Laundry dryer

Abstract

The present invention relates to a laundry dryer including a drum rotatably provided inside a cabinet forming an appearance and for accommodating laundry to be dried, a duct portion for supplying air discharged from the drum again to the drum, a circulating fan for moving air along the duct portion, a heat exchange portion provided on the duct portion and including an evaporator and a condenser for performing heat exchange with air circulating along the duct portion, a compressor for compressing a refrigerant for performing heat exchange with air circulating along the duct portion, a steam portion for generating steam and supplying the steam to the inside of the drum, and a control portion for controlling the drum, the circulating fan, the compressor, and the steam portion, wherein when steam is supplied to the inside of the drum by the steam portion, the control portion rotates the drum and stops the circulating fan from rotating, thereby having effects of uniformly supplying the steam to the laundry to be dried, preventing the laundry to be dried from being damaged, and improving sterilization effects of the laundry to be dried.

Description

Technical Field

[0001] This invention relates to a laundry dryer and its control method, and more specifically, to a laundry dryer and its control method that utilizes a steam unit to inject high-temperature steam into the interior of a drum and controls the rotation of the drum and the fan, respectively. Background Technology

[0002] Recently, a garment processing device has emerged that removes moisture from clothing by performing a drying process. In existing garment processing devices, clothes are dried by supplying hot air to a drum that holds the clothes, which not only greatly shortens the drying time but also sterilizes and disinfects the clothes.

[0003] In addition, there is a prior art garment processing device that supplies steam to the garments in the garment processing device that performs the drying process, in order to remove wrinkles from the garments, improve drying efficiency, or sterilize them.

[0004] Korean Patent Publication No. 10-1319874 discloses a control method for a dryer that dries clothes after supplying them with steam.

[0005] In existing dryers, the drum and blower units are combined into a single motor, and the drum and blower units rotate simultaneously with the rotation of the motor, or stop rotating simultaneously.

[0006] Therefore, when steam is injected into the inside of the drum, the rotation of the drum and blower unit is stopped in order to supply steam adequately to the items to be dried.

[0007] However, when steam is sprayed while the drum is stopped, the steam is only supplied to the upper surface of the items to be dried, thus limiting its effectiveness in preventing damage to the items and providing sterilization. Summary of the Invention

[0008] The present invention is proposed to improve the problems of the prior art laundry dryers and their control methods as described above. Its purpose is to supply steam evenly to the clothes to be dried by spraying steam while rotating the drum, thereby preventing the clothes to be dried from being damaged and providing a sterilization effect on the clothes to be dried.

[0009] To achieve the above objectives, the laundry dryer according to the present invention may include: a drum rotatably disposed inside a housing for forming the appearance and for accommodating the laundry to be dried; a duct section configured to resupply air discharged from the drum to the drum; a circulating fan providing flow power to the air moving along the duct section; a heat exchange section disposed on the duct section and including an evaporator and a condenser for exchanging heat with the air circulating along the duct section; a compressor for compressing a refrigerant for exchanging heat with the air circulating along the duct section; a steam section supplying steam to the interior of the drum; and a control section for controlling the drum, the circulating fan, the compressor, and the steam section.

[0010] The control unit can keep the drum rotating, and can stop the circulating fan from rotating when steam is injected from the steam section.

[0011] The control unit can stop driving the compressor when the steam unit is running.

[0012] The control unit can drive the compressor to raise the internal temperature of the drum. After the temperature of the compressor rises to the preset drying temperature, the steam unit can be activated to supply steam to the inside of the drum.

[0013] The control unit can supply steam to the inside of the drum by operating the steam unit, and then drive the compressor again.

[0014] The control unit can rotate the circulating fan after supplying water for steam generation to the steam unit.

[0015] The control unit can drive the compressor after supplying water for steam generation to the steam unit.

[0016] The control unit can cause the circulating fan to rotate at a preset first drying speed for a preset drying time, or it can accelerate the circulating fan to a preset second drying speed and cause it to rotate.

[0017] When the temperature of the compressor is above the preset drying temperature, the control unit can accelerate the rotation speed of the circulating fan from the second drying speed to the preset third drying speed and make it rotate.

[0018] To achieve the above objectives, according to the control method of the laundry dryer of the present invention, high-temperature steam is generated by a steam unit, and the rotation of the drum and the rotation of the circulating fan are controlled respectively. The control method may include: a steam drying process drying step, which increases the internal temperature of the drum to dry the items to be dried; a steam drying process steam supply step, which supplies steam to the inside of the drum after the steam drying process drying step; and a re-drying step, which supplies hot air to the inside of the drum after the steam drying process steam supply step.

[0019] The steam supply step of the steam drying process may include: a steam preheating step, in which water is heated for a preset preheating time by applying electricity to the steam unit; and a steam injection step, in which steam generated in the steam unit is injected after the steam preheating step.

[0020] During the steam injection step of the steam drying process, the circulating fan can be stopped from rotating.

[0021] In the drying step of the steam drying process, the compressor can be driven at a preset operating frequency.

[0022] During the drying step of the steam drying process, the circulating fan and the drum can be rotated.

[0023] The steam drying process may include: a first drying step, in which the circulating fan rotates at a preset first drying speed; and a second drying step, in which the rotation speed of the circulating fan is accelerated from the first drying speed to a preset second drying speed and the circulating fan is rotated.

[0024] The steam drying process may further include a third drying step, in which the rotational speed of the circulating fan is increased from the second drying speed to a preset third drying speed, and the circulating fan is rotated.

[0025] In the first drying step, the circulating fan can be driven for a preset drying time period.

[0026] When the compressor discharge temperature is above the preset drying temperature, the process can proceed from the steam drying process to the third drying step.

[0027] In the steam injection step of the steam drying process, a preset amount of steam can be injected from the steam section.

[0028] According to the control method of the laundry dryer of the present invention, a process input step may be included before the drying step of the steam drying process, wherein a control input is input in the process input step, the control input being a control input for the steam drying process that prevents damage to the clothes to be dried and enhances the sterilization of the clothes to be dried.

[0029] In the process input step, control inputs for either the first steam drying process or the second steam drying process can be entered based on the material to be dried.

[0030] In the steam injection step of the steam drying process, when the second steam drying process is input, the amount of steam injected may be less than the amount of steam injected in the first steam drying process.

[0031] In the re-drying step, when the second steam drying process is input, the time for supplying hot air to the inside of the drum can be less than the time for supplying hot air to the inside of the drum during the first steam drying process.

[0032] The preheating time can be set to more than the time required for water to reach its boiling point.

[0033] On the other hand, when the steam generating device is running, the control unit can stop driving the compressor.

[0034] The control unit supplies steam to the inside of the drum by operating the steam unit, and then drives the compressor, thereby raising the internal temperature of the drum. If the internal temperature of the drum rises to a preset sterilization temperature, the steam unit is operated again to supply steam to the inside of the drum.

[0035] The control unit can drive the compressor at a preset safe frequency after supplying steam to the inside of the drum by re-running the steam unit.

[0036] The control unit can measure the internal temperature of the pipe section and control the drive frequency of the compressor based on the measured internal temperature of the pipe section in order to maintain the internal temperature of the pipe section.

[0037] The control unit can maintain the internal temperature of the pipe section above the sterilization temperature during a preset temperature holding time, and then stop the compressor from driving.

[0038] The control unit can cause the steam unit to run a preset preheating time, thereby heating the water used to generate steam.

[0039] The control unit can cause the circulating fan to rotate for the preheating time, and if steam is injected from the steam unit, the circulating fan will stop rotating.

[0040] To achieve the above objectives, according to the control method of the laundry dryer of the present invention, high-temperature steam is generated by a steam generating device, and the rotation of the drum and the rotation of the fan are controlled respectively. The control method may include: a sterilization steam heating step, supplying steam to the interior of the drum; a sterilization drying step, increasing the interior temperature of the drum after the steam is supplied; a steam re-sterilization step, supplying steam to the interior of the drum after the sterilization drying step; and a temperature holding step, maintaining the interior temperature of the drum for a preset holding time after the steam re-sterilization step.

[0041] The sterilization steam heating step may include: a sterilization steam preheating step, in which water is heated for a preset preheating time by applying electricity to the steam unit; and a sterilization steam injection step, in which steam generated in the steam unit is injected after the sterilization steam preheating step.

[0042] During the steam preheating step, the circulating fan and the drum can be rotated.

[0043] During the steam injection step, the circulating fan can be stopped rotating.

[0044] In the sterilization and drying step, the compressor can be driven at a preset operating frequency.

[0045] During the sterilization and drying step, the circulating fan and the drum can be rotated.

[0046] During the steam re-sterilization step, the circulating fan can be stopped from rotating.

[0047] The temperature holding step may include a reheating step in which the compressor is driven at a preset safe frequency.

[0048] The temperature holding step may further include a heating adjustment step, in which the internal temperature of the pipe section is measured after the reheating step, and the operating frequency of the compressor is changed according to the internal temperature of the pipe section.

[0049] During the temperature holding step, the circulating fan and the roller can be rotated.

[0050] The preheating time can be set to more than the time required for water to reach its boiling point.

[0051] In the sterilization and drying step, if the internal temperature of the drum rises to the preset sterilization temperature, the compressor can be stopped and the process can proceed to the steam re-sterilization step.

[0052] As described above, the laundry dryer and its control method according to the present invention have the advantage that, with motors installed in both the drum and the circulating fan, and by controlling the rotation of the drum and the rotation of the circulating fan respectively to spray steam while the drum rotates, steam is evenly supplied to the clothes to be dried.

[0053] In addition, when the process begins, heating starts simultaneously by spraying high-temperature steam onto the items to be dried, thereby achieving the effect of heating the items to the temperature required for sterilization while retaining their moisture.

[0054] In addition, by spraying steam after drying and then re-drying, a high enthalpy value can be transferred to the material to be dried, thus achieving the effect of sterilizing bacteria and other organisms through high heat.

[0055] In addition, by having the compressor and steam generator operate alternately, it can prevent malfunctions or power outages caused by a sudden increase in power consumption. Attached Figure Description

[0056] Figure 1 This is a diagram illustrating the appearance of a laundry dryer according to an embodiment of the present invention.

[0057] Figure 2 This is a cross-sectional view used to illustrate the internal structure of a laundry dryer according to an embodiment of the present invention.

[0058] Figure 3 This is a block diagram illustrating the control configuration in a laundry dryer according to an embodiment of the present invention.

[0059] Figure 4 This is a flowchart illustrating the sequence of control methods for a laundry dryer according to an embodiment of the present invention.

[0060] Figure 5A This is an example diagram illustrating a first steam drying process as a specific application example of a steam drying method according to an embodiment of the present invention.

