Heat pump clothes dryer

Abstract

The application discloses a heat pump clothes dryer. The first valve, the second valve and the third valve are arranged on the circulating air duct. The first valve is arranged on the side of the condenser away from the evaporator. The second valve is arranged between the condenser and the evaporator. The third valve is arranged on the side of the evaporator away from the condenser. The evaporator, the condenser and the circulating fan are arranged in the gas flow direction of the circulating air duct in sequence. In the open state of the circulating fan, when the first valve is opened, the gas in the circulating air duct flows to the outside. When the first valve is closed, the gas in the circulating air duct flows to the drying barrel. When the second valve is opened, the outside gas enters the circulating air duct through the second valve. When the third valve is opened, the outside gas enters the circulating air duct through the third valve. By opening and closing the first valve, the second valve and the third valve, the gas flow direction in the circulating air duct is controlled, the evaporator surface is frozen or the ice layer is melted, and the lint is cleaned.

Description

Technical Field

[0001] This application relates to the field of clothing processing equipment technology, and in particular to a heat pump dryer. Background Technology

[0002] With the continuous improvement of people's living standards, clothes dryers have gradually become an indispensable appliance in home life. A clothes dryer is a clothing processing device used to dry clothes, and they are generally divided into direct-vent dryers and heat pump dryers according to their working method. In a direct-vent dryer, the drying air is directly discharged into the air after passing through the drying drum, while in a heat pump dryer, the drying air circulates throughout the entire air circulation system.

[0003] During the clothes drying process, when the high-temperature airflow passes over the surface of the clothes to be dried in the drying drum, some fine lint is carried out and flows with the drying air. For heat pump dryers, if the lint enters the circulating air duct, it may adhere to the evaporator, affecting the heat exchange efficiency between the evaporator and the circulating gas, resulting in low operating efficiency of the heat pump system. One approach is to install a filter in the circulating air duct to filter the lint. However, after prolonged operation, the lint gradually accumulates inside the filter, clogging the filter screen and causing blockage in the circulating air duct, affecting air circulation and resulting in low ventilation and low drying efficiency in the heat pump dryer. Another approach is to install a sprayer in the circulating air duct, using the condensate in the circulating air duct to spray the evaporator and remove the lint from its surface. However, the amount of condensate in the circulating air duct is limited, and the spray flow is slow, making it ineffective at removing lint from the evaporator surface.

[0004] Therefore, other methods are needed to clean up the lint. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a heat pump clothes dryer.

[0006] In some embodiments of this application, the heat pump dryer includes a casing, a drying drum, a circulating air duct, a heat pump system, a circulating fan, multiple valves, and a control device. The casing has an internal accommodating space. The drying drum is rotatably disposed in the accommodating space. The circulating air duct is disposed in the accommodating space, and its two ends are respectively connected to the two axial ends of the drying drum. The heat pump system includes a compressor, a condenser, and an evaporator. The compressor, evaporator, and condenser are connected in sequence through pipelines for refrigerant flow. The evaporator and condenser are disposed in the circulating air duct. The circulating fan is disposed in the circulating air duct, and the evaporator, condenser, and circulating fan are arranged in sequence along the gas flow direction of the circulating air duct.

[0007] Multiple valves are installed on the circulating air duct to control the entry and exit of external air into and out of the circulating air duct. The multiple valves include a first valve, a second valve, and a third valve. The first valve is located on the side of the condenser away from the evaporator, the second valve is located between the condenser and the evaporator, and the third valve is located on the side of the evaporator away from the condenser. The control device is electrically connected to the first valve, the second valve, and the third valve to control the opening and closing of the first valve, the second valve, and the third valve.

[0008] Thus, in the above technical solution, a first valve, a second valve, and a third valve are installed on the circulating air duct. The first valve is located on the side of the condenser facing away from the evaporator, the second valve is located between the condenser and the evaporator, and the third valve is located on the side of the evaporator facing away from the condenser. The evaporator, condenser, and circulating fan are arranged sequentially in the gas flow direction of the circulating air duct. When the circulating fan is on, when the first valve is open, the gas in the circulating air duct flows to the outside; when the first valve is closed, the gas in the circulating air duct flows towards the drying drum. When the second valve is open, outside gas can enter the circulating air duct through the second valve. When the third valve is open, outside gas can enter the circulating air duct through the third valve. Therefore, by opening and closing the first, second, and third valves, the flow direction of the gas in the circulating air duct can be controlled. This allows the ice formation or melting of the ice layer on the evaporator surface to be achieved through the opening and closing of the circulating fan, the first valve, the second valve, and the third valve, thereby cleaning up lint.

[0009] In some embodiments of this application, a circulating fan is disposed between the first valve and the condenser.

[0010] In the above technical solution, the circulating fan is located between the first valve and the condenser, which helps to blow the gas in the circulating air duct to the outside when the first valve is open.

[0011] In some embodiments of this application, the circulating air duct is provided with a drain outlet, and the heat pump dryer also includes a water storage tank and a drain pump, wherein the water storage tank is connected to the drain outlet and is used to receive water discharged through the drain outlet; the drain pump is used to extract water from the water storage tank.

