Drying system and control method thereof

Abstract

The present invention relates to the field of drying technology, and provides a drying system and a control method thereof. The drying system includes: a drying room, in which a wet-bulb temperature sensor is provided; a dryer, wherein the dryer and the drying room are connected via two air ducts, the gas conveying directions in the two air ducts being opposite, and the dryer includes: an internal dehumidification unit and an external dehumidification unit; a control unit, wherein the control unit is electrically connected to the wet-bulb temperature sensor, the internal dehumidification unit, and the external dehumidification unit, respectively, and the control unit is used to control the start and stop of the internal dehumidification unit and the external dehumidification unit based on a wet-bulb temperature signal sent by the wet-bulb temperature sensor. Under the control of the control unit, the dehumidification unit and the external dehumidification unit can be used in combination based on the wet-bulb temperature signal in the drying room, thereby achieving dehumidification of the gas. This drying system can reduce heat loss, improve dehumidification efficiency, and make the wet-bulb temperature control of the drying room more precise, and increase the utilization rate of the internal dehumidification module.

Description

Technical Field

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

[0002] A drying system typically consists of a circulation system consisting of a dryer and a baking chamber. The dryer feeds high-temperature dry air into the baking chamber through an air duct, drying the material inside. The low-temperature, high-humidity air flowing out of the baking chamber returns to the dryer, where it dehumidifies and heats the air before being recirculated back into the baking chamber.

[0003] However, in the above-mentioned drying system, when the dryer is used to dehumidify and heat the gas, if the internal dehumidification mode is used alone, the dehumidification efficiency is low; if the external dehumidification mode is used alone, the heat loss is high, wasting energy. Summary of the Invention

[0004] The present invention provides a drying system and a control method thereof, which are used to solve the defects in the prior art that when the internal dehumidification mode is used alone, the dehumidification efficiency is low; when the external dehumidification mode is used alone, the heat loss is high and energy is wasted. The system reduces heat loss, improves dehumidification efficiency, and makes the wet-bulb temperature of the drying room more accurately controlled, and the utilization rate of the internal dehumidification module is higher.

[0005] The present invention provides a drying system, comprising:

[0006] A curing room, wherein a wet-bulb temperature sensor is provided in the curing room;

[0007] The dryer is connected to the drying room through two air ducts, the gas conveying directions in the two air ducts are opposite, and the dryer includes: an internal dehumidification unit and an external dehumidification unit;

[0008] A control unit is electrically connected to the wet-bulb temperature sensor, the internal dehumidification unit, and the external dehumidification unit, and is used to control the start and stop of the internal dehumidification unit and the external dehumidification unit based on the wet-bulb temperature signal sent by the wet-bulb temperature sensor.

[0009] According to a drying system provided by the present invention, the dryer includes an air inlet and an air outlet.

[0010] Wherein, the air inlet is arranged at the bottom of the side wall of the dryer, and the air outlet is arranged at the top of the dryer.

[0011] According to a drying system provided by the present invention, the external dehumidification unit includes: a dehumidification port and an external evaporator, the dehumidification port is arranged on the side wall of the dryer, the external evaporator is arranged outside the side wall of the dryer, and the external evaporator corresponds to the dehumidification port.

[0012] According to a drying system provided by the present invention, the dryer further includes: a fresh air inlet, which is connected to the air inlet.

[0013] According to a drying system provided by the present invention, the internal dehumidification unit includes: a built-in evaporator and a condenser,

[0014] Wherein, the built-in evaporator corresponds to the air inlet, and the condenser corresponds to the air outlet.

[0015] The present invention also provides a control method for a drying system, comprising:

[0016] Get the target dry-bulb temperature;

[0017] If the target dry-bulb temperature is lower than the preset switching temperature, the internal dehumidification priority mode is executed;

[0018] If the target dry-bulb temperature is higher than or equal to the preset switching temperature, the external dehumidification priority mode is executed.

[0019] According to a control method for a drying system provided by the present invention, the internal dehumidification priority mode includes:

[0020] If the actual wet-bulb temperature is lower than the target wet-bulb temperature, the internal dehumidification unit will be turned on as the temperature rises;

[0021] If the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the internal dehumidification unit is kept open first, and then the external dehumidification unit is opened.

