Device and method for controlling coal ethylene glycol rectification by APC system

Abstract

The invention belongs to the technical field of coal ethylene glycol rectification, and particularly relates to a device and a method for controlling coal ethylene glycol rectification by an APC system, the coal ethylene glycol rectification system is coupled with the APC system, so that the operation of the ethylene glycol rectification system is optimally controlled, the load of a reboiler and the power consumption of a condenser are reduced, and the energy consumption is reduced. The energy waste is reduced, the automation of the rectification control process is improved, the labor intensity and the operation error of frequent operation of operators are reduced, and meanwhile, the product quality change caused by operation fluctuation is reduced. In addition, the working condition adaptive capacity is high, and the APC system can adapt to different working condition changes such as raw material fluctuation and environmental condition changes.

Description

Technical Field

[0001] The invention belongs to the technical field of coal-based ethylene glycol distillation, in particular to a device and method for controlling coal-based ethylene glycol distillation by an APC system. Background Art

[0002] In the production process of coal-to-ethylene glycol, the distillation process is the core unit operation, which mainly includes methanol recovery tower, dehydration tower, dealcoholization tower, product tower and recovery tower. The operation of each tower directly affects the purity and energy consumption of ethylene glycol products. At present, the control system of coal-to-ethylene glycol distillation is a distributed control system (DCS for short), which is mainly conventional single-loop PID and manual remote operation. Most of the PID loops are still manually operated, and some automatic loops contain a single factor. There are problems such as excessive fluctuations during control. At the same time, the correlation of single-loop PID control is not high enough, the automatic control degree is not perfect, there are many manual operations, and the control accuracy is low. When adding and reducing loads, the entire device fluctuates frequently, for example: temperature, steam flow, liquid level, pressure and other parameters are unstable. When the external parameters such as temperature, steam, pressure are unstable or the system is lifting and lowering the load, it is heavily dependent on the central control operator, and the operators have uneven experience, poor timeliness of processing, different operation methods, and different judgment bases for the operating status, which cannot make the device in the best operating state. Not only is the labor intensity very high, but the production operation is unstable, which makes the energy consumption of ethylene glycol distillation high.

[0003] By introducing advanced process control (APC) technology, we can achieve global optimization of multi-tower multi-variable systems, effectively reduce energy consumption, and improve the stability of system operation. In particular, for core unit operations such as methanol recovery tower, dehydration tower, dealcoholization tower, product tower and recovery tower, through the optimization control of the APC system, we can significantly reduce the energy consumption in the distillation process and the labor intensity of frequent operations of operators, and stably produce high-purity ethylene glycol products. Summary of the invention

[0004] Based on the problems of the prior art, the present invention provides a device and method for controlling the distillation of ethylene glycol from coal by an APC system, which can achieve dynamic optimization and minimization of the energy consumption of each tower while ensuring the purity of the ethylene glycol product, reduce production costs, improve the operating efficiency of the equipment, and reduce the intensity of frequent operations by operators.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows: An APC system controls the distillation of ethylene glycol from coal, comprising a methanol recovery tower device, a dehydration tower device, a dealcoholization tower device, a product tower device, and a recovery tower device connected in sequence according to a process sequence; the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device, and the recovery tower device each respectively comprise a distillation tower, a reboiler, a condensation cooling device, and a pump; the temperature sensors and / or pressure sensors and / or component sensors and / or liquid level sensors and / or flow sensors and / or pumps and / or regulating valves provided on the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device, and the recovery tower device are all connected to a DCS system and an APC system; The methanol recovery tower device is used to recover methanol from the hydrogenated crude ethylene glycol product.

[0006] The dehydration tower device is used to remove water and low-boiling alcohols from the crude ethylene glycol product. Low-boiling alcohols include methanol, ethanol, etc.

[0007] The alcohol remover unit is used to remove residual alcohol from the crude ethylene glycol product.

[0008] The product tower device is used to purify ethylene glycol to obtain high-purity ethylene glycol products and ensure the quality of the final product.

[0009] The recovery tower device is used to separate the heavy fractions in the bottom discharge of the product tower device and recover ethylene glycol.