[0012] In the above technical solution, water in the circulating air duct can be discharged by setting up a drain outlet, a water storage tank and a drain pump.

[0013] In some embodiments of this application, the heat pump dryer includes a water collection box, which is detachably disposed in the housing and connected to a drain pump via a pipe to receive water pumped by the drain pump.

[0014] In the above technical solution, the water pumped by the drain pump is collected by the water collection box, so there is no need to set a drain outlet on the outer shell of the heat pump dryer. The heat pump dryer can still be placed in a location without a reserved drainage channel. The water collection box is detachably installed in the outer shell, so that users can empty the water in the water collection box at any time.

[0015] In some embodiments of this application, the control device is configured to perform a self-cleaning procedure, including: opening a first valve and a second valve, closing a third valve, starting a compressor and a circulating fan until a first set condition is met, so that the temperature of the evaporator surface drops below freezing; when the first set condition is met, opening the third valve, keeping the first valve open, closing the second valve or keeping the second valve open, keeping the compressor and circulating fan on, until a second set condition is met, so that an ice layer forms on the evaporator surface; when the second set condition is met, closing the first valve, the second valve, the third valve, and the circulating fan, keeping the compressor on.

[0016] In the above technical solution, during self-cleaning, the first and second valves are opened, the third valve is closed, and the compressor and circulating fan are started. At this time, the condenser side is under high pressure, and outside gas enters the circulating air duct through the second valve and flows out through the first valve, carrying away the heat of the refrigerant in the condenser, causing the refrigerant in the evaporator to cool down rapidly. When the first set condition is met, the third valve is opened, allowing outside gas to enter the circulating air duct through the third valve. The outside gas passes through the evaporator, and the moisture in the outside gas causes ice to form on the evaporator surface. When the second set condition is met, the first, second, and third valves and the circulating fan are closed, while the compressor remains running. The compressor raises the temperature of the refrigerant in the evaporator, melting the ice layer on the evaporator and removing lint and debris from the evaporator surface, thus achieving rapid self-cleaning of the evaporator.

[0017] In some embodiments of this application, the evaporator is provided with a temperature sensor, which is used to detect the temperature of the refrigerant in the evaporator and meet a first set condition, including: the temperature of the refrigerant detected by the temperature sensor reaches below the target temperature, and the target temperature is less than or equal to zero degrees.

[0018] In the above technical solution, the decision to open the third valve is based on whether the refrigerant temperature detected by the temperature sensor has reached or fallen below the target temperature. The refrigerant temperature is easy to monitor, which simplifies the control logic of this embodiment.

[0019] In some embodiments of this application, the second set condition is satisfied, including: the duration for which the third valve remains open reaches or exceeds a target duration.

[0020] In the above technical solution, the decision to close the first valve, the second valve, the third valve, and the circulating fan is made based on whether the duration for which the third valve remains open reaches or exceeds the target duration. The duration for which the third valve remains open is easy to obtain, which can further simplify the control logic of this embodiment.

[0021] In some embodiments of this application, the circulating air duct is provided with a drain outlet, and the heat pump dryer also includes a water storage tank and a drain pump. The water storage tank is connected to the drain outlet and is used to receive water discharged through the drain outlet; the drain pump is used to pump water out of the water storage tank. The self-cleaning procedure includes: after closing the first valve, the second valve, the third valve, and the circulating fan, starting the drain pump.

[0022] In the above technical solution, the water from the melting ice and the wire debris are pumped to the water collection box by a drainage pump to keep the circulating air duct dry and clean.

[0023] In some embodiments of this application, before opening the first valve and the second valve, closing the third valve, and starting the compressor and the circulating fan, the self-cleaning procedure further includes: determining whether the heat pump dryer has ended the drying program; when the heat pump dryer ends the drying program, performing the steps of opening the first valve and the second valve, closing the third valve, and starting the compressor and the circulating fan.

[0024] In the above technical solution, the self-cleaning program is automatically activated whenever the heat pump dryer finishes the drying cycle. Since some lint will always enter the circulating air duct with the drying air flow during the drying process, the automatic activation of the self-cleaning program when the heat pump dryer finishes the drying cycle can promptly clean the lint adhering to the evaporator, ensuring the drying efficiency when the heat pump dryer is used subsequently.

[0025] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the principles of this application.

[0027] Figure 1 A schematic diagram of the structure of a heat pump dryer according to an embodiment of this application is shown.

[0028] Figure 2 It shows Figure 1 The diagram shows a partial structural composition of a heat pump dryer.

[0029] Figure 3 It shows Figure 1 The diagram shows the airflow of the heat pump dryer under the first operating condition.

[0030] Figure 4 It shows Figure 1 The diagram shows the airflow of the heat pump dryer under the second operating condition.

[0031] Figure 5 It shows Figure 1 The diagram shows the airflow of the heat pump dryer under the third operating condition.

[0032] Figure 6 It shows Figure 1 The diagram shows the airflow of the heat pump dryer under the fourth operating condition.

[0033] Figure 7 A flowchart of the self-cleaning procedure of the first embodiment of this application is shown.

[0034] Figure 8 A flowchart of the self-cleaning procedure according to the second embodiment of this application is shown.

[0035] Figure 9 A flowchart of the self-cleaning procedure according to the third embodiment of this application is shown.

