Intelligent precise regulation and control system and method for whole tea withering process

Abstract

The invention relates to a tea leaf withering whole-course intelligent precise regulation and control system and method.The tea leaf withering whole-course intelligent precise regulation and control system comprises a withering unit and is characterized by further comprising a central control unit and a weight monitoring unit arranged on the withering unit; the humidity monitoring unit, the temperature monitoring unit and the wind speed monitoring unit are arranged according to needs. By adopting the system, weight data of fresh leaves are continuously collected in real time, the total water loss amount of each stage is accurately calculated in combination with the initial weight, the water loss trend is pre-judged in advance, and parameters such as temperature, humidity and air volume are actively adjusted; parameters such as temperature and humidity, air volume, material turning frequency and leaf spreading thickness are integrated, a multi-dimensional coordinated regulation and control system is constructed, internal and external fluctuation influences are counteracted, the withering process is ensured to meet process requirements, and stable quality is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of tea processing technology, and specifically relates to an intelligent and precise control system and method for the entire tea withering process. Background Technology

[0002] Withering is a core preliminary step in tea processing, transforming fresh leaves from a "green" state to a "processable" state. This process directly determines the aroma and flavor profile of the finished tea, and also significantly impacts the efficiency and final results of subsequent processes such as rolling, fermentation, and drying. Therefore, the quality of withering directly determines the upper limit of tea quality and is an indispensable key step in tea processing.

[0003] CN119257168A discloses a Lichuan Red intelligent withering machine and its digital withering method, including a withering tank, a heat pump unit, a hot air unit, a vibrating leaf-turning mechanism, an adjustable tilt conveyor mechanism, an online moisture content detection device, and a main control system. The machine performs hot air withering and yellow light withering on both the upper and lower parts of the tea leaves; the online moisture content detection device acquires the real-time overall average moisture content of the tea leaves; the main control system is used to determine the degree of difference in moisture content of tea leaves in areas corresponding to photos taken by different cameras, and to determine the degree of difference between the moisture content of tea leaves in the areas corresponding to the photos and the overall average moisture content calculated based on the weight measured by a weight sensor. The Lichuan Red intelligent withering machine disclosed in this patent application has a complex structure, consisting of three layers. The digital withering method disclosed in this patent application collects too many parameters, and its control method relies solely on the tilt conveyor mechanism and the vibration of the excitation motor, which cannot achieve precise control.

[0004] CN117705757A discloses a dynamic monitoring system for the withering degree of black tea. A withering platform is used to lay the black tea to be withered and to provide the withering environment. A data acquisition unit collects data on the black tea during the process, which is then processed by a data processing unit to establish a withering model based on water loss rate, moisture content of withered leaves, and withering time. A control unit tracks the withering state based on the withering model and adjusts the withering platform accordingly. However, this monitoring system suffers from the problem of collecting too many parameters and relying solely on turning the tea leaves up and down for control, making it impossible to precisely regulate the withering process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing technology lacks a tea withering system that can dynamically adjust process parameters according to the real-time state of fresh leaves and can not achieve precise control of multiple parameters. To address this, the present invention provides an intelligent and precise control system and method for the entire tea withering process. It continuously collects the weight data of fresh leaves in real time, and based on the weight changes during withering, tracks the dynamic change curve of the weight data in real time. Combined with the initial weight of the fresh leaves, it can accurately calculate the total water loss at different stages, and then reversely deduce and control the real-time changes in the moisture content of the fresh leaves. The system calculates the water loss rate per unit time of the fresh leaves in real time and dynamically compares this real-time data with a preset standard water loss rate curve. It does not need to wait for a significant deviation in the water loss rate, but rather predicts the subsequent water loss trend based on the rate difference and proactively adjusts key parameters such as temperature, humidity, and airflow. It integrates multiple key process parameters such as temperature, humidity, airflow, turning frequency, and leaf thickness to construct a multi-dimensional collaborative control system. Through the coordinated linkage of multiple parameters, it can effectively offset the fluctuations in the external environment and the conditions of the fresh leaves themselves, ensuring that the entire withering process always precisely conforms to the preset processing requirements and guarantees the stability of the withered quality of the fresh leaves.

[0006] In a first aspect, the present invention provides an intelligent and precise control system for the entire withering process of tea, which includes a withering unit. The system is characterized in that it also includes a central control unit, a weight monitoring unit installed on the withering unit, and a humidity monitoring unit, a temperature monitoring unit, and a wind speed monitoring unit as needed.

[0007] Preferably, in the intelligent and precise control system for the entire tea withering process described above, the weight monitoring unit uses weighing sensors arranged at the four corners, and the weight monitoring unit as a whole supports the structure used for feeding tea in the withering unit.

[0008] Alternatively, preferably, according to the intelligent and precise control system for the entire tea withering process described above, the humidity monitoring unit includes an ambient humidity sensor and a withering humidity sensor, which collect ambient humidity and withering humidity data respectively.

[0009] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes an ambient temperature sensor and a withering temperature sensor, which collect ambient temperature and withering temperature data respectively.

[0010] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes a wind speed monitoring unit for collecting wind speed data of the temperature control fan within the withering unit.

