Polycrystalline silicon cold hydrogenation heat exchange system

Abstract

The utility model discloses a polycrystalline silicon cold hydrogenation heat exchange system, and relates to the technical field of polycrystalline silicon cold hydrogenation, according to the polycrystalline silicon cold hydrogenation heat exchange system provided by the utility model, a heat exchange tube in a secondary heat exchanger is an internally corrugated externally threaded tube, and after mixed gas enters the secondary heat exchanger, the mixed gas has a turbulent flow effect and takes away silicon powder adsorbed on the tube wall. When a heat exchange tube in the prior art is a straight tube, airflow basically passes through the middle of the straight tube after flowing down and does not take away silicon powder adsorbed on the tube wall; according to the inner-corrugated and outer-threaded pipe, after air flow enters the inner-corrugated and outer-threaded pipe, the air flow flows up and down along the corrugations, the silicon powder adsorbed on the pipe wall is knocked off and taken away, the probability that the silicon powder is adsorbed on the inner wall of the heat exchange pipe is reduced, and the service life of the heat exchange pipe is prolonged. Therefore, the probability that the flux of the heat exchange tube is reduced and the heat exchange effect of the heat exchange tube is reduced due to the fact that the silicon powder is adsorbed on the inner wall of the heat exchange tube is reduced, and the service life of the heat exchange tube is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon cold hydrogenation, and more specifically to a polysilicon cold hydrogenation heat exchange system. Background Art

[0002] At present, the process technology used in the production of polysilicon in my country is basically the modified Siemens method. Polysilicon produced by this technology accounts for more than 80% of the total national output. An important link in the modified Siemens method technology is cold hydrogenation. Cold hydrogenation is to mix and heat hydrogen and silicon tetrachloride, and react with silicon powder in a fluidized bed reactor at 530℃-560℃ and 2.5MPa-3.0MPa for endothermic reaction: 3SiCl4+2H2+Si→4SiHCl3. This reaction requires the addition of a certain proportion of catalyst to increase the conversion rate. The tail gas after the reaction needs to be heat recovered, dusted, washed, and condensed to obtain chlorosilane products, and finally sent to the distillation process for the next step of treatment. The unreacted hydrogen is compressed by a circulating hydrogen compressor and reused. The emergence of cold hydrogenation effectively converts silicon tetrachloride into trichlorosilane, solves the problem of closed-loop circulation of chlorine elements, reduces the comprehensive power consumption of polysilicon production, and is an important cost-reduction method for the production of polysilicon by the modified Siemens method.

[0003] In the field of polysilicon production, the selection of heat exchanger materials and structures for the second-stage heat exchanger after the cold hydrogenation reactor under corresponding working conditions has always been a pain point that plagues the industry. The main difficulties are as follows:

[0004] 1. When using a heat exchanger made of 31608 material, due to the temperature range (the outlet temperature of the secondary heat exchanger tube is 200-230°C, and the temperature that is prone to intergranular corrosion is 180-220°C), intergranular corrosion occurs on the tube bundle and shell during operation, causing internal and external leakage to varying degrees.

[0005] 2. The heat exchanger using 800H material did not suffer from intergranular corrosion, but due to the high cost (the cost of 800H heat exchanger (5.18 million / unit) is nearly three times higher than that of 31608 (1.9 million / unit) material), the cost also increased significantly.

[0006] 3. Since the flow rate of the secondary heat exchanger is low, the synthesized silicon powder has adsorption properties. The residual silicon powder on the tube wall cannot be taken away under low flow rate, so it is easy to cause scaling on the inner wall of the tube bundle, resulting in poor heat exchange efficiency and failure to meet the existing operating conditions. Specifically, in the secondary heat exchanger, the heat exchange tube is a straight tube, and the mixed cooling gas contains silicon powder. The inlet temperature of the silicon powder is about 290°C and the outlet temperature is about 220°C. The temperature of the silicon powder decreases after passing through the secondary heat exchanger. After the temperature decreases, the silicon powder will be adsorbed on the heat exchange tube to form scale, reducing the flux of the heat exchange tube and reducing the heat exchange effect between the tube walls of the heat exchange tube.

