Polysilicon industry reduction furnace feeding system and feeding pressure control method
By eliminating the buffer tank and adopting a bidirectional conveying device and a stability analysis module to monitor and control the feeding pressure in real time, the problem of unstable pressure in the polysilicon reduction furnace was solved, improving production efficiency and safety, and reducing equipment costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INNER MONGOLIA DAQO NEW ENERGY CO LTD
- Filing Date
- 2023-12-27
- Publication Date
- 2026-08-04
AI Technical Summary
In existing polysilicon reduction furnaces, the use of buffer tanks leads to unstable pressure, poses safety hazards, and results in significant losses of trichlorosilane, increasing construction investment and equipment costs and affecting production efficiency.
The buffer tank was eliminated, and a two-way conveying device and a stability control analysis module were adopted. Through a high-purity TCS storage device, a vaporization device, a parameter monitoring module, and a stability control analysis module, the feed pressure was monitored and controlled in real time, a loop control mode was established, and valve control was optimized.
It achieves stable control of feed pressure, reduces trichlorosilane loss, saves equipment costs, improves production efficiency and safety, and simplifies the operation process.
Smart Images
Figure CN117772068B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polycrystalline silicon preparation technology, and in particular to a polycrystalline silicon reduction furnace feeding system and a feeding pressure control method. Background Technology
[0002] In the polysilicon industry, the raw material commonly used in reduction furnaces is trichlorosilane (SiHCl3), a colorless liquid with a pungent odor. The reduction furnace reduces the silicon element in trichlorosilane to pure polysilicon blocks, which are used to manufacture solar cells, integrated circuit chips and other semiconductor devices. The current method of controlling the pressure of gaseous trichlorosilane in the vaporizer is still based on stabilizing the pressure of the buffer tank to ensure a stable flow of liquid trichlorosilane into the vaporizer, which is then heated and vaporized to reach the pressure required by the system. When the pressure of the buffer tank is unstable, it is necessary to replenish or release the pressure, and when the pressure is released, there will be a loss of trichlorosilane. Secondly, the buffer tank is large in volume, and the amount of trichlorosilane stored is higher than the critical amount of major hazard sources. The reduction plant is a densely populated and enclosed place, which poses a great safety hazard. Therefore, the present invention provides a feeding system for a reduction furnace in the polysilicon industry and a feeding pressure control method to solve the above problems. Summary of the Invention
[0003] This invention provides a feeding system and feeding pressure control method for a reduction furnace in the polysilicon industry. Its purpose is to: eliminate the feeding buffer tank of the reduction furnace, save construction investment costs, establish a loop control mode, shorten the process route, save equipment costs, reduce the loss of trichlorosilane due to the buffer tank during pressure replenishment and depressurization, improve production efficiency, and ensure production safety and stability.
[0004] On one hand, the present invention provides a feeding system for a reduction furnace in the polysilicon industry, comprising: A high-purity TCS storage device for storing high-purity liquid trichlorosilane; A vaporization device, whose output end is connected to a reduction furnace, is used to vaporize liquid trichlorosilane, stabilize the pressure of gaseous trichlorosilane and transport it into the reduction furnace. A bidirectional conveying device includes a main pipeline, a reverse branch, and an electric valve. The first end of the main pipeline is connected to the high-purity TCS storage device, and the last end is connected to the vaporization device. The first end of the reverse branch is connected to the middle of the main pipeline, and the last end is connected to the high-purity TCS storage device. The electric valve is used to control the flow rate of liquid trichlorosilane in the main pipeline and the reverse branch. A parameter monitoring module, which is connected to the bidirectional conveying device and is installed on the main pipeline and the reverse branch, is used to acquire various conveying parameter data of the main pipeline and the reverse branch in real time. The stability control analysis module is connected to the bidirectional conveying device and the parameter monitoring module. It is used to pre-establish a stability control analysis model and input the detected conveying parameter data into the model for analysis to obtain the ideal opening degree of the electric valve at the reverse branch.
