Patent Application
20240068151
The present subject matter relates generally to laundry appliances, and more particularly to laundry appliances having a heat pump heating system including a multi-pass heat exchanger.
Closed loop airflow circuit laundry appliances can efficiently dry laundry articles. Example closed loop airflow circuit laundry appliances include condenser dryers, heat pump dryers, and spray tower dryer appliances. Such dryer appliances include a closed loop airflow circuit along which process air is moved. The process air is conditioned by a conditioning system, e.g., to remove moisture from the process air after the air has absorbed water from articles and also heats the air to increase the moisture capacity of the air.
For example, a heat pump dryer uses a refrigerant cycle to both provide hot air to the dryer and to condense water vapor in air coming from the dryer. Since the moisture content in the air from the dryer is reduced by condensation over the evaporator, this same air can be reheated again using the condenser and then passed through the dryer again to remove more moisture.
In many closed loop airflow circuit dryer appliances (or combination laundry appliances operating in a dry cycle), it is desirable to maximize heat exchanger capacity, e.g., mass flow rate, while minimizing the size, cost, and complexity of the closed loop airflow circuit system. For example, multi-pass, parallel flow heat exchangers allow for a high refrigerant mass flow rate while maintaining low system pressure drop. Such heat exchangers, however, are less effective when the refrigerant quality varies across the multiple inlets of the multiple passes. Conventional means for equalizing refrigerant quality across the inlets, such as complex separator valves, result in increased cost and complexity, e.g., due to the number of moving parts therein, as well as increasing the size of the system.
Accordingly, improved laundry appliances including improved features for equalizing refrigerant quality across the inlets of a multi-pass heat exchanger are desired in the art.
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 aspect, a laundry appliance is provided. The laundry appliance includes a cabinet. The cabinet defines a vertical direction, a lateral direction, and a transverse direction. The laundry appliance also includes a drum rotatably mounted within the cabinet. The drum defines a chamber for receipt of articles for drying. The laundry appliance further includes a sealed system configured to heat and remove moisture from process air flowing therethrough. The sealed system includes a multi-pass heat exchanger having a plurality of inlets. The sealed system also includes a refrigerant splitter upstream of the plurality of inlets. The refrigerant splitter is oriented generally along the vertical direction.
In another aspect, a laundry appliance is provided. The laundry appliance includes a cabinet and a drum rotatably mounted within the cabinet. The drum defines a chamber for receipt of articles for drying. The laundry appliance further includes a sealed system configured to heat and remove moisture from process air flowing therethrough. The sealed system includes a multi-pass heat exchanger and a refrigerant splitter upstream of the multi-pass heat exchanger. The refrigerant splitter is configured to direct a flow of refrigerant against the force of gravity.
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, terms of approximation, such as “generally,” or “about” 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. For example, “generally vertical” includes directions within ten degrees of vertical in any direction, e.g., clockwise or counter-clockwise. 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, 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 terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Cabinet 12 includes a front panel 14, a rear panel 16, a pair of side panels 18 and 20 spaced apart from each other by front and rear panels 14 and 16 along the lateral direction L, a bottom panel 22, and a top cover 24. Cabinet 12 defines an interior volume 29. A drum or container 26 is mounted for rotation about a substantially horizontal axis within the interior volume 29 of cabinet 12. Drum 26 defines a chamber 25 for receipt of articles for tumbling and/or drying. Drum 26 extends between a front portion 37 and a back portion 38, e.g., along the transverse direction T. Drum 26 also includes a back or rear wall 34, e.g., at back portion 38 of drum 26. A supply duct 41 may be mounted to rear wall 34. Supply duct 41 receives heated air that has been heated by a conditioning system 40 and provides the heated air to drum 26 via one or more holes defined in rear wall 34.
As used herein, the terms “clothing” or “articles” includes but need not be limited to fabrics, textiles, garments, linens, papers, or other items from which the extraction of moisture is desirable. Furthermore, the term “load” or “laundry load” refers to the combination of clothing that may be washed together in a washing machine or dried together in a dryer appliance (e.g., clothes dryer) and may include a mixture of different or similar articles of clothing of different or similar types and kinds of fabrics, textiles, garments and linens within a particular laundering process.
In some embodiments, a motor 31 is provided to rotate drum 26 about the horizontal axis, e.g., via a pulley and a belt (not pictured). Drum 26 is generally cylindrical in shape. Drum 26 has an outer cylindrical wall 28 and a front flange or wall 30 that defines an opening 32 of drum 26, e.g., at front portion 37 of drum 26, for loading and unloading of articles into and out of chamber 25 of drum 26. Drum 26 includes a plurality of lifters or baffles 27 that extend into chamber 25 to lift articles therein and then allow such articles to tumble back to a bottom of drum 26 as drum 26 rotates. Baffles 27 may be mounted to drum 26 such that baffles 27 rotate with drum 26 during operation of dryer appliance 10.
