Patent Application
20210127939
The present subject matter relates generally to washing appliances, such as dishwashing appliances and, more particularly, to a dishwashing appliance with features for efficiently providing a hot start and related methods.
Dishwashing appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber for receipt of articles for washing where, e.g., detergent, water, and heat, can be applied to remove food or other materials from dishes and other articles being washed. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle. In addition, spray-arm assemblies within the wash chamber may be used to apply or direct fluid towards the articles disposed within the rack assemblies in order to clean such articles, e.g., during the wet cycle.
Some dishwashing appliances provide hot water at the start of the wet cycle. However, water received from the plumbing system may not be sufficiently hot when the dishwashing appliance is first started, for example, due to residual cold water in the supply line between a water heater and the dishwashing appliance. In such instances, the dishwashing appliance may discard an initial fill of water when the initial fill of water is not hot enough. Due to variations in usage conditions of the dishwashing appliance, e.g., length of the supply line between the water heater and the dishwashing appliance, amount of time since the appliance or a nearby appliance or fixture connected to the same line was last used, local climate and seasonal temperature variations, etc., it may be more efficient in some instances to heat the initial fill in the dishwashing appliance rather than discarding it and re-filling the dishwashing appliance, whereas in other instances discarding and re-filling may be more efficient.
Accordingly, improved systems and methods for a dishwashing appliance which provide improved energy and water consumption would be welcomed.
Aspects and advantages of the technology 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 technology.
In one embodiment, a method of operating a dishwashing appliance is provided. The method includes characterizing the dishwashing appliance.
Characterizing the dishwashing appliance includes measuring an initial temperature of water in a sump of the dishwashing appliance, measuring a subsequent temperature of the water in the sump after a predetermined period of time, and calculating a heat rise rate based on the initial temperature, the subsequent temperature, and the predetermined period of time. The method further includes filling the sump of the dishwashing appliance with an initial fill of water of a current operational cycle of the dishwashing appliance after characterizing the dishwashing appliance. The method also includes measuring a temperature of the initial fill of water of the current operational cycle in the sump, comparing the temperature of the initial fill of water of the current operational cycle to a reference temperature, and calculating an energy demand for the dishwashing appliance to heat the initial fill of water of the current operational cycle to the reference temperature, based on the heat rise rate calculated during characterization of the dishwashing appliance. The method then heats the initial fill of water of the current operational cycle to the reference temperature in the dishwashing appliance based on the calculated energy demand.
In another embodiment, a method of operating a dishwashing appliance is provided. The method includes filling a sump of the dishwashing appliance with an initial fill of water of a current operational cycle of the dishwashing appliance and measuring a temperature of the initial fill of water of the current operational cycle in the sump. The method also includes comparing the temperature of the initial fill of water of the current operational cycle to a reference temperature and calculating an energy demand for the dishwashing appliance to heat the initial fill of water of the current operational cycle to the reference temperature, based on a heat rise rate of the dishwashing appliance. The method further includes comparing the calculated energy demand to a predetermined energy demand for an external heating unit to provide a fill of water to the dishwashing appliance at the reference temperature. Based on the comparison of the calculated energy demand to the predetermined energy demand, the initial fill of water of the current operational cycle is heated to the reference temperature in the dishwashing appliance when the calculated energy demand is less than the predetermined energy demand.
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.
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, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.
As used herein, terms of approximation such as “generally,” “about,” or “approximately” include values within ten percent greater or less than the stated value. 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, e.g., clockwise or counterclockwise, with the vertical direction V.
Referring now to the drawings,
As is understood, the tub 104 may generally have a rectangular cross-section defined by various wall panels or walls. For example, as shown in
As particularly shown in
Additionally, the dishwashing appliance 100 may also include a lower spray-arm assembly 144 that is configured to be rotatably mounted within a lower region 146 of the wash chamber 106 directly above the bottom wall 162 of the tub 104 so as to rotate in relatively close proximity to the rack assembly 132. As shown in
As is generally understood, the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 may generally form part of a fluid circulation system 152 for circulating fluid (e.g., water and dishwasher fluid which may also include water, detergent, and/or other additives, and may be referred to as wash fluid) within the tub 104. As shown in
Moreover, each spray-arm assembly 144, 148 may include an arrangement of discharge ports or orifices for directing washing fluid onto dishes or other articles located in rack assemblies 130 and 132, which may provide a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly 144 provides coverage of dishes and other dishwasher contents with a washing spray.
A drain pump 156 may also be provided in the machinery compartment 140 and in fluid communication with the sump 142. The drain pump 156 may be in fluid communication with an external drain (not shown) to discharge fluid, e.g., used wash liquid, from the sump 142.
The dishwashing appliance 100 may be further equipped with a controller 137 configured to regulate operation of the dishwasher 100. The controller 137 may generally include one or more memory devices and one or more microprocessors, such as one or more general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. 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 stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.
