Temperature control method of cold hydrogenation reactor

Abstract

The invention provides a temperature control method of a cold hydrogenation reactor, and relates to the technical field of polycrystalline silicon production. An electric heater is arranged in front of the cold hydrogenation reactor, temperature adjustment of the electric heater is controlled by a temperature controller, and the control method comprises the following steps that when blanking and purging of the cold hydrogenation reactor start, the temperature set value of the electric heater is reduced in advance through the temperature controller so as to prevent the temperature from rising; and when blanking and purging of the cold hydrogenation reactor are stopped, the temperature set value of the electric heater is increased in advance through the temperature controller, so that the temperature is prevented from being reduced. The problem of temperature control lag caused by material blanking and gas flow fluctuation can be effectively improved, and the response speed and stability of temperature control are improved.

Description

Technical Field

[0001] The present application relates to the technical field of polysilicon production, and in particular to a temperature control method for a cold hydrogenation reactor. Background Art

[0002] In the polysilicon production process, the temperature stability of the cold hydrogenation reactor is a key factor in ensuring efficient conversion rate. At present, the gas phase feed temperature of the reactor relies on electric heaters for regulation. However, the inventors of the present application have found that during the process of silicon powder feeding and hydrogen purging, the mixed gas flow rate through the electric heater will be significantly affected, thereby causing the problem of increased difficulty in regulating the heater temperature. After the silicon powder is fed, due to the low temperature of the silicon powder itself, when it is mixed with the high-temperature gas in the reactor, it will quickly absorb heat, causing the reactor temperature to drop. At this time, it is difficult for the electric heater to respond quickly and maintain the set temperature, resulting in a temporary drop in the temperature inside the reactor. This temperature fluctuation directly weakens the efficiency and stability of the cold hydrogenation reaction. Summary of the invention

[0003] The embodiment of the present application provides a temperature control method for a cold hydrogenation reactor, which can effectively improve the temperature control lag problem caused by material unloading and gas flow fluctuations, and improve the response speed and stability of temperature control.

[0004] The embodiment of the present application is implemented as follows: The present application provides a temperature control method for a cold hydrogenation reactor, wherein an electric heater is provided in front of the cold hydrogenation reactor, and the temperature of the electric heater is controlled by a temperature controller. The control method comprises the following steps: When the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced in advance through the temperature controller to prevent the temperature from rising; when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased in advance through the temperature controller to prevent the temperature from falling.

[0005] In a possible embodiment, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by 1-5° C. in advance through the temperature controller.

[0006] In a possible embodiment, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by a temperature controller 1 to 4 minutes in advance.

[0007] In a possible embodiment, when the unloading and purging of the cold hydrogenation reactor are stopped, the temperature setting value of the electric heater is increased by 1-5° C. in advance through the temperature controller.

[0008] In a possible embodiment, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased by a temperature controller 1 to 4 minutes in advance.

[0009] In a possible implementation, the control method further comprises: separately and sequentially purging the four legs of the cold hydrogenation reactor for multiple times, with a preset time interval between two adjacent purges.

[0010] In a possible implementation manner, the purge time is 5-10 minutes, and the preset time of the gap is 30-60 minutes.

[0011] In a possible implementation, during silicon powder feeding or hydrogen purging, when the temperature of the cold hydrogenation reactor begins to decrease, the temperature setting value of the electric heater is increased in advance through the temperature controller; as the internal temperature of the cold hydrogenation reactor increases, the temperature setting value of the electric heater is gradually reduced in advance through the temperature controller.

[0012] In a possible implementation, the temperature controller is a PID controller.

[0013] The embodiments of the present application have at least the following beneficial effects: The temperature control method for a cold hydrogenation reactor of the present application uses the mixed gas flow rate affected by silicon powder feeding and hydrogen purging as a feedforward signal, and combines it with the temperature control of a temperature controller. The change in the mixed gas flow rate is predicted by whether the cold hydrogenation reactor is fed and purged, and the set value of the temperature control of the electric heater is adjusted in advance accordingly to offset the effect of the flow change on the temperature, effectively solving the temperature control lag problem caused by material feeding and gas flow fluctuations, and improving the response speed and stability of the temperature control. DETAILED DESCRIPTION Example

[0016] The present embodiment provides a temperature control method for a cold hydrogenation reactor, wherein an electric heater is provided in front of the cold hydrogenation reactor, and the temperature of the electric heater is controlled by a temperature controller, and illustratively, the temperature controller is a PID controller. The inventors of the present application found in their research that when the cold hydrogenation reactor starts to unload and purge, it indicates that the flow rate of the mixed gas flowing through the electric heater decreases; when the unloading and purge operations of the cold hydrogenation reactor stop, it indicates that the flow rate of the mixed gas passing through the electric heater increases accordingly.

[0017] The control method of this embodiment includes the following steps: when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced in advance through the temperature controller to prevent the temperature from rising; when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased in advance through the temperature controller to prevent the temperature from falling. This ensures the stability and continuity of temperature control. This control method can effectively overcome the adverse effects of temperature control lag and ensure the overall stability and efficiency of reactor operation.

[0018] Exemplarily, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by 1-5°C in advance through the temperature controller, for example, the temperature setting value of the electric heater is reduced by 1°C, 2°C, 3°C, 4°C or 5°C in advance.

