Efficient trichlorosilane synthetic furnace and intelligent temperature control method thereof

Abstract

The invention provides an efficient trichlorosilane synthetic furnace and an intelligent temperature control method thereof. The efficient trichlorosilane synthetic furnace comprises a reactor body and an intelligent temperature control module, the reactor body comprises a shell; the shell comprises a conical area and a cylindrical area; the cylindrical area sequentially comprises a lower-section reaction area, a middle-section reaction area and an upper-section reaction area from bottom to top, and cooling devices are independently arranged on the outer sides of the reaction areas respectively; an internal part is arranged in the lower section reaction area; the intelligent temperature control module comprises a temperature sensor unit, an intelligent control unit and a flow adjusting unit. According to the invention, by arranging the internal part and the intelligent temperature control module, intelligent temperature control is realized, the temperature uniformity of each reaction area in the trichlorosilane synthetic furnace is effectively improved, and the conversion rate of trichlorosilane is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon chemical industry, and in particular to a high-efficiency trichlorosilane synthesis furnace and an intelligent temperature control method thereof. Background Art

[0002] The synthesis of trichlorosilane mainly uses 99% pure silicon powder to react with hydrogen chloride in a fluidized bed reactor at 300-320℃ and 0.1-0.2MPaG pressure. The main reaction is:

[0003]

[0004] This reaction is exothermic, requiring heat to be removed from the synthesis furnace. An earlier approach involved using heat exchange tubes to remove heat from the furnace. This method balanced the furnace temperature, but the long-term impact of silicon powder on the surface of the heat exchange tubes caused wear, leading to leakage of the heat removal medium, contamination of the reactants, and impact on the safe operation of the device.

[0005] Existing synthesis furnaces mostly use jackets to remove heat from the furnace body. The walls near the cooling water are at lower temperatures, while the center, away from the walls, is at higher temperatures. Due to varying degrees of reaction progress in different zones, the amount of heat removal required varies at different heights in the reactor. The lower portion of the reaction zone releases a greater amount of heat, requiring more heat removal. The upper portion requires less heat removal, leading to significant temperature differences between the furnace walls and the center, and between the lower and upper sections. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a high-efficiency trichlorosilane synthesis furnace and an intelligent temperature control method thereof. By disposing internal components in the lower reaction zone of the reactor, the airflow distribution in the synthesis furnace is improved, the temperature at the center of the synthesis furnace is reduced, the temperature uniformity in the reaction area is improved, and the conversion rate of trichlorosilane is thereby increased. An intelligent temperature control module is also provided to monitor the temperature of each reaction zone of the reactor in real time, rationally regulate the cooling water flow rate, and thereby precisely adjust the internal temperature of the reactor, thereby avoiding an increase in thermal stress in the furnace due to regulation hysteresis and improving the service life of the reactor.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a high-efficiency trichlorosilane synthesis furnace, which includes a reactor body and an intelligent temperature control module;

[0009] The reactor body includes a shell; the shell includes a conical area and a cylindrical area; the cylindrical area includes, from bottom to top, a lower reaction area, a middle reaction area, and an upper reaction area, and each reaction area is independently provided with a cooling device on the outside;

[0010] The lower reaction zone is provided with an internal component; the internal component includes a central axis and a guide grid block perpendicular to the central axis; the number of the guide grid blocks is at least two, and they are evenly spaced on the central axis; the shape of the guide grid block includes a circle; the guide grid block is divided into a plurality of square spaces; guide baffle structures are evenly spaced in the square spaces; the angle between the guide baffle structure and the horizontal direction is 40° to 60°;

[0011] The intelligent temperature control module includes a temperature sensor unit, an intelligent control unit and a flow regulation unit; the temperature sensor unit includes temperature sensors respectively arranged in the lower reaction zone, the middle reaction zone and the upper reaction zone; the flow regulation unit includes cooling water flow control valves respectively arranged in the lower reaction zone, the middle reaction zone and the upper reaction zone; the flow regulation unit is connected to the cooling device.

[0012] The high-efficiency trichlorosilane synthesis furnace of the present invention has a cylindrical reactor section divided into a lower reaction zone, a middle reaction zone, and an upper reaction zone. Specially structured internals are installed in the lower reaction zone to promote fluid converging toward the edge, forcing the central high-temperature zone to move toward the edge of the annular reaction zone, thereby shortening the cooling distance and lowering the reaction temperature in the central region of the lower reaction zone. This, in turn, uniformly distributes the temperature within the synthesis furnace and improves the conversion rate of trichlorosilane. Each reaction zone of the high-efficiency trichlorosilane synthesis furnace is independently equipped with a cooling device. The intelligent temperature control module dynamically adjusts and controls the cooling water flow rate of each reaction zone, overcoming the hysteresis of traditional temperature feedback control, achieving active predictive regulation of heat removal demand, improving temperature control accuracy, and thereby increasing the conversion rate of trichlorosilane. The high-efficiency trichlorosilane synthesis furnace of the present invention can achieve a temperature difference of 20°C to 30°C between the center temperature of the core area and the wall surface temperature, while the temperature difference between the center temperature of the core area and the wall surface temperature of the existing trichlorosilane synthesis furnace is 70°C to 100°C. The present invention effectively avoids the increase of thermal stress in the furnace due to regulation hysteresis, thereby increasing the service life of the synthesis furnace equipment and being suitable for large-scale promotion and application.