[0007] In the prior art, a patent with the publication number CN117225312A discloses a method and system for temperature rise and fall in polysilicon cold hydrogenation, which relates to the technical field of polysilicon production and includes the following steps: S1. Mix hydrogen and silicon tetrachloride, and after mixing, send the mixed material into the material heating line, vaporize and perform cascade heat exchange to heat up the mixed material, and then send the mixed material into the fluidized bed; S2. In the fluidized bed, high-temperature hydrogen, silicon tetrachloride and silicon powder react to generate trichlorosilane, and send the trichlorosilane, unreacted silicon tetrachloride and high-temperature mixed material of hydrogen in the fluidized bed into the material cooling line; S3. The material cooling line performs cascade heat exchange cooling, silicon powder filtration and washing on the high-temperature mixed material, and sends the finally cascade heat exchange cooled material into the downstream device; S4. When the temperature rise and fall in cold hydrogenation needs to be shut down for maintenance after running for a period of time, adopt the cascade cooling method and combine with the material heating line to cool down the fluidized bed, and the cooling speed is uniform and the cooling is faster.

[0008] For the method and system for temperature rise and fall in polysilicon cold hydrogenation disclosed in the above patent, during the heat exchange cooling of the heat exchanger, there will still be problems that silicon powder adsorbs on the heat exchange tubes to form scale, reducing the flux of the heat exchange tubes and the heat exchange effect between the tube walls of the heat exchange tubes. Utility Model Content

[0009] In order to overcome the defects existing in the above prior art, the purpose of the present utility model is to provide a heat exchange system for polysilicon cold hydrogenation to solve the problem that silicon powder adsorbs on the heat exchange tubes in the second-stage heat exchanger in the above prior art. In the present utility model, the heat exchange tubes in the secondary heat exchanger are inner corrugated and outer threaded tubes. After the mixed gas enters, there will be a turbulent flow effect to carry away the adsorbed silicon powder.

[0010] In order to achieve the above purpose, the technical solution adopted by the present utility model is:

[0011] A heat exchange system for polysilicon cold hydrogenation includes a cold hydrogenation reactor, a primary heat exchanger and a secondary heat exchanger;

[0012] The top of the cold hydrogenation reactor is connected to the tube-side inlet of the primary heat exchanger through a pipeline, the tube-side outlet of the primary heat exchanger is connected to the tube-side inlet of the secondary heat exchanger through a pipeline, and the tube-side outlet of the secondary heat exchanger is connected to a separator through a pipeline;

[0013] The shell-side inlet of the secondary heat exchanger is connected to a silicon tetrachloride pipeline, the shell-side outlet of the secondary heat exchanger is connected to the shell-side inlet of the primary heat exchanger through a pipeline, the shell-side outlet of the primary heat exchanger is connected to an electric heater through a pipeline, and the electric heater is then connected to the bottom material inlet of the cold hydrogenation reactor through a pipeline;

[0014] The heat exchange tubes in the secondary heat exchanger are inner corrugated and outer threaded tubes.

[0015] Preferably, the silicon tetrachloride pipeline is also connected to the shell-side inlet pipeline and the shell-side outlet pipeline of the primary heat exchanger through branch pipes respectively.

[0016] Preferably, the cold hydrogeneration reactor is also connected with a silicon powder feed tank, a pusher hydrogen tank I, a pusher hydrogen tank II, a hydraulic hydrogen tank and a spent catalyst body tank;

[0017] The silicon powder feed tank and the pusher hydrogen tank I are aggregated to the main pipeline and then connected to the lower part of the cold hydrogeneration reactor. The pusher hydrogen tank II and the spent catalyst body tank are respectively connected to the lower part of the cold hydrogeneration reactor through pipelines. The hydraulic hydrogen tank is connected with a plurality of hydraulic hydrogen branch pipes, and the outlets of the plurality of hydraulic hydrogen branch pipes are arranged at different height positions inside the cold hydrogeneration reactor.