[0010] The APC system monitors the operating parameters of each distillation tower, reboiler, and condensing cooling device in real time by installing temperature sensors and / or pressure sensors and / or liquid level sensors and / or flow sensors and / or component sensors on the methanol recovery tower device, dehydration tower device, dealcoholization tower device, product tower device, and recovery tower device.

[0011] The APC system is based on the MPC algorithm, i.e. the multivariable predictive control algorithm, combined with the process model to optimize the operating conditions of each distillation tower, reboiler, and condensing cooling device.

[0012] The APC system dynamically adjusts key operating parameters such as the reflux ratio, reboiler load, and condensing cooling cold medium flow of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit to achieve the purpose of reducing energy consumption and stabilizing product quality.

[0013] Furthermore, the APC system is connected to the remote service system via a 4G network and a DTU device, that is, the DUT device is a wireless terminal device.

[0014] Furthermore, an isolation hardware firewall is set between the DCS system and the APC server, and between the APC server and the remote service system.

[0015] Further, the APC server of the APC system is connected to the OPC server of the DCS system.

[0016] A method for controlling the distillation of ethylene glycol from coal using an APC system comprises the following steps: Data collection: The key process parameters such as temperature, pressure, composition, flow rate and liquid level of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit and recovery tower unit are collected in real time through temperature sensors, pressure sensors, liquid level sensors, flow sensors and component sensors.

[0017] Step test: In the control system, the step test is used to determine the dynamic characteristics of the coal-to-ethylene glycol distillation system by changing the set values ​​of key process parameters such as temperature, pressure, composition, flow rate and liquid level, observing the output changes of the coal-to-ethylene glycol distillation system, and recording data such as the speed of parameter rise or fall, overshoot, and adjustment time.

[0018] Process modeling: Based on historical operating data and operating experience, a mathematical model of the distillation process is established to ensure accurate prediction of the entire system.

[0019] Energy consumption optimization: Based on the energy consumption model in the APC system, the operating conditions of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit are dynamically optimized to reduce unnecessary energy consumption, such as optimizing steam consumption by controlling the reflux ratio and reboiler load.

[0020] Product purity control: The APC system adjusts the operating parameters of the methanol recovery tower, dehydration tower, dealcoholization tower, product tower, and recovery tower in real time to ensure the purity of the final ethylene glycol product while avoiding increased energy consumption caused by over-purification.

[0021] Disturbance handling: When the raw material composition and / or temperature and / or pressure and / or flow rate changes, the APC system can respond quickly and automatically adjust the operating parameters of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit to ensure continuous and stable production.

[0022] Furthermore, the APC system and the DCS system can switch and control the temperature, pressure, composition, flow rate and liquid level of the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device and the recovery tower device.

[0023] Furthermore, the communication between the APC system and the DCS system adopts the international standard OPC communication protocol to complete the two-way data exchange between the two systems.

[0024] Furthermore, the communication between the APC system and the remote service system (HeroRTS) is based on 4G network and DTU equipment, using virtual VPN data transmission technology to complete the real-time remote service function of the APC server; the system is equipped with a dedicated hardware firewall for isolation between the DCS system and the APC server, and between the APC server and the remote service system.

[0025] Furthermore, the APC server of the APC system is connected to the OPC server of the DCS system, and the operator can select DCS system control or APC system control by means of disturbance-free switching.

[0026] Furthermore, PID parameter tuning: by tuning the PID parameters of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit, and by reasonably adjusting the PID parameters, the system can quickly recover to a stable state after being disturbed, while improving the self-control rate and stability of the control system, providing data basis for step testing and process modeling of the APC system.

[0027] Furthermore, the APC system sets a voice alarm for equipment failure. Beneficial Effects

[0028] (1) Significant energy-saving effect: By optimizing and controlling the operating parameters of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit, unnecessary energy waste is reduced, especially the reboiler load and condenser power consumption.

[0029] (2) Stable product quality: The APC system can ensure the high purity of ethylene glycol products while reducing product quality changes caused by operational fluctuations.

[0030] (3) High system automation: The control process of the entire device has a high degree of automation, which reduces dependence on operators, reduces manual operation errors, and also reduces the labor intensity of frequent operations by operators.

