Load adjusting system and method for automatic feeding and returning process of ethylene cracking furnace group

Abstract

The invention relates to the technical field of petrochemical engineering, in particular to a load adjusting system and method for the automatic feeding and returning process of an ethylene cracking furnace group, and the system comprises a feeding load obtaining module which is used for obtaining the feeding load of each cracking furnace in real time and obtaining the residual feeding load of each cracking furnace according to the feeding load of each cracking furnace, selecting a material returning cracking furnace, and selecting a feeding cracking furnace group according to the feeding load of the material returning cracking furnace and the residual feeding load of other cracking furnaces; the material feeding and returning process load adjustment control module is used for controlling the material returning cracking furnace to perform material returning according to the feeding load of the material returning cracking furnace, and controlling the selected feeding cracking furnace group to perform feeding in the process of controlling the material returning cracking furnace to perform material returning; and the material feeding and returning execution module is used for feeding and returning materials according to the control instruction of the material feeding and returning process load adjustment control module. By applying the system, the load stability of the cracking furnace group in the feeding and returning process can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, and in particular to a load adjustment system and method for the automatic material feeding and withdrawing process of an ethylene cracking furnace group. Background Art

[0002] Ethylene is an important basic raw material for petrochemical industry and one of the petrochemical products with the largest demand and production volume. Its output, scale and technical level indicate the development level of a country's petrochemical industry. The tubular cracking furnace is used for hydrocarbon cracking and is the core device for producing ethylene. It determines the production capacity, stable operation and overall energy consumption of the entire ethylene device. When hydrocarbons undergo steam cracking reaction in the radiation section of the tubular cracking furnace, coke will accumulate on the inner wall of the furnace tube due to secondary reactions such as polymerization and condensation in the radiation section, forming coke. When the temperature of the outer wall of the furnace tube in the radiation section or the outlet temperature of the quench boiler reaches the production limit or the pressure difference before and after the Venturi tube reaches the production limit due to coking, it will seriously affect the production of ethylene, and cause problems such as reduced ethylene yield, increased energy consumption, shortened furnace tube life, and even affect production safety.

[0003] Due to the coking characteristics of ethylene cracking furnaces, in actual application, it is necessary to frequently and intermittently perform operations such as feeding and withdrawing materials from the furnace of the cracking furnace. At present, when switching cracking furnaces in the ethylene industry, one cracking furnace is usually shut down before another is put into use. The switching operation of a single cracking furnace is prone to cause changes in the cracking gas flow rate, thereby causing production fluctuations in the downstream ethylene quenching, compression, and separation units, and the withdrawal operation of a single cracking furnace will also cause a decrease in ethylene production. At the same time, the withdrawal and feeding operations of multiple cracking furnaces require multiple operators to operate independently. Controlling a single cracking furnace to complete the corresponding process is not only labor-intensive and inefficient, but also requires the coordination and cooperation of multiple operators. Due to the uneven experience of operators, in this long-term operation of multiple cracking furnaces for simultaneous feeding or withdrawing, it is very easy to have a mismatch between the withdrawal and feeding loads, which leads to system instability. If the operator further makes a mistake during the operation, it will greatly increase the instability of the system, causing downstream production fluctuations, thereby affecting the output of ethylene.

[0004] Therefore, there is an urgent need for a load adjustment system and method for the automatic material feeding and withdrawal process of an ethylene cracking furnace group. Summary of the invention

[0005] The present invention aims to solve the problems in the prior art of load adjustment for material feeding and withdrawal switching of an ethylene cracking furnace group, such as lack of a corresponding automatic material feeding and withdrawal load adjustment system, and the use of manual operation for material feeding and withdrawal, which easily leads to the failure of the material feeding amount to match the material withdrawal amount during the material feeding and withdrawal load adjustment process of the cracking furnace group, and the existence of load instability and low load switching efficiency. A load adjustment system and method for the automatic material feeding and withdrawal process of an ethylene cracking furnace group are provided.

[0006] In order to achieve the above object, in the first aspect of the present invention, a load adjustment system for the automatic feeding and discharging process of an ethylene cracking furnace group is provided. The system includes:

[0007] A feed load acquisition module, configured to acquire the feed load of each cracking furnace in real time, obtain the remaining feeding load of each cracking furnace according to the feed load of each cracking furnace, select a discharging cracking furnace, and select a feeding cracking furnace group according to the feed load of the discharging cracking furnace and the remaining feeding loads of other cracking furnaces;

[0008] A load adjustment control module for the feeding and discharging process, configured to control the discharging cracking furnace to discharge materials according to the feed load of the discharging cracking furnace, and control the selected feeding cracking furnace group to feed materials during the process of controlling the discharging cracking furnace to discharge materials;

[0009] A feeding and discharging execution module, configured to perform feeding and discharging according to the control instructions of the load adjustment control module for the feeding and discharging process.

[0010] Preferably, the controlling the discharging cracking furnace to discharge materials according to the feed load of the discharging cracking furnace specifically includes:

[0011] In the first discharging stage, discharge materials through the furnace header pipe of the discharging cracking furnace at a first discharging rate to a first discharging value, and stabilize for a set time;

[0012] In the second discharging stage, discharge materials through the single furnace pipes of the discharging cracking furnace at a second discharging rate to a second discharging value, and stabilize the set time;

[0013] In the third discharging stage, discharge all the remaining materials to be discharged through the control valve of the single furnace pipe of the discharging cracking furnace at a valve position rate.

[0014] Preferably, the first discharging value is 60-80% of the feed load of the discharging cracking furnace, the second discharging value is 20-45% of the feed load of the discharging cracking furnace, and the set time is 0-20 min; the first discharging rate is 50-500 (kg / h) / min, the second discharging rate is 20-300 (kg / h) / min, and the valve position rate is 0.5-10% / min.

[0015] Preferably, the system further includes a pre-feeding and discharging state confirmation module, configured to confirm the initial states of the discharging cracking furnace and the feeding cracking furnace before feeding and discharging;

[0016] The confirming the initial state of the discharging cracking furnace before feeding and discharging specifically includes:

[0017] Confirm the initial discharging parameters of the discharging cracking furnace. When the initial discharging parameters are within the initial range, indicate that discharging can be carried out. When the initial discharging parameters are not within the initial range, alarm one or more of the initial discharging parameters that are not within the initial range.

[0018] Preferably, the initial discharging parameters include the sulfur injection amount, the cracking furnace outlet temperature, and the ultra-high pressure steam temperature.

[0019] Among them, the initial range of the sulfur injection amount is 2 - 5 kg / h, the initial range of the cracking furnace outlet temperature is 730 - 750 °C, and the initial range of the ultra-high pressure steam temperature is 505 - 520 °C.

[0020] Preferably, during the process of controlling the discharging cracking furnace to discharge, simultaneously control the selected feeding cracking furnace group to feed. Specifically, it includes:

[0021] In the first discharging stage and the second discharging stage, control the feeding cracking furnaces in the selected feeding cracking furnace group to feed through the feeding model; in the third discharging stage, control the feeding by controlling the single-tube control valve of the furnace chamber of the feeding cracking furnace.

[0022] Preferably, the feeding model includes:

[0023]

[0024]

[0025] Among them, V 组投 is the feeding rate of the feeding cracking furnace group, V 单投 is the feeding rate of a single feeding cracking furnace, V 退 is the discharging rate of the discharging cracking furnace, F 组投 is the feeding amount of the feeding cracking furnace group, F 单投 is the feeding amount of a single feeding cracking furnace, F 退 is the discharging amount of the discharging cracking furnace.

[0026] Preferably, before feeding and discharging, confirm the initial state of the feeding cracking furnace. Specifically, it includes:

[0027] Confirm the initial feeding parameters of the feeding cracking furnace. When the initial feeding parameters are within the initial range, indicate that feeding can be carried out. When the initial feeding parameters are not within the initial range, alarm one or more of the initial feeding parameters that are not within the initial range.

[0028] Preferably, the initial feeding parameters include the quenching oil temperature, the pressure after the Venturi tube, the cracking furnace outlet temperature, and the ultra-high pressure steam temperature.

[0029] Among them, the initial range of the quench oil temperature is 190 - 210 °C, the initial range of the pressure after the venturi tube is 0.04 - 0.1 MPa, the initial range of the cracking furnace outlet temperature is 780 °C - 860 °C, and the initial range of the ultra-high pressure steam temperature is 480 - 510 °C.

[0030] Preferably, the system further includes a key parameter control module for controlling the key parameters of the discharging cracking furnace and the feeding cracking furnace during the charging and discharging process; among them, the key parameters include the single-tube dilution steam flow rate in the furnace chamber, the cracking furnace outlet temperature, and the oxygen content in the furnace chamber.

[0031] Preferably, the control of the key parameters of the discharging cracking furnace specifically includes:

[0032] When the discharging of the discharging cracking furnace starts, control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to increase to a first dilution steam value at a first set rate and remain constant; when the charging and discharging process ends, then control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to increase from the first dilution steam value to a second dilution steam value at a second set rate and remain stable;

[0033] During the discharging process of the discharging cracking furnace, control the oxygen content in the furnace chamber of the discharging cracking furnace within a first set oxygen content range, and when the oxygen content in the furnace chamber of the discharging cracking furnace is lower than the lower limit value of the first set oxygen content range, open the damper of the discharging cracking furnace by a first damper amplitude. After a preset time interval, if the oxygen content in the furnace chamber of the discharging cracking furnace is still lower than the lower limit value of the first set oxygen content range, continue to open the damper of the discharging cracking furnace by the first damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range; when the oxygen content in the furnace chamber of the discharging cracking furnace is higher than the upper limit value of the first set oxygen content range, close the damper of the discharging cracking furnace by a second damper amplitude. After a preset time interval, if the oxygen content in the furnace chamber of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, continue to close the damper of the discharging cracking furnace by the second damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range;

[0034] During the material discharging process of the material discharging cracking furnace, control the cracking furnace outlet temperature of the material discharging cracking furnace within the first set temperature range. When the cracking furnace outlet temperature of the material discharging cracking furnace is between the first furnace discharging lower limit value and the second furnace discharging lower limit value, control the calorific value of the fuel gas to increase by the first amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material discharging cracking furnace is still between the first furnace discharging lower limit value and the second furnace discharging lower limit value, control the calorific value of the fuel gas to continue to increase by the first amplitude until the cracking furnace outlet temperature of the material discharging cracking furnace is within the first set temperature range. When the cracking furnace outlet temperature of the material discharging cracking furnace is lower than the second furnace discharging lower limit value, control the calorific value of the fuel gas to increase by the second amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material discharging cracking furnace is still lower than the second furnace discharging lower limit value, control the calorific value of the fuel gas to continue to increase by the second amplitude until the cracking furnace outlet temperature of the material discharging cracking furnace is within the first set temperature range.

[0035] When the cracking furnace outlet temperature of the material discharging cracking furnace is between the first furnace discharging upper limit value and the second furnace discharging upper limit value, control the calorific value of the fuel gas to decrease by the third amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material discharging cracking furnace is still between the first furnace discharging upper limit value and the second furnace discharging upper limit value, control the calorific value of the fuel gas to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the material discharging cracking furnace is within the first set temperature range. When the cracking furnace outlet temperature of the material discharging cracking furnace is higher than the second furnace discharging upper limit value, control the calorific value of the fuel gas to decrease by the fourth amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material discharging cracking furnace is still higher than the second furnace discharging upper limit value, control the calorific value of the fuel gas to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the material discharging cracking furnace is within the first set temperature range.

