Heat exchange device and cold hydrogenation reaction system

Abstract

The utility model provides a heat exchange device and a cold hydrogenation reaction system. The heat exchange device comprises a raw material unit, a heat exchange unit and a reaction unit, the raw material unit comprises a first mixing outlet and a second mixing outlet, the first mixing outlet is communicated with the low-temperature medium inlet of the heat exchange unit, the reaction gas outlet of the reaction unit is communicated with the high-temperature medium inlet of the heat exchange unit, and the second mixing outlet is communicated with the raw material inlet of the reaction unit. The heat exchange device can be directly communicated with the raw material inlet of the reaction unit through the second mixing outlet of the raw material unit, and the second mixing outlet plays a role in shunting reaction raw material gas, so that the temperature of reaction tail gas can be flexibly controlled, and the problems that the temperature of the reaction tail gas is too low after heat exchange and metal chloride is precipitated and accumulated are avoided; and the pipeline is corroded.

Description

Technical Field

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

[0002] In recent years, with the increasing demand in the new energy field, the global polysilicon production capacity has entered a period of rapid growth. Currently, more than 85% of the polysilicon in the world is produced by the improved Siemens method. In this method, a very important link is the cold hydrogenation of silicon tetrachloride to produce trichlorosilane. The reaction tail gas output from the cold hydrogenation reactor enters the cold hydrogenation reaction tail gas heat exchange system to be cooled step by step and then enters the subsequent process sections.

[0003] In the cold hydrogenation reaction tail gas heat exchange system, the high-temperature (520 - 560 °C) reaction tail gas in the tube side transfers heat to the raw material gas mixture of hydrogen and silicon tetrachloride in the shell side through 2 - 4 stages of heat exchange, heating the hydrogen and silicon tetrachloride mixture to 470 - 510 °C, and the temperature of the reaction tail gas decreases. When the temperature of the reaction tail gas is relatively low, although more heat can be recovered, there is a tendency for a large amount of metal chlorides to precipitate and accumulate in the heat exchange tubes, resulting in chloride ion corrosion of the heat exchange tubes, making them prone to fracture, and also affecting the operation of the subsequent process sections and the corrosion of equipment. Summary of the Utility Model

[0004] The main purpose of the utility model is to provide a heat exchange device. Using this device to conduct heat exchange between the cold hydrogenation reaction tail gas and the raw material gas (silicon tetrachloride and hydrogen) can avoid the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0005] The utility model also provides a cold hydrogenation reaction system, which includes the above heat exchange device. Therefore, the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline can be avoided.

[0006] In the first aspect, the utility model provides a heat exchange device, which includes a raw material unit, a heat exchange unit, and a reaction unit;

[0007] The raw material unit includes a first mixing outlet and a second mixing outlet. The first mixing outlet is communicated with the low-temperature medium inlet of the heat exchange unit. The reaction gas outlet of the reaction unit is communicated with the high-temperature medium inlet of the heat exchange unit. The second mixing outlet is communicated with the raw material inlet of the reaction unit.

[0008] For the heat exchange device as described above, the second mixing outlet and the reaction unit are communicated through a first control valve.

[0009] The heat exchange device as described above further includes a temperature detection unit, which is communicated with the high-temperature medium outlet of the heat exchange unit and is used to detect the real-time temperature of the high-temperature medium after heat exchange and temperature reduction output by the heat exchange unit.

[0010] The heat exchange device as described above further includes a control unit, which is electrically connected to the temperature detection unit and the first control valve respectively.

[0011] In the heat exchange device as described above, the heat exchange unit sequentially includes N heat exchange sub-units connected in series in the order of gradually moving away from the reaction unit in sequence, N≥2, and the set of the numbers of the N heat exchange sub-units is denoted as P = {1, 2, …, i, i + 1, …, j - 1, j, … N - 1, N};

[0012] The raw material unit further includes a third mixing outlet, which is communicated with at least one of the first N - 1 heat exchange sub-units.

[0013] In the heat exchange device as described above, the third mixing outlet is communicated with at least one heat exchange sub-unit through a second control valve.

[0014] In the heat exchange device as described above, the control unit is also electrically connected to the second control valve.

[0015] In the heat exchange device as described above, the first mixing outlet and the low-temperature medium inlet are communicated through a first pipeline;

[0016] The second mixing outlet and the reaction unit are communicated through a second pipeline;

[0017] The third mixing outlet and at least one heat exchange sub-unit are communicated through a third pipeline;

[0018] Wherein, the diameter ratio of the first pipeline to the second pipeline is 2 - 5:1, and the diameter ratio of the first pipeline to the third pipeline is 2 - 5:1.

