Material drying control method, device and equipment and storage medium

Abstract

The invention provides a material drying control method and device, equipment and a storage medium, relates to the technical field of drying treatment, solves the technical problem that the material drying effect is poor due to the fact that control and adjustment in the drying process are not matched with the material moisture evaporation condition in the related art, and can more accurately judge the environment parameters in the drying process and improve the drying efficiency. Therefore, the operation parameters of the equipment are adjusted to be matched with the material moisture evaporation condition, and the material drying effect of the equipment is improved.

Description

Technical Field

[0001] The present application relates to the field of drying processing technology, and in particular to a material drying control method, device, equipment and storage medium. Background Art

[0002] The drying process of materials is widely used in the food processing, textile, animal husbandry and other industries. For example, in the pasture production process, the grass needs to be further dried to remove the moisture in the grass and extend its shelf life for easy storage and transportation. During the drying process, the drying equipment heats the air entering the drying chamber through the heating device on it, and then usually passes the hot air with a certain wind pressure and air volume into the drying chamber through the fan to dry the material. In the related technology, the fan, heating device and other components in the drying equipment are usually controlled according to environmental parameters such as wind pressure, temperature, and humidity to control the drying process.

[0003] However, due to the inconsistencies in the stacking structure of the materials, the initial temperature and humidity at different positions of the materials, etc., the environmental parameters detected by the sensors cannot adapt well to the actual situation of the materials, resulting in the control and adjustment in the drying process failing to meet the needs, resulting in the mismatch between the adjusted environmental parameters such as wind pressure and temperature and the evaporation of material moisture, which will not only cause a sharp decline in drying efficiency, but also affect the entire production progress and product quality. Summary of the invention

[0004] The present application provides a material drying control method, device, equipment and storage medium, which solves the technical problem in the related art that the control adjustment of the drying process does not match the evaporation of material moisture, resulting in poor material drying effect. The present solution can more accurately judge the environmental parameters of the drying process, thereby adjusting the operating parameters of the equipment to match the evaporation of material moisture, thereby improving the drying effect of the equipment on the material.

[0005] In a first aspect, the present application provides a material drying control method, which is applied to a drying device. The material drying control method includes:

[0006] Determine the initial hot air temperature, the initial material temperature and the operation time, and determine the current material temperature of the material based on a preset heat exchange model;

[0007] Determine the saturated water vapor pressure of the material according to the current material temperature, and determine the water vapor partial pressure in the air according to the current hot air temperature;

[0008] When the saturated water vapor pressure and the water vapor partial pressure are determined, the corresponding water evaporation rate is determined based on a preset water evaporation model, so as to determine the current moisture content of the material according to the water evaporation rate and the initial moisture content of the material;

[0009] According to the current moisture content of the material and the moisture content range corresponding to each heating stage, the current target heating stage is determined among the multiple heating stages in the drying process, and the operating parameters of the equipment are adjusted according to the control strategy corresponding to the target heating stage to dry the material.

[0010] In a second aspect, the present application further provides a material drying control device, which is applied to a drying device. The material drying control device comprises:

[0011] a temperature determination module configured to determine an initial hot air temperature, an initial material temperature, and an operation time, and determine a current material temperature of the material based on a preset heat exchange model;

[0012] A parameter calculation module is configured to determine the saturated water vapor pressure of the material according to the current material temperature, and to determine the water vapor partial pressure in the air according to the current hot air temperature;

[0013] A moisture content determination module is configured to determine the corresponding moisture evaporation rate based on a preset moisture evaporation model when the saturated water vapor pressure and the water vapor partial pressure are determined, so as to determine the current moisture content of the material according to the moisture evaporation rate and the initial moisture content of the material;

[0014] The drying control module is configured to determine the current target heating stage among multiple heating stages in the drying process according to the current moisture content of the material and the moisture content range corresponding to each heating stage, and adjust the operating parameters of the equipment according to the control strategy corresponding to the target heating stage to dry the material.

[0015] In a third aspect, the present application also provides a drying device, which includes:

[0016] one or more processors;

[0017] The storage device is used to store one or more programs. When the one or more programs are executed by one or more processors, the one or more processors implement the material drying control method of the present application.

[0018] In a fourth aspect, the present application further provides a storage medium storing computer executable instructions, which, when executed by a processor, are used to execute the material drying control method of the present application.

[0019] The present application scheme is based on a heat exchange model and a moisture evaporation model. It can accurately determine the current heating stage in the drying process by analyzing the moisture evaporation of the material, so as to adjust the operating parameters of the equipment according to the corresponding control strategy of the heating stage, so that the environmental parameters of the drying process can match the moisture evaporation of the material, thereby improving the drying effect of the drying equipment on the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the steps of a material drying control method provided in one embodiment of the present application;

[0021] Figure 2 A schematic diagram of the steps of drying materials provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the structure of a material drying control device provided in one embodiment of the present application;

[0023] Figure 4 A schematic diagram of the structure of a drying device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0024] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are only used to explain the embodiments of the present application, rather than to limit the embodiments of the present application. It should also be noted that, for ease of description, only the parts related to the embodiments of the present application rather than all structures are shown in the accompanying drawings, and those skilled in the art should be able to think of it after reading the specification of this application that as long as the technical features do not contradict each other, any combination of the technical features can constitute an optional implementation method.

