A heat pump drying system
By designing a heat pump drying system with diversified internal dehumidification and external dehumidification modes, utilizing internal circulation ducts and fan control, combined with multi-stage heating and waste heat recovery, the problem of low efficiency of traditional heat pump drying systems in high humidity environments is solved, achieving rapid dehumidification and efficient drying.
Patent Information
- Application Number
- CN202521488096.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2026-05-29
- Estimated Expiration
- 2035-07-16
Smart Images
Figure CN224302661U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of drying technology, and in particular to a heat pump drying system. Background Technology
[0002] Drying technology, as an energy-saving and environmentally friendly drying technology, has been widely used in agricultural product processing, food industry, textile industry and other fields. Traditional heat pump drying systems mainly use the heat pump cycle principle to transfer and recover heat through the phase change process of refrigerant between the evaporator and condenser, thereby achieving a highly efficient and energy-saving drying effect.
[0003] Traditional heat pump drying systems mainly rely on the condensation and dehumidification function of the evaporator to remove water vapor generated during the drying process. However, when the ambient humidity is high or the moisture content of the material to be dried is too high, a single dehumidification method often cannot meet the demand for rapid dehumidification, resulting in decreased drying efficiency and extended drying time. Utility Model Content
[0004] This application aims to at least partially address one of the aforementioned technical problems in the prior art. To this end, embodiments of this application provide a heat pump drying system capable of meeting the need for rapid dehumidification and improving drying efficiency.
[0005] A heat pump drying system for installation in a drying chamber, comprising:
[0006] A hot air input channel is installed at the entrance of the drying chamber;
[0007] An exhaust gas discharge channel is installed at the outlet of the drying chamber;
[0008] An internal circulation air duct connects the hot air input channel and the exhaust gas discharge channel. The internal circulation air duct is provided with a fresh air inlet and an exhaust air outlet. The fresh air inlet is connected to the hot air input channel and is equipped with a fresh air valve. The exhaust air outlet is connected to the exhaust gas discharge channel. An internal circulation valve is provided inside the internal circulation air duct and is located between the fresh air inlet and the exhaust air outlet.
[0009] A fan is installed in the exhaust gas discharge channel. The fan drives the airflow to flow out from the outlet of the drying chamber, and then flow into the inlet of the drying chamber after passing through the hot gas input channel, the internal circulation air duct and the exhaust gas discharge channel.
[0010] A heat pump assembly includes a compressor, a condenser, a throttling element, and an evaporator that form a refrigerant cycle. The condenser is disposed in the hot gas inlet channel to heat the airflow flowing into the hot gas inlet channel, and the evaporator is disposed in the exhaust gas outlet channel to absorb the waste heat in the airflow flowing out of the exhaust gas outlet channel.
[0011] The heat exchanger has a first heat exchange unit and a second heat exchange unit that exchange heat with each other. The first heat exchange unit is disposed in the exhaust gas discharge channel, and the second heat exchange unit is disposed in the hot gas input channel, thereby exchanging heat between the airflow flowing out of the exhaust gas discharge channel and the airflow flowing into the hot gas input channel.
[0012] In an optional or preferred embodiment, an internal circulation fan is provided inside the internal circulation duct. The internal circulation fan is located on the leeward side of the internal circulation valve. The internal circulation fan is used to drive the gas in the exhaust gas discharge channel through the internal circulation duct to the hot gas input channel.
[0013] In an optional or preferred embodiment, a dehumidifier is provided in the internal circulation duct, and the dehumidifier is located on the windward side of the internal circulation valve.
[0014] In an optional or preferred embodiment, the second heat exchange unit is disposed on the windward side of the condenser, so that the airflow in the hot gas input channel passes through the second heat exchange unit before flowing to the condenser; the first heat exchange unit is disposed on the windward side of the evaporator, so that the airflow in the exhaust gas discharge channel passes through the first heat exchange unit before flowing to the evaporator.
