A true accumulated temperature calculation method suitable for continuous grain dryer operation process control

Abstract

The present application discloses a true accumulated temperature calculation method suitable for the control of the operation process of a continuous grain dryer, and relates to the technical field of grain drying process control. The method comprises: firstly, clarifying the working performance parameter set of the grain dryer, and then, in the working process of the grain dryer, selecting any section of the complete grain drying process as the drying process window for calculating the true accumulated temperature value, and for the drying process window, forming a time unit matrix with the time units of each drying section of the grain to be dried during the drying process window, and based on the time unit matrix and the full process temperature matrix of the grain dryer, the true accumulated temperature value of the grain to be dried during the drying process window can be calculated. The present application calculates the true accumulated temperature value of the continuous drying process, and the true accumulated temperature is the true reaction of the grain heating process. Using it as a control factor of the continuous grain drying process can better reflect the changes in grain characteristics and quality during the drying process, 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 calculation method suitable for continuous grain dryer operation process control. Background Art

[0002] The basic goal of grain drying is to remove moisture from grains at the lowest drying cost and energy consumption while maintaining a stable drying process. The control of grain moisture and quality during the drying process is particularly important.

[0003] The invention patent application with application number 201910626904.8 involves a grain continuous drying window control method based on equivalent accumulated temperature, which divides the grain moisture control in the grain drying control process into two levels: primary control and precise control, so as to make the control accuracy and stability higher; at the same time, the drying process is controlled by a graphical method, making the control process simpler, more intuitive and easier to implement, solving the technical problems of nonlinearity and large lag in grain drying process control. However, the equivalent accumulated temperature in this method cannot be the real "accumulated temperature", and there are certain deficiencies in the disturbance over-regulation. Therefore, how to measure the real accumulated temperature of the grain heating process as a control factor of the drying process is very important to better reflect the changes in grain characteristics and quality during the drying process and improve the drying control effect. Summary of the invention

[0004] The purpose of this application is to provide a true accumulated temperature calculation method suitable for the operation process control of a continuous grain dryer, which can 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 true accumulated temperature calculation method suitable for continuous grain dryer operation process control, 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 the 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] For the drying process window, the time units of the to-be-dried grains passing through the various drying sections during the drying process window are used to form a time unit matrix.

[0010] Based on the time unit matrix and the whole process temperature matrix of the grain dryer, the true accumulated temperature value of the grain to be dried during the drying process window is calculated.

[0011] Optionally, obtaining a working performance parameter set of a grain dryer specifically comprises the following steps:

[0012] Obtain the volume of each drying section and slow recovery section of the grain dryer.

[0013] Obtain the number of grain discharge wheel revolutions per unit time and the grain volume discharged per revolution of the grain discharge wheel when the grain dryer operates at the maximum grain discharge motor frequency.

[0014] The volume of grain discharged by the grain discharge wheel per unit time is calculated based on the number of revolutions of the grain discharge wheel per unit time and the volume of grain discharged per revolution of the grain discharge wheel.

[0015] Set the length of a single time unit, the real-time grain discharge motor frequency and the theoretical grain discharge idle time according to actual conditions.

[0016] Optionally, the volume of grain discharged by the grain discharge wheel per unit time can be calculated according to the following formula:

[0017]

[0018] Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

[0019] Optionally, the volume of grain discharged by the grain discharge wheel per unit time can be calculated according to the following formula:

[0020]

[0021] Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, t w is the theoretical grain discharge idle time, t s is the running time, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

[0022] 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:

[0023] During the operation of the grain dryer, any moment when the grain to be dried passes through the grain dryer outlet is selected as the window end point.

[0024] The window starting point is determined according to the volume of each drying 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 to be dried at the grain dryer outlet enters the grain dryer inlet.

[0025] According to the window starting point and the window end point, the drying process window for calculating the true accumulated temperature value is determined.