[0061] Figure 5B This is an example diagram illustrating a second steam drying process as a specific application example of a steam drying method according to an embodiment of the present invention.

[0062] Figure 6AThis is an example diagram illustrating the temperature changes of the piping section and compressor under room temperature conditions in a control method for a laundry dryer according to an embodiment of the present invention.

[0063] Figure 6B This is an example diagram illustrating the temperature changes of the piping section and compressor under low-temperature conditions in a control method for a laundry dryer according to an embodiment of the present invention.

[0064] Figure 6C This is an example diagram illustrating the temperature changes of the piping section and compressor under high-temperature conditions in a control method for a laundry dryer according to an embodiment of the present invention.

[0065] Figure 7A This is an example diagram illustrating the principle of a control method for a laundry dryer according to an embodiment of the present invention, which performs high-temperature sterilization of the laundry under low-temperature conditions.

[0066] Figure 7B This is an example diagram illustrating the principle of a control method for a laundry dryer according to an embodiment of the present invention, which performs high-temperature sterilization of the laundry at room temperature.

[0067] Figure 7C This is an example diagram illustrating the principle of a control method for a laundry dryer according to an embodiment of the present invention, which performs high-temperature sterilization of the laundry under high-temperature conditions.

[0068] Figure 8 This is an example diagram illustrating the moisture balance of the laundry to be dried, used to explain the control method of a laundry dryer according to an embodiment of the present invention.

[0069] Figure 9 This is a graph illustrating the increase in enthalpy of a control method for a laundry dryer according to an embodiment of the present invention.

[0070] Figure 10 This is a flowchart illustrating the sequence of control methods for a laundry dryer performing a steam sterilization process according to another embodiment of the present invention.

[0071] Figure 11A and Figure 11B This is an example diagram illustrating a specific application example of a steam drying method related to another embodiment of the present invention.

[0072] Figure 12 This is an example diagram illustrating the temperature change of the laundry to be dried using a control method for a laundry dryer according to another embodiment of the present invention.

[0073] Figure 13 This is an example diagram illustrating the humidity change of the laundry to be dried using a control method for a laundry dryer according to another embodiment of the present invention.

[0074] Figure 14 This is a table illustrating the sterilization conditions of the laundry to be dried in a control method for a laundry dryer according to another embodiment of the present invention.

[0075] Explanation of reference numerals in the attached figures

[0076] 1: Laundry dryer

[0077] 20: Roller

[0078] 30: Piping Department

[0079] 40: Heat Exchange Section

[0080] 43: Circulating fan

[0081] 43b: Impeller motor

[0082] 45: Compressor

[0083] 45a: Compressor motor

[0084] 51: Drum motor

[0085] 90: Steam Department

[0086] 91: Steam generator

[0087] 100: Control Department

[0088] 116: Testing Department

[0089] 118: Input Section Detailed Implementation

[0090] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0091] Various modifications and embodiments are possible in this invention, and specific embodiments will be shown in the accompanying drawings and described in detail in the description. This is not intended to limit the invention to the specific embodiments, but should be interpreted to include all modifications, equivalents, and substitutions within the spirit and technical scope of the invention.

[0092] In this invention, terms such as "first" and "second" are used to describe multiple constituent elements; however, these structural elements are not limited to these terms. These terms are used only to distinguish one constituent element from another. For example, without departing from the scope of this invention, a first constituent element can be a second constituent element, and similarly, a second constituent element can be a first constituent element.

[0093] The term “and / or” can include a combination of multiple related descriptions or any one of multiple related descriptions.

[0094] It should be understood that when an element is referred to as being "connected" or "connected" to another element, the element may be directly connected or connected to the other element, or there may be an intermediate element. Conversely, when an element is "directly connected" or "directly connected" to another element, it should be understood that there are no other elements between them.

[0095] The terminology used in this specification is for illustrative purposes only and is not intended to limit the invention. Unless the context clearly specifies otherwise, the singular expression includes plural expressions.

[0096] The terms “comprising” or “having” as used in this specification shall be understood to indicate the presence of the features, quantities, steps, actions, constituent elements, components or combinations thereof disclosed in this specification, and shall also be understood to mean without pre-excluding the presence or additional possibility of one or more other features, numbers, steps, actions, constituent elements, components or combinations thereof.

[0097] Unless otherwise defined, all terms, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art. Commonly used terms, such as those defined in dictionaries, should be interpreted as consistent with their meaning in the context of the relevant art and should not be interpreted in an ideal or excessive form unless expressly defined in this specification.

[0098] Furthermore, the following embodiments are provided to provide a more complete explanation to those skilled in the art, and for clarity, the shapes and dimensions of the various elements in the accompanying drawings may be enlarged.

[0099] Figure 1 This is a diagram illustrating the appearance of a laundry dryer according to an embodiment of the present invention. Figure 2 This is a cross-sectional view used to illustrate the internal structure of a laundry dryer according to an embodiment of the present invention.

[0100] like Figure 1 and Figure 2 As shown, the housing 10 for forming the appearance of the laundry dryer 1 includes: a front panel 11 constituting the front surface of the laundry dryer 1; a rear panel 12 constituting the rear surface of the laundry dryer 1; a pair of side panels 14 constituting the side surfaces of the laundry dryer 1; and an upper panel 13 constituting the top surface of the laundry dryer 1.

[0101] The front panel 11 may be provided with a dispensing port 111 and a door 112. The dispensing port 111 is configured to communicate with the roller 20 described later. The door 112 is rotatably coupled to the box body 10 and opens and closes the dispensing port 111.

[0102] A control panel 117 can be installed on the front panel 11.

[0103] The control panel 117 may include: an input unit 118 for receiving control commands from the user; a display unit 119 for outputting information such as control commands that can be selected by the user; and a main control unit (not shown) for controlling commands used to execute the program of the laundry dryer 1.

[0104] On the other hand, the input unit 118 may be configured to include: a power supply request unit for requesting power to the laundry dryer 1; a process input unit for allowing the user to select a desired process from multiple processes; and an execution request unit for requesting the start of execution of the process selected by the user.

[0105] The display unit 119 may be configured to include at least one of a display panel capable of outputting characters and / or graphics and a speaker capable of outputting voice signals and sounds. Through the information output by the display unit 119, the user can easily grasp the status of the ongoing program, remaining time, etc.

[0106] Inside the housing 10 are a drum 20, a duct section 30, and a heat exchange section 40. The drum 20 is rotatably disposed inside the housing 10 and provides space for accommodating clothes (items to be dried). The duct section 30 forms a flow path for resupplying air discharged from the drum 20 back to the drum 20. The heat exchange section 40 dehumidifies and heats the air flowing into the duct section 30 before resupplying it to the drum 20. That is, the duct section 30 allows the air inside the drum 20 to circulate. Alternatively, the heat exchange section 40 can be located inside the duct section 30, dehumidifying and heating the circulating air by exchanging heat with the air circulating in the duct section 30.

[0107] The roller 20 includes a roller body 21, which is formed into a cylindrical shape with its front surface open; inside the housing 10, there may be a first support 22 that rotatably supports the front surface of the roller body 21; and a second support 23 that rotatably supports the rear surface of the roller body 21.

[0108] The first support portion 22 may be configured to include: a first fixing body 22a, which is fixed inside the housing 10; a roller feeding port 22b, which is configured to pass through the first fixing body 22a, thereby connecting the feeding port 111 and the interior of the roller body 21; and a first support body 22c, which is disposed on the first fixing body 22a and inserted into the front surface of the roller body 21.

[0109] The first support portion 22 may be configured to further include a connecting body 22d, which connects the dispensing port 111 and the roller dispensing port 22b. As shown, the connecting body 22d may be configured as a tube extending from the roller dispensing port 22b toward the dispensing port 111. Additionally, the connecting body 22d may be provided with an air outlet 22e communicating with the pipe portion 30.

[0110] like Figure 2 As shown, the air outlet 22e is a channel that allows the internal air of the roller body 21 to move to the pipe section 30, and can be configured as a through hole that connects to the body 22d.

[0111] The second support part 23 is configured to include: 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 surface of the roller body 21.

[0112] An air inlet 23c may be provided in the second support part 23. The air inlet 23c is configured to pass through the second fixed body 23a and connect the interior of the roller body 21 with the interior of the box 10.

[0113] In this case, the duct section 30 is configured to connect the air outlet 22e and the air inlet 23c.

[0114] The cylindrical roller body 21 can be rotated by means of various types of drive units 50.

[0115] For example, Figure 2 An embodiment of the drive unit 50 is shown, which includes: a roller motor 51 fixed inside the housing 10; a pulley 52 that rotates by the roller motor 51; and a belt 53 for connecting the circumferential surface of the pulley 52 to the circumferential surface of the roller body 21.

[0116] In this case, a first roller R1 that rotatably supports the circumferential surface of the roller body 21 may be provided in the first support portion 22; and a second roller R2 that rotatably supports the circumferential surface of the roller body 21 may be provided in the second support portion 23.

[0117] However, the present invention is not limited thereto. It can also be applied to a direct drive type where the roller motor 51 is directly connected to the roller 20 and rotates the roller 20 without passing through a pulley and belt; and this naturally falls within the scope of the present invention. For convenience, the following description will be based on an embodiment of the drive unit 50 shown.

[0118] 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 that connects the exhaust duct 31 and the supply duct 32, and has a heat exchange section 40 disposed therein.

[0119] The heat exchange section 40 can be implemented by various devices capable of sequentially dehumidifying and heating the air flowing into the duct section 30. For example, the heat exchange section 40 can be implemented by a heat pump system.

[0120] The heat exchange section 40, which is a heat pump system, may include: a circulating fan 43 that moves air along the duct section 30; a first heat exchanger (heat absorption section) 41 that reduces the humidity of the air flowing into the duct section 30 and performs a dehumidification function; and a second heat exchanger (heat generation section) 42 that is disposed inside the duct section 30 and heats the air passing through the first heat exchanger 41.

[0121] The circulating fan 43 is configured to include: an impeller 43a disposed inside the duct section 30; and an impeller motor 43b for rotating the impeller 43a, and the circulating fan 43 provides flow power to the air moving along the duct section 30. This is because the rotation of the impeller 43a can generate an attractive force for moving the air.

[0122] The impeller 43a can be located at any position in the exhaust pipe 31, the connecting pipe 33, and the supply pipe 32; however, in Figure 2 The illustration shows an embodiment in which the impeller 43a is disposed in the connecting pipe 32. The present invention is not limited thereto, but for convenience, the following description will be based on an embodiment in which the impeller 43a is disposed in the connecting pipe 32.