[0013] In the present invention, the number of temperature sensors respectively arranged in the lower reaction zone, the middle reaction zone and the upper reaction zone is at least one group, and can also be two, three or four groups; the length of the temperature measuring end of the temperature sensor extending into the synthesis furnace is 0.3 to 0.4 times the inner diameter of the synthesis furnace, for example, it can be 0.3 times, 0.32 times, 0.35 times, 0.38 times or 0.4 times, but is not limited to the listed values, and other values not listed within this numerical range are also applicable.

[0014] The angle between the guide baffle structure of the present invention and the horizontal direction is 40° to 60°, for example, it can be 40°, 42°, 45°, 48°, 50°, 55° or 60°, but it is not limited to the listed values. Other values not listed within this numerical range are also applicable.

[0015] The central axis of the present invention has closed ends and circular arc transitions.

[0016] Preferably, a silicon powder outlet is provided at the bottom of the conical region, and a reaction gas inlet is provided on one side of the bottom.

[0017] Preferably, a gas distribution component is provided above the reaction gas inlet.

[0018] Preferably, the gas distribution assembly includes a gas distribution plate and nozzles vertically arranged on the gas distribution plate.

[0019] Preferably, the gas distribution assembly is arranged below the internal part.

[0020] Preferably, the distance between the bottom of the internal part and the gas distribution assembly is 300 to 500 mm, for example, it can be 300 mm, 320 mm, 350 mm, 380 mm, 400 mm, 450 mm or 500 mm, etc., but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0021] The present invention preferably has a distance of 300 to 500 mm between the bottom of the internal component and the gas distribution assembly, so that the gas can be evenly distributed and then move toward the edge through the action of the internal component, forcing the central high-temperature zone to move toward the edge of the annular reaction zone, thereby shortening the cooling distance and reducing the reaction temperature in the central area of the lower reaction zone.

[0022] Preferably, a silicon powder feed port is provided on one side of the columnar region.

[0023] Preferably, the silicon powder feed port is arranged above the inner part.

[0024] Preferably, an air outlet is provided at the top of the columnar region.

[0025] Preferably, the diameter of the central axis is equal at the top and bottom or gradually increases from top to bottom, and the maximum diameter of the central axis is 0.15 to 0.25 times the inner diameter of the columnar region, for example, it can be 0.15 times, 0.18 times, 0.2 times, 0.22 times, 0.24 times or 0.25 times, etc., but is not limited to the listed values, and other values not listed within this numerical range are also applicable.

[0026] The minimum diameter of the central axis is 0.05 to 0.2 times the inner diameter of the columnar region, for example, it can be 0.05 times, 0.08 times, 0.1 times, 0.12 times, 0.14 times, 0.18 times or 0.2 times, etc., but is not limited to the listed values. Other values not listed within this numerical range are also applicable.

[0027] Preferably, the height of the internal part is 0.7 to 1 times the height of the lower reaction zone, for example, it can be 0.7 times, 0.75 times, 0.8 times, 0.85 times, 0.9 times, 0.95 times or 1 times, etc., but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0028] In the present invention, the maximum diameter of the central axis is preferably 0.15 to 0.25 times the inner diameter of the columnar zone, the minimum diameter is 0.05 to 0.2 times the inner diameter of the columnar zone, and the height of the internal component is 0.7 to 1 times the height of the lower reaction zone. This reduces the reaction temperature in the central area of the lower reaction zone without affecting the full reaction process of silicon powder and hydrogen chloride.

[0029] Preferably, the guide baffle structures in adjacent square spaces are perpendicular to each other.

[0030] Preferably, the outer diameters of the upper and lower layers of guide grid blocks are the same.

[0031] Preferably, the guide baffle structures in the same square space in the upper and lower guide grid blocks are perpendicular to each other, that is, when the guide baffle structures in the upper guide grid blocks are arranged horizontally, the guide baffle structures in the lower guide grid blocks are arranged vertically; when the guide baffle structures in the upper guide grid blocks are arranged vertically, the guide baffle structures in the lower guide grid blocks are arranged horizontally, thereby extending the residence time of the reaction gas.

[0032] Preferably, the spacing between the upper and lower layers of guide grid blocks is 400 to 700 mm, for example, it can be 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm or 700 mm, etc., but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0033] Preferably, the thickness of the guide baffle structure is 4 to 8 mm, for example, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 7 mm or 8 mm, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0034] Preferably, the vertical height of the guide baffle structure is 20 to 40 mm, for example, it can be 20 mm, 23 mm, 25 mm, 30 mm, 35 mm, 38 mm or 40 mm, etc., but it is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0035] Preferably, the central shaft is connected to the cylindrical region via a support structure.

[0036] Preferably, the surfaces of the guide grid blocks and the guide baffle structures are coated with a wear-resistant coating.

[0037] Preferably, the cooling device provided in the lower reaction zone comprises a cooling jacket.

[0038] Preferably, the bottom of the cooling jacket is at the same height as the gas distribution assembly, and the top is located below the silicon powder feed port.

