CN110702968A - Grounding current grading detection method for power supply system of polycrystalline silicon reduction furnace - Google Patents
Grounding current grading detection method for power supply system of polycrystalline silicon reduction furnace Download PDFInfo
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- CN110702968A CN110702968A CN201911118770.5A CN201911118770A CN110702968A CN 110702968 A CN110702968 A CN 110702968A CN 201911118770 A CN201911118770 A CN 201911118770A CN 110702968 A CN110702968 A CN 110702968A
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- reduction furnace
- grounding current
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/021—Preparation
- C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
- C01B33/035—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material by decomposition or reduction of gaseous or vaporised silicon compounds in the presence of heated filaments of silicon, carbon or a refractory metal, e.g. tantalum or tungsten, or in the presence of heated silicon rods on which the formed silicon is deposited, a silicon rod being obtained, e.g. Siemens process
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/027—Details with automatic disconnection after a predetermined time
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- Organic Chemistry (AREA)
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Abstract
The invention discloses a method for detecting grounding current of a power supply system of a polycrystalline silicon reduction furnace in a grading manner. When the grounding current corresponding to the maintaining voltage reaches an early warning value, early warning is carried out, and an operator adjusts process parameters according to the early warning to avoid or delay the grounding current from reaching an action value; and when the grounding current corresponding to the maintaining voltage reaches the action value, stopping the operation of the power supply system of the polycrystalline silicon reduction furnace. The invention has higher protection precision, can reduce phase loss and delay phase loss while ensuring the safe operation and production of the reduction furnace, and increases the effective operation time of the reduction furnace, thereby increasing the productivity.
Description
Technical Field
The invention relates to the technical field of polycrystalline silicon reduction furnaces, in particular to a grounding current grading detection method for a power supply system of a polycrystalline silicon reduction furnace.
Background
Since 2005, polysilicon was popularized in China in succession, and reduction power supplies used by polysilicon manufacturers were monopolized by the AEG-early stage reduction electrical system technology (for 9-pair rod and 12-pair rod polysilicon reduction furnaces). In 2007-2009, some domestic reduction power supply manufacturers break through the technical monopoly abroad, and successively put into domestic new polysilicon projects (aiming at 12, 18, 24, 36 and 72 pairs of rod polysilicon reduction furnaces), and for the ground leakage current detection caused by the working condition change in the reduction furnace in the production process of polysilicon, the scheme of detecting the ground leakage current value by using an AEG reduction power supply is continuously adopted, but the problems that the current detection value is fixed and cannot adapt to the production process adjustment of the reduction furnace exist, so that frequent open-phase production is caused, and a large amount of manpower and material resources are wasted.
The existing power supply grounding current detection system of the polycrystalline silicon reduction furnace judges whether silicon cores in the reduction furnace lean against a furnace wall or silicon rods at different phases lean against the furnace wall or not by detecting the magnitude of a grounding current value, and stops running when the grounding current reaches a set protection value. In the process that the operating voltage of the whole operating period is reduced to the lowest 520V from 2650V, the grounding current protection value is fixed at 900mA and is unchanged, when the operating voltage is too low (lower than 520V), the grounding point cannot be effectively protected, the grounding current value of the point is 600mA at the maximum, the protection value is 900mA, and potential safety hazards exist; on the contrary, when the high voltage is operated (more than 1500V), the actual grounding current 1500mA of the point is far more than the protection value 900mA, so that the operation is stopped in advance, the open-phase operation is caused, and the output of a single furnace is reduced.
In addition, when false grounding or transient grounding occurs during operation, the operation is directly stopped, and the method is not suitable for the actual production process of the polycrystalline silicon.
Disclosure of Invention
In order to solve the above problems, the present invention provides a method for detecting grounding current stepping of a power supply system of a polysilicon reduction furnace, which comprises the steps of stepping a holding voltage according to the difference of constant current holding voltages required by different stages of silicon core growth, wherein the protection precision is higher, each step is provided with a corresponding early warning value and action value of grounding current, and the early warning value is smaller than the action value, specifically:
when the grounding current corresponding to the maintaining voltage reaches an early warning value, early warning is carried out, and an operator adjusts process parameters according to the early warning to avoid or delay the grounding current from reaching an action value;
when the grounding current corresponding to the maintaining voltage reaches an action value, the operation of a power supply system of the polysilicon reduction furnace is stopped, so that the silicon core can operate for a long time, the occurrence of ground faults is reduced or avoided, the yield loss caused by the ground faults is reduced, and water, gas and gas resources are saved.
Furthermore, when the grounding current corresponding to the maintaining voltage reaches the action value and exceeds the set extension time, the operation of the power supply system of the polysilicon reduction furnace is stopped, so that the problem that the operation is directly stopped when false grounding or transient grounding occurs in the operation period can be solved.