[0011] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes multiple withering units, each group being independent and parallel to the others, and each withering unit including withering equipment.

[0012] Alternatively, preferably, the intelligent and precise control system for the entire tea withering process described in any of the paragraphs above, wherein the withering unit includes a bidirectional belt conveyor, a return unit, and an unloading unit.

[0013] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes a return material unit comprising a lifting belt conveyor.

[0014] Alternatively, preferably, the intelligent and precise control system for the entire tea withering process described in any of the above paragraphs includes a water replenishment unit on the lifting belt conveyor.

[0015] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes a withering unit comprising a mobile feeding device and a distributing device.

[0016] Alternatively, preferably, according to any of the paragraphs above, the intelligent and precise control system for the entire tea withering process includes a light-assisted withering device installed above it.

[0017] Alternatively, preferably, for any of the above-described intelligent and precise control systems for the entire tea withering process, the central control unit has a built-in control model for determining the increase or decrease of temperature, wind speed and / or humidity based on the water loss rate during the tea withering process, temperature data from the temperature monitoring unit, wind speed data from the wind speed detection unit and humidity data from the humidity monitoring unit.

[0018] Secondly, the present invention provides a method for precisely controlling the withering of tea leaves using the aforementioned intelligent and precise control system for the entire withering process, comprising the following steps: (1) Input the ambient temperature, ambient humidity, and the detected moisture content (MR) of fresh tea leaves into the central control unit. fresh ; (2) Input the total withering duration T in the central control unit. total The target moisture content (MR) of tea leaves after withering target ; (3) The weight monitoring unit detects the total weight W of the fresh tea leaves to be withered. initial And feed it back to the central control unit; (4) The central control unit according to MR fresh MR target W initial and T total Achieve the ideal water loss rate ZR; (5) At any time t after the start of withering, the weight monitoring unit detects the total weight W of the withered tea leaves. t and feedback to the central control unit; and (6) The central control unit automatically calculates the actual water loss rate LR at time t and compares it with ZR. Based on the comparison result, the temperature and / or wind speed of the temperature control fan in the withering unit are adjusted.

[0019] Alternatively, preferably, according to the precise control method in the above paragraph, in step (5), t is an integer multiple of 3-8 minutes, that is, t=(3-8 minutes)n, where n is a positive integer.

[0020] Alternatively, preferably, the precise control method described in any of the paragraphs above is used, where t is an integer multiple of 5 minutes, i.e., t = (5 minutes)n, where n is a positive integer.

[0021] Alternatively, preferably, according to the precise control method described in any of the paragraphs above, wherein the total withering time T is... total Divide into m-1 nodes, each located at (1 / m)T total (2 / m)T total (3 / m)T total , …… ((m-1) / m)T total At that time, the withering equipment unloads the material onto the bidirectional belt conveyor, and then transports it back to the material distribution unit via the lifting belt conveyor. The material is then returned to the withering unit, where the fresh leaves are rolled over and spread out again.

[0022] Alternatively, preferably, the precise control method described in any of the paragraphs above, where m equals 4.

[0023] Alternatively, preferably, according to the precise control method described in any of the paragraphs above, where T total It equals 11-14 hours.

[0024] Alternatively, preferably, according to the precise control method described in any of the paragraphs above, where T total It equals 12 hours.

[0025] Alternatively, preferably, according to any of the above-described precise control methods, in step (6), if LR is less than ZR, the temperature and / or wind speed of the temperature control fan are increased, and the light-assisted withering device is started; if LR is greater than ZR, the temperature and / or wind speed of the temperature control fan are decreased, and the water replenishment unit is started as needed during material return.

[0026] Alternatively, preferably, according to any of the above-described precise control methods, in step (6), the control model built into the central control unit queries a preset control table based on the deviation value Δ (%) between LR and ZR to determine the increase or decrease in temperature, wind speed, and humidity.

[0027] Alternatively, preferably, according to the precise control method described in any of the paragraphs above, when Δ>5%, the temperature decreases by 2°C, the wind speed decreases by 15%, and the humidity increases by 10%; when Δ<-5%, the temperature increases by 2°C, the wind speed increases by 15%, and the humidity decreases by 5%. This invention can achieve the following beneficial effects: (1) Real-time and continuous collection of fresh leaf weight data. Based on the weight change of fresh leaves during the withering process, the dynamic change curve of weight data is tracked in real time. Combined with the initial weight of fresh leaves, the total water loss at different stages can be accurately calculated, and then the real-time change of fresh leaf moisture content can be deduced and controlled. (2) The system calculates the water loss rate per unit time of fresh leaves in real time and dynamically compares the real-time data with the preset standard water loss rate curve. It does not need to wait for the water loss rate to show a significant deviation, but can predict the subsequent water loss trend in advance based on the rate difference and actively adjust key parameters such as temperature, humidity and air volume. (3) Integrate multiple key process parameters such as temperature, humidity, air volume, turning frequency and leaf thickness to build a multi-dimensional collaborative control system. Through the collaborative linkage of multiple parameters, the fluctuations of the external environment and the fresh leaves themselves can be effectively offset, ensuring that the entire withering process always accurately conforms to the preset processing requirements and ensuring the stability of the fresh leaf withering quality. Attached Figure Description

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is the overall system flowchart of the present invention; Figure 2 This is a schematic diagram of the withering unit. Figure 3 This is a schematic diagram of the withering equipment; Figure 4 This is a schematic diagram of the structure of a mobile feeding and conveying device; Figure 5 This is a schematic diagram of the water replenishment unit. Figure 6 This is a schematic diagram of the material distribution device.

