Heat pump dryer unit

Abstract

This invention discloses a heat pump dryer unit, relating to the field of drying equipment technology, which helps reduce user costs. The heat pump dryer unit includes a circulating air duct, a first fan, a heating and dehumidification system, a cooling system, a second fan, and a controller. The first fan drives airflow from the return air inlet to the outlet air outlet. The heating and dehumidification system includes a compressor, an evaporator, a throttling device, and a condenser connected in sequence. Both the evaporator and condenser are located within the circulating air duct, with the evaporator upstream of the condenser in the airflow direction within the circulating air duct. The cooling system includes a first heat exchanger, a fluid drive component, and a second heat exchanger, which are connected in sequence to form a circulating flow path. The first heat exchanger is located within the circulating air duct, and the second heat exchanger is located outside the circulating air duct. The second fan is located to one side of the second heat exchanger. This heat pump dryer unit is used to dry materials in a drying chamber.

Description

Technical Field

[0001] This invention relates to the field of drying equipment technology, and in particular to a heat pump drying unit. Background Technology

[0002] Closed-loop heat pump dryers use a heating-based dehumidification method. However, during this process, if the drying chamber temperature reaches the target temperature, the heat pump dryer will stop and restart when the temperature drops to its startup temperature. Dehumidification is impossible when the heat pump drying system is shut down. Related technologies address this by adding an exhaust system to the drying chamber to expel the hot, humid air, thus limiting the continuous temperature rise and allowing the heat pump dryer to dehumidify continuously. However, this increases costs. Furthermore, since the exhaust system removes hot, humid air, it can negatively impact oil extraction, especially in applications like flower and leaf drying where the extraction of active ingredients can be problematic. In sludge drying, it can release toxic or harmful gases into the air. Summary of the Invention

[0003] The embodiments of the present invention provide a heat pump dryer unit, which helps to reduce user costs.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0005] This application embodiment provides a heat pump dryer unit, including: a circulating air duct having an air outlet and a return air outlet; a first fan for driving airflow from the return air outlet to the air outlet; a heating and dehumidification system including a compressor, an evaporator, a throttling device, and a condenser connected in sequence, wherein the evaporator and the condenser are both located within the circulating air duct, and the evaporator is located upstream of the condenser in the airflow direction within the circulating air duct; and a cooling system including a first heat exchanger, a fluid drive component, and... A second heat exchanger, wherein the first heat exchanger, the fluid drive unit, and the second heat exchanger are sequentially connected to form a circulating flow path, the first heat exchanger being located inside the circulating air duct, and the second heat exchanger being located outside the circulating air duct; a second fan, wherein the second fan is located on one side of the second heat exchanger; and a controller configured to: control the compressor and the first fan to start when the heat pump dryer unit is operating in heating and dehumidification mode; and control the compressor, the first fan, the fluid drive unit, and the second fan to start when the heat pump dryer unit is operating in cooling and dehumidification mode.

[0006] The air conditioning system provided in this application embodiment adds a cooling system to the heat pump dryer unit. The first heat exchanger in the cooling system is placed within the circulating air duct, allowing the airflow from the return air inlet to the outlet to cool as it passes through the first heat exchanger. A fluid drive unit drives the heat exchange medium, after heat exchange in the first heat exchanger, to flow to a second heat exchanger. The second heat exchanger cools the air under the action of a second fan. After cooling, the heat exchange medium flows back to the first heat exchanger under the action of the fluid drive unit, allowing the first heat exchanger to continue cooling the airflow. This enables the cooling system to continuously cool the airflow passing through the first heat exchanger, limiting the continuous rise in temperature inside the drying chamber and allowing the heat pump dryer unit to continuously dehumidify. This improves the reliability of dehumidification in the heat pump dryer unit and prevents airflow from being released into the external atmosphere.

[0007] In some embodiments, the air outlet and the air return outlet are used to communicate with the drying chamber; the controller is further configured to acquire the dry-bulb set temperature, the wet-bulb set temperature, the actual dry-bulb temperature of the drying chamber, and the actual wet-bulb temperature of the drying chamber; and selectively control the heat pump dryer unit to operate in heating dehumidification mode or cooling dehumidification mode according to the relationship between the dry-bulb set temperature and the actual dry-bulb temperature of the drying chamber, and the relationship between the wet-bulb set temperature and the actual wet-bulb temperature of the drying chamber.

[0008] In some embodiments, the controller is configured to: control the heat pump dryer to operate in heating and dehumidification mode if the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature and the actual wet-bulb temperature of the drying chamber is higher than the set wet-bulb temperature; control the heat pump dryer to operate in cooling and dehumidification mode if the actual dry-bulb temperature of the drying chamber is higher than the set dry-bulb temperature and the actual wet-bulb temperature of the drying chamber is higher than the set wet-bulb temperature; and control the heat pump dryer to stop if the actual dry-bulb temperature of the drying chamber is higher than the set dry-bulb temperature and the actual wet-bulb temperature of the drying chamber is lower than the set wet-bulb temperature.