[0022] According to a control method for a drying system provided by the present invention, the internal dehumidification priority mode includes:

[0023] If 50% ΔTs1 ≤ Ts-Ts0 < 50% ΔTs2, the internal dehumidification unit is turned on;

[0024] If 50% ΔTs2 ≤ Ts-Ts0, then turn on

[0025] If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the external dehumidification unit is closed;

[0026] If -50% ΔTs2 ≥ Ts-Ts0, the internal dehumidification unit is turned off;

[0027] Among them, T s Indicates the actual wet-bulb temperature of the baking room, in degrees Celsius;

[0028] Ts0 represents the target wet-bulb temperature in degrees Celsius;

[0029] ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius;

[0030] ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

[0031] According to a control method for a drying system provided by the present invention, the external moisture exhaust priority mode includes:

[0032] If the actual wet-bulb temperature is lower than the target wet-bulb temperature, the external dehumidification unit will be turned on as the temperature rises;

[0033] If the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the external dehumidification unit is kept open first, and then the internal dehumidification unit is opened.

[0034] According to a control method for a drying system provided by the present invention, the external dehumidification priority mode includes:

[0035] If 50% ΔTs1 ≤ Ts-Ts0 < 50% ΔTs2, the external dehumidification unit is turned on;

[0036] If 50% ΔTs2 ≤ Ts-Ts0, the internal dehumidification unit is turned on;

[0037] If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the internal dehumidification unit is turned off;

[0038] If -50% ΔTs2 ≥ Ts-Ts0, close the external dehumidification unit;

[0039] Among them, T s Indicates the actual wet-bulb temperature of the baking room, in degrees Celsius;

[0040] Ts0 represents the target wet-bulb temperature in degrees Celsius;

[0041] ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius;

[0042] ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

[0043] The drying system provided by the present invention incorporates an internal dehumidification unit and an external dehumidification unit within the dryer. Under the control of a control unit, these two units are combined based on the wet-bulb temperature signal within the drying room to dehumidify the air. This drying system reduces heat loss, improves dehumidification efficiency, and enables more precise wet-bulb temperature control within the drying room, while increasing the utilization rate of the internal dehumidification module.

[0044] In the control method of the drying system provided in the embodiment of the present invention, since the method provided according to the present invention as described above is applied, it also has the advantages as described above, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0046] Figure 1 It is a structural schematic diagram of the drying system provided by the present invention;

[0047] Figure 2 1 is a flow chart of a control method for a drying system provided by the present invention;

[0048] Figure 3 This is a control process diagram of the internal dehumidification mode provided by the present invention;

[0049] Figure 4 This is a control process diagram of the external dehumidification mode provided by the present invention.

[0050] Reference numerals:

[0051] 100: baking room; 110: wet bulb temperature sensor;

[0052] 200: Dryer;

[0053] 210: Internal dehumidification unit; 211: Built-in evaporator; 212: Condenser;

[0054] 220: External dehumidification unit; 221: Dehumidification port; 222: External evaporator;

[0055] 230: air inlet;

[0056] 240: air outlet;

[0057] 250: New outlet;

[0058] 300: Control unit. DETAILED DESCRIPTION

[0059] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0060] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0061] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0062] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0063] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0064] A drying system typically consists of a circulation system consisting of a dryer and a baking chamber. The dryer feeds high-temperature dry air into the baking chamber through an air duct, drying the material inside. The low-temperature, high-humidity air flowing out of the baking chamber returns to the dryer, where it dehumidifies and heats the air before being recirculated back into the baking chamber.

[0065] For example, in the tobacco drying system, the dry-bulb and wet-bulb temperatures in the curing room are controlled to make the tobacco leaves yellow and dehydrated. That is, while the temperature is raised, the water evaporated from the fresh tobacco leaves in the curing room is discharged in time to achieve the purpose of drying the tobacco leaves.

[0066] The temperature control solution is generally to provide heat to the drying room through a heat pump to achieve temperature increase. The humidity control solution has two dehumidification solutions: internal dehumidification and external dehumidification:

[0067] Among them, in the internal dehumidification scheme, since no heat is discharged to the outside during dehumidification, the heat loss is small and it is more energy-saving, but the dehumidification efficiency is greatly affected by the temperature of the baking room, and the dehumidification amount is small in the high temperature range; the external dehumidification scheme has a fast dehumidification speed and is less affected by temperature. It can still effectively dehumidify under high temperature and low humidity conditions, but the heat loss during dehumidification is large.

