A method for predicting and optimizing the operation of delayed coking unit for producing shot coke
By comprehensively considering the raw material properties and operating conditions of the delayed coking device, a projectile coke tendency model is established, and the operating conditions are adjusted to avoid the occurrence of projectile coke, which solves the safety hazards and economic losses of the device under high liquid collection conditions, and improves the accuracy of prediction and operational timeliness.
Patent Information
- Application Number
- CN202411404531.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2044-10-10
AI Technical Summary
It is difficult for delayed coking devices to avoid the occurrence of projectile coking under high liquid collection conditions, resulting in safety hazards and economic losses. The existing prediction methods have poor accuracy and insufficient timeliness, so they cannot adapt to frequent changes in the properties of raw materials.
By comprehensively considering the properties of the raw materials (density, asphaltene content, residual carbon value, total metal Ni and V content) and the operating conditions of the device (coking furnace outlet temperature, circulation ratio, and coke tower reaction pressure), the projectile coke tendency Pshot index is established. The calculation device generates the tendency of the projectile coke and adjusts the operating conditions according to this to avoid the projectile coke generation.
It improves the accuracy of projectile coke prediction and the timeliness of operation adjustment, reduces the frequency of projectile coke generation, maximizes the liquid yield of the device, enhances economic benefits, and reduces safety hazards.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of petrochemical industry, and in particular to a method for predicting and optimizing the operation of producing shot coke in a delayed coking device. Background Art
[0002] Due to its outstanding advantage of strong adaptability to raw materials, delayed coking units are still one of the main means for domestic and foreign oil refining companies to process residual oil, especially low-quality residual oil. There are more than 100 delayed coking units in operation in China, with a total processing capacity of more than 120 million tons / year, ranking second in the world after the United States. With the increasing trend of heavy and low-quality crude oil in the world, the efficient utilization of heavy oil resources has posed higher challenges to delayed coking technology. How to improve the optimization operation level of delayed coking units and give full play to the role of delayed coking units in heavy oil processing is one of the most urgent tasks for current oil refining companies.
[0003] Delayed coking is a process in which the raw materials are quickly heated to 490-500℃ through a coking furnace, and then enter a coke tower to complete the coking reaction to generate dry gas, liquefied gas, gasoline, diesel, wax oil and petroleum coke. For delayed coking units that process inferior raw materials, petroleum coke is a low value-added product. Therefore, the core goal of a delayed coking unit is to increase the liquid yield of the unit (liquefied gas + gasoline + diesel + wax oil yield) and reduce the petroleum coke yield. In the actual production process, the liquid yield of the unit is increased by increasing the severity of the reaction mainly by increasing the outlet temperature of the coking furnace, reducing the circulation ratio and reaction pressure, etc. However, excessively high reaction severity will lead to the production of shot coke, which will cause safety hazards such as pipeline vibration, drill jamming, and collapse during the coking and decoking process of the unit.
[0004] The advantage of producing shot coke in a delayed coking unit is that it can increase the liquid yield of the unit. The disadvantage is that the selling price of shot coke is lower than that of sponge coke, which results in a loss of economic benefits. At the same time, there are safety hazards in the unit. Therefore, the economic feasibility of producing shot coke depends on many factors, such as the increase in the yield of liquid products when producing shot coke, the product price system, the impact on the safety of the unit and the operating cycle. The current status of the industry is that few companies increase the yield of liquid products and thus improve economic benefits by producing shot coke. There are two main reasons: First, with the rapid growth in demand for power batteries for new energy vehicles, sponge coke can be used to produce lithium battery negative electrode materials, which expands its application scenarios and increases its price accordingly, while shot coke can only be used as fuel. In order to ensure the long-term operation of the boiler, the proportion of shot coke added to the fuel must be controlled not to be too high, which makes the price difference between sponge coke and shot coke greater than 500 yuan / ton. A 1 million ton / year delayed coking unit, with a petroleum coke yield of 28%, produces 800 tons of petroleum coke per day. The loss of reduced petroleum coke sales price due to the production of shot coke is Ten thousand yuan / day; while when producing shot coke, the liquid yield is increased by 3%, and the comprehensive price difference between liquid yield and petroleum coke is 2,000 yuan / ton. The benefit of increasing liquid yield is only 171,000 yuan / day. Second, most delayed coking units are limited by the original design conditions and are still unable to adapt to the conditions of large-scale production of shot coke. There are certain safety hazards when producing shot coke. Therefore, most companies currently consider economic and safety comprehensively, hoping to maximize the increase in the liquid yield of the unit without producing shot coke, that is, to achieve edge optimization operation. The premise of edge operation is to be able to predict the conditions for the production of shot coke in the unit according to the properties of different raw materials, so as to adjust and optimize the operating conditions of the unit according to the actual situation of the unit.
