WATER HEATING SYSTEM

Abstract

A water heating system includes a tank, a combustion chamber, an exhaust pathway that includes a flue that extends through the tank, and a damper assembly that includes a damper and an actuator operable to move the damper between open and closed positions. A burner is disposed within the combustion chamber and is operable to combust fuel in a firing state of the water heating system. A standing pilot burner is disposed within the combustion chamber and is operable to combust fuel in a standby state of the water heating system. The water heating system further includes a standing pilot burner output sensor, an exhaust pathway temperature sensor, and a tank temperature sensor. Control circuitry of the water heating system controls operation of the damper assembly based on data received from the standing pilot burner output sensor, the exhaust pathway temperature sensor, and the tank temperature sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application No. 63/766,718, filed on Mar. 4, 2025, entitled “WATER HEATING SYSTEM,” the disclosure of which is hereby incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a water heating system. More specifically, the present disclosure relates to a water heating system that controls a position of a damper based on various types of sensor data.

BACKGROUND OF THE DISCLOSURE

Natural draft water heaters that include standing pilot ignition systems and flue dampers operate by utilizing the buoyancy of hot gases to expel combustion by-products through a vertical flue. The standing pilot remains lit at all times to provide immediate ignition for a main burner when called upon. The flue extends through the water tank, transferring heat to the water before the gases exit through the venting system. The flue damper is often positioned above the tank, closing when the main burner is off to minimize standby heat losses by preventing unnecessary heat escape. This setup can enhance efficiency but may also introduce operational challenges.

For example, in a standing pilot system with a flue damper, when the damper is closed and standby losses are low, heat from flue gases originating from the standing pilot can build within the flue. Without an open damper to allow heat dissipation, this process can elevate the water temperatures proximate to the top of the tank of the water heater beyond desired levels. Further, when the damper is closed while the standing pilot is burning, airflow can be restricted, reducing the natural draft effect that normally helps remove combustion by-products and introduce fresh oxygen into the combustion chamber. This issue can be further exacerbated when the water heater is disposed in an environment with high ambient temperatures where available oxygen concentration and combustion product buoyancy is relatively reduced. Low oxygen availability and reduced natural draft effect can cause the pilot flame to become unstable and flicker as it struggles to maintain proper combustion. Under these conditions, the pilot flame may fail to maintain proper contact with a sensor, such as a thermopile, that is responsible for generating electrical power required to keep a gas valve open. When the thermopile does not receive sufficient heat from the pilot flame, its output voltage drops, leading to the gradual loss of power needed to sustain normal operation. Eventually the gas valve may close, extinguishing the pilot and requiring relighting before the water heater can function again.

SUMMARY OF THE DISCLOSURE

According to a first aspect of the present disclosure, a water heating system is provided. The water heating system includes a tank for holding water to be heated and a combustion chamber adjacent to the tank. An exhaust pathway includes a flue that is in communication with the combustion chamber and that extends through the tank. A damper assembly includes a damper disposed within the exhaust pathway and an actuator operable to move the damper between an open position and a closed position. A burner is disposed within the combustion chamber and is operable to combust fuel in a firing state of the water heatg system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper. A standing pilot burner is disposed within the combustion chamber and is operable to combust fuel in a standby state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper. A standing pilot burner output sensor senses a characteristic of an output of the standing pilot burner. An exhaust pathway temperature sensor is coupled to the exhaust pathway upstream of the damper and is configured to sense a temperature corresponding with a temperature of the combustion gas within the exhaust pathway proximate to and upstream of the damper. A tank temperature sensor is configured to sense a temperature corresponding with a temperature of water disposed within the tank. Control circuitry is configured to control operation of the damper assembly based on data received from the standing pilot burner output sensor, the exhaust pathway temperature sensor, and the tank temperature sensor.

Embodiments of the first aspect of the disclosure can include any one or a combination of the following features:

• • a top of the tank is nearer than a bottom of the tank to the exhaust pathway temperature sensor that is coupled to the exhaust pathway;
  • the exhaust pathway temperature sensor is positioned above the top of the tank between the top of the tank and the damper;
  • the tank temperature sensor is positioned relative to the tank such that the temperature that the tank temperature sensor senses corresponds with a temperature of water disposed within the tank that is nearer to the bottom of the tank than to the top of the tank;
  • the water heating system does not include a second tank temperature sensor configured to sense a temperature corresponding with a temperature of water disposed within the tank that is nearer to the top of the tank than to the bottom of the tank;
  • the standing pilot burner output sensor comprises a thermopile;
  • in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on the temperature sensed by the exhaust pathway temperature sensor;
  • in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor;
  • in the standby state of the water heating system, the control circuitry is configured to determine a temperature value corresponding with a temperature of water disposed within the tank proximate to the top of the tank based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor, and to control the actuator to move the damper from the closed position to the open position responsive to the temperature value being greater than a threshold temperature value;
  • the threshold temperature value is at least one of a water temperature setpoint value and related to a water temperature setpoint value;
  • responsive to the water heating system entering the standby state from the firing state, the control circuitry is configured to control the actuator of the damper assembly to move the damper from the open position to the closed position after a length of time has elapsed since the water heating system entered the standby state from the firing state, wherein the length of time is determined by the control circuitry based on the temperature sensed by an ambient air temperature sensor that is configured to sense a temperature corresponding with a temperature of ambient air external to the water heating system;
  • the control circuitry is configured such that a first length of time is determined by the control circuitry based on a first temperature sensed by the ambient air temperature sensor and a second length of time is determined by the control circuitry based on a second temperature sensed by the ambient air temperature sensor, wherein the first length of time is shorter than the second length of time, and the first temperature is less than the second temperature;
  • in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on at least one sensed characteristic of the output of the standing pilot burner;
  • the standing pilot burner output sensor includes a thermopile that senses a characteristic of the combustion of fuel by the standing pilot burner, and in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on at least one of a rate of change of voltage output from the thermopile and an average voltage output from the thermopile over a period of time; and
  • in the standby state of the water heating system, the control circuitry is configured to control the actuator to move the damper from the closed position to the open position based on the rate of change of voltage output from the thermopile, the average voltage output from the thermopile over the period of time, and the temperature sensed by the ambient air temperature sensor.

