Drying system and drying method

Abstract

The invention relates to the technical field of lithium battery production, in particular to a drying system and a drying method.The drying system comprises a drying production line provided with an air supply outlet and an air exhaust outlet; the heat pump mechanism is provided with an evaporation side and a condensation side; the sensible heat exchanger is provided with a first channel and a second channel; the first end of the first channel communicates with outside fresh air, the second end of the first channel is connected with the air supply outlet, and the fresh air exchanges heat with the condensation side in the air supply process; the first end of the second channel is communicated with the evaporation side, and the second end of the second channel is communicated with the exhaust outlet. According to the embodiment of the invention, the condensation side of the heat pump mechanism is adopted for heat exchange, the energy efficiency ratio is obviously higher, meanwhile, after the sensible heat exchanger is adopted, heat of exhausted air can be further recycled, and therefore energy consumption can be reduced. And meanwhile, the heat of the exhaust air can preheat the fresh air, so that the energy consumption can be further reduced, and the energy utilization rate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery production, and in particular to a drying system and a drying method. Background Art

[0002] The drying step in the traditional lithium battery production process uses electric heating to heat the air in the oven through thermal oil and its heat exchanger. Currently, more than 90% of traditional electric heating oven equipment uses a unified single oven unit with the same electric heating configuration.

[0003] However, this method results in low energy efficiency and is not conducive to environmental protection. Summary of the invention

[0004] In view of this, the present invention provides a drying system to solve the problem of low energy utilization rate when drying by electric heating in the lithium battery production process.

[0005] In a first aspect, the present invention provides a drying system, the drying system comprising:

[0006] The drying production line is equipped with air supply and exhaust vents;

[0007] A heat pump mechanism is provided with an evaporation side and a condensation side;

[0008] The sensible heat exchanger is provided with a first channel and a second channel which are staggered and crossed; the first channel and the second channel perform heat exchange at an overlapping position;

[0009] The first end of the first channel is connected to the fresh air from the outside, the second end of the first channel is connected to the air supply port, and the fresh air exchanges heat with the condensation side during the air supply process;

[0010] The first end of the second channel is communicated with the evaporation side, and the second end of the second channel is communicated with the exhaust port.

[0011] Beneficial effects: The embodiment of the present invention uses the condensing side of the heat pump mechanism for heat exchange, which is significantly more energy efficient than the traditional electric heating heating method. At the same time, after using the sensible heat exchanger, the heat of the exhaust air can be further recovered, thereby reducing energy consumption. In addition, after the fresh air passes through the sensible heat exchanger, the heat of the exhaust air can be used to preheat the fresh air, thereby reducing the energy consumed by the heat pump mechanism, thereby further reducing energy consumption and improving energy utilization. Furthermore, compared with the traditional heat pipe heat exchanger, the sensible heat exchanger can be directly used as an intermediate exchange medium, and can directly exchange the temperature and humidity of the air without setting up traditional complex pipelines, further simplifying the overall structural layout.

[0012] In an optional embodiment, the drying production line includes:

[0013] A drying chamber, provided with the air supply port and the air exhaust port;

[0014] A conveying assembly, arranged in the drying chamber, and used for conveying the medium to be dried;

[0015] The air duct assembly is provided with an air inlet channel and an air exhaust channel, wherein the first end of the air inlet channel is connected to the air supply port, the second end of the air inlet channel is connected to the second end of the first channel, one end of the exhaust channel is connected to the second end of the second channel, and the second end of the exhaust channel is connected to the exhaust port.

[0016] In an optional embodiment, along the conveying direction of the conveying component, a portion of the exhaust outlets are arranged on the upstream side of the conveying component, another portion of the exhaust outlets are arranged on the downstream side of the conveying component, and all the air supply outlets are correspondingly arranged in the middle area of ​​the conveying component.

[0017] In an optional embodiment, along the conveying direction of the conveying component, a portion of the air supply outlets are arranged on the upstream side of the conveying component, another portion of the air supply outlets are arranged on the downstream side of the conveying component, and all the exhaust outlets are correspondingly arranged in the middle area of ​​the conveying component.

[0018] Beneficial effects: In this embodiment, the exhaust port or air supply port is set on the upstream and downstream sides, which can ensure that the fresh air is discharged from multiple positions or enters the drying chamber and is evenly distributed in the entire drying area. In addition, the fresh air can be introduced more effectively, the air circulation speed can be increased, and the drying efficiency can be improved. At the same time, a more uniform temperature gradient can be formed to avoid uneven drying caused by temperature differences. Further, in this embodiment, the air supply port or exhaust port is set in the middle area, which can effectively avoid the retention of moisture in the drying chamber, ensure the uniform distribution of air flow, and thus improve the overall drying effect. In particular, based on the principle of air humidity saturation, when the fresh air enters from the air supply port on the upstream side, the temperature is relatively low, and the water vapor evaporates relatively slowly on the upstream side. Therefore, the amount of fresh air entering can be controlled, the demand for fresh air heating is reduced, and excessive water vapor is avoided from accumulating in the system. Near the exhaust port in the middle area, the temperature is the highest, and the amount of water vapor that can be accommodated in the air is the largest at this time. Therefore, exhausting in the middle area can quickly reduce the humidity in the system, which is conducive to the diffusion of water vapor from the materials in the production line, thereby forming an efficient dehumidification cycle. The working conditions on the downstream side are the same as those on the upstream side. In summary, the dehumidification efficiency can be significantly improved.

[0019] In an optional embodiment, the condensation side comprises:

[0020] The condenser is arranged between the second end of the first channel and the air supply port; during the air supply process, the fresh air enters the air supply port after heat exchange with the condenser.

[0021] In an optional embodiment, the condensation side comprises:

[0022] The condenser is arranged between the second end of the first channel and the air supply port; during the air supply process, the fresh air enters the air supply port after heat exchange with the condenser.

[0023] In an optional embodiment, the condensation side comprises:

[0024] Condenser;

[0025] A heat exchange component is provided with a first heat exchange side and a second heat exchange side; a heat exchange medium in the heat exchange component circulates between the first heat exchange side and the second heat exchange side;

[0026] The first heat exchange side is arranged close to the condenser and exchanges heat with the condenser; the second heat exchange side is arranged in the drying production line, and after the fresh air enters the drying production line, it exchanges heat with the second heat exchange side.

