Hcc-240fa separation process based on multiple-input multiple-output control and separation device thereof

Abstract

The present application relates to HCC-240fa separation process based on multiple input multiple output control and its separation device, after receiving cold material flow and feed temperature information in feed total pipeline, multiple input multiple output controller carries out analysis processing, adjusts normal temperature material flow set value; after receiving total flow information of cold material flow and normal temperature material flow addition, tower top condenser backflow information, separation tower tower kettle liquid level information, tower kettle temperature information, carries out analysis processing, adjusts tower top backflow flow set value, adjusts reboiler steam flow set value and tower kettle intermittent discharge time set value, realizes the tower kettle temperature control of separation tower, tower kettle liquid level control and the discharge control of separation tower.The present application guarantees the requirement of upstream material balance discharge, simultaneously reaches the purpose of heat stable feed, makes the stability of separation tower greatly improve, and guarantees the quality of tower top product, greatly reduces the discharge of tower kettle recombination waste, and the economy has been significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the refrigerant technical field, especially to a HCC-240fa separation process based on multiple-input multiple-output control and a separation device thereof. BACKGROUND

[0002] The stability of the current HCC-240fa separation process control is crucial to the separation effect, and the current 240fa separation process control is mainly realized through the existing DCS multiple single-loop control. Due to the high coupling between the fluctuations of the two feedstocks and the process variables of the separation process, it is difficult to achieve long-term stable control of the separation process, and the problems are as follows:

[0003] (1) The multiple single-loop control separation process cannot respond economically and timely when the process condition fluctuates, resulting in substandard separation effect.

[0004] (2) The current control scheme cannot effectively control the fluctuations of the flow and temperature of the two feedstocks, resulting in stability problems of the separation process.

[0005] (3) The current heavy component discharge cannot be fully automated.

[0006] (4) The operator will frequently interfere with the control loop, affecting the stability of the control. SUMMARY

[0007] Therefore, the technical problem to be solved by the present application is to overcome the stability problem in the HCC-240fa separation process in the prior art. The multiple parameter input and output control and the intermittent discharge control ensure the upstream material balance and discharge requirements, achieve the purpose of heat stable feed, greatly improve the stability of the separation tower, ensure the quality of the tower top product, minimize the discharge of heavy component waste from the tower, and significantly improve the economy.

[0008] To solve the above technical problems, the present application provides a separation device, comprising:

[0009] a cold material feed tank;

[0010] a normal temperature material feed tank;

[0011] a separation tower; the separation tower is provided with a feed inlet on the side, and the discharge outlets of the cold material feed tank and the normal temperature material feed tank are respectively connected to the feed inlet of the separation tower through branch pipelines one and two and a feed total pipeline;

[0012] a tower top condenser connected to the gas outlet and the liquid inlet of the separation tower through pipelines;

[0013] A steam reboiler, a process side of the steam reboiler being connected with a liquid phase material outlet and a gas phase material inlet of the separation tower through a pipeline; an inlet of a heat source side of the steam reboiler being connected with a steam supply pipeline, and an outlet of the steam reboiler being connected with a steam condensate pipeline;

[0014] A multi-input multi-output controller; the multi-input multi-output controller receives and analyzes cold material flow and feed temperature information in a feed total pipeline, and realizes feed thermal stability control of the separation tower by adjusting a cold material flow set value; the multi-input multi-output controller receives and analyzes total flow information of a sum of the cold material flow and the normal temperature material flow, reflux flow information of a tower top condenser, tower kettle liquid level information of the separation tower, and tower kettle temperature information, and realizes tower kettle temperature control, tower kettle liquid level control and discharge control of the separation tower by adjusting a tower top reflux flow set value, adjusting a reboiler steam flow set value and adjusting a tower kettle intermittent discharge time set value;

[0015] A discharge flow intermittent controller; the discharge flow intermittent controller receives control signals of the multi-input multi-output controller, and controls discharge of the separation tower at intervals to realize intermittent discharge of heavy component waste.

[0016] In an embodiment of the present application, a branch pipeline one of the cold material feed tank is provided with a first liquid level controller and a first flow controller for controlling cold material feed flow.

[0017] In an embodiment of the present application, the first flow controller and the first liquid level controller are arranged in series.

[0018] In an embodiment of the present application, a branch pipeline two of the normal temperature material feed tank is provided with a second flow controller for controlling normal temperature material feed flow, and flow signal output ends of the first flow controller and the second flow controller are connected with an input end of a total feed flow controller FI1 arranged on the feed total pipeline.