[0036] Preferably, the control of the key parameters of the feeding cracking furnace specifically includes:

[0037] When starting the feeding of the feeding cracking furnace, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to increase at the third set rate until the feeding is completed. At the end of the feeding, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to be adjusted to the preset dilution steam value at the fourth set rate and maintain stability.

[0038] During the feeding process of the feeding cracking furnace, control the oxygen content in the furnace of the feeding cracking furnace within the second set oxygen content range. When the oxygen content in the furnace of the feeding cracking furnace is lower than the lower limit value of the second set oxygen content range, open the air damper of the feeding cracking furnace by the first air damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still lower than the lower limit value of the second set oxygen content range, continue to open the air damper of the feeding cracking furnace by the first air damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range; when the oxygen content in the furnace of the feeding cracking furnace is higher than the upper limit value of the second set oxygen content range, close the air damper of the feeding cracking furnace by the second air damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, continue to close the air damper of the feeding cracking furnace by the second air damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range;

[0039] During the feeding process of the feeding cracking furnace, control the cracking furnace outlet temperature of the feeding cracking furnace within the second set temperature range. When the cracking furnace outlet temperature of the feeding cracking furnace is between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the fuel gas calorific value to increase by the first amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the fuel gas calorific value to continue to increase by the first amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feeding cracking furnace is lower than the first furnace feeding lower limit value, control the fuel gas calorific value to increase by the second amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still lower than the first furnace feeding lower limit value, control the fuel gas calorific value to continue to increase by the second amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range;

[0040] When the cracking furnace outlet temperature of the feeding cracking furnace is between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the fuel gas calorific value to decrease by the third amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the fuel gas calorific value to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feeding cracking furnace is higher than the second furnace feeding upper limit value, control the fuel gas calorific value to decrease by the fourth amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still higher than the second furnace feeding upper limit value, control the fuel gas calorific value to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range.

[0041] Preferably, the first set rate is 10 - 150 (kg / h) / min, the second set rate is 50 - 500 (kg / h) / min, the first dilution steam value is 3500 - 4500 kg / h, the second dilution steam value is 3800 - 5000 kg / h, the first set oxygen content range is 1 - 10%, the first damper amplitude and the second damper amplitude are 0.5 - 5%, the first set temperature range is 710 - 780 °C, the first furnace withdrawal lower limit is the lower limit of the first set temperature range, the second furnace withdrawal lower limit is less than the first furnace withdrawal lower limit and the difference between the two is 2 - 10 °C, the first furnace withdrawal upper limit is the upper limit of the first set temperature range, the second furnace withdrawal upper limit is greater than the first furnace withdrawal upper limit and the difference between the two is 2 - 10 °C, the first amplitude and the second amplitude are 0 - 0.3 MW, and the third amplitude and the fourth amplitude are 0.1 - 0.6 MW;

[0042] The third set rate is 300 - 600 (kg / h) / t of feedstock, the fourth set rate is 50 - 500 (kg / h) / min, the preset dilution steam value is 3800 - 5000 kg / h, the second set oxygen content range is 1 - 6%, the second set temperature range is 780 - 880 °C, the first furnace charging lower limit is the lower limit of the second set temperature range, the second furnace charging lower limit is less than the first furnace charging lower limit and the difference between the two is 2 - 10 °C, the first furnace charging upper limit is the upper limit of the second set temperature range, and the second furnace charging upper limit is greater than the first furnace charging upper limit and the difference between the two is 2 - 10 °C.

[0043] Preferably, the system further includes an operation navigation function module, which is used to, during the furnace withdrawal process of the furnace withdrawal cracking furnace, when the damper opening of the furnace withdrawal cracking furnace is less than or equal to 10% and the oxygen content in the furnace chamber of the furnace withdrawal cracking furnace is still higher than the upper limit of the first set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the furnace withdrawal cracking furnace is greater than or equal to 90% and the oxygen content in the furnace chamber of the furnace withdrawal cracking furnace is still higher than the upper limit of the first set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05 - 0.1 Mpa, prompt to perform the operation of closing or opening the auxiliary burner to maintain the fuel gas pressure within 0.1 - 0.3 Mpa;

[0044] During the feeding process of the feeding cracking furnace, when the damper opening of the feeding cracking furnace is less than or equal to 8-12%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the feeding cracking furnace is greater than or equal to 88-92%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05-0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1-0.3 Mpa.

[0045] Preferably, the system further includes a key parameter monitoring and alarm module for monitoring the key feeding and discharging parameters during the feeding and discharging stage and alarming when the key feeding and discharging parameters exceed the preset range.

[0046] Preferably, the key feeding and discharging parameters include the cracking furnace outlet temperature, the single furnace tube carbon hydrocarbon flow rate and its change rate, the total carbon hydrocarbon flow rate of the main pipe and its change rate, the single tube dilution steam flow rate, the fuel gas calorific value, the fuel gas pressure, the furnace O2 content, the CO content in the cracked gas, the pressure after the Venturi tube, the cracking furnace damper opening, the dilution steam ratio, the VHS steam drum liquid level, the VHS temperature, the temperature after the oil cooler, the cracking furnace cross-section temperature, the carbon hydrocarbon raw material pressure, and the single furnace tube raw material control valve position rate.

[0047] Preferably, the monitoring of the key feeding and discharging parameters and the alarming when the key feeding and discharging parameters exceed the preset range specifically include:

[0048] Alarm when the key feeding and discharging parameters exceed the first preset range;

[0049] When the key feeding and discharging parameters exceed the second preset range, adjust the key feeding and discharging parameters exceeding the second preset range to within the first preset range at a preset ratio based on their current values and alarm;

[0050] Wherein, 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 ratio is ±0.1% - 10%.

[0051] Preferably, the system further includes an alarm optimization management module for automatically shielding the instrument alarms of the feeding system and turning the indicator light of the feeding and discharging alarm on when the feeding load of the cracking furnace is less than 65-75% of the design load; and automatically enabling the instrument alarms of the feeding system and turning the indicator light of the feeding and discharging alarm off when the feeding load is greater than 65-75% of the design load.

[0052] Preferably, the types of instrument alarms of the feeding system include total withdrawal alarm, liquid-phase withdrawal flow alarm of cracking furnace, gas-phase withdrawal flow alarm of cracking furnace, withdrawal interlock pressure alarm, DMDS force alarm, DMDS flow alarm, anti-coking steam pressure difference alarm, cracking furnace outlet temperature alarm, cross-section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, cracking gas analysis indication alarm, cross-section flue gas oxygen content alarm, fuel heat load ratio alarm, low liquid raw material flow alarm of furnace tube, and low gas raw material pressure alarm.

[0053] Preferably, the system further includes a deep learning function module for learning the control advantages and disadvantages of the key parameters of the withdrawal cracking furnace and the feeding cracking furnace based on empirical values and big data, and deriving the optimal control values of the key parameters of the withdrawal cracking furnace and the feeding cracking furnace.

[0054] Preferably, the system further includes a control performance evaluation module for real-time collecting the loop information of the cracking furnace before and during the feeding and withdrawal process, evaluating the control loop performance of the cracking furnace according to the loop information, and giving an alarm when the control loop performance of the cracking furnace is abnormal.

[0055] Preferably, the feeding load acquisition module is further used for replacing one or more feeding cracking furnaces in the feeding cracking furnace group during the feeding and withdrawal process.

[0056] To achieve the above object, the second aspect of the present invention provides a load adjustment method for the automatic feeding and withdrawal process of an ethylene cracking furnace group. The method is implemented using the described system and includes:

[0057] The feeding load acquisition module real-time obtains the feeding load of each cracking furnace, obtains the remaining feeding load of each cracking furnace according to the feeding load of each cracking furnace, selects the withdrawal cracking furnace, and selects the feeding cracking furnace group according to the feeding load of the withdrawal cracking furnace and the remaining feeding loads of other cracking furnaces;

[0058] The load adjustment control module for the feeding and withdrawal process controls the withdrawal cracking furnace to withdraw materials according to the feeding load of the withdrawal cracking furnace, and simultaneously controls the selected feeding cracking furnace group to feed materials during the process of controlling the withdrawal cracking furnace to withdraw materials;

[0059] The feeding and withdrawal execution module performs feeding and withdrawal according to the control instructions of the load adjustment control module for the feeding and withdrawal process.

[0060] According to the above technical solution, based on the system and method, in the actual application process, the feed load acquisition module obtains the feed load of each cracking furnace in the cracking furnace group in real time, obtains the remaining feeding load of each cracking furnace, and can quickly select at least one feeding cracking furnace as the feeding cracking furnace group according to the feed load of the discharging cracking furnace after selecting the discharging cracking furnace according to the actual production needs; and further through the load adjustment control module during the charging and discharging process, according to the feed load of the discharging cracking furnace, control the discharging cracking furnace to discharge materials, and during the process of controlling the discharging cracking furnace to discharge materials, control the selected feeding cracking furnace group to feed materials, which can effectively ensure that the discharging amount and the feeding amount match during the charging and discharging process, thereby ensuring the stability of the load of the ethylene cracking furnace group during the charging and discharging process, avoiding the decrease in ethylene production due to the unstable load during the charging and discharging process, and having the advantages of high charging and discharging accuracy, small fluctuation of key charging and discharging parameters, and high load adjustment and switching efficiency of the cracking furnace group. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a flowchart of a load adjustment system for the automatic charging and discharging process of an ethylene cracking furnace group. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0062] The following details the specific embodiments of the embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining and illustrating the embodiments of the present invention, and are not used to limit the embodiments of the present invention.

[0063] The first aspect of the present invention provides a load adjustment system for the automatic charging and discharging process of an ethylene cracking furnace group, as Figure 1 shown. The load adjustment system for the automatic charging and discharging process of the ethylene cracking furnace group includes:

[0064] A feed load acquisition module, configured to obtain the feed load of each cracking furnace in real time (i.e., the amount of material that can be discharged from the discharging cracking furnace), and obtain the remaining feeding load of each cracking furnace according to the feed load of each cracking furnace, select the discharging cracking furnace, and select the feeding cracking furnace group according to the feed load of the discharging cracking furnace and the remaining feeding loads of other cracking furnaces;

[0065] A load adjustment control module during the charging and discharging process, configured to control the discharging cracking furnace to discharge materials according to the feed load of the discharging cracking furnace, and control the selected feeding cracking furnace group to feed materials during the process of controlling the discharging cracking furnace to discharge materials;

[0066] A charging and discharging execution module, configured to perform charging and discharging according to the control instructions of the load adjustment control module during the charging and discharging process.

