Ethylene cracking furnace feeding process automatic execution system and method

Abstract

The present application relates to the technical field of petroleum chemical industry, in particular to an automatic execution system and method for ethylene cracking furnace feeding process, which comprises a state confirmation module before feeding, used for confirming initial parameters before feeding, and when the initial parameters are within the initial range, indicating that feeding can be carried out, and when the initial parameters are not within the initial range, giving an alarm; a feeding process control module, used for controlling key feeding parameters in the feeding stage, and issuing feeding instructions, wherein the key feeding parameters include the feeding rate of single pipe of the furnace and the feeding rate of total pipe of the furnace; and a feeding module, used for receiving the feeding instructions and feeding. By using the system, the state before feeding is confirmed by the state confirmation module before feeding, and the key feeding parameters in the feeding process are controlled by the feeding process control module, which can effectively improve the accuracy of feeding, and has the advantages of high feeding efficiency, high safety and small fluctuation.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, specifically to an automated system and method for the feeding process of an ethylene cracking furnace. Background Technology

[0002] Ethylene is a crucial basic raw material in the petrochemical industry and one of the petrochemical products with the largest demand and production volume. Its output, scale, and technological level signify the development level of a country's petrochemical industry. Tubular cracking furnaces, used for hydrocarbon cracking, are the core unit in ethylene production, determining the overall production capacity, stable operation, and total energy consumption of the entire ethylene plant. When hydrocarbons undergo steam cracking reactions in the radiant section of the tubular cracking furnace, secondary reactions such as polymerization and condensation occur, leading to coke accumulation on the inner wall of the furnace tubes, forming coke deposits. When coking causes the temperature of the outer wall of the radiant section furnace tubes, the outlet temperature of the quench boiler, or the pressure difference across the Venturi tubes to reach the production limit, it severely impacts ethylene production, causing a decrease in ethylene yield, increased energy consumption, shortened furnace tube life, and even affecting production safety.

[0003] Due to the coking characteristics of ethylene cracking furnaces, frequent and intermittent furnace feeding operations are necessary in practical applications. Currently, the feeding process in most domestic ethylene cracking furnaces is still manually controlled. Manual feeding requires frequent operation by technicians, is labor-intensive, and relies entirely on individual experience and operator responsibility, resulting in a high rate of error. Furthermore, due to varying operator experience, temporary interruptions or repeated feeding operations are prone to occur. These interruptions or repeated feeding operations can cause significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate, potentially leading to unplanned shutdowns of the ethylene plant, affecting its long-term safe and stable operation, and causing a decrease in ethylene production.

[0004] Therefore, there is an urgent need for an automated system and method for the feeding process of an ethylene cracking furnace. Summary of the Invention

[0005] This invention addresses the problem in existing technologies where manual feeding of ethylene cracking furnaces is used. Due to varying operator experience, this often results in temporary interruptions or repeated feeding operations. These interruptions or repeated feeding operations can lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate during the feeding process, potentially causing unplanned shutdowns of the ethylene plant. The invention provides an automated system and method for the feeding process of ethylene cracking furnaces.

[0006] To achieve the above objectives, the first aspect of this invention provides an automatic execution system for the feeding process of an ethylene cracking furnace, the system comprising:

[0007] The pre-feeding status confirmation module is used to confirm the initial parameters before feeding, and when the initial parameters are within the initial range, it indicates that feeding can proceed, and when the initial parameters are not within the initial range, it issues an alarm.

[0008] The feeding process control module is used to control the key feeding parameters and issue feeding instructions during the feeding stage. The key feeding parameters include the feeding rate of the single tube in the furnace and the feeding rate of the main tube in the furnace.

[0009] The feeding module is used to receive feeding instructions and feed materials.

[0010] Preferably, the step of issuing an alarm when the initial parameter is not within the initial range specifically includes:

[0011] When the initial parameter is not within the initial range, an alarm is triggered for one or more of the initial parameters that are not within the initial range.

[0012] Preferably, the initial parameters include the pressure after the Venturi tube, the dilution steam flow rate of the single tube in the furnace, the outlet temperature of the pyrolysis furnace, and the ultra-high pressure steam temperature.

[0013] Preferably, the initial range of the pressure after the Venturi tube is 0.04 to 0.1 MPa, the initial range of the ultra-high pressure steam temperature is 480 to 530°C, the initial range of the pyrolysis furnace outlet temperature is 700 to 740°C, and the initial range of the single-tube dilution steam flow rate in the furnace is 4000 to 6000 kg / h.

[0014] Preferably, the feeding stage includes a first feeding stage and a second feeding stage. In the first feeding stage, material is fed to a first feeding value through the single tube of the furnace and remains stable for a preset time T1. In the second feeding stage, material is fed to a target feeding value through the main tube of the furnace and remains stable for a preset time T2.

[0015] Preferably, during the feeding stage, controlling key feeding parameters and issuing feeding instructions specifically includes:

[0016] In the first feeding stage and the second feeding stage, the feeding rate of the furnace single tube and the feeding rate of the furnace main tube are controlled respectively, so that the dilution steam flow rate of the furnace single tube decreases at a preset rate, and when the feeding is completed, the ratio of the dilution steam flow rate of the furnace single tube to the feeding amount of the furnace single tube is 0.2 to 0.6.

[0017] Preferably, the feeding rate of the single tube in the furnace is 125-500 kg / h / min, and the feeding rate of the main tube in the furnace is 500-2000 kg / h / min.