[0039] Preferably, the cooling device provided in the middle reaction zone includes a semi-tubular cooling structure.

[0040] Preferably, the cooling device provided in the upper reaction zone comprises a semi-tubular cooling structure.

[0041] The present invention takes into account that in the process of synthesizing trichlorosilane by reacting silicon powder with hydrogen chloride, the lower reaction zone releases a large amount of heat and needs to remove more heat, while the middle reaction zone and the upper reaction zone need to remove less heat. Therefore, a jacket is used for heat removal in the lower reaction zone, and half-tubes are used for heat removal in the middle reaction zone and the upper reaction zone. In addition, the heat exchange area of the upper reaction zone using the half-tubes for heat removal is larger than the heat removal area of the middle reaction zone.

[0042] The semi-tubular cooling structure in the present invention can be any existing semi-tubular cooling structure in the art.

[0043] In a second aspect, the present invention further provides an intelligent temperature control method for a high-efficiency trichlorosilane synthesis furnace as described in the first aspect, the intelligent temperature control method comprising the following steps:

[0044] The temperature sensor unit in the intelligent temperature control module collects the temperature data of each reaction zone in real time and transmits it to the intelligent control unit; after receiving the temperature data of each reaction zone, the intelligent control unit uses a preset algorithm to obtain the cooling water flow data of each reaction zone and transmits it to the flow regulation unit; the flow regulation unit regulates the cooling water flow in the cooling device of each reaction zone.

[0045] Preferably, the step of obtaining the cooling water flow data of each reaction zone using a preset algorithm includes:

[0046] (1) Using non-steady-state multi-physics field coupling simulation technology, based on the synthesis reaction kinetics model of silicon powder and the reaction gas hydrogen chloride, and solving the heat and mass transfer equations simultaneously, a three-dimensional transient reaction-thermodynamic coupling model is established to characterize the nonlinear relationship between the thermal power in different regions and the reactant concentration and temperature gradient;

[0047] (2) Based on the data obtained from the three-dimensional transient reaction-thermodynamic coupling model, the key characteristic parameters are extracted using a sparse regression algorithm to construct a thermal power-reactant concentration-temperature transfer function matrix:

[0048] P(t)=K p C(t)e -β / T(t) +B;

[0049] Where: P is thermal power, W;

[0050] t is the instantaneous time, s;

[0051] C is the reactant concentration, mol / L;

[0052] K P is the dynamic correction coefficient of chemical reaction heat, (J / mol)·(L / s);

[0053] β is the dynamic correction coefficient of temperature, K;

[0054] T is temperature, K;

[0055] B is the dynamic correction coefficient of the system thermal power, W;

[0056] (3) The heat power-reactant concentration-temperature transfer function matrix is embedded in the improved PID algorithm framework, and the gain weights of the proportional, integral, and differential terms are dynamically adjusted according to the reaction process to achieve time-varying parameter self-tuning; and the transfer function is used to predict the heat removal feedforward compensation, combined with the temperature sensor network feedback correction to form a dual-loop control structure; then, by solving the constrained convex optimization problem, the cooling water flow data of each reaction zone is obtained.

[0057] The PID algorithm in the present invention refers to an algorithm for controlling according to the proportion (P), integration (I) and differentiation (D) of the deviation.

[0058] Preferably, the key characteristic parameters in step (2) include temperature, reactant concentration, pressure and flow rate in different regions and at different times within the reactor body.

[0059] The intelligent temperature control method for a high-efficiency trichlorosilane synthesis furnace disclosed in the present invention is simple to operate and convenient to control. First, temperature data of each reaction zone is collected in real time by a temperature sensor unit and transmitted to an intelligent control unit. Then, the intelligent control unit obtains cooling water flow data of each reaction zone through an algorithm model based on the temperature data of each reaction zone. Finally, a flow regulation unit dynamically regulates the cooling water flow in a cooling device of each reaction zone. This method overcomes the hysteresis of traditional temperature feedback control, improves temperature control accuracy, and increases the conversion rate while also extending the service life of the synthesis furnace.

[0060] The internal control logic of the intelligent control unit described in the present invention is to adjust the control strategy based on the temperature data of the temperature sensor unit to derive the working conditions of the synthesis furnace and the change trend of the bed temperature, predict the temperature change in advance, and then adopt an adaptive nonlinear PID control strategy to accurately adjust the cooling water flow of each reaction zone according to the heat removal requirements of the reaction at different reaction stages.

[0061] As a preferred technical solution of the present invention, the intelligent temperature control method includes the following steps:

[0062] The temperature sensor unit in the intelligent temperature control module collects temperature data of each reaction zone in real time and transmits it to the intelligent control unit; after receiving the temperature data of each reaction zone, the intelligent control unit uses a preset algorithm to obtain cooling water flow data of each reaction zone and transmits it to the flow regulation unit; the flow regulation unit regulates the cooling water flow in the cooling device of each reaction zone;

[0063] The step of using a preset algorithm to obtain the cooling water flow data of each reaction zone includes:

[0064] (1) Using non-steady-state multi-physics field coupling simulation technology, based on the synthesis reaction kinetics model of silicon powder and the reaction gas hydrogen chloride, and solving the heat and mass transfer equations simultaneously, a three-dimensional transient reaction-thermodynamic coupling model is established to characterize the nonlinear relationship between the thermal power in different regions and the reactant concentration and temperature gradient;

