Patent Application
20250102187
The present subject matter relates generally to water heater appliances, and more particularly to systems and methods for improved operation.
A variety of energy sources are used in creating hot water for commercial and residential use including electric, solar, and various fuels. Natural gas and propane are preferred by some customers due to, for example, the relatively quick heating rate. These fuels are supplied as a gas that is burned in a combustion chamber to provide heat energy to raise the water temperature.
If the water heater is, for example, installed in a dusty area containing above average levels of contaminant (e.g., lint, dust, or oil) the air intake of water heater can become clogged. The lack of enough air can cause the temperature of the combustion chamber to become too hot. As another example, a flammable vapor event such as the ignition of vapor from liquid fuel present near the water heater can also create elevated temperatures in the water heater combustion chamber.
Accordingly, it is desirable to monitor temperature and terminate the combustion process if the temperature becomes excessive. One conventional approach is the use of a bi-metal switch placed in direct contact with the wall of the combustion chamber so as to activate the switch. The metals of the bi-metal switch have different thermal expansion characteristics. Once the temperature of the bi-metal switch reaches a predetermined maximum temperature, the switch is activated so as to cause a control system to close off the flow of gas-even if the temperature is only high for a relatively short period of time. Due to its limited design, such switches may lead to a number of inaccurate or nuisance activations, particularly if the increased temperature was not due to a unwanted event such as clogging of the air flow.
Additionally or alternatively, because a bi-metal switch must be placed in contact with the combustion chamber wall, it does not provide a direct measurement of the temperature of the combustion process. Instead, heat must be transmitted to the wall of the combustion chamber before the bi-metal switch can be triggered due to an unsafe condition. Further additionally or alternatively, a bi-metal switch does not adjust or account for fluctuations in ambient conditions, which might affect the bi-metal switch. Instead, the bi-metal switch is simply activated upon reaching a predetermined maximum temperature.
Accordingly, an improved system for measuring and monitoring the temperature of the combustion chamber of a gas water heater is needed.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one exemplary aspect of the present disclosure, a gas fueled water heater appliance is provided. The gas fueled water heater appliance may include a tank, a chamber wall, a gas burner, a chamber sensor, and a controller. The tank may be for storage of water for heating. The chamber wall may define a combustion chamber. The gas burner may be positioned adjacent to the tank and within the combustion chamber to heat water in the tank. The chamber sensor may be attached to the chamber wall. The chamber sensor may be configured to detect a temperature within the combustion chamber. The controller may be mounted to the gas fueled water heater appliance in operable communication with the gas burner, and the chamber sensor. The controller may be configured to direct a water heating operation that includes detecting a combustion chamber temperature (CCT) value during a contemporaneous cycle of the gas burner, determining a contemporary temperature-change rate based on the detected CCT value, comparing the determined contemporary temperature-change rate to a set rate, and directing heating at the gas burner based on comparing the determined contemporary temperature-change rate to the set rate.
In another exemplary aspect of the present disclosure, a method of operating a gas fueled water heater appliance is provided. The method may include detecting a combustion chamber temperature (CCT) value during a contemporaneous cycle of a gas burner. The method may also include determining a contemporary temperature-change rate based on the detected CCT value. The method may further include comparing the determined contemporary temperature-change rate to a set rate. The method may yet further include directing heating at the gas burner based on comparing the determined contemporary temperature-change rate to the set rate.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one element or component from another and are not intended to signify location or importance of the individual elements or components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,” “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components or systems. For example, the approximating language may refer to being within a 10 percent margin (i.e., including values within ten percent greater or less than the stated value). In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction (e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, such as, clockwise or counterclockwise, with the vertical direction V).
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, references to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention.
