Laundry dryer and control method of laundry dryer

Abstract

The present invention relates to a control method of a laundry dryer, including a steam supply step of supplying steam to a heat exchange part, a washing step of spraying washing water to the heat exchange part by controlling a washing part according to a preset spraying reference after the steam supply step, and a drying step of drying the heat exchange part after the washing step, thereby having an effect of removing foreign substances and microorganisms, etc. present in a heat exchanger and sterilizing the same.

Description

Technical Field

[0001] This invention relates to a laundry dryer and a control method for the laundry dryer, and more specifically, to a laundry dryer and a control method for the laundry dryer that generates high-temperature steam through a steam generator and controls the rotation of the drum and the fan respectively. Background Technology

[0002] In recent years, garment processing devices have emerged that perform drying processes to remove moisture from clothing. In existing garment processing devices, clothes are dried by supplying hot air to a drum containing the clothes, which not only significantly shortens the drying time but also sterilizes and disinfects the clothes.

[0003] On the other hand, there are also garment processing devices that supply steam to the garments in the garment processing device that performs the drying process to remove wrinkles, improve drying efficiency, or perform sterilization.

[0004] A condenser dryer with a heat pump system is disclosed in Korean Patent Publication No. 10-2013-0127816 (November 25, 2013), which is an existing patent document.

[0005] This type of condenser dryer has the problem of contamination caused by condensate. Specifically, condensate is generated in the evaporator as the humidity of the air passing through the drum while drying the items decreases. At this time, the condensate may contain contaminants or bacteria contained in the drum and the items being dried, and bacteria may contaminate one or more of the following components: the evaporator, the tank, the cleaning section, and the pump through which the condensate passes.

[0006] If the heat exchanger structure is contaminated by bacteria, an unpleasant odor caused by bacteria may remain in the air circulating in the flow path. This odor may penetrate the dried goods, leading to a decrease in drying quality. Furthermore, the large amount of condensate generated in the heat exchanger provides an environment conducive to bacterial growth, thus accelerating bacterial contamination of the heat exchanger.

[0007] As described above, the heat exchanger of the dryer requires direct cleaning by the user to eliminate contamination caused by bacteria or pollutants generated during the heat exchange process. However, due to the structure of the dryer, cleaning the heat exchanger inside is inherently difficult, thus creating inconvenience for the user.

[0008] In other words, existing dryers suffer from contamination caused by bacteria generated during the heat exchange process, but there is no specific method to prevent or eliminate bacterial contamination. Therefore, there are limitations that cannot meet the requirements of dryer performance, hygiene, drying quality, user convenience, and satisfaction. Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The present invention is proposed to improve the problems existing in the existing laundry dryers and control methods for laundry dryers as described above, and its purpose is to provide a structure that can clean the heat exchanger of the dryer itself.

[0011] Technical solutions to the problem

[0012] To achieve the objectives described above, the laundry dryer of the present invention includes: a drum rotatably disposed inside a housing forming the exterior, for accommodating the laundry to be dried; a duct section for resupplying air discharged from the drum to the drum; a circulating fan for providing flow power to the air moving along the duct section; a heat exchange section disposed on the duct section for exchanging heat with the air circulating along the duct section; a compressor for compressing refrigerant for exchanging heat with the air circulating along the duct section; a steam section for supplying steam to the interior of the drum; a cleaning section for spraying cleaning water onto the surface side of the heat exchange section for cleaning the surface of the heat exchange section; a sensing section for sensing the temperature of the heat exchange section; and a control section for controlling the drum, the circulating fan, the compressor, the steam section, and the cleaning section.

[0013] When cleaning and sterilizing the heat exchange unit, the control unit supplies steam by operating the steam unit, and then the heat exchange unit can be cleaned and sterilized by driving the compressor.

[0014] When the steam section is in operation, the control section can drive the circulating fan to direct steam to the heat exchange section.

[0015] When the steam section is in operation, the control section can rotate the drum.

[0016] The control unit can control the steam unit to interrupt the steam injection for a preset pause time after the preset steam injection time, and then resume the steam injection for the preset injection time.

[0017] The control unit can make the circulating fan rotate at a preset first circulation speed.

[0018] The cleaning unit may include: a cleaning water spraying unit for spraying cleaning water into the heat exchange unit; a drain pump for delivering condensate stored in the housing; and a control valve for distributing the condensate delivered by the drain pump to the cleaning water spraying unit.

[0019] The control unit can control the operation of the cleaning unit to spray the cleaning water onto the heat exchange unit according to a preset spray reference after the steam supply ends.

[0020] When the cleaning unit starts operating, the control unit can drive the compressor at a preset first compression frequency.

[0021] After the cleaning unit finishes operating, the control unit can accelerate the compressor at a preset second compression frequency.

[0022] After the cleaning unit finishes operating, the control unit can make the circulating fan rotate at a preset second circulation speed.

[0023] After the supply of steam ends, the control unit can cause the drain pump to operate for a pre-input cleaning time.

[0024] The control unit can be configured to perform cleaning and sterilization operations on the heat exchange unit when the item to be dried is not contained in the drum.

[0025] To achieve the above objectives, the control method of the laundry dryer of the present invention may include: a steam supply step of supplying steam to a heat exchange unit; a cleaning step of controlling a cleaning unit to spray cleaning water onto the heat exchange unit according to a preset spray reference after the steam supply step; a drying step of drying the heat exchange unit after the cleaning step; and an air supply step of heating the heat exchange unit by utilizing a thermal equilibrium phenomenon to sterilize the heat exchange unit.

[0026] In the steam supply step, steam is supplied to the heat exchange unit by operating the steam unit, and the circulating fan can be rotated at a preset first circulation speed.

[0027] The cleaning step may include a cleaning water spraying step, in which the cleaning water is sprayed onto the heat exchange unit according to a preset spraying reference.

[0028] The cleaning step may also include a first heating step, in which the compressor is driven at a preset first compression frequency.

[0029] The cleaning step may also include a pump driving step that drives the drain pump for a preset cleaning time.

[0030] The drying step may include a second heating step in which the compressor is driven at a preset second compression frequency.

[0031] During the air supply step, the compressor drive can be interrupted to heat the evaporator using the thermal equilibrium phenomenon to sterilize the evaporator.

[0032] The steam supply step may include: a steam supply step of supplying water to the steam unit; a steam preheating step of applying power to the steam unit to heat the supplied water; and a steam injection step of injecting steam generated in the steam unit.

[0033] In the steam injection step, after the steam is injected for a preset injection time, the steam injection is interrupted for a preset pause time, and the steam can be injected again for the preset injection time.

[0034] Invention Effects

[0035] As described above, according to the laundry dryer and its control method of the present invention, the heat exchanger is sterilized by controlling the surface temperature of the heat exchanger to a reference temperature or higher for sterilization.

[0036] In addition, by controlling the compressor drive, the surface temperature of the heat exchanger can be raised above the reference temperature for sterilization, thus enabling the heat exchanger to be sterilized simply without the need for additional components / devices for sterilization.

[0037] In addition, by supplying steam to the heat exchanger during the steam supply step, the surface tension and viscosity of foreign matter and microorganisms adhering to the surface of the heat exchanger are reduced, thereby making them easier to remove from the heat exchanger. Attached Figure Description

[0038] Figure 1 This is a diagram illustrating the external shape of the laundry dryer according to an embodiment of the present invention.

[0039] Figure 2 This is a cross-sectional view used to illustrate the internal structure of the laundry dryer according to an embodiment of the present invention.

[0040] Figure 3 This is a perspective view showing the internal structure of a laundry dryer according to an embodiment of the present invention.

[0041] Figure 4 This is a block diagram illustrating the control configuration in a laundry dryer according to an embodiment of the present invention.

[0042] Figure 5 This is a flowchart illustrating the sequence of control methods for a laundry dryer according to an embodiment of the present invention.

[0043] Figure 6a and Figure 6b This is an example diagram illustrating a specific application example of a steam drying method related to embodiments of the present invention.

[0044] Figure 7 This is a graph showing the viscosity of foreign matter and microorganisms as a function of temperature in the control method of the laundry dryer according to an embodiment of the present invention.

[0045] Figure 8 This is a graph illustrating the surface tension of foreign objects and microorganisms as a function of temperature in the control method of the laundry dryer according to an embodiment of the present invention.

[0046] Figure 9 This is a diagram illustrating the sterilization conditions of a control method for a laundry dryer based on an embodiment of the present invention. Detailed Implementation

[0047] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] This invention can be modified and has various embodiments, specific embodiments of which are shown in the accompanying drawings and are intended to be specifically described in the detailed description. This is not intended to limit the invention to the specific embodiments, but should be construed as including all modifications, equivalents, and substitutions within the spirit and scope of the invention.