[0027] In an optional embodiment, the heat exchange component includes:

[0028] A containing box, in which the heat exchange medium is arranged; the containing box exchanges heat with the condenser;

[0029] A heating coil is connected to the containing box; the heating coil is arranged in the drying line along the conveying direction of the drying line, and after the fresh air enters the drying line, it exchanges heat with the heating coil.

[0030] In an optional embodiment, two heating coils are provided, one heating coil is provided on the upstream side of the drying line, and the other heating coil is provided on the downstream side of the drying line; and the two heating coils are extended along the conveying direction of the drying line.

[0031] In an optional embodiment, the containing box includes a first box body and a second box body, and the heat exchange assembly further includes:

[0032] a first pipeline, one end of which is connected to the water outlet of the first box, and the other end of which is connected to the water inlet of the heating coil;

[0033] A second pipeline, one end of the second pipeline is connected to the water outlet of the heating coil, and the other end of the second pipeline is connected to the water return port of the second box;

[0034] a third pipeline, one end of which is connected to the water outlet of the second box, and the other end of which is connected to the heat exchange inlet of the condenser;

[0035] A fourth pipeline, one end of which is connected to the heat exchange outlet of the condenser, and the other end of which is connected to the water return port of the first box.

[0036] In an optional embodiment, the drying production line further includes:

[0037] The heat-insulating layer is laid on the inner wall of the drying chamber.

[0038] Beneficial effects: The insulation layer can effectively reduce the heat exchange inside and outside the drying chamber, reduce heat loss, and improve the energy efficiency of the entire system. In addition, by reducing heat loss, energy consumption can be significantly reduced, thereby saving operating costs. At the same time, the insulation layer helps to maintain a stable temperature in the drying chamber, avoid temperature fluctuations, and ensure the uniformity and consistency of the drying process. The stable temperature environment can thus improve the drying effect and ensure product quality. Furthermore, it can also improve energy efficiency and reduce energy consumption, help reduce carbon emissions, and meet environmental protection requirements.

[0039] In a second aspect, the present invention further provides a drying method, which is applied to the drying system described in any one of the above embodiments, and the drying method comprises:

[0040] Get the current drying temperature and target drying temperature in the drying production line;

[0041] The heat release amount on the condensation side is adjusted based on the temperature difference between the current drying temperature and the target drying temperature.

[0042] Beneficial effects: The embodiment of the present invention uses the condensing side of the heat pump mechanism for heat exchange, which is significantly more energy efficient than the traditional electric heating heating method. At the same time, after using the sensible heat exchanger, the heat of the exhaust air can be further recovered, thereby reducing energy consumption. At the same time, after the fresh air passes through the sensible heat exchanger, the heat of the exhaust air can be used to preheat the fresh air, thereby reducing the energy consumed by the heat pump mechanism, thereby further reducing energy consumption and improving energy utilization. Furthermore, the heat release on the condensing side is adjusted according to the temperature difference, so that the heat release on the condensing side can correspond to the temperature of the fresh air after absorbing heat, thereby preventing the fresh air from being unable to be absorbed in time due to excessive heat release, thereby reducing energy utilization efficiency.

[0043] In an optional implementation, adjusting the heat release amount on the condensation side based on the temperature difference between the current drying temperature and the target drying temperature includes:

[0044] Based on the temperature difference, adjusting the operating frequency of the compressor in the heat pump mechanism to control the heat release of the condenser in the heat pump mechanism;

[0045] The opening value of the expansion valve in the heat pump mechanism is adjusted to control the heat absorption amount of the evaporator.

[0046] In an optional embodiment, the drying method further comprises:

[0047] Get the air volume in the drying line;

[0048] When the air intake volume is greater than a preset threshold, reducing the operating frequency of the compressor and the opening value of the expansion valve in the heat pump mechanism;

[0049] When the air intake volume is less than a preset threshold, the operating frequency of the compressor and the opening value of the expansion valve in the heat pump mechanism are increased.

[0050] In an optional embodiment, the drying method further comprises:

[0051] A fresh air valve is provided at one end of the first channel close to the outside, and an exhaust valve is provided at one end of the second channel close to the evaporation side;

[0052] Get the current humidity and target humidity in the drying production line;

[0053] Based on the humidity difference between the current humidity and the target humidity, adjusting the working state of the evaporator to control the humidity of the exhaust air;

[0054] Based on the humidity difference, feedback is provided to adjust the opening values ​​of the fresh air valve and the exhaust valve.

[0055] In an optional implementation, the feedback adjustment of the opening value of the fresh air valve and the opening value of the exhaust valve based on the humidity difference includes:

[0056] When the humidity difference is greater than the preset humidity, the opening value of the exhaust valve is increased and the opening value of the fresh air valve is reduced;

[0057] When the humidity difference is less than the preset humidity, the opening value of the exhaust valve is reduced and the opening value of the fresh air valve is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 This is the drying principle diagram of the current electric heating method;

[0060] Figure 2 This is the drying efficiency diagram of the current electric heating method;

[0061] Figure 3 This is a schematic diagram of the structure of the first implementation mode of the drying system in the embodiment of the present invention and only the condenser is provided;

[0062] Figure 4 for Figure 3 Schematic diagram of medium moisture content and dehumidification efficiency in the drying system along the production line direction;

[0063] Figure 5 A second embodiment of the drying system in the embodiment of the present invention and a schematic diagram of the structure provided with a condenser and a heat exchange component;

[0064] Figure 6 for Figure 5 Schematic diagram of medium moisture content and dehumidification efficiency in the drying system along the production line direction.

[0065] Figure 7 for Figure 5 Schematic diagram of temperature and humidity curve of the drying system;

[0066] Figure 8 Enthalpy-humidity diagram in an embodiment of the present invention.

[0067] Description of reference numerals:

[0068] 1. Drying production line; 11. Air supply outlet; 12. Air exhaust outlet; 13. Drying chamber; 14. Conveying assembly; 15. Air duct assembly; 16. Insulation layer;

[0069] 2. heat pump mechanism; 21. evaporator; 22. expansion valve; 23. compressor; 24. condenser; 25. heat exchange assembly; 251. containing box; 2511. first box body; 2512. second box body; 2513. first pipeline; 2514. second pipeline; 2515. third pipeline; 2516. fourth pipeline; 252. heating coil;

[0070] 3. Sensible heat exchanger; 31. First channel; 32. Second channel. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0072] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0073] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0075] The drying step in the traditional lithium battery production process uses electric heating to heat the air in the oven through thermal oil and its heat exchanger. Currently, more than 90% of traditional electric heating oven equipment uses a unified single oven unit with the same electric heating configuration. However, this method has low energy utilization efficiency and is not conducive to environmental protection.

