Process verification method and process verification system for PO / MTBE device

Abstract

The invention discloses a process verification method and a process verification system for a PO / MTBE device. The process verification method comprises the following steps: (S1) establishing a process model; (S2) a simulation control system is configured; (S3) modules are interconnected; and (S4) process verification. Based on the computer simulation technology, the technological process, equipment operation and control logic of a real chemical device are simulated, technological verification is carried out before the device is started, the limitation of a traditional method can be overcome, and the efficiency and accuracy of technological verification are improved. The method provided by the invention has high flexibility, not only can comprehensively and deeply verify the process performance and reliability, but also can provide powerful support for optimizing and improving the process by comprehensively and accurately collecting and analyzing data, thereby assisting efficient and stable operation and development of chemical production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical industry, in particular to a process verification method and a process verification system for PO / MTBE device. BACKGROUND

[0002] The co-oxidation method for producing PO (propylene oxide) and MTBE (methyl tert-butyl ether) avoids the problems of wastewater and waste residue generated by the chlorohydrination method, and conforms to the development trend of green chemical industry. However, the process is complex and involves multiple chemical reactions and physical separation processes. During the construction, reconstruction or operation of the PO / MTBE device, the process of the device needs to be comprehensively verified to ensure that the device can operate stably, efficiently and safely, and achieve the expected product quality and production indicators.

[0003] The co-oxidation method for producing PO / MTBE involves multiple chemical reactions, such as the oxidation reaction of isobutylene with oxygen to produce tert-butyl hydroperoxide (TBHP), the reaction of TBHP with propylene in the presence of a molybdenum-containing catalyst to produce propylene oxide (PO) and tert-butyl alcohol (TBA), and the reaction of TBA with methanol to synthesize MTBE. Each step of the reaction has its specific reaction conditions, such as temperature, pressure, reactant concentration, etc., which are interrelated and interdependent. Especially for the oxidation reaction, it is not only related to the concentration of reactants, but also closely related to the activity of catalysts and the content of impurities in the reaction system. It is very difficult to accurately control the reaction rate to achieve the ideal product distribution during the debugging process. This makes the verification in actual production require a large amount of time, resources and energy, and slight deviation in process conditions may affect the reaction effect, and the peroxide unit may even bring safety hazards. Factors such as equipment stability and personnel operation experience also increase the control difficulty, which may pose risks to product quality and production stability, and it is difficult to simulate various fault conditions and optimization schemes, which cannot comprehensively verify the process performance. In addition, some traditional equipment is not suitable for new verification requirements, which seriously restricts the efficiency and development of chemical production.

[0004] The traditional process verification method mainly relies on actual production tests and data analysis, which has some limitations. For example, actual production tests may be affected by production plans, raw material supply, equipment maintenance and other factors, resulting in long test cycles and high costs. Moreover, when adjusting and optimizing the process in actual production, it may cause certain risks to product quality and production stability.

[0005] Currently, there are few known PO / MTBE co-production devices, and there is a shortage of resources for learning and reference. It is difficult to verify the process only by traditional methods. Therefore, it is necessary to provide a more efficient, flexible and safe process verification method. SUMMARY

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A process validation method, the process validation method comprising the following steps: (S1) Establishing a process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the PO / MTBE unit; (S2) Configure the simulation control system: Based on the actual control system of the PO / MTBE device, a three-dimensional simulation control system is built. The simulation control system includes simulation control logic and operation interface. (S3) Module interconnection: Module interconnection is formed between the process model and the simulation control system to ensure the consistency and real-time performance of the simulation control system data; (S4) Process verification: During simulation, the signals of the process model are transmitted to the simulation control system, and the simulation control system sends instructions to the process model, thus forming a closed-loop operation of process simulation and control simulation; the verification results of the process model are output. Optionally, the process verification method further includes: evaluating the verification results based on evaluation indicators and generating an optimized process scheme.

[0007] In this invention, PO refers to propylene oxide, MTBE refers to methyl tert-butyl ether, and PO / MTBE unit refers to a unit that co-produces MTBE (methyl tert-butyl ether) from PO (propylene oxide).

[0008] According to an embodiment of the present invention, in step (S1), the process model adopts multi-dimensional coupling modeling. Preferably, the multi-dimensional coupling modeling refers to modeling the PO / MTBE unit into different sub-units according to the production process package. Each sub-unit operates independently without affecting the others. After the sub-units are debugged, they are connected according to the production process package. For example, in multi-dimensional coupling modeling, the material A entering the second sub-unit from the first sub-unit is defined as A1 and A2 respectively. A1 is the output of the first sub-unit, and the physical and chemical properties of A1 are affected by the operating conditions of the first sub-unit. In the production process package, A1 is defined as the standard state. A2 is the feed of the second sub-unit, and the physical and chemical properties of A2 are defined as the fixed state according to the production process package during modeling. During the debugging of each sub-unit, each sub-unit operates independently without affecting the others. After the debugging of each sub-unit is completed, they are connected. During connection, A1 is adjusted to the standard state, and A1 and A2 are merged into A to realize the connection between the first sub-unit and the second sub-unit. Similarly, other sub-units in the production process package are connected to achieve multi-dimensional coupled modeling.