Rear wall 34 of drum 26 is rotatably supported within cabinet 12 by a suitable bearing. Rear wall 34 can be fixed or can be rotatable. Rear wall 34 may include, for instance, a plurality of holes that receive hot air that has been heated by a conditioning system 40, e.g., a heat pump or refrigerant-based conditioning system as will be described further below. Moisture laden, heated air is drawn from drum 26 by an air handler, such as a blower fan 48, which generates a negative air pressure within drum 26. The moisture laden heated air passes through a duct 44 enclosing screen filter 46, which traps lint particles. As the air passes from blower fan 48, it enters a duct 50 and then is passed into conditioning system 40. In some embodiments, dryer appliance 10 is a heat pump dryer appliance and thus conditioning system 40 may be or include a heat pump including a sealed refrigerant circuit, as described in more detail below with reference to
In some embodiments, one or more selector inputs 70, such as knobs, buttons, touchscreen interfaces, etc., may be provided or mounted on a cabinet 12 (e.g., on a backsplash 71) and are communicatively coupled with (e.g., electrically coupled or coupled through a wireless network band) a processing device or controller 56. Controller 56 may also be communicatively coupled with various operational components of dryer appliance 10, such as motor 31, blower 48, and/or components of conditioning system 40. In turn, signals generated in controller 56 direct operation of motor 31, blower 48, or conditioning system 40 in response user inputs to selector inputs 70. As used herein, “processing device” or “controller” may refer to one or more microprocessors, microcontrollers, application-specific integrated controllers (ASICS), or semiconductor devices and is not restricted necessarily to a single element. The controller 56 may be programmed to operate dryer appliance 10 by executing instructions stored in memory (e.g., non-transitory media). The controller 56 may include, or be associated with, one or more memory elements such as RAM, ROM, or electrically erasable, programmable read only memory (EEPROM). For example, the instructions may be software or any set of instructions that when executed by the processing device, cause the processing device to perform operations. It should be noted that controller 56 as disclosed herein is capable of and may be operable to perform any methods or associated method steps as disclosed herein. For example, in some embodiments, methods disclosed herein may be embodied in programming instructions stored in the memory and executed by the controller 56.
In some embodiments, the sealed system 80 may optionally include one or more sensors for measuring characteristics of the sealed system 80. For example, the sealed system 80 may include a suction line temperature sensor 94, e.g., upstream of the compressor 84. As another example, the sealed system 80 may include an evaporator inlet temperature sensor 96 positioned at an inlet of the evaporator 82 and configured to measure a temperature of the refrigerant at the inlet of the evaporator 82.
In performing a drying and/or tumbling cycle, one or more laundry articles LA may be placed within the chamber 25 of drum 26. Hot dry air DA is supplied to chamber 25 via duct 41. The hot dry air DA enters chamber 25 of drum via a drum inlet 52 defined by drum 26, e.g., the plurality of holes defined in rear wall 34 of drum 26 as shown in
After exiting chamber 25 of drum 26, the warm moisture laden air MLA flows downstream to conditioning system 40. Blower fan 48 moves the warm moisture laden air MLA, as well as the air more generally, through a process air flow path 58 defined by drum 26, conditioning system 40, and the duct system 60. Thus, generally, blower fan 48 is operable to move air through or along the process air flow path 58. Duct system 60 includes all ducts that provide fluid communication (e.g., airflow communication) between drum outlet 54 and conditioning system 40 and between conditioning system 40 and drum inlet 52. Although blower fan 48 is shown positioned between drum 26 and conditioning system 40 along duct 44, it will be appreciated that blower fan 48 can be positioned in other suitable positions or locations along duct system 60.
As further depicted in
Air passing over evaporator 82 becomes cooler than when it exited drum 26 at drum outlet 54. As shown in
In some embodiments, conditioning system 40 of dryer appliance 10 optionally includes an electric heater 102 positioned to provide heat to process air flowing along the process air flow path 58, e.g., as shown in
With respect to sealed system 80, compressor 84 pressurizes refrigerant (i.e., increases the pressure of the refrigerant) passing therethrough and generally motivates refrigerant through the sealed refrigerant circuit or refrigerant line 90 of conditioning system 40. Compressor 84 may be communicatively coupled with controller 56 (communication lines not shown in
Upon exiting condenser 86, the refrigerant is fed through refrigerant line 90 to expansion valve 88. Expansion valve 88 lowers the pressure of the refrigerant and controls the amount of refrigerant that is allowed to enter the evaporator 82. The flow of liquid refrigerant into evaporator 82 is limited by expansion valve 88 in order to keep the pressure low and allow expansion of the refrigerant back into the gas phase in evaporator 82. The evaporation of the refrigerant in evaporator 82 converts the refrigerant from its liquid-dominated phase to a gas phase while cooling and drying the moisture laden air MLA received from chamber 25 of drum 26. The process is repeated as air is circulated along process air flow path 58 while the refrigerant is cycled through sealed system 80, as described above.