[0019] In an embodiment of the present application, a fourth flow controller is arranged on the discharge pipeline, an output end of the intermittent controller is connected with an input end of the fourth flow controller to realize intermittent flow control.

[0020] In an embodiment of the present application, a first temperature measuring table for detecting feed temperature of the separation tower is arranged on the feed total pipeline, and the first temperature measuring table is connected with an input end of the multi-input multi-output controller.

[0021] In an embodiment of the present application, a second temperature measuring table for detecting tower kettle temperature of the separation tower is arranged on an outer wall of the separation tower, and a second liquid level controller for detecting liquid in the tower kettle of the separation tower is arranged in the separation tower, and the second temperature measuring table and the second liquid level controller are connected with an input end of the multi-input multi-output controller.

[0022] In one embodiment of the present application, a fifth flow controller is arranged on the reflux pipeline between the overhead condenser and the liquid inlet of the separation column; the input end of the fifth flow controller is connected with the output end of the multiple-input multiple-output controller.

[0023] In one embodiment of the present application, a third flow controller is arranged on the steam supply pipeline of the steam reboiler, and the input end of the third flow controller is connected with the output end of the multiple-input multiple-output controller.

[0024] A HCC-240fa separation process based on multiple-input multiple-output control, specifically comprising:

[0025] S1, the cold material and the normal-temperature material are mixed into the total feed pipeline through the branch feed pipeline one and the branch feed pipeline two respectively, and the total feed pipeline sends the mixed material into the separation column for separation;

[0026] S2, the gas discharged from the gas outlet at the top of the separation column is sent into the overhead condenser for condensation, and after the overhead condenser condenses the gas, a part of the condensed gas is refluxed to the top of the separation column through the overhead reflux pipeline, and the other part is discharged through the overhead take-out pipeline;

[0027] S3, steam is sent into the steam reboiler through the steam supply pipeline, and a part of the liquid phase at the bottom of the separation column is refluxed to the bottom of the separation column through the steam reboiler, and the other part is discharged as heavy component waste through the high-boiling material discharge pump and the discharge pipeline;

[0028] S4, the multiple-input multiple-output controller receives the flow information of the first flow controller, the total feed flow controller, the reflux flow of the overhead condenser, the temperature information of the first temperature measuring table and the second temperature measuring table, and the liquid level information of the second liquid level controller of the separation column, and further obtains the cold material flow of the cold material feed tank, the total feed flow, the reflux flow of the overhead condenser, the feed temperature of the total feed pipeline, the bottom temperature and the bottom liquid level of the separation column;

[0029] S5, the multiple-input multiple-output controller analyzes and processes the above flow data, temperature data and liquid level data, and then sends control signals to the second flow controller, the third flow controller, the fifth flow controller and the intermittent controller;

[0030] S6, the second flow controller receives the control signal of the multiple-input multiple-output controller to control the feed of the normal-temperature material;

[0031] S7, the third flow controller receives the control signal of the multiple-input multiple-output controller to control the steam flow of the steam reboiler;

[0032] S8, the fifth flow controller receives the control signal of the multiple-input multiple-output controller to realize flow control of the reflux of the overhead condenser;

[0033] S9, the intermittent controller receives the control signal of the multiple-input multiple-output controller to adjust the intermittent time of the heavy component waste in the tower kettle;

[0034] S10, the fourth flow controller receives the control signal of the intermittent controller to realize intermittent discharge of the heavy component waste in the tower kettle.

[0035] The above technical scheme of the present application has the following advantages compared with the prior art:

[0036] The HCC-240fa separation process based on multiple-input multiple-output control and the separation device thereof have the following advantages: the multiple-parameter input-output controller is used to realize steam flow control of the normal-temperature material feeding tank, the overhead condenser and the steam reboiler, and to set the feeding temperature, the tower kettle temperature and the liquid level of the separation tower, so that the requirements of upstream material balance discharge are guaranteed, the purpose of hot temperature feeding is achieved, the stability of the separation tower is greatly improved, the intermittent controller is continuously adjusted by the multiple-parameter input-output controller on the heavy component discharge side of the tower kettle of the separation tower, intermittent discharge at a high tower kettle temperature is realized, the quality of the overhead product is guaranteed, the discharge of the heavy component waste is reduced to the maximum extent, and the economy is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in combination with the drawings.

[0038] Figure 1 is a structure schematic view of the separation device in the preferred embodiment of the present application.