[0018] Preferably, the primary heat exchanger is a spiral wound heat exchanger.

[0019] Preferably, the primary heat exchanger includes a primary upper head, a primary cylinder body and a primary lower head arranged from top to bottom;

[0020] A primary tube-side inlet and a vent port are arranged on the primary upper head; a spiral wound heat exchange tube bundle is arranged inside the primary cylinder body, and a primary shell-side inlet and a primary shell-side outlet are arranged on the side wall. An impact plate is arranged inside the primary shell-side inlet; a primary tube-side outlet is arranged on the primary lower head.

[0021] Preferably, a heat preservation support ring, a grounding plate and a lifting lug are arranged on the outer side wall of the primary cylinder body.

[0022] Preferably, the overall material of the secondary heat exchanger is carbon steel.

[0023] Preferably, the secondary heat exchanger includes a secondary upper head, a secondary cylinder body and a secondary lower head arranged from top to bottom;

[0024] A mixed gas inlet is arranged on the secondary upper head; a plurality of fixed tube sheets are arranged inside the secondary cylinder body, and vertical inner corrugated and outer threaded heat exchange tubes are assembled inside the plurality of fixed tube sheets. A material inlet and a material outlet are arranged on the side wall of the secondary cylinder body; a mixed gas outlet is arranged on the secondary lower head.

[0025] The beneficial effects of the present utility model:

[0026] The polysilicon cold hydrogenation heat exchange system provided by the present utility model has heat exchange tubes in the secondary heat exchanger that are internally corrugated and externally threaded tubes. After the mixed gas enters, there will be a flow disturbance effect, which takes away the silicon powder adsorbed on the tube wall. When the heat exchange tubes in the prior art are straight tubes, after the air flow comes down, it basically passes through the middle of the straight tube and cannot take away the silicon powder adsorbed on the tube wall. However, in the internally corrugated and externally threaded tubes of the present utility model, after the air flow enters, it will flow along the corrugations, going up and down, knocking off the silicon powder adsorbed on the tube wall and taking away the silicon powder adsorbed on the tube wall, reducing the probability of silicon powder being adsorbed on the inner wall of the heat exchange tube. Thus, it reduces the probability of the heat exchange tube flux decreasing and the heat exchange effect of the heat exchange tube decreasing due to silicon powder being adsorbed on the inner wall of the heat exchange tube, and further increases the service life of the heat exchange tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the polysilicon cold hydrogenation heat exchange system of the present utility model;

[0028] Figure 2 Schematic diagram of the primary heat exchanger of the present utility model;

[0029] Figure 3 Schematic diagram of the secondary heat exchanger of the present utility model;

[0030] Figure 4 Schematic diagram of the internally corrugated and externally threaded tube of the present utility model;

[0031] Figure 5 is Figure 4 partial enlarged view in

[0032] Figure 6 Fluid flow state inside the plain tube;

[0033] Figure 7 Fluid flow state inside and outside the internally corrugated and externally threaded tube;

[0034] Reference numerals:

[0035] 1, Cold hydrogenation reactor; 2, Primary heat exchanger; 201, Primary upper head; 202, Primary cylinder; 203, Primary lower head; 204, Primary tube side inlet; 205, Venting port; 206, Primary shell side inlet; 207, Primary shell side outlet; 208, Impact plate; 209, Primary tube side outlet; 210, Thermal insulation support ring; 211, Earthing plate; 212, Lifting lug; 3, Secondary heat exchanger; 301, Secondary upper head; 302, Secondary cylinder; 303, Secondary lower head; 304, Mixed gas inlet; 305, Fixed tube sheet; 306, Internally corrugated and externally threaded heat exchange tube; 307, Material inlet; 308, Material outlet; 309, Mixed gas outlet; 4, Separator; 5, Electric heater; 6, Silicon powder feed tank; 7, Pushing hydrogen tank I; 8, Pushing hydrogen tank II; 9, Hydraulic hydrogen tank; 10, Spent catalyst tank. Detailed Implementation Modes

[0036] The following will clearly and completely describe the concept, specific structure, and technical effects generated by the present utility model in combination with embodiments and the drawings, so as to fully understand the purpose, features, and effects of the present utility model.