[0015] In an optional or preferred embodiment, the fresh air inlet is aligned with the hot air input channel, and the exhaust outlet is aligned with the waste gas discharge channel.
[0016] In an optional or preferred embodiment, an air inlet filter is provided in the hot air input channel, and the air inlet filter is located between the fresh air inlet and the second heat exchange unit.
[0017] In an optional or preferred embodiment, an air filter is installed at the outlet of the drying chamber.
[0018] In an optional or preferred embodiment, an auxiliary heater is provided in the hot gas input channel, and the auxiliary heater is located on the leeward side of the condenser.
[0019] In an optional or preferred embodiment, at least two heat pump components are provided. Each of the condensers is arranged side by side at intervals along the inflow direction of the overall airflow in the hot gas input channel to perform multi-stage heating of the airflow flowing into the hot gas input channel. Each of the evaporators is arranged side by side at intervals along the outflow direction of the overall airflow in the exhaust gas discharge channel to perform multi-stage absorption of the waste heat in the airflow flowing out of the exhaust gas discharge channel.
[0020] In an optional or preferred embodiment, the drying chamber includes a drying drum or a drying room.
[0021] Based on the above technical solution, the embodiments of this application have at least the following beneficial effects: In external dehumidification mode, the fresh air valve is open, the internal circulation valve is closed, and the fan operates. Fresh air entering from the fresh air inlet passes through the hot air input channel and enters the drying chamber, carrying the moisture in the drying chamber through the exhaust gas outlet channel and finally exiting from the exhaust port. In internal dehumidification mode, the fresh air valve is closed, the internal circulation valve is open, and the fan operates. The fan drives the moisture in the drying chamber to be heated by the condenser, thus circulating until the moisture is removed. Therefore, the dehumidification mode of the heat pump drying system of this application is more diversified. It can switch between internal dehumidification mode and external dehumidification mode according to changes in the external environment. When the external humidity is high, the internal dehumidification mode is used; when the external environment is dry, the external dehumidification mode is used, thereby meeting the need for rapid dehumidification and improving drying efficiency. Attached Figure Description
[0022] The present application will be further described below with reference to the accompanying drawings and embodiments;
[0023] Figure 1 This is a schematic diagram of the gas flow direction in the internal dehumidification mode of the heat pump drying system of Embodiment 1 of this application;
[0024] Figure 2 This is a schematic diagram of the gas flow direction of the heat pump drying system in the internal dehumidification and external dehumidification mode of Embodiment 1 of this application;
[0025] Figure 3 This is a schematic diagram of the gas flow direction of the heat pump drying system in the internal dehumidification and external dehumidification mode of Embodiment 2 of this application;
[0026] Figure 4 This is a schematic diagram of the gas flow direction of the heat pump drying system in external dehumidification mode according to Embodiment 3 of this application;
[0027] Figure 5 This is a schematic diagram of the gas flow direction in the internal dehumidification mode of the heat pump drying system of Embodiment 3 of this application;
[0028] Figure 6 This is a schematic diagram of the gas flow direction in the internal dehumidification mode of the heat pump drying system of Embodiment 5 of this application.
[0029] Figure label:
[0030] 110-Drum; 120-Drying room; 200-Hot air input channel; 210-Air inlet filter; 220-Auxiliary heater; 300-Exhaust gas discharge channel; 400-Internal circulation air duct; 410-Fresh air inlet; 420-Exhaust outlet; 430-Internal circulation air valve; 440-Fresh air valve; 450-Internal circulation fan; 460-Dehumidifier; 500-Fan; 510-Exhaust air filter; 600-Heat pump assembly; 610-Compressor; 620-Condenser; 630-Throttling element; 640-Evaporator; 700-Heat exchanger; 710-First heat exchange unit; 720-Second heat exchange unit. Detailed Implementation
[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0032] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0033] Furthermore, 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 at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0037] Drying technology, as an energy-saving and environmentally friendly drying technology, has been widely used in agricultural product processing, food industry, textile industry and other fields. Traditional heat pump drying systems mainly use the heat pump cycle principle to transfer and recover heat through the phase change process of refrigerant between the evaporator and condenser, thereby achieving a highly efficient and energy-saving drying effect.
