US20090277399A1

US20090277399A1 - Water heater and method of operating a waterheater

Info

Publication number: US20090277399A1
Application number: US12/152,083
Authority: US
Inventors: Steven E. Guzorek; Cory A. Weiss
Original assignee: PPC Broadband Inc
Current assignee: Field Controls LLC; PPC Broadband Inc
Priority date: 2008-05-09
Filing date: 2008-05-09
Publication date: 2009-11-12
Also published as: CA2640791A1

Abstract

A water heater having of a tank defining a storage space for water. A heat source in a combustion chamber is operable to heat water in the storage space and has a first state and a heating state. A flue is part of a gas flow passage through which combustion gases are communicated towards a first location. A flue damper has closed and open states. A powered device in an on state induces flow of combustion gases from the combustion chamber towards the first location. A control is configured to: a) process a user input identifying a target output water temperature and generate a call for heat; and b) in response thereto i) cause the powered device to change from its first state; ii) cause the flue damper to change from its closed state towards its open state; and iii) cause the heat source to change from its first state into its heating state.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to water heaters and, more particularly, to a water heater with a heat source that generates combustion gases that are controllably discharged therefrom.
2. Background Art
Many different designs currently exist for hot water heaters. The components common to most of these water heaters, that utilize a water storage tank, are a heat source that generates combustion gases, and a flue that is part of a gas flow passage through which combustion gases, generated during operation of the heat source, are controllably directed to a desired location.
In operation, a user selects a desired/target output water temperature. With the temperature of the water at a first predetermined temperature, lower than the target output temperature, a call for heat is generated. The heat source is operated in response to the call for heat until the temperature of the water in the tank is elevated to a second predetermined temperature, at which point the heat source is shut off or caused to operate at a lower temperature level.
One form of water heater is configured so that combustion gas draft is developed solely by the heated gases themselves, as they tend to rise.
It is also known to produce a forced draft. This “power venting” extends the length of a path through which combustion gases can be directed between the water heater and a desired discharge location, which is generally outside of an edifice in which the water heater is located, as through a wall or roof thereon.
In all water heater designs, it is desirable to minimize heat losses once the temperature of water in the storage space has been elevated to the aforementioned second predetermined temperature. Heat losses are commonly and effectively controlled through the incorporation of a flue damper that is placed in a closed state once the heat source is shut off. This avoids discharge of heated gases that might otherwise advantageously remain in heat exchange relationship with the water in the storage space.
In the event that a power venter is incorporated, the power venter, in an off or idling state, has been relied upon by itself to limit the exhaustion of heated combustion gases that remain in the gas flow passage, upstream of the power venter, once the heat source is turned off or adjusted to operate at a lower temperature.
The industry continues to strive to maximize overall efficiency in terms of both: a) extracting energy from combusted fuels; and b) reducing heat losses from water in the tank storage space.