[0019] The heat exchange device as described above further includes a heating unit. The second mixing outlet is communicated with the raw material inlet of the reaction unit through the heating unit, and the low-temperature medium outlet of the heat exchange unit is communicated with the raw material inlet of the reaction unit through the heating unit. Wherein, the low-temperature medium outlet is used to output the low-temperature medium after heat exchange and temperature increase output by the heat exchange unit.

[0020] In a second aspect, the present invention provides a cold hydrogenation reaction system, including the heat exchange device as described above.

[0021] The heat exchange device provided by the present utility model can be directly communicated with the raw material inlet of the reaction unit through the second mixing outlet of the raw material unit. The second mixing outlet plays a role in diverting the reaction raw material gas, and can flexibly control the temperature of the reaction tail gas, avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or related technologies, the following briefly introduces the drawings required for use in the description of the embodiments of the present utility model or related technologies. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 A heat exchange device provided by the present utility model.

[0024] Description of the Reference Numerals:

[0025] 101 - Raw material unit; 102 - Reaction unit; 103 - First control valve; 104 - Temperature detection unit; 105 - Control unit; 106 - Second control valve; 107 - Heating unit; 108 - First heat exchange sub-unit; 109 - Second heat exchange sub-unit. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0027] Figure 1 A heat exchange device provided by the present utility model. As Figure 1 shown, in the first aspect, the present utility model provides a heat exchange device, including a raw material unit 101, a heat exchange unit, and a reaction unit 102;

[0028] The raw material unit 101 includes a first mixing outlet and a second mixing outlet. The first mixing outlet is communicated with the low-temperature medium inlet of the heat exchange unit. The reaction gas outlet of the reaction unit 102 is communicated with the high-temperature medium inlet of the heat exchange unit. The second mixing outlet is communicated with the raw material inlet of the reaction unit 102.

[0029] It can be understood that the reaction tail gas temperature of the cold hydrogeneration reaction is relatively high, between 520 - 560 °C. Passing it into the heat exchange device to exchange heat with the reaction raw material gas (silicon tetrachloride and hydrogen) can achieve full utilization of heat and the purpose of saving energy consumption.

[0030] In the present utility model, the raw material unit 101 can be used to mix, vaporize and heat up the reaction raw material gas (silicon tetrachloride and hydrogen). For example, it can be a silicon tetrachloride / hydrogen mixing and vaporizing heater. The reaction raw material gas can be used as the raw material for the subsequent cold hydrogeneration reaction; the reaction unit 102 is used for carrying out the cold hydrogeneration reaction. For example, it can be a cold hydrogeneration reactor. The heat exchange unit is used to exchange heat between the reaction tail gas of the cold hydrogeneration reaction and the reaction raw material gas (silicon tetrachloride and hydrogen).

[0031] Specifically, the reaction raw material gas (silicon tetrachloride and hydrogen) is output from the first mixing outlet in the raw material unit 101 and enters the shell side of the heat exchange unit through the low-temperature medium inlet of the heat exchange unit for heat exchange; the reaction tail gas of the cold hydrogeneration reaction is output from the reaction gas outlet of the reaction unit 102 and enters the tube side of the heat exchange unit through the high-temperature medium inlet of the heat exchange unit for heat exchange. The reaction raw material gas (silicon tetrachloride and hydrogen) can also be output from the second mixing outlet in the raw material unit 101 and directly enter the reaction unit 102 through the raw material inlet of the reaction unit 102 to participate in the reaction. According to the temperature of the reaction tail gas, the second mixing outlet can be opened or closed, that is, the second mixing outlet can play a certain role in diverting the reaction raw material gas, and can flexibly control the temperature of the reaction tail gas. In the heat exchange unit, heat exchange between the reaction tail gas and the reaction raw material gas (silicon tetrachloride and hydrogen) can be achieved. The temperature of the reaction tail gas is reduced from 520 - 560 °C to 210 - 250 °C, and the temperature of the reaction raw material gas (silicon tetrachloride and hydrogen) is heated to 470 - 510 °C. The heat of the reaction tail gas can be fully utilized to heat the reaction raw material gas (silicon tetrachloride and hydrogen), and the purpose of saving energy consumption can be achieved. Moreover, the second mixing outlet of the raw material unit 101 is connected to the raw material inlet of the reaction unit 102, and the temperature of the reaction tail gas can be flexibly controlled to avoid the temperature of the reaction tail gas being too low. For example, when it is lower than 210 °C, it is close to the sublimation temperature of aluminum chloride, causing metal chlorides to precipitate and accumulate in the heat exchange tubes, resulting in corrosion of the heat exchange tubes.

