A hot air circulation drying method and system for fabric

Abstract

The present application relates to a kind of hot air circulation drying method and system for fabric, including machine case, be located in the material module of machine case, fan module, heat exchange module, temperature acquisition module and control module;Material module is used to install external material, fan module is used to make the heat flow generated by heat exchange module pass through external material and produce heat exchange, temperature acquisition module is used to detect the temperature before heat exchange and the temperature after heat exchange of heat flow;Control module is configured to judge the moisture content state of external material according to temperature difference value, and the operating parameter of fan module or / and the operating parameter of heat exchange module is adjusted.The present application avoids the energy waste caused by continuous high-power operation by monitoring the temperature of airflow before and after heat exchange in real time, dynamically adjusting the output power of heat exchange module and the wind speed of fan module, and has significant energy-saving effect.

Description

Technical Field

[0001] This invention relates to the field of fabric drying technology, and in particular discloses a hot air circulation drying method and system for fabrics. Background Technology

[0002] Drying is a crucial step in the production and processing of textile products. Traditional fabric drying equipment typically uses electric heating or steam heating, and blows hot air onto the fabric surface through a fan to evaporate the moisture contained within, thereby achieving the purpose of drying.

[0003] However, most existing drying equipment has significant shortcomings in practical use. First, the internal heat circulation system is usually open-loop or has fixed parameters, making it impossible to dynamically adjust key parameters such as hot air temperature and wind speed according to the real-time drying status of the fabric. This results in low energy utilization and increased production costs. Second, due to the lack of effective temperature monitoring and feedback mechanisms, the drying equipment struggles to ensure uniform hot air temperature, easily causing overheating damage to the fabric or incomplete drying, affecting product quality. Furthermore, lint tends to accumulate inside the equipment after long-term operation, affecting heat exchange efficiency and posing certain safety hazards, and traditional equipment lacks effective measures to address this issue.

[0004] Therefore, developing a fabric drying equipment that can achieve intelligent control, energy efficiency, and stable operation is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a hot air circulation drying method and system for fabrics.

[0006] To achieve the above objectives, the present invention provides a hot air circulation drying method and system for fabrics, comprising a chassis, a fan module disposed within the chassis, a heat exchange module, and a temperature acquisition module; the chassis is used to house external materials, the fan module is used to cause the heat flow generated by the heat exchange module to pass through the external materials to generate heat exchange, and the temperature acquisition module is used to detect the temperature of the heat flow before and after heat exchange.

[0007] Preferably, it also includes a control module, which is electrically connected to the fan module, the heat exchange module and the temperature acquisition module respectively. The control module is used to control the air volume of the fan module and the temperature of the heat exchange module based on the temperature difference between the temperature of the heat flow before and after heat exchange detected by the temperature acquisition module.

[0008] Furthermore, the heat exchange module has an air outlet and an air return outlet, and the fan module is connected to the air outlet of the heat exchange module; the temperature acquisition module has a first sensor and a second sensor, the first sensor is close to the air outlet and is used to detect the temperature of the heat flow before heat exchange, and the second sensor is close to the air return outlet and is used to detect the temperature of the heat flow after heat exchange.

[0009] Preferably, the heat exchange module is located at one end of the lower part of the chassis, the air outlet and the air return outlet are located at the two ends of the heat exchange module, and the fan module is located at the other end of the lower part of the chassis and is connected to the air outlet. The fan module is used to blow the heat generated by the heat exchange module onto the external material in the form of hot air. The hot air that has completed the heat exchange then enters the heat exchange module through the air return outlet to form a hot air circulation.

[0010] Preferably, the fan module has a first frequency converter.

[0011] Furthermore, it also has an air duct installed in the chassis, the air duct having a first air outlet facing the external material; the fan module is connected to the air outlet of the heat exchange module and one end of the air duct, and the other end of the air duct extends towards the return air outlet.

[0012] Preferably, the air duct has a hollow structure, and hot air is guided through the air duct to blow towards the external materials.

[0013] Furthermore, the air duct has an air outlet duct and a first air spray duct. One end of the air outlet duct is connected to the fan module, and the other end of the air outlet duct is bent and connected to one end of the first air spray duct. The other end of the first air spray duct extends towards the return air outlet. The first air outlet is located in the first air spray duct.

[0014] Preferably, the air outlet duct is vertically connected to the fan module, the first air jet duct is located above the heat exchange module, and the air outlet and return air outlet are located on both sides of the first air jet duct.

[0015] Furthermore, the air duct also has a second air spray duct connected to the air outlet duct, and a second air outlet provided in the second air spray duct. The second air outlet is arranged opposite to the first air outlet, and the external material is located between the first air outlet and the second air outlet.

[0016] Preferably, the first air duct and the second air duct are arranged parallel to each other and spaced apart, and the first air outlet and the second air outlet respectively deliver air to both sides of the external material.

[0017] Furthermore, the first air outlet has multiple first air outlet holes, which are arranged along the length of the first air duct; the second air outlet has multiple second air outlet holes, which are arranged along the length of the second air duct.

[0018] Preferably, the axes of the plurality of first air outlets and the plurality of second air outlets are inclined, such that the air delivery direction of the first air duct and the second air duct is towards the return air inlet.

[0019] Furthermore, the heat exchange module has a filter that covers the return air vent.

[0020] Preferably, the filter element is a filter screen structure used to block lint and dust in the airflow.

[0021] Preferably, the second sensor is mounted on the filter element.

[0022] Furthermore, it also includes a dehumidification module located in the chassis, which has an exhaust damper and an exhaust fan; the chassis has a dehumidification port, and the exhaust damper is movably installed in the dehumidification port.