[0009] In some embodiments, the heat pump dryer unit further includes: a first heating device, wherein the first heating device is located within the circulating air duct and between the condenser and the air outlet; the controller is further configured to: during the process of controlling the heat pump dryer unit to operate the heating and dehumidification mode, determine whether the actual dry-bulb temperature of the drying chamber is lower than the dry-bulb set temperature, and when it is determined that the actual dry-bulb temperature of the drying chamber is lower than the dry-bulb set temperature, control the first heating device to start.

[0010] In some embodiments, the cooling system further includes a second heating device for heating the heat exchange medium flowing to the first heat exchanger in the circulation path; the controller is further configured to: determine whether the actual dry-bulb temperature of the drying chamber is less than the set dry-bulb temperature during the process of controlling the heat pump dryer to operate the heating and dehumidification mode; and when it is determined that the actual dry-bulb temperature of the drying chamber is less than the set dry-bulb temperature, control the fluid drive and the second heating device to start.

[0011] In some embodiments, the cooling system further includes a parallel branch and a three-way valve. The parallel branch is connected in parallel with the second heat exchanger. The three-way valve has a first interface, a second interface, and a third interface. The first interface is switched with one of the second interface and the third interface. The first interface is connected to the fluid drive component, the second interface is connected to the second heat exchanger, and the third interface is connected to the parallel branch. The controller is further configured to: determine whether the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature during the process of controlling the heat pump dryer to operate the heating and dehumidification mode; and control the first interface and the third interface to be connected when the actual dry-bulb temperature of the drying chamber is determined to be lower than the set dry-bulb temperature; and control the heat pump dryer to operate the cooling and dehumidification mode when the heat pump dryer is controlled to operate the cooling and dehumidification mode.

[0012] In some embodiments, the heat pump dryer unit further includes: a first heating device located between the condenser and the air outlet; the controller is further configured to: control the first heating device and the first fan to turn on when the heat pump dryer unit is operating in drying mode.

[0013] In some embodiments, the cooling system further includes a second heating device for heating the heat exchange medium flowing to the first heat exchanger; the controller is configured to: control the second heating device to not work when the heat pump dryer unit starts the cooling and dehumidification mode; and control the fluid drive, the first fan and the second heating device to start when the heat pump dryer unit starts the drying mode.

[0014] In some embodiments, the air outlet and the air return outlet are used to communicate with the drying chamber; the controller is further configured to acquire the dry-bulb set temperature, the wet-bulb set temperature, the actual dry-bulb temperature of the drying chamber, and the actual wet-bulb temperature of the drying chamber; and control the heat pump dryer unit to operate in a drying mode according to the relationship between the dry-bulb set temperature and the actual dry-bulb temperature of the drying chamber, and the relationship between the wet-bulb set temperature and the actual wet-bulb temperature of the drying chamber.

[0015] In some embodiments, the controller is configured to: control the heat pump dryer to operate in drying mode if the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature and the actual wet-bulb temperature of the drying chamber is lower than the set wet-bulb temperature; and control the heat pump dryer to shut down if the actual dry-bulb temperature of the drying chamber is higher than the set dry-bulb temperature and the actual wet-bulb temperature of the drying chamber is lower than the set wet-bulb temperature. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the connection between the heat pump dryer unit and the drying room provided in an embodiment of this application;

[0017] Figure 2 A schematic diagram illustrating the operation of the heat pump drying system in heating and dehumidification mode according to an embodiment of this application;

[0018] Figure 3 A schematic diagram illustrating the cooling and dehumidification mode of the heat pump dryer unit provided in the embodiments of this application;

[0019] Figure 4 A schematic diagram of another heat pump dryer unit provided in the embodiments of this application;

[0020] Figure 5 A schematic diagram of another heat pump dryer unit provided in the embodiments of this application;

[0021] Figure 6 A schematic diagram of yet another heat pump dryer unit provided in the embodiments of this application;

[0022] Figure 7 A flowchart illustrating a first control method for a heat pump dryer unit provided in this application embodiment;

[0023] Figure 8 A flowchart illustrating the control method for a second type of heat pump dryer unit provided in this application embodiment;

[0024] Figure 9 A flowchart illustrating the control method for a third type of heat pump dryer unit provided in this application embodiment;

[0025] Figure 10 A flowchart illustrating the fourth control method for a heat pump dryer unit provided in this application embodiment;

[0026] Figure 11 A flowchart illustrating the fifth control method for a heat pump dryer unit provided in this application embodiment.

