Methods, apparatus, media, and equipment for propane removal from tail gas using gas-phase fluidization based on propane removal tower steam control.

Abstract

This application discloses a control method, device, medium, and equipment for steam regulation in a propane stripper, comprising the following steps: Step S1: When the measured value of the side stream liquid level is ≥95.5% and the differential pressure on the tray is >35 kPa, the setting value of the steam flow regulating valve is lowered at intervals of 10 times / minute; Step S2: When the measured value of the side stream liquid level is <95% and the differential pressure on the tray is <48 kPa, the setting value of the steam flow regulating valve is raised at intervals of 10 times / minute; Step S3: The propylene reflux flow rate is measured using a flow detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the steam feed rate is increased; Step S4: When the propylene reflux flow rate is higher than 4500 kg / h, the steam feed rate is reduced in multiple adjustments to maintain the propylene reflux flow rate at or above 5100 kg / h. After adopting this method, the top reflux flow rate of the propane stripper was stabilized at around 5100 kg / h, which solved the problem of intermittent and large fluctuations in the top reflux flow rate. After being put into use, the top output of the tower is sufficient and stable, and the side output level gauge is stable at 104%, ensuring the stable operation of the propylene recovery pump.

Description

Technical Field

[0001] This application relates to the field of polypropylene production technology, and in particular to a method, apparatus, medium, and equipment for controlling propane removal from tail gas using a gas-phase fluidization method based on steam control of a propane removal tower. Background Technology

[0002] The existing polypropylene production unit uses a gas-phase fluidized bed process. The recovered propylene tail gas contains a large amount of propane, which needs to be removed by a propane stripper. A U-tube reboiler is installed at the bottom of the propane stripper, and the steam flow rate in the reboiler is regulated by a control valve. The gas phase, heated at the bottom of the tower, rises through the trays. Before entering the top condenser, the light and heavy components in the gas phase are separated. The light components are condensed after reaching a preset temperature through a circulating water regulating valve in the top condenser and a preset pressure through a pressure regulating valve in the non-condensable gas discharge pipeline at the top of the tower.

[0003] Propylene obtained from the side stream separation is pumped back to the reactor via a circulating pump on the pipeline; the propane discharge flow rate at the bottom of the tower is controlled by a flow control valve, and after a trace amount of water is injected for deactivation, it is discharged to the tank area for storage; the liquid evaporation in the tower is controlled by the reboiler steam flow control valve through the pressure difference of all the tower trays.

[0004] As can be seen from the above vapor-liquid motion process, in the process of removing propane from the tail gas, the control of the reboiler steam flow rate is the key to the stable operation of the propane removal tower. If the steam flow rate is too high, the evaporation of heavy propane components at the bottom of the tower will increase, the entrainment of propane in the rising gas phase will increase, and the propane removal effect of the equipment will be poor. If the steam flow rate is too low, the propylene component content in the separated propane will be too high, and the propylene consumption will increase.

[0005] The current steam flow regulation process of reboilers is manually adjusted, which has problems such as untimely adjustment, high labor intensity for operators, and is limited by individual operating experience and skill differences, resulting in unstable control results. This is not conducive to the stable operation of the overall equipment, the efficient separation of propane and propylene, or energy saving and consumption reduction.

[0006] The existing reboiler has low steam flow control accuracy and poor propane removal effect, resulting in a large amount of propylene entrained in the propane discharged from the bottom of the tower, which increases the propylene consumption during the production process. It also leads to insufficient reflux flow at the top of the propane removal tower and low side stream output, which in turn frequently causes propylene circulation pump tripping and shutdown accidents, affecting normal production.

[0007] The current control method results in a high reboiler steam flow rate, with a large amount of propane still entrained in the rising gas phase. This leads to poor propane removal efficiency in the overall tower, increased steam consumption, high tower top temperature, increased consumption of circulating water for cooling, and high tower top pressure, resulting in increased emissions of non-condensable gases from the tower top, which further increases propylene consumption.