[0038] Traditional heat pump drying systems mainly rely on the condensation and dehumidification function of the evaporator to remove water vapor generated during the drying process. However, when the ambient humidity is high or the moisture content of the material to be dried is too high, a single dehumidification method often cannot meet the demand for rapid dehumidification, resulting in decreased drying efficiency and extended drying time.
[0039] Example 1
[0040] Reference Figure 1 , Figure 2This embodiment provides a heat pump drying system for installation in a drying chamber. The heat pump drying system includes a hot air input channel 200, a waste gas discharge channel 300, an internal circulation air duct 400, a fan 500, a heat pump assembly 600, and a heat exchanger 700.
[0041] The hot air inlet channel 200 is installed at the inlet of the drying chamber, and the exhaust gas outlet channel 300 is installed at the outlet of the drying chamber. Figure 1 As shown, the hot air inlet channel 200 is connected to the top of the drying chamber, and the exhaust gas outlet channel 300 is connected to the bottom of the drying chamber. The interior of the drying chamber is used to place the material to be dried.
[0042] The internal circulation duct 400 connects the hot air input channel 200 and the exhaust gas discharge channel 300. The internal circulation duct 400 is equipped with a fresh air inlet 410 and an exhaust outlet 420. The fresh air inlet 410 connects to the hot air input channel 200, and the exhaust outlet 420 connects to the exhaust gas discharge channel 300. Specifically, the fresh air inlet 410 is aligned with the hot air input channel 200, and the exhaust outlet 420 is aligned with the exhaust gas discharge channel 300. This facilitates the entry of fresh air and the discharge of exhaust gas. External fresh air can enter the internal circulation duct 400 through the fresh air inlet 410, then enter the drying chamber through the hot air input channel 200. Exhaust gas flowing out of the drying chamber passes through the exhaust gas discharge channel 300 and can be discharged through the exhaust outlet 420.
[0043] An internal circulation air duct 400 is equipped with an internal circulation air valve 430, located between the fresh air inlet 410 and the exhaust outlet 420. A fan 500 is installed in the exhaust gas discharge channel 300, driving the airflow from the outlet of the drying chamber, through the hot air inlet channel 200, the internal circulation air duct 400, and the exhaust gas discharge channel 300 before flowing back into the drying chamber. A fresh air valve 440 is installed at the fresh air inlet 410 to manage its opening and closing.
[0044] An internal circulation fan 450 is installed inside the internal circulation duct 400. The internal circulation fan 450 is located on the leeward side of the internal circulation valve 430. The internal circulation fan 450 is used to drive the gas in the exhaust gas discharge channel 300 through the internal circulation duct 400 to the hot gas input channel 200.
[0045] The heat pump assembly 600 includes a compressor 610 forming a refrigerant cycle, a condenser 620, a throttling element 630, and an evaporator 640. The condenser 620 is disposed in the hot gas inlet channel 200 to heat the airflow flowing into the hot gas inlet channel 200, and the evaporator 640 is disposed in the exhaust gas outlet channel 300 to absorb the waste heat in the airflow flowing out of the exhaust gas outlet channel 300. The heat pump assembly 600 is existing technology. The refrigerant operates in a circulation loop connecting the compressor 610, condenser 620, throttling element 630, and evaporator 640. The condenser 620 provides heating. The condenser 620 is located in the hot gas input channel 200 to heat the incoming airflow. The heated airflow can heat and dry the materials in the drying chamber and remove moisture. After becoming exhaust gas, it is discharged through the exhaust gas discharge channel 300. The evaporator 640 of the heat pump assembly 600 can absorb the waste heat in the exhaust gas and transfer the waste heat to the condenser 620 through refrigerant circulation to heat the airflow after natural heat exchange, further increasing its temperature.
