Heat pump drying system, method and laundry treating apparatus

Abstract

The present application relates to the technical field of household appliances, and particularly provides a heat pump drying system and a clothes processing device. The drying system comprises: a drying cylinder; a circulating air duct, which is communicated with the drying cylinder and forms an air flow circulation channel; a heat pump module, which is communicated in the circulating air duct and is configured to perform dehumidification treatment on the wet hot air discharged from the drying cylinder; a first heat exchanger, which is arranged on the drying cylinder or between the drying cylinder and the heat pump module and is configured to perform primary heat exchange on the wet hot air before dehumidification; a second heat exchanger, which is arranged in the circulating air duct and located between the first heat exchanger and the heat pump module and is configured to perform secondary heat exchange on the wet hot air after the primary heat exchange; and a cooling medium pipeline, which is connected with the first heat exchanger and the second heat exchanger and is configured to supply cooling medium to the first heat exchanger and the second heat exchanger. The present application reduces the system heat load from the source and the circulation path through double pre-cooling and dehumidification, avoids the compressor frequency reduction, shortens the drying cycle and reduces the energy consumption.

Description

Technical Field

[0001] This invention relates to the field of household appliance technology, and more specifically, to a heat pump drying system, method, and clothing treatment equipment. Background Technology

[0002] Currently, heat pump drying technology, with its advantages of energy saving, high efficiency, and minimal damage to clothing, has been widely used in various clothing processing equipment. However, during the operation of existing heat pump drying systems, especially in the later stages of drying, the evaporator's cooling capacity often decreases significantly as the system's heat load continues to rise. To maintain system balance, the compressor is usually forced to operate at a reduced frequency, resulting in a substantial decrease in dehumidification efficiency and consequently, an excessively long drying cycle.

[0003] Although existing technologies include solutions such as setting up a pre-cooling device before the evaporator or introducing fresh air to assist in cooling, pre-cooling at a single location cannot effectively handle the large amount of humid and hot air remaining inside the drum, and the overall dehumidification capacity is still insufficient in the mid-to-late stages; while frequently introducing fresh air can reduce the heat load, it will take away a large amount of heat from the system, leading to increased energy consumption.

[0004] Therefore, there is an urgent need for a heat pump drying system that can effectively reduce the heat load in the later stages of the system and maintain efficient dehumidification without significantly increasing energy consumption. Summary of the Invention

[0005] To address the problems of excessive heat load in the later stages of existing heat pump drying systems, which leads to compressor frequency reduction, low drying efficiency, and high energy consumption, this application provides a heat pump drying system, control method, and clothing processing equipment. Through a dual pre-cooling structure and precise adjustment of the cooling medium flow rate, the system heat load can be significantly reduced, maintaining the compressor's efficient operation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A heat pump drying system includes: a drying drum configured to hold clothes to be dried; a circulating air duct connected to the drying drum and forming an airflow circulation channel; a heat pump module disposed within the circulating air duct and configured to dehumidify the humid air discharged from the drying drum; a first heat exchanger connected to the drying drum or between the drying drum and the heat pump module and configured to perform a primary heat exchange on the humid air before dehumidification; a second heat exchanger disposed within the circulating air duct and located between the first heat exchanger and the heat pump module and configured to perform a secondary heat exchange on the humid air after the primary heat exchange; and a cooling medium pipeline connected to the first heat exchanger and the second heat exchanger and configured to supply a cooling medium to the first heat exchanger and the second heat exchanger.

[0007] Furthermore, the drying cylinder includes an inner cylinder and an outer cylinder; the first heat exchanger is disposed between the inner cylinder and the outer cylinder for contact heat exchange with the humid and hot air discharged from the inner cylinder.

[0008] Furthermore, the first heat exchanger includes a condenser plate, which is integrally formed with the inner wall of the outer cylinder; a water inlet is provided on the outer wall of the outer cylinder, and condensate flows from the water inlet through the condenser plate.

[0009] Furthermore, the heat pump module includes an evaporator, and the second heat exchanger is disposed on the air inlet side of the evaporator, and the two are integrated into one unit.

[0010] Furthermore, the cooling medium pipeline includes a main pipeline, a first branch pipeline, and a second branch pipeline; a flow regulating valve and an on / off valve are provided on the main pipeline, the flow regulating valve being used to adjust the flow distribution ratio of the cooling medium flowing from the main pipeline through the first branch pipeline and the second branch pipeline; the on / off valve being used to control the on / off state of the main pipeline.

