True accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control

Abstract

The invention discloses a true accumulated temperature accurate calculation method suitable for operation process control of a continuous grain dryer, and relates to the technical field of grain drying process control, and the method comprises the following steps: obtaining a working performance parameter set of the grain dryer, and selecting a drying process window in a continuous working process, then forming a time matrix according to the data sampling period of the time when the grains enter each drying section, and forming a temperature matrix according to the temperature of the corresponding time; and then performing interpolation processing on the temperature matrix based on an interpolation method, and finally calculating to obtain a true accumulated temperature value of the grain during the drying process window period based on the time matrix and the interpolation temperature matrix. According to the scheme, the temperature change of the grain in the drying process is estimated based on the interpolation method and is closer to the actual value, then the true accumulated temperature value of the continuous drying process is calculated through the matrix analysis method, the true accumulated temperature value serves as the control factor of the drying process, the change of the characteristics and quality of the grain in the drying process can be better reflected, and the control effect is more ideal.

Description

Technical Field

[0001] The present application relates to the technical field of grain drying process control, and in particular to a true accumulated temperature accurate calculation method suitable for the operation process control of a continuous grain dryer. Background Art

[0002] The basic goal of grain drying is to remove moisture from grain at the lowest cost and energy consumption by using simple and easy control methods while maintaining a stable drying process, while also monitoring the moisture content of the grain and controlling the process quality.

[0003] In the invention patent application with application number 201711469624.8, a method for measuring equivalent accumulated temperature in the continuous drying process of grain is involved. The temperature measuring cable is used to measure the exhaust temperature of the moisture outlet, and the grain temperature in each slow-suction section of the grain dryer is detected instead of the grain temperature sensor element. The average value of the measured value is taken to calculate the equivalent accumulated temperature, which is easy to cause a certain deviation between the calculation result and the actual result. In the invention patent application with application number 201910626904.8, a method for controlling the continuous drying window of grain based on equivalent accumulated temperature is involved. The drying process is controlled by a graphical method, and the moisture content of the grain out of the machine is used as the primary control indicator. The equivalent accumulated temperature value is used as the indicator of precise control to adjust the machine, so that the control accuracy and stability are higher, and the control process is simpler, more intuitive, and easier to implement. However, the equivalent accumulated temperature cannot reflect the real accumulated temperature, and the control effect is limited. Therefore, accurately calculating the real accumulated temperature of the grain heating process not only better reflects the changes in grain characteristics and quality during the drying process, but also uses it as a control factor of the drying process, and the drying control effect is more ideal. Summary of the invention

[0004] The purpose of this application is to provide a method for accurately calculating the true accumulated temperature suitable for the operation process control of a continuous grain dryer, which can more accurately calculate the true accumulated temperature value in the continuous drying process and provide a basis for the continuous drying process control.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] The present application provides a method for accurately calculating true accumulated temperature suitable for the operation process control of a continuous grain dryer, comprising the following steps:

[0007] A working performance parameter set of a grain dryer is obtained; the grain dryer comprises a plurality of drying sections and slow-deceleration sections which are sequentially arranged and connected, and the grain to be dried passes through the plurality of drying sections and slow-deceleration sections sequentially.

[0008] During the working process of the grain dryer, any section of the complete grain drying process is selected as the drying process window for calculating the true accumulated temperature value.

[0009] The data sampling periods of the grain entering each drying stage during the drying process window form a time matrix.

[0010] The temperature of the grain when it enters each drying stage during the drying process window constitutes a temperature matrix.

[0011] The temperature matrix is ​​interpolated based on the interpolation method to obtain an interpolated temperature matrix.

[0012] Based on the time matrix and the interpolated temperature matrix, the true accumulated temperature value of the grain during the drying process window is calculated.

[0013] Optionally, obtaining a working performance parameter set of a grain dryer specifically comprises the following steps:

[0014] According to the structural dimensions of the grain dryer in the drawings, the volumes of each drying section and each slow-release section of the grain dryer are estimated.

[0015] Set the initial data sampling period and initial grain discharge period according to actual conditions.

[0016] Get the volume of grain discharged by the grain discharge wheel per unit time when the grain dryer works at the maximum grain discharge motor frequency.