[0049] In describing this invention, the terms "first," "second," etc., can be used to describe various constituent elements, but the constituent elements are not limited by these terms. These terms are only used to distinguish one constituent element from another. For example, without departing from the scope of this invention, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element.

[0050] The term "and / or" can include a combination of multiple related terms or a single term of multiple related terms.

[0051] When it is mentioned that a constituent element is "connected" or "linked" to another constituent element, it should be understood that it can be directly connected or linked to another constituent element, but there may also be other constituent elements between them. Conversely, when it is mentioned that a constituent element is "directly connected" or "directly linked" to another constituent element, it should be understood that there are no other constituent elements between them.

[0052] The terminology used in this application is for illustrative purposes only and is not intended to limit the invention. Unless explicitly stated in the context, singular expressions may include plural expressions.

[0053] In this application, it should be understood that terms such as "comprising" or "having" are intended only to indicate the presence of features, figures, steps, actions, constituent elements, components, or combinations thereof described in the specification, and do not preclude the possibility of the presence or addition of one or more other features or figures, steps, actions, constituent elements, components, or combinations thereof.

[0054] Unless otherwise defined, all terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms as defined in common dictionaries may be interpreted as having a meaning consistent with their meaning in the relevant technical context, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0055] Furthermore, the following embodiments are provided to provide a complete explanation to those skilled in the art, and for the sake of clarity, the shapes and sizes of the elements in the accompanying drawings may be exaggerated.

[0056] Figure 1 A diagram illustrating the external shape of a laundry dryer according to an embodiment of the present invention is shown. Figure 2 A cross-sectional view is shown to illustrate the internal structure of a laundry dryer according to an embodiment of the present invention.

[0057] like Figure 1 and Figure 2 As shown, the housing 10 forming the outer shell of the laundry dryer 1 includes: a front panel 11, constituting the front of the laundry dryer 1; a rear panel 12, constituting the rear; a pair of side panels 14, constituting the sides; and a top panel 13, constituting the top.

[0058] The front panel 11 may include: an inlet 111 configured to communicate with the roller 20 described later; and a door 112 rotatably coupled to the housing 10 to open and close the inlet 111.

[0059] A control panel 117 is located on the front panel 11.

[0060] The control panel 117 may include: an input unit 118 for receiving control commands from the user; an output unit 119 for outputting information such as control commands that the user can select; and a main control unit (not shown) for controlling the execution of the program of the laundry dryer 1.

[0061] On the other hand, the input unit 118 may include: a power supply request unit, which requests power to be supplied to the laundry dryer; a process input unit, which allows the user to select a desired process from a plurality of processes; and an implementation request unit, which requests the start of the process selected by the user.

[0062] The output unit 119 may include at least one of a display panel capable of outputting text and / or graphics and a speaker capable of outputting voice signals and sounds. Users can easily grasp the status of the currently running program, the remaining time, etc., through the information output via the output unit 119.

[0063] The interior of the housing 10 includes: a drum 20, configured to rotate, providing space for accommodating clothes (items to be dried); a duct section 30, forming a flow path for resupplying air discharged from the drum 20 to the drum 20; and a heat exchange section 40, which dehumidifies and heats the air flowing into the duct section 30, and then resupplyes it to the drum 20.

[0064] The roller 20 includes a cylindrical roller body 21 that is open at the front. The interior of the housing 10 may have: a first support 22 that supports the front of the roller body 21 so that it can rotate; and a second support 23 that supports the rear of the roller body 21 so that it can rotate.

[0065] The first support part 22 may include: a first fixing body 22a, fixed inside the housing 10; a roller inlet 22b, penetrating the first fixing body 22a to connect the inlet 111 and the inside of the roller body 21; and a first support body 22c, disposed on the first fixing body 22a and inserted into the front of the roller body 21.

[0066] The first support portion 22 may further include a connecting body 22d that connects the inlet 111 and the roller inlet 22b. As shown in the figure, the connecting body 22d may have a tube shape extending from the roller inlet 22b toward the inlet 111. In addition, an air outlet 22e communicating with the pipe portion 30 may be provided in the connecting body 22d.

[0067] like Figure 2 As shown, the air outlet 22e is a channel through which the internal air of the roller body 21 can move to the pipe section 30, and it can be a through hole that passes through and connects to the body 22d.

[0068] The second support part 23 includes: a second fixing body 23a, which is fixed inside the housing 10; and a second support body 23b, which is disposed on the second fixing body 23a and inserted into the rear of the roller body 21.

[0069] An air inlet 23c is provided in the second support part 23. The air inlet 23c passes through the second fixed body 23a to connect the interior of the roller body 21 and the interior of the box 10.

[0070] In this case, the duct section 30 is configured to connect the air outlet 22e and the air inlet 23c.

[0071] The cylindrical roller body 21 can be rotated by various types of drive units 50.

[0072] For example, Figure 2One embodiment is shown, wherein the drive unit 50 includes: a roller motor 51 fixed inside the housing 10; a pulley 52 rotated by the roller motor 51; and a belt 53 connecting the circumferential surface of the pulley 52 and the circumferential surface of the roller body 21.

[0073] In this case, the first support portion 22 may be provided with a first roller R1 that rotatably supports the circumferential surface of the roller body 21, and the second support portion 23 may be provided with a second roller R2 that rotatably supports the circumferential surface of the roller body 21.

[0074] However, the present invention is not limited thereto. A direct-drive mechanism, where the roller motor 51 is directly connected to the roller to rotate it, can also be used without the aid of pulleys and belts. This approach is also within the scope of the present invention. For ease of explanation, the following description will be based on the embodiment of the illustrated drive unit 50.

[0075] The duct section 30 includes: an exhaust duct 31 connected to an air outlet 22e; a supply duct 32 connected to an air inlet 23c; and a connecting duct 33 connecting the exhaust duct 31 and the supply duct 32, wherein a heat exchange section 40 is provided inside the connecting duct 33.

[0076] The heat exchange section 40 can be any device capable of sequentially dehumidifying and heating the air flowing into the duct section 30. For example, the heat exchange section 40 can be a heat pump system.

[0077] As a heat pump system, the heat exchange section 40 may include: a circulating fan 43 that moves air along the pipe section 30; a first heat exchanger (heat absorber or evaporator) 41 that performs a dehumidification function by reducing the humidity of the air flowing into the pipe section 30; and a second heat exchanger (heating unit or condenser) 42 that is disposed inside the pipe section 30 and heats the air that has passed through the first heat exchanger 41.

[0078] The circulating fan 43 includes: an impeller 43a disposed inside the duct section 30; and an impeller motor 43b that rotates the impeller 43a. The circulating fan 43 provides flow power to the air moving along the duct section 30.

[0079] Impeller 43a can be installed at any position in exhaust pipe 31, connecting pipe 33, and supply pipe 32. Figure 2 An embodiment in which the impeller 43a is disposed in the connecting pipe 33 is shown. The present invention is not limited thereto, but for convenience, the following description is based on the embodiment in which the impeller 43a is disposed in the connecting pipe 33.

[0080] The heat exchange section 40 can exchange heat with the air circulating along the pipe section 30.

[0081] The heat-absorbing part 41 and the heat-generating part 42 are located inside the connecting pipe 33 and are arranged sequentially in the direction from the exhaust pipe 31 to the supply pipe 32. They are connected to each other by the refrigerant pipe 44, which forms a refrigerant circulation path.

[0082] The heat absorption section 41 is a device that cools the air and causes the refrigerant to evaporate by transferring the heat of the air flowing into the exhaust pipe 31 to the refrigerant. (Hereinafter, it may be referred to as evaporator 41)

[0083] The heating element 42 is a device that heats the air and condenses the refrigerant by transferring the heat of the refrigerant that has passed through the compressor 45 to the air. (Hereinafter, it may be referred to as condenser 42)

[0084] The compressor 45 receives rotational force from the compressor motor 45a and compresses the refrigerant that exchanges heat with the air circulating along the pipe section 30.

[0085] In this situation, the moisture contained in the air moves along the surface of the evaporator 41 as it passes through the evaporator 41 and accumulates on the bottom surface of the connecting pipe 33.

[0086] On the other hand, in order to collect the condensate that accumulates on the bottom surface of the connecting pipe 33 due to the condensation of air passing through the evaporator 41, the laundry dryer 1 of the present invention has a water collection section 60.

[0087] The condensate that forms in the evaporator 41 can be collected once in the water collection section 60, and then collected again in the water storage section 70. As shown in the figure, the water collection section 60 can be located inside the connecting pipe 33, or it can be set up independently in a space separated from the connecting pipe 33.

[0088] The condensate collected in the water collection section 60 is supplied to the water storage section 70 through the condensate supply pipe 61. At this time, in order to smoothly drain the condensate, a drain pump 62 is installed in the condensate supply pipe 61.