[0037] Embodiment 1

[0038] A polysilicon cold hydrogenation heat exchange system, as Figure 1 shown, includes a cold hydrogenation reactor 1, a primary heat exchanger 2, and a secondary heat exchanger 3;

[0039] The top of the cold hydrogenation reactor 1 is connected to the tube side inlet of the primary heat exchanger 2 through a pipeline, the tube side outlet of the primary heat exchanger 2 is connected to the tube side inlet of the secondary heat exchanger 3 through a pipeline, and the tube side outlet of the secondary heat exchanger 3 is connected to a separator 4 through a pipeline;

[0040] The shell side inlet of the secondary heat exchanger 3 is connected to a silicon tetrachloride pipeline, the shell side outlet of the secondary heat exchanger 3 is connected to the shell side inlet of the primary heat exchanger 2 through a pipeline, the shell side outlet of the primary heat exchanger 2 is connected to an electric heater 5 through a pipeline, and the electric heater 5 is then connected to the bottom material inlet of the cold hydrogenation reactor 1 through a pipeline;

[0041] The heat exchange tubes in the secondary heat exchanger 3 are internally corrugated and externally threaded tubes.

[0042] In this embodiment, a cold hydrogenation reaction occurs in the cold hydrogenation reactor 1, 3SiCl4 + 2H2 + Si → 4SiHCl3. The reaction mixture gas (including SiHCl3, silicon powder, etc.) first enters the primary heat exchanger 2 for heat exchange and temperature reduction, then enters the secondary heat exchanger 3 for heat exchange and temperature reduction, and finally enters the cyclone separator 4 for separation.

[0043] The silicon tetrachloride raw material in the silicon tetrachloride pipeline first enters the secondary heat exchanger 3 for heat exchange and temperature increase, then enters the primary heat exchanger 2 for heat exchange and temperature increase, then enters the electric heater 5 for temperature increase, and finally is sent into the cold hydrogenation reactor 1 for cold hydrogenation reaction.

[0044] That is, in the present utility model, in the primary heat exchanger 2, the reaction mixture gas after cold hydrogenation reaction and the silicon tetrachloride raw material perform heat exchange; in the secondary heat exchanger 3, the mixture gas and the silicon tetrachloride raw material also perform heat exchange to make full use of heat.

[0045] In the secondary heat exchanger 3, the inlet temperature of the mixture gas is about 290 °C, and the outlet temperature is about 220 °C. After the silicon powder in the mixture gas is cooled by heat exchange, it will adsorb on the heat exchange tubes to form scale, reducing the flux of the heat exchange tubes and the heat exchange effect between the tube walls of the heat exchange tubes.

[0046] When the heat exchange tubes of the prior art secondary heat exchanger 3 are straight tubes, when the air flow passes through the straight tubes, it basically passes through the middle of the straight tubes and cannot carry away the silicon powder adsorbed on the tube walls, as Figure 6 shown.

[0047] In this embodiment, the heat exchange tubes in the secondary heat exchanger 3 are inner corrugated and outer threaded tubes. After the air flow enters, it will flow along the corrugations, going up and down, knocking off the silicon powder adsorbed on the tube walls, as Figure 7 shown, carrying away the silicon powder adsorbed on the tube walls, reducing the probability of silicon powder adsorbing on the inner wall of the heat exchange tubes, thereby reducing the probability of the heat exchange tube flux decreasing and the heat exchange effect of the heat exchange tubes decreasing due to silicon powder adsorbing on the inner wall of the heat exchange tubes, and further increasing the service life of the heat exchange tubes.