[0008] The information disclosed in the background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] This application addresses the aforementioned technical problems by providing a gas-phase fluidization tail gas propane removal control method based on propane removal tower steam control. This method achieves intelligent control and regulation of the steam flow rate of the propane removal tower, effectively reducing the tower top temperature, reducing the tower top pressure, reducing the amount of non-condensable gas emitted from the tower top, reducing steam consumption, increasing propylene recovery, reducing the amount of propylene used in production, avoiding propylene circulation pump tripping and shutdown, reducing the amount of propylene entrained in the propane discharged from the bottom of the tower, and achieving the best propane removal effect, thus achieving the goal of energy saving and consumption reduction.

[0010] This application provides a gas-phase fluidized bed propane removal control method based on propane removal tower steam control, comprising the following steps:

[0011] Step S1: The liquid level is measured using a side-line sampling liquid level detection device, and the tray pressure difference is measured using a tray pressure difference detection tube group. When the liquid level measurement value is greater than or equal to 95.5% of the maximum liquid level and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve is lowered at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not be lower than the lower limit setting value of 1320 kg / h.

[0012] Step S2: When the liquid level measurement value of the side-stream sampling expansion section is less than 95% of the maximum liquid level and the pressure difference of the tray is less than 48 kPa, adjust the setting value of the first steam flow regulating valve at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not exceed the upper limit setting value of 1500 kg / h.

[0013] Step S3: The propylene reflux flow rate is measured using a propylene reflux flow rate detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the opening of the first steam flow rate regulating valve is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane depropanizer 4 without decreasing.

[0014] Step S4: When the obtained propylene reflux rate is higher than 4500 kg / h, adjust the first steam flow regulating valve multiple times to reduce the steam feed rate and keep the propylene reflux rate of the propane depropanizer at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve is controlled within 5 kg / h.

[0015] Preferably, a cooler is installed at the top of the propane stripper, and the cooler is connected to the expansion section; the side-stream propylene discharge pipe is installed at the upper part of the expansion section; the side-stream propylene level detection device is installed on the side-stream propylene discharge pipe; the side-stream propylene discharge pipe is connected to the expansion section through a reflux branch pipe; and the reflux propylene flow detection device is installed on the reflux branch pipe.

[0016] Preferably, a U-shaped reboiler is installed on the lower side wall of the propane dehydrogenator; a first steam flow regulating valve is installed on the steam inlet pipe of the U-shaped reboiler.

[0017] Preferably, the lower sidewall of the enlarged section is connected to the differential pressure detection pipe assembly of the tray.

[0018] Preferably, it includes: a tower level detection tube assembly; the tower level detection tube assembly is installed on the other side wall of the propane removal tower.

[0019] Preferably, it includes: a branch pipe, a first side-line extraction valve, and a second side-line extraction valve; the branch pipe is connected in parallel with the side-line extraction propylene discharge pipe; the first side-line extraction valve, the second side-line extraction valve, and the side-line extraction liquid level detection device are spaced apart on the branch pipe; the first side-line extraction valve and the second side-line extraction valve are respectively located on both sides of the side-line extraction liquid level detection device.

[0020] Preferably, it includes: a branch pipe, a first reflux propylene valve, and a second reflux propylene valve; the branch pipe is connected in parallel with the side-line propylene discharge pipe; a reflux propylene flow detection device, the first reflux propylene valve, and the second reflux propylene valve are spaced apart on the branch pipe; the first reflux propylene valve and the second reflux propylene valve are respectively located on both sides of the reflux propylene flow detection device.

[0021] Another aspect of this application provides an apparatus for a gas-phase fluidized bed gas propane removal control method based on propane removal tower steam control as described above, comprising:

[0022] The first acquisition and adjustment module is used to measure the liquid level using a side-line liquid level detection device and measure the tray pressure difference using a tray pressure difference detection tube group. When the liquid level measurement value is greater than or equal to 95.5% of the maximum liquid level and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve is lowered at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment does not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve is not lower than the lower limit setting value of 1320 kg / h.