[0025] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally represents that the objects associated before and after are in an "or" relationship. In the description of the present application, "multiple" means two or more, and "several" means one or more.

[0026] In the pasture production process, materials (such as forage) are usually dried by drying equipment. During the drying process, the drying equipment heats the air entering the drying chamber through the heating device on it, and then passes the hot air with a certain wind pressure and air volume into the drying chamber through the fan to dry the materials. Usually, the fan, heating device and other components in the drying equipment are controlled according to environmental parameters such as wind pressure, temperature, humidity, etc. to control the drying process.

[0027] However, in actual application, the inventors found that the stacking structure of materials is different, and their pore structure has a corresponding impact on the drying process. Among them, the special structure of the material (such as slender fibers or porous structures) is prone to fiber entanglement and pore clogging during drying, and high-humidity materials produce a large amount of water vapor mixed with viscous components and attached to the air duct and fan, thereby increasing the resistance to air flow, causing the wind pressure to rise rapidly, and hindering the air circulation during the drying process, resulting in a serious decline in drying efficiency. In this regard, due to the increase in wind resistance, the solutions in the relevant technology usually adopt the strategy of frequently restarting the fan to deal with the situation where the wind pressure rises rapidly due to the increase in wind resistance. Although the wind pressure can be reduced, the frequent changes in wind pressure will cause the drying process to be unstable, which in turn leads to poor drying effect and energy waste.

[0028] Moreover, parameters such as the initial temperature and initial humidity detected at different positions of the material may also be inconsistent. The detected environmental parameters cannot adapt well to the actual situation of the material, and the control adjustment adopted during drying cannot meet the requirements of drying the material, resulting in the mismatch between the adjusted environmental parameters such as wind pressure and temperature and the evaporation of material moisture, which will not only cause a sharp decline in drying efficiency, but also affect the entire production progress and product quality.

[0029] In this regard, an embodiment of the present application provides a material drying control method, which can be applied to a drying device so that the drying device can provide an effective control and adjustment strategy, and then dry the material to ensure that the moisture content of the material can meet the production requirements. It can be imagined that the drying device includes a fan, a heating device and corresponding sensors, such as a wind pressure sensor, a temperature sensor, and a humidity sensor, and the above sensors can be correspondingly arranged in the drying device and / or the drying chamber. In addition, the drying device also includes a processor and a memory, so that the corresponding computer executable instructions are stored in the memory, so that the processor implements the material drying control method provided in the present application when executing the computer executable instructions, and then reasonably regulates the drying equipment to achieve better drying efficiency and drying quality.

[0030] like Figure 1 As shown, Figure 1 This is a schematic diagram of the steps of a material drying control method provided in an embodiment of the present application. The method can be implemented when a processor in a drying device executes corresponding instructions. The specific steps are as follows:

[0031] Step S110, determining the initial hot air temperature, the initial material temperature and the operating time, and determining the current material temperature of the material based on a preset heat exchange model.

[0032] It is conceivable that the initial hot air temperature and the initial material temperature can be collected by corresponding temperature sensors, and then the above data are transmitted to the processor. The running time is the time for the material to be dried. Furthermore, based on the preset heat exchange model, it is conceivable that the heat exchange model is a mathematical model with the initial hot air temperature, the initial material temperature and the running time as input parameters, and the output parameters corresponding to the heat exchange model can be used to determine the current material temperature of the material.

[0033] In one embodiment, the heat exchange model is used to determine the heat change value during the operation time. In the process of constructing the heat exchange model, based on Newton's law of cooling, the heat transfer rate is proportional to the temperature difference, and heat transfer will cause the material temperature to rise. Then, according to the definition of specific heat capacity, the temperature change over a period of time can be determined. In addition, the heat exchange model also considers the influence of hot air flow and material thermal conductivity on heat transfer, and finally determines the heat exchange function in the heat exchange model. The specific calculation formula is as follows:

[0034]

[0035] Where, ΔT m is the heat change value, k is the heat transfer coefficient, which is related to the convection heat transfer coefficient, heat transfer area and material thermal conductivity, Q air is the hot air flow rate, t is the running time, T0 is the initial hot air temperature, T m is the initial material temperature, C m The output parameter of the heat exchange model is the ratio of the product of the difference between the initial hot air temperature and the initial material temperature, the hot air flow rate, the heat transfer coefficient and the operating time to the material specific heat capacity.

[0036] According to the constructed heat exchange model, the processor inputs the initial hot air temperature, initial material temperature and operating time as input parameters into the heat exchange model when the hot air flow rate, heat transfer coefficient and material specific heat capacity are determined, and uses the output parameters of the heat exchange model as the heat change value during the operating time. It can be imagined that the above-mentioned hot air flow rate, heat transfer coefficient and material specific heat capacity are fixed values. When the specific values ​​of the input parameters are determined, the corresponding heat change value can also be determined based on the heat exchange model.

[0037] Then, according to the heat change value and the initial material temperature, the current material temperature after the material has been dried for the running time is determined, such as adding the heat change value and the initial material temperature to serve as the current material temperature after the material has been dried for the running time. Therefore, through the heat exchange model, the equipment can accurately determine the temperature corresponding to the material after the corresponding drying time, which helps to better analyze the moisture content of the material, thereby improving the effect of the material drying process.