[0018] Preferably, the preset time T1 is 0 to 30 minutes, and the preset time T2 is 1 to 15 minutes.

[0019] Preferably, the preset rate is 30-120 (kg / h) / 1000kg feeding.

[0020] Preferably, the key parameters for feeding also include the rate of increase in the calorific value of the fuel gas, the fuel gas pressure, the oxygen content in the furnace, and the carbon monoxide content in the pyrolysis gas.

[0021] Preferably, the step of controlling key feeding parameters and issuing feeding instructions during the feeding stage further includes:

[0022] During the feeding process through the single furnace tube or the main furnace tube, the rate of increase of the calorific value of the fuel gas is controlled at 0.5–2.0 MW / 1000 kg, the fuel gas pressure is controlled at 0.06–0.22 MPa, the oxygen content in the furnace is controlled at 1.5–5%, and the carbon monoxide content in the pyrolysis gas is controlled at 0.05–0.07 mol%, so that the outlet temperature of the pyrolysis furnace rises to the set target temperature at a preset heating rate based on its initial temperature, wherein the preset heating rate is 0.3–2 °C / min, and the set target temperature is 750–800 °C.

[0023] Preferably, the system further includes a key feeding parameter monitoring and alarm module, which monitors the key feeding parameters during the feeding stage and issues an alarm when the key feeding parameters exceed a preset range.

[0024] Preferably, the monitoring of the key feeding parameters and the triggering of an alarm when the key feeding parameters exceed a preset range specifically includes:

[0025] An alarm will be triggered when the key parameters for material feeding exceed the first preset range;

[0026] When the key feeding parameter exceeds the second preset range, the key feeding parameter exceeding the second preset range will be adjusted to the first preset range according to a preset ratio based on its current value, and an alarm will be triggered;

[0027] Wherein, the upper limit of the second preset range is greater than the upper limit of the first preset range, the lower limit of the second preset range is less than the lower limit of the first preset range, and the preset ratio is ±0.1% to 10%.

[0028] Preferably, the system further includes a feeding process alarm optimization management module, which is used to automatically disable the feeding instrument alarm and turn the feeding instrument alarm activation indicator light red when the total feeding amount is less than 40-65% of the design load of the feeding equipment of the feeding module; and to activate the feeding instrument alarm and turn the feeding instrument alarm activation indicator light green when the total feeding amount is greater than 65-75% of the design load of the feeding equipment.

[0029] Preferably, the types of alarms from the feeding instruments include: total feeding alarm, liquid phase feeding flow alarm for pyrolysis furnace, gas phase feeding flow alarm for pyrolysis furnace, feeding interlock pressure alarm, DMDS pressure alarm, DMDS flow alarm, anti-coking steam differential pressure alarm, pyrolysis furnace outlet temperature alarm, cross section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, pyrolysis gas analysis indication alarm, cross section flue gas oxygen content alarm, fuel heat load ratio alarm, fuel heat load ratio alarm, low liquid feedstock flow alarm for furnace tubes, and low gas feedstock pressure alarm.

[0030] Preferably, the system further includes an operation navigation function module, which provides operation prompts during the feeding stage according to the control instructions of the feeding process control module.

[0031] Preferably, the system further includes a deep learning module, which is used to learn the advantages and disadvantages of controlling each key feeding parameter in the feeding stage based on experience values ​​and big data, and to derive the optimal control value of the key feeding parameter in the feeding stage.

[0032] To achieve the above objectives, a second aspect of the present invention provides an automatic execution method for the charging process of an ethylene cracking furnace. This method is implemented using the aforementioned automatic execution system for the charging process of the ethylene cracking furnace, and includes:

[0033] A pre-feeding status confirmation module is used to confirm the initial parameters before feeding. When the initial parameters are within the initial range, it indicates that feeding can proceed. When the initial parameters are outside the initial range, an alarm is triggered.

[0034] During the feeding stage, a feeding process control module is used to control key feeding parameters and issue feeding commands. The key feeding parameters include the feeding rate of a single furnace tube and the feeding rate of the main furnace tube.

[0035] The feeding module receives feeding instructions and feeds materials during the feeding stage.

[0036] According to the above technical solution, based on this system, in practical applications, the pre-feeding status confirmation module confirms the status before feeding, ensuring that the cracking furnace can be fed normally. At the same time, the feeding process control module can control the key feeding parameters during the feeding process based on the current initial parameters. This ensures linear feeding while avoiding large fluctuations in the key feeding parameters, which could cause significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate, resulting in unplanned shutdowns of the ethylene plant. It has the advantages of high feeding efficiency, small fluctuations in key feeding parameters, and high stability. Attached Figure Description

[0037] Figure 1 This is a flowchart of the automated system for the feeding process of an ethylene cracking furnace. Detailed Implementation

[0038] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0039] The first aspect of this invention provides an automatic execution system for the feeding process of an ethylene cracking furnace, such as... Figure 1 As shown, the automated feeding system for the ethylene cracking furnace includes:

[0040] The pre-feeding status confirmation module is used to confirm the initial parameters before feeding, and when the initial parameters are within the initial range, it indicates that feeding can proceed, and when the initial parameters are not within the initial range, it issues an alarm.

[0041] The feeding process control module is used to control the key feeding parameters and issue feeding instructions during the feeding stage. The key feeding parameters include the feeding rate of the single tube in the furnace and the feeding rate of the main tube in the furnace.