[0036] Figure 10 A flowchart of the self-cleaning procedure according to the fourth embodiment of this application is shown.

[0037] The annotations in the attached figures are explained as follows:

[0038] 100. Heat pump dryer; 101. Front support shell; 102. Base; 103. Rear cover; 104. Door; 20. Drying drum; 31. Bottom air duct; 32. Rear air duct; 33. Front air duct; 34. Drain outlet; 35. Water storage tank; 41. Circulating fan; 42. Compressor; 43. Condenser; 44. Evaporator; 51. Drain pump; 52. Water collection box; 53. Piping; 54. Tray; 61. Motor; 62. Belt; 71. First valve; 72. Second valve; 73. Third valve; 80. Temperature sensor; 90. Control device. Detailed Implementation

[0039] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0040] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0041] Furthermore, the terms “including” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0042] In the description of this application, it should be understood that the terms "top", "bottom", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] The terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature specified with ordinal numbers such as "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature.

[0044] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0046] In related technologies, heat pump dryers often suffer from low ventilation and low drying efficiency after prolonged operation. This is because they incorporate filters in the circulating air duct to remove lint and debris, preventing it from adhering to the evaporator and affecting heat exchange efficiency between the evaporator and the circulating air. However, these technologies often fail to effectively remove lint from the evaporator surface because they use sprayers in the circulating air duct to spray the evaporator with condensate. The condensate in the circulating air duct is limited, and the spray flow is slow.

[0047] In view of this, this application provides a first valve, a second valve, and a third valve in the circulating air duct. The first valve is located on the side of the condenser facing away from the evaporator, the second valve is located between the condenser and the evaporator, and the third valve is located on the side of the evaporator facing away from the condenser. The evaporator, condenser, and circulating fan are arranged sequentially in the gas flow direction of the circulating air duct. By opening and closing the first, second, and third valves, the gas flow direction within the circulating air duct is changed. In conjunction with the compressor and the circulating fan, this causes ice to form on the evaporator surface or melts the ice layer on the evaporator surface, thereby achieving the cleaning of lint and avoiding problems such as low ventilation and low drying efficiency caused by the installation of filter devices.

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] For the heat pump dryer 100, for ease of understanding, the direction from which the user faces the control panel of the heat pump dryer 100 is defined as the front side, because typically, the user will stand in this direction to interact with the heat pump dryer 100, such as loading clothes and operating the control panel. Correspondingly, the direction from which the user faces away, that is, the other side of the heat pump dryer 100, is defined as the rear side.

[0050] Figure 1 A schematic diagram of the structure of a heat pump dryer according to an embodiment of this application is shown. Figure 2 It shows Figure 1 The diagram shown is a partial structural component of a heat pump dryer. Figures 3 to 6 It shows Figure 1 The diagram shows the airflow of a heat pump dryer under different operating conditions.

[0051] like Figure 1 As shown, the heat pump dryer 100 of this application embodiment includes a shell, which is a hollow shell structure with an internal accommodating space (not shown in the figure). The accommodating space of the shell may house other component structures of the heat pump dryer 100, such as the drying drum, circuit structure, and drive device. The external shape of the shell can be designed as needed, for example, it can be a hollow cuboid shape or a hollow cylinder shape, etc.

[0052] In some embodiments, the outer casing includes a front support shell 101, a base 102, and a rear cover 103. The front support shell 101 is located on the front side of the heat pump dryer 100, and the rear cover 103 is located on the rear side of the heat pump dryer 100. Both the front support shell 101 and the rear cover 103 are perpendicular to the base 102. The base 102 connects the front support shell 101 and the rear cover 103 to support them. Furthermore, the base 102 is in contact with the ground. It is understood that the base 102 may be equipped with downwardly protruding feet or other components that contact the ground, so that the base 102 as a whole has a certain gap with the ground to ensure the drying effect of the base 102. The base 102 may also be equipped with sliding casters to facilitate the movement of the heat pump dryer 100.

[0053] In some embodiments, the front side of the housing is provided with a clothing loading and unloading opening (not shown in the figure), which connects to the internal space of the housing, and the clothing to be dried can be placed into the interior of the housing through the clothing loading and unloading opening.

[0054] In some embodiments, a door 104 is provided on the front side of the housing. The door 104 is movably disposed at the clothing loading and unloading opening for opening or closing the clothing loading and unloading opening, thereby opening or closing the internal space of the housing.

[0055] In some embodiments, the door 104 and the outer shell can be connected by a hinge, and the door 104 can rotate about the axis of the hinge to open and close the door 104, thereby opening or closing the clothing access port.

[0056] The heat pump dryer 100 of this embodiment further includes a drying tub 20, which is rotatably disposed within the housing of the outer casing. The drying tub 20 has a clothing processing chamber (not shown in the figure) inside for drying clothes. The drying tub 20 may have a cylindrical structure, with its opposite ends in the axial direction connected to a front support shell 101 and a rear cover 103, respectively. Both the front support shell 101 and the rear cover 103 support the drying tub 20, ensuring its stability within the outer casing. The axial front end of the drying tub 20 has an opening (not shown in the figure) directly opposite the clothing loading / unloading opening of the outer casing, allowing communication with the opening. This opening also faces a door 104. When the door 104 is opened, clothes can be sequentially placed into the clothing processing chamber within the drying tub 20 through the clothing loading / unloading opening of the outer casing and the opening of the drying tub 20 for drying.