[0011] Furthermore, the present invention also provides a control method for a heat pump drying system, applied to the aforementioned heat pump drying system, comprising: acquiring the temperature of the drying airflow entering the drying cylinder; determining, according to the current drying mode of the heat pump drying system, an opening temperature threshold and a closing temperature threshold for the cooling medium pipeline corresponding to the current drying mode; when the drying airflow temperature is greater than or equal to the opening temperature threshold, opening the cooling medium pipeline to supply cooling medium to the first heat exchanger and the second heat exchanger; and after the cooling medium pipeline is opened, closing the cooling medium pipeline when the drying airflow temperature is less than or equal to the closing temperature threshold.

[0012] Further, the drying mode includes a first drying mode, a second drying mode, and a third drying mode; in the first drying mode, the range of the opening temperature threshold is 63°C to 75°C, and the range of the closing temperature threshold is 60°C to 70°C; in the second drying mode, the range of the opening temperature threshold is 58°C to 70°C, and the range of the closing temperature threshold is 55°C to 65°C; in the third drying mode, the range of the opening temperature threshold is 30°C to 40°C, and the range of the closing temperature threshold is 28°C to 38°C; wherein, the opening temperature threshold is lower than the closing temperature threshold.

[0013] Furthermore, the control method further includes: obtaining the load category of the clothes to be dried, and adjusting the opening temperature threshold and the closing temperature threshold according to the load category; if the load category is cotton fabric, lowering the opening temperature threshold and the closing temperature threshold by a first preset compensation value; if the load category is chemical fiber fabric, raising the opening temperature threshold and the closing temperature threshold by a second preset compensation value.

[0014] Furthermore, the control method further includes: while adjusting the opening temperature threshold and the closing temperature threshold according to the load category based on the reference compensation, determining the initial flow distribution ratio of the flow regulating valve according to the load category; when the load category is cotton fabric, controlling the flow regulating valve to increase the cooling medium flow distribution ratio of the first branch and decrease the cooling medium flow distribution ratio of the second branch; when the load category is chemical fiber fabric, controlling the flow regulating valve to decrease the cooling medium flow distribution ratio of the first branch and increase the cooling medium flow distribution ratio of the second branch.

[0015] Furthermore, the control method also includes: acquiring the ambient temperature; when the ambient temperature is lower than a preset ambient temperature threshold, controlling the cooling medium pipeline to enter an intermittent on-off mode, the intermittent on-off mode including alternating on and off states.

[0016] Furthermore, in the intermittent start-stop mode, the control method further includes: adjusting the flow distribution ratio of the flow regulating valve according to the difference between the ambient temperature and the preset ambient temperature threshold; the greater the difference between the ambient temperature and the preset ambient temperature threshold, the more the flow regulating valve is controlled to reduce the cooling medium distribution ratio of the first branch and increase the cooling medium distribution ratio of the second branch.

[0017] Furthermore, the control method further includes: acquiring the casing temperature of the compressor in the heat pump drying system; calculating the temperature difference between the compressor casing temperature and the ambient temperature; adjusting the duty cycle of the on state in the intermittent on-off mode according to the preset difference range of the temperature difference; wherein the duty cycle refers to the ratio of the duration of the on state to the sum of the durations of the on state and the off state in the intermittent on-off mode.

[0018] Furthermore, the control method further includes: adjusting the duty cycle according to the temperature difference while adjusting the flow regulating valve to adjust the cooling medium flow distribution ratio between the first branch and the second branch; when the temperature difference is greater than a first preset difference threshold, increasing the duty cycle of the open state and / or adjusting the flow distribution ratio to a first ratio range; when the temperature difference is less than a second preset difference threshold, decreasing the duty cycle of the open state and / or adjusting the flow distribution ratio to a second ratio range; wherein, in the first ratio range, the proportion of cooling medium flowing to the first branch is greater than the proportion of cooling medium flowing to the second branch; and in the second ratio range, the proportion of cooling medium flowing to the second branch is greater than the proportion of cooling medium flowing to the first branch.

[0019] Furthermore, when the temperature difference is greater than the first preset difference threshold, the duty cycle is 55%~70%, and the cooling medium flow distribution ratio between the first branch and the second branch is 55%~65%:35%~45%; when the temperature difference is between the first preset difference threshold and the second preset difference threshold, the duty cycle is 40%~55%, and the cooling medium flow distribution ratio between the first branch and the second branch is 45%~55%:45%~55%; when the temperature difference is less than the second preset difference threshold, the duty cycle is 25%~40%, and the cooling medium flow distribution ratio between the first branch and the second branch is 35%~45%:55%~65%.

[0020] In addition, the present invention also provides a garment processing device, including the above-described heat pump drying system, or employing the above-described control method.

