Variable frequency through-flow grain dryer and control method thereof

Abstract

This invention relates to a variable frequency through-flow grain dryer and its control method, belonging to the technical field of grain drying equipment. The dryer includes a dryer body, with at least one suction device at the upper end and a blowing device at the lower end. A heating device is located near the blowing end of the blowing device on the side of the dryer body. A through-flow dispersion plate is located inside the dryer body above the heating device. At least one first monitoring element and at least one second monitoring element are installed on the inner wall of the dryer body. Each first monitoring element monitors the temperature inside the dryer body, and each second monitoring element monitors the humidity inside the dryer body. The dryer also includes a fuzzy PID controller. The blowing device, heating device, each first monitoring element, each second monitoring element, and each suction device are all connected to the fuzzy PID controller. This application has the effect of improving the drying efficiency of the dryer and reducing its energy consumption.

Description

Technical Field

[0001] This invention relates to the technical field of grain drying equipment, and in particular to a variable frequency through-flow grain dryer and its control method. Background Technology

[0002] With global population growth and rising food demand, ensuring efficient, safe, and environmentally friendly food production and storage has become crucial. Grain drying, as a vital post-harvest processing step, plays an indispensable role in increasing grain yield, reducing resource waste, promoting grain trade, minimizing environmental pollution, and creating employment opportunities.

[0003] In grain drying technology, through-flow dryers are a commonly used device that uses high-speed airflow to dry grains. However, in practical applications, controlling the internal temperature and humidity of the dryer is a key challenge.

[0004] First, excessive drying of the grain surface leads to rapid evaporation of internal moisture, causing the grain to crack and lose its edible and storable value. Conversely, excessively low temperatures reduce drying efficiency, increase machine operating time, and raise energy consumption. Second, excessively high internal humidity also affects drying performance. High humidity causes the grain to absorb moisture during drying, resulting in rehydration, which not only reduces drying efficiency but also increases machine energy consumption. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a variable frequency through-flow grain dryer and its control method, thereby solving at least one of the above-mentioned technical problems.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] In the first aspect, this application provides a variable frequency through-flow grain dryer, which adopts the following technical solution:

[0008] A variable frequency through-flow grain dryer includes a dryer body, with a feed inlet connected to one side and a discharge outlet connected to the other side. At least one suction device is provided at the upper end of the dryer body, and a blowing device is provided at the lower end. A heating device is provided on the side of the blowing end of the blowing device near the dryer body. A through-flow dispersion plate is provided above the heating device and is disposed inside the dryer body. At least one first monitoring element and at least one second monitoring element are also installed on the inner wall of the dryer body. Each first monitoring element is used to monitor the internal temperature of the dryer body, and each second monitoring element is used to monitor the internal humidity of the dryer body.

[0009] The dryer also includes a controller, and the blowing device, the heating device, each of the first monitoring elements, each of the second monitoring elements and each of the suction devices are all connected to the controller, which is a fuzzy PID controller.

[0010] The fuzzy PID controller is used to adjust the working status of the blowing device, the heating device and the suction device in real time based on the internal temperature and humidity of the dryer body and through preset fuzzy logic rules.

[0011] The beneficial effects of this invention are: by using a fuzzy PID controller for frequency conversion control, the working status of the blowing device, heating device, and suction device can be adjusted in real time according to the temperature and humidity inside the dryer through fuzzy logic rules. Through precise temperature and humidity monitoring and intelligent control strategies, the fuzzy PID controller can ensure that the grain is dried at the set temperature, avoid energy waste, and improve drying quality and efficiency.

[0012] When grain drying is required, the controller activates the blowing, heating, and suction devices. The blowing device evenly distributes hot air from the heating device to the flow dispersion plate, which in turn creates a uniform and effective flow circulation within the dryer, significantly improving drying efficiency. Simultaneously, the heating device can adjust the temperature according to actual needs, ensuring the grain is dried at the optimal temperature. Thanks to the flow dispersion plate, the grain is heated more evenly during drying, further improving energy efficiency.

[0013] Based on the above technical solution, the present invention can be further improved as follows.

[0014] Furthermore, a detachable first baffle is provided between the feed inlet and the dryer body, and a detachable second baffle is provided between the discharge outlet and the dryer body.

[0015] The beneficial effects of adopting the above-mentioned further scheme are as follows: before the dryer starts working, the first baffle is pulled out to add grain. By adjusting its opening, the flow rate of material entering the dryer body can be controlled. After the dryer finishes working, the second baffle is pulled out to discharge grain. Similarly, by adjusting its opening, the speed at which material is discharged from the dryer body can be controlled.

[0016] During the drying process, a first baffle is inserted at the feed inlet and a second baffle is inserted at the discharge outlet to ensure the airtightness of the internal space of the dryer.

[0017] Furthermore, the blowing device includes a first frequency converter, a first output resistor, a blowing fan, and a first fixed barrel. The first fixed barrel is fixedly connected to the bottom of the dryer body and communicates with the dryer body. The blowing fan is installed inside the first fixed barrel. The blowing fan is connected to the first output resistor. The first output resistor is connected to the first frequency converter. The first frequency converter is connected to the controller.

[0018] The suction device includes a second frequency converter, a second output resistor, a suction fan, and a second fixed barrel. The second fixed barrel is fixedly connected to the top of the dryer body and communicates with the dryer body. The suction fan is installed inside the second fixed barrel and is connected to the second output resistor. The second output resistor is connected to the second frequency converter, and the second frequency converter is connected to the controller.

