Liquid level control method, device, system and equipment

Abstract

The invention provides a liquid level control method, device, system and equipment. The method comprises the steps that real-time liquid level data of a first container and at least two second containers are collected; determining an output control parameter of the first container according to the real-time liquid level data, a control function corresponding to the first container and a first preset liquid level; according to the real-time liquid level data, a control function corresponding to each second container and a second preset liquid level, initial input control parameters of each second container are determined; according to the initial input control parameter of each second container, determining a material input proportion of each second container by using a balance function; determining a target input control parameter of each second container according to the output control parameter and the material input proportion; and controlling the control valves of the second containers according to the target input control parameters. And the stability and the control precision of liquid level control of each container are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polysilicon production, and in particular to a liquid level control method, device, system and equipment. Background Art

[0002] The modified Siemens process, also known as the trichlorosilane process, is the world's mainstream polysilicon production method, accounting for more than 95% of my country's polysilicon production. In the production process, metallurgical-grade silicon is first reacted with hydrogen chloride (HCl) to generate trichlorosilane (SiHCl3), which is then purified by distillation to obtain high-purity trichlorosilane, which is then reduced with hydrogen at high temperature (about 1100°C) to finally obtain high-purity polysilicon. The acquisition of high-purity trichlorosilane requires processes such as rough separation and distillation to separate substances such as silicon tetrachloride and dichlorosilane, in which a buffer tank feeds multiple towers.

[0003] In the prior art, a single-loop PID control scheme is used for the buffer tank and the tower to supply materials to multiple towers. However, this method cannot effectively handle the liquid level balance problem when the buffer tank supplies materials to multiple towers, resulting in poor system stability. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a liquid level control method, device, system and equipment to improve the stability of liquid level control between connected containers in view of the above-mentioned deficiencies in the prior art.

[0005] In a first aspect, the present invention provides a liquid level control method, the method comprising:

[0006] Collecting real-time liquid level data of a first container and at least two second containers, wherein the first container is respectively associated with each second container and delivers material to the second containers;

[0007] determining an output control parameter of the first container according to the real-time liquid level data, a corresponding control function of the first container, and a first preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container;

[0008] Determining an initial input control parameter of each second container according to the real-time liquid level data, a control function corresponding to each second container, and a second preset liquid level;

[0009] Determine the material input ratio of each second container by using a balance function according to the initial input control parameter of each second container;

[0010] Determining a target input control parameter for each of the second containers according to the output control parameter and the material input ratio;

[0011] According to the target input control parameter, a control valve of each second container is controlled, and the control valve is a control valve of a pipeline connecting the first container and the second container.

[0012] Furthermore, the method further comprises:

[0013] Acquiring geometric parameters and historical liquid level change data of the first container;

[0014] Obtaining a liquid level-volume change function of the first container according to the geometric parameters, the historical liquid level change data and the real-time liquid level data;

[0015] The liquid level-volume change function is converted into a PID formula to obtain a control function of the first container.

[0016] Furthermore, the liquid level-volume change function includes the following formula (1):

[0017] E0=f(LIC0.SP)-f(LIC0.PV) (1)

[0018] Among them, E0 is the volume adjustment value of the first container, LIC0.PV is the real-time value of the liquid level of the first container, f(LIC0.PV) is the liquid level volume of the first container, LIC0.SP is the first preset liquid level of the first container, and f(LIC0.SP) is the material volume of the first container corresponding to the first preset liquid level of the first container.

[0019] Furthermore, the control function of the first container includes the following formula (2):

[0020] OUT0=K0(1+1 / (T0*s)+D0*s)*E0(2)

[0021] Among them, OUT0 is the input control parameter of the first container, K0, T0 and D0 are PID parameters, K0 is the proportion of the first container, T0 is the integral of the first container, D0 is the differential constant of the first container, and E0 is the volume adjustment value of the first container.

[0022] Furthermore, all the second container control functions include the following formula (3):

[0023] OUTi=Ki(1+1 / (Ti*s)+Di*s)*Ei(3)

[0024] Wherein, OUTi is the initial input control parameter of the second container, Ki, Ti and Di are PID parameters. Ki is the proportion of the second container, Ti is the integral of the second container, Di is the differential constant of the second container, s is the result of Laplace transformation of the time parameter, Ei is the liquid level adjustment value of the second container, Ei=LICi.SP-LICi.PV, LICi.PV is the real-time value of the liquid level of the second container, LICi.SP is the second preset liquid level of the second container, i=1, 2, 3, ...

[0025] Furthermore, the balance function includes the following formulas (5) to (7):

[0026] OUT=ΣOUTi+0.0001(5)

[0027] Wherein, i=1, 2, 3, ..., n, n is the number of second containers, OUT is the total material input amount of all second containers, and OUTi is the initial input control parameter of the second container;

[0028] ai=OUTi / (ΣOUTi)*100% (6)

[0029] Among them, ai is the material input ratio of the second container.

