Advanced control system and method for C2 front-end hydrogenation reactor

Abstract

The embodiment of the invention provides an advanced control system and method for a C2 front hydrogenation reactor, and the system comprises an APC server, an OPC server, a DCS server, the C2 front hydrogenation reactor, and the APC server, and is used for setting preset control parameters, receiving real-time parameters uploaded by the OPC server, comparing the preset control parameters with the real-time parameters, determining corresponding optimization values, and outputting the optimization values. The optimization value is sent to the DCS server through the OPC server; the OPC server is used for receiving real-time parameters collected in the C2 front hydrogenation process, sending the real-time parameters to the APC server and sending the received optimization value to the DCS server; the DCS server is used for receiving the optimization value, converting the optimization value into a corresponding parameter control instruction and sending the parameter control instruction to the C2 hydrogenation reactor; and the C2 hydrogenation reactor is used for uploading real-time parameters acquired in a C2 pre-hydrogenation process to the DCS server and completing corresponding parameter adjustment based on the parameter control instruction.

Description

Technical Field

[0001] The invention relates to the technical field of ethylene cracking, and in particular to an advanced control system and method for a carbon two pre-hydrogenation reactor. Background Art

[0002] The trienes (ethylene, propylene, butadiene) produced by ethylene cracking technology are the basic raw materials for petrochemical industry. The level of triene production is the main indicator of the development level of a country's petrochemical industry. After the liquid hydrocarbon raw materials such as naphtha in the ethylene cracking unit are steam cracked and separated, the carbon distillate contains ethylene, ethane and 0.5-3% acetylene by volume. In the downstream polymerization reaction, the presence of acetylene will poison the polyolefin promoter. In order to obtain polymerization-grade ethylene, the industry mainly uses the selective hydrogenation method to remove acetylene, that is, under the action of a catalyst, the acetylene in the carbon distillate is selectively hydrogenated and converted into ethylene. According to different process routes, the selective hydrogenation deacetylation technology can be divided into two processes: pre-hydrogenation and post-hydrogenation.

[0003] Compared with the post-hydrogenation process, the pre-hydrogenation process has the advantages of simplified process, investment saving, low energy consumption and simple operation, and is more widely used in industry. The pre-hydrogenation reactor of C2 achieves the purpose of removing acetylene by controlling the inlet temperature. The reaction temperature is maintained by the heat generated by the compressor at the initial stage of operation, and the reaction temperature is reached by heating with low-pressure steam at the end of operation.

[0004] However, in the existing technology, when performing pre-hydrogenation of carbon 2, most of them adopt manual experience and manual adjustment methods, that is, the reactor inlet temperature is adjusted by two reversely operated temperature control valves of the cold material and hot material of the reactor inlet heat exchanger. Due to the lengthy cracking and separation process and complex process, the operator cannot monitor and adjust the pre-hydrogenation reactor of carbon 2 in real time. In actual operation, because the adjustment is not timely, two major problems will occur. First, if the inlet temperature is adjusted too high, the catalyst activity will be too high, which will reduce the selectivity of the catalyst and may cause the reactor to overheat; second, if the inlet temperature is adjusted too low, the catalyst activity will be too low, causing the acetylene content at the reactor outlet to exceed the standard and leak acetylene, thereby affecting the quality of ethylene products. Summary of the invention

[0005] In view of the problems existing in the prior art, an embodiment of the present invention provides an advanced control system and method for a C2 pre-hydrogenation reactor.

[0006] The embodiment of the present invention provides an advanced control method for a carbon two pre-hydrogenation reactor, comprising: an APC server, an OPC server, a DCS server, a carbon two hydrogenation reactor, The APC server is used to set preset control parameters, receive real-time parameters uploaded by the OPC server, compare the preset control parameters with the real-time parameters, determine corresponding optimized values, and send the optimized values ​​to the DCS server through the OPC server; The OPC server is used to receive the real-time parameters collected in the pre-hydrogenation process of C2, and send the real-time parameters to the APC server, and send the received optimization values ​​to the DCS server; A DCS server is used to receive the optimization value, convert the optimization value into a corresponding parameter control instruction, and send the parameter control instruction to the C2 hydrogenation reactor; The C2 hydrogenation reactor is used to upload the real-time parameters collected in the C2 pre-hydrogenation process to the DCS server, and complete the corresponding parameter adjustment based on the parameter control instructions.

[0007] In one embodiment, the system further comprises: The fault detection module is used to shield the preset control parameters, receive the fault control parameters, and determine the fault optimization value in combination with the real-time control parameters when abnormal information of the acetylene concentration online analyzer is detected, and send the optimization value to the DCS server through the OPC server.