[0023] Preferably, the control module is electrically connected to the dehumidification module, and the control module determines the opening or closing range of the dehumidification damper based on the temperature difference between the temperature before and after the heat exchange detected by the temperature acquisition module.

[0024] Preferably, the dehumidification module has a second frequency converter.

[0025] Preferably, the exhaust damper has a pivot in the middle, and the exhaust damper is rotatably mounted to the dehumidification port via the pivot.

[0026] Furthermore, the exhaust port is located at the end of the chassis furthest from the fan module.

[0027] Preferably, the exhaust vent is located at the top of the chassis and is positioned opposite the return air vent.

[0028] Furthermore, the bottom of the chassis is equipped with an air intake vent that connects to the outside atmosphere. The air intake vent is located at the end of the chassis near the return air vent, and the return air vent is located between the second sensor and the air intake vent.

[0029] Furthermore, the air duct has a main body and a first interface and a second interface connected to the main body, and the first air duct and the second air duct are respectively installed at the first interface and the second interface.

[0030] Preferably, one end of the first interface and one end of the second interface are connected to the main body, and the other ends of the first interface and the second interface are bent and extended toward the return air vent.

[0031] Preferably, it also has a control panel electrically connected to the control module, and the user can set the temperature difference threshold and the adjustment status of the fan module, heat exchange module and dehumidification module according to the control panel.

[0032] Another object of the present invention is to provide a hot air circulation drying method for fabrics, comprising the following steps: S1. Install the two ends of the external material onto the automatic receiving roller and the automatic discharging roller respectively; S2. Select the drying program on the control panel; S3, the heat exchange module preheats and generates heat flow according to the selected drying program, and the fan module blows the heat flow to the external material to generate heat exchange and dry the external material according to the selected drying program. S4. The temperature acquisition module detects the temperature of the heat flow before it reaches the external material and the temperature of the heat flow after heat exchange with the external material, obtaining the first temperature and the second temperature respectively: S5. The control module calculates the temperature difference value based on the first temperature and the second temperature, judges the moisture content of the external material based on the temperature difference value, and adjusts the operating parameters of the fan module, the heat exchange module and / or the dehumidification module. S6. When the temperature difference reaches the set value of the selected drying program, the control module controls the automatic take-up roller and the automatic unload roller to run, take up the dried external material and unload the undried external material. S7. Repeat steps S4-S6 until all external materials on the automatic feeding roller are dried.

[0033] Furthermore, in step S2, the drying program includes an energy-saving mode, a fast mode, and a protection mode; Among them, the energy-saving mode is configured to prioritize adjusting the operating parameters of the dehumidification module to discharge humid gas; if the temperature difference value still exceeds the threshold after adjusting the operating parameters of the dehumidification module, the speed of the fan module is adjusted; if the temperature difference value still exceeds the threshold after adjusting the speed of the fan module, the power of the heat exchange module is adjusted. The fast mode is configured to simultaneously adjust the operating parameters of at least two of the following modules: the dehumidification module, the fan module, and the heat exchange module; The protection mode is configured to limit the maximum power of the heat exchange module and control the temperature difference value by adjusting the operating parameters of the dehumidification module and / or the fan module.

[0034] Furthermore, the drying program also includes a shaping mode. The drying program is configured such that when the temperature difference reaches a preset threshold, the control module switches from energy-saving mode / fast mode / protection mode to shaping mode.

[0035] Furthermore, in step S5, the control module is configured to calculate the temperature difference change rate based on the temperature difference value to determine the changing trend of the moisture content of the external material; when the temperature difference change rate exceeds the set rate threshold, the control module adjusts the operating parameters of the fan module, the operating parameters of the heat exchange module and / or the operating parameters of the dehumidification module to control the fluctuation range of the temperature difference value.

[0036] Furthermore, the control module has a predictive control model unit, which is configured to establish a mapping model between the temperature difference change trend and the optimal adjustment action based on the operating data, thereby realizing feedforward predictive control. The operational data includes the fabric and specifications of external materials, temperature difference data, temperature difference change rate, and the adjustment actions corresponding to the temperature difference data and temperature difference change rate. The adjustment actions include adjusting the fan speed, adjusting the heating power, and adjusting the opening of the dehumidification damper.

[0037] The beneficial effects of this invention are: (1) Achieve intelligent temperature control and significant energy saving effect: By setting up a temperature acquisition module, the airflow temperature before and after heat exchange can be monitored in real time. The heat loss of heat flow when passing through the fabric can be accurately calculated. Combined with the control system, the output power of the heat exchange module and the wind speed of the fan module can be dynamically adjusted according to the temperature difference, avoiding energy waste caused by continuous high power operation, realizing on-demand heating, and thus achieving significant energy saving effect.

[0038] (2) High drying quality and protection of fabrics: The combined use of the first and second sensors forms a closed-loop temperature monitoring system. This equipment can ensure that the temperature of the hot air acting on the fabric is stable within the preset process range, avoiding problems such as local overheating, hardening or shrinkage of the fabric caused by temperature runaway or uneven distribution in traditional equipment, and effectively improving the drying uniformity of the fabric and the quality of the final product. (3) High-efficiency hot air circulation improves drying efficiency: Through the combined design of air outlets, fan modules, air ducts, spray ducts, and return air inlets, an efficient internal hot air circulation path is formed. Hot air is sprayed out from both sides of the fabric simultaneously through the first and second air outlets, achieving double-sided and uniform drying, which greatly increases the heat exchange area and efficiency. At the same time, the airflow finally flows back to the heat exchange module through the return air inlet, reducing heat loss and further shortening the drying time.