[0089] The water storage section 70 has a water tank 72 that can be pulled outward from one side of the front panel 11. The water tank 72 is configured to collect condensate transferred from the water collection section 60, which will be described later.

[0090] The user can pull the water tank 72 out of the housing 10 to remove the condensate, and then reinstall it into the housing 10. Therefore, the laundry dryer of the present invention can be installed in locations without drainage systems.

[0091] More specifically, the water storage section 70 may include: a water storage tank 72, which is detachably disposed in the tank body 10 to provide space for storing water; and an inlet 72a, which penetrates the water storage tank 72 to allow water discharged from the condensate supply pipe 61 to flow into the interior of the water storage tank 72.

[0092] The water tank 72 can be a drawer-type tank that can be pulled out from the tank body 10. In this case, the front panel 11 of the tank body has a water storage section mounting hole for inserting the water tank 72.

[0093] Panel 71 is fixed to the front of water tank 72. Panel 71 can be detachably attached to the water storage section mounting hole to form part of front panel 11.

[0094] The panel 71 may also have a groove 71a for the user's hand to insert and hold. In this case, the panel 71 also functions as a handle for pulling the water tank 72 out of or inserting it into the tank.

[0095] The inlet 72a is configured to receive condensate discharged from a condensate nozzle fixed to the housing 10. The condensate nozzle may be fixed to the upper panel 13 of the housing 10 so that it is located above the inlet 72a when the water tank 72 is inserted into the housing 10.

[0096] The user can pull out the water tank 72 from the housing 10, and then invert or tilt the water tank 72 toward the inlet 72a to pour out the water inside the water tank 72. It may also include a connecting hole 72b that extends through the upper surface of the water tank 72, allowing water inside the water tank 72 to easily drain through the inlet 72a.

[0097] In addition, the laundry dryer 1 of the present invention includes a first filter section F1 and a second filter section F2, which are devices for removing foreign objects such as lint and dust generated during the drying process of laundry items such as clothes.

[0098] The first filter unit F1 is provided in the exhaust pipe 31 to filter foreign objects contained in the air discharged from the drum 20.

[0099] The second filter section F2 is positioned downstream of the first filter section F1 along the airflow direction to perform secondary filtration of foreign matter contained in the air that has passed through the first filter section F1. More specifically, as shown in the figure, the second filter section F2 is preferably positioned inside the connecting pipe 33 and upstream of the first heat exchanger 41. This is to prevent foreign matter contained in the air from accumulating on the first heat exchanger 41, which functions as a heat-absorbing section, and thus contaminating the first heat exchanger 41 or causing performance degradation.

[0100] The detailed structure of the first filter section F1 and the second filter section F2 can be described using any device known in the art, therefore a detailed description of their structure is omitted.

[0101] On the other hand, the laundry dryer 1 of the present invention further includes: a water supply unit 80, including an internal water supply unit 81 and an external water supply unit 82; and a steam unit 90, which receives water from the water supply unit 80 and generates steam.

[0102] The steam unit 90 can be configured to receive fresh, non-condensed water to generate steam. The steam unit 90 can also be configured to generate steam by heating water or by utilizing ultrasound or vaporization.

[0103] The steam unit 90 can be controlled to supply steam to the interior of the drum body 21 by receiving water through the internal water supply unit 81 and the external water supply unit 82 as needed.

[0104] The external water supply unit 82 may include: a straight-through water valve 82a, which is adjacent to or fixed to the rear panel 12; and a straight-through water pipe 82b, which supplies water from the straight-through water valve 82a to the steam unit 90.

[0105] The direct-flow water valve 82a can be configured to connect to an external water supply source. For example, the direct-flow water valve 82a can be connected to a water supply pipe (not shown) extending to the rear of the housing. Thus, the steam unit 90 can directly receive water through the direct-flow water valve 82a.

[0106] Therefore, even if the internal water supply unit 81 is omitted or no water is stored in the internal water supply unit 81, the steam unit 90 can receive water for generating steam through the direct water valve 82a when needed.

[0107] The direct-flow water valve 82a can be directly controlled by the control unit 100.

[0108] The control unit 100 can be located in the control panel 117, such as Figure 1 As shown, in order to prevent overloading of control panel 117 and avoid increasing manufacturing costs, control panels can also be set up separately.

[0109] At this time, the control unit 100 can be arranged adjacent to the steam unit 90. The control unit 100 is provided on the side panel 14 on which the steam unit 90 is mounted, thereby shortening the length of the control lines and the like connected to the steam unit 90.

[0110] On the other hand, the steam section 90 is preferably arranged adjacent to the straight-through water valve 82a. This prevents unnecessary residual water from remaining in the straight-through water pipe 82b and allows water to be received immediately when needed.

[0111] The control unit 100 is configured to control the operation of the laundry dryer 1 based on user input applied via the input unit 118. The control unit 100 may consist of a printed circuit board and components mounted on the printed circuit board. If the user selects a laundry processing process or inputs control commands such as the operation of the laundry processing device via the input unit 118, the control unit 100 can control the operation of the laundry dryer 1 according to a preset algorithm.

[0112] The specific control functions of the control unit 100 in this invention will be described later.

[0113] on the other hand, Figure 3 A perspective view illustrating the internal structure of a laundry dryer according to an embodiment of the present invention is disclosed.

[0114] The lower panel 15 is configured to support the mechanical components of the laundry dryer 1, including the heat exchange unit 40. For mounting the mechanical components, the lower panel 15 has a plurality of mounting sections. Each mounting section is an area provided for mounting the mechanical components. The mounting sections are separated from each other by steps on the lower panel. The constituent elements will be described below in a counter-clockwise direction based on the connecting pipe 33.

[0115] Unlike the case where the drum 20 is centrally located with the laundry dryer 1 in a left-right orientation, the air circulation path is eccentrically located on the left or right side of the drum 20. This eccentric arrangement of the air circulation path is for efficient drying of the items being processed and for effective component placement.

[0116] The inlet portion of the connecting pipe 33 is positioned below the exhaust pipe 31 and connects to it. The inlet portion 33a of the connecting pipe 33 is configured to guide air in an inclined direction together with the exhaust pipe 31. For example, the inlet portion of the connecting pipe 33 narrows downwards. In particular, the left side of the inlet portion is inclined to the lower right. If the air circulation path is positioned on the lower left side of the roller 20, the right side of the inlet portion can be inclined to the lower left.

[0117] Based on airflow, an evaporator 41, a condenser 42, and a circulating fan 43 are sequentially arranged downstream of the inlet section. When viewed from the front, the condenser 42 is positioned behind the evaporator 41, and the circulating fan 43 is positioned behind the condenser 42. The evaporator 41, condenser 42, and circulating fan 43 are mounted on various mounting sections provided on the lower panel 15.

[0118] A base cover 15a may be provided above the evaporator 41 and the condenser 42. The base cover 15a may be composed of a single component or a plurality of components.

[0119] The heat exchange unit 40 includes an evaporator 41, a condenser 42, and a compressor 45, which can constitute a heat pump system. A brief description of the heat pump system is as follows.

[0120] The refrigerant absorbs heat and evaporates (liquid -> gas) in evaporator 41, becoming a low-temperature, low-pressure gaseous state and being drawn into compressor 45. The gaseous refrigerant is compressed in compressor 45, becoming a high-temperature, high-pressure state and flowing into condenser 42. The refrigerant releases heat and is liquefied in condenser 42. The pressure of the liquefied, high-pressure refrigerant decreases in expander (not shown). The low-temperature, low-pressure liquid refrigerant then enters evaporator 41.

[0121] High-temperature dry air is supplied to the drum 20 through supply pipe 32 to dry the object being dried. The high-temperature dry air evaporates the moisture in the object being processed, turning it into high-temperature humid air. The high-temperature humid air is recovered through exhaust pipe 31 and receives heat from the refrigerant through evaporator 41, becoming low-temperature air. As the air temperature decreases, the amount of saturated water vapor in the air decreases, and the vapor contained in the air is condensed. Then, the low-temperature dry air receives heat from the refrigerant through evaporator 41, becoming high-temperature dry air again, and is supplied to the drum 20.

[0122] The base cover 15a is formed to cover the evaporator 41 and the condenser 42. The base cover 15a is attached to the steps or sidewalls of the lower panel 15 formed on the left and right sides of the evaporator 41 and the condenser 42, thereby forming part of the connecting pipe 33.

[0123] The circulating fan 43 is surrounded by a lower panel 15 and a circulating fan cover. An outlet portion of the circulating fan cover is formed on the upper side of the circulating fan 43. The outlet portion is connected to a supply pipe 32. High-temperature, dry air generated by the heat exchange section 40 is supplied to the drum 20 through the supply pipe 32.