[0032] The present utility model does not limit the connection form of the first mixing outlet and the second mixing outlet. For example, they can be two outlets directly led out from the raw material unit 101 respectively, or one outlet led out from the raw material unit 101 and then realized by installing a three-way valve.

[0033] The heat exchange device provided by the present utility model can be directly connected to the raw material inlet of the reaction unit 102 through the second mixing outlet of the raw material unit 101. The second mixing outlet plays a role in shunting the reaction raw material gas, and can flexibly control the temperature of the reaction tail gas, avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0034] In some embodiments of the present utility model, the second mixing outlet and the reaction unit 102 are connected through a first control valve 103.

[0035] In the present utility model, the second mixing outlet of the raw material unit 101 is connected to the reaction unit 102 through the first control valve 103. That is, the opening and closing of the second mixing outlet can be controlled through the first control valve 103. When the temperature of the reaction tail gas is low, the first control valve 103 controls the opening of the second mixing outlet to shunt the reaction raw material gas, so that part of the reaction raw material gas does not exchange heat with the reaction tail gas, avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange and cooling, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline. The first control valve 103 makes the operation more flexible and convenient.

[0036] In some embodiments of the present utility model, it further includes a temperature detection unit 104, which is connected to the high-temperature medium outlet of the heat exchange unit and is used to detect the real-time temperature of the high-temperature medium after heat exchange and cooling output by the heat exchange unit.

[0037] The heat exchange device of the present utility model further includes a temperature detection unit 104, which is connected to the high-temperature medium outlet of the heat exchange unit and is used to detect the real-time temperature of the reaction tail gas after heat exchange and cooling output by the heat exchange unit. According to the temperature of the reaction tail gas detected by the temperature detection unit 104, the first control valve 103 can control whether the second mixing outlet is opened. For example, when the detection unit 104 detects that the temperature of the reaction tail gas is low, the first control valve 103 is used to control the opening of the second mixing outlet, so that part of the reaction raw material gas directly enters the reaction unit 102 and does not exchange heat with the reaction tail gas in the heat exchange unit. Therefore, the problem that the temperature of the reaction tail gas is too low due to heat exchange and cooling, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline, can be avoided.

[0038] In some embodiments of the present utility model, it further includes a control unit 105, and the control unit 105 is electrically connected to the temperature detection unit 104 and the first control valve 103 respectively.

[0039] The heat exchange device of the present utility model further includes a control unit 105, which is electrically connected to the temperature detection unit 104 and the first control valve 103 respectively, enabling automatic control. According to the real-time temperature detected by the temperature detection unit 104, the control unit 105 can automatically adjust the opening degree of the first control valve 103, thereby controlling the flow direction and flow rate of the reaction raw material gas (silicon tetrachloride and hydrogen) during the heat exchange process, avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange and cooling, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline, simplifying the operation process and reducing the operation difficulty.

[0040] In some embodiments of the present utility model, the heat exchange unit sequentially includes N heat exchange sub-units connected in series in the order of gradually moving away from the reaction unit 102, where N≥2, and the set of the number of the N heat exchange sub-units is denoted as P = {1, 2, …, i, i + 1, …, j - 1, j, … N - 1, N};

[0041] The raw material unit 101 further includes a third mixing outlet, and the third mixing outlet is communicated with at least one of the first N - 1 heat exchange sub-units.

[0042] The heat exchange unit of the present utility model sequentially includes N heat exchange sub-units connected in series, where N≥2, and the set of the number of the N heat exchange sub-units is denoted as P = {1, 2, …, i, i + 1, …, j - 1, j, … N - 1, N}, and the N heat exchange sub-units are arranged in the order of gradually moving away from the reaction unit 102. Here, moving away from the reaction unit 102 does not mean a large absolute distance and relative displacement from the reaction unit 102, but rather a longer distance that the reaction tail gas flows through, and the farther the reaction tail gas flows through, the lower its temperature. Each of the N heat exchange sub-units includes a low-temperature medium inlet, a low-temperature medium outlet, a high-temperature medium inlet, and a high-temperature medium outlet. The low-temperature medium inlet of the (N - 1)th heat exchange sub-unit is communicated with the low-temperature medium outlet of the Nth heat exchange sub-unit, the low-temperature medium outlet of the (N - 1)th heat exchange sub-unit is communicated with the low-temperature medium inlet of the (N - 2)th heat exchange sub-unit, the high-temperature medium inlet of the (N - 1)th heat exchange sub-unit is communicated with the high-temperature medium outlet of the (N - 2)th heat exchange sub-unit, and the high-temperature medium outlet of the (N - 1)th heat exchange sub-unit is communicated with the high-temperature medium inlet of the Nth heat exchange sub-unit.