[0039] (4) Compact structure and convenient maintenance: The design of the filter covering the return air vent can effectively intercept fabric lint and dust brought back by hot air, preventing them from entering the heat exchange module and fan module, ensuring the cleanliness and long-term stable operation of the core components, and reducing the failure rate. At the same time, the movable exhaust damper can adjust the opening and closing angle according to the humidity in the chassis, so as to discharge high humidity air in time and optimize the drying environment. The overall layout of the equipment is reasonable, and each function is modular, which facilitates daily inspection and maintenance.

[0040] (5) Multiple drying modes with strong adaptability: Preset energy-saving mode, fast mode, protection mode and setting mode, users can flexibly choose according to fabric characteristics and process requirements. The energy-saving mode adopts a step-by-step adjustment strategy, prioritizing dehumidification, then adjusting the fan and finally adjusting the heating, resulting in low energy consumption; the fast mode drives multiple actuators in parallel to shorten the drying time; the protection mode limits the heating power and is suitable for heat-sensitive fabrics; the setting mode maintains a stable temperature difference at the end of the drying process to ensure that the fabric dimensions are stable and do not deform.

[0041] (6) Intelligent predictive control with fast response and small fluctuations: The control module has a built-in predictive control model unit. By collecting historical operating data, it establishes a mapping model between the temperature difference change trend and the optimal adjustment action to achieve feedforward predictive control. The system can directly output the adjustment amount of fan speed, heating power and dehumidification damper opening according to the current temperature difference and rate of change, effectively suppressing temperature difference fluctuations and improving the system response speed and stability. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a hot air circulation drying method and system for fabrics according to the present invention; Figure 2 This is a schematic diagram of the heat flow direction of the present invention; Figure 3 This is a partial perspective structural diagram of the first and second air jet ducts of the present invention; Figure 4 This is a schematic diagram of the electrical connection structure between the present invention and the control module.

[0043] The reference numerals in the attached drawings include: 100, chassis; 101, air duct; 102, first air outlet; 103, air outlet duct; 104, first spray duct; 105, second spray duct; 106, second air outlet; 107, first air outlet; 108, second air outlet; 109, dehumidification port; 110, main body; 111, first interface; 112, second interface; 113, shelf; 200, fan module; 201, first frequency converter. 300. Heat exchange module; 301. Air outlet; 302. Air return outlet; 303. Filter element; 400. Temperature acquisition module; 401. First sensor; 402. Second sensor; 500. External material; 600. Control module; 700. Dehumidification module; 701. Exhaust damper; 702. Exhaust fan; 703. Second frequency converter; 704. Air supply outlet; 800. Automatic receiving roller; 900. Automatic discharging roller. Detailed Implementation

[0044] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0045] Please see Figures 1 to 4 As shown, a hot air circulation drying method and system for fabrics according to the present invention includes a housing 100, a fan module 200, a heat exchange module 300, and a temperature acquisition module 400 disposed in the housing 100; the housing 100 is used to accommodate external material 500, the fan module 200 is used to cause the heat flow generated by the heat exchange module 300 to pass through the external material 500 to generate heat exchange, and the temperature acquisition module 400 is used to detect the temperature of the heat flow before heat exchange and the temperature after heat exchange.

[0046] In actual use, it also includes a control module 600, which is electrically connected to the fan module 200, the heat exchange module 300 and the temperature acquisition module 400 respectively. The control module 600 is used to control the air volume of the fan module 200 and the temperature of the heat exchange module 300 based on the temperature difference between the temperature of the heat flow before and after heat exchange detected by the temperature acquisition module 400.

[0047] For example, when the control module 600 detects that the temperature difference is less than the set value, the control module 600 issues a command to the fan module 200 to reduce the air volume and at the same time reduce the temperature of the heat exchange module 300.

[0048] Specifically, the heat exchange module 300 has an air outlet 301 and an air return outlet 302, and the fan module 200 is connected to the air outlet 301 of the heat exchange module 300; the temperature acquisition module 400 has a first sensor 401 and a second sensor 402, the first sensor 401 is close to the air outlet 301 and is used to detect the temperature of the heat flow before heat exchange, and the second sensor 402 is close to the air return outlet 302 and is used to detect the temperature of the heat flow after heat exchange.

[0049] In actual use, the heat exchange module 300 is located at one end of the lower part of the chassis 100, the air outlet 301 and the return air outlet 302 are located at the two ends of the heat exchange module 300 respectively, and the fan module 200 is located at the other end of the lower part of the chassis 100 and is connected to the air outlet 301. The fan module 200 is used to blow the heat generated by the heat exchange module 300 onto the external material 500 by means of hot air. The hot air that has completed the heat exchange then enters the heat exchange module 300 through the return air outlet 302 to form a hot air circulation.

[0050] In actual use, the fan module 200 has a first frequency converter 201.

[0051] Specifically, it also has an air duct 101 installed in the chassis 100, the air duct 101 has a first air outlet 102 facing the external material 500; the fan module 200 is connected to the air outlet 301 of the heat exchange module 300 and one end of the air duct 101, and the other end of the air duct 101 extends toward the return air outlet 302.

[0052] In actual use, the air duct 101 is a hollow structure, and hot air is guided by the air duct 101 to blow towards the external material 500.

[0053] Specifically, the air duct 101 has an air outlet duct 103 and a first air spray duct 104. One end of the air outlet duct 103 is connected to the fan module 200, and the other end of the air outlet duct 103 is bent and connected to one end of the first air spray duct 104. The other end of the first air spray duct 104 extends toward the return air port 302. The first air outlet 102 is located in the first air spray duct 104.

