Heat exchanger and water heater including same

Patent metadata

Field	Value
Publication number	US-10794640-B2
Application number	US-201916418494-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	Jul 27, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A heat exchanger includes a heat transfer tube in which a plurality of tube body portions are arranged in a two-tier staggered pattern in a flow direction of heating gas, and a fin, wherein a plurality of cut-out recessed portions are provided in the fin by cutting out sites between first and second upstream side tube body portions, and each cut-out recessed portion extends toward a downstream side in the flow direction of the heating gas beyond the site between the first and second upstream side tube body portions so as to cross straight lines linking a center of a first downstream side tube body portion, which is positioned between the first and second upstream side tube body portions in the width direction, and respective centers of the first and second upstream side tube body portions. Thus, the temperature distribution of the fin is made even, thereby suppressing the generation of thermal stress, and as a result, distortion of the heat transfer tube is suppressed.

First claim

The invention claimed is:

1. A heat exchanger, comprising:
a case into which heating gas flows;
a heat transfer tube that is disposed inside the case and includes a plurality of tube body portions arranged at intervals in a width direction intersecting a flow direction of the heating gas, the plurality of tube body portions being arranged in a two-tier staggered pattern in the flow direction of the heating gas so as to be divided into a plurality of upstream side tube body portions and a plurality of downstream side tube body portions; and
a fin that is penetrated by and bonded to the plurality of tube body portions,
wherein a plurality of cut-out recessed portions are provided in upstream side parts of the fin in the flow direction of the heating gas by cutting out sites between adjacent first and second upstream side tube body portions among the plurality of upstream side tube body portions, and
each cut-out recessed portion extends toward a downstream side in the flow direction of the heating gas beyond the site between the first and second upstream side tube body portions so as to cross straight lines linking a center of a first downstream side tube body portion of the plurality of downstream side tube body portions, the first downstream side tube body portion being positioned between the first and second upstream side tube body portions in the width direction, and respective centers of the first and second upstream side tube body portions.

2. The heat exchanger according to claim 1 , wherein
a downstream side part of each cut-out recessed portion in the flow direction of the heating gas is constituted by two extension portions that bifurcate in the width direction, and
the two extension portions respectively extend to positions on left and right sides of a part of the first downstream side tube body portion near the upstream side in the flow direction of the heating gas.

3. The heat exchanger according to claim 1 , wherein
at least one slit is provided in the fin between the plurality of downstream side tube body portions, a length of the slit in the flow direction of the heating gas being equal to or greater than an outer diameter of each of the plurality of downstream side tube body portions.

4. The heat exchanger according to claim 1 , further comprising:
a plurality of cut and raised pieces provided in the fin and erected on a front side or a rear side of the fin so as to extend in the width direction,
wherein the cut and raised pieces are respectively positioned between the plurality of downstream side tube body portions on the downstream side thereof in the flow direction of the heating gas, and a width thereof is greater than an inside width between the plurality of downstream side tube body portions.

5. The heat exchanger according to claim 1 , further comprising:
contact portions provided on parts of respective end portions of the fin on the upstream side in the flow direction of the heating gas so as to be capable of contacting respective side wall portions of the case,
wherein cut-out recessed portions positioned on respective width direction ends, among the plurality of cut-out recessed portions, extend beyond the contact portions toward the downstream side in the flow direction of the heating gas.

6. A water heater, comprising:
the heat exchanger according to claim 1 .

7. The water heater according to claim 6 , further comprising:
a burner that supplies combustion gas into the case of the heat exchanger,
wherein the combustion gas serves as the heating gas.

Assignees

• Noritz Corp

Inventors

• Kondo Masaki
• Ohigashi Takeshi

Classifications

• F28F1/325

  Fins with openings · CPC title

• F24H9/0005 Primary

  for water heaters · CPC title

• F28F2009/0292

  with fins · CPC title

• F24H1/40

  with water tube or tubes · CPC title

• F28F9/0131 Primary

  formed by plates (F28F9/0138 takes precedence) · CPC title