[0005] According to the present invention, a polysilicon reduction furnace feeding system is provided, wherein the high-purity TCS storage device comprises: The tank contains a storage space for high-purity liquid trichlorosilane, and the outside of the tank is wrapped with an insulation layer to store the liquid trichlorosilane and maintain its temperature stability. A liquid level sensor is installed inside the tank to monitor changes in the liquid level inside the tank in real time and transmit the monitoring data to the stability analysis module. An outlet valve, located at the outlet end of the tank, is used to control the outflow of liquid trichlorosilane from the tank. An inlet valve, located at the inlet end of the tank, is used to control the flow of liquid trichlorosilane into the tank.
[0006] According to the polysilicon industry reduction furnace feeding system provided by the present invention, the high-purity TCS storage device further includes a temperature monitoring unit for real-time monitoring of the temperature data of liquid trichlorosilane in the tank, and simultaneously transmitting the real-time temperature data to the stability analysis module.
[0007] According to the present invention, a polysilicon reduction furnace feeding system is provided, wherein the vaporization device comprises: A vaporizer, whose input end is connected to the main pipeline and whose output end is connected to the reduction furnace, is used to receive liquid trichlorosilane from the main pipeline and to transport the vaporized gaseous trichlorosilane to the reduction furnace. The LPS unit, which is connected to the vaporizer, is used to provide low-pressure steam inside the vaporizer to heat the liquid trichlorosilane and convert it into gaseous trichlorosilane. The LPC unit, connected to the vaporizer, provides low-pressure condensate to the vaporizer and recovers heat during the conversion process.
[0008] According to the present invention, a polysilicon reduction furnace feeding system is provided, wherein the bidirectional conveying device comprises: The main pipeline has one end connected to the outlet valve and the other end connected to the vaporizer input, which is used to establish a passage between the tank and the vaporizer; a branch node is provided in the middle of the main pipeline; The reverse branch is connected at one end to the branch node and at the other end to the inlet valve, and is used to establish a passage between the main pipeline and the inlet valve; A pump set, comprising a pump body, a pump shaft, and a motor; the pump body is disposed on the main pipeline and between the outlet valve and the diversion node; the pump shaft is connected to the pump body via a seal, and the motor drives the pump shaft to rotate for conveying liquid trichlorosilane; The sealing element is disposed in the sealing cavity between the pump shaft and the pump body to ensure the sealing performance of liquid trichlorosilane during the transportation process; A first electric valve is installed on the main pipeline and between the outlet valve and the pump set to control the flow rate of liquid trichlorosilane flowing out of the outlet valve so that it reaches the rated capacity of the pump set. The second electric valve is located on the main pipeline and between the pump set and the branch node, and is used to control the flow rate of liquid trichlorosilane delivered by the pump set to the main pipeline and the reverse branch. The third electric valve, located on the reverse branch, is used to control the flow rate of liquid trichlorosilane supplied from the pump unit to the inlet valve.
[0009] According to the present invention, a polysilicon reduction furnace feeding system is provided, wherein the parameter monitoring module includes: A main flow meter is installed on the main pipeline between the branching node and the vaporizer to obtain the current flow data of the main pipeline. A branch flow meter, which is installed on the reverse branch, is used to obtain the current flow data of the reverse branch; An inlet flow meter is installed at the input end of the vaporizer to obtain the current flow data at the input end of the vaporizer. A main pressure gauge is installed on the main pipeline between the branch node and the vaporizer to obtain the current pressure data of the main pipeline. An inlet pressure gauge is installed at the input end of the vaporizer to obtain the current pressure data at the input end of the vaporizer. The front-end aggregation unit is connected to the main flow meter, the branch flow meter, the inlet flow meter, the main pressure gauge, and the inlet pressure gauge, and is used to aggregate the detected parameter data in real time.
[0010] According to the present invention, a polysilicon reduction furnace feeding system is provided, wherein the stability control and analysis module includes: The model analysis unit is connected to the front-end aggregation unit and has a preset stability analysis model. The current parameters data are aggregated and substituted into the stability analysis model for calculation to obtain the scheduling analysis results of each valve. A valve control unit, which is electrically connected to the model analysis unit and the third electric valve, is used to control the opening degree of each valve according to the scheduling analysis results; An abnormal alarm unit, which is connected to the front-end aggregation unit, is used to determine the difference between the current parameter data and the parameter data at the previous moment, determine whether a leak has occurred, and issue an alarm accordingly.