[0005] How to avoid the production of shot coke in delayed coking units under high reaction severity, i.e., high liquid recovery conditions, is an important technical problem that has not been well solved. Patents CN201510140787.6 and CN201110277535.X both use experimental evaluation methods to predict the conditions for the production of shot coke, but the reaction conditions of the experimental units, such as reaction temperature, time, flow rate, etc., are quite different from those of industrial units. Therefore, the reaction conditions explored in the experiment cannot be directly used in industrial units, and the timeliness of the experimental evaluation is poor, and it cannot guide production optimization in a timely manner.
[0006] In existing literature, such as Guangzhou Chemical Industry [J]. 2011, 39(03): 82-84, the ratio of coking raw material carbon residue to asphaltene content is used to predict the generation of shot coke: when the ratio of carbon residue to asphaltene is less than 1.4, the device is likely to produce shot coke; when the ratio of carbon residue to asphaltene is between 1.4 and 1.6, the device may produce shot coke; when the ratio of carbon residue to asphaltene is greater than 1.6, the device is less likely to produce shot coke. The prediction model for shot coke in public literature mainly uses single physical property data such as raw material carbon residue value, asphaltene, density, etc., without considering the combined effects of multiple physical properties and the effects of operating conditions on the generation of shot coke.
[0007] In existing literature such as Petroleum Refining and Chemical Engineering, 2013, 44(12):23-26, for specific delayed coking units and raw materials, the coking reaction is brought close to the critical state of shot coke generation by continuously increasing the reaction temperature, reducing the circulation ratio and reaction pressure, so as to maximize the yield of liquid products in the unit. At the same time, a shot coke generation prediction system based on the indication value of the neutron level meter at point C of the coke tower, the amount of quenching oil, and the wall temperature at point C is proposed, which provides a safety guarantee and basis for the critical edge operation of shot coke generation. This method is a prediction system established for specific units and specific raw materials based on production experience data. It is relatively effective for coking units with stable raw materials. Its limitations are as follows: no universal quantitative shot coke prediction model has been formed. When the prediction system is applied to other delayed coking units or the properties of the raw materials change, a new prediction system needs to be explored again, and the new prediction system requires long-term experience accumulation to establish. As mentioned above, the loss of shot coke produced by a 1 million tons / year delayed coking unit is as high as hundreds of thousands of yuan per day. Therefore, the trial-and-error cost of establishing a prediction system through this method is high, and it is difficult to apply to delayed coking units where the properties of raw materials change frequently.
[0008] In summary, how to maximize the liquid recovery of the delayed coking unit without producing shot coke, that is, to achieve optimized edge operation, is a key issue that needs to be solved for high-level operation of the unit. It is a common practice in the industry to avoid the production of shot coke by reducing the furnace outlet temperature, increasing the circulation ratio and reaction pressure, but the key to edge operation is to achieve the following two points: first, according to the different raw material properties, obtain the critical operating conditions of the unit (furnace outlet temperature, circulation ratio and reaction pressure) to reduce the loss of liquid recovery caused by excessive reduction of reaction severity; second, be able to predict the tendency of shot coke production according to the raw material properties, and formulate the critical operating conditions of the unit in advance to adapt to the frequent changes in the raw material properties of the unit and reduce the trial and error cost of gradual optimization and adjustment based on experience.