[0067] According to the above technical solution, based on the system and method, in the actual application process, the feed load acquisition module obtains the feed load of each cracking furnace in the cracking furnace group in real time, obtains the remaining feeding load of each cracking furnace, and can quickly select at least one feeding cracking furnace as the feeding cracking furnace group according to the feed load of the discharging cracking furnace after selecting the discharging cracking furnace according to the actual production needs; and further through the feeding and discharging process load adjustment control module, according to the feed load of the discharging cracking furnace, control the discharging cracking furnace to discharge materials, and during the process of controlling the discharging cracking furnace to discharge materials, control the selected feeding cracking furnace group to feed materials, which can effectively ensure that the discharging amount and the feeding amount match during the feeding and discharging process, thereby ensuring the stability of the load of the ethylene cracking furnace group during the feeding and discharging process, avoiding the decrease of ethylene production due to the unstable load during the feeding and discharging process, and having the advantages of high feeding and discharging accuracy, small fluctuation of key feeding and discharging parameters, and high load adjustment and switching efficiency of the cracking furnace group.

[0068] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the feed load acquisition module is further configured to replace one or more feeding cracking furnaces in the feeding cracking furnace group during the feeding and discharging process.

[0069] In the embodiment of the present invention, by further designing that during the feeding and discharging process, one or more cracking furnaces in the feeding cracking furnace group can be replaced at any time according to actual needs, and the feeding and discharging process load adjustment control module reallocates and calculates and then controls the feeding and discharging, it can further effectively meet the load adjustment needs of the cracking furnace group in the actual application process and improve the applicability.

[0070] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the system further includes a pre-feeding and discharging state confirmation module for confirming the initial states of the discharging cracking furnace and the feeding cracking furnace before feeding and discharging;

[0071] The confirmation of the initial state of the discharging cracking furnace before feeding and discharging specifically includes:

[0072] Confirm the initial discharging parameters of the discharging cracking furnace, and when the initial discharging parameters are within the initial range, indicate that discharging can be performed, and when the initial discharging parameters are not within the initial range, alarm one or more of the initial discharging parameters that are not within the initial range.

[0073] In a specific embodiment, the initial discharging parameters include sulfur injection amount, cracking furnace outlet temperature, and ultra-high pressure steam temperature; wherein, the initial range of the sulfur injection amount is 2 - 5 kg / h, the initial range of the cracking furnace outlet temperature is 730 - 750 °C, and the initial range of the ultra-high pressure steam temperature is 505 - 520 °C.

[0074] In another preferred embodiment, the confirmation of the initial state of the feeding cracking furnace before feeding and discharging specifically includes:

[0075] Confirm the initial feeding parameters of the feeding cracking furnace, and when the initial feeding parameters are within the initial range, indicate that feeding can be carried out. When the initial feeding parameters are not within the initial range, alarm for one or more of the initial feeding parameters that are not within the initial range.

[0076] In a specific embodiment, the initial feeding parameters include the quench oil temperature, the pressure after the Venturi tube, the cracking furnace outlet temperature, and the ultra-high pressure steam temperature;

[0077] Among them, the initial range of the quench oil temperature is 190 - 210 °C, the initial range of the pressure after the Venturi tube is 0.04 - 0.1 MPa, the initial range of the cracking furnace outlet temperature is 780 °C - 860 °C, and the initial range of the ultra-high pressure steam temperature is 480 - 510 °C.

[0078] In the embodiment of the present invention, by confirming the initial discharging parameters of the discharging cracking furnace and the initial feeding parameters of the feeding cracking furnace before feeding and discharging and keeping them within the initial range, it is beneficial to ensure the accuracy and stability of the feeding and discharging process. Among them, the discharging cracking furnace and the feeding cracking furnace include DCS, CSL, and the cracking furnace mode. Specifically, before switching, the DCS is in the "running" state, the CSL is in the "running" state, and the cracking furnace is in the "full furnace" mode.

[0079] Further in a more preferred embodiment, the system further includes a control performance evaluation module, which is used to collect the loop information of the cracking furnace in real time before and during feeding and discharging, evaluate the control loop performance of the cracking furnace according to the loop information, and alarm when the control loop performance of the cracking furnace is abnormal. Thereby, it can further effectively ensure the stability of the cracking furnace group during the feeding and discharging process and ensure safety.

[0080] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the control of the discharging cracking furnace to discharge according to the feeding load of the discharging cracking furnace specifically includes:

[0081] In the first discharging stage, discharge through the furnace main pipe of the discharging cracking furnace at the first discharging rate to the first discharging value and stabilize for the set time;

[0082] In the second discharging stage, discharge through the furnace single pipe of the discharging cracking furnace at the second discharging rate to the second discharging value and stabilize the set time;

[0083] In the third material discharging stage, all the remaining materials to be discharged are discharged at the valve position rate through the furnace single-tube control valve of the material discharging cracking furnace.

[0084] In a specific embodiment, the first material discharging value is 60-80% of the feed load of the material discharging cracking furnace, preferably 65-75%, the second material discharging value is 20-45% of the feed load of the material discharging cracking furnace, preferably 25-40%, the set time is 0-20 min, preferably 0-10 min; the first material discharging rate is 50-500 (kg / h) / min, preferably 100-300 (kg / h) / min, the second material discharging rate is 20-300 (kg / h) / min, preferably 20-100 (kg / h) / min, and the valve position rate is 0.5-10% / min, preferably 1-3% / min.

[0085] In the embodiment of the present invention, by dividing the material discharging process into three stages and using the furnace main pipe or the furnace single tube at different material discharging rates in different material discharging stages to discharge to the set value, the stability and accuracy in the material discharging process can be effectively ensured, the efficiency can be improved, and the influence on the material discharging accuracy by directly using the furnace main pipe and the influence on the material discharging efficiency by directly using the furnace single tube can be avoided. Further, in the third material discharging stage, all the remaining materials to be discharged are discharged at the valve position rate through the furnace single-tube control valve of the material discharging cracking furnace, which can further effectively improve the accuracy of material discharging and ensure the stability of the cracking furnace group during the load adjustment and switching. Among them, the furnace main pipe of the cracking furnace usually includes at least one furnace single tube.

[0086] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, during the process of controlling the material discharging cracking furnace to discharge materials, the selected feeding cracking furnace group is controlled to feed materials, specifically including:

[0087] In the first material discharging stage and the second material discharging stage, the feeding cracking furnace in the selected feeding cracking furnace group is controlled to feed materials through the feeding model; in the third material discharging stage, the feeding is carried out by controlling the furnace single-tube control valve of the feeding cracking furnace. Among them, the feedable amount of the feeding cracking furnace is usually more than 70% and less than 110% of the design load.

[0088] In a specific embodiment, the feeding model includes:

[0089]

[0090]

[0091] Among them, V 组投 is the feeding rate of the feeding cracking furnace group, V 单投 is the feeding rate of a single feeding cracking furnace, V退 is the discharging rate of the discharging cracking furnace, F 组投 is the feeding amount of the feeding cracking furnace group, F 单投 is the feeding amount of a single feeding cracking furnace, F 退 is the discharging amount of the discharging cracking furnace.

[0092] In the embodiment of the present invention, through the feeding model, in the first and second discharging stages, according to the discharging amount and discharging rate of the discharging cracking furnace, and the feeding amount of a single feeding cracking furnace, the feeding rate of a single feeding cracking furnace can be accurately calculated, so as to ensure the accuracy of feeding during the discharging process, and further ensure the stability during the load adjustment and switching process; while in the third discharging stage, due to the fact that in the actual application process, when the discharging amount is low, the discharging rate of the discharging cracking furnace cannot be accurately measured, so the discharging cracking furnace controls the discharging through the valve position. In this process, the feeding rate of the feeding cracking furnace needs to be based on the discharging cracking furnace. When it is detected that the discharging amount of the discharging cracking furnace is an integer n times of 100 kg / h, the feeding amount of the feeding cracking furnace increases by the corresponding 100(n + 1) kg / h to keep the incoming and discharging amounts consistent, so as to ensure the accuracy of feeding during the discharging process, and further ensure the stability during the load adjustment and switching process. Among them, the feeding amount of the feeding cracking furnace group is usually equal to or less than the discharging amount of the discharging cracking furnace. When the feeding amount of the feeding cracking furnace group is less than the discharging amount of the discharging cracking furnace (that is, the remaining feeding load in the current cracking furnace group cannot meet the feeding load of the discharging cracking furnace), at this time, the load adjustment control module for the feeding and discharging process can allocate the feeding amount according to the actual available feeding amount of the feeding cracking furnace group. Further, when the remaining feeding load in the cracking furnace group meets the feeding load of the discharging cracking furnace, the load adjustment control module for the feeding and discharging process can further allocate the feeding amount.

[0093] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the system further includes a key parameter control module for controlling the key parameters of the discharging cracking furnace and the feeding cracking furnace during the feeding and discharging process; wherein, the key parameters include the single-tube dilution steam flow rate in the furnace, the cracking furnace outlet temperature, and the oxygen content in the furnace.

[0094] In a specific embodiment, the control of the key parameters of the discharging cracking furnace specifically includes:

[0095] When the discharging cracking furnace starts to discharge, control the single-tube dilution steam flow rate in the furnace of the discharging cracking furnace to rise to the first dilution steam value at the first set rate and remain constant; when the feeding and discharging process ends, then control the single-tube dilution steam flow rate in the furnace of the discharging cracking furnace to rise from the first dilution steam value to the second dilution steam value at the second set rate and remain stable;

[0096] During the material discharge process of the material discharge cracking furnace, control the oxygen content in the furnace of the material discharge cracking furnace within the first set oxygen content range. When the oxygen content in the furnace of the material discharge cracking furnace is lower than the lower limit value of the first set oxygen content range, open the damper of the material discharge cracking furnace by the first damper amplitude. After a preset time interval, if the oxygen content in the furnace of the material discharge cracking furnace is still lower than the lower limit value of the first set oxygen content range, continue to open the damper of the material discharge cracking furnace by the first damper amplitude until the oxygen content in the furnace of the material discharge cracking furnace is within the first set oxygen content range. When the oxygen content in the furnace of the material discharge cracking furnace is higher than the upper limit value of the first set oxygen content range, close the damper of the material discharge cracking furnace by the second damper amplitude. After a preset time interval, if the oxygen content in the furnace of the material discharge cracking furnace is still higher than the upper limit value of the first set oxygen content range, continue to close the damper of the material discharge cracking furnace by the second damper amplitude until the oxygen content in the furnace of the material discharge cracking furnace is within the first set oxygen content range;

[0097] During the material discharge process of the material discharge cracking furnace, control the cracking furnace outlet temperature of the material discharge cracking furnace within the first set temperature range. When the cracking furnace outlet temperature of the material discharge cracking furnace is between the first furnace discharge lower limit value and the second furnace discharge lower limit value, control the fuel gas calorific value to increase by the first amplitude. After a preset time interval, if the cracking furnace outlet temperature of the material discharge cracking furnace is still between the first furnace discharge lower limit value and the second furnace discharge lower limit value, control the fuel gas calorific value to continue to increase by the first amplitude until the cracking furnace outlet temperature of the material discharge cracking furnace is within the first set temperature range. When the cracking furnace outlet temperature of the material discharge cracking furnace is lower than the second furnace discharge lower limit value, control the fuel gas calorific value to increase by the second amplitude. After a preset time interval, if the cracking furnace outlet temperature of the material discharge cracking furnace is still lower than the second furnace discharge lower limit value, control the fuel gas calorific value to continue to increase by the second amplitude until the cracking furnace outlet temperature of the material discharge cracking furnace is within the first set temperature range;

[0098] When the cracking furnace outlet temperature of the material discharge cracking furnace is between the first furnace discharge upper limit value and the second furnace discharge upper limit value, control the fuel gas calorific value to decrease by the third amplitude. After a preset time interval, if the cracking furnace outlet temperature of the material discharge cracking furnace is still between the first furnace discharge upper limit value and the second furnace discharge upper limit value, control the fuel gas calorific value to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the material discharge cracking furnace is within the first set temperature range. When the cracking furnace outlet temperature of the material discharge cracking furnace is higher than the second furnace discharge upper limit value, control the fuel gas calorific value to decrease by the fourth amplitude. After a preset time interval, if the cracking furnace outlet temperature of the material discharge cracking furnace is still higher than the second furnace discharge upper limit value, control the fuel gas calorific value to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the material discharge cracking furnace is within the first set temperature range.