[0038] Step S120: determining the saturated water vapor pressure of the material according to the current material temperature, and determining the water vapor partial pressure in the air according to the current hot air temperature.

[0039] In one embodiment, the saturated water vapor pressure of the material is related to the current material temperature, and the corresponding calculation formula is as follows:

[0040]

[0041] Where E is the saturated water vapor pressure, T e is the current material temperature. The water vapor partial pressure in the air is related to the current hot air temperature, and the corresponding calculation formula is as follows;

[0042]

[0043] Where P is the water vapor partial pressure, H is the relative humidity, T a Therefore, when the current material temperature and the current hot air temperature are determined, the processor can calculate the saturated water vapor pressure of the corresponding material and the water vapor partial pressure in the air according to the corresponding formula.

[0044] Step S130: When the saturated water vapor pressure and the water vapor partial pressure are determined, the corresponding water evaporation rate is determined based on a preset water evaporation model, so as to determine the current moisture content of the material according to the water evaporation rate and the initial moisture content of the material.

[0045] The water evaporation model is a mathematical model used to determine the water evaporation rate. The input parameters of the water evaporation model are the saturated water vapor pressure and the water vapor partial pressure, and the output parameter of the water evaporation model can be used as the water evaporation rate during the running time. In the constructed water evaporation model, the output parameter of the water evaporation model is the product of the difference between the water vapor partial pressure and the saturated water vapor pressure, the evaporation coefficient, and the porosity influence coefficient. The porosity influence coefficient is used to indicate the degree of influence of the pore structure of the material on the evaporation rate.

[0046] After determining the water vapor partial pressure corresponding to the air and the saturated water vapor pressure on the surface of the material, the evaporation coefficient and the pore influence coefficient related to the pore structure are obtained by combining actual measurement or empirical estimation. Substituting these known data into the water evaporation rate model, the water evaporation rate of this stage can be accurately calculated, and then the trend of the change of the material moisture content over time can be scientifically analyzed, so as to reasonably arrange the subsequent control actions. The specific calculation formula is as follows:

[0047] W=k w (P s -P a )×g(ε,τ)

[0048] Where W is the water evaporation rate, k w is the evaporation coefficient, P s is the water vapor partial pressure, P a is the saturated water vapor pressure, and g(ε, τ) is the porosity influence coefficient.

[0049] Optionally, in one embodiment, after the saturated water vapor pressure and water vapor partial pressure are determined according to the corresponding formula, the saturated water vapor pressure and water vapor partial pressure are used as input parameters of the water evaporation model, and the processor can obtain the corresponding output parameters through the water evaporation model, and use the output parameters of the water evaporation model as the water evaporation rate during the running time. In this regard, based on the water evaporation rate and the running time, the corresponding evaporation amount is determined, such as the product of the water evaporation rate and the running time is used as the evaporation amount during this period of time. Then, combined with the initial moisture content of the material, when the evaporation amount is determined, the processor can further determine the change value of the moisture content during this period of running time, thereby determining the current moisture content of the material.

[0050] In this regard, using the moisture evaporation model, the equipment can accurately analyze the changes in the moisture content of the material over time, and then determine the current moisture content of the material, so as to accurately judge the current heating stage, so that the equipment can more accurately adjust the corresponding operating parameters during the drying process of the material.

[0051] Step S140, according to the current moisture content of the material and the moisture content range corresponding to each heating stage, determine the current target heating stage in the multiple heating stages in the drying process, and adjust the operating parameters of the equipment according to the control strategy corresponding to the target heating stage to dry the material.

[0052] It can be imagined that as the drying process proceeds, the moisture content of the material continues to decrease until it reaches the target moisture content. In this regard, there are multiple heating stages in the drying process, and different heating stages correspond to different moisture content ranges, and different heating stages also correspond to different control strategies, so as to adjust the moisture content of the material.

[0053] By analyzing the evaporation of water, the processor can determine the current moisture content of the material, and then, when the current moisture content of the material is within the moisture content range of one of the heating stages, determine that the drying process is currently in that heating stage, and then adjust the operating parameters of the equipment according to the preset control strategy corresponding to the heating stage, such as adjusting the parameters of the fan and the heating device, to achieve the adjustment of parameters such as heating power and fan frequency, so as to dry the material.

[0054] It can be seen from the above scheme that based on the heat exchange model and the moisture evaporation model, the drying equipment can accurately determine the current heating stage in the drying process by analyzing the moisture evaporation of the material, so as to adjust the operating parameters of the equipment according to the corresponding control strategy of the heating stage, so that the environmental parameters of the drying process can match the moisture evaporation of the material, thereby improving the drying effect of the material.

[0055] Moreover, through corresponding control strategies, materials at different heating stages are dried. The drying equipment can effectively control the temperature and humidity of the materials, and promptly send the water vapor generated during the drying process out of the drying chamber, reducing the occurrence of materials mixing with water vapor and adhering to the air duct and fan, which helps to maintain air circulation during the drying process, thereby improving the drying efficiency and eliminating the need to frequently restart the equipment, thereby maintaining the stability of the drying process, further improving the drying effect, and saving energy.