[0029] In the diagram: 1-Wilting equipment, 2-Feeding and conveying device, 3-Mobile feeding device, 4-Bidirectional belt conveyor, 5-Unloading unit, 6-Lifting belt conveyor, 7-Water replenishment unit, 8-Distribution device, 9-Outer shell, 10-Temperature control fan, 11-Weight monitoring unit, 12-Guide plate, 13-Light-assisted wilting device, 30-Feeding conveyor, 31-Wide inlet trough, 32-First limit drive mechanism, 33-First limit track, 35-Water replenishment cover, 36-Distribution water pipe, 37-Water supply pipe, 38-Water tank with pump, 39-Spray head, 40-Support frame, 41-Fixed arm, 42-Receiving conveyor, 43-Second limit track, 44-Mobile conveyor. Detailed Implementation

[0031] Through dedicated research, the inventors discovered that while the moisture content of tea leaves at optimal withering is typically 58-62%, increasing the withering temperature and accelerating airflow can quickly bring the leaves to this optimal moisture content (58%-62%), improving production efficiency. However, this process doesn't fully convert and form quality components due to insufficient bioactive enzymes like hydrolases and glycosidases within the tea leaves, resulting in a lack of precursor substances and a generally mild taste and aroma. Conversely, allowing fresh tea leaves to wither for more than 18 hours to reach the optimal moisture content leads to excessive consumption and degradation of internal quality components by respiratory and oxidative enzymes, severely impacting the quality of the finished tea. Furthermore, the unpleasant odors from these degradation products also affect the sensory quality of the tea. Therefore, controlling both the degree of withering and the overall process is crucial for achieving high-quality withered leaves. Existing withering processes and related improvement technologies have not broken through the core bottleneck of "precise synchronization between withering time and target water loss rate". They cannot dynamically adjust process parameters according to the real-time status of fresh leaves, nor can they achieve multi-parameter coordinated control. Therefore, it is difficult to fundamentally solve problems such as unstable withering quality and low standardization. Therefore, there is an urgent need for a technical solution that can achieve precise and intelligent control of the withering process.

[0032] To address the aforementioned problems, this invention provides an intelligent and precise control system for the entire tea withering process, comprising a withering unit, characterized in that it further comprises a central control unit, and a weight monitoring unit, a humidity monitoring unit, a temperature monitoring unit, and a wind speed monitoring unit installed on the withering unit.

[0033] This invention also provides a method for precisely controlling the withering of tea leaves, comprising the following steps: (1) Input the ambient temperature, ambient humidity, and the detected moisture content (MR) of fresh tea leaves into the central control unit of the tea withering control system. 鲜 ; (2) Input the total withering duration T in the central control unit.总 The target moisture content (MR) of tea leaves after withering 目 ; (3) The total weight W of the fresh tea leaves to be withered is measured using a weight monitoring unit. 初 And feed it back to the central control unit; (4) The central control unit, based on MR 鲜 MR 目 W 初 and T 总 Achieve the ideal water loss rate ZR; (5) At any time t after the start of withering, the weight monitoring unit detects the total weight W of the withered tea leaves. t and feedback to the central control unit; and (6) The central control unit automatically calculates the actual water loss rate LR under time t and compares it with ZR. Based on the comparison result, the temperature and / or wind speed of the temperature control fan in the withering unit are adjusted.

[0034] The following description, in conjunction with the accompanying drawings, details the intelligent and precise control system for the entire tea withering process and the method for precisely controlling tea withering.

[0035] like Figure 1 As shown, the intelligent and precise control system for the entire tea withering process includes a central control unit, a withering unit, and various monitoring units. Each monitoring unit includes a weight monitoring unit, a humidity monitoring unit, a temperature monitoring unit, and a wind speed monitoring unit installed on the withering unit.

[0036] In one specific implementation scheme, the withering unit includes withering equipment 1, a material distribution device 8, and a mobile feeding device 3. The withering unit also includes a return material unit and an unloading unit 5. The return material unit includes a lifting belt conveyor device 6 and a water replenishment unit 7. The central control unit is the core of the system, responsible for receiving data from each monitoring unit, performing logical calculations, and sending control commands. The withering unit consists of multiple units, serving as the core operating area for fresh leaf withering; the core of the withering unit is the withering equipment. The material distribution device 8 is used to evenly distribute fresh leaves to each withering device. The return material unit realizes the cyclic turning and secondary distribution of fresh leaves. The unloading unit 5 is used for the centralized output of fresh leaves after withering. Each unit is linked to the central control unit 1 via wired or wireless signals, forming a complete control closed loop.

[0037] The withering unit is equipped with a weight monitoring unit, a humidity monitoring unit, a temperature monitoring unit, and a wind speed monitoring unit. Each monitoring unit collects data in real time and transmits the data synchronously to the central control unit to provide a basis for control decisions.