According to a second aspect of the present disclosure, a water heating system is provided that includes a tank for holding water to be heated and a combustion chamber adjacent to the tank. An exhaust pathway includes a flue that is in communication with the combustion chamber and that extends through the tank. A burner is disposed within the combustion chamber and is operable to combust fuel such that combustion gas is conveyed along the exhaust pathway. A damper assembly includes a damper disposed within the exhaust pathway, an actuator operable to move the damper between an open position and a closed position, and an exhaust pathway temperature sensor coupled to the exhaust pathway at a position that is upstream of the damper when the damper is in the closed position. The exhaust pathway temperature sensor is configured to sense a temperature corresponding with a temperature of the combustion gas within the exhaust pathway. Control circuitry is in communication with the exhaust pathway temperature sensor and is configured to determine a temperature value corresponding with a temperature of water disposed within the tank proximate to a top of the tank based on the temperature sensed by the exhaust pathway temperature sensor.

Embodiments of the second aspect of the disclosure can include any one or a combination of the following features:

• • a tank temperature sensor is positioned nearer to a bottom of the tank than to the top of the tank and is configured to sense a temperature corresponding with a temperature of water disposed within the tank adjacent to the tank temperature sensor, and the control circuitry is in communication with the exhaust pathway temperature sensor and the tank temperature sensor and is configured to determine the temperature value corresponding with the temperature of water disposed within the tank proximate to the top of the tank based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor; and
  • in a standby state of the water heating system in which a standing pilot burner of the water heating system combusts fuel such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper, the control circuitry is configured to control the actuator of the damper assembly to move the damper from the closed position to the open position responsive to the temperature value being greater than a threshold temperature value.

According to a third aspect of the present disclosure, a water heating system is provided. The system includes a tank for holding water to be heated and a combustion chamber adjacent to the tank. An exhaust pathway includes a flue that is in communication with the combustion chamber and that extends through the tank. A damper assembly includes a damper disposed within the exhaust pathway and an actuator operable to move the damper between an open position and a closed position. A burner is disposed within the combustion chamber and is operable to combust fuel in a firing state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper. A standing pilot burner is disposed within the combustion chamber and is operable to combust fuel in a standby state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper. A standing pilot burner output sensor senses a characteristic of an output of the standing pilot burner. Control circuitry is in communication with the standing pilot burner output sensor and, in the standby state of the water heating system, controls the actuator of the damper assembly to move the damper from the closed position to the open position based on the sensed characteristic of the output of the standing pilot burner.

Embodiments of the third aspect of the disclosure can include the following feature:

• • the standing pilot burner output sensor includes a thermopile, and the control circuitry is configured to control the actuator to move the damper from the closed position to the open position based on at least one of a rate of change of voltage output from the thermopile and an average voltage output from the thermopile over a period of time.

These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a top perspective view of a water heating system, illustrating a damper assembly disposed atop a shell of the water heating system, according to one embodiment;

FIG. 2 is an exploded view of the water heating system, illustrating various components thereof, according to one embodiment;

FIG. 3 is a side elevational view of the water heating system, illustrating a plurality of components in phantom, including a tank of the water heating system, an exhaust pathway of the water heating system, and a damper assembly of the water heating system, according to one embodiment;

FIG. 4 of the water heating system is an elevational view of a portion of the damper assembly of the water heating system, illustrating a damper, an actuator configured to move the damper between open and closed positions, and an exhaust pathway temperature sensor in phantom, according to one embodiment; and

FIG. 5 is a block diagram of the water heating system, illustrating the control circuitry of the water heating system in communication with various components of the water heating system, according to one embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Additional features and advantages of the disclosure will be set forth in the detailed description which follows and will be apparent to those skilled in the art from the description, or recognized by practicing the disclosure as described in the following description, together with the claims and appended drawings.

As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

In this document, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

For purposes of this disclosure, the term “coupled” (in all of its forms: couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and/or any additional intermediate members. Such joining may include members being integrally formed as a single unitary body with one another (i.e., integrally coupled) or may refer to joining of two components. Such joining may be permanent in nature, or may be removable or releasable in nature, unless otherwise stated.

As used herein, the terms “the,” “a,” or “an,” mean “at least one,” and should not be limited to “only one” unless explicitly indicated to the contrary. Thus, for example, reference to “a component” includes embodiments having two or more such components unless the context clearly indicates otherwise.