[0048] The inner corrugated and outer threaded tube is made with a smooth tube as the blank tube by a non-cutting rolling process. The inner wall of the tube is corrugated, and the outer wall of the tube is a special-shaped tube with a threaded shape. During the rolling process of the heat exchange tube, the outer wall of the heat exchange tube is pressed inward to form spiral corrugations. After the inner corrugated and outer threaded tube is formed, the effective pressure-bearing wall thickness is almost the same as that of the smooth tube.

[0049] As Figure 4 and Figure 5 shown, it is a schematic structural diagram of the inner corrugated and outer threaded tube. Among them, D is the outer diameter of the straight tube section of the tube, S is the thickness of the tube, l is the length of the straight tube section of the tube, d i is the inner diameter after the corrugated tube is formed, d of is the outer diameter after the corrugated tube is formed, r is the radius of the outer thread pressing angle, h is the depth after the outer thread is pressed and formed, h i is the forming height of the inner corrugation, and p is the distance between single wave peaks of the inner corrugation.

[0050] In this embodiment, D is 25 mm, S is 2.0 mm, d of is 24.8 mm, h is 0.6 mm, and p is 6.0 mm.

[0051] Embodiment 2

[0052] This embodiment is further elaborated on the basis of Embodiment 1. As Figure 1 shown, the silicon tetrachloride pipeline is also connected to the shell-side inlet pipeline and the shell-side outlet pipeline of the primary heat exchanger 2 through branch pipes respectively. Under certain working conditions, the silicon tetrachloride material in the silicon tetrachloride pipeline can be directly transported into the primary heat exchanger 2 or the electric heater 5 through the branch pipes without passing through the secondary heat exchanger 3 or the primary heat exchanger 2 for heat exchange.

[0053] As Figure 1 shown, the cold hydrofluorination reactor 1 is also connected with a silicon powder feed tank 6, a pusher hydrogen tank I 7, a pusher hydrogen tank II 8, a hydraulic hydrogen tank 9 and a waste catalyst body tank 10.

[0054] The silicon powder feed tank 6 and the pusher hydrogen tank I 7 are aggregated to the main pipe and then connected to the lower part of the cold hydrofluorination reactor 1. The pusher hydrogen tank II 8 and the waste catalyst tank 10 are respectively connected to the lower part of the cold hydrofluorination reactor 1 through pipelines. The hydraulic hydrogen tank 9 is connected with a number of hydraulic hydrogen branch pipes, and the outlets of the number of hydraulic hydrogen branch pipes are arranged at different height positions inside the cold hydrofluorination reactor 1.

[0055] The silicon powder feed tank 6 is used to add silicon powder into the cold hydrofluorination reactor 1 for cold hydrofluorination reaction; the pusher hydrogen tank I 7 is used to push the silicon powder into the cold hydrofluorination reactor 1 by using pusher hydrogen; the pusher hydrogen tank II 8 is used to add hydrogen into the cold hydrofluorination reactor 1; the hydraulic hydrogen tank 9 is used to add hydraulic hydrogen into the cold hydrofluorination reactor 1; the waste catalyst tank 10 is used to store the waste materials in the cold hydrofluorination reactor 1.

[0056] Example 3

[0057] This example is further elaborated on the basis of Example 2, as Figure 2 shown, the primary heat exchanger 2 is a spiral wound heat exchanger. The primary heat exchanger 2 includes a primary upper head 201, a primary cylinder 202, and a primary lower head 203 arranged from top to bottom;

[0058] A primary tube side inlet 204 and a vent port 205 are arranged on the primary upper head 201; a spiral wound heat exchange tube bundle is arranged inside the primary cylinder 202, and a primary shell side inlet 206 and a primary shell side outlet 207 are arranged on the side wall. An impact plate 208 is arranged inside the primary shell side inlet 206 to prevent material impact; a primary tube side outlet 209 is arranged on the primary lower head 203.