[0038] The weight monitoring unit employs four corner-arranged weighing sensors, which together support the tea-feeding structure within the withering equipment. Data is collected synchronously by the four weighing sensors, and the average value is calculated by the central control unit to avoid single-point weighing errors and ensure accurate fresh leaf weight detection.

[0039] In a preferred embodiment, the humidity monitoring unit includes an ambient humidity sensor and a wilting humidity sensor, which collect ambient humidity and wilting humidity data, respectively. The ambient humidity sensor is placed in the air surrounding the wilting unit, while the wilting humidity sensor is inserted into the pile of fresh leaves to directly obtain the humidity of the microenvironment surrounding the fresh leaves.

[0040] Alternatively, in a preferred embodiment, the temperature monitoring unit includes an ambient temperature sensor and a wilting temperature sensor, which collect ambient temperature and wilting temperature data respectively. The ambient temperature sensor is arranged in the same position as the ambient humidity sensor, and the wilting temperature sensor is close to the surface of the fresh leaves to provide real-time feedback on the temperature status of the fresh leaves themselves.

[0041] Alternatively, in a preferred embodiment, the wind speed monitoring unit is used to collect wind speed data of the fans in the withering unit. The number of these units is the same as the number of temperature-controlled fans in the withering unit, with each temperature-controlled fan corresponding to one wind speed monitoring unit, ensuring full coverage of wind speed monitoring in each area.

[0042] In one specific implementation, the intelligent and precise control system for the entire tea withering process of the present invention, such as... Figure 2 As shown, the withering unit includes multiple sets of withering equipment 1 arranged in parallel and a material conveying system. These multiple sets of withering equipment 1 are independent of each other and arranged in parallel, allowing for the simultaneous withering of multiple batches of fresh leaves. Operating gaps are reserved between adjacent withering equipment 1 to facilitate equipment maintenance and troubleshooting. The structure and dimensions of each set of withering equipment 1 are completely identical, ensuring uniform processing conditions for fresh leaves and making it suitable for large-scale operations, thereby significantly improving processing efficiency. The material conveying system is responsible for the precise transfer of fresh leaves between the various devices, ensuring a smooth and continuous withering process.

[0043] The material conveying system includes a feeding conveying device 2, a distributing device 8, and a mobile feeding device 3, which cooperate with the feeding ends of multiple sets of parallel withering equipment 1. The feeding conveying device 2 is used to transport the fresh tea leaves to be withered from the raw material storage area to the subsequent distributing device 8. Its conveying speed can be adjusted according to the total processing volume and the feeding requirements of the withering equipment 1. The distributing device 8 can evenly distribute the fresh leaves delivered by the feeding conveying device 2 to different mobile feeding devices 3. The mobile feeding device 3 is responsible for accurately feeding the distributed fresh leaves into the corresponding feeding end of the withering equipment 1, ensuring that the feeding amount of each set of withering equipment 1 is consistent, laying the foundation for subsequent uniform withering. The mobile feeding device 3 can move along the arrangement direction of the withering equipment 1 to realize continuous feeding of multiple sets of withering equipment 1. The distributing device 8 has a built-in flow control module to accurately control the distribution amount of fresh tea leaves according to the preset load capacity of each set of withering equipment 1. Preferably, the discharge end of the multiple sets of parallel withering equipment 1 is equipped with a bidirectional belt conveyor 4 that works in conjunction with it. The bidirectional belt conveyor 4 can realize bidirectional conveying function: when the tea leaves meet the withering requirements, they are conveyed to the unloading end; when the withering process of the fresh leaves does not meet the expectations and secondary processing is required, they are conveyed to the return end. One side of the bidirectional belt conveyor 4 is equipped with an unloading unit 5, which is used to convey the withered tea leaves to the feed inlet of the subsequent processing step, realizing seamless connection between withering and subsequent processes; the other side of the bidirectional belt conveyor 4 is equipped with a lifting belt conveyor 6 that works in conjunction with the distributing device 8. The lifting belt conveyor 6 can send the tea leaves that need secondary processing back to the distributing device 8 and re-enter the withering process; the lifting belt conveyor 6 is equipped with a water replenishment unit 7. When the fresh tea leaves lose water too quickly and the moisture content is lower than expected, the water replenishment unit 7 can accurately replenish the moisture of the fresh tea leaves, adjust the state of the fresh leaves, and ensure that the subsequent withering can proceed normally.

