A continuous control system and method for a rectifier reboiler

Abstract

The present application belongs to the technical field of rectifying column reboiler, and particularly relates to a continuous control system and method of rectifying column reboiler. The technical scheme is as follows: a continuous control system of rectifying column reboiler, comprising a rectifying column, a reboiler and a condensate tank, a pressure gauge is connected to a steam inlet pipeline of the reboiler, an outlet regulating valve is connected to a condensate outlet pipeline of the condensate tank, a liquid level gauge is connected to the condensate tank, an outlet selection switching unit is electrically connected between the liquid level gauge and the pressure gauge, and the outlet selection switching unit is electrically connected to the outlet regulating valve. A continuous control method of rectifying column reboiler, comprising the following steps: after the pressure gauge on the steam inlet pipeline and the liquid level gauge on the condensate tank are selected at a low value, the outlet regulating valve on the condensate outlet pipeline is controlled. The present application provides a continuous control system and method of rectifying column reboiler, which can avoid water hammer caused by condensate to a condensate pipeline network.

Description

Technical Field

[0001] This invention belongs to the technical field of distillation column reboilers, and specifically relates to a continuous control system and method for a distillation column reboiler. Background Technology

[0002] As a crucial component of distillation columns, the stability of the reboiler directly impacts the product quality. Steam is a stable and readily available medium, making it widely used as the heat transfer medium in reboilers. The latent heat of the steam is returned as condensate after heat exchange within the reboiler.

[0003] The main factors affecting the heat transfer load of a reboiler include the heat transfer coefficient (K), heat transfer area (A), and heat transfer temperature difference (Δt). Inside the reboiler, the steam side undergoes a condensation process, and the heated medium side undergoes a reboiling process; both sides involve phase change, resulting in high heat transfer coefficients, while the overall heat transfer coefficient (K) remains relatively stable. Therefore, the heat transfer load can typically be adjusted by changing the heat transfer area (A) and the average heat transfer temperature difference (Δt). m Two commonly used reboiler heat load control processes are described above. Based on the theoretical analysis, in practical engineering, there are two control methods for conventional distillation column reboilers: 1) "Steam control process," where a regulating valve is installed on the reboiler steam inlet pipeline, and after heat exchange in the reboiler, the condensate is discharged through a drain valve or condensate tank; 2) "Condensate control process," where a level regulating valve is installed on the condensate outlet pipeline, and the heat exchange area (A) of the reboiler is controlled by the submersion height. Both of these methods can form a cascade loop with the temperature of the sensitive trays, ultimately achieving control of the distillation column.

[0004] "Steam control technology" uses regulating valves in the steam system to control steam pressure, thereby changing the steam condensation temperature and flow rate, essentially altering the average heat transfer temperature difference (Δt). m The control valve opening and flow rate affect the heat load of the reboiler. When the valve opening increases, the downstream steam pressure rises, the steam saturation temperature increases, the heat transfer temperature difference in the reboiler increases, and the heat transfer rate increases accordingly. Conversely, when the valve closing decreases, the heat transfer rate of the reboiler decreases. However, for systems with a large average heat transfer temperature difference (such as systems where the temperature of the heated medium is too low), the change in steam saturation temperature caused by the change in valve opening is limited, i.e., the effect on the average heat transfer temperature difference (Δt) is limited. m The impact of this control process is limited, and its ability to regulate the heat load of the reboiler is also limited. Typically, when the temperature of the heated medium fluctuates significantly, the control signal will automatically reduce the opening of the regulating valve to minimize the average temperature difference (Δt) in the heat transfer process. mAs the opening of the regulating valve continues to decrease, the amount of steam entering the heat exchanger decreases continuously. This eventually leads to the steam pressure after condensation falling below the back pressure of the condensate system, preventing condensate from being discharged. During this process, condensate accumulates in the system until it submerges the heat exchanger tube bundle. Due to the reduced heat exchange area of ​​the reboiler, the control signal will trigger the regulating valve opening to gradually increase again. The condensate pressure then gradually rises and eventually exceeds the back pressure of the condensate system, causing the condensate to be automatically discharged. At this point, the self-balancing cycle regulation of the system is complete. However, water hammer may occur at the moment the condensate pipeline regulating valve opens.