Except as explicitly indicated otherwise, recitation of a singular processing element (e.g., “a controller,” “a processor,” “a microprocessor,” etc.) is understood to include more than one processing element. In other words, “a processing element” is generally understood as “one or more processing element.” Furthermore, barring a specific statement to the contrary, any steps or functions recited as being performed by “the processing element” or “said processing element” are generally understood to be capable of being performed by “any one of the one or more processing elements.” Thus, a first step or function performed by “the processing element” may be performed by “any one of the one or more processing elements,” and a second step or function performed by “the processing element” may be performed by “any one of the one or more processing elements and not necessarily by the same one of the one or more processing elements by which the first step or function is performed.” Moreover, it is understood that recitation of “the processing element” or “said processing element” performing a plurality of steps or functions does not require that at least one discrete processing element be capable of performing each one of the plurality of steps or functions.
From line 104, water travels into tank 102 through a cold water dip tube 122 that extends along vertical direction V towards the bottom 114 of tank 102. After being heated, water exits tank 102 by travelling vertically upward and out through outlet line 106. Anode rod 126 provides protection against corrosion attacks on tank 102 and other metal components of water heater 100. A pressure relief valve 128 provides for a release of water from tank 102 in the event the pressure rises above a predetermined amount.
Water heater 100 includes a combustion chamber 110 in which a gas burner 108 is centrally located. Gas burner 108 is supplied with a gaseous fuel (e.g., propane or natural gas). Air travels into combustion chamber 110 through air intake 112 in cabinet 130. The resulting mixture of air and gas is ignited and burned to heat bottom 114 of tank 102 and its water contents. Hot combustion gas exits combustion chamber 110 through a vent or flue 124 centrally located within tank 102. Heat exchange with flue 124 also helps heat water in tank 102. A baffle 120 promotes this heat exchange. Gas exits water heater 100 though vent hood 136, which may be connected with additional vent piping (not shown).
A thermostat 116 measures the temperature of water in tank 102 and provides a signal to gas control valve module 118. As used herein, “a signal” is not limited to a single measurement of temperature and, instead, may include multiple measurements over time or continuous measurements over time. The signal may be provided through, for example, changes in current, voltage, resistance, or others. Depending upon whether the desired temperature has been reached as determined (e.g., from the signal from thermostat 116), gas control valve module 118 regulates the flow of gas to burner 108.
Referring now to
Turning especially to
In certain embodiments, gas valve control module 118 includes at least one controller 154. By way of example, controller 154 may include memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of water heater 100 as further described herein. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 154 may be constructed without using a microprocessor (e.g., using a combination of discrete analog or digital logic circuitry-such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
As shown, water heater 100 includes a pilot burner 148 that provides a pilot light 150 (
In some embodiments, a chamber sensor 156, which is generally configured to detect temperature, is positioned at, on, or adjacent to the combustion chamber 110. For instance, chamber sensor 156 may be attached to chamber wall 138 (e.g., supported thereon). As shown, chamber sensor 156 may be disposed, at least in part, within combustion chamber 110. Generally, chamber sensor 156 may be any suitable temperature sensor (e.g., thermocouple, thermistor, IR sensor, etc.) configured to detect a temperature within combustion chamber 110 (e.g., as a signal or voltage corresponding to a combustion chamber temperature (CCT) value). For instance, an output voltage from chamber sensor 156 may be proportional to the temperature or CCT value within the combustion chamber 110 or at chamber sensor 156. The voltage signal transmitted to controller 154 (e.g., and interpreted thereby) through conductors may thus represent representing the measured CCT value.
Further separate from or in addition to chamber sensor 156, water heater 100 may include an ambient sensor 176. Ambient sensor 176 may be spaced apart from chamber sensor 156. In some embodiments, ambient sensor 176 is attached to the tank 102, such as indirectly or through the gas valve control module 118 (e.g., such that the ambient sensor 176 is generally fixed relative to the tank 102). For instance, ambient sensor 176 may be disposed within module 118 on or in operable (e.g., electrical or wireless) communication with controller 154. Generally, ambient sensor 176 is configured to detect temperature outside of the chamber 110 (e.g., directly or indirectly). In particular, ambient sensor 176 may be configured to detect an ambient temperature outside of combustion chamber 110 (e.g., as a voltage or corresponding ambient temperature (AT) value). In some such embodiment, ambient sensor 176 includes or is provided as a suitable temperature sensor (e.g., thermocouple, thermistor, IR sensor, etc.) configured to detect temperate outside of combustion chamber 110. For instance, an output voltage from ambient sensor 176 may be proportional to the temperature or AT value. The voltage signal transmitted to controller 154 (e.g., and interpreted thereby) through conductors 180 may thus represent representing the measured AT value. In additional or alternative embodiments, ambient sensor 176 communicates (e.g., wirelessly) with a separate probe or database (e.g., weather station) to receive an AT value detected apart from the tank 102 or water heater 100 generally.