[0023] The second acquisition and adjustment module is used to: when the liquid level measurement value of the side-stream sampling expansion section is less than 95% of the maximum liquid level and the pressure difference of the tray is less than 48 kPa, adjust the setting value of the first steam flow regulating valve at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not exceed the upper limit setting value of 1500 kg / h.

[0024] The third acquisition and regulation module is used to measure the propylene reflux flow rate using a reflux propylene flow rate detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the opening of the first steam flow rate regulating valve is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane depropanizer 4 without decreasing.

[0025] The fourth acquisition and adjustment module is used to adjust the first steam flow regulating valve multiple times to reduce the steam feed rate when the obtained propylene reflux rate is higher than 4500 kg / h, so as to keep the propylene reflux rate of the propane dehydrogenator at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve is controlled within 5 kg / h.

[0026] Another aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the above-described gas phase fluidization tail gas depropane control method based on depropane tower steam control.

[0027] Another aspect of this application provides a computer device, including a processor, a memory, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the gas phase fluidization tail gas depropane control method based on depropane tower steam control as described above.

[0028] The beneficial effects that this application can produce include:

[0029] 1) The gas phase fluidization tail gas propane removal control method based on propane removal tower steam control provided in this application can reduce the consumption of propane removal tower steam, circulating water and propylene, stabilize the system operation, and solve the problem of high labor intensity for operators.

[0030] 2) The propane removal control method for gas-phase fluidization tail gas based on propane removal tower steam control provided in this application controls the liquid level and tower pressure difference of the propane removal tower by adjusting the steam flow rate of the tower bottom heat source; the system adjusts the steam flow rate according to the changes in liquid level and pressure difference within the set tower plate pressure difference range and the set steam flow rate adjustment range by giving a liquid level target and buffer zone, thereby realizing automatic control of the propane removal tower and saving steam as much as possible.

[0031] 3) The gas-phase fluidization tail gas propane removal control method based on propane removal tower steam control provided in this application can reduce the workload of operators and reduce the consumption of propane removal tower steam, circulating water and propylene; the propane removal tower reflux flow rate can be stabilized at 5100 kg / h, the propylene liquid level of the tower top side line can be stabilized at 104% of the design value, and at the same time, it can ensure the stable operation of the propylene recovery pump and avoid the pump tripping and shutdown, so that the propane removal tower can reach the optimal stable operation, enhance the propane removal capacity, reduce the propylene content in propane and reduce propylene consumption. Attached Figure Description

[0032] Figure 1 A schematic diagram of the gas-phase fluidization tail gas propane removal control method based on propane removal tower steam control provided in this application;

[0033] Figure 2 A schematic diagram of the gas-phase fluidized bed gas propane removal production unit provided in this application;

[0034] Figure 3 This is a schematic diagram of the steam flow rate indication trend of the propane removal tower in the embodiments of this application; the horizontal axis in the figure represents the time interval between any two points in time, which is 8 hours, including 24:00, 8:00 and 16:00 in a day, and the vertical axis represents the steam flow rate in kg / h.

[0035] Figure 4 This is a schematic diagram showing the trend of the tower top reflux flow rate in an embodiment of this application; the horizontal axis in the figure represents a time interval of 14 days between any two points, and the vertical axis represents the tower top reflux flow rate in kg / h.