[0123] The heat exchange section 40 can perform heat exchange with the air circulating along the pipe section 30.

[0124] The heat-absorbing part 41 and the heat-generating part 42 are disposed inside the connecting pipe 33 and are arranged sequentially in the direction from the exhaust pipe 31 toward the supply pipe 32, and are connected to each other via the refrigerant pipe 44 for forming a refrigerant circulation path.

[0125] 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.

[0126] 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.

[0127] The compressor 45 compresses the refrigerant that exchanges heat with the air circulating along the pipe section 30 by receiving the rotational force provided by the compressor motor 45a.

[0128] In this case, the moisture contained in the air moves along the surface of the heat absorber 41 as it passes through the heat absorber 41 and accumulates on the bottom surface of the connecting pipe 33.

[0129] As described above, the configuration of the heat exchange unit 40, which includes the heat absorption unit 41 and the heat generation unit 42, in the form of a heat pump system, can be based on configurations known in the art, and a detailed description of the related construction will be omitted.

[0130] On the other hand, in order to collect the condensate that condenses from the air passing through the heat absorption section 41 and gathers on the bottom surface of the connecting pipe 33, a water collection section 60 is provided in the laundry dryer 1 according to the present invention.

[0131] The condensate that is condensed in the heat absorption section 41 can be collected by the water collection section 60 for the first time, and then by the water storage section 70 for the second time. As shown in the figure, the water collection section 60 can be located inside the connecting pipe 33, or it can be set separately in a space separated from the connecting pipe 33.

[0132] The condensate collected by the water collection unit 60 for the first time is supplied to the water storage unit 70 via the condensate supply pipe 61. At this time, in order to smoothly drain the condensate, a condensate pump 62 is installed in the condensate supply pipe 61.

[0133] The water storage section 70 includes a water tank 72, which is configured to extend to the outside from one side of the front panel 11. The water tank 72 is configured to collect condensate transferred from the water collection section 60 described later.

[0134] The user can draw water from the water tank 72 out of the housing 10 to remove condensate, and then install the water tank 72 back into the housing 10. Therefore, the laundry dryer according to the invention can be installed even in places where there is no drain or similar facility.

[0135] More specifically, the water storage section 70 may be configured to include: a water storage tank 72, which is detachably disposed on the tank body 10 and provides space for storing water; and an inlet 72a, which is configured to pass through the water storage tank 72 and allow water discharged from the condensate supply pipe 61 to flow into the interior of the water storage tank 72.

[0136] The water storage tank 72 can be configured as a drawer-type water tank extending from the tank body 10. In this case, a water storage section mounting hole is provided in the front panel 11 of the tank body, and the water storage tank 72 is inserted into the water storage section mounting hole.

[0137] Panel 71 is fixed to the front surface of water tank 72. Panel 71 can be configured to be detachably attached to the mounting hole of the water storage section and form part of the front panel 11.

[0138] The panel 71 may also be provided with a recess 71a into which the user's hand is inserted and gripped. In this case, the panel 71 also functions as a handle for leading the water tank 72 out of or into the tank body.

[0139] The inlet 72a is configured to receive condensate discharged from the condensate nozzle 63 fixed to the housing 10. The condensate nozzle 63 can be fixed to the upper panel 13 of the housing 10 so that when the water tank 72 is inserted into the housing 10, the condensate nozzle 63 is located above the inlet 72a.

[0140] After the water tank 72 is pulled out of the tank body 10, the user can flip or tilt the water tank 72 toward the direction of the phase flow inlet 72a to empty the water inside the water tank 72. A connecting hole 72b can also be provided, which is configured to penetrate the upper surface of the water tank 72 so that the water inside the water tank 72 can be easily discharged from the inlet 72a.

[0141] Furthermore, the laundry dryer 1 according to the present invention includes a first filter section F1 and a second filter section F2, the first filter section F1 and the second filter section F2 being devices for removing foreign matter such as lint and dust generated during the drying process of clothes and other items to be washed.

[0142] The first filter unit F1 is provided in the exhaust pipe 31, which is capable of filtering foreign matter contained in the air discharged from the drum 20 for the first time.

[0143] The second filter F2 is positioned downstream of the first filter F1 in the airflow direction to filter foreign matter contained in the air passing through the first filter F1 a second time. More specifically, as shown in the figure, the second filter F2 is preferably positioned upstream of the first heat exchanger 41 inside the connecting pipe 33. This is to prevent foreign matter contained in the air from accumulating on the first heat exchanger 41, which serves as a heat-absorbing part, and thus contaminating the first heat exchanger 41 or reducing its performance.

[0144] The detailed construction of the first filter unit F1 and the second filter unit F2 can be applied to any device known in the art, therefore, a detailed description of their construction will be omitted.

[0145] On the other hand, the laundry dryer 1 according to the present invention further includes a water supply section 80 and a steam section 90, the water supply section 80 including an internal water supply section 81 and an external water supply section 82, and the steam section 90 receiving water from the water supply section 80 and generating steam.

[0146] The steam unit 90 can be configured to receive fresh non-condensed water and generate steam. The steam unit 90 can be configured to generate steam by heating water, using ultrasound, or vaporization.

[0147] As needed, the steam unit 90 can be controlled to receive water from the internal water supply unit 81 and the external water supply unit 82, and supply the generated steam to the interior of the drum body 21.

[0148] The external water supply unit 82 may include a straight water valve 82a and a straight water pipe 82b. The straight water valve 82a is adjacent to or fixed to the rear panel 13, and the straight water pipe 82b supplies water from the straight water valve 82a to the steam unit 90.

[0149] The direct water valve 82a can be configured to be connected to an external water supply source. For example, the direct water valve 82a can be connected to a water supply pipe (not shown) extending to the back of the housing. Thus, the steam unit 90 can be configured to receive water directly through the direct water valve 82a.

[0150] Therefore, even if the internal water supply unit 81 is omitted, or if the internal water supply unit 81 does not store water, the steam unit 90 can receive water for generating steam through the direct water valve 82a when necessary.

[0151] The direct water valve 82a can be directly controlled by the control unit 100.

[0152] The control unit 100 can be located in the control panel 117, but if Figure 1 As shown, it can also be set by a separate control panel to prevent overloading of control panel 117 and to prevent increased manufacturing costs.

[0153] At this time, the control unit 100 can be arranged adjacent to the steam unit 90. The control unit 100 can be arranged on the side panel 14 for mounting the steam unit 90, thereby shortening the length of the control lines and the like connected to the steam unit 90.

[0154] On the other hand, the steam section 90 is preferably arranged adjacent to the straight water valve 82a. This prevents unnecessary residual water from remaining in the straight water pipe 82b and allows water to be received immediately when necessary.

[0155] 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 multiple components mounted on the printed circuit board. When the user selects a laundry processing procedure or inputs control commands such as the operation of the laundry dryer 1 via the input unit 118, the control unit 100 can control the operation of the laundry dryer 1 according to a preset algorithm.

[0156] In this invention, the specific control content of the control unit 100 will be described later.

[0157] On the other hand, Figure 3 The diagram shows a block diagram illustrating the control configuration in a laundry dryer according to an embodiment of the present invention.

[0158] Reference Figures 1 to 3 According to an embodiment of the present invention, a laundry dryer 1 may include at least one of an input unit 118, an output unit 119, a communication unit 115, a detection unit 116, a motor 51, 43b, 45a, a steam unit 90, and a control unit 100.

[0159] The input unit 118 can receive control commands from the user related to the operation of the laundry dryer 1. The input unit 118 can consist of a plurality of buttons or a touch screen.

[0160] Specifically, the input unit 118 may be configured to receive selections of the operation process of the garment handling device, or to receive control inputs related to the execution of the selected operation process.

[0161] 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.

[0162] The information output by the output unit 119 may include information related to the operating status of the washer-dryer 1. That is, the output unit 119 may output information related to at least one of the selected operating process, whether a malfunction has occurred, the operation end time, and the amount of laundry contained in the drum 20.

[0163] As an example, the output unit 119 may be a touch screen that is integrally formed with the input unit 118.

[0164] 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.

[0165] In addition, the communications unit 115 can send information related to the operation results of the clothing processing device to a designated server via an external network.

[0166] In addition, the Communications Department 115 can communicate with other electronic devices to build an Internet of Things (IoT) environment.

[0167] The detection unit 116 can detect information related to the operation of the laundry dryer 1.

[0168] Specifically, the detection 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), an electrode sensor, and a temperature sensor.

[0169] As an example, the current sensor of the detection unit 116 can detect the current flowing through a point in the control circuit of the laundry dryer 1.

[0170] As another example, the temperature sensor of the detection unit 116 can detect the temperature inside the pipe section 30, and according to the embodiment, it can detect the temperature inside the drum 20.

[0171] As another example, the electrode sensor of the detection unit 116 can detect moisture inside the drum 20.

[0172] The detection unit 116 may include one or more temperature sensors that detect the temperature of the heat exchange unit 40 and send the detection results to the control unit 100.

[0173] As an example, the detection unit 116 may include more than one temperature sensor, thereby detecting more than one of the temperatures of the air and refrigerant circulating in each of the first heat exchanger 41 and the second heat exchanger 42.

[0174] As another example, the detection unit 116 may include one or more temperature sensors to detect the temperature of the refrigerant circulating in the compressor 45. Preferably, to detect the temperature of the compressor 45, a thermistor can be placed at the refrigerant discharge point of the compressor. This allows for the measurement of the compressor's discharge temperature.

[0175] The detection unit 116 may further include a plurality of temperature sensors for detecting the temperature of air flowing into or out of the roller 20.

[0176] As described above, the detection unit 116, which includes a plurality of the temperature sensors, can be configured such that a sensing module for detecting temperature is provided in the heat exchange unit 40, and the temperature sensing module is provided in the control unit 100 by receiving the sensing results of the plurality of the temperature sensors.

[0177] As described above, the detection unit 116 may include at least one of various types of sensors, and the type of sensors installed in the laundry dryer 1 is not limited. Furthermore, the number and placement of each sensor can be designed in various ways to suit different purposes.

[0178] Motors 51, 43b, and 45a include a drum motor 51, an impeller motor 43b, and a compressor motor 45a, which can change at least one of power, current, voltage, and speed according to the control command (instruction) of the control unit 100.

[0179] As an example, the roller motor 51 can change the rotational speed (rpm) of the roller 20 according to the control command of the control unit 100.

[0180] 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.

[0181] 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.

[0182] The steam unit 90 can be controlled as needed to receive water through the internal water supply unit 81 and the external water supply unit 82, and supply steam to the interior of the drum body 21.