In exemplary embodiments, water heater 100 includes a gas valve 146 positioned along main gas supply line 168. Controller 154 is in communication with gas valve 146 to control the flow of gas therethrough by determining when valve 146 is energized. For this exemplary embodiment, gas valve 146 may operate so that when energized, valve 146 is fully open to allow a flow of gaseous fuel to burner 108. When not fully energized, valve 146 is fully closed (i.e. a “fail-closed” type valve) so as to prevent the flow of gaseous fuel to burner 108.
During use, opening or closing of valve 146 may generally be directed or controlled by controller 154. For instance, valve 146 may be directed to the open position to create a flame 162 at burner 108. Controller 154 may receive one or more signals (e.g., from thermostat 116) to determine whether the temperature of water in tank 102 has reached a desired setpoint temperature. In response to the same, the controller 154 may direct the valve 146 to the closed position. In some embodiments, an open interval (i.e., time period in which gas valve 146 is continuously opened or flame 162 is generated) may be demarcated or observed as a single cycle.
Turning now to
The methods (e.g., 600) may occur as, or as part of, a water heating operation of water heater appliance 100. In particular, the methods (e.g., 600) disclosed herein may accurately detect excess temperatures within a combustion chamber, such as to maintain desired or safe operation while avoiding inaccurate or nuisance trips. Moreover, such methods may account for variations in ambient conditions.
It is noted that the order of steps within method 600 are for illustrative purposes. Except as otherwise indicated, one or more steps in the below method 600 may be changed, rearranged, performed in a different order, or otherwise modified without deviating from the scope of the present disclosure.
As shown in
In some embodiments, the set rate is determined over or as part of a preliminary cycle of the burner. In particular, the set rate may be based on or provided as the temperature-change rate (i.e., preliminary temperature-change rate, such as a rate of temperature increase or, alternatively, as a rate of temperature decrease).
Thus, 610 may include determining a preliminary temperature-change rate during a preliminary cycle of the water heater appliance. Such a preliminary cycle may occur prior to any contemporaneous cycle or detection of any combustion chamber temperature value during the same (e.g., as described below, such as with respect to 620). For instance, turning briefly to
Optionally, a minimum active-burn time may be required for the preliminary cycle prior to 610. In other words, the method 600 may include determining, prior to 610, a minimum active-burn time is met during the preliminary cycle of 610. Thus, the preliminary cycle may be required to continue (e.g., unabated) for the minimum active-burn time before values for the preliminary temperature-change rate may be tracked or the preliminary temperature-change rate is otherwise determined.
Additionally or alternatively, as part of 610, a plurality of preliminary temperature-change rates may be determined for multiple corresponding preliminary cycles of the burner. In some such embodiments, the set rate may be based on the plurality of preliminary temperature-change rates (e.g., as applied to a predetermined formula, program, or algorithm; such as to find the median or mean increase rate to be included with or provided as the set rate).
As noted above, the preliminary cycle may occur prior to one or more contemporaneous cycles (e.g., described below), which are subsequent to the preliminary cycle. Generally, the preliminary cycle(s) of 610 follow an initial activation (e.g., prompted by installation or reset of the water heater appliance).
In some embodiments, the preliminary cycle(s) is (are) (e.g., programmed or required to occur) within a predetermined number of cycles. Thus, the number of cycles of the burner may be counted following initial activation. The predetermined number of cycles may represent the maximum number of cycles that may be permitted to occur prior to 610. Optionally, a minimum number of cycles may be programmed (e.g., separate from or in addition to the maximum number) as a required event prior to 610.