[0008] In one embodiment, the system further comprises: The dynamic optimization module is used to receive the real-time control parameters of the first-stage carbon two hydrogenation reactor as a reference when determining the optimization value of the second-stage carbon two hydrogenation reactor, and to receive the real-time control parameters of the second-stage carbon two hydrogenation reactor as a reference when determining the optimization value of the third-stage carbon two hydrogenation reactor. The carbon two hydrogenation reactor includes a first-stage carbon two hydrogenation reactor, a second-stage carbon two hydrogenation reactor, and a third-stage carbon two hydrogenation reactor.

[0009] In one embodiment, the system further comprises: A PID controller is used to receive parameter control instructions from the DCS server and adjust the actuator in the carbon two hydrogenation reactor based on the parameter control instructions.

[0010] In one embodiment, the system further comprises: The optimization module is used to receive the adjusted control parameters and perform iterative optimization based on the adjusted control parameters and the preset control parameters.

[0011] In one embodiment, the system further comprises: The parameter module is used to receive and store preset control parameters, which include: the upper limit, lower limit and target value of the inlet temperature / outlet temperature / bed temperature / outlet acetylene concentration of the carbon two hydrogenation reactor, the upper limit and lower limit of the acetylene concentration of the demethanizer bottom material outlet, and the acetylene concentration in the ethylene product.

[0012] The embodiment of the present invention provides an advanced control method for a C2 pre-hydrogenation reactor, based on the advanced control system of the C2 pre-hydrogenation reactor, comprising: Setting preset control parameters on the APC server, receiving real-time control parameters uploaded by the OPC server, comparing the preset control parameters with the real-time control parameters, determining corresponding optimization values, and sending the optimization values ​​to the DCS server through the OPC server; The OPC server sends the received optimization value to the DCS server; The DCS server receives the optimization value, converts the optimization value into a corresponding parameter control instruction, and sends the parameter control instruction to the C2 hydrogenation reactor; The carbon two hydrogenation reactor completes corresponding parameter adjustment based on the parameter control instruction.

[0013] In one embodiment, the method further comprises: When abnormal information of the acetylene concentration online analyzer is detected, the preset control parameters are shielded, the fault control parameters are received, and the fault optimization value is determined in combination with the real-time control parameters, and the optimization value is sent to the DCS server through the OPC server.

[0014] In one embodiment, the method further comprises: When determining the optimization value of the two-stage carbon two hydrogenation reactor, the real-time control parameters of the one-stage carbon two hydrogenation reactor are received as a reference, and when determining the optimization value of the three-stage carbon two hydrogenation reactor, the real-time control parameters of the two-stage carbon two hydrogenation reactor are received as a reference. The carbon two hydrogenation reactor includes a one-stage carbon two hydrogenation reactor, a two-stage carbon two hydrogenation reactor, and a three-stage carbon two hydrogenation reactor.

[0015] In one embodiment, the method further comprises: The APC server receives the adjusted adjustment control parameters, and performs iterative optimization on the preset control parameters based on the adjustment control parameters.