[0027] Figure label:

[0028] 100. Heat pump drying unit;

[0029] 200. Drying room;

[0030] 1. Circulating air duct; 11. Return air inlet; 12. Air outlet; 13. Primary fan;

[0031] 2. Heating and dehumidification system; 21. Compressor; 22. Evaporator; 23. Throttling device; 24. Condenser;

[0032] 3. Cooling system; 31. First heat exchanger; 32. Fluid drive component; 33. Second heat exchanger; 34. Second fan; 35. Second heating device; 36. Three-way valve; 361. First port; 362. Second port; 363. Third port; 37. Parallel branch;

[0033] 4. First heating device. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0036] The terms "first" and "second" 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Closed-loop heat pump dryers use a heating-based dehumidification method. However, during this process, if the drying chamber temperature reaches the target temperature, the heat pump dryer will stop and restart when the temperature drops to its startup temperature. Dehumidification is impossible when the heat pump drying system is shut down. Related technologies address this by adding an exhaust system to the drying chamber to expel the hot, humid air, thus limiting the continuous temperature rise and allowing the heat pump dryer to dehumidify continuously. However, this increases costs. Furthermore, since the exhaust system removes hot, humid air, it can negatively impact oil extraction, especially in applications like flower and leaf drying where the extraction of active ingredients can be problematic. In sludge drying, it can release toxic or harmful gases into the air.

[0039] To address the aforementioned technical issues, a cooling system is added to the heat pump dryer unit. The first heat exchanger in this system is placed within the circulating air duct, allowing the airflow from the return air inlet to the outlet to be cooled as it passes through it. A fluid-driven component propels the heat exchange medium, after heat exchange in the first heat exchanger, to a second heat exchanger. The second heat exchanger, driven by a second fan, further cools the airflow. The cooled medium then flows back to the first heat exchanger under the same fluid-driven component, allowing the first heat exchanger to continue cooling the airflow. This continuous cooling system limits the temperature rise within the drying chamber, enabling the heat pump dryer unit to continuously dehumidify, improving its dehumidification reliability, and preventing airflow from being released into the external atmosphere.

[0040] The heat pump dryer unit of this application embodiment will be described below.

[0041] Please see Figure 1 , Figure 1 This is a schematic diagram showing the connection between the heat pump dryer unit 100 and the drying room 200 provided in the embodiments of this application.

[0042] The heat pump dryer unit 100 includes a circulating air duct 1, a first fan 13, a heating and dehumidification system 2, a cooling system 3, a second fan 34, and a controller.

[0043] Please continue reading. Figure 1 The circulating air duct 1 has an air outlet 12 and a return air inlet 11. The air outlet 12 and the return air inlet 11 are used to communicate with the drying chamber 200. Thus, the airflow in the circulating air duct 1 can flow from the air outlet 12 to the drying chamber, and then flow back from the drying chamber 200 to the circulating air duct 1 through the return air inlet 11.

[0044] Please continue reading. Figure 1The first fan 13 drives the airflow from the return air inlet 11 to the air outlet 12. Thus, the first fan 13 provides power to the airflow from the return air inlet 11 to the air outlet 12, allowing the airflow to circulate between the drying chamber 200 and the circulating air duct 1. Exemplarily, the first fan 13 is located inside the circulating air duct 1. Alternatively, the first fan 13 may be located outside the circulating air duct 1, at the air outlet 12, or at the return air inlet 11.

[0045] Please continue reading. Figure 1 The heating and dehumidification system 2 includes a compressor 21, an evaporator 22, a throttling device 23, and a condenser 24 connected in sequence. The compressor 21, evaporator 22, throttling device 23, and condenser 24 connected in sequence can form a refrigerant circulation path.

[0046] The compressor 21 has an intake port and an exhaust port. Specifically, the intake port of the compressor 21 is used to draw in refrigerant, which enters the compression chamber of the compressor 21 through the intake port and is compressed to form a high-temperature, high-pressure refrigerant gas. The high-temperature, high-pressure refrigerant gas is then discharged from the exhaust port of the compressor 21. For example, the compressor 21 can be a scroll compressor, a rotary compressor, a screw compressor, etc.

[0047] The throttling device 23 can throttle and reduce the pressure of the refrigerant flowing through it. For example, the throttling device 23 can be a capillary tube, a throttling valve, an electronic expansion valve, or a thermostatic expansion valve, etc.

[0048] Please continue reading. Figure 1 Both the evaporator 22 and the condenser 24 are located within the circulating air duct 1, and are arranged sequentially in the direction of airflow within the circulating air duct 1. Specifically, the evaporator 22 is located upstream of the condenser 24. Thus, the airflow in the circulating air duct 1 can be cooled and dehumidified when passing through the evaporator 22, and heated when passing through the condenser 24.

[0049] Please continue reading. Figure 1 The cooling system 3 includes a first heat exchanger 31, a fluid drive element 32, and a second heat exchanger 33. The first heat exchanger 31, the fluid drive element 32, and the second heat exchanger 33 are connected in sequence to form a circulation path. This arrangement allows the heat exchange medium to circulate between the first heat exchanger 31 and the second heat exchanger 33 via the fluid drive element 32.