[0005] In practical engineering applications, for the "steam control process" control scheme, a condensate tank is usually installed downstream of the reboiler to solve the problem of selecting a steam trap when the condensate flow rate is too high, and to effectively prevent steam from entering the downstream condensate pipeline. The gas-liquid balance line installed at the top of the condensate tank is connected to the inlet steam pipeline, while ensuring a certain height difference between the reboiler and the condensate tank (so that the liquid column can overcome pipeline resistance, reboiler pressure drop, and regulating valve pressure drop), achieving the goal of continuous condensate discharge into the condensate tank. This means that this process requires a moderate increase in the height of the distillation column skirt, which may result in a certain increase in investment. Furthermore, general engineering designs consider a certain margin for the heat transfer area of ​​the reboiler; therefore, this process will cause the condensate to become subcooled. Since the pressure in the condensate tank is kept consistent with the steam pressure through the balance line, there will be a certain temperature difference between the vapor saturation temperature at the corresponding pressure and the subcooled condensate. When this temperature difference is small, dynamic equilibrium is easily achieved; however, when a large disturbance occurs, it may disrupt the gas / liquid film heat transfer balance within the tank, leading to pressure fluctuations or even water hammer. Therefore, a drawback of this control scheme is that changes in operating parameters may cause water hammer in downstream pipelines.

[0006] The "condensate control process" controls the discharge rate of condensate through regulating valves in the condensate system, altering the condensate level and thus affecting the reboiler heat exchange area (A), ultimately regulating the reboiler's heat load. Compared to the steam control process, this process uses smaller regulating valves, and the inlet steam pressure remains constant equal to the steam system pressure, effectively avoiding the problem of condensate not being discharged due to pressure drop at the inlet steam valve. However, since this control scheme is a "post-regulation" process after temperature or steam pressure fluctuations, and condensate has a relatively higher density than steam, the automatic control process takes longer, potentially leading to operational instability. Furthermore, the condensate control process requires a certain vertical distance in the condensate pipeline at the reboiler outlet. This is to ensure a certain liquid column forms within the tube bundle, preventing energy loss due to steam entrainment in the condensate, and to overcome the condensate back pressure to avoid water hammer during regulation. The disadvantages of this control scheme are response lag, which is detrimental to continuous and stable operation, and the potential for water hammer. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, the present invention aims to provide a continuous control system and method for a distillation column reboiler that controls the outlet regulating valve on the condensate outlet pipeline by comparing the lower value of the pressure signal from the steam inlet pipeline of the reboiler with the liquid level signal from the condensate tank, thereby overcoming water hammer caused by condensate to the condensate pipeline network.

[0008] The technical solution adopted in this invention is as follows:

[0009] A continuous control system for a distillation column reboiler includes a distillation column, a reboiler connected to the lower part of the distillation column via a pipeline, a feed pipeline connected to the upper part of the distillation column, and a product pipeline connected to the bottom of the distillation column. A steam inlet pipeline is connected to the reboiler, a pressure gauge is connected to the steam inlet pipeline, a condensate tank is connected to the reboiler via a pipeline, a condensate outlet pipeline is connected to the condensate outlet pipeline, an outlet regulating valve is connected to the condensate tank, a level gauge is connected to the condensate tank, an outlet selection switching unit is electrically connected between the level gauge and the pressure gauge, and the outlet selection switching unit is electrically connected to the outlet regulating valve.

[0010] This invention uses a pressure gauge on the steam inlet pipeline to compare the lower value with the level gauge of the condensate tank, and then controls the outlet regulating valve on the condensate outlet pipeline. Compared to traditional "steam control processes," this invention overcomes water hammer in the condensate network by switching between level control and pressure control on the condensate outlet pipeline. When the pressure on the steam inlet pipeline is lower than the level of the condensate tank through the lower value comparison, the pressure gauge controls the outlet regulating valve, thus eliminating the need to install equipment too high to increase the pressure. Therefore, this invention can reduce the equipment installation height, optimize the condensate pipe diameter, and reduce investment in the condensate network.

[0011] As a preferred embodiment of the present invention, the feed pipeline is connected to a feed flow meter, the distillation column is connected to a thermometer, the feed flow meter and the thermometer are electrically connected to a steam inlet selection switching unit, the steam inlet pipeline is connected to a steam inlet regulating valve and a steam inlet flow meter, the steam inlet selection switching unit is electrically connected to the steam inlet flow meter, and the steam inlet flow meter is electrically connected to the steam inlet regulating valve.