[0016] An advanced control system and method for a pre-C2 hydrogenation reactor provided by an embodiment of the present invention include: an APC server, an OPC server, a DCS server, and a C2 hydrogenation reactor. The APC server is used to set preset control parameters, receive real-time parameters uploaded by the OPC server, compare the preset control parameters with the real-time parameters, determine the corresponding optimization value, and send the optimization value to the DCS server through the OPC server; the OPC server is used to receive the real-time parameters collected in the pre-C2 hydrogenation process, send the real-time parameters to the APC server, and send the received optimization value to the DCS server; the DCS server is used to receive the optimization value, convert the optimization value into a corresponding parameter control instruction, and send the parameter control instruction to the C2 hydrogenation reactor; the C2 hydrogenation reactor is used to upload the real-time parameters collected in the pre-C2 hydrogenation process to the DCS server, and complete the corresponding parameter adjustment based on the parameter control instruction. In this way, the pre-C2 hydrogenation reactor can be monitored in real time, adjusted and optimized after problems occur, avoiding the problem of reactor overheating, and improving the quality of ethylene products. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a structural diagram of an advanced control system of a carbon two pre-hydrogenation reactor according to an embodiment of the present invention; Figure 2 This is a process flow chart of a carbon two pre-hydrogenation process in an embodiment of the present invention; Figure 3 It is a structural diagram of an advanced control system of a carbon two pre-hydrogenation reactor in another embodiment of the present invention; Figure 4 The present invention is a flowchart of an advanced control method for a C2 pre-hydrogenation reactor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Figure 1The structure of an advanced control system of a carbon 2 pre-hydrogenation reactor provided in an embodiment of the present invention is applied to a carbon 2 pre-hydrogenation process, such as Figure 1 As shown, the system comprises: APC server 101, OPC server 102, DCS server 103, C2 hydrogenation reactor 104, wherein APC (Advanced Process Control) server 101 is used to receive real-time parameters collected in the C2 pre-hydrogenation process, integrating modules such as data platform, model prediction controller, expert intelligent design, and online engineering management, and is used for pre-control operation monitoring configuration, data acquisition, processing and storage, controller modeling configuration simulation, controller debugging optimization output, and expert intelligent control system design. Figure 2 As shown, in Figure 2In the process, the cracked gas after drying enters the high-pressure depropanizer, and the gas phase at the top of the tower enters the fifth stage of the cracked gas compressor. The cracked gas after the fifth stage compression enters the first stage of the carbon two hydrogenation reactor after heating, and enters the second and third stages of the hydrogenation reactor after cooling. The PID split-range regulation system is set at the entrance of each reactor to control the feed temperature. The three-stage reactor removes acetylene and most of the methyl acetylene MA and propadiene PD and enters the dryer, and then cools with propylene of different grades, and then enters the reflux tank of the high-pressure depropanizer. After the cracked gas is flashed by gas and liquid, in addition to being used as reflux, the gas phase and liquid phase enter the pre-cooling fractionation system. In the carbon two pre-hydrogenation process, sensors such as temperature sensors and pressure sensors are used to monitor the temperature, pressure and other parameters in the reactor. The parameters are transmitted from the field equipment to the APC platform through the OPC (OLE for Process Control) server. OPC is a standard interface that allows data exchange between hardware and software from different manufacturers. Specific real-time parameters may include reactor (C2 hydrogenation reactor) inlet temperature (including stage one, stage two, and stage three), reactor outlet acetylene concentration, outlet temperature, and bed temperature rise (including stage one, stage two, and stage three), demethanizer bottom outlet acetylene concentration, acetylene concentration in ethylene products, etc. In addition, the preset control parameters may be parameters of the pre-C2 hydrogenation process set by the operator in advance in the APC server, or may be temporarily set by the operator according to the requirements of the current pre-C2 hydrogenation process. After determining the preset control parameters, the preset control parameters are compared with the real-time parameters, wherein the preset control parameters may include: high limit, low limit, and target value of C2 hydrogenation reactor inlet temperature / outlet temperature / bed temperature / outlet acetylene concentration, high limit and low limit of demethanizer bottom outlet acetylene concentration, and ethylene product. Compare the preset control parameters with the real-time parameters. The comparison strategy can be, for example, using pre-built expert programs and model relationships for data processing and analysis, and finding the optimal control strategy that meets all constraints through optimization algorithms. The optimization algorithm can be, for example, a model predictive controller MPC (multivariable control strategy), which predicts the future process behavior of real-time parameters based on a dynamic model, and combines the constraints of preset control parameters to determine the best parameter adjustment action through optimization calculation, thereby determining the optimal value corresponding to the parameter. The MPC optimization process can specifically include: Optimizing reactor temperature control: By precisely controlling the inlet temperature of the first reactor, the acetylene conversion rate is maximized while maintaining ethylene selectivity; Monitoring and adjusting the second and third reactors: Based on the model established with historical data, MPC can predict and adjust the temperature of the second and third reactors to optimize the overall acetylene removal efficiency, etc., and send the optimized value to the DCS (Distributed Control System) server through the OPC server.

[0021] The OPC server 102 includes OPC interface software, which is used for data reading and writing interactive transmission between the advanced control APC layer and the conventional control DCS layer, and is used for data exchange. It receives real-time parameters uploaded by the DCS server in the pre-hydrogenation process of carbon two, and sends the real-time parameters to the APC server for the APC server to determine the optimized value of the real-time parameter, and after the APC server determines the optimized value, it sends the received optimized value to the DCS server.

[0022] The DCS server 103 includes DCS configuration management and monitoring software, which is used for the configuration design and operation monitoring of the human-computer interaction interface (including APC and DCS operation screen), the auxiliary bit number of the first control, communication monitoring, safety logic switching and PID conventional controller. The DCS server is a distributed control system, which is used to receive the optimization value transmitted by the OPC server, and convert the optimization value into a corresponding parameter control instruction, and send the parameter control instruction to the carbon two hydrogenation reactor. In addition, the DCS server can also integrate a PID controller, which is used to receive the parameter control instruction of the DCS server and adjust the actuator in the carbon two hydrogenation reactor based on the parameter control instruction.