[0017] According to the volume of grain discharged by the grain discharge wheel per unit time, the real-time grain discharge motor frequency and the real-time data sampling period, the volume of grain discharged by the grain discharge wheel within the real-time data sampling period is calculated.

[0018] Optionally, the volume of grain discharged by the grain discharge wheel during the real-time data sampling period is calculated according to the following formula:

[0019]

[0020] Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, and V0 is the volume of grain discharged by the grain discharge wheel per unit time.

[0021] Optionally, the volume of grain discharged by the grain discharge wheel during the real-time data sampling period is calculated according to the following formula:

[0022]

[0023] Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, f tis the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, V0 is the volume of grain discharged by the grain discharge wheel per unit time, τ i is the i-th grain discharge cycle, t w Free time for food preparation.

[0024] Alternatively, the grain discharge idle time can be expressed according to the following formula:

[0025]

[0026] Among them, AT0 is the initial theoretical accumulated temperature of grain, T j is the grain temperature in the jth drying stage, V j is the volume of the jth drying section, and N is the number of drying sections.

[0027] Optionally, during the working process of the grain dryer, any section of the complete grain drying process is selected as the drying process window for calculating the true accumulated temperature value, which specifically includes the following steps:

[0028] During the working process of the grain dryer, any moment when the grain passes through the grain dryer outlet is selected as the window end point.

[0029] The starting point of the window is determined according to the volume of each drying section and each slow recovery section of the grain dryer and the volume of grain discharged by the grain discharge wheel per unit time. The starting point of the window is the moment when the grain at the outlet of the grain dryer enters the entrance of the grain dryer.

[0030] According to the window starting point and the window end point, the drying process window for calculating the true accumulated temperature value is determined.

[0031] Optionally, the time matrix is ​​as follows:

[0032]

[0033] Among them, λ k is the time matrix, t i The data sampling period at time, t i is the moment when the grain enters the i-th drying stage.

[0034] Optionally, the temperature matrix is ​​as follows:

[0035]

[0036] Among them, T k is the temperature matrix, is the number of drying stages N at t i The grain temperature at time t iis the moment when the grain enters the i-th drying stage.

[0037] Optionally, the interpolated temperature matrix is ​​as follows:

[0038]

[0039] Among them, T′ k is the interpolation temperature matrix, Δ i,j The interpolation incremental data can be calculated by linear interpolation, drying equation interpolation or polynomial interpolation.

[0040] Optionally, the true accumulated temperature value of the grain during the drying process window is calculated according to the following formula:

[0041]

[0042] Among them, AT is the true accumulated temperature of grain during the drying process window, T dk is the diagonal element matrix of the interpolated temperature matrix.

[0043] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0044] The present application provides a method for accurately calculating the true accumulated temperature suitable for the process control of a continuous grain dryer, including the following contents: obtaining the working performance parameter set of the grain dryer, and selecting any section of the complete grain drying process as the drying process window during the working process of the grain dryer, and then forming a time matrix with the data sampling period of the grain entering each drying section during the drying process window, and forming a temperature matrix with the corresponding temperature at each drying section; then interpolating the temperature matrix based on the interpolation method to obtain the interpolation temperature matrix, and finally calculating the true accumulated temperature value of the grain during the drying process window based on the time matrix and the interpolation temperature matrix. When calculating the true accumulated temperature in the grain drying operation, the above scheme of the present application estimates the temperature change of the grain during the drying process based on the interpolation method, which is closer to the actual value, and further uses the matrix analysis method to calculate the true accumulated temperature value of the continuous drying process, providing a basis for the control of the continuous drying process, and selecting the true accumulated temperature as the control factor of the drying process can better reflect the changes in the characteristics and quality of the grain during the drying process, and the control effect is more ideal. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A flow chart of a method for accurately calculating true accumulated temperature suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0047] Figure 2 A flowchart of step A1 in a method for accurately calculating true accumulated temperature suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0048] Figure 3 A flowchart of step A2 in a method for accurately calculating true accumulated temperature suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0049] Figure 4 A structural schematic diagram of a grain dryer to which a true accumulated temperature accurate calculation method suitable for controlling the operation process of a continuous grain dryer is applied, provided in one embodiment of the present application.