In additional or alternative embodiments, the preliminary cycle(s) is (are) (e.g., programmed or required to occur) within a predetermined time period (e.g., as measured in hours, days, or weeks following initial activation). Thus, the general passage of time may be tracked or counted following initial activation. The predetermined time period may represent the maximum amount of time that may be permitted to occur as prior to 610. Optionally, a minimum time period may be programmed (e.g., separate from or in addition to the maximum amount of time) as a required event prior to 610.
At 620, the method 600 includes detecting a combustion chamber temperature (CCT) value during a contemporaneous cycle of the gas burner. In particular, after the set rate has been determined or otherwise established, the CCT temperature value may be detected at the chamber sensor. Optionally, multiple CCT values may be detected (e.g., according to a programmed detection schedule or rate) over the course of the same contemporaneous cycle.
Optionally, a minimum active-burn time may be required for the contemporaneous cycle prior to 620. In other words, the method 600 may include determining, prior to 620, a minimum active-burn time is met during the contemporaneous cycle of 620. Thus, the contemporaneous cycle may have to continue (e.g., unabated) for the minimum active-burn time before values for CCT values of the contemporaneous cycle are detected or the method 600 is otherwise able to proceed to 630.
At 630, the method 600 includes determining a contemporary temperature-change rate based on the detected CCT value (e.g., change rate, such as a rate of temperature increase or, alternatively, as a rate of temperature decrease). Specifically, 630 may include determining the contemporary temperature-change rate during a contemporary cycle of the water heater appliance. For instance, turning briefly to
At 640, the method 600 includes comparing the determined contemporary temperature-change rate to the set rate. For instance, the determined contemporary temperature-change rate of 630 may be compared to the set temperature rate that is previously determined (e.g., at 610). Thus, it may be determined if at least one of two conditions exist. The first condition being the determined contemporary temperature-change rate value deviates from the set rate (e.g., above in the case of a set temperature-increase rate or below in the case of a set temperature-decrease rate), such as being greater than the set rate. The second condition being the determined contemporary temperature-change rate is within the bounds from 0 as the set rate (e.g., below in the case of a set temperature-increase rate or above in the case of a set temperature-decrease rate), such as being less than or equal to the set rate. In some embodiments, 640 can include determining the determined contemporary temperature-change rate value is greater than the set rate or, alternately, 640 can include determining the determined contemporary temperature-change rate is less than or equal to the set rate.
At 650, the method 600 includes directing heating at the gas burner based on comparing the determined contemporary temperature-change rate to the set rate (i.e., based on the comparison of 640). Thus, 640 may influence how, when, or if gas flows to the burner or how the flame is otherwise generated (e.g., permitted to generate) at the burner. As one example, 650 may include halting burner activation in response to determining the determined contemporary temperature-change (e.g., as a temperature-increase) rate value is greater than the set rate. Alternatively, 650 may include halting burner activation in response to determining the determined contemporary temperature-change (e.g., as a temperature-decrease) rate value is less than the set rate. For instance, the gas valve may be directed to close or the flame may otherwise be reduced or extinguished. Thus, deviant temperature changes within the combustion chamber (e.g., relative to a baseline) may prompt the burner to stop generating further heat. As another example, 650 may include permitting burner activation in response to determining the determined contemporary temperature-change (e.g., as a temperature-increase) rate is less than or equal to the set rate. Alternatively, 650 may include permitting burner activation in response to determining the determined contemporary temperature-change (e.g., as a temperature-decrease) rate is greater than or equal to the set rate. For instance, the gas may be allowed to remain open according to one or more other operational algorithms (e.g., directing water within the tank to a set temperature as measured by a thermostat). In turn, relatively conforming or desirable temperature changes within the combustion chamber (e.g., relative to the baseline) may indicate regular or default operation is appropriate.
As would be understood, various steps may be repeated over the course of future operations or cycles. For instance, for each new contemporaneous cycle (or within the same contemporaneous cycle), the steps 620 through 650 may be repeated to promote safety or efficient performance.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