[0068] The on-off integrated heat pump tobacco dryer is a dryer that has both external dehumidification and internal dehumidification. This solution currently has two disadvantages:

[0069] 1. When the internal dehumidification and external dehumidification are working at the same time, the dehumidification efficiency is high and the wet-bulb temperature drops rapidly. When the internal dehumidification and external dehumidification are stopped at the same time, the wet-bulb temperature rises rapidly, resulting in large fluctuations in the wet-bulb temperature in the baking room.

[0070] 2. Internal dehumidification does not discharge heat to the outside, so the heat loss is low.

[0071] Now combined Figures 1 to 2 , various embodiments provided by the present invention are described. It should be understood that the following are merely illustrative embodiments of the present invention and do not constitute any particular limitation to the present invention.

[0072] Figure 1 This is a structural diagram of the drying system provided by the present invention, see Figure 1 The drying system includes a curing barn 100, a dryer 200, and a control unit 300. The curing barn 100 contains material, and high-temperature dry air is introduced into the barn 100 to dry the material. For example, the drying system may be a tobacco drying system, and the material may be tobacco leaves. Furthermore, a wet-bulb temperature sensor 110 is provided within the curing barn 100 to detect the wet-bulb temperature within the barn 100.

[0073] The wet-bulb temperature (WBT) refers to the temperature of a system when the air in the system is saturated and thermal equilibrium is reached, with the latent heat required for evaporation of a large amount of water in contact with a limited amount of moist air under adiabatic conditions coming entirely from the sensible heat released by the cooling of the moist air. In layman's terms, the WBT is the lowest temperature that can be reached by evaporating water alone. The thermodynamic WBT is also known as the adiabatic saturation temperature.

[0074] It should be noted that the wet-bulb temperature is relative to the dry-bulb temperature. The dry-bulb temperature is the true temperature of the air and can be directly measured with an ordinary thermometer. This true temperature is called the dry-bulb temperature, or simply temperature.

[0075] The dryer 200 and curing barn 100 are connected by two air ducts, with the air flowing in opposite directions. This means that air circulates between the dryer 200 and the curing barn 100 through these two air ducts. The dryer 200 delivers high-temperature, dry air into the curing barn 100 through the air ducts, drying the material inside. The low-temperature, high-humidity air flowing out of the curing barn 100 returns to the dryer 200, where it dehumidifies and heats the air before being re-circulated back into the curing barn 100.

[0076] The dryer 200 includes an internal dehumidification unit 210 and an external dehumidification unit 220. The internal dehumidification unit 210 is used to remove moisture from the air inside the dryer 200, thereby reducing the humidity of the air entering the curing room 100. The external dehumidification unit 220 discharges high-temperature, high-humidity air through a dehumidification port 221 and reduces the humidity of the air by replenishing air, thereby reducing the humidity inside the curing room 100.

[0077] The control unit 300 is electrically connected to the wet-bulb temperature sensor 110, the internal dehumidification unit 210, and the external dehumidification unit 220. The wet-bulb temperature sensor 110 detects the wet-bulb temperature within the drying room 100 and transmits a wet-bulb temperature signal to the control unit 300. Based on this wet-bulb temperature signal, the control unit 300 activates and deactivates the internal dehumidification unit 210 and the external dehumidification unit 220. The combined use of the internal dehumidification unit 210 and the external dehumidification unit 220 dehumidifies the air, reduces heat loss, and improves dehumidification efficiency.

[0078] The drying system provided in this embodiment of the present invention includes an internal dehumidification unit 210 and an external dehumidification unit 220 within the dryer 200. Under the control of the control unit 300, the dehumidification unit and the external dehumidification unit 220 can be used in conjunction with each other based on the wet-bulb temperature signal within the drying room 100 to dehumidify the air. This drying system reduces heat loss, improves dehumidification efficiency, and provides more precise control of the wet-bulb temperature within the drying room 100, while increasing the utilization rate of the internal dehumidification module.