Furthermore, a high-voltage switch electric appliance is arranged in the silicon core grounding loop, and the high-voltage switch electric appliance is closed when the power supply system of the polycrystalline silicon reduction furnace normally operates and is disconnected when in maintenance, so that the time for checking remote measurement of detaching or installing bolts in insulation before the furnace is taken out is reduced.
Further, the high-voltage switch electric appliance comprises an isolation knife switch.
Further, the integral setting of the maintaining voltage is set to 5 grades, which are respectively 520-999V, 1000-1499V, 1500-1999V, 2000-2499V and 2500-2650V.
Further, the action values of the ground current corresponding to the 5 th gear maintaining voltage are sequentially as follows: 601mA, 1157mA, 1500mA, 2314mA and 2893 mA.
Furthermore, an adjustable resistor for detecting grounding current is arranged in the silicon core grounding loop, and when the voltage is maintained to be 1000V or more, the resistance value of the adjustable resistor is fixed; when the voltage is maintained at 520-999V, the resistance value of the adjustable resistor is reduced so as to keep the detection precision and realize accurate protection.
The invention has the beneficial effects that:
(1) according to the invention, the maintaining voltage is set in a grading way according to the change of the maintaining voltage of the silicon core in the polysilicon reducing furnace, each grade is provided with the early warning value and the action value corresponding to the grounding current, the protection precision is higher, the phase loss can be reduced and delayed while the safe operation and production of the reducing furnace are ensured, the effective operation time of the reducing furnace is increased, and the productivity is increased;
(2) the early warning can enable an operator to avoid or delay the grounding current from reaching an action value to cause shutdown of the reducing furnace according to adjustment of process parameters, so that the silicon core runs for a long time, the occurrence of ground faults is reduced or avoided, the yield loss caused by the ground faults is reduced, and water, electricity and gas resources are saved;
(3) after the grounding current reaches the action value and needs to exceed the set extension time, the reduction furnace stops running, so that the problem that the running is directly stopped when false grounding or transient grounding occurs in the running period can be avoided;
(4) the adjustable resistor for detecting the grounding current is arranged in the silicon core grounding loop so as to keep the detection precision and realize accurate protection;
(5) according to the invention, the high-voltage switch electric appliance is arranged in the silicon core grounding loop, and the high-voltage switch electric appliance is closed when the power supply system of the polycrystalline silicon reduction furnace normally operates and is disconnected when in maintenance, so that the time for checking remote measurement of insulation dismounting or bolt mounting before furnace lifting is reduced;
(6) under the condition of frequent adjustment of the process, compared with a fixed protection value of 900mA of grounding current in the traditional method, the method has the advantages that the operation voltage of the silicon core is more than 1000V, the reduction furnace is delayed to stop operation when the grounding current is 1157mA or more, the grounding action time is delayed, and the operation time of the reduction furnace can be increased by more than 10 hours; when the operating voltage of the silicon core is within 520V, the reduction furnace is stopped in a delayed mode when the grounding current is 600mA, the protection precision is higher, the corrosion of the grounding current to an insulating part of a chassis of the reduction furnace can be reduced, the service cycle of the insulating part is prolonged, the replacement and maintenance time of the insulating part is reduced, and therefore the effective operating time of the reduction furnace is increased.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, specific embodiments of the present invention will now be described. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment provides a method for detecting grounding current grading of a power supply system of a polycrystalline silicon reduction furnace, wherein according to the difference of constant current maintaining voltages required by different phases of silicon core growth, the maintaining voltages are graded, the protection precision is higher, each grade is provided with a corresponding grounding current early warning value and an action value, the early warning value is smaller than the action value, wherein:
(1) when the grounding current corresponding to the maintaining voltage reaches an early warning value, early warning is carried out, and an operator adjusts process parameters according to the early warning to avoid or delay the grounding current from reaching an action value;
(2) when the grounding current corresponding to the maintaining voltage reaches an action value, the operation of a power supply system of the polysilicon reduction furnace is stopped, so that the silicon core can operate for a long time, the occurrence of ground faults is reduced or avoided, the yield loss caused by the ground faults is reduced, and water, gas and gas resources are saved.
Specifically, when the grounding current corresponding to the maintaining voltage reaches the action value and exceeds the set extension time, the operation of the power supply system of the polysilicon reduction furnace is stopped, so that the problem that the operation is directly stopped when false grounding or transient grounding occurs during the operation period can be solved.
An adjustable resistor for detecting grounding current is arranged in the silicon core grounding loop, and when the voltage is maintained to be 1000V or more, the resistance value of the adjustable resistor is fixed; when the voltage is maintained at 520-999V, the resistance value of the adjustable resistor is reduced so as to keep the detection precision and realize accurate protection.
And a high-voltage switch electric appliance is also arranged in the silicon core grounding loop, and the high-voltage switch electric appliance is closed when the power supply system of the polycrystalline silicon reduction furnace normally operates and is disconnected when in maintenance so as to reduce the time for checking and telemetering insulation dismounting or mounting bolts before the furnace is taken out. Wherein, the high-voltage switch electric appliance can adopt an isolation knife switch.
