The subject matter of the present disclosure relates generally to an oven appliance, such as a full-size gas oven appliance or gas range appliance, and more specifically to systems and methods for flame proving in a gas oven appliance.
Oven appliances generally include a cabinet that defines a cooking chamber for cooking food items therein, such as by baking or broiling the food items. To heat the cooking chamber for cooking, oven appliances include one or more heating elements positioned at a top portion, a bottom portion, or both the top portion and the bottom portion of the cooking chamber. Some oven appliances also include a convection heating element and fan for convection cooking cycles. The heating element or elements may be used for various cycles of the oven appliance, such as a preheat cycle, a cooking cycle, or a self-cleaning cycle.
Residential gas oven burner system have safety requirements regarding flame proving. Typical flame proving methods use flame rectification sensors that feed a signal into a control board that give the proper indication that the burner flame has been lit or not, however, flame rectification sensors and accompanying circuitry may be complex, expensive, and prone to being contaminated. Additionally, visual systems for flame proving may be easily soiled with food in an oven and prone to nuisance failures. Traditional thermocouple systems may also be too slow to respond in an oven that runs as high as eight hundred degrees Fahrenheit (800° F.).
Accordingly, an oven appliance that includes a simplified, cheaper, and faster flame proving system and related methods would be desirable.
Aspects and advantages of the invention will be set forth in part in the following description, may be apparent from the description, or may be learned through practice of the invention.
In one example embodiment, an oven appliance is provided. The oven appliance includes a cabinet and a chamber within the cabinet for receipt of food items for cooking. The chamber is delineated by a plurality of walls including a bottom wall, a left side wall, and a right side wall. A gas burner is positioned within the chamber, and a first temperature sensor is positioned proximate the gas burner. A second temperature sensor is distal from the first temperature sensor and the gas burner. The second temperature sensor is positioned and configured to measure a temperature in the chamber. and a controller positioned within the cabinet and in data communication with the first temperature sensor and the second temperature sensor. The controller is configured for measuring a first temperature with the first temperature sensor, measuring a second temperature with the second temperature sensor, calculating a difference between the first temperature and the second temperature, and determining a flame is emanating from the gas burner in response to a positive difference between the first temperature and the second temperature.
In another example embodiment, a method of operating an oven appliance is provided. The oven appliance includes a cabinet, a chamber defined within the cabinet for receipt of food items for cooking, a gas burner positioned in the cabinet, and a controller positioned within the cabinet. The method includes measuring a first temperature with the first temperature sensor, measuring a second temperature with the second temperature sensor, calculating a difference between the first temperature and the second temperature, and determining a flame is emanating from the gas burner in response to a positive difference between the first temperature and the second temperature, without receiving a signal from a flame rectification sensor.
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 or spirit 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, terms of approximation, such as “generally,” or “about” include values within ten percent greater or less than the stated value. In the context of an angle or direction, such terms include values within ten degrees of the stated direction. For example, “generally vertical” includes directions within ten degrees of vertical in any direction, e.g., clockwise or counter-clockwise.
Still referring to
Oven appliance 100 can include a seal (not shown) between door 108 and cabinet 102 that assists with maintaining heat and cooking vapors within cooking chamber 104 when door 108 is closed as shown in
One or more heating elements may be included at the top, bottom, or both of cooking chamber 104 to provide heat to cooking chamber 104 for cooking. Such heating element(s) may be gas, electric, microwave, or a combination thereof. For example, in the embodiment shown in
In the illustrated example embodiment, oven appliance 100 also has a convection heating element 136 and convection fan 138 positioned adjacent back wall 116 of cooking chamber 104. Convection fan 138 is powered by a convection fan motor 139. Further, convection fan 138 can be a variable speed fan-meaning the speed of fan 138 may be controlled or set anywhere between and including, e.g., zero and one hundred percent (0%-100%). In certain embodiments, oven appliance 100 may also include a bidirectional triode thyristor (not shown), i.e., a triode for alternating current (TRIAC), to regulate the operation of convection fan 138 such that the speed of fan 138 may be adjusted during operation of oven appliance 100. The speed of convection fan 138 can be determined by controller 140. In addition, a sensor 137 such as, e.g., a rotary encoder, a Hall effect sensor, or the like, may be included at the base of fan 138, for example, between fan 138 and motor 139 as shown in the example embodiment of
Oven appliance 100 may generally include a user interface 128 having a display 130 positioned on an interface panel 132 and having a variety of controls 134. Interface 128 allows the user to select various options for the operation of oven 100 including, e.g., various cooking and cleaning cycles. Operation of oven appliance 100 can be regulated by a controller 140 that is operatively coupled to, i.e., in communication with, user interface 128, heating elements 124, 126, and other components of oven 100 as will be further described.
