Grounding detection method for polycrystalline silicon reduction furnace

Abstract

The invention provides a grounding detection method for a polycrystalline silicon reduction furnace in order to solve the problems that in the prior art, the voltage of a silicon rod is high during pressing, electrode insulating materials are possibly broken down, misinformation current is easily collected, loop stopping operation is executed, losses are caused, and the voltage is low after pressing is completed and cannot be collected easily. The method comprises the following steps: acquiring current on a grounding resistor branch and voltage at two ends of a grounding resistor; and performing data processing according to the current on the grounding resistor branch and the voltage at the two ends of the grounding resistor to generate three alarm mechanisms, namely a fixed current threshold alarm mechanism, a dynamic threshold alarm mechanism and a fluctuation monitoring alarm mechanism, so as to trigger primary alarm and danger alarm. The three alarm mechanisms are executed in parallel to break through the limitation of a traditional single threshold value alarm mode, a fixed threshold value is used for achieving quick response to obvious abnormity, and a dynamic threshold value alarm mechanism and a fluctuation monitoring alarm mechanism are used for accurately capturing a dynamic grounding fault.

Description

Technical Field

[0001] This invention relates to polysilicon production technology, and more particularly to a method for detecting grounding in a polysilicon reduction furnace. Background Technology

[0002] Polysilicon reduction production involves a wide range of technical fields, and the conditions inside the reduction furnace are complex. During operation, due to the high temperature inside the furnace, when the electrode insulation material of the reduction furnace is nearing the end of its service life, a grounding current will form between the neutral point of the secondary coil of the step-up transformer and ground. Therefore, it is necessary to collect the grounding current and perform a loop-stop operation based on its threshold. The loop-stop operation refers to disconnecting the power supply to the silicon rod.

[0003] In existing technologies, most alarm modes employ a single threshold, which uses a single grounding current transformer to collect the current in the grounding resistance branch. The collected current is compared to a fixed threshold; if the collected current exceeds the threshold, an alarm is triggered, initiating a loop shutdown. This single grounding current transformer approach presents two problems. First, during voltage testing, the silicon rod voltage is very high, reaching 7000V-10000V, potentially damaging the electrode insulation and leading to false alarms and loop shutdown, resulting in losses. Second, after voltage testing, the silicon rod voltage drops to a maximum of 2650V and a minimum of 100V, making it difficult to collect a reading. Summary of the Invention

[0004] This invention addresses two problems in existing technologies: firstly, during the pressure test, the silicon rod voltage is high, reaching 7000V-10000V, which may break down the electrode insulation material, easily leading to false current readings and triggering a shutdown operation, causing losses; secondly, after the pressure test, the silicon rod voltage is at most 2650V and as low as 100V, making it easy to fail to collect the data. The invention provides a grounding detection method for polycrystalline silicon reduction furnaces.

[0005] The technical solution adopted in this invention is:

[0006] A method for detecting grounding in a polysilicon reduction furnace includes the following steps:

[0007] Step S1: Obtain the current on the grounding resistor branch and the voltage across the grounding resistor.

[0008] Step S2: Data processing is performed based on the current on the grounding resistor branch and the voltage across the grounding resistor to generate three alarm mechanisms: a fixed current threshold alarm mechanism, a dynamic threshold alarm mechanism, and a fluctuation monitoring alarm mechanism to trigger primary alarms and danger alarms.

[0009] Among them, the three alarm mechanisms are executed in parallel.

[0010] Furthermore, the fixed current threshold alarm mechanism is expressed as follows: the current in the grounding resistor branch triggers the primary alarm and the danger alarm according to the preset primary alarm threshold and the danger alarm threshold.

[0011] The dynamic threshold alarm mechanism is expressed as triggering a primary alarm based on the voltage across the grounding resistor and the current in the grounding resistor branch;

[0012] The fluctuation monitoring and alarm mechanism is expressed as triggering a danger alarm based on the fluctuation behavior of the voltage across the grounding resistor.

[0013] Furthermore, step S2 specifically performs the following sub-steps:

[0014] Step S21: Set the primary alarm threshold and the danger alarm threshold;

[0015] Step S22: Determine whether the current on the grounding resistance branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm.