[0057] The heat pump dryer 100 of this embodiment further includes a circulating air duct, which is disposed in the accommodating space of the outer casing. Gas within the circulating air duct can circulate inside the heat pump dryer 100 to dry the clothes inside the drying drum 20. The circulating air duct includes a bottom air duct 31 located on the base 102, a rear air duct 32 located between the drying drum 20 and the rear cover 103, and a front air duct 33 located between the front support shell 101 and the drying drum 20. The front end of the front air duct 33 is connected to one axial end of the drying drum 20, and the rear end of the rear air duct 32 is connected to the other axial end of the drying drum 20.

[0058] In other words, after the gas is heated by the heat pump system described below, the circulating fan 41 described below draws the gas from the bottom air duct 31 into the rear air duct 32, and then enters the clothes processing chamber inside the drying drum 20 from the rear air duct 32. At this time, the gas dries the clothes inside the drying drum 20. After drying the clothes, the gas enters the bottom air duct 31 again from the front air duct 33 for heating treatment, and this process is repeated to dry the clothes. That is to say, the gas flows sequentially through the bottom air duct 31, the rear air duct 32, the drying drum 20, and the front air duct 33. The gas flowing through the front air duct 33 passes through the bottom air duct 31 again for circulation to dry the clothes.

[0059] The heat pump dryer 100 of this application embodiment further includes a heat pump system and a circulating fan 41. The circulating fan 41 is disposed in a circulating air duct and is used to drive the gas circulation in the circulating air duct.

[0060] In some embodiments, a circulating fan 41 is disposed between the first valve 71 and the condenser 43, as described below, which helps to blow the gas in the circulating duct to the outside when the first valve 71 is open.

[0061] The heat pump system includes a compressor 42, a condenser 43, a throttling device (not shown in the figure), and an evaporator 44. The compressor 42, evaporator 44, and condenser 43 are connected in sequence by pipes (not shown in the figure) to form a refrigerant circulation pipeline for refrigerant flow. The refrigerant circulation pipeline is filled with refrigerant. The evaporator 44, condenser 43, and circulating fan 41 are arranged in sequence along the gas flow direction of the circulating air duct.

[0062] When the heat pump system is running, the compressor 42 pressurizes and heats the refrigerant and sends it to the condenser 43. The high-temperature refrigerant exchanges heat with the air in the circulating air duct at the condenser 43 and is converted into low-temperature, low-pressure gas. The low-temperature, low-pressure gas is delivered to the evaporator 44 after passing through the throttling device. After entering the evaporator 44, it absorbs the heat from the high-temperature, humid gas flowing across the surface of the evaporator 44, heats up, and flows back to the compressor 42, completing the refrigerant flow cycle. Meanwhile, the air in the bottom air duct 31 enters the drying drum 20 through the rear air duct 32 under the action of the circulating fan 41. When the high-temperature gas passes through the drying drum 20, it comes into contact with the damp clothes and becomes humid and hot gas. The humid and hot gas enters the bottom air duct 31 through the front air duct 33 and is blown toward the evaporator 44. At the evaporator 44, it exchanges heat with the low-temperature refrigerant. The humid and hot gas is condensed and dehumidified to form dry air. After passing through the condenser 43, the dry air exchanges heat with the high-temperature refrigerant in the condenser 43 to form high-temperature dry air. The high-temperature dry air continues to flow and re-enters the drying drum 20 through the rear air duct 32, forming a circulation. The circulation of the gas carries away the moisture in the clothes, thus drying the clothes.

[0063] In some embodiments, since the hot and humid air is condensed and cooled in the evaporator 44 to form condensate, the circulating air duct is also provided with a drain outlet 34, which is connected to a water storage tank 35 to collect the water discharged through the drain outlet 34. Simultaneously, a drain pump 51 is provided, which is installed in the water storage tank 35, to pump out the water from the water storage tank 35. Through the arrangement of the drain outlet 34, the water storage tank 35, and the drain pump 51, water in the circulating air duct can be discharged.

[0064] In some embodiments, a water collection box 52 is further provided, which is detachably disposed in the housing. The water collection box 52 is connected to the drain pump 51 via a pipe 53 to collect the water pumped by the drain pump 51. By collecting the water pumped by the drain pump 51 through the water collection box 52, there is no need to provide a drain outlet on the housing of the heat pump dryer 100, allowing the heat pump dryer 100 to still be placed in locations without pre-reserved drainage channels. The detachable nature of the water collection box 52 allows the user to easily empty the water in the water collection box 52 at any time.

[0065] exist Figure 1 In the embodiment shown, a tray 54 is provided in the outer casing, and a water collection box 52 is detachably disposed in the tray 54.

[0066] The heat pump dryer 100 of this application embodiment also includes a drive device, which may include a motor 61, a drive wheel (not shown in the figure), and a belt 62. Exemplarily, the belt 62 is tightly wound around the output end of the motor 61 and the drive wheel. The drive wheel is connected to the drying tub 20, so that the motor 61 is indirectly connected to the drying tub 20. The rotation of the motor 61 causes the drive wheel to drive the drying tub 20 to rotate, thereby drying the clothes in the drying tub 20.