[0046] In this embodiment, two heat pump components 600 are provided. Two condensers 620 are arranged side by side at intervals along the inflow direction of the overall airflow in the hot gas input channel 200 to perform two-stage heating on the airflow flowing into the hot gas input channel 200, thereby further improving the heating efficiency. Two evaporators 640 are arranged side by side at intervals along the outflow direction of the overall airflow in the exhaust gas discharge channel 300 to perform two-stage absorption on the waste heat in the airflow flowing out of the exhaust gas discharge channel 300.
[0047] Of course, in other embodiments, the heat pump assembly 600 may be provided in three or more forms, the specific number of which shall be determined according to the actual situation.
[0048] The heat exchanger 700 has a first heat exchange unit 710 and a second heat exchange unit 720 that exchange heat with each other. The first heat exchange unit 710 is located in the exhaust gas discharge channel 300, and the second heat exchange unit 720 is located in the hot gas input channel 200, thereby exchanging heat between the airflow flowing out of the exhaust gas discharge channel 300 and the airflow flowing into the hot gas input channel 200. Specifically, the second heat exchange unit 720 is located on the windward side of the condenser 620, so that the airflow in the hot gas input channel 200 passes through the second heat exchange unit 720 before flowing into the condenser 620; the first heat exchange unit 710 is located on the windward side of the evaporator 640, so that the airflow in the exhaust gas discharge channel 300 passes through the first heat exchange unit 710 before flowing into the evaporator 640.
[0049] In this embodiment, the heat exchanger 700 is a composite phase change heat exchanger, such as a heat pipe heat exchanger. The first heat exchange unit 710 and the second heat exchange unit 720 are respectively a first heat exchange end and a second heat exchange end located at opposite ends. The first heat exchange end is located in the exhaust gas discharge channel 300, and the second heat exchange end is located in the hot gas input channel 200.
[0050] During the operation of the heat pump drying system, the first heat exchange end in the exhaust gas discharge channel 300 absorbs the waste heat from the exhaust gas, and then transfers the heat to the second heat exchange end to heat the airflow. The first heat exchange end is located on the inlet side of the evaporator 640 because the waste heat in the exhaust gas is relatively high when it is first discharged from the exhaust gas discharge channel 300. The first heat exchange end of the heat exchanger 700 allows for maximum heat transfer to the second heat exchange end. The fresh airflow is preheated at the second heat exchange end, receiving its first heating. Then, as it flows through the condenser 620, it undergoes a second heating via the heat pump assembly 600. The heated airflow then enters the drying chamber to dry the materials, carrying away moisture, and is discharged as exhaust gas. The heat pump assembly 600 simultaneously absorbs heat from the exhaust gas, thus recovering and reusing the heat. In this embodiment, the exhaust gas undergoes two stages of waste heat utilization through the heat exchanger 700 and the evaporator 640, increasing the drying and heating speed of the drying chamber, improving the drying effect, reducing thermal pollution emissions, and contributing to a better working environment.
[0051] An air inlet filter 210 is installed in the hot air input channel 200. The air inlet filter 210 is located between the fresh air inlet 410 and the second heat exchange unit 720. An air outlet filter 510 is installed at the outlet of the drying chamber.
[0052] The airflow entering from the fresh air inlet 410 first passes through the inlet air filter device 210 before flowing to the second heat exchange end. In this way, the fresh air is purified first, then heated, and then sent into the drying chamber to dry the materials. The purified fresh air reduces contamination of the materials. Similarly, the airflow exiting the drying chamber first passes through the outlet air filter device 510 before flowing into the exhaust gas discharge channel 300. After the fresh air dries the materials in the drying chamber, the exhaust gas will contain debris and other impurities. This can be treated by the outlet air filter device 510 to avoid affecting the operation of the heat exchanger 700 and evaporator 640, and to prevent the exhaust gas from polluting the environment. The inlet air filter device 210 and the outlet air filter device 510 can be made of filter cotton or conventional filter structures in this field.