The controller 137 may be positioned in a variety of locations throughout dishwashing appliance 100. In the illustrated embodiment, the controller 137 is located within a control panel area 121 of the door 108, as shown in
It should be appreciated that the present subject matter is not limited to any particular style, model, or configuration of dishwashing appliance. The exemplary embodiment depicted in
Embodiments of the present disclosure also include methods of characterizing and/or operating a dishwashing appliance, such as the exemplary methods 200, 300, 400, and 500 illustrated in
Turning now to
In some embodiments, methods of characterizing the dishwashing appliance may also include circulating the water and/or wash liquid from the sump through the dishwashing appliance. For example, such circulation may be provided by activating a recirculation pump of the dishwashing appliance to motivate the water from the sump through a circulation system, e.g., including one or more spray apparatus such as a spray arm, of the dishwashing appliance. In various embodiments, such circulation may be provided before and/or after measuring and recording the initial temperature. Circulating the water from the sump through the dishwashing appliance may include circulating the water throughout a wash chamber of the dishwashing appliance, e.g., via one or more spray apparatus as mentioned, whereupon the water returns to the sump, e.g., drains to the sump by gravity when the sump is positioned at a bottom of the wash chamber. The predetermined period of time may be or correspond to a time period of an operational cycle of the dishwashing appliance, such as a wash cycle, for example.
The characterizing method 200 may also include a step 204 of measuring and recording a subsequent water temperature after a predetermined period of time, such as a predetermined period of time in a main wash cycle of the dishwashing appliance. For example, in some embodiments, methods of characterizing the dishwashing appliance may include circulating the water from the sump through the dishwashing appliance for the predetermined period of time after measuring the initial temperature of the water in the sump. Based on the initial water temperature, the subsequent water temperature, and the predetermined period of time, the method 200 may then calculate a heat rise rate of the dishwashing appliance at step 206. For example, the heat rise rate may be calculated by taking the mathematical difference between the initial water temperature and the subsequent water temperature, such as by subtracting the initial water temperature from the subsequent water temperature, and dividing that difference by the period of time. The heat rise rate thus may be expressed in terms of temperature per time, such as ° F./min, where typical heat rise rates for exemplary dishwashing appliances may range from about 1° F./min to about 2.5° F./min, purely by way of example.
As illustrated in
For example, the heat rise rate may be used in determining whether to heat an initial fill of a subsequent operational cycle in the dishwashing appliance or to drain the initial fill and re-fill the dishwashing appliance with fresh, hot water. Such determination may, in various embodiments, be based on the heat rise rate. For example, the determination may be based on a calculated energy demand which is calculated based on the heat rise rate. For example, the determination may be based on comparing the calculated energy demand to a predetermined energy demand for an external heating unit, such as a water heater, to provide a fill of water to the dishwashing appliance at a reference temperature.
One example embodiment of a method 300 of operating a dishwashing appliance according to the present disclosure is illustrated in
As illustrated in
The method 300 may then, at step 306, calculate the energy (E) required for the dishwashing appliance to heat the system to the reference temperature. The “system” may include, e.g., the water in the sump as well as the overall thermal load in the dishwashing appliance including articles, e.g., dishes, loaded therein. The thermal load may vary over time, such as from one operation to the next, due to, e.g., the size, type, and amount of articles in the dishwashing appliance. The energy calculation may include or be based on a prior measured heat rate rise, e.g., the recorded heat rate rise from the characterization method of
The method 300 may then include comparing the calculated energy (E) to a reference energy (Er). For example, the reference energy (Er) may be the energy charged to the dishwashing appliance for the energy consumed by a hot water heater to heat the inlet water (that is, incoming water to the dishwashing appliance from the hot water heater, which may be received by the dishwashing appliance via a supply line which is a part of a plumbing system, such as a residential plumbing system in a house or apartment building, where the hot water from the water heater is received by the dishwashing appliance at an inlet of the dishwashing appliance, and is thus referred to as inlet water) to the reference temperature. In at least some embodiments, comparing the calculated energy (E) to the reference energy (Er) may include determining whether the calculated energy (E) is greater than the reference energy (Er), e.g., as illustrated at step 308 in
In some embodiments, when the calculated energy (E) is greater than the reference energy (Er), the method 300 may include an Auto Hot Start feature, e.g., may include draining the dishwashing appliance and re-filling the dishwashing appliance, as illustrated in
In some embodiments, when the calculated energy (E) is not greater than, e.g., is less than, the reference energy (Er), the method 300 may include continuing the current operational cycle, such as a wash segment or rinse cycle, etc., without executing the Auto Hot Start feature, e.g., the method 300 may include heating the water in the dishwashing appliance, as illustrated in
Turning now to
As illustrated in
As shown at step 404 in
After measuring the temperature of the initial fill, the method 400 may then include comparing the measured (recorded) temperature of the initial fill of water of the current operational cycle to a reference temperature, e.g., about 120° F. as described above, at step 406.
As illustrated at step 408 in
Finally, at step 410 in
Turning now to
In some embodiments, the method 500 may include a step 504 of measuring a temperature of the initial fill of water of the current operational cycle in the sump. The method 500 may also include a step 506 of comparing the measured temperature of the initial fill of water of the current operational cycle to a reference temperature. The method 500 may then use a heat rise rate, e.g., that is calculated or obtained from a characterization of the dishwashing appliance, as described above, to calculate an energy demand (E) for the dishwashing appliance to heat the initial fill of water of the current operational cycle to the reference temperature based on the heat rise rate of the dishwashing appliance, as shown at 508 in
The method 500 may then include a step 510 of comparing the calculated energy demand (E) to a predetermined energy demand (ER) for an external heating unit to provide a fill of water to the dishwashing appliance at the reference temperature. For example, the external heating unit may be a water heater which is typically located in a separate room or area from the dishwashing appliance, e.g., the dishwashing appliance may be located in a kitchen while the water heater is located in a garage or basement, etc.
As shown at step 520 in
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.