[0067] In this application, the casing, dryer tub 20, heat pump system, and drive device can all be configured with reference to the prior art, and will not be described in detail here.

[0068] The heat pump dryer 100 of this application embodiment also includes a first valve 71, a second valve 72 and a third valve 73. The first valve 71, the second valve 72 and the third valve 73 are disposed on the circulating air duct and are used to control the entry and exit of external air into and out of the circulating air duct.

[0069] The first valve 71 is located on the side of the condenser 43 facing away from the evaporator 44, that is, on the rear side of the condenser 43. The second valve 72 is located between the condenser 43 and the evaporator 44. The third valve 73 is located on the side of the evaporator 44 facing away from the condenser 43, that is, on the front side of the evaporator 44.

[0070] In some embodiments, the circulating fan 41 is disposed between the first valve 71 and the condenser 43, and the first valve 71 is disposed between the circulating fan 41 and the dryer tub 20.

[0071] With the circulating fan 41 on, when the first valve 71 is open, the gas in the circulating duct flows to the outside; when the first valve 71 is closed, the gas in the circulating duct flows to the drying drum 20. When the second valve 72 is open, outside gas can enter the circulating duct through the second valve 72. When the third valve 73 is open, outside gas can enter the circulating duct through the third valve 73. Therefore, by opening and closing the first valve 71, the second valve 72, and the third valve 73, the flow direction of the gas in the circulating duct can be controlled. This allows the opening and closing of the circulating fan 41, the compressor 42, and the first, second, and third valves 71 and 72 to melt or freeze the surface of the evaporator 44, thereby cleaning the lint adhering to the surface of the evaporator 44.

[0072] In detail, when the circulating fan 41 is on, and the first valve 71 and the second valve 72 are open while the third valve 73 is closed, outside air enters the circulating air duct through the second valve 72 and flows to the outside through the first valve 71, such as... Figure 3As shown. When the circulating fan 41 is on, and the first valve 71 and the third valve 73 are open while the second valve 72 is closed, outside air enters the circulating air duct through the third valve 73 and flows to the outside through the first valve 71, as shown. Figure 4 As shown. When the circulating fan 41 is on, and the first valve 71, the second valve 72, and the third valve 73 are all open, outside air enters the circulating air duct through the second valve 72 and the third valve 73, and flows to the outside through the first valve 71, as shown. Figure 5 As shown. When the first valve 71, the second valve 72, and the third valve 73 are all closed, the gas circulates within the circulating air duct and the drying drum 20, as... Figure 6 As shown.

[0073] The heat pump dryer 100 of this application embodiment also includes a temperature sensor 80 for detecting temperature. The temperature sensor 80 may be disposed inside the evaporator 44 on a pipe for supplying refrigerant flow, and is used to detect the temperature of the refrigerant in the evaporator 44. Alternatively, the temperature sensor 80 may be disposed on the surface of the evaporator 44, and is used to detect the temperature of the surface of the evaporator 44.

[0074] The heat pump dryer 100 of this embodiment may further include a control device 90. The control device 90 is electrically connected to a motor 61 and can send control signals to the motor 61 to control its operation, thereby executing a drying program, or to stop the motor 61. The control device 90 is electrically connected to a first valve 71, a second valve 72, and a third valve 73, and is used to control the opening and closing of these valves. The control device 90 is also electrically connected to a temperature sensor 80, and can receive temperature signals input from the temperature sensor 80, and control the first valve 71, the second valve 72, and the third valve 73 based on these temperature signals. The control device 90 may also be electrically connected to other structures of the heat pump dryer 100, such as a circulating fan 41 and a compressor 42, to control their operation, thereby executing a drying program or a self-cleaning program, or to stop the circulating fan 41 and the compressor 42.

[0075] Figure 7 A flowchart of the self-cleaning procedure of the first embodiment of this application is shown.

[0076] Control device 90 is configured to perform a self-cleaning procedure, such as Figure 7 As shown, the self-cleaning procedure includes at least steps S710 to S750, which are described in detail below:

[0077] In step S710, the first valve and the second valve are opened, the third valve is closed, and the compressor and the circulating fan are started.

[0078] At this point, outside gas enters the circulating air duct through the second valve and flows to the outside through the first valve. Because the compressor is on, the condenser surface is hot and the evaporator surface is cold. The compressor performs work on the refrigerant, converting electrical energy into heat energy. Simultaneously, the circulating fan starts, drawing gas from the circulating air duct to the condenser side. Outside gas continuously flows through the condenser, carrying away heat and causing the refrigerant temperature in the condenser to drop. This, in turn, causes the refrigerant temperature in the evaporator to drop continuously, leading to a decrease in the evaporator surface temperature. Because outside gas does not pass through the evaporator, it avoids affecting the low-temperature evaporator temperature, preventing subsequent icing on the evaporator surface.

[0079] That is, by controlling the opening and closing of the first valve, the second valve, and the third valve, as well as starting the compressor and the circulating fan, the heat of the refrigerant is carried away by the outside gas until the first set condition is met, so that the temperature of the evaporator surface is reduced to below the freezing point.