SUMMARY OF THE INVENTION

One form of the invention is directed to a water heater having a tank defining a storage space for water. The tank has an inlet for communicating water from a supply to the storage space and an outlet through which water heated in the storage space is directed towards a point of use. A heat source is provided in a combustion chamber and is operable to heat water in the storage space. The heat source has a first state and a heating state. A flue is part of a gas flow passage through which combustion gases from the combustion chamber are communicated towards a first location. A flue damper is provided and has closed and open states. The flue damper: a) in its closed state obstructs communication of combustion gases through the gas flow passage from the combustion chamber to the first location; and b) in its open state permits substantially unobstructed communication of combustion gases through the gas flow passage from the combustion chamber to the first location. A powered device has a first state and an on state. In its on state, the powered device induces flow of combustion gases from the combustion chamber towards the first location. A control coordinates operation of the heat source, the flue damper and the powered device. The control is configured to: a) process a user input identifying a target output water temperature and generate a call for heat with the water in the storage space below a first predetermined temperature; and b) process the call for heat and in response thereto i) cause the powered device to change from its first state into its on state; ii) cause the flue damper to change from its closed state towards its open state; and iii) cause the heat source to change from its first state into its heating state.
In one form, the control is configured so that the heat source is caused to be changed from its first state into its heating state upon the flue damper realizing its open state.
In one form, the control consists of a first switch that has first and second states. The first switch is changed from its first state into its second state as an incident of the flue damper realizing its open state, thereby causing the heat source to be changed from its first state into its heating state.
In one form, the control consists of a second switch that has first and second states. As an incident of the powered device changing from its first state into its on state, the second switch is changed from its first state into its second state, thereby causing the heat source to change from its first state into its heating state.
In one form, the control is configured so that upon water in the storage space realizing a second predetermined temperature, correlated to the target output water temperature, the control causes: a) the heat source to be changed from its heating state; b) the flue damper to be changed from its open state; and c) the powered device to be changed from its on state.
In one form, the control is configured so that upon the water in the storage space realizing a second predetermined temperature, correlated to the target output water temperature, the control causes: a) the heat source to be changed from its heating state into its first state, that is an off state; b) the flue damper to be changed from its open state into its closed state; and c) the powered device to be changed from its on state into its first state, that is an off state.
In one form, the flue damper consists of at least one element that resides in the flow passage and repositions within the flow passage as the flue damper changes between its closed and open states.
In one form, the flue damper consists of at least one element that repositions between within and outside the flow passage as the flue damper changes between its closed and open states.
In one form, the powered device consists of a bladed element that is rotatable around a first axis and the second switch is changed from its first state into its second state in response to one of: a) pressure generated through rotation of the bladed element; and b) a change in speed of rotation of the bladed element around the first axis.
In one form, the flow passage is upstream of the powered device so that combustion gases from the combustion chamber flow past the flue damper and thereafter to the powered device.
In one form, the flow passage is bounded by a vertically extending conduit section at which the flue damper and powered device are provided.
In one form, the vertically extending conduit section is located directly above the storage space.
In another form, the invention is directed to a method of operating a water heater including: a tank defining a storage space for water and having an inlet and an outlet; a combustion chamber; a heat source having a first state and a heating state; a flue that is part of a gas flow passage; a flue damper having closed and open states; a powered device having a first state and an on state; and a control. The method includes the steps of: inputting a target output water temperature through the control and in response thereto causing: a) the powered device to be placed in its on state to induce flow through the gas flow passage away from the water heater towards a first location; b) the flue damper to be changed from its closed state towards its open state; and c) the heat source to be placed in its heating state to raise the temperature of the water in the storage space to a predetermined temperature correlated to the target output water temperature.
In one form, after water in the storage is heated to the predetermined temperature, the method includes the steps of causing: a) the heat source to be changed from its heating state into its first state; b) the powered device to be changed from its on state into its first state; and c) the flue damper to be changed from its open state into its closed state.
In one form, the heat source in its operating state generates combustion gases, and the method further includes the step of causing the combustion gases to be directed past the flue damper and thereafter to the powered device.
In one form, the step of causing the heat source to be placed in its heating state includes causing the heat source to be placed in its heating state after causing the powered device to be placed in its on state and the flue damper to be moved from its closed state towards its open state.
In one form, the first state of the heat source is an off state and the first state of the powered device is an off state.
In one form, the powered device includes a bladed element that rotates within the gas flow passage.
In one form, the flow passage is bounded by a vertically extending conduit section at which the flue damper and powered device are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of one form of water heater, according to the present invention, and including a flue damper and powered device/power venter;

FIG. 2 is a schematic representation of a heat source on the water heater in FIG. 1;

FIG. 3 is a schematic representation of a control on the water heater in FIG. 1;

FIG. 4 is a schematic representation of the flue damper on the water heater in FIG. 1;

FIG. 5 is a schematic representation of the powered device/power venter in FIG. 1;

FIG. 6 is a side elevation view of one specific form of water heater, as shown in FIG. 1, with a support for the powered device/power venter removed, an exposed portion of the flue shown in cross-section, and a drive assembly for the flue damper shown in schematic form;

FIG. 7 is an enlarged, fragmentary, partial cross-sectional view of the flue damper and powered device/power venter on the water heater in FIG. 6 and with one specific form of drive assembly for the flue damper;

FIG. 8 is a flow diagram representation of one method of operating a water heater to bring the water therein up to a predetermined temperature; and

FIG. 9 is a flow diagram representation of a method of operating a water heater, according to the invention, after the predetermined temperature for the water in the water heater has been realized.

