Water heater

Patent metadata

Field	Value
Publication number	US-2016010892-A1
Application number	US-201514732478-A
Country	US
Kind code	A1
Filing date	Jun 5, 2015
Priority date	Jul 8, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A water heater includes: a burner; a heat exchanger; a fan for supplying air to the burner and emitting combustion gas having passed through the heat exchanger to outside of the water heater; and a drainage water discharge path connected to the heat exchanger. The drainage water discharge path has a water-sealing structure that is water-sealed by drainage water. The water heater further includes a control unit: having a water-seal determination unit giving permission that the water heater can operate in a normal mode based on a condition that the drainage water discharge path has been water-sealed; and issuing an instruction to cause the burner to intermittently operate for a time period until the water-seal determination unit gives the permission.

First claim

What is claimed is:

1 . A water heater of a latent heat recovery type capable of heating water by recovering latent heat of combustion gas, said water heater comprising:
a burner generating combustion gas by burning fuel gas in a combustion region; a heat exchanger heating water flowing through inside by heat exchange with combustion gas generated in said burner; a fan for supplying air to said burner; a drainage water discharge path connected to said heat exchanger for discharging drainage water to outside of said heat exchanger, drainage water being produced by recovering latent heat in said heat exchanger, and said drainage water discharge path having a water-sealing structure that is water-sealed by said drainage water; and a control unit including a water-seal determination unit giving permission that said water heater can operate in a normal mode based on a condition that said drainage water discharge path has been water-sealed, said control unit issuing an instruction to cause said burner to intermittently operate for a time period until said water-seal determination unit gives said permission.

2 . The water heater according to claim 1 , wherein
in said burner, said combustion region is formed of a plurality of unit regions that can be independently controlled such that a generation amount of combustion gas can be changed in accordance with a required hot-water supply capability, and said control unit issues an instruction to said burner to cause combustion to occur in all of said unit regions for a time period until said water-seal determination unit gives said permission.

3 . The water heater according to claim 1 , wherein
said burner is configured to be capable of adjusting a supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

4 . The water heater according to claim 3 , wherein
in said burner, said combustion region is formed of a plurality of unit regions that can be independently controlled such that a generation amount of combustion gas can be changed in accordance with a required hot-water supply capability, and said control unit issues an instruction to said burner to cause combustion to occur in all of said unit regions for a time period until said water-seal determination unit gives said permission.

5 . The water heater according to claim 1 , wherein said water-seal determination unit gives said permission on a condition that an estimate drainage water discharge amount becomes equal to or greater than a prescribed threshold value, said estimate drainage water discharge amount being calculated using at least one selected from a group consisting of a supply amount of fuel gas to said combustion region, a temperature of water supplied to said water heater, and a temperature of hot water discharged from said water heater.

6 . The water heater according to claim 5 , wherein
in said burner, said combustion region is formed of a plurality of unit regions that can be independently controlled such that a generation amount of combustion gas can be changed in accordance with a required hot-water supply capability, and said control unit issues an instruction to said burner to cause combustion to occur in all of said unit regions for a time period until said water-seal determination unit gives said permission.

7 . The water heater according to claim 5 , wherein
said burner is configured to be capable of adjusting the supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

8 . The water heater according to claim 6 , wherein
said burner is configured to be capable of adjusting the supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

9 . The water heater according to claim 1 , wherein
said fan is configured to be arranged downstream of said heat exchanger in a flow direction of combustion gas to suction air into said burner, said water heater further comprising an exhaust temperature detection unit measuring a temperature of combustion gas and provided downstream of said heat exchanger in the flow direction of combustion gas, and said water-seal determination unit gives said permission on a condition that the temperature of combustion gas measured in said exhaust temperature detection unit tends to increase to a value equal to or greater than a prescribed threshold value.

10 . The water heater according to claim 9 , wherein
in said burner, said combustion region is formed of a plurality of unit regions that can be independently controlled such that a generation amount of combustion gas can be changed in accordance with a required hot-water supply capability, and said control unit issues an instruction to said burner to cause combustion to occur in all of said unit regions for a time period until said water-seal determination unit gives said permission.

11 . The water heater according to claim 9 , wherein
said burner is configured to be capable of adjusting a supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

12 . The water heater according to claim 10 , wherein
said burner is configured to be capable of adjusting a supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

13 . The water heater according to claim 1 , wherein said fan is configured to be arranged upstream of said heat exchanger in a flow direction of combustion gas to force air into said burner.

14 . The water heater according to claim 13 , wherein
in said burner, said combustion region is formed of a plurality of unit regions that can be independently controlled such that a generation amount of combustion gas can be changed in accordance with a required hot-water supply capability, and said control unit issues an instruction to said burner to cause combustion to occur in all of said unit regions for a time period until said water-seal determination unit gives said permission.

15 . The water heater according to claim 13 , wherein
said burner is configured to be capable of adjusting a supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

16 . The water heater according to claim 14 , wherein
said burner is configured to be capable of adjusting the supply amount of fuel gas to said combustion region, and said control unit issues an instruction to said burner to maximize the supply amount of fuel gas for a time period until said water-seal determination unit gives said permission.

17 . The water heater according to claim 13 , wherein said water-seal determination unit gives said permission on a condition that an estimate drainage water discharge amount becomes eq

Assignees

• Noritz Corp

Inventors

• Kimura Sakiko
• Oohigashi Takeshi

Classifications

• F24H8/00

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

• F24H8/006

  Means for removing condensate from the heater · CPC title

• F24H9/1836

  using fluid fuel · CPC title

• F24H1/145

  using fluid fuel · CPC title

• F24H9/2042 Primary

  Preventing or detecting the return of combustion gases · CPC title