[0044] In the more specific intelligent and precise control system solution for the entire tea withering process provided by this invention, such as... Figure 3As shown, the withering equipment 1 includes a housing 9, which provides a relatively sealed environment for the withering process, reducing the impact of external temperature and humidity fluctuations on the withering effect. A temperature-controlled fan 10 is installed on the housing 9, which can simultaneously adjust the temperature and airflow of the output air, delivering airflow that meets the process requirements into the withering equipment 1, providing suitable environmental conditions for the dehydration of fresh tea leaves. A weight monitoring unit 11 is installed inside the housing 9, employing weighing sensors arranged at four corners. The weight monitoring unit 11 supports the structure used for feeding tea leaves in the withering equipment 1. The weighing sensors can collect the total weight of the fresh tea leaves in real time. A light-assisted withering device 13 is installed on the upper part of the housing 9. The light-assisted withering device 13 can simulate the natural light spectrum and is activated when ambient light is insufficient or when accelerated withering is required. It promotes enzymatic reactions within the fresh leaves while avoiding the destruction of aroma substances by high temperatures, assisting in regulating the physiological metabolic processes of the fresh tea leaves, promoting the formation and transformation of aroma substances within the fresh leaves, and appropriately increasing the local temperature to help control the rate of dehydration of the fresh leaves, further improving the withering quality. The withering equipment 1 has a guide plate 12 at the feed end. The guide plate 12 is inclined, with one end connected to the discharge end of the moving feeding device 3 and the other end extending above the chain conveyor belt of the withering equipment 1. It can guide the fresh tea leaves to fall smoothly and evenly on the chain conveyor belt, avoid the fresh tea leaves from scattering or piling up during the feeding process, and ensure that the thickness of the fresh leaves spread on the chain conveyor belt is uniform. More specifically, such as Figure 4 As shown, the mobile feeding device 3 includes a feeding conveyor 30, which provides conveying power for feeding fresh tea leaves. The feeding conveyor 30 is equipped with a wide-mouth feed chute 31 and a first limit drive mechanism 32. The wide-mouth feed chute 31 can increase the area of ​​the feed inlet, making it easier to receive the fresh tea leaves sent by the distributing device 8 and preventing the fresh tea leaves from leaking out. The first limit drive mechanism 32 can drive the feeding conveyor 30 to move along a preset trajectory to realize the multi-station feeding function. The position of the feeding conveyor 30 can be adjusted according to the feeding requirements of each withering device 1. A first limiting track 33 is arranged directly below the first limiting drive mechanism 32. The first limiting track 33 provides guidance and limitation for the movement of the first limiting drive mechanism 32, ensuring the stability and accuracy of the feeding conveyor 30 during its movement. The feeding conveyor 30 is equipped with a material leveling mechanism that is linked to it. The material leveling mechanism can comb and flatten the fresh leaves during the conveying process, so that the fresh leaves are evenly distributed on the conveyor belt of the feeding conveyor 30, thereby ensuring that the thickness of the fresh leaves entering the withering equipment 1 is consistent. More specifically, such as Figure 5As shown, the water replenishment mechanism 7 includes a water replenishment cover 35 mounted on the lifting belt conveyor 6. The water replenishment cover 35 can confine the water replenishment process to a certain area, preventing water mist from overflowing and affecting other equipment. The water replenishment cover 35 is equipped with a water distribution pipe 36, which is connected to a pumped water tank 38 via a water supply pipe 37. The pumped water tank 38 provides stable water pressure, transporting water from the tank to the water distribution pipe 36 through the water supply pipe 37. Multiple sets of spray nozzles 39 are evenly distributed on the water distribution pipe 36. The spray nozzles 39 can atomize water and spray it evenly onto the surface of the fresh tea leaves on the lifting belt conveyor 6, achieving precise humidification. The humidification amount can be adjusted to avoid over- or under-humidification. More specifically, as... Figure 6 As shown, the material distribution device 8 includes a support frame 40, which provides support for the entire material distribution device 8 to ensure the stability of the mechanism; the support frame 40 is provided with multiple sets of fixed arms 41 and a second limiting rail 43. The fixed arms 41 are used to fix the receiving conveyor 42, so that the receiving conveyor 42 maintains a stable working posture; a mobile conveyor 44 is provided below the receiving conveyor 42 to cooperate with its discharge end, and the receiving conveyor 42 can carry out material distribution such as... Figure 2 After receiving the fresh tea leaves from the feeding and conveying device 2 shown, the tea leaves are conveyed to the mobile conveyor 44. The bottom of the mobile conveyor 44 is equipped with a second limit drive mechanism that cooperates with the second limit track 43 and multiple sets of limit support pulleys. The second limit track 43 provides guidance for the movement of the mobile conveyor 44. The second limit drive mechanism drives the mobile conveyor 44 to move along the second limit track 43, which can accurately convey the fresh leaves to different mobile feeding devices 3, realizing the multi-station material distribution function.

[0045] On the other hand, the present invention provides a method for precisely controlling the withering of tea leaves using the above-mentioned intelligent and precise control system for the entire withering process, comprising the following steps: (1) Input the ambient temperature, ambient humidity, and the detected moisture content (MR) of fresh tea leaves into the central control unit. 鲜 ; (2) Input the total withering duration T in the central control unit. 总 The target moisture content (MR) of tea leaves after withering 目 ; (3) The weight monitoring unit detects the total weight W of the fresh tea leaves to be withered. 初 And feed it back to the central control unit; (4) The central control unit according to MR 鲜 MR 目 W 初 and T 总 Achieve the ideal water loss rate ZR; (5) At any time t after the start of withering, the weight monitoring unit detects the total weight W of the withered tea leaves. t and feedback to the central control unit; and (6) The central control unit automatically calculates the actual water loss rate LR at time t and compares it with ZR. Based on the comparison result, the temperature and / or wind speed of the temperature control fan in the withering unit are adjusted.