[0079] In one embodiment provided by the present invention, the above-mentioned dryer 200 includes an air inlet 230 and an air outlet 240. The gas output from the baking room 100 flows into the dryer 200 through the air inlet 230. After being dehumidified and heated in the dryer 200, the gas flows back to the baking room 100 through the air outlet 240, so that the moisture on the surface of the material and in the material is removed by the flow in the baking room 100, thereby drying the material.

[0080] The air inlet 230 is provided at the bottom of the side wall of the dryer 200, and the air outlet 240 is provided at the top of the dryer 200. This structure facilitates the upward flow of high-temperature gas and outflow from the air outlet 240 located at the top of the dryer 200.

[0081] In any of the above embodiments, the external dehumidification unit 220 includes a dehumidification port 221 and an external evaporator 222. The dehumidification port 221 is disposed on the side wall of the dryer 200, and the external evaporator 222 is disposed outside the side wall of the dryer 200, corresponding to the dehumidification port 221. The external evaporator 222 is configured to accelerate the flow of humid air out of the dryer 200 through the dehumidification port 221 and outward diffusion. Specifically, the external evaporator 222 may include a fan.

[0082] In addition, the control unit 300 may also be disposed on the outer wall of the dryer 200 . Furthermore, the control unit 300 may be disposed on the external evaporator 222 , which is not limited in this embodiment.

[0083] In the above embodiment, the dryer 200 further includes a fresh air vent 250, which is connected to the air inlet 230 and is used to replenish air. When using the external dehumidification mode, since high-temperature, high-humidity air is discharged through the dehumidification vent 221, relatively dry, relatively low-temperature air from the outside can be introduced through the fresh air vent 250 for ventilation, thereby reducing the humidity of the air and, in turn, the humidity within the drying room 100.

[0084] In the above embodiment, the internal dehumidification unit 210 includes a built-in evaporator 211 and a condenser 212. The built-in evaporator 211 corresponds to the air inlet 230, and the condenser 212 corresponds to the air outlet 240. Specifically, in the internal dehumidification mode, the built-in evaporator 211 absorbs heat, cooling the humid air passing through it to below the dew point. This causes the moisture in the humid air to condense into liquid and be discharged, thereby reducing the humidity of the air. The dehumidified air continues to flow upward. The heat absorbed by the built-in evaporator 211 is transferred to the condenser 212 via a heat pump. The condenser 212 is used to heat the dehumidified air flowing upward. The dehumidified and heated air then returns to the drying room 100 through the air outlet.

[0085] The drying system provided in this embodiment of the present invention includes an internal dehumidification unit 210 and an external dehumidification unit 220 within the dryer 200. Under the control of the control unit 300, the dehumidification unit and the external dehumidification unit 220 can be used in conjunction with each other based on the wet-bulb temperature signal within the drying room 100 to dehumidify the air. This drying system reduces heat loss, improves dehumidification efficiency, and provides more precise control of the wet-bulb temperature within the drying room 100, while increasing the utilization rate of the internal dehumidification module.

[0086] Furthermore, the dryer 200 includes an air inlet 230 and an air outlet 240. Air exiting the curing room 100 flows into the dryer 200 through the air inlet 230. After being dehumidified and heated in the dryer 200, the air returns to the curing room 100 through the air outlet 240. This flow within the curing room 100 removes moisture from the surface of and within the material, thereby drying the material. The air inlet 230 is located at the bottom of the sidewall of the dryer 200, while the air outlet 240 is located at the top of the dryer 200. This structure facilitates the upward flow of high-temperature air, which then exits through the air outlet 240 at the top of the dryer 200.

[0087] During the application of the above drying system, different control methods can be adopted according to different materials to achieve different drying effects.

[0088] Continuing with the tobacco drying system as an example, according to the three-stage tobacco leaf curing process, the temperature inside curing room 100 must rise from ambient temperature to approximately 68°C during the drying process. During the first and second stages of yellowing and coloring, the temperature in curing room 100 is low, the humidity is high, and the air moisture content is high, which improves internal dehumidification and saves energy. During the third stage of drying, the temperature is above 55°C, the dry-bulb temperature is high, the wet-bulb temperature is low, and the air moisture content is low, which reduces internal dehumidification and improves external dehumidification. Therefore, this solution achieves both energy savings and effective humidity control through segmented dehumidification control.