DETAILED DESCRIPTION OF THE DRAWINGS

As shown schematically in FIG. 1, a water heater 10, according to the present invention, consists of a tank 12 defining a storage space 14 for water. The tank 12 has an inlet 16 for communicating water from a supply 18 to the storage space 14 in the tank 12, and an outlet 20 through which water heated in the storage space 14 is directed towards a point of use 22, that may be at a sink or any other site at which hot water is desired.
The water heater 10 further has a combustion chamber 24. A heat source 26 is provided in the combustion chamber 24 and is operable to heat water in the storage space 14. The heat source 26 has a first state and a heating state. The first state may be an off state or a state in which the heating level thereof is less than that resulting with the heat source in the heating state.
The water heater 10 further includes a flue 28 that is part of a gas flow passage 30 through which gases from the combustion chamber 24 are communicated towards a first location 32. A flue damper 34 is associated with the flue 28. The flue damper 34 has closed and open states. The flue damper 34 a) in the closed state obstructs communication of combustion gases from the combustion chamber 24 to the first location 32; and b) in the open state permits substantially unobstructed communication of combustion gases from the combustion chamber 24 to the first location 32.
The water heater 10 further includes a powered device/power venter 36 that has a first state and an on state. The first state may be an off state or an idle state. In the on state, the powered device 36 induces flow of combustion gases from the combustion chamber 24 towards the first location 32. The powered device/power venter 36 is incorporated primarily to increase operating efficiency for the water heater 10. Additionally, the powered device/power venter 36 reduces flue gas temperature to allow use of plastic pipe to convey the flue gases away from the water heater 10.
A control 38 coordinates operation of the heat source 26, the flue damper 34, and the powered device 36. The control 38 is configured to: a) process a user input identifying a target/desired output water temperature and generate a call/demand for heat with the water temperature in the storage space 14 below a first predetermined value; and b) process the call for heat and in response thereto: i) cause the powered device 36 to change from its first state into its on state; ii) cause the flue damper 34 to change from its closed state towards its open state; and iii) cause the heat source 26 to change from its first state into its heating state. The control 38 may consist of a number of components that are spaced from, or reside within, upon, or externally of, an insulated casing 40. The insulated casing 40 bounds the storage space 14 and the combustion chamber 24 to reduce heat losses from both the storage space 14 and combustion chamber 24.
The components of the water heater 10 are shown in schematic form because it is contemplated that these components might take virtually a limitless number of different forms consistent with the inventive concepts disclosed herein.
As just examples, the heat source 26 might incorporate a burner that combusts a fuel such as natural gas, propane, or fuel oil. The heat source 26 used to combust the fuel, as shown schematically in FIG. 2, consists of a burner 42 with an ignition device 44. The ignition device 44 may be intermittently operated to in sequence ignite a pilot 46, as when there is a call/demand for heat. Alternatively, the pilot 46 may be continuously operated, whereupon the control 38 will cause additional delivery of fuel from a supply 48 to the burner 42, as when there is a demand/call for heat.
The flue 28 may be in the form of a length of conduit, and is part of a passage 30 that extends from the combustion chamber 24 to the first location 32.
The nature of the control 38 may vary significantly, as required to perform as described herein. In one exemplary form, as shown schematically in FIG. 3, the control 38 consists of a first switch 50 that has first and second states. The first switch 50 is changed from its first state into its second state as an incident of the flue damper 34 realizing its open state. Operation of the first switch 50 causes the heat source 26 to be changed from its first state into its heating state.
The control 38 has a second switch 52 that has first and second states. As an incident of the powered device 36 changing from its first state into its on state, the second switch 52 is changed from its first state into its second state. As this occurs, the heat source 26 is caused to change from its first state into its heating state.