[0046] Theoretically, t can be any time after the start of withering. However, in practice, the number of times various monitoring data are collected can be reduced. According to the inventor's research, t can be an integer multiple of 3-8 minutes, that is, the detection data is collected every (3-8 minutes), for example, every 5 minutes, such as at the 5th minute, 10th minute, 15th minute, etc.

[0047] To more precisely control the withering process, we will adjust the total withering time T. 总 Divide into m-1 nodes, each located at (1 / m)T 总 (2 / m)T 总 (3 / m)T 总 , …… ((m-1) / m)T 总 At that time, the withering equipment unloads the material onto the bidirectional belt conveyor and then transports it back to the material distribution unit via the lifting belt conveyor. The material is then returned to the withering unit, where the fresh leaves are rolled and spread out again. Here, m is an integer greater than zero; m is preferably 4-6; more preferably 4.

[0048] Through years of research, the inventors have discovered that the best quality finished tea is produced when the moisture content of tea leaves is withered to 58-62% within 11-14 hours, and more preferably to 60% within 12 hours.

[0049] In step (6) above, if LR is less than ZR, the temperature and / or wind speed of the temperature control fan are increased, and the light-assisted withering device is started; if LR is greater than ZR, the temperature and / or wind speed of the temperature control fan are decreased, and the water replenishment unit is started when the material is returned.

[0050] Example 1 of Intelligent and Precise Control of Tea Withering Process Below, we will describe in detail the working principle and process of the intelligent and precise control system for the entire tea withering process of the present invention using the best implementation method.

[0051] First, the intelligent and precise control system for the entire tea withering process is started, and an empty-machine operation test is conducted: the central control unit is turned on, and all equipment, including the feeding and conveying device 2, the distributing device 8, the withering equipment 1, and the return unit, are run unloaded for 30 minutes. During this period, the system self-test module detects the motor operation, belt conveying, sensor communication, and other statuses of each device. After confirming that there is no jamming, abnormal noise, or abnormal data transmission, the system is restored to its initial state (the temperature of the temperature control fan 10 is preset to 25°C, and the wind speed is preset to medium speed (in this field, wind speed is divided into three levels: low speed (0.5–1.0 m / s), medium speed (1.0–2.0 m / s), and high speed (2.0–3.5 m / s). In this embodiment, the medium speed is 1.5 m / s). The spreading mechanism of the withering equipment 1 is reset, and the calibration of each monitoring unit is zeroed). Parameter import and target calculation.

[0052] 1. Importing basic parameters Import the following parameters through the human-machine interface of the central control unit 1: Environmental parameters: The system collects the current ambient temperature (24℃) and humidity (65%) through an external temperature and humidity sensor and uploads the data to the central control unit. Fresh leaf basic data: Import the moisture content (MR) of the fresh leaves to be processed (one bud and two leaves). 鲜 Initial data (based on preliminary testing, the initial moisture content MR of this batch of fresh leaves) 鲜 (75%). 2. Process parameter setting and target calculation Based on processing requirements, process parameters are set in the central control unit: Total withering time T 总 12 hours; Target moisture content MR 目 60%; Temperature control range of the temperature-controlled fan: 25℃~30℃; Leaf thickness: 8cm (suitable for tender fresh leaves with one bud and two leaves). Subsequently, the initial total weight W of the fresh leaves was measured by the weighing module of the feeding and conveying device. 初 =1000kg, based on the principle of "constant dry matter weight", calculate the total weight w of the product at the target moisture content: Dry matter weight = initial total weight × (1 - initial moisture content) = 1000 kg × (1 - 75%) = 250 kg; That is, the dry matter weight is one-quarter of the initial total weight.

[0053] Target total weight w = dry matter weight / (1 - target moisture content) = 250 kg / (1 - 60%) = 625 kg; This means that the batch of fresh leaves needs to lose water to 625kg, and the total water loss is 1000kg-625kg=375kg. Through research, the inventors discovered that the more uniform the water loss rate of tea leaves during withering, the better. Therefore, the ideal water loss rate is the linear water loss rate.

[0054] Therefore, the central control unit generates an ideal water loss rate curve based on the total withering time of 12 hours: the ideal water loss rate ZR changes uniformly with time, the ideal water loss per hour is 375kg / 12=31.25kg, the ideal water loss per 5 minutes is 31.25kg / 12≈2.604kg, and the corresponding ideal water loss rate per 5 minutes is ZR=(2.604kg / 375kg)×100%≈0.694%. III. Fresh Leaf Sorting and Initial Withering 1000 kg of fresh leaves with one bud and two leaves are fed uniformly into the distribution device 8 via the feeding conveyor 2. The distribution device 8 has a built-in weight sensor and equalization mechanism. According to the number of groups of withering equipment 1, the fresh leaves are evenly distributed into 4 groups of withering equipment 1 at a weight of 250 kg per group. The spreading mechanism of each group of withering equipment 1 automatically spreads the fresh leaves to a thickness of 8 cm. Then, the withering unit 2 is started to enter the withering stage. IV. Real-time monitoring and dynamic control 1. Data Acquisition and Calculation During the withering process, the central control unit sends a data collection command every 5 minutes, and the real-time weight W of the fresh leaves in each group is collected through the weight monitoring unit (one unit is installed at the bottom of each withering device). t Meanwhile, real-time humidity, temperature and wind speed data within the withering equipment 1 are collected through humidity monitoring unit, temperature monitoring unit and wind speed monitoring unit.