[0054] In actual use, the air outlet duct 103 is vertically connected to the fan module 200, the first air jet duct 104 is located above the heat exchange module 300, and the air outlet 301 and the return air outlet 302 are located on both sides of the first air jet duct 104.

[0055] Specifically, the air duct 101 also has a second air spray duct 105 connected to the air outlet duct 103, and a second air outlet 106 disposed on the second air spray duct 105. The second air outlet 106 is disposed opposite to the first air outlet 102, and the external material 500 is located between the first air outlet 102 and the second air outlet 106.

[0056] In actual use, the first air duct 104 and the second air duct 105 are arranged parallel and spaced apart, and the first air outlet 102 and the second air outlet 106 respectively deliver air to both sides of the external material 500.

[0057] Specifically, the first air outlet 102 has a plurality of first air outlet holes 107, which are arranged along the length of the first air spray duct 104; the second air outlet 106 has a plurality of second air outlet holes 108, which are arranged along the length of the second air spray duct 105.

[0058] In actual use, the axes of the multiple first air outlets 107 and the multiple second air outlets 108 are inclined, so that the air supply direction of the first air duct 104 and the second air duct 105 is towards the return air inlet 302.

[0059] Specifically, the heat exchange module 300 has a filter 303 that covers the return air vent 302.

[0060] In actual use, filter element 303 is a filter screen structure used to block lint and dust in the airflow.

[0061] In actual use, the second sensor 402 is installed on the filter element 303.

[0062] Specifically, it also includes a dehumidification module 700 disposed in the chassis 100, the dehumidification module 700 having an exhaust damper 701 and an exhaust fan 702; the chassis 100 has a dehumidification port 109, and the exhaust damper 701 is movably mounted on the dehumidification port 109.

[0063] In actual use, the control module 600 is electrically connected to the dehumidification module 700. The control module 600 determines the opening or closing range of the dehumidification damper based on the temperature difference between the temperature before and after the heat exchange detected by the temperature acquisition module 400.

[0064] In actual use, the dehumidification module 700 has a second frequency converter 703.

[0065] In actual use, the exhaust damper 701 has a pivot in the middle, and the exhaust damper 701 is mounted on the exhaust port 109 by rotating via the pivot.

[0066] Specifically, the exhaust port 109 is located at the end of the chassis 100 away from the fan module 200.

[0067] In actual use, the exhaust port 109 is located on the top of the chassis 100 and is positioned relative to the return air port 302.

[0068] Specifically, the air duct 101 has a main body 110, and a first interface 111 and a second interface 112 connected to the main body 110. The first air duct 104 and the second air duct 105 are respectively installed at the first interface 111 and the second interface 112.

[0069] Specifically, one end of the first interface 111 and one end of the second interface 112 are connected to the main body 110, and the other ends of the first interface 111 and the second interface 112 bend and extend toward the return air vent 302.

[0070] In actual use, it also has a control panel that is electrically connected to the control module 600. Users can set the temperature difference threshold and the adjustment status of the fan module 200, heat exchange module 300 and dehumidification module 700 according to the control panel.

[0071] In actual use, the intelligent drying equipment also has an automatic take-up roller 800 and an automatic release roller 900 located on the left and right sides of the air guide duct 101, respectively. The automatic take-up roller 800 and the automatic release roller 900 realize the automatic take-up and automatic release of the external material 500. The automatic take-up roller 800 is used to block the gap between the second air outlet 106 and one end of the first air outlet 102, and the automatic release roller 900 is used to block the gap between the second air outlet 106 and the other end of the first air outlet 102.

[0072] The roller shafts of the automatic receiving roller 800 and the automatic discharging roller 900 are aligned with the length direction of the air duct. The automatic receiving roller 800 is located inside the housing 100. One end of the external material 500 is placed on the automatic receiving roller 800. The automatic discharging roller 900 is used to support the remaining part of the external material 500. As the automatic receiving roller 800 rotates, the automatic discharging roller 900 rotates accordingly. The portion of the external material 500 supported by the automatic discharging roller 900 is unfolded and enters between the second air outlet 106 and the first air outlet 102. The movement direction of the external material 500 is perpendicular to the length direction of the air duct.

[0073] In actual use, the bottom of the chassis 100 is also equipped with an air intake vent, which is close to the return air vent 302 of the heat exchange module 300. The return air vent 302 is located between the second sensor 402 and the air intake vent. The heat flow that has completed the heat exchange first passes through the second sensor 402 and then enters the return air vent 302. The air intake vent is connected to the outside atmosphere and is used to automatically replenish the outside air when the dehumidification module 700 discharges moisture. The outside air enters the heat exchange module 300 through the return air vent 302, is heated, and then flows out from the air outlet 301.

[0074] Specifically, the control module 600 is a PLC or embedded controller, including a temperature difference calculation unit, a data analysis unit, and a PID control unit. The temperature difference calculation unit is used to calculate the temperature difference between the first temperature and the second temperature in real time. The data analysis unit is used to analyze the temperature difference change trend and the moisture content of the external material 500 based on the real-time calculated temperature difference value. The PID control unit is used to output a continuous adjustment signal to the fan module 200 and / or the heat exchange module 300 based on the judgment of the data analysis unit.

[0075] In actual use, the temperature difference calculation unit samples at a frequency of 10Hz, reading the first temperature T1 value from the first sensor 401 and the second temperature T2 value from the second sensor 402 in real time. To avoid misjudgments caused by sensor noise or transient disturbances, the unit employs a first-order low-pass filtering algorithm: for each sensor, the filtered temperature value... T_filter(k) = α * T_raw(k) + (1-α) * T_filter(k-1), Where α is the filter coefficient.