[0056] In some embodiments, the drying device can determine whether the current drying process stage enters another heating stage according to the moisture content interval corresponding to each heating stage as the drying progresses, so as to further adjust the operating parameters according to different control strategies corresponding to different stages. Figure 2 As shown, Figure 2 A schematic diagram of the steps of drying materials provided in an embodiment of the present application, wherein the processor can adjust the operating parameters accordingly according to the corresponding moisture content change, and the specific steps are as follows:

[0057] Step S210: Compare the current moisture content of the material with the thresholds of the moisture content intervals corresponding to the heating stages, so as to take the heating stage corresponding to the moisture content interval in which the current moisture content is located as the target heating stage.

[0058] Step S220: Control the temperature and humidity of the material according to the control strategy corresponding to the target heating stage, so as to control the temperature and humidity of the material within the target range corresponding to the target heating stage.

[0059] It can be understood that the interval endpoints of the moisture content interval corresponding to each heating stage correspond to a threshold value respectively. In this regard, in the comparison process, based on the two threshold values ​​of each heating stage, when the current moisture content of the material is between the two threshold values, the processor can determine the current heating stage and use the heating stage as the target heating stage. Exemplarily, the multiple heating stages set are the first heating stage, the second heating stage and the third heating stage, wherein the first heating stage can be used to preheat the material to initially reduce the moisture content of the material; the second heating stage can be used to dry the moisture content of the material at a constant speed so that a large amount of water on the surface of the material evaporates; and the third heating stage can be used to reduce the drying speed of the material so that the moisture content of the material slowly approaches the target moisture content.

[0060] Then, according to the control strategy corresponding to the target heating stage, the temperature and humidity of the material are controlled, such as adjusting the heating device to control the temperature of the material, and adjusting the fan to control the humidity of the material. It can be imagined that by controlling the heating power of the heating device, the temperature of the drying process can be controlled, thereby achieving the control of the temperature of the material, and by controlling the fan, it can be ensured that the hot air circulates in the drying chamber at a corresponding flow rate and pressure, thereby taking the water vapor generated by the evaporation of the material out of the drying chamber to achieve the control of the humidity of the material. In this regard, the drying equipment can control the temperature and humidity of the material within the target range corresponding to the target heating stage by controlling the temperature and humidity of the material, thereby gradually reducing the moisture content of the material.

[0061] Therefore, by adjusting the operating parameters of the equipment according to the corresponding control strategy in the heating stage, this solution can make the environmental parameters match the evaporation of material moisture, which helps to improve the drying effect.

[0062] In one embodiment, for the first heating stage, when it is determined that the target heating stage is the first heating stage, the drying device controls the heating device to operate at a first preset heating power, and gradually increases the heating power of the heating device according to the corresponding heating change function. Optionally, in one embodiment, the heating change function may be a function in which the output variable and the input variable change linearly, that is, the heating power increases linearly with time. At the same time, in the first heating stage, the drying device also controls the speed of the fan, such as making the fan run at a preset speed.

[0063] In addition, after completing the preliminary adjustment of the heating device and the fan, the drying equipment also controls the heating power of the heating device according to the current material temperature. It can be imagined that based on the heat exchange model, it can be determined that as the operating time increases, the current material temperature of the material will also increase. Moreover, the drying equipment is provided with a preheating temperature upper limit value corresponding to the first heating stage, and the temperature protection range corresponding to the preheating temperature upper limit value can form a temperature interval. For example, the preheating temperature upper limit value is 40°C, and the corresponding temperature protection value is 2°C, and the value of the temperature interval formed is 38°C to 42°C.

[0064] In this regard, when the current material temperature rises to the temperature protection range corresponding to the upper limit of the preheating temperature, the drying equipment reduces the heating power of the heating device according to a preset heating power change function, such as using the same heating power change function as when increasing the heating power, so that the heating power decreases linearly with time, thereby slowing down the temperature rise rate and avoiding too rapid temperature rise.

[0065] It is conceivable that, in some embodiments, the heating power change function corresponding to increasing the heating power and the heating power change function corresponding to reducing the heating power can also be two different functions to achieve different heating power controls to adapt to actual application conditions.

[0066] Moreover, when the current material temperature exceeds the temperature protection range corresponding to the upper limit value of the preheating temperature, that is, the current material temperature is greater than the maximum value of the formed temperature range (such as 42°C mentioned above), the drying equipment will control the heating device to stop heating, for example, shut down the heating device to stop heating the material. And the drying equipment controls the heating device to operate at a second preset heating power after stopping heating for a preset period of time, wherein the second preset heating power is lower than the heating power before stopping heating. Exemplarily, the heating power before stopping heating is 40kW, while the second preset heating power can be 38kW. It should be noted that the decrease ratio of the second preset heating power relative to the heating power before stopping heating can be set according to the actual application situation.

[0067] In addition, the drying equipment needs to further adjust the fan according to the material humidity. For example, after the fan is operated at a preset speed, the drying equipment detects the change trend of the material humidity. When the change trend of the material humidity is a downward trend and the decline speed is less than the preset decline speed, that is, the current material humidity is declining too slowly, the drying equipment increases the fan speed according to the first preset amplitude, thereby speeding up the air circulation speed, promoting the discharge of water vapor, and allowing the humidity to drop as quickly as possible.

[0068] When the material humidity is decreasing and the decreasing speed is greater than the preset decreasing speed, that is, the current material humidity decreases too fast, the drying equipment reduces the fan speed according to the second preset amplitude, and also reduces the heating power of the heating device according to the first preset ratio, thereby slowing down the evaporation of water, so that the decrease of humidity is stabilized within the corresponding range. Among them, the second preset amplitude is smaller than the first preset amplitude. It should be noted that the specific values ​​of the first preset amplitude and the second preset amplitude can be set according to the actual application needs.