[0050] Please continue reading. Figure 1The first heat exchanger 31 is located inside the circulating air duct 1, and the second heat exchanger 33 is located outside the circulating air duct 1. A second fan 34 is located to one side of the second heat exchanger 33. Therefore, when the second fan 34 rotates, it drives the airflow through the second heat exchanger 33, thereby exchanging heat with the second heat exchanger 33 to cool it down. The cooled heat exchange medium then flows back to the first heat exchanger 31 via the fluid drive 32, allowing the first heat exchanger 31 to continue cooling the airflow.

[0051] The heat pump dryer unit 100 has a heating dehumidification mode and a cooling dehumidification mode.

[0052] Please see Figure 2 , Figure 2 This is a schematic diagram of the heat pump drying system operating in heating and dehumidification mode according to an embodiment of this application. When heating and dehumidification of the drying chamber 200 is required, the heating and dehumidification mode is activated. In the heating and dehumidification mode, the controller controls the compressor 21 and the first fan 13 to start. At this time, the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port of the compressor 21 flows into the condenser 24, where it undergoes sufficient heat exchange to become a high-temperature and medium-pressure liquid refrigerant. Then, the refrigerant flowing out of the condenser 24 flows to the throttling device 23, where it undergoes throttling and pressure reduction to become a low-temperature and low-pressure two-phase refrigerant. The refrigerant flowing out of the throttling device 23 flows to the evaporator 22, where it undergoes heat exchange to become a low-temperature and low-pressure gaseous refrigerant. Finally, it flows back from the evaporator 22 to the suction port of the compressor 21. At this time, the airflow in the circulating air duct 1 flows from the return air port 11 to the outlet air port 12, first passing through the evaporator 22. The evaporator absorbs heat during evaporation, causing water to be released from the airflow, thus cooling and dehumidifying the airflow. The airflow then flows through the condenser 24, where it condenses and releases heat, heating the passing airflow.

[0053] Please see Figure 3 , Figure 3 This is a schematic diagram of the cooling and dehumidification mode of the heat pump drying system provided in this application embodiment. When cooling and dehumidification of the drying chamber 200 is required, the cooling and dehumidification mode is activated. In the cooling and dehumidification mode, the controller controls the compressor 21, the first fan 13, the fluid drive component 32, and the second fan 34 to start. Unlike the heating and dehumidification mode, the airflow in the circulating air duct 1 also needs to exchange heat with the first heat exchanger 31. The first heat exchanger 31 cools the airflow. The heat exchange medium after heat exchange with the airflow flows to the second heat exchanger 33 under the drive of the fluid drive component 32. The second fan 34 cools the second heat exchanger 33. After cooling, the heat exchange medium flows back to the first heat exchanger 31 under the drive of the fluid drive component 32.

[0054] Therefore, by adding a cooling system 3 to the heat pump dryer unit 100, and placing the first heat exchanger 31 in the cooling system 3 within the circulating air duct 1, the airflow from the return air inlet 11 to the outlet air inlet 12 is cooled by the first heat exchanger 31 as it passes through. The fluid drive unit 32 drives the heat exchange medium that has completed heat exchange in the first heat exchanger 31 to flow to the second heat exchanger 33. The second heat exchanger 33 is cooled by the second fan 34, and the cooled heat exchange medium flows back to the first heat exchanger 31 under the action of the fluid drive unit 32, allowing the first heat exchanger 31 to continue cooling the airflow. This enables the cooling system 3 to continuously cool the airflow passing through the first heat exchanger 31, limiting the continuous rise in temperature inside the drying chamber 200, allowing the heat pump dryer unit 100 to continuously dehumidify, improving the reliability of dehumidification in the heat pump dryer unit 100, and preventing airflow from being discharged into the external atmosphere.

[0055] In some embodiments, the first heat exchanger 31 may be located upstream of the evaporator 22 in the direction of airflow within the circulating air duct 1. This allows the airflow to be cooled before dehumidification.

[0056] In another embodiment, the first heat exchanger 31 may be located between the evaporator 22 and the condenser 24 in the direction of airflow within the circulating air duct 1. This allows for cooling of the airflow after dehumidification.

[0057] In some other embodiments, the first heat exchanger 31 is located downstream of the condenser 24 in the direction of airflow within the circulating air duct 1. This allows the airflow to be heated and then cooled by the first heat exchanger 31, thereby controlling the temperature of the airflow exiting the outlet 12.

[0058] Please see Figure 4 , Figure 4 This is a schematic diagram of another heat pump dryer unit provided in an embodiment of this application. In some embodiments, the heat pump dryer unit 100 further includes a first heating device 4. Exemplarily, the first heating device 4 can be a resistance wire, a heating wire, etc.

