Leakage detection in condensing water heater

Patent metadata

Field	Value
Publication number	US-11573148-B2
Application number	US-201916538514-A
Country	US
Kind code	B2
Filing date	Aug 12, 2019
Priority date	Aug 12, 2019
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

A water heater system includes a gas burner configured to selectively produce flue gases, and a heat exchanger for heating water in the water heater system. The water heater system is operable in a heating mode, and a standby mode. An exhaust assembly is in communication with the heat exchanger, and includes a condensate collector configured to receive the flue gases and condensate. A first temperature sensor is positioned to sense a temperature of the condensate within the condensate collector. The first temperature sensor is configured to detect a rate of temperature change of the condensate. A controller is configured to determine a leakage when the rate of temperature change adjusts from a first state to a second state when the water heater system is in the standby mode after the water heater system was in the heating mode.

First claim

What is claimed is:

1. A water heater system comprising:
a gas burner configured to selectively produce flue gases;
a heat exchanger for heating water in the water heater system, the heat exchanger configured to receive one of the water and the flue gases, wherein the water heater system is operable in a heating mode in which the flue gases are flowing through the water heater system to heat the water in the water heater system, and a standby mode in which there is an absence of the flue gases flowing through the water heater system;
an exhaust assembly in fluid communication with the heat exchanger, the exhaust assembly including a condensate collector configured to receive the flue gases and condensate produced by the flue gases, the condensate collector including a condensate management portion;
a temperature sensor positioned to sense a temperature of fluid within the condensate collector, the temperature sensor configured to detect a rate of temperature change of the fluid; and
a controller configured to determine the presence of a leak in the water heater system when the rate of temperature change transitions from a negative rate of change to a positive rate of change while the water heater system is in the standby mode after the water heater system was in the heating mode,
wherein the condensate management portion delays the transition of the rate of temperature change from the negative rate of change to the positive rate of change when the water heater system enters the standby mode from the heating mode.

2. The water heater of claim 1 , wherein the condensate collector includes a drain line, and wherein the temperature sensor is positioned at least partially within the drain line.

3. The water heater of claim 2 , wherein the fluid flowing from the heat exchanger toward the condensate collector defines a downstream direction, wherein the condensate collector includes a drain pipe fluidly connected to the drain line and positioned upstream of the drain line, and wherein the condensate management portion includes the drain pipe and a portion of the drain line upstream of the predetermined location of the temperature sensor.

4. The water heater of claim 2 , wherein the condensate management portion includes an internal volume and delays the transition of the rate of temperature change by accumulating fluid within the internal volume.

5. The water heater of claim 4 , wherein the transition of the rate of temperature change from the negative rate of change to the positive rate of change occurs once leaking water has reached a predetermined location within the internal volume.

6. The water heater of claim 1 , wherein a length of time between the water heater system entering the stand-by mode and the transition of the rate of change from the negative state to the positive state is proportional to a leakage rate.

7. The water heater of claim 1 wherein the temperature sensor is a first temperature sensor, further comprising a second temperature sensor positioned to sense a temperature of the flue gases flowing through the exhaust assembly, the second temperature sensor electrically connected to the controller.

8. The water heater system of claim 7 , wherein the condensate collector includes a drain, and wherein the controller is further configured to determine a drain blockage of the drain based on a comparison between a temperature reading of the first temperature sensor and a temperature reading of the second temperature sensor when the water heater is in the heating mode.

9. The water heater system of claim 8 , wherein the drain blockage is determined by the controller when the temperature reading of the first temperature sensor is about the same as the temperature reading of the second temperature sensor.

10. The water heater system of claim 1 , wherein the condensate management portion includes a drain pipe, and wherein water leaking from the water heater system accumulates in the drain pipe after the water heater system enters the standby mode from the heating mode.

11. A method for determining an error in a water heater system, the water heater system including a heat exchanger, a gas burner, and an exhaust assembly in fluid communication with the heat exchanger, the method comprising:
operating the water heater system in a heating mode, in which flue gases produced by the gas burner are flowing through the water heater system;
operating the water heater system in a standby mode, in which there is an absence of the flue gases flowing through the water heater system;
condensing water from the flue gases to form condensate when the water heater system is operating in the heating mode, and flowing the condensate through the exhaust assembly;
monitoring, by a controller, a rate of temperature change detected by a temperature sensor positioned to sense a temperature of fluid within a condensate collector of the exhaust assembly, the condensate collector having a condensate management portion;
determining a leakage of the water heater system by the controller when the rate of temperature change adjusts from a negative rate of change to a positive rate of change when the water heater system is in the standby mode after the water heater system was in the heating mode; and
delaying, by the condensate management portion, the adjustment of the rate of temperature change from the negative rate of change to the positive rate of change for a predetermined time period when the water heater enters the standby mode from the heating mode.

12. The method of claim 11 , wherein the adjustment of the rate of temperature change from the negative rate of temperature change to the positive rate of temperature change occurs at an end of the predetermined time period.

13. The method of claim 11 wherein the temperature sensor is a first temperature sensor, wherein monitoring, by the controller, further includes monitoring a temperature reading of the first temperature sensor, and monitoring a temperature reading of a second temperature sensor positioned to sense a temperature of the flue gases flowing through the exhaust assembly.

14. The method of claim 13 , wherein the condensate collector further includes a drain configured to receive the condensate, the method further comprising determining a drain blockage of the drain by the controller based on a comparison between the temperature reading of the first temperature sensor and the temperature reading of the second temperature sensor when the water heater is in the heating mode.

15. The method of claim 14 , wherein the drain blockage is determined by the controller when the temperature reading of the first temperature sensor is about the same as the temperature reading of the second temperature sensor.

16. The method of claim 11 , wherein the condensate collector includes a drain line, and wherein the temperature sensor is positioned at least partially within the drain line at a predetermined location on the drain line.

17. The method of claim 16 , wherein the fluid flows from the heat exchanger through the exhaust assembly to define a downstream direction, wherein the condensate collector includes a drain pipe fluidly connected to the drain line upstream of the drain line, and wherein the condensate management portion includes the drain pipe and a portion of the drain line upstream of the predetermined location of the first temperature sensor.

18. The method of claim 16 , wherein delaying, by the condensate management portion, further includes inhibiting flow of leaking water through the drain line, by the condensate managemen

Assignees

• Smith Corp A O

Inventors

• Yin Jianmin
• Critchley Matthew W
• Keller Quinn Thomas

Classifications

• F24H9/2007

  for water heaters · CPC title

• F23J15/06

  of coolers · CPC title

• F24H9/18

  Arrangement or mounting of grates or heating means · CPC title

• F28D21/0014

  the heat being recuperated from waste air or from vapors (for air conditioning F24F12/001) · CPC title

• F24H1/28 Primary

  including one or more furnace or fire tubes · CPC title