[0042] The feeding module is used to receive feeding instructions and feed materials.

[0043] According to the above technical solution, based on this system, in practical applications, the pre-feeding status confirmation module confirms the status before feeding, ensuring that the cracking furnace can be fed normally. At the same time, the feeding process control module can control the key feeding parameters during the feeding process based on the current initial parameters. This ensures linear feeding while avoiding large fluctuations in the key feeding parameters, which could cause significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate, resulting in unplanned shutdowns of the ethylene plant. It has the advantages of high feeding efficiency, small fluctuations in key feeding parameters, and high stability.

[0044] In a preferred embodiment of the automatic execution system for the ethylene cracking furnace feeding process described in this invention, the alarm activation when the initial parameters are outside the initial range specifically includes:

[0045] When the initial parameter is not within the initial range, an alarm is triggered for one or more of the initial parameters that are not within the initial range.

[0046] In one specific implementation, the initial parameters include the pressure after the Venturi tube, the dilution steam flow rate of the single tube in the furnace, the pyrolysis furnace outlet temperature, and the ultra-high pressure steam temperature. In a more specific embodiment, the initial range of the pressure after the Venturi tube is 0.04–0.1 MPa, preferably 0.05–0.07 MPa, and most preferably 0.06 MPa; the initial range of the ultra-high pressure steam temperature is 480–530°C, preferably 490–510°C, and most preferably 500°C; the initial range of the pyrolysis furnace outlet temperature is 700–740°C, and most preferably 720°C; and the initial range of the furnace single-tube dilution steam flow rate is 4000–6000 kg / h, preferably 4300–4800 kg / h, and most preferably 4500 kg / h. This is to ensure that the pyrolysis furnace can be fed normally, while allowing the feeding process control module to control key feeding parameters during the feeding process based on the furnace single-tube dilution steam flow rate and the pyrolysis furnace outlet temperature.

[0047] In a preferred embodiment, the automatic execution system for the ethylene cracking furnace feeding process of the present invention includes a first feeding stage and a second feeding stage. In the first feeding stage, the material is fed to a first feeding value through the single tube of the furnace and remains stable for a preset time T1. In the second feeding stage, the material is fed to a target feeding value through the main tube of the furnace and remains stable for a preset time T2.

[0048] In one specific embodiment, the feeding rate of the single furnace tube is 125-500 kg / h / min, preferably 200-300 kg / h / min, and the feeding rate of the main furnace tube is 500-2000 kg / h / min, preferably 800-1200 kg / h / min (i.e., the main furnace tube contains 4 single furnace tubes). The preset time T1 is 0-30 min, preferably 5-12 min, and the preset time T2 is 1-15 min, preferably 5-10 min. In practical applications, the main furnace pipe typically includes several individual furnace pipes. When feeding materials into the pyrolysis furnace, if the amount of material fed into the furnace is less than the first feeding value, for example, less than 4000 kg / h, directly using the main furnace pipe for feeding will result in a large feeding error. In this case, feeding through individual furnace pipes can effectively ensure feeding accuracy. Specifically, feeding is carried out by controlling the feed regulating valve on the individual furnace pipe at a valve position rate of 1-10% / min. Preferably, feeding is carried out by controlling the feed regulating valve on the individual furnace pipe at a valve position rate of 1-3% / min until the feeding amount reaches the first feeding value. Then, feeding is carried out through the main furnace pipe at a feeding rate of 800-1200 (kg / h) / min until the feeding amount reaches the target feeding value, for example, the target feeding value can be 27000-35000 kg / h, preferably 27000-30000 kg / h.

[0049] In another preferred embodiment, the step of controlling key feeding parameters and issuing feeding instructions during the feeding stage specifically includes:

[0050] In the first feeding stage and the second feeding stage, the feeding rate of the furnace single tube and the feeding rate of the furnace main tube are controlled respectively, so that the dilution steam flow rate of the furnace single tube decreases at a preset rate, and when the feeding is completed, the ratio of the dilution steam flow rate of the furnace single tube to the feeding amount of the furnace single tube is 0.2 to 0.6.

[0051] In one specific embodiment, the preset feeding rate is 30-120 kg / h / 1000 kg, preferably 50-80 kg / h / 1000 kg. Here, "30-120 kg / h / 1000 kg" means that for every 1000 kg of material fed, the dilution steam flow rate in the furnace single tube decreases by 30-120 kg / h. To ensure that the decrease in the furnace single tube dilution steam flow rate is linear and does not fluctuate significantly as with manual feeding, the decrease in the furnace single tube dilution steam flow rate can be adjusted by controlling the feeding rate of the furnace single tube or the feeding rate of the furnace main tube. When feeding is complete, the ratio of the furnace single tube dilution steam flow rate to the amount of material fed into the furnace single tube is guaranteed to be 0.2-0.6. Preferably, when feeding is complete, the ratio is guaranteed to be 0.35-0.45.