Referring now to FIGS. 1-5, a water heating system 10 includes a tank 12 for holding water to be heated. A combustion chamber 14 is positioned adjacent to the tank 12. An exhaust pathway 16 includes a flue 18 that is in communication with the combustion chamber 14. The flue 18 extends through the tank 12. A damper assembly 20 includes a damper 22 that is disposed within the exhaust pathway 16 and an actuator 24 that is operable to move the damper 22 between an open position and a closed position. A burner 26 is disposed within the combustion chamber 14 and is operable to combust fuel in a firing state of the water heating system 10, such that combustion gas is conveyed along the exhaust pathway 16 from the combustion chamber 14, into the flue 18, and onward to the damper 22. A standing pilot burner 28 is disposed within the combustion chamber 14 and is operable to combust fuel in a standby state of the water heating system 10, such that combustion gas is conveyed along the exhaust pathway 16 from the combustion chamber 14, into the flue 18, and onward to the damper 22.

The water heating system 10 includes a standing pilot burner output sensor 30 that senses a characteristic of an output of the standing pilot burner 28. An exhaust pathway temperature sensor 32 is coupled to the exhaust pathway 16 upstream of the damper 22 and is configured to sense a temperature corresponding with a temperature of the combustion gas within the exhaust pathway 16 proximate to and upstream of the damper 22. A tank temperature sensor 34 is configured to sense a temperature corresponding with the temperature of water disposed within the tank 12. An ambient air temperature sensor 36 is configured to sense a temperature corresponding with a temperature of ambient air that is external to the water heating system 10. The water heating system 10 further includes control circuitry 38 that controls operation of the damper assembly 20 based on data received from the standing pilot burner output sensor 30, the exhaust pathway temperature sensor 32, the tank temperature sensor 34, and the ambient air temperature sensor 36.

Referring now to FIGS. 1-3, the water heating system 10 includes the tank 12. The tank 12 is configured to hold water to be heated. As illustrated in FIGS. 1-3, the tank 12 may be disposed within an outer shell 40. The tank 12 can be insulated. For example, insulation material may be disposed between the exterior surface of the tank 12 and the shell 40, in some embodiments. As illustrated in FIGS. 1 and 2, the tank 12 can include a cold water inlet 42 and a hot water outlet 44. In the illustrated embodiments, fittings 46 associated with the cold water inlet 42 and the hot water outlet 44 extend from the tank 12 proximate to a top 48 of the tank 12. The tank 12 includes the top 48 and a bottom 50 opposite the top 48.

Referring now to FIGS. 1-3, the water heating system 10 includes the combustion chamber 14. The combustion chamber 14 can be positioned adjacent to the tank 12. For example, as illustrated in FIG. 3, the combustion chamber 14 is disposed adjacent to the tank 12 proximate to the bottom 50 of the tank 12. As described further herein, the combustion chamber 14 can have the burner 26 and the standing pilot burner 28 of the water heating system 10 disposed therein.

Referring still to FIGS. 1-3, the water heating system 10 includes the exhaust pathway 16. The exhaust pathway 16 can include at least a portion of the combustion chamber 14, in various embodiments. The exhaust pathway 16 can include the flue 18 that is in communication with the combustion chamber 14. The flue 18 may extend through the tank 12 of the water heating system 10. In the embodiment illustrated in FIG. 3, the flue 18 is in fluid communication with the combustion chamber 14 and extends vertically upward therefrom through the tank 12 of the water heating system 10 and out of the top 48 of the tank 12. The exhaust pathway 16 of the water heating system 10 can include portions in addition to the flue 18 and the combustion chamber 14, in various embodiments. For example, in some embodiments, the exhaust pathway 16 includes a vent portion that is in fluid communication with the flue 18, and through which combustion gases are configured to be vented out of the environment (e.g., attic of a home) within which the tank 12 of the water heating system 10 is disposed.

Referring still FIGS. 1-3, the water heating system 10 includes a combustion assembly 52. The combustion assembly 52 includes the burner 26. The burner 26 can be disposed within the combustion chamber 14 and is operable to combust fuel in a firing state of the water heating system 10. The combustion assembly 52 further includes the standing pilot burner 28. The standing pilot burner 28 is disposed within the combustion chamber 14 and is operable to combust fuel in the standby state of the water heating system 10 and/or the firing state of the water heating system 10. As such, combustion gas from the burner 26 and/or the standing pilot burner 28 is conveyed along the exhaust pathway 16 from the combustion chamber 14, into the flue 18 and onward to the damper 22. In various implementations, the combustion assembly 52 includes a fuel supply line and a fuel valve 54 that controls the supply of fuel to the burner 26 and/or the standing pilot burner 28 in operation of the water heating system 10. The fuel valve 54 may be electrically coupled with a standing pilot burner output sensor 30, such as a thermopile 56, and the output of the standing pilot burner 28 sensed by the standing pilot burner output sensor 30 may control operation of the fuel valve 54, in some embodiments, as described further herein. Control circuitry 38 of the water heating system 10 may control transition of the water heating system 10 between the standby state and the firing state in operation of the water heating system 10, as described further herein. In various implementations, in the firing state, the burner 26 combusts fuel. In the standby state, the standing pilot burner 28 combusts fuel. In various embodiments, in the standby state, the burner 26 does not combust fuel.