[0030] In a second aspect, the present invention provides a liquid level control device, comprising:

[0031] A collection module, used to collect real-time liquid level data of a first container and at least two second containers, wherein the first container is respectively associated with each second container and delivers material to the second containers;

[0032] a first control module, connected to the acquisition module, for determining an output control parameter of the first container according to the real-time liquid level data and a corresponding control function of the first container and a first preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container;

[0033] A second control module, connected to the acquisition module, for determining an input control parameter of each second container according to the real-time liquid level data and a control function corresponding to each second container and a second preset liquid level;

[0034] a balancing module connected to the second control module, and configured to determine the material input ratio of each second container by using a balancing function according to the initial input control parameter of each second container;

[0035] a third control module, connected to the first control module, the second control module and the balancing module respectively, and configured to determine a target input control parameter of each of the second containers according to the initial input control parameter and the material input ratio;

[0036] The fourth control module is connected to the third control module and is used to control the control valve of each second container according to the second control parameter, and the control valve is a control valve of the pipeline connecting the first container and the second container.

[0037] In a third aspect, the present invention provides a polysilicon production system, characterized in that the system comprises:

[0038] A reactor for performing a chemical vapor deposition reaction to generate production materials including trichlorosilane;

[0039] A buffer tank, connected to the reactor through a pipeline, for receiving and storing the production material;

[0040] At least two distillation towers are connected to the buffer tank through pipelines, respectively, for receiving the production materials transported by the buffer tank, and performing distillation separation and purification to obtain high-purity trichlorosilane;

[0041] The liquid level control device of the second aspect is electrically connected to the buffer tank and the distillation tower, respectively, and is used to control the liquid levels of the buffer tank and the distillation tower;

[0042] The reduction furnace is connected to the distillation tower and is used to convert high-purity trichlorosilane into polysilicon through hydrogen reduction reaction.

[0043] In a fourth aspect, the present invention provides an electronic device comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the liquid level control method as described in the first aspect.

[0044] The liquid level control method, device, system and equipment provided by the present invention collect the liquid level data of the first container and multiple second containers in real time, and use the control function based on the liquid level and volume change data to calculate the initial control parameters for each container. By introducing the balance function, the scheme can dynamically adjust the material input ratio of each second container, so as to achieve accurate liquid level balance. Finally, the target input control parameters are calculated by combining the output control parameters of the main container and the material input ratio of each slave container to control the valve on the connecting pipeline. It overcomes the limitations of traditional single-loop PID control when dealing with multi-container systems, and can also adapt to the dynamic changes of the system, significantly improving the stability and control accuracy of the liquid level control of each container. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of a liquid level control method according to Embodiment 1 of the present invention;

[0046] Figure 2 A system device for liquid level control of an associated container based on high-purity polysilicon production according to Example 1 of the present invention;

[0047] Figure 3 This is another system device for liquid level control of associated containers based on high-purity polysilicon production according to Example 1 of the present invention;

[0048] Figure 4 The BALANCE module operation and visualization device of Embodiment 1 of the present invention;

[0049] Figure 5 This is a schematic structural diagram of a liquid level control device according to Embodiment 2 of the present invention;

[0050] Figure 6 This is a schematic structural diagram of a liquid level control device according to Example 4 of the present invention. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0052] It should be understood that the specific embodiments and drawings described herein are only used to explain the present invention rather than to limit the present invention.

[0053] It can be understood that, in the absence of conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other.

[0054] It can be understood that, for the convenience of description, the drawings of the present invention only show the parts related to the present invention, while the parts irrelevant to the present invention are not shown in the drawings.

[0055] It can be understood that each unit and module involved in the embodiments of the present invention may correspond to only one physical structure, or may be composed of multiple physical structures, or multiple units and modules may be integrated into one physical structure.

[0056] It can be understood that the terms "first", "second", etc. in the embodiments of the present invention are used to distinguish different objects, or to distinguish different processing of the same object, rather than to describe a specific order of objects.

[0057] It can be understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of the present invention may occur in an order different from that marked in the drawings.

[0058] It is understood that the flowcharts and block diagrams of the present invention illustrate the possible architectures, functions, and operations of the systems, devices, equipment, and methods according to the various embodiments of the present invention. Each box in the flowchart or block diagram may represent a unit, module, program segment, or code, which contains executable instructions for implementing the specified functions. Moreover, each box or combination of boxes in the block diagram and flowchart may be implemented by a hardware-based system that implements the specified functions, or may be implemented by a combination of hardware and computer instructions.

[0059] It can be understood that the units and modules involved in the embodiments of the present invention can be implemented by software or hardware. For example, the units and modules can be located in a processor.

[0060] It should be noted that the scenario diagram described in the embodiment of the present application is for the purpose of more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided in the embodiment of the present application. A person of ordinary skill in the art can know that with the evolution of network architecture and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

[0061] The modified Siemens process, also known as the trichlorosilane process, is the world's mainstream polysilicon production method, accounting for more than 95% of my country's polysilicon production. In the production process, metallurgical-grade silicon is first reacted with hydrogen chloride (HCl) to produce trichlorosilane (SiHCl3), which is then purified by distillation to obtain high-purity trichlorosilane, which is then reduced with hydrogen at high temperature (about 1100°C) to finally obtain high-purity polysilicon.

[0062] The acquisition of high-purity trichlorosilane requires processes such as crude fractionation and distillation to separate substances such as silicon tetrachloride and dichlorosilane. This involves a buffer tank feeding multiple towers.