[0039] The description of the drawing reference signs is as follows: V-1, cold material feeding tank; V-2, normal-temperature material feeding tank; T-1, separation tower; E-1, steam reboiler; E-2, overhead condenser; LC1, first liquid level controller; FC1, first flow controller; FC2, second flow controller; FC3, third flow controller; FC4, fourth flow controller; FC5, fifth flow controller; FI1, total feeding flow controller; TI1, first temperature measuring table; TI2, second temperature measuring table; LI1, second liquid level controller; S1, branch pipeline one; S2, branch pipeline two; S3, steam supply pipeline; S4, discharge pipeline; S5, overhead reflux material flow of T-1; S6, overhead product flow pipeline; 1, high-boiling material discharge pump; 2, multiple-input multiple-output controller; 3, intermittent controller. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the drawings and specific embodiments so that those skilled in the art can better understand the application and implement it. The embodiments are not intended to limit the application.

[0041] Referring to Figure 1 The separation device of the application comprises:

[0042] A cold material feed tank V-1;

[0043] A normal-temperature material feed tank V-2;

[0044] A separation column T-1; the separation column T-1 is provided with a feed inlet, and the discharge outlets of the cold material feed tank V-1 and the normal-temperature material feed tank V-2 are connected to the feed main pipeline through branch pipelines S1 and S2 respectively and then communicated with the feed inlet of the separation column T-1;

[0045] A column top condenser E-2 connected with the gas outlet and the liquid inlet of the separation column T-1 through pipelines;

[0046] A steam reboiler E-1; the process side of the steam reboiler E-1 is connected with the liquid-phase material outlet and the gas-phase material inlet of the separation column T-1 through pipelines; the heat source side inlet of the steam reboiler E-1 is connected with a steam supply pipeline S3, and its outlet is connected with a steam condensate pipeline; the process side of the steam reboiler E-1 refers to the side that the liquid-phase process material flowing out of the bottom of the separation column T-1 is heated to become gas-phase process material and then returned to the separation column T-1;

[0047] A high-boiling material discharge pump 1 connected with the discharge outlet at the bottom end of the separation column T-1 through a discharge pipeline,

[0048] The multi-input multi-output controller receives the cold material flow and the feed temperature information in the feed main pipeline, analyzes and processes them, adjusts the normal-temperature material flow set value, and realizes the feed thermal stable control of the separation column T-1; the multi-input multi-output controller receives the total flow information of the sum of the cold material flow and the normal-temperature material flow, the reflux flow information of the column top condenser E-2, the column still liquid level information of the separation column T-1, and the column still temperature information, analyzes and processes them, adjusts the column top reflux flow set value, the steam flow set value of the steam reboiler E-1, and the column still intermittent discharge time set value, and realizes the column still temperature control, the column still liquid level control, and the discharge control of the separation column T-1.

[0049] A discharge flow intermittent controller 3 receiving the control signal of the multi-input multi-output controller, which controls the discharge of the separation column T-1 at intervals and realizes the intermittent discharge of the heavy component waste.

[0050] The branch pipe S1 of the cold material feeding tank V-1 is provided with a first liquid level controller LC1 and a first flow controller FC1 for controlling the flow of the cold material.

[0051] Further, the branch pipe S2 of the normal temperature material feeding tank V-2 is provided with a second flow controller FC2 for controlling the flow of the normal temperature material, and the flow signal output ends of the first flow controller FC1 and the second flow controller FC2 are connected with the input end of a total feeding flow controller FIl provided on the feeding main pipe. The feeding main pipe is provided with a fourth flow controller FC4, and the output end of the intermittent controller 3 is connected with the input end of the fourth flow controller FC4 to realize intermittent flow control. The intermittent discharge time is introduced into the intermittent feeding flow controller 3, and the fourth flow controller FC4 is controlled to realize the flow control of the heavy component waste in the tower kettle of the separation tower T-1, so that the heavy component waste in the tower kettle is discharged from the feeding pipe S4. The feeding main pipe is provided with a first temperature measuring table TI1 for detecting the feeding temperature of the separation tower T-1, and the first temperature measuring table TI1 is connected with the input end of the multiple-input multiple-output controller. The outer wall of the separation tower T-1 is provided with a second temperature measuring table TI2 for detecting the temperature of the tower kettle of the separation tower T-1, and the inside of the separation tower T-1 is provided with a second liquid level controller LI1 for detecting the liquid in the tower kettle of the separation tower T-1, and the second temperature measuring table TI2 and the second liquid level controller LI1 are connected with the input end of the multiple-input multiple-output controller. The reflux pipe between the overhead condenser E-2 and the liquid inlet of the separation tower T-1 is provided with a fifth flow controller FC5, and the input end of the fifth flow controller FC5 is connected with the output end of the multiple-input multiple-output controller. The steam supply pipe S3 of the steam reboiler E-1 is provided with a third flow controller FC3, and the input end of the third flow controller FC3 is connected with the output end of the multiple-input multiple-output controller.