Referring now to FIGS. 1-5, the water heating system 10 includes the damper assembly 20. The damper assembly 20 includes the damper 22 that is disposed within the exhaust pathway 16. In various implementations, the damper 22 of the damper assembly 20 is positioned upward of the top 48 of the tank 12. The damper 22 is operable between an open position and a closed position. The damper assembly 20 further includes the actuator 24. The actuator 24 is operable to actuate to move the damper 22 between the open and closed positions. In some embodiments, the damper assembly 20 includes the exhaust pathway temperature sensor 32. The exhaust pathway temperature sensor 32 is coupled to the exhaust pathway 16 upstream of the damper 22. In other words, the exhaust pathway temperature sensor 32 is coupled to the exhaust pathway 16 at a position that is nearer to the source of combustion gas being conveyed within the exhaust pathway 16 than the damper 22 is to the source of the combustion gases conveyed within the exhaust pathway 16. In the embodiment illustrated in FIG. 3, the burner 26 and/or the standing pilot burner 28 are the source of the combustion gas that flows within the exhaust pathway 16. The burner 26 and/or the standing pilot burner 28 are disposed proximate to the bottom 50 of the tank 12 of the water heating system 10, and the combustion gas rises upward from the combustion chamber 14 into the flue 18 and onward in the upward direction to the damper 22. The exhaust pathway temperature sensor 32, being positioned upstream of the damper 22, is positioned below the damper 22 of the damper assembly 20. In various implementations, the exhaust pathway temperature sensor 32 is positioned upstream of the damper 22 in the closed position of the damper 22.

The exhaust pathway temperature sensor 32 is configured to sense a temperature corresponding with the temperature of the combustion gas within the exhaust pathway 16 proximate to and upstream of the damper 22. In some embodiments, the exhaust pathway temperature sensor 32 may, for example, sense a temperature of a wall of the exhaust pathway 16 that corresponds with the temperature of the combustion gas within the exhaust pathway 16 proximate to an upstream of the damper 22. In some embodiments, the exhaust pathway temperature sensor 32 may be in communication with the combustion gas within the exhaust pathway 16, such that the exhaust pathway temperature sensor 32 senses a temperature that corresponds with the temperature of the combustion gas within the exhaust pathway 16. The exhaust pathway temperature sensor 32 may be part of a sensing system 58 of the water heating system 10, as described further herein.

In the embodiment illustrated in FIGS. 1-4, the damper assembly 20 is disposed atop the shell 40 of the water heating system 10 within which the tank 12 is disposed. In the illustrated embodiment, the damper assembly 20 includes a housing 60 that houses the damper 22, the actuator 24, and the exhaust pathway temperature sensor 32. The housing 60 of the damper assembly 20 further includes a conduit portion 62 that forms a portion of the exhaust pathway 16. The damper 22 of the damper assembly 20 is disposed within the conduit portion 62 of the damper assembly 20 and is operable to move between the open and closed positions therein. It is contemplated that a variety of configurations of damper assemblies and various types of dampers may be utilized in the water heating system 10.

Referring now to FIGS. 1-5, the water heating system 10 includes the sensing system 58. The sensing system 58 can include a plurality of sensors configured to sense various conditions. In some embodiments, the sensing system 58 includes the exhaust pathway temperature sensor 32 that is configured to sense the temperature of the combustion gas within the exhaust pathway 16. In some implementations, the top 48 of the tank 12 is nearer than the bottom 50 of the tank 12 to the exhaust pathway temperature sensor 32 that is coupled to the exhaust pathway 16. In some embodiments, the exhaust pathway temperature sensor 32 is positioned above the top 48 of the tank 12 between the top 48 of the tank 12 and the damper 22. In some embodiments, the exhaust pathway temperature sensor 32 is a portion of the damper assembly 20. However, it is contemplated that the exhaust pathway temperature sensor 32 may be in a spaced relationship with the damper assembly 20, in some implementations.

In some embodiments, the sensing system 58 includes the tank temperature sensor 34. The tank temperature sensor 34 may be configured to sense a temperature corresponding with a temperature of water disposed within the tank 12. In some embodiments, the tank temperature sensor 34 may be, for example, an immersion well temperature sensor that senses a temperature corresponding with the temperature of water disposed within the tank 12. A variety of types of tank temperature sensors 34 are contemplated. In some embodiments, the tank temperature sensor 34 is positioned relative to the tank 12, such that the temperature that the tank temperature sensor 34 senses corresponds with a temperature of water that is nearer to the bottom 50 of the tank 12 than to the top 48 of the tank 12. In some embodiments, the water heating system 10 does not include a second tank temperature sensor that is configured to sense a temperature corresponding with the temperature of water that is nearer to the top 48 of the tank 12 than the bottom 50 of the tank 12. In such embodiments, the tank temperature sensor 34 that is disposed nearer to the bottom 50 of the tank 12 than the top 48 of the tank 12 may be the sole tank temperature sensor utilized.