[0099] Further, in a specific embodiment, the control of the key parameters of the feeding cracking furnace specifically includes:

[0100] When starting the feeding of the feeding cracking furnace, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to increase at a third set rate until the feeding is completed. At the end of the feeding, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to be adjusted to a preset dilution steam value at a fourth set rate and maintain stability;

[0101] During the feeding process of the feeding cracking furnace, control the oxygen content in the furnace of the feeding cracking furnace within a second set oxygen content range. When the oxygen content in the furnace of the feeding cracking furnace is lower than the lower limit value of the second set oxygen content range, open the damper of the feeding cracking furnace by a first damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still lower than the lower limit value of the second set oxygen content range, continue to open the damper of the feeding cracking furnace by the first damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range; when the oxygen content in the furnace of the feeding cracking furnace is higher than the upper limit value of the second set oxygen content range, close the damper of the feeding cracking furnace by a second damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, continue to close the damper of the feeding cracking furnace by the second damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range;

[0102] During the feeding process of the feeding cracking furnace, control the cracking furnace outlet temperature of the feeding cracking furnace within a second set temperature range. When the cracking furnace outlet temperature of the feeding cracking furnace is between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the fuel gas calorific value to increase by a first amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the fuel gas calorific value to continue to increase by the first amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feeding cracking furnace is lower than the first furnace feeding lower limit value, control the fuel gas calorific value to increase by a second amplitude. After a preset time interval, if the cracking furnace outlet temperature of the feeding cracking furnace is still lower than the first furnace feeding lower limit value, control the fuel gas calorific value to continue to increase by the second amplitude until the cracking furnace outlet temperature of the feeding cracking furnace is within the second set temperature range;

[0103] When the cracking furnace outlet temperature of the feedstock cracking furnace is between the first furnace feed upper limit value and the second furnace feed upper limit value, control the calorific value of the fuel gas to decrease by the third amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feedstock cracking furnace is still between the first furnace feed upper limit value and the second furnace feed upper limit value, control the calorific value of the fuel gas to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the feedstock cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feedstock cracking furnace is higher than the second furnace feed upper limit value, control the calorific value of the fuel gas to decrease by the fourth amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feedstock cracking furnace is still higher than the second furnace feed upper limit value, control the calorific value of the fuel gas to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the feedstock cracking furnace is within the second set temperature range.

[0104] The first set rate is 10 - 150 (kg / h) / min, the second set rate is 50 - 500 (kg / h) / min, the first dilution steam value is 3500 - 4500 kg / h, the second dilution steam value is 3800 - 5000 kg / h, the first set oxygen content range is 1 - 10%, the first air damper amplitude and the second air damper amplitude are 0.5 - 5%, the first set temperature range is 710 - 780 °C, the first furnace withdrawal lower limit value is the lower limit value of the first set temperature range, the second furnace withdrawal lower limit value is less than the first furnace withdrawal lower limit value and the difference between the two is 2 - 10 °C, the first furnace withdrawal upper limit value is the upper limit value of the first set temperature range, the second furnace withdrawal upper limit value is greater than the first furnace withdrawal upper limit value and the difference between the two is 2 - 10 °C, the first amplitude and the second amplitude are 0 - 0.3 MW, the third amplitude and the fourth amplitude are 0.1 - 0.6 MW;

[0105] The third set rate is 300 - 600 (kg / h) / t of feedstock, the fourth set rate is 50 - 500 (kg / h) / min, the dilution steam preset value is 3800 - 5000 kg / h, the second set oxygen content range is 1 - 6%, the second set temperature range is 780 - 880 °C, the first furnace feed lower limit value is the lower limit value of the second set temperature range, the second furnace feed lower limit value is less than the first furnace feed lower limit value and the difference between the two is 2 - 10 °C, the first furnace feed upper limit value is the upper limit value of the second set temperature range, the second furnace feed upper limit value is greater than the first furnace feed upper limit value and the difference between the two is 2 - 10 °C.

[0106] In the embodiments of the present invention, by controlling the key parameters of the discharging cracking furnace and the feeding cracking furnace during the charging and discharging process, the stability of the feeding cracking furnace and the discharging cracking furnace can be effectively ensured during the charging and discharging process, and large fluctuations in key parameters such as the single-tube dilution steam flow rate in the furnace, the outlet temperature of the cracking furnace, and the oxygen content in the furnace of the feeding cracking furnace and the discharging cracking furnace can be avoided during the charging and discharging process, resulting in instability of the feeding cracking furnace and / or the discharging cracking furnace, and further leading to instability in the load adjustment process of the cracking furnace group.

[0107] In a preferred embodiment of the load adjustment system for the automatic charging and discharging process of the ethylene cracking furnace group of the present invention, the system further includes an operation navigation function module, which is used to, during the discharging process of the discharging cracking furnace, when the damper opening of the discharging cracking furnace is less than or equal to 8-12%, and the oxygen content in the furnace of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the discharging cracking furnace is greater than or equal to 88-92%, and the oxygen content in the furnace of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05-0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1-0.3 Mpa;

[0108] During the feeding process of the feeding cracking furnace, when the damper opening of the feeding cracking furnace is less than or equal to 8-12%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the feeding cracking furnace is greater than or equal to 88-92%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05-0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1-0.3 Mpa.

[0109] In the embodiments of the present invention, by further designing the operation navigation function module, the stability and safety of the discharging cracking furnace and the feeding cracking furnace during the feeding process can be further ensured.

[0110] In a preferred embodiment of the load adjustment system for the automatic charging and discharging process of the ethylene cracking furnace group of the present invention, the system further includes a key parameter monitoring and alarm module, which is used to monitor the key charging and discharging parameters during the charging and discharging stage, and alarm when the key charging and discharging parameters exceed the preset range.

[0111] In a specific embodiment, the key parameters of charging and discharging include the outlet temperature of the cracking furnace, the carbon hydrocarbon flow rate and change rate of a single furnace tube, the total carbon hydrocarbon flow rate and change rate of the main pipe, the single-tube dilution steam flow rate, the calorific value of the fuel gas, the fuel gas pressure, the O2 content in the furnace chamber, the CO content in the cracked gas, the pressure after the Venturi tube, the opening degree of the cracking furnace damper, the dilution steam ratio, the level of the VHS steam drum, the VHS temperature, the temperature after the oil cooler, the temperature of the cracking furnace cross section, the carbon hydrocarbon raw material pressure, and the valve position rate of the raw material control valve of a single furnace tube.

[0112] In another specific embodiment, monitoring the key parameters of charging and discharging, and when the key parameters of charging and discharging exceed a preset range, an alarm is given, specifically including:

[0113] When the key parameters of charging and discharging exceed the first preset range, an alarm is given;

[0114] When the key parameters of charging and discharging exceed the second preset range, the key parameters of charging and discharging that exceed the second preset range are adjusted to within the first preset range at a preset ratio based on their current values, and an alarm is given;

[0115] Wherein, 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 ratio is ±0.1% - 10%.

[0116] In the embodiment of the present invention, by further designing the key parameter monitoring and alarm module, the stability and safety of the discharging cracking furnace and the charging cracking furnace during the charging and discharging process can be further ensured. Specifically, taking the temperature after the oil cooler among the key parameters of charging and discharging as an example, the first preset range is 200 - 208 °C, then the second preset range is 195 - 212 °C. When the key parameter monitoring and alarm module monitors that the temperature after the oil cooler is 199 °C, an alarm is given; when the key parameter monitoring and alarm module monitors that the temperature after the oil cooler is 194 °C, then the temperature after the oil cooler is expanded to within the first preset range at a ratio of 0.1% - 10% based on 194 °C, thereby improving the safety of the system during the entire charging and discharging switching process.

[0117] Further, the key parameter monitoring and alarm module can set the alarm display status according to the priority, and the alarm sound and light signals should be easily distinguishable. For example, when the temperature after the oil cooler exceeds the first preset range, a first-level alarm is adopted; when the temperature after the oil cooler exceeds the second preset range, a second-level alarm is carried out. Specifically, the first-level alarm uses yellow background with black characters, flashing, and low-frequency sound; the second-level alarm uses orange background with black characters, flashing, and medium-frequency sound. Moreover, the boundary values of the first preset range and the second preset range should not coincide with the instrument range of the alarm device of the key parameter monitoring and alarm module, and should be set within the range of 10% - 90% of the maximum instrument range.

[0118] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the system further includes an alarm optimization management module, which is used to automatically shield the instrument alarm of the feeding system and turn on the red prompt light for the feeding and discharging alarm when the feeding load of the cracking furnace is less than 65 - 75% of the design load; when the feeding load is greater than 65 - 75% of the design load, it automatically enables the instrument alarm of the feeding system and turns on the green prompt light for the feeding and discharging alarm.

[0119] In a specific embodiment, the types of the instrument alarm of the feeding system include total discharging amount alarm, liquid-phase discharging flow alarm of the cracking furnace, gas-phase discharging flow alarm of the cracking furnace, discharging interlock pressure alarm, DMDS force alarm, DMDS flow alarm, anti-coking steam pressure difference alarm, cracking furnace outlet temperature alarm, cross-section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, cracking gas analysis indication alarm, cross-section flue gas oxygen content alarm, fuel heat load ratio alarm, low liquid raw material flow alarm in the furnace tube, and low gas raw material pressure alarm.

[0120] In the embodiment of the present invention, by further designing the alarm optimization management module, it can effectively avoid frequent false alarms during the feeding and discharging processes of the feeding cracking furnace and the discharging cracking furnace, which may affect the efficiency.

[0121] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the system further includes a deep learning function module, which is used to learn the control advantages and disadvantages of the key parameters of the discharging cracking furnace and the feeding cracking furnace based on empirical values and big data, and derive the optimal control values of the key parameters of the discharging cracking furnace and the feeding cracking furnace. Thus, by further optimizing the control advantages and disadvantages of the key parameters, the stability of the discharging cracking furnace and the feeding cracking furnace during the feeding and discharging process can be improved, and further the stability during the load switching adjustment process of the cracking furnace group can be improved.