[0043] The raw material unit 101 further includes a third mixing outlet, which is communicated with at least one of the first N-1 heat exchange sub-units. When the first control valve 103 is closed, the reaction raw material gas is output from the first mixing outlet, and the third mixing outlet can shunt the reaction raw material gas output from the first mixing outlet, so that part of the reaction raw material gas exchanges heat with part of the reaction tail gas in the heat exchange unit; when the first control valve 103 is opened, part of the reaction raw material gas is output from the second mixing outlet, and the other part of the reaction raw material gas is output from the first mixing outlet. The third mixing outlet can shunt the other part of the reaction raw material gas output from the first mixing outlet, so that this part of the reaction raw material gas exchanges heat with part of the reaction tail gas in the heat exchange unit, which can avoid the problem that the temperature of the reaction tail gas after heat exchange and cooling is too low, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline. Similarly, the present invention does not limit the connection form of the third mixing outlet. For example, it can be an outlet directly led out from the raw material unit 101, or an outlet led out from the raw material unit 101 and then realized by installing a valve.

[0044] In one embodiment, N = 2. The low-temperature medium inlet of the first heat exchange sub-unit 108 is communicated with the low-temperature medium outlet of the second heat exchange sub-unit 109. The low-temperature medium outlet of the first heat exchange sub-unit 108 is communicated with the raw material inlet of the reaction unit 102. The high-temperature medium inlet of the first heat exchange sub-unit 108 is communicated with the reaction gas outlet of the reaction unit 102. The high-temperature medium outlet of the first heat exchange sub-unit 108 is communicated with the high-temperature medium inlet of the second heat exchange sub-unit 109. The low-temperature medium inlet of the second heat exchange sub-unit 109 is communicated with the first mixing outlet of the raw material unit 101. The high-temperature medium outlet of the second heat exchange sub-unit 109 is communicated with the temperature detection unit 104. The second mixing outlet of the raw material unit 101 is communicated with the raw material inlet of the reaction unit 102. The third mixing outlet of the raw material unit 101 is communicated with the low-temperature medium inlet of the second heat exchange sub-unit 109.

[0045] The heat exchange unit of the present invention includes N heat exchange sub-units connected in series in sequence. The raw material unit 101 further includes a third mixing outlet, which can further avoid the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0046] In some embodiments of the present invention, the third mixing outlet is communicated with at least one of the heat exchange sub-units through a second control valve 106.

[0047] In the present utility model, the third mixing outlet and at least one heat exchange sub-unit are connected through a second control valve 106. That is, the opening and closing of the third mixing outlet can be controlled through the second control valve 106. When the temperature of the reaction tail gas is relatively low, the second control valve 106 controls the opening of the third mixing outlet to divert the reaction raw material gas, so that part of the reaction raw material gas exchanges heat with part of the reaction tail gas, avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange and cooling, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline. The second control valve 106 makes the operation more flexible and convenient.

[0048] In some embodiments of the present utility model, the control unit 105 is also electrically connected to the second control valve 106.

[0049] In the present utility model, the control unit 105 is also electrically connected to the second control valve 106. According to the real-time temperature detected by the temperature detection unit 104, the control unit 105 can also automatically adjust the opening degree of the second control valve 106, thereby controlling the flow direction and flow rate of the reaction raw material gas (silicon tetrachloride and hydrogen) during the heat exchange process, and further avoiding the problem that the temperature of the reaction tail gas is too low after heat exchange and cooling, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0050] In some embodiments of the present utility model, the first mixing outlet and the low-temperature medium inlet are connected through a first pipeline;

[0051] The second mixing outlet and the reaction unit 102 are connected through a second pipeline;

[0052] The third mixing outlet and at least one of the heat exchange sub-units are connected through a third pipeline;

[0053] Wherein, the diameter ratio of the first pipeline to the second pipeline is 2 - 5:1, and the diameter ratio of the first pipeline to the third pipeline is 2 - 5:1.