[0009] According to an embodiment of the present invention, in step (S1), the production process package includes a process flow and production process data.

[0010] According to an embodiment of the present invention, the process model includes an apparatus module and a parameter module.

[0011] Preferably, the device module includes a reaction unit and a utility unit. Further, the reaction unit includes a first unit (isobutane peroxidation), a second unit (propylene epoxidation), a third unit (purification), and a fourth unit (MTBE reaction).

[0012] Preferably, the parameter module includes raw material parameters (such as physicochemical properties) and system parameters (such as a production process package formulated based on reaction kinetics and heat and mass transfer laws, including process flow and process parameters). The process model constructed by this invention is a high-precision dynamic model, which breaks through the limitations of traditional single-unit modeling and realizes full-system modeling of complex chemical processes.

[0013] In this invention, the process flow of the PO / MTBE unit specifically includes: reacting isobutane with oxygen, and then reacting the intermediate product tert-butyl hydroperoxide (TBHP) with propylene to generate PO. The byproduct of the oxidation reaction, tert-butanol (TBA), reacts with methanol to form the final byproduct MTBE.

[0014] Furthermore, the first unit, the isobutane peroxidation unit, is a reaction unit for isobutane and oxygen; the second unit, the propylene epoxidation unit, is a reaction unit for the intermediate product TBHP and propylene; the third unit, the purification unit, is a separation and purification unit for crude PO and TBA (e.g., including a heavy component removal tower); and the fourth unit, the MTBE reaction unit, is a reaction unit for TBA and methanol.

[0015] Furthermore, the public works unit, also known as the public auxiliary unit, includes water systems, steam systems, and instrument ventilation systems, etc.

[0016] In the process model of this invention, the device modules and parameter modules are independent of each other. Preferably, the units within the device modules and parameter modules are also independent of each other. For example, the operation of the first unit (isobutylene peroxidation unit) and the second unit (propylene epoxidation unit) is described as follows: The first unit (isobutylene peroxidation unit) generates the intermediate product TBHP. The composition, temperature, pressure, flow rate, etc., of the TBHP material are all based on the production process package (but the actual results may deviate from this). When the TBHP material enters the second unit (propylene epoxidation unit) as a raw material, the TBHP material as a raw material needs to be reset according to the product parameters or system parameters in the process package of the first unit (isobutylene peroxidation unit). It does not need to rely on the calculation results of the first unit; it is sufficient to ensure that its physical properties are the same.

[0017] According to an embodiment of the present invention, in step (S2), the control logic mirroring technique is used when configuring the control system.

[0018] According to an embodiment of the present invention, the three-dimensional method includes: (S21) determining the device modules and parameter modules in the device based on the process characteristics, and determining the control target; (S22) parameter analysis: analyzing key parameters (such as temperature, pressure, flow rate, etc.) in the control target, and determining the core parameters that need to be monitored and controlled; (S23) algorithm matching: selecting control logic (such as PID control, etc.) based on the control target and core parameters to achieve precise regulation.

[0019] According to an embodiment of the present invention, in step (S21), the control objective preferably includes key parameters in the production process package, such as the liquid level and pressure of the tower and storage tank, and the flow rate of important materials.

[0020] For example, in step (S21), the control target is determined based on the control requirements in the production process package, combined with the equipment type, reaction, and material properties. For example, for a distillation column, its key parameters include top pressure, bottom temperature, and reflux ratio. For instance, the bottom temperature can be controlled by adjusting the vapor in the distillation column bottom, and the top pressure can be controlled by venting the top of the distillation column. The reflux ratio is a process control parameter, which operators can adjust in real time according to the actual operating conditions of the distillation column.

[0021] According to the embodiment of the present invention, the core parameters controlled in steps (S22) and (S23) jointly determine the stability of the entire system, thereby determining the product quality, capacity and operating cost of the PO / MTBE device.

[0022] According to an embodiment of the present invention, the simulation control logic includes process control and operation control. Preferably, real-time data and historical data are collected and monitored through the simulation control logic, and then organized into a data pool. Further, the data pool also includes production process data from the production process package.