[0124] The circulating fan 43 is located at the rearmost side within the housing 10. It is positioned downstream of the condenser 42 in the air circulation path, based on the airflow. The circulating fan 43 can be configured as a centrifugal fan. A centrifugal fan is configured to draw in air axially and eject it radially. If the rotation axis of the circulating fan 43 extends toward the condenser 42, then the condenser 42 is positioned in the direction in which the rotation axis of the circulating fan 43 extends.

[0125] The circulating fan 43 draws in hot, dry air from the condenser 42. Furthermore, the hot, dry air drawn in by the circulating fan 43 is ejected through an outlet formed in the circulating fan cover on the upper side of the circulating fan 43. Compared to axial fans, centrifugal fans generate a larger airflow and higher air velocity based on a stronger suction force.

[0126] A drain pump 62 is provided on one side of the condenser 42 or on one side of the circulating fan 43. The drain pump 62 is configured to transport condensate that accumulates in the mounting section where the drain pump 62 is provided.

[0127] The lower panel 15 is configured to discharge condensate generated during the operation of the heat exchange section 40 to the water collection section 60 where the drain pump 62 is installed. For example, the bottom surface of the mounting section may be inclined or the step height of the water collection section 60 where the drain pump 62 is installed may be locally lower, so that condensate flows to the mounting section where the drain pump 62 is installed.

[0128] If the air circulating in the drum 20 undergoes heat exchange in the heat exchange section 40, condensation occurs, and the condensate falls to the bottom of the lower panel 15. Therefore, the condensate accumulates at the mounting section at the lower end of the condenser 42. Here, the mounting section where the condenser 42 is located is formed adjacent to the water collection section 60 where the drain pump 62 is located, separated by a partition wall that forms the air circulation path.

[0129] A flow path is provided through the partition wall, allowing condensate that accumulates in the mounting portion where the condenser 42 is installed to flow into the water collection portion 60. The water collection portion 60 is formed at a height lower than the bottom of the mounting portion of the heat exchange portion 40. Therefore, the flow path is formed such that it slopes downward from the water collection portion 60 as it gets closer to the mounting portion of the heat exchange portion 40.

[0130] With this structure of the lower panel 15, condensate that accumulates in the water collection section 60, where the drain pump 62 is installed, can be pumped by the drain pump 62 to the water storage section 70. Additionally, the condensate pumped by the drain pump 62 can be used for cleaning the evaporator 41 or the condenser 42.

[0131] The drain pump 62 is connected to the control valve 63 via the condensate supply pipe 61. When the drain pump 62 is running, the condensate collected in the water collection section 60 is delivered to the control valve 63. The control valve 63 is configured to distribute the condensate delivered by the drain pump 62 to the cleaning water supply pipe 64 and the drain pipe 65.

[0132] The cleaning water supply pipe 64 and drain pipe 65 connected to the control valve 63 can be made of a soft material.

[0133] Drain pipe 65 connects to control valve 63 and water tank 72. Drain pipe 65 is connected to water tank 72 via the upper part of the bucket support frame, rather than directly to water tank 72.

[0134] If the condensate pumped by the drain pump 62 flows to the drain pipe 65 due to the action of the control valve 63, the condensate flows into the water storage tank 72 along the drain pipe 65. The condensate is temporarily stored in the water storage tank 72 until the user empties the water storage tank 72.

[0135] A cleaning water supply pipe 64 is connected to a control valve 63 and a cleaning water spray nozzle 66. The cleaning water spray nozzle 66 is configured to spray condensate onto the surface of the evaporator 41 or the condenser 42. As the laundry dryer 1 operates for a certain period of time, dust or foreign matter may adhere to the surfaces of the evaporator 41 and the condenser 42. Since dust or foreign matter reduces the heat exchange efficiency of the evaporator 41 and the condenser 42, it is necessary to remove them quickly.

[0136] If condensate is supplied to the cleaning water spray unit 66 through the cleaning water supply pipe 64, the cleaning water spray unit 66 will spray the received condensate onto the evaporator 41 or the condenser 42.

[0137] For this purpose, the nozzle of the cleaning water spray unit 66 is configured to face the evaporator 41 or the condenser 42. If condensed water is sprayed onto the evaporator 41 or the condenser 42 through the nozzle, dust or foreign matter can be removed from the evaporator 41 or the condenser 42.

[0138] In order to spray condensate water onto a wider area, the cleaning water supply pipe 64 and the cleaning water spray unit 66 may have a plurality of components.

[0139] As described above, in this invention, the water collection unit 60, the condensate supply pipe 61, the drain pump 62, the control valve 63, the cleaning water supply pipe 64, the drain pipe 65, and the cleaning water spraying unit 66 are connected to each other to form a cleaning unit 200. The cleaning unit 200 uses the condensate stored in the housing 10 as cleaning water, and can remove foreign objects and bacteria by spraying the cleaning water onto the surface of the heat exchange unit 40.

[0140] on the other hand, Figure 4 A block diagram illustrating the control configuration in a laundry dryer according to an embodiment of the present invention is disclosed.

[0141] Reference Figure 4 The laundry dryer 1 of the present invention may include at least one of the following: an input unit 118, an output unit 119, a communication unit 115, a sensing unit 116, a motor 51, 43b, 45a, a drain pump 62, a control valve 63, a steam unit 90, and a control unit 100.

[0142] The input unit 118 can receive control commands related to the operation of the laundry dryer 1 from the user. The input unit 118 can consist of a plurality of buttons or a touch screen.

[0143] Specifically, the input unit 118 may be configured to select the operating mode of the garment handling device or to receive control inputs related to the implementation of the selected operating mode.

[0144] The output unit 119 can output information related to the operation of the laundry dryer 1. The output unit 119 may include at least one display.

[0145] The information output by the output unit 119 may include information related to the operating status of the laundry dryer 1. That is, the output unit 119 may output information related to at least one of the following: the selected operating mode, whether a malfunction has occurred, the operation completion time, and the amount of fabric contained in the drum 20.

[0146] As an example, the output unit 119 may be a touch screen that is integrally formed with the input unit 118.

[0147] The communication unit 115 can communicate with an external network. The communication unit 115 can receive control commands related to the operation of the laundry handling device from the external network. For example, the communication unit 115 can receive operation control commands for the laundry dryer sent from an external terminal via the external network. Thus, the user can remotely control the laundry dryer.

[0148] In addition, the communications unit 115 can send information related to the operation results of the garment processing device to a designated server via an external network.

[0149] In addition, in order to build an Internet of Things (IoT) environment, the Communications Department 115 can also communicate with other electronic devices.

[0150] The sensing unit 116 can sense information related to the operation of the laundry dryer.

[0151] Specifically, the sensing unit 116 may include at least one of a current sensor, a voltage sensor, a vibration sensor, a noise sensor, an ultrasonic sensor, a pressure sensor, an infrared sensor, a vision sensor (camera sensor), and a temperature sensor.

[0152] As an example, the current sensor of the sensing unit 116 can sense the current flowing at a point in the control circuit of the laundry dryer 1.

[0153] As another example, the temperature sensor of the sensing unit 116 can sense the temperature inside the pipe section 30, and according to the embodiment, it can sense the temperature inside the drum 20.

[0154] The sensing unit 116 may include one or more temperature sensors that sense the temperature of the heat exchange unit 40 and transmit the sensing results to the control unit 100.

[0155] As an example, the sensing unit 116 includes one or more temperature sensors that can sense one or more of the temperatures of the air and refrigerant circulating in the evaporator 41 and condenser 42, respectively.

[0156] As another example, the sensing unit 116 includes one or more temperature sensors that can sense the temperature of the refrigerant circulating in the compressor 45.

[0157] The sensing unit 116 may also include a plurality of temperature sensors for sensing the temperature of air flowing into or out of the roller 20.

[0158] Thus, the sensing unit 116, which includes a plurality of the temperature sensors, can be configured such that a sensing module for sensing temperature is provided in the heat exchange unit 40, and a sensing module for receiving the sensing results of the plurality of temperature sensors to sense temperature is provided in the control unit 100.

[0159] As described above, the sensing unit 116 may include at least one of various types of sensors, and the type of sensors possessed by the laundry dryer 1 is not limited. Furthermore, the number or placement of the individual sensors can be designed in various ways depending on the purpose.

[0160] Motors 51, 43b, and 45a include a drum motor 51, an impeller motor 43b, and a compressor motor 45a. According to the control command (instruction) of the control unit 100, at least one of the following can be changed: power, current, voltage, and speed.

[0161] As an example, the rotational speed (rpm) of the roller motor 51 can be changed under the control command of the control unit 100, and the rotational speed (rpm) of the roller 20 connected to the output shaft of the roller motor 51 can be changed.

[0162] As another example, the impeller motor 43b can change the speed (rpm) of the circulating fan 43 according to the control command of the control unit 100.

[0163] As another example, the compressor motor 45a can change the frequency (Hz) of the compressor 45 according to the control command of the control unit 100.