[0031] (4) Strong adaptability to working conditions: The APC system can adapt to different working conditions, such as raw material fluctuations and changes in environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of ethylene glycol distillation of the present invention; Figure 2 This is the APC operation menu diagram of ethylene glycol distillation of the present invention; Figure 3 APC system structure schematic diagram of ethylene glycol distillation of the present invention In the figure: 1-methanol recovery tower device; 2-dehydration tower device; 3-dealcoholization tower device; 4-product tower device; 5-recovery tower device; 6-DCS system; 7-APC system. DETAILED DESCRIPTION Example 1

[0033] Reference Figure 1 , in order to minimize the energy consumption of the coal-to-ethylene glycol distillation system and reduce production costs while ensuring the production of ethylene glycol products, while reducing the operating errors and operating intensity of operators. The present invention provides an APC system to control the distillation of coal-to-ethylene glycol, comprising a methanol recovery tower device 1, a dehydration tower device 2, a dealcoholization tower device 3, a product tower device 4, and a recovery tower device 5 connected in sequence according to the process sequence; the methanol recovery tower device 1, the dehydration tower device 2, the dealcoholization tower device 3, the product tower device 4, and the recovery tower device 5 each include a distillation tower, a reboiler, a condensation cooling device and a pump, and a regulating valve; the temperature sensors and / or pressure sensors and / or component sensors and / or liquid level sensors and / or flow sensors and / or pumps and / or regulating valves provided on the methanol recovery tower device 1, the dehydration tower device 2, the dealcoholization tower device 3, the product tower device 4, and the recovery tower device 5 are all connected to the DCS system 6 and the APC system 7; The methanol recovery tower device 1 is used to recover methanol from the hydrogenated crude ethylene glycol product; the dehydration tower device 2 is used to remove water and low-boiling alcohols from the crude ethylene glycol product, and the low-boiling alcohols include methanol and ethanol; the dealcoholization tower device 3 is used to remove residual alcohols from the crude ethylene glycol product, including removing light fractions such as 2,3-butanediol, 1,2-propylene glycol, 1,2-butanediol, and methyl glycolate; the product tower device 4 is used to purify ethylene glycol to obtain a high-purity ethylene glycol product to ensure the quality of the final product; the recovery tower device 5 is used to separate the heavy fractions in the bottom discharge of the product tower device 4 and recover the ethylene glycol in the bottom discharge of the product tower device 4.

[0034] The APC system 7 monitors the operating parameters of each distillation tower, reboiler, and condensation cooling device in real time by installing temperature sensors and / or pressure sensors and / or liquid level sensors and / or flow sensors and / or component sensors on the methanol recovery tower device 1, the dehydration tower device 2, the dealcoholization tower device 3, the product tower device 4, and the recovery tower device 5.

[0035] APC system 7 is based on MPC algorithm, i.e. multivariable predictive control algorithm, combined with process model to optimize the operating conditions of each distillation tower, reboiler, condensation cooling device, etc.

[0036] The APC system 7 dynamically adjusts key operating parameters such as the reflux ratio, reboiler load, and condensing cooling cold medium flow rate of the methanol recovery tower unit 1, the dehydration tower unit 2, the dealcoholization tower unit 3, the product tower unit 4, and the recovery tower unit 5 to achieve the purpose of reducing energy consumption and stabilizing product quality.

[0037] APC system 7 is equipped with a voice alarm for equipment failure. When equipment fails, the operator is reminded by a voice alarm.

[0038] The APC system 7 is connected to the remote service system via a 4G network and a DTU device, that is, the DUT device is a wireless terminal device.

[0039] An isolation hardware firewall is set between the DCS system 6 and the APC server, and between the APC server and the remote service system.

[0040] The APC server of the APC system 7 is connected to the OPC server of the DCS system 6 .

[0041] A method for controlling the distillation of ethylene glycol from coal using an APC system comprises the following steps: Data collection: The key process parameters such as temperature, pressure, composition, flow rate and liquid level of methanol recovery tower unit 1, dehydration tower unit 2, dealcoholization tower unit 3, product tower unit 4 and recovery tower unit 5 are collected in real time through temperature sensors, pressure sensors, liquid level sensors, flow sensors and component sensors.