For example, in response to user manipulation of the user interface 128, controller 140 can operate the heating element(s). Controller 140 can receive measurements from one or more temperature sensors, such as a first temperature sensor 210 (
Controller 140 may include a 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 oven appliance 100. The memory may represent random access memory such as DRAM or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions or methods stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. The memory can store information accessible by the processor(s), including instructions that can be executed by processor(s). For example, the instructions can be software or any set of instructions that when executed by the processor(s), cause the processor(s) to perform operations. For the embodiment depicted, the instructions may include a software package configured to operate the system, e.g., to execute example methods of operating the oven appliance 100. Controller 140 may also be or include the capabilities of either a proportional (P), proportional-integral (PI), or proportional-integral-derivative (PID) control for feedback-based control implemented with, e.g., temperature feedback from one or more sensors such as temperature sensors and/or probes, etc. For example, controller 140 may be configured for operating gas burner 126 in a closed-loop cooking operation based on temperature feedback from a main temperature sensor, such as temperature sensor 212 (
Controller 140 may be positioned in a variety of locations throughout oven appliance 100. In the illustrated embodiment, controller 140 is located next to user interface 128 within interface panel 132. In other embodiments, controller 140 may be located under or next to the user interface 128, otherwise within interface panel 132, or at any other appropriate location with respect to oven appliance 100.
Generally, controller 140 may be positioned within cabinet 102. In the embodiment illustrated in
Although shown with touch type controls 134 in
While oven 100 is shown as a wall oven, the present invention could also be used with other cooking appliances such as, e.g., a stand-alone oven, an oven with a stove-top, or other configurations of such ovens. Numerous variations in the oven configuration are possible within the scope of the present subject matter. For example, variations in the type and/or layout of the controls 134, as mentioned above, are possible. As another example, the oven appliance 100 may include multiple doors 108 instead of or in addition to the single door 108 illustrated. Such examples include a dual cavity oven, a French door oven, and others. The examples described herein are provided by way of illustration only and without limitation.
Referring specifically to
Referring now to
In another example embodiment, as illustrated in
In some example embodiments, both of first temperature sensor 210 and second temperature sensor 212 may be identical types of sensors. For example, both of first temperature sensor 210 and second temperature sensor 212 may be thermocouple sensors, or, in some additional/alternative embodiments, both of first temperature sensor 210 and second temperature sensor 212 may be resistance temperature detector (RTD) sensors. In some other example embodiments, first temperature sensor 210 and second temperature sensor 212 may be a combination of a thermocouple sensor and a RTD sensor, such as, first temperature sensor 210 may be an RTD sensor and second temperature sensor 212 may be a thermocouple sensor. Regardless of the type of sensor, first temperature sensor 210 and second temperature sensor 212 may be positioned within a probe sheath 220. In general, probe sheath 220 may provide additional protection to first temperature sensor 210 and second temperature sensor 212 against flame(s) 230, and/or undesired contamination within oven appliance 100. As shown in
In general, controller 140 may be in data communication with first temperature sensor 210 and second temperature sensor 212. In particular, first temperature sensor 210 and second temperature sensor 212 may transmit temperature data to controller 140, such that controller 140 may compare a difference between the temperatures of first temperature sensor 210 and second temperature sensor 212. For example, a positive difference in temperature between first temperature sensor 210 and second temperature sensor 212, e.g., controller 140 may be configured for determining the flame(s) 230 emanating from gas burner 126 in response to a positive difference in temperature from the second temperature from second temperature sensor 212 to the first temperature from first temperature sensor 210. Furthermore, controller 140 may be further configured for igniting gas burner 126 and waiting a predetermined amount of time after igniting gas burner 126 before calculating the difference between the first temperature and the second temperature. As such, determining flame(s) 230 is/are emanating from gas burner 126 may occur in response to the positive difference between the first temperature and the second temperature reaching a threshold temperature differential after a predetermined amount of time. Additionally, the threshold temperature differential may indicate flame(s) 230 emanating from gas burner 126 when the threshold temperature differential is reached within the predetermined amount of time.
For example, the threshold temperature differential may be between one hundred degrees Fahrenheit (100° F.) and two hundred degrees Fahrenheit (200° F.), such as between one hundred and twenty five degrees Fahrenheit (125° F.) and one hundred and seventy five degrees Fahrenheit (175° F.), such as about one hundred and fifty degrees Fahrenheit (150° F.). The predetermined amount of time may be between one second (1 s) and four seconds (4 s), such as between two seconds (2 s) and three seconds (3 s), or otherwise about four seconds (4 s). In other words, for the temperature sensors to indicate the presence of flames within oven appliance 100, first temperature sensor 210 and second temperature sensor 212 may reach the positive temperature difference of about one hundred and fifty degrees Fahrenheit (150° F.) within about four seconds (4 s).
As one skilled in the art will appreciate, the above described embodiments are used only for the purpose of explanation. Modifications and variations may be applied, other configurations may be used, and the resulting configurations may remain within the scope of the invention. For example, oven appliance 100 is provided by way of example only and aspects of the present subject matter may be incorporated into any other suitable oven appliance.
Referring now to
As shown in
As may be seen from the above, an oven appliance may include a gas burner system, wherein the oven appliance may include two temperature sensors located inside a cabinet in order to detect flame(s). The sensors may be arranged in such a manner that one sensor remains close to the flame(s) of the gas burner, whereas the other sensor may be positioned away from the flame, but at a location where a general oven temperature may be measured. The sensors could be two separate probes, or two temperature sensors combined into one probe, wherein one of the sensors may be the main oven temperature control sensor and is supplemented with the other sensor which may be positioned close to the flame(s).
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 language of the claims.