[0011] On the other hand, the present invention provides a method for controlling the feed pressure of a reduction furnace in the polysilicon industry, based on a polysilicon reduction furnace feeding system, comprising the following steps: Step 1: Start the system; open the first, second, and third electric valves to the preset initial opening degree, start the pump set, and ensure that the liquid trichlorosilane in the main pipeline is delivered normally; Step 2, monitoring parameters; real-time monitoring of various system parameters using the main flow meter, the branch flow meter, the inlet flow meter, the main pressure gauge, and the inlet pressure gauge; Step 3, stability control analysis; the stability control analysis model is established in advance, and the monitored parameter data is substituted into the stability control analysis model to perform stability control analysis and generate the ideal opening value of the third electric valve.
[0012] Step four, valve control; based on the stability analysis results, adjust the opening of the third electric valve to stabilize the pressure at the input end of the vaporizer.
[0013] Step 5, abnormal alarm; monitor the changes of various parameter data in real time, determine the differences between the current parameter data and the previous parameter data, determine whether a leak has occurred, and issue an alarm accordingly.
[0014] The beneficial effects provided by this invention are as follows: 1. Establishment of stability control analysis model: Based on the characteristics of the feeding system of the reduction furnace in the polysilicon industry, a stability control analysis model is established, which can accurately reflect the relationship between system parameters and provide strong support for feeding pressure control.
[0015] 2. Real-time monitoring and control: By monitoring various system parameters in real time, such as flow rate, pressure, and temperature, abnormal situations can be detected and adjustments can be made in a timely manner to ensure stable control of the feed pressure.
[0016] 3. Valve control optimization: Eliminating the feed buffer tank of the reduction furnace saves construction investment costs, reduces the safety risks caused by the presence of the buffer tank, and adopts a design loop to achieve precise control of feed pressure, shortens the process route, saves equipment costs, and solves the loss of trichlorosilane due to the pressure replenishment and depressurization of the buffer tank.
[0017] 4. Abnormal alarm function: Real-time monitoring of changes in various parameter data. When an abnormal situation is detected, an alarm is promptly triggered and the operator is prompted to handle the situation, ensuring production safety and stability.
[0018] 5. Easy to operate: The polysilicon industry reduction furnace feeding system and feeding pressure control method of the present invention are easy to operate, easy to achieve automated control, and improve production efficiency.
[0019] In summary, the polysilicon industry reduction furnace feeding system and feeding pressure control method provided by this invention have advantages such as stable control analysis model establishment, real-time monitoring and control, valve control optimization, abnormal alarm function and simple operation, which can improve production efficiency and ensure production safety and stability. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of a polysilicon reduction furnace feeding system provided by the present invention; Figure 2 This is a schematic diagram of a method for controlling the feed pressure of a reduction furnace in the polysilicon industry, provided by the present invention. Reference numerals: 1. Tank; 2. Outlet valve; 3. Inlet valve; 4. Vaporizer; 5. LPS unit; 6. LPC unit; 7. Main pipeline; 8. Reverse branch; 9. Pump set; 10. First solenoid valve; 11. Second solenoid valve; 12. Third solenoid valve; 13. Main flow meter; 14. Branch flow meter; 15. Inlet flow meter; 16. Main pressure gauge; 17. Inlet pressure gauge; 18. Reduction furnace; 19. Diversion node. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0023] In one embodiment, see Figure 1 A polysilicon reduction furnace feeding system, comprising: A high-purity TCS storage device for storing high-purity liquid trichlorosilane; The vaporization device, whose output end is connected to the reduction furnace 18, is used to vaporize liquid trichlorosilane, stabilize the pressure of gaseous trichlorosilane and transport it into the reduction furnace 18. The bidirectional conveying device includes a main pipeline 7, a reverse branch 8, and an electric valve. The first end of the main pipeline 7 is connected to a high-purity TCS storage device, and the last end is connected to a vaporization device. The first end of the reverse branch 8 is connected to the middle of the main pipeline 7, and the last end is connected to the high-purity TCS storage device. The electric valve is used to control the flow rate of liquid trichlorosilane in the main pipeline 7 and the reverse branch 8. The parameter monitoring module, which is connected to the bidirectional conveying device, is installed on the main pipeline 7 and the reverse branch 8, and is used to acquire various conveying parameter data of the main pipeline 7 and the reverse branch 8 in real time. The stability control analysis module, which is connected to the bidirectional conveying device and the parameter monitoring module, is used to pre-establish a stability control analysis model and input the detected conveying parameter data into the model for analysis to obtain the ideal opening degree of the eight electric valves in the reverse branch.