[0036] Figure 5 This is a schematic diagram of the trend of the liquid level at the top of the tower in an embodiment of this application; the horizontal axis in the figure represents the time interval between any two points, which is 14 days, and the vertical axis represents the percentage of the liquid level at the top of the tower to the total liquid level, in %;

[0037] Figure 6 A connection structure diagram of the gas phase fluidization tail gas propane removal control module based on propane removal tower steam control provided in this application;

[0038] Legend:

[0039] Cooler 1, Tower top temperature control valve 12, Circulating water circulation pipe assembly 11, Tower top pressure control valve 13, Non-condensable gas discharge pipe 14, Propane removal tower 4, Tail gas inlet pipe assembly 5, U-shaped reboiler 41, Tower liquid level detection pipe assembly 42, Steam inlet pipe 31, Propane discharge pipe 32, First steam flow regulating valve 312, Second steam flow regulating valve 311, Reflux propylene flow detection device 21, First reflux propylene valve 211, Second reflux propylene valve 212, Tower tray differential pressure detection pipe assembly 22, First tower tray differential pressure detection valve 221, Second tower tray differential pressure detection valve 222, Side stream liquid level detection device 23, First side stream discharge valve 231, Second side stream discharge valve 232, Side stream propylene discharge pipe 24. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] The controller used in this implementation scheme is an existing structure, and the control circuit can be implemented by those skilled in the art through simple programming. It is common knowledge in the field, and it is only used without modification. Therefore, the control method and circuit connection will not be described in detail.

[0043] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0044] See Figures 1-2 The propane removal control method for gas-phase fluidized bed gas based on propane removal tower steam control provided in this application includes the following steps:

[0045] Step S1: The liquid level is measured using the side-stream sampling liquid level detection device 23, and the tray pressure difference is measured using the tray pressure difference detection tube group 22. When the liquid level measurement value of the side-stream sampling expansion section is greater than or equal to 95.5% of the maximum liquid level, and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve 312 is lowered at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve 312 in a single adjustment does not exceed 5 kg / h. The setting value range of the first steam flow regulating valve 312 is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve 312 is not lower than the lower limit setting value of 1320 kg / h.

[0046] Step S2: When the liquid level measurement value of the side-stream sampling expansion section is less than 95% of the maximum liquid level and the pressure difference of the tray is less than 48 kPa, the setting value of the first steam flow regulating valve 312 is adjusted upward at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve 312 in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve 312 is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve 312 shall not exceed the upper limit setting value of 1500 kg / h.

[0047] Step S3: The propylene reflux flow rate is measured using the reflux propylene flow rate detection device 21. When the propylene reflux flow rate measured by the reflux propylene flow rate detection device 21 on the propane dehydrogenator 4 is lower than 4100 kg / h, the opening of the first steam flow regulating valve 312 is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane dehydrogenator 4 without decreasing.

[0048] Step S4: When the propylene reflux rate of the propane dehydrogenator 4 is higher than 4500 kg / h, adjust the first steam flow regulating valve 312 multiple times to reduce the steam feed rate and keep the propylene reflux rate of the propane dehydrogenator 4 at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve 312 is controlled within 5 kg / h.

[0049] By adjusting the steam flow rate of the heat source in the reboiler, the liquid level and pressure difference in the propane stripper can be controlled. This adjustment method achieves automatic control of the recovery tower and saves steam as much as possible by adjusting the steam flow rate according to changes in liquid level and pressure difference within a set tray pressure difference range and a given steam flow rate adjustment range.

[0050] The device controlled by this method includes: a cooler 1 installed at the top of the propane dehydrogenator 4 and connected to the propane dehydrogenator 4 through an expansion section; a non-condensable gas discharge pipe 14 is installed on the side wall 2 of the expansion section, and a tower top pressure control valve 13 is installed on the non-condensable gas discharge pipe 14; the cooler 1 is cooled by a circulation pipeline connected to the cooling jacket of the cooler 1, and the circulation pipeline includes: a circulating water supply pipe (CWS) and a circulating water return pipe (CWR); the circulating water supply pipe connects the circulating water storage tank and the cooling jacket of the cooler; a tower top temperature control valve 12 is installed on the circulating water return pipe, and the flow rate and flow of circulating water in the circulation pipeline are controlled by the opening degree of the tower top temperature control valve 12, thereby controlling the tower top temperature.