[0012] In this invention, the flow rate value of the feed flow meter on the feed line is compared with the temperature value of the thermometer, and the higher value is selected. Then, the steam flow meter cascades to control the steam inlet regulating valve on the reboiler steam inlet line. Compared to the "condensate control process," this invention automatically controls the reboiler inlet steam line based on the feed situation in the distillation column, between the flow rate signal of the feed stream to the distillation column and the temperature signal of the sensitive trays on the distillation column, overcoming the lag of the "condensate control process." This invention can meet the requirements of continuous and stable operation under various conditions, including start-up, normal operation, low-load operation, planned shutdown, and instantaneous disturbances.

[0013] In a preferred embodiment of the present invention, a correction calculation unit is also electrically connected between the feed flow meter and the steam inlet selection switching unit. The parameters of the feed flow meter on the feed line of the distillation column are calculated with the correction coefficient (HC) (feedforward signal). The calculated value is compared with the higher value of the thermometer (feedback signal), and then the steam inlet regulating valve on the steam inlet line of the reboiler is controlled by the cascade control of the steam inlet flow meter.

[0014] As a preferred embodiment of the present invention, an emergency shut-off valve is also connected to the steam inlet pipeline.

[0015] In a preferred embodiment of the present invention, a balancing pipeline is connected between the condensate tank and the steam inlet pipeline. The pressure in the condensate tank is kept consistent with the pressure in the steam tank through the balancing pipeline.

[0016] A method for continuous control of a reboiler in a distillation column includes the following steps:

[0017] After comparing the lower value of the pressure gauge on the steam inlet pipeline with the level gauge on the condensate tank, the outlet regulating valve on the condensate outlet pipeline is controlled. Compared with the traditional "steam control process", this invention overcomes the water hammer of condensate on the condensate network by switching between level control and pressure control on the condensate outlet pipeline.

[0018] As a preferred embodiment of the present invention, the following steps are included:

[0019] When setting a preset pressure value and comparing the lower values ​​of the pressure gauge and the level gauge, the level gauge controls the outlet regulating valve when the pressure value of the pressure gauge is higher than the preset pressure value, and the pressure gauge controls the outlet regulating valve when the pressure value of the pressure gauge is less than or equal to the preset pressure value. The first method of comparing the lower values ​​of the pressure gauge and the level gauge is to set a preset pressure value, so that the outlet regulating valve can be controlled by the level gauge when the steam pressure is low.

[0020] As a preferred embodiment of the present invention, the following steps are included:

[0021] When comparing the lower values ​​of pressure gauges and level gauges, the pressure gauge's pressure value as a percentage of the maximum pressure in the steam inlet pipe is compared with the level gauge's level value as a percentage of the highest level in the condensate tank. A second method for comparing the lower values ​​of pressure gauges and level gauges is through percentage comparison.

[0022] As a preferred embodiment of the present invention, the following steps are included:

[0023] After comparing the flow rate value of the feed flow meter on the feed line of the distillation column with the temperature value of the thermometer, the steam inlet regulating valve on the steam inlet line is controlled in cascade by the steam inlet flow meter. Compared with the "condensate control process," this invention automatically controls the reboiler inlet steam line based on the feed situation of the distillation column, between the flow rate signal of the feed stream to the distillation column and the temperature signal of the sensitive trays on the distillation column, overcoming the lag of the "condensate control process." As a preferred embodiment of this invention, the following steps are included:

[0024] The flow rate value of the feed flow meter on the feed pipeline is calculated with a correction factor, and the calculated value is compared with the temperature value of the thermometer to select the higher value.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. In this invention, the pressure gauge on the steam inlet pipeline and the level gauge on the condensate tank are compared at a lower value to control the outlet regulating valve on the condensate outlet pipeline. Compared with the traditional "steam control process," this invention overcomes the water hammer of condensate on the condensate network by switching between level control and pressure control on the condensate outlet pipeline.

[0027] 2. When the pressure on the steam inlet pipeline is lower than the condensate tank level by a low-value selection, the outlet regulating valve is controlled by a pressure gauge, thus eliminating the need to install the equipment too high to increase the pressure. Therefore, this invention can reduce the equipment installation height, optimize the condensate pipe diameter, and reduce investment in the condensate piping network.