[0019] The beneficial effects of adopting the above-mentioned further solutions are: by controlling the blower and exhaust fans through the frequency converter, their operating status can be adjusted according to actual needs, avoiding unnecessary energy waste and achieving energy saving and consumption reduction; by outputting anti-voltage devices, the effective transmission distance of the frequency converter can be extended, instantaneous high voltage can be suppressed, and the service life and safety of the equipment can be extended.

[0020] By using both blower and suction fans, an effective air circulation is formed, ensuring airflow inside the dryer and preventing localized overheating or overhumidification, thereby guaranteeing drying quality.

[0021] Furthermore, the first monitoring element is a temperature sensor, the second monitoring element is a humidity sensor, and the heating device is a heating plate.

[0022] The beneficial effects of adopting the above-mentioned further solution are: the temperature sensor can monitor the temperature inside the dryer in real time, and the humidity sensor can monitor the humidity inside the dryer in real time.

[0023] Secondly, this application provides a control method for a variable frequency through-flow grain dryer, employing the following technical solution:

[0024] A control method for a variable frequency through-flow grain dryer includes:

[0025] Obtain the grain information of the grain to be dried and the drying mode corresponding to the grain to be dried. The drying mode is a first drying mode or a second drying mode. The first drying mode is a mode for drying non-seed crops, and the second drying mode is a mode for drying seed crops.

[0026] Based on the grain information and the drying mode, at least one drying condition is recommended;

[0027] In response to a user's selection of a target drying condition among the at least one drying conditions, the target drying condition corresponding to the drying mode is obtained;

[0028] In response to the user's start-up trigger action, the blowing device and each suction device are controlled based on the preset first fan power, and the heating device is controlled based on the preset drying temperature. The current internal monitoring information of the variable frequency through-flow grain dryer is acquired in real time, including the current temperature and current humidity.

[0029] When the current humidity reaches a preset first humidity threshold, the variable frequency through-flow grain dryer is controlled to dry the grain to be dried based on the drying mode, the target drying conditions and the current warehouse monitoring information.

[0030] The beneficial effects of this invention are: by distinguishing between the first drying mode (non-seed crops) and the second drying mode (seed crops), the efficiency of the dryer is improved; by recommending different drying conditions, such as temperature and duration, based on grain information and drying mode, different drying conditions can be recommended to ensure that the grain is dried under optimal conditions, thereby improving drying efficiency and grain quality.

[0031] When the grain reaches the preset humidity threshold, a control strategy is generated based on the drying mode, drying conditions, and current monitoring information in the warehouse. This ensures that the grain is dried using the optimal control strategy, reducing problems such as decreased germination rate and reduced viability caused by improper drying. This guarantees the quality and safety of the grain, improves drying efficiency, avoids unnecessary energy waste, and enhances energy utilization efficiency.

[0032] Furthermore, the step of controlling the variable frequency through-flow grain dryer to dry the grain to be dried based on the drying mode, the target drying conditions, and the current warehouse monitoring information includes:

[0033] When the drying mode is the first drying mode, a first control strategy is generated based on the first drying mode, the target drying conditions and the current on-site monitoring information, and the variable frequency cross-flow grain dryer is controlled to dry the grain to be dried based on the first control strategy;

[0034] When the drying mode is the second drying mode, a second control strategy is generated based on the second drying mode, the target drying conditions and the current on-site monitoring information. Based on the second control strategy, the variable frequency through-flow grain dryer is controlled to dry the grain to be dried.

[0035] The beneficial effects of adopting the above-mentioned further solutions are: different drying modes correspond to different control strategies, making the variable frequency through-flow grain dryer suitable for more types of grains and improving the efficiency of the dryer.

[0036] Furthermore, the step of controlling the variable frequency through-flow grain dryer to dry the grain based on the first control strategy includes:

[0037] Step S11: Based on the current in-warehouse monitoring information, the target drying conditions, and the preset temperature and humidity confirmation rules, determine the temperature range where the current temperature is located and the humidity range where the current humidity is located.

[0038] Step S12: Based on the temperature range where the current temperature is located, the humidity range where the current humidity is located, and the preset adjustment rules, an adjustment strategy is generated, and the working status of the heating device, the blowing device, and each suction device is controlled according to the adjustment strategy.

[0039] The adjustment strategy includes at least a strategy of controlling the heating device to adjust the heating temperature, a strategy of controlling the blower fan to adjust the blowing air through frequency conversion, and a strategy of controlling each of the suction fans to adjust the suction air through frequency conversion.

[0040] The beneficial effects of adopting the above-mentioned further solution are as follows: By acquiring real-time monitoring information within the warehouse, including current temperature and humidity, and combining this with the set drying conditions and preset temperature and humidity confirmation rules, the temperature range and humidity range of the current temperature and humidity can be accurately determined. Based on the current temperature and humidity ranges and preset adjustment rules, adjustment strategies can be dynamically generated, and the operating status of the heating device, blowing device, and various suction devices can be controlled according to these strategies. Dynamic adjustment can respond in real time to changes during the grain drying process, ensuring high efficiency and stability, while ensuring uniform drying of the grain and improving drying quality. By controlling the speed of the blowing and suction fans through frequency conversion, the heating temperature of the heating device can be adjusted in a timely manner according to changes in the temperature and humidity ranges, avoiding unnecessary energy waste.

[0041] Furthermore, determining the temperature range within which the current temperature falls includes:

[0042] When the current temperature is not greater than the first temperature threshold, the temperature range in which the current temperature is located is determined to be the first temperature range;

[0043] When the current temperature is greater than a first temperature threshold and not greater than a second temperature threshold, the interval in which the current temperature is located is determined to be the target temperature interval.

