A control method for resuming production after scheduled maintenance under the high-load production state of a coke oven

Abstract

The present invention belongs to the field of coke oven production, and relates to a control method for resuming production after scheduled maintenance under the high-load production state of a coke oven. By means of a specific scheduled maintenance mode, a production resumption plan is formulated. Before scheduled maintenance, parameters such as gas consumption, temperature and pressure systems are optimized and controlled according to the scheduled maintenance plan. During scheduled maintenance, temperature control is carried out according to the established heating system. After scheduled maintenance, the gas consumption, temperature and pressure systems are adjusted progressively according to the production resumption plan, ensuring good maturity of coke during the scheduled maintenance process and production resumption, reducing the risk of difficult coke pushing caused by overheating and undercooking, reducing the environmental protection risk caused by undercooked coke, reducing the damage to the coke oven masonry caused by undercooked coke and overheated coke. At the same time, a reasonable temperature and pressure system can effectively reduce gas consumption and improve heating efficiency, solve the safety and environmental protection risks in production after coke oven scheduled maintenance, and ensure the safe control of coke oven production.

Description

Technical Field

[0001] The present invention belongs to the field of coke oven production and relates to a control method for resuming production after scheduled maintenance under the high-load production state of a coke oven. Background Art

[0002] The coke oven in our factory is of the JN60-6 type. In order to ensure the stable and smooth production of the coke oven, it is necessary to regularly arrange scheduled maintenance or planned maintenance (hereinafter collectively referred to as scheduled maintenance) to eliminate defects in equipment or process hazards. During the scheduled maintenance, the corresponding coke oven is in a shutdown state, the coking time of the coke oven is correspondingly extended, and the temperature control difficulty increases. If the normal heating system is used during this period, it will cause the temperature to rise and then cause the coke to be overcooked, which not only affects the quality of the coke but also increases the risk of difficult coke pushing, and further damages the coke oven masonry. Therefore, it is necessary to reduce the consumption of heating gas.

[0003] With the increasing demand for coke by enterprises, the production load of the coke oven gradually approaches the design level. The control method of immediately resuming the normal production rhythm after scheduled maintenance of the coke oven in the low-load state is difficult to meet the requirements. If the normal production rhythm is immediately resumed after scheduled maintenance in the high-load state, it will lead to difficult coke pushing due to overcooked coke, difficult coke pushing due to green coke, and environmental pollution caused by green coke. How to control the temperature and production rhythm after scheduled maintenance has become the key in the high-load state; how to avoid overcooking and undercooking of coke after scheduled maintenance and minimize the impact on coke production is the control difficulty; how to solve the problems of overcooked and undercooked coke through reasonable process control, reduce the environmental protection risk and the risk of damage to the coke oven masonry is the core.

[0004] Chinese Patent with Application No. 201610311991.4 discloses "A method for controlling the temperature of a coke oven before and after scheduled maintenance", which "controls and manages the temperature of the coke oven in sections to achieve the matching of temperature management and turnover time. During the scheduled maintenance of the coke oven or before and after planned maintenance, by timely and reasonably adjusting the standard temperature, the coking heat consumption of the coke oven can be effectively reduced, the heating system of the coke oven can be stabilized, the damage to the coke oven body can be reduced, the occurrence of high-temperature accidents in the vertical flue or the phenomenon of secondary coke formation due to undercooked coke can be avoided, the quality of the coke can be stabilized, and environmental pollution caused by undercooked coke can be avoided." However, this technology only targets the heating mode using mixed gas under a certain load, does not explain the heating mode of coke oven gas with a higher calorific value, and only qualitatively introduces the temperature and coking time, does not systematically elaborate on the temperature and pressure systems, and does not explain the specific temperature treatment and production resumption rhythm. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a control method for resuming production after scheduled maintenance under the high-load production state of a coke oven, ensuring that the coke is well matured during the scheduled maintenance process and during the production resumption period, reducing the risk of difficult coke pushing caused by overcooking and undercooking, reducing the environmental protection risk caused by green coke, and reducing the damage to the coke oven masonry caused by green coke and overcooked coke.