[0065] (2) Based on the data obtained from the three-dimensional transient reaction-thermodynamic coupling model, the key characteristic parameters, temperature, reactant concentration, pressure and flow rate in different regions and at different times in the reactor body, are extracted using a sparse regression algorithm to construct a thermal power-reactant concentration-temperature transfer function matrix:

[0066] P(t)=K p C(t)e -β / T(t) +B;

[0067] Where: P is thermal power, W;

[0068] t is the instantaneous time, s;

[0069] C is the reactant concentration, mol / L;

[0070] K P is the dynamic correction coefficient of chemical reaction heat, (J / mol)·(L / s);

[0071] β is the dynamic correction coefficient of temperature, K;

[0072] T is temperature, K;

[0073] B is the dynamic correction coefficient of the system thermal power, W;

[0074] (3) The heat power-reactant concentration-temperature transfer function matrix is embedded in the improved PID algorithm framework, and the gain weights of the proportional, integral, and differential terms are dynamically adjusted according to the reaction process to achieve time-varying parameter self-tuning; and the transfer function is used to predict the heat removal feedforward compensation, combined with the temperature sensor network feedback correction to form a dual-loop control structure; then, by solving the constrained convex optimization problem, the cooling water flow data of each reaction zone is obtained.

[0075] Compared with the prior art, the present invention has at least the following beneficial effects:

[0076] (1) The high-efficiency trichlorosilane synthesis furnace provided by the present invention improves the airflow distribution in the synthesis furnace by arranging internal parts in the lower reaction zone of the reactor, thereby reducing the center temperature of the synthesis furnace and improving the conversion rate of trichlorosilane;

[0077] (2) The high-efficiency trichlorosilane synthesis furnace provided by the present invention is provided with an intelligent temperature control module, which can dynamically adjust the temperature of each reaction zone, further improve the conversion rate of trichlorosilane, and increase the service life of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a schematic structural diagram of a high-efficiency trichlorosilane synthesis furnace in Example 1 of the present invention.

[0079] Figure 2 This is a front view of the inner part in Example 1 of the present invention.

[0080] Figure 3 It is a top view of the guide grid block in Example 1 of the present invention.

[0081] Figure 4 It is a cross-sectional view of the guide baffle structure in Example 1 of the present invention.

[0082] Figure 5 This is a schematic diagram of the connection between the central axis and the supporting structure in Example 1 of the present invention.

[0083] Figure 6 This is a temperature distribution cloud diagram calculated by CFD of the high-efficiency trichlorosilane synthesis furnace in Example 1 of the present invention.

[0084] Figure 7 This is a temperature distribution cloud diagram of the trichlorosilane synthesis furnace calculated by CFD in Example 6 of the present invention.

[0085] In the picture:

[0086] 1-shell; 11-conical area; 12-cylindrical area;

[0087] 121-lower reaction zone; 1211-cooling water inlet of lower reaction zone; 1212-cooling water outlet of lower reaction zone;

[0088] 122-middle reaction zone; 1221-middle reaction zone cooling water inlet; 1222-middle reaction zone cooling water outlet;

[0089] 123-upper reaction zone; 1231-upper reaction zone cooling water inlet; 1232-upper reaction zone cooling water outlet;

[0090] 2-internal parts; 21-center axis; 22-guide grid block; 23-guide baffle structure;

[0091] 3-lower reaction zone temperature sensor; 4-middle reaction zone temperature sensor; 5-upper reaction zone temperature sensor; 6-silicon powder outlet; 7-reaction gas inlet;

[0092] 8-gas distribution assembly; 81-gas distribution plate; 82-nozzle;

[0093] 9-Silicon powder feed port; 10-Air outlet; 13-Cooling jacket; 14-Support structure. DETAILED DESCRIPTION

[0094] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0095] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0096] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0097] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0098] Those skilled in the art should understand that the present invention must include necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main invention point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0099] The current temperature regulation method uses PID control, where a thermocouple detects the temperature inside the synthesis furnace, feeds it back to the control system, compares it with the set value, and then adjusts the water flow in the jacket. The problems with this regulation method are:

[0100] 1) Inaccurate temperature control and hysteresis: The thermocouple measurement point location is affected by the inability to capture dynamic temperature field changes. If the measurement point is close to the center of the synthesis furnace, the measured temperature is high, increasing the cooling water flow rate and causing the furnace wall temperature to be low. If the measurement point is close to the furnace wall, the measured temperature is low, resulting in high SiH2Cl2 production. Low cooling water flow rate leads to high temperatures in the center of the synthesis furnace, resulting in high SiHCl4 production.

[0101] 2) Due to the concentration of thermal stress caused by frequent switching of cooling water, the flange near the cooling water jacket is prone to cracking.

[0102] CN215598088U discloses a heat exchanger for a trichlorosilane synthesis furnace. The heat exchanger employs a split design and includes a cooling water supply unit, a steam recovery unit connected to the cooling water supply unit, a sealing connection unit connected to the furnace body, a pressure detection unit for detecting the pressure of the heat exchanger, and an outflow conveying unit for conveying mixed gas within the heat exchanger.