[0009] The existing technology for predicting shot coke is mostly based on simple experimental raw material evaluation and production experience data summary of specific devices, lacking a quantitative prediction model that comprehensively considers the properties of multiple raw materials and the operating conditions of industrial devices. Therefore, it is a technical problem that needs to be solved to establish a fast and accurate method for predicting the production of shot coke in delayed coking devices, and to guide the formulation of optimized operation plans based on this method, so as to realize dynamic edge control operation of devices under conditions of frequent raw material changes. Summary of the invention
[0010] The purpose of the present invention is to provide a method for predicting and optimizing the production of shot coke in a delayed coking device in view of the defects of the prior art, which mainly solves the problems of poor accuracy in predicting the production of shot coke in a delayed coking device and poor timeliness in operation adjustment in the prior art.
[0011] The applicant of the present invention has found in theoretical research and production practice that the production of shot coke in a delayed coking unit is mainly affected by the properties of the raw materials and the operating conditions of the unit. The raw material properties that affect the production of shot coke mainly include density, asphaltene content, residual carbon value and total content of metal Ni and V. The above raw material properties all contribute to the production of shot coke to varying degrees. The prior art only predicts from a single raw material property or residual carbon value / asphaltene content, and does not fully consider the comprehensive impact of the above physical properties. The main operating conditions for the unit to regulate the production of shot coke include the coking furnace outlet temperature, the unit circulation ratio and the coke tower reaction pressure. Different units have different adjustable ranges of the above parameters according to their actual equipment and process requirements. The prior art is mainly based on data feedback after the production of shot coke from specific raw materials, and relies on experience to adjust operating parameters, that is, to explore critical conditions through continuous trial and error, and has failed to establish a quantitative model of operating conditions and the probability of shot coke production. Therefore, a quantitative prediction model for shot coke is established which comprehensively considers the above-mentioned raw material properties and operating conditions. This model can warn of shot coke production before raw material processing and formulate a control operation plan in advance, which can effectively reduce the frequency of shot coke production and improve the overall efficiency of the device.
[0012] In actual production, there are three states: no shot coke, partial shot coke and full shot coke. The three states are in a gradual process. In order to conveniently represent the shot coke generation state and conform to the actual situation, the present invention proposes a shot coke tendency P when establishing a shot coke prediction model. shot Indicator, the projectile focal tendency P shot Less than 50% is defined as no pellet scorch state; pellet scorch tendency P shot A value above 90% is defined as a state of large amount of pellet coke. At this time, it is difficult to avoid the generation of pellet coke through small operational adjustments, and we need to be alert to the safety hazards caused by pellet coke.
[0013] The technical solution of the present invention is: a method for predicting and optimizing the operation of delayed coking device for producing shot coke, the delayed coking device comprising: a coking furnace and a coke tower, characterized in that: the method for predicting and optimizing the operation comprises the following steps:
[0014] (1) Calculate the tendency of the delayed coking unit to produce shot coke based on the operating conditions of the delayed coking unit and the physical properties of the raw materials;
[0015] (2) According to the shot coke tendency calculated in step (1), and taking the shot coke tendency of 49%-50% as the adjustment target, the operating conditions are adjusted to determine the edge clamping operating conditions;
[0016] In step (1), the delayed coking unit operating conditions include the coking furnace outlet temperature, the unit circulation ratio, and the coke drum reaction pressure, and the equivalent circulation ratio inside the coke drum is calculated based on the delayed coking unit operating conditions;
[0017] The method for calculating the equivalent circulation ratio inside the coke drum is as follows:
[0018] Formula 1: ;
[0019] in:
[0020] R_e is the equivalent circulation ratio inside the coke tower;
[0021] K is the device coefficient, which is used to correct the differences caused by the measurement positions of different device instruments and the measurement errors of the instruments. The value range is 0.8-1.2, and the default value K=1.0;
[0022] Tout is the coking furnace outlet temperature, in °C;
[0023] R is the device circulation ratio, which is equal to the mass of the device circulating oil / the mass of the raw materials entering the device;
[0024] Pr is the reaction pressure of the coke tower, in MPa;
[0025] In step (1), the raw material physical properties of the delayed coking device include: raw material density at 20°C, asphaltene content, residual carbon value, total content of metal Ni and V, and the shot coke contribution rate of each single physical property is calculated respectively;
[0026] The calculation method of the contribution rate of shot coke of a single physical property is as follows:
[0027] Formula 2: ;
[0028] Formula 3: ;
[0029] Formula 4: ;
[0030] Formula 5: ;
[0031] in:
[0032] Asp is the asphaltene content of the raw material;
[0033] CCR is the carbon residue value;
[0034] d20 is the density of the raw material at 20°C, in kg / m 3 ;
[0035] Ni+V is the total content of metal Ni and V, in mg / kg;
[0036] P_asp is the shot coke contribution rate of raw asphaltene;
[0037] P_ccr is the shot coke contribution rate to the carbon residue value;
[0038] P_d20 is the shot coke contribution rate of the raw material density at 20°C;
[0039] P_NiV is the contribution rate of shot coke to the metal Ni+V content;
[0040] In step (1), the method for calculating the pellet focus inclination by the calculation device is as follows:
[0041] Formula 6: ;
[0042] in:
[0043] P shot The tendency of the device to produce shot coke.