[0052] In another, more preferred embodiment, the key parameters for feeding also include the rate of increase in the calorific value of the fuel gas, the fuel gas pressure, the oxygen content in the furnace, and the carbon monoxide content in the pyrolysis gas. Specifically, controlling these key parameters and issuing feeding commands during the feeding stage includes: controlling the rate of increase in the calorific value of the fuel gas to 0.5–2.0 MW / 1000 kg during feeding through the single furnace pipe or the main furnace pipe; controlling the fuel gas pressure to 0.06–0.22 MPa; controlling the oxygen content in the furnace to 1.5–5%; and controlling the carbon monoxide content in the pyrolysis gas to 0.05–0.07 mol%, so that the outlet temperature of the pyrolysis furnace rises to a set target temperature at a preset heating rate based on its initial temperature, wherein the preset heating rate is 0.3–2 °C / min, and the set target temperature is 750–800 °C. The phrase "0.5~2.0MW / 1000kg feed" means that the calorific value of the fuel gas increases by 0.5~2.0MW for every 1000kg of feed added. The preferred rate of increase in the calorific value is 0.8~1.2MW / 1000kg feed, and the preferred oxygen content in the furnace is 1.5~3%. The automatic pressure protection value for the fuel gas pressure is 0.06MPa.

[0053] In practical applications, the feeding process control module dynamically adjusts the pyrolysis furnace outlet temperature by further controlling the rate of increase in the calorific value of the fuel gas, the fuel gas pressure, the oxygen content in the furnace, and the carbon monoxide content in the pyrolysis gas. Preferably, the pyrolysis furnace outlet temperature is maintained at 750–800°C. More preferably, throughout the feeding process, the pyrolysis furnace outlet temperature rises linearly without the violent fluctuations seen in manual feeding. In one specific embodiment, the pyrolysis furnace outlet temperature can be adjusted using feedback values ​​of the carbon monoxide content in the pyrolysis gas, and the damper opening of the pyrolysis furnace can also be adjusted using feedback values ​​of the oxygen content in the furnace.

[0054] In a preferred embodiment, the automatic execution system for the ethylene cracking furnace feeding process of the present invention further includes a key feeding parameter monitoring and alarm module, used to monitor the key feeding parameters during the feeding stage and to issue an alarm when the key feeding parameters exceed a preset range. In a specific embodiment, monitoring the key feeding parameters and issuing an alarm when the key feeding parameters exceed a preset range specifically includes: issuing an alarm when the key feeding parameters exceed a first preset range; and adjusting the key feeding parameters exceeding the second preset range to the first preset range based on their current value according to a preset ratio when the key feeding parameters exceed a second preset range, and issuing an alarm; wherein the upper limit of the second preset range is greater than the upper limit of the first preset range, the lower limit of the second preset range is less than the lower limit of the first preset range, and the preset ratio is ±0.1% to 10%. In another specific implementation, the key feeding parameters also include the pressure after the Venturi tube, the dilution steam flow rate of the single tube in the furnace, the outlet temperature of the pyrolysis furnace, the ultra-high pressure steam temperature, the VHS drum level, the VHS temperature, the temperature after the oil cooler, and the temperature of the pyrolysis furnace cross section, thereby further improving the safety of the entire system. Taking the furnace oxygen content among the key feeding parameters as an example, the first preset range is 1.5%–3%, and the second preset range is 1%–6%. When the key feeding parameter monitoring and alarm module detects that the furnace oxygen content is 1.4%, an alarm is triggered; when the key feeding parameter monitoring and alarm module detects that the furnace oxygen content is 0.8%, the furnace oxygen content is increased from 0.8% to 0.1%–10% within the first preset range, thereby improving the safety of the system throughout the feeding process. Furthermore, the key feeding parameter monitoring and alarm module can set alarm display status according to priority, and the alarm sound and light signals should be easily distinguishable. For example, when the oxygen content in the furnace exceeds the first preset range, a level one alarm is used, and when the oxygen content in the furnace exceeds the second preset range, a level two alarm is used. Specifically, the level one alarm uses a yellow background with black text, flashing, and a low-frequency sound, while the level two alarm uses an orange background with black text, flashing, and a medium-frequency sound. The boundary values ​​of the first and second preset ranges should not coincide with the instrument range of the alarm device of the key feeding parameter monitoring and alarm module, and should be set within 10% to 90% of the maximum range of the instrument.

[0055] In a preferred embodiment, the automatic execution system for the ethylene cracking furnace feeding process of the present invention further includes a feeding process alarm optimization management module. This module automatically disables the feeding instrument alarm and turns the alarm activation indicator light red when the total feeding amount is less than 40-65% of the design load of the feeding equipment. Conversely, when the total feeding amount exceeds 65-75% of the design load of the feeding equipment, it activates the feeding instrument alarm and turns the alarm activation indicator light green. This allows operators to easily determine whether the alarm is functioning correctly during practical applications, preventing interference from invalid alarms that could affect feeding efficiency. In one specific implementation, the types of alarms from the feeding instruments include total feed alarm, pyrolysis furnace liquid phase feed flow alarm, pyrolysis furnace gas phase feed flow alarm, feeding interlock pressure alarm, DMDS pressure alarm, DMDS flow alarm, anti-coking steam differential pressure alarm, pyrolysis furnace outlet temperature alarm, cross-section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, pyrolysis gas analysis indication alarm, cross-section flue gas oxygen content alarm, fuel heat load ratio alarm, fuel heat load ratio alarm, low furnace tube liquid feed flow alarm, and low gas feed pressure alarm. The design load of the feeding equipment is typically fixed.

[0056] In a preferred embodiment of the automatic execution system for the feeding process of the ethylene cracking furnace described in this invention, the system further includes a parameter setting module for setting the preset range of the key feeding parameters. Thus, in actual production, the operator can set the key feeding parameters and the allowable deviations or upper and lower limits of each key feeding parameter according to the actual production needs.