[0055] According to the collected W t Calculate the current real-time moisture content CR and the actual water loss rate LR: Real-time moisture content CR=(W t - (dry matter weight / 4) / W t ×100% (the dry matter weight of each group is 250kg / 4=62.5kg); Actual water loss rate LR = (Initial weight per unit - W) t ) / (total water loss / 4)×100%=(250kg-W t ) / (93.75kg)×100%.

[0056] The central control unit 1 compares the LR (Rapid Reduction) of each group with the ZR (Zero Reduction) of the same period (0.694% every 5 minutes), and generates control commands based on temperature, humidity, and wind speed data, which are then sent to the actuators of each withering unit. Specifically, the central control unit has a built-in control model. Based on the deviation value Δ (%) between LR and ZR, it queries a preset control table to determine the adjustment amount of temperature, wind speed, and humidity. In a specific implementation plan, when Δ > 5%, the temperature decreases by 2°C, the wind speed decreases by 15%, and the humidity increases by 10%; when Δ < -5%, the temperature increases by 2°C, the wind speed increases by 15%, and the humidity decreases by 5%. 2. Phased regulation and control operations 3rd hour (rapid water loss was detected in the 3rd hour): At this moment, the central control unit collects the real-time weight W of a certain group of fresh leaves. t =220kg, calculated LR=(250-220) / 93.75×100%≈32%; ZR=(3×60 / 5)×0.694%≈24.98% during the same period, that is, LR (32%) is higher than ZR (24.98%), and it is judged as "rapid water loss". According to the control logic, the central control unit issues the following instructions: The temperature of the temperature control fan in the withering equipment 1 group was reduced from the current 28℃ to 26℃; Lower the fan frequency (from 50Hz to 40Hz), reducing the fan speed by 15%; The built-in humidifier in the withering unit is activated to increase the humidity inside the unit from 55% to 65%. By "lowering the temperature, reducing the wind speed, and increasing the humidity", the LR is lowered, so that the actual water loss curve is closer to the ideal curve. 8th hour (slower water loss was detected in the 8th hour): The real-time weight W of the fresh leaves in this group was collected. t =193.75kg, calculated LR=(250-193.75) / 93.75×100%≈60.00%; ZR=(8×60 / 5)×0.694%≈66.62%, that is, LR (60.00%) is lower than ZR (66.62%), and is judged as "slow water loss". According to the control logic, the central control unit issues the following instructions: Increase the air temperature of the temperature-controlled fan from 26℃ to 28℃; Increase the fan frequency (from 40Hz to 48Hz) to increase airflow by 12%; Activate the light-assisted wilting equipment (LED lights with a wavelength of 660nm) to help increase the evaporation rate on the surface of fresh leaves. By "increasing temperature, increasing air volume, and light assistance", the LR is increased to ensure that the water loss progress meets the preset curve. V. Fresh Leaf Reclaiming and Secondary Spreading The total wilting time is T=12 hours, and the three evenly distributed nodes are as follows: 1 / 4 T (3 hours); Half a T (6 hours); Three-quarters of a T (9 hours). At each node, the central control unit controls the unloading mechanism of each withering unit to start, unloading the fresh leaves onto the bidirectional belt conveyor 4 of the return unit; the bidirectional belt conveyor 4 transports the fresh leaves to the lifting belt conveyor 6, which then transports them back to the distribution device 8. The distribution device 8 then returns the fresh leaves to each withering device 1 in groups of 250kg (which decreases slightly due to water loss, and is distributed evenly according to the real-time total weight). The spreading mechanism of the withering device 1 spreads the fresh leaves to a thickness of 8cm, achieving the rolling and even spreading of the fresh leaves and avoiding uneven withering in some areas. During the third hour of material return (when water loss is relatively rapid), the central control unit determines that the actual water loss rate LR is too high. According to the processing logic, during the process of conveying fresh leaves by the lifting belt conveyor 6, the atomizing nozzle of the water replenishment unit 7 is activated to replenish water to the surface of the fresh leaves through external contact (the amount of water replenishment is calculated according to "lowering LR to ZR", and the amount of water replenishment per group is about 1.2kg). After replenishment, the weight of the fresh leaves is restored to the weight corresponding to the ideal water loss, ensuring the uniformity of subsequent withering. VI. End of withering and automatic material discharge Repeat the above cycle of "data collection - calculation and comparison - dynamic control - material return and spreading" until the total withering time of 12 hours ends. Upon arrival at the 12th hour, the central control unit collected the real-time weight of each group of fresh leaves and calculated the total weight to be 625 kg (compared to the target weight W). 目 Consistent), real-time moisture content CR = 60% (consistent with target moisture content MR) 目 (If the objective is consistent), the withering is determined to be complete. Then, all control actuators are automatically shut down, and the unloading mechanism of the withering unit unloads the withered fresh leaves onto the discharge belt, completing the automatic discharge.