[0103] CN202054615U discloses a cooling system for a trichlorosilane synthesis furnace, comprising: a cooling water inlet pipe, a steam outlet pipe with an opening at the top, an inert gas sleeve filled with inert gas, and a pressure sensing device; the pipe body of the cooling water inlet pipe is located inside the steam outlet pipe; the water inlet of the cooling water inlet pipe extends from the side wall of the steam outlet pipe; the inert gas sleeve is sleeved on the outside of the steam outlet pipe; and the outer wall of the inert gas sleeve is provided with an air inlet and the pressure sensing device.

[0104] CN118026184A discloses a trichlorosilane synthesis furnace and a method for balancing the temperature of the trichlorosilane synthesis furnace. The device comprises: a furnace body comprising an upper furnace body, an intermediate furnace body, and a lower furnace body connected in sequence, the furnace body forming a sealed chamber; a feed port disposed on the furnace wall of the intermediate furnace body near the upper furnace body; a cooling outer jacket mounted on the outer furnace wall of the intermediate furnace body; a faceplate disposed on one end of the intermediate furnace body near the lower furnace body; a hood and a temperature balancing assembly disposed on the faceplate; small holes disposed on the sidewall of the longitudinally extending portion of the temperature balancing assembly for diffusing gas into the furnace body through the holes; a temperature measuring device disposed on the intermediate furnace body; and a raw gas inlet disposed on the lower furnace body. The temperature balancing assembly is installed in the center of the faceplate, and hydrogen is introduced into the reaction center through the temperature balancing assembly. The hydrogen diffuses through the small holes of the temperature balancing assembly to the surrounding area, removing heat from the reaction center and bringing the heat to the area near the outer jacket, thereby achieving a balanced reaction temperature.

[0105] However, none of the aforementioned trichlorosilane synthesis furnaces can achieve intelligent temperature control, and the conversion rate of trichlorosilane needs to be further improved. This application improves the airflow distribution within the synthesis furnace by installing internal components in the lower reaction zone of the reactor, thereby lowering the temperature at the center of the synthesis furnace and improving the temperature uniformity of the reaction area, thereby increasing the conversion rate of trichlorosilane. Furthermore, an intelligent temperature control module is provided to monitor the temperature of each reaction zone in the reactor in real time, rationally regulating the cooling water flow rate, and thus accurately adjusting the internal temperature of the reactor, thereby avoiding the increase in thermal stress in the furnace caused by hysteresis in the regulation and improving the service life of the reactor.

[0106] Example 1

[0107] This embodiment provides a high-efficiency trichlorosilane synthesis furnace, the structural diagram of which is shown in FIG. Figure 1 shown.

[0108] The high-efficiency trichlorosilane synthesis furnace includes a reactor body and an intelligent temperature control module;

[0109] The reactor body includes a shell 1, including a conical zone 11 and a cylindrical zone 12; the inner diameter of the cylindrical zone 12 is 1100 mm, and the total height of the conical zone 11 and the cylindrical zone 12 is 9000 mm; the cylindrical zone 12 includes, from bottom to top, a lower reaction zone 121, a middle reaction zone 122 and an upper reaction zone 123, and a cooling device is independently provided on the outside of each reaction zone.

[0110] The lower reaction zone 121 is provided with an internal part 2; the main view of the internal part 2 is as follows Figure 2 shown.

[0111] The inner part 2 includes a central axis 21 and a guide grid block 22 perpendicular to the central axis 21. The top view of the guide grid block 22 is as shown in FIG. Figure 3 shown.

[0112] The number of the guide grid blocks 22 is three and they are arranged at equal intervals on the central axis 21. The guide grid blocks 22 are circular in shape. All the guide grid blocks 22 have the same diameter. The guide grid blocks 22 are divided into a plurality of square spaces. The guide baffle structures 23 are arranged at equal intervals in the square spaces.

[0113] The intelligent temperature control module includes a temperature sensor unit, an intelligent control unit and a flow regulation unit; the temperature sensor unit includes temperature sensors respectively arranged in the lower reaction zone 121, the middle reaction zone 122 and the upper reaction zone 123; Figure 1 3 is the temperature sensor for the lower reaction zone, 4 is the temperature sensor for the middle reaction zone, and 5 is the temperature sensor for the upper reaction zone. The length of the temperature measuring end of each temperature sensor extending into the synthesis furnace is 0.35 times the inner diameter of the columnar zone 12.

[0114] The flow regulating unit includes cooling water flow control valves respectively arranged in the lower reaction zone 121, the middle reaction zone 122 and the upper reaction zone 123. The flow regulating unit is connected to a cooling device.

[0115] A silicon powder outlet 6 is provided at the bottom of the conical region 11 , and a reaction gas inlet 7 is provided at one side of the bottom.

[0116] A gas distribution component 8 is provided above the reaction gas inlet 7;

[0117] The gas distribution assembly 8 includes a gas distribution plate 81 and a nozzle 82 vertically arranged on the gas distribution plate 81;

[0118] The gas distribution assembly 8 is arranged below the inner part 2;

[0119] The distance between the bottom of the inner part 2 and the gas distribution assembly 8 is 300 mm.