[0051] A side-line propylene discharge pipe 24 is installed at the upper part of the expansion section, and a side-line propylene discharge pipe 24 is equipped with a side-line propylene level detection device 23 for detecting the liquid level value of the side-line propylene expansion section. It also includes: a branch pipe, a first side-line propylene discharge valve 231, and a second side-line propylene discharge valve 232; the branch pipe is connected in parallel with the side-line propylene discharge pipe 24, and the first side-line propylene discharge valve 231, the second side-line propylene discharge valve 232, and the side-line propylene level detection device 23 are installed on the branch pipe; the first side-line propylene discharge valve 231 and the second side-line propylene discharge valve 232 are respectively located at both ends of the side-line propylene level detection device 23.

[0052] The middle part of the propylene discharge pipe 24 from the side line is connected to the expansion section through a propylene return pipe, and a propylene return flow detection device 21 is installed on the propylene return pipe; it also includes: a branch pipe, a first propylene return valve 211, and a second propylene return valve 212; the branch pipe is connected in parallel with the propylene return pipe; the first propylene return valve 211, the second propylene return valve 212, and the propylene return flow detection device 21 are installed on the branch pipe; the first propylene return valve 211 and the second propylene return valve 212 are respectively located on both sides of the propylene return flow detection device 21.

[0053] A tray differential pressure detection pipe assembly 22 is installed on the lower side wall of the expansion section via parallel branch pipes; the first tray differential pressure detection valve 221 and the second tray differential pressure detection valve 222 are respectively located on both sides of the tray differential pressure detection pipe assembly 22 and installed on the branch pipes. The tray differential pressure of the propane stripper 4 is measured through the tray differential pressure detection pipe assembly 22.

[0054] The middle section of the expansion section is also equipped with a tail gas inlet pipe group 5. The tail gas contains propylene. The tail gas to be treated carries the propylene into the propane removal tower 4 for propane and propylene separation.

[0055] The propane stripper 4 is equipped with a tower liquid level detection pipe group 42 and a U-shaped reboiler 41 on both sides of the side wall. A steam inlet pipe 31 is installed on the steam inlet of the U-shaped reboiler 41, and a first steam flow regulating valve 312 is installed on the steam inlet pipe 31. An exhaust pipe is installed on the steam outlet of the U-shaped reboiler 41.

[0056] A propane discharge pipe 32 is installed at the bottom of the propane removal tower 4, and a second steam flow regulating valve 311 is installed on the propane discharge pipe 32.

[0057] See Figure 6 Another aspect of this application provides an apparatus for a gas-phase fluidized bed gas propane removal control method based on propane removal tower steam control as described above, comprising:

[0058] The first acquisition and adjustment module is used to measure the liquid level using a side-line liquid level detection device and measure the tray pressure difference using a tray pressure difference detection tube group. When the liquid level measurement value is greater than or equal to 95.5% of the maximum liquid level and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve is lowered at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment does not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve is not lower than the lower limit setting value of 1320 kg / h.

[0059] The second acquisition and adjustment module is used to: when the liquid level measurement value of the side-stream sampling expansion section is less than 95% of the maximum liquid level and the pressure difference of the tray is less than 48 kPa, adjust the setting value of the first steam flow regulating valve at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not exceed the upper limit setting value of 1500 kg / h.

[0060] The third acquisition and regulation module is used to measure the propylene reflux flow rate using a reflux propylene flow rate detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the opening of the first steam flow rate regulating valve is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane depropanizer 4 without decreasing.

[0061] The fourth acquisition and adjustment module is used to adjust the first steam flow regulating valve multiple times to reduce the steam feed rate when the obtained propylene reflux rate is higher than 4500 kg / h, so as to keep the propylene reflux rate of the propane dehydrogenator at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve is controlled within 5 kg / h.