[0044] When the current temperature is greater than the second temperature threshold, the interval in which the current temperature is located is determined to be the second temperature interval;

[0045] Wherein, the first temperature threshold is less than the second temperature threshold, and the second temperature threshold is less than the third temperature threshold;

[0046] Determining the humidity range in which the current humidity falls includes:

[0047] When the current humidity is not greater than a preset second humidity threshold and is greater than a preset third humidity threshold, the interval in which the current humidity is located is determined as the target humidity interval;

[0048] When the current humidity is greater than a preset second humidity threshold, the interval in which the current humidity is located is determined to be the first humidity interval;

[0049] The second humidity threshold is greater than the third humidity threshold.

[0050] The beneficial effects of adopting the above-mentioned further scheme are: by dividing temperature and humidity into different ranges, the state of the drying process can be more accurately determined, and control strategies can be formulated and adjusted based on these states. Different control strategies can be adopted under different temperature and humidity ranges to more effectively accelerate the drying process, especially when approaching the target temperature and humidity range. Fine-tuning control parameters can achieve faster drying while avoiding quality degradation caused by over-drying. The range-based control method has strong adaptability; temperature and humidity thresholds can be set and adjusted according to different grain types, initial states, and environmental conditions to meet different drying requirements.

[0051] Furthermore, it is determined whether the temperature range is the target temperature range, and whether the humidity range is the target humidity range;

[0052] If the temperature range is not the target temperature range and the humidity range is not the target humidity range, then based on the temperature range and the preset temperature fuzzy control rules, a corresponding first adjustment strategy is determined and the first adjustment strategy is used as the adjustment strategy.

[0053] If the temperature range is not the target temperature range, but the humidity range is the target humidity range, then a corresponding first adjustment strategy is determined based on the temperature range and the preset temperature fuzzy control rules.

[0054] If the temperature range is the target temperature range and the humidity range is not the target humidity range, then a corresponding second adjustment strategy is determined based on the humidity range and the preset humidity fuzzy control rules.

[0055] The preset temperature fuzzy control rule is as follows:

[0056] When the temperature range is the first temperature range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current temperature is raised to the target temperature range;

[0057] When the temperature range is the second temperature range, the temperature of the heating device is reduced, and the fan power of the blowing device and each suction device is reduced, so that the current temperature is reduced to the target temperature range.

[0058] The preset humidity fuzzy control rule is as follows:

[0059] When the humidity range is the first humidity range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current humidity drops to the target humidity range.

[0060] The beneficial effects of adopting the above-mentioned further solutions are as follows: By employing appropriate adjustment strategies based on the current temperature and humidity ranges, the temperature and humidity can be quickly adjusted to the target range, thereby improving drying efficiency. When the temperature and humidity do not meet the target range, adjusting the operating status of the heating device, blowing device, and suction device can maximize energy utilization efficiency and avoid unnecessary energy waste. Through fuzzy control rules, changes in temperature and humidity can be comprehensively considered, thereby accurately determining the adjustment strategy. This ensures that the grain achieves optimal drying results during the drying process, preventing the grain from being affected by over-drying or insufficient humidity.

[0061] Furthermore, the step of controlling the variable frequency through-flow grain dryer to dry the grain based on the second control strategy includes:

[0062] When the current drying time of the variable frequency cross-flow grain dryer is not greater than the first time threshold, steps S11 to S12 are executed.

[0063] When the current drying time of the variable frequency through-flow grain dryer is greater than the first time threshold and not greater than the second time threshold, the heating device is controlled to be in the off state, and the blowing device and each of the suction devices are controlled according to the preset second fan power.

[0064] When the current drying time of the variable frequency cross-flow grain dryer is greater than the second time threshold and not greater than the third time threshold, steps S11 to S12 are executed.

[0065] Wherein, the first time threshold is less than the second time threshold, the second time threshold is less than the third time threshold, the first time threshold is the product of the first preset threshold and the first set duration, the second time threshold is the sum of the first time threshold and the first set duration, and the third time threshold is the product of the second preset threshold and the first set duration.

[0066] The beneficial effects of adopting the above-mentioned further scheme are: when drying seed crops, using the second drying mode, by setting different time thresholds, different control methods are employed at different drying stages according to the actual needs of grain drying, ensuring that the grain can be dried under optimal conditions.

[0067] If the current drying time does not exceed the first time threshold, by adopting an appropriate adjustment strategy based on the current temperature and humidity range, the temperature and humidity can be quickly adjusted to the target range, thereby improving drying efficiency. If the current drying time exceeds the first time threshold but does not exceed the second time threshold, turning off the heating device and using a fixed fan power can maintain the stable state of the grain.

[0068] If the current drying time is greater than the second time threshold but not greater than the third time threshold, the temperature and humidity can be quickly adjusted to the target range by adopting an appropriate adjustment strategy based on the current temperature and humidity range. This can prevent the grain from being over-dried and ensure the drying quality and taste. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the structure of a variable frequency through-flow grain dryer according to an embodiment of the present invention;

[0070] Figure 2 A cross-sectional view of a variable frequency through-flow grain dryer provided in one embodiment of the present invention;

[0071] Figure 3 A control block diagram of a variable frequency cross-flow grain dryer provided in one embodiment of the present invention;

[0072] Figure 4 This is a control block diagram of a variable frequency cross-flow grain drying control method provided in one embodiment of the present invention;

[0073] Figure 5 A schematic flowchart of a control method for variable frequency cross-flow grain drying provided in one embodiment of the present invention;

[0074] Figure 6 This is a schematic diagram of a drying process for grains to be dried using a first control strategy, provided as an embodiment of the present invention.