As shown schematically in FIG. 4, the flue damper 34 has at least one element 54 that is movable as the flue damper 34 changes between its closed and open states. In one form, the element(s) 54 resides at the flue 28 in the flow passage 30 at all times and repositions therewithin, as by movement around an axis, as it changes state. In FIG. 7, one form of this type of flue damper 34 is shown that uses one or more pivoting elements. A detailed description of this type of flue damper 34 appears below.
Alternatively, a proof damper (not shown), of known construction, utilizes a pivoting element(s) 54 that moves around a differently located axis.
In a further alternative form, the element(s) 54 repositions between at least partially within and outside of the flow passage 30, as the flue damper 34 changes between its closed and opens states. This element(s) 54 may be part of a slide damper. In this form, part or all of the element(s) 54 translates/slides into and out of the passage 30 as the state of the flue damper 34 is changed.
The powered device/power venter 36 may take a multitude of different forms. In one preferred form, the powered device/power venter 36 is mounted in line in the passage 30 and is of a type as disclosed in commonly owned U.S. Pat. No. 7,290,981, the disclosure of which is incorporated herein by reference. As shown in FIG. 5, the powered device 36 generally will include a bladed element 56 that is rotatable around an axis by a drive 58 that may be an electric motor, or the like. The second switch 52 is changed from its first state into its second state in response to a signal indicative of the fact that the powered device/power venter 36 is operating. For example, the change in switch state may result from pressure generated through rotation of the bladed element 56 or, alternatively, a change in speed of rotation of the bladed element 56 around its axis, regardless of how these conditions are sensed.
A more specific form of the water heater depicted schematically in FIGS. 1-5 at 10 is shown in FIGS. 6 and 7, with corresponding components identified with the same reference numerals. The insulated casing 40 surrounds the storage space 14 and combustion chamber 24 and may have a conventional overall cylindrical shape.
In FIG. 6, a drive assembly for the flue damper 34 is shown schematically at 61 to encompass virtually an unlimited number of different forms thereof. One specific form of the drive assembly 61 is shown in FIG. 7.
The flue 28 is defined by a section of a conduit 60 that bounds the passage 30. The flue 28 has a vertically extending conduit section 62 at which the powered device/power venter 36 and flue damper 34 are provided. The vertically extending conduit section 62 is located directly above the storage space 14. In one form, the conduit section 62 is substantially cylindrical in cross section and has a central axis 64 that is substantially coincident with the central axis 66 of the cylindrical casing 40.
The flue damper 34 is located upstream of the powered device/power venter 36 so that combustion gases from the combustion chamber 24 flow past the flue damper 34, are mixed with incoming dilution air 67, and continue therefrom to the powered device/power venter 36.
At least part of the control 38 is shown mounted to the outside of the casing 40 to be accessible for user operation and setting.
The portion of the conduit section 62 extending between the top of the casing 40 and the powered device 36 is surrounded by a secondary conduit 68 which defines an annular space 70 in which an insulating material 72 may be provided.
A mounting plate 74 is provided atop the secondary conduit 68 and supports the powered device/power venter 36. The conduit 60 is telescopingly engaged with a coupling component 76 at the top of the casing 40 and extends through the mounting plate 74 into operative communication with the powered device 36. The conduit 60 extends from the powered device/power venter 36 and communicates, as through a wall or roof, to the first location 32, which may be external to the space 78 within which the water heater 10 resides.
As seen particularly in FIG. 7, the flue damper 34 has a disk-shaped element 54 with a peripheral edge 80 surrounded by a flexible component 82, that establishes a seal against the surrounding, internal conduit surface 84 with the element 54 situated as in FIG. 6, representing the closed state for the flue damper 34.