[0024] The beneficial effects of the above embodiments are: 1. Improve production efficiency: Through a bidirectional conveying device and parameter monitoring module, the system can adjust the flow rate and pressure of liquid trichlorosilane in real time through the loop, ensuring the stability and efficiency of the production process.
[0025] 2. Reduced energy consumption: The stability analysis module can adjust the opening of the electric valve based on real-time data, thereby optimizing energy consumption and reducing production costs.
[0026] 3. Improved product quality: The high-purity TCS storage device ensures the high purity of liquid trichlorosilane, thereby improving the quality of polycrystalline silicon products.
[0027] 4. Enhance system stability: Through parameter monitoring and stability control analysis, the system can promptly identify and resolve potential problems, ensuring stable system operation.
[0028] To further optimize the above embodiments, please refer to Figure 1 The high-purity TCS storage device includes: Tank 1 has a storage space for high-purity liquid trichlorosilane inside. Tank 1 is wrapped with an insulation layer to store liquid trichlorosilane and maintain its temperature stability. A liquid level sensor is installed inside the tank 1 to monitor the changes in the liquid level inside the tank 1 in real time and transmit the monitoring data to the stability analysis module; Outlet valve 2, which is located at the outlet end of tank 1, is used to control the outflow of liquid trichlorosilane from tank 1; The inlet valve 3 is located at the inlet end of the tank 1 and is used to control the flow of liquid trichlorosilane into the tank 1.
[0029] It should be noted that both outlet valve 2 and inlet valve 3 are equipped with sealing structures to prevent leakage; the liquid level sensor can obtain the current liquid level of liquid trichlorosilane in real time; the design of the high-purity TCS storage device takes into account multiple aspects such as the storage of liquid trichlorosilane, temperature stability, liquid level monitoring, and sealing performance; the high-purity liquid trichlorosilane storage space inside tank 1 can ensure the purity and stability of the substance during storage; the insulation layer can effectively maintain the temperature stability of liquid trichlorosilane and reduce its impact from external temperature fluctuations; the liquid level sensor can monitor the liquid level changes in tank 1 in real time and transmit the monitoring data to the stability analysis module to realize real-time monitoring and data analysis of the substance; the outlet valve 2 and inlet valve 3 can control the inflow and outflow of liquid trichlorosilane to ensure its safety and controllability during storage and use; the sealing structure can effectively prevent leakage and ensure the safety and environmental friendliness of the substance during use.
[0030] To further optimize the above embodiments, please refer to Figure 1 The high-purity TCS storage device also includes a temperature monitoring unit, which is used to monitor the temperature data of liquid trichlorosilane in tank 1 in real time, and transmit the real-time temperature data to the stability analysis module.
[0031] It should be noted that the monitoring principle of the temperature monitoring unit is based on existing technology and will not be elaborated upon. Temperature changes affect the vapor pressure and vaporization rate of liquid trichlorosilane. The higher the temperature, the greater the vapor pressure of liquid trichlorosilane. This means that at higher temperatures, liquid trichlorosilane is more likely to convert into a gaseous state, making the vaporization process more rapid. At the same time, the increase in temperature can accelerate the average kinetic energy of liquid trichlorosilane molecules, making it more likely to overcome surface tension and other interaction forces to change from a liquid to a gaseous state. Therefore, as the temperature increases, the vaporization rate increases.
