b, and a space between the pair of heat transfer plates 11b defines a flow path for passage of combustion gas.
A pair of pipe joint portions 14 is attached to front plate portion 11a. Pipe joint portion 14 is configured to allow water and/or hot water to flow in and out of the plurality of heat transfer plates 11b. Uppermost heat transfer plate 11b is connected to the pair of pipe joint portions 14 with front plate portion 11a being interposed. Each of the pair of pipe joint portions 14 is a pipe joint for connecting a pipe. A flow path in each of the pair of pipe joint portions 14 is connected to an internal flow path of each of the plurality of heat transfer plates 11b.
A pipe connected to one of the pair of pipe joint portions 14 is a pipe for allowing water and/or hot water to flow into an internal flow path in each of a pair of heat transfer plates 11b. A pipe connected to the other of the pair of pipe joint portions 14 is a pipe for allowing water and/or hot water to flow out of the internal flow path in each of the pair of heat transfer plates 11b.
A through hole is provided in each of the plurality of heat transfer plates 11b. Each through hole communicates with an internal flow path in the pair of heat transfer plates 11b. The through hole is arranged directly under pipe joint portion 14. The through hole communicates with a flow path in pipe joint portion 14. Therefore, water and/or hot water introduced from pipe joint portion 14 on the water entry side flows through the internal flow path in each of the pair of heat transfer plates 11b and thereafter exits from pipe joint portion 14 on the hot water exit side.
Case 12 accommodates a plurality of heat transfer plates 11b of heat exchange portion 11. Front plate portion 11a of heat exchange portion 11 forms a part of case 12. Front plate portion 11a and case 12 form a frame which opens upward and downward. Combustion gas is fed through an upper opening and exhausted through a lower opening. Front plate portion 11a and case 12 surround the plurality of heat transfer plates 11b.
Case 12 includes a rear wall portion 12a and a pair of sidewall portions 12b. Rear wall portion 12a is arranged to sandwich the plurality of heat transfer plates 11b between rear wall portion 12a and front plate portion 11a. Rear wall portion 12a is arranged opposite to front plate portion 11a with the plurality of heat transfer plates 11b lying therebetween. The pair of sidewall portions 12b extends from opposing ends of rear wall portion 12a toward front plate portion 11a. The pair of sidewall portions 12b is joined to front plate portion 11a.
Opposing ends of front plate portion 11a are bent in a direction intersecting a surface (a main surface) of front plate portion 11a. The opposing ends of front plate portion 11a are preferably bent at a right angle with respect to the surface (main surface) of front plate portion 11a. The opposing ends of front plate portion 11a extend along inner surfaces of the pair of sidewall portions 12b. Outer surfaces of the opposing ends of front plate portion 11a are joined to the inner surfaces of the pair of sidewall portions 12b. Specifically, the outer surfaces of the opposing ends of front plate portion 11a are welded to inner surfaces of front ends of the pair of sidewall portions 12b. Since the opposing ends of front plate portion 11a extend along the inner surfaces of the pair of sidewall portions 12b, the opposing ends of front plate portion 11a are readily welded to the inner surfaces of the pair of sidewall portions 12b.
Referring to
Extension portion 13a includes a first stepped portion and a second stepped portion arranged on an outer side of the first stepped portion. The first stepped portion is arranged on a side of opening 13b. The second stepped portion is arranged opposite to opening 13b with respect to the first stepped portion. The second stepped portion is arranged above the first stepped portion. Rising coupling portion 13c is constructed to rise upward from extension portion 13a along opening 13b. Upper end portion 12c of case 12 is inserted in opening 13b. Rising coupling portion 13c is joined from the outer side to upper end portion 12c of case 12 inserted in opening 13b. Specifically, rising coupling portion 13c is welded to upper end portion 12c of case 12.
Rising coupling portion 13c includes a peripheral wall portion 13c1 and a first cut portion 13c2. Peripheral wall portion 13c1 is provided to surround opening 13b. First cut portion 13c2 is provided in an upper edge of peripheral wall portion 13c1. Therefore, rising coupling portion 13c is low in height in first cut portion 13c2. Case 12 includes a second cut portion 12d provided in an upper edge of upper end portion 12c of case 12. Therefore, upper end portion 12c of case 12 is low in height in second cut portion 12d. First cut portion 13c2 is arranged to be superimposed on second cut portion 12d. First cut portion 13c2 and second cut portion 12d are arranged to communicate with each other.
Opening 13b is quadrangular when flange member 13 is viewed from above. First cut portion 13c2 and second cut portion 12d are provided in each of four corners of opening 13b.
Referring to
Any one of first cut portion 13c2 and second cut portion 12d provided in each of four corners of opening 13b of flange member 13 shown in
As shown in
Referring to
Functions and effects of the present embodiment will now be described in comparison with a comparative example.
Comparative Example 1 will initially be described with reference to
Furthermore, a not-shown sealing member such as a gasket is required for sealing a gap at the boundary between front member 121 and rear member 122 of case 12.
In latent heat recovery heat exchanger 10 in Comparative Example 1, a not-shown pipe joint portion is attached to front member 121 of case 12 instead of front plate portion 11a of heat exchange portion 11. Specifically, pipe 11d for allowing water and/or hot water to flow in and out is connected to heat transfer plate 11b. Pipe 11d is inserted in a through hole 121a provided in front member 121 of case 12. Pipe 11d is inserted also in the pipe joint portion. Namely, the pipe joint portion is attached to front member 121 of case 12 while pipe 11d is inserted therein. Therefore, a not-shown sealing member such as a gasket is required for sealing a gap between the pipe joint portion and front member 121 of case 12.