[0183] The steam unit 90 may include: a steam generator 91 that generates steam by heating the received water; a steam pipe 92 for flowing the generated steam; and a steam nozzle 93 that injects steam into the interior of the drum body 21.

[0184] As an example, it is illustrated that the steam generator 91 generates steam by heating a predetermined amount of water contained inside using a heater (not labeled) (hereinafter referred to as "overall heating method" for convenience), but it is not limited to this.

[0185] The control unit 100 can control the components included in the laundry dryer 1.

[0186] 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.

[0187] In this invention, the control unit 100 can control the drum motor 51, the impeller motor 43b, and the compressor motor 45a respectively.

[0188] Therefore, the control unit 100 can control the operation of at least one of the roller 20, the circulating fan 43, and the heat exchange unit 40 based on the control input input to the input unit 118.

[0189] That is, the control unit 100 can control the rotation speed and rotation mode of the roller 20 based on user control inputs to the input unit 118. In addition, the control unit 100 can control the rotation speed or the start time of the circulation fan 43 based on user control inputs to the input unit 118.

[0190] In addition, the control unit 100 can control the heat exchange unit 40 based on the user's control input to the input unit 118 to adjust the temperature inside the drum 20.

[0191] As an example, the control unit 100 can control the drive (operation) frequency (Hz) of the compressor 45 based on the user's control input to the input unit 118.

[0192] 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.

[0193] That is, the control unit 100 can control the heating time of the steam generator 91 based on the user's control input to the input unit 118.

[0194] At this time, the control unit 100 can use information such as external temperature or amount of clothing to adjust the heating time of the steam generator 91.

[0195] On the other hand, in the case of existing laundry dryers, both the drum and the circulating fan are connected to a single motor. Therefore, the drum and the circulating fan rotate simultaneously and also stop rotating at the same time.

[0196] 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 to be dried, the circulating fan needs to be stopped, and the drum also needs to be stopped to stop rotating.

[0197] However, when the drum stops rotating, the items to be dried cannot be tumbled, and even if steam is supplied to the items, the steam can only be supplied to the items placed in the direction of the steam injection, thus limiting the ability to supply steam evenly to the entire item.

[0198] To solve this problem, in a laundry dryer 1 according to an embodiment of the present invention, the drum motor 51 and the impeller motor 43b are provided separately. Furthermore, the control unit 100 can control the drum motor 51, the impeller motor 43b, and the compressor motor 45a separately.

[0199] Therefore, according to an embodiment of the present invention, the control unit 100 can stop the rotation of the circulating fan 43 while maintaining the rotation of the drum 20 and when steam is injected from the steam unit 90.

[0200] In addition, in order to prevent the power supply from being cut off due to a sharp increase in the instantaneous power consumption of the laundry dryer 1 as a whole, the control unit 100 of the present invention can stop the compressor 45 from driving when the steam unit 90 is running.

[0201] In detail, when preheating water or generating steam by operating the steam generator 91, the control unit 100 can stop the compressor motor 45a from rotating.

[0202] That is, the control unit 100 drives the compressor 45 to raise the internal temperature of the drum 20. After the temperature of the compressor 45 rises to the preset drying temperature Td, the compressor 45 is stopped and the steam unit 90 is run, thereby supplying steam to the inside of the drum 20.

[0203] In addition, after the control unit 100 supplies steam to the inside of the drum 20 by operating the steam unit 90, it can stop operating the steam unit 90 and restart the compressor 45, thereby restarting the drying of the items to be dried.

[0204] On the other hand, the following will refer to Figure 4 Figure 5 illustrates the control of the control unit 100 over time.

[0205] exist Figure 4 The present invention discloses a flowchart illustrating the sequence of a control method for a laundry dryer 1 according to an embodiment of the present invention. Figure 5A and Figure 5B The present invention discloses example diagrams illustrating a first steam drying process and a second steam drying process, which are specific application examples of a steam drying method related to an embodiment of the present invention.

[0206] Reference Figure 1 As shown in Figure 5, the control method of the laundry dryer 1 according to an embodiment of the present invention is as follows.

[0207] The control method of the laundry dryer 1 according to an embodiment of the present invention may include: process input step S10, laundry quantity detection step S20, drying step S30, steam supply step S40, re-drying step S50, and cooling step S60.

[0208] In the process input step S10, control inputs are input for performing the steam drying process to prevent damage to the items to be dried and to enhance the sterilization of the items to be dried.

[0209] A process refers to a pre-set program in a garment handling device. If a user selects a process, the control unit can execute multiple steps to control the various components in order to execute the selected process. Therefore, a step refers to a part of the program that distinguishes whether a component is in motion or not in order to execute the process. Thus, a process may include multiple steps.

[0210] For example, the garment handling apparatus may include a steam drying process (or drying process) for drying and / or a sterilization process for sterilization.

[0211] In detail, in the process input step S10, the control input for the first steam drying process or the second steam drying process can be input according to the material of the item (or clothing) to be dried.

[0212] That is, when power is applied to the laundry dryer 1 of the present invention, the user can input control input to the input unit 118 by selecting the desired process. At this time, the user can input a steam drying process to prevent damage to the clothes to be dried and to enhance the sterilization of the clothes to be dried.

[0213] Specifically, depending on the material (or fabric) of the item to be dried, a first steam drying process (e.g., which may be called a "standard + steam process" or "towel + steam process") can be selected when drying thicker or hydrophilic materials with a relatively high moisture content, and a second steam drying process (which may be called a "shirt + steam process") can be selected when drying thin or hydrophobic materials with a relatively low moisture content.

[0214] In this invention, the control in the steam supply step S40 and the re-drying step S50 of the steam drying process may differ depending on the control input for the first steam drying process or the second steam drying process in the process input step S10.

[0215] In addition, in the process input step S10, the control in each step may differ depending on the control input during the sterilization process.

[0216] In the clothing quantity detection step S20 of the steam drying process, the quantity of clothing to be dried can be detected by the rotation of the drum 20. Typically, the quantity of wet clothes after dehydration is detected.

[0217] That is, the control unit 100 can sense the load of the clothes to be dried by rotating the drum 20, and can use the sensed load to detect the amount of clothes to be dried (S21).

[0218] At this time, the control unit 100 does not drive the compressor 45 (S22). In addition, the control unit 100 prevents the circulating fan 43 from rotating (S23).

[0219] On the other hand, in this invention, the control unit 100 can be controlled to supply water for generating steam to the steam unit 90 (S24).

[0220] That is, the control unit 100 can control the supply of 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 interior of the steam generator 91 by operating the water supply pump provided in the internal water supply unit 81, and can also supply water to the interior of the steam generator 91 by opening the direct water valve 82a provided in the external water supply unit 82.

[0221] For example, in the step of supplying water for generating steam (S24), 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.

[0222] On the other hand, in this embodiment, the step of sensing the amount of clothes to be dried (S21) and the step of supplying water to the steam unit 90 (S24) can be performed simultaneously. However, it is not limited to this. The step of supplying water to the steam unit 90 (S24) can also be performed during the drying step S30 of the steam drying process described later.

[0223] In the steam drying process, in drying step S30, the internal temperature of the drum 20 can be increased in order to dry the object to be dried.

[0224] At this time, in the drying step S30 of the steam drying process, the control unit 100 can set the time for performing the drying step S30 of the steam drying process based on the amount of clothes to be dried detected in the clothes amount detection step S20 of the steam drying process.

[0225] On the other hand, in this invention, the time for performing the drying step S30 of the steam drying process can be updated or shortened based on the amount of moisture detected during the drying process.

[0226] The steam drying process drying step S30 may include a step (S31) in which the control unit 100 rotates the drum 20 at a pre-input reference speed Wr. As an example, the control unit 100 may keep the drum 20 rotating at a speed of 45 rpm or higher and 55 rpm or lower.

[0227] Additionally, the steam drying process drying step S30 may include a step (S32) in which the control unit 100 drives (rotates) the compressor 45 at a preset operating frequency f. As an example, the control unit 100 may drive the compressor 45 at a frequency of 85 Hz or higher and 105 Hz or lower.

[0228] At this time, the control unit 100 can output a control command to increase the output of the compressor 45 to the operating frequency f in one go. However, in order to prevent failure caused by overload of the compressor motor 45a, it is preferable to execute the control command in a manner that increases the speed of the compressor motor 45a in several steps.

[0229] As an example, after generating a control command to drive the compressor 45 for the first time at a frequency of 55Hz or higher and 65Hz or lower, the control unit 100 generates a control command to drive the compressor 45 for the second time 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 operating frequency f.

[0230] In addition, the steam drying process drying step S30 may include the step of the control unit 100 causing the circulating fan 43 to rotate (S33).

[0231] In detail, the steam drying process drying step S30 may include: a first drying step S33a, which drives the circulating fan 43 at a preset first drying speed V1; a second drying step S33b, which accelerates the rotation speed of the circulating fan 43 from the first drying speed V1 to a preset second drying speed V2 and drives the circulating fan 43; and a third drying step S33c, which accelerates the rotation speed of the circulating fan 43 from the second drying speed V2 to a preset third drying speed V3 and drives the circulating fan 4.

[0232] In the first drying step S33a, the control unit 100 can drive the circulating fan 43 at a first drying speed V1 for a preset drying time tc.

[0233] As an example, in the first drying step S33a, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of 2700 rpm or more and 3100 rpm or less for a time of 3 minutes or more and 5 minutes or less.

[0234] In the second drying step S33b, after the drying time tc has elapsed, the control unit 100 can accelerate the circulating fan 43 to the second drying speed V2 and drive the circulating fan 43.

[0235] As an example, in the second drying step S33b, the control unit 100 can drive (rotate) the circulating fan 43 at a speed exceeding 3100 rpm and below 3500 rpm.

[0236] On the other hand, in the second drying step S33b, if the discharge temperature of the compressor 45 (which may refer to the temperature of the refrigerant discharged after being compressed in the compressor) is above a preset drying temperature Td, the control unit 100 may proceed to the third drying step S33c. The discharge temperature may be measured by a temperature sensor (not shown) located near the discharge port of the compressor 45.

[0237] That is, in the third drying step S33c, when the discharge temperature T of the compressor 45 is above the drying temperature Td (T≥Td), the control unit 100 can accelerate the rotation speed of the circulating fan 45 from the second drying speed V2 to the preset third drying speed V3 and make the circulating fan 45 rotate (drive).

[0238] As an example, in the third drying step S33c, when the discharge temperature of the compressor 45 is in the temperature range of 75 degrees Celsius or higher and 85 degrees Celsius or lower, the control unit 100 can accelerate the speed of the circulating fan 45 to a speed of 3700 rpm or higher and 4100 rpm or lower and drive (rotate) the circulating fan 45.