[0059] In this example, in the primary heat exchanger 2, the mixed gas enters the spiral wound heat exchange tube bundle inside the primary heat exchanger 2 through the primary tube side inlet 204, and the silicon tetrachloride material enters the spiral wound heat exchange tube bundle inside the primary heat exchanger 2 through the primary shell side inlet 206. Inside the spiral wound heat exchange tube bundle, the mixed gas and the silicon tetrachloride material exchange heat. The mixed gas is cooled, and the silicon tetrachloride material is heated. The cooled mixed gas is discharged through the primary tube side outlet 209, and the heated silicon tetrachloride material is discharged from the primary shell side outlet 207.

[0060] As Figure 2 shown, a heat preservation support ring 210, a grounding plate 211, and a lifting lug 212 are arranged on the outer side wall of the primary cylinder 202. The heat preservation support ring 210 is used to install the heat preservation layer, the grounding plate 211 is used for grounding, and the lifting lug 212 is used for lifting the tank body.

[0061] Example 4

[0062] This embodiment is further elaborated on the basis of Embodiment 3. The overall material of the secondary heat exchanger 3 is carbon steel. In this embodiment, regarding the material selection issue: a wound tube heat exchanger is used for the primary heat exchanger, and carbon steel material (15CrMo) is used for the secondary heat exchanger. Only by reducing the inlet temperature of the secondary heat exchanger to within the allowable temperature range of the carbon steel material through an efficient wound tube heat exchanger can the long-term stable operation of the 15CrMo material under the permitted working conditions be ensured.

[0063] As Figure 3 shown, the secondary heat exchanger 3 includes a secondary upper head 301, a secondary cylinder 302, and a secondary lower head 303 arranged from top to bottom;

[0064] A mixed gas inlet 304 is provided on the secondary upper head 301; a number of fixed tube sheets 305 are arranged inside the secondary cylinder 302, and vertical internally corrugated externally threaded heat exchange tubes 306 are assembled inside the number of fixed tube sheets 305. A material inlet 307 and a material outlet 308 are provided on the side wall of the secondary cylinder 302; a mixed gas outlet 309 is provided on the secondary lower head 303.

[0065] In this embodiment, in the secondary heat exchanger 3, the mixed gas enters the internally corrugated externally threaded heat exchange tubes 306 inside the secondary heat exchanger 3 through the mixed gas inlet 304, and the silicon tetrachloride material enters the internally corrugated externally threaded heat exchange tubes 306 inside the secondary heat exchanger 3 through the material inlet 307. Inside the internally corrugated externally threaded heat exchange tubes 306, the mixed gas and the silicon tetrachloride material exchange heat. The mixed gas is cooled, and the silicon tetrachloride material is heated. The cooled mixed gas is discharged through the mixed gas outlet 309, and the heated silicon tetrachloride material is discharged from the material outlet 308.

[0066] In this embodiment, regarding the process flow selection issue: the original tertiary heat exchanger is cancelled. After replacement, it can be ensured that the outlet temperatures of the primary wound tube heat exchanger and the secondary fixed tube sheet heat exchanger can be reduced to the outlet temperature of the previous tertiary heat exchanger. Therefore, the previous three-stage heat exchange can be changed to two-stage heat exchange, reducing equipment investment.

[0067] Therefore, in this embodiment, a wound tube heat exchanger with higher heat exchange efficiency is used for the primary stage, and a fixed tube sheet heat exchanger (carbon steel, with high-efficiency heat exchange tubes inside) is used for the secondary stage. In this combined way, energy consumption and equipment procurement costs are reduced. It reduces the equipment weight, increases the heat exchange efficiency, saves the energy consumption of the electric heater, and avoids the influence of scale blockage inside the tube bundle flow channel on production.