[0063] The existing technology adopts a single-loop PID control scheme with independent buffer tanks and towers, that is, each device (buffer tank or tower) has an independent control loop, which usually consists of a sensor (such as a liquid level transmitter), a PID controller and an actuator (such as a control valve). The sensor measures the current process variable (for example, the liquid level of the buffer tank) and transmits this value to the PID controller. The PID controller calculates the required control action based on the deviation between the set value and the measured value, and finally controls the device through the actuator (such as a control valve).

[0064] When the output signal of the tank liquid level transmitter changes, it will cause the regulating valve to change, which will lead to changes in the flow and pressure of the entire pipeline, causing disturbances to the liquid level adjustment of all towers, and thus it cannot be put into automatic operation, and can only rely on manual operation by process personnel. On the contrary, if the tower kettle liquid level adjustment head is automatic, the tank liquid level adjustment cannot be put into automatic operation, which will increase the workload of personnel. Even if the tank liquid level is adjusted manually, the liquid level adjustment of each tower will compete with each other.

[0065] Based on the problems existing in the prior art, the present application provides a liquid level control method to improve the stability of liquid level control in multiple connected containers.

[0066] Embodiment 1:

[0067] This embodiment provides a liquid level control method, which is applied to a scenario where a main container (first container) supplies material to multiple slave containers (second containers).

[0068] like Figure 1 As shown, the method specifically includes the following steps S101 to S105:

[0069] S101: Collecting real-time liquid level data of a first container and at least two second containers.

[0070] The first container is respectively associated with each second container and conveys materials to the second containers.

[0071] Specifically, a liquid level sensor can be installed in the first container and each second container. The sensor is responsible for real-time monitoring of the height of the liquid in the container, and the sensor transmits the collected liquid level data to the central control system by wire or wireless means. The first container is connected to each second container through a pipeline, and the pipeline is equipped with a control valve for regulating the flow of materials. The first container is responsible for conveying materials to each second container, and by adjusting the control valve on the connecting pipeline, the system can control the flow of materials from the first container to the second container.

[0072] S102: Determine an output control parameter of the first container according to the real-time liquid level data, a corresponding control function of the first container, and a first preset liquid level.

[0073] The control function is used to describe the relationship between the liquid level of the first container and the output flow rate. The preset liquid level is used as a reference point of the control function to calculate the deviation (the difference between the actual liquid level and the preset liquid level).

[0074] Optionally, the control function can be PID (proportional-integral-derivative) control: adjusting the output according to the size, accumulation and rate of change of the deviation; fuzzy control: using fuzzy logic to handle imprecise input data; adaptive control: able to automatically adjust control parameters based on system response; and predictive control: predicting future behavior and making control decisions based on a system model.

[0075] Specifically, it is used to calculate how to adjust the output of the first container to maintain its liquid level near a preset value (first preset liquid level).

[0076] Optionally, the control function of the first container can be created based on the liquid level and volume change data of the container. The volume can be determined based on the liquid level and geometric parameters of the container, and the geometric parameters of the first container and historical liquid level change data are obtained to establish a relationship function between the liquid level and the volume.

[0077] S103: Determine the initial input control parameter of each second container according to the real-time liquid level data, the control function corresponding to each second container, and the second preset liquid level.

[0078] Here, the control function of the first container and the control function of the second container can use the same type of function or different control functions. The control function of each container can be created according to the actual situation with reference to different influencing factors such as container liquid level change or volume change, such as liquid level deviation, volume deviation, change rate, etc.

[0079] Specifically, the difference (deviation) between the real-time liquid level of each second container and its corresponding preset liquid level (second preset liquid level) can be calculated; the deviation is input into the control function specific to each container to calculate the initial input control parameters; the control function takes into account the liquid level and volume change data in the container to ensure that the output parameters can respond quickly to liquid level changes.

[0080] S104: According to the initial input control parameters of each second container, the material input ratio of each second container is determined by using a balance function.

[0081] The balance function is used to calculate the input proportion of each second container in the entire system. The balance function can be used to determine the input proportion of each second container based on the overall material demand of the system, the priority of each container, the current liquid level status, etc. The balance function can be a linear function, a nonlinear function, or a model based on an optimization algorithm.

[0082] The material input ratio determines the share of each second container in the total material input and is used to adjust the actual material input flow to ensure the balance and stability of the system. This ensures that the liquid level of each container can quickly reach or maintain the preset level by reasonably allocating the material input.

[0083] S105: Determine the target input control parameter of each second container according to the output control parameter and the material input ratio.

[0084] Specifically, the target input control parameter of each second container is calculated based on the output control parameter of the first container and the previously calculated material input ratio of each second container, thereby ensuring that the liquid level control of each second container can be performed independently while serving the overall balance and stability of the entire system.

[0085] The target input control parameters are ultimately used for the actual control operation, ensuring that the liquid level of each second container reaches or is maintained at a preset level, thereby achieving overall balance and optimization of the system.

[0086] S106: Controlling the control valve of each second container according to the target input control parameter, where the control valve is a control valve of the pipeline connecting the first container and the second container.

[0087] Specifically, the target input control parameter can be converted into a specific operating instruction of the control valve (such as opening percentage or flow setting) to achieve the required material input. Then the corresponding control signal is sent to each control valve, and the control valve adjusts the opening according to the received signal.