[0026] Alternatively, the time unit matrix can be expressed as follows:

[0027]

[0028] Among them, τ n is a time unit matrix, recording the drying process of the grain to be dried in the drying process window; τ D,1 represents the time unit located in the Dth row and the first column. The time unit ends in the first column and starts in the second column, indicating that the grain to be dried in the drying process window has left the first drying section and entered the second drying section. V is the total volume of the dryer. t i represents the time spent in the i-th drying section; τ is the length of a single time unit; D is the start point of the window, and n is the end point of the window; p represents the number of the drying section when the grain discharge speed changes, and m is the number of drying sections; v is the grain discharge speed before the change, is the changed grain discharge speed.

[0029] Alternatively, the whole process temperature matrix of the grain dryer can be expressed by the following formula:

[0030]

[0031] in, is the temperature matrix of the whole process of grain dryer, T n,m Represents the grain temperature in the mth drying section at the nth time.

[0032] Optionally, the true accumulated temperature value of the grain to be dried during the drying process window is calculated according to the following formula:

[0033]

[0034] Among them, AT0 is the true accumulated temperature value of the grain to be dried during the drying process window.

[0035] Optionally, the window start point can be calculated as follows:

[0036]

[0037] V k =V-(nk)×v.

[0038] Among them, k represents the time when the grain discharge speed changes, V k represents the total volume of grain discharged from time 1 to k,

[0039] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0040] The present application provides a true accumulated temperature calculation method suitable for the control of the operation process of a continuous grain dryer, the method comprising: firstly clarifying the working performance parameter set of the grain dryer, then in the working process of the grain dryer, selecting any section of the complete grain drying process as the drying process window for calculating the true accumulated temperature value, for the drying process window, the time units of the grain to be dried passing through each drying section during the drying process window are used to form a time unit matrix, based on the time unit matrix and the full process temperature matrix of the grain dryer, the true accumulated temperature value of the grain to be dried during the drying process window can be calculated. The present application adopts a matrix analysis method to calculate the true accumulated temperature value of the continuous grain drying process, providing a basis for the control of the continuous grain drying process. The true accumulated temperature is a true reflection of the grain heating process, so the selection of the true accumulated temperature as the control factor of the continuous grain drying process can better reflect the changes in the grain characteristics and quality during the drying process, and the control effect is more ideal. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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.

[0042] Figure 1 A flow chart of a true accumulated temperature calculation method suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0043] Figure 2 A flowchart of step A1 in a true accumulated temperature calculation method suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0044] Figure 3 A flowchart of step A2 in a true accumulated temperature calculation method suitable for controlling the operation process of a continuous grain dryer provided in one embodiment of the present application.

[0045] Figure 4A structural schematic diagram of a grain dryer to which a true accumulated temperature calculation method suitable for continuous grain dryer operation process control is provided in one embodiment of the present application. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] In an exemplary embodiment, Figure 1 The flowchart shown provides a true accumulated temperature calculation method suitable for continuous grain dryer operation process control, comprising the following steps:

[0049] A1. 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.

[0050] In this embodiment, if Figure 2 In the flowchart shown, step A1 specifically includes the following steps:

[0051] A11. Obtain the volume of each drying section and slow recovery section of the grain dryer.

[0052] A12. Obtain the number of grain discharge wheel revolutions per unit time and the grain volume discharged per revolution of the grain discharge wheel when the grain dryer operates at the maximum grain discharge motor frequency.

[0053] A13. The volume of grain discharged by the grain discharge wheel per unit time is calculated based on the number of revolutions of the grain discharge wheel per unit time and the volume of grain discharged per revolution of the grain discharge wheel.

[0054] A14. Set the length of a single time unit, the real-time grain discharge motor frequency and the theoretical grain discharge idle time according to the actual situation.

[0055] A2. During the working process of the grain dryer, select any 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:

[0056] A21. During the operation of the grain dryer, any moment when the grain to be dried passes through the grain dryer outlet is selected as the window end point.