[0023] The C2 hydrogenation reactor is a field device in the C2 pre-hydrogenation process. Its control logic can be integrated with the APC server to achieve closed-loop control, including uploading the real-time parameters collected in the C2 pre-hydrogenation process to the DCS server, and completing the corresponding parameter adjustment based on the parameter control instructions transmitted by the DCS server. The parameters can be adjusted by the PID controller or by a more sophisticated expert intelligent controller. The expert intelligent controller is used to solve complex, nonlinear or time-varying problems that are difficult for traditional PID controllers to handle, such as the abnormal increase in the COT (Cracking Outlet Temperature) of the cracking furnace, severe coking on the surface of the furnace tube, the sudden increase in CO concentration caused by nickel exposure, and the sudden decrease in CO after the normal operation of the cracking furnace in the C2 pre-hydrogenation process. These professional problems can be handled by a more professional expert intelligent controller instead of the PID controller. The C2 hydrogenation reactor includes the operation and regulation control of the inlet temperature of the first, second and third stage reactors on site, and the measurement values ​​of multiple process parameters such as the reactor feed flow, feed pressure, feed temperature, feed components (such as butadiene, acetylene, CO, MA, PD concentrations), outlet material temperature, discharge components (such as acetylene, ethylene, MA, PD concentrations), temperature of each measuring point of the catalyst bed, and real-time monitoring of the operation of each inlet temperature range control valve.

[0024] In addition, in the present embodiment, the advanced control system of the C2 pre-hydrogenation reactor may further include a fault detection module, which is used to generate corresponding abnormal information when abnormal information of the acetylene concentration online analyzer is detected, such as the acetylene concentration online analyzer issues an alarm, or the data fluctuates abnormally, the data is significantly different from other identical instruments, etc., and then shield the preset control parameters pre-set by the operator, receive the new fault control parameters reset by the operator after the fault occurs, and determine the fault optimization value in combination with the real-time control parameters, and send the optimization value to the DCS server through the OPC server, wherein the fault control parameter is to maintain the stable operation of the reactor by controlling the temperature and temperature rise of the C2 hydrogenation reactor in the absence of acetylene concentration data, so that when the acetylene concentration online analyzer fails, the control strategy can be quickly adjusted to ensure the stable operation of the reactor, while avoiding adverse effects on product quality and process safety.

[0025] In addition, the APC server also includes a dynamic optimization module for dynamically optimizing real-time parameters and determining optimization values. For example, when determining the optimization value of the second-stage carbon two hydrogenation reactor, the real-time control parameters of the first-stage carbon two hydrogenation reactor are received as a reference, and when determining the optimization value of the third-stage carbon two hydrogenation reactor, the real-time control parameters of the second-stage carbon two hydrogenation reactor are received as a reference. The carbon two hydrogenation reactor includes a first-stage carbon two hydrogenation reactor, a second-stage carbon two hydrogenation reactor, and a third-stage carbon two hydrogenation reactor. The detailed dynamic optimization process may include: In the first-stage carbon dihydrogenation reactor (first reactor), the expert intelligent controller is used to mainly suppress the impact of the drastic change of the interference variable of the cracking gas CO concentration on the reaction. The first reactor outlet temperature and the bed temperature rise are used as the controlled variables to quickly adjust the first reactor inlet temperature, which is a feedforward regulation module. When the CO concentration is within the process safety range, the first reactor outlet acetylene concentration, the demethanizer bottom material outlet acetylene concentration, and the acetylene concentration in the ethylene product are used as the final process optimization targets to further control the first reactor inlet temperature, which is a feedback regulation module.

[0026] In the two-stage carbon dihydrogenation reactor (second reactor), a model predictive controller is used to overcome the interference of cracking gas flow, acetylene at the first reactor outlet, and CO concentration. The outlet acetylene, outlet temperature and bed temperature rise of the second reactor are used as controlled variables to optimize the control of the second reactor inlet temperature.

[0027] In the three-stage carbon dihydrogenation reactor (three reactors), a model predictive controller is used to overcome the interference of cracking gas flow, acetylene at the second reactor outlet, and CO concentration. The outlet acetylene, outlet temperature and bed temperature rise of the third reactor are used as controlled variables to optimize the control of the third reactor inlet temperature.

[0028] In addition, in this embodiment, the advanced control system of the C2 pre-hydrogenation reactor also includes a PID controller, which can calculate the action amount of the actuator through a PID algorithm based on the control parameters (set point, etc.) received from the DCS server and the actual value of the field sensor feedback. The PID controller sends this action amount to the actuator to adjust the operating state of the field equipment (such as the C2 hydrogenation reactor).

[0029] In addition, in this embodiment, the APC server also includes an optimization module, which can receive the adjusted control parameters after adjusting the parameters of the carbon two hydrogenation reactor, and save the adjusted control parameters and the corresponding real-time parameters accordingly, and iteratively optimize the preset control parameters based on the saved adjusted control parameters, so as to determine more accurate preset control parameters.

[0030] In addition, in this embodiment, the APC server also includes a parameter module, which is used to receive and store preset control parameters. The preset control parameters may include: the upper limit, lower limit, and target value of the inlet temperature / outlet temperature / bed temperature / outlet acetylene concentration of the carbon two hydrogenation reactor, the upper limit and lower limit of the acetylene concentration at the outlet of the demethanizer bottom material, and the acetylene concentration in the ethylene product.