[0076] Then calculate the temperature difference ΔT = T1_filter - T2_filter.

[0077] The calculated ΔT is stored in the register of the control module in numerical form, along with a timestamp, forming a temperature difference data sequence.

[0078] The data analysis unit reads the real-time temperature difference value ΔT and the historical ΔT sequence output by the temperature difference calculation unit, and performs the following analysis: (1) Current humidity status determination: Compare ΔT with multiple pre-stored threshold intervals. For example, set the high humidity zone: ΔT > 20℃; medium humidity zone: 10℃ ≤ ΔT ≤ 20℃; low humidity zone: 5℃ ≤ ΔT < 10℃; dry zone: ΔT < 5℃. Based on the interval where ΔT is located, output the corresponding humidity status label, such as "high humidity".

[0079] (2) Analysis of temperature difference change trend: Calculate the rate of change of ΔT over time, i.e., the rate of change of temperature difference d(ΔT) / dt. The specific calculation method is as follows: Take the most recent N sampling points (N≥10), and use the least squares method to linearly fit the slope k, which is the rate of change of ΔT. If k is negative, it indicates that the material is drying rapidly; if k is a positive value close to 0 or a small negative value, it indicates that the drying process is stable; if k is positive, it indicates that ΔT is increasing, and the cause needs to be investigated. The calculation results of the rate of change are used for subsequent predictive adjustments.

[0080] (3) Stability analysis: Calculate the standard deviation of ΔT in the most recent period (e.g., 30 seconds). If the standard deviation is less than the set threshold (e.g., 0.5℃), the drying process is considered to be in a stable state and step-by-step winding and unwinding can be performed.

[0081] The PID control unit receives the current humidity level, ΔT deviation (e = ΔT_target - ΔT_actual), and ΔT rate of change from the data analysis unit. The PID control unit employs a positional or incremental PID algorithm to output a continuous adjustment signal. Specifically: (1) For the fan module 200, the PID control unit outputs a 4-20mA current signal or a 0-10V voltage signal to the frequency converter of the fan to continuously adjust the fan speed. For example, when ΔT is large, the PID output increases and the fan speed increases; when ΔT is small, the PID output decreases and the fan speed decreases.

[0082] (2) For the heat exchange module 300, the PID control unit outputs a thyristor phase-shift trigger signal or a solid-state relay PWM signal to continuously adjust the heating power.

[0083] (3) The PID parameters (including proportional coefficient Kp, integral time Ti, and derivative time Td) can be switched according to the selected drying mode (for example, a weaker proportional action is used in energy-saving mode to avoid over-adjustment, and a stronger proportional and derivative action is used in fast mode to improve the response speed). All output signals are continuous analog signals or high-frequency PWM signals, which realizes stepless fine adjustment of the fan and heating, avoiding the drastic temperature / wind speed fluctuations caused by traditional on / off control.

[0084] Another object of the present invention is to provide a hot air circulation drying method for fabrics, comprising the following steps: S1. Install the two ends of the external material 500 onto the automatic receiving roller 800 and the automatic discharging roller 900 respectively; S2. Select the drying program on the control panel; S3, the heat exchange module 300 preheats and generates heat flow according to the selected drying program, and the fan module 200 blows the heat flow to the external material 500 to generate heat exchange and dry the external material 500 according to the selected drying program. S4. The temperature acquisition module 400 detects the temperature of the heat flow before it reaches the external material 500 and the temperature after the heat flow exchanges heat with the external material 500, and obtains the first temperature and the second temperature respectively: S5. The control module 600 calculates the temperature difference value based on the first temperature and the second temperature, judges the moisture content of the external material 500 based on the temperature difference value, and adjusts the operating parameters of the fan module 200, the operating parameters of the heat exchange module 300 and / or the operating parameters of the dehumidification module 700. S6. When the temperature difference reaches the set value of the selected drying program, the control module 600 controls the automatic take-up roller 800 and the automatic unload roller 900 to run, take up the dried external material 500, and unload the undried external material 500. S7. Repeat steps S4-S6 until all external materials 500 on the automatic feeding roller 900 are dried.

[0085] In actual use, in step S2, the operator needs to select the corresponding drying program based on parameters such as the material, thickness, and initial moisture content of the external material 500.

[0086] In step S6, when the control module 600 detects that ΔT consistently and stably reaches the judgment value set by the selected drying program (e.g., ΔT ≤ 3℃ and the duration exceeds 10 seconds), it indicates that the material at the current stationary position has been dried. At this time, the control module 600 instructs the automatic take-up roller 800 and the automatic discharge roller 900 to simultaneously run a preset length (e.g., 0.5 meters, generally the width of the air duct), thereby winding up the dried material and simultaneously pulling the next undried material into the drying working area.

[0087] In step S7, the automatic feeding roller 900 is equipped with a photoelectric sensor to detect whether the external material 500 has been used up.

[0088] Specifically, in step S2, the drying program includes an energy-saving mode, a fast mode, and a protection mode; Among them, the energy-saving mode is configured to prioritize adjusting the operating parameters of the dehumidification module 700 to discharge humid gas; if the temperature difference value still exceeds the threshold after adjusting the operating parameters of the dehumidification module 700, the speed of the fan module 200 is adjusted; if the temperature difference value still exceeds the threshold after adjusting the speed of the fan module 200, the power of the heat exchange module 300 is adjusted. The fast mode is configured to simultaneously adjust the operating parameters of at least two of the following modules: the dehumidification module 700, the fan module 200, and the heat exchange module 300. The protection mode is configured to limit the maximum power of the heat exchange module 300 and control the temperature difference value by adjusting the operating parameters of the dehumidification module 700 and / or the fan module 200.