[0021] Beneficial effects: The heat pump drying system provided in this application establishes a first heat exchanger inside the drying drum or upstream of the heat pump module, and a second heat exchanger upstream of the heat pump module in the circulating air duct. Cooling medium is supplied in parallel via parallel cooling medium pipelines, forming a dual pre-cooling and dehumidification process at both the source and the path. The first heat exchanger performs heat exchange at the source of the humid air, pre-extracting moisture and reducing the air's heat content. The second heat exchanger performs secondary pre-cooling of the circulating air upstream of the heat pump module, further reducing the temperature and moisture content of the air entering the heat pump module.

[0022] Meanwhile, the control method of this application, by setting multiple drying modes and temperature thresholds, can precisely control the opening and closing of the cooling medium pipeline according to the temperature of the drying airflow. Furthermore, a temperature compensation mechanism based on load type (such as cotton or synthetic fibers) is introduced, making the control strategy more closely aligned with the actual drying characteristics of the clothing. Further, when the ambient temperature is low, the system maintains stable operation while avoiding excessive heat consumption through intermittent on / off mode and adaptive proportional adjustment of the flow regulating valve. By introducing the difference between the compressor casing temperature and the ambient temperature for linkage adjustment of duty cycle and flow distribution, the system's adaptability under different operating conditions is further enhanced. This application, through the coordinated use of multiple methods, effectively reduces the heat load of the heat pump module, avoids forced frequency reduction of the compressor in the later stages of drying, maintains efficient system operation, and thus significantly shortens the drying cycle and reduces energy consumption. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the heat pump drying system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the connection structure of the cooling medium pipeline in an embodiment of the present invention; Figure 3 This is a schematic diagram of the installation position structure of the first heat exchanger in an embodiment of the present invention; Figure 4 This is a schematic diagram of the installation position structure of the second heat exchanger according to an embodiment of the present invention; Figure 5 This is the control flowchart in Embodiment 4 of the present invention; Figure 6 This is the control flowchart in Embodiment 5 of the present invention.

[0025] The annotations in the attached figures are explained as follows: 1. Drying drum; 11. Inner drum; 12. Outer drum; 121. Water inlet; 2. Heat pump module; 21. Evaporator; 22. Condenser; 3. Circulating air duct; 31. Drying fan; 4. First heat exchanger; 5. Second heat exchanger; 6. Cooling medium pipeline; 61. Main pipeline; 62. First branch pipeline; 63. Second branch pipeline; 64. Flow regulating valve; 65. On / off valve. Detailed Implementation

[0026] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0027] It should be noted that, as shown in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list; the method or apparatus may also include other steps or elements.

[0028] If the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0031] The heat pump drying system, method, and clothing treatment equipment of this application will be described in detail below through the following embodiments.

[0032] Example 1

[0033] like Figure 1 As shown, this embodiment provides a heat pump drying system, including a drying cylinder 1, a heat pump module 2 (the heat pump module includes an evaporator 21), a circulating air duct 3, a first heat exchanger 4, a second heat exchanger 5, and a cooling medium pipeline 6.

[0034] The drying drum 1 is used to hold clothes to be dried. During the drying process, the clothes continuously release hot and humid air. In this embodiment, the drying drum 1 includes a rotatable inner drum 11 and a fixed outer drum 12. The inner drum 11 is used to carry the clothes and rotates under the drive of a motor, so that the clothes tumble continuously inside the drum for uniform heating. The outer drum forms a sealed chamber space to prevent hot and humid air from leaking out of the machine. The evaporator 21 is the dehumidification component in the heat pump module 2. It absorbs heat through refrigerant evaporation, causing water vapor in the air to condense and precipitate. The circulating air duct 3 connects the drying drum 1 and the heat pump module 2, guiding the hot and humid air to circulate between the two, forming a closed or semi-closed airflow circulation channel.

[0035] This embodiment sets up two heat exchange points in the system. The first heat exchanger 4 can perform a heat exchange with the humid and hot air inside the drum. After the high-temperature and low-humidity air enters the inner drum 11 of the drying drum 1 and acts on the damp clothes, some of the moisture on the clothes is carried away, and the high-temperature and low-humidity air becomes high-temperature and high-humidity air. Then, before entering the air outlet of the outer drum 12 (before entering the circulating air duct), the high-temperature and high-humidity airflow is pre-cooled and cooled by the first heat exchanger 4, which pre-extracts some moisture and reduces the heat of the air, thereby reducing the heat load entering the air circulation system from the source.

[0036] The second heat exchanger 5 is located within the circulating air duct 3, between the first heat exchanger 4 and the heat pump module 2. Specifically, along the airflow direction, the hot, humid air first passes through the first heat exchanger 4, then the second heat exchanger 5, and finally reaches the heat pump module 2. The air, pre-treated by the first heat exchanger 4, undergoes a second heat exchange through the second heat exchanger 5 before entering the evaporator 21, further reducing its temperature and moisture content. The structure of the second heat exchanger 5 is not limited; it can be a tubular, plate, or finned type, or any structure capable of achieving gas-liquid or gas-gas heat exchange.