[0016] When a primary alarm is triggered, an alarm notification message is issued so that staff can closely monitor the current change trend and promptly investigate potential hazards, but the equipment continues to operate normally.

[0017] When a hazard alarm is triggered, an alarm hazard warning message is issued, and a loop stop operation is performed;

[0018] Step S23: Obtain the grounding current threshold based on the voltage across the grounding resistor. When the grounding current threshold is greater than the current in the grounding resistor branch, trigger a primary alarm.

[0019] Step S24: Trigger a hazard alarm based on the fluctuation behavior of the grounding current threshold;

[0020] The execution order of steps S22, S23, and S24 can be adjusted arbitrarily or performed simultaneously.

[0021] Furthermore, in step S22, the method for determining whether the current in the grounding resistance branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm, is as follows:

[0022] When the current in the grounding resistor branch reaches the primary alarm threshold but does not reach the danger alarm threshold, the primary alarm is triggered.

[0023] A hazard alarm is triggered when the current in the grounding resistor branch reaches the hazard alarm threshold.

[0024] Further, in step S23, the calculation formula for the grounding current threshold is obtained based on the voltage across the grounding resistor:

[0025] Grounding current threshold = voltage across grounding resistor ÷ 2 ÷ resistance value of grounding resistor;

[0026] The grounding resistance is a known quantity.

[0027] Furthermore, step S24 specifically executes the following sub-steps:

[0028] By continuously monitoring the grounding current threshold, the fluctuation amplitude is calculated and expressed as:

[0029] Fluctuation amplitude = |current ground current threshold -previous ground current threshold|;

[0030] Set a threshold for fluctuation amplitude; when

[0031] (Fluctuation amplitude ÷ grounding current threshold at the previous moment)

[0032] When the fluctuation amplitude exceeds the threshold, a fluctuation is recorded.

[0033] If the cumulative number of fluctuation records reaches the upper limit during the monitoring period, a danger alarm will be triggered.

[0034] Furthermore, the fluctuation amplitude threshold is 30%.

[0035] Furthermore, the three alarm mechanisms are executed in parallel; when the triggering conditions for the primary alarm and the danger alarm are met simultaneously, the danger alarm is executed first.

[0036] Furthermore, the primary alarm threshold, danger alarm threshold, fluctuation amplitude threshold, maximum number of records, and monitoring cycle can all be flexibly adjusted according to actual operational needs to improve the adaptability and accuracy of the solution.

[0037] Furthermore, it also includes step S3, which integrates and analyzes the alarm information generated in steps S22, S23 and S24 to provide comprehensive data support for subsequent fault diagnosis and equipment optimization, and further improve the reliability and accuracy of grounding alarms.

[0038] The beneficial effects of this invention are:

[0039] The grounding detection method for polycrystalline silicon reduction furnaces disclosed in this invention overcomes the limitations of traditional single-threshold alarm modes by implementing, coordinating, complementing, and verifying three alarm mechanisms: a fixed current threshold alarm mechanism, a dynamic threshold alarm mechanism, and a fluctuation monitoring alarm mechanism. It utilizes a fixed threshold to achieve rapid response to obvious anomalies, while the dynamic threshold alarm mechanism and the fluctuation monitoring alarm mechanism accurately capture dynamic grounding faults, greatly improving alarm accuracy and reliability, and providing a completely new approach and method for grounding fault monitoring. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart of the grounding detection method for polysilicon reduction furnaces. Detailed Implementation

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.

[0044] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0045] In existing technologies, most alarm methods employ a single threshold mode. This involves using a single grounding current transformer to collect the current in the grounding resistance branch. The collected current is compared to a fixed threshold; if the collected current exceeds the threshold, an alarm is triggered, initiating a loop-stopping operation. Chinese patent publication CN216351147U, titled "Reduction Power Supply Adjustment Circuit Based on Full-Cycle Grounding Monitoring of Polycrystalline Silicon Growth," describes the reduction power supply adjustment circuit used to collect the current. The single grounding current transformer acquisition scheme presents two problems. First, during voltage suppression, the silicon rod voltage is high, reaching 2650V, which may break down the electrode insulation material, easily leading to false current detection and loop-stopping operations, causing losses. Second, after voltage suppression, the voltage is low, as low as 200V, making it difficult to collect the current.