[0023] According to an embodiment of the present invention, the simulation control logic further includes device interlocking protection logic, forming a simulation model that is a complete mirror image of the actual control logic, significantly improving the realism of control strategy verification. Preferably, the device interlocking protection logic refers to triggering an alarm or automatically taking emergency measures when key parameters (such as temperature, pressure, flow rate, etc.) in the production process data are not within the threshold range, so that the operator can promptly adjust the equipment unit corresponding to the production process data, thereby bringing the production process data back to the corresponding threshold range.

[0024] According to an embodiment of the present invention, in step (S3), the module interconnection utilizes known software for data acquisition and data transmission, for example, using an OPC SERVER.

[0025] According to an embodiment of the present invention, in step (S3), the module interconnection specifically includes establishing bidirectional data transmission between the process model and the simulation control system.

[0026] According to an embodiment of the present invention, in step (S4), during simulation operation, the signal transmission of the process model specifically includes: sending the analog input signal AI and the digital input signal DI of the process model to the simulation control system, for example, transmitting them to the human-machine interface at the front end of the operating interface. Preferably, the signal transmission of the process model preferably includes signals of key parameters and / or core parameters.

[0027] According to an embodiment of the present invention, in step (S4), the instructions sent by the simulation control system to the process model are specifically operation signals, such as start, stop, and adjustment operation signals. Preferably, the operation signals are transmitted from the simulation control system to various device modules of the process model, such as valve positions and pump switches of each device module, to achieve rapid response. The present invention overcomes the problems of data silos and response delays in traditional simulation control systems through module interconnection. This module interconnection enables the process verification method of the present invention to simulate the actual production environment and better verify the process.

[0028] According to an embodiment of the present invention, in step (S4), the process verification includes normal operating condition process verification and / or fault operating condition process verification.

[0029] Preferably, the normal operating condition process refers to the normal operation of the device modules.

[0030] Preferably, the fault condition process verification can simulate device faults, such as pump faults, temperature sensor faults, power outage faults, and other faults known in the art. Further, the simulated device faults are pre-defined in the process model with fault types and triggering conditions. The fault is triggered when a preset time or preset scenario is reached, and simultaneously, the process model transmits the signal to the simulation control system, which is then displayed on the human-machine interface of the operating interface.

[0031] According to an embodiment of the present invention, the evaluation indicators include at least one of the following: device stability, product purity, production efficiency, and energy consumption. Preferably, device stability, product purity, production efficiency, and energy consumption are based on the design range in the production process package, and the deviation from the design range is within 3%. In this invention, "at least one" means that when there are n optional elements, 1, 2, 3, 4, ... or all n optional elements can be selected.

[0032] Preferably, the stability of the device refers to the fact that all circuits of the device are in a stable control state, and the pressure, flow rate, temperature, liquid level, product concentration, etc. are all within the normal value or within the normal range with slight fluctuations.

[0033] Preferably, the product purity refers to the mass or molar percentage of the target component (such as a chemical, element, or compound) in the product. Product purity is shown below.

[0034]

[0035] Preferably, the production efficiency refers to the ratio of the actual output of the production device in converting raw materials into qualified products per unit time to the theoretical maximum output, as shown below.

[0036]

[0037] Preferably, the energy consumption refers to the total amount of various energy sources (such as electricity, steam, fuel, cooling water, etc.) consumed in producing one unit of product. Energy efficiency is shown below.

[0038]

[0039] According to an embodiment of the present invention, the process verification method further includes: (S5) constructing a simulation process database based on the data pool collected during the process verification process; and optimizing the process model and initial conditions of the production process package based on the PO / MTBE device design parameters and the simulation process database.

[0040] Preferably, the simulation process database includes production process data, historical data, and real-time data. The simulation process database can be used to further debug the process model and simulation control system in steps (1)-(4) above, so that the process model and simulation control system are more in line with actual production.

[0041] According to the embodiment of the present invention, in step (S5), optimizing the initial conditions of the process specifically involves: using dynamic boundary condition embedding technology, constructing a multivariate initial condition library (feed flow rate / component, etc.) based on the design parameters of the PO / MTBE device and the simulation process database, supporting one-click loading of actual production scenarios, so that the process model results have industrial value that directly guides process optimization.