[0053] To improve drying efficiency, an auxiliary heater 220 is provided in the hot air input channel 200 in this embodiment. The auxiliary heater 220 is located on the leeward side of the condenser 620.
[0054] When the external dehumidification mode is in operation in this embodiment, the fresh air valve 440 is opened and the internal circulation valve 430 is closed. The fresh air entering from the fresh air inlet 410 enters the drying chamber after passing through the hot air input channel 200. The fresh air carrying the moisture in the drying chamber passes through the exhaust gas discharge channel 300 and is finally discharged from the exhaust port 420.
[0055] Reference Figure 1When the internal dehumidification mode is in operation in this embodiment, the fresh air valve 440 is closed, the internal circulation valve 430 is opened, and the internal circulation fan 450 is running. The internal circulation fan 450 drives the moisture in the drying chamber to be heated by the condenser 620 and the auxiliary heater 220, so as to circulate until the moisture is removed.
[0056] Reference Figure 2 When the internal dehumidification and external dehumidification mode is in operation in this embodiment, the fresh air valve 440 is opened at a certain angle, the internal circulation valve 430 is opened, and the internal circulation fan 450 operates at part power. The fresh air entering from the fresh air inlet 410 enters the drying chamber, carrying some moisture through the exhaust gas discharge channel 300 and finally being discharged from the exhaust port 420. Another part of the moisture is removed by heating the condenser 620 and the auxiliary heater 220 after passing through the internal circulation air duct 400.
[0057] In this embodiment, the exhaust vent 420 is not equipped with a damper. After the internal circulation damper 430 is opened, a portion of the exhaust gas flowing out of the drying chamber is discharged from the exhaust vent 420, and a portion of the exhaust gas flows into the internal circulation duct 400. The exhaust vent 420 is used for exhausting air. During use, a small amount of air will enter the internal circulation duct 400, but this will not affect the overall performance.
[0058] In some other embodiments, a damper can be provided at the exhaust port 420 to further control the air intake and exhaust of the exhaust port 420.
[0059] Example 2
[0060] Reference Figure 3 In this embodiment, based on Embodiment 1, a dehumidification device 460 is installed in the internal circulation duct 400, and the dehumidification device 460 is located on the windward side of the internal circulation air valve 430. Specifically, the dehumidification device 460 can be a rotary dehumidifier, a dehumidifier, or a desiccant box. This embodiment can also perform the external dehumidification mode, internal dehumidification mode, and internal dehumidification combined with external dehumidification mode as in Embodiment 1.
[0061] Example 3
[0062] Reference Figure 4 , Figure 5 This embodiment removes the internal circulation fan 450 from Embodiment 1. This embodiment can perform both internal dehumidification and external dehumidification modes. (Refer to...) Figure 4 In this embodiment, when the external dehumidification mode is activated, the fresh air valve 440 is opened, the internal circulation valve 430 is closed, and the fan 500 is running. Fresh air entering from the fresh air inlet 410 passes through the hot air input channel 200 and enters the drying chamber, carrying moisture from the drying chamber through the exhaust gas discharge channel 300 and finally exiting from the exhaust outlet 420. (Refer to...) Figure 5In this embodiment, when the internal dehumidification mode is activated, the fresh air valve 440 is closed, the internal circulation valve 430 is opened, and the fan 500 is running. The fan 500 drives the moisture in the drying chamber to be heated by the condenser 620 and the auxiliary heater 220, thus circulating until the moisture is removed.
[0063] The heat pump drying system in this embodiment offers more diversified dehumidification methods. It can switch between internal dehumidification mode and external dehumidification mode according to changes in the external environment. Internal dehumidification mode is used when the external humidity is high, and external dehumidification mode is used when the external environment is dry, thereby meeting the need for rapid dehumidification and improving drying efficiency. In this embodiment, the exhaust vent 420 does not have a damper. After the internal circulation damper 430 is opened, a portion of the exhaust gas flowing out of the drying chamber is discharged from the exhaust vent 420, and a portion flows into the internal circulation duct 400. The exhaust vent 420 is for exhaust; during use, a small amount of air will enter the internal circulation duct 400, but this does not affect the overall performance.