[0075] Figure 7This is a schematic diagram of a drying process for grains to be dried using a second control strategy, provided as an embodiment of the present invention.

[0076] The accompanying drawings are as follows: 001, Second fixed barrel; 002, Top cover; 003, Drying barrel; 004, Feed inlet; 005, Support frame; 006, Heating mixing chamber; 007, Discharge outlet; 008, First fixed barrel; 009, Suction fan; 010, Temperature sensor; 011, Humidity sensor; 012, Through-flow dispersion plate; 013, Fan blade mounting base; 014, Drive motor; 015, Fan blade; 016, Heating plate;

[0077] 101. Fuzzy PID controller; 102. First frequency converter; 103. Second frequency converter; 104. First output resistor; 105. Second output resistor; 106. Blowing device; 107. Suction device. Detailed Implementation

[0078] The present application will be further described in detail below with reference to the accompanying drawings.

[0079] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0080] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0081] This application provides a variable frequency through-flow grain dryer, such as... Figure 1 , Figure 2 and Figure 3As shown, the variable frequency through-flow grain dryer includes a dryer body, with a feed inlet 004 connected to one side of the dryer body and a discharge outlet 007 connected to the other side. At least one suction device 107 is provided at the upper end of the dryer body, and a blowing device 106 is provided at the lower end of the dryer body. A heating device is provided on the side of the blowing end of the blowing device 106 near the dryer body. A through-flow dispersion plate 012 is provided inside the dryer body above the heating device. At least one first monitoring element and at least one second monitoring element are also installed on the inner wall of the dryer body. The first monitoring element is used to monitor the temperature inside the dryer body, and the second monitoring element is used to monitor the humidity inside the dryer body.

[0082] The dryer also includes a controller, and each of the suction devices 107, the blowing devices 106, the heating devices, the first monitoring devices and the second monitoring devices are connected to the controller, which is a fuzzy PID controller 101;

[0083] The fuzzy PID controller 101 is used to adjust the working status of the blowing device 106, the heating device and the suction device 107 in real time based on the internal temperature and humidity of the dryer body through preset fuzzy logic rules.

[0084] Through the frequency conversion control of the fuzzy PID controller 101, the working status of the blowing device 106, heating device and suction device 107 can be adjusted in real time according to the temperature and humidity inside the dryer through fuzzy logic rules. Through precise temperature and humidity monitoring and intelligent control strategy, the fuzzy PID controller 101 can ensure that the grain is dried at the set temperature, avoid energy waste and improve drying quality and efficiency.

[0085] When grain drying is required, the controller activates the blowing device 106, heating device, and suction device 107. The blowing device 106 evenly blows hot air from the heating device onto the through-flow dispersion plate 012, which in turn creates a uniform and effective through-flow circulation within the dryer. This puts the grain in a state of flux, causing internal moisture to migrate, thus greatly improving drying efficiency. Simultaneously, the heating device can adjust the temperature according to actual needs, ensuring the grain is dried at the optimal temperature. Due to the use of the through-flow dispersion plate 012, the grain is heated more evenly during the drying process, further improving energy utilization efficiency.

[0086] Furthermore, the dryer body includes an upper cover 002, a drying barrel 003, a heating mixing chamber 006, and a support frame 005. The drying barrel 003 is located at the upper end of the heating mixing chamber 006, and the end of the drying barrel 003 near the heating mixing chamber 006 is connected to the heating mixing chamber 006. The end of the drying barrel 003 away from the heating mixing chamber 006 is fixedly connected to the upper cover 002. The heating mixing chamber 006 is fixedly connected to the support frame 005, and the support frame 005 supports the drying barrel 003 and the heating mixing chamber 006.

[0087] Both the feed inlet 004 and the discharge outlet 007 are located on the drying barrel 003, with the feed inlet 004 positioned higher than the discharge outlet 007. A detachable first baffle is provided between the feed inlet 004 and the drying barrel 003, and a detachable second baffle is provided between the discharge outlet 007 and the drying barrel 003.

[0088] Before the dryer starts working, the first baffle is pulled out to add grain into the drying barrel 003. After the dryer finishes working, the second baffle is pulled out to discharge the grain from the drying barrel 003. During the drying process, the first baffle is inserted at the feed inlet 004 and the second baffle is inserted at the discharge outlet 007 to ensure the airtightness of the internal space of the dryer.

[0089] In this embodiment of the application, the heating device is a heating plate 016, and the heating plate 016 is temperature adjustable, with temperature levels of 40°C, 60°C, 80°C, 100°C and 120°C.

[0090] Both the first and second monitoring elements are located on the inner wall of the drying chamber 003, with the first monitoring element being a temperature sensor 010 and the second monitoring element being a humidity sensor 011. At least one suction device 107 is provided on the top cover 002, and a blowing device 106 is provided at the end of the heating mixing chamber 006 away from the drying chamber 003.

[0091] The blower device 106 includes a first frequency converter 102, a first output resistor 104, a blower fan, and a first fixed barrel 008. The first fixed barrel 008 is fixedly connected to the bottom of the heating mixing chamber 006 and communicates with the heating mixing chamber 006. The blower fan is installed inside the first fixed barrel 008, and the blower fan is supported by the first fixed barrel 008 and guides air to the heating mixing chamber 006. The heating plate 016 is installed inside the first fixed barrel and located above the blower fan. The blower fan is electrically connected to the first output resistor 104, the first output resistor 104 is electrically connected to the first frequency converter 102, and the first frequency converter 102 is electrically connected to the controller.