[0042] According to an exemplary embodiment of the present invention, the process validation method includes: (S1') Establishing the process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the heavy component removal tower of the PO / MTBE unit, specifically as follows: Based on the basic data in the production process package, configure the key equipment parameters of the heavy component removal tower, such as operating conditions including temperature, pressure, catalyst loading, etc. Input the raw material composition and flow rate, run a steady-state simulation and calibrate the model through sensitivity analysis to ensure that the deviation of key indicators (such as product yield, purity, etc.) from the design values ​​of the production process package is within 0.1%. Data regression is used to fit the experimental data, thereby improving the model accuracy. Finally, the calculation results of the steady-state model are used to establish a dynamic model, complete the basic configuration of dynamic simulation, establish a PID control scheme, and output a complete simulation report including material balance, equipment parameters and flow chart, providing a digital benchmark for subsequent process optimization and operation training. (S2') Configure the simulation control system: Based on the actual control system of the heavy component removal tower of the PO / MTBE unit, a three-dimensional simulation control system is built. The simulation control system includes simulation control logic and control screen; the key parameters of a certain heavy component removal tower are as follows: tower bottom temperature 150-160℃, operating pressure 0.1-0.2MPa, and top product concentration not less than 99.14wt%; (S3') Module Interconnection: OPC SERVER is used to form a module interconnection between the process model and the simulation control system, ensuring the consistency and real-time performance of the simulation control system data; (S4') Process verification: The operating parameters of the process model are transmitted to the simulation control system through signals. The simulation control system sends instructions to the process model to form a closed-loop operation of process simulation and control simulation. After running for 24 hours, the verification results of the process model are output. The verification results are evaluated based on the evaluation indicators, and an optimized process plan is generated; the evaluation indicators include at least one of the following: device stability, product purity, production efficiency, and energy consumption.

[0043] According to an exemplary embodiment of the present invention, the process validation method includes: (S1'') Establishing the process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the heavy component removal tower of the PO / MTBE unit, specifically as follows: Based on the basic data in the production process package, configure the key equipment parameters of the heavy component removal tower, such as operating conditions including temperature, pressure, catalyst loading, etc. Input the raw material composition and flow rate, run a steady-state simulation and calibrate the model through sensitivity analysis to ensure that the deviation of key indicators (such as product yield, purity, etc.) from the design values ​​of the production process package is within 0.1%. Data regression is used to fit the experimental data, thereby improving the model accuracy. Finally, the calculation results of the steady-state model are used to establish the basic configuration of the dynamic model, complete the basic configuration of the dynamic simulation, establish a PID control scheme, and output a complete simulation report including material balance, equipment parameters and flow chart, providing a digital benchmark for subsequent process optimization and operation training. (S2'') Configure the simulation control system: Based on the actual control system of the heavy component removal tower of the PO / MTBE unit, a three-dimensional simulation control system is built. The simulation control system includes simulation control logic and control screen; the key parameters of a certain heavy component removal tower are as follows: tower bottom temperature 150-160℃, operating pressure 0.1-0.2MPa, and top product concentration not less than 99.14wt%; (S3'') Module Interconnection: OPC SERVER is used to form a module interconnection between the process model and the simulation control system, ensuring the consistency and real-time performance of the simulation control system data; (S4'') Perform fault condition process verification: Preset fault types and triggering conditions in the process model. When the preset time or preset scenario is reached, the fault is triggered (such as the temperature of the reflux pump at the top of the heavy component removal tower rising to 140°C, triggering the interlock, causing the pump to automatically stop and the bottom shut-off valve of the reflux tank to be closed urgently). At the same time, the process model transmits the signal to the simulation control system, which is displayed in the human-machine interface of the operation interface.

[0044] The present invention also provides a process verification system for the above-described process verification method.

[0045] According to an embodiment of the present invention, the process verification system includes a process model and a simulation control system, wherein bidirectional data transmission is realized between the process model and the simulation control system; The process model includes a device module and a parameter module; The simulation control system includes simulation control logic and a user interface.

[0046] According to an embodiment of the present invention, the analog control logic further includes device interlocking protection logic.

[0047] Beneficial effects This invention, based on computer simulation technology, simulates the process flow, equipment operation, and control logic of a real chemical plant. Performing process verification before plant start-up overcomes the limitations of traditional methods and improves the efficiency and accuracy of process verification. Specifically: Improved verification efficiency: Compared with traditional process verification methods, this method does not require extensive testing and adjustments on actual production equipment. Multi-scenario verification can be carried out quickly through a virtual environment, effectively improving verification efficiency and greatly shortening the verification cycle. This invention avoids the large consumption of raw materials and energy in actual production and the economic losses caused by possible waste, thus reducing verification costs.

[0048] Reduced verification risks: This method performs process verification in a virtual environment, so even if a fault or abnormal situation occurs, it will not pose a threat to the safety of actual production equipment and personnel, nor will it affect product quality, thus effectively reducing the risks in the process verification.

[0049] Comprehensive verification of process performance: By simulating various scenarios such as normal operating conditions, fault conditions, and process optimization, the process performance and reliability of the PO / MTBE unit can be comprehensively verified, providing strong support for the design, construction, and operation of the unit.