Referring now to FIG. 5, the sensing system 58 can include the ambient air temperature sensor 36. The ambient air temperature sensor 36 is configured to sense a temperature corresponding with the temperature of ambient air that is external to the water heating system 10. In an exemplary implementation, the water heating system 10 may be disposed within a room of a house, and the ambient air temperature sensor 36 is configured to sense a temperature corresponding with an ambient air temperature within that room of the house.

Referring still to FIG. 5, the sensing system 58 of the water heating system 10 includes the standing pilot burner output sensor 30. The standing pilot burner output sensor 30 is configured to sense a characteristic of an output of the standing pilot burner 28. In various implementations, the standing pilot burner output sensor 30 senses the output of the standing pilot burner 28 by sensing a temperature. For example, the standing pilot burner output sensor 30 can include the thermopile 56 that is positioned such that the flame emitted from the standing pilot burner 28 is configured to coincide with the thermopile 56 in optimal operation of the water heating system 10. The thermopile 56 may be configured to supply voltage and/or another signal to the fuel valve 54 and/or the control circuitry 38 of the water heating system 10 based on the temperature transmitted from the flame of the standing pilot burner 28 to the thermopile 56. It is contemplated that the standing pilot burner output sensor 30 may be one or more of a variety of types of sensors that are configured to sense one or more of a variety of characteristics of the output of the standing pilot burner 28 (e.g., imager, etc.).

Referring still to FIG. 5, the water heating system 10 includes the control circuitry 38. The control circuitry 38 of the water heating system 10 can be configured with a processor 64 to process logic and routines stored in memory 66 that receives information from the above-described components and/or systems of the water heating system 10, including the sensing system 58, the damper assembly 20, the gas valve, and/or a variety of other components and systems of the water heating system 10. The control circuitry 38 may generate information and commands as a function of all or a portion of the information received. Thereafter, the information and commands may be utilized to control operation of the water heating system 10, as described further herein. The control circuitry 38 may include a microprocessor and/or other analog and/or digital circuitry for processing one or more routines. Further, the control circuitry 38 may include the memory 66 for storing one or more routines.

It should be appreciated that the control circuitry 38 may include a standalone dedicated controller 68 or may include a shared controller 68 integrated with other control functions. In various implementations, the control circuitry 38 can include a plurality of controllers 68. It should further be appreciated that one or more routines or subroutines of the water heating system 10 may be carried out by a dedicated processor 64, in some implementations.

Referring now to FIGS. 1-5, the control circuitry 38 is configured to control operation of the water heating system 10. In various implementations, the control circuitry 38 controls the operating state of the water heating system 10. For example, the control circuitry 38 may be configured to control the water heating system 10 to enter the standby state and/or the firing state based on sensor data received from the sensing system 58 (e.g., temperature data received from the tank temperature sensor 34, temperature data received from the exhaust pathway temperature sensor 32, etc.), as well as a setpoint temperature for the water within the tank 12. In various implementations, the control circuitry 38 is operable to control operation of the damper assembly 20 based on data received from the sensing system 58. In some embodiments, the control circuitry 38 controls operation of the damper assembly 20 based on data received from the standing pilot burner output sensor 30, the exhaust pathway temperature sensor 32, the tank temperature sensor 34, and the ambient air temperature sensor 36.

In some implementations of the water heating system 10, in the standby state, the control circuitry 38 is configured to control operation of the damper assembly 20 based on the temperature sensed by the exhaust pathway temperature sensor 32. For example, in the standby state of the water heating system 10, the control circuitry 38 may be configured to control operation of the damper assembly 20 based on the temperature sensed by the exhaust pathway temperature sensor 32 and the temperature sensed by the tank temperature sensor 34. In an exemplary embodiment, in the standby state of the water heating system 10, the control circuitry 38 is configured to determine a temperature value corresponding with a temperature of water disposed within the tank 12 proximate to the top 48 of the tank 12 based on the temperature sensed by the exhaust pathway temperature sensor 32 and the temperature sensed by the tank temperature sensor 34. The control circuitry 38 is further configured to control the actuator 24 of the damper assembly 20 to move the damper 22 from the closed position to the open position responsive to the temperature value being above a threshold temperature value. The threshold temperature value may be the water temperature setpoint value that may, for example, be stored in memory 66 of the control circuitry 38.

Referring now to FIG. 5, in some implementations, responsive to the water heating system 10 entering the standby state from the firing state, the control circuitry 38 may be configured to control the actuator 24 of the damper assembly 20 to move the damper 22 from the open position to the closed position after a length of time has elapsed since the water heating system 10 entered the standby state from the firing state. The length of time may be determined by the control circuitry 38 based on the temperature sensed by the ambient air temperature sensor 36. In various embodiments, the control circuitry 38 is configured such that a first length of time is determined by the control circuitry 38 based on a first temperature sensed by the ambient air temperature sensor 36 and a second length of time is determined by the control circuitry 38 based on a second temperature sensed by the ambient air temperature sensor 36. In various implementations, the first length of time is shorter than the second length of time, and the first temperature is less than the second temperature.