The element 54 is connected to a control rod 86 that is rotatable around an axis 88, that is substantially orthogonal to the axis 64, through a drive motor 90. The drive motor 90 is mounted on a support 92 that vertically spans between the casing 40 and mounting plate 74.
The drive motor 90 is operated through the control 38. By operating the motor 90, the control rod 86 pivots the element 54 between the position in FIG. 7, representing the open state for the damper 34, wherein substantially unobstructed flow is permitted through the passage 30 at the conduit section 62, and the position shown in FIG. 6, representing the closed state for the flue damper 34, wherein communication of combustion gases from the combustion chamber 24 to the first location 32 is obstructed and substantially blocked.
In an alternative design within the schematic disclosure in FIG. 4, a sliding-type element might be employed. That is, a part of the element 54 may reposition between within and outside the flow passage 30 as the flue damper 34 changes between its closed and open states. For example, a relatively solid plate might be translated out of the passage 30 to place the flue damper 34 in the open state and into the passage 30 to place the flue damper 34 in the closed state.
The control 38 is configured so that the heat source 26 is caused to be changed from its first state into its heating state upon the flue damper 34 realizing its open state of FIG. 7. This may occur as soon as the damper 34 realizes its open state. Alternatively, the heat source 26 may be operated only after a built in delay, that may be of a fixed or variable duration. This minimizes the likelihood of the heat source 26 operating before the flue damper 34 is fully opened. Other safeguards to avoid this condition may also be incorporated.
The control 38 is configured so that upon water in the storage space 14 realizing a second predetermined temperature, correlated to the target output water temperature, the control 38 causes: a) the heat source 26 to be changed from its heating state; b) the flue damper 34 to be changed from its open state; and c) the powered device 36 to be changed from its on state. The heat source 26 may be changed from the heating state into its first state, that is an off state. The flue damper 34 may be changed from its open state into its closed state, with the powered device 36 changing from its on state into its first state, that likewise may be an off state. The control 38 may be configured to monitor all events and accommodate any sensed malfunction of components or a delay in a programmed change in state of any of the components.
With the water heater 10 as described above, the following method of operating a water heater may be carried out, as described with respect to FIG. 8. The basic construction of the water heater 10 includes the tank 12 defining the storage space 14 for water and having the inlet 16 and outlet 18, the combustion chamber 24, the heat source 26, the flue 28, the flue damper 34, the powered device 36, and the control 38.
As shown at block 94, the target output water temperature is input through the control 38. In response thereto and through the control 38, the powered device/power venter 36 is caused to be placed in its on state, as shown at block 96, thereby so that it induces flow through the gas flow passage 30 away from the water heater 10 towards the first location 32. As shown at block 98, the flue 28 is caused to be changed from a closed state towards its open state. As shown at block 100, the heat source 26 is caused to be placed in its heating state to raise the temperature of the water in the storage space 14 to a predetermined temperature correlated to the target output water temperature.
Once the water in the storage space 14 is heated to the predetermined temperature, the method of operating the water heater 10 is carried out as shown in FIG. 9. More specifically, as shown at block 102, the heat source 26 is changed from its heating state into its first state. As shown at block 104, the powered device/power venter 36 is changed from its on state into its first state. Further, as shown at block 106, the flue damper 34 is changed from its open state into its closed state.
With the heat source 26 in its operating state, combustion gases are generated that are directed past the flue damper 24 and thereafter to the powered device 36.
Preferably, the heat source 26 is caused to be placed in its heating state after causing the powered device 36 to be placed in its on state and the flue damper 34 to be moved from its closed state towards its open state.
As noted previously, the first states of the heat source 26 and powered device 36 may be off states.
The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.