[0089] In actual use, the energy-saving mode prioritizes minimizing energy consumption. Its adjustment logic is configured as follows: first, adjust the operating parameters of the dehumidification module 700 (i.e., the opening of the exhaust damper 701 and the speed of the exhaust fan 702), because dehumidification is a low-energy-consuming adjustment method. After adjusting the dehumidification module, if the temperature difference ΔT still exceeds the allowable target range (e.g., ΔT deviates from the target value by more than ±3℃), then adjust the speed of the fan module 200. If ΔT still exceeds the threshold after adjusting the fan module 200 speed, then finally adjust the power of the heat exchange module 300. This step-by-step adjustment strategy recovers as much heat as possible, reducing energy loss caused by frequent changes in heating power. For example, when ΔT is found to be too large, the system first increases the exhaust damper 701 to 100% and turns on the exhaust fan 702. If ΔT is still too large, then the speed of the fan module 200 is increased. If this is still insufficient, then the heating power of the heat exchange module 300 is increased.

[0090] The rapid mode aims for the shortest drying time, allowing for higher energy consumption. Its regulation logic is configured to simultaneously adjust the operating parameters of at least two modules among the dehumidification module 700, fan module 200, and heat exchange module 300. Specifically, during startup, the system simultaneously instructs the dehumidification damper to open fully, the fan to run at full speed, and the heater to output full power, maximizing the rate at which heat is transferred to the material and moisture is removed. During the drying process, the system coordinates adjustments based on the rate of change of ΔT: for example, when ΔT decreases rapidly, the heating power and fan speed can be reduced simultaneously to avoid overshoot. This mode allows for large-scale, multi-parameter parallel adjustments to achieve the fastest dynamic response.

[0091] The protection mode is used for drying temperature-sensitive materials (such as wool, silk, and spandex-containing fabrics) to prevent overheating damage. Its regulation logic is configured as follows: First, the maximum allowable power of the heat exchange module 300 is limited in the software, for example, limiting its maximum output to no more than 60% of its rated power or setting an upper limit T1_max based on the material's temperature tolerance. Then, ΔT is controlled primarily by adjusting the operating parameters of the dehumidification module 700 and / or the fan module 200. For example, when ΔT is lower than the target value, the dehumidification damper is appropriately reduced or the fan speed is lowered to reduce heat loss; when ΔT is higher than the target value but the heating power has reached its upper limit, the system will issue an alarm and suggest reducing the stepping speed (i.e., extending the drying time) instead of forcibly drying by increasing the temperature, thereby ensuring material quality.

[0092] Specifically, the drying program also includes a shaping mode. The drying program is configured such that when the temperature difference reaches a preset threshold, the control module 600 switches between energy-saving mode / fast mode / protection mode and shaping mode.

[0093] In actual use, the shaping mode is a special post-processing mode. Its trigger condition is: when the control module 600 detects that the temperature difference value ΔT has dropped and stabilized at a preset small threshold (e.g., ΔT ≤ 5℃), the control module 600 will automatically switch to the shaping mode, regardless of whether it is currently in energy-saving mode, fast mode or protection mode.

[0094] The specific parameter settings for the finalization mode are as follows: Target temperature difference ΔT_target_final: Set between 2℃ and 4℃. At this temperature difference, the moisture on the surface of the material has basically evaporated, but the heat flow still maintains a slight heat exchange, which is used to heat-set the material.

[0095] Temperature T1 control inside the chassis: In the setting mode, the power of the heat exchange module 300 is adjusted to keep T1 at a constant setting temperature, for example, 180℃~200℃ for polyester fabrics and 150℃~160℃ for cotton fabrics.

[0096] Fan speed: Reduce to 30% to 50% of the rated speed to provide gentle hot air and avoid strong winds that could deform the fabric.

[0097] Dehumidification module: The exhaust damper 701 is closed to 10% to 20% of its opening, and the exhaust fan 702 stops or runs at a very low speed to reduce heat loss and maintain a stable thermal environment.

[0098] Setting time: The control module 600 has an internal timer. The duration of the setting mode is set according to the material and process requirements, generally from 30 to 120 seconds. During this period, the automatic take-up and untake-down rollers remain stationary, and the material is heat-set in a constant hot air environment to eliminate internal stress and stabilize the fabric size and hand feel.

[0099] Finishing action: After the finishing timer ends, the control module 600 exits the finishing mode and executes the unwinding and winding action of step S6 to wind up the finished material and continue drying the next section of material (if there is still undried material) or directly end the entire process.

[0100] Specifically, in step S5, the control module 600 is configured to calculate the temperature difference change rate based on the temperature difference value and determine the changing trend of the moisture content of the external material 500; when the temperature difference change rate exceeds the set rate threshold, the control module 600 adjusts the operating parameters of the fan module 200, the operating parameters of the heat exchange module 300 and / or the operating parameters of the dehumidification module 700 to control the fluctuation range of the temperature difference value.

[0101] In actual use, the control module 600 not only uses the absolute value of the current temperature difference ΔT, but is also configured to calculate the rate of change of temperature difference based on the numerical value of the temperature difference. The specific implementation method is as follows: (1) The control module 600 calculates ΔT once every fixed period (e.g., 1 second) and stores at least the most recent 10 ΔT values.

[0102] (2) Calculate the rate of change using linear regression or simple difference method. For example, using backward difference method: ΔT_rate = (ΔT_current - ΔT_prev) / Δt, where Δt is the sampling interval.