[0037] The cooling medium pipeline 6 connects the first heat exchanger 4 and the second heat exchanger 5 in parallel, simultaneously delivering an external cooling medium source (such as tap water) to both heat exchangers. Compared to a series connection, the parallel design avoids the problem of reduced cooling efficiency of the downstream heat exchanger due to temperature rise in the front-end heat exchanger, ensuring that both pre-cooling nodes can operate with a high heat exchange temperature difference.

[0038] It should be noted that the heat pump drying system in this embodiment also includes conventional components of the heat pump cycle, such as a variable frequency compressor, condenser 22, and throttling device. The connection relationships and working principles of these components are well-known in the art and will not be described in detail here. The variable frequency compressor has a rated power of 1200W and a maximum frequency of 120Hz, enabling it to maintain high-frequency operation in the later stages of drying. The condenser 22 and evaporator 21 form the two components of the heat pump cycle, achieving heat transfer through a refrigerant compression-condensation-throttling-evaporation cycle. The throttling device can be an electronic expansion valve or a capillary tube to control the refrigerant flow rate. The improvement in this embodiment focuses on the aforementioned two-stage precooling structure and its parallel cooling medium supply method, rather than the heat pump cycle itself.

[0039] In addition, a drying fan 31 is installed in the circulating air duct 3 to drive the airflow to circulate within the system. The drying fan 31 is located downstream of the heat pump module 2, meaning that along the airflow direction, the air passes sequentially through the evaporator 21 for dehumidification and the condenser 22 for heating. The drying fan 31 then pressurizes the air, blowing the high-temperature, low-humidity airflow towards the drying drum, allowing the dry, hot air to re-enter the drum and exchange heat and mass with the clothes, forming a complete airflow circulation loop. In this embodiment, the drying fan 31 can be a DC fan, and its speed can be adjusted according to different drying stages. For example, it can rotate at a higher speed in the early and middle stages of drying to achieve rapid airflow circulation, while the speed can be appropriately reduced in the later stages of drying to reduce energy consumption. Of course, the specific installation location of the drying fan is not limited to the above example and can also be located in other positions within the circulating air duct 3, as long as it can drive the airflow to circulate within the system.

[0040] Example 2

[0041] This embodiment is a further optimization based on Embodiment 1.

[0042] In this embodiment, as Figure 1 As shown, the first heat exchanger 4 is disposed between the inner cylinder 11 and the outer cylinder 12 of the drying cylinder 1 or on the outer wall of the outer cylinder 12, for contact heat exchange with the humid and hot air discharged from the inner cylinder 11 of the drying cylinder 1. As a preferred embodiment, the first heat exchanger 4 is disposed on the rear wall or side wall inside the outer cylinder 12, which can more effectively exchange heat with the humid and hot air discharged from the inner cylinder 11.

[0043] As one implementation method, such as Figure 1 and Figure 3As shown, the first heat exchanger 4 includes a condenser plate, which is integrally formed with the inner wall of the outer cylinder 12. A water inlet 121 is provided on the outer wall of the outer cylinder 12, through which condensate flows. The surface of the condenser plate is provided with guide grooves, configured to guide the cooling medium to form a water film. When the cooling medium is injected into the condenser plate, the guide grooves utilize gravity and surface tension to evenly disperse the water flow and extend it into a continuous water film covering the plate surface, increasing the effective specific surface area for gas-liquid contact and improving the heat exchange effect.

[0044] As one implementation method, such as Figure 1 and Figure 4 As shown, the second heat exchanger 5 is located on the air inlet side of the evaporator 21, and the two are integrated into one unit. That is, the two are structurally integrated into a single module. This integrated design simplifies the assembly process of the whole machine, reduces the number of parts, and avoids the air leakage gaps and vortex dead zones that may occur with separate installation, thereby reducing the system's air resistance.

[0045] In a preferred embodiment, the second heat exchanger and the evaporator share the same water collection tray. The condensate from the precooling process and the condensate from the evaporator dehumidification process are collected in the same water collection tray and discharged through a unified drain pipe, simplifying the overall water circuit design. Of course, the two can also be installed separately, as long as the order of airflow is maintained.

[0046] Through the above structure, the first heat exchanger 4 cools the humid air in the source cooling cylinder, and the second heat exchanger 5 pre-cools the airflow a second time along the path. This two-stage pre-cooling effectively reduces the peak heat load of the evaporator 21, preventing the compressor from being forced to reduce its frequency due to overheat protection in the later stages of drying. This maintains efficient system operation, shortens the drying cycle, and reduces overall energy consumption. Simultaneously, with the system's heat load effectively controlled, the reliance on the fresh air system in the later stages of drying is reduced, minimizing heat loss caused by frequent fresh air introduction.