[0164] The steam unit 90 can be controlled to supply steam to the interior of the drum body 21 by receiving water through the internal water supply unit 81 and the external water supply unit 82 as needed.

[0165] The steam unit 90 may include: a steam generator 91 that generates steam by heating the received water; a steam pipe 92 that supplies the generated steam flow; and a steam nozzle 93 that injects steam into the interior of the drum body 21.

[0166] As an example, the steam generator 91 is described as generating steam by heating a predetermined amount of water contained inside using a heater (not marked) (hereinafter referred to as "barrel heating method" for ease of explanation), but it is not limited to this.

[0167] The control unit 100 can control the components included in the laundry dryer 1.

[0168] First, in order to control the rotation of the drum motor 51, the impeller motor 43b and the compressor motor 45a, the control unit 100 can generate at least one of the following: power command value, current command value, voltage command value and speed command value.

[0169] In this invention, the control unit 100 can control the drum motor 51, the impeller motor 43b, and the compressor motor 45a respectively.

[0170] Therefore, the control unit 100 can control the operation of one or more of the drum 20, the circulating fan 43, and the heat exchange unit 40 based on the control inputs input to the input unit 118.

[0171] That is, the control unit 100 can control the rotation speed and rotation mode of the roller 20 based on the user's control input to the input unit 118. In addition, the control unit 100 can control the rotation speed or operating timing of the circulating fan 43 based on the user's control input to the input unit 118.

[0172] On the other hand, in existing laundry dryers, the drum and the circulating fan are connected to a single motor. Therefore, the drum and the circulating fan rotate simultaneously and stop rotating at the same time.

[0173] At this point, when steam is being injected into the laundry dryer, in order to ensure that the injected steam is fully supplied to the clothes being dried, the rotation of the circulating fan needs to be stopped. In order to stop the circulating fan, the rotation of the drum also needs to be stopped.

[0174] However, if the drum stops rotating, the items being dried cannot be tumbled. Even if steam is supplied to the items being dried, the steam is only supplied to the items that are positioned in the direction of the steam jet. Therefore, there are limitations in supplying steam evenly to the entire item being dried.

[0175] To solve this problem, the laundry dryer 1 of this embodiment of the invention is provided with a drum motor 51 and an impeller motor 43b separately. In addition, the control unit 100 can control the drum motor 51, the impeller motor 43b and the compressor motor 45a respectively.

[0176] In addition, the control unit 100 can control the heat exchange unit 40 according to the user's control input to the input unit 118 to adjust the temperature inside the drum 20.

[0177] As an example, the control unit 100 can control the drive frequency (Hz) of the compressor 45 based on the control input from the user input to the input unit 118.

[0178] In addition, in order to control the operation of the steam generator 91, the control unit 100 can generate at least one of the following: power command value, current command value, and voltage command value.

[0179] On the other hand, in this invention, the control unit 100 can be controlled to, after driving the compressor 45, when one or more of the temperature change and operating states correspond to the reference conditions, stop driving the compressor 45 to make the surface temperature of the heat exchange unit 40 reach above the reference temperature, thereby performing sterilization.

[0180] For example, such as Figure 7 As shown, the control unit 100 can control the compressor 45 to reach a surface temperature of 60°C or higher, which is a reference temperature, by stopping the operation of the compressor 45 when the operating frequency f of the compressor 45 corresponds to a cyclic stable range that pulsates at a predetermined frequency for a predetermined time after the compressor 45 is driven.

[0181] On the other hand, in order to spray cleaning water onto the heat exchange unit 40, the control unit 100 can control the drain pump 62 and the control valve 63.

[0182] That is, the control unit 100 can move the stored condensate water by controlling the drive speed (rpm) of the drain pump 62 so that it can be used as cleaning water.

[0183] Additionally, the control unit 100 can control the opening and closing of the control valve 63, causing the cleaning water moving from the drain pump 62 to flow to the cleaning water supply pipe 64. That is, the control unit 100 can connect the condensate supply pipe 61 and the cleaning water supply pipe 64 or connect the condensate supply pipe 61 and the drain pipe 65 by controlling the control valve 63.

[0184] For ease of explanation, in this invention, the case in which the control unit 100 is connected to the condensate supply pipe 61 and the drain pipe 65 is set as the default value, and the condensate supply pipe 61 and the cleaning water supply pipe 64 are connected when the control valve 63 is operated is described. However, it is not limited to this. The connection between the condensate supply pipe 61 and the cleaning water supply pipe 64 can also be set as the default value, and the condensate supply pipe 61 and the drain pipe 65 can be connected by operating the control valve 63.

[0185] In this invention, when cleaning and sterilizing the heat exchange unit 40, the control unit 100 can supply steam by operating the steam unit 90, and then clean and sterilize the heat exchange unit 40 by driving the compressor 45. At this time, the control unit 100 can control the cleaning and sterilization of the heat exchange unit 40 to be performed even when the items to be dried are not contained in the drum 20.

[0186] That is, when power is applied to the steam generator 91 to operate the steam unit 90, the control unit 100 can drive the circulating fan 43 and rotate the drum 20 to make steam flow to the heat exchange unit 40. At this time, the control unit 100 can rotate the circulating fan 43 at a preset first circulation speed V1.

[0187] In addition, the control unit 100 can control the steam generator 91 to interrupt the steam injection for a preset rest time tp after the steam is injected for a preset injection time ts when the steam unit 90 is running, and then resume the steam injection for the preset injection time ts.

[0188] Furthermore, to prevent a sudden surge in power consumption of the entire laundry dryer 1 that could lead to a power supply cutoff, the control unit 100 can stop the operation of the compressor 45 while the steam unit 90 is running. Specifically, the control unit 100 can stop the rotation of the compressor motor 45a when the steam generator 91 is running to preheat hot water or generate steam.

[0189] On the other hand, after the steam supply ends, the control unit 100 can control the operation of the cleaning unit 200 to spray the cleaning water onto the heat exchange unit 40 according to a preset spray reference. Furthermore, when the cleaning unit 200 starts operating, the control unit 100 can drive the compressor 45 at a preset first compression frequency f1.

[0190] On the other hand, after the cleaning unit 200 finishes operating, the control unit 100 can accelerate the compressor 45 at a preset second compression frequency f2. At this time, the control unit 100 can rotate the circulating fan 43 at a preset second circulation speed V2.

[0191] After the steam supply ends, the control unit 100 can make the drain pump 62 run for the pre-input cleaning time tw.

[0192] On the other hand, the control of the time-based control unit 100 will be discussed later. Figure 5 The following explanation is provided in conjunction with Figure 6.

[0193] Figure 5 A flowchart illustrating the sequence of control methods for a laundry dryer according to an embodiment of the present invention is disclosed. Figure 6a and Figure 6b Example figures illustrating specific application examples of the steam drying method related to embodiments of the present invention are disclosed.

[0194] Reference Figure 1 As shown in Figure 6, the control method of the laundry dryer 1 according to an embodiment of the present invention is as follows.

[0195] The control method of the laundry dryer 1 in this embodiment of the invention may include a process input step S10, a steam supply step S20, a cleaning step S30, a drying step S40, and an air supply step S50.

[0196] In the process input step S10, the control input for executing the condenser maintenance process of cleaning and sterilizing the heat exchange section is input.

[0197] That is, when the power is turned on to the laundry dryer 1 of the present invention, the user can input control input to the input unit 118. At this time, the user can input the condenser maintenance process to clean and sterilize foreign objects and microorganisms that may exist in the heat exchange unit 40 due to the use of the laundry dryer 1.

[0198] At this time, during the condenser maintenance process, it is preferable to clean and sterilize the heat exchange section 40 while the dried material is not contained in the drum 20.

[0199] In the steam supply step S20, the control unit 100 can control the steam unit 90 to supply steam to the heat exchange unit 40.

[0200] In the steam supply step S20, the control unit 100 can rotate the drum motor 51 at a pre-input reference speed Wr (S21). As an example, the control unit 100 can continuously rotate the drum motor 51 while keeping its rotational speed between 3000 rpm and 3300 rpm, thereby enabling the drum 20 to rotate continuously at a predetermined speed.

[0201] In this invention, the drum 20 rotates while the item to be dried is not contained within it. This is to prevent steam from condensing on the surface of the drum 20 when steam is injected while the drum 20 is stationary and not rotating.

[0202] In the steam supply step S20, the control unit 100 does not drive the compressor 45 to prevent the instantaneous power consumption of the laundry dryer 1 from increasing (S22).

[0203] In the steam supply step S20, the control unit 100 can make the circulating fan 43 rotate at a preset first circulation speed V1 (S23).

[0204] As an example, in the steam supply step S20, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of 1000 rpm or more and 2000 rpm or less.