[0120] A silicon powder feed port 9 is provided on one side of the columnar area 12, and the silicon powder feed port 9 is provided above the inner part 2;

[0121] An air outlet 10 is provided at the top of the columnar region 12 .

[0122] The diameter of the central shaft 21 is equal at the top and bottom, and the diameter of the central shaft 21 is 0.2 times the inner diameter of the columnar area 12; the diameter of the guide grid block 22 is the inner diameter of the columnar area 12; the height of the internal part 2 is 0.7 times the height of the lower reaction zone 121.

[0123] The guide baffle structures 23 at the same square space in the upper and lower layers of the guide grid blocks 22 are perpendicular to each other;

[0124] The interval L between the upper and lower layers of guide grid blocks 22 is 500 mm;

[0125] The thickness of the guide baffle structure 23 is 6 mm;

[0126] The cross-sectional view of the guide baffle structure 23 is as follows: Figure 4 The included angle θ between the guide baffle structure 23 and the horizontal direction is 50°; the vertical height d of the guide baffle structure 23 is 30 mm;

[0127] The central axis 21 is connected to the columnar area 12 via the support structure 14. The connection diagram is shown in FIG. Figure 5 shown.

[0128] The surfaces of the guide grid blocks 22 and the guide baffle structures 23 are coated with a wear-resistant coating, such as a ceramic coating.

[0129] The cooling device provided in the lower reaction zone 121 includes a cooling jacket 13;

[0130] The bottom of the cooling jacket 13 is at the same height as the gas distribution assembly 8, and the top is located below the silicon powder feed port 9; Figure 1 In the middle, 1211 is the cooling water inlet of the lower reaction zone, and 1212 is the cooling water outlet of the lower reaction zone.

[0131] The cooling device provided in the middle reaction zone 122 comprises a semi-tubular cooling structure that is wound around the outside of the reactor and rises in a spiral; Figure 1 1221 is the cooling water inlet of the middle reaction zone, and 1222 is the cooling water outlet of the middle reaction zone.

[0132] The cooling device provided in the upper reaction zone 123 includes a semi-tubular cooling structure. Figure 1 In the middle, 1231 is the cooling water inlet of the upper reaction zone, and 1232 is the cooling water outlet of the upper reaction zone.

[0133] This embodiment also provides the intelligent temperature control method of the above-mentioned high-efficiency trichlorosilane synthesis furnace, and the intelligent temperature control method includes the following steps:

[0134] The temperature sensor unit in the intelligent temperature control module collects the temperature data of each reaction zone in real time and transmits it to the intelligent control unit;

[0135] The intelligent control unit receives temperature data from each reaction zone, and when the temperature of the temperature sensor of any reaction zone reaches 290°C, starts the adjustment program, uses a preset algorithm to obtain cooling water flow data for each reaction zone, and transmits it to the flow adjustment unit; when the temperature of the temperature sensor of any reaction zone reaches 350°C, it starts a shutdown signal, transmits the signal to the control valve, and the control valve actuates to close.

[0136] The flow regulating unit adjusts the opening of the cooling water flow control valve of each reaction zone, regulates the cooling water flow in the cooling device of each reaction zone, and stabilizes the temperature of the temperature sensor in the three reaction zones in the range of 290-350°C;

[0137] The step of using a preset algorithm to obtain the cooling water flow data of each reaction zone includes:

[0138] (1) Using non-steady-state multi-physics field coupling simulation technology, based on the synthesis reaction kinetics model of silicon powder and the reaction gas hydrogen chloride, and solving the heat and mass transfer equations simultaneously, a three-dimensional transient reaction-thermodynamic coupling model is established to characterize the nonlinear relationship between the thermal power in different regions and the reactant concentration and temperature gradient;

[0139] (2) Based on the data obtained from the three-dimensional transient reaction-thermodynamic coupling model, the key characteristic parameters, temperature, reactant concentration, pressure and flow rate in different regions and at different times in the reactor body, are extracted using a sparse regression algorithm to construct a thermal power-temperature transfer function matrix:

[0140] P(t)=K p C(t)e -β / T(t) +B;

[0141] Where: P is thermal power, W;

[0142] t is the instantaneous time, s;

[0143] C is the reactant concentration, mol / L;

[0144] K P is the dynamic correction coefficient of chemical reaction heat, (J / mol)·(L / s);

[0145] β is the dynamic correction coefficient of temperature, K;

[0146] T is temperature, K;

[0147] B is the dynamic correction coefficient of the system thermal power, W;

[0148] (3) The thermal power-reactant concentration-transfer function matrix is embedded in the improved PID algorithm framework, and the gain weights of the proportional, integral, and differential terms are dynamically adjusted according to the reaction process to achieve time-varying parameter self-tuning; and the transfer function is used to predict the heat removal feedforward compensation, combined with the temperature sensor network feedback correction to form a dual-loop control structure; then, by solving the constrained convex optimization problem, the cooling water flow data of each reaction zone is obtained.