[0047] Example 3

[0048] This embodiment is a further optimization based on Embodiment 1 or Embodiment 2.

[0049] In this embodiment, as Figure 2 As shown, the cooling medium pipeline 6 includes a main pipeline 61, a first branch pipeline 62, and a second branch pipeline 63. A flow regulating valve 34 and an on / off valve 65 are installed on the main pipeline 61. The flow regulating valve 64 is used to adjust the flow distribution ratio of the cooling medium flowing from the main pipeline 61 through the first branch pipeline 62 and the second branch pipeline 63; the on / off valve 65 is used to control the opening and closing of the main pipeline 61. Through the cooperation of the flow regulating valve 64 and the on / off valve 65, the system can achieve precise control of the cooling medium path.

[0050] Example 4

[0051] This embodiment provides a control method for a heat pump drying system, which is applied to the heat pump drying system in any of the above embodiments.

[0052] like Figure 5 As shown, in this embodiment, the control method first acquires the temperature of the drying airflow entering the drying cylinder. Specifically, the temperature of the drying airflow is acquired in real time by an air inlet temperature sensor installed in the air inlet duct. Then, based on the current drying mode of the heat pump drying system, the opening and closing temperature thresholds of the cooling medium pipeline corresponding to the current drying mode are determined.

[0053] Specifically, the drying modes include a first drying mode, a second drying mode, and a third drying mode.

[0054] The first drying mode is a rapid drying mode (suitable for high-temperature resistant fabrics such as cotton and linen), which has a high system heat load and requires high temperature efficiency. In this mode, the preferred range of the opening temperature threshold is 63°C to 75°C, and the preferred range of the closing temperature threshold is 60°C to 70°C.

[0055] In a preferred embodiment, under the first drying mode (rapid drying mode), the opening temperature threshold is 70°C and the closing temperature threshold is 67°C.

[0056] The second drying mode is a standard drying mode (suitable for commonly used fabrics such as synthetic fibers), and its system heat load is relatively conventional. In this mode, the preferred range for the opening temperature threshold is 58°C to 70°C, and the preferred range for the closing temperature threshold is 55°C to 65°C.

[0057] In a preferred embodiment, under the second drying mode (standard drying mode), the opening temperature threshold is 65°C and the closing temperature threshold is 60°C.

[0058] The third drying mode is a low-temperature drying mode (suitable for temperature-sensitive fabrics such as wool and silk). Its core purpose is to strictly control the temperature of the drying airflow to prevent heat damage to clothing, resulting in a low system heat load. In this mode, the preferred range for the opening temperature threshold is 30°C to 40°C, and the preferred range for the closing temperature threshold is 28°C to 38°C.

[0059] In a preferred embodiment, under the third drying mode (low temperature drying mode), the opening temperature threshold is 35°C and the closing temperature threshold is 34°C.

[0060] When the temperature of the drying airflow is greater than or equal to the aforementioned determined opening temperature threshold, the main control board controls the on / off valve on the main pipeline to open, thereby opening the cooling medium pipeline and supplying cooling medium to the first and second heat exchangers. After the cooling medium pipeline is opened, the system monitors the drying airflow temperature in real time. When the drying airflow temperature is less than or equal to the aforementioned determined closing temperature threshold, the main control board controls the on / off valve to close. Through this closed-loop control based on temperature thresholds, the timing of the cooling medium's intervention and withdrawal can be precisely controlled, ensuring effective control of the system's heat load while avoiding excessive waste of cooling medium.

[0061] In practical applications, different models and specifications of garment processing equipment have varying compressor performance and duct resistance, and tap water temperatures also differ under different regional climate conditions. Therefore, those skilled in the art can fully understand that the specific values ​​of the aforementioned on / off temperature thresholds (70℃ / 67℃, 65℃ / 60℃, 35℃ / 34℃) are the optimal reference parameters for this solution. These values ​​can be finely adjusted according to the type of equipment and operating environment. The combined application of the aforementioned range (e.g., 63℃~75℃) and the specific value (70℃) constitutes the core solution protected by this application, in order to achieve the best heat pump drying control effect.