[0088] In an embodiment of the present application, by collecting the liquid level data of the first container and multiple second containers in real time, the initial control parameters are calculated for each container using a control function based on the liquid level and volume change data. By introducing a balance function, the scheme can dynamically adjust the material input ratio of each second container to achieve accurate liquid level balance. Finally, the target input control parameters are calculated by combining the output control parameters of the main container and the material input ratio of each slave container to control the valve on the connecting pipe. It overcomes the limitations of traditional single-loop PID control when dealing with multi-container systems, and can also adapt to the dynamic changes of the system, significantly improving the stability and control accuracy of the liquid level control of each container.

[0089] Optionally, the method further comprises:

[0090] Acquiring geometric parameters and historical liquid level change data of the first container;

[0091] Obtaining a liquid level-volume change function of the first container according to the geometric parameters, the historical liquid level change data and the real-time liquid level data;

[0092] The liquid level-volume change function is converted into a PID formula to obtain the control function of the first container.

[0093] The geometric parameters include the shape and size of the container, etc. The historical liquid level change data includes the liquid level data detected by each container at different time points.

[0094] Specifically, the dynamic characteristics of liquid level changes are analyzed through geometric parameters and historical liquid level change data, and a mathematical model of liquid level and volume change data is established to describe the rate of change of material volume corresponding to the liquid level over time; then the liquid level-volume change function is converted into a PID control formula, and the parameters of the controller (such as gain, integral time, and differential time) are determined to obtain the control function of each container.

[0095] The PID formula is used to generate a control signal to adjust the input flow or valve opening of the container to achieve precise control of the liquid level.

[0096] Optionally, the above-mentioned potential-volume change function includes the following formula (1):

[0097] E0=f(LIC0.SP)-f(LIC0.PV) (1)

[0098] Wherein, E0 is the volume adjustment value of the first container (i.e., the difference between the real-time volume and the target volume), LIC0.PV is the real-time value of the liquid level of the first container, f(LIC0.PV) is the liquid level volume of the first container, LIC0.SP is the liquid level setting value of the first container, and f(LIC0.SP) is the volume of the first container under the liquid level setting value of the first container.

[0099] Specifically, E0 in formula (1) is obtained through volume deviation to ensure the unity of the length unit dimension on the left and right sides of the control formula, thereby improving the efficiency and stability of liquid level control, adapting to different container shapes, and providing accurate data support for PID control.

[0100] By accurately calculating the volume difference and taking into account the geometric characteristics of the container, real-time and accurate monitoring of liquid level changes is achieved. The calculated volume difference is converted into a non-negative output control parameter. It is highly adaptable and can be adjusted according to different container shapes and liquid characteristics.

[0101] Optionally, the first container control function includes the following formula (2):

[0102] OUT0=K0(1+1 / (T0*s)+D0*s)*E0 (2)

[0103] Among them, OUT0 is the initial input control parameter of the first container, K0, T0 and D0 are PID parameters. K0 is the proportion of the first container, T0 is the integral of the first container, D0 is the differential constant of the first container, and E0 is the volume adjustment value of the first container.

[0104] In this embodiment, by obtaining the geometric parameters and real-time liquid level data of the first container and the manually set target liquid level data (i.e., the first preset liquid level), the system can calculate the corresponding volumes, and then obtain the difference between the real-time volume and the target volume, and use the flow change OUT0 as the operating variable, convert it into a PID control formula, thereby generating a control function for the first container and achieving precise liquid level regulation.

[0105] Optionally, the second container control function includes the following formula (3):

[0106] OUTi=Ki(1+1 / (Ti*s)+Di*s)*Ei (3)

[0107] Among them, OUTi is the initial input control parameter of the second container, Ki, Ti and Di are PID parameters. Ki is the proportion of the second container, Ti is the integral of the second container, Di is the differential constant of the second container, s is the result of the Laplace transformation of the time parameter, Ei is the liquid level adjustment value of the second container, Ei=LICi.SP-LICi.PV, LICi.PV is the real-time value of the liquid level of the second container, LICi.SP is the second preset liquid level of the second container, i=1, 2, 3, ..., n, n is the number of second containers.

[0108] Formula (3) is a standard PID controller transfer function that can be used for level control of the second container. Accurate level control is achieved through the combination of three parts: proportional (P), integral (I), and differential (D). The proportional term provides immediate response, the integral term eliminates steady-state errors, and the differential term predicts and suppresses rapid changes.

[0109] In an example, the above formula (3) can be converted by formula (1), as follows:

[0110] The control function of this embodiment can be obtained by converting the above-mentioned liquid level-volume change function, that is, using the liquid level and volume change data to dynamically adjust the set point LICi.SP of the PID controller to ensure that it reflects the current system status and expected trends.

[0111] Optionally, the above balance function includes the following formula (4) and formula (5):

[0112] OUT=ΣOUTi+0.0001(4)

[0113] Wherein, i=1, 2, 3, ..., n, n is the number of second containers, OUT is the total material input amount of all second containers, and OUTi is the material input amount of the second container;

[0114] ai=OUTi / (ΣOUTi)*100% (5)

[0115] Among them, ai is the material input proportion of the second container.

[0116] Specifically, first, the total material input amount OUT of all second containers in the system is calculated by formula (4); then, the material input proportion ai of each container is calculated using formula (5), thereby determining the material distribution between different containers.