[0052] Corresponding to the above-mentioned embodiment of the separation device, the embodiment of the present application also provides an HCC-240fa separation process based on multiple-input multiple-output control, which is realized based on the separation device as mentioned above, and the separation process comprises the following steps:

[0053] S1, the cold material and the normal temperature material are mixed into the feeding main pipe through the branch pipe S1 and the branch pipe S2 respectively, and the feeding main pipe sends the mixed material into the separation tower T-1 for separation;

[0054] S2, the gas discharged from the gas outlet at the top of the separation tower T-1 is sent to the overhead condenser E-2 for condensation, and after the overhead condenser E-2 condenses the gas, part of the gas is returned to the top of the separation tower through the overhead reflux pipeline S5, and the other part is discharged through the overhead pipeline S6;

[0055] S3, steam is sent to the steam reboiler E-1 through the steam supply pipeline S3, and part of the liquid phase in the tower kettle of the separation tower T-1 is returned to the tower kettle of the separation tower T-1 through the steam reboiler E-1, and the other part is discharged as heavy component waste through the high-boiling material discharge pump 1 through the discharge pipeline S4;

[0056] S4, the multi-input multi-output controller receives the flow information of the first flow controller FC1, the total feed flow controller FI1, the reflux flow of the overhead condenser, the temperature information of the first temperature measuring table TI1 and the second temperature measuring table TI2, and the liquid level information of the second liquid level controller LI1 of the separation tower T-1, and then obtains the cold material flow of the cold material feed tank V-1, the total feed flow, the reflux flow of the overhead condenser, the feed temperature of the feed total pipeline, the tower kettle temperature and the tower kettle liquid level of the separation tower T-1;

[0057] S5, the multi-input multi-output controller analyzes and processes the above-mentioned flow data, temperature data and liquid level data, and then sends control signals to the second flow controller FC2, the third flow controller FC3, the fifth flow controller FC5 and the intermittent controller 3; the temperature control setting parameters of the first temperature table TI1 and the second temperature table TI2 and the liquid level control setting parameters of the second liquid level controller LI1 are configured in the multi-input multi-output controller, so that the temperature control setting parameters of the first temperature measuring table TI1 and the second temperature measuring table TI2 and the liquid level control setting parameters of the second liquid level controller of the separation tower can be set;

[0058] S6, the second flow controller FC2 receives the control signal of the multi-input multi-output controller to control the feed of the normal temperature material;

[0059] S7, the third flow controller FC3 receives the control signal of the multi-input multi-output controller to control the steam flow of the steam reboiler E-1;

[0060] S8, the fifth flow controller FC5 receives the control signal of the multi-input multi-output controller to control the reflux flow of the overhead condenser E-2.

[0061] S9, the intermittent controller 3 receives the control signal of the multi-input multi-output controller to adjust the intermittent time of the tower kettle heavy component waste.

[0062] S10, the fourth flow controller FC4 receives the control signal of the intermittent controller 3, and realizes intermittent discharge of the heavy component waste in the tower kettle.

[0063] Obviously, the above embodiments are only examples for clearly illustrating, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A separation device, Its characteristics include: Cold material feed tank; Ambient temperature material feed tank; Separation tower; the separation tower is provided with a feed inlet on its side, and the outlets of the cold material feed tank and the normal temperature material feed tank are respectively connected to the feed main pipeline through branch pipe one and branch pipe two, and then connected to the feed inlet of the separation tower. A top condenser is provided, which is connected to the gas outlet and liquid inlet of the separation tower via pipelines. A steam reboiler, wherein the process side of the steam reboiler is connected to the liquid phase material outlet and the gas phase material inlet of the separation tower via pipelines; the heat source side inlet of the steam reboiler is connected to a steam supply pipeline, and its outlet is connected to a steam condensate pipeline. A high-boiling-point discharge pump; the high-boiling-point discharge pump is connected to the discharge port at the bottom of the separation tower via a discharge pipe; A multi-input multi-output (MIMO) controller is provided. This controller receives and analyzes information on the flow rate of cold material and the feed temperature in the main feed pipeline. By adjusting the setpoint for the ambient temperature material flow rate, it achieves thermal stability control of the feed to the separation tower. The controller also receives and analyzes information on the total flow rate (sum of the cold material flow rate and the ambient temperature material flow rate), the reflux flow rate of the condenser at the top of the tower, the bottom liquid level of the separation tower, and the bottom temperature. By adjusting the setpoints for the reflux flow rate at the top of the tower, the reboiler steam flow rate, and the intermittent discharge time at the bottom of the tower, it achieves bottom temperature control, bottom liquid level control, and feed control of the separation tower. Discharge flow intermittent controller; The discharge flow intermittent controller receives control signals from the multi-input multi-output controller to control the interval of discharge from the separation tower, thereby realizing the intermittent discharge of heavy component waste.