[0062] Furthermore, this embodiment introduces a compensation adjustment mechanism based on the clothing load category. Specifically, the load category of the clothing to be dried is obtained, and the start-up and stop-down temperature thresholds corresponding to the current drying mode are adjusted based on the load category. If the load category is cotton fabric, it indicates that the clothing has a high water absorption rate and a large evaporation load, so the start-up and stop-down temperature thresholds need to be lowered by a first preset compensation value (in this embodiment, the preferred range of this compensation value is 4℃ to 6℃, and as a preferred specific implementation, 5℃ can be selected as the compensation benchmark); if the load category is synthetic fiber fabric, it indicates that the clothing has a low water absorption rate and requires less heat for drying, so in order to maintain drying efficiency and avoid wasting cold energy, the start-up and stop-down temperature thresholds need to be raised by a second preset compensation value (in this embodiment, the preferred range of this compensation value is 1℃ to 3℃, and as a preferred specific implementation, 2℃ can be selected as the compensation benchmark). This is because cotton fabrics have a large moisture absorption and require a high amount of heat during evaporation, so cooling needs to be introduced earlier; while synthetic fiber fabrics have a low moisture absorption, so the cooling can be introduced later to save energy.

[0063] While adjusting the temperature threshold compensation according to the load type, the initial flow distribution ratio of the flow regulating valve is determined based on the load type. When the load type is cotton fabric, in order to intercept a large amount of heat from the humid air at the source, the main control board controls the flow regulating valve to increase the cooling medium flow distribution ratio of the first branch 62 and decrease the cooling medium flow distribution ratio of the second branch 63. When the load type is synthetic fiber fabric, the system's heat mainly needs to be alleviated by secondary pre-cooling near the evaporator. Therefore, the main control board controls the flow regulating valve to decrease the cooling medium flow distribution ratio of the first branch 62 and increase the cooling medium flow distribution ratio of the second branch 63. This control method significantly improves the system's adaptive drying capability for different fabric materials.

[0064] To address the significant differences in moisture absorption and system heat load between cotton and synthetic fabrics, different temperature compensation values ​​were set for each. This approach allows the timing of the cooling medium's intervention to match the load characteristics: cotton fabrics have high moisture absorption and heat load, so early pre-cooling effectively suppresses the risk of compressor overload; synthetic fabrics have low moisture absorption, so delayed intervention reduces cooling waste and achieves energy-saving effects.

[0065] Furthermore, this solution achieves coordinated regulation of temperature control and water distribution. While compensating for temperature thresholds based on load type, it further adjusts the flow regulating valve to redistribute the flow ratio between the first and second branches. Since the first heat exchanger is closer to the drying drum and bears a heavier heat exchange load, when drying cotton fabrics with high moisture absorption, the cooling medium is preferentially distributed to the first branch, reducing the system's heat load more efficiently from the source; while when drying synthetic fiber fabrics, the cooling medium is appropriately biased towards the second branch. This coordinated control allows the cooling medium to be effectively distributed between the two heat exchangers according to actual needs, improving the overall utilization rate of water resources and thermal energy, and playing a positive role in extending the compressor's high-frequency operating time and shortening the overall drying cycle.

[0066] It should be noted that in the above control method, 'drying mode' and 'clothing load category' correspond to different control dimensions. The drying mode reflects the drying strategy and target temperature range set by the user; the clothing load category reflects the physical properties of the clothing to be processed.

[0067] In actual drying processes, the heat and moisture load released by clothing of different materials varies significantly under the same drying mode. For example, when the system is running in low-temperature drying mode, if the fabric being dried is a cotton towel, which carries a lot of moisture and has a high evaporation rate, the system will still generate a high heat load; if the fabric being dried is a synthetic fiber fabric, which loses moisture quickly, the heat load will be relatively small.

[0068] Therefore, this solution first determines the baseline temperature threshold for system operation through the drying mode, and then performs secondary correction and compensation based on this baseline through the clothing load category.

[0069] Example 5

[0070] This embodiment is a further optimization based on embodiment 4.

[0071] In this embodiment, when the ambient temperature is low, the system heat load is small. If the cooling medium pipeline remains continuously open, it will carry away a large amount of heat, leading to a decrease in drying efficiency. Therefore, this embodiment introduces ambient temperature detection and an intermittent on / off mode into the control method. Specifically, the ambient temperature is acquired. When the ambient temperature is lower than a preset ambient temperature threshold, the cooling medium pipeline is controlled to enter an intermittent on / off mode, which includes alternating on and off states. When the ambient temperature is equal to or higher than the preset ambient temperature threshold, the intermittent on / off mode is exited. Preferably, the duration of the on state is 8 to 15 seconds, and the duration of the off state is 8 to 15 seconds.

[0072] In intermittent start-stop mode, due to the low overall system heat load and the need to avoid overcooling, the control method also adjusts the flow distribution ratio of the flow regulating valve based on the difference between the ambient temperature and the preset ambient temperature threshold. The larger the difference between the ambient temperature and the preset ambient temperature threshold, the lower the ambient temperature. Therefore, the flow regulating valve reduces the cooling medium distribution ratio of the first branch 62 and increases the cooling medium distribution ratio of the second branch 63. This prevents the first heat exchanger from overcooling the air inside the drying cylinder in extremely low temperature environments, prioritizing the precooling effect of the second heat exchanger, thereby achieving a reasonable distribution of heat.