[0117] In this embodiment, the balance function realizes the material allocation and monitoring of multiple second container systems through formulas (4) and (5). Formula (4) calculates the total input of all containers, adding a small constant to avoid zero division errors; formula (5) calculates the input proportion of each container to ensure efficient use of resources and stable operation of the system.

[0118] Optionally, the above S105 may specifically include the following steps:

[0119] The target input control parameter of the second container is calculated by the following formula (6):

[0120] MVi=OUT0*ai (6)

[0121] Among them, MVi is the target input control parameter of the second container, and OUT0 is the output control parameter of the first container.

[0122] Specifically, combining the total output of the first container (OUT0) with the predetermined input ratio (ai) of each second container ensures accurate distribution of materials and overall balance of the system.

[0123] In this embodiment, the output control parameter (OUT0) of the first container is distributed according to the material input ratio (ai) of each container, and the target input control parameter of each second container is determined, thereby ensuring that the distribution of materials is consistent with the overall control strategy of the system. The input of each container can be flexibly adjusted to ensure the optimization and stability of the overall production process.

[0124] In one example, after obtaining the target input control parameter, the valve between the first container and the second container can be regulated by converting the target input control parameter into a valve control signal. Specifically, the following steps can be adopted:

[0125] 1. Get the current status:

[0126] The data of the current flow sensor is monitored to understand the actual input flow of each second container.

[0127] 2. Calculate the adjustment amount:

[0128] Calculate the difference between the current flow and the target input control parameter (MVi).

[0129] Difference = MVi - current traffic

[0130] 3. Adjust the valve opening:

[0131] Adjust the valve opening according to the difference. Usually, when the difference is positive, the valve opening needs to be increased; when the difference is negative, the valve opening needs to be reduced. Use a proportional controller (such as a PID controller) to accurately adjust the valve to avoid over-adjustment.

[0132] 4. Real-time monitoring and feedback:

[0133] Continuously monitor flow changes to ensure that the adjusted flow rate gradually approaches the target value. Use feedback loops to automatically adjust the valve to keep the flow rate stable at the target value.

[0134] 5. Safety and calibration:

[0135] Ensure valves are adjusted within a safe range to avoid damage to the system. Regularly calibrate sensors and valves to ensure measurement and control accuracy.

[0136] Through the above steps, the valve can be effectively adjusted to achieve the target input control parameters, ensuring the smooth operation of the system and the accurate distribution of materials.

[0137] In a specific embodiment, Figure 2 The system device for controlling the liquid level of the associated container based on the production of high-purity polysilicon specifically includes:

[0138] DCS data acquisition storage device 11;

[0139] P, I, D input module 12;

[0140] Buffer tank data center 13;

[0141] Tower equipment data center 14;

[0142] BALANCE module 15;

[0143] Valve position control module 16;

[0144] Bumpless switching device 17.

[0145] Among them, the DCS data acquisition device 11 is used to obtain the real-time value and set value of the buffer tank and the tower bottom liquid level.

[0146] It is used to receive the real-time position of the buffer tank level transmitter and the tower bottom level transmitter participating in the single-loop PID control; it is used to store the real-time value and set value of the buffer tank and tower bottom level. The real-time value of the buffer tank is recorded as OUT0.PV, and the set value of the buffer tank is recorded as OUT0.SP; accordingly, the real-time value and set value of the tower bottom level are recorded as LICi.PV and LICi.SP respectively (i = 1, 2, 3, ..., n, n is the number of towers).

[0147] P, I, D input module 12:

[0148] It is used to input the initial P, I, and D coefficients of the single-loop PID control of the buffer tank liquid level and the single-loop control of the tower bottom liquid level, and is used to construct the initial closed-loop (or open-loop) control transfer function when the initial control model is established, and is supplied to the buffer tank data center 13 and the tower equipment data center 14. For ease of expression, the buffer tank output value is represented as OUT0, and the tower bottom output value is represented as OUTi. The transfer relationship is as follows: Formula (2) and Formula (3):

[0149] OUTi=Ki(1+1 / (Ti*s)+Di*s)*Ei (2)

[0150] OUT0=K0(1+1 / (T0*s)+D0*s)*E0(3)

[0151] Among them, the transfer function is Ki(1+1 / (Ti*s)+Di*s), which is the result of the time function after Laplace transformation; Ki, Ti, Di are the proportional, integral, and differential constants of the corresponding equipment respectively, Ei=(LICi.SP-LICi.PV), LICi.PV is the real-time value of the liquid level of the second container, LICi.SP is the second preset liquid level of the second container, i=1, 2, 3,...

[0152] The buffer tank data center 13 is connected to the DCS data acquisition storage device 11 to establish a port connection, and is used to receive the position number, real-time value and set value information of the buffer tank liquid level stored in the DCS data acquisition device 11, and connect its information to the transfer function obtained by the P, I, D input module 12, and then obtain the converted output value as the output signal.

[0153] The tower equipment data center 14 is connected to the DCS data acquisition storage device 11 to establish a port connection, and is used to receive the position number, real-time value and set value information of the tower bottom liquid level stored in the DCS data acquisition device 11, and connect its information to the transfer function obtained by the P, I, D input module 12, and then obtain the converted output value as the output signal.

[0154] BALANCE module 15 is used to construct a buffer tank output.