[0028] 3. In this invention, the flow rate value of the feed flow meter on the feed line is compared with the temperature value of the thermometer, and the higher value is selected. Then, the steam inlet regulating valve on the reboiler steam inlet line is controlled by the cascade control of the steam inlet meter. Compared with the "condensate control process", this invention automatically controls the reboiler inlet steam line between the flow rate signal of the feed stream to the distillation column and the temperature signal of the sensitive tray on the distillation column according to the feed situation of the distillation column, thus overcoming the lag of the "condensate control process".

[0029] 4. This invention overcomes the lag in control and water hammer in condensate pipe networks, and can ensure continuous and stable operation under various working conditions such as start-up, normal operation, low-load operation, planned shutdown, and instantaneous disturbances. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] In the diagram: 1-Distillation column; 2-Reboiler; 3-Condensate tank; 4-Feed flow meter; 5-Thermometer; 6-Pressure gauge; 7-Steam flow meter; 8-Steam regulating valve; 9-Emergency shut-off valve; 10-Level gauge; 11-Outlet regulating valve. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0034] like Figure 1 As shown, the continuous control system of the reboiler in this embodiment includes a distillation column 1, a reboiler 2 connected to the lower part of the distillation column 1 via a pipeline, a feed pipeline connected to the top of the distillation column 1, and a product pipeline connected to the bottom of the distillation column 1; a steam inlet pipeline is connected to the reboiler 2, a pressure gauge 6 and an emergency shut-off valve 9 are connected to the steam inlet pipeline, a condensate tank 3 is connected to the reboiler 2 via a pipeline, a condensate outlet pipeline is connected to the condensate outlet pipeline, an outlet regulating valve 11 is connected to the condensate tank 3, a level gauge 10 is connected to the condensate tank 3, an outlet selection switching unit is electrically connected between the level gauge 10 and the pressure gauge 6, and the outlet selection switching unit is electrically connected to the outlet regulating valve 11; a balancing pipeline is connected between the condensate tank 3 and the steam inlet pipeline, and the pressure of the condensate tank 3 is kept consistent with the steam pressure through the balancing pipeline. The feed pipeline is connected to a feed flow meter 4, and a thermometer 5 is connected to the distillation column 1. A steam inlet selection switching unit is electrically connected between the feed flow meter 4 and the thermometer 5. A steam inlet regulating valve 8 and a steam inlet flow meter 7 are connected to the steam inlet pipeline. The steam inlet selection switching unit is electrically connected to the steam inlet flow meter 7, and the steam inlet flow meter 7 is electrically connected to the steam inlet regulating valve 8.

[0035] In this invention, the pressure gauge 6 on the steam inlet pipeline and the level gauge 10 of the condensate tank 3 perform a low-value comparison to control the outlet regulating valve 11 on the condensate outlet pipeline. Compared to the traditional "steam control process," this invention overcomes the water hammer problem in the condensate network by switching between level control and pressure control on the condensate outlet pipeline. When the pressure on the steam inlet pipeline is lower than the level value of the condensate tank 3 through low-value comparison, the pressure gauge 6 controls the outlet regulating valve 11, thus eliminating the need to install the equipment too high to increase the pressure value. Therefore, this invention can reduce the equipment installation height, optimize the condensate pipe diameter, and reduce investment in the condensate network.

[0036] In this invention, the flow rate value of the feed flow meter 4 on the feed line is compared with the temperature value of the thermometer 5, and then the steam inlet regulating valve 8 on the reboiler 2 steam inlet line is controlled in cascade by the steam inlet flow meter 7. Compared to the "condensate control process," this invention automatically controls the reboiler 2 inlet steam line based on the feed situation of the distillation column, between the flow rate signal of the feed stream to the distillation column 1 and the temperature signal of the sensitive trays on the distillation column 1, overcoming the lag of the "condensate control process." This invention can meet the requirements of continuous and stable operation under various conditions such as start-up, normal operation, low-load operation, planned shutdown, and instantaneous disturbances.