[0103] (3) The control module 600 uses this rate of change to determine the trend of the moisture content of the external material 500: If ΔT_rate is a very large negative value (e.g., less than -1.5℃ / s), it indicates that the moisture content is decreasing rapidly, the material is drying very quickly, and the system judges that it is about to enter the low humidity zone.

[0104] If ΔT_rate is a very large positive value (e.g., greater than +1.0℃ / s), it indicates that the moisture content is increasing instead of decreasing, which may be due to poor moisture removal causing the material to absorb water.

[0105] If ΔT_rate is close to 0, it indicates that the drying process is stable.

[0106] When the rate of change of temperature difference exceeds a set threshold (e.g., an absolute value greater than 1.0℃ / s), the control module 600 adjusts the operating parameters of the fan module 200, the dehumidification module 700, and / or the heat exchange module 300 to control the fluctuation range of the temperature difference. The adjustment strategy employs a "feedforward + feedback" approach: for example, if a ΔT_rate of -2.0℃ / s is detected in fast mode, even if the current ΔT (e.g., 15℃) is still in the medium humidity zone, the system will reduce the heating power and fan speed in advance to prevent ΔT from overshooting below the target value (i.e., over-drying). Conversely, if ΔT_rate is positive and exceeds the threshold, the dehumidification and airflow are increased in advance. This dynamic adjustment based on the rate of change effectively avoids system oscillations, making the transition process of ΔT smoother and the drying quality more consistent.

[0107] Specifically, the control module 600 has a predictive control model unit, which is configured to establish a mapping model between the temperature difference change trend and the optimal adjustment action based on the operating data, so as to realize feedforward predictive control. The operational data includes the fabric and specifications of external material 500, temperature difference data, temperature difference change rate, and the adjustment actions corresponding to the temperature difference data and temperature difference change rate. The adjustment actions include adjusting the fan speed, adjusting the heating power, and adjusting the opening of the dehumidification damper.

[0108] In practical applications, the predictive control model unit is an intelligent model that is trained offline or learns online. Its internal structure can be a neural network, a fuzzy inference system, or a regression model based on support vector machines. This model is configured to establish a mapping model between temperature difference change trends and optimal adjustment actions based on historical operating data, thereby achieving feedforward predictive control.

[0109] Specifically, the operational data includes: the fabric and specifications of the external material 500 (e.g., "polyester taffeta, weight 120g / m²"). 2 The system includes real-time recorded temperature difference data ΔT sequence, temperature difference change rate ΔT_rate sequence, and the optimal adjustment actions corresponding to these temperature difference data and change rates, determined by engineers or optimization algorithms. The adjustment actions include: the speed adjustment of the fan module 200 (unit: rpm or Hz), the power adjustment of the heat exchange module 300 (unit: kW or percentage), the opening and closing angle of the exhaust damper 701 (unit: degrees), and the speed adjustment of the exhaust fan 702 (unit: rpm).

[0110] The usage process of this predictive control model unit is as follows: (1) Learning phase: When the system is used for the first time or when a new material is received, it can be run several times with conventional PID control to record a large number of "(material parameters, ΔT, ΔT_rate) → adjustment action" data pairs. Then, the model can be trained offline using these data, or the model parameters can be continuously updated using the online recursive least squares method.

[0111] (2) Predictive Control Stage: When the system dries materials of the same or similar specifications again, the predictive control model unit directly calculates the expected optimal adjustment action that will make ΔT quickly and smoothly approach the target value based on the material specifications, current temperature difference ΔT, and current temperature difference change rate ΔT_rate input at the current moment, and outputs this action as a feedforward signal to the corresponding actuators (fan module 200, heat exchange module 300, dehumidification module 700). At the same time, traditional PID feedback control can still be superimposed on this feedforward signal to compensate for model errors.

[0112] (3) Self-optimization: After the system actually performs the adjustment action, it will observe new ΔT and rate of change. These data and actual effects (such as whether ΔT overshoots or whether the adjustment time is the shortest) are used as new samples to continue training the model, so that the prediction accuracy of the model is continuously improved.

[0113] Through the aforementioned predictive control model unit, the system can achieve "advance prediction and precise action," significantly shortening the response time to changes in the moisture content of materials. It is particularly suitable for situations where materials change continuously and process requirements are highly consistent, greatly improving the system's intelligence level and adaptability.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method and system for hot air circulation drying of fabrics, characterized in that, Including the chassis (100), and the components located within the chassis (100): The storage module includes an automatic take-up roller (800) and an automatic unwind roller (900). The automatic take-up roller (800) and the automatic unwind roller (900) work together to realize the automatic take-up and automatic unwinding of external materials (500). The heat exchange module (300) has an air outlet (301) and a return air outlet (302). The heat generated by the heat exchange module (300) is blown out through the air outlet (301) and returned through the return air outlet (302). The fan module (200) is installed at the air outlet (301) of the heat exchange module (300) to guide the hot flow blown out through the air outlet (301) through the external material (500) to generate heat exchange and dry the external material (500). The temperature acquisition module (400) has a first sensor (401) and a second sensor (402). The first sensor (401) is close to the air outlet (301) and is used to detect the first temperature before the hot flow is blown to the external material (500). The second sensor (402) is close to the air return outlet (302) and is used to detect the second temperature after the hot flow exchanges heat with the external material (500). The control module (600) is electrically connected to the fan module (200), the heat exchange module (300), and the temperature acquisition module (400) respectively. It is used to calculate the temperature difference between the first temperature and the second temperature. The control module (600) is configured to determine the moisture content of the external material (500) based on the temperature difference and to adjust the operating parameters of the fan module (200) and / or the operating parameters of the heat exchange module (300).