Although dryer appliance 10 is depicted and described herein as a heat pump dryer appliance, in at least some embodiments, dryer appliance 10 can be a combination washer/dryer appliance.
Dryness of the laundry articles LA may be detected based on one or more parameters of the sealed system 80. For example, such parameters may include temperature, pressure, and/or superheat. Over the course of the drying cycle or operation, as the moisture content in the laundry articles LA decreases, i.e., when the laundry articles LA are dry or nearly dry, the capacity of the moisture laden air MLA to transfer heat to the refrigerant in the evaporator decreases. More particularly, as the remaining moisture content in the laundry articles LA decreases, the humidity and latent heat of the moisture laden air MLA decreases. Thus, when there is less latent heat in the MLA for the vaporization process to absorb, the refrigerant may transition from liquid phase to vapor phase more slowly and/or incompletely. For example, this may result in a reduction in the degree of superheat in the refrigerant system, whereby the refrigerant remains in a liquid phase for a longer time. For example, liquid refrigerant may be present at the end of the evaporator coil 82 when the moisture laden air MLA is relatively (e.g., as compared to earlier in the dry cycle) less humid. Those of ordinary skill in the art will recognize that the degree of superheat refers to the extent to which the vaporized refrigerant exceeds the boiling point of the refrigerant. Thus, when the refrigerant in the evaporator absorbs less heat from the moisture laden air MLA, e.g., when there is less latent heat in the moisture laden air MLA because there is less moisture in the laundry articles LA, the degree of superheat in the sealed system 80, and in particular at or around the evaporator 82, such as at the evaporator inlet and/or in the suction line between the evaporator 82 and the compressor 84, will be less than the degree of superheat in the sealed system 80 when the moisture laden air MLA is relatively high (e.g., earlier in the dry cycle, when the remaining moisture content of the laundry articles is high). Accordingly, when the superheat in the sealed system 80 is relatively low, e.g., is at a low point relative to other times during the dry cycle, it may be inferred or determined that the remaining moisture content of the laundry articles LA is also at a low point, i.e., that the laundry articles LA are dry.
The electronic expansion valve 88 is operable to adjust a pressure of the refrigerant flowing along sealed system 80. For example, controller 56 may be configured to cause the electronic expansion valve 88 to adjust the pressure of the refrigerant flowing along the sealed system 80. For instance, the electronic expansion valve 88 can be moved from a first position to a second position which is a closed position or an intermediate position (e.g., not fully open or fully closed) which is closer to the closed position than the first position. This can increase the pressure on the high side of sealed system 80 and decrease the pressure on the low side of sealed system 80. Accordingly, the temperature of the refrigerant increases on the high side of sealed system 80 and the temperature of the refrigerant decreases on the low side of sealed system 80. That is, adjustment of the electronic expansion valve can drive higher temperatures in condenser 86 and can lower the temperature of the evaporator 82. Further, adjustment of the electronic expansion valve 88 can maintain a constant superheat in the sealed system 80 and in particular a constant level of superheat into the compressor 84, such as to avoid liquid refrigerant reaching the compressor 84. For example, the controller 56 may be configured to automatically adjust the electronic expansion valve 88 to maintain a constant degree of superheat into the compressor 84. As the degree of superheat in the sealed system 80 decreases, e.g., when the remaining moisture content in the laundry articles LA is below a certain level or threshold, the electronic expansion valve 88 may be closed (or partially closed, e.g., moved to an intermediate position which is closer to the closed position than a prior position) to restrict the flow of refrigerant in the sealed system 80. Thus, in some embodiments, the degree of superheat in the sealed system 80 and therefore the dryness of the laundry articles LA may be determined based on the position of the electronic expansion valve 88. For example, the laundry appliance 10 may include a position sensor or other expansion valve position tracking system which may be used to determine the position of the electronic expansion valve 88 and thereby determine or detect dryness of the laundry articles LA based on the position of the electronic expansion valve 88.
As may be seen in
Referring generally to
In some embodiments, the plurality of tubes may also contribute to equalizing the refrigerant quality at each inlet of the multiple passes of the heat exchanger 200. For example, where the quality at each outlet of the refrigerant splitter 202 is not exactly, the restriction of each tube of the plurality of tubes may vary to optimize the refrigerant quality across the multiple inlets of the heat exchanger 200. In some embodiments, e.g., as may be seen in
As mentioned above, the multi-pass heat exchanger 200 may be incorporated into the sealed system of a laundry appliance, e.g., a dryer appliance, such as the exemplary sealed system 80. For example, the sealed system 80 may include a compressor 84 and a fan 48, e.g., as described above with respect to
Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
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.