[0073] To achieve better adaptive adjustment, this embodiment also introduces compressor status feedback. For example... Figure 6 As shown, this specifically includes: obtaining the casing temperature of the compressor in the heat pump drying system; calculating the temperature difference between the compressor casing temperature and the ambient temperature; and adjusting the duty cycle of the on state in the intermittent on-off mode according to the preset difference range of the temperature difference (where the duty cycle refers to the ratio of the duration of the on state to the sum of the durations of the on state and the off state in the intermittent on-off mode).

[0074] Furthermore, while adjusting the duty cycle based on the temperature difference, the flow control valve is also adjusted to regulate the cooling medium flow distribution ratio between the first branch 62 and the second branch 63. Specifically: When the temperature difference is greater than the first preset difference threshold (indicating a high risk of compressor overheating), the duty cycle of the on state is increased (for example, increased to 55%~70%), and the flow distribution ratio is adjusted to the first ratio range (for example, the distribution ratio of the first branch 62 to the second branch 63 is 55%~65%: 35%~45%, that is, the first branch where the first heat exchanger is located is cooled first). When the temperature difference is between the first preset difference threshold and the second preset difference threshold, the duty cycle is maintained in the middle range (e.g., 40%~55%), and the flow distribution ratio is maintained in a balanced state (e.g., 45%~55%: 45%~55%). When the temperature difference is less than the second preset difference threshold (indicating that the compressor is in the low temperature safety range), the duty cycle of the on state is reduced (for example, reduced to 25%~40%), and the flow distribution ratio is adjusted to the second ratio range (for example, the distribution ratio of the first branch 62 to the second branch 63 is 35%~45%: 55%~65%, that is, the second branch where the second heat exchanger is located is cooled first).

[0075] By adjusting the duty cycle and flow distribution ratio based on the temperature difference between the compressor casing and the ambient temperature, the system can automatically adapt to different heat load conditions. This effectively prevents the compressor from overheating and avoids energy waste caused by excessive cooling, greatly improving the system's adaptability and drying efficiency under complex conditions.

[0076] Example 6

[0077] This embodiment provides a garment processing device, including a heat pump drying system and control method as described in any of the above embodiments. In this embodiment, the garment processing device may be a heat pump washer-dryer combo, a stand-alone heat pump dryer, or other garment care device with drying function.

[0078] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A heat pump drying system, characterized in that, include: Drying drum (1) is configured to hold clothes to be dried; The circulating air duct (3) is connected to the drying cylinder (1) and forms an airflow circulation channel; The heat pump module (2) is connected to the circulating air duct (3) and is configured to dehumidify the hot and humid air discharged from the drying cylinder (1); The first heat exchanger (4) is configured to perform a heat exchange on the humid and hot air before dehumidification. The second heat exchanger (5) is disposed within the circulating air duct (3) and located between the first heat exchanger (4) and the heat pump module (2), and is configured to perform a secondary heat exchange on the humid and hot air after the first heat exchange; and A cooling medium pipeline (6) is connected to the first heat exchanger (4) and the second heat exchanger (5) and is configured to supply cooling medium to the first heat exchanger (4) and the second heat exchanger (5).

2. The heat pump drying system according to claim 1, characterized in that, The drying cylinder includes an inner cylinder (11) and an outer cylinder (12). The first heat exchanger (4) is disposed between the inner cylinder (11) and the outer cylinder (12) for contact heat exchange of the humid and hot air discharged from the inner cylinder (11); The first heat exchanger (4) includes a condenser plate; an inlet (121) is provided on the outer wall of the outer cylinder (12), and condensate flows from the inlet (121) through the condenser plate.

3. The heat pump drying system according to claim 1, characterized in that, The cooling medium pipeline (6) includes a main pipeline (61), a first branch pipeline (62), and a second branch pipeline (63); The main pipeline (61) is provided with a flow regulating valve (64) and an on / off valve (65). The flow regulating valve (64) is used to regulate the flow distribution ratio of the cooling medium flowing from the main pipeline through the first branch (62) and the second branch (63). The on / off valve (65) is used to control the on / off of the main pipeline.

4. A control method for a heat pump drying system, applied to the heat pump drying system as described in claim 3, characterized in that, The control method includes: Obtain the temperature of the drying airflow entering the drying cylinder; Based on the current drying mode of the heat pump drying system, determine the opening temperature threshold and closing temperature threshold of the cooling medium pipeline corresponding to the current drying mode; When the temperature of the drying airflow is greater than or equal to the opening temperature threshold, the cooling medium pipeline is opened to supply cooling medium to the first heat exchanger and the second heat exchanger. After the cooling medium pipeline is opened, the cooling medium pipeline is closed when the temperature of the drying airflow is less than or equal to the closing temperature threshold.