[0122] In a preferred embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group according to the present invention, the system further includes a parameter setting module for setting the rate parameters and key parameters of the discharging cracking furnace and the feeding cracking furnace, so that in actual production, the operator can set each rate parameter, key parameter, and the allowable deviation or upper and lower limit range values of each parameter according to the actual production needs.

[0123] In a specific embodiment of the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group according to the present invention, the system is composed of a human-machine interaction interface and a program control system, so as to realize online control through a combined method based on the field distributed control system (DCS) configuration and the upper computer server programming. At the same time, in order to realize the automatic execution of the automatic feeding and discharging process of the ethylene cracking furnace group, an independent server needs to be deployed on the industrial control network. The program for the switching process of the ethylene cracking furnace feeding and discharging obtains relevant parameter values or states through the OPC server OPC DA interface of Emerson DCS for data interaction. In order to ensure the safe operation of the DCS system, an industrial firewall is added between the system server and the communication interface. By configuring corresponding rule policies, deep isolation and protection of the DCS control system are realized, the virus transmission path is cut off, and the normal, safe and stable operation of the device DCS production control system is ensured. The industrial firewall incorporates private communication protocols of multiple mainstream automation product manufacturers, enabling seamless access to various mainstream automation products such as Honeywell DCS, Yokogawa DCS, Emerson DCS, etc., as well as servers or databases such as OPC SERVER, IP21 / PHD / PI.

[0124] Among them, the interface of the human-machine interaction interface is designed with function buttons such as "parameter setting", "cracking furnace status confirmation", "program running", "running pause", "running continue", "running stop", "parameter alarm", etc. to realize the human-machine interaction function. Specifically, in the actual use process, clicking the "parameter setting" button can manually set the control threshold of the program key parameters and the preset upper and lower limit values of the key parameters, etc.; clicking the "cracking furnace status confirmation" button completes the status confirmation work before the feeding and discharging switch, and the interface jumps to the feeding and discharging operation interface, otherwise the feeding and discharging switch program cannot run; clicking the "program running" button, the feeding and discharging switch program starts to run; clicking "pause", the system stops the next step of the program, and the control values of each parameter of the feeding and discharging switch program remain the current values. Clicking "continue", the program will continue according to the current execution steps; manually clicking "stop", the system stops the automatic feeding and discharging switch program of the cracking furnace and switches to manual operation; clicking the "alarm button", the human-machine interaction interface switches to the alarm interface, where the system alarm situation can be viewed in detail, and at the same time, it is possible to select whether to enable the alarm shielding function during the feeding and discharging switch process according to needs.

[0125] Furthermore, the human-machine interaction interface function also includes system operation status display, system operation buttons, key parameter trend charts, and system alarm prompt information. Among them, for function buttons such as "Run", "Stop", "Pause", "Continue", and "Parameter Setting" designed on the human-machine interaction interface, during the system operation, users can execute the above function buttons at any time according to the actual operation conditions of the ethylene plant and the compressor.

[0126] The second aspect of the present invention provides a load adjustment method for the automatic feeding and discharging process of an ethylene cracking furnace group. This method is implemented using the described system, and the method includes:

[0127] The feed load acquisition module continuously obtains the feed load of each cracking furnace, and based on the feed load of each cracking furnace, obtains the remaining feeding load of each cracking furnace, selects the discharging cracking furnace, and selects the feeding cracking furnace group according to the feed load of the discharging cracking furnace and the remaining feeding loads of other cracking furnaces;

[0128] The load adjustment control module for the feeding and discharging process controls the discharging cracking furnace to discharge materials according to the feed load of the discharging cracking furnace, and during the process of controlling the discharging cracking furnace to discharge materials, simultaneously controls the selected feeding cracking furnace group to feed materials;

[0129] The feeding and discharging execution module performs feeding and discharging according to the control instructions of the load adjustment control module for the feeding and discharging process.

[0130] In the actual application process of the load adjustment method for the automatic feeding and discharging process of the ethylene cracking furnace group described in the present invention, by using the feed load acquisition module and the load adjustment control module for the feeding and discharging process in cooperation, the load stability of the cracking furnace group during the feeding and discharging process can be effectively improved.

[0131] The present invention will be described in detail below through embodiments, but the protection scope of the present invention is not limited thereto.

[0132] Embodiment 1

[0133] Based on an ethylene plant with a production capacity of 1 million tons per year, among which the production capacities of cracking furnaces No. 1 to No. 6 are 140,000 tons per year, and the production capacity of furnace No. 7 is 200,000 tons per year. The load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group as described in the present invention is implemented as shown in Figure 1 Specifically, the described system includes:

[0134] The feed load acquisition module is used to continuously obtain the feed load of each cracking furnace, and based on the feed load of each cracking furnace, obtain the remaining feeding load of each cracking furnace, select the discharging cracking furnace, and select the feeding cracking furnace group according to the feed load of the discharging cracking furnace and the remaining feeding loads of other cracking furnaces;

[0135] The feed withdrawal and feeding process load adjustment control module is used to control the feed withdrawal cracking furnace to perform feed withdrawal according to the feed load of the feed withdrawal cracking furnace, and during the process of controlling the feed withdrawal cracking furnace to perform feed withdrawal, simultaneously control the selected feeding cracking furnace group to perform feeding;

[0136] The feed withdrawal and feeding execution module is used to perform feed withdrawal and feeding according to the control instructions of the feed withdrawal and feeding process load adjustment control module.

[0137] Specifically, the system further includes a pre-feed withdrawal and feeding status confirmation module, which is used to confirm the initial status of the feed withdrawal cracking furnace and the feeding cracking furnace before feed withdrawal and feeding;

[0138] The confirmation of the initial status of the feed withdrawal cracking furnace before feed withdrawal and feeding specifically includes:

[0139] Confirm the initial feed withdrawal parameters of the feed withdrawal cracking furnace, and when the initial feed withdrawal parameters are within the initial range, indicate that feed withdrawal can be performed. When the initial feed withdrawal parameters are not within the initial range, alarm for one or more of the initial feed withdrawal parameters that are not within the initial range.

[0140] The initial feed withdrawal parameters include sulfur injection amount, cracking furnace outlet temperature, and ultra-high pressure steam temperature;

[0141] Among them, the initial range of the sulfur injection amount is 2 - 5 kg / h, the initial range of the cracking furnace outlet temperature is 730 - 750 °C, and the initial range of the ultra-high pressure steam temperature is 505 - 520 °C.

[0142] The confirmation of the initial status of the feeding cracking furnace before feed withdrawal and feeding specifically includes:

[0143] Confirm the initial feeding parameters of the feeding cracking furnace, and when the initial feeding parameters are within the initial range, indicate that feeding can be performed. When the initial feeding parameters are not within the initial range, alarm for one or more of the initial feeding parameters that are not within the initial range.

[0144] The initial feeding parameters include quench oil temperature, pressure after the venturi tube, cracking furnace outlet temperature, and ultra-high pressure steam temperature;

[0145] Among them, the initial range of the quench oil temperature is 190 - 210 °C, the initial range of the pressure after the venturi tube is 0.04 - 0.1 MPa, the initial range of the cracking furnace outlet temperature is 780 °C - 860 °C, and the initial range of the ultra-high pressure steam temperature is 480 - 510 °C.

[0146] Before the feed withdrawal cracking furnace and the feeding cracking furnace are switched, the DCS is in the "running" state, the CSL is in the "running" state, and the cracking furnace is in the "full furnace" mode.

[0147] The system further includes a control performance evaluation module, which is used to collect the loop information of the cracking furnace in real time before and during the feeding and discharging process, evaluate the control loop performance of the cracking furnace according to the loop information, and give an alarm when the control loop performance of the cracking furnace is abnormal. The feeding load acquisition module is also used to replace one or more feeding cracking furnaces in the feeding cracking furnace group during the feeding and discharging process.

[0148] Controlling the discharging cracking furnace to discharge materials according to the feeding load of the discharging cracking furnace specifically includes:

[0149] In the first discharging stage, discharge materials through the furnace header of the discharging cracking furnace at a first discharging rate until the first discharging value is reached, and maintain the set time stably;

[0150] In the second discharging stage, discharge materials through the single furnace tubes of the discharging cracking furnace at a second discharging rate until the second discharging value is reached, and maintain the set time stably;

[0151] In the third discharging stage, discharge all the remaining materials to be discharged through the control valve of the single furnace tube of the discharging cracking furnace at a valve position rate.

[0152] The first discharging value is 60-80% of the feeding load of the discharging cracking furnace, the second discharging value is 20-45% of the feeding load of the discharging cracking furnace, and the set time is 0-20 min; the first discharging rate is 50-500 (kg / h) / min, the second discharging rate is 20-300 (kg / h) / min, and the valve position rate is 0.5-10% / min.

[0153] During the process of controlling the discharging cracking furnace to discharge materials, the selected feeding cracking furnace group is controlled to feed materials simultaneously, specifically including:

[0154] In the first discharging stage and the second discharging stage, control the feeding cracking furnaces in the selected feeding cracking furnace group to feed materials through the feeding model; in the third discharging stage, control the feeding through the control valve of the single furnace tube of the feeding cracking furnace.

[0155] The feeding model includes:

[0156]

[0157]

[0158] Wherein, V 组投 is the feeding rate of the feeding cracking furnace group, V 单投 is the feeding rate of a single feeding cracking furnace, V 退 is the discharging rate of the discharging cracking furnace, F 组投 is the feeding amount of the feeding cracking furnace group单投 is the feeding rate of a single feeding cracking furnace, F 退 is the discharging rate of the discharging cracking furnace.

[0159] In the actual application process, taking naphtha as the type of feedstock oil as an example, first, the feed load acquisition module obtains the feed loads of cracking furnaces No. 1 - 7 in real time, and obtains the remaining feeding loads of each cracking furnace according to the feed loads of each cracking furnace. Cracking furnace No. 1 is selected as the discharging cracking furnace, and based on the feed load of cracking furnace No. 1 being 28000 kg / h and the remaining feeding loads of cracking furnaces No. 3, 6, and 7 being 8000 kg / h, 9000 kg / h, and 11000 kg / h respectively, cracking furnaces No. 3, 6, and 7 are selected to form a feeding cracking furnace group; then, the initial discharging parameters of the discharging cracking furnace and the initial feeding parameters of the feeding cracking furnace are confirmed respectively. Specifically, the sulfur injection amount of the discharging cracking furnace is 3 kg / h, the cracking furnace outlet temperature is 740 °C, the ultra - high - pressure steam temperature is 510 °C, the quenching oil temperature of the feeding cracking furnace is 200 °C, the pressure after the Venturi tube is 0.09 MPa, the cracking furnace outlet temperature is 820 °C, the ultra - high - pressure steam temperature is 500 °C, and the control performance evaluation module confirms that the control loops of each cracking furnace are normal; then the feeding and discharging process starts. Specifically, in the first discharging stage, the discharging is carried out through the furnace header of the discharging cracking furnace at a rate of 200 kg / h until 70% of the feed load of the discharging cracking furnace, that is, 19600 kg / h, and it is stabilized for 2 min; in the second discharging stage, the discharging is carried out through the single furnace tube of the discharging cracking furnace at a rate of 50 kg / h until 30% of the feed load of the discharging cracking furnace, that is, 8400 kg / h, and it is stabilized for 2 min; in the third discharging stage, the remaining material to be discharged is all discharged through the single furnace tube control valve of the discharging cracking furnace at a rate of 2% / min; meanwhile, during the feeding and discharging process load adjustment control module, in the first discharging stage, when the discharging rate of the furnace header of the discharging cracking furnace is 200 kg / h, the feeding rates of cracking furnaces No. 3, 6, and 7 are controlled to be 57.1 (kg / h) / min, 64.3 (kg / h) / min, and 78.6 (kg / h) / min respectively. In the second discharging stage, it is calculated with reference to the first discharging stage. In the third discharging stage, the discharging cracking furnace discharges materials through valve position control. During this process, the feeding rate of the feeding cracking furnace is based on the discharging cracking furnace. When it is detected that the discharging amount of the discharging cracking furnace is an integer n times of 100 kg / h, the feeding amount of the feeding cracking furnace increases by the corresponding 100(n + 1) kg / h to keep the feeding and discharging amounts consistent until the feeding and discharging are completed and the switching is finished.