[0057] In a preferred embodiment, the automatic execution system for the ethylene cracking furnace feeding process of the present invention further includes an operation navigation function module, which provides operation prompts during the feeding stage according to the control instructions of the feeding process control module, thereby improving feeding efficiency and safety during the feeding process.

[0058] In a preferred embodiment, the automatic execution system for the ethylene cracking furnace feeding process of the present invention further includes a deep learning function module, which is used to learn the control advantages and disadvantages of each key feeding parameter in the feeding stage based on experience values ​​and big data, and to derive the optimal control values ​​of the key feeding parameters in the feeding stage, thereby maintaining the linear addition of feeding to the greatest extent and reducing the fluctuation of the key feeding parameters.

[0059] A second aspect of the present invention provides an automatic execution method for the charging process of an ethylene cracking furnace, the method being implemented using the aforementioned automatic execution system for the charging process of the ethylene cracking furnace, the method comprising:

[0060] A pre-feeding status confirmation module is used to confirm the initial parameters before feeding. When the initial parameters are within the initial range, it indicates that feeding can proceed. When the initial parameters are outside the initial range, an alarm is triggered.

[0061] During the feeding stage, a feeding process control module is used to control key feeding parameters and issue feeding commands. The key feeding parameters include the feeding rate of a single furnace tube and the feeding rate of the main furnace tube.

[0062] The feeding module receives feeding instructions and feeds materials during the feeding stage.

[0063] The automatic execution method for the ethylene cracking furnace feeding process described in this invention, in practical application, confirms the state before feeding through a pre-feeding status confirmation module. While ensuring that the cracking furnace can be fed normally, the feeding process control module can control the key feeding parameters during the feeding process based on the current initial parameters. This ensures linear feeding while avoiding large fluctuations in the key feeding parameters, which could cause unplanned shutdowns of the ethylene plant. It has the advantages of high feeding efficiency, small fluctuations in key feeding parameters, and high stability.

[0064] In a preferred embodiment, the automatic execution method for the ethylene cracking furnace feeding process of the present invention employs a key feeding parameter monitoring and alarm module. This module monitors the key feeding parameters during the feeding stage and triggers an alarm when the key feeding parameters exceed a preset range. Specifically, an alarm is triggered when the key feeding parameter exceeds a first preset range; when the key feeding parameter exceeds a second preset range, the parameter exceeding the second preset range is adjusted to the first preset range based on its current value according to a preset ratio, and an alarm is triggered again. The upper limit of the second preset range is greater than the upper limit of the first preset range, and the lower limit of the second preset range is less than the lower limit of the first preset range. The preset ratio is ±0.1% to 10%. This improves the safety performance of the entire system.

[0065] In a preferred embodiment, the automatic execution method for the feeding process of an ethylene cracking furnace described in this invention employs a deep learning module to learn the control advantages and disadvantages of each key feeding parameter in the feeding stage based on experience values ​​and big data, and derives the optimal control values ​​of the key feeding parameters in the feeding stage, thereby maximizing the linear addition of feed and reducing the fluctuations of the key feeding parameters.

[0066] In this invention, the system may further include a post-feeding inspection module, used to check the status of the pyrolysis furnace after feeding is completed, in order to further ensure production safety. Specifically, this may include checking whether the pyrolysis furnace is operating normally; using an online analyzer in the pyrolysis furnace to check whether the pyrolysis gas analysis data is abnormal; after the pyrolysis furnace is running stably, setting the ultra-high pressure steam temperature to 500-525℃, preferably 517-521℃; and confirming that the high-high negative pressure in the pyrolysis furnace, high-high ultra-high temperature, low-low steam drum liquid level, and low-low fuel gas (bottom and long-burning line) pressure interlock are in normal condition.

[0067] The automatic execution system for the ethylene cracking furnace feeding process described in this invention, in one specific embodiment, comprises a human-machine interface and a program control system, thereby achieving online control through a combination of field distributed control system (DCS) configuration and upper-level server programming. To automate the ethylene cracking furnace feeding process, an independent server needs to be deployed on the industrial control network. The ethylene cracking furnace feeding process execution program interacts with data through the OPC DA interface of the Emerson DCS OPC server to obtain the values ​​or status of relevant parameters. To ensure the secure operation of the DCS system, an industrial-grade firewall is added between the system server and the communication interface. By configuring corresponding rules and policies, deep isolation and protection of the DCS control system are achieved, cutting off virus propagation paths and ensuring the normal, safe, and stable operation of the plant's DCS production control system. The industrial firewall incorporates proprietary communication protocols from various mainstream automation product manufacturers, enabling seamless access to systems such as Honeywell DCS, Yokogawa DCS, and Emerson DCS, as well as servers or databases such as OPC SERVER, IP21 / PHD / PI.

[0068] The human-machine interface (HMI) includes function buttons for parameter "setting," cracking furnace status "confirmation," program "run," "pause," "continue," "stop," and parameter "alarm" to enable HMI interaction. Specifically, clicking the "parameter setting" button allows manual setting of key program parameter control thresholds and upper / lower limit presets; clicking the "cracking furnace status confirmation" button confirms the pre-feeding status, and the interface jumps to the feeding operation interface; otherwise, the feeding program cannot run; clicking the "program run" button starts the feeding program; clicking "pause" stops the system from proceeding to the next step, keeping the current parameter control values; clicking "continue" resumes the program; manually clicking "stop" stops the automatic feeding program and switches to manual operation; clicking the "alarm" button switches the HMI to the alarm interface, allowing detailed viewing of system alarms and enabling or disabling alarm masking during the feeding process.