[0149] From Example 1 and Figure 6It can be seen that the high-efficiency trichlorosilane synthesis furnace provided by the present invention can promote the fluid to move closer to the edge, forcing the central high-temperature zone to move toward the edge of the annular reaction zone, thereby shortening the cooling distance and reducing the reaction temperature in the central area of the lower reaction zone. Simple internal parts are used to make the temperature distribution in the synthesis furnace uniform, thereby improving the conversion rate of trichlorosilane. According to the different heights of the synthesis reaction, different heat removal is required. Different cooling structures are set in the lower reaction zone, the middle reaction zone and the upper reaction zone. In the lower reaction zone, a large amount of heat removal is required, and a cooling jacket is used. In the middle reaction zone and the upper reaction zone, the heat removal is relatively small, and a semi-tubular cooling structure is set to avoid the temperature in the middle reaction zone and the upper reaction zone being too low due to the excessive heat exchange area, and to avoid the increase of thermal stress in the furnace caused by frequent switching of the cooling medium, thereby improving the service life of the equipment.

[0150] Example 2

[0151] This embodiment provides a high-efficiency trichlorosilane synthesis furnace. The high-efficiency trichlorosilane synthesis furnace is the same as that of embodiment 1 except that the distance between the bottom of the internal part and the gas distribution assembly is 200 mm.

[0152] Example 3

[0153] This embodiment provides a high-efficiency trichlorosilane synthesis furnace. The high-efficiency trichlorosilane synthesis furnace is the same as that of embodiment 1 except that the distance between the bottom of the internal part and the gas distribution assembly is 600 mm.

[0154] Combining Example 1 with Examples 2 to 3, it can be seen that in Example 2, due to the small distance between the bottom of the internal component and the gas distribution assembly, the fluid will pass through the internal component at an excessively high speed, resulting in severe wear of the internal component. In Example 3, due to the large distance between the bottom of the internal component and the gas distribution assembly, the fluid in the reaction area is not fully mixed. Due to the side wall effect, the fluid will gather toward the center, resulting in a large amount of heat released by the synthesis reaction in the central area that cannot be removed in time, causing uneven temperature distribution in the synthesis furnace, thereby reducing the conversion rate of trichlorosilane.

[0155] Example 4

[0156] This embodiment provides a high-efficiency trichlorosilane synthesis furnace. The high-efficiency trichlorosilane synthesis furnace is the same as that of embodiment 1 except that the diameter of the central axis is 0.1 times the inner diameter of the columnar region.

[0157] Example 5

[0158] This embodiment provides a high-efficiency trichlorosilane synthesis furnace. The high-efficiency trichlorosilane synthesis furnace is the same as that of embodiment 1 except that the diameter of the central axis is 0.3 times the inner diameter of the columnar region.

[0159] From Example 1 and Examples 4 to 5, it can be seen that a smaller diameter of the central axis will reduce the guiding effect of the central fluid, while a larger diameter will reduce the fluid circulation space, both of which will affect fluid mixing and thus reduce the conversion rate of trichlorosilane.

[0160] Example 6

[0161] This embodiment provides a trichlorosilane synthesis furnace, which is the same as that of embodiment 1 except that the intelligent temperature control module is not provided and the lower reaction zone is not provided with internal parts.

[0162] Since this embodiment does not have an intelligent temperature control module and no internal parts are set in the lower reaction zone, the temperature control will be inaccurate and there will be hysteresis; and there is a large temperature difference between the inner wall of the synthesis furnace and the lower reaction zone, the middle reaction zone and the upper reaction zone.

[0163] The temperature distribution cloud of the high-efficiency trichlorosilane synthesis furnace calculated by CFD in Example 1 is as follows Figure 6 As shown, the temperature distribution cloud of the trichlorosilane synthesis furnace calculated by CFD in Example 6 is as follows: Figure 7 As shown, the temperature unit in the temperature cloud diagram is K. CFD is Computational Fluid Dynamics.

[0164] contrast Figure 6 and Figure 7 It can be seen that in Example 1, the high-efficiency trichlorosilane synthesis furnace provided by the present invention is provided with internal parts in the lower reaction zone and an intelligent temperature control module. Under the same boundary conditions, the high-temperature zone in the axis area is divided into two sub-high-temperature zones, the center temperature of the synthesis furnace is significantly reduced, and the average temperature in the synthesis furnace is more uniform; while in Example 6, there are no internal parts and no intelligent temperature control module. The temperature in the lower reaction zone of the synthesis furnace near the central axis is high, and the temperature in the upper reaction zone of the synthesis furnace is low.

[0165] It should be noted that the present invention uses the above-described embodiments to illustrate the detailed structural features of the present invention. However, the present invention is not limited to these detailed structural features, and this does not mean that the present invention must rely on these detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for selected components, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0166] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

Claims

1. A high-efficiency trichlorosilane synthesis furnace, characterized in that: The high-efficiency trichlorosilane synthesis furnace includes a reactor body and an intelligent temperature control module; The reactor body includes a shell; the shell includes a conical area and a cylindrical area; the cylindrical area includes, from bottom to top, a lower reaction area, a middle reaction area, and an upper reaction area, and each reaction area is independently provided with a cooling device on the outside; The lower reaction zone is provided with an internal component; the internal component includes a central axis and a guide grid block perpendicular to the central axis; the number of the guide grid blocks is at least two, and they are evenly spaced on the central axis; the shape of the guide grid block includes a circle; the guide grid block is divided into a plurality of square spaces; guide baffle structures are evenly spaced in the square spaces; the angle between the guide baffle structure and the horizontal direction is 40° to 60°; The intelligent temperature control module includes a temperature sensor unit, an intelligent control unit and a flow regulation unit; the temperature sensor unit includes temperature sensors respectively arranged in the lower reaction zone, the middle reaction zone and the upper reaction zone; the flow regulation unit includes cooling water flow control valves respectively arranged in the lower reaction zone, the middle reaction zone and the upper reaction zone; the flow regulation unit is connected to the cooling device.