[0239] On the other hand, in the drying step S30 of the steam drying process, the control unit 100 can prevent the steam unit 90 from operating (S34). That is, the control unit 100 can supply water for generating steam to the steam unit 90 in the clothing quantity detection step S20 of the steam drying process, and then rotate the circulating fan 43 (S33) and drive the compressor 45 in the drying step S30 of the steam drying process (S32).

[0240] Therefore, in the drying step 30 of the steam drying process, the control unit 100 can simultaneously drive the drum 20, the compressor 45 and the circulating fan 43 without operating the steam unit 90.

[0241] In the steam supply step S40 of the steam drying process, the control unit 100 can control the steam unit 90 to supply steam to the inside of the drum 20 after the drying step S30 of the steam drying process.

[0242] The steam supply step S40 of the steam drying process may include a step (S41) in which the control unit 100 rotates the drum 20 at a pre-input reference speed Wr. As an example, the control unit 100 may continue to rotate the drum 20 while maintaining the rotational speed of the drum 20 at more than 45 rpm and less than 55 rpm.

[0243] At this time, in the steam supply step S40 of the steam drying process, in order to prevent the instantaneous power consumption of the laundry dryer 1 from increasing, the control unit 100 can stop the compressor 45 from driving (S42).

[0244] In addition, during the steam supply step S40 of the steam drying process, when the control unit 100 preheats the steam unit 90 for injecting steam after the third drying step S33c, the circulating fan 43 can continue to rotate (drive) at the third drying speed V3 (S43a).

[0245] Furthermore, the control unit 100 can stop the circulating fan 43 from rotating when the steam unit 90 injects steam (S43b).

[0246] The steam supply step S40 of the steam drying process may include a steam preheating step S44a and a steam injection step S44b.

[0247] In the steam preheating step S44a of the steam drying process, the control unit 100 can apply power to the steam unit 90, thereby heating the water used to generate steam during a preset preheating time th.

[0248] Specifically, in the steam preheating step S44a of the steam drying process, the control unit 100 can apply power to a heater (not labeled) installed in the steam generator 91, thereby heating the water supplied to the steam generator 91. At this time, the control unit 100 can apply power to the heater during the preheating time th, which can be set to more than the time required for the water to reach its boiling point.

[0249] For example, in the steam preheating step S44a of the steam drying process, the control unit 100 can generate a control command to apply power to the steam unit 90 for a period of more than 3 minutes and 30 seconds and less than 4 minutes and 30 seconds.

[0250] In the steam injection step S44b of the steam drying process, 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 S44a of the steam drying process.

[0251] In detail, in the steam injection step S44b of the steam drying process, the control unit 100 can generate and output control commands to the steam generator 91, so that the water heated and started to boil 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.

[0252] At this time, in the steam injection step S44b of the steam drying process, the control unit 100 can control the steam injection time according to whether the first steam drying process or the second steam drying process has been input in the process input step S10.

[0253] That is, in the steam injection step S44b of the steam drying process, when the control input of the first steam drying process is input in the process input step S10, the control unit 100 can control the water to be injected, and the amount of water injected is equivalent to the amount supplied in the step (S24) of supplying water for generating steam.

[0254] For example, in the steam injection step S44b of the steam drying process, the control unit 100 can inject 150cc or more and 250cc or less of water from the steam generator 91 into the interior of the drum 20. At this time, the time required for steam injection can be 6 minutes and 30 seconds or more and 7 minutes and 30 seconds or less.

[0255] In contrast, in the steam injection step S44b of the steam drying process, when a control command for the second steam drying process is input in the process input step S10, the control unit 100 can control the steam injection amount to be less than the steam injection amount in the first steam drying process. Specifically, in the steam injection step S44b of the steam drying process, when a control command for the second steam drying process is input in the process input step S10, the control unit 100 can control the injection of water, the injection amount of which is less than half of the amount supplied in the step (S24) for supplying water for generating steam.

[0256] For example, in the steam injection step S44b of the steam drying process, the control unit 100 can inject 60cc or more and 120cc or less of water from the steam generator 91 into the interior of the drum 20. At this time, the time required for steam injection can be more than 2 minutes and 30 seconds and less than 3 minutes and 30 seconds.

[0257] Therefore, according to the present invention, after removing moisture from the material to be dried in the drying step S30 of the steam drying process, the steam supply step S40 of the steam drying process is performed. The heat inside the drum 20, which rises due to the supplied high-temperature steam, can sterilize bacteria and other contaminants that may be present in the material to be dried. Therefore, it has the effect of enhancing the hygiene of the material to be dried.

[0258] Furthermore, by supplying moisture to the material to be dried that has been over-dried in the steam drying process S30 during the steam supply step S40 of the steam drying process, it has the effect of preventing damage caused by friction.

[0259] In addition, during the period when steam is injected onto the items to be dried, the drum 20 rotates at a fixed speed, while the circulating fan 43 does not operate, thus enabling the steam to be injected evenly onto the items to be dried.

[0260] Therefore, steam is supplied evenly to the entire item to be dried, thus providing a sterilization effect on the entire item and enhancing hygiene.

[0261] In the re-drying step S50, the control unit 100 can generate a control command for supplying hot air to the interior of the drum 20 after the steam supply step S40 of the steam drying process.

[0262] At this time, in the re-drying step S50, the control unit 100 can control the execution time of the re-drying step S50 according to whether the first steam drying process or the second steam drying process was input in the process input step S10.

[0263] That is, in the re-drying step S50, when the control input of the first steam drying process is input in the process input step S10, the control unit 100 can set the execution time of the re-drying step S50 to a preset first re-drying time tr1.

[0264] For example, in the re-drying step S50, when the control input for the first steam drying process is input, the control unit 100 can make the re-drying step S50 run for a period of 20 minutes or more but less than 30 minutes.

[0265] That is, in the re-drying step S50, when the control input of the second steam drying process is input in the process input step S10, the control unit 100 can set the execution time of the re-drying step S50 to a preset second re-drying time tr2.

[0266] For example, in the re-drying step S50, when the control input for the second steam drying process is input, the control unit 100 can make the re-drying step S50 run for a period of 10 minutes or more but less than 20 minutes.

[0267] That is, in the re-drying step S50, when the second steam drying process is input, the control unit 100 can set the execution time tr2 of the re-drying step S50 to be less than the execution time tr1 of the re-drying step S50 in the first steam drying process (tr2 < tr1).

[0268] The re-drying step S50 may include a step (S51) in which the control unit 100 rotates the drum 20 at a pre-input reference speed Wr. As an example, the control unit 100 may keep the drum 20 rotating at a speed of 45 rpm or higher and 55 rpm or lower.

[0269] The re-drying step S50 may include a step (S52) in which the control unit 100 re-drives (rotates) the compressor 45. As an example, the control unit 100 may drive the compressor 45 while increasing its frequency to 80 Hz or higher and 100 Hz or lower.

[0270] At this time, in order to prevent malfunctions caused by overload of the compressor motor 45a, the control unit 100 preferably executes a control command to increase the speed of the compressor motor 45a after several steps.

[0271] As an example, after generating a control command to drive the compressor 45 for the first time at a frequency of 55Hz or higher and 65Hz or lower, the control unit 100 can generate a control command to drive the compressor 45 for the second time at a frequency of 75Hz or higher and 85Hz or lower.

[0272] On the other hand, in this embodiment, if the compressor 45 cannot provide an exhaust temperature sufficient to sterilize the items to be dried due to external temperature or other factors, the control unit 100 can generate a control command that ultimately drives the compressor 45 at a frequency of 90 Hz or higher and 100 Hz or lower.

[0273] In the re-drying step S50, the control unit 100 can keep the rotation speed of the circulating fan 43 at the speed of the third drying speed V3 and make it rotate (drive) (S53).

[0274] On the other hand, in the re-drying step S50, after the control unit 100 supplies sufficient moisture to the material to be dried, it may not operate the steam unit 90 (stop operation) (S54).

[0275] In the cooling step S60 of the steam drying process, the control unit 100 can control the blowing of hot air for a pre-input blowing time into the interior of the drum 20 after the re-drying step S50, thereby cooling the object to be dried.

[0276] As an example, in the cooling step S60 of the steam drying process, the control unit 100 can blow hot air into the drum 20 for more than 3 minutes and 30 seconds and less than 4 minutes and 30 seconds, thereby cooling the item to be dried.

[0277] In the cooling step S60 of the steam drying process, the control unit 100 may include a step (S61) in which the roller 20 is rotated at a pre-input reference speed Wr. As an example, the control unit 100 may keep the roller 20 at a speed of 45 rpm or more and 55 rpm or less and continue to rotate it.

[0278] At this time, in the cooling step S60 of the steam drying process, in order to reduce the temperature of the dried material that has finished drying, the control unit 100 can stop the drive of the compressor 45 (S62).

[0279] Additionally, in the cooling step S60 of the steam drying process, the control unit 100 can maintain the rotation speed of the circulating fan 43 at the third drying speed V3 and make it rotate (drive) to blow heated air into the interior of the drum 20 (S63).

[0280] On the other hand, in the cooling step S60 of the steam drying process, after the control unit 100 supplies sufficient moisture to the material to be dried, it may not operate the steam unit 90 (stop operation) (S64).

[0281] On the other hand, Figures 6A to 6C The document discloses an example diagram illustrating the temperature changes of the piping section and compressor in a control method for a laundry dryer according to an embodiment of the present invention. Figures 7A to 7C The document discloses an example diagram illustrating the principle of a control method for a laundry dryer according to an embodiment of the present invention, which involves high-temperature sterilization of the laundry. Figure 8 The document discloses an example diagram illustrating the moisture balance of a laundry dryer according to an embodiment of the present invention, showing the control method of the dryer. Figure 9 The present invention discloses a graph illustrating the increase of enthalpy value in a control method for a laundry dryer according to an embodiment of the present invention.

[0282] Reference Figures 1 to 9 The effects of the present invention on preventing damage to the items to be dried and on the sterilization (hygiene) effect of the items to be dried are explained below.

[0283] According to a control method of a laundry dryer 1 according to an embodiment of the present invention, the drum 20 of the present invention is controlled to rotate in the laundry load detection step S20 of the steam drying process to detect the load (S21), and to maintain a fixed speed and rotate in the drying step S30, the steam supply step S40, the re-drying step S50 and the cooling step S60 of the steam drying process (S31, S41, S51, S61).

[0284] That is, the drum 20 continues to rotate after the clothing quantity detection step S20 in the steam drying process. Therefore, in this invention, the drum 20 serves to tumble and mix the items to be dried, so that hot air and steam are supplied evenly to the items to be dried.