[0069] Furthermore, the human-machine interface also includes system operation status display, system operation buttons, key parameter trend graphs, and system alarm prompts. Among these, the "Run," "Stop," "Pause," "Continue," and "Parameter Setting" function buttons on the human-machine interface can be executed by the user at any time during system operation, based on the actual operating conditions of the ethylene unit and compressor.

[0070] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0071] Example 1

[0072] Based on an ethylene cracking furnace with a production capacity of 140,000 tons / year, the present invention is adopted as follows: Figure 1 The automated system for the ethylene cracking furnace charging process described above is implemented as follows: Specifically, the automated system for the ethylene cracking furnace charging process includes:

[0073] The pre-feeding status confirmation module is used to confirm the initial parameters before feeding, and when the initial parameters are within the initial range, it indicates that feeding can proceed, and when the initial parameters are not within the initial range, it issues an alarm.

[0074] The feeding process control module is used to control the key feeding parameters and issue feeding instructions during the feeding stage. The key feeding parameters include the feeding rate of the single tube in the furnace and the feeding rate of the main tube in the furnace.

[0075] The feeding module is used to receive feeding instructions and feed materials.

[0076] The alarm is triggered when the initial parameter is not within the initial range, specifically including:

[0077] When the initial parameter is not within the initial range, an alarm is triggered for one or more of the initial parameters that are not within the initial range.

[0078] The feeding stage includes a first feeding stage and a second feeding stage. In the first feeding stage, the material is fed to a first feeding value through the single tube of the furnace and remains stable for a preset time T1. In the second feeding stage, the material is fed to a target feeding value through the main tube of the furnace and remains stable for a preset time T2.

[0079] During the feeding stage, key feeding parameters are controlled and feeding instructions are issued, specifically including:

[0080] In the first feeding stage and the second feeding stage, the feeding rate of the furnace single tube and the feeding rate of the furnace main tube are controlled respectively, so that the dilution steam flow rate of the furnace single tube decreases at a preset rate, and when the feeding is completed, the ratio of the dilution steam flow rate of the furnace single tube to the feeding amount of the furnace single tube is 0.2 to 0.6.

[0081] Specifically, the initial value of the pressure after the Venturi tube is 0.06 MPa, the initial value of the dilution steam flow rate of the single tube in the furnace is 4500 kg / h, the initial value of the outlet temperature of the pyrolysis furnace is 720℃, the initial value of the ultra-high pressure steam temperature is 500℃, the preset time T1 is 10 min, the preset time T2 is 8 min, the feeding rate of the single tube in the furnace is 250 (kg / h) / min, the feeding rate of the main tube in the furnace is 1000 (kg / h) / min, the preset rate is 100 (kg / h) / 1000 kg feeding, and when the feeding is completed, the ratio of the dilution steam flow rate of the single tube in the furnace to the feeding amount of the single tube in the furnace is 0.4. The first feeding value is 4000 kg / h, and the target feeding value is 30000 kg / h.

[0082] In practical application, the pre-feeding status confirmation module first confirms the initial parameters before feeding. When the initial parameters are within the initial range, it indicates that feeding can proceed. Then, the feeding process control module feeds materials through the furnace single pipe at a rate of 250 kg / h / min in the first feeding stage, up to 4000 kg / h, and then stabilizes for 10 minutes. In the second feeding stage, materials are fed through the furnace main pipe at a rate of 1000 kg / h / min, and then stabilized for 8 minutes after reaching 30000 kg / h. During the feeding process through the furnace single pipe or the furnace main pipe, the feeding process control module controls the feeding rate of the furnace single pipe or the furnace main pipe in real time to reduce the dilution steam flow rate of the furnace single pipe at a rate of 50 kg / h / 1000 kg feeding. At the end of feeding, the ratio of the dilution steam flow rate of the furnace single pipe to the feeding amount of the furnace single pipe is 0.35.

[0083] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters during the feeding process based on the initial value of the current single-tube dilution steam flow rate in the furnace. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate, causing unplanned shutdowns of the ethylene plant. The system boasts advantages such as high feeding efficiency, small fluctuations in key feeding parameters, and high stability.

[0084] Example 2

[0085] Referring to Example 1, the key parameters for feeding also include the rate of increase of the calorific value of the fuel gas, the fuel gas pressure, the oxygen content in the furnace, and the carbon monoxide content in the pyrolysis gas. Specifically, during the feeding stage, controlling these key parameters and issuing feeding instructions further includes: controlling the rate of increase of the calorific value of the fuel gas to 0.5–2.0 MW / 1000 kg during feeding through the single furnace pipe or the main furnace pipe; controlling the fuel gas pressure to 0.06–0.22 MPa; controlling the oxygen content in the furnace to 1.5–5%; and controlling the carbon monoxide content in the pyrolysis gas to 0.05–0.07 mol%, so that the outlet temperature of the pyrolysis furnace rises to a set target temperature at a preset heating rate based on its initial temperature. The preset heating rate is 0.3–2 °C / min, and the set target temperature is 750–800 °C.

[0086] Specifically, the rate of increase of the calorific value of the fuel gas is 1.0MW / 1000kg feed, the fuel gas pressure is 0.06MPa, the oxygen content in the furnace is 2%, the carbon monoxide content in the cracked gas is 0.06mol%, the preset heating rate is 1℃ / min, and the target temperature is set at 760℃.