[0059] Please continue reading. Figure 4 The first heating device 4 is located inside the circulating air duct 1, between the condenser 24 and the air outlet 12. Therefore, the first heating device 4 can reheat the airflow after it has been heated by the condenser 24, avoiding the problem of the condenser 24 failing to reach the preset temperature, and improving the reliability of the heat pump dryer unit 100. Simultaneously, when dehumidification of the drying chamber 200 is not required and the heating and dehumidification system 2 is not activated, the first heating device 4 can also be used to heat the airflow.

[0060] Please continue reading. Figure 4 The heat pump dryer unit 100 has a drying mode. When the controller controls the heat pump dryer unit 100 to operate in drying mode, the controller controls the first heating device 4 and the first fan 13 to turn on. At this time, the airflow circulates between the circulating air duct 1 and the drying chamber 200, so that the airflow flowing through the first heating device 4 can be heated and sent into the drying chamber 200 with heated airflow.

[0061] It is understandable that in other examples, the first heating device 4 may not be provided.

[0062] Please see Figure 5 , Figure 5 This is a schematic diagram of another heat pump dryer unit provided in an embodiment of this application. The cooling system 3 also includes a second heating device 35. The second heating device 35 is used to heat the heat exchange medium flowing to the first heat exchanger 31 in the circulation path. For example, the second heating device 35 is disposed in the pipeline between the fluid drive member and the first heat exchanger 31 to heat the heat exchange medium flowing through the pipeline. In this way, when the cooling system 3 is used to heat the circulation duct 1, the second heating device 35 can be turned on, so that the heat exchange medium flowing to the first heat exchanger 31 can be heated by the second heating device 35, and then the airflow flowing through the first heat exchanger 31 in the circulation duct 1 can be heated by the first heat exchanger 31.

[0063] In some embodiments, when the controller activates the cooling and dehumidification mode of the heat pump dryer unit 100, the controller activates the fluid drive unit 32 and the first fan 13, and deactivates the second heating device 35. This avoids the problem of the first heat exchanger 31 being unable to cool the airflow when the second heating device 35 is activated, thus improving the reliability of the heat pump dryer unit 100 operation.

[0064] In some embodiments, please continue reading Figure 5 The heat pump dryer unit 100 also has a drying mode. When the controller activates the drying mode, it controls the fluid drive unit 32, the first fan 13, and the second heating device 35 to start. At this time, the airflow circulates between the circulating air duct 1 and the drying chamber 200, so that the airflow flowing through the first heat exchanger 31 can be heated and sent into the drying chamber 200.

[0065] Please see Figure 6 , Figure 6 This is a schematic diagram of another heat pump dryer unit provided in the embodiments of this application. Figure 6 The illustrated embodiments and Figure 5The difference in the illustrated embodiment is that the cooling system 3 further includes a parallel branch 37 and a three-way valve 36. The parallel branch 37 is connected in parallel with the second heat exchanger 33. The three-way valve 36 has a first port 361, a second port 362, and a third port 363. The first port 361 is switched with one of the second port 362 and the third port 363. The first port 361 is connected to the fluid drive 32, the second port 362 is connected to the second heat exchanger 33, and the third port 363 is connected to the parallel branch. That is, when the first port 361 and the second port 362 are connected, the heat exchange medium can flow between the second heat exchanger 33, the three-way valve 36, the second heating device 35, and the first heat exchanger 31 under the drive of the fluid drive 32. When the first port 361 and the third port 363 are connected, the heat exchange medium, driven by the fluid drive 32, can flow through the parallel branch 37 between the second heating device 35, the three-way valve 36, and the first heat exchanger 31. At this time, the heat exchange medium does not flow to the second heat exchanger 33. Therefore, by setting the three-way valve 36, the flow of the heat exchange medium through the second heat exchanger 33 can be controlled, and the control method is simple.

[0066] Please continue reading. Figure 6 When the controller activates the cooling and dehumidification mode of the heat pump dryer unit 100, it activates the fluid drive component 32 and the first fan 13, connects the first interface 361 and the second interface 362, and disables the second heating device 35. This avoids the problem of the first heat exchanger 31 being unable to cool the airflow when the second heating device 35 is activated, thus improving the reliability of the heat pump dryer unit 100.

[0067] When the controller activates the drying mode of the heat pump dryer unit 100, it also activates the fluid drive unit 32, the first fan 13, and the second heating device 35, and connects the first interface 361 to the second interface 362. This prevents the heat exchange medium from flowing to the second heat exchanger 33, reduces the flow path of the heat exchange medium, and improves the heating efficiency of the second heating device 35, thereby enhancing the efficiency of the heat pump dryer unit 100 in heating the airflow.

[0068] In some embodiments, the heat pump dryer unit 100 may further include a first heating device 4 and a second heating device 35. This arrangement is beneficial for improving the heating efficiency of the heat pump dryer unit 100.