[0032] To further optimize the above embodiments, please refer to Figure 1 The vaporization device includes: Vaporizer 4, whose input end is connected to the main pipeline 7 and whose output end is connected to the reduction furnace 18, is used to receive liquid trichlorosilane from the main pipeline 7 and transport the vaporized gaseous trichlorosilane to the reduction furnace 18. LPS unit 5, which is connected to vaporizer 4, is used to provide low-pressure steam inside vaporizer 4 to heat liquid trichlorosilane and convert it into gaseous trichlorosilane. LPC unit 6, which is connected to vaporizer 4, is used to provide low-pressure condensate water inside vaporizer 4 to recover heat during the conversion process.
[0033] It should be noted that the LPS unit 5 and LPC unit 6 cause pressure changes at the inlet of the vaporizer 4 during operation, which is also the reason for the need for adjustment. The vaporization device also includes a temperature control unit, which monitors the temperature of the vaporizer 4 through sensors and adjusts the output of the LPS unit 5 and LPC unit 6 as needed to maintain a stable temperature inside the vaporizer 4. In addition, the vaporization device is also equipped with a safety valve and a pressure regulator to ensure the safe and stable operation of the system.
[0034] To further optimize the above embodiments, please refer to Figure 1 The bidirectional conveying device includes: The main pipeline 7 is connected to the outlet valve 2 at one end and to the input end of the vaporizer 4 at the other end, and is used to establish a passage between the tank 1 and the vaporizer 4; a branch node 19 is provided in the middle of the main pipeline 7. Reverse branch 8, one end of which is connected to the branch node 19 and the other end of which is connected to the inlet valve 3, is used to establish a passage between the main pipeline 7 and the inlet valve 3; Pump set 9 includes a pump body, a pump shaft and a motor; the pump body is set on the main pipeline 7 and is located between the outlet valve 2 and the diversion node 19; the pump shaft is connected to the pump body through a seal and the motor drives the pump shaft to rotate for conveying liquid trichlorosilane. A sealing element, located in the sealing cavity between the pump shaft and the pump body, is used to ensure the sealing of liquid trichlorosilane during the transportation process; The first electric valve 10 is installed on the main pipeline 7 and between the outlet valve 2 and the pump group 9. It is used to control the flow rate of liquid trichlorosilane flowing out of the outlet valve 2 so that it reaches the rated standard of the pump group 9. The second electric valve 11 is installed on the main pipeline 7 and between the pump set 9 and the branch node 19, and is used to control the flow rate of liquid trichlorosilane delivered by the pump set 9 to the main pipeline 7 and the reverse branch 8. The third electric valve 12, which is located on the reverse branch 8, is used to control the flow rate of liquid trichlorosilane delivered from the pump unit 9 to the inlet valve 3.
[0035] It should be noted that the function of the main pipeline 7 is to transport the liquid trichlorosilane in the tank 1 to the shell side of the vaporizer 4, while the function of the reverse branch 8 is to transport the liquid trichlorosilane in the main pipeline 7 back to the tank 1. This allows for the regulation of the flow and pressure of the main pipeline 7 while preventing the leakage of raw materials, thus avoiding the dangerous problems caused by using a buffer tank to regulate pressure in traditional methods. The working principles of the pump set 9 and each electric valve are existing technologies and do not need to be explained.
[0036] To further optimize the above embodiments, please refer to Figure 1 The parameter monitoring module includes: The main flow meter 13 is installed on the main pipeline 7 between the branch node 19 and the vaporizer 4 to obtain the current flow data of the main pipeline 7. Branch flow meter 14 is installed on the reverse branch 8 and is used to obtain the current flow data of the reverse branch 8; The inlet flow meter 15 is installed at the input end of the vaporizer 4 and is used to obtain the current flow data at the input end of the vaporizer 4. The main line pressure gauge 16 is installed on the main line 7 between the branch node 19 and the vaporizer 4 to obtain the current pressure data of the main line 7. The inlet pressure gauge 17 is located at the input end of the vaporizer 4 and is used to obtain the current pressure data at the input end of the vaporizer 4. The front-end aggregation unit is connected to the main flow meter 13, branch flow meter 14, inlet flow meter 15, main pressure gauge 16, and inlet pressure gauge 17 for real-time aggregation of various detected parameter data.