[0092] The blower fan includes a drive motor 014, a fan blade 015 mounting base 013, and multiple fan blades 015 mounted on the fan blade 015 mounting base 013. The drive motor 014 is fixedly mounted on the first fixed barrel 008. The output shaft of the drive motor 014 is fixedly connected to the fan blade 015 mounting base 013. The fixed mounting base is provided with mounting holes, through which the angle and number of fan blades 015 can be adjusted.

[0093] In this embodiment, two suction devices 107 are provided on the upper cover 002. Each suction device 107 includes a second frequency converter 103, a first output resistor 104, a suction fan 009, and a second fixed container 001. The second fixed container 001 is fixedly connected to the upper cover 002 and communicates with the drying container 003. The suction fan 009 is installed inside the second fixed container 001 and is electrically connected to the second output resistor 105. The second output resistor 105 is electrically connected to the second frequency converter 103, and the second frequency converter 103 is electrically connected to the controller. The suction fan 009 has the same structure as the blower fan and will not be described again here.

[0094] Furthermore, this application also provides a control method for a variable frequency through-flow grain dryer, which is applied to the aforementioned variable frequency through-flow grain dryer. This control method can be executed by a fuzzy PID controller, but is not limited thereto.

[0095] like Figure 4 and Figure 5 As shown, a control method for a variable frequency through-flow grain dryer includes:

[0096] Step S1: Obtain the grain information of the grain to be dried and the drying mode corresponding to the grain to be dried. The drying mode is either a first drying mode or a second drying mode. The first drying mode is a mode for drying non-seed crops, and the second drying mode is a mode for drying seed crops.

[0097] In this embodiment, the display interface of the variable frequency through-flow grain dryer is pre-set with drying modes and grain information for various grains. Operators can select grain information and drying modes in the display interface of the variable frequency through-flow grain dryer, and can also input new grain information in the display interface. They can also recommend drying modes corresponding to the grains to be dried based on the selected grain information, etc., and are not limited to these.

[0098] For drying non-seed crops, it is necessary to ensure the temperature during the drying process and the moisture content of the dried product. For drying seed crops, it is also necessary to ensure the tempering temperature and tempering time during the drying process; the second drying mode is the tempering drying mode. Therefore, this dryer is equipped with a first drying mode suitable for drying non-seed crops and a second drying mode suitable for drying seed crops.

[0099] In addition, other drying modes can be set according to the characteristics of grains such as oil content and moisture content, and are not limited to this.

[0100] Step S2: Recommend at least one drying condition based on the grain information and the drying mode;

[0101] In this application embodiment, when the drying mode is a first drying mode, the drying conditions include at least a first set temperature; when the drying mode is a second drying mode, the drying conditions include at least a first set temperature, a second set temperature (warming temperature), and a first set time (warming time).

[0102] Different grains require different drying modes and temperatures. For example, non-seed crops with low internal oil content, such as millet, corn, and wheat, need to be dried at high temperatures, while crops with high internal oil content, such as soybeans and tiger nuts, need to be dried at low temperatures. Therefore, at least one drying condition is preset for different grains. At least one drying condition is matched according to the grain information and drying mode of the grain to be dried. Recommendations can also be made based on the grain's historical drying condition information, such as recommending drying conditions based on the number of times each drying condition has been used for the grain within a preset time period. In addition, users can set the drying conditions corresponding to the drying mode.

[0103] Step S3: In response to the user's selection of a target drying condition among the at least one drying conditions, obtain the target drying condition corresponding to the drying mode;

[0104] In this embodiment, the operator can trigger the selection button through the buttons, touch screen, or other means of the variable frequency through-flow grain dryer to generate a drying condition selection trigger operation. The fuzzy PID controller responds to the drying condition selection operation and obtains the drying conditions.

[0105] Step S4: In response to the user's start trigger action, control the blowing device and each suction device based on the preset first fan power, and control the heating device based on the preset drying temperature. At the same time, obtain the current internal monitoring information of the variable frequency through flow grain dryer in real time. The current internal monitoring information includes the current temperature and the current humidity.

[0106] In this embodiment, to ensure the integrity of the dried material's surface, the power of the first fan is set to 60% of the total power of the machine to control the blowing device and each suction device. The current temperature inside the chamber is obtained in real time through a temperature sensor, and the humidity inside the chamber is obtained in real time through a humidity sensor.

[0107] Step S5: When the current humidity reaches a preset first humidity threshold, the variable frequency through-flow grain dryer is controlled to dry the grain to be dried based on the drying mode, the target drying conditions and the current warehouse monitoring information.

[0108] In this embodiment, during the initial drying stage, as the moisture in the grain to be dried evaporates, the humidity inside the silo gradually increases. Once the humidity sensor detects that the humidity has reached a first humidity threshold, indicating that the surface of the grain is dry and the damage is minimal, the controller generates a control strategy based on the drying mode, drying conditions, and current silo monitoring information. The first humidity threshold is set to 80%.

[0109] Specifically, step S5 includes:

[0110] When the drying mode is the first drying mode, a first control strategy is generated based on the first drying mode, the target drying conditions and the current on-site monitoring information, and the variable frequency cross-flow grain dryer is controlled to dry the grain to be dried based on the first control strategy;

[0111] When the drying mode is the second drying mode, a second control strategy is generated based on the second drying mode, the target drying conditions and the current on-site monitoring information. Based on the second control strategy, the variable frequency through-flow grain dryer is controlled to dry the grain to be dried.

[0112] The process of controlling the variable frequency through-flow grain dryer to dry the grain based on the first control strategy includes:

[0113] Step S11: Based on the current in-warehouse monitoring information, the target drying condition information, and the preset temperature and humidity confirmation rules, determine the temperature range where the current temperature is located and the humidity range where the current humidity is located.