[0069] In some embodiments, the heat exchange medium used in the cooling system 3 is water, and the fluid drive component 32 is a water pump. This configuration can reduce the cost of the heat pump dryer unit 100.

[0070] In some embodiments, a controller refers to a device that can generate operation control signals based on instruction opcodes and timing signals to instruct the execution of control instructions from the heat pump dryer unit 100. Exemplarily, the controller can be a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller can also be other devices with processing capabilities, such as circuits, devices, or software modules; this application embodiment does not impose any limitations on this.

[0071] In addition, the controller can be used to control the operation of various components inside the heat pump dryer unit 100 so that each component of the heat pump dryer unit 100 can perform its predetermined functions.

[0072] Based on the above-described structure of the heat pump dryer unit 100, the control method of the heat pump dryer unit 100 according to an embodiment of this application will be described below. This method is applied to a controller, which can be the controller described above.

[0073] Please see Figure 7 , Figure 7 A flowchart illustrating a first control method for a heat pump dryer unit provided in this application embodiment. The control method for the heat pump dryer unit 100 includes:

[0074] S1: Obtain the dry-bulb set temperature, the wet-bulb set temperature, the actual dry-bulb temperature of the drying chamber 200, and the actual wet-bulb temperature of the drying chamber 200; for example, the wet-bulb set temperature and the dry-bulb set temperature can be the temperature set by the user, or the temperature set by the heat pump dryer unit 100 according to preset conditions.

[0075] In some embodiments, a dry-bulb thermometer may be installed inside the drying chamber 200 to measure the actual dry-bulb temperature of the drying chamber 200. The dry-bulb thermometer can be wirelessly connected to the controller. A wet-bulb thermometer may also be installed inside the drying chamber 200 to measure the actual wet-bulb temperature of the drying chamber 200. The wet-bulb thermometer can be wirelessly connected to the controller. Both the dry-bulb and wet-bulb thermometers can communicate wirelessly with the controller.

[0076] In other embodiments, the dry-bulb thermometer and the wet-bulb thermometer may be located at the return air vent 11.

[0077] S2: When the dry-bulb set temperature, wet-bulb set temperature, actual dry-bulb temperature of drying chamber 200, and actual wet-bulb temperature of drying chamber 200 are obtained, the heat pump dryer unit 100 is selectively controlled to operate in heating dehumidification mode, cooling dehumidification mode, or drying mode according to the relationship between the dry-bulb set temperature and the actual dry-bulb temperature of drying chamber 200, and the relationship between the wet-bulb set temperature and the actual wet-bulb temperature of drying chamber 200.

[0078] Therefore, the controller can control the heat pump dryer unit 100 to operate in heating and dehumidification mode or cooling and dehumidification mode according to the actual needs of the drying room 200, thereby improving the intelligence level of the heat pump dryer unit 100.

[0079] Please see Figure 8 , Figure 8 A flowchart illustrating a second control method for a heat pump dryer unit provided in an embodiment of this application. In some embodiments, step S2 specifically includes:

[0080] If the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber 200 is higher than the set wet-bulb temperature, then the heat pump dryer unit 100 is controlled to operate in heating and dehumidification mode. Since the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber 200 is higher than the set wet-bulb temperature, it means that the actual dry-bulb temperature in the drying chamber 200 is lower than the set dry-bulb temperature, and the actual humidity in the drying chamber 200 is higher than the set humidity. Therefore, the controller controls the heat pump dryer unit 100 to enter the heating and dehumidification mode.

[0081] If the actual dry-bulb temperature of the drying chamber 200 is greater than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber 200 is greater than the set wet-bulb temperature, then the heat pump dryer unit 100 is controlled to operate in cooling and dehumidification mode. Since the actual dry-bulb temperature is greater than the set dry-bulb temperature and the actual wet-bulb temperature is greater than the set wet-bulb temperature, it means that the actual dry-bulb temperature in the drying chamber 200 is too high and the humidity in the drying chamber 200 is greater than the set humidity. Therefore, the controller controls the heat pump dryer unit 100 to enter the cooling and dehumidification mode.

[0082] If the actual dry-bulb temperature of the drying chamber 200 is greater than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber 200 is less than the set wet-bulb temperature, then the heat pump dryer unit 100 will be shut down. This indicates that the actual dry-bulb temperature and the actual wet-bulb temperature in the drying chamber 200 meet the set requirements, allowing the controller to shut down the heat pump dryer unit 100. This improves the intelligence of the heat pump dryer unit 100 and reduces its energy consumption.