In some implementations, responsive to the water heating system 10 entering the standby state from the firing state, the control circuitry 38 may be configured to control the actuator 24 of the damper assembly 20 to move the damper 22 from the open position to the closed position based on the temperature sensed by the exhaust pathway temperature sensor 32. For example, in operation of an exemplary embodiment, when the water heating system 10 enters the standby state, the control circuitry 38 is configured to control the actuator 24 to move the damper 22 to the closed position responsive to the exhaust pathway temperature sensor 32 sensing a temperature that coincides with and/or is below a predetermined temperature value (indicating that a sufficient amount of heat has escaped the exhaust pathway 16 to achieve desired operational outcomes of the water heating system 10 in the standby state).

In some implementations, responsive to the water heating system 10 transitioning from the firing state, wherein the damper 22 is in the open position, to the standby state, the control circuitry 38 may be configured to control the actuator 24 of the damper assembly 20, and thereby the position of the damper 22, based on the temperature sensed by the ambient air temperature sensor 36. For example, in operation of an exemplary embodiment, when the water heating system 10 enters the standby state, the control circuitry 38 may control the actuator 24 to maintain the damper 22 in the open position responsive to the temperature sensed by the ambient air temperature sensor 36 coinciding with and/or exceeding a predetermined temperature value (e.g., ambient air threshold temperature value). In such embodiments, wherein the ambient air temperature is equal to or greater than the predetermined temperature value, the ambient air temperature may be warm enough that desired water heating outcomes can be achieved without closing the damper 22 and undesired outcomes (heating water beyond desired temperature levels, pilot burner flame instability, etc.) can be avoided or mitigated. Further, it is contemplated that, in the standby state of the water heating system 10, the control circuitry 38 may control the actuator 24 to move the damper 22 from the closed position to the open position based on the temperature sensed by the ambient air temperature sensor 36 coinciding with and/or exceeding a predetermined temperature value, in some embodiments.

In some implementations, when the water heating system 10 enters the standby state from the firing state, the control circuitry 38 is configured to control the actuator 24, and thereby the position of the damper 22 based on data received from the exhaust pathway temperature sensor 32 and the ambient air temperature sensor 36. For example, in operation of an exemplary embodiment of the water heating system 10, the control circuitry 38 determines a threshold temperature value based on the temperature sensed by the ambient air temperature sensor 36. When the water heating system 10 enters the standby state, the control circuitry 38 is configured to control the actuator 24 to move the damper 22 to the closed position responsive to a temperature sensed by the exhaust pathway temperature sensor 32 coinciding with and/or falling below the threshold temperature value determined based on the temperature sensed by the ambient air temperature sensor 36.

Referring still to FIG. 5, in some embodiments, the standing pilot burner output sensor 30 includes the thermopile 56. The thermopile 56 senses a characteristic of the combustion of fuel by the standing pilot burner 28. In some such embodiments of the water heating system 10, when the water heating system 10 is in the standby state, the control circuitry 38 is configured to control operation of the damper assembly 20 based on at least one of a rate of change of voltage output from the thermopile 56 and an average voltage output from the thermopile 56 over a period of time. In some implementations, in the standby state of the water heating system 10, the control circuitry 38 is configured to control the actuator 24 of the damper assembly 20 to move the damper 22 from the closed position to the open position based on the rate of change of voltage output from the thermopile 56, the average voltage output from the thermopile 56 over the period of time, and the temperature sensed by the ambient air temperature sensor 36 of the water heating system 10.

Referring now to FIGS. 1-5, in a first exemplary implementation of the water heating system 10, the water heating system 10 includes the tank 12, the combustion chamber 14 that is adjacent to the tank 12, the exhaust pathway 16 that includes the flue 18 that extends through the tank 12, the burner 26 that is disposed within the combustion chamber 14, and the damper assembly 20. The damper assembly 20 includes the damper 22 that is disposed within the exhaust pathway 16, the actuator 24 that is operable to move the damper 22 between the open position and the closed position, and the exhaust pathway temperature sensor 32 that is coupled to the exhaust pathway 16 at a position that is upstream of the damper 22 when the damper 22 is in the closed position. The exhaust pathway temperature sensor 32 is configured to sense a temperature that corresponds with the temperature of the combustion gas output by the burner 26 within the exhaust pathway 16.

In the first exemplary implementation of the water heating system 10, control circuitry 38 is in communication with the exhaust pathway temperature sensor 32 and is configured to determine a temperature value corresponding with the temperature of water disposed within the tank 12 proximate to the top 48 of the tank 12 based on the temperature sensed by the exhaust pathway temperature sensor 32. The water heating system 10 of the exemplary embodiment further includes the tank temperature sensor 34. The tank temperature sensor 34 is positioned nearer to the bottom 50 of the tank 12 than to the top 48 of the tank 12 and is configured to sense a temperature corresponding with the temperature of water disposed with the tank 12 adjacent to the tank temperature sensor 34. The control circuitry 38 of the water heating system 10 is in communication with the tank temperature sensor 34 in addition to the exhaust pathway temperature sensor 32 and is configured to determine the temperature value corresponding with the temperature of water disposed in the tank 12 proximate to the top 48 of the tank 12 based on the temperature sensed by the exhaust pathway temperature sensor 32 and the temperature sensed by the tank temperature sensor 34.