[0076] In view of this, the present invention provides a drying system to solve the problem of low energy utilization rate when drying by electric heating in the lithium battery production process.

[0077] Combine the following Figures 1 to 8 , describing an embodiment of the present invention.

[0078] According to an embodiment of the present invention, on the one hand, a drying system is provided. The drying system includes a drying production line 1, a heat pump mechanism 2 and a sensible heat exchanger 3.

[0079] Specifically, in this embodiment, the drying production line 1 includes a roller drive combination that drives the medium to be dried to move in one direction, for example, it may be composed of a roller, a drive motor and its supporting electrical equipment. The drying production line 1 is also provided with an air supply port 11 and an air exhaust port 12, and the air exhaust port 12 and the air supply port 11 are both located at the top of the drying production line 1 to facilitate the installation of the air duct connection. Of course, the air supply port 11 and the air exhaust port 12 can also be installed at other positions of the drying production line 1. This embodiment is only an example for illustration, but it is not limited to this. Those skilled in the art can make changes according to actual conditions as long as they can achieve the same technical effect.

[0080] Furthermore, in the present embodiment, the heat pump mechanism 2 generally includes four major components of a heat pump, namely, a compressor 23, an evaporator 21, a condenser 24 and an expansion valve 22. The refrigerant circulates in the heat pump mechanism 2 to complete efficient heat transfer: it is compressed by the compressor 23, releases heat by the condenser 24, expands and reduces pressure, absorbs heat by the evaporator 21, and returns to the compressor 23. The evaporation side of the heat pump mechanism 2 is the cooling side where the evaporator 21 is located, and the condensation side of the heat pump mechanism 2 is the heating side where the condenser 24 is located. After the normal temperature wind passes through the evaporator 21, it absorbs the heat of the evaporator 21, so that the temperature of the normal temperature wind becomes lower, so it is the cooling side. After the normal temperature wind passes through the condenser 24, it absorbs the heat of the condenser 24, so that the temperature of the normal temperature wind becomes higher, so it is the heating side.

[0081] Specifically, in this embodiment, the compressor 23 is a power source for the fluorine circuit system, compressing the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure gas, and entering the condenser 24. The compressor 23 is a high-temperature refrigerant compressor 23, wherein the high-temperature refrigerant can be a refrigerant with a critical temperature greater than 100°C, such as R134a, R515B, R245fa, R1233zd, R1234yd, and R1336mzz.

[0082] The function of the condenser 24 is to release heat from the high-temperature and high-pressure refrigerant inside and cool it into a high-temperature and high-pressure liquid. The condensation and heat release process of the refrigerant in the condenser 24 directly heats the air, which is heated to high-temperature dry air at the target temperature and enters the air supply port 11. This avoids possible heat loss in other heat exchange processes and makes the operation more efficient.

[0083] The function of the expansion valve 22 is: the refrigerant is decompressed after passing through the expansion valve 22 , becomes a low-temperature and low-pressure liquid, and enters the evaporator 21 .

[0084] The function of the evaporator 21 is that the refrigerant absorbs heat from the air in the exhaust duct under low temperature and low pressure conditions and evaporates into gas. At the same time, the medium-temperature exhaust air with moisture from the drying medium is cooled and dehumidified after passing through the evaporator 21, reduced to low-temperature air and discharged. The cooling process is accompanied by condensation of water, thereby completing the dehumidification, cooling and heat recovery of the exhaust air.

[0085] Further, in this embodiment, the sensible heat exchanger 3 is provided with a staggered and crossed first channel 31 and second channel 32, and the first channel 31 and the second channel 32 perform heat exchange at the overlapping position. The first end of the first channel 31 is connected to the fresh air from the outside, and the second end of the first channel 31 is connected to the air supply port 11, and the fresh air performs heat exchange with the condensation side during the air supply process. The first end of the second channel 32 is connected to the evaporation side, and the second end of the second channel 32 is connected to the exhaust port 12.

[0086] In the actual working process, the low-temperature dry fresh air first passes through the first channel 31 of the sensible heat exchanger 3, and is heated by the high-temperature exhaust air in the second channel 32, and the temperature is raised to medium temperature to achieve preheating. Then the medium-temperature dry air passes through the condensation side, and the air is heated to the target temperature. The humidity of the air heated on the condensation side is significantly reduced. The high-temperature dry air is sent to the drying production line 1 to dry the product. The moisture content of the high-temperature exhaust air after drying increases, and it is sent to the second channel 32 of the sensible heat exchanger 3 through the exhaust port 12. After the high-temperature exhaust air in the second channel 32 heats the low-temperature fresh air, the exhaust air temperature is reduced to medium temperature. The medium-temperature and high-humidity exhaust air passes through the evaporation side for heat recovery, and then condensed water is precipitated and discharged. The exhaust air becomes air at a lower temperature and is discharged from the entire system.

[0087] With such a configuration, the embodiment of the present invention uses the condensing side of the heat pump mechanism 2 for heat exchange, which is significantly more energy efficient than the traditional electric heating heating method. At the same time, after using the sensible heat exchanger 3, the heat of the exhaust air can be further recovered, thereby reducing energy consumption. At the same time, after the fresh air passes through the sensible heat exchanger 3, the heat of the exhaust air can be used to preheat the fresh air, thereby reducing the energy consumed by the heat pump mechanism 2, thereby further reducing energy consumption and improving energy utilization. Furthermore, compared with the traditional heat pipe heat exchanger, the sensible heat exchanger 3 can be directly used as an intermediate exchange medium, and can directly perform heat exchange on the temperature and humidity of the air without setting up traditional complex pipelines, further simplifying the overall structural layout.

[0088] Furthermore, in an optional embodiment, the drying production line 1 includes a drying chamber 13 , a conveying component 14 and an air duct component 15 .