[0044] Preferably, in step (2), when determining the clamping edge operation conditions, the coke tendency P of the pellets produced by the device is calculated according to Formula 6: shot Make adjustments;
[0045] If the projectile focal inclination P shot If it is 49%-50% lower than the adjustment target, the severity of the reaction shall be increased within the adjustable range of the device operating conditions, such as increasing the coking furnace outlet temperature, reducing the device circulation ratio or the coke drum reaction pressure;
[0046] If the projectile focal inclination P shot If it is 49%-50% higher than the adjustment target, the severity of the reaction should be reduced within the adjustable range of the device operating conditions, such as reducing the coking furnace outlet temperature, increasing the device circulation ratio or the coke tower reaction pressure;
[0047] The specific method for adjusting the operating conditions in step (2) is as follows: Substitute the existing circulation ratio of the device, the reaction pressure of the coke drum, and the physical properties of the raw materials to be processed, including density, asphaltene content, residual carbon value, and the total content of metal Ni and V, into formulas 1 to 6, and set P shot =50%, the outlet temperature of the coking furnace can be solved;
[0048] If the solved coking furnace outlet temperature is within the adjustable range of the device, the critical operating conditions can be determined: the solved coking furnace outlet temperature, the existing circulation ratio of the device and the reaction pressure of the coke drum;
[0049] If the solved coking furnace outlet temperature exceeds the adjustable range of the device, the upper or lower limit of the adjustable range of the coking furnace outlet temperature is used to fix the new coking furnace outlet temperature, and then adjust the device circulation ratio or coke tower reaction pressure.
[0050] Preferably, when any one or both of the operating conditions and physical properties of the delayed coking unit change, steps (1) and (2) are repeated to dynamically adjust the unit's edge operating conditions.
[0051] Compared with the prior art, the present invention has the following advantages:
[0052] (1) Compared with the prior art which only considers a single physical property model and cannot determine the quantitative relationship between operating conditions and shot coke production, the shot coke prediction method of the present invention comprehensively considers the effects of multiple raw material properties, including density, asphaltene content, residual carbon value, metal Ni+V content, and device operating conditions, including coking furnace outlet temperature, device circulation ratio, and coke tower reaction pressure, on shot coke production, and proposes a quantitative prediction model, which is one of the main innovations of the present invention.
[0053] (2) The present invention can predict the tendency of shot coke production according to the properties of the raw materials to be processed and the operating conditions of the device, and formulate a clamping operation plan in advance. This overcomes the problem that the prior art needs to rely on production feedback data, continuous trial and error adjustment, long cycle and high cost, and is more adaptable to the production characteristics of the delayed coking device where the raw materials change frequently. This is the main improvement of the present invention over the prior art.