[0062] Another aspect of this application provides a computer-readable storage medium, characterized in that it stores a computer program thereon, which, when executed, implements the steps of the cross-site scripting attack detection method based on the improved particle swarm optimization algorithm as described in any one of claims 1 to 5.

[0063] Another aspect of this application provides a computer device, including a processor, a memory, and a computer program stored in the memory, characterized in that, when the processor executes the computer program, it implements the steps of the cross-site scripting attack detection method based on the improved particle swarm optimization algorithm as described in any one of claims 1 to 5.

[0064] See the results after implementing this method. Figures 3-5 The steam flow rate of the propane dehydrogenator 4 gradually decreased and stabilized at 1310 kg / h from a large fluctuation of 1200-1600 kg / h, which reduced the steam consumption during the propane dehydrogenation process and effectively improved the stability of the steam flow rate.

[0065] The stability of the propylene reflux flow rate at the top of propane stripper 4 has been significantly improved after testing. Previously, the flow rate fluctuated greatly, but now it is stable, ensuring a more reliable and consistent propylene reflux flow rate. The reflux flow rate at the top of propane stripper 4 can be stabilized at around 5100 kg / h, resolving the issue of intermittent and large fluctuations in the reflux flow rate. After commissioning, the top output is sufficient and stable.

[0066] The liquid level from the top side stream of the propane stripper 4 has been stabilized at 104% of the total liquid level, up from 95% of the previous lower level. This ensures the stable operation of the propylene recovery pump and effectively avoids the shutdown of the propylene reflux pump.

[0067] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling propane removal from tail gas in a gas-phase fluidized bed based on steam control of a propane removal tower, characterized in that, Includes the following steps: Step S1: The liquid level is measured using a side-stream sampling liquid level detection device, and the tray pressure difference is measured using a tray pressure difference detection tube group. When the liquid level measurement value is greater than or equal to 95.5% of the maximum liquid level and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve is lowered at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not be lower than the lower limit setting value of 1320 kg / h. Step S2: When the liquid level measured by the side-stream sampling liquid level detection device is less than 95% of the maximum liquid level, and the pressure difference of the tray is less than 48 kPa, the setting value of the first steam flow regulating valve is adjusted upward at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not exceed the upper limit setting value of 1500 kg / h. Step S3: The propylene reflux flow rate is measured using a propylene reflux flow rate detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the opening of the first steam flow rate regulating valve is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane dehydrogenator. Step S4: When the obtained propylene reflux rate is higher than 4500 kg / h, adjust the first steam flow regulating valve multiple times to reduce the steam feed rate and keep the propylene reflux rate of the propane depropanizer at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve is controlled within 5 kg / h.

2. The method for controlling propane removal from tail gas using a gas-phase fluidization process based on steam control of a propane removal tower according to claim 1, characterized in that, A cooler is installed at the top of the propane stripper, and the cooler is connected to the expansion section; the side-stream propylene discharge pipe is located at the top of the expansion section; the side-stream propylene level detection device is installed on the side-stream propylene discharge pipe; the side-stream propylene discharge pipe is connected to the expansion section through a reflux branch pipe; the reflux propylene flow detection device is installed on the reflux branch pipe.

3. The method for controlling propane removal from tail gas using a gas-phase fluidized bed based on propane removal tower steam control according to claim 2, characterized in that, A U-shaped reboiler is installed on the lower side wall of the propane dehydrogenator; a first steam flow regulating valve is installed on the steam inlet pipe of the U-shaped reboiler.

4. The method for controlling propane removal from tail gas using a gas-phase fluidized bed based on propane removal tower steam control according to claim 2, characterized in that, The lower sidewall of the expanded section is connected to the differential pressure detection pipe group of the tower plate.

5. The method for controlling propane removal from tail gas using a gas-phase fluidized bed based on propane removal tower steam control according to claim 2, characterized in that, Includes: exhaust gas intake pipe assembly, which is connected to the middle side wall of the expansion section.