[0160] After detection, by using the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group described in the present invention, the synchronous progress of the feeding and discharging process is achieved. Moreover, during the entire feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group never exceeds 800 kg / h. It has the advantages of high feeding and discharging accuracy, high load adjustment and switching efficiency of the cracking furnace group, and high stability.

[0161] Example 2

[0162] Implemented with reference to Example 1. The difference is that this system further includes a key parameter control module for controlling the key parameters of the discharging cracking furnace and the feeding cracking furnace during the feeding and discharging process. Among them, the key parameters include the single-tube dilution steam flow rate in the furnace chamber, the cracking furnace outlet temperature, and the oxygen content in the furnace chamber. The control of the key parameters of the discharging cracking furnace specifically includes:

[0163] When the discharging cracking furnace starts to discharge, control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to rise to the first dilution steam value at the first set rate and remain constant. When the feeding and discharging process ends, then control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to rise from the first dilution steam value to the second dilution steam value at the second set rate and remain stable.

[0164] During the discharging process of the discharging cracking furnace, control the oxygen content in the furnace chamber of the discharging cracking furnace within the first set oxygen content range. When the oxygen content in the furnace chamber of the discharging cracking furnace is lower than the lower limit value of the first set oxygen content range, open the damper of the discharging cracking furnace by the first damper amplitude. After an interval of the preset time, if the oxygen content in the furnace chamber of the discharging cracking furnace is still lower than the lower limit value of the first set oxygen content range, continue to open the damper of the discharging cracking furnace by the first damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range. When the oxygen content in the furnace chamber of the discharging cracking furnace is higher than the upper limit value of the first set oxygen content range, close the damper of the discharging cracking furnace by the second damper amplitude. After an interval of the first preset time, if the oxygen content in the furnace chamber of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, continue to close the damper of the discharging cracking furnace by the second damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range.

[0165] During the material withdrawal process of the material withdrawal cracking furnace, control the cracking furnace outlet temperature of the material withdrawal cracking furnace within the first set temperature range. When the cracking furnace outlet temperature of the material withdrawal cracking furnace is between the first furnace withdrawal lower limit value and the second furnace withdrawal lower limit value, control the fuel gas calorific value to increase by the first amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still between the first furnace withdrawal lower limit value and the second furnace withdrawal lower limit value, control the fuel gas calorific value to continue to increase by the first amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range; when the cracking furnace outlet temperature of the material withdrawal cracking furnace is lower than the second furnace withdrawal lower limit value, control the fuel gas calorific value to increase by the second amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still lower than the second furnace withdrawal lower limit value, control the fuel gas calorific value to continue to increase by the second amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range;

[0166] When the cracking furnace outlet temperature of the material withdrawal cracking furnace is between the first furnace withdrawal upper limit value and the second furnace withdrawal upper limit value, control the fuel gas calorific value to decrease by the third amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still between the first furnace withdrawal upper limit value and the second furnace withdrawal upper limit value, control the fuel gas calorific value to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range; when the cracking furnace outlet temperature of the material withdrawal cracking furnace is higher than the second furnace withdrawal upper limit value, control the fuel gas calorific value to decrease by the fourth amplitude. After an interval of the preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still higher than the second furnace withdrawal upper limit value, control the fuel gas calorific value to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range;

[0167] The control of the key parameters of the feeding cracking furnace specifically includes:

[0168] When the feeding cracking furnace starts feeding, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to increase at the third set rate until the feeding ends. At the end of the feeding, control the single-tube dilution steam flow rate in the furnace of the feeding cracking furnace to be adjusted to the preset dilution steam value at the fourth set rate and keep it stable;

[0169] During the feeding process of the feeding cracking furnace, control the oxygen content in the furnace of the feeding cracking furnace within the second set oxygen content range. When the oxygen content in the furnace of the feeding cracking furnace is lower than the lower limit value of the second set oxygen content range, open the damper of the feeding cracking furnace by the first damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still lower than the lower limit value of the second set oxygen content range, continue to open the damper of the feeding cracking furnace by the first damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range. When the oxygen content in the furnace of the feeding cracking furnace is higher than the upper limit value of the second set oxygen content range, close the damper of the feeding cracking furnace by the second damper amplitude. After a preset time interval, if the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, continue to close the damper of the feeding cracking furnace by the second damper amplitude until the oxygen content in the furnace of the feeding cracking furnace is within the second set oxygen content range.

[0170] During the feeding process of the feeding cracking furnace, control the outlet temperature of the cracking furnace of the feeding cracking furnace within the second set temperature range. When the outlet temperature of the cracking furnace of the feeding cracking furnace is between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the calorific value of the fuel gas to increase by the first amplitude. After a preset time interval, if the outlet temperature of the cracking furnace of the feeding cracking furnace is still between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the calorific value of the fuel gas to continue to increase by the first amplitude until the outlet temperature of the cracking furnace of the feeding cracking furnace is within the second set temperature range. When the outlet temperature of the cracking furnace of the feeding cracking furnace is lower than the first furnace feeding lower limit value, control the calorific value of the fuel gas to increase by the second amplitude. After a preset time interval, if the outlet temperature of the cracking furnace of the feeding cracking furnace is still lower than the first furnace feeding lower limit value, control the calorific value of the fuel gas to continue to increase by the second amplitude until the outlet temperature of the cracking furnace of the feeding cracking furnace is within the second set temperature range.

[0171] When the outlet temperature of the cracking furnace of the feeding cracking furnace is between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the calorific value of the fuel gas to decrease by the third amplitude. After a preset time interval, if the outlet temperature of the cracking furnace of the feeding cracking furnace is still between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the calorific value of the fuel gas to continue to decrease by the third amplitude until the outlet temperature of the cracking furnace of the feeding cracking furnace is within the second set temperature range. When the outlet temperature of the cracking furnace of the feeding cracking furnace is higher than the second furnace feeding upper limit value, control the calorific value of the fuel gas to decrease by the fourth amplitude. After a preset time interval, if the outlet temperature of the cracking furnace of the feeding cracking furnace is still higher than the second furnace feeding upper limit value, control the calorific value of the fuel gas to continue to decrease by the fourth amplitude until the outlet temperature of the cracking furnace of the feeding cracking furnace is within the second set temperature range.

[0172] Specifically, the first set rate is 20 (kg / h) / min, the second set rate is 100 (kg / h) / min, the first dilution steam value is 4000 kg / h, the second dilution steam value is 4500 kg / h, the first set oxygen content range is 2 - 3.5%, the first and second damper amplitudes are 2%, the first set temperature range is 730 - 740 °C, the first furnace withdrawal lower limit is 730 °C, the second furnace withdrawal lower limit is 725 °C, the first furnace withdrawal upper limit is 740 °C, the second furnace withdrawal upper limit is 745 °C, the first amplitude is 0.1 MW, the second amplitude is 0.2 MW, the third amplitude is 0.15 MW, and the fourth amplitude is 0.3 MW;

[0173] The third set rate is 450 (kg / h) / t for feeding, the fourth set rate is 200 (kg / h) / min, the preset value of dilution steam is 4500 kg / h, the second set oxygen content range is 1.8 - 2.8%, the second set temperature range is 815 - 825 °C, the first furnace charging lower limit is 815 °C, the second furnace charging lower limit is 810 °C, the first furnace charging upper limit is 825 °C, and the second furnace charging upper limit is 830 °C.

[0174] After testing, by using the load adjustment system for the automatic feeding and withdrawal process of the ethylene cracking furnace group of the present invention, the synchronization of the feeding and withdrawal processes is achieved. And during the entire feeding and withdrawal process, the difference between the withdrawal amount of the withdrawal cracking furnace and the feeding amount of the feeding cracking furnace group never exceeds 650 kg / h. It has the advantages of small fluctuations in key parameters, high safety, higher feeding and withdrawal accuracy, high efficiency in load adjustment and switching of the cracking furnace group, and higher stability.

[0175] Example 3

[0176] Implemented with reference to Example 2, the difference is that this system further includes an operation navigation function module, which is used to, during the withdrawal process of the withdrawal cracking furnace, when the damper opening of the withdrawal cracking furnace is less than or equal to 10% and the oxygen content in the furnace chamber of the withdrawal cracking furnace is still higher than the upper limit of the first set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the withdrawal cracking furnace is greater than or equal to 90% and the oxygen content in the furnace chamber of the withdrawal cracking furnace is still higher than the upper limit of the first set oxygen content range, then stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1 - 0.3 Mpa;

[0177] During the feeding process of the feeding cracking furnace, when the damper opening of the feeding cracking furnace is less than or equal to 10%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the feeding cracking furnace is greater than or equal to 90%, and the oxygen content in the furnace of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening, and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1 - 0.3 Mpa.

[0178] After testing, the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group described in the present invention realizes the synchronous progress of the feeding and discharging process. And during the whole feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group always does not exceed 650 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0179] Example 4

[0180] Implemented with reference to Example 3, the difference is that the system further includes a key parameter monitoring and alarm module, which is used to monitor the key parameters of feeding and discharging during the feeding and discharging stage, and alarm when the key parameters of feeding and discharging exceed the preset range. The key parameters of feeding and discharging include the cracking furnace outlet temperature, the carbon hydrocarbon flow rate and change rate of a single furnace tube, the total carbon hydrocarbon flow rate and change rate of the main pipe, the single tube dilution steam flow rate, the calorific value of the fuel gas, the fuel gas pressure, the furnace O2 content, the CO content in the cracked gas, the pressure after the Venturi tube, the cracking furnace damper opening, the dilution steam ratio, the VHS steam drum liquid level, the VHS temperature, the temperature after the oil cooler, the cracking furnace cross-section temperature, the carbon hydrocarbon raw material pressure, and the valve position rate of the raw material control valve of a single furnace tube.

[0181] After testing, the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group described in the present invention realizes the synchronous progress of the feeding and discharging process. And during the whole feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group always does not exceed 630 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0182] Example 5

[0183] Implemented with reference to Example 4, the difference is that monitoring the key parameters of feeding and discharging and alarming when the key parameters of feeding and discharging exceed the preset range specifically include:

[0184] When the key feeding / discharging parameters exceed the first preset range, an alarm is given.