[0050] The method of this invention is highly flexible, and can not only comprehensively and thoroughly verify process performance and reliability, but also provide strong support for optimizing and improving processes by comprehensively and accurately collecting and analyzing data, thereby contributing to the efficient and stable operation and development of chemical production. Attached Figure Description

[0051] Figure 1 This is the system structure of the process verification method of the present invention.

[0052] Figure 2 This refers to the instruction transmission line during the specific implementation of the process verification method of the present invention.

[0053] Figure 3 This is a schematic diagram of the process and control of the heavy component removal tower in an embodiment of the present invention; wherein, E01 represents a cooler; E02 represents a heater; P01-02 is a centrifugal pump; V01-02 is a storage tank; and PV1-4 are valves. Detailed Implementation

[0054] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0055] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0056] The specific process of the process verification method of the present invention is described below, such as... Figure 1 As shown, an embodiment of the process validation method for the PO / MTBE unit is as follows: In one specific embodiment, process modeling and configuration of a simulation control system are developed.

[0057] Preferably, the process model of the PO / MTBE unit is established, including: Equipment modules include: reaction vessel, distillation column, heavy component removal column, heat exchanger, pump, valve, etc. Parameter module: Processes such as material feeding, reaction, and separation; production process data of the device; setting model parameters such as reaction kinetic equations, heat and mass transfer coefficients.

[0058] Preferably, a simulation control system is configured: the simulation control system is configured according to the actual control scheme, important control parameters are selected, and upper and lower limits and control algorithms such as temperature, pressure, and flow rate are set, such as PID control; at the same time, interlock protection logic is set, such as automatically cutting off the heating source when the reactor temperature is too high.

[0059] In a specific embodiment, when a certain heavy component removal tower in the device module is selected for process verification, the control parameter range is set as follows: tower bottom temperature 140-150℃, operating pressure 0.1-0.2MPa, feed (crude PO from the bottom of a stripping tower) flow rate 30-40t / h, and feed temperature 80℃.

[0060] In one specific embodiment, process validation is selected from normal operating condition process validation and / or fault condition process validation.

[0061] In one specific embodiment, the process validation is a normal operating condition process validation. Specifically, the PO / MTBE unit is started, and each piece of equipment is started step by step according to the operating procedures, adjusting the production process data. The start-up process of the unit is observed, and the changes in the production process data are recorded. After the unit is successfully started up, all production process data stabilize within the design range.

[0062] In one specific embodiment, prior to process verification, after successful startup, the unit was kept running stably for 24 hours. Process parameters such as reaction conversion rate, product purity, and yield were monitored and recorded, and all three parameters met design requirements. During operation, with appropriate adjustments to the feed flow rate and temperature, the unit responded quickly and maintained stable operation.

[0063] In one specific embodiment, during normal operation, the operating parameters are adjusted multiple times, such as changing the feed composition and adjusting the reflux ratio, to verify the operational flexibility of the device.

[0064] The results show that the device maintains good performance under different operating conditions, and the product quality is not affected.

[0065] In one specific embodiment, process verification is fault condition process verification. Preferably, the fault condition is selected from at least one or more fault scenarios such as simulated pump failure, temperature sensor failure, and power outage failure. For example, when a pump failure occurs, the system automatically triggers an alarm. Engineers promptly detect the fault through the simulation control system's operating interface and take measures to switch to a backup pump, restoring the device to normal operation. After the fault is resolved, a recovery operation is performed on the device. The device can smoothly return to normal operation in a short time, and all production process data stabilize back within the design range.

[0066] In one specific embodiment, process validation also includes process optimization validation, specifically: developing a process optimization plan, adjusting reaction temperature and pressure, and optimizing the operating conditions of the distillation column. After implementing the optimization plan, the energy consumption of the unit decreased by 1%-3%, indicating that the process optimization plan is effective and feasible.

[0067] In one specific embodiment, the process validation method further includes evaluating the validation results. Specifically, this involves collecting and organizing recorded data through a simulation control system, compiling a process database, and evaluating indicators such as device stability, product quality pass rate, production efficiency, and energy consumption. Based on these evaluation indicators, it is determined whether the process validation of the PO / MTBE device has passed.

[0068] In one specific embodiment, the process validation method further includes compiling a process validation report, which describes in detail the validation process, results, and analytical conclusions, providing a reference for the design, construction, and operation of the device.