[0058] The above description is merely the preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. This preferred embodiment is intended to illustrate the present invention and is only for the purpose of aiding understanding the invention, and is not intended to limit the invention. Those skilled in the art to which this invention pertains can make several simple deductions, modifications, or substitutions based on the concept of the present invention. These deductions, modifications, or substitutions are also within the scope of protection of the present invention.

Claims

1. A fully intelligent and precise control system for the entire tea withering process, comprising a withering unit, characterized in that, It also includes a central control unit, a weight monitoring unit installed on the withering unit, and humidity monitoring units, temperature monitoring units and wind speed monitoring units as needed.

2. The intelligent and precise control system for the entire tea withering process according to claim 1, wherein, The weight monitoring unit uses weighing sensors placed at the four corners, and the entire weight monitoring unit supports the device used for feeding tea leaves in the withering unit.

3. The intelligent and precise control system for the entire tea withering process according to claim 1 or 2, wherein, The humidity monitoring unit includes an ambient humidity sensor and a wilting humidity sensor, which collect ambient humidity and wilting humidity data respectively; And / or, the temperature monitoring unit includes an ambient temperature sensor and a wilting temperature sensor, which collect ambient temperature and wilting temperature data respectively.

4. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-3, wherein, The precision control system includes a material feeding and conveying device 2.

5. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-4, wherein, The wind speed monitoring unit is used to collect wind speed data of the temperature control fan in the withering unit.

6. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-5, wherein, The withering unit is provided in multiple groups, each group is independent and parallel to each other, and each withering unit includes withering equipment; preferably, the withering equipment includes a light-assisted withering device disposed above it.

7. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-6, wherein, The withering unit includes a bidirectional belt conveyor, a return material unit, and an unloading unit; preferably, the return material unit includes a lifting belt conveyor 7; more preferably, the lifting belt conveyor is equipped with a water replenishment unit.

8. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-7, wherein, The withering unit includes a moving feeding device and a distributing device.

9. The intelligent and precise control system for the entire tea withering process according to any one of claims 1-8, wherein, The central control unit has a built-in control model for determining the increase or decrease of temperature, wind speed and / or humidity based on the water loss rate during the tea withering process, temperature data from the temperature monitoring unit, wind speed data from the wind speed detection unit and humidity data from the humidity monitoring unit.

10. A method for precisely controlling the withering of tea leaves using the intelligent and precise control system for the entire withering process as described in any one of claims 1-9, comprising the following steps: (1) Input the ambient temperature, ambient humidity, wind speed, and the detected moisture content (MR) of fresh tea leaves into the central control unit. 鲜 ; (2) Input the total withering duration T in the central control unit. 总 The target moisture content (MR) of tea leaves after withering 目 ; (3) The total weight W of the fresh tea leaves to be withered is measured using a weight monitoring unit. 初 And feed it back to the central control unit; (4) The central control unit, based on MR 鲜 MR 目 W 初 and T 总 Achieve the ideal water loss rate ZR; (5) At any time t after the start of withering, the weight monitoring unit detects the total weight W of the withered tea leaves. t and feedback to the central control unit; and (6) The central control unit automatically calculates the actual water loss rate LR under time t and compares it with ZR. Based on the comparison result, it adjusts one, two or three of the parameters of temperature, wind speed and humidity of the temperature control fan in the withering unit.

11. The method for precise control according to claim 10, wherein, In step (5), t is an integer multiple of 3-8 minutes, that is, t = (3-8 minutes) * n, where n is a positive integer 10. Preferably, t is an integer multiple of 5 minutes, that is, t = 5 minutes * n, where n is a positive integer.

12. The method for precise control according to claim 11, wherein, The total withering time T total Divide into m-1 nodes, each located at (1 / m)T total (2 / m)T total (3 / m)T total , …… ((m-1) / m)T total At that time, the withering equipment unloads the material onto the bidirectional belt conveyor, and then transports it back to the material distribution unit via the lifting belt conveyor. The material is then returned to the withering unit, where the fresh leaves are rolled over and spread out again.

13. The method for precise control according to claim 12, wherein, in, m is 4-6, and / or T total The time is 11-14 hours; preferably m is 4; or preferably T total It lasts for 12 hours.

14. The method for precise control according to any one of claims 9-13, wherein, In step (6), if LR is less than ZR, the temperature and / or wind speed of the temperature-controlled fan are increased, and the light-assisted withering device is started; if LR is greater than ZR, the temperature and / or wind speed of the temperature-controlled fan are decreased; and the water replenishment unit is started or the humidity is increased as needed during material return.

15. The method for precise control according to any one of claims 9-14, wherein, In step (6), the control model built into the central control unit queries the preset control table based on the deviation value Δ (%) between LR and ZR to determine the increase or decrease of temperature, wind speed and humidity.

16. The method for precise control according to any one of claims 9-15, wherein, When Δ > 5%, the temperature decreases by 2℃, the wind speed decreases by 15%, and the humidity increases by 10%; when Δ < -5%, the temperature increases by 2℃, the wind speed increases by 15%, and the humidity decreases by 5%.

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