5. The control method according to claim 4, characterized in that, The drying modes include a first drying mode, a second drying mode, and a third drying mode; In the first drying mode, the range of the opening temperature threshold is 63°C to 75°C, and the range of the closing temperature threshold is 60°C to 70°C. In the second drying mode, the range of the opening temperature threshold is 58°C to 70°C, and the range of the closing temperature threshold is 55°C to 65°C. In the third drying mode, the range of the opening temperature threshold is 30°C to 40°C, and the range of the closing temperature threshold is 28°C to 38°C. Wherein, the opening temperature threshold is lower than the closing temperature threshold.

6. The control method according to claim 5, characterized in that, Also includes: Obtain the load category of the clothes to be dried, and adjust the opening temperature threshold and the closing temperature threshold according to the load category; If the load type is cotton fabric, the opening temperature threshold and the closing temperature threshold are respectively lowered by the first preset compensation value; If the load type is chemical fiber fabric, the opening temperature threshold and the closing temperature threshold are respectively increased by the second preset compensation value.

7. The control method according to claim 6, characterized in that, Also includes: While adjusting the opening temperature threshold and the closing temperature threshold according to the load category, the initial flow split ratio of the flow regulating valve is determined according to the load category; When the load type is cotton fabric, the flow regulating valve is controlled to increase the cooling medium flow distribution ratio of the first branch and decrease the cooling medium flow distribution ratio of the second branch. When the load type is chemical fiber fabric, the flow regulating valve is controlled to reduce the cooling medium flow distribution ratio of the first branch and increase the cooling medium flow distribution ratio of the second branch.

8. The control method according to claim 4, characterized in that, Also includes: Obtain the ambient temperature; When the ambient temperature is lower than a preset ambient temperature threshold, the cooling medium pipeline is controlled to enter an intermittent start-stop mode, which includes alternating on and off states. When the ambient temperature is equal to or higher than the preset ambient temperature threshold, the intermittent on / off mode is exited.

9. The control method according to claim 8, characterized in that, The method for controlling the cooling medium pipeline in the intermittent start-stop mode further includes: The flow distribution ratio of the flow regulating valve is adjusted according to the difference between the decrease of the ambient temperature and the preset ambient temperature threshold. The greater the difference between the ambient temperature and the preset ambient temperature threshold, the more the flow regulating valve is controlled to reduce the cooling medium distribution ratio of the first branch and increase the cooling medium distribution ratio of the second branch.

10. The control method according to claim 8, characterized in that, Also includes: Obtain the casing temperature of the compressor in the heat pump drying system; Calculate the temperature difference between the compressor casing temperature and the ambient temperature; Based on the preset difference range of the temperature difference, adjust the duty cycle of the on / off state in the intermittent on / off mode; The duty cycle refers to the ratio of the duration of the on state to the sum of the durations of the on state and the off state in the intermittent on / off mode.

11. The control method according to claim 10, characterized in that, Also includes: While adjusting the duty cycle according to the temperature difference, the flow regulating valve is also adjusted to adjust the cooling medium flow distribution ratio between the first branch and the second branch. When the temperature difference is greater than the first preset difference threshold, the duty cycle of the on state is increased, and / or the flow distribution ratio is adjusted to the first ratio range. When the temperature difference is less than the second preset difference threshold, reduce the duty cycle of the on state and / or adjust the flow distribution ratio to the second ratio range. In the first proportion range, the proportion of cooling medium flowing to the first branch is greater than the proportion of cooling medium flowing to the second branch. In the second ratio range, the proportion of cooling medium flowing to the second branch is greater than the proportion of cooling medium flowing to the first branch.

12. The control method according to claim 11, characterized in that, When the temperature difference is greater than the first preset difference threshold, the duty cycle is 55%~70%, and the cooling medium flow distribution ratio between the first branch and the second branch is 55%~65%:35%~45%. When the temperature difference is between the first preset difference threshold and the second preset difference threshold, the duty cycle is 40%~55%, and the cooling medium flow distribution ratio between the first branch and the second branch is 45%~55%:45%~55%. When the temperature difference is less than the second preset difference threshold, the duty cycle is 25%~40%, and the cooling medium flow distribution ratio between the first branch and the second branch is 35%~45%:55%~65%.

13. A garment processing device, characterized in that, It includes a heat pump drying system as described in any one of claims 1 to 3, or employs a control method as described in any one of claims 4 to 12.

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