[0089] Figure 2 This is a flow chart of the control method of the drying system provided by the present invention, see Figure 2 The control method of the drying system includes:

[0090] 101. Obtain the target dry-bulb temperature.

[0091] The dry-bulb temperature is the actual temperature of the air, which can be directly measured with an ordinary thermometer. This actual temperature is called the dry-bulb temperature, or simply the temperature. The target dry-bulb temperature can be set according to the type of material, and this embodiment does not limit this.

[0092] If the set target dry-bulb temperature is low, the internal dehumidification priority mode is adopted, which has the advantage of energy saving; if the set target dry-bulb temperature is high, the external dehumidification priority mode is adopted, which has the advantage of good dehumidification effect.

[0093] Different types of materials require different temperatures at each drying stage. Temperature and humidity also vary during each drying stage. For example, in the tobacco drying system described above, in the first and second stages, where temperatures are low and humidity is high, internal dehumidification can save energy. In the third stage, where temperatures are higher and humidity is lower, internal dehumidification becomes less effective, and external dehumidification is more effective.

[0094] Therefore, a preset switching temperature can be set. If the target dry-bulb temperature is lower than the preset switching temperature, the internal dehumidification priority mode is activated. If the target dry-bulb temperature is higher than or equal to the preset switching temperature, the external dehumidification priority mode is activated. Of course, the preset switching temperature can be set based on the type of material and the drying stage, and this embodiment is not limited to this. For example, in the aforementioned tobacco drying system, the preset switching temperature can be the boundary temperature between the second and third stages.

[0095] Furthermore, the internal dehumidification mode and the external dehumidification mode can be started and stopped respectively according to different wet-bulb temperature ranges, so that the wet-bulb temperature fluctuation in the baking room 100 is small and the humidity control is more accurate.

[0096] 102. If the target dry-bulb temperature is lower than the preset switching temperature, the internal dehumidification priority mode will be executed.

[0097] In this step, the internal dehumidification priority mode includes the following: if the actual wet-bulb temperature is lower than the target wet-bulb temperature, the internal dehumidification unit 210 is turned on as the temperature rises; if the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the internal dehumidification unit 210 is kept on first, and then the external dehumidification unit 220 is turned on. In other words, in low temperatures, dehumidification is not turned on; in medium temperatures, only the internal dehumidification unit 210 is used for dehumidification, which achieves sufficient dehumidification while saving energy; in high temperatures, the internal dehumidification unit 210 and the external dehumidification unit 220 are used together for dehumidification, achieving a better dehumidification effect.

[0098] In a further embodiment, the above-mentioned internal dehumidification priority mode includes:

[0099] If 50% ΔTs1 ≤ Ts-Ts0 < 50% ΔTs2, the internal dehumidification unit 210 is turned on;

[0100] If 50% ΔTs2 ≤ Ts-Ts0, the external dehumidification unit 220 is turned on;

[0101] If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the external dehumidification unit 220 is closed;

[0102] If -50% ΔTs2 ≥ Ts-Ts0, the internal dehumidification unit 210 is turned off;

[0103] Among them, T s Indicates the actual wet-bulb temperature of the baking room at 100°C, in degrees Celsius;

[0104] Ts0 represents the target wet-bulb temperature in degrees Celsius;

[0105] ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius;

[0106] ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

[0107] The aforementioned weak dehumidification static temperature range and strong dehumidification static temperature range can be set as needed. Based on the above embodiment, multiple nodes are clarified. Based on these nodes, the baking process is divided into multiple stages. These multiple stages can correspond to different dehumidification modes, which improves the flexibility of the dehumidification process. As the temperature rises, the dehumidification mode can also enter the next stage. In the next stage, the dehumidification mode of the previous stage can be maintained, or the dehumidification mode can be changed, which can save energy and achieve a better dehumidification effect.

[0108] Figure 3 This is the control process diagram of the internal dehumidification mode provided by the present invention, please refer to Figure 3 ,exist Figure 3 In the figure, a solid line with an upward arrow indicates on, and a dashed line with a downward arrow indicates off. As the temperature changes from the target wet-bulb temperature in the middle to the ends, each time a node is reached, the corresponding unit can be switched according to the situation in the figure.