[0155] The specific construction method is as follows:

[0156] Output value OUT = ΣOUTi + 0.0001 (4)

[0157] Wherein, i=1, 2, 3, ..., n represents the sum of the tower equipment requirements. It should be noted that the addition of 0.0001 is to avoid equipment failure caused by zeroing.

[0158] Normalization of tower output:

[0159] ai=OUTi / OUT*100% (5).

[0160] Valve position signal value:

[0161] MVi=OUT0*ai(6)

[0162] MVi is the output point signal of BALANCE.

[0163] The valve position control module 16 is used to receive the output signal of the BALANCE module, to refer to the target flow value and valve position of each output tower line, and to automatically adjust the valve position opening.

[0164] The disturbance-free switching device 17 is used for adjusting the emergency state, specifically:

[0165] When it is identified that the BALANCE module 15 is not operating, the action connections of the various valves are established and regulated by their own independent PID blocks; the PID block at the buffer tank is set to manual, and its output value OUT0 satisfies: OUT0 = 1 / (ai+0.0001)*OUTi.

[0166] In this embodiment, the buffer tank is equivalent to the first container mentioned above, and the tower equipment (tower kettle, tower vessel or distillation tower) is equivalent to the second container mentioned above.

[0167] In another specific embodiment, the P, I, D input module S102 in the system device for controlling the liquid level of the associated container based on the production of high-purity polysilicon may specifically include the following modules: Figure 3 As shown:

[0168] Tank area physical property library storage device 21: used to store and record the necessary parameters of tanks of different shapes, specifically:

[0169] Spherical: Get the internal radius R of the tank;

[0170] Column shape: Get the tank bottom area A;

[0171] Elliptical head storage tank: obtain the inner height hi of the elliptical head, the radius r of the cylindrical part, and the length L of the cylindrical part.

[0172] In addition, if there are tanks with shapes different from those in the physical property library 21, they can be entered manually.

[0173] Tank liquid level signal conversion device 22: used for converting the measured liquid level value into the real-time value of the actual stored liquid volume for tanks of different shapes, specifically:

[0174] The real-time value f(x) of the liquid volume in the elliptical head tank is:

[0175] f(x)=L*[π*r 2 / 2-(rx)*Sqrt(2*r*xx 2 )-r 2 *arcsin((rx) / r)]+π*x / 3 / r*[3*r 2 *xr 3 +(rx) 3 ] (7)

[0176] f(x) of a spherical tank is: f(x) = 1 / 3*π*x 2 *(3*Rx) (8)

[0177] f(x) of the column tank is: f(x)=A*x(8)

[0178] Custom formulas for f(x) of other types of tanks.

[0179] Transfer function preliminary construction module 23: The specific formula of its internal processing core is:

[0180] E0=f(LIC0.SP)-f(LIC0.PV) (1)

[0181] Transfer function PID conversion module 24: The transfer function obtained in 24, i.e., formula (8), is converted into the relationship between the P, I, D parameters and Δt as described above, and Laplace transformation is performed to directly obtain the initial P, I, D parameters. Based on the initial P, I, D parameters, the above control function, i.e., formula (1), is obtained.

[0182] Real-time PID parameter adjustment module 25: It is mainly provided to on-site parameter adjustment personnel. It adjusts PID parameters by displaying the timing curve of the set value and target value of the liquid level value. In addition, the initial value can also be adjusted through module 25.

[0183] The above-mentioned system device for liquid level control of associated containers based on high-purity polysilicon production solves the problem of increased manual workload and multiple towers snatching materials from each other due to manual operation caused by the degree of freedom of 1 in the control scheme of feeding multiple towers from a buffer tank involved in the process of coarse separation and distillation of trichlorosilane and other chlorosilanes in the modified Siemens method.

[0184] Based on the system device for liquid level control of associated containers based on high-purity polysilicon production in the above embodiment, a BALANCE module operation and visualization device is also provided, such as Figure 4 As shown, including:

[0185] 31. BALANCE module receiving module, used to receive and store output signals from the buffer tank and tower kettle;

[0186] 32. BALANCE module visualization module, used to display the timing curve content of the above output signal and the timing content of the output valve position signal;

[0187] 33, BALANCE module core processing module, used to perform normalization processing of tower output: ai = OUTi / (ΣOUTi) * 100%, and schedule input and output signals;

[0188] 34. BALANCE module switching module is used to display the operating status of the BALANCE module and can perform disturbance-free switching in time according to its status.

[0189] Embodiment 2:

[0190] like Figure 5 As shown, this embodiment provides a liquid level control device, which is used to execute the above liquid level control method, including:

[0191] A collection module 501 is used to collect real-time liquid level data of a first container and at least two second containers, the first container is respectively associated with each second container and delivers material to the second container;

[0192] A first control module 502, connected to the acquisition module, is used to determine the output control parameter of the first container according to the real-time liquid level data and the corresponding control function of the first container and the first preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container;

[0193] A second control module 503, connected to the acquisition module, is used to determine the initial input control parameters of each second container according to the real-time liquid level data and the control function corresponding to each second container and the second preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container;

[0194] A balancing module 504, connected to the second control module, is used to determine the material input ratio of each second container using a balancing function according to the initial input control parameters of each second container;

[0195] The third control module 505 is connected to the first control module, the second control module and the balancing module respectively, and is used to determine the target input control parameter of each second container according to the output control parameter and the material input ratio;

[0196] The fourth control module 506 is connected to the third control module, and is used to control the control valve of each second container according to the second control parameter, and the control valve is a control valve of the pipeline connecting the first container and the second container.