[0205] On the other hand, in the steam supply step S20 of the present invention, the control unit 100 may supply steam to the inside of the drum 20 (S24) to supply steam to the heat exchange unit 40.

[0206] The steam supply step S20 may include a steam water supply step S24a, a steam preheating step S24b, and a steam injection step S24c.

[0207] In the steam supply step S24a, the control unit 100 can supply water from the water supply unit 80 to the steam unit 90. At this time, according to the embodiment, the control unit 100 can supply water to the inside of the steam generator 91 by operating the water supply pump provided in the internal water supply unit 81, or by opening the direct water valve 82a provided in the external water supply unit 82.

[0208] For example, in the steam water supply step S24a, water of 150cc or more and 250cc or less can be supplied from the water supply unit 80 to the steam generator 91, and the time required to supply water from the water supply unit 80 to the steam generator 91 can be 30 seconds or more and 1 minute and 30 seconds or less.

[0209] In the steam preheating step S24b, in order to generate steam, the control unit 100 can heat the supplied water for a preset preheating time th by applying power to the steam unit 90.

[0210] In detail, in the steam preheating step S24b, the control unit 100 can heat the water supplied to the steam generator 91 by applying power to a heater (not labeled) installed in the steam generator 91. At this time, the control unit 100 can apply power to the heater for a preheating time th, which can be set to more than the time required for the water to reach its boiling point.

[0211] For example, in the steam preheating step S24b, the control unit 100 can generate a control command to apply power to the steam unit 90 for a period of 3 minutes and 30 seconds or more and 4 minutes and 30 seconds or less.

[0212] In the steam injection step S24c, the control unit 100 can inject the steam generated in the steam unit 90 into the interior of the drum 20 at a preset injection amount after the steam preheating step S24b.

[0213] In detail, in the steam injection step S24c, the control unit 100 can generate a control command for the steam generator 91, so that the water heated and boiling in the steam generator 91 flows through the steam pipe 92 and is injected into the interior of the drum body 21 through the steam nozzle 93.

[0214] In the steam injection step S24c, after the preset injection time ts of the steam injection, the control unit 100 interrupts the preset rest time tp of the steam injection and can resume the steam injection for the preset injection time ts.

[0215] As an example, in the steam injection step S24c, the control unit 100 injects steam three times at the injection time ts, and the rest time tp between each injection time ts can be stopped.

[0216] That is, in the steam injection step S24c, the control unit 100 injects 150cc to 200cc of water from the steam generator 91 into the interior of the drum 20 in three separate injections. At this time, the control unit 100 injects steam into the interior of the drum 20 for 110 to 130 seconds (first injection), then stops injecting steam for 20 to 40 seconds (first pause), then injects steam into the interior of the drum 20 for 110 to 130 seconds (second injection), then stops injecting steam for 20 to 40 seconds (second pause). Finally, the control unit 100 injects steam into the interior of the drum 20 for 110 to 130 seconds (third injection). As a result, in the steam injection step S24c, the control unit 100 can perform three steam injections and two pause steps.

[0217] In other words, in the steam injection step S24c, the control unit 100 heats 50 cc to 70 cc of water in the steam generator 91 each time and vaporizes it into steam to inject into the interior of the drum 20, and this process can be repeated three times. Furthermore, there is a first pause of 20 to 40 seconds between the first and second injections, and a second pause of 20 to 40 seconds between the second and third injections.

[0218] Therefore, in the steam supply step S20, the control unit 100 can supply high-temperature steam to the heat exchange unit 40 by operating the drum 20, the circulating fan 43 and the steam unit 90.

[0219] As described above, according to the steam supply step S20, high-temperature steam is injected into the interior of the drum 20 and flows along the pipe section 30 to the heat exchange section 40 by the operation of the circulating fan 43. Therefore, the high-temperature steam is supplied to foreign objects and microorganisms present on the surface of the heat exchange section 40, such as... Figure 7 As shown, the viscosity and surface tension of foreign objects and microorganisms decrease. Therefore, according to the steam supply step S20 of the present invention, by supplying high-temperature steam to the heat exchange section 40, the viscosity and surface tension are reduced, thereby having the effect of making it easier for foreign objects and microorganisms to fall off the heat exchange section 40.

[0220] In the cleaning step S30, after the steam supply step S20, the control unit 100 can control the cleaning unit 200 to spray cleaning water onto the heat exchange unit 40 according to a preset spray reference.

[0221] In the cleaning step S30, the control unit 100 can rotate the drum motor 51 at a pre-input reference speed Wr (S31). As an example, the control unit 100 can continuously rotate the drum motor 51 while keeping its rotation speed between 3000 rpm and 3300 rpm, thereby enabling the drum 20 to rotate continuously at a predetermined speed.

[0222] The cleaning step S30 may also include a first heating step (S32) in which the control unit 100 drives the compressor 45 at a preset first compression frequency f1.

[0223] As an example, in the first heating step S32, the control unit 100 can drive the compressor by maintaining the operating frequency f of the compressor 45 at a frequency of 25Hz or higher and 35Hz or lower.

[0224] In the first heating step S32, if the compressor 45 is driven at the first compression frequency f1, the refrigerant discharge temperature of the compressor 45 can be increased, and heat exchange occurs between the air and the refrigerant in the heat exchange section 40, thereby increasing the temperature inside the drum 20 and the pipe section 30.

[0225] On the other hand, in the first heating step S32, when the compressor 45 is driven at the first compression frequency f1, unlike the second compression frequency f2 described later, since the power consumption of the compressor 45 is low, even if the drain pump 62 and the control valve 63 are operated, there is no need to worry about failures and power interruptions caused by a sharp increase in power consumption.

[0226] In the cleaning step S30, the control unit 100 can keep the circulating fan 43 rotating at a preset first circulation speed V1 after the steam supply step S20 (S33).

[0227] As an example, in the cleaning step S30, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of 1000 rpm or more and 2000 rpm or less.

[0228] Therefore, as the compressor 45 drives the circulating fan 43 to rotate, the temperature inside the drum 20 and the duct section 30 can rise while the air is circulating for heat exchange. In addition, the circulating fan 43 rotates at a relatively low speed compared to the second circulation speed V2 described later, so even if the drain pump 62 and the control valve 63 are operating, there is no need to worry about malfunctions and power outages caused by a sharp increase in power consumption.

[0229] On the other hand, during the cleaning step S30, the control unit 100 may not operate the steam unit 90 (S34).

[0230] On the other hand, the cleaning step S30 of the present invention may also include a pump driving step (S35) in which the drain pump 62 is driven for a preset cleaning time tc.

[0231] In the pump drive step S35, the control unit 100 causes the drain pump 62 to rotate at a preset drive speed (rpm) for a preset cleaning time tc to move the stored condensate to the control valve 63 and use it as cleaning water.

[0232] As an example, the control unit 100 can cause the drain pump 62 to rotate at a speed of 3000 rpm or more and 4000 rpm or less for 20 minutes or more and less than 30 minutes.

[0233] The cleaning step S30 of the present invention may include a cleaning water spraying step (S36) of spraying cleaning water into the heat exchange unit 40.

[0234] In the cleaning water spraying step S36, the control unit 100 controls the control valve 63 to direct the condensate flowing from the drain pump 62 to the cleaning water supply pipe 64.

[0235] Specifically, the control valve 63 of the present invention is connected to the condensate supply pipe 61, the cleaning water supply pipe 64 and the drain pipe 65, thereby adjusting the flow direction of the condensate.

[0236] If the cleaning water spraying step S36 is entered, the control unit 100 can control the control valve 63 to connect the condensate supply pipe 61 and the cleaning water supply pipe 64. As a result, the condensate, which is given flow force by the drain pump 62, flows into the cleaning water supply pipe 64 as cleaning water and can be sprayed to the heat exchange unit 40 through the cleaning water spraying unit 66.

[0237] On the other hand, in the cleaning water spraying step S36, the control unit 100 can control the control valve 63 according to the preset cleaning mode Pc.

[0238] As an example, the cleaning mode Pc can refer to a time during which the control valve 63 operates for more than 85 seconds and less than 95 seconds, and a time during which the operation of the control valve 63 stops for more than 170 seconds and less than 190 seconds.

[0239] At this point, in order to increase the cleaning volume, the cleaning mode Pc described above can be repeated five times.

[0240] Therefore, according to the present invention, the collected condensate can be directed to the control valve 63 by the drain pump 62, and the cleaning water can be sprayed onto the heat exchange section 40 by the operation of the control valve 63.

[0241] Therefore, according to the cleaning water spraying step S36, cleaning water with a specified water pressure is sprayed into the heat exchange section 40. While passing through the steam supply step S20, foreign matter including cotton lint with reduced viscosity and surface tension, as well as microorganisms including bacteria, are removed from the heat exchange section 40.

[0242] Therefore, according to the cleaning step S30, it has the effect of cleaning and removing foreign matter and microorganisms present in the heat exchange section 40.