[0069] Example 1 The process verification method in this embodiment includes: (S1) Establishing the process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the PO / MTBE unit. The process model is established using professional modeling software based on the production process package of the PO / MTBE unit, specifically as follows: Based on the fundamental data in the production process package, a steady-state model is built. For example, a steady-state model for a heavy component removal tower is built: according to the process flow of the heavy component removal tower, the process flow is constructed, and the key parameters of the heavy component removal tower process are configured, such as the composition of the raw materials, flow rate, temperature, and pressure; the basic parameters of the tower equipment are configured, such as tower height, tower diameter, and number of trays. During operational calculations, the operating parameters of the tower are specified, such as the pressure at the top and bottom of the tower, and the reflux ratio.

[0070] Input the raw material composition and flow rate, run steady-state simulation and calibrate the model through sensitivity analysis, select an appropriate physical property equation, and in this case, use the PR equation to ensure that the key indicators such as product yield and purity deviate from the design values ​​of the production process package within 0.1%. Product purity:

[0071] Using the established steady-state model, confirm the suitability of the selected property methods (e.g., PR equation, NRTL equation, etc.) and various parameters (e.g., binary interaction parameters of each component, reaction parameters, and equipment operating coefficients). Based on the steady-state model, complete the basic configuration of the dynamic model, outputting a comprehensive simulation report including material balance, equipment parameters, and flow diagrams. This provides a digital benchmark for subsequent process optimization and operational training. For example, to build a dynamic model of a heavy component removal tower: first, keep the raw material composition, flow rate, temperature, and pressure constant, and keep the tower's equipment parameters (tower height, tower diameter, number of trays) constant, selecting the PR equation selected from the steady-state model. The tower's operating parameters need to be adjusted based on the steady-state calculation results, adjusting the remaining coefficients to ultimately achieve the tower's operating state as calculated in the steady-state model, ensuring that the product purity meets design requirements.

[0072] For complex units, data regression is used to fit experimental data, thereby improving model accuracy. Finally, a PID control scheme was established to ensure the long-term stable operation of the tower. For example, in the control scheme for the heavy component removal tower, the tower top pressure is controlled using a split-loop control. When the tower top pressure exceeds the set pressure, PV2 is opened to increase the flow rate. When the tower top pressure is significantly higher than the set value and exceeds a certain threshold, the vent valve PV1 is opened to discharge the tower top vapor to the low-pressure flare. When the tower top pressure is lower than the set pressure, the vent valve PV1 is closed, and the regulating valve PV2 after the E01 cooler is shut down to control the flow rate of the condensate and increase the tower top pressure. The tower bottom temperature is controlled through cascade control, limiting the flow rate of E02 steam by controlling the opening of PV3. The tower bottom liquid level is controlled by the flow rate of PV4 using a simple loop control. The other parameters, such as the tower top return flow rate, feed flow rate, and V01-02 liquid levels, are all controlled using the same principle. Figure 3 They will not be listed in order. The establishment of these PID control schemes allows the model to run stably on its own, facilitating the construction of the remaining processes in this unit.

[0073] Note that these PID control schemes are implemented within the model during the initial stage of dynamic model building, utilizing internal software function blocks for control and long-term stable operation of the already built parts of the model, thereby completing the entire process setup. After the S3 module interconnection is completed, the S2 part of the control simulation system takes over and implements the control.

[0074] The entire modeling process must strictly adhere to the production process package design requirements to ensure that the established process model accurately reflects the actual operation of the PO / MTBE unit. The steady-state model is used to determine parameters and build the dynamic model; the dynamic model is used in actual system operation. The difference between the two is that the steady-state model's input data is the output result, and it cannot be continuously calculated; the dynamic model can be calculated continuously in real time.

[0075] (S2) Configuration of the simulation control system: Strictly following the actual DCS system architecture and process logic of the PO / MTBE unit. An advanced 3D dynamic simulation method was used to construct a highly realistic virtual twin system. This system not only accurately simulates all control strategies, from PID regulation and complex cascade control to safety interlocking (ESD), but also reproduces the control screen in a 1:1 ratio, completely consistent with the actual operating interface. The simulation control system includes simulated control logic and control screen; (S3) Module Interconnection: OPC SERVER is used to form a module interconnection between the process model and the simulation control system, ensuring the consistency and real-time performance of the simulation control system data; (S4) Process verification: The simulation is carried out under normal operating conditions. The operating parameters of the process model are transmitted to the simulation control system through signals. The simulation control system sends instructions to the process model to form a closed-loop operation of process simulation and control simulation. After running for 24 hours, the verification results of the process model are output.

[0076] In this embodiment, a heavy component removal tower in the PO / MTBE unit is selected as an example for illustration. The process model of the heavy component removal tower is established according to step (S1). In step (S2), the key parameters of the target heavy component removal tower are controlled as follows: tower bottom temperature 150-160℃, operating pressure 0.1-0.2MPa, and top product concentration not less than 99.14wt%. The modules are interconnected according to step (S3), and the process verification in step (S4) is performed.