[0109] 103. If the target dry-bulb temperature is higher than or equal to the preset switching temperature, the external dehumidification priority mode is executed.

[0110] In this step, the external dehumidification priority mode includes the following: if the actual wet-bulb temperature is lower than the target wet-bulb temperature, the external dehumidification unit 220 is turned on as the temperature rises; if the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the external dehumidification unit 220 is kept on first, and then the internal dehumidification unit 210 is turned on. In other words, in low temperatures, dehumidification is not turned on; in medium temperatures, only the external dehumidification unit 220 is used for dehumidification, achieving sufficient dehumidification; in high temperatures, the internal and external dehumidification units 210 and 220 are used together for dehumidification, achieving better dehumidification results.

[0111] In a further embodiment, the above-mentioned external moisture removal priority mode includes:

[0112] If 50% ΔTs1 ≤ Ts-Ts0 < 50% ΔTs2, the external dehumidification unit 220 is turned on;

[0113] If 50% ΔTs2 ≤ Ts-Ts0, the internal dehumidification unit 210 is turned on;

[0114] If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the internal dehumidification unit 210 is turned off;

[0115] If -50% ΔTs2 ≥ Ts-Ts0, the external dehumidification unit 220 is closed;

[0116] Among them, T s Indicates the actual wet-bulb temperature of the baking room at 100°C, in degrees Celsius;

[0117] Ts0 represents the target wet-bulb temperature in degrees Celsius;

[0118] ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius;

[0119] ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

[0120] The aforementioned weak dehumidification static temperature range and strong dehumidification static temperature range can be set as needed. Based on the above embodiment, multiple nodes are clarified. Based on these nodes, the baking process is divided into multiple stages. These multiple stages can correspond to different dehumidification modes, which improves the flexibility of the dehumidification process. As the temperature rises, the dehumidification mode can also enter the next stage. In the next stage, the dehumidification mode of the previous stage can be maintained, or the dehumidification mode can be changed, which can save energy and achieve a better dehumidification effect.

[0121] Figure 4 This is the control process diagram of the external dehumidification mode provided by the present invention, please refer to Figure 4 ,exist Figure 4 In the figure, a solid line with an upward arrow indicates on, and a dashed line with a downward arrow indicates off. As the temperature changes from the target wet-bulb temperature in the middle to the ends, each time a node is reached, the corresponding unit can be switched according to the situation in the figure.

[0122] Based on the above-mentioned dehumidification logic of temperature segment control, the low-temperature segment is mainly operated with internal dehumidification, and the high-temperature segment is mainly operated with external dehumidification, maximizing the advantages of the two dehumidification methods to achieve energy-saving and high efficiency in the entire dehumidification process.

[0123] The drying system control method provided in an embodiment of the present invention incorporates an internal dehumidification unit 210 and an external dehumidification unit 220 within the dryer 200. Under the control of the control unit 300, the dehumidification unit and the external dehumidification unit 220 are combined to dehumidify the air based on the wet-bulb temperature signal within the drying room 100. This drying system reduces heat loss, improves dehumidification efficiency, and enables more precise control of the wet-bulb temperature within the drying room 100, while increasing utilization of the internal dehumidification module.

[0124] Furthermore, the internal dehumidification mode and the external dehumidification mode can be started and stopped respectively according to different wet-bulb temperature ranges, so that the wet-bulb temperature fluctuation in the baking room 100 is small and the humidity control is more accurate.