[0054] (3) Since the production of shot coke in a delayed coking unit is a very complex problem affected by many factors, the prediction and control of shot coke is still a recognized industry problem at home and abroad. The shot coke prediction method proposed in the present invention cannot guarantee 100% accuracy, but compared with the prior art, it can consider more comprehensive influencing factors and provide a quantitative prediction model, which has made significant progress in the accuracy of shot coke prediction, the timeliness and economy of optimization and adjustment, and can maximize the liquid recovery of the unit while reducing the probability of shot coke production, thereby improving the comprehensive benefits of the delayed coking unit. DETAILED DESCRIPTION
[0055] The present invention is further described below in conjunction with embodiments. Example 1
[0056] The present invention provides a method for predicting and optimizing the operation of delayed coking device production of shot coke, providing a method for predicting shot coke that comprehensively considers raw material properties and operating conditions, and its main steps are as follows:
[0057] (1) Using the operating conditions of the delayed coking unit, including the coking furnace outlet temperature, unit circulation ratio, and coke drum reaction pressure, the equivalent circulation ratio inside the coke drum is calculated as follows:
[0058] Formula 1: ;
[0059] Among them, R_e is the equivalent circulation ratio inside the coke tower, K is the device coefficient, which is used to correct the differences caused by the measurement positions and instrument measurement errors of different devices, and the default value K=1.0; Tout is the outlet temperature of the coke furnace ℃, R is the device circulation ratio, which is equal to the mass of the device circulating oil / the mass of the raw materials entering the device, and Pr is the reaction pressure of the coke tower Mpa;
[0060] (2) Using the raw material properties of the delayed coking unit, including 20°C density, asphaltene content, residual carbon value, and total content of metal Ni and V, the contribution rate of shot coke of a single physical property is calculated as follows:
[0061] Formula 2: ;
[0062] Formula 3: ;
[0063] Formula 4: ;
[0064] Formula 5: ;
[0065] Among them, Asp, CCR, d20, and Ni+V are respectively the raw material asphaltene content m%, the residual carbon value m%, and the density at 20℃ kg / m 3 , total content of metallic Ni and V mg / kg; P_asp, P_ccr, P_d20, P_NiV are the shot coke contribution rates of raw asphaltene, residual carbon value, 20℃ density and metallic Ni+V content, respectively, %;
[0066] (3) Based on the results of step (1) and step (2), the tendency of shot coke production is calculated by comprehensively considering the raw material properties and operating conditions. The calculation method is as follows:
[0067] Formula 6: ;
[0068] Among them, P shot is the tendency of the device to produce shot coke, %.
[0069] The above-mentioned delayed coking unit production shot coke prediction and optimization operation method was adopted. Vacuum residue oil was used as raw material and applied to 1.6 million tons / year delayed coking unit for 6 groups of control experiments. The production data were statistically analyzed. The main raw material properties, operating conditions, actual production petroleum coke morphology and prediction results are shown in Table 1.
[0070] Table 1 ;
[0071] According to the existing technical prediction method (Guangzhou Chemical Industry [J]. 2011, 39(03): 82-84 and Qilu Petrochemical [J]. 2024, 52(02): 122-126), when the residual carbon value / asphaltene is >1.6~1.75, shot coke will not be produced;
[0072] Based on this, it can be judged that Group 1, Group 3, Group 4, and Group 5 will not produce shot coke. The actual production results show that Group 3, Group 4, and Group 5 all produce local shot coke.
[0073] According to the projectile focal tendency P proposed by the present invention shot It is predicted that Group 3, Group 4, Group 5 and Group 6 will produce shot coke, which is basically consistent with the actual production. This shows that the shot coke prediction method proposed in the present invention which comprehensively considers the properties of raw materials and operating conditions has higher accuracy compared with the prior art. Example 2
[0074] The method for predicting and optimizing the operation of producing shot coke in the delayed coking unit in Example 1 is applied to a 1 million tons / year delayed coking unit. When Castile deep drawn vacuum residue is first processed, the raw material properties are shown in Table 2:
[0075] Table 2 ;
[0076] The operating conditions adopted are: coking furnace outlet temperature 497°C, circulation ratio 0.20, and coke tower reaction pressure 0.17Mpa.
[0077] Due to the serious deterioration of the raw materials, the device produced about 15% shot coke under the above operating conditions. However, because the shot coke was mixed with sponge coke, the entire tower of petroleum coke had to be sold at a low price as shot coke.
[0078] At this time, the dry gas yield of the device was 5.08%, the liquefied gas yield was 3.17%, the gasoline yield was 18.92%, the diesel yield was 23.16%, the wax oil yield was 17.03%, the petroleum coke yield was 32.64%, and the liquid yield of the device was 62.28%.