[0114] Step S12: Based on the temperature range where the current temperature is located, the humidity range where the current humidity is located, and the preset adjustment rules, an adjustment strategy is generated, and the working status of the heating device, the blowing device, and each suction device is controlled according to the adjustment strategy.

[0115] The adjustment strategy includes at least a strategy of controlling the heating device to adjust the heating temperature, a strategy of controlling the blower fan to adjust the blowing air through frequency conversion, and a strategy of controlling each of the suction fans to adjust the suction air through frequency conversion.

[0116] In this embodiment of the application, the controller calculates the range of the first temperature range, the second temperature range, and the target temperature range according to the set drying conditions and the preset temperature and humidity rules, and determines the range of the first humidity range and the target humidity range.

[0117] Specifically, based on the current warehouse monitoring information, the set drying conditions, and the preset temperature and humidity confirmation rules, the temperature range in which the current temperature falls is determined, including:

[0118] When the current temperature is not greater than the first temperature threshold, the temperature range in which the current temperature is located is determined to be the first temperature range;

[0119] When the current temperature is greater than a first temperature threshold and not greater than a second temperature threshold, the interval in which the current temperature is located is determined to be the target temperature interval.

[0120] When the current temperature is greater than the second temperature threshold, the interval in which the current temperature is located is determined to be the second temperature interval;

[0121] The first temperature threshold is less than the second temperature threshold; both the first and second temperature thresholds are calculated using the first set temperature and preset temperature and humidity rules.

[0122] In this embodiment of the application, the first temperature threshold is the product of 65% and the first set temperature, and the second temperature threshold is the product of 85% and the first set temperature.

[0123] Determining the humidity range in which the current humidity falls includes:

[0124] When the current humidity is not greater than a preset second humidity threshold and is greater than a preset third humidity threshold, the interval in which the current humidity is located is determined as the target humidity interval;

[0125] When the current humidity is greater than a preset second humidity threshold, the interval in which the current humidity is located is determined to be the first humidity interval;

[0126] The second humidity threshold is greater than the third humidity threshold.

[0127] In this embodiment, the second humidity threshold is 70%, and the third humidity threshold is the humidity requirement determined based on the grain information. When the grain to be dried reaches the humidity requirement, the controller sends a prompt message to the display screen of the dryer to remind the staff to turn off the variable frequency through-flow grain dryer.

[0128] Furthermore, such as Figure 6 As shown, based on the temperature range of the current temperature, the humidity range of the current humidity, and preset adjustment rules, an adjustment strategy is generated, including:

[0129] Determine whether the temperature range is the target temperature range, and determine whether the humidity range is the target humidity range;

[0130] If the temperature range is not the target temperature range and the humidity range is not the target humidity range, then based on the temperature range and the preset temperature fuzzy control rules, a corresponding first adjustment strategy is determined and the first adjustment strategy is used as the adjustment strategy.

[0131] If the temperature range is not the target temperature range, but the humidity range is the target humidity range, then a corresponding first adjustment strategy is determined based on the temperature range and the preset temperature fuzzy control rules.

[0132] If the temperature range is the target temperature range and the humidity range is not the target humidity range, then a corresponding second adjustment strategy is determined based on the humidity range and the preset humidity fuzzy control rules.

[0133] During the adjustment process, changes in temperature and humidity are continuously monitored, and adjustment strategies are determined in real time based on feedback results to ensure the efficiency and safety of the drying process.

[0134] The preset temperature fuzzy control rule is as follows:

[0135] When the temperature range is the first temperature range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current temperature is raised to the target temperature range;

[0136] When the temperature range is the second temperature range, the temperature of the heating device is reduced, and the fan power of the blowing device and each suction device is reduced, so that the current temperature is reduced to the target temperature range.

[0137] The preset humidity fuzzy control rule is as follows:

[0138] When the humidity range is the first humidity range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current humidity drops to the target humidity range.

[0139] By employing appropriate adjustment strategies based on the current temperature and humidity ranges, the temperature and humidity can be quickly adjusted to the target range, thereby improving drying efficiency. When both temperature and humidity do not meet the target range, the adjustment strategy corresponding to the current temperature range is determined based on temperature priority. By adjusting the operating status of the heating, blowing, and suction devices, energy utilization efficiency can be maximized, avoiding unnecessary energy waste. Through fuzzy control rules, changes in temperature and humidity can be comprehensively considered, thus accurately determining the adjustment strategy. This ensures that the grain achieves optimal drying results during the drying process, preventing it from being affected by over-drying or insufficient humidity.

[0140] like Figure 7As shown, the process of controlling the variable frequency through-flow grain dryer to dry the grain based on the second control strategy includes:

[0141] When the current drying time of the variable frequency cross-flow grain dryer is not greater than the first time threshold, the steps S11 to S12 above are executed, which will not be repeated here.

[0142] When the current drying time of the variable frequency through-flow grain dryer is greater than the first time threshold and not greater than the second time threshold, the heating device is controlled to be in the off state. At the same time, the blowing device and each of the suction devices are controlled according to the preset second fan power to maintain ventilation but no longer heat, so that the grain continues to dry at a lower temperature. At this time, the grain to be dried continues to dry at the set tempering temperature (i.e. the second set temperature) to reduce cracks or damage caused by rapid drying and improve the drying quality.

[0143] When the current drying time of the variable frequency cross-flow grain dryer is greater than the second time threshold and not greater than the third time threshold, steps S11 to S12 are executed.