[0046] As attached Figure 1 As shown, the grounding detection method for polysilicon reduction furnace disclosed in this embodiment includes the following steps:

[0047] Step S1: Obtain the current on the grounding resistor branch of the polysilicon reduction furnace (such as the current collected by the current transformer JDCT in "Reduction Power Supply Adjustment Circuit Based on Full-Cycle Grounding Monitoring of Polysilicon Growth") and the voltage across the grounding resistor.

[0048] Step S2 involves processing data based on the current in the grounding resistor branch of the polysilicon reduction furnace and the voltage across the grounding resistor to generate three alarm mechanisms: a fixed current threshold alarm mechanism, a dynamic threshold alarm mechanism, and a fluctuation monitoring alarm mechanism, which trigger primary and hazard alarms. These three alarm mechanisms are executed in parallel.

[0049] The beneficial effects of the above technical solution are as follows: the three alarm mechanisms—fixed current threshold alarm mechanism, dynamic threshold alarm mechanism, and fluctuation monitoring alarm mechanism—are executed in parallel, work collaboratively, complement each other, and verify each other, breaking through the limitations of the traditional single threshold alarm mode. It utilizes a fixed threshold to achieve rapid response to obvious anomalies, while the dynamic threshold alarm mechanism and fluctuation monitoring alarm mechanism accurately capture dynamic grounding faults, greatly improving alarm accuracy and reliability, and providing a completely new approach and method for grounding fault monitoring.

[0050] Furthermore, the fixed current threshold alarm mechanism is expressed as follows: the current in the grounding resistor branch triggers the primary alarm and the danger alarm according to the preset primary alarm threshold and the danger alarm threshold.

[0051] The dynamic threshold alarm mechanism is expressed as triggering a primary alarm based on the voltage across the grounding resistor and the current in the grounding resistor branch;

[0052] The fluctuation monitoring and alarm mechanism is expressed as triggering a danger alarm based on the fluctuation behavior of the voltage across the grounding resistor.

[0053] In this embodiment, all parameters and operational logic settings can be implemented through software.

[0054] Furthermore, step S2 specifically performs the following sub-steps:

[0055] Step S21: Set the primary alarm threshold and the danger alarm threshold;

[0056] Step S22: Determine whether the current on the grounding resistance branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm.

[0057] When a primary alarm is triggered, an alarm notification message is issued so that staff can closely monitor the current change trend and promptly investigate potential hazards, but the equipment continues to operate normally.

[0058] When a hazard alarm is triggered, an alarm hazard warning message is issued, and a loop stop operation is performed;

[0059] Step S23: Obtain the grounding current threshold based on the voltage across the grounding resistor. When the grounding current threshold is greater than the current in the grounding resistor branch, trigger a primary alarm.

[0060] Step S24: Trigger a hazard alarm based on the fluctuation behavior of the grounding current threshold;

[0061] The execution order of steps S22, S23, and S24 can be adjusted arbitrarily or performed simultaneously.

[0062] In step S22, the method for determining whether the current on the grounding resistance branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm, is as follows:

[0063] When the current in the grounding resistor branch reaches the primary alarm threshold but does not reach the danger alarm threshold, the primary alarm is triggered.

[0064] A hazard alarm is triggered when the current in the grounding resistor branch reaches the hazard alarm threshold.

[0065] Further, in step S23, the calculation formula for the grounding current threshold is obtained based on the voltage across the grounding resistor:

[0066] Grounding current threshold = voltage across grounding resistor ÷ 2 ÷ resistance value of grounding resistor;

[0067] The grounding resistance value is a known quantity; in this embodiment, the grounding resistance value is 2000Ω.