[0079] In order to avoid the production of shot coke in the delayed coking unit and minimize the liquid recovery loss of the delayed coking unit, the edge clamping operation plan is adjusted. The main implementation steps are as follows:
[0080] Firstly, according to the operating conditions of the delayed coking unit and the physical properties of the raw materials, the tendency of the unit to produce shot coke is calculated;
[0081] Then, according to the calculated tendency of producing shot coke, and taking the tendency of producing shot coke of 49%-50% as the adjustment target, the operating conditions are adjusted and the card edge operating conditions are determined.
[0082] The specific steps are:
[0083] (1) First, based on the existing operating conditions of the device and the properties of the raw materials, the operating conditions include the existing coking furnace outlet temperature, the device circulation ratio, and the coke drum reaction pressure;
[0084] The raw material properties include density, asphaltene content, residual carbon value, and total content of metal Ni and V. The equivalent circulation ratio is calculated by formula 1 in Example 1. The shot coke contribution rate of a single physical property is calculated by formula 2-formula 5 in Example 1. The shot coke tendency P of the device output is calculated by formula 6 in Example 1. shot 57.6%
[0085] (2) Substitute the existing circulation ratio of 0.20, the reaction pressure of the coke drum of 0.17 MPa, the raw material properties in Table 2 including density, asphaltene content, residual carbon value, and the total content of metal Ni and V into formulas 1-6 in Example 1, and set P shot =50%, the outlet temperature of the coking furnace can be solved to be 493℃. Within the adjustable range of this device, the edge clamping operating conditions of the raw materials in Table 2 are determined as follows: furnace outlet temperature 493℃, circulation ratio 0.20, reaction pressure 0.17Mpa. The shot coke tendency P of this scheme is shot The calculated value is 49.67%. No shot coke is produced by adopting this operation scheme.
[0086] Comparative Example 1
[0087] For example, the delayed coking device and raw materials of Example 2 use existing technology. Since it is impossible to accurately predict the impact of the device operating conditions on the shot coke, initially only a more conservative solution can be adopted to reduce the severity of the reaction: furnace outlet temperature 490°C, circulation ratio 0.30, reaction pressure 0.18Mpa.
[0088] The comparison results of product distribution of the devices of Example 2 and Comparative Example 1 are shown in Table 3.
[0089] Table 3 ;
[0090] Benefit calculation:
[0091] (1) Difference in benefits between Example 1 and Comparative Example 1: The price of petroleum coke produced by processing inferior residual oil in a delayed coking unit is only RMB 2,000 / ton, while the price of coking gas and liquid products is RMB 2,000-4,000 / ton higher than that of petroleum coke. Considering that the comprehensive price of gas and liquid products is RMB 3,000 / ton higher than that of petroleum coke.
[0092] For a 1 million t / a delayed coking unit, the coking cycle of the coke drum switching is 24h. Compared with Example 1, Example 2 reduces the output of petroleum coke by 30.8 tons per coking cycle (the petroleum coke yield decreases by 1.08%, and the corresponding liquid yield of the unit increases by 1.30%), and increases the economic benefit by 30.8*3000=924,000 yuan / day.
[0093] The difference between Example 2 and shot coke operating conditions: the price difference between sponge coke and shot coke in the delayed coking unit is 500 yuan / ton. When producing shot coke, the yield of high-value gasoline and diesel is reduced and the yield of low-value wax oil is increased. The comprehensive price of gas and liquid products is 2,000 yuan / ton higher than that of sponge petroleum coke.
[0094] A 1 million ton / year delayed coking unit produces 932 tons of shot coke per day. The loss of petroleum coke sales price caused by the production of shot coke is 932*500=466,000 yuan / day; the unit liquid yield increases by 13.43 tons per day (petroleum coke yield decreases by 0.45%, and the corresponding unit liquid yield increases by 0.47%), increasing economic benefits by 13.43*2000=26,900 yuan / day. Therefore, the economic benefits of the shot coke production condition loss are 439,100 yuan / day.