[0050] Figure 5 A schematic diagram of the installation position of a temperature sensor in a grain dryer provided in one embodiment of the present application, which is applicable to a true accumulated temperature accurate calculation method for controlling the operation process of a continuous grain dryer. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0053] In an exemplary embodiment, Figure 1 As shown, a true accumulated temperature accurate calculation method suitable for the operation process control of a continuous grain dryer is provided, comprising the following steps:

[0054] A1. Obtain the working performance parameter set of the grain dryer. The grain dryer includes a plurality of drying sections and slow revival sections that are sequentially arranged and connected. The grain to be dried passes through the plurality of drying sections and slow revival sections in sequence. The continuous grain drying process often uses a slow revival section that is alternately arranged with one or more drying sections. During the slow revival process, the grains can fully transfer heat and moisture inside and outside the grains to balance, which is beneficial to accelerate the precipitation rate, reduce thermal damage to the grains, and improve the quality after drying. In this embodiment, if Figure 2 In the flowchart shown, step A1 specifically includes the following steps:

[0055] A11. According to the structural dimensions of the grain dryer drawing, estimate the volume of each drying section and each slow recovery section of the grain dryer.

[0056] A12. Set the initial data sampling cycle and initial grain discharge cycle according to the actual situation. The initial data sampling cycle and the initial grain discharge cycle have the following relationship:

[0057] τ0=ω×λ0;

[0058] Among them, τ0 is the initial grain discharge period, λ0 is the initial data sampling period, and ω is a positive integer.

[0059] A13. Obtain the volume of grain discharged by the grain discharge wheel per unit time when the grain dryer operates at the maximum grain discharge motor frequency.

[0060] A14. The volume of grain discharged by the grain discharge wheel within the real-time data sampling period is calculated based on the volume of grain discharged by the grain discharge wheel within the real-time data sampling period, the real-time grain discharge motor frequency and the real-time data sampling period.

[0061] A2. During the working process of the grain dryer, select any section of the complete grain drying process as the drying process window to be calculated for the true accumulated temperature value. Figure 3 In the flowchart shown, step A2 specifically includes the following steps:

[0062] A21. During the operation of the grain dryer, any moment when the grain passes through the grain dryer outlet is selected as the window end point.

[0063] A22. Determine the window starting point based on the volume of each drying section and each slow recovery section of the grain dryer and the volume of grain discharged by the grain discharge wheel per unit time; the window starting point is the moment when the grain at the grain dryer outlet enters the grain dryer inlet. k Then, the reverse method can be used to determine the starting time t1 of the grain entering the dryer, that is, the starting point of the window, and determine the t that meets the following conditions. k The first n moments, the corresponding moment is t k The starting time t1 of the grain entering the dryer:

[0064]

[0065] Accordingly, the time point at which grain enters each drying stage can be determined according to the following conditions:

[0066]

[0067] It can be understood that when calculating the time point when the grain enters each drying section using the above formula, the volume of the adjacent slow recovery section is included in the adjacent drying section. Although the temperature of the slow recovery section is not as high as that of the drying section, there is still moisture migration.

[0068] A23. Determine the drying process window for calculating the true accumulated temperature value based on the window starting point and window end point.

[0069] A3. The data sampling period of the grain entering each drying stage during the drying process window forms a time matrix. In this embodiment, the time matrix is ​​shown as follows:

[0070]

[0071] Among them, λ k is the time matrix, t i The data sampling period at time, t i is the moment when the grain enters the i-th drying stage.

[0072] A4. The temperature of the grain at each drying stage during the drying process window is used to form a temperature matrix. In this embodiment, the temperature matrix is ​​shown as follows:

[0073]

[0074] Among them, T k is the temperature matrix, is the number of drying stages N at t i The grain temperature at time t i is the moment when the grain enters the i-th drying stage.

[0075] A5. Perform interpolation processing on the temperature matrix based on the interpolation method to obtain an interpolation temperature matrix. In this embodiment, the interpolation temperature matrix is ​​shown as follows:

[0076]

[0077] Among them, T′ k is the interpolation temperature matrix, Δ i,j The interpolation incremental data can be calculated by linear interpolation, drying equation interpolation or polynomial interpolation.