[0243] On the other hand, the cleaning step S30 may also include a first drainage step (S39) to discharge the cleaning water (condensate) collected after cleaning for a preset drainage time td.

[0244] In the first drainage step S39, the control unit 100 moves the condensate collected in the water collection unit 60 by operating the drainage pump 62, and can also cause the condensate to flow to the drain pipe 65 by operating the control valve 63. As a result, the condensate can be moved to the water storage tank 72.

[0245] At this time, the drainage time td can be more than 50 seconds and less than 70 seconds.

[0246] In the drying step S40, in order to dry the heat exchange section 40 which was sprayed with cleaning water in the cleaning step S30, the control unit 100 can dry the drum 20 and the pipe section 30 by supplying hot air into the inside of the drum 20.

[0247] In the drying step S40, the control unit 100 can rotate the drum motor 51 at a pre-input reference speed Wr. As an example, the control unit 100 can continuously rotate the drum motor 51 while keeping its rotation speed between 3000 rpm and 3300 rpm, thereby enabling the drum 20 to rotate continuously at a predetermined speed.

[0248] In addition, the drying step S40 may also include a second heating step (S42) in which the control unit 100 drives the compressor at a preset second compression frequency f2.

[0249] That is, in the second heating step S42, the control unit 100 can adjust the operating frequency f of the compressor 45 to the second compression frequency f2 to drive the compressor (S42a).

[0250] As an example, the control unit 100 can drive the compressor 45 by setting a frequency of 85Hz or higher and 105Hz or lower as the operating frequency f.

[0251] At this time, the control unit 100 can control the output of the drive compressor 45 to rise to the second compression frequency f2 all at once. However, in order to prevent malfunctions caused by overload of the compressor motor 45a, it is preferable to control the speed of the compressor motor 45a to rise in several stages.

[0252] As an example, the control unit 100 generates a control command to drive the compressor 45 at a frequency of 55Hz or higher and 65Hz or lower, and then generates a control command to drive the compressor 45 at a frequency of 75Hz or higher and 85Hz or lower. Finally, it can generate a control command to drive the compressor 45 at the second compression frequency f2.

[0253] After the operating frequency f of the compressor 45 is driven to the second compression frequency f2, in order to improve energy efficiency and prevent malfunctions, the control unit 100 senses the temperature inside the drum 20. Based on this, the operating frequency f of the compressor 45 can be kept less than (lower than) the second compression frequency f2 and the compressor can be driven (S42b).

[0254] At this time, the control unit 100 can sense (measure) the temperature of the pipe section 30 by means of the sensing unit 116 provided in the pipe section 30. On the other hand, the sensing unit 116 provided in the pipe section 30 can be a temperature sensor.

[0255] On the other hand, the control unit 100 of the present invention can terminate the drying step (S40) by stopping the driving of the compressor 45 based on reference conditions.

[0256] The reference conditions may include the following conditions: temperature change of air flowing into evaporator 41, temperature change of air flowing out of evaporator 41, temperature change of refrigerant flowing into evaporator 41, temperature change of refrigerant flowing out of evaporator 41, temperature change of air flowing into condenser 42, temperature change of air flowing out of condenser 42, temperature change of refrigerant flowing into condenser 42, and temperature change of refrigerant flowing out of condenser 42; and the following conditions: operating time of compressor 45, operating range of compressor 45, and operating frequency of compressor 45.

[0257] Therefore, under each of the following conditions—temperature changes of the air flowing into the evaporator 41, temperature changes of the air flowing out of the evaporator 41, temperature changes of the refrigerant flowing into the evaporator 41, temperature changes of the refrigerant flowing out of the evaporator 41, temperature changes of the air flowing into the condenser 42, temperature changes of the air flowing out of the condenser 42, temperature changes of the refrigerant flowing into the condenser 42, and temperature changes of the refrigerant flowing out of the condenser 42—and under one or more operating states, including the operating time of the compressor 45, the operating range of the compressor 45, and the operating frequency of the compressor 45, corresponding to the aforementioned reference condition, the control unit 100 can stop the operation of the compressor 45.

[0258] For example, under the condition that the temperature change of the air flowing into the evaporator 41 remains above 70 degrees Celsius for more than 20 minutes in the reference condition, the control unit 100 judges the result of the temperature change. If the temperature change of the air flowing into the evaporator 41 remains above 70 degrees Celsius for more than 20 minutes, the compressor 45 can be stopped in accordance with the reference condition.

[0259] Alternatively, if the operating frequency of the compressor 45 is set to change within a specified range within a specified time period under the reference conditions, the control unit 100 determines the operating state. If the operating frequency of the compressor 45 changes within a specified range within a specified time period, the operating state corresponds to the operating frequency condition in the reference conditions, and the operation of the compressor 45 can be stopped.

[0260] On the other hand, the control unit 100 can change the setting of the reference conditions by reflecting the weighted value to the reference conditions based on the external temperature and operating status.

[0261] For example, the baseline conditions can be set by changing the weighted values ​​reflected in the baseline conditions based on weather or water volume.

[0262] More specifically, when the current weather corresponds to winter or when the external temperature is lower than the specified temperature, the control unit 100 reflects the point where the temperature of the drum 20 and the pipe section 30 decreases, and thus changes the setting of the reference conditions by reflecting the weighted value of ±A[℃ in the reference conditions.

[0263] On the other hand, the drying step S40 may include a second cycle step (S43) in which the control unit 100 causes the circulating fan 43 to rotate at a preset second cycle speed V2.

[0264] As an example, in the second cycle step S43, during the period when the compressor 45 is driven, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of more than 3500 rpm and less than 4500 rpm.

[0265] On the other hand, in the drying step S40, the control unit 100 may not operate the steam unit 90 (S34).

[0266] That is, the control unit 100 can drive the drum 20, the circulating fan 43 and the compressor 45 in the drying step S40.

[0267] Therefore, according to the drying step S40, the temperature inside the drum 20 and the pipe section 30 is raised by driving the compressor 45, and the evaporator 41 can be sterilized by raising the temperature of the compressor 45 and the condenser 42.

[0268] On the other hand, in this embodiment, the control unit 100 may also include a second drainage step (S49) with a preset drainage time td before entering the air supply step S50.

[0269] That is, in the second drainage step S49, the control unit 100 can move the condensate collected in the water collection unit 60 by operating the drainage pump 62, and make the condensate flow to the drain pipe 65 by operating the control valve 63. As a result, the condensate can move to the water storage tank 72.

[0270] At this time, the drainage time td can be more than 50 seconds and less than 70 seconds.

[0271] In the air supply step S50, after the drying step S40, the control unit 100 sterilizes the evaporator 41 by stopping the drive of the compressor 45 and utilizing the thermal equilibrium phenomenon. The moisture remaining in the drum 20 and the pipe section 30 can be evaporated by blowing hot air inside the drum 20 and the pipe section 30 for a preset air supply time.

[0272] As an example, in the air supply step S50, the control unit 100 sterilizes the evaporator 41 for more than 20 minutes and less than 30 minutes, which can evaporate the moisture remaining in the drum 20 and the pipe section 30.

[0273] In the air supply step S50, the control unit 100 can rotate the drum motor 51 at a pre-input reference speed Wr (S51). As an example, the control unit 100 can continuously rotate the drum motor 51 while keeping its rotational speed between 3000 rpm and 3300 rpm, thereby enabling the drum 20 to rotate continuously at a predetermined speed.

[0274] Therefore, the control unit 100 can control the air circulation path to achieve thermal balance by driving the roller 20, so that the surface temperature of the heat exchange unit 40 rises above the reference temperature for sterilization.

[0275] On the other hand, in the air supply step S50 of the present invention, the control unit 100 may stop the driving of the compressor 45 so as to transfer the heat of the condenser 42 to the evaporator 41 by utilizing the thermal equilibrium phenomenon (S52).

[0276] Specifically, during the heat pump cycle maintained by the compressor 45, the temperatures of the air circulation path formed by the drum 20 and the pipe section 30, as well as the condenser 42, are maintained above a predetermined temperature by the heat pump cycle. If the compressor 45 stops operating, the heat pump cycle is interrupted, and the temperatures of the air circulation path and condenser 42 cannot be maintained. Heat from one or more of the air circulation path and condenser 42 moves to the evaporator 41, resulting in a thermal equilibrium. That is, the temperatures of the air circulation path and condenser 42 decrease, and the surface temperature of the evaporator 41 increases, allowing the surface temperature of the evaporator 41 to rise above the reference temperature Ts used for sterilization.

[0277] Furthermore, in the air supply step S50, the control unit 100 stops the compressor 45 and utilizes the residual heat inside the heated drum 20 and duct section 30 to remove moisture remaining in the drum 20 and duct section 30.