[0087] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, and higher stability.

[0088] Example 3

[0089] The system is implemented in accordance with Embodiment 2, but with the difference that it also includes a key feeding parameter monitoring and alarm module, which is used to monitor the key feeding parameters during the feeding stage and to issue an alarm when the key feeding parameters exceed the preset range; the key feeding parameters also include the pressure after the Venturi tube, the dilution steam flow rate of the single tube in the furnace, the outlet temperature of the pyrolysis furnace, the ultra-high pressure steam temperature, the VHS drum liquid level, the VHS temperature, the temperature after the oil cooler, and the temperature of the pyrolysis furnace cross section.

[0090] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and higher safety.

[0091] Example 4

[0092] Referring to Embodiment 3, the difference is that the monitoring of the key feeding parameters and the alarm being triggered when the key feeding parameters exceed the preset range specifically include:

[0093] An alarm will be triggered when the key parameters for material feeding exceed the first preset range;

[0094] When the key feeding parameter exceeds the second preset range, the key feeding parameter exceeding the second preset range is adjusted to the first preset range according to a preset ratio based on its current value, and an alarm is triggered; wherein, the upper limit of the second preset range is greater than the upper limit of the first preset range, the lower limit of the second preset range is less than the lower limit of the first preset range, and the preset ratio is ±0.1% to 10%.

[0095] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0096] Example 5

[0097] The system is implemented in accordance with Embodiment 4, but with the difference that it also includes a deep learning function module, which is used to learn the control advantages and disadvantages of the key feeding parameters in the feeding stage based on experience values ​​and big data, and to derive the optimal control values ​​of the key feeding parameters in the feeding stage.

[0098] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0099] Example 6

[0100] The implementation follows the same procedure as Example 5, except that when feeding is completed, the ratio of the dilution steam flow rate of the single furnace tube to the feeding amount of the single furnace tube is 0.37, and the preset rate is 60 (kg / h) / 1000kg feeding.

[0101] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0102] Example 7

[0103] The implementation follows the same procedure as Example 5, except that when feeding is completed, the ratio of the dilution steam flow rate of the single furnace tube to the feeding amount of the single furnace tube is 0.39, and the preset rate is 65 (kg / h) / 1000kg feeding.

[0104] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0105] Example 8

[0106] The same method is implemented as in Example 5, except that when the feeding is completed, the ratio of the dilution steam flow rate of the single tube in the furnace to the feeding amount of the single tube in the furnace is 0.41, and the preset rate is 70 (kg / h) / 1000kg feeding.

[0107] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0108] Example 9

[0109] The same method is implemented as in Example 5, except that when the feeding is completed, the ratio of the dilution steam flow rate of the single tube in the furnace to the feeding amount of the single tube in the furnace is 0.45, and the preset rate is 80 (kg / h) / 1000kg feeding.

[0110] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0111] Example 10

[0112] The implementation follows the same procedure as in Example 5, except that when the key feeding parameter exceeds the second preset range, the key feeding parameter exceeding the second preset range is adjusted to ±3% of its current value, and an alarm is triggered.

[0113] Testing revealed that the automatic execution system for the ethylene cracking furnace feeding process described in this invention, in practical applications, confirms the pre-feeding status through a pre-feeding status confirmation module. This ensures normal feeding of the cracking furnace while allowing the feeding process control module to control key feeding parameters based on the initial values ​​of the current furnace single-tube dilution steam flow and the cracking furnace outlet temperature. This ensures linear feeding while preventing large fluctuations in key feeding parameters, which could lead to significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow, causing unplanned shutdowns of the ethylene plant. The system offers advantages such as high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and greater safety.

[0114] The automatic execution system and method for the ethylene cracking furnace feeding process provided by this invention confirms the state before feeding through a pre-feeding state confirmation module. While ensuring that the cracking furnace can be fed normally, the feeding process control module can control the key feeding parameters during the feeding process based on the initial values ​​of the current single-tube dilution steam flow rate in the furnace and the cracking furnace outlet temperature. This ensures linear feeding while avoiding large fluctuations in the key feeding parameters, which could cause significant fluctuations in parameters such as the cracking furnace outlet temperature and dilution steam flow rate, resulting in unplanned shutdowns of the ethylene plant. It has the advantages of high feeding efficiency, smaller fluctuations in key feeding parameters, higher stability, and higher safety.