6. The method for controlling propane removal from tail gas using a gas-phase fluidized bed based on propane removal tower steam control according to claim 2, characterized in that, include: The circulation pipeline is connected to the cooling jacket pipeline on the cooler.

7. The method for controlling propane removal from tail gas using a gas-phase fluidization process based on steam control of a propane removal tower according to claim 3, characterized in that, include: Tower level detection pipe assembly; the tower level detection pipe assembly is installed on the other side wall of the propane removal tower.

8. The method for controlling propane removal from tail gas in a gas-phase fluidized bed based on steam control of a propane removal tower according to claim 2, characterized in that, include: The first branch pipe, the first side-line extraction valve, and the second side-line extraction valve; the first branch pipe is connected in parallel with the side-line extraction propylene discharge pipe; the first side-line extraction valve, the second side-line extraction valve, and the side-line extraction liquid level detection device are spaced apart on the first branch pipe; the first side-line extraction valve and the second side-line extraction valve are respectively located on both sides of the side-line extraction liquid level detection device.

9. The method for controlling propane removal from tail gas using a gas-phase fluidization process based on steam control of a propane removal tower according to claim 2, characterized in that, include: The second branch pipe, the first reflux propylene valve, and the second reflux propylene valve are connected in parallel with the side-line propylene discharge pipe. The reflux propylene flow detection device, the first reflux propylene valve, and the second reflux propylene valve are spaced apart on the second branch pipe. The first reflux propylene valve and the second reflux propylene valve are located on both sides of the reflux propylene flow detection device.

10. An apparatus for a gas-phase fluidized bed gas propane removal control method based on propane removal tower steam control as described in any one of claims 1 to 9, characterized in that, include: The first acquisition and adjustment module is used to measure the liquid level using a side-line liquid level detection device and measure the tray pressure difference using a tray pressure difference detection tube group. When the liquid level measurement value is greater than or equal to 95.5% of the maximum liquid level and the tray pressure difference is greater than 35 kPa, the setting value of the first steam flow regulating valve is adjusted down at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment does not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve is not lower than the lower limit setting value of 1320 kg / h. The second acquisition and adjustment module is used to: when the liquid level measured by the side-line liquid level detection device is less than 95% of the maximum liquid level and the pressure difference of the tray is less than 48 kPa, adjust the setting value of the first steam flow regulating valve at intervals of 10 times / minute. The maximum adjustment amount of the setting value of the first steam flow regulating valve in a single adjustment shall not exceed 5 kg / h. The setting value range of the first steam flow regulating valve is 1320 kg / h to 1500 kg / h. After multiple adjustments, the steam flow of the first steam flow regulating valve shall not exceed the upper limit setting value of 1500 kg / h. The third acquisition and regulation module is used to measure the propylene reflux flow rate using a reflux propylene flow rate detection device. When the propylene reflux flow rate is lower than 4100 kg / h, the opening of the first steam flow rate regulating valve is increased to increase the steam feed rate and maintain the propylene reflux flow rate of the propane dehydrogenator. The fourth acquisition and adjustment module is used to adjust the first steam flow regulating valve multiple times to reduce the steam feed rate when the obtained propylene reflux rate is higher than 4500 kg / h, so as to keep the propylene reflux rate of the propane dehydrogenator at greater than or equal to 5100 kg / h; the maximum single adjustment of the first steam flow regulating valve is controlled within 5 kg / h.

11. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed, implements the steps of the gas-phase fluidization tail gas depropane control method based on depropane tower steam control as described in any one of claims 1 to 9.

12. A computer device comprising a processor, a memory, and a computer program stored in the memory, characterized in that, When the processor executes the computer program, it implements the steps of the gas phase fluidization tail gas depropane control method based on depropane tower steam control as described in any one of claims 1 to 9.

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