[0278] In addition, in the air supply step S50, in order to remove the moisture remaining in the roller 20 and the pipe section 30 by using heated air inside the circulating roller 20 and the pipe section 30, the control unit 100 can keep the rotation speed of the circulating fan 43 at the second circulation speed V2 (drive) (S53).

[0279] Therefore, the control unit 100 can control the surface temperature of the heat exchange unit 40 to rise above the reference temperature by promoting the occurrence of a thermal balance phenomenon in the air circulation path driven by the circulating fan 43.

[0280] On the other hand, in the air supply step S50, the control unit 100 can make the circulating fan 43 rotate for a preset air supply time.

[0281] At this point, the air supply time tc is preferably executed at or above the baseline time tr (tc≥tr).

[0282] In addition, the reference time tr may refer to the time required for the heat exchange section 40 to sterilize.

[0283] In particular, the reference time tr can be set according to the operating frequency of the compressor 45.

[0284] For example, the reference time can be set according to the magnitude of the operating frequency before the compressor 45 stops driving.

[0285] Specifically, when the operating frequency f before the compressor 45 stops operating is less than the reference value, the reference time can be set to a longer value equivalent to the time less than the reference value; when the operating frequency f is greater than the reference value, the reference time can be set to a shorter value equivalent to the time greater than the reference value.

[0286] Therefore, after stopping the drive of compressor 45, control unit 100 maintains the stop of compressor 45 drive based on the magnitude of the operating frequency f before the drive of compressor 45 was stopped.

[0287] Therefore, the control unit 100 can complete the air supply step S50 after the reference time tr.

[0288] On the other hand, the air supply step S50 is a step for removing moisture, so the control unit 100 may not operate (stop operation) the steam unit 90 (S54).

[0289] According to the air supply step S50, the surface temperature of the heat exchange section 40 can be maintained above the reference temperature Ts and above the reference time tr for sterilization by utilizing the thermal balance phenomenon. The cleaning water that may remain in the heat exchange section 40 is removed by the air, thereby preventing moisture from remaining in the heat exchange section 40.

[0290] on the other hand, Figure 7 The invention discloses a graph showing the viscosity of foreign matter and microorganisms as a function of temperature in the control method of a laundry dryer according to an embodiment of the present invention. Figure 8 The invention discloses a graph showing the surface tension of foreign objects and microorganisms as a function of temperature in the control method of a laundry dryer according to an embodiment of the present invention. Figure 9 A diagram is disclosed illustrating the sterilization conditions for a control method of a laundry dryer based on an embodiment of the present invention.

[0291] The following is for reference Figures 1 to 9 This demonstrates the effectiveness of the control method for the laundry dryer of the present invention.

[0292] First, the effects of each constituent element of the present invention are as follows.

[0293] In this invention, the drum 20 rotates continuously from the steam supply step S20 to the air supply step S50 (S21, S31, S41, S51) at a preset reference speed Wr. Therefore, when supplying steam, the drum 20 prevents steam from condensing on its surface and helps to balance the heat when the compressor 45 stops driving.

[0294] In this invention, the compressor 45 has the effect of not being driven when supplying steam (S22), being driven at a first compression frequency f1 in the cleaning step S30 (S32), being driven at a second compression frequency f2 in the drying step S40 (S42), and being stopped in the air supply step S50, while simultaneously heating the evaporator 41 using the thermal equilibrium phenomenon.

[0295] In this invention, the circulating fan 43 rotates at a first circulation speed V1 in the steam supply step S20 and the cleaning step S30 (S23, S33), and accelerates its rotation at a second circulation speed V2 in the drying step S40 and the air supply step S50 (S43, S53). Therefore, the circulating fan 43 has the effect of drying and sterilizing the heat exchange section 40 by circulating high-temperature steam and hot air.

[0296] In this invention, the steam unit 90 operates in the steam supply step S20 (S24) and stops operating after this step (S34, S44, S54).

[0297] In this invention, the drain pump 62 operates in the cleaning step S35, the first drain step S39, and the second drain step S49, thereby supplying or discharging condensate as cleaning water.

[0298] In this invention, the control valve 63 is controlled during the cleaning step, thereby supplying cleaning water to the heat exchange unit 40.

[0299] The results of each step are as follows.

[0300] In this invention, steam is supplied to the heat exchange section 40 in the steam supply step S20, thereby reducing the surface tension and viscosity of foreign matter and microorganisms attached to the surface of the heat exchange section 40.

[0301] That is, such as Figure 7 and Figure 8 As shown, if high-temperature steam is supplied to the heat exchange section 40 through the steam supply step S20, the surface temperature of the heat exchange section 40 will increase, and the surface tension and viscosity of foreign matter and microorganisms attached to the surface of the heat exchange section 40 will decrease, so that they can fall off the heat exchange section 40 more easily.

[0302] On the other hand, in the steam supply step S20 of the present invention, water stored in the steam generator 91 is injected three times in the steam injection step S24c. This has the effect of preventing water vapor condensation inside the drum 20 due to excessive steam supply.

[0303] Next, the control unit 100 of the present invention controls the output of the circulating fan 43 and the compressor 45 to be reduced during the cleaning step S30, so that stable power can be used even when driving the drain pump 62 and the control valve 63.

[0304] In addition, in the drying step S40 and the air supply step S50, the temperature inside the drum 20 and the pipe section 30 is increased by the drive control of the compressor 45, and the temperature of the compressor 45 and the condenser 42 is also increased, thereby achieving the effect of sterilizing the evaporator 41 by utilizing the thermal equilibrium phenomenon.

[0305] That is, the control unit 100 controls the drive of the compressor 45 to maintain the sterilization action against the evaporator 41 at a temperature above the reference temperature (60 degrees Celsius) for a reference time (10 minutes) or more, thereby effectively sterilizing the bacteria present in the evaporator 41.

[0306] Furthermore, in the air supply step S50, due to the rotation of the circulating fan 43, the cleaning and sterilization effect of the heat exchange section 40 is improved by removing any moisture that may remain in the heat exchange section 40.

[0307] Although the present invention has been described in detail above through specific embodiments, it is intended to specifically illustrate the present invention. The present invention is not limited thereto. Obviously, those skilled in the art can modify or improve the present invention within the technical concept of the present invention.

[0308] Any simple modifications or alterations to this invention fall within the scope of this invention, and the specific scope of protection of this invention will become clear from the appended claims.

Claims

1. A laundry dryer, characterized in that, include: A drum, rotatably mounted inside the housing that forms the exterior, holds the items to be dried; The piping section resupply the air discharged from the roller to the roller; A circulating fan provides flow power to the air moving along the duct section; A heat exchange section is provided on the pipe section to exchange heat with the air circulating along the pipe section; A compressor compresses refrigerant to exchange heat with air circulating along the duct section; The steam section generates steam and includes steam nozzles that inject steam into the interior of the drum; The cleaning unit sprays cleaning water onto the surface of the heat exchange unit to clean its surface. The sensing unit senses the temperature of the heat exchange unit; and The control unit controls the drum, the circulating fan, the compressor, the steam unit, and the cleaning unit; When cleaning and sterilizing the heat exchange unit, the control unit supplies steam by operating the steam unit, and then cleans and sterilizes the heat exchange unit by driving the compressor; When the steam section is in operation, the control unit drives the circulating fan. If the circulating fan is driven, the steam supplied to the inside of the drum through the steam nozzle of the steam section moves to the heat exchange section.

2. The laundry dryer according to claim 1, characterized in that, When the steam section is in operation, the control section causes the drum to rotate.

3. The laundry dryer according to claim 1, characterized in that, The control unit controls the steam unit to interrupt the steam injection for a preset pause time after the preset steam injection time, and then resume the steam injection for the preset time.

4. The laundry dryer according to claim 1, characterized in that, The control unit causes the circulating fan to rotate at a preset first circulation speed.

5. The laundry dryer according to claim 1, characterized in that, The cleaning unit includes: The cleaning water spray unit sprays the cleaning water into the heat exchange unit; A drain pump is used to transport condensate stored in the tank; and A control valve distributes the condensate pumped by the drain pump to the cleaning water jet section; The control unit controls the operation of the cleaning unit to spray the cleaning water onto the heat exchange unit according to a preset spray reference after the steam supply ends.

6. The laundry dryer according to claim 5, characterized in that, When the cleaning unit starts operating, the control unit drives the compressor at a preset first compression frequency.

7. The laundry dryer according to claim 5, characterized in that, After the cleaning unit finishes operating, the control unit causes the compressor to accelerate at a preset second compression frequency.

8. The laundry dryer according to claim 5, characterized in that, After the cleaning unit finishes operating, the control unit causes the circulating fan to rotate at a preset second circulation speed.

9. The laundry dryer according to claim 5, characterized in that, After the supply of steam ends, the control unit causes the drain pump to operate for the pre-input cleaning time.

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