[0197] Optionally, the device further comprises:

[0198] An acquisition module, used for acquiring geometric parameters and historical liquid level change data of the first container;

[0199] A calculation module, connected to the acquisition module, for obtaining a liquid level-volume change function of the first container according to the geometric parameters, the historical liquid level change data and the real-time liquid level data;

[0200] The conversion module is connected to the calculation module and is used to convert the liquid level-volume change function into a PID formula to obtain the control function of the first container.

[0201] In an embodiment of the present application, the liquid level control device collects the liquid level data of the first container and multiple second containers in real time, and calculates the initial control parameters for each container using a control function based on the liquid level change rate, liquid level, and volume change data. By introducing a balance function, the solution can dynamically adjust the material input ratio of each second container to achieve accurate liquid level balance. Finally, the target input control parameters are calculated based on the output control parameters of the main container and the material input ratio of each slave container to control the valve on the connecting pipe. It overcomes the limitations of traditional single-loop PID control when dealing with multi-container systems, and can also adapt to the dynamic changes of the system, significantly improving the stability and control accuracy of the liquid level control of each container.

[0202] Embodiment 3:

[0203] This embodiment provides a polysilicon production system, the system comprising:

[0204] A reactor for performing a chemical vapor deposition reaction to generate production materials including trichlorosilane;

[0205] A buffer tank, connected to the reactor through a pipeline, for receiving and storing the production material;

[0206] At least two distillation towers are connected to the buffer tank through pipelines, respectively, for receiving the production materials transported by the buffer tank, and performing distillation separation and purification to obtain high-purity trichlorosilane;

[0207] The liquid level control device provided in any of the above embodiments is electrically connected to the buffer tank and the distillation tower, respectively, and is used to control the liquid levels of the buffer tank and the distillation tower;

[0208] The reduction furnace is connected to the distillation tower and is used to convert high-purity trichlorosilane into polysilicon through hydrogen reduction reaction.

[0209] Specifically, the polysilicon production system consists of a reactor, a buffer tank, at least two distillation towers, a liquid level control device and a reduction furnace. First, the reactor performs a chemical vapor deposition reaction to generate production materials containing trichlorosilane; these materials are transported to the buffer tank for storage and voltage stabilization. Then, the buffer tank transports the materials to the distillation tower through a pipeline, and the distillation tower performs distillation separation and purification on the materials to obtain high-purity trichlorosilane. The liquid level control device is electrically connected to the buffer tank and the distillation tower to monitor and adjust the liquid level in real time to ensure stable operation of the system. Finally, the high-purity trichlorosilane is sent to the reduction furnace, undergoes a reduction reaction with hydrogen, and generates a high-purity polysilicon product.

[0210] In this embodiment, the polysilicon production system generates trichlorosilane through a reactor, stabilizes the material supply by using a buffer tank, and performs distillation separation and purification through at least two distillation towers, and finally converts high-purity trichlorosilane into polysilicon in a reduction furnace. The liquid level control device in the system realizes automated liquid level monitoring and regulation, ensuring the efficiency, stability and safety of the production process, while realizing resource recycling through by-product recovery, meeting the demand for high-purity polysilicon in the photovoltaic and semiconductor industries.

[0211] It should be noted that, in this embodiment, the buffer tank is equivalent to the first container mentioned above, and the distillation tower is equivalent to the second container mentioned above.

[0212] Embodiment 4:

[0213] Figure 6 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0214] The electronic device may include a processor 601 and a memory 602 storing computer program instructions.

[0215] Specifically, the processor 601 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0216] The memory 602 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 602 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 602 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 602 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 602 is a non-volatile solid-state memory.

[0217] The memory may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. Thus, typically, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0218] The processor 601 implements any one of the liquid level control methods in the above embodiments by reading and executing computer program instructions stored in the memory 602 .

[0219] In one example, the electronic device may further include a liquid level control interface 603 and a bus 604. Figure 6 As shown, the processor 601, the memory 602, and the liquid level control interface 603 are connected via a bus 604 and perform mutual liquid level control.

[0220] The liquid level control interface 603 is mainly used to implement liquid level control between various modules, devices, units and / or equipment in the embodiments of the present application.

[0221] Bus 604 includes hardware, software or both, and the parts of online data flow billing equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-end bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 604 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0222] In addition, in combination with the liquid level control method in the above embodiments, the present application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the liquid level control methods in the above embodiments is implemented.

[0223] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0224] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a liquid level control link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0225] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0226] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0227] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A liquid level control method, characterized in that: The method comprises: Collecting real-time liquid level data of a first container and at least two second containers, wherein the first container is respectively associated with each second container and delivers material to the second containers; determining an output control parameter of the first container according to the real-time liquid level data, a corresponding control function of the first container, and a first preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container; Determining an input control parameter of each second container according to the real-time liquid level data, a control function corresponding to each second container, and a second preset liquid level; Determine the material input ratio of each second container by using a balance function according to the initial input control parameter of each second container; Determining a target input control parameter for each of the second containers according to the output control parameter and the material input ratio; According to the target input control parameter, a control valve of each second container is controlled, and the control valve is a control valve of a pipeline connecting the first container and the second container.