[0042] Step test: In the control system, the step test is used to determine the dynamic characteristics of the coal-to-ethylene glycol distillation system by changing the set values ​​of key process parameters such as temperature, pressure, composition, flow, liquid level, etc., and observing the output changes of the coal-to-ethylene glycol distillation system, and recording data such as the speed of parameter rise or fall, overshoot, and adjustment time.

[0043] Process modeling: Based on historical operating data and operating experience, a mathematical model of the distillation process is established to ensure accurate prediction of the entire system.

[0044] Energy consumption optimization: Based on the energy consumption model in the APC system 7, the operating conditions of the methanol recovery tower unit 1, the dehydration tower unit 2, the dealcoholization tower unit 3, the product tower unit 4, and the recovery tower unit 5 are dynamically optimized to reduce unnecessary energy consumption, such as optimizing steam consumption and cooling medium consumption by controlling the reflux ratio, reboiler load, and condensing cooling unit load.

[0045] Product purity control: APC system 7 adjusts the operating parameters of methanol recovery tower unit 1, dehydration tower unit 2, dealcoholization tower unit 3, product tower unit 4, and recovery tower unit 5 in real time to ensure the purity of the final ethylene glycol product while avoiding increased energy consumption caused by over-purification.

[0046] Disturbance handling: When the raw material composition and / or temperature and / or pressure and / or flow rate changes, the APC system 7 can respond quickly and automatically adjust the operating parameters of the methanol recovery tower device 1, the dehydration tower device 2, the dealcoholization tower device 3, the product tower device 4, and the recovery tower device 5 to ensure continuous and stable production.

[0047] PID parameter tuning: By tuning the PID parameters of the methanol recovery tower unit 1, the dehydration tower unit 2, the dealcoholization tower unit 3, the product tower unit 4, and the recovery tower unit 5, and by reasonably adjusting the PID parameters, the system can quickly recover to a stable state after being disturbed, while improving the self-control rate and stability of the control system, providing data basis for the step test and process modeling of the APC system 7.

[0048] The APC server of the APC system 7 is connected to the OPC server of the DCS system 6. Through the non-disturbance switching, the operator can choose to control the DCS system 6 or the APC system 7. The APC system 7 and the DCS system 6 can switch and control the temperature, pressure, composition, flow rate and liquid level of the methanol recovery tower device 1, the dehydration tower device 2, the dealcoholization tower device 3, the product tower device 4 and the recovery tower device 5.

[0049] The communication between the APC system 7 and the DCS system 6 adopts the international standard OPC communication protocol to complete the two-way data exchange between the two systems.

[0050] The communication between the APC system 7 and the remote service system (HeroRTS) is based on the 4G network and DTU equipment, using virtual VPN data transmission technology to complete the real-time remote service function of the APC server; the system is equipped with a dedicated hardware firewall for isolation between the DCS system 6 and the APC server, and between the APC server and the remote service system.