[0037] It should be noted that the front-end aggregation unit and each monitoring element can be wirelessly connected; this embodiment can monitor various parameter data during the operation of the vaporizer 4 in real time, improving the stability and safety of the vaporizer 4 operation; at the same time, the front-end aggregation unit and each monitoring element can be wirelessly connected, which facilitates installation and maintenance and reduces costs.
[0038] To further optimize the above embodiments, please refer to Figure 1 The stability control analysis module includes: The model analysis unit is connected to the front-end aggregation unit. It has a preset stability control analysis model. The current parameters collected are substituted into the stability control analysis model for calculation to obtain the scheduling analysis results of each valve. The valve control unit, which is electrically connected to the model analysis unit and the third electric valve 12, is used to control the opening degree of each valve according to the scheduling analysis results; The abnormal alarm unit is connected to the front-end aggregation unit. It is used to determine the difference between the current parameter data and the parameter data at the previous moment, determine whether a leak has occurred, and issue an alarm accordingly.
[0039] The specific explanation of the stability control analysis model will be described in the following methods. The beneficial effect of this embodiment is that, through the stability control analysis module, the scheduling analysis results of each valve can be acquired and analyzed in real time, and the opening degree of each valve can be controlled according to the scheduling analysis results to ensure stable system operation. Simultaneously, the abnormal alarm unit can promptly detect and alarm abnormal situations such as leakage, improving the safety and reliability of the system. In this embodiment, the stability control analysis model is a complex mathematical model. By calculating and analyzing various parameters of the system, key information such as the ideal opening degree of each valve can be obtained. This information is of great significance for controlling the valve opening degree and maintaining stable system operation.
[0040] In one embodiment, see Figure 2 A method for controlling the feeding pressure of a polysilicon reduction furnace 18, based on the aforementioned polysilicon reduction furnace 18 feeding system, includes the following steps: Step 1: Start the system; open the first electric valve 10, the second electric valve 11 and the third electric valve 12 to the preset initial opening, start the pump group 9, and ensure that the liquid trichlorosilane in the main pipeline 7 is delivered normally. Step 2, monitor parameters; monitor various system parameters in real time using the main flow meter 13, branch flow meter 14, inlet flow meter 15, main pressure gauge 16, and inlet pressure gauge 17; Step 3, stability control analysis; a stability control analysis model is established in advance, and the monitored parameter data are substituted into the stability control analysis model to perform stability control analysis and generate the ideal opening value of the third electric valve 12.
[0041] Step 4, valve control; based on the stability analysis results, adjust the opening of the third electric valve 12 to stabilize the pressure at the input end of the vaporizer 4.
[0042] Step 5, abnormal alarm; monitor the changes of various parameter data in real time, determine the differences between the current parameter data and the previous parameter data, determine whether a leak has occurred, and issue an alarm accordingly.
[0043] On the other hand, the present invention provides a method for controlling the feeding pressure of a polysilicon reduction furnace 18, based on a polysilicon reduction furnace 18 feeding system, comprising the following steps: Step 1: Start the system; open the first electric valve 10, the second electric valve 11 and the third electric valve 12 to the preset initial opening, start the pump group 9, and ensure that the liquid trichlorosilane in the main pipeline 7 is delivered normally. Step 2, monitor parameters; monitor various system parameters in real time using the main flow meter 13, branch flow meter 14, inlet flow meter 15, main pressure gauge 16, and inlet pressure gauge 17; Step 3, stability control analysis; a stability control analysis model is established in advance, and the monitored parameter data are substituted into the stability control analysis model to perform stability control analysis and generate the ideal opening value of the third electric valve 12.
[0044] Step 4, valve control; based on the stability analysis results, adjust the opening of the third electric valve 12 to stabilize the pressure at the input end of the vaporizer 4.
[0045] Step 5, abnormal alarm; monitor the changes of various parameter data in real time, determine the differences between the current parameter data and the previous parameter data, determine whether a leak has occurred, and issue an alarm accordingly.