[0095] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for predicting and optimizing the operation of a delayed coking device for producing shot coke, the delayed coking device comprising: Coking furnace and coke drum, characterized in that: the method for predicting and optimizing operation comprises the following steps: (1) Calculate the tendency of the delayed coking unit to produce shot coke based on the operating conditions of the delayed coking unit and the physical properties of the raw materials; (2) According to the shot coke tendency calculated in step (1), and taking the shot coke tendency of 49%-50% as the adjustment target, the operating conditions are adjusted to determine the edge clamping operating conditions; In step (1), the delayed coking unit operating conditions include the coking furnace outlet temperature, the unit circulation ratio, and the coke drum reaction pressure, and the equivalent circulation ratio inside the coke drum is calculated based on the delayed coking unit operating conditions; The method for calculating the equivalent circulation ratio inside the coke drum is as follows: Formula 1: ; in: R_e is the equivalent circulation ratio inside the coke tower; K is the device coefficient, which is used to correct the differences caused by the measurement positions of different device instruments and the measurement errors of the instruments. The value range is 0.8-1.2, and the default value K=1.0; Tout is the coking furnace outlet temperature, in °C; R is the device circulation ratio, which is equal to the mass of the device circulating oil / the mass of the raw materials entering the device; Pr is the reaction pressure of the coke tower, in MPa; In step (1), the raw material physical properties of the delayed coking device include: raw material density at 20°C, asphaltene content, residual carbon value, total content of metal Ni and V, and the shot coke contribution rate of each single physical property is calculated respectively; The calculation method of the contribution rate of shot coke of a single physical property is as follows: Formula 2: ; Formula 3: ; Formula 4: ; Formula 5: ; in: Asp is the asphaltene content of the raw material; CCR is the carbon residue value; d20 is the density of the raw material at 20°C, in kg / m 3 ; Ni+V is the total content of metal Ni and V, in mg / kg; P_asp is the shot coke contribution rate of raw asphaltene; P_ccr is the shot coke contribution rate to the carbon residue value; P_d20 is the shot coke contribution rate of the raw material density at 20°C; P_NiV is the contribution rate of shot coke to the metal Ni+V content; In step (1), the method for calculating the pellet focus inclination by the calculation device is as follows: Formula 6: ; in: P shot The tendency of the device to produce shot coke.
2. The method for predicting and optimizing the operation of delayed coking device for producing shot coke according to claim 1, characterized in that: In step (2), when determining the clamping edge operation conditions, the device output shot coke tendency P is calculated according to formula 6 shot Make adjustments; If the projectile focal inclination P shot If it is 49%-50% lower than the adjustment target, the severity of the reaction shall be increased within the adjustable range of the device operating conditions, such as increasing the coking furnace outlet temperature, reducing the device circulation ratio or the coke drum reaction pressure; If the projectile focal inclination P shot If it is 49%-50% higher than the adjustment target, the severity of the reaction should be reduced within the adjustable range of the device operating conditions, such as reducing the coking furnace outlet temperature, increasing the device circulation ratio or the coke tower reaction pressure; The specific method for adjusting the operating conditions in step (2) is as follows: Substitute the existing circulation ratio of the device, the reaction pressure of the coke drum, and the physical properties of the raw materials to be processed, including density, asphaltene content, residual carbon value, and the total content of metal Ni and V, into formulas 1 to 6, and set P shot =50%, the outlet temperature of the coking furnace can be solved; If the solved coking furnace outlet temperature is within the adjustable range of the device, the critical operating conditions can be determined: the solved coking furnace outlet temperature, the existing circulation ratio of the device and the reaction pressure of the coke drum; If the solved coking furnace outlet temperature exceeds the adjustable range of the device, the upper or lower limit of the adjustable range of the coking furnace outlet temperature is used to fix the new coking furnace outlet temperature, and then adjust the device circulation ratio or coke tower reaction pressure.
3. A method for predicting and optimizing the operation of delayed coking device for producing shot coke according to any one of claims 1 or 2, characterized in that: When any one or both of the operating conditions and physical properties of the delayed coking unit change, steps (1) and (2) are repeated to dynamically adjust the unit's edge operating conditions.