Claims

1. A water heater comprising:

a tank defining a storage space for water, the tank having an inlet for communicating water from a supply to the storage space and an outlet through which water heated in the storage space is directed towards a point of use;

a combustion chamber;

a heat source in the combustion chamber operable to heat water in the storage space,

the heat source having a first state and a heating state;

a flue that is part of a gas flow passage through which combustion gases from the combustion chamber are communicated towards a first location;

a flue damper having closed and open states,

the flue damper: a) in the closed state obstructing communication of combustion gases through the gas flow passage from the combustion chamber to the first location; and b) in the open state permitting substantially unobstructed communication of combustion gases through the gas flow passage from the combustion chamber to the first location;

a powered device that has a first state and an on state and in the on state induces flow of combustion gases from the combustion chamber towards the first location; and

a control for coordinating operation of the heat source, the flue damper and the powered device,

the control configured to: a) process a user input identifying a target output water temperature and generate a call for heat with the water in the storage space below a first predetermined temperature; and b) process the call for heat and in response thereto i) cause the powered device to change from its first state into its on state; ii) cause the flue damper to change from its closed state towards its open state; and iii) cause the heat source to change from its first state into its heating state.

2. The water heater according to claim 1 wherein the control is configured so that the heat source is caused to be changed from its first state into its heating state upon the flue damper realizing its open state.

3. The water heater according to claim 2 wherein the control comprises a first switch that has first and second states and the first switch is changed from its first state into its second state as an incident of the flue damper realizing its open state, thereby causing the heat source to be changed from its first state into its heating state.

4. The water heater according to claim 2 wherein the control comprises a second switch that has first and second states and as an incident of the powered device changing from its first state into its on state the second switch is changed from its first state into its second state, thereby causing the heat source to change from its first state into its heating state.

5. The water heater according to claim 3 wherein the control comprises a second switch that has first and second states and as an incident of the powered device changing from its first state into its on state the second switch is changed from its first state into its second state, thereby causing the heat source to change from its first state into its heating state.

6. The water heater according to claim 1 wherein the control is configured so that upon water in the storage space realizing a second predetermined temperature correlated to the target output water temperature, the control causes: a) the heat source to be changed from its heating state; b) the flue damper to be changed from its open state; and c) the powered device to be changed from its on state.

7. The water heater according to claim 1 wherein the control is configured so that upon the water in the storage space realizing a second predetermined temperature correlated to the target output water temperature, the control causes: a) the heat source to be changed from its heating state into its first state, that is an off state; b) the flue damper to be changed from its open state into its closed state; and c) the powered device to be changed from its on state into its first state, that is an off state.

8. The water heater according to claim 1 wherein the flue damper comprises at least one element that resides in the flow passage and repositions within the flow passage as the flue damper changes between its closed and open states.

9. The water heater according to claim 1 wherein the flue damper comprises at least one element that repositions between within and outside of the flow passage as the flue damper changes between its closed and open states.

10. The water heater according to claim 4 wherein the powered device comprises a bladed element that is rotatable around a first axis and the second switch is changed from its first state into its second state in response to one of: a) pressure generated through rotation of the bladed element; and b) a change in speed of rotation of the bladed element around the first axis.

11. The water heater according to claim 1 wherein the flow passage is upstream of the powered device so that combustion gases from the combustion chamber flow past the flue damper and thereafter to the powered device.

12. The water heater according to claim 1 wherein the flow passage is bounded by a vertically extending conduit section at which the flue damper and powered device are provided.

13. The water heater according to claim 12 wherein the vertically extending conduit section is located directly above the storage space.

14. A method of operating a water heater comprising: a tank defining a storage space for water and having an inlet and an outlet; a combustion chamber; a heat source having a first state and a heating state; a flue that is part of a gas flow passage; a flue damper having closed and open states; a powered device having a first state and an on state; and a control, the method comprising the steps of:

inputting a target output water temperature through the control and in response thereto causing:

a) the powered device to be placed in its on state to induce flow through the gas flow passage away from the water heater towards a first location;

b) the flue damper to be changed from its closed state towards its open state; and

c) the heat source to be placed in its heating state to raise the temperature of the water in the storage space to a predetermined temperature correlated to the target output water temperature.

15. The method of operating a water heater according to claim 14 whereupon after water in the storage is heated to the predetermined temperature, the method includes the steps of causing: a) the heat source to be changed from its heating state into its first state; b) the powered device to be changed from its on state into its first state; and c) the flue damper to be changed from its open state into its closed state.

16. The method of operating a water heater according to claim 14 wherein the heat source in its operating state generates combustion gases and the method further comprises the step of causing the combustion gases to be directed past the flue damper and thereafter to the powered device.

17. The method of operating a water heater according to claim 14 wherein the step of causing the heat source to be placed in its heating state comprises causing the heat source to be placed in its heating state after causing the powered device to be placed in its on state and the flue damper to be moved from its closed state towards its open state.

18. The method of operating a water heater according to claim 14 wherein the first state of the heat source is an off state and the first state of the powered device is an off state.

19. The method of operating a water heater according to claim 14 wherein the powered device comprises a bladed element that rotates within the gas flow passage.

20. The method of operating a water heater according to claim 14 wherein the flow passage is bounded by a vertically extending conduit section at which the flue damper and powered device are provided.