[0080] Understandably, the temperature of the evaporator surface being below the freezing point can be determined directly by detecting the temperature of the evaporator surface. For example, a temperature sensor can be installed on the evaporator surface, and when the temperature detected by the sensor is below the freezing point, the first preset condition is met. Alternatively, the temperature of the evaporator surface being below the freezing point can be indirectly inferred by detecting other factors. For example, a temperature sensor can be installed on the refrigerant piping inside the evaporator, and when the temperature detected by the sensor is below the freezing point, the first preset condition is met.

[0081] In step S720, it is determined whether the first set condition is met. If yes, proceed to step S730; otherwise, continue to keep the first valve and the second valve open and the third valve closed.

[0082] When the first set condition is met, it is determined that the actual temperature of the evaporator surface has dropped below the freezing point, and the process proceeds to step S730 to allow the evaporator surface to freeze. If the first set condition is not met, it is determined that the temperature of the evaporator surface is not below the freezing point, and the first and second valves remain open while the third valve remains closed, so that the temperature of the evaporator surface continues to drop until the first set condition is met, and then the process proceeds to step S730.

[0083] In step S730, the third valve is opened while the first and second valves remain open, and the compressor and circulating fan remain on.

[0084] At this time, outside air enters the circulating air duct through the third valve and flows to the outside through the first valve. Outside air continuously flows through the evaporator and condenser, continuously carrying away the heat from the condenser, causing the temperature of the refrigerant in the condenser to drop. The surface of the evaporator remains at a low temperature. When outside air passes over the surface of the evaporator, the moisture in the outside air condenses into ice on the low-temperature surface of the evaporator.

[0085] That is, by controlling the opening and closing of the first valve, the second valve, and the third valve, and keeping the compressor and the circulating fan on, the outside gas continuously passes over the surface of the evaporator until the second set condition is met, so that an ice layer forms on the surface of the evaporator.

[0086] Understandably, the presence of ice on the evaporator surface can be indirectly determined by other factors, such as the duration the third valve remains open, which can indirectly indicate whether ice has formed on the evaporator surface or whether the ice layer has reached the target thickness.

[0087] In step S740, it is determined whether the second set condition is met. If yes, proceed to step S750; otherwise, continue to keep the first valve, the second valve, and the third valve open.

[0088] When the second set condition is met, it is determined that an ice layer has formed on the surface of the evaporator and the ice layer has reached the target thickness. Then, proceed to step S750 to melt the ice layer on the surface of the evaporator. If the second set condition is not met, it is determined that no ice layer has formed on the surface of the evaporator or the ice layer has not reached the target thickness. Then, the first valve, the second valve, and the third valve remain open to use the moisture in the outside gas to make the surface of the evaporator continue to freeze until the second set condition is met, and then proceed to step S750.

[0089] In step S750, the first valve, the second valve, the third valve, and the circulating fan are closed, while the compressor remains on.

[0090] At this point, outside air cannot enter or exit the circulating air duct, and no outside air flows over the surface of the condenser, so its heat will not be carried away. The compressor continues to work on the refrigerant, causing its temperature to rise continuously. This causes the temperature of the refrigerant in the evaporator to rise rapidly to above the freezing point and above the outer surface temperature of the ice layer on the evaporator. Therefore, the part of the ice layer close to the evaporator surface melts first, and then the ice layer separates from the evaporator. The ice layer, along with the lint, detaches from the evaporator surface, achieving self-cleaning of the evaporator.

[0091] exist Figure 7In the illustrated embodiment, during self-cleaning, the first and second valves are first opened, the third valve is closed, and the compressor and circulating fan are started. At this time, the condenser side is under high pressure, and outside gas enters the circulating air duct through the second valve and flows out through the first valve, carrying away the heat of the refrigerant in the condenser, causing the refrigerant in the evaporator to cool down rapidly. When the first set condition is met, the third valve is opened, and outside gas enters the circulating air duct through the third valve. The outside gas passes through the evaporator, and the moisture in the outside gas causes ice to form on the evaporator surface. When the second set condition is met, the first, second, and third valves and the circulating fan are closed, while the compressor remains running. The compressor raises the temperature of the refrigerant in the evaporator, melting the ice layer on the evaporator and removing lint and debris from the evaporator surface, achieving rapid self-cleaning of the evaporator. In this way, the evaporator is kept clean, thereby maintaining the heat exchange efficiency between the evaporator and the gas, ensuring the drying efficiency of the dryer.

[0092] In some embodiments, after closing the first valve, the second valve, the third valve, and the circulating fan to separate the ice layer from the evaporator and remove lint from the evaporator surface, a drain pump is also started. The drain pump draws the melted ice water and lint into a collection box, keeping the circulating air duct dry and clean.

[0093] Figure 8 A flowchart of the self-cleaning procedure according to the second embodiment of this application is shown. Figure 8 As shown, the self-cleaning procedure includes at least steps S810 to S860, which are described in detail below:

[0094] In step S810, the first valve and the second valve are opened, the third valve is closed, and the compressor and the circulating fan are started.