[0054] The first mixing outlet and the low-temperature medium inlet of the present utility model are connected through a first pipeline, the second mixing outlet and the reaction unit 102 are connected through a second pipeline, the third mixing outlet and at least one heat exchange sub-unit are connected through a third pipeline, and the diameter ratios of the first pipeline to the second pipeline and the first pipeline to the third pipeline are limited, which is beneficial to the precise control of the reaction tail gas temperature. Specifically, the diameter of the first pipeline can be 350 - 500 mm, the diameter of the second pipeline can be 100 - 200 mm, and the diameter of the third pipeline can be 100 - 200 mm.

[0055] In one embodiment, N = 2. When the temperature of the reaction tail gas at the high-temperature medium outlet of the second heat exchange sub-unit 109 is 200 - 210 °C, the second control valve 106 is opened to allow part of the reaction raw material gas (silicon tetrachloride and hydrogen) to pass through the primary heat exchange; when the temperature of the reaction tail gas at the high-temperature medium outlet of the second heat exchange sub-unit 109 is 190 - 200 °C, the first control valve 103 is opened to allow part of the reaction raw material gas (silicon tetrachloride and hydrogen) to directly enter the reaction unit 102; when the temperature of the reaction tail gas at the high-temperature medium outlet of the second heat exchange sub-unit 109 is 180 - 190 °C, both the first control valve 103 and the second control valve 106 are opened to allow part of the reaction raw material gas (silicon tetrachloride and hydrogen) to directly enter the reaction unit 102 and part of the reaction raw material gas (silicon tetrachloride and hydrogen) to pass through the primary heat exchange.

[0056] The present utility model limits the pipe diameter ratios of the first pipeline and the second pipeline, and the first pipeline and the third pipeline. Different control valves can be opened according to the detected temperature of the reaction tail gas, making the operation of precisely controlling the temperature of the reaction tail gas more convenient.

[0057] In some embodiments of the present utility model, a heating unit 107 is further included. The second mixing outlet is communicated with the raw material inlet of the reaction unit 102 through the heating unit 107, and the low-temperature medium outlet of the heat exchange unit is communicated with the raw material inlet of the reaction unit 102 through the heating unit 107. Among them, the low-temperature medium outlet is used to output the low-temperature medium after heat exchange and temperature rise output by the heat exchange unit.

[0058] The heat exchange device in the present utility model further includes a heating unit 107 for heating the reaction raw material gas (silicon tetrachloride and hydrogen). Since the temperature of the reaction raw material gas (silicon tetrachloride and hydrogen) after heat exchange and temperature rise by the heat exchange unit does not meet the requirements of the cold hydrogenation reaction, it needs to be heated again.

[0059] In one embodiment, the reaction raw material gas (silicon tetrachloride and hydrogen) is output from the second mixing outlet in the raw material unit 101, first enters the heating unit 107 for heating, and then enters the reaction unit 102 through the raw material inlet of the reaction unit 102 to participate in the cold hydrogenation reaction.

[0060] In another embodiment, the reaction raw material gas (silicon tetrachloride and hydrogen) is first heat-exchanged with the reaction tail gas in the heat exchange unit to increase the temperature, then output from the low-temperature medium outlet of the heat exchange unit, then enters the heating unit 107 for heating, and then enters the reaction unit 102 through the raw material inlet of the reaction unit 102 to participate in the cold hydrogenation reaction.

[0061] The heat exchange device of the present utility model further includes a heating unit 107, which is used to heat the reaction raw material gas (silicon tetrachloride and hydrogen) entering the reaction unit 102 to meet the requirements of the cold hydrogenation reaction and facilitate the smooth progress of the cold hydrogenation reaction.

[0062] In a second aspect, the present utility model provides a cold hydrogenation reaction system, including the heat exchange device as described above.

[0063] The cold hydrogenation reaction system of the present utility model includes the above heat exchange device. Therefore, this cold hydrogenation reaction system can avoid the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0064] Hereinafter, the technical solution of the present utility model will be further described in conjunction with specific embodiments.

[0065] Embodiment 1

[0066] The device in this embodiment is a heat exchange device, as Figure 1 shown, including a raw material unit 101; a reaction unit 102; a first control valve 103; a temperature detection unit 104; a control unit 105; a second control valve 106; a heating unit 107; a first heat exchange sub-unit 108; a second heat exchange sub-unit 109.