[0037] To enable the comparison between the flow rate signal of the feed stream to distillation column 1 and the temperature signal of the sensitive tray on distillation column 1, a correction calculation unit is electrically connected between the feed flow meter 4 and the steam inlet selection switching unit. The parameters of the feed flow meter 4 on the feed line of distillation column 1 are calculated with the correction coefficient (HC) (feedforward signal). The calculated value is compared with the higher value of the thermometer 5 (feedback signal), and then the steam inlet regulating valve 8 on the steam inlet line of reboiler 2 is controlled in cascade via the steam inlet flow meter 7.

[0038] The continuous control method for the reboiler of the distillation column in this embodiment includes the following steps:

[0039] After comparing the lower value of the pressure gauge 6 on the steam inlet pipeline with the level gauge 10 on the condensate tank 3, the outlet regulating valve 11 on the condensate outlet pipeline is controlled.

[0040] The low-value comparison between pressure gauge 6 and level gauge 10 can be performed in two ways: First, a preset pressure value is set. When comparing the low values ​​of pressure gauge 6 and level gauge 10, if the pressure value of pressure gauge 6 exceeds the preset pressure value, level gauge 10 controls outlet regulating valve 11; if the pressure value of pressure gauge 6 is less than or equal to the preset pressure value, pressure gauge 6 controls outlet regulating valve 11. Second, the low-value comparison is performed by comparing the percentage of pressure value of pressure gauge 6 relative to the maximum pressure of the steam inlet pipeline with the percentage of level value of level gauge 10 relative to the highest level of condensate tank 3. In the first comparison method, the set value of pressure gauge 6 should fully consider the installation height of condensate tank 3, the maximum back pressure of the condensate pipeline network, and the pressure drop of outlet regulating valve 11.

[0041] The parameters of the feed flow meter 4 on the feed line of distillation column 1 are calculated with the correction coefficient (HC) (feedforward signal). The calculated value is compared with the high value of the thermometer 5 (feedback signal), and then the steam regulating valve 8 on the steam inlet line of reboiler 2 is controlled by the steam flow meter 7 in cascade.

[0042] This invention uses cascaded control of the inlet flow rate of distillation column 1 and the temperature of the sensitive tray to compare feedforward and feedback parameters and automatically switch the cascade control master variables. Specifically, the flow rate signal of the inlet stream of distillation column 1 serves as the feedforward signal, and the temperature signal of the sensitive tray of distillation column 1 serves as the feedback signal. Through the continuous control method of this invention, the following control results can be achieved.

[0043] When the flow rate disturbance of the feed is higher than the set parameter, the flow rate signal of the feed stream of the distillation column 1 controls the steam inlet regulating valve 8 on the steam inlet pipeline, and the outlet regulating valve 11 on the condensate outlet pipeline of the condensate tank 3 controls the liquid level of the condensate tank 3.

[0044] When the feed is stable, the temperature signal of the sensitive tray on the distillation column 1 is used to cascade control the steam inlet regulating valve 8 on the steam inlet pipeline, and the outlet regulating valve 11 on the condensate outlet pipeline of the condensate tank 3 controls the liquid level of the condensate tank 3.

[0045] Meanwhile, for systems with a large average temperature difference in heat transfer, when the heat exchange area of ​​reboiler 2 meets the design requirements and will not cause the condensate to be lower than the back pressure of the condensate pipeline, the steam inlet pipeline of reboiler 2 will be automatically controlled between the flow signal of the feed stream of distillation column 1 and the temperature signal of the sensitive tray on distillation column 1 according to the feed situation of the distillation column. The outlet regulating valve 11 of the condensate outlet pipeline controls the liquid level of condensate tank 3.

[0046] When the heat exchange area of ​​reboiler 2 does not meet the design requirements, such as excessive heat exchange area margin or small actual fouling thermal resistance, or excessively low temperature of the heated medium, the steam inlet pipeline of reboiler 2 is automatically controlled between the flow rate signal of the feed stream of distillation column 1 and the temperature signal of the sensitive tray on distillation column 1 according to the feed situation of distillation column 1. The condensate is controlled by the level gauge 10 on the condensate tank 3 to switch the outlet regulating valve 11 of the condensate outlet pipeline to the pressure gauge 6 on the steam inlet pipeline to control the outlet regulating valve 11 of the condensate outlet pipeline of the condensate tank 3, so as to ensure that the condensate is discharged smoothly and stably.