[0115] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An automatic execution system for an ethylene cracking furnace feeding process, characterized by, The system comprises: A pre-feeding state confirmation module, configured to confirm initial parameters before feeding, and when the initial parameters are within an initial range, instruct that feeding can be performed, and when the initial parameters are not within the initial range, alarm; A feeding process control module, configured to control key feeding parameters in a feeding stage, and issue a feeding instruction, wherein the key feeding parameters comprise a feeding rate of a single pipe of a furnace and a feeding rate of a total pipe of the furnace; A feeding module, configured to receive the feeding instruction and perform feeding; The feeding stage comprises a first feeding stage and a second feeding stage, when in the first feeding stage, feeding is performed to a first feeding value through the single pipe of the furnace, and the first feeding value is stable for a preset time T1, when in the second feeding stage, feeding is performed to a target feeding value through the total pipe of the furnace, and the target feeding value is stable for a preset time T2; The control of the key feeding parameters in the feeding stage and the issuance of the feeding instruction specifically comprise: In the first feeding stage and the second feeding stage, the feeding rate of the single pipe of the furnace and the feeding rate of the total pipe of the furnace are controlled respectively, so that the dilution steam flow of the single pipe of the furnace decreases at a preset rate, and when feeding is completed, the ratio of the dilution steam flow of the single pipe of the furnace to the feeding amount of the single pipe of the furnace is 0.2-0.6; The key feeding parameters further comprise an ascending rate of a fuel gas calorific value, a fuel gas pressure, a furnace oxygen content and a carbon monoxide content in a cracking gas; The control of the key feeding parameters in the feeding stage and the issuance of the feeding instruction further specifically comprise: In the process of feeding through the single pipe of the furnace or the total pipe of the furnace, the ascending rate of the fuel gas calorific value is controlled to be 0.5-2.0 MW / 1000 kg of feeding, the fuel gas pressure is controlled to be 0.06-0.22 MPa, the furnace oxygen content is controlled to be 1.5-5%, and the carbon monoxide content in the cracking gas is controlled to be 0.05-0.07 mol%, so that the outlet temperature of the cracking furnace increases to a set target temperature at a preset temperature ascending rate on the basis of an initial temperature of the outlet temperature, wherein the preset temperature ascending rate is 0.3-2 ℃ / min, and the set target temperature is 750-800 ℃.

2. The system of claim 1, wherein, The alarm when the initial parameters are not within the initial range specifically comprises: When the initial parameters are not within the initial range, one or more initial parameters not within the initial range are alarmed.

3. The system of claim 1 or 2, wherein, The initial parameters comprise a Venturi tube post pressure, a dilution steam flow of a single pipe of a furnace, an outlet temperature of a cracking furnace and an ultra-high pressure steam temperature.

4. The system of claim 3, wherein, The initial range of the Venturi tube post pressure is 0.04-0.1 MPa, the initial range of the ultra-high pressure steam temperature is 480-530 ℃, the initial range of the outlet temperature of the cracking furnace is 700-740 ℃, and the initial range of the dilution steam flow of the single pipe of the furnace is 4000-6000 kg / h.

5. The system of claim 1, wherein, The feeding rate of the single pipe of the furnace is 125-500 (kg / h) / min, and the feeding rate of the total pipe of the furnace is 500-2000 (kg / h) / min.

6. The system of claim 1, wherein, The preset time T1 is 0-30 min, and the preset time T2 is 1-15 min.

7. The system of claim 1, wherein, The preset rate is 30-120 (kg / h) / 1000 kg of feeding.

8. The system of claim 1, wherein, The system further comprises a feeding key parameter monitoring and alarm module, which is used for monitoring the feeding key parameter during the feeding stage, and performing alarm when the feeding key parameter exceeds the preset range.

9. The system of claim 8, wherein, The monitoring of the feeding key parameter and the alarm when the feeding key parameter exceeds the preset range specifically include: When the feeding key parameter exceeds the first preset range, alarm is performed; When the feeding key parameter exceeds the second preset range, the feeding key parameter exceeding the second preset range is adjusted to the first preset range by a preset proportion based on the current value of the feeding key parameter, and alarm is performed; The upper limit value of the second preset range is greater than the upper limit value of the first preset range, the lower limit value of the second preset range is less than the lower limit value of the first preset range, and the preset proportion is ±0.1%-10%.

10. The system of any of claims 1, 5-9, wherein, The system further comprises a feeding process alarm optimization management module, which is used for automatically shielding the feeding instrument alarm when the total feeding amount is less than 40-65% of the design load of the feeding device of the feeding module, and changing the feeding instrument alarm enable prompt light to red, and enabling the feeding instrument alarm when the total feeding amount is greater than 65-75% of the design load of the feeding device, and changing the feeding instrument alarm enable prompt light to green.

11. The system of claim 10, wherein, The types of the feeding instrument alarm include total feeding amount alarm, cracking furnace liquid phase feeding flow alarm, cracking furnace gas phase feeding flow alarm, feeding interlock pressure alarm, DMDS force alarm, DMDS flow alarm, anti-coking steam pressure difference alarm, cracking furnace outlet temperature alarm, cross section temperature alarm, quenching oil flow alarm, Venturi inlet pressure alarm, cracking gas analysis indication alarm, cross section flue gas oxygen content alarm, fuel heat load ratio alarm, furnace pipe liquid raw material flow low alarm, and gas raw material pressure low alarm.

12. The system of claim 1, wherein, The system further comprises an operation navigation function module, which is used for performing operation prompt during the feeding stage according to the control instruction of the feeding process control module.

13. The system of claim 1, wherein, The system further comprises a deep learning function module, which is used for learning the control advantages and disadvantages of each feeding key parameter in the feeding stage based on experience value and big data, and deriving the optimal control value of the feeding key parameter in the feeding stage.

14. An automatic execution method of an ethylene cracking furnace charging process, characterized by, The method is implemented by using the system of any one of claims 1-13, and the method comprises: An initial parameter is confirmed before feeding by using a feeding before state confirmation module, and when the initial parameter is within an initial range, it is indicated that feeding can be performed, and when the initial parameter is not within the initial range, alarm is performed; During the feeding stage, a feeding key parameter is controlled by using a feeding process control module, and a feeding instruction is issued, wherein the feeding key parameter includes the feeding rate of the single pipe of the furnace and the feeding rate of the total pipe of the furnace; The feeding module receives feeding instructions and feeds in the feeding stage. The feeding module receives feeding instructions and feeds in the feeding stage.

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