[0083] If the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber 200 is lower than the set wet-bulb temperature, then the heat pump dryer unit 100 is controlled to operate in drying mode. Since the actual dry-bulb temperature is lower than the set dry-bulb temperature and the actual wet-bulb temperature is lower than the set wet-bulb temperature, it means that the actual dry-bulb temperature in the drying chamber 200 is too low and the humidity in the drying chamber 200 meets the requirements. Therefore, the controller controls the heat pump dryer unit 100 to enter drying mode.

[0084] Please see Figure 9 , Figure 9 This is a flowchart illustrating a third control method for a heat pump dryer unit provided in this application embodiment. In some embodiments, when the heat pump dryer unit 100 includes a first heating device, during the process of controlling the heat pump dryer unit 100 to operate in heating and dehumidification mode, it is determined whether the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature. When it is determined that the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, the first heating device 4 is activated. This avoids the problem that, during the operation of the heat pump dryer unit 100 in heating and dehumidification mode, the actual dry-bulb temperature flowing into the drying chamber 200 cannot reach the set dry-bulb temperature due to heating by the condenser 24. By controlling the activation of the first heating device 4, the airflow in the circulating air duct 1 can be reheated, thereby ensuring that the temperature of the airflow flowing into the drying chamber 200 meets the requirements, which is beneficial to improving the stability and reliability of the heat pump dryer unit 100. Furthermore, since the first heating device 4 can be turned on and off at any time, it helps to reduce the power consumption of the heat pump dryer unit 100 when the cooling and heating of the heat pump dryer unit 100 frequently switch. On the other hand, the first heating device 4, the heating and dehumidification system 2 and the cooling system 3 are independent of each other, which can avoid mutual interference between the heating device, the heating and dehumidification system 2 and the cooling system 3, so that the heat pump dryer unit 100 can better control the temperature and humidity, which is conducive to improving the working efficiency of the heat pump dryer unit 100.

[0085] Please see Figure 10 , Figure 10This is a flowchart illustrating a fourth control method for a heat pump dryer unit provided in this application embodiment. In some embodiments, when the heat pump dryer unit 100 includes a second heating device, during the process of controlling the heat pump dryer unit 100 to operate in heating and dehumidification mode, it is determined whether the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature. When it is determined that the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, the fluid drive unit 32 and the second heating device 35 are activated. This avoids the problem that, during the operation of the heat pump dryer unit 100 in heating and dehumidification mode, the actual dry-bulb temperature flowing into the drying chamber 200 cannot reach the required set dry-bulb temperature after being heated by the condenser 24. By controlling the activation of the fluid drive unit 32 and the second heating device 35, the airflow in the circulating air duct 1 can be reheated, thereby ensuring that the temperature of the airflow flowing into the drying chamber 200 meets the requirements, which is beneficial to improving the stability and reliability of the heat pump dryer unit 100.

[0086] Please see Figure 11 , Figure 11 This is a flowchart illustrating a fifth control method for a heat pump dryer unit provided in this application embodiment. In some embodiments, when the heat pump dryer unit 100 includes a second heating device and a three-way valve, during the process of controlling the heat pump dryer unit 100 to operate in heating and dehumidification mode, it is determined whether the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature. When it is determined that the actual dry-bulb temperature of the drying chamber 200 is lower than the set dry-bulb temperature, the first interface 316 and the third interface 363 are connected, and the fluid drive unit 32 and the second heating device 35 are started. This avoids the problem that when the heat pump dryer unit 100 operates in heating and dehumidification mode, the actual dry-bulb temperature flowing into the drying chamber 200 cannot reach the required set dry-bulb temperature after being heated by the condenser 24. By controlling the fluid drive unit 32 and the second heating device 35 to start and controlling the first interface 316 and the third interface 363 to connect, the airflow in the circulating air duct 1 can be reheated, thereby ensuring that the temperature of the airflow flowing into the drying chamber 200 meets the requirements, which is beneficial to improving the stability and reliability of the heat pump dryer unit 100.

[0087] This invention also provides a computer-readable storage medium, which includes computer-executable instructions. When the computer-executable instructions are executed on the computer, the computer performs a control method for an air conditioning system as provided in the above embodiments.

[0088] This invention also provides a computer program product that can be directly loaded into a memory and contains software code. After being loaded and executed by a computer, the computer program product can realize the control method of an air conditioning system provided in the above embodiments.