[0144] Wherein, the first time threshold is less than the second time threshold, the second time threshold is less than the third time threshold, the first time threshold is the product of the first preset threshold and the first set duration, the second time threshold is the sum of the first time threshold and the first set duration, and the third time threshold is the product of the second preset threshold and the first set duration.

[0145] Since the warming time for seed crops is determined by their type, the warming time for hulled crops is 1 / 8 of their normal drying time, and the warming time for unhulled crops is 1 / 12 of their normal drying time. The warming time is the first preset time. Therefore, in this embodiment, the first preset threshold is 3.7. The second preset threshold is determined based on the grain information of the grain to be dried. When the grain to be dried is a hulled crop, the second preset threshold is 8, and when the grain to be dried is an unhulled crop, the second preset threshold is 12.

[0146] By setting different second preset thresholds based on the different types of grains to be dried, the drying needs of different grains can be better met. Hulled and unhulled crops have different optimal drying times during the drying process, making the control strategy more targeted and optimized.

[0147] It should be noted that the first preset threshold is derived from expert experience and historical data, and is not limited to this.

[0148] Furthermore, when the current drying time of the variable frequency through-flow grain dryer is not less than the third time threshold, the controller sends a prompt message to the display interface of the dryer. The prompt message is used to remind the operator to turn off the variable frequency through-flow grain dryer.

[0149] When drying seed crops, a second drying mode is employed, and different time thresholds are set to allow for varying control methods at different drying stages, based on the actual drying requirements of the grain. This ensures that the grain is dried under optimal conditions.

[0150] If the current drying time does not exceed the first time threshold, by employing an appropriate adjustment strategy based on the current temperature and humidity ranges, the temperature and humidity can be quickly adjusted to the target range, thereby improving drying efficiency. If the current drying time exceeds the first time threshold but does not exceed the second time threshold, turning off the heating device and using a fixed fan power can maintain the stable state of the grain. If the current drying time exceeds the second time threshold but does not exceed the third time threshold, again by employing an appropriate adjustment strategy based on the current temperature and humidity ranges, the temperature and humidity can be quickly adjusted to the target range, preventing over-drying of the grain and ensuring drying quality and taste.

[0151] This method, by acquiring real-time information on the current temperature and humidity inside the storage chamber, combined with pre-defined drying conditions and preset temperature and humidity confirmation rules, can accurately determine the temperature and humidity ranges for the current conditions. Based on these ranges and the preset adjustment rules, an adjustment strategy can be dynamically generated. This strategy controls the operation of the heating, blowing, and suction devices, enabling dynamic adjustments that respond in real-time to changes during the grain drying process. This ensures efficient and stable drying while maintaining uniform drying, thus improving drying quality. By controlling the speed of the blowing and suction fans using frequency conversion, the heating temperature of the heating device is adjusted in a timely manner according to changes in the temperature and humidity ranges, avoiding unnecessary energy waste.

[0152] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0153] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions claimed in this application.