[0046] The beneficial effects of the above embodiments are as follows: 1. By starting the system, monitoring parameters, performing stability analysis, controlling valves, and triggering alarms, stable control of the feed pressure of the reduction furnace 18 in the polysilicon industry was achieved, thereby improving production efficiency.
[0047] 2. The application of the stability analysis model enables the system to calculate and generate the ideal opening value of the third electric valve 12 based on the real-time monitored parameter data, thereby realizing the automatic adjustment of the system.
[0048] 3. The acquisition of the ideal pressure data P3 of the reverse branch 8 enables the system to adjust the opening of the third electric valve 12 based on this data, further improving the system's stability and production efficiency.
[0049] 4. Real-time monitoring of abnormal alarms enables the system to detect and handle abnormal situations in a timely manner, ensuring production safety.
[0050] In summary, the feeding pressure control method for the polysilicon reduction furnace 18 in this embodiment has advantages such as automation, high efficiency, stability, and safety.
[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A polysilicon industry reduction furnace feed system, characterized by, include: A high-purity TCS storage device for storing high-purity liquid trichlorosilane; A vaporization device, whose output end is connected to a reduction furnace, is used to vaporize liquid trichlorosilane, stabilize the pressure of gaseous trichlorosilane and transport it into the reduction furnace. A bidirectional conveying device includes a main pipeline, a reverse branch, and an electric valve. The first end of the main pipeline is connected to the high-purity TCS storage device, and the last end is connected to the vaporization device. The first end of the reverse branch is connected to the middle of the main pipeline, and the last end is connected to the high-purity TCS storage device. The electric valve is used to control the flow rate of liquid trichlorosilane in the main pipeline and the reverse branch. A parameter monitoring module, which is connected to the bidirectional conveying device and is installed on the main pipeline and the reverse branch, is used to acquire various conveying parameter data of the main pipeline and the reverse branch in real time. The stability control analysis module is connected to the bidirectional conveying device and the parameter monitoring module. It is used to pre-establish a stability control analysis model and input the detected conveying parameter data into the model for analysis to obtain the ideal opening degree of the electric valve at the reverse branch. The transmission parameter data includes the ideal pressure data at the vaporizer input, the current flow rate data of the main pipeline, the current pressure data at the vaporizer input, the ideal pressure data of the reverse branch, the density of liquid trichlorosilane, the acceleration due to gravity, the height data at the second solenoid valve, the height data at the vaporizer input, the height data at the inlet valve, the ideal flow rate data of the reverse branch, the cross-sectional area of the reverse branch, the conversion coefficient between flow rate and pressure in the reverse branch, the ideal velocity data at the vaporizer input, the current velocity data of the main pipeline, the current velocity data of the vaporizer input, the ideal velocity data of the reverse branch, the flow coefficient of the third solenoid valve, and the characteristic constant of the third solenoid valve. Substituting the various transmission parameter data into the stability analysis model, the ideal opening degree d of the third electric valve is calculated, and the valve control unit controls the opening degree of the third electric valve to be at the ideal opening degree d.
2. A polysilicon industry reduction furnace feed system as claimed in claim 1, wherein, The high-purity TCS storage device includes: The tank contains a storage space for high-purity liquid trichlorosilane, and the outside of the tank is wrapped with an insulation layer to store the liquid trichlorosilane and maintain its temperature stability. A liquid level sensor is installed inside the tank to monitor changes in the liquid level inside the tank in real time and transmit the monitoring data to the stability analysis module. An outlet valve, located at the outlet end of the tank, is used to control the outflow of liquid trichlorosilane from the tank. An inlet valve, located at the inlet end of the tank, is used to control the flow of liquid trichlorosilane into the tank.
3. A polysilicon industry reduction furnace feed system as claimed in claim 2, wherein, The high-purity TCS storage device also includes a temperature monitoring unit, which is used to monitor the temperature data of liquid trichlorosilane in the tank in real time, and transmit the real-time temperature data to the stability analysis module.