[0047] In actual operation, the flow rate of the feed stream to distillation column 1 varies at different stages, such as the gradual increase in feed flow rate during start-up, the gradual decrease in feed flow rate during planned shutdown or low-load operation, and the possibility of large instantaneous disturbances during operation. Additionally, the fouling thermal resistance of reboiler 2 also varies. Newly commissioned reboilers 2 or those whose tube bundles have been cleaned of fouling thermal resistance after maintenance have lower fouling thermal resistance. For systems with a large average temperature difference in heat transfer, this can cause condensate to become subcooled, leading to discontinuous condensate drainage and water hammer.

[0048] Compared to the traditional "steam control process," this invention overcomes the water hammer problem in the condensate network by switching between level and pressure control on the condensate outlet pipeline. Furthermore, unlike the "condensate control process," the reboiler 2 inlet steam pipeline is automatically controlled based on the feed flow rate of distillation column 1 and the temperature signal of the sensitive trays on distillation column 1, overcoming the lag inherent in the "condensate control process." This allows for continuous and stable operation under various conditions, including start-up, normal operation, low-load operation, planned shutdown, and instantaneous disturbances.

[0049] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A continuous control method for a reboiler in a distillation column, characterized in that: A continuous control system using a distillation column reboiler includes a distillation column (1), a reboiler (2) connected to the lower part of the distillation column (1) via a pipeline, a feed pipeline connected to the top of the distillation column (1), and a product pipeline connected to the bottom of the distillation column (1); a steam inlet pipeline is connected to the reboiler (2), a pressure gauge (6) is connected to the steam inlet pipeline, a condensate tank (3) is connected to the reboiler (2) via a pipeline, a condensate outlet pipeline is connected to the condensate outlet pipeline, an outlet regulating valve (11) is connected to the condensate tank (3), a level gauge (10) is connected to the condensate tank (3), an outlet selection switching unit is electrically connected between the level gauge (10) and the pressure gauge (6), and the outlet selection switching unit is electrically connected to the outlet regulating valve (11); Includes the following steps: After the pressure gauge (6) on the steam inlet pipeline and the level gauge (10) on the condensate tank (3) are compared at a lower value, the outlet regulating valve (11) on the condensate outlet pipeline is controlled.

2. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: Includes the following steps: When setting a pressure preset value and comparing the low value of the pressure gauge (6) and the level gauge (10), when the pressure value of the pressure gauge (6) exceeds the pressure preset value, the level gauge (10) controls the outlet regulating valve (11), and when the pressure value of the pressure gauge (6) is less than or equal to the pressure preset value, the pressure gauge (6) controls the outlet regulating valve (11).

3. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: Includes the following steps: When comparing the lower values ​​of the pressure gauge (6) and the level gauge (10), the pressure value of the pressure gauge (6) relative to the maximum pressure of the steam inlet pipeline is compared with the level value of the level gauge (10) relative to the highest level of the condensate tank (3).

4. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: Includes the following steps: After comparing the flow rate of the feed flow meter (4) on the feed line of the distillation column (1) with the temperature value of the thermometer (5), the steam inlet regulating valve (8) on the steam inlet line is controlled by the steam inlet flow meter (7) in cascade.

5. The continuous control method for a reboiler in a distillation column according to claim 4, characterized in that: Includes the following steps: The flow rate of the feed flow meter (4) on the feed pipeline is calculated with the correction coefficient, and the calculated value is compared with the temperature value of the thermometer (5) to select the higher value.

6. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: The feed pipeline is connected to a feed flow meter (4), and a thermometer (5) is connected to the distillation column (1). A steam inlet selection switching unit is electrically connected between the feed flow meter (4) and the thermometer (5). A steam inlet regulating valve (8) and a steam inlet flow meter (7) are connected to the steam inlet pipeline. The steam inlet selection switching unit is electrically connected to the steam inlet flow meter (7), and the steam inlet flow meter (7) is electrically connected to the steam inlet regulating valve (8).

7. The continuous control method for a reboiler in a distillation column according to claim 6, characterized in that: The feed flow meter (4) is also electrically connected to the steam inlet selection switching unit, and a correction calculation unit is also connected to it.

8. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: An emergency shut-off valve (9) is also connected to the steam inlet pipeline.

9. The continuous control method for a reboiler in a distillation column according to claim 1, characterized in that: A balancing pipeline is connected between the condensate tank (3) and the steam inlet pipeline.

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