[0031] The advanced control system of the pre-carbon 2 hydrogenation reactor provided in this embodiment includes: an APC server, an OPC server, a DCS server, and a carbon 2 hydrogenation reactor. The APC server is used to set preset control parameters, receive real-time parameters uploaded by the OPC server, compare the preset control parameters with the real-time parameters, determine the corresponding optimization value, and send the optimization value to the DCS server through the OPC server; the OPC server is used to receive the real-time parameters collected in the pre-carbon 2 hydrogenation process, send the real-time parameters to the APC server, and send the received optimization value to the DCS server; the DCS server is used to receive the optimization value, and convert the optimization value into a corresponding parameter control instruction, and send the parameter control instruction to the carbon 2 hydrogenation reactor; the carbon 2 hydrogenation reactor is used to upload the real-time parameters collected in the pre-carbon 2 hydrogenation process to the DCS server, and complete the corresponding parameter adjustment based on the parameter control instruction. In this way, the pre-carbon 2 hydrogenation reactor can be monitored in real time, and the optimization can be adjusted after a problem occurs, avoiding the problem of reactor temperature rise, and improving the quality of ethylene products.

[0032] In another embodiment, an advanced control system for a C2 hydrogenation reactor can be as follows: Figure 3 As shown, in Figure 3It not only includes APC server, OPC server, DCS server, and C2 hydrogenation reactor, but also includes the industrial control firewall connecting the APC server and OPC server. The service protocols and security policies in the industrial control firewall can further ensure the security of data transmission.

[0033] In another embodiment, the specific implementation steps of an advanced control system based on a C2 pre-hydrogenation reactor may include: The inlet temperature control steps of the first stage C2 hydrogenation reactor are as follows: (1) The operator inputs the control parameter data through the APC operation screen according to production needs. The control parameters include the upper and lower limits of the acetylene concentration at the outlet of the first reactor, the target, upper and lower limits of the outlet temperature of the first reactor, the upper and lower limits of the bed temperature difference of the first reactor, the upper and lower limits of the acetylene concentration at the bottom of the demethanizer, the upper and lower limits of the acetylene concentration of the ethylene tower top product, and the upper and lower limits of the inlet temperature of the first reactor.

[0034] (2) The control platform obtains real-time data of a section of reactor-related variables every 5 seconds through OPC, and collects, processes, stores and applies the data.

[0035] (3) The expert intelligent controller reads data through the advanced control platform according to the control cycle. Generally speaking, when the interference variable changes suddenly or the quality control required by the process exceeds the index, the inlet temperature set value can be quickly corrected and adjusted according to a certain deviation rate. The specific design can be shown in the following table: Serial number Working condition trigger conditions 1. Reverse inlet temperature setpoint output 1 CO concentration exceeds the process safety value and the increase exceeds the threshold C1 Positive temperature correction coefficient K1*C1 2 The CO concentration exceeds the process safety value and the increase exceeds the threshold C2. The bed temperature rises and is lower than the upper limit. On the contrary, the outlet temperature rises Positive temperature correction coefficient K2*C2 3 The CO concentration exceeds the process safety value and the drop exceeds the threshold C3. The bed temperature rises above the upper limit, and the outlet temperature rises. Negative temperature correction coefficient K3*C3 4 The CO concentration exceeds the process safety value and the drop exceeds the threshold C4. The bed temperature rise drops below the lower limit, and the outlet temperature drops. Positive temperature correction coefficient K4*C4 5 CO concentration exceeds process danger value Direct output to high temperature limit 6 When the CO concentration is within the process safety value, perform the following 6.1 The acetylene in the demethanizer bottom exceeds the upper limit, and the acetylene in the ethylene product exceeds the lower limit Preferably add (0.3-0.4)℃ 6.2 Acetylene at the bottom of the demethanizer exceeds the upper limit and rises Preferably add (0.2-0.3)℃ 6.3 The acetylene at the bottom of the demethanizer is between the upper limit and the upper upper limit and is rising, and the acetylene of the ethylene product is higher than the lower limit Preferably add (0.2-0.3)℃ 6.4 The acetylene at the bottom of the demethanizer is between the lower limit and the upper limit, and the acetylene of the ethylene product is between the lower limit and the upper limit and is decreasing. Preferably reduce (0.1-0.2)℃ 6.5 Ethylene product acetylene exceeds upper limit and rises Preferably add (0.3-0.4)℃ 6.6 The acetylene at the bottom of the demethanizer is below the lower limit and is decreasing, and the acetylene of the ethylene product is below the lower limit Preferably reduce (0.2-0.3)℃ 6.7 The ethylene product acetylene is below the lower limit, while the outlet temperature is higher than the target temperature and rising Positive temperature correction coefficient K5*negative temperature (target value-measured value) 6.8 The ethylene product acetylene is higher than the upper limit, while the outlet temperature is lower than the target temperature and is decreasing. Positive temperature correction coefficient K6*negative temperature (target value-measured value) (4) The control platform communicates via OPC and sends the inlet temperature set point calculated in step (3) to the DCS control system every 15 seconds for PID controller adjustment, which runs periodically.