[0057] A22. Determine the window starting point based on the volume of each drying 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 to be dried at the grain dryer outlet enters the grain dryer inlet. Specifically in this embodiment, the window starting point can be calculated by the following formula:

[0058]

[0059] V k =V-(nk)×v.

[0060] Among them, k represents the time when the grain discharge speed changes, V k represents the total volume of grain discharged from time 1 to k,

[0061] A23. Determine the drying process window for calculating the true accumulated temperature value based on the window starting point and window end point.

[0062] A3. For the drying process window, the time units of the grain to be dried passing through each drying section during the drying process window are used to form a time unit matrix. Specifically in this embodiment, the time unit matrix can be expressed by the following formula:

[0063]

[0064] Among them, τ n is a time unit matrix, recording the drying process of the grain to be dried in the drying process window; τ D,1 represents the time unit located in the Dth row and the first column. The time unit ends in the first column and starts in the second column, indicating that the grain to be dried in the drying process window has left the first drying section and entered the second drying section. V is the total volume of the dryer. t i represents the time spent in the i-th drying section; τ is the length of a single time unit; D is the start point of the window, and n is the end point of the window; p represents the number of the drying section when the grain discharge speed changes, and m is the number of drying sections; v is the grain discharge speed before the change, is the changed grain discharge speed,

[0065] A4. Based on the time unit matrix and the whole process temperature matrix of the grain dryer, the true accumulated temperature value of the grain to be dried during the drying process window is calculated. Specifically in this embodiment, the true accumulated temperature value of the grain to be dried during the drying process window is calculated according to the following formula:

[0066]

[0067] Among them, AT0 is the true accumulated temperature value of the grain to be dried during the drying process window. The whole process temperature matrix of the grain dryer can be expressed by the following formula:

[0068]

[0069] in, is the temperature matrix of the whole process of grain dryer, T n,m Represents the grain temperature in the mth drying section at the nth time.

[0070] In an exemplary embodiment, in step A13, the volume of grain discharged by the grain discharge wheel per unit time is calculated according to the following formula:

[0071]

[0072] Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

[0073] In a specific embodiment, the true accumulated temperature calculation method suitable for continuous grain dryer operation process control 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 by 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 calculate, display and store the true accumulated temperature; the continuous dryer and its ancillary equipment include a grain hopper 210, an elevator 211, a pre-drying bin 212, a dryer body 213, a fan 214, a discharger 215, a temperature cable 110, a temperature transmitter 112, a conversion interface 113 and a data processor 114.

[0074] When the grain dryer is performing drying operation, the grain enters the first elevator 211 through the grain loading hopper 210. The first elevator transports the grain to the pre-drying bin 212 and waits. When the grain in the grain dryer body 213 is insufficient, the grain in the pre-drying bin is transported into the grain dryer body through the second elevator. The grain slowly falls in the grain dryer due to its own gravity, is dried by the hot drying medium in the drying section, is cooled in the cooling section, and is finally discharged from the grain dryer body through the discharger 215. The whole drying process is completed.

[0075] In the process of calculating the true accumulated temperature in this embodiment, the drying section of the grain dryer is divided into 4 parts, that is, the value of m is 4. At the maximum grain discharge motor frequency f m Under the condition of 50Hz, the grain dryer's grain discharge wheel revolution number in 1 minute is Q=16, and the grain volume discharged per grain discharge wheel revolution is V s =2L / r; measure the volume V of each drying section of the grain dryer m , where V1 = 110.38L, V2 = 220.76L, V3 = 220.76L, V4 = 184.02L, calculate the volume of grain discharged by the grain discharge wheel per unit time V according to the following formula t ;

[0076]

[0077] In another exemplary embodiment, in step A13, the volume of grain discharged by the grain discharge wheel per unit time is calculated according to the following formula:

[0078]

[0079] Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, t w is the theoretical grain discharge idle time, t s is the running time, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

[0080] The present application provides a true accumulated temperature calculation method suitable for the control of the operation process of a continuous grain dryer. The true accumulated temperature value of the continuous grain drying process is calculated by a matrix analysis method to provide a basis for the control of the continuous grain drying process. Since the true accumulated temperature is a true reflection of the grain heating process, the true accumulated temperature is selected as the control factor of the continuous grain drying process to better reflect the changes in grain characteristics and quality during the drying process, and the control effect is more ideal.