[0089] Specifically, in this embodiment, the drying chamber 13 is provided with the air supply port 11 and the air exhaust port 12. The conveying assembly 14 is provided in the drying chamber 13, and the conveying assembly 14 is used to convey the medium to be dried. The conveying assembly 14 may be composed of a roller, a driving motor and its supporting electrical equipment. Of course, this embodiment is only an example of the composition of the conveying assembly 14, but it is not limited thereto, and those skilled in the art may make changes according to actual conditions, as long as the same technical effect can be achieved.

[0090] Furthermore, the air duct assembly 15 is provided with an air inlet channel and an air exhaust channel, the first end of the air inlet channel is connected to the air supply port 11, the second end of the air inlet channel is connected to the second end of the first channel 31, one end of the exhaust channel is connected to the second end of the second channel 32, and the second end of the exhaust channel is connected to the exhaust port 12.

[0091] Furthermore, if Figure 1 As shown, the current electric heating drying method is usually to evenly arrange matching air inlets and outlets along the conveying direction of the production line, so that the overall dehumidification efficiency presents a wave of ups and downs, such as Figure 2 As shown, the overall dehumidification efficiency is low, the multi-air outlet system is complex, and the energy utilization efficiency is low, which is not conducive to environmental protection.

[0092] Further, in the first embodiment, if Figure 3 As shown, along the conveying direction of the conveying component 14, a part of the exhaust ports 12 are arranged on the upstream side of the conveying component 14, another part of the exhaust ports 12 are arranged on the downstream side of the conveying component 14, and all the air supply ports 11 are correspondingly arranged in the middle area of ​​the conveying component 14.

[0093] In this embodiment, along the conveying direction of the conveying assembly 14, that is, along the conveying direction of the drying production line 1, the change in the moisture content of the drying medium and the overall flow direction of the air are as follows: Figure 4 shown.

[0094] It can be seen from this that after the airflow enters the drying production line 1, the air flows from the middle area to the upstream and downstream sides of the drying production line 1. The upstream side of the drying production line 1 is the side close to the inlet of the drying production line 1, and the downstream side of the drying production line 1 is the side close to the outlet of the drying production line. Figure 4 It can also be seen that as the medium to be dried is transported, the moisture content of the medium to be dried is continuously reduced, and the overall dehumidification efficiency shows a trend of first increasing and then decreasing. This trend corresponds to the principle of air humidity saturation.

[0095] The overall dehumidification efficiency shows a trend of first increasing and then decreasing as follows:

[0096] In the heating and dehumidification stage, the temperature gradually rises, but the relative humidity is high. According to the air humidity saturation theory, the amount of water vapor that air can hold at a lower temperature is less. When the temperature begins to rise, although the humidity is relatively high, if a large amount of fresh air is introduced at this time, the fresh air needs to be heated to the corresponding working temperature after entering the drying production line. However, since the temperature itself is not very high at this stage, the water vapor of the medium to be dried evaporates relatively slowly. The large amount of fresh air introduced not only increases the energy consumption of heating the fresh air, but also cannot effectively discharge the water vapor from the system due to the low dehumidification efficiency. Therefore, by controlling the amount of fresh air entering, the demand for fresh air heating is reduced, and at the same time, excessive water vapor is avoided from accumulating in the system, because the dehumidification capacity of the system itself is limited at this time. Of course, for the way to control the amount of fresh air entering, a fresh air valve can be installed at the fresh air inlet.

[0097] After that, it enters the high-temperature dehumidification stage. The high-temperature dehumidification stage is the stage with the highest temperature in the entire process. At this time, the air can accommodate the largest amount of water vapor, and the dehumidification efficiency is significantly higher in this stage. According to the humidity saturation curve, at high temperatures, water vapor is more likely to evaporate from the medium to be dried.

[0098] Exhausting air at this stage is the most effective for dehumidification. Exhausting a large amount of wet air can quickly reduce the humidity in the system. As the humidity in the system decreases, the partial pressure difference between the water vapor in the medium to be dried and the water vapor in the surrounding air increases, which is conducive to the continued diffusion of water vapor from the material, forming an efficient dehumidification cycle.

[0099] Finally, it enters the cooling and dehumidification stage. The cooling and dehumidification stage is similar to the heating and dehumidification stage. The temperature of the cooling and dehumidification stage gradually decreases, and the air's ability to hold water vapor also decreases. At this time, if a large amount of fresh air is introduced, the fresh air may reach a saturated state during the cooling process and precipitate moisture, which may increase the humidity in the system.

[0100] Moreover, at lower temperatures, the rate at which water vapor evaporates from the material slows down, and the dehumidification efficiency is low. Controlling the amount of fresh air can prevent unnecessary water vapor accumulation in the system, reduce the impact on subsequent equipment, such as cooling equipment, and avoid problems such as water vapor condensing on the surface of the material during the cooling process, thereby ensuring product quality.

[0101] Further, in the second embodiment, if Figure 5 As shown, along the conveying direction of the conveying component 14, a part of the air supply outlets 11 are arranged on the upstream side of the conveying component 14, another part of the air supply outlets 11 are arranged on the downstream side of the conveying component 14, and all the exhaust outlets 12 are correspondingly arranged in the middle area of ​​the conveying component 14.

[0102] In this embodiment, along the conveying direction of the conveying assembly 14, that is, along the conveying direction of the drying production line 1, the change in the moisture content of the drying medium and the overall flow direction of the air are as follows: Figure 6 shown.

[0103] It can be seen from this that after the airflow enters the drying production line 1, the air flows to the middle area of ​​the drying production line 1 from the upstream side and the downstream side at the same time. Figure 6 Because the heat exchange medium flows in the opposite direction to the fresh air direction, the temperature and moisture content are highest in the middle of the heat exchange medium inlet. However, because the fresh air carries the moisture of the material blown in from the inlet, the dehumidification efficiency is not as high as at the beginning. The humidity at the medium inlet is also the highest at the beginning, and the humidity at the fresh air inlet is also the lowest. In addition, due to radiation heat exchange, the heat exchange efficiency is relatively high at the beginning, but in comparison Figure 3 This solution is still the best solution because the overall efficiency curve is relatively flat, and it can make full use of the temperature and humidity curve for dehumidification. It can also use the reverse heat exchange effect of the heating element and the fresh air to increase the heat exchange efficiency, and the radiation heat exchange will be better. Figure 3 The heating curve of convection heat transfer is more uniform, and there will not be large temperature deviations.