[0064] In some other embodiments, a damper can be provided at the exhaust port 420 to further control the air intake and exhaust of the exhaust port 420.
[0065] Example 4
[0066] In this embodiment, the drying chamber is set as a drum 110, such as Figures 1 to 5 As shown.
[0067] Example 5
[0068] In this embodiment, the drying room is set as drying chamber 120, such as Figure 6 As shown.
[0069] The following describes several dehumidification modes of this application:
[0070] Figure 1 This is a schematic diagram of the gas flow direction of the heat pump drying system in the internal dehumidification mode according to Embodiment 1 of this application. When the internal dehumidification mode is in operation, the fresh air valve 440 is closed, the internal circulation valve 430 is opened, and the internal circulation fan 450 is turned on. The internal circulation fan 450 drives the moisture in the drying chamber to be heated by the condenser 620 and the auxiliary heater 220, and so on until the moisture is removed.
[0071] Figure 2This is a schematic diagram of the gas flow direction of the heat pump drying system in the internal dehumidification and external exhaust mode of Embodiment 1 of this application. When the internal dehumidification and external exhaust mode is in operation, the fresh air valve 440 is opened at a certain angle, the internal circulation valve 430 is opened, and the internal circulation fan 450 operates at part power. The fresh air entering from the fresh air inlet 410 enters the drying chamber, carrying some moisture through the exhaust gas discharge channel 300 and finally being discharged from the exhaust port 420. Another part of the moisture is removed by heating the condenser 620 and the auxiliary heater 220 after passing through the internal circulation air duct 400.
[0072] Figure 3 This is a schematic diagram of the gas flow in the heat pump drying system of Embodiment 2 of this application under the internal dehumidification and external exhaust mode. During operation, the fresh air valve 440 is opened at a certain angle, the internal circulation valve 430 is opened, and the internal circulation fan 450 operates at part power. The fresh air entering from the fresh air inlet 410 enters the drying chamber, carrying some moisture through the exhaust gas discharge channel 300 and finally being discharged from the exhaust port 420. Another part of the moisture is removed by heating the condenser 620 and the auxiliary heater 220 after passing through the internal circulation air duct 400. When the moisture passes through the internal circulation air duct 400, the dehumidification device 460 can also absorb the moisture, thereby further improving the dehumidification effect.
[0073] Figure 4 This is a schematic diagram of the gas flow direction of the heat pump drying system in the external dehumidification mode according to Embodiment 3 of this application. During operation, the fresh air valve 440 is opened, the internal circulation valve 430 is closed, and the fan 500 is running. The fresh air entering from the fresh air inlet 410 enters the drying chamber after passing through the hot air input channel 200. Carrying the moisture in the drying chamber, it passes through the exhaust gas discharge channel 300 and is finally discharged from the exhaust port 420.
[0074] Figure 5 When the heat pump drying system of Embodiment 3 of this application is in internal dehumidification mode, the fresh air valve 440 is closed, the internal circulation valve 430 is opened, and the fan 500 is running. The fan 500 drives the moisture in the drying chamber to be heated by the condenser 620 and the auxiliary heater 220, thus circulating until the moisture is removed. It should be noted that in this mode, most of the airflow circulates internally in the hot air input channel 200, the exhaust gas outlet channel 300, and the internal circulation duct 400. When the temperature rises and the gas expands, a small amount of internal gas will be discharged from the exhaust port 420.