[0051] The control variables set in the methanol recovery tower device 1 include the liquid level of the top reflux tank, the liquid level of the methanol recovery tower kettle, the intermediate temperature of the methanol recovery tower, the pressure of the condensing cooling device, the temperature of the methanol recovery tower kettle, the feed temperature, the suction port pressure, and the top pressure of the methanol recovery tower; the operating variables set in the methanol recovery tower device 1 include the top reflux volume of the methanol recovery tower, the bottom production volume of the methanol recovery tower, the middle steam volume, the steam volume of the methanol recovery tower kettle, and the top vacuum valve position; the load adjustment set in the methanol recovery tower device 1 includes the crude methanol feed volume and the crude ethylene glycol feed volume; the interference variables include the side production refined methanol volume; The control variables set in the dehydration tower device 2 include the dehydration tower top temperature, the dehydration tower kettle temperature, the tower top reflux tank liquid level, the dehydration tower kettle liquid level, the suction port pressure, and the dehydration tower top pressure; the operating variables set in the dehydration tower device 2 include the dehydration tower top reflux flow, the dehydration tower kettle steam flow, the tower top production flow, the dehydration tower kettle production flow, and the tower top vacuum valve position; the interference variables set in the dehydration tower device 2 include the tower top reflux flow and the dehydration tower feed flow; The control variables set in the dealcoholization tower device 3 include the dealcoholization tower top temperature, the tower top reflux tank liquid level, the tower top reflux ratio, the tower top ethylene glycol content, the tower top butanediol content, the tower top water content, the dealcoholization tower kettle temperature, the dealcoholization tower kettle liquid level, the suction port pressure, and the dealcoholization tower top pressure; the operating variables set in the dealcoholization tower device 3 include the dealcoholization tower top reflux rate, the dealcoholization tower top extraction rate, the dealcoholization tower kettle steam rate, the dealcoholization tower kettle extraction rate, and the tower top vacuum valve position; the interference variables set in the dealcoholization tower device 3 include the dealcoholization tower feed rate and the dealcoholization tower top reflux rate; The control variables set in the product tower device 4 include the liquid level of the tower top reflux tank, the temperature of the product tower kettle, the liquid level of the product tower kettle, the liquid level of the refined ethylene glycol product tank, the suction port pressure, and the tower top pressure of the product tower; the operating variables set in the product tower device 4 include the tower top reflux valve position, the steam volume of the product tower kettle, the product tower side extraction volume, the refined ethylene glycol product tank extraction valve position, the tower top vacuum valve position, and the suction port pressure valve position; the interference variables set in the product tower device 4 include the side extraction volume and the product tower feed volume; The control variables set in the recovery tower device 5 include the recovery tower kettle temperature, the recovery tower kettle liquid level, the suction port pressure, and the recovery tower top pressure; the operating variables set in the recovery tower device 5 include the recovery tower kettle steam, the recovery tower kettle output, and the tower top vacuum valve position.

[0052] Communication timer: monitors whether the communication between the APC controller and the DCS is normal. Starting from 0, the fixed number of cycles is increased each time. If the controller operation cycle is 30 seconds, when the timer increases by 30 seconds, if the communication between the APC server and the DCS is normal, it will restart counting from 0 and cycle; when a communication abnormality occurs, the counter will gradually increase to 120, and the monitoring logic will switch all the APC circuits in use to normal operation of the DCS and trigger a prompt message.

[0053] The main controller is set to three states: off, hot standby, and control. Off means the main controller is in the off state; hot standby means the main controller is in the standby state; control means the main controller is in the control state. The sub-controller is set to two states: on and off. On means the sub-controller is in the commissioning state; off means the sub-controller is in the cut-off state.

[0054] The control variable and the manipulated variable set the measured value or set value or valve position value. The control variable also sets the control high line and control low limit; the manipulated variable sets the operation high line and operation low limit.

[0055] The control variable sets the measured value, current value, steady-state value, lower limit, upper limit, actual mode and request mode a, and the request mode a sets the open mode and the closed mode; the actual mode is the actual use state of the control variable, reflecting whether the control variable is controlled by the operating variable through APC, including the use state and the non-use state.

[0056] The operating variables set the valve position, measured value, set value, lower limit, upper limit, next step amplitude modulation, DCS mode and request mode b. The request mode b sets the APC mode and DCS mode. The DCS mode is the current control mode of the corresponding operating variable. The next step amplitude modulation represents the adjustment amplitude of the valve position or set value of the corresponding operating variable within the current cycle.

[0057] The load adjustment sets the valve position, measurement value, set value, lower limit, upper limit, downward adjustment range, DCS mode, and request mode c, wherein the request mode c includes APC mode and DCS mode.

[0058] The disturbance variable sets a disturbance value, a change value, a change state, an actual mode, and a request mode d, and the request mode d sets an on mode and a off mode.

[0059] The operation method of the APC system 7 comprises the following steps: 1. Preparation steps before starting the controller: Before starting to use the DCS operation interface, when the APC system 7 is in offline mode "off", the engineer must first start the APC controller from the APC server. When the engineer starts to start the controller, the controller will enter the "hot standby" mode and the timer will start to count up. The count is repeated, indicating that the communication between the APC system 7 and the DCS system 6 is normal and is in the "hot standby" state ready for use.