4. A polysilicon industry reduction furnace feed system as claimed in claim 3, wherein, The vaporization device includes: A vaporizer, whose input end is connected to the main pipeline and whose output end is connected to the reduction furnace, is used to receive liquid trichlorosilane from the main pipeline and to transport the vaporized gaseous trichlorosilane to the reduction furnace. The LPS unit, which is connected to the vaporizer, is used to provide low-pressure steam inside the vaporizer to heat the liquid trichlorosilane and convert it into gaseous trichlorosilane. The LPC unit, connected to the vaporizer, provides low-pressure condensate to the vaporizer and recovers heat during the conversion process.
5. A polysilicon industry reduction furnace feed system as claimed in claim 4, wherein, The bidirectional conveying device includes: The main pipeline has one end connected to the outlet valve and the other end connected to the vaporizer input, which is used to establish a passage between the tank and the vaporizer; a branch node is provided in the middle of the main pipeline; The reverse branch is connected at one end to the branch node and at the other end to the inlet valve, and is used to establish a passage between the main pipeline and the inlet valve; A pump set, comprising a pump body, a pump shaft, and a motor; the pump body is disposed on the main pipeline and between the outlet valve and the diversion node; the pump shaft is connected to the pump body via a seal, and the motor drives the pump shaft to rotate for conveying liquid trichlorosilane; The sealing element is disposed in the sealing cavity between the pump shaft and the pump body to ensure the sealing performance of liquid trichlorosilane during the transportation process; A first electric valve is installed on the main pipeline and between the outlet valve and the pump set to control the flow rate of liquid trichlorosilane flowing out of the outlet valve so that it reaches the rated capacity of the pump set. The second electric valve is located on the main pipeline and between the pump set and the branch node, and is used to control the flow rate of liquid trichlorosilane delivered by the pump set to the main pipeline and the reverse branch. The third electric valve, located on the reverse branch, is used to control the flow rate of liquid trichlorosilane supplied from the pump unit to the inlet valve.
6. A polysilicon industry reduction furnace feed system as claimed in claim 5, wherein, The parameter monitoring module includes: A main flow meter is installed on the main pipeline between the branching node and the vaporizer to obtain the current flow data of the main pipeline. A branch flow meter, which is installed on the reverse branch, is used to obtain the current flow data of the reverse branch; An inlet flow meter is installed at the input end of the vaporizer to obtain the current flow data at the input end of the vaporizer. A main pressure gauge is installed on the main pipeline between the branch node and the vaporizer to obtain the current pressure data of the main pipeline. An inlet pressure gauge is installed at the input end of the vaporizer to obtain the current pressure data at the input end of the vaporizer. The front-end aggregation unit is connected to the main flow meter, the branch flow meter, the inlet flow meter, the main pressure gauge, and the inlet pressure gauge, and is used to aggregate the detected parameter data in real time.
7. A polysilicon industry reduction furnace feed system as claimed in claim 6, wherein, The stability analysis module includes: The model analysis unit is connected to the front-end aggregation unit and has a preset stability analysis model. The current parameters data are aggregated and substituted into the stability analysis model for calculation to obtain the scheduling analysis results of each valve. A valve control unit, which is electrically connected to the model analysis unit and the third electric valve, is used to control the opening degree of each valve according to the scheduling analysis results; An abnormal alarm unit, which is connected to the front-end aggregation unit, is used to determine the difference between the current parameter data and the parameter data at the previous moment, determine whether a leak has occurred, and issue an alarm accordingly.
8. A method for feed pressure control of a reduction furnace in a polysilicon industry, based on the system of any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Start the system; open the first, second, and third electric valves to the preset initial opening degree, start the pump set, and ensure that the liquid trichlorosilane in the main pipeline is delivered normally; Step 2: Parameter monitoring; Real-time monitoring of various system parameters using main flow meters, branch flow meters, inlet flow meters, main pressure gauges, and inlet pressure gauges; Step 3, stability control analysis; the stability control analysis model is established in advance, and the monitored parameter data is substituted into the stability control analysis model to perform stability control analysis and generate the ideal opening value of the third electric valve; Step 4, valve control; based on the stability analysis results, adjust the opening of the third electric valve to stabilize the pressure at the input end of the vaporizer; Step 5, abnormal alarm; monitor the changes of various parameter data in real time, determine the differences between the current parameter data and the previous parameter data, determine whether a leak has occurred, and issue an alarm accordingly.