2. The high-efficiency trichlorosilane synthesis furnace according to claim 1, characterized in that: The bottom of the conical area is provided with a silicon powder outlet, and one side of the bottom is provided with a reaction gas inlet; Preferably, a gas distribution component is provided above the reaction gas inlet; Preferably, the gas distribution assembly comprises a gas distribution plate and a nozzle vertically arranged on the gas distribution plate; Preferably, the gas distribution assembly is arranged below the inner part; Preferably, the distance between the bottom of the internal component and the gas distribution assembly is 300 to 500 mm.

3. The high-efficiency trichlorosilane synthesis furnace according to claim 1 or 2, characterized in that: A silicon powder feed port is provided on one side of the columnar area; Preferably, the silicon powder feed port is arranged above the inner part; Preferably, an air outlet is provided at the top of the columnar region.

4. The high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 3, characterized in that: The diameter of the central axis is equal at the top and bottom or gradually increases from top to bottom, the maximum diameter is 0.15 to 0.25 times the inner diameter of the columnar region, and the minimum diameter is 0.05 to 0.2 times the inner diameter of the columnar region.

5. The high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 4, characterized in that: The height of the internal part is 0.7 to 1 times the height of the lower reaction zone.

6. The high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 5, characterized in that: The guide baffle structures in adjacent square spaces are perpendicular to each other; Preferably, the outer diameters of the upper and lower layers of guide grid blocks are the same; Preferably, the guide baffle structures at the same square space in the upper and lower layers of guide grid blocks are perpendicular to each other; Preferably, the interval between the upper and lower layers of guide grid blocks is 400 to 700 mm; Preferably, the thickness of the guide baffle structure is 4 to 8 mm; Preferably, the vertical height of the guide baffle structure is 20-40 mm.

7. The high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 6, characterized in that: The central axis is connected to the cylindrical area via a supporting structure; Preferably, the surfaces of the guide grid blocks and the guide baffle structures are coated with a wear-resistant coating.

8. The high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 7, characterized in that: The cooling device provided in the lower reaction zone includes a cooling jacket; Preferably, the bottom of the cooling jacket is at the same height as the gas distribution assembly, and the top is located below the silicon powder feed port; Preferably, the cooling device provided in the middle reaction zone comprises a semi-tubular cooling structure; Preferably, the cooling device provided in the upper reaction zone comprises a semi-tubular cooling structure.

9. An intelligent temperature control method for a high-efficiency trichlorosilane synthesis furnace, characterized in that: The intelligent temperature control method is applied to the high-efficiency trichlorosilane synthesis furnace according to any one of claims 1 to 8; the intelligent temperature control method comprises the following steps: The temperature sensor unit in the intelligent temperature control module collects the temperature data of each reaction zone in real time and transmits it to the intelligent control unit; after receiving the temperature data of each reaction zone, the intelligent control unit uses a preset algorithm to obtain the cooling water flow data of each reaction zone and transmits it to the flow regulation unit; the flow regulation unit regulates the cooling water flow in the cooling device of each reaction zone.

10. The intelligent temperature control method according to claim 9, characterized in that: The step of using a preset algorithm to obtain the cooling water flow data of each reaction zone includes: (1) Using non-steady-state multi-physics field coupling simulation technology, based on the synthesis reaction kinetics model of silicon powder and the reaction gas hydrogen chloride, and solving the heat and mass transfer equations simultaneously, a three-dimensional transient reaction-thermodynamic coupling model is established to characterize the nonlinear relationship between the thermal power in different regions and the reactant concentration and temperature gradient; (2) Based on the data obtained from the three-dimensional transient reaction-thermodynamic coupling model, the key characteristic parameters are extracted using a sparse regression algorithm to construct a thermal power-reactant concentration-temperature transfer function matrix: P(t)=K p C(t)e -βIT(t) +B; Where: P is thermal power, W; t is the instantaneous time, s; C is the reactant concentration, mol / L; K P is the dynamic correction coefficient of chemical reaction heat, (J / mol)·(L / s); β is the dynamic correction coefficient of temperature, K; T is temperature, K; B is the dynamic correction coefficient of the system thermal power, W; (3) The heat power-reactant concentration-temperature transfer function matrix is embedded in the improved PID algorithm framework, and the gain weights of the proportional, integral, and differential terms are dynamically adjusted according to the reaction process to achieve time-varying parameter self-tuning; and the transfer function is used to predict the heat removal feedforward compensation, combined with the temperature sensor network feedback correction to form a dual-loop control structure; and then the cooling water flow data of each reaction zone is obtained by solving the constrained convex optimization problem; Preferably, the key characteristic parameters in step (2) include temperature, reactant concentration, pressure and flow rate in different regions and at different times within the reactor body.

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