[0078] There are a total of (n i -n i-1 ) column data, then in the temperature matrix T k Insert (n i -n i-1 -1) rows, the temperature matrix T kbecomes the interpolation temperature matrix T′ k .

[0079] Using linear interpolation:

[0080]

[0081] In another embodiment, the drying equation interpolation method is used:

[0082]

[0083] Among them, K is the coefficient, t is the time, M is the current outlet moisture, M0 is the initial moisture, M e It is the equilibrium moisture content of grain under normal pressure.

[0084] In another embodiment, a polynomial interpolation method is used to process:

[0085]

[0086] Among them, a0, a1…a i is a constant, is the data sampling period at the corresponding moment.

[0087] A6. Based on the time matrix and the interpolated temperature matrix, the true accumulated temperature value of the grain during the drying process window is calculated. In this embodiment, the true accumulated temperature value of the grain during the drying process window is calculated according to the following formula:

[0088]

[0089] Among them, AT is the true accumulated temperature of grain during the drying process window, T dk is the diagonal element matrix of the interpolated temperature matrix.

[0090] In one embodiment, the volume of grain discharged by the grain discharge wheel during the real-time data sampling period can be calculated according to the following formula:

[0091]

[0092] Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, which is generally 1. Small adjustments are made based on the grain moisture and actual conditions. t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, and V0 is the volume of grain discharged by the grain discharge wheel per unit time.

[0093] In another embodiment, the volume of grain discharged by the grain discharge wheel during the real-time data sampling period can be calculated according to the following formula:

[0094]

[0095] Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, V0 is the volume of grain discharged by the grain discharge wheel per unit time, τ i is the i-th grain discharge cycle, t w is the idle time for grain discharging. Specifically, the idle time for grain discharging can be expressed according to the following formula:

[0096]

[0097] Among them, AT0 is the initial theoretical accumulated temperature of grain, T j is the grain temperature in the jth drying stage, V j is the volume of the jth drying section, and N is the number of drying sections.

[0098] In a specific embodiment, the above embodiment provides a true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control, which is applied to Figure 4 In the grain dryer shown, the grain dryer includes a temperature cable 110, a moisture meter 111, a temperature transmitter 112, and a data processor 114; wherein the temperature cable 110 includes a plurality of temperature sensing elements connected and transmitting data via a serial bus, and the temperature sensing elements distributed therein can directly sense the grain temperature inside the drying section; the temperature transmitter 112 is connected to the temperature cable 110, and is used to receive the temperature signal detected by the temperature sensing element in the temperature cable and convert it into a digital signal that can be received by the data processor; the data processor 114 is used to receive the temperature signal transmitted by the temperature transmitter 112 and to calculate, display and store the true accumulated temperature; the continuous dryer and its ancillary equipment include a dryer body 211, a fan 212, a discharger 213, a temperature cable 110, a moisture meter 111, a temperature transmitter 112, a conversion interface 113 and a data processor 114. In addition, as Figure 5 As shown, a plurality of temperature sensors T0-T5 are installed in each drying section of the dryer body.

[0099] When the grain dryer is performing the drying operation, the grain in the dryer body 211 falls slowly in the dryer due to its own gravity. During the falling process, the grain will pass through the grain storage section, drying section, slow recovery section, cooling section, and grain discharge section in sequence. In the drying section, the grain will be dried by the hot drying medium in the fan 212, and will be cooled in the cooling section. Finally, the discharger 213 will discharge the cooled grain out of the dryer body, and the whole drying process is completed.

[0100] The present application provides a method for accurately calculating the true accumulated temperature suitable for the control of the operation process of a continuous grain dryer. When calculating the true accumulated temperature in the grain drying operation, the temperature change of the grain in the drying process is estimated based on the interpolation method, which is closer to the actual value. The true accumulated temperature value of the continuous drying process is further calculated using a matrix analysis method to provide a basis for the control of the continuous drying process. Since the true accumulated temperature is a true reflection of the grain heating process, the use of the true accumulated temperature as a control factor of the drying process can better reflect the changes in grain characteristics and quality during the drying process, and the control effect is more ideal.