[0077] The evaluation of a heavy component removal tower based on the evaluation indicators revealed that, under this system, the heavy component removal tower can operate stably at the corresponding parameter design values, and the operating parameters are normal, with product quality and output within a reasonable range.

[0078] Example 2 The process verification method in this embodiment also selects a heavy component removal tower in the PO / MTBE unit for verification. The verification method is basically the same as in Embodiment 1, except that: in (S4), during process verification, insufficient lubrication of the bearing of the top reflux pump of the heavy component removal tower causes the pump body temperature to rise to 140°C, triggering an interlock that causes the pump to automatically trip and urgently close the bottom shut-off valve of the reflux tank. An alarm transmission signal is sent to the operation interface of the simulation control system. After the operator discovers the abnormality, he confirms the status of the standby pump and switches to the standby pump, isolates the faulty pump, and monitors the operating status of the removal tower until the unit returns to normal operation. After the fault is handled, the unit is restored and verification continues according to the normal procedure.

[0079] The troubleshooting process took a total of 20 seconds, and the equipment was able to return to normal operation smoothly within 2 minutes, with all production process data stabilizing back within the design range.

[0080] After assessment, the pump failure occurred within 60 seconds. The solution to the failure was to switch to the backup pump and isolate the faulty pump. The unit was able to return to normal operation in a short time, and all production process data were restored to the design range without causing any production loss.

[0081] Example 3 The process validation method in this embodiment also selects a heavy component removal tower in the PO / MTBE unit for validation. The validation method is basically the same as in Embodiment 1, except that: in (S4), the process validation also includes process optimization validation, specifically: based on the evaluation results of Embodiment 1, a process optimization plan is formulated, specifically: Adjust the temperature of the tower bottom to 140-150℃, and the rest is the same as in Example 1.

[0082] By appropriately optimizing the operating conditions, while ensuring product output and quality, energy consumption is effectively reduced. Compared with the design value of the production process package, steam is effectively saved by 1-2% and condensate is reduced by 2-3%, indicating that the process optimization scheme of this embodiment is effective and feasible.

[0083] Comparative Example 1 The process verification method in this embodiment is basically the same as in embodiment 2, except that: (S3) there is no module interconnection between the process model and the simulation control system; Because of the lack of module interconnection, abnormal production process data occurred 10 minutes after the pump failure, and operators began troubleshooting. The entire troubleshooting process, from the time the unit returned to normal operation and all production process data stabilized within the design range, took 20 minutes.

[0084] After assessment, it was found that the pump failure occurred more than 60 seconds later and the troubleshooting took more than 2 minutes. As a result, the equipment could not be restored to normal operation in a short period of time, and various production process data could not be stabilized back to the design range in a short period of time. This caused the heavy component removal tower to fluctuate for a long time, the product purity could not meet the standard in time, the reflux flow at the top of the tower increased, and the energy consumption increased. The failure to deliver products to subsequent equipment in a timely manner also had a certain impact on the entire equipment.

[0085] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A process verification method, characterized in that, The process validation method includes the following steps: (S1) Establishing a process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the PO / MTBE unit; the process model includes a unit module and a parameter module; the unit module includes a reaction unit, a separation unit, and utilities; the parameter module includes raw material parameters and system parameters; (S2) Configure the simulation control system: Based on the actual control system of the PO / MTBE device, a three-dimensional simulation control system is built. The simulation control system includes simulation control logic and operation interface. The three-dimensional method includes: (S21) Based on the process characteristics, identifying the device modules and parameter modules in the device, and determining the control target; (S22) Parameter analysis: analyzing the key parameters in the control target, and determining the core parameters that need to be monitored and controlled; (S23) Algorithm matching: selecting the control logic based on the control target and core parameters to achieve precise control. The simulation control logic includes process control and operation control; real-time data and historical data are collected and monitored through the simulation control logic, and then organized to obtain the data pool; the data pool also includes production process data contained in the production process package; The simulation control logic also includes device interlocking protection logic, forming a simulation model that is a complete mirror image of the actual control logic, thereby improving the authenticity of the control strategy verification. The device interlocking protection logic refers to triggering an alarm or automatically taking emergency measures when key parameters in the production process data are not within the threshold range. Operators can then promptly adjust the equipment unit corresponding to the production process data to bring the production process data back to the corresponding threshold range. (S3) Module interconnection: Module interconnection is formed between the process model and the simulation control system to ensure the consistency and real-time performance of the simulation control system data; (S4) Process verification: During simulation, the signals of the process model are transmitted to the simulation control system, and the simulation control system sends instructions to the process model, thereby forming a closed-loop operation of process simulation and control simulation; the verification results of the process model are output; the process verification includes normal operating condition process verification and / or fault operating condition process verification. The verification results are evaluated based on the evaluation indicators, and an optimized process plan is generated; the evaluation indicators include at least one of the following: device stability, product purity, production efficiency, and energy consumption.