[0285] Therefore, in this invention, by continuing to rotate the drum 20, the items to be dried can be dried evenly, thereby preventing damage caused by hot air concentrating on only one part of the items. Furthermore, since the rotation of the drum 20 allows steam to be supplied evenly to the items, a uniform sterilization (hygienic) effect can be achieved on the entire item.

[0286] On the other hand, the compressor 45 of the present invention is driven in the drying step S30 of the steam drying process, thereby raising the temperature inside the drum 20 (S32). Then, in the steam supply step S40 of the steam drying process, the compressor 45 will stop driving (S42), and will be driven again in the re-drying step S50, thereby drying the material to be dried (S52).

[0287] The compressor 45 functions to provide hot air (heat) to the interior of the drum 20 by heating the air flowing inside the pipe section 30. Therefore, the moisture in the items to be dried can be evaporated by driving the compressor 45, and the heat supplied by the compressor 45 can achieve a sterilization (hygiene) effect.

[0288] On the other hand, the circulating fan 43 of the present invention starts to rotate in the drying step S30 of the steam drying process, and gradually increases the rotation speed and rotates according to preset conditions (S33a, S33b, S33c). In the steam supply step S40 of the steam drying process, the circulating fan 43 stops rotating when steam is injected (S43b). Then, it is rotated again in the re-drying step S50 and the cooling step S60 of the steam drying process (S53, S63).

[0289] In this invention, the circulating fan 43 is controlled independently of the rotation of the drum 20, and the circulating fan 43 rotates when air heated by the compressor 45 is flowing, or when cooling is required after drying, and stops rotating when steam jets do not require air flow.

[0290] Therefore, the circulating fan 43 of the present invention improves the steam supply efficiency, thereby improving the sterilization (hygienic) efficiency of the items to be dried.

[0291] Furthermore, the circulating fan 43 of the present invention can change its rotation speed independently of the rotation speed of the drum 20. Therefore, in the drying step S30 of the steam drying process, the circulating fan 43 changes its rotation speed according to the temperature of the object to be dried, the temperature inside the drum 20, or the temperature of the refrigerant discharged from the compressor 45, thereby improving the circulation efficiency of the hot air.

[0292] The steam unit 90 of the present invention receives water for generating steam in the clothing quantity detection step S20 of the steam drying process (S24), and operates in the steam supply step S40 of the steam drying process for preheating (S44a) and injecting steam (S44b) for generating steam.

[0293] After the drying step S30 of the steam drying process is completed, the steam unit 90 alleviates the moisture imbalance that may occur between the items to be dried by supplying steam to the items to be dried, and can improve the sterilization (hygiene) effect by increasing the enthalpy inside the drum 20.

[0294] First, the mitigation effect of the present invention on water imbalance will be explained in detail.

[0295] When multiple items are dried simultaneously, the rate of moisture evaporation can vary depending on the thickness of the items and the properties of the raw materials. That is, even after the steam drying step S30, items that are thicker or made of hydrophilic materials may still contain moisture, while items that are thinner or made of hydrophobic materials will contain almost no moisture after the steam drying step S30.

[0296] At this time, if moisture is supplied to the material to be dried in the steam supply step S40 of the steam drying process, the moisture will be absorbed again by the thinner material or the material made of hydrophobic material, while in the thicker material or the material made of hydrophilic material, the evaporation rate increases with the increase of humidity, thereby balancing the overall moisture content of the material to be dried.

[0297] Therefore, according to the present invention, the overall drying degree of the material to be dried can be made more uniform through the steam supply step S40 and the re-drying step S50 of the steam drying process (see reference). Figure 8 ).

[0298] In addition, even if the material to be dried is over-dried in the drying step S30 of the steam drying process, moisture will be replenished through the steam supply step S40 of the steam drying process, thus preventing damage to the material to be dried.

[0299] Next, the sterilization (hygiene) effect according to the present invention will be described in detail.

[0300] If hot air is supplied to the object to be dried in the steam drying process drying step S30, the moisture in the object to be dried is removed first. Afterwards, if the steam drying process drying step S30 continues, the temperature inside the drum 20 or the temperature of the object to be dried reaches the reference temperature required for the sterilization (hygiene) process (see Figures 6 and 7). At this time, if high-temperature steam is injected into the object to be dried in the steam unit 90 of the present invention, the humidity of the object to be dried rises instantaneously (see Figure 7), and microorganisms and the like present in the object to be dried may be exposed to the high heat energy of the high-temperature steam, thereby destroying their cells and killing the microorganisms.

[0301] In contrast, without the steam supply step S40 of the steam drying process of the present invention, the heat generated by the compressor 45 in the drying step S30 of the steam drying process is used in the process of removing moisture from the item to be dried, and even if the temperature of the item to be dried rises and reaches the reference temperature required for sterilization (e.g., 60 degrees Celsius), there is a limitation in providing sufficient heat for sterilization since the moisture has already been almost removed from the item to be dried or the drum 20.

[0302] If further heat is required, the temperature of the drum 20 can be increased further. However, if only hot air is supplied, the items to be dried will become too dry and may be damaged due to friction.

[0303] Therefore, according to the present invention, the steam supply step S40 and the re-drying step S50 of the steam drying process have the effect of sterilizing the items to be dried while preventing damage to the items.

[0304] exist Figure 10 The present invention discloses a flowchart illustrating the sequence of control methods for a laundry dryer 1 according to another embodiment of the present invention. Figure 11A and Figure 11B The present invention discloses example figures illustrating a specific application example of a steam drying method related to a steam sterilization process according to another embodiment of the present invention.

[0305] Reference Figures 1 to 3 , Figure 10 And as shown in Figure 11, the control method of the laundry dryer 1 according to another embodiment of the present invention is as follows.

[0306] The control method of the laundry dryer 1 according to another embodiment of the present invention may include: process input step S100, sterilization steam heating step S200, sterilization drying step S300, steam re-sterilization step S400, temperature holding step S500, and sterilization cooling step S600.

[0307] In the process input step S100, control inputs for performing the steam sterilization process are input, in which microorganisms that may exist in the items to be dried, including clothing, towels, bedding, etc., are sterilized.

[0308] That is, when power is applied 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 a steam sterilization process for sterilizing microorganisms or the like that may exist on the clothes to be dried.

[0309] At this time, microorganisms may include Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and dust mites, etc.

[0310] In the sterilization steam heating step S200, the control unit 100 can control the supply of steam to the inside of the drum 20.

[0311] At this time, in the sterilization steam heating step S200, the control unit 100 can control the amount of clothes to be dried to be detected by the rotation of the drum 20 (S210a), and after detecting the amount of clothes, the drum 20 can be kept at a fixed speed and continue to rotate (S210b).

[0312] That is, in the sterilization garment quantity detection step S210a, which is used to detect the quantity of garments, the control unit 100 can control the roller 20 to rotate to detect the load of the garments to be dried, and the quantity of garments to be dried can be detected by the detected load.

[0313] In the step (S210b) for rotating the roller at a fixed speed, the control unit 100 can rotate the roller 20 at a pre-input reference speed Wr. As an example, the control unit 100 can maintain the roller 20 at a speed of 45 rpm or more and 55 rpm or less and continue to rotate it.

[0314] At this time, in order to prevent the instantaneous power consumption of the laundry dryer 1 from increasing, the control unit 100 may not drive the compressor 45 (S220).

[0315] In the sterilization steam heating step S200, the control unit 100 can be linked with the operation control of the steam unit 90 (described later) to control the rotation of the circulating fan 43 (S230).

[0316] On the other hand, in this invention, the control unit 100 can control the steam unit 90 to supply steam to the interior of the drum 20 (S240).

[0317] The sterilization steam heating step S200 may further include a sterilization steam water supply step S240a, a sterilization steam preheating step S240b, and a sterilization steam injection step S240c.

[0318] In the sterilization steam water supply step S240a, 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 operate the water supply pump provided in the internal water supply unit 81 to supply water to the inside of the steam generator 91, or it can supply water to the inside of the steam generator 91 by opening the direct water valve 82a provided in the external water supply unit 82.

[0319] For example, in the sterilization steam water supply step S240a, 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.

[0320] At this time, in the sterilization steam water supply step S240a, the control unit 100 can prevent the circulating fan 43 from rotating (S230a).

[0321] In the sterilization steam preheating step S240b, the control unit 100 can apply electricity to the steam unit 90, thereby heating the water supplied for generating steam for a preset preheating time th.

[0322] Specifically, in the sterilization steam preheating step S240b, the control unit 100 can apply power to a heater (not labeled) installed in the steam generator 91, thereby heating the water supplied to the steam generator 91. At this time, the control unit 100 can apply power to the heater during the preheating time th, which can be set to more than the time required for the water to reach its boiling point.

[0323] For example, in the sterilization steam preheating step S240b, the control unit 100 can generate a control command for applying electricity to the steam unit 90 for a period of 3 minutes and 30 seconds or more but less than 4 minutes and 30 seconds.

[0324] At this time, in the sterilization steam preheating step S240b, the control unit 100 can drive the circulating fan 43 at a preset first circulation speed Vs1 for a preset circulation time tcs.

[0325] As an example, in the sterilization steam preheating step S240b, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of 2500 rpm or more and 3500 rpm or less for a time of 3 minutes and 30 seconds or more and 4 minutes and 30 seconds or less (S230b).

[0326] In the sterilization steam injection step S240c, the control unit 100 can inject a preset amount of steam generated by the steam unit 90 into the drum 20 after the sterilization steam preheating step S240b.

[0327] In detail, in the sterilization steam injection step S240c, the control unit 100 can generate a control command to the steam generator 91, which is used to cause the water heated in the steam generator 91 to begin boiling to flow through the steam pipe 92 and be injected into the interior of the drum body 21 via the steam nozzle 93.

[0328] For example, in the sterilization steam injection step S240c, the control unit 100 can control the injection of 150cc or more and 250cc or less of water from the steam generator 91 into the drum 20. At this time, the time required for steam injection can be 6 minutes and 30 seconds or more and 7 minutes and 30 seconds or less.

[0329] At this time, in the sterilization steam injection step S240c, in order to supply steam sufficiently to the items to be dried, the control unit 100 may stop the rotation of the circulating fan 43 after the cycle time tcs (S230c).

[0330] Therefore, in the sterilization steam heating step S200, the control unit 100 can operate the steam generator 91 and the drum 20, and rotate the circulating fan 43 during steam preheating, while stopping the rotating of the circulating fan 43 during steam injection and not driving the compressor 45.

[0331] Therefore, in the sterilization steam heating step S200, when the item to be dried absorbs high-temperature steam, the temperature of the item to be dried will rise, thereby preventing damage to the item to be dried caused by hot air heating in the sterilization drying step S300 described later.