[0095] In step S820, it is determined whether the refrigerant temperature detected by the temperature sensor has reached below the target temperature. If so, proceed to step S830; otherwise, continue to keep the first and second valves open and the third valve closed.

[0096] The target temperature is less than or equal to zero degrees Celsius. For example, the target temperature is 0°C; or, the target temperature is -1°C.

[0097] In step S830, the third valve is opened while the first and second valves remain open, and the compressor and circulating fan remain on.

[0098] In step S840, it is determined whether the duration for which the third valve remains open has reached or exceeded the target duration. If so, proceed to step S850; otherwise, continue to keep the first, second, and third valves open.

[0099] Specifically, when the third valve remains open for a duration exceeding the target duration, an ice layer forms on the evaporator surface, and the ice layer reaches the target thickness. For example, the target duration is 8 minutes, or the target duration is 10 minutes.

[0100] In step S850, the first valve, the second valve, the third valve, and the circulating fan are closed, while the compressor remains on. Then, in step S860...

[0101] In step S860, the drainage pump is started.

[0102] Alternatively, step S860 can be entered after the first valve, second valve, third valve, and circulating fan have been kept closed for a set period of time, or step S860 can be entered immediately after the first valve, second valve, third valve, and circulating fan have been closed.

[0103] exist Figure 8 In the illustrated embodiment, the decision to open the third valve is based on whether the refrigerant temperature detected by the temperature sensor reaches below the target temperature. The refrigerant temperature is easy to monitor, which simplifies the control logic of this embodiment. The decision to close the first valve, second valve, third valve, and circulating fan is based on whether the duration for which the third valve remains open reaches or exceeds the target duration. The duration for which the third valve remains open is easy to obtain, which further simplifies the control logic of this embodiment.

[0104] In some embodiments, it is determined whether the heat pump dryer has ended the drying program. When the heat pump dryer ends the drying program, the steps of opening the first valve and the second valve, closing the third valve, and starting the compressor and the circulating fan are performed.

[0105] In other words, the self-cleaning program automatically starts whenever the heat pump dryer finishes its drying cycle. Since some lint will inevitably enter the circulating air duct with the drying airflow during the drying process, the automatic self-cleaning program can promptly clean the lint adhering to the evaporator, ensuring the drying efficiency of the heat pump dryer in subsequent uses.

[0106] Of course, in some embodiments, the self-cleaning program can also be started based on the received control command. For example, when a control command is received instructing the start of the self-cleaning program, the steps of opening the first valve and the second valve, closing the third valve, starting the compressor and the circulating fan, and subsequent steps are executed.

[0107] Figure 9 A flowchart of the self-cleaning procedure according to the third embodiment of this application is shown, as follows: Figure 9 As shown, the self-cleaning procedure includes at least steps S910 to S950, which are described in detail below:

[0108] In step S910, the first valve and the second valve are opened, the third valve is closed, and the compressor and the circulating fan are started.

[0109] In step S920, it is determined whether the first set condition is met. If yes, proceed to step S930; otherwise, continue to keep the first and second valves open and the third valve closed.

[0110] In step S930, the third valve is opened, the second valve is closed, and the first valve remains open, keeping the compressor and the circulating fan running.

[0111] In step S940, it is determined whether the second set condition is met. If yes, proceed to step S950; otherwise, continue to keep the first valve, the second valve, and the third valve open.

[0112] In step S950, the first valve, the second valve, the third valve, and the circulating fan are closed, while the compressor remains on.

[0113] exist Figure 9 In the illustrated embodiment, during self-cleaning, the first and second valves are first opened, the third valve is closed, and the compressor and circulating fan are started. At this time, the condenser side is under high pressure, and outside gas enters the circulating air duct through the second valve and flows out through the first valve, carrying away the heat of the refrigerant in the condenser, causing the refrigerant in the evaporator to cool down rapidly. When the first set condition is met, the third valve is opened and the second valve is closed, allowing outside gas to enter the circulating air duct through the third valve. The outside gas passes through the evaporator, and the moisture in the outside gas causes ice to form on the evaporator surface. When the second set condition is met, the first, second, and third valves and the circulating fan are closed, while the compressor remains running. The compressor raises the temperature of the refrigerant in the evaporator, melting the ice layer and removing lint from the evaporator surface, thus achieving rapid self-cleaning of the evaporator. In this way, the evaporator is kept clean, thereby maintaining the heat exchange efficiency between the evaporator and the gas, ensuring the drying efficiency of the dryer.

[0114] Figure 10 A flowchart of the self-cleaning procedure according to the fourth embodiment of this application is shown. Figure 10 As shown, the self-cleaning procedure includes at least steps S1010 to S1060, which are described in detail below:

[0115] In step S1010, open the first valve and the second valve, close the third valve, and start the compressor and the circulating fan.

[0116] In step S1020, it is determined whether the refrigerant temperature detected by the temperature sensor has reached below the target temperature. If so, proceed to step S1030; otherwise, continue to keep the first and second valves open and the third valve closed.

[0117] The target temperature is less than or equal to zero degrees Celsius. For example, the target temperature is 0°C; or, the target temperature is -1°C.

[0118] In step S1030, the third valve is opened, the second valve is closed, and the first valve remains open, while the compressor and the circulating fan remain on.