Utilizing the tank temperature sensor 34 that is proximate to the bottom 50 of the tank 12 and the exhaust pathway temperature sensor 32 that senses a temperature corresponding with combustion gas proximate to the top 48 of the tank 12 advantageously allows the control circuitry 38 to determine a temperature value that corresponds with the temperature of water at the top 48 of the tank 12 (which is different than the temperature of water at the bottom 50 of the tank 12 proximate to the tank temperature sensor 34 due to stratification) without needing to utilize a second tank temperature sensor 34 proximate to the top 48 of the tank 12. This eliminates the need for drilling a second port into the tank 12 to accommodate the second tank temperature sensor 34, saving costs and time in manufacturing.

In operation of the first exemplary implementation of the water heating system 10, in the standby state of the water heating system 10 in which the standing pilot burner 28 of the water heating system 10 combusts fuel such that combustion gas is conveyed along the exhaust pathway 16 from the combustion chamber 14, into the flue 18, and onward to the damper 22, the control circuitry 38 is configured to control the actuator 24 of the damper assembly 20 to move the damper 22 from the closed position to the open position responsive to the temperature value registering above a threshold temperature value. In sum, the water heating system 10 of the first exemplary implementation may advantageously determine a temperature value corresponding with the temperature of water proximate the top 48 of the tank 12 without utilizing a tank temperature sensor 34 disposed proximate the top 48 of the tank 12 and, thereby, may control the damper assembly 20 to allow heat to escape the portion of the exhaust pathway 16 that is upstream of the damper 22 when the determined temperature value reaches a threshold temperature value that is indicative of a maximum desired water temperature at the top 48 of the tank 12.

In second exemplary implementation of the water heating system 10, the water heating system 10 includes the tank 12, the combustion chamber 14 that is positioned adjacent to the tank 12, the exhaust pathway 16 that includes the flue 18 that extends through the tank 12, the damper assembly 20 that includes the damper 22 and the actuator 24 operable to move the damper 22 between the open position and the closed position, the burner 26 that is disposed within the combustion chamber 14, the standing pilot burner 28 that is also disposed in the combustion chamber 14, the standing pilot burner output sensor 30, and control circuitry 38.

In operation of the second exemplary implementation, in the standby state of the water heating system 10, the standing pilot burner 28 combusts fuel, such that combustion gas is conveyed along the exhaust pathway 16 from the combustion chamber 14, into the flue 18, and onward to the damper 22 that is initially in the closed position. The standing pilot burner output sensor 30 senses a characteristic of the output of the standing pilot burner 28. In particular, the thermopile 56 of the standing pilot output sensor senses a temperature that is output by the flame of the standing pilot burner 28. As the standing pilot burner 28 combusts fuel and the temperature within the exhaust pathway 16 increases due to the damper 22 being in the closed position, the effectiveness of the natural draft mechanism of the water heating system 10 to draw oxygenated air into the combustion chamber 14 to feed the flame of the standing pilot burner 28 is diminished. As such, the flame of the standing pilot burner 28 becomes unstable (e.g., flickers, changes shape, etc.), such that less heat is transferred from the flame to the thermopile 56. The thermopile 56, in turn, signals this change in output from the standing pilot burner 28 (e.g., through a change in voltage output from the thermopile 56) to the control circuitry 38. The control circuitry 38 processes the signal from the thermopile 56 and controls the actuator 24 of the damper assembly 20 to move the damper 22 from the closed position to the open position based on the rate of change of voltage output from the thermopile 56 and/or the average voltage output from the thermopile 56 over a period of time. The damper 22 moving from the closed position to the open position releases combustion gas and heat from the flue 18 allowing oxygenated air to be more efficiently drawn into the combustion chamber 14, which steadies the flame of the standing pilot burner 28.

It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present disclosure, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.

Claims

1. A water heating system, comprising:

a tank for holding water to be heated;

a combustion chamber adjacent to the tank;

an exhaust pathway that includes a flue that is in communication with the combustion chamber and that extends through the tank;

a damper assembly that includes a damper disposed within the exhaust pathway and an actuator operable to move the damper between an open position and a closed position;

a burner disposed within the combustion chamber and operable to combust fuel in a firing state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper;

a standing pilot burner disposed within the combustion chamber and operable to combust fuel in a standby state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper;

a standing pilot burner output sensor that senses a characteristic of an output of the standing pilot burner;

an exhaust pathway temperature sensor coupled to the exhaust pathway upstream of the damper and configured to sense a temperature corresponding with a temperature of the combustion gas within the exhaust pathway proximate to and upstream of the damper;

a tank temperature sensor configured to sense a temperature corresponding with a temperature of water disposed within the tank; and

control circuitry that controls operation of the damper assembly based on data received from the standing pilot burner output sensor, the exhaust pathway temperature sensor, and the tank temperature sensor.

2. The water heating system of claim 1, wherein a top of the tank is nearer than a bottom of the tank to the exhaust pathway temperature sensor coupled to the exhaust pathway.

3. The water heating system of claim 2, wherein the exhaust pathway temperature sensor is positioned above the top of the tank between the top of the tank and the damper.

4. The water heating system of claim 3, wherein the tank temperature sensor is positioned relative to the tank, such that the temperature that the tank temperature sensor senses corresponds with a temperature of water disposed within the tank that is nearer to the bottom of the tank than to the top of the tank.

5. The water heating system of claim 4, wherein said water heating system does not include a second tank temperature sensor configured to sense a temperature corresponding with a temperature of water disposed within the tank that is nearer to the top of the tank than to the bottom of the tank.