[0036] Steps for controlling the inlet temperature of the second-stage carbon dihydrogenation reactor: (1) The operator inputs the control parameter data through the APC operation screen according to the production requirements. The control parameters include the upper and lower limits of the acetylene concentration at the outlet of the second-stage reactor, the target, upper and lower limits of the outlet temperature of the second-stage reactor, the upper and lower limits of the bed temperature difference of the second-stage reactor, and the upper and lower limits of the inlet temperature of the second-stage reactor.

[0037] (2) The control platform obtains real-time data of the relevant variables of the second-stage reactor every 5 seconds through OPC, and collects, processes, stores and applies the data.

[0038] (3) The model predictive controller reads data every 90 seconds through the advanced control platform. Based on the variable control model and the current process parameter values, the advanced control algorithm program is used within the constraints to calculate the predicted change value of the controlled variable, the optimal steady-state process conditions, and the future multi-step predicted output value of the operating variable. The controller only executes the current first step of the second stage inlet temperature set value output, which is stored in the advanced control platform and runs periodically. When the acetylene concentration analyzer at the outlet of the second stage reactor fails, the advanced control switch of the controlled variable is cut off, and the controller can still operate normally.

[0039] The variables of the second-stage reactor control model are designed as follows: Controlled variable Manipulating variables Interference variables Acetylene concentration at the outlet of the second stage reactor Second stage reactor inlet temperature Acetylene concentration at the outlet of the first stage reactor Second stage reactor outlet temperature Cracking gas flow Second stage reactor bed temperature rise Pyrolysis gas CO concentration (4) The control platform communicates via OPC and sends the second-stage inlet temperature set value calculated in step (3) to the DCS control system every 90 seconds for PID controller adjustment, which runs periodically.

[0040] Three-stage C2 hydrogenation reactor inlet temperature control steps: (1) The operator inputs the control parameter data through the APC operation screen according to the production requirements. The control parameters include the upper and lower limits of the acetylene concentration at the outlet of the three-stage reactor, the target, upper and lower limits of the outlet temperature of the three-stage reactor, the upper and lower limits of the bed temperature difference of the three-stage reactor, and the upper and lower limits of the inlet temperature of the three-stage reactor.

[0041] (2) The advanced control platform obtains real-time data of relevant variables of the three-stage reactor every 5 seconds through OPC, and collects, processes, stores and applies the data.

[0042] (3) The model predictive controller reads data every 90 seconds through the advanced control platform. Based on the variable control model and the current process parameter values, the advanced control algorithm program is used within the constraints to calculate the predicted change value of the controlled variable, the optimal steady-state process conditions, and the future multi-step predicted output value of the operating variable. The controller only executes the current first step of the three-stage inlet temperature set value output, which is stored in the advanced control platform and runs periodically. When the acetylene concentration analyzer at the outlet of the three-stage reactor fails, the advanced control switch of the controlled variable is cut off, and the controller can still operate normally.

[0043] The variables of the three-stage reactor control model are designed as follows: Controlled variable Manipulating variables Interference variables Acetylene concentration at the outlet of the three-stage reactor Three-stage reactor inlet temperature Acetylene concentration at the outlet of the second stage reactor Three-stage reactor bed temperature rise Cracking gas flow The outlet temperature of the three-stage reactor Pyrolysis gas CO concentration (4) The advanced control platform communicates via OPC and sends the three-stage inlet temperature set values ​​calculated in step (3) to the DCS control system every 90 seconds to perform the PID split-range controller of the three-stage anti-cooler. The advanced control controller runs periodically.

[0044] Figure 3A flow chart of an advanced control method for a C2 pre-hydrogenation reactor provided in an embodiment of the present invention includes: Step 401, setting preset control parameters in the APC server, receiving real-time control parameters uploaded by the OPC server, comparing the preset control parameters with the real-time control parameters, determining corresponding optimization values, and sending the optimization values ​​to the DCS server through the OPC server.