[0104] In this way, the present embodiment sets the air supply port 11 on the upstream side and the downstream side, which can ensure that fresh air enters the drying chamber 13 from multiple positions and is evenly distributed in the entire drying area. In addition, fresh air can be introduced more effectively, the air circulation speed can be increased, and the drying efficiency can be improved. At the same time, a more uniform temperature gradient can be formed to avoid uneven drying due to temperature differences. Furthermore, the present embodiment sets the exhaust port 12 in the middle area to effectively discharge moisture from the middle position, avoid moisture retention in the drying chamber 13, ensure uniform distribution of airflow, and thus improve the overall drying effect. In addition, the exhaust port 12 is concentrated in the middle area, which can better utilize the heat generated during the drying process and reduce energy waste.

[0105] Further, in an optional embodiment, as Figure 5 As shown, the drying chamber 13 is provided with two air supply ports 11 and one air exhaust port 12 . The two air supply ports 11 are respectively arranged at the upstream end and the downstream end of the conveying component 14 , and the air exhaust port 12 is correspondingly arranged at the middle position of the conveying component 14 .

[0106] Of course, this embodiment is only an example of the arrangement of the air supply port 11 and the air exhaust port 12, but it is not limited thereto. Those skilled in the art can make changes according to actual conditions as long as the same technical effect can be achieved.

[0107] Further, as an embodiment, if Figure 3As shown, the condensation side includes a condenser 24, which is arranged between the second end of the first channel 31 and the air outlet 11. During the air supply process, the fresh air exchanges heat with the condenser 24 and enters the air outlet 11. That is, after being heated by the condenser 24, the fresh air is directly transported to the inside of the drying production line 1. Since a pure refrigerant cycle is adopted, no additional hot water storage and circulation system is required, and the equipment is more compact.

[0108] Further, as a preferred embodiment, Figure 5 As shown, the condensation side includes a condenser 24 and a heat exchange component 25 .

[0109] In this embodiment, the condenser 24 is only used as a heat source for the heat exchange component 25. In actual operation, the heat exchange component 25 exchanges heat with the condenser 24 and then exchanges heat with the fresh air. Specifically, the heat exchange component 25 is provided with a first heat exchange side and a second heat exchange side, and the heat exchange medium in the heat exchange component 25 circulates between the first heat exchange side and the second heat exchange side.

[0110] The first heat exchange side is arranged close to the condenser 24, and exchanges heat with the condenser 24. The second heat exchange side is arranged in the drying production line 1, and after the fresh air enters the drying production line 1, it exchanges heat with the second heat exchange side.

[0111] In this embodiment, the second heat exchange side is set in the drying production line 1, which can reduce the heat loss. At the same time, the higher temperature of the second heat exchange side can further improve the drying efficiency of the drying production line 1. That is to say, in the drying production line 1, the second heat exchange side and the fresh air after heat exchange with the second heat exchange side can act on the medium to be dried on the drying production line 1 at the same time, and the fresh air can further circulate and evenly distribute the internal heat of the drying production line 1, which has the effect of doubly improving the drying efficiency.

[0112] Further, in an optional embodiment, the heat exchange assembly 25 includes a containing box 251 and a heating coil 252. In this embodiment, the containing box 251 can be considered as a first heat exchange side, and the heating coil 252 can be considered as a second heat exchange side.

[0113] Specifically, in this embodiment, the heat exchange medium is disposed inside the container 251. The heat exchange medium may be various heat exchange liquids, such as oil, water, ethanol, and other materials. Of course, this embodiment is only an example of the specific material of the heat exchange medium, but it is not limited thereto, and those skilled in the art may make changes according to actual conditions as long as the same technical effect can be achieved.

[0114] In the container box 251, the interior needs to be separated by a partition, one side of the partition is a hot water chamber, in which hot water after heat exchange with the condenser 24 is stored, and the other side of the partition is a return water chamber, in which return water from the heating coil 252 is stored. The return water in the return water chamber is connected to the first end of the heat exchange tube of the condenser 24, and the return water forms hot water after heat exchange, and flows into the hot water chamber from the second end of the heat exchange tube of the condenser 24.

[0115] Further, in this embodiment, the heating coil 252 is connected to the containing box 251, for example, one end of the heating coil 252 is connected to the hot water chamber of the containing box 251, and the other end of the heating coil 252 is connected to the return water chamber of the containing box 251. The heating coil 252 is arranged in the drying line 1 along the conveying direction of the drying line 1, and after the fresh air enters the drying line 1, it exchanges heat with the heating coil 252.

[0116] In the actual working process, the high-temperature hot water after heat exchange with the condenser 24 flows through the pipeline, exchanges heat with the medium-temperature air entering the drying production line 1, and is continuously heated to high-temperature air as the air flows. At the same time, the heating coil 252 is close to the medium to be dried, and part of the heat is transferred to the dried medium in the form of thermal radiation to complete the drying and heating process. The heat exchanger type of the heating coil 252 is a high-efficiency microchannel heat exchanger or a fin-tube heat exchanger with fins. High-temperature pure water (80-120°C) flows inside the heating coil 252, and air flows outside. The fins are straight, corrugated or windowed fins that are set to increase the heat exchange area in order to fully contact with the air. The medium-temperature hot water after heat exchange returns to the return water chamber, and after heat exchange with the condenser 24, it is re-formed into high-temperature hot water.

[0117] Of course, the specific flow direction of the hot water in the heating coil 252 can be set to the opposite direction to the flow direction of the fresh air, so as to achieve countercurrent heat exchange. In countercurrent heat exchange, the temperature of the hot water gradually decreases, while the temperature of the air gradually increases, and the temperature difference between the two is more evenly distributed along the length of the heat exchanger. This makes the average temperature difference of the entire heat exchange process larger than that of the parallel flow, thereby improving the heat transfer efficiency. In the countercurrent arrangement, the air at the outlet is close to the outlet temperature of the hot water, which can heat the air to a higher temperature and improve the drying capacity. Countercurrent heat exchange is closer to the ideal heat exchanger performance, and in theory, it can achieve minimum irreversibility, reduce heat loss, and thus improve the performance coefficient of the system. During the drying process, the humid air is gradually heated, the humidity decreases, the absolute humidity remains unchanged, and the enthalpy value increases. The countercurrent method better matches the needs of heat and mass transfer.