[0332] In the sterilization and drying step S300, the internal temperature of the drum 20 can be increased to raise the internal temperature of the drum 20 that has been supplied with steam.

[0333] At this time, in the sterilization and drying step S300, if the internal temperature of the drum 20 rises to the preset sterilization temperature Ts, the control unit 100 can proceed to the steam re-sterilization step S400 described later.

[0334] The sterilization and drying step S300 may include a step (S310) in which the control unit 100 rotates the drum 20 at a pre-input reference speed Wr. As an example, the control unit 100 may keep the drum 20 rotating at a speed of 45 rpm or more and 55 rpm or less.

[0335] Additionally, the sterilization and drying step S300 may include a step (S320) in which the control unit 100 drives (rotates) the compressor 45.

[0336] At this time, the control unit 100 can adjust the operating frequency f of the compressor 45 within the preset maximum frequency fmax range and drive the compressor 45.

[0337] As an example, the control unit 100 can increase or decrease the operating frequency f of the compressor 45 and drive the compressor 45 within a maximum frequency fmax range of 85Hz to 105Hz.

[0338] When entering the sterilization and drying step S300, in order to rapidly raise the internal temperature of the drum 20, the control unit 100 can drive the compressor 45 at the operating frequency f of the maximum frequency fmax (S320a).

[0339] At this time, the control unit 100 can output a control command to increase the output of the drive compressor 45 to the maximum frequency fmax in one go. However, in order to prevent failure caused by overload of the compressor motor 45a, it is preferable to execute the control command in a manner that increases the speed of the compressor motor 45a through multiple steps.

[0340] As an example, after generating a control command to drive the compressor 45 for the first time at a frequency of 55Hz or higher and 65Hz or lower, the control unit 100 generates a control command to drive the compressor 45 for the second time 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 operating frequency f.

[0341] After the compressor 45 is driven at an operating frequency f that is the maximum frequency fmax, in order to improve energy efficiency and prevent malfunctions, the control unit 100 can detect the temperature inside the drum 20, and based on this, the compressor 45 can maintain the operating frequency f at a frequency lower than (below) the maximum frequency fmax and drive it (S320b).

[0342] At this time, the control unit 45 can use the detection unit 116 provided in the pipe section 30 to detect (measure) the temperature inside the drum 20. In the sterilization and drying step S300, as described later, as the circulating fan 43 continues to rotate, the air inside the drum 20 will continue to flow and circulate inside the pipe section 30. Therefore, the control unit 100 can use the detection unit 116 provided in the pipe section 30 to measure the temperature inside the drum 20. Alternatively, the detection unit 116 provided in the pipe section 30 can be a temperature sensor.

[0343] On the other hand, in the sterilization and drying step S300, if the internal temperature T of the drum 20 rises to the preset sterilization temperature Ts (T≥Ts), the control unit 100 can stop driving the compressor 45 and proceed to the steam re-sterilization step S400 (S320c) described later.

[0344] Specifically, when the temperature T measured by the detection unit 116 installed in the pipeline section 30 is 60 degrees Celsius or higher, the control unit 100 can stop driving the compressor 45.

[0345] In addition, the sterilization and drying step S300 may include the step of the control unit 100 causing the circulating fan 43 to rotate (S330).

[0346] In detail, during the sterilization and drying step S300, the control unit 100 can drive the circulating fan 43 at a preset second circulation speed Vs2 during the operation of the compressor 45.

[0347] As an example, in the sterilization and drying step S300, the control unit 100 can drive (rotate) the circulating fan 43 at a speed of 3500 rpm or more and 4500 rpm or less during the operation of the compressor 45.

[0348] On the other hand, in the sterilization and drying step S300, the control unit 100 may not operate the steam unit 90 (S340).

[0349] That is, in the sterilization and drying step S300, the control unit 100 can drive the drum 20, the circulating fan 43 and the compressor 45.

[0350] Therefore, according to the sterilization and drying step S300, the air flowing in the drum 20 and pipe section 30 and the refrigerant in the heat exchange section 40 are driven by the compressor 45 to achieve heat exchange, thereby raising the temperature of the drum 20 and pipe section 30, and the temperature inside the drum 20 and pipe section 30 can rise to the temperature Ts required to sterilize the items to be dried.

[0351] In the steam re-sterilization step S400, the control unit 100 can supply steam to the inside of the drum 20.

[0352] At this time, in the steam re-sterilization step S400, the control unit 100 can cause the drum 20 to continue rotating at a pre-input reference speed Wr (S410). As an example, the control unit 100 can cause the drum 20 to maintain a speed of 45 rpm or more and 55 rpm or less and continue to rotate it.

[0353] In the steam re-sterilization step S400, in order to prevent an increase in the instantaneous power consumption of the laundry dryer 1, the control unit 100 stops the compressor 45 from driving (S420).

[0354] In the steam re-sterilization step S400, in order to reduce the flow of steam and supply enough steam to the inside of the drum 20, the control unit 100 stops the circulation fan 43 from rotating (S430).

[0355] In the steam re-sterilization step S400, the control unit 100 can control the steam unit 90 to supply steam to the inside of the drum 20 (S440).

[0356] The steam re-sterilization step S400 may include: a steam resupply step S440a, a steam re-preheating step S440b, and a steam re-injection step S440c.

[0357] In the steam resupply step S440a, 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, and can also supply water to the inside of the steam generator 91 by opening the direct water valve 82a provided in the external water supply unit 82.

[0358] For example, in the steam resupply step S440a, 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 for water to be supplied 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.

[0359] In the steam reheating step S440b, the control unit 100 can apply electricity to the steam unit 90, thereby heating the water supplied for generating steam during a preset preheating time th.

[0360] Specifically, in the steam reheating step S440b, the control unit 100 can heat the water supplied to the steam generator 91 by applying electricity to a heater (not labeled) installed in the steam generator 91. At this time, the control unit 100 can apply electricity to the heater during the preheating time th, which can be set to more than the time required for the water to reach its boiling point.

[0361] For example, in the steam reheating step S440b, the control unit 100 can generate a control command for applying power to the steam unit 90 for a period of more than 3 minutes and 30 seconds and less than 4 minutes and 30 seconds.

[0362] In the steam re-injection step S440c, the control unit 100 can inject a preset amount of steam generated by the steam unit 90 into the drum 20 after the steam re-preheating step S440b.

[0363] In detail, in the steam re-injection step S440c, the control unit 100 can generate a control command for the steam generator 91, which is used to cause the water heated and started to boil in the steam generator 91 to flow through the steam pipe 92 and be injected into the interior of the drum body 21 via the steam nozzle 93.

[0364] For example, in the steam re-injection step S440c, the control unit 100 can control the injection of 150cc or more and 250cc or less of water from the steam generator 91 into the interior of the drum 20. At this time, the time required for steam injection can be 6 minutes and 30 seconds or more and 7 minutes and 30 seconds or less.

[0365] Therefore, according to the steam re-sterilization step S400, the control unit 100 supplies high-temperature moisture to the inside of the drum 20 through the steam unit 90, thereby increasing the enthalpy inside the drum 20 and thus improving the sterilization (hygiene) effect.

[0366] In the temperature holding step S500, the control unit 100 can maintain the internal temperature of the drum 20 for a preset holding time after the steam re-sterilization step S400.

[0367] In the temperature holding step S500, the control unit 100 can cause the roller 20 to continue rotating at a pre-input reference speed Wr (S510). As an example, the control unit 100 can cause the roller 20 to maintain a speed of 45 rpm or more and 55 rpm or less and continue to rotate it.

[0368] The temperature holding step S500 may include a reheating step S520a and a heating adjustment step S520b.

[0369] The reheating step S520a can be performed when moving from the steam re-sterilization step S400 to the temperature holding step S500.

[0370] In the reheating step S520a, the control unit 100 can drive the compressor 100 at a preset safe frequency fs.

[0371] As an example, in the reheating step S520a, the control unit 100 can drive the compressor 100 at a frequency of 25Hz or higher and 35Hz or lower.

[0372] That is, the control unit 100 can restart the steam unit 90, thereby supplying steam to the interior of the drum 20, and then driving the compressor 45 at the safe frequency fs.

[0373] Therefore, according to the present invention, it has the effect of preventing the laundry dryer 1 from malfunctioning or preventing the power supply to the laundry dryer 1 from being suddenly cut off.

[0374] In detail, when moving from the steam re-sterilization step S400 to the temperature holding step S500, the power supplied to the steam generator 91 and the power supplied to the compressor 45 may momentarily overlap.

[0375] As a result, the total power consumption of the laundry dryer 1 may increase sharply, which may lead to malfunctions in the laundry dryer 1 or a sudden power outage to the laundry dryer 1.

[0376] To address the aforementioned problems, in this invention, the control unit 100 can set the operating frequency f of the compressor 45 during the temperature holding step S500 to a safe frequency fs and drive the compressor 45. In this case, the power supplied to the compressor 45 is relatively low, thus preventing a sharp increase in total power consumption.

[0377] In the heating adjustment step S520b, the control unit 100 can measure the temperature inside the pipe section 30 after the reheating step S510a, and can control the compressor 45 to change its operating frequency f based on the temperature inside the pipe section 30 measured in order to maintain the temperature inside the pipe section 30.

[0378] In detail, in the heating adjustment step S520b, if the operation of the steam generator 91 is terminated and the total power consumption becomes stable during the reheating step S510a, the control unit 100 measures the temperature inside the pipe section 30 and changes the operating frequency f so that the temperature T inside the pipe section 30 is maintained above the sterilization temperature Ts.

[0379] That is, when the temperature T inside the pipe section 30 continues to rise from a state above the sterilization temperature Ts, the control unit 100 generates a control command to reduce the operating frequency f and drive the compressor 45. Conversely, when the temperature T inside the pipe section 30 begins to decrease from a state above the sterilization temperature Ts, the control unit 100 generates a control command to increase the operating frequency f and drive the compressor 45.

[0380] Therefore, according to the present invention, in the heating adjustment step S520b, the control unit 100 can continue to maintain the sterilization temperature Ts.

[0381] On the other hand, in the heating adjustment step S520b, the control unit 100 can maintain the temperature T inside the pipe section 30 at or above the sterilization temperature Ts during the preset temperature holding time tm, and then stop the compressor 45 from driving.

[0382] As an example, in the heating adjustment step S520b, the control unit 100 can maintain the temperature T inside the pipe section 30 at 60 degrees or higher for a period of 70 minutes or more and 80 minutes or more (preferably 75 minutes), and then stop the compressor 45 from driving.