Claims

1. A control method for a variable frequency through-flow grain dryer, characterized in that, An application is made in a variable frequency through-flow grain dryer, the variable frequency through-flow grain dryer including a suction device (107), a blowing device (106), a heating device, and a controller. The variable frequency through-flow grain dryer is equipped with at least one first monitoring element and at least one second monitoring element. The blowing device (106), the heating device, each of the first monitoring elements, each of the second monitoring elements, and the suction device (107) are all connected to the controller. The blowing device (106) includes a first frequency converter (102) and a blowing fan, and the suction device (107) includes a second frequency converter (103) and a suction fan (009). The method includes: Obtain the grain information of the grain to be dried and the drying mode corresponding to the grain to be dried. The drying mode is a first drying mode or a second drying mode. The first drying mode is a mode for drying non-seed crops, and the second drying mode is a mode for drying seed crops. Based on the grain information and the drying mode, at least one drying condition is recommended; In response to a user's selection of a target drying condition among the at least one drying conditions, the target drying condition corresponding to the drying mode is obtained; In response to the user's start-up trigger action, the blowing device and each suction device are controlled based on the preset first fan power, and the heating device is controlled based on the preset drying temperature. The current internal monitoring information of the variable frequency through-flow grain dryer is acquired in real time, including the current temperature and current humidity. When the current humidity reaches a preset first humidity threshold, the variable frequency cross-flow grain dryer is controlled to dry the grain to be dried based on the drying mode, the target drying conditions and the current warehouse monitoring information; The process of controlling the variable frequency through-flow grain dryer to dry the grain to be dried based on the drying mode, the target drying conditions, and the current warehouse monitoring information includes: When the drying mode is the first drying mode, a first control strategy is generated based on the first drying mode, the target drying conditions and the current on-site monitoring information, and the variable frequency cross-flow grain dryer is controlled to dry the grain to be dried based on the first control strategy; When the drying mode is the second drying mode, a second control strategy is generated based on the second drying mode, the target drying conditions and the current on-site monitoring information. Based on the second control strategy, the variable frequency cross-flow grain dryer is controlled to dry the grain to be dried. The process of controlling the variable frequency through-flow grain dryer to dry the grain to be dried based on the first control strategy includes: Step S11: Based on the current in-warehouse monitoring information, the target drying conditions, and the preset temperature and humidity confirmation rules, determine the temperature range where the current temperature is located and the humidity range where the current humidity is located. Step S12: Based on the temperature range where the current temperature is located, the humidity range where the current humidity is located, and the preset adjustment rules, an adjustment strategy is generated, and the working status of the heating device, the blowing device, and each suction device is controlled according to the adjustment strategy. The adjustment strategy includes at least a strategy of controlling the heating device to adjust the heating temperature, a strategy of controlling the blower fan to adjust the blowing air through frequency conversion, and a strategy of controlling each of the suction fans to adjust the suction air through frequency conversion. The process of controlling the variable frequency through-flow grain dryer to dry the grain to be dried based on the second control strategy includes: When the current drying time of the variable frequency cross-flow grain dryer is not greater than the first time threshold, steps S11 to S12 are executed. When the current drying time of the variable frequency through-flow grain dryer is greater than the first time threshold and not greater than the second time threshold, the heating device is controlled to be in the off state, and the blowing device and each of the suction devices are controlled according to the preset second fan power. When the current drying time of the variable frequency cross-flow grain dryer is greater than the second time threshold and not greater than the third time threshold, steps S11 to S12 are executed. Wherein, the first time threshold is less than the second time threshold, the second time threshold is less than the third time threshold, the first time threshold is the product of the first preset threshold and the first set duration, the second time threshold is the sum of the first time threshold and the first set duration, and the third time threshold is the product of the second preset threshold and the first set duration; determining the temperature range in which the current temperature falls includes: When the current temperature is not greater than the first temperature threshold, the temperature range in which the current temperature is located is determined to be the first temperature range; When the current temperature is greater than a first temperature threshold and not greater than a second temperature threshold, the interval in which the current temperature is located is determined to be the target temperature interval. When the current temperature is greater than the second temperature threshold, the interval in which the current temperature is located is determined to be the second temperature interval; Wherein, the first temperature threshold is less than the second temperature threshold, and the second temperature threshold is less than the third temperature threshold; Determining the humidity range in which the current humidity falls includes: When the current humidity is not greater than a preset second humidity threshold and is greater than a preset third humidity threshold, the interval in which the current humidity is located is determined as the target humidity interval; When the current humidity is greater than a preset second humidity threshold, the interval in which the current humidity is located is determined to be the first humidity interval; Wherein, the second humidity threshold is greater than the third humidity threshold; The adjustment strategy is generated based on the temperature range of the current temperature, the humidity range of the current humidity, and preset adjustment rules, including: Determine whether the temperature range is the target temperature range, and determine whether the humidity range is the target humidity range; If the temperature range is not the target temperature range and the humidity range is not the target humidity range, then based on the temperature range and the preset temperature fuzzy control rules, a corresponding first adjustment strategy is determined and the first adjustment strategy is used as the adjustment strategy. If the temperature range is not the target temperature range, but the humidity range is the target humidity range, then a corresponding first adjustment strategy is determined based on the temperature range and the preset temperature fuzzy control rules. If the temperature range is the target temperature range and the humidity range is not the target humidity range, then a corresponding second adjustment strategy is determined based on the humidity range and the preset humidity fuzzy control rules. The preset temperature fuzzy control rule is as follows: When the temperature range is the first temperature range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current temperature is raised to the target temperature range; When the temperature range is the second temperature range, the temperature of the heating device is reduced, and the fan power of the blowing device and each suction device is reduced, so that the current temperature is reduced to the target temperature range. The preset humidity fuzzy control rule is as follows: When the humidity range is the first humidity range, the temperature of the heating device is increased, and the fan power of the blowing device and each suction device is increased, so that the current humidity drops to the target humidity range.

2. The control method for a variable frequency through-flow grain dryer according to claim 1, characterized in that, The variable frequency through-flow grain dryer includes a dryer body, with a feed inlet (004) connected to one side of the dryer body and a discharge outlet (007) connected to the other side. At least one suction device (107) is provided at the upper end of the dryer body, and a blowing device (106) is provided at the lower end of the dryer body. A heating device is provided on the side of the blowing end of the blowing device (106) near the dryer body. A through-flow dispersion plate (012) is provided on the upper side of the heating device, and the through-flow dispersion plate (012) is located inside the dryer body. At least one first monitoring element and at least one second monitoring element are also installed on the inner wall of the dryer body. Each first monitoring element is used to monitor the internal temperature of the dryer body, and each second monitoring element is used to monitor the internal humidity of the dryer body. The controller is a fuzzy PID controller (101); The fuzzy PID controller (101) is used to adjust the working status of the blowing device (106), the heating device and the suction device (107) in real time based on the internal temperature and humidity of the dryer body through preset fuzzy logic rules.

3. The control method for a variable frequency through-flow grain dryer according to claim 2, characterized in that, A detachable first baffle is provided between the feed inlet (004) and the dryer body, and a detachable second baffle is provided between the discharge outlet (007) and the dryer body.

4. The control method for a variable frequency through-flow grain dryer according to claim 2, characterized in that, The blowing device (106) includes a first output resistor (104) and a first fixed barrel (008). The first fixed barrel (008) is fixedly connected to the bottom of the dryer body and communicates with the dryer body. The blowing fan is installed in the first fixed barrel (008). The blowing fan is connected to the first output resistor (104). The first output resistor (104) is connected to the first frequency converter (102). The first frequency converter (102) is connected to the controller. The suction device (107) further includes a second output resistor (105) and a second fixed barrel (001). The second fixed barrel (001) is fixedly connected to the top of the dryer body and communicates with the dryer body. The suction fan (009) is installed inside the second fixed barrel (001). The suction fan (009) is connected to the second output resistor (105). The second output resistor (105) is connected to the second frequency converter (103). The second frequency converter (103) is connected to the controller.

5. The control method for a variable frequency through-flow grain dryer according to claim 2, characterized in that, The first monitoring element is a temperature sensor (010), the second monitoring element is a humidity sensor (011), and the heating device is a heating plate (016).

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