[0118] Further, in an optional embodiment, two heating coils 252 are provided, one heating coil 252 is provided on the upstream side of the drying production line 1, and the other heating coil 252 is provided on the downstream side of the drying production line 1. Both heating coils 252 are arranged to extend along the conveying direction of the drying production line 1. The upstream side of the drying production line 1 is the side close to the inlet of the drying production line 1, and the downstream side of the drying production line 1 is the side close to the outlet of the drying production line.

[0119] Furthermore, in an optional embodiment, the containing box 251 includes a first box body 2511 and a second box body 2512 , and the heat exchange component 25 also includes a first pipeline 2513 , a second pipeline 2514 , a third pipeline 2515 , and a fourth pipeline 2516 .

[0120] Specifically, one end of the first pipeline 2513 is connected to the water outlet of the first box 2511, and the other end of the first pipeline 2513 is connected to the water inlet of the heating coil 252. One end of the second pipeline 2514 is connected to the water outlet of the heating coil 252, and the other end of the second pipeline 2514 is connected to the water return port of the second box 2512. One end of the third pipeline 2515 is connected to the water outlet of the second box 2512, and the other end of the third pipeline 2515 is connected to the heat exchange inlet of the condenser 24. One end of the fourth pipeline 2516 is connected to the heat exchange outlet of the condenser 24, and the other end of the fourth pipeline 2516 is connected to the water return port of the first box 2511.

[0121] When the drying line 1 is large, the corresponding heating coil 252 is also large, and the temperature difference of the hot water before and after the heat exchange in the drying line 1 is also large. In order to avoid the return water affecting the inlet water temperature and to ensure the stability of the inlet water temperature, two water tanks are used, namely the first tank 2511 and the second tank 2512. Due to the large heat exchange capacity, the water flow rate of this part of the heat exchange will also be large. The large water flow rate will have a certain impact on the water temperature in the water tank. Using two water tanks for hot and cold separation is a relatively safe way.

[0122] Furthermore, the enthalpy-humidity diagram of the drying production line 1 is as follows: Figure 8 As shown, the drying process is: 1-2 heating process: sensible heat exchanger 3 + condenser 24; 2-3 drying process: drying air duct of the production line body; 3-4 sensible heat recovery process: sensible heat exchanger 3; 4-5 dehumidification and cooling process (mainly heat recovery heat): evaporator 21.

[0123] In summary, this embodiment significantly improves the system energy efficiency ratio (COP) through efficient heat recovery technology and refrigerant direct heating system, and reduces energy consumption by more than 30% compared with the traditional electric heating drying system. This embodiment adopts environmentally friendly refrigerant to reduce the impact on the environment, and the closed-loop design avoids pollution to the external environment. In addition, the various components of this embodiment can be automatically controlled, reducing the need for manual operation, reducing the difficulty of operation, and improving production efficiency. Due to the reduction in energy consumption and the improvement in drying efficiency, the operating cost of the system is greatly reduced, with good economic benefits.

[0124] Furthermore, in an optional embodiment, the drying production line 1 further includes a heat-insulating layer 16, and the heat-insulating layer 16 is laid on the inner wall of the drying chamber 13. Of course, the specific material of the heat-insulating layer 16 is not limited in this embodiment, and those skilled in the art can change it according to actual conditions as long as the same technical effect can be achieved.

[0125] With such a configuration, the thermal insulation layer 16 can effectively reduce the heat exchange inside and outside the drying chamber 13, reduce heat loss, and improve the energy efficiency of the entire system. In addition, by reducing heat loss, energy consumption can be significantly reduced, thereby saving operating costs. At the same time, the thermal insulation layer 16 helps to maintain the temperature stability in the drying chamber 13, avoid temperature fluctuations, ensure the uniformity and consistency of the drying process, and the stable temperature environment can improve the drying effect and ensure product quality. Furthermore, it can also improve energy efficiency and reduce energy consumption, help reduce carbon emissions, and meet environmental protection requirements.

[0126] In a second aspect, the present invention further provides a drying method, which is applied to the drying system described in any one of the above embodiments, and the drying method comprises:

[0127] S1, obtaining the current drying temperature and target drying temperature in the drying production line 1;

[0128] S2. Adjust the heat release amount on the condensation side based on the temperature difference between the current drying temperature and the target drying temperature.

[0129] In the actual operation process, the change of moisture content of the medium to be dried and the change of the outside fresh air temperature will inevitably affect the fresh air temperature and the exhaust temperature. Therefore, it is inevitable that there will be a certain difference between the overall current drying temperature in the drying production line 1 and the target drying temperature pre-set when starting the drying.

[0130] Therefore, the heat release on the condensation side can be adjusted by the temperature difference between the current drying temperature and the target drying temperature, which can save a certain amount of energy consumption while ensuring that the drying temperature approaches the target drying temperature as much as possible.

[0131] With such a configuration, the embodiment of the present invention uses the condensation side of the heat pump mechanism 2 for heat exchange, which is significantly more energy efficient than the traditional electric heating heating method. At the same time, after using the sensible heat exchanger 3, the heat of the exhaust air can be further recovered, thereby reducing energy consumption. At the same time, after the fresh air passes through the sensible heat exchanger 3, the heat of the exhaust air can preheat the fresh air, thereby reducing the energy consumed by the heat pump mechanism 2, thereby further reducing energy consumption and improving energy utilization. Furthermore, the heat release on the condensation side is adjusted according to the temperature difference, so that the heat release on the condensation side can correspond to the temperature of the fresh air after absorbing heat, preventing the fresh air from being unable to be absorbed in time due to excessive heat release, thereby reducing energy utilization efficiency.

[0132] Further, in an optional implementation, the step S2 includes:

[0133] S21, based on the temperature difference, adjusting the operating frequency of the compressor 23 in the heat pump mechanism 2 to control the heat release of the condenser 24 in the heat pump mechanism 2;

[0134] S22, and adjusting the opening value of the expansion valve 22 in the heat pump mechanism 2 to control the heat absorption amount of the evaporator 21.

[0135] In this embodiment, the operating frequency of the compressor 23 can be adjusted according to the temperature difference to control the heat release of the condenser 24. At the same time, the heat absorption of the evaporator 21 is controlled by adjusting the opening of the expansion valve 22, thereby affecting the temperature of the air.