Specifically, the rounding of the sustain voltage of this embodiment is set to 5 steps, which are 520 to 999V, 1000 to 1499V, 1500 to 1999V, 2000 to 2499V, and 2500 to 2650V, respectively, and the corresponding action values of the ground current are sequentially: 601mA, 1157mA, 1500mA, 2314mA and 2893mA, as shown in table 1, are the ground current protection values of the present embodiment corresponding to the sustain voltage in the conventional method.
TABLE 1
| Serial number | Sustain voltage | Ground current protection value of conventional method | Ground current operation value of the present embodiment |
| 1 | 520V | 900mA | 601mA |
| 2 | 1000V | 900mA | 1157mA |
| 3 | 1500V | 900mA | 1500mA |
| 4 | 2000V | 900mA | 2314mA |
| 5 | 2500V | 900mA | 2893mA |
As can be seen from the comparison of the above table, the grounding current protection value of the conventional method is 900mA, the grounding point cannot be effectively protected when the maintaining voltage is too low (lower than 520v), the actual grounding current value of the point is 600mA at the maximum, the protection value is 900mA, and potential safety hazards exist; similarly, when the maintaining voltage is too high (more than 1500V), the actual grounding current 1500mA of the point is far more than the protection value 900mA, so that the operation is stopped in advance, the phase-failure operation is performed, and the output of a single furnace is reduced.
In the embodiment, the reduction furnace is delayed to stop running when the running voltage of the silicon core is more than 1000V and the grounding current is 1157mA or more, so that the grounding action time is delayed, and the running time of the reduction furnace can be increased by more than 10 hours; when the operating voltage of the silicon core is within 520V, the reduction furnace is stopped in a delayed mode when the grounding current is 600mA, the protection precision is higher, the corrosion of the grounding current to an insulating part of a chassis of the reduction furnace can be reduced, the service cycle of the insulating part is prolonged, the replacement and maintenance time of the insulating part is reduced, and therefore the effective operating time of the reduction furnace is increased.
The statistics of the off-line time experiment of the present embodiment and the conventional method are shown in table 2.
TABLE 2
As can be seen from table 2, the phase loss time of the present embodiment is significantly delayed compared to the conventional method, and the delayed phase loss time is 28 hours or more, so that the effective operation time of the reduction furnace is increased, thereby significantly increasing the productivity.
The foregoing is illustrative of the preferred embodiments of this invention, and it is to be understood that the invention is not limited to the precise form disclosed herein and that various other combinations, modifications, and environments may be resorted to, falling within the scope of the concept as disclosed herein, either as described above or as apparent to those skilled in the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (7)
1. A grounding current stepping detection method of a power supply system of a polysilicon reduction furnace is characterized in that maintenance voltages are set in a stepping mode according to the difference of constant current maintenance voltages required by different stages of silicon core growth, each step is provided with a corresponding early warning value and action value of grounding current, and the early warning value is smaller than the action value; when the grounding current corresponding to the maintaining voltage reaches the early warning value, early warning is carried out, and an operator adjusts process parameters according to the early warning to avoid or delay the grounding current from reaching an action value; and when the grounding current corresponding to the maintaining voltage reaches the action value, stopping the operation of the power supply system of the polycrystalline silicon reduction furnace.
2. The method according to claim 1, wherein when the ground current corresponding to the holding voltage reaches the action value and exceeds a predetermined extension time, the operation of the polysilicon reduction furnace power supply system is stopped.
3. The method for detecting the grounding current grading of the power supply system of the polycrystalline silicon reduction furnace according to claim 1, wherein a high-voltage switch electric appliance is arranged in a silicon core grounding loop, and the high-voltage switch electric appliance is closed when the power supply system of the polycrystalline silicon reduction furnace operates normally and is disconnected when the power supply system of the polycrystalline silicon reduction furnace is overhauled.
4. The method for detecting the grounding current stepping of the power supply system of the polycrystalline silicon reduction furnace according to claim 3, wherein the high-voltage switching device comprises an isolation switch.
5. The method for detecting the grounding current grading of the power supply system of the polycrystalline silicon reduction furnace according to claim 1, wherein the rounding of the maintaining voltage is set to be 5 grades which are respectively 520-999V, 1000-1499V, 1500-1999V, 2000-2499V and 2500-2650V.
6. The method for detecting the grounding current grading of the power supply system of the polycrystalline silicon reduction furnace according to claim 5, wherein the action values of the grounding current corresponding to the 5-grade maintaining voltage are as follows in sequence: 601mA, 1157mA, 1500mA, 2314mA and 2893 mA.
7. The method for detecting the grounding current stepping of the power supply system of the polysilicon reduction furnace according to claim 5, wherein an adjustable resistor for detecting the grounding current is arranged in a silicon core grounding loop, and when the maintaining voltage is 1000V or more, the resistance value of the adjustable resistor is fixed; when the voltage is maintained at 520-999V, the resistance value of the adjustable resistor is reduced.
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