[0185] When the key feeding / discharging parameters exceed the second preset range, the key feeding / discharging parameters that exceed the second preset range are adjusted to within the first preset range at a preset ratio based on their current values, and an alarm is given.

[0186] Wherein, 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 ratio is ±2%.

[0187] Through detection, by using the load adjustment system for the automatic feeding / discharging process of the ethylene cracking furnace group of the present invention, the synchronous progress of the feeding / discharging process is realized, and during the entire feeding / discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group always does not exceed 550 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding / discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0188] Example 6

[0189] Implemented with reference to Example 5, the difference is that this system further includes an alarm optimization management module, which is used to automatically shield the instrument alarm of the feeding system and turn on the red prompt light for the feeding / discharging alarm when the feeding load of the cracking furnace is less than 65-75% of the design load; when the feeding load is greater than 65-75% of the design load, automatically enable the instrument alarm of the feeding system and turn on the green prompt light for the feeding / discharging alarm. The types of the instrument alarm of the feeding system include total discharging amount alarm, liquid-phase discharging flow alarm of the cracking furnace, gas-phase discharging flow alarm of the cracking furnace, discharging interlock pressure alarm, DMDS force alarm, DMDS flow alarm, anti-coking steam pressure difference alarm, cracking furnace outlet temperature alarm, cross-section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, cracking gas analysis indication alarm, cross-section flue gas oxygen content alarm, fuel heat load ratio alarm, low flow alarm of furnace tube liquid raw material, and low pressure alarm of gas raw material.

[0190] Through detection, by using the load adjustment system for the automatic feeding / discharging process of the ethylene cracking furnace group of the present invention, the synchronous progress of the feeding / discharging process is realized, and during the entire feeding / discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group always does not exceed 550 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding / discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0191] Example 7

[0192] Implemented with reference to Example 6, except that the system further includes a deep learning function module for learning the control advantages and disadvantages of the key parameters of the discharging cracking furnace and the feeding cracking furnace based on empirical values and big data, and deriving the optimal control values of the key parameters of the discharging cracking furnace and the feeding cracking furnace.

[0193] After testing, the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention realizes the synchronous progress of the feeding and discharging process. And during the entire feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group is always not more than 500 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0194] Example 8

[0195] Implemented with reference to Example 7, except that the first discharging value is 66% of the feeding load of the discharging cracking furnace, the second discharging value is 25% of the feeding load of the discharging cracking furnace, and the set time is 3 min; the first discharging rate is 240 (kg / h) / min, the second discharging rate is 60 (kg / h) / min, and the valve position rate is 1.5% / min.

[0196] After testing, the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention realizes the synchronous progress of the feeding and discharging process. And during the entire feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group is always not more than 500 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0197] Example 9

[0198] Implemented with reference to Example 7, except that the first discharging value is 60% of the feeding load of the discharging cracking furnace, the second discharging value is 20% of the feeding load of the discharging cracking furnace, and the set time is 1.5 min; the first discharging rate is 300 (kg / h) / min, the second discharging rate is 40 (kg / h) / min, and the valve position rate is 1.2% / min.

[0199] After testing, the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention realizes the synchronous progress of the feeding and discharging process. And during the entire feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group is always not more than 500 kg / h, having the advantages of small fluctuations in key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group, and higher stability.

[0200] Example 10

[0201] It was implemented with reference to Example 7, except that the remaining feeding loads of cracking furnaces No. 3, No. 6 and No. 7 were 7000 kg / h, 8000 kg / h and 10000 kg / h respectively.

[0202] After testing, by using the load adjustment system for the automatic feeding and discharging process of the ethylene cracking furnace group of the present invention, the synchronous progress of the feeding and discharging process was achieved. And during the whole feeding and discharging process, the difference between the discharging amount of the discharging cracking furnace and the feeding amount of the feeding cracking furnace group was always not more than 500 kg / h + ΔQ, where ΔQ was the difference between the feeding load of cracking furnace No. 1 and the sum of the remaining feeding loads of cracking furnaces No. 3, No. 6 and No. 7. It had the advantages of small fluctuations of key parameters, higher safety, higher feeding and discharging accuracy, higher load adjustment and switching efficiency of the cracking furnace group and higher stability.

[0203] The load adjustment system and method for the automatic feeding and discharging process of the ethylene cracking furnace group provided by the present invention can effectively improve the load stability of the cracking furnace group during the feeding and discharging process by the combined use of the feeding load acquisition module and the load adjustment control module for the feeding and discharging process.

[0204] 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 technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. To avoid unnecessary repetition, the present invention does not separately describe various possible combinations. But these simple modifications and combinations should also be regarded as the content disclosed by the present invention and all fall within the protection scope of the present invention.

Claims

1. A load adjustment system for the automatic feeding and discharging process of an ethylene cracking furnace group, characterized in that The system includes: A feed load acquisition module, which is used to acquire the feed load of each cracking furnace in real time, obtain the remaining feeding load of each cracking furnace according to the feed load of each cracking furnace, select the furnace for discharging materials, and select a group of furnaces for feeding materials according to the feed load of the furnace for discharging materials and the remaining feeding loads of other cracking furnaces; A feeding and discharging process load adjustment and control module, which is used to control the furnace for discharging materials to discharge materials according to the feed load of the furnace for discharging materials, and during the process of controlling the furnace for discharging materials to discharge materials, simultaneously control the selected group of furnaces for feeding materials to feed materials; A feeding and discharging execution module, which is used to perform feeding and discharging according to the control instructions of the feeding and discharging process load adjustment and control module.

2. The system according to claim 1, wherein The controlling the furnace for discharging materials to discharge materials according to the feed load of the furnace for discharging materials specifically includes: In the first discharging stage, discharging materials through the main furnace tube of the furnace for discharging materials at a first discharging rate to a first discharging value, and stabilizing for a set time; In the second discharging stage, discharging materials through the single furnace tubes of the furnace for discharging materials at a second discharging rate to a second discharging value, and stabilizing the set time; In the third discharging stage, discharging all the remaining materials to be discharged through the control valve of the single furnace tube of the furnace for discharging materials at a valve position rate.

3. The system according to claim 2, wherein The first discharging value is 60-80% of the feed load of the furnace for discharging materials, the second discharging value is 20-45% of the feed load of the furnace for discharging materials, and the set time is 0-20 min; the first discharging rate is 50-500 (kg / h) / min, the second discharging rate is 20-300 (kg / h) / min, and the valve position rate is 0.5-10% / min.

4. The system according to any one of claims 1 to 3, characterized in that, The system further includes a feeding and discharging pre-state confirmation module, which is used to confirm the initial states of the furnace for discharging materials and the furnaces for feeding materials before feeding and discharging; The confirming the initial state of the furnace for discharging materials before feeding and discharging specifically includes: Confirming the initial discharging parameters of the furnace for discharging materials, and when the initial discharging parameters are within the initial range, indicating that discharging can be carried out, and when the initial discharging parameters are not within the initial range, alarming one or more of the initial discharging parameters that are not within the initial range.

5. The system according to claim 4, characterized in that, The initial discharging parameters include the sulfur injection amount, the cracking furnace outlet temperature, and the ultra-high pressure steam temperature; Among them, the initial range of the sulfur injection amount is 2-5 kg / h, the initial range of the cracking furnace outlet temperature is 730-750 °C, and the initial range of the ultra-high pressure steam temperature is 505-520 °C.

6. The system according to claim 2 or 5, characterized in that, The simultaneously controlling the selected group of furnaces for feeding materials to feed materials during the process of controlling the furnace for discharging materials to discharge materials specifically includes: In the first discharging stage and the second discharging stage, controlling the furnaces for feeding materials in the selected group of furnaces for feeding materials to feed materials through a feeding model; in the third discharging stage, feeding materials by controlling the control valve of the single furnace tube of the furnace for feeding materials.

7. The system according to claim 6, wherein The feeding model includes: Among them, V 组投 is the feeding rate of the feeding cracking furnace group, V 单投 is the feeding rate of a single feeding cracking furnace, V 退 is the discharging rate of the discharging cracking furnace, F 组投 is the feeding amount of the feeding cracking furnace group, F 单投 is the feeding amount of a single feeding cracking furnace, F 退 is the discharging amount of the discharging cracking furnace.

8. The system according to claim 4, wherein The confirming the initial state of the furnace for feeding materials before feeding and discharging specifically includes: Confirm the initial feeding parameters of the feeding cracking furnace. When the initial feeding parameters are within the initial range, indicate that feeding can be carried out. When the initial feeding parameters are not within the initial range, alarm one or more of the initial feeding parameters that are not within the initial range.

9. The system according to claim 8, wherein The initial feeding parameters include the quench oil temperature, the pressure after the Venturi tube, the cracking furnace outlet temperature, and the ultra-high pressure steam temperature. Among them, the initial range of the quench oil temperature is 190 - 210 °C, the initial range of the pressure after the Venturi tube is 0.04 - 0.1 MPa, the initial range of the cracking furnace outlet temperature is 780 °C - 860 °C, and the initial range of the ultra-high pressure steam temperature is 480 - 510 °C.

10. The system according to claim 1, wherein, This system also includes a key parameter control module for controlling the key parameters of the discharging cracking furnace and the feeding cracking furnace during the charging and discharging process. Among them, the key parameters include the single-tube dilution steam flow rate in the furnace chamber, the cracking furnace outlet temperature, and the oxygen content in the furnace chamber.

11. The system according to claim 10, wherein The control of the key parameters of the discharging cracking furnace specifically includes: When the discharging of the discharging cracking furnace starts, control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to increase to a first dilution steam value at a first set rate and remain constant; when the charging and discharging process ends, then control the single-tube dilution steam flow rate in the furnace chamber of the discharging cracking furnace to increase from the first dilution steam value to a second dilution steam value at a second set rate and remain stable. During the discharging process of the discharging cracking furnace, control the oxygen content in the furnace chamber of the discharging cracking furnace within a first set oxygen content range. When the oxygen content in the furnace chamber of the discharging cracking furnace is lower than the lower limit value of the first set oxygen content range, open the damper of the discharging cracking furnace by a first damper amplitude. After a preset time interval, if the oxygen content in the furnace chamber of the discharging cracking furnace is still lower than the lower limit value of the first set oxygen content range, continue to open the damper of the discharging cracking furnace by the first damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range; when the oxygen content in the furnace chamber of the discharging cracking furnace is higher than the upper limit value of the first set oxygen content range, close the damper of the discharging cracking furnace by a second damper amplitude. After a preset time interval, if the oxygen content in the furnace chamber of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, continue to close the damper of the discharging cracking furnace by the second damper amplitude until the oxygen content in the furnace chamber of the discharging cracking furnace is within the first set oxygen content range. During the material withdrawal process of the material withdrawal cracking furnace, control the cracking furnace outlet temperature of the material withdrawal cracking furnace within the first set temperature range. When the cracking furnace outlet temperature of the material withdrawal cracking furnace is between the first furnace withdrawal lower limit value and the second furnace withdrawal lower limit value, control the calorific value of the fuel gas to increase by the first amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still between the first furnace withdrawal lower limit value and the second furnace withdrawal lower limit value, control the calorific value of the fuel gas to continue to increase by the first amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range; when the cracking furnace outlet temperature of the material withdrawal cracking furnace is lower than the second furnace withdrawal lower limit value, control the calorific value of the fuel gas to increase by the second amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still lower than the second furnace withdrawal lower limit value, control the calorific value of the fuel gas to continue to increase by the second amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range; When the cracking furnace outlet temperature of the material withdrawal cracking furnace is between the first furnace withdrawal upper limit value and the second furnace withdrawal upper limit value, control the calorific value of the fuel gas to decrease by the third amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still between the first furnace withdrawal upper limit value and the second furnace withdrawal upper limit value, control the calorific value of the fuel gas to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range; when the cracking furnace outlet temperature of the material withdrawal cracking furnace is higher than the second furnace withdrawal upper limit value, control the calorific value of the fuel gas to decrease by the fourth amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the material withdrawal cracking furnace is still higher than the second furnace withdrawal upper limit value, control the calorific value of the fuel gas to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the material withdrawal cracking furnace is within the first set temperature range.