[0383] In the temperature holding step S500, the control unit 100 can keep the rotation speed of the circulating fan 43 at the second circulation speed Vs2 and make it rotate (drive) (S530).

[0384] In the temperature holding step S500, sufficient moisture has been supplied to the material to be dried, so the control unit 100 can stop the steam unit 90 from operating (stop operation) (S540).

[0385] Therefore, in the temperature holding step S500, the control unit 100 can operate the drum 20, the compressor 45 and the circulating fan 43. In particular, it can maintain the temperature T inside the pipe section 30 above the sterilization temperature Ts while changing the operating frequency of the compressor 45.

[0386] Therefore, through the temperature holding step S500, the items to be dried can be kept at a temperature above the sterilization temperature Ts for a time above the baseline required for sterilization.

[0387] In the sterilization and cooling step S600, the control unit 100 can control the hot air to be blown into the interior of the drum 20 for a pre-input air blowing time after the temperature holding step S500, thereby cooling the items to be dried.

[0388] As an example, in the sterilization and cooling step S600, the control unit 100 can blow hot air into the interior of the drum 20 for a period of more than 3 minutes and 30 seconds and less than 4 minutes and 30 seconds, thereby cooling the items to be dried.

[0389] The sterilization and cooling step S600 may include a step (S610) in which the control unit 100 rotates the roller 20 at a pre-input reference speed Wr. As an example, the control unit 100 may keep the rotational speed of the roller 20 at 45 rpm or more and 55 rpm or less and continue to rotate it.

[0390] At this time, in the sterilization and cooling step S600, in order to reduce the temperature of the items to be dried which has been raised, the control unit 100 can stop the drive of the compressor 45 (S620).

[0391] In addition, in the sterilization and cooling step S600, in order to blow heated air into the interior of the drum 20, the control unit 100 can keep the rotation speed of the circulating fan 43 at the second circulation speed Vs2 and make it rotate (drive) (S630).

[0392] On the other hand, since sufficient moisture has been supplied to the material to be dried in the sterilization and cooling step S600, the control unit 100 may not operate the steam unit 90 (stop operating the steam unit 90) (S640).

[0393] Therefore, in the sterilization and cooling step S600, the control unit 100 can reduce the temperature of the items to be dried by rotating the drum 20 and the circulating fan 43.

[0394] On the other hand, Figure 12 The document discloses an example diagram illustrating the temperature change of the laundry to be dried, showing a control method for a laundry dryer according to another embodiment of the present invention. Figure 13 The present invention discloses an example diagram illustrating the change in humidity of the laundry to be dried, showing a control method for a laundry dryer according to another embodiment of the present invention. Figure 14 The present invention discloses a table of sterilization conditions for a laundry dryer control method according to another embodiment of the present invention.

[0395] Reference Figures 10 to 14 The sterilization (hygienic) effect of the items to be dried according to the present invention is explained below.

[0396] According to another embodiment of the control method of the laundry dryer 1, the drum 20 of the present invention is controlled to rotate in the sterilization steam heating step S200 to detect the load (S210), and in the sterilization drying step S300, the steam re-sterilization step S400, the temperature holding step S500 and the sterilization cooling step S600, it is controlled to maintain a fixed speed and rotate (S310, S410, S510, S610).

[0397] That is, the drum 20 continues to rotate after the sterilization steam heating step S200. Therefore, in this invention, the drum 20 serves to tumble and mix the items to be dried, so that hot air and steam are supplied evenly to the items to be dried.

[0398] Therefore, in this invention, by continuously rotating the drum 20, the items to be dried can be dried evenly, thereby preventing damage caused by hot air concentrating on only one part of the items. Furthermore, the rotation of the drum 20 ensures that steam is supplied evenly to the items, thus achieving a uniform sterilization effect on the entire item.

[0399] On the other hand, the compressor 45 of the present invention is started to drive in the sterilization and drying step S300, thereby raising the temperature inside the drum 20 (S320). Then, in the steam re-sterilization step S400, the compressor 45 will stop driving (S420), and will be driven again in the temperature holding step S500, thereby sterilizing the items to be dried (S520).

[0400] The compressor 45 serves to provide hot air (heat) to the interior of the drum 20 by heating the air flowing inside the pipe section 30. Therefore, by driving the compressor 45, the moisture in the items to be dried can be evaporated, and sterilization (hygiene) can be achieved using the heat supplied by the compressor 45.

[0401] On the other hand, the circulating fan 43 of the present invention starts to rotate in the sterilization steam preheating step S230b, stops rotating in the sterilization steam injection step (S230c), rotates again in the sterilization drying step S300 (S330), stops rotating in the steam re-sterilization step S400 (S430), and then rotates again in the temperature holding step S500 and the sterilization cooling step S600 (S530, S630).

[0402] In this invention, the circulating fan 43 is controlled independently of the rotation of the drum 20, and the circulating fan 43 is rotated when air heated by the compressor 45 is circulated, or when cooling is required after sterilization, and the circulating fan 43 stops rotating when air-driven steam is not required.

[0403] Therefore, the circulating fan 43 of the present invention improves the steam supply efficiency and the sterilization (hygiene) efficiency of the items to be dried.

[0404] Furthermore, the circulating fan 43 of the present invention can change its rotation speed independently of the rotation speed of the drum 20. Therefore, in the sterilization and drying step S300, the circulating fan 43 changes its rotation speed according to the temperature of the object to be dried, the temperature inside the drum 20, or the temperature inside the duct section 30, thereby improving the circulation efficiency of the hot air.

[0405] The steam unit 90 of the present invention receives water for generating steam in the sterilization steam heating step S200 and the steam re-sterilization step S400, and operates for preheating and steam injection for generating steam.

[0406] In the sterilization steam heating step S200, the control unit 100 uses the steam unit 90 to supply high-temperature moisture to the inside of the drum 20, thereby increasing the heating efficiency of the inside of the drum 20.

[0407] That is, in all cases where the item to be dried has finished washing or has not been washed, if high-temperature steam is supplied to the item to be dried, heat will be transferred to the item. At this time, if hot air is supplied in the sterilization and drying step S300, the temperature of the item to be dried or the temperature inside the drum 20 can rise more quickly.

[0408] In the steam re-sterilization step S400, the control unit 100 uses the steam unit 90 to supply high-temperature moisture to the inside of the drum 20, thereby increasing the enthalpy inside the drum 20 and thus improving the sterilization (hygiene) effect.

[0409] The sterilization (hygiene) effect according to the present invention is described in detail.

[0410] If hot air is supplied to the object to be dried in the sterilization and drying step S300, the temperature inside the drum 20 or the object to be dried will reach the reference temperature (60 degrees Celsius or above) required for sterilization (hygiene). At this time, if the steam unit 90 sprays high-temperature steam onto the object to be dried in the steam re-sterilization step S400 of the present invention, the enthalpy of the object to be dried will increase.

[0411] Subsequently, through the temperature holding step S500, the temperature T inside the drum 20 is maintained at a temperature above the sterilization temperature Ts for a holding time (tm). Therefore, microorganisms and other microorganisms present on the items to be dried may be exposed to high heat energy, thereby destroying their cells and killing them. At this time, as... Figure 14 As shown, the temperature holding time (tm) exceeds the time required to kill microorganisms, etc.

[0412] In contrast, without the steam re-sterilization step S400 of the present invention, the heat generated by driving the compressor 45 in the sterilization drying step S300 is used to remove moisture from the items to be dried. Even if the temperature of the items to be dried rises and reaches the reference temperature required for sterilization (e.g., 60 degrees Celsius), the moisture has almost been removed from the items to be dried or the drum 20. Therefore, there is a limitation in providing sufficient heat for sterilization.

[0413] If, in order to supply more heat, the temperature of the drum 20 can be further increased, however, if only hot air is supplied, the items to be dried will become too dry, and the items to be dried may be damaged due to friction.

[0414] Therefore, according to the present invention, the steam re-sterilization step S400 and the temperature holding step S500 have the effect of sterilizing the items to be dried while preventing damage to the items.

[0415] The present invention has been described in detail above through specific embodiments. However, these embodiments are only for illustrating the present invention in detail. The present invention is not limited thereto. It should be understood that within the scope of the technical concept of the present invention, those skilled in the art can make modifications or improvements to the present invention.

[0416] Any simple modifications or alterations to this invention fall within its scope, and the specific scope of protection of this invention is defined by the appended claims.

Claims

1. A laundry dryer, characterized in that, include: A drum, which is rotatably arranged inside the housing that forms the exterior, and is used to hold the items to be dried; The piping section is configured to resupply the air discharged from the roller to the roller; A circulating fan moves air along the duct section; A heat exchange section is provided on the pipe section and includes an evaporator and a condenser for exchanging heat with the air circulating along the pipe section; A compressor for compressing a refrigerant that exchanges heat with air circulating along the pipe section; The steam section generates steam and supplies the steam into the interior of the drum; and The control unit controls the drum, the circulating fan, the compressor, and the steam unit. During the preheating of the steam in the steam section, the control unit rotates the drum and the circulating fan. During the injection of preheated steam into the interior of the drum, the control unit causes the drum to rotate and stops the circulating fan from rotating. The control unit drives the compressor to raise the internal temperature of the drum. After the compressor discharge temperature rises to a preset drying temperature, it supplies steam to the inside of the drum by operating the steam unit.

2. The laundry dryer according to claim 1, characterized in that, When steam is supplied to the interior of the drum through the steam section, the control section causes the compressor to stop driving.

3. The laundry dryer according to claim 1, characterized in that, After supplying steam to the interior of the drum by operating the steam unit, the control unit drives the compressor again.

4. The laundry dryer according to claim 1, characterized in that, After supplying water for steam generation to the steam unit, the control unit causes the circulating fan to rotate.

5. The laundry dryer according to claim 1, characterized in that, The control unit drives the compressor after supplying water to the steam unit for generating steam.

6. The laundry dryer according to claim 1, characterized in that, When power is applied to the steam unit to begin preheating the steam, the control unit stops the compressor from operating.

7. The laundry dryer according to claim 6, characterized in that, Before power is applied to the steam unit, the control unit drives the compressor and the circulating fan.

8. The laundry dryer according to claim 7, characterized in that, After the steam is injected, the control unit dries the object to be dried by driving the compressor and the circulating fan. The rotational speed of the circulating fan during the preheating time is different from the rotational speed of the circulating fan after the steam is injected.

9. The laundry dryer according to claim 1, characterized in that, After supplying steam to the interior of the drum by operating the steam unit, the control unit drives the compressor to raise the internal temperature of the drum. If the inside temperature of the drum rises to a preset sterilization temperature, the control portion supplies steam to the inside of the drum by operating the steam portion again.

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