[0045] Specifically, the APC server receives real-time parameters collected in the pre-C2 hydrogenation process. In the pre-C2 hydrogenation process, sensors such as temperature sensors and pressure sensors are used to monitor the temperature, pressure and other parameters in the reactor. The parameters are transmitted from the field equipment to the APC platform through the OPC server. OPC is a standard interface that allows data exchange between hardware and software from different manufacturers. Specific real-time parameters may include the reactor (C2 hydrogenation reactor) inlet temperature (including the first, second and third stages), the reactor outlet acetylene concentration, outlet temperature and bed temperature rise (including the first, second and third stages), the demethanizer bottom material outlet acetylene concentration, the acetylene concentration in the ethylene product, and so on. In addition, the preset control parameters can be the parameters of the C2 pre-hydrogenation process set in advance by the operator in the APC server, or can be temporarily set by the operator according to the requirements of the current C2 pre-hydrogenation process. After determining the preset control parameters, the preset control parameters are compared with the real-time parameters, among which the preset control parameters may include: the upper limit, lower limit, and target value of the inlet temperature / outlet temperature / bed temperature / outlet acetylene concentration of the C2 hydrogenation reactor, the upper limit and lower limit of the acetylene concentration at the outlet of the demethanizer bottom material, and the acetylene concentration in the ethylene product. Compare the preset control parameters with the real-time parameters. The comparison strategy can be, for example, using pre-built expert programs and model relationships for data processing and analysis, and finding the optimal control strategy that meets all constraints through optimization algorithms. The optimization algorithm can be, for example, a model predictive controller MPC (multivariable control strategy), which predicts the future process behavior of real-time parameters based on a dynamic model, and combines the constraints of preset control parameters to determine the best parameter adjustment action through optimization calculation, thereby determining the optimal value corresponding to the parameter. The MPC optimization process can specifically include: Optimizing reactor temperature control: By precisely controlling the inlet temperature of the first reactor, the acetylene conversion rate is maximized while maintaining ethylene selectivity; Monitoring and adjusting the second and third reactors: Based on the model established with historical data, MPC can predict and adjust the temperature of the second and third reactors to optimize the overall acetylene removal efficiency, etc., and send the optimized value to the DCS server through the OPC server.

[0046] Step 402: The OPC server sends the received optimization value to the DCS server.

[0047] Specifically, the OPC server receives real-time parameters uploaded by the DCS server in the pre-hydrogenation process of C2, and sends the real-time parameters to the APC server for the APC server to determine the optimized values ​​of the real-time parameters. After the APC server determines the optimized values, it sends the received optimized values ​​to the DCS server.

[0048] Step 403: The DCS server receives the optimization value, converts the optimization value into a corresponding parameter control instruction, and sends the parameter control instruction to the C2 hydrogenation reactor.

[0049] Specifically, the DCS server is a distributed control system, which receives the optimization value transmitted by the OPC server, converts the optimization value into a corresponding parameter control instruction, and sends the parameter control instruction to the carbon two hydrogenation reactor. In addition, the DCS server can also integrate a PID controller, which is used to receive the parameter control instruction of the DCS server and adjust the actuator in the carbon two hydrogenation reactor based on the parameter control instruction.

[0050] Step 404: the C2 hydrogenation reactor completes corresponding parameter adjustment based on the parameter control instruction.

[0051] Specifically, the C2 hydrogenation reactor is a field device in the C2 pre-hydrogenation process, and its control logic can be integrated with the APC server to achieve closed-loop control, including uploading the real-time parameters collected in the C2 pre-hydrogenation process to the DCS server, and completing the corresponding parameter adjustment based on the parameter control instructions transmitted by the DCS server. The parameters can be adjusted by a PID controller or by a more sophisticated expert intelligent controller. The expert intelligent controller is used to solve complex, nonlinear or time-varying problems that are difficult for traditional PID controllers to handle, such as abnormal increase in COT (Cracking Outlet Temperature) of the cracking furnace, severe coking on the surface of the furnace tube, sudden increase in CO concentration caused by nickel exposure, and sudden decrease in CO after the normal operation of the cracking furnace in the C2 pre-hydrogenation process. These professional problems can be handled by a more professional expert intelligent controller instead of the PID controller.

[0052] In addition, when abnormal information of the acetylene concentration online analyzer is detected, the preset control parameters are shielded, the fault control parameters are received, and the fault optimization value is determined in combination with the real-time control parameters. The optimization value is sent to the DCS server through the OPC server. In this way, when a fault occurs in the acetylene concentration online analyzer, the control strategy can be quickly adjusted to ensure the stable operation of the reactor while avoiding adverse effects on product quality and process safety.

[0053] In addition, when determining the optimization value of the second-stage carbon two hydrogenation reactor, the real-time control parameters of the first-stage carbon two hydrogenation reactor are received as a reference, and when determining the optimization value of the third-stage carbon two hydrogenation reactor, the real-time control parameters of the second-stage carbon two hydrogenation reactor are received as a reference, thereby realizing dynamic optimization of real-time parameters.

[0054] In addition, the APC server receives the adjusted adjustment control parameters, and performs iterative optimization on the preset control parameters based on the adjustment control parameters, thereby determining more accurate preset control parameters.