[0089] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0090] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A heat pump drying unit, characterized in that, include: A circulating air duct, wherein the circulating air duct has an air outlet and an air return outlet; A first fan is used to drive airflow from the return air inlet to the air outlet. A heating and dehumidification system, comprising a compressor, an evaporator, a throttling device, and a condenser connected in sequence, wherein the evaporator and the condenser are both located within the circulating air duct, and the evaporator is located upstream of the condenser in the airflow direction within the circulating air duct; A cooling system, comprising a first heat exchanger, a fluid drive unit, and a second heat exchanger, wherein the first heat exchanger, the fluid drive unit, and the second heat exchanger are sequentially connected to form a circulating flow path, the first heat exchanger being located inside the circulating air duct, and the second heat exchanger being located outside the circulating air duct. The second fan is located on one side of the second heat exchanger; The cooling system further includes a second heating device, a parallel branch, and a three-way valve. The second heating device is used to heat the heat exchange medium flowing to the first heat exchanger in the circulation path. The parallel branch is connected in parallel with the second heat exchanger. The three-way valve has a first port, a second port and a third port. The first port is in communication with one of the second port and the third port. The first port is connected to the fluid drive unit, the second port is connected to the second heat exchanger, and the third port is connected to the parallel branch. The controller is configured as follows: When the heat pump dryer unit is controlled to operate in heating and dehumidification mode, the compressor and the first fan are controlled to start. When the heat pump dryer unit is controlled to operate in cooling and dehumidification mode, the compressor, the first fan, the fluid drive component, and the second fan are started. The controller is also configured to: Obtain the dry-bulb set temperature, the wet-bulb set temperature, the actual dry-bulb temperature of the drying chamber, and the actual wet-bulb temperature of the drying chamber; During the process of controlling the heat pump dryer unit to operate the heating and dehumidification mode, it is determined whether the actual dry-bulb temperature of the drying chamber is lower than the dry-bulb set temperature. When it is determined that the actual dry-bulb temperature of the drying chamber is lower than the dry-bulb set temperature, the first interface and the third interface are connected, and the fluid drive and the second heating device are started. The first heat exchanger heats the airflow flowing through the circulating air duct. When the heat pump dryer unit is controlled to operate in cooling and dehumidification mode, the first interface and the second interface are connected, and the second heating device is controlled to not work. The first heat exchanger cools the airflow flowing through the circulating air duct. When the heat pump dryer unit starts the drying mode, the first interface and the third interface are connected, and the fluid drive, the first fan and the second heating device are started. The first heat exchanger heats the airflow flowing through the circulating air duct.

2. The heat pump dryer unit according to claim 1, characterized in that, The air outlet and the air return outlet are used to connect with the drying room; The controller is also configured to Obtain the dry bulb set temperature, the wet bulb set temperature, the actual dry bulb temperature of the drying chamber, and the actual wet bulb temperature of the drying chamber; Based on the relationship between the dry-bulb set temperature and the actual dry-bulb temperature of the drying chamber, and the relationship between the wet-bulb set temperature and the actual wet-bulb temperature of the drying chamber, the heat pump dryer unit is selectively controlled to operate in either heating dehumidification mode or cooling dehumidification mode.

3. The heat pump dryer unit according to claim 2, characterized in that, The controller is configured as follows: If the actual dry bulb temperature of the drying chamber is lower than the set dry bulb temperature, and the actual wet bulb temperature of the drying chamber is higher than the set wet bulb temperature, then the heat pump dryer unit is controlled to operate in heating and dehumidification mode. If the actual dry bulb temperature of the drying chamber is greater than the set dry bulb temperature, and the actual wet bulb temperature of the drying chamber is greater than the set wet bulb temperature, then the heat pump dryer unit is controlled to operate in cooling and dehumidification mode. If the actual dry-bulb temperature of the drying chamber is greater than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber is less than the set wet-bulb temperature, then the heat pump dryer unit will be shut down.

4. The heat pump dryer unit according to claim 2, characterized in that, Also includes: A first heating device is located inside the circulating air duct and between the condenser and the air outlet; The controller is also configured to: During the process of controlling the heat pump dryer unit to operate the heating and dehumidification mode, it is determined whether the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature. When it is determined that the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature, the first heating device is controlled to start.

5. The heat pump dryer unit according to claim 1, characterized in that, Also includes: A first heating device is located between the condenser and the air outlet; The controller is also configured to: When controlling the heat pump dryer unit to operate in drying mode, the first heating device and the first fan are turned on.

6. The heat pump dryer unit according to claim 1, characterized in that, The air outlet and the air return outlet are used to connect with the drying room; The controller is also configured to Obtain the dry bulb set temperature, the wet bulb set temperature, the actual dry bulb temperature of the drying chamber, and the actual wet bulb temperature of the drying chamber; The drying mode of the heat pump dryer is controlled based on the relationship between the dry bulb set temperature and the actual dry bulb temperature of the drying chamber, as well as the relationship between the wet bulb set temperature and the actual wet bulb temperature of the drying chamber.

7. The heat pump dryer unit according to claim 1, characterized in that, The controller is configured as follows: If the actual dry-bulb temperature of the drying chamber is lower than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber is lower than the set wet-bulb temperature, then the heat pump dryer unit is controlled to operate in drying mode. If the actual dry-bulb temperature of the drying chamber is greater than the set dry-bulb temperature, and the actual wet-bulb temperature of the drying chamber is less than the set wet-bulb temperature, then the heat pump dryer unit will be shut down.

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