In succession, Comparative Example 2 will be described with reference to
According to latent heat recovery heat exchanger 10 in the present embodiment in comparison with Comparative Example 1, as shown in
According to latent heat recovery heat exchanger 10 in the present embodiment, pipe joint portion 14 is attached to front plate portion 11a. Therefore, no sealing member such as a gasket is required for sealing a gap between pipe joint portion 14 and front plate portion 11a. Since no sealing member such as a gasket is required for sealing a gap between pipe joint portion 14 and front plate portion 11a, there is no possibility of leakage of heating gas (combustion gas) through the gap between pipe joint portion 14 and front plate portion 11a to the outside of latent heat recovery heat exchanger 10 due to poor sealing. Therefore, sealability can be improved.
According to latent heat recovery heat exchanger 10 in the present embodiment, a pair of sidewall portions 12b which extends from opposing ends of rear wall portion 12a arranged to sandwich the plurality of heat transfer plates 11b between rear wall portion 12a and front plate portion 11a toward front plate portion 11a is joined to front plate portion 11a. Therefore, no sealing member such as a gasket is required for sealing a gap between front plate portion 11a and the pair of sidewall portions 12b. Since no sealing member such as a gasket is required for sealing a gap between front plate portion 11a and the pair of sidewall portions 12b, there is no possibility of leakage of heating gas (combustion gas) through the gap between front plate portion 11a and the pair of sidewall portions 12b to the outside of latent heat recovery heat exchanger 10 due to poor sealing. Since no sealing member such as a gasket is required for sealing a gap between front plate portion 11a and the pair of sidewall portions 12b, no operation for attaching the sealing member is required. Therefore, assembly of latent heat recovery heat exchanger 10 is facilitated.
According to latent heat recovery heat exchanger 10 in the present embodiment, as shown in
According to latent heat recovery heat exchanger 10 in the present embodiment, as shown in
According to latent heat recovery heat exchanger 10 in the present embodiment in comparison with Comparative Example 2, as shown in
According to latent heat recovery heat exchanger 10 in the present embodiment, as shown in
Since hot water apparatus 100 in the present embodiment includes combustion apparatus 30, sensible heat recovery heat exchanger 20, and latent heat recovery heat exchanger 10 as shown in
According to hot water apparatus 100 in the present embodiment, as shown in
A construction in which first cut portion 13c2 and second cut portion 12d are provided in a portion other than four corners of opening 13b in flange member 13 as a modification of the present embodiment will be described with reference to
In the modification of the present embodiment, first cut portion 13c2 and second cut portion 12d are provided in a portion between corners of opening 13b in flange member 13. Namely, first cut portion 13c2 and second cut portion 12d are provided in a side between corners of opening 13b in flange member 13. At least one first cut portion 13c2 and at least one second cut portion 12d should only be provided. Namely, a single first cut portion 13c2 or a plurality of first cut portions 13c2 and a single second cut portion 12d or a plurality of second cut portions 12d may be provided.
Since the modification of the present embodiment is otherwise similar in features to the present embodiment, the same elements have the same reference numerals allotted and description thereof will not be repeated.
According to the modification of the present embodiment, first cut portion 13c2 and second cut portion 12d can be arranged at any position other than four corners of opening 13b in flange member 13. Thus, drainage water can be discharged from a portion other than four corners of opening 13b in flange member 13.
A construction in which first cut portion 13c2 and second cut portion 12d are provided in each of four corners of opening 13b in flange member 13 is described in the present embodiment and a construction in which first cut portion 13c2 and second cut portion 12d are provided in a portion other than four corners of opening 13b in flange member 13 is described in the modification of the present embodiment. Arrangement of first cut portion 13c2 and second cut portion 12d, however, is not limited as such. First cut portion 13c2 and second cut portion 12d may be provided also in a portion other than four corners, in addition to each of four corners of opening 13b in flange member 13.
In the present embodiment and the modification, heat exchange portion 11 may be configured to exchange heat by flow of water and/or hot water between front plate portion 11a and the front surface of heat transfer plate 11b arranged in the forefront.
It should be understood that the embodiment disclosed herein is illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims rather than the description above and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
10 latent heat recovery heat exchanger; 11 heat exchange portion; 11a front plate portion; 11b heat transfer plate; 11c rear plate portion; 12 case; 12a rear wall portion; 12b sidewall portion; 12c upper end portion; 12d second cut portion; 13 flange member; 13a extension portion; 13b opening; 13c rising coupling portion; 13c1 peripheral wall portion; 13c2 first cut portion; 14 pipe joint portion; 20 sensible heat recovery heat exchanger; 22 header; 23 heat transfer tube; 30 combustion apparatus; 31 chamber; 32 fan assembly; 33 duct; 34 venturi; 35 orifice; 36 gas valve; 40 pipe; 41 bypass pipe; 42 three-way valve; 43 liquid to liquid heat exchanger; 44 hydronic pipe; 50 housing; 60 sealing member; 100 hot water apparatus
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-164888 | Aug 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/027972 | 8/2/2017 | WO | 00 |