[0075] The heat pump drying system of this application has more diversified dehumidification methods, with three modes: internal dehumidification mode, external dehumidification mode, and internal dehumidification combined with external dehumidification mode. When the external environment humidity is high, the internal dehumidification mode is used, and when the external environment is dry, the external dehumidification mode or internal dehumidification combined with external dehumidification mode is used, thereby meeting the needs of rapid dehumidification and improving drying efficiency.
[0076] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.
Claims
1. A heat pump drying system for installation in a drying chamber, characterized in that: include A hot air input channel is installed at the entrance of the drying chamber; An exhaust gas discharge channel is installed at the outlet of the drying chamber; An internal circulation air duct connects the hot air input channel and the exhaust gas discharge channel. The internal circulation air duct is provided with a fresh air inlet and an exhaust air outlet. The fresh air inlet is connected to the hot air input channel and is equipped with a fresh air valve. The exhaust air outlet is connected to the exhaust gas discharge channel. An internal circulation valve is provided inside the internal circulation air duct and is located between the fresh air inlet and the exhaust air outlet. A fan is installed in the exhaust gas discharge channel. The fan drives the airflow to flow out from the outlet of the drying chamber, and then flow into the inlet of the drying chamber after passing through the hot gas input channel, the internal circulation air duct and the exhaust gas discharge channel. A heat pump assembly includes a compressor, a condenser, a throttling element, and an evaporator that form a refrigerant cycle. The condenser is disposed in the hot gas inlet channel to heat the airflow flowing into the hot gas inlet channel, and the evaporator is disposed in the exhaust gas outlet channel to absorb the waste heat in the airflow flowing out of the exhaust gas outlet channel. The heat exchanger has a first heat exchange unit and a second heat exchange unit that exchange heat with each other. The first heat exchange unit is disposed in the exhaust gas discharge channel, and the second heat exchange unit is disposed in the hot gas input channel, thereby exchanging heat between the airflow flowing out of the exhaust gas discharge channel and the airflow flowing into the hot gas input channel.
2. The heat pump drying system according to claim 1, characterized in that: An internal circulation fan is installed inside the internal circulation duct. The internal circulation fan is located on the leeward side of the internal circulation valve. The internal circulation fan is used to drive the gas in the exhaust gas discharge channel through the internal circulation duct to the hot gas input channel.
3. The heat pump drying system according to claim 2, characterized in that: A dehumidification device is installed in the internal circulation air duct, and the dehumidification device is located on the windward side of the internal circulation air valve.
4. The heat pump drying system according to claim 1, characterized in that: The second heat exchange unit is located on the windward side of the condenser, so that the airflow in the hot gas input channel passes through the second heat exchange unit before flowing to the condenser; the first heat exchange unit is located on the windward side of the evaporator, so that the airflow in the exhaust gas discharge channel passes through the first heat exchange unit before flowing to the evaporator.
5. The heat pump drying system according to claim 1, characterized in that: The fresh air inlet is aligned with the hot air input channel, and the exhaust outlet is aligned with the waste gas discharge channel.
6. The heat pump drying system according to claim 1, characterized in that: An air inlet filter is provided in the hot air input channel, and the air inlet filter is located between the fresh air inlet and the second heat exchange unit.
7. The heat pump drying system according to claim 1, characterized in that: An air filter device is installed at the outlet of the drying chamber.
8. The heat pump drying system according to claim 1, characterized in that: An auxiliary heater is provided in the hot gas input channel, and the auxiliary heater is located on the leeward side of the condenser.
9. The heat pump drying system according to any one of claims 1 to 8, characterized in that: At least two heat pump components are provided. Each of the condensers is arranged side by side at intervals along the inflow direction of the overall airflow in the hot gas input channel to perform multi-stage heating of the airflow flowing into the hot gas input channel. Each of the evaporators is arranged side by side at intervals along the outflow direction of the overall airflow in the exhaust gas discharge channel to perform multi-stage absorption of the waste heat in the airflow flowing out of the exhaust gas discharge channel.
10. The heat pump drying system according to claim 9, characterized in that: The drying chamber includes a drying drum or a drying room.