[0055] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0056] The above is only a partial implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An advanced control system for a C2 pre-hydrogenation reactor, applied to a C2 pre-hydrogenation process, characterized in that: include: APC server, OPC server, DCS server, C2 hydrogenation reactor, The APC server is used to set preset control parameters, receive real-time parameters uploaded by the OPC server, compare the preset control parameters with the real-time parameters, determine corresponding optimized values, and send the optimized values ​​to the DCS server through the OPC server; The OPC server is used to receive the real-time parameters collected in the pre-hydrogenation process of C2, and send the real-time parameters to the APC server, and send the received optimization values ​​to the DCS server; A DCS server is used to receive the optimization value, convert the optimization value into a corresponding parameter control instruction, and send the parameter control instruction to the C2 hydrogenation reactor; The C2 hydrogenation reactor is used to upload the real-time parameters collected in the C2 pre-hydrogenation process to the DCS server, and complete the corresponding parameter adjustment based on the parameter control instructions.

2. The advanced control system of the C2 pre-hydrogenation reactor according to claim 1, characterized in that: The system further comprises: The fault detection module is used to shield the preset control parameters, receive the fault control parameters, and determine the fault optimization value in combination with the real-time control parameters when abnormal information of the acetylene concentration online analyzer is detected, and send the optimization value to the DCS server through the OPC server.

3. The advanced control system of the C2 pre-hydrogenation reactor according to claim 1, characterized in that: The APC server further includes: The dynamic optimization module is used to receive the real-time control parameters of the first-stage carbon two hydrogenation reactor as a reference when determining the optimization value of the second-stage carbon two hydrogenation reactor, and to receive the real-time control parameters of the second-stage carbon two hydrogenation reactor as a reference when determining the optimization value of the third-stage carbon two hydrogenation reactor. The carbon two hydrogenation reactor includes a first-stage carbon two hydrogenation reactor, a second-stage carbon two hydrogenation reactor, and a third-stage carbon two hydrogenation reactor.

4. The advanced control system of the C2 pre-hydrogenation reactor according to claim 1, characterized in that: The system further comprises: A PID controller is used to receive parameter control instructions from the DCS server and adjust the actuator in the carbon two hydrogenation reactor based on the parameter control instructions.

5. The advanced control system of the C2 pre-hydrogenation reactor according to claim 1, characterized in that: The APC server further includes: The optimization module is used to receive the adjusted control parameters and perform iterative optimization based on the adjusted control parameters and the preset control parameters.

6. The advanced control system of the C2 pre-hydrogenation reactor according to any one of claims 1 to 5, characterized in that: The APC server further includes: The parameter module is used to receive and store preset control parameters, which include: the upper limit, lower limit and target value of the inlet temperature / outlet temperature / bed temperature / outlet acetylene concentration of the carbon two hydrogenation reactor, the upper limit and lower limit of the acetylene concentration of the demethanizer bottom material outlet, and the acetylene concentration in the ethylene product.

7. An advanced control method for a C2 pre-hydrogenation reactor, based on the advanced control system of the C2 pre-hydrogenation reactor as claimed in claim 1, applied to a C2 pre-hydrogenation process, characterized in that: include: Setting preset control parameters on the APC server, receiving real-time control parameters uploaded by the OPC server, comparing the preset control parameters with the real-time control parameters, determining corresponding optimization values, and sending the optimization values ​​to the DCS server through the OPC server; The OPC server sends the received optimization value to the DCS server; The DCS server receives the optimization value, converts the optimization value into a corresponding parameter control instruction, and sends the parameter control instruction to the C2 hydrogenation reactor; The carbon two hydrogenation reactor completes corresponding parameter adjustment based on the parameter control instruction.

8. The advanced control method for a C2 pre-hydrogenation reactor according to claim 7, characterized in that: The method further comprises: When abnormal information of the acetylene concentration online analyzer is detected, the preset control parameters are shielded, the fault control parameters are received, and the fault optimization value is determined in combination with the real-time control parameters, and the optimization value is sent to the DCS server through the OPC server.

9. The advanced control method for a C2 pre-hydrogenation reactor according to claim 7, characterized in that: The determining of the corresponding optimization value comprises: When determining the optimization value of the two-stage carbon two hydrogenation reactor, the real-time control parameters of the one-stage carbon two hydrogenation reactor are received as a reference, and when determining the optimization value of the three-stage carbon two hydrogenation reactor, the real-time control parameters of the two-stage carbon two hydrogenation reactor are received as a reference. The carbon two hydrogenation reactor includes a one-stage carbon two hydrogenation reactor, a two-stage carbon two hydrogenation reactor, and a three-stage carbon two hydrogenation reactor.

10. The advanced control method for a C2 pre-hydrogenation reactor according to claim 7, characterized in that: The determining of the corresponding optimization value comprises: The APC server receives the adjusted adjustment control parameters, and performs iterative optimization on the preset control parameters based on the adjustment control parameters.

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