[0081] The technical features of the above embodiments may be arbitrarily combined. 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.

[0082] 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 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-delay sections which are sequentially arranged and connected, and the grain to be dried sequentially passes through the plurality of the drying sections and slow-delay 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; For the drying process window, the time units of the grain to be dried passing through each drying section during the drying process window form a time unit matrix; Based on the time unit matrix and the whole process temperature matrix of the grain dryer, the true accumulated temperature value of the grain to be dried during the drying process window is calculated; Get the working performance parameter set of the grain dryer, including: Obtaining the volumes of each drying section and slow drying section of the grain dryer; Obtaining the number of grain discharge wheel revolutions per unit time and the grain volume discharged per revolution of the grain discharge wheel when the grain dryer operates at the maximum grain discharge motor frequency; The volume of grain discharged by the grain discharge wheel per unit time is calculated according to the number of revolutions of the grain discharge wheel per unit time and the volume of grain discharged per revolution of the grain discharge wheel; Set the length of a single time unit, the real-time grain discharge motor frequency and the theoretical grain discharge idle time according to the actual situation; The time unit matrix can be expressed by the following formula: Among them, τ n is a time unit matrix, recording the drying process of the grain to be dried in the drying process window; τ D,1 represents the time unit located in the Dth row and the first column. The time unit ends in the first column and starts in the second column, indicating that the grain to be dried in the drying process window has left the first drying section and entered the second drying section. V is the total volume of the dryer. t i represents the time spent in the i-th drying section; τ is the length of a single time unit; D is the start point of the window, and n is the end point of the window; p represents the number of the drying section when the grain discharge speed changes, and m is the number of drying sections; v is the grain discharge speed before the change, is the changed grain discharge speed; The whole process temperature matrix of the grain dryer can be expressed by the following formula: in, is the whole process temperature matrix of the grain dryer, T n,m represents the grain temperature in the mth drying section at the nth time; The true accumulated temperature value of the grain to be dried during the drying process window is calculated according to the following formula: Wherein, AT0 is the true accumulated temperature value of the grain to be dried during the drying process window; The window starting point can be calculated by the following formula: V k =V-(nk)×v; Among them, k represents the time when the grain discharge speed changes, V k represents the total volume of grain discharged from time 1 to k, 2. The true accumulated temperature calculation method suitable for continuous grain dryer operation process control according to claim 1 is characterized in that: The volume of grain discharged by the grain discharge wheel per unit time can be calculated according to the following formula: Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

3. The true accumulated temperature calculation method suitable for continuous grain dryer operation process control according to claim 1 is characterized in that: The volume of grain discharged by the grain discharge wheel per unit time can be calculated according to the following formula: Among them, V t is the volume of grain discharged by the grain discharge wheel per unit time, f t is the real-time grain discharge motor frequency, f m is the maximum grain discharge motor frequency, t w is the theoretical grain discharge idle time, t s is the running time, V s is the volume of grain discharged per revolution of the grain discharge wheel, Q is the number of revolutions of the grain discharge wheel per unit time, and t is the unit time.

4. The true accumulated temperature calculation method suitable for continuous grain dryer operation process control according to claim 1 is 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 the grain to be dried passes through the exit of the grain dryer is selected as the window end point; The starting point of the window is determined according to the volume of each drying 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 to be dried 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.

Images