[0136] The specific control formula is as follows:

[0137] ΔT=T 目标 -T 当前 ;

[0138] Q=C p ×m×ΔT;

[0139] Among them, T 目标 is the target temperature, T 当前 is the current temperature, ΔT is the difference between the target temperature and the current temperature, Q is the amount of heat to be transferred, C p is the specific heat capacity of air, and m is the mass flow rate of air.

[0140] Furthermore, in an optional embodiment, the drying method further comprises:

[0141] S3, obtaining the air intake volume in the drying production line 1;

[0142] S4. When the air intake volume is greater than a preset threshold, reducing the operating frequency of the compressor 23 and the opening value of the expansion valve 22 in the heat pump mechanism 2;

[0143] S5. When the air intake volume is less than a preset threshold, the operating frequency of the compressor 23 and the opening value of the expansion valve 22 in the heat pump mechanism 2 are increased.

[0144] Specifically, in this embodiment, the air intake in the drying production line 1 will largely affect the drying efficiency of the medium to be dried. Generally, the drying efficiency has a certain relationship with the drying temperature and the air intake. When the drying temperature remains unchanged, the air intake is proportional to the drying efficiency. However, after the air intake exceeds a certain threshold, the drying efficiency will gradually tend to a stable value. Therefore, controlling the air intake within a certain threshold can not only ensure a certain drying efficiency, but also improve energy utilization.

[0145] However, the drying temperature can also be adjusted. The drying temperature is related to the heat exchange capacity of the condenser 24, and the state of the refrigerant in the heat pump mechanism 2 determines the heat exchange capacity of the condenser 24.

[0146] Therefore, when the air intake volume is greater than the preset threshold, the operating frequency of the compressor 23 in the heat pump mechanism 2 and the opening value of the expansion valve 22 can be appropriately reduced to control the drying temperature. Similarly, when the air intake volume is less than the preset threshold, the operating frequency of the compressor 23 in the heat pump mechanism 2 and the opening value of the expansion valve 22 can be appropriately increased.

[0147] Furthermore, the heat recovery efficiency of the sensible heat exchanger 3 and the evaporator 21 may be adjusted by adjusting the operating parameters of the sensible heat exchanger 3 and the evaporator 21 .

[0148] The specific control formula is as follows:

[0149] ΔU=QW;

[0150] ΔU=m×C p ×ΔT;

[0151] Among them, ΔU is the change in internal energy of the system, Q is the heat absorbed by the system, and W is the work done by the system on the outside.

[0152] When the air intake volume is greater than a preset threshold, the energy recovery efficiency can be optimized and the working states of the sensible heat exchanger 3 and the evaporator 21 can be adjusted to fully utilize the excess air volume for heat recovery.

[0153] When the air intake volume is less than a preset threshold, the operating frequencies of the compressor 23 and the fan are increased to compensate for energy loss.

[0154] In addition, a blower and an exhaust fan can be set in the drying system, and the speed of the blower and the exhaust fan can be adjusted according to the needs of air flow. The blower and the exhaust fan can promote air circulation, ensure that the air flows evenly through each component, and enhance the heat and mass transfer effect.

[0155] The specific control formula is as follows:

[0156] V = A × v;

[0157] P = ρ × g × h;

[0158] Among them, V is the air volume, A is the cross-sectional area of ​​the air duct in the drying system, v is the wind speed, P is the pressure loss, ρ is the air density, g is the acceleration of gravity, and h is the length of the air duct.

[0159] Control when air volume does not match:

[0160] When the air intake volume is greater than a preset threshold, the fan speed is reduced to reduce unnecessary energy consumption.

[0161] When the air intake volume is less than a preset threshold, the fan speed is increased to meet the air flow demand.

[0162] Furthermore, in an optional embodiment, the drying method further comprises:

[0163] S6. A fresh air valve is provided at one end of the first channel 31 close to the outside, and an exhaust valve is provided at one end of the second channel 32 close to the evaporation side;

[0164] S7, obtaining the current humidity and target humidity in the drying production line 1;

[0165] S8, based on the humidity difference between the current humidity and the target humidity, adjusting the working state of the evaporator 21 to control the humidity of the exhaust air;

[0166] S9. Based on the humidity difference, feedback is provided to adjust the opening value of the fresh air valve and the opening value of the exhaust valve.

[0167] In this embodiment, the function of the evaporator 21 is: the medium-temperature exhaust air with moisture from the drying medium is cooled and dehumidified after passing through the evaporator 21, reduced to low-temperature air and discharged from the dryer, and the cooling process is accompanied by condensation of water, thereby completing the dehumidification, cooling and heat recovery of the exhaust air. Therefore, the working state of the evaporator 21 directly determines the humidity of the exhaust air.

[0168] The specific control formula of the evaporator 21 is as follows:

[0169] ΔW=W 目标 -W 当前 ;

[0170] Q = L × ΔW;

[0171] Among them, W 目标 is the target humidity, W 当前 is the current humidity, ΔW is the difference between the target humidity and the current humidity, Q is the latent heat to be transferred, and L is the latent heat capacity of the air.

[0172] At the same time, the air intake and exhaust volume will also affect the exhaust humidity to a certain extent. The details are as follows:

[0173] The step S9 comprises:

[0174] S91. When the humidity difference is greater than the preset humidity, the opening value of the exhaust valve is increased and the opening value of the fresh air valve is reduced, thereby reducing the humidity.

[0175] S92. When the humidity difference is less than the preset humidity, the opening value of the exhaust valve is reduced and the opening value of the fresh air valve is increased, so as to increase the humidity.

[0176] In summary, by combining the heating and dehumidification process of the sensible heat exchanger 3 with the condenser 24 and the evaporator 21, the temperature and humidity of the air can be accurately adjusted to a range suitable for drying requirements. The precise air conditioning capability of this embodiment makes the drying process more uniform and stable, and improves the drying quality of the product.

[0177] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A drying system, characterized in that: include: The drying production line (1) is provided with an air supply port (11) and an air exhaust port (12); A heat pump mechanism (2) is provided with an evaporation side and a condensation side; A sensible heat exchanger (3) is provided with a first channel (31) and a second channel (32) that are staggered and crossed; the first channel (31) and the second channel (32) perform heat exchange at an overlapping position; The first end of the first channel (31) is in communication with the fresh air from the outside, the second end of the first channel (31) is connected to the air supply port (11), and the fresh air exchanges heat with the condensation side during the air supply process; The first end of the second channel (32) is in communication with the evaporation side, and the second end of the second channel (32) is in communication with the air outlet (12).