[0067] Among them, the first mixing outlet of the raw material unit 101 is connected to the low-temperature medium inlet of the second heat exchange sub-unit 109 through a first pipeline (with a pipe diameter of 350 mm), the second mixing outlet of the raw material unit 101 is connected to the low-temperature medium inlet of the heating unit 107 through the first control valve 103, the low-temperature medium outlet of the heating unit 107 is connected to the raw material inlet of the reaction unit 102, the third mixing outlet of the raw material unit 101 is connected to the low-temperature medium inlet of the second heat exchange sub-unit 109 through the second control valve 106, the reaction gas outlet of the reaction unit 102 is connected to the high-temperature medium inlet of the first heat exchange sub-unit 108, the low-temperature medium inlet of the first heat exchange sub-unit 108 is connected to the low-temperature medium outlet of the second heat exchange sub-unit 109, the low-temperature medium outlet of the first heat exchange sub-unit 108 is connected to the raw material inlet of the reaction unit 102 through the heating unit, the high-temperature medium outlet of the first heat exchange sub-unit 108 is connected to the high-temperature medium inlet of the second heat exchange sub-unit 109, the high-temperature medium outlet of the second heat exchange sub-unit 109 is connected to the temperature detection unit 104, the second mixing outlet of the raw material unit 101 is connected to the low-temperature medium inlet of the heating unit 107 through a second pipeline (with a pipe diameter of 150 mm), the third mixing outlet of the raw material unit 101 is connected to the low-temperature medium inlet of the second heat exchange sub-unit 109 through a third pipeline (with a pipe diameter of 150 mm), and the control unit 105 is electrically connected to the temperature detection unit 104, the first control valve 103, and the second control valve 106.

[0068] Comparative Example 1

[0069] The heat exchange device of Comparative Example 1 is basically the same as that of Example 1, except that it does not include the second mixing outlet.

[0070] Compared with Comparative Example 1, Example 1 can avoid the problem that the temperature of the reaction tail gas is too low after heat exchange, resulting in the precipitation and accumulation of metal chlorides and corrosion of the pipeline.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat exchange device, characterized in that: It includes a raw material unit, a heat exchange unit and a reaction unit; The raw material unit comprises a first mixing outlet and a second mixing outlet, the first mixing outlet is connected to the low-temperature medium inlet of the heat exchange unit, the reaction gas outlet of the reaction unit is connected to the high-temperature medium inlet of the heat exchange unit, and the second mixing outlet is connected to the raw material inlet of the reaction unit; The second mixing outlet and the reaction unit are connected via a first control valve; It also includes a temperature detection unit, which is connected to the high-temperature medium outlet of the heat exchange unit and is used to detect the real-time temperature of the high-temperature medium after heat exchange and temperature reduction output by the heat exchange unit; It also includes a control unit, which is electrically connected to the temperature detection unit and the first control valve respectively; The heat exchange unit includes N heat exchange subunits connected in series in the order of gradually moving away from the reaction unit, N≥2, and the number set of the N heat exchange subunits is recorded as P={1,2,…,i,i+1,…,j-1,j,…N-1,N}; The raw material unit further includes a third mixing outlet, and the third mixing outlet is connected to at least one of the first N-1 heat exchange subunits.

2. The heat exchange device according to claim 1, characterized in that: The third mixing outlet and at least one of the heat exchange subunits are in communication with each other through a second control valve.

3. The heat exchange device according to claim 2, characterized in that: The control unit is also electrically connected to the second control valve.

4. The heat exchange device according to claim 2, characterized in that: The first mixing outlet and the low-temperature medium inlet are connected through a first pipeline; The second mixing outlet and the reaction unit are connected via a second pipeline; The third mixing outlet is connected to at least one of the heat exchange subunits via a third pipeline; Among them, the pipe diameter ratio of the first pipeline and the second pipeline is 2-5:1, and the pipe diameter ratio of the first pipeline and the third pipeline is 2-5:

1.

5. The heat exchange device according to claim 4, characterized in that: It also includes a heating unit, the second mixing outlet is connected to the raw material inlet of the reaction unit through the heating unit, and the low-temperature medium outlet of the heat exchange unit is connected to the raw material inlet of the reaction unit through the heating unit, wherein the low-temperature medium outlet is used to output the low-temperature medium after heat exchange and temperature increase output by the heat exchange unit.

6. A cold hydrogenation reaction system, characterized in that: The heat exchange device comprises the heat exchange device according to any one of claims 1 to 5.

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