[0068] Furthermore, step S24 specifically executes the following sub-steps:

[0069] By continuously monitoring the grounding current threshold, the fluctuation amplitude is calculated and expressed as:

[0070] Fluctuation amplitude = |current ground current threshold -previous ground current threshold|;

[0071] In this embodiment, the fluctuation amplitude threshold is set to 30%; when

[0072] (Fluctuation amplitude ÷ grounding current threshold at the previous moment)

[0073] When the fluctuation amplitude exceeds the threshold, a fluctuation is recorded.

[0074] If the cumulative number of fluctuation records reaches the upper limit within the monitoring period, a danger alarm is triggered. In this embodiment, the monitoring period is set to 30 seconds, and the upper limit for the number of records is set to 20.

[0075] Furthermore, when the triggering conditions for both primary alarms and hazard alarms are met simultaneously, the hazard alarm will be executed first.

[0076] Furthermore, the primary alarm threshold, danger alarm threshold, fluctuation amplitude threshold, maximum number of records, and monitoring cycle can all be flexibly adjusted according to actual operational needs to improve the adaptability and accuracy of the solution.

[0077] Furthermore, as shown in the appendix Figure 1 As shown, the grounding detection method for polycrystalline silicon reduction furnace also includes step S3, which integrates and analyzes the alarm information generated in steps S22, S23 and S24 to provide comprehensive data support for subsequent fault diagnosis and equipment optimization, and further improve the reliability and accuracy of grounding alarm.

[0078] The following approach can be used for alarm information fusion analysis: First, integrate the alarm information from steps S22, S23, and S24 in chronological order, recording the specific time, type, and corresponding parameter values ​​of the alarm occurrence. Next, analyze the correlation between different alarms, such as whether fixed current threshold alarms and dynamic threshold alarms are triggered at similar times, or whether fluctuation monitoring alarms occur under specific voltage and current conditions. Then, conduct a comprehensive evaluation based on the alarm level, prioritizing the handling of dangerous alarms, and combining other alarm information to determine the severity and urgency of the fault. Finally, based on the fusion analysis results, generate a comprehensive alarm report, including alarm details, possible causes, and handling suggestions, providing clear guidance for maintenance personnel to help them respond quickly and handle faults accurately.

[0079] The beneficial effects of the above technical solutions are as follows: The fixed current threshold alarm mechanism sets a primary alarm threshold and a danger alarm threshold, which can quickly respond to obvious abnormal currents. When the current in the grounding resistance branch reaches the primary alarm threshold, the primary alarm is triggered in a timely manner to remind the staff to pay attention. When the danger alarm threshold is reached, the danger alarm is triggered and a shutdown operation is performed, effectively preventing serious faults. The dynamic threshold alarm mechanism calculates the grounding current threshold based on the voltage across the grounding resistance and adjusts it in real time according to the voltage. This avoids false alarms caused by high voltage during voltage suppression and can accurately trigger alarms when the voltage is low after voltage suppression, improving alarm adaptability. The fluctuation monitoring alarm mechanism continuously monitors the fluctuation of the grounding current threshold, accurately calculates the fluctuation amplitude and compares it with the set threshold. When the number of fluctuation records reaches the upper limit, a danger alarm is triggered, accurately capturing dynamic grounding faults. The three alarm mechanisms are executed in parallel and complement each other. When working together, they greatly improve the accuracy and reliability of the alarms, reduce losses caused by false alarms or missed alarms, provide strong protection for the safe and stable operation of the polysilicon reduction furnace, and the alarm parameters can be flexibly adjusted according to actual needs to adapt to different operating requirements. At the same time, they provide comprehensive data support for subsequent fault diagnosis and equipment optimization, significantly improving the performance of the entire grounding detection system.

Claims

1. A method for detecting grounding in a polycrystalline silicon reduction furnace, characterized in that, Includes the following steps: Step S1: Obtain the current on the grounding resistor branch of the polysilicon reduction furnace and the voltage across the grounding resistor. Step S2: Data processing is performed based on the current in the grounding resistor branch of the polysilicon reduction furnace and the voltage across the grounding resistor to generate three alarm mechanisms: a fixed current threshold alarm mechanism, a dynamic threshold alarm mechanism, and a fluctuation monitoring alarm mechanism to trigger primary alarms and danger alarms. The three alarm mechanisms are executed in parallel.