[0069] Therefore, in the first heating stage, by monitoring the temperature and humidity and adjusting the equipment according to the control strategy of this stage, the drying equipment can heat the material evenly, and the humidity of the material can gradually decrease and be controlled within the target range corresponding to the target heating stage, so as to facilitate the processing in the subsequent heating stage, which helps to ensure the stability and efficiency of the entire drying process.

[0070] In one embodiment, for the second heating stage, the drying equipment needs to monitor the wind pressure, current material temperature and material humidity in real time, so as to control and adjust the fan and the heating device. With respect to the wind pressure, when the wind pressure rises to the wind pressure protection range corresponding to the first preset wind pressure upper limit value, the operating frequency of the fan is reduced according to the second preset ratio. It can be imagined that, similarly, the drying equipment is provided with a first preset wind pressure upper limit value for the fan, and the wind pressure protection range corresponding to the first preset wind pressure upper limit value can form a wind pressure interval, for example, the first preset wind pressure upper limit value is 500Pa, and the corresponding wind pressure protection value is 20Pa, and the value of the wind pressure interval formed is 480Pa to 520Pa.

[0071] In response to the current material temperature, the drying equipment is correspondingly provided with a first drying temperature upper limit value and a first drying temperature lower limit value, and corresponding temperature protection ranges are provided for the above two limits. For example, the first drying temperature upper limit value is 60°C, and the temperature interval formed by the temperature protection range corresponding to the first drying temperature upper limit value can be 58°C to 62°C; the first drying temperature lower limit value is 50°C, and the temperature interval formed by the temperature protection range corresponding to the first drying temperature lower limit value can be 48°C to 52°C.

[0072] Furthermore, when the current material temperature rises to the temperature protection range corresponding to the first drying temperature upper limit value, such as when the current material temperature rises to 58°C, the drying device reduces the heating power of the heating device according to the preset first adjustment step. It is conceivable that if the current material temperature continues to rise, even exceeding the temperature protection range corresponding to the first drying temperature upper limit value, the drying device further reduces the heating power of the heating device.

[0073] When the current material temperature drops to the temperature protection range corresponding to the lower limit of the first drying temperature, such as the current material temperature is 52°C, it means that the hot air heat supply is insufficient, and the drying equipment increases the heating power of the heating device according to the preset second adjustment step to increase the temperature of the material. Similarly, it can be imagined that if the current material temperature is lower than the temperature value within the temperature protection range corresponding to the lower limit of the first drying temperature, the drying equipment also needs to increase the heating power of the heating device.

[0074] In addition, with respect to the material humidity, the drying equipment is provided with a target humidity value corresponding to the second heating stage, so as to adjust the heating power. For example, when the rate of decrease of the material humidity is less than the preset rate of decrease and the material humidity is greater than the target humidity value, that is, the water evaporation rate is slow, the drying equipment increases the heating power of the heating device according to the third adjustment step to promote the discharge of water vapor so that the humidity decreases as quickly as possible. When the rate of decrease of the material humidity is greater than the preset rate of decrease and the material humidity is less than the target humidity value, that is, the water evaporates too quickly, the drying equipment reduces the heating power of the heating device according to the fourth adjustment step, thereby reducing the amount of water evaporation.

[0075] In this regard, in the second heating stage, the drying equipment monitors the environmental parameters to adjust the fan and heating device to maintain a good temperature and humidity balance in the drying room, ensure the efficient and stable progress of the second heating stage, and achieve precise control of the drying process, thereby improving drying efficiency and product quality.

[0076] In one embodiment, for the third heating stage, the drying device monitors the wind pressure and the current material temperature to further control and adjust the fan and the heating device. In the third heating stage, the drying device is provided with a second preset wind pressure upper limit value, and the wind pressure protection range corresponding to the second preset wind pressure upper limit value can form a wind pressure interval, for example, the second preset wind pressure upper limit value is 400Pa, and the corresponding wind pressure protection value is 20Pa, and the value of the wind pressure interval formed is 380Pa to 420Pa.

[0077] Furthermore, when the wind pressure rises to the wind pressure protection range corresponding to the second preset wind pressure upper limit value, the drying device reduces the operating frequency of the fan according to the third preset ratio. Optionally, in one embodiment, the third preset ratio is less than the second preset ratio, that is, in the third heating stage, the drying device adjusts the operating frequency of the fan at a smaller frequency adjustment ratio to adapt to the situation in which the material in this stage is more sensitive to drying conditions.

[0078] Similarly, in the third heating stage, the drying equipment is provided with a second drying temperature upper limit value and a second drying temperature lower limit value, and respectively provided with corresponding temperature protection ranges. Exemplarily, the second drying temperature upper limit value is 50°C, and the temperature interval formed by the temperature protection range corresponding to the second drying temperature upper limit value can be 48°C to 52°C; the second drying temperature lower limit value is 40°C, and the temperature interval formed by the temperature protection range corresponding to the second drying temperature lower limit value can be 38°C to 42°C.