[0125] Based on the above-mentioned dehumidification logic of temperature segment control, the low-temperature segment is mainly operated with internal dehumidification, and the high-temperature segment is mainly operated with external dehumidification, maximizing the advantages of the two dehumidification methods to achieve energy-saving and high efficiency in the entire dehumidification process.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A control method for a drying system, characterized in that: The drying system comprises: A curing room (100), wherein a wet-bulb temperature sensor (110) is provided in the curing room (100); A dryer (200), wherein the dryer (200) and the curing room (100) are connected via two air ducts, wherein the conveying directions of the gases in the two air ducts are opposite, wherein the dryer (200) inputs high-temperature dry gas into the curing room (100) via the air ducts, and the low-temperature and high-humidity gas flowing out of the curing room (100) returns to the dryer (200), and the dryer (200) dehumidifies and heats the gas before conveying it back into the curing room (100), and the dryer (200) comprises an internal dehumidification unit (210) and an external dehumidification unit (220); a control unit (300), the control unit (300) being electrically connected to the wet-bulb temperature sensor (110), the internal dehumidification unit (210), and the external dehumidification unit (220), respectively, and the control unit (300) being used to control the start and stop of the internal dehumidification unit (210) and the external dehumidification unit (220) based on a wet-bulb temperature signal sent by the wet-bulb temperature sensor (110); The control method includes: obtaining a target dry-bulb temperature; When the target dry-bulb temperature is lower than the preset switching temperature, the internal dehumidification priority mode is executed, including: if the actual wet-bulb temperature is lower than the target wet-bulb temperature, as the temperature rises, the internal dehumidification unit (210) is turned on; if the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the internal dehumidification unit (210) is kept turned on first, and then the external dehumidification unit (220) is turned on; When the target dry-bulb temperature is higher than or equal to the preset switching temperature, the external dehumidification priority mode is executed, including: if the actual wet-bulb temperature is lower than the target wet-bulb temperature, as the temperature rises, the external dehumidification unit (220) is turned on; if the actual wet-bulb temperature is higher than the target wet-bulb temperature, as the temperature rises, the external dehumidification unit (220) is kept turned on first, and then the internal dehumidification unit (210) is turned on.

2. The control method of the drying system according to claim 1, characterized in that: The dryer (200) includes an air inlet (230) and an air outlet (240). The air inlet (230) is arranged at the bottom of the side wall of the dryer (200), and the air outlet (240) is arranged at the top of the dryer (200).

3. The control method of the drying system according to claim 2, characterized in that: The external dehumidification unit (220) comprises: a dehumidification port (221) and an external evaporator (222); the dehumidification port (221) is arranged on the side wall of the dryer (200); the external evaporator (222) is arranged outside the side wall of the dryer (200), and the external evaporator (222) corresponds to the dehumidification port (221).

4. The control method of the drying system according to claim 3, characterized in that: The dryer (200) further comprises: a fresh air inlet (250), wherein the fresh air inlet (250) is in communication with the air inlet (230).

5. The control method of the drying system according to any one of claims 2 to 4, characterized in that: The internal dehumidification unit (210) includes a built-in evaporator (211) and a condenser (212). The built-in evaporator (211) corresponds to the air inlet (230), and the condenser (212) corresponds to the air outlet (240).

6. The control method of the drying system according to claim 1, characterized in that: The internal dehumidification priority mode includes: If 50% ΔTs1≤Ts-Ts0<50% ΔTs2, then turning on the internal dehumidification unit (210); If 50% ΔTs2≤Ts-Ts0, the external dehumidification unit (220) is turned on; If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the external dehumidification unit (220) is closed; If -50% ΔTs2 ≥ Ts-Ts0, the internal dehumidification unit (210) is turned off; Among them, T s Indicates the actual wet-bulb temperature of the baking room (100), in degrees Celsius; Ts0 represents the target wet-bulb temperature in degrees Celsius; ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius; ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

7. The control method of the drying system according to claim 1, characterized in that: The external dehumidification priority mode includes: If 50% ΔTs1≤Ts-Ts0<50% ΔTs2, the external dehumidification unit (220) is turned on; If 50% ΔTs2≤Ts-Ts0, the internal dehumidification unit (210) is turned on; If -50% ΔTs1 ≥ Ts-Ts0 > -50% ΔTs2, the internal dehumidification unit (210) is turned off; If -50% ΔTs2 ≥ Ts-Ts0, the external dehumidification unit (220) is closed; Among them, T s Indicates the actual wet-bulb temperature of the baking room (100), in degrees Celsius; Ts0 represents the target wet-bulb temperature in degrees Celsius; ΔTs1 represents the static temperature range of weak dehumidification, in degrees Celsius; ΔTs2 represents the strong dehumidification static temperature range, the unit is Celsius, and ΔTs2>ΔTs1.

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