[0019] Exemplarily, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by the temperature controller 1 to 4 minutes in advance. For example, the temperature setting value of the electric heater is reduced by the temperature controller 1 minute, 2 minutes, 3 minutes or 4 minutes in advance.

[0020] Exemplarily, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased by 1-5°C in advance through the temperature controller, for example, the temperature setting value of the electric heater is increased by 1°C, 2°C, 3°C, 4°C or 5°C in advance.

[0021] Exemplarily, when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased by the temperature controller 1 to 4 minutes in advance. For example, the temperature setting value of the electric heater is increased by the temperature controller 1 minute, 2 minutes, 3 minutes or 4 minutes in advance.

[0022] The temperature control method for a cold hydrogenation reactor of the present application uses the mixed gas flow rate affected by silicon powder feeding and hydrogen purging as a feedforward signal, and combines it with the temperature control of a temperature controller. The change in the mixed gas flow rate is predicted by whether the cold hydrogenation reactor is fed and purged, and the set value of the temperature control of the electric heater is adjusted in advance accordingly to offset the effect of the flow change on the temperature, effectively solving the temperature control lag problem caused by material feeding and gas flow fluctuations, and improving the response speed and stability of the temperature control.

[0023] The control method also includes: purging the four legs of the cold hydrogenation reactor in sequence for multiple times, with a preset time interval between two adjacent purgings.

[0024] Optionally, the purge time is 5-10 minutes, and the preset interval time is 30-60 minutes. The pressure fluctuation amplitude of the cold hydrogenation reactor and the instability of the mixed gas flow through the electric heater can be reduced by purging at intervals.

[0025] Exemplarily, the purge time is 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, and the preset time of the gap is 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0026] Furthermore, during the silicon powder feeding or hydrogen purging process, when the temperature of the cold hydrogenation reactor begins to decrease, the temperature setting value of the electric heater is increased in advance through the temperature controller (to slow down the temperature drop trend caused by the entry of silicon powder); as the internal temperature of the cold hydrogenation reactor increases, the pre-temperature controller gradually lowers the temperature setting value of the electric heater to ensure that the temperature of the cold hydrogenation reactor can be stably maintained within a preset range, thereby achieving efficient and precise temperature control.

[0027] The temperature control method for the cold hydrogenation reactor in the embodiment of the present application combines uniform purging in time periods with dynamic PID temperature control to ensure that during the silicon powder feeding period, even in the face of a sudden temperature drop, the temperature drop trend can be alleviated by pre-adjusting the temperature setting value of the electric heater by the PID controller, and in the subsequent process, the output of the electric heater is gradually optimized according to the actual temperature feedback to maintain the temperature of the cold hydrogenation reactor within a preset range.

[0028] The control method can realize accurate control of the temperature of the cold hydrogenation reactor, ensure that the reaction is carried out under optimal conditions, thereby improving the reaction efficiency; through effective temperature control, ensure that the internal temperature of the cold hydrogenation reactor is always kept within a safe range, prevent the occurrence of overheating; reduce the fluctuation of the internal temperature of the cold hydrogenation reactor, ensure the stability and consistency of product quality; and reduce unnecessary energy consumption and improve energy utilization; reduce the operating temperature of the equipment and reduce the damage of high temperature to the equipment materials, thereby extending the service life of the equipment.

[0029] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A temperature control method for a cold hydrogenation reactor, characterized in that: An electric heater is provided in front of the cold hydrogenation reactor, and the temperature of the electric heater is controlled by a temperature controller. The control method comprises the following steps: When the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced in advance through the temperature controller to prevent the temperature from rising; when the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased in advance through the temperature controller to prevent the temperature from falling.

2. The temperature control method for a cold hydrogenation reactor according to claim 1, characterized in that: When the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by 1-5° C. in advance through the temperature controller.

3. The temperature control method for a cold hydrogenation reactor according to claim 2, characterized in that: When the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is reduced by the temperature controller 1 to 4 minutes in advance.

4. The temperature control method for a cold hydrogenation reactor according to any one of claims 1 to 3, characterized in that: When the cold hydrogenation reactor is stopped from being unloaded and purged, the temperature setting value of the electric heater is increased by 1-5° C. in advance through the temperature controller.

5. The temperature control method for a cold hydrogenation reactor according to claim 4, characterized in that: When the cold hydrogenation reactor is unloaded and purged, the temperature setting value of the electric heater is increased by the temperature controller 1 to 4 minutes in advance.

6. The temperature control method for a cold hydrogenation reactor according to any one of claims 1 to 3, characterized in that: The control method further includes: purging the four legs of the cold hydrogenation reactor in sequence for multiple times, with a preset time interval between two adjacent purges.

7. The temperature control method for a cold hydrogenation reactor according to claim 6, characterized in that: The purge time is 5-10 minutes, and the preset time of the gap is 30-60 minutes.

8. The temperature control method for a cold hydrogenation reactor according to any one of claims 1 to 3, characterized in that: During silicon powder feeding or hydrogen purging, when the temperature of the cold hydrogenation reactor begins to decrease, the temperature setting value of the electric heater is increased in advance through the temperature controller; as the internal temperature of the cold hydrogenation reactor increases, the temperature setting value of the electric heater is gradually reduced in advance through the temperature controller.

9. The temperature control method for a cold hydrogenation reactor according to any one of claims 1 to 3, characterized in that: The temperature controller is a PID controller.