[0119] In step S1040, it is determined whether the duration for which the third valve remains open has reached or exceeded the target duration. If so, proceed to step S1050; otherwise, continue to keep the first, second, and third valves open.

[0120] Specifically, when the third valve remains open for a duration exceeding the target duration, an ice layer forms on the evaporator surface, and the ice layer reaches the target thickness. For example, the target duration is 8 minutes, or the target duration is 10 minutes.

[0121] In step S1050, the first valve, the second valve, the third valve, and the circulating fan are closed, while the compressor remains on.

[0122] In step S1060, the drainage pump is started.

[0123] The process can proceed to step S1060 after the first valve, second valve, third valve, and circulating fan have been kept closed for a set period of time, or it can proceed to step S1060 immediately after the first valve, second valve, third valve, and circulating fan have been closed.

[0124] exist Figure 10 In the illustrated embodiment, the decision to open the third valve is based on whether the refrigerant temperature detected by the temperature sensor reaches below the target temperature. The refrigerant temperature is easy to monitor, which simplifies the control logic of this embodiment. The decision to close the first valve, second valve, third valve, and circulating fan is based on whether the duration for which the third valve remains open reaches or exceeds the target duration. The duration for which the third valve remains open is easy to obtain, which further simplifies the control logic of this embodiment.

[0125] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of this application is limited only by the appended claims.

Claims

1. A heat pump clothes dryer, characterized in that, The heat pump dryer includes: The outer shell has an internal storage space. The clothes dryer is rotatably disposed within the accommodating space; A circulating air duct is provided in the accommodating space, and the two ends of the circulating air duct are respectively connected to the two axial ends of the drying tub; A heat pump system includes a compressor, a condenser, and an evaporator. The compressor, the evaporator, and the condenser are connected in sequence by pipes for refrigerant to flow through. The evaporator and the condenser are located in the circulating air duct. A circulating fan is installed in the circulating air duct, and the evaporator, the condenser, and the circulating fan are arranged in sequence along the gas flow direction of the circulating air duct; Multiple valves are installed on the circulating air duct to control the entry and exit of external gas into and out of the circulating air duct. The multiple valves include a first valve, a second valve, and a third valve. The first valve is installed on the side of the condenser away from the evaporator. The second valve is installed between the condenser and the evaporator. The third valve is installed on the side of the evaporator away from the condenser. A control device, electrically connected to the first valve, the second valve, and the third valve, is used to control the opening and closing of the first valve, the second valve, and the third valve.

2. The heat pump dryer according to claim 1, characterized in that, The circulating fan is positioned between the first valve and the condenser.

3. The heat pump dryer according to claim 1 or 2, characterized in that, The circulating air duct is equipped with a drain outlet, and the heat pump dryer also includes: A water storage tank, connected to the drain outlet, is used to receive water discharged through the drain outlet; A drain pump is used to extract water from the water storage tank.

4. The heat pump dryer according to claim 3, characterized in that, The heat pump dryer includes: A water collection box is detachably installed in the housing and is connected to the drain pump via a pipeline to receive the water pumped by the drain pump.

5. The heat pump dryer according to claim 1, characterized in that, The control device is configured to perform a self-cleaning procedure, including: Open the first valve and the second valve, close the third valve, and start the compressor and the circulating fan until the first set condition is met, so that the temperature of the evaporator surface drops below the freezing point; When the first set condition is met, the third valve is opened, the first valve is kept open, the second valve is closed or the second valve is kept open, and the compressor and the circulating fan are kept on until the second set condition is met, so that an ice layer is formed on the surface of the evaporator. When the second set condition is met, the first valve, the second valve, the third valve and the circulating fan are closed, while the compressor remains on.

6. The heat pump dryer according to claim 5, characterized in that, The evaporator is equipped with a temperature sensor, which is used to detect the temperature of the refrigerant in the evaporator. Meeting the first set condition includes: the refrigerant temperature detected by the temperature sensor reaches below the target temperature, and the target temperature is less than or equal to zero degrees.

7. The heat pump dryer according to claim 5, characterized in that, The condition of satisfying the second setting includes: the duration for which the third valve remains open reaches or exceeds the target duration.

8. The heat pump dryer according to claim 5, characterized in that, The circulating air duct is provided with a drain outlet, and the heat pump dryer includes: A water storage tank, connected to the drain outlet, is used to receive water discharged through the drain outlet; A drainage pump is used to pump water out of the water storage tank; The self-cleaning procedure includes: After closing the first valve, the second valve, the third valve, and the circulating fan, start the drain pump.

9. The heat pump dryer according to claim 8, characterized in that, The heat pump dryer includes: A water collection box is detachably installed in the housing and is connected to the drain pump via a pipeline to receive the water pumped by the drain pump.

10. The heat pump dryer according to any one of claims 5 to 9, characterized in that, Before opening the first valve and the second valve, closing the third valve, and starting the compressor and the circulating fan, the self-cleaning procedure further includes: Determine whether the heat pump dryer has finished the drying program. When the heat pump dryer finishes the drying program, execute the steps of opening the first valve and the second valve, closing the third valve, and starting the compressor and the circulating fan.

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