2. The drying system according to claim 1, characterized in that: The drying production line (1) comprises: A drying chamber (13) provided with the air supply port (11) and the air exhaust port (12); A conveying component (14) is arranged in the drying chamber (13), and the conveying component (14) is used to convey the medium to be dried; An air duct assembly (15) is provided with an air inlet channel and an air exhaust channel, wherein a first end of the air inlet channel is connected to the air supply port (11), a second end of the air inlet channel is connected to the second end of the first channel (31), one end of the air exhaust channel is connected to the second end of the second channel (32), and the second end of the air exhaust channel is connected to the air exhaust port (12).

3. The drying system according to claim 2, characterized in that: Along the conveying direction of the conveying component (14), a portion of the exhaust ports (12) are arranged on the upstream side of the conveying component (14), another portion of the exhaust ports (12) are arranged on the downstream side of the conveying component (14), and all the air supply ports (11) are correspondingly arranged in the middle area of ​​the conveying component (14).

4. The drying system according to claim 2, characterized in that: Along the conveying direction of the conveying component (14), a portion of the air supply ports (11) are arranged on the upstream side of the conveying component (14), another portion of the air supply ports (11) are arranged on the downstream side of the conveying component (14), and all the air exhaust ports (12) are correspondingly arranged in the middle area of ​​the conveying component (14).

5. The drying system according to any one of claims 1 to 4, characterized in that: The condensation side comprises: The condenser (24) is arranged between the second end of the first channel (31) and the air supply port (11); during the air supply process, the fresh air exchanges heat with the condenser (24) and then enters the air supply port (11).

6. The drying system according to any one of claims 1 to 4, characterized in that: The condensation side comprises: Condenser (24); A heat exchange component (25) is provided with a first heat exchange side and a second heat exchange side; a heat exchange medium in the heat exchange component (25) circulates between the first heat exchange side and the second heat exchange side; The first heat exchange side exchanges heat with the condenser (24); the second heat exchange side is arranged in the drying production line (1), and after the fresh air enters the drying production line (1), it exchanges heat with the second heat exchange side.

7. The drying system according to claim 6, characterized in that: The heat exchange component (25) comprises: A containing box (251) having the heat exchange medium disposed therein; the containing box (251) exchanges heat with the condenser (24); A heating coil (252) is connected to the containing box (251); the heating coil (252) is arranged in the drying production line (1) along the conveying direction of the drying production line (1); after the fresh air enters the drying production line (1), it exchanges heat with the heating coil (252).

8. The drying system according to claim 7, characterized in that: Two heating coils (252) are provided, one heating coil (252) is provided on the upstream side of the drying production line (1), and the other heating coil (252) is provided on the downstream side of the drying production line (1); and both heating coils (252) are arranged to extend along the conveying direction of the drying production line (1).

9. The drying system according to claim 8, characterized in that: The containing box (251) comprises a first box body (2511) and a second box body (2512), and the heat exchange component (25) further comprises: A first pipeline (2513), one end of the first pipeline (2513) being connected to the water outlet of the first box (2511), and the other end of the first pipeline (2513) being connected to the water inlet of the heating coil (252); A second pipeline (2514), one end of the second pipeline (2514) is connected to the water outlet of the heating coil (252), and the other end of the second pipeline (2514) is connected to the water return port of the second box (2512); a third pipeline (2515), one end of the third pipeline (2515) being connected to the water outlet of the second box (2512), and the other end of the third pipeline (2515) being connected to the heat exchange inlet of the condenser (24); A fourth pipeline (2516), one end of the fourth pipeline (2516) is connected to the heat exchange outlet of the condenser (24), and the other end of the fourth pipeline (2516) is connected to the return water outlet of the first box (2511).

10. The drying system according to any one of claims 1 to 4, characterized in that: The drying production line (1) further comprises: The thermal insulation layer (16) is laid on the inner wall of the drying production line (1).

11. A drying method, characterized in that: Applicable to the drying system according to any one of claims 1 to 10, the drying method comprising: Obtaining the current drying temperature and the target drying temperature in the drying production line (1); The heat release amount on the condensation side is adjusted based on the temperature difference between the current drying temperature and the target drying temperature.

12. The drying method according to claim 11, characterized in that: The adjusting the heat release amount on the condensation side based on the temperature difference between the current drying temperature and the target drying temperature includes: Based on the temperature difference, adjusting the operating frequency of the compressor (23) in the heat pump mechanism (2) to control the heat release of the condenser (24) in the heat pump mechanism (2); The opening value of the expansion valve (22) in the heat pump mechanism (2) is adjusted to control the amount of heat absorbed by the evaporator (21).

13. The drying method according to claim 12, characterized in that: The drying method also includes: Obtaining the air intake volume in the drying production line (1); When the air intake volume is greater than a preset threshold, reducing the operating frequency of the compressor (23) and the opening value of the expansion valve (22) in the heat pump mechanism (2); When the air intake volume is less than a preset threshold, the operating frequency of the compressor (23) and the opening value of the expansion valve (22) in the heat pump mechanism (2) are increased.

14. The drying method according to any one of claims 11 to 13, characterized in that: The drying method also includes: A fresh air valve is provided at one end of the first channel (31) close to the outside, and an exhaust valve is provided at one end of the second channel (32) close to the evaporation side; Obtaining the current humidity and target humidity in the drying production line (1); Based on the humidity difference between the current humidity and the target humidity, adjusting the working state of the evaporator (21) to control the humidity of the exhaust air; Based on the humidity difference, feedback is provided to adjust the opening values ​​of the fresh air valve and the exhaust valve.

15. The drying method according to claim 14, characterized in that: The feedback adjustment of the opening value of the fresh air valve and the opening value of the exhaust valve based on the humidity difference includes: When the humidity difference is greater than the preset humidity, the opening value of the exhaust valve is increased and the opening value of the fresh air valve is reduced; When the humidity difference is less than the preset humidity, the opening value of the exhaust valve is reduced and the opening value of the fresh air valve is increased.

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