[0079] In this regard, when the current material temperature rises to the temperature protection range corresponding to the second drying temperature upper limit value, for example, when the current material temperature is 48°C, the drying device reduces the heating power of the heating device according to the preset fifth adjustment step. It is conceivable that if the current material temperature continues to rise, even exceeding the temperature protection range corresponding to the second drying temperature upper limit value, the drying device continues to reduce the heating power of the heating device.

[0080] When the current material temperature drops to the temperature protection range corresponding to the lower limit of the second drying temperature, for example, the current material temperature is 38°C, the drying device increases the heating power of the heating device according to the preset sixth adjustment step. Similarly, it can be imagined that if the current material temperature is lower than the temperature value within the temperature protection range corresponding to the lower limit of the second drying temperature, the drying device continues to increase the heating power of the heating device.

[0081] Therefore, in the third heating stage, the drying equipment still monitors the environmental parameters to adjust the fan and heating device to further maintain a good temperature and humidity balance in the drying room, which helps to achieve precise control of the drying process, thereby improving drying efficiency and product quality.

[0082] Figure 3 This is a structural diagram of a material drying control device provided in an embodiment of the present application. The material drying control device is applied to a drying device. The device is used to execute the material drying control method provided in the above embodiment and has functional modules and beneficial effects corresponding to the execution method. As shown in the figure, the material drying control device includes a temperature determination module 301, a parameter calculation module 302, a moisture content determination module 303 and a drying control module 304.

[0083] The temperature determination module 301 is configured to determine the initial hot air temperature, the initial material temperature and the operation time, and determine the current material temperature of the material based on a preset heat exchange model;

[0084] The parameter calculation module 302 is configured to determine the saturated water vapor pressure of the material according to the current material temperature, and to determine the water vapor partial pressure in the air according to the current hot air temperature;

[0085] The moisture content determination module 303 is configured to determine the corresponding moisture evaporation rate based on a preset moisture evaporation model when the saturated water vapor pressure and the water vapor partial pressure are determined, so as to determine the current moisture content of the material according to the moisture evaporation rate and the initial moisture content of the material;

[0086] The drying control module 304 is configured to determine the current target heating stage among multiple heating stages in the drying process based on the current moisture content of the material and the moisture content ranges corresponding to each heating stage, and adjust the operating parameters of the equipment according to the control strategy corresponding to the target heating stage to dry the material.

[0087] Based on the above embodiment, the heat exchange model is used to determine the heat change value during the running time, and the temperature determination module 301 is specifically configured as follows:

[0088] When the hot air flow rate, heat transfer coefficient and material specific heat capacity are determined, the initial hot air temperature, initial material temperature and operation time are input into the heat exchange model as input parameters, and the output parameter of the heat exchange model is used as the heat change value during the operation time;

[0089] According to the heat change value and the initial material temperature, determine the current material temperature after the material is dried for the running time;

[0090] The output parameters of the heat exchange model are the difference between the initial hot air temperature and the initial material temperature, the hot air flow rate, the heat transfer coefficient, and the ratio of the product of the operating time to the specific heat capacity of the material.

[0091] Based on the above embodiment, the moisture content determination module 303 is specifically configured as follows:

[0092] The saturated water vapor pressure and water vapor partial pressure are used as input parameters of the water evaporation model, and the output parameter of the water evaporation model is used as the water evaporation rate during the running time;

[0093] Based on the water evaporation rate and the running time, the corresponding evaporation amount is determined, so as to determine the current moisture content of the material according to the evaporation amount and the initial moisture content;

[0094] The output parameters of the water evaporation model are the product of the difference between the water vapor partial pressure and the saturated water vapor pressure, the evaporation coefficient and the porosity influence coefficient. The porosity influence coefficient is used to indicate the influence of the pore structure of the material on the evaporation rate.

[0095] Based on the above embodiment, the drying control module 304 is specifically configured as follows:

[0096] Compare the current moisture content of the material and the thresholds of the moisture content intervals corresponding to each heating stage, so as to take the heating stage corresponding to the moisture content interval in which the current moisture content is located as the target heating stage;

[0097] According to the control strategy corresponding to the target heating stage, the temperature and humidity of the material are controlled to control the temperature and humidity of the material within the target range corresponding to the target heating stage.

[0098] Based on the above embodiment, the drying control module 304 is specifically configured as follows:

[0099] When the target heating stage is the first heating stage, the heating device is operated at a first preset heating power, and the heating power of the heating device is gradually increased according to a preset heating power variation function;

[0100] When the current material temperature rises to the temperature protection range corresponding to the upper limit of the preheating temperature, the heating power of the heating device is reduced according to the preset heating power change function;

[0101] When the current material temperature exceeds the temperature protection range corresponding to the upper limit value of the preheating temperature, the heating device stops heating for a preset time and then operates at a second preset heating power, the second preset heating power being lower than the heating power of the heating device before stopping heating;

[0102] as well as,

[0103] When the target heating stage is the first heating stage, the fan is operated at a preset speed and the change trend of the material humidity is detected;

[0104] When the change trend of the material humidity is a downward trend and the decreasing speed is less than the preset decreasing speed, the speed of the fan is increased according to the first preset amplitude;

[0105] When the change trend of the material humidity is a downward trend and the downward speed is greater than the preset speed reduction, the fan speed is reduced according to the second preset amplitude, the second preset amplitude is smaller than the first preset amplitude, and the heating power of the heating device is reduced according to the first preset ratio.