[0101] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control, characterized in that: include: Obtaining a set of working performance parameters of a grain dryer; the grain dryer comprises a plurality of drying sections and slow recovery sections which are sequentially arranged and connected, and the grain to be dried sequentially passes through the plurality of drying sections and slow recovery sections; During the working process of the grain dryer, any complete grain drying process is selected as a drying process window for calculating the true accumulated temperature value; The data sampling periods of the grain entering each drying section during the drying process window form a time matrix; The temperature of the grain at each drying stage during the drying process window forms a temperature matrix; Performing interpolation processing on the temperature matrix based on an interpolation method to obtain an interpolation temperature matrix; Based on the time matrix and the interpolated temperature matrix, the true accumulated temperature value of the grain during the drying process window is calculated.

2. A true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control according to claim 1, characterized in that: Get the working performance parameter set of the grain dryer, including: According to the structural dimensions of the grain dryer in the drawings, the volumes of each drying section and each slow-release section of the grain dryer are estimated; Set the initial data sampling cycle and initial grain discharge cycle according to actual conditions; Obtaining the volume of grain discharged by the grain discharge wheel per unit time when the grain dryer operates at the maximum grain discharge motor frequency; The volume of grain discharged by the grain discharge wheel within the real-time data sampling period is calculated based on the volume of grain discharged by the grain discharge wheel within the real-time data sampling period.

3. A true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control according to claim 2, characterized in that: The volume of grain discharged by the grain discharge wheel during the real-time data sampling period is calculated according to the following formula: Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, and V0 is the volume of grain discharged by the grain discharge wheel per unit time.

4. A true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control according to claim 2, characterized in that: The volume of grain discharged by the grain discharge wheel during the real-time data sampling period is calculated according to the following formula: Among them, Q i is the volume of grain discharged by the grain discharge wheel in the i-th data sampling period, K f is the correction factor, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, λ i is the i-th data sampling period, V0 is the volume of grain discharged by the grain discharge wheel per unit time, τ i is the i-th grain discharge cycle, t w Free time for food preparation.

5. A true accumulated temperature accurate calculation method suitable for continuous grain dryer operation process control according to claim 4, characterized in that: The idle time of grain discharge can be expressed according to the following formula: Among them, AT0 is the initial theoretical accumulated temperature of grain, T j is the grain temperature in the jth drying stage, V j is the volume of the jth drying section, and N is the number of drying sections.

6. The method for accurately calculating true accumulated temperature suitable for the operation process control of a continuous grain dryer according to claim 1, characterized in that: During the working process of the grain dryer, any complete grain drying process is selected as the drying process window to be calculated for the true accumulated temperature value, specifically including: During the operation of the grain dryer, any moment when grain passes through the grain dryer outlet is selected as the window end point; The starting point of the window is determined according to the volume of each drying section and each slow recovery section of the grain dryer and the volume of grain discharged by the grain discharge wheel per unit time; the starting point of the window is the moment when the grain at the outlet of the grain dryer enters the inlet of the grain dryer; A drying process window for calculating the true accumulated temperature value is determined according to the window starting point and the window end point.

7. The method for accurately calculating true accumulated temperature suitable for the operation process control of a continuous grain dryer according to claim 1, characterized in that: The time matrix is ​​shown as follows: Among them, λ k is the time matrix, t i The data sampling period at time, t i is the moment when the grain enters the i-th drying stage.

8. The method for accurately calculating true accumulated temperature suitable for the operation process control of a continuous grain dryer according to claim 1, characterized in that: The temperature matrix is ​​shown as follows: Among them, T k is the temperature matrix, is the number of drying stages N at t i The grain temperature at time t i is the moment when the grain enters the i-th drying stage.

9. A true accumulated temperature accurate calculation method suitable for the operation process control of a continuous grain dryer according to claim 8, characterized in that: The interpolation temperature matrix is ​​shown as follows: Among them, k is the interpolation temperature matrix, Δ i,j The interpolation incremental data may be calculated by using a linear interpolation method, a drying equation interpolation method or a polynomial interpolation method.

10. A true accumulated temperature accurate calculation method suitable for the operation process control of a continuous grain dryer according to claim 9, characterized in that: The true accumulated temperature value of the grain during the drying process window is calculated according to the following formula: Wherein, AT is the true accumulated temperature of the grain during the drying process window, T dk is the diagonal element matrix of the interpolation temperature matrix.

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