Water heater having secondary heat exchanger

Patent metadata

Field	Value
Publication number	US-10473407-B2
Application number	US-201414521255-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Oct 22, 2014
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A water heater includes a combustion device, a primary heat exchanger, and a secondary heat exchanger. The combustion device burns gas to generate high-temperature air. The primary and the secondary heat exchangers are provided sequentially above the combustion device. When the high-temperature air passes through the primary heat exchanger, part of thermal energy is absorbed by exchange plates and a water pipe therein. When the high-temperature air continues to pass through the secondary heat exchanger, part of the rest thermal energy is absorbed by a heat tube set therein to preheat water flowing through the heat tube set. The preheated water then flows into the water pipe of the primary heat exchanger. The secondary heat exchanger includes a case and a cover board which detachably seals a bore on the case. Whereby, it is convenient for a user to clean pipes inside the secondary heat exchanger.

First claim

What is claimed is:

1. A secondary heat exchanger, which is mounted on a water heater having a primary heat exchanger and is adapted for performing heat exchange between water and a high-temperature flue gas, wherein the primary heat exchanger has a first exit opening, comprising: a case having an enter opening, a second exit opening, and a bore, wherein the enter opening is communicated with the first exit opening of the primary heat exchanger; a heat tube set received in the case, and having an inlet and an outlet for water entering the heat tube set via the inlet and leaving via the outlet; a cover board detachably connected to the case to seal the bore; and a collecting member received in the case under the heat tube set; wherein the case has a plate at a top thereof and a board; the second exit opening is provided on the plate, and the bore is provided on the board; the cover board is detachably provided on the board to seal the bore; and the bore exposes the heat tube set; wherein the collecting member has a top board and a low board; the top board is stacked on the low board, and a space is formed between the top board and the low board; wherein the case has a plate at a top thereof; the cover board has an inner side; the collecting member has a front edge; a first distance is formed between the front edge of the collecting member and the board, and a second distance is formed between the front edge of the collecting member and the inner side of the cover board; the second distance is longer than the first distance; wherein the cover board protrudes relative to an outer surface of the board of the case to form a protruding portion, whereby to increase a space to be passed through by the high-temperature flue gas, and wherein the cover board has a flange, which surrounds the protruding portion and is detachably engaged with the board of the case; the secondary heat exchanger further comprises a separating board connected to the inner side of the cover board to be located in the protruding portion, and an interval is formed between the separating board and the cover board, wherein the interval does not communicate with the space to be passed through by the high-temperature flue gas such that the high-temperature flue gas does not enter the interval and can only be in contact with an inner surface of the separating board facing the collecting member; a third distance is formed between the front edge of the collecting member and the separating board, and the third distance is shorter than the second distance, but longer than the first distance to thereby guide the high-temperature flue gas flow generally upwardly through the space including the first distance and the third distance.

2. The secondary heat exchanger of claim 1 , wherein the case further has a board, which is connected to the plate, and has an exhausting bore; the collecting member is inclined as a whole related to a horizontal direction, and the exhausting bore is at a low side of the collecting member, whereby water on the collecting member flows to the low side and flow out of the case through the exhausting bore; and wherein the heat tube set is in an inclined position.

3. The secondary heat exchanger of claim 1 , further comprising a gasket between the cover board and the case and surrounding the bore.

4. A water heater, comprising: a combustion device where gas is burned to generate heat; a primary heat exchanger above the combustion device, and having a first case and a water pipe, wherein the first case has a first exit opening, and the water pipe is received in the first case; the water pipe has an inlet and an outlet; and a secondary heat exchanger above the primary heat exchanger, which is adapted for performing heat exchange between water and a high-temperature flue gas, and includes a second case having an enter opening, a second exit opening, and a bore, wherein the enter opening is communicated with the first exit opening of the primary heat exchanger; a heat tube set received in the case, and having an inlet and an outlet for water entering the heat tube set via the inlet and leaving via the outlet; a cover board detachably connected to the case to seal the bore; and a collecting member received in the case under the heat tube set; wherein the second case of the secondary heat exchanger has a plate at a top thereof and a board; the second exit opening is provided on the plate, and the bore is provided on the board; the cover board is detachably provided on the board to seal the bore; and the bore exposes the heat tube set wherein the collecting member has a top board and a low board; the top board is stacked on the low board, and a space is formed between the top board and the low board; wherein the water heater comprises a base and a main case, and the secondary heat exchanger is mounted on the base; the main case is detachably connected to the base; the cover board has an inner side; the collecting member has a front edge; such that a first distance is formed between the front edge of the collecting member and the board, and a second distance is formed between the front edge of the collecting member and the inner side of the cover board; and the second distance is longer than the first distance; wherein the cover board protrudes relative to an outer surface of the board of the second case, whereby to increase a space to be passed through by the high-temperature flue gas; the secondary heat exchanger further has a separating board connected to the inner side of the cover board, and an interval is formed between the separating board and the cover board, wherein the interval does not communicate with the space to be passed through by the high-temperature flue gas such that the high-temperature air does not enter the interval and can only be in contact with an inner surface of the separating board facing the collecting member; a third distance is formed between the front edge of the collecting member and the separating board, and the third distance is shorter than the second distance, but longer than the first distance to thereby guide the high-temperature flue gas flow generally upwardly through the space including the first distance and the third distance.

5. The water heater of claim 4 , wherein the second case of the secondary heat exchanger further has a board, which is connected to the plate, and has an exhausting bore; the collecting member is inclined as a whole related to a horizontal direction, and the exhausting bore is at a low side of the collecting member, whereby water on the collecting member flows to the low side and flow out of the second case through the exhausting bore; wherein the heat tube set is in an inclined condition.

6. The water heater of claim 4 , wherein the secondary heat exchanger further has a gasket between the cover board and the second case and surrounding the bore.

Assignees

• Grand Mate Co Ltd

Inventors

• Huang Chung-Chin
• Huang Chin-Ying
• Huang Hsin-Ming
• Huang Hsing-Hsiung
• Yeh Yen-Jen
• Lin Kuan-Chou

Classifications

• F24H8/00

  Fluid heaters characterised by means for extracting latent heat from flue gases by means of condensation · CPC title

• F28F1/32

  the means having portions engaging further tubular elements · CPC title

• F24H9/1836

  using fluid fuel · CPC title

• F24H9/0042

  Cleaning arrangements · CPC title

• F24H9/146

  Connecting elements of a heat exchanger · CPC title