2. The hot air circulation drying method and system for fabrics according to claim 1, characterized in that: It also has an air duct (101) installed in the chassis (100), one end of the air duct (101) is connected to the fan module (200), and the other end of the air duct (101) extends toward the return air inlet (302); the hot flow is sent into the air duct (101) through the fan module (200); The storage module is located between the air duct (101) and the heat exchange module (300). The air duct (101) has a first air outlet (107) on the side facing the storage module. The first air outlet (107) is arranged along the length of the air duct (101). The central axis of the first air outlet (107) is inclined so that the heat flow is blown towards the return air port (302). The second sensor (402) is located between the air duct (101) and the return air inlet (302).

3. The hot air circulation drying method and system for fabrics according to claim 1, characterized in that: It also includes a dehumidification module (700) located in the chassis (100), the dehumidification module (700) having an exhaust damper (701) and an exhaust fan (702); the chassis (100) has a dehumidification port (109), the exhaust damper (701) and the exhaust fan (702) being installed in the dehumidification port (109); the control module (600) is electrically connected to the dehumidification module (700), and the control module (600) is configured to automatically adjust the opening angle of the exhaust damper (701) and the operating parameters of the exhaust fan (702) according to the temperature difference value.

4. The hot air circulation drying method and system for fabrics according to claim 3, characterized in that: The bottom of the chassis (100) is provided with an air supply port (704) that communicates with the outside atmosphere. The air supply port is located at one end of the chassis (100) near the return air port (302), and the return air port (302) is located between the second sensor (402) and the air supply port (704).

5. The hot air circulation drying method and system for fabrics according to claim 1, characterized in that: The control module (600) is a PLC or embedded controller, including a temperature difference calculation unit, a data analysis unit and a PID control unit; wherein, the temperature difference calculation unit is used to calculate the temperature difference between the first temperature and the second temperature in real time, the data analysis unit is used to analyze the temperature difference change trend and the humidity state of the external material (500) based on the real-time calculated temperature difference value, and the PID control unit is used to output a continuous adjustment signal to the fan module (200) and / or the heat exchange module (300) based on the judgment of the data analysis unit.

6. The hot air circulation drying method and system for fabrics according to claim 1, characterized in that, Includes the following steps: S1. Install the two ends of the external material (500) onto the automatic receiving roller (800) and the automatic discharging roller (900) respectively. S2. Select the drying program on the control panel; S3, the heat exchange module (300) preheats and generates heat flow according to the selected drying program, and the fan module (200) blows the heat flow to the external material (500) according to the selected drying program to generate heat exchange and dry the external material (500). S4. The temperature acquisition module (400) detects the temperature of the heat flow before it reaches the external material (500) and the temperature of the heat flow after heat exchange with the external material (500), and obtains the first temperature and the second temperature respectively: S5. The control module (600) calculates the temperature difference value based on the first temperature and the second temperature, judges the moisture content of the external material (500) based on the temperature difference value, and adjusts the operating parameters of the fan module (200), the operating parameters of the heat exchange module (300) and / or the operating parameters of the dehumidification module (700). S6. When the temperature difference reaches the set value of the selected drying program, the control module (600) controls the automatic take-up roller (800) and the automatic unload roller (900) to run, take up the dried external material (500), and unload the undried external material (500). S7. Repeat steps S4-S6 until all external materials (500) on the automatic feeding roller (900) are dried.

7. A hot air circulation drying method and system for fabrics according to claim 6, characterized in that, In step S2, the drying program includes an energy-saving mode, a fast mode, and a protection mode; Among them, the energy-saving mode is configured to prioritize adjusting the operating parameters of the dehumidification module (700); if the temperature difference value still exceeds the threshold after adjusting the operating parameters of the dehumidification module (700), the speed of the fan module (200) is adjusted; if the temperature difference value still exceeds the threshold after adjusting the speed of the fan module (200), the power of the heat exchange module (300) is adjusted. The fast mode is configured to simultaneously adjust the operating parameters of at least two of the following modules: the dehumidification module (700), the fan module (200), and the heat exchange module (300); The protection mode is configured to limit the maximum power of the heat exchange module (300) and control the temperature difference value by adjusting the operating parameters of the dehumidification module (700) and / or the fan module (200).

8. A hot air circulation drying method and system for fabrics according to claim 7, characterized in that, The drying program also includes a setting mode, which is configured such that when the temperature difference reaches a preset threshold, the control module (600) switches from energy-saving mode / fast mode / protection mode to setting mode.

9. A hot air circulation drying method and system for fabrics according to claim 6, characterized in that, In step S5, the control module (600) is configured to calculate the temperature difference change rate based on the temperature difference value and determine the changing trend of the moisture content of the external material (500); when the temperature difference change rate exceeds the set rate threshold, the control module (600) adjusts the operating parameters of the fan module (200), the operating parameters of the heat exchange module (300) and / or the operating parameters of the dehumidification module (700) to control the fluctuation range of the temperature difference value.

10. A hot air circulation drying method and system for fabrics according to claim 6, characterized in that, The control module (600) has a predictive control model unit, which is configured to establish a mapping model between the temperature difference change trend and the adjustment action based on the operating data, so as to realize feedforward predictive control. The operational data includes the fabric and specifications of the external material (500), temperature difference data, temperature difference change rate, and the adjustment actions corresponding to the temperature difference data and temperature difference change rate. The adjustment actions include the speed adjustment of the fan module (200), the power adjustment of the heat exchange module (300), the opening and closing angle of the exhaust damper (701), and the speed adjustment of the exhaust fan (702).

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