[0106] Based on the above embodiment, the drying control module 304 is specifically configured as follows:

[0107] When the target heating stage is the second heating stage, the wind pressure, current material temperature and material humidity are monitored in real time;

[0108] When the wind pressure rises to the wind pressure protection range corresponding to the first preset wind pressure upper limit value, the operating frequency of the fan is reduced according to the second preset ratio;

[0109] When the current material temperature rises to the temperature protection range corresponding to the first drying temperature upper limit value, the heating power of the heating device is reduced according to the preset first adjustment step;

[0110] When the current material temperature drops to a temperature protection range corresponding to the lower limit of the first drying temperature, the heating power of the heating device is increased according to a preset second adjustment step;

[0111] When the decreasing speed of the material humidity is less than the preset decreasing speed and the material humidity is greater than the target humidity value, the heating power of the heating device is increased according to the third adjustment step;

[0112] When the decreasing speed of the material humidity is greater than the preset decreasing speed and the material humidity is less than the target humidity value, the heating power of the heating device is reduced according to the fourth adjustment step.

[0113] Based on the above embodiment, the drying control module 304 is specifically configured as follows:

[0114] When the target heating stage is the third heating stage, when the wind pressure rises to the wind pressure protection range corresponding to the second preset wind pressure upper limit value, the operating frequency of the fan is reduced according to the third preset ratio;

[0115] When the current material temperature rises to the temperature protection range corresponding to the second drying temperature upper limit value, the heating power of the heating device is reduced according to the preset fifth adjustment step;

[0116] When the current material temperature drops to a temperature protection range corresponding to the lower limit of the second drying temperature, the heating power of the heating device is increased according to the preset sixth adjustment step.

[0117] It is worth noting that in the embodiment of the above-mentioned device, the modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present application.

[0118] Figure 4 The structural schematic diagram of the drying equipment provided in one embodiment of the present application is used to execute the material drying control method provided in the above embodiment, and has the functional modules and beneficial effects corresponding to the execution method. As shown in the figure, the drying equipment includes a processor 401, a memory 402, an input device 403 and an output device 404. The number of processors 401 can be one or more, and one processor 401 is taken as an example in the figure; the processor 401, the memory 402, the input device 403 and the output device 404 can be connected by a bus or other means, and the figure takes the connection through a bus as an example. The memory 402, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as the program instructions / modules corresponding to the material drying control method in the embodiment of the present application. The processor 401 executes the corresponding various functional applications and data processing by running the software programs, instructions and modules stored in the memory 402, that is, realizing the above-mentioned material drying control method.

[0119] The memory 402 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data recorded or created during use, etc. In addition, the memory 402 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 402 may further include a memory remotely arranged relative to the processor 401, and these remotely arranged memories may be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0120] The input device 403 can be used to input corresponding digital or character information to the processor 401, and to generate key signal input related to the user settings and function control of the device; the output device 404 can be used to send or display key signal output related to the user settings and function control of the device.

[0121] An embodiment of the present application also provides a storage medium storing computer executable instructions, which, when executed by a processor, are used to perform relevant operations in the material drying control method provided in any embodiment of the present application.

[0122] Computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0123] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0124] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A material drying control method, characterized in that: Applied to drying equipment, the material drying control method includes: Determine the initial hot air temperature, the initial material temperature and the operation time, and determine the current material temperature of the material based on a preset heat exchange model; Determining the saturated water vapor pressure of the material according to the current material temperature, and determining the water vapor partial pressure in the air according to the current hot air temperature; When the saturated water vapor pressure and the water vapor partial pressure are determined, a corresponding water evaporation rate is determined based on a preset water evaporation model, so as to determine a current water content of the material according to the water evaporation rate and the initial water content of the material; According to the current moisture content of the material and the moisture content range corresponding to each heating stage, the current target heating stage is determined among the multiple heating stages in the drying process, and the operating parameters of the equipment are adjusted according to the control strategy corresponding to the target heating stage to dry the material.

2. The material drying control method according to claim 1, characterized in that: The heat exchange model is used to determine the heat change value during the operation time; The determining of the initial hot air temperature, the initial material temperature and the running time, and determining the current material temperature of the material based on a preset heat exchange model, includes: When the hot air flow rate, the heat transfer coefficient and the material specific heat capacity are determined, the initial hot air temperature, the initial material temperature and the operating time are input as input parameters into the heat exchange model, and the output parameter of the heat exchange model is used as the heat change value during the operating time; Determining the current material temperature of the material after the drying process for the running time according to the heat change value and the initial material temperature; The output parameter of the heat exchange model is the ratio of the product of the difference between the initial hot air temperature and the initial material temperature, the hot air flow rate, the heat transfer coefficient and the operating time to the specific heat capacity of the material.

3. The material drying control method according to claim 1 or 2, characterized in that: When the saturated water vapor pressure and the water vapor partial pressure are determined, the corresponding water evaporation rate is determined based on a preset water evaporation model, so as to determine the current water content of the material according to the water evaporation rate and the initial water content of the material, including: Using the saturated water vapor pressure and the water vapor partial pressure as input parameters of the water evaporation model, and using the output parameter of the water evaporation model as the water evaporation rate during the running time; Based on the water evaporation rate and the running time, a corresponding evaporation amount is determined, so as to determine a current moisture content of the material according to the evaporation amount and the initial moisture content; The output parameter of the water evaporation model is the product of the difference between the water vapor partial pressure and the saturated water vapor pressure, the evaporation coefficient and the porosity influence coefficient. The porosity influence coefficient is used to indicate the influence of the pore structure of the material on the evaporation rate.