6. The water heating system of claim 5, wherein the standing pilot burner output sensor comprises a thermopile.

7. The water heating system of claim 6, wherein, in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on the temperature sensed by the exhaust pathway temperature sensor.

8. The water heating system of claim 7, wherein, in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor.

9. The water heating system of claim 8, wherein, in the standby state of the water heating system, the control circuitry is configured to:

determine a temperature value corresponding with a temperature of water disposed within the tank proximate to the top of the tank based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor; and

control the actuator to move the damper from the closed position to the open position responsive to the temperature value being greater than a threshold temperature value.

10. The water heating system of claim 9, wherein the threshold temperature value is at least one of a water temperature setpoint value and related to a water temperature setpoint value.

11. The water heating system of claim 5, wherein, responsive to the water heating system entering the standby state from the firing state, the control circuitry is configured to:

control the actuator of the damper assembly to move the damper from the open position to the closed position after a length of time has elapsed since the water heating system entered the standby state from the firing state, wherein the length of time is determined by the control circuitry based on the temperature sensed by an ambient air temperature sensor that is configured to sense a temperature corresponding with a temperature of ambient air external to the water heating system.

12. The water heating system of claim 11, wherein the control circuitry is configured such that a first length of time is determined by the control circuitry based on a first temperature sensed by the ambient air temperature sensor and a second length of time is determined by the control circuitry based on a second temperature sensed by the ambient air temperature sensor, wherein the first length of time is shorter than the second length of time, and the first temperature is less than the second temperature.

13. The water heating system of claim 12, wherein, in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on at least one sensed characteristic of the output of the standing pilot burner.

14. The water heating system of claim 13, wherein the standing pilot burner output sensor includes a thermopile that senses a characteristic of the combustion of fuel by the standing pilot burner, and wherein, in the standby state of the water heating system, the control circuitry is configured to control operation of the damper assembly based on at least one of a rate of change of voltage output from the thermopile and an average voltage output from the thermopile over a period of time.

15. The water heating system of claim 14, wherein, in the standby state of the water heating system, the control circuitry is configured to control the actuator to move the damper from the closed position to the open position based on the rate of change of voltage output from the thermopile, the average voltage output from the thermopile over the period of time, and the temperature sensed by the ambient air temperature sensor.

16. A water heating system, comprising:

a tank for holding water to be heated;

a combustion chamber adjacent to the tank;

an exhaust pathway that includes a flue that is in communication with the combustion chamber and that extends through the tank;

a burner disposed within the combustion chamber and operable to combust fuel, such that combustion gas is conveyed along the exhaust pathway; and

a damper assembly that includes a damper disposed within the exhaust pathway, an actuator operable to move the damper between an open position and a closed position, and an exhaust pathway temperature sensor coupled to the exhaust pathway at a position that is upstream of the damper when the damper is in the closed position, wherein the exhaust pathway temperature sensor is configured to sense a temperature corresponding with a temperature of the combustion gas within the exhaust pathway; and

control circuitry in communication with the exhaust pathway temperature sensor and configured to determine a temperature value corresponding with a temperature of water disposed within the tank proximate to a top of the tank based on the temperature sensed by the exhaust pathway temperature sensor.

17. The water heating system of claim 16, further comprising:

a tank temperature sensor positioned nearer to a bottom of the tank than to the top of the tank and being configured to sense a temperature corresponding with a temperature of water disposed within the tank adjacent to the tank temperature sensor, wherein the control circuitry is in communication with the exhaust pathway temperature sensor and the tank temperature sensor and is configured to determine the temperature value corresponding with the temperature of water disposed within the tank proximate to the top of the tank based on the temperature sensed by the exhaust pathway temperature sensor and the temperature sensed by the tank temperature sensor.

18. The water heating system of claim 17, wherein, in a standby state of the water heating system in which a standing pilot burner of said water heating system combusts fuel such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper, the control circuitry is configured to:

control the actuator of the damper assembly to move the damper from the closed position to the open position responsive to the temperature value being greater than a threshold temperature value.

19. A water heating system, comprising:

a tank for holding water to be heated;

a combustion chamber adjacent to the tank;

an exhaust pathway that includes a flue that is in communication with the combustion chamber and that extends through the tank;

a damper assembly that includes a damper disposed within the exhaust pathway and an actuator operable to move the damper between an open position and a closed position;

a burner disposed within the combustion chamber and operable to combust fuel in a firing state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper;

a standing pilot burner disposed within the combustion chamber and operable to combust fuel in a standby state of the water heating system, such that combustion gas is conveyed along the exhaust pathway from the combustion chamber, into the flue, and onward to the damper;

a standing pilot burner output sensor that senses a characteristic of an output of the standing pilot burner; and

control circuitry in communication with the standing pilot burner output sensor that, in the standby state of the water heating system, controls the actuator of the damper assembly to move the damper from the closed position to the open position based on the sensed characteristic of the output of the standing pilot burner.

20. The water heating system of claim 19, wherein the standing pilot burner output sensor includes a thermopile, and the control circuitry is configured to control the actuator to move the damper from the closed position to the open position based on at least one of a rate of change of voltage output from the thermopile and an average voltage output from the thermopile over a period of time.