2. The grounding detection method for a polycrystalline silicon reduction furnace according to claim 1, characterized in that, The fixed current threshold alarm mechanism is expressed as follows: the current through the grounding resistor branch triggers the primary alarm and the danger alarm according to the preset primary alarm threshold and danger alarm threshold. The dynamic threshold alarm mechanism is expressed as triggering the primary alarm based on the voltage across the grounding resistor and the current in the branch of the grounding resistor; The fluctuation monitoring and alarm mechanism is expressed as triggering the danger alarm based on the fluctuation behavior of the voltage across the grounding resistor.

3. The grounding detection method for polycrystalline silicon reduction furnace according to claim 2, characterized in that, Step S2 specifically involves the following sub-steps: Step S21: Set the primary alarm threshold and the danger alarm threshold; Step S22: Determine whether the current on the grounding resistor branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm. When the primary alarm is triggered, an alarm notification is issued so that staff can closely monitor the current change trend and promptly investigate potential hazards, but the equipment continues to operate normally. When the danger alarm is triggered, an alarm danger warning message is issued and a loop stop operation is performed; Step S23: Obtain the grounding current threshold based on the voltage across the grounding resistor. When the grounding current threshold is greater than the current in the branch of the grounding resistor, trigger the primary alarm. Step S24: Trigger a hazard alarm based on the fluctuation behavior of the grounding current threshold.

4. The grounding detection method for a polycrystalline silicon reduction furnace according to claim 3, characterized in that, In step S22, the method for determining whether the current on the grounding resistor branch reaches the primary alarm threshold and the danger alarm threshold, thereby triggering the primary alarm or the danger alarm, is as follows: The primary alarm is triggered when the current in the grounding resistor branch reaches the primary alarm threshold but does not reach the danger alarm threshold. The danger alarm is triggered when the current in the grounding resistor branch reaches the danger alarm threshold.

5. The grounding detection method for a polycrystalline silicon reduction furnace according to claim 3, characterized in that, In step S23, the calculation formula for the grounding current threshold based on the voltage across the grounding resistor is as follows: The grounding current threshold is calculated as: voltage across the grounding resistor ÷ 2 ÷ resistance value of the grounding resistor.

6. The grounding detection method for a polycrystalline silicon reduction furnace according to claim 3, characterized in that, The following sub-steps are specifically performed in step S24: By continuously monitoring the grounding current threshold, the fluctuation amplitude is calculated and expressed as: Fluctuation amplitude = |the current grounding current threshold at the current moment - the previous grounding current threshold at the previous moment|; Set a threshold for fluctuation amplitude; when The fluctuation amplitude ÷ the ground current threshold at the previous moment When the fluctuation amplitude exceeds the threshold value, a fluctuation is recorded. If the cumulative number of fluctuation records reaches the upper limit during the monitoring period, the aforementioned danger alarm will be triggered.

7. The grounding detection method for a polycrystalline silicon reduction furnace according to claim 6, characterized in that, The fluctuation amplitude threshold is 30%.

8. The method for detecting grounding of a polycrystalline silicon reduction furnace according to any one of claims 2-7, characterized in that, The three alarm mechanisms are executed in parallel; when the triggering conditions of the primary alarm and the danger alarm are met simultaneously, the danger alarm is executed first.

9. The method for detecting grounding of a polycrystalline silicon reduction furnace according to any one of claims 2-5, characterized in that, The primary alarm threshold, the danger alarm threshold, the fluctuation amplitude threshold, the upper limit of the number of records, and the monitoring period can all be flexibly adjusted according to actual operational needs to improve the adaptability and accuracy of the solution.

10. The method for detecting grounding of a polycrystalline silicon reduction furnace according to any one of claims 3-7, characterized in that, It also includes step S3, which integrates and analyzes the alarm information generated in steps S22, S23 and S24 to provide comprehensive data support for subsequent fault diagnosis and equipment optimization, and further improve the reliability and accuracy of grounding alarm.

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