2. The separation device according to claim 1, characterized in that: The branch pipe of the cold material feed tank is equipped with a first level controller and a first flow controller for controlling the cold material feed flow rate.

3. The separation device according to claim 2, characterized in that: The first flow controller and the first liquid level controller are connected in series.

4. The separation device according to claim 3, characterized in that: The branch pipe of the ambient temperature material feed tank is equipped with a second flow controller for controlling the feed flow rate of ambient temperature material. The flow signal output terminals of the first flow controller and the second flow controller are connected to the input terminal of the main feed flow controller installed on the main feed pipe.

5. A separation device according to claim 4, characterized in that: The discharge pipe is equipped with a fourth flow controller, and the output end of the intermittent controller is connected to the input end of the fourth flow controller to realize intermittent flow control.

6. The separation device according to claim 5, characterized in that: The feed main pipeline is equipped with a first temperature measuring instrument for detecting the feed temperature of the separation tower, and the first temperature measuring instrument is connected to the input terminal of the multiple input multiple output controller.

7. A separation device according to claim 6, characterized in that: The outer wall of the separation tower is equipped with a second temperature measuring instrument for detecting the temperature of the tower bottom. The interior of the separation tower is equipped with a second liquid level controller for detecting the liquid in the tower bottom. The second temperature measuring instrument and the second liquid level controller are connected to the input terminal of a multi-input multi-output controller.

8. A separation device according to claim 7, characterized in that: A fifth flow controller is installed on the reflux pipe between the top condenser and the liquid inlet of the separation tower; the input end of the fifth flow controller is connected to the output end of the multiple input multiple output controller.

9. A separation device according to claim 8, characterized in that: The steam supply pipe of the steam reboiler is equipped with a third flow controller, the input of which is connected to the output of a multiple-input multiple-output controller.

10. An HCC-240fa separation process based on multiple-input multiple-output control, characterized in that: The separation process is implemented based on the separation apparatus as described in any one of claims 1-9, and the separation process includes: S1. Cold material and room temperature material are mixed and fed into the main feed pipe through branch pipe one and branch pipe two respectively. The main feed pipe sends the mixed material into the separation tower for separation. S2. The gas discharged from the gas outlet at the top of the separation tower is sent to the top condenser for condensation. After the gas is condensed by the top condenser, part of it flows back to the top of the separation tower through the top return pipe, and the other part is discharged through the top outlet pipe. S3. Steam is fed into the steam reboiler through the steam supply pipeline. Part of the liquid phase in the bottom of the separation tower is returned to the bottom of the separation tower through the steam reboiler, and the other part is discharged as heavy component waste through the discharge pipeline via the high boiling point discharge pump. S4. The multi-input multi-output controller receives flow information from the first flow controller, the total feed flow controller, and the reflux flow from the top condenser, temperature information from the first and second temperature measuring instruments, and level information from the second level controller of the separation column, thereby obtaining the cold material flow rate of the cold material receiving tank, the total feed flow rate, the reflux flow rate of the top condenser, the feed temperature of the main feed pipeline, the bottom temperature of the separation column, and the bottom liquid level. S5. The multiple input multiple output controller analyzes and processes the above-mentioned flow data, temperature data and liquid level data, and then sends the control signal to the second flow controller, the third flow controller, the fifth flow controller and the intermittent controller. S6. The second flow controller receives the control signal from the multiple input multiple output controller to control the feeding of materials at room temperature; S7. The third flow controller receives the control signal from the multiple input multiple output controller to control the steam flow of the steam reboiler. S8. The fifth flow controller receives the control signal from the multiple input multiple output controller to realize the flow control of the return flow of the top condenser. S9. The intermittent controller receives the control signal from the multiple input multiple output controller and adjusts the intermittent time of the heavy component waste in the tower bottom; S10, the fourth flow controller receives the control signal from the intermittent controller to realize the intermittent discharge of heavy component waste from the tower bottom.

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