2. The method according to claim 1, characterized in that The method further comprises: Acquiring geometric parameters and historical liquid level change data of the first container; Obtaining a liquid level-volume change function of the first container according to the geometric parameters, the historical liquid level change data and the real-time liquid level data; The liquid level-volume change function is converted into a PID formula to obtain a control function of the first container.

3. The method according to claim 2, characterized in that The liquid level-volume change function includes the following formula (1): E0=f(LIC0.SP)-f(LIC0.PV) (1) Among them, E0 is the volume adjustment value of the first container, LIC0.PV is the real-time value of the liquid level of the first container, f(LIC0.PV) is the liquid level volume of the first container, LIC0.SP is the first preset liquid level of the first container, and f(LIC0.SP) is the material volume of the first container corresponding to the first preset liquid level of the first container.

4. The method according to claim 3, characterized in that The control function of the first container includes the following formula (2): OUT0=K0(1+1 / (T0*s)+D0*s)*E0(2) Among them, OUT0 is the input control parameter of the first container, K0, T0 and D0 are PID parameters, K0 is the proportion of the first container, T0 is the integral of the first container, D0 is the differential constant of the first container, and E0 is the volume adjustment value of the first container.

5. The method according to claim 1, characterized in that All the second container control functions include the following formula (3): OUTi=Ki(1+1 / (Ti*s)+Di*s)*Ei(3) Wherein, OUTi is the initial input control parameter of the second container, Ki, Ti and Di are PID parameters. Ki is the proportion of the second container, Ti is the integral of the second container, Di is the differential constant of the second container, s is the result of Laplace transformation of the time parameter, Ei is the liquid level adjustment value of the second container, Ei=LICi.SP-LICi.PV, LICi.PV is the real-time value of the liquid level of the second container, LICi.SP is the second preset liquid level of the second container, i=1, 2, 3, ...

6. The method according to claim 1, characterized in that The balance function includes the following formula (4) and formula (5): OUT=ΣOUTi+0.0001(4) Wherein, i=1, 2, 3, ..., n, n is the number of second containers, OUT is the total material input amount of all second containers, and OUTi is the initial input control parameter of the second container; ai=OUTi / OUT *100% (5) Among them, ai is the material input ratio of the second container.

7. The method according to claim 1, characterized in that Determining the target input control parameter of each second container according to the output control parameter and the material input ratio specifically includes: The target input control parameter of the second container is calculated by the following formula (6): MVi=OUT0*ai (6) Among them, MVi is the target input control parameter of the second container, and OUT0 is the output control parameter of the first container.

8. A liquid level control device, characterized in that: The device comprises: A collection module, used to collect real-time liquid level data of a first container and at least two second containers, wherein the first container is respectively associated with each second container and delivers material to the second containers; a first control module, connected to the acquisition module, for determining an output control parameter of the first container according to the real-time liquid level data and a corresponding control function of the first container and a first preset liquid level, wherein the control function is created according to the liquid level and volume change data of the container; A second control module, connected to the acquisition module, for determining an input control parameter of each second container according to the real-time liquid level data and a control function corresponding to each second container and a second preset liquid level; a balancing module connected to the second control module, and configured to determine the material input ratio of each second container by using a balancing function according to the initial input control parameter of each second container; a third control module, connected to the first control module, the second control module and the balancing module respectively, and configured to determine a target input control parameter of each of the second containers according to the initial input control parameter and the material input ratio; The fourth control module is connected to the third control module and is used to control the control valve of each second container according to the second control parameter, and the control valve is a control valve of the pipeline connecting the first container and the second container.

9. The device according to claim 8, characterized in that The device also includes: An acquisition module, used to acquire geometric parameters and historical liquid level change data of the first container; a calculation module connected to the acquisition module, and configured to obtain a liquid level-volume change function of the first container according to the geometric parameters, the historical liquid level change data and the real-time liquid level data; A conversion module is connected to the calculation module and is used to convert the liquid level-volume change function into a PID formula to obtain a control function of the first container.

10. The device according to claim 8, characterized in that The liquid level-volume change function includes the following formula (1): E0=f(LIC0.SP)-f(LIC0.PV) (1) Among them, E0 is the volume adjustment value of the first container, LIC0.PV is the real-time value of the liquid level of the first container, f(LIC0.PV) is the liquid level volume of the first container, LIC0.SP is the first preset liquid level of the first container, and f(LIC0.SP) is the material volume of the first container corresponding to the first preset liquid level of the first container.

11. A polysilicon production system, characterized in that: The system comprises: A reactor for performing a chemical vapor deposition reaction to generate production materials including trichlorosilane; A buffer tank, connected to the reactor through a pipeline, for receiving and storing the production material; At least two distillation towers are connected to the buffer tank through pipelines, respectively, for receiving the production materials transported by the buffer tank, and performing distillation separation and purification to obtain high-purity trichlorosilane; The liquid level control device according to any one of claims 8 to 10 is electrically connected to the buffer tank and the distillation tower, respectively, and is used to control the liquid levels of the buffer tank and the distillation tower; The reduction furnace is connected to the distillation tower and is used to convert high-purity trichlorosilane into polysilicon through hydrogen reduction reaction.

12. An electronic device, characterized in that: It comprises a processor, a memory and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the liquid level control method as claimed in any one of claims 1 to 7.

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