[0060] 2. Steps to start the sub-controller: a. Check whether the communication counter is in addition operation and whether the control mode is in "hot standby" mode; b. Verify whether the high and low limits of the manipulated variable are set normally, that is, confirm whether the given value of the controller or the valve opening is within the high and low limits of the manipulated variable to ensure that there is enough adjustment range for the APC system 7; c. Press the "Control" button in the main controller; d. Then press the "ON" button of the sub-controller. Wait for a control cycle to confirm whether the corresponding control variable switch is in the "ON" state; e. Confirm that the corresponding control variable switch is in the "on" state; f. Press the "APC" button of the operating variable activation switch, and the operating variable will be switched from the local mode request to the remote mode; g. After waiting for a control cycle, the main controller mode will change to the "control" state, and the sub-controller mode will also change to the "on" state; if the main controller mode is in the "control" state and the sub-controller mode is in the "on" state, the APC system 7 will take over the operation of the PID controller to maintain the operation of the factory.

[0061] All the above steps must be completed within one control cycle. If the main controller is already in the "control" mode, starting the sub-controller only requires steps d to f; if the sub-controller is already in the control mode, the operating variables under the commissioning controller are only required to step f.

[0062] 3. Steps to remove the main controller, sub-controller and operating variables: (1) If the APC system 7 is not needed for control, just press the "hot standby" button; when executing the next control cycle, the DCS system 6 switching program will switch the operating variables used in the main controller back to local operation, and all sub-controllers will be switched to the "off" state.

[0063] (2) If a sub-controller is not needed for control, for example, to cut off the atmospheric tower controller, just press the "off" button of the sub-controller. When executing the next control cycle, the DCS system 6 will switch the operating variables used in the sub-controller back to local operation, and at the same time, the sub-controller will be switched to the "off" state, while the states of other sub-controllers remain unchanged.

[0064] (3) If you want to cut off a certain operating variable separately, click the "DCS" button of the operating variable in the APC system 7 screen, and the switching program will complete the operation of switching back to local control.

[0065] (4) If an emergency occurs, simply press the "Hot Standby" button, all sub-controllers will be switched to the "Off" state, the main controller will switch to the "Hot Standby" state, all operating variables that have been put into remote mode will switch back to local mode, and the APC system 7 will release control to the operator.

[0066] The APC system 7 is also provided with an assay data input interface, and the assay data is input into the APC system 7, so that the APC system 7 performs corresponding operations according to the assay data.

[0067] Working principle of the present invention: The present invention optimizes and controls the coal-to-ethylene glycol distillation system by introducing the APC technology, thereby realizing global optimization of the multi-tower and multi-variable system, effectively reducing energy consumption, and improving the stability of system operation, especially for core unit operations such as the methanol recovery tower, dehydration tower, dealcoholization tower, product tower and recovery tower. Through the optimization control of the APC system 7, the energy consumption in the distillation process can be greatly reduced, and unnecessary energy waste, especially the reboiler load and the power consumption of the condenser, can be reduced; the present invention greatly improves the degree of automation of the entire device control process, reduces dependence on operators, reduces manual operation errors, and also reduces the labor intensity of frequent operations of operators, and stably produces high-purity ethylene glycol products, reducing product quality changes caused by operation fluctuations; the present invention can also adapt to different operating conditions, such as raw material fluctuations and environmental conditions.

[0068] Modifications and changes to the present invention made by the inventors familiar with the present invention are all within the patent scope of the present invention and are not limited to the embodiments.

Claims

1. An APC system controls the distillation of ethylene glycol from coal, characterized by: It includes a methanol recovery tower device, a dehydration tower device, a dealcoholization tower device, a product tower device and a recovery tower device which are connected in sequence according to the process sequence; the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device and the recovery tower device each include a distillation tower, a reboiler, a condensation cooling device and a pump; the temperature sensors and / or pressure sensors and / or component sensors and / or liquid level sensors and / or flow sensors and / or pumps and / or regulating valves arranged on the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device and the recovery tower device are all connected to the DCS system and the APC system.

2. The device for controlling the distillation of ethylene glycol from coal by an APC system according to claim 1, characterized in that: The APC system is connected to the remote service system through the 4G network and the DTU device, that is, the DUT device is a wireless terminal device.