12. The system according to claim 11, wherein The control of the key parameters of the feedstock cracking furnace specifically includes: When starting to feed the feedstock cracking furnace, control the single-tube dilution steam flow rate in the furnace of the feedstock cracking furnace to increase at the third set rate until the feeding is completed. At the end of the feeding, control the single-tube dilution steam flow rate in the furnace of the feedstock cracking furnace to be adjusted to the preset dilution steam value at the fourth set rate and keep it stable; During the feeding process of the feedstock cracking furnace, control the oxygen content in the furnace of the feedstock cracking furnace within the second set oxygen content range. When the oxygen content in the furnace of the feedstock cracking furnace is lower than the lower limit value of the second set oxygen content range, open the damper of the feedstock cracking furnace by the first damper amplitude. After an interval of a preset time, if the oxygen content in the furnace of the feedstock cracking furnace is still lower than the lower limit value of the second set oxygen content range, continue to open the damper of the feedstock cracking furnace by the first damper amplitude until the oxygen content in the furnace of the feedstock cracking furnace is within the second set oxygen content range; when the oxygen content in the furnace of the feedstock cracking furnace is higher than the upper limit value of the second set oxygen content range, close the damper of the feedstock cracking furnace by the second damper amplitude. After an interval of a preset time, if the oxygen content in the furnace of the feedstock cracking furnace is still higher than the upper limit value of the second set oxygen content range, continue to close the damper of the feedstock cracking furnace by the second damper amplitude until the oxygen content in the furnace of the feedstock cracking furnace is within the second set oxygen content range; During the feeding process of the feed cracking furnace, control the cracking furnace outlet temperature of the feed cracking furnace within the second set temperature range. When the cracking furnace outlet temperature of the feed cracking furnace is between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the calorific value of the fuel gas to increase by the first amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feed cracking furnace is still between the first furnace feeding lower limit value and the first furnace feeding lower limit value, control the calorific value of the fuel gas to continue to increase by the first amplitude until the cracking furnace outlet temperature of the feed cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feed cracking furnace is lower than the first furnace feeding lower limit value, control the calorific value of the fuel gas to increase by the second amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feed cracking furnace is still lower than the first furnace feeding lower limit value, control the calorific value of the fuel gas to continue to increase by the second amplitude until the cracking furnace outlet temperature of the feed cracking furnace is within the second set temperature range; When the cracking furnace outlet temperature of the feed cracking furnace is between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the calorific value of the fuel gas to decrease by the third amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feed cracking furnace is still between the first furnace feeding upper limit value and the second furnace feeding upper limit value, control the calorific value of the fuel gas to continue to decrease by the third amplitude until the cracking furnace outlet temperature of the feed cracking furnace is within the second set temperature range; when the cracking furnace outlet temperature of the feed cracking furnace is higher than the second furnace feeding upper limit value, control the calorific value of the fuel gas to decrease by the fourth amplitude. After an interval of a preset time, if the cracking furnace outlet temperature of the feed cracking furnace is still higher than the second furnace feeding upper limit value, control the calorific value of the fuel gas to continue to decrease by the fourth amplitude until the cracking furnace outlet temperature of the feed cracking furnace is within the second set temperature range.

13. The system according to claim 12, wherein, The first set rate is 10 - 150 (kg / h) / min, the second set rate is 50 - 500 (kg / h) / min, the first dilution steam value is 3500 - 4500 kg / h, the second dilution steam value is 3800 - 5000 kg / h, the first set oxygen content range is 1 - 10%, the first damper amplitude and the second damper amplitude are 0.5 - 5%, the first set temperature range is 710 - 780 °C, the first furnace withdrawal lower limit value is the lower limit value of the first set temperature range, the second furnace withdrawal lower limit value is less than the first furnace withdrawal lower limit value and the difference between the two is 2 - 10 °C, the first furnace withdrawal upper limit value is the upper limit value of the first set temperature range, the second furnace withdrawal upper limit value is greater than the first furnace withdrawal upper limit value and the difference between the two is 2 - 10 °C, the first amplitude and the second amplitude are 0 - 0.3 MW, the third amplitude and the fourth amplitude are 0.1 - 0.6 MW; The third set rate is 300 - 600 (kg / h) / t of feedstock, the fourth set rate is 50 - 500 (kg / h) / min, the preset value of dilution steam is 3800 - 5000 kg / h, the second set oxygen content range is 1 - 6%, the second set temperature range is 780 - 880 °C, the lower limit value of the first furnace charging is the lower limit value of the second set temperature range, the lower limit value of the second furnace charging is less than the lower limit value of the first furnace charging and the difference between the two is 2 - 10 °C, the upper limit value of the first furnace charging is the upper limit value of the second set temperature range, and the upper limit value of the second furnace charging is greater than the upper limit value of the first furnace charging and the difference between the two is 2 - 10 °C.

14. The system according to claim 13, wherein The system further includes an operation navigation function module, which is used to, during the discharging process of the discharging cracking furnace, when the damper opening of the discharging cracking furnace is less than or equal to 8 - 12% and the oxygen content in the furnace chamber of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the discharging cracking furnace is greater than or equal to 88 - 92% and the oxygen content in the furnace chamber of the discharging cracking furnace is still higher than the upper limit value of the first set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05 - 0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1 - 0.3 Mpa. During the feeding process of the feeding cracking furnace, when the damper opening of the feeding cracking furnace is less than or equal to 8 - 12% and the oxygen content in the furnace chamber of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the damper opening of the feeding cracking furnace is greater than or equal to 88 - 92% and the oxygen content in the furnace chamber of the feeding cracking furnace is still higher than the upper limit value of the second set oxygen content range, stop adjusting the damper opening, prompt to check whether the on-site opening is consistent with the central control opening and check whether all the viewing holes and ignition holes are tightly closed; when the fuel gas pressure is lower than 0.05 - 0.1 Mpa, prompt to close or open the auxiliary burner operation to maintain the fuel gas pressure within 0.1 - 0.3 Mpa.

15. The system according to claim 1, wherein The system further includes a key parameter monitoring and alarm module, which is used to monitor the key parameters of feeding and discharging during the feeding and discharging stage and give an alarm when the key parameters of feeding and discharging exceed the preset range.

16. The system according to claim 15, wherein The key parameters of feeding and discharging include the cracking furnace outlet temperature, the carbon hydrocarbon flow rate and change rate of a single furnace tube, the total carbon hydrocarbon flow rate and change rate of the main pipe, the single tube dilution steam flow rate, the fuel gas calorific value, the fuel gas pressure, the furnace chamber O2 content, the CO content in the cracked gas, the pressure after the Venturi tube, the cracking furnace damper opening, the dilution steam ratio, the VHS steam drum liquid level, the VHS temperature, the temperature after the oil cooler, the cracking furnace cross-section temperature, the carbon hydrocarbon raw material pressure, and the valve position rate of the raw material control valve of a single furnace tube.

17. The system according to claim 15 or 16, characterized in that, Monitoring the key parameters of material feeding and discharging, and alarming when the key parameters of material feeding and discharging exceed the preset range, specifically including: When the key parameters of material feeding and discharging exceed the first preset range, alarming is performed; When the key parameters of material feeding and discharging exceed the second preset range, the key parameters of material feeding and discharging that exceed the second preset range are adjusted to within the first preset range at a preset ratio based on their current values, and alarming is performed; Wherein, 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 ratio is ±0.1% - 10%.

18. The system according to claim 1, wherein, The system further includes an alarm optimization management module, which is used to automatically shield the instrument alarm of the feeding system and turn on the red prompt light for the material feeding and discharging alarm when the feeding load of the cracking furnace is less than 65 - 75% of the design load; When the feeding load is greater than 65 - 75% of the design load, the instrument alarm of the feeding system is automatically enabled and the prompt light for the material feeding and discharging alarm turns green.

19. The system according to claim 18, wherein The types of the instrument alarm of the feeding system include total discharge amount alarm, liquid discharge flow alarm of the cracking furnace, gas discharge flow alarm of the cracking furnace, discharge interlock pressure alarm, DMDS force alarm, DMDS flow alarm, anti-coking steam pressure difference alarm, cracking furnace outlet temperature alarm, cross-section temperature alarm, quench oil flow alarm, Venturi inlet pressure alarm, cracking gas analysis indication alarm, cross-section flue gas oxygen content alarm, fuel heat load ratio alarm, low flow alarm of the liquid raw material in the furnace tube, and low pressure alarm of the gas raw material.

20. The system according to any one of claims 1, 10, 15, and 18, characterized in that The system further includes a deep learning function module, which is used to learn the control advantages and disadvantages of the key parameters of the discharging cracking furnace and the feeding cracking furnace based on empirical values and big data, and derive the optimal control values of the key parameters of the discharging cracking furnace and the feeding cracking furnace.

21. The system according to claim 1, characterized in that, The system further includes a control performance evaluation module, which is used to collect the loop information of the cracking furnace in real time before and during the material feeding and discharging, evaluate the control loop performance of the cracking furnace according to the loop information, and alarm when the control loop performance of the cracking furnace is abnormal.

22. The system according to claim 1, wherein The feeding load acquisition module is further used to replace one or more feeding cracking furnaces in the feeding cracking furnace group during the material feeding and discharging process.

23. A load adjustment method for the automatic feeding and discharging process of an ethylene cracking furnace group, characterized in that, This method is implemented using the system described in any one of claims 1 - 22, and this method includes: The feeding load acquisition module obtains the feeding load of each cracking furnace in real time, obtains the remaining feeding load of each cracking furnace according to the feeding load of each cracking furnace, selects the discharging cracking furnace, and selects the feeding cracking furnace group according to the feeding load of the discharging cracking furnace and the remaining feeding load of other cracking furnaces; The load adjustment and control module during the material feeding and discharging process controls the discharging cracking furnace to discharge materials according to the feeding load of the discharging cracking furnace, and simultaneously controls the selected feeding cracking furnace group to feed materials during the process of controlling the discharging cracking furnace to discharge materials; The material feeding and discharging execution module performs material feeding and discharging according to the control instruction of the load adjustment and control module during the material feeding and discharging process.

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