2. The process verification method according to claim 1, characterized in that, In step (S1), the process model adopts multi-dimensional coupled modeling; The multi-dimensional coupling modeling refers to modeling the PO / MTBE device into different sub-units according to the production process. Each sub-unit does not affect the others and operates independently. After each sub-unit is debugged, the sub-units are connected according to the production process package. In step (S1), the production process package includes the process flow and production process data.

3. The process verification method according to claim 1, characterized in that, In step (S2), the control logic mirroring technique is used when configuring the control system.

4. The process verification method according to claim 1, characterized in that, In step (S3), the module interconnection specifically includes establishing bidirectional data transmission between the process model and the simulation control system; In step (S4), during simulation, the signal transmission of the process model specifically includes: sending the analog input signal AI and the digital input signal DI of the process model to the simulation control system; the signal transmission of the process model includes the signals of key parameters and / or core parameters. In step (S4), the instructions sent by the simulation control system to the process model are specifically operation signals. The operation signals are transmitted from the simulation control system to the various device modules of the process model to achieve rapid response.

5. The process verification method according to claim 1, characterized in that, In step (S4), the normal operating condition process refers to the normal operation of the device modules in the device; The fault condition process verification is a simulation of a device fault. The simulation device fault is triggered by pre-setting fault types and triggering conditions in the process model. When a preset time or preset scenario is reached, the fault is triggered. At the same time, the process model transmits the signal to the simulation control system, which is then displayed on the human-machine interface in the operation interface.

6. The process verification method according to claim 1, characterized in that, The stability of the equipment, the purity of the product, the production efficiency, and the energy consumption shall be based on the design range in the production process package, and the deviation from the design range shall be within 3%.

7. The process verification method according to claim 1, characterized in that, The process verification method further includes: (S5) Construct a simulation process database based on the data pool collected during the process verification; optimize the initial conditions of the process package based on the design parameters of the PO / MTBE unit and the simulation process database; In step (S5), optimizing the initial conditions of the process specifically involves: using dynamic boundary condition embedding technology, constructing a multivariate initial condition library based on the design parameters of the PO / MTBE device and the simulation process database, supporting one-click loading of actual production scenarios, so that the process model results have industrial value that can directly guide process optimization.

8. The process verification method according to claim 1, characterized in that, The process validation method includes: (S1') Establishing the process model: Using multi-dimensional coupled modeling technology, a process model is established based on the production process package of the heavy component removal tower of the PO / MTBE unit, specifically as follows: Based on the basic data in the production process package, configure the key equipment parameters of the heavy component removal tower; Input the raw material composition and flow rate, run a steady-state simulation and calibrate the model through sensitivity analysis to ensure that the deviation of key indicators from the design values ​​of the production process package is within 0.1%; Data regression is used to fit the experimental data, thereby improving the model accuracy. Finally, a PID control scheme was established, the basic configuration of dynamic simulation was completed, and a complete simulation report containing material balance, equipment parameters and flow charts was output, providing a digital benchmark for subsequent process optimization and operation training. (S2') Configure the simulation control system: Based on the actual control system of the heavy component removal tower of the PO / MTBE unit, a three-dimensional simulation control system is built. The simulation control system includes simulation control logic and control screen; the key parameters of a certain heavy component removal tower are as follows: tower bottom temperature 150-160℃, operating pressure 0.1-0.2MPa, and top product concentration not less than 99.14wt%; (S3') Module Interconnection: OPC SERVER is used to form a module interconnection between the process model and the simulation control system, ensuring the consistency and real-time performance of the simulation control system data; (S4') Process verification: The operating parameters of the process model are transmitted to the simulation control system through signals. The simulation control system sends instructions to the process model to form a closed-loop operation of process simulation and control simulation. After running for 24 hours, the verification results of the process model are output. The verification results are evaluated based on the evaluation indicators, and an optimized process plan is generated; the evaluation indicators include at least one of the following: device stability, product purity, production efficiency, and energy consumption.

9. A process validation system for the process validation method according to any one of claims 1-8, characterized in that, The process verification system includes a process model and a simulation control system, and bidirectional data transmission is realized between the process model and the simulation control system. The process model includes a device module and a parameter module; The simulation control system includes simulation control logic and a user interface.

10. The process verification system according to claim 9, characterized in that, The analog control logic also includes device interlocking protection logic.

Images