[0068] The above has specifically described the embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A polysilicon cold hydrogenation heat exchange system, characterized in that, It includes a cold hydrofluorination reactor (1), a primary heat exchanger (2) and a secondary heat exchanger (3); The top of the cold hydrofluorination reactor (1) is connected to the tube-side inlet of the primary heat exchanger (2) through a pipeline. The tube-side outlet of the primary heat exchanger (2) is connected to the tube-side inlet of the secondary heat exchanger (3) through a pipeline. The tube-side outlet of the secondary heat exchanger (3) is connected to a separator (4) through a pipeline; The shell-side inlet of the secondary heat exchanger (3) is connected to a silicon tetrachloride pipeline. The shell-side outlet of the secondary heat exchanger (3) is connected to the shell-side inlet of the primary heat exchanger (2) through a pipeline. The shell-side outlet of the primary heat exchanger (2) is connected to an electric heater (5) through a pipeline. The electric heater (5) is then connected to the bottom material inlet of the cold hydrofluorination reactor (1) through a pipeline; The heat exchange tubes in the secondary heat exchanger (3) are internally corrugated and externally threaded tubes.

2. The polysilicon cold hydrogenation heat exchange system according to claim 1, wherein The silicon tetrachloride pipeline is also connected to the shell-side inlet pipeline and the shell-side outlet pipeline of the primary heat exchanger (2) respectively through branch pipes.

3. The polysilicon cold hydrogenation heat exchange system according to claim 1, characterized in that, The cold hydrofluorination reactor (1) is also connected to a silicon powder feed tank (6), a pusher hydrogen tank I (7), a pusher hydrogen tank II (8), a hydraulic hydrogen tank (9) and a waste catalyst body tank (10); The silicon powder feed tank (6) and the pusher hydrogen tank I (7) are aggregated to the main pipeline and then connected to the lower part of the cold hydrofluorination reactor (1). The pusher hydrogen tank II (8) and the waste catalyst body tank (10) are respectively connected to the lower part of the cold hydrofluorination reactor (1) through pipelines. The hydraulic hydrogen tank (9) is connected with a number of hydraulic hydrogen branch pipes, and the outlets of the number of hydraulic hydrogen branch pipes are arranged at different height positions inside the cold hydrofluorination reactor (1).

4. The polysilicon cold hydrogenation heat exchange system according to claim 1, wherein, The primary heat exchanger (2) is a wound tube heat exchanger.

5. The polysilicon cold hydrogenation heat exchange system according to claim 4, wherein The primary heat exchanger (2) includes a primary upper head (201), a primary cylinder body (202) and a primary lower head (203) arranged from top to bottom; A primary tube-side inlet (204) and a vent port (205) are arranged on the primary upper head (201); A wound tube heat exchange tube bundle is arranged inside the primary cylinder body (202), and a primary shell-side inlet (206) and a primary shell-side outlet (207) are arranged on the side wall. An impact plate (208) is arranged inside the primary shell-side inlet (206); A primary tube-side outlet (209) is arranged on the primary lower head (203).

6. The polysilicon cold hydrogenation heat exchange system according to claim 5, wherein, A heat preservation support ring (210), a grounding plate (211) and a lifting lug (212) are arranged on the outer side wall of the primary cylinder body (202).

7. The polysilicon cold hydrogenation heat exchange system according to claim 1, wherein The overall material of the secondary heat exchanger (3) is carbon steel.

8. The polysilicon cold hydrogenation heat exchange system according to claim 1, wherein, The secondary heat exchanger (3) includes a secondary upper head (301), a secondary cylinder body (302) and a secondary lower head (303) arranged from top to bottom; A mixed gas inlet (304) is arranged on the secondary upper head (301); A number of fixed tube sheets (305) are arranged inside the secondary cylinder body (302), and vertically arranged internally corrugated and externally threaded heat exchange tubes (306) are assembled inside the number of fixed tube sheets (305). A material inlet (307) and a material outlet (308) are arranged on the side wall of the secondary cylinder body (302); A mixed gas outlet (309) is arranged on the secondary lower head (303).

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