3. The device for controlling the distillation of ethylene glycol from coal by an APC system according to claim 1, characterized in that: An isolation hardware firewall is set up between the DCS system and the APC server, and between the APC server and the remote service system.

4. The device for controlling the distillation of ethylene glycol from coal by an APC system according to claim 1, characterized in that: The APC server of the APC system is connected to the OPC server of the DCS system.

5. A method for controlling the distillation of ethylene glycol from coal by an APC system, comprising the following steps: Data collection: The temperature, pressure, composition, flow rate, liquid level and other key process parameters of the methanol recovery tower, dehydration tower, dealcoholization tower, product tower and recovery tower are collected in real time through temperature sensors, pressure sensors, liquid level sensors, flow sensors and component sensors; Step test: In the control system, the step test is used to determine the dynamic characteristics of the coal-to-ethylene glycol distillation system. By changing the set values ​​of key process parameters such as temperature, pressure, composition, flow rate and liquid level, and observing the output changes of the coal-to-ethylene glycol distillation system, the data such as the speed of parameter rise or fall, overshoot, and adjustment time are recorded; Process modeling: Based on historical operating data and operating experience, a mathematical model of the distillation process is established to ensure accurate prediction of the entire system; Energy consumption optimization: Based on the energy consumption model in the APC system, the operating conditions of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit are dynamically optimized to reduce unnecessary energy consumption, such as optimizing steam consumption by controlling the reflux ratio and reboiler load; Product purity control: The APC system adjusts the operating parameters of the methanol recovery tower, dehydration tower, dealcoholization tower, product tower, and recovery tower in real time to ensure the purity of the final ethylene glycol product while avoiding increased energy consumption due to over-purification; Disturbance handling: When the raw material composition and / or temperature and / or pressure and / or flow rate changes, the APC system can respond quickly and automatically adjust the operating parameters of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit to ensure continuous and stable production; The APC system monitors the operating parameters of each distillation tower, reboiler, and condensation cooling device in real time by installing temperature sensors and / or pressure sensors and / or liquid level sensors and / or flow sensors and / or component sensors on the methanol recovery tower device, dehydration tower device, dealcoholization tower device, product tower device, and recovery tower device; The APC system is based on the MPC algorithm, i.e., the multivariable predictive control algorithm, combined with the process model to optimize the operating conditions of each distillation tower, reboiler, and condensing cooling device; The APC system dynamically adjusts key operating parameters such as the reflux ratio, reboiler load, and condensing cooling cold medium flow of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit to achieve the purpose of reducing energy consumption and stabilizing product quality.

6. The method for controlling the distillation of ethylene glycol from coal by an APC system according to claim 5, characterized in that: It also includes PID parameter tuning: by tuning the PID parameters of the methanol recovery tower unit, dehydration tower unit, dealcoholization tower unit, product tower unit, and recovery tower unit, and by reasonably adjusting the PID parameters, the system can quickly recover to a stable state after being disturbed, while improving the self-control rate and stability of the control system, providing data basis for step testing and process modeling of the APC system.

7. The method for controlling the distillation of ethylene glycol from coal by an APC system according to claim 6, characterized in that: The communication between the APC system and the remote service system (HeroRTS) is based on 4G network and DTU equipment, using virtual VPN data transmission technology to complete the real-time remote service function of the APC server; the system is equipped with a dedicated hardware firewall for isolation between the DCS system and the APC server, and between the APC server and the remote service system.

8. The method for controlling coal-to-ethylene glycol distillation by an APC system according to any one of claim 7, characterized in that: The APC system sets up voice alarm for equipment failure.

9. A method for controlling coal-to-ethylene glycol distillation by an APC system according to any one of claims 5 to 8, characterized in that: The APC server of the APC system is connected to the OPC server of the DCS system. Through disturbance-free switching, the operator can choose DCS system control or APC system control, so that the APC system and the DCS system can switch to control the temperature and / or pressure and / or components and / or flow and / or liquid level on the methanol recovery tower device, the dehydration tower device, the dealcoholization tower device, the product tower device, and the recovery tower device.

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