4. The material drying control method according to claim 1, characterized in that: The method of determining the current target heating stage in the multiple heating stages during the drying process according to the current moisture content of the material and the moisture content intervals corresponding to each heating stage, and adjusting the operating parameters of the equipment according to the control strategy corresponding to the target heating stage to dry the material includes: Comparing the current moisture content of the material with the thresholds of the moisture content intervals corresponding to the heating stages, so as to take the heating stage corresponding to the moisture content interval in which the current moisture content is located as the target heating stage; According to the control strategy corresponding to the target heating stage, the temperature and humidity of the material are controlled to control the temperature and humidity of the material within the target range corresponding to the target heating stage.

5. The material drying control method according to claim 4, characterized in that: The drying equipment includes a fan and a heating device, and the temperature and humidity of the material are controlled according to the control strategy corresponding to the target heating stage to control the temperature and humidity of the material within the target range corresponding to the target heating stage, including: When the target heating stage is the first heating stage, the heating device is operated at a first preset heating power, and the heating power of the heating device is gradually increased according to a preset heating power variation function; When the current material temperature rises to a temperature protection range corresponding to the upper limit value of the preheating temperature, the heating power of the heating device is reduced according to a preset heating power variation function; When the current material temperature exceeds the temperature protection range corresponding to the upper limit value of the preheating temperature, the heating device stops heating for a preset time and then operates at a second preset heating power, wherein the second preset heating power is lower than the heating power of the heating device before stopping heating; as well as, When the target heating stage is the first heating stage, the fan is operated at a preset speed, and a change trend of the material humidity is detected; When the change trend of the material humidity is a downward trend and the decreasing speed is less than the preset decreasing speed, the speed of the fan is increased according to a first preset amplitude; When the change trend of the material humidity is a downward trend and the downward speed is greater than the preset speed reduction, the speed of the fan is reduced according to a second preset amplitude, the second preset amplitude is smaller than the first preset amplitude, and the heating power of the heating device is reduced according to a first preset ratio.

6. The material drying control method according to claim 4 or 5, characterized in that: The drying equipment includes a fan and a heating device, and the temperature and humidity of the material are controlled according to the control strategy corresponding to the target heating stage to control the temperature and humidity of the material within the target range corresponding to the target heating stage, including: When the target heating stage is the second heating stage, wind pressure, current material temperature and material humidity are monitored in real time; When the wind pressure rises to the wind pressure protection range corresponding to the first preset wind pressure upper limit value, the operating frequency of the fan is reduced according to the second preset ratio; When the current material temperature rises to a temperature protection range corresponding to the first drying temperature upper limit value, the heating power of the heating device is reduced according to a preset first adjustment step; When the current material temperature drops to a temperature protection range corresponding to the lower limit of the first drying temperature, the heating power of the heating device is increased according to a preset second adjustment step; When the decreasing speed of the material humidity is less than the preset decreasing speed and the material humidity is greater than the target humidity value, the heating power of the heating device is increased according to the third adjustment step; When the decreasing speed of the material humidity is greater than the preset decreasing speed and the material humidity is less than the target humidity value, the heating power of the heating device is reduced according to the fourth adjustment step.

7. The material drying control method according to claim 4 or 5, characterized in that: The drying equipment includes a fan and a heating device, and the temperature and humidity of the material are controlled according to the control strategy corresponding to the target heating stage to control the temperature and humidity of the material within the target range corresponding to the target heating stage, including: When the target heating stage is the third heating stage, when the wind pressure rises to a wind pressure protection range corresponding to the second preset wind pressure upper limit value, the operating frequency of the fan is reduced according to a third preset ratio; When the current material temperature rises to a temperature protection range corresponding to the second drying temperature upper limit value, the heating power of the heating device is reduced according to a preset fifth adjustment step; When the current material temperature drops to a temperature protection range corresponding to the lower limit of the second drying temperature, the heating power of the heating device is increased according to a preset sixth adjustment step.

8. A material drying control device, characterized in that: Applied to drying equipment, the material drying control device comprises: a temperature determination module configured to determine an initial hot air temperature, an initial material temperature, and an operation time, and determine a current material temperature of the material based on a preset heat exchange model; a parameter calculation module configured to determine the saturated water vapor pressure of the material according to the current material temperature, and to determine the water vapor partial pressure in the air according to the current hot air temperature; a moisture content determination module, configured to determine the corresponding moisture evaporation rate based on a preset moisture evaporation model when the saturated water vapor pressure and the water vapor partial pressure are determined, so as to determine the current moisture content of the material according to the moisture evaporation rate and the initial moisture content of the material; The drying control module is configured to determine the current target heating stage among multiple heating stages in the drying process according to the current moisture content of the material and the moisture content range corresponding to each heating stage, and adjust the operating parameters of the equipment according to the control strategy corresponding to the target heating stage to dry the material.

9. A drying device, characterized in that: include: one or more processors; A storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the material drying control method as described in any one of claims 1 to 7.

10. A storage medium storing computer executable instructions, characterized in that: The computer executable instructions are used to execute the material drying control method according to any one of claims 1 to 7 when executed by a processor.

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