[0006] To achieve the above object, the present invention provides the following technical solution: A method for controlling the resumption of production after scheduled maintenance in the high-load production state of a coke oven, comprising the following steps:

[0007] S1. Determine the scheduled maintenance date and time period according to the coke oven scheduled maintenance plan, and prepare the coke pushing plan for the day of scheduled maintenance. Before scheduled maintenance, prepare the coke pushing plan according to the normal production rhythm, and after scheduled maintenance, take the shortest coking time of 23h (4h of scheduled maintenance) as the standard;

[0008] S2. Start reducing the consumption of heating gas 6 hours before scheduled maintenance, with a reduction of 3%-4%, and the suction on both the machine side and the coke side is reduced by 1 Pa each; start reducing the consumption of heating gas 2 hours before scheduled maintenance, with a reduction of 10-11%, and the suction on both the machine side and the coke side is reduced by 3 Pa each;

[0009] S3. After the scheduled maintenance starts, reduce the consumption of heating gas again, with a reduction of 13-15%, and the suction on both the machine side and the coke side is reduced by 4 Pa each. The coke oven heating is basically in a heat preservation state, ensuring that the standard temperature during scheduled maintenance is controlled at 1230°C on the machine side and 1280°C on the coke side;

[0010] S4. After the scheduled maintenance ends, resume production according to the coke pushing plan. At the same time, according to the actual production furnace number, timely and specifically open the furnace numbers with the regulating cocks closed during scheduled maintenance to ensure normal temperature during the resumption of production;

[0011] S5. After the scheduled maintenance ends, the first cycle all experiences a long-time soaking process. The standard temperature is controlled at 1230°C on the machine side and 1280°C on the coke side. According to the actually measured temperature, timely fine-tune the consumption of coke oven gas and the suction on both the machine side and the coke side;

[0012] S6. In the second cycle after the scheduled maintenance ends, the coking time is shortened by 1h compared with the first cycle. The standard temperature is controlled at 1240°C on the machine side and 1290°C on the coke side. According to the actually measured temperature in the second cycle, increase the consumption of coke oven gas by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the consumption of coke oven gas and the suction on both the machine side and the coke side;

[0013] S7. In the third cycle after the scheduled maintenance ends, the coking time is shortened by 1h compared with the second cycle. The standard temperature is controlled at 1245°C on the machine side and 1295°C on the coke side. According to the actually measured temperature in the third cycle, increase the consumption of coke oven gas by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the consumption of coke oven gas and the suction on both the machine side and the coke side;

[0014] S8. In the fourth cycle after the scheduled maintenance is completed, the coking time is shortened by 1 h compared with the third cycle. The standard temperature is controlled at 1,250 °C on the pusher side and 1,300 °C on the coke side. According to the actually measured temperature in the fourth cycle, the consumption of coke oven gas is increased by 5%-6%, and the suction on both the pusher side and the coke side is increased by 2 Pa. During the production of this cycle, according to the actually measured temperature, the consumption of coke oven gas and the suction on the pusher side and the coke side are adjusted in a timely manner;

[0015] S9. In the fifth cycle after the scheduled maintenance is completed, the normal production rhythm is restored. The standard temperature is controlled at 1,255 °C on the pusher side and 1,305 °C on the coke side. The consumption of coke oven gas is increased by 5%-6%, and the suction on both the pusher side and the coke side is increased by 2 Pa. According to the actually measured temperature, the consumption of coke oven gas and the suction on the pusher side and the coke side are adjusted in a timely manner;

[0016] S10. Observe the maturity of the coke cake through the pusher side and the coke side. The criterion is that the coke cake is rice yellow and there are three obvious shrinkage cracks on the coke cake. If the coke cake is black, it means the coke is undercooked. In this case, the amount of coke oven gas for heating and the corresponding suction should be increased in a timely manner, and the temperature and the coke cake should be continuously monitored until it returns to normal. If the coke cake is golden yellow and shiny, it means the coke is overcooked. In this case, the amount of coke oven gas for heating and the corresponding suction should be reduced in a timely manner, and the temperature and the coke cake should be continuously monitored until it returns to normal.

[0017] Optionally, during the scheduled maintenance, precise control is carried out according to the actually measured temperature. At the end of the coking period, the temperature of the combustion chambers on both sides of the furnace number is higher than the standard temperature. For the furnace number with a temperature difference higher than 70 °C, the corresponding regulating plug is closed by half.

[0018] Optionally, after the scheduled maintenance is completed and production resumes, according to the temperature situation after the first temperature measurement, the consumption of coke oven gas is increased by 5%-6%, and the suction on both the pusher side and the coke side is increased by 2 Pa.

[0019] The beneficial effects of the present invention are as follows: The present invention provides a method for controlling the resumption of production after scheduled maintenance under the high-load production state of a coke oven. By means of a specific scheduled maintenance mode, a production resumption plan is formulated. Before the scheduled maintenance, parameters such as gas consumption, temperature and pressure systems are optimized and controlled according to the scheduled maintenance plan. During the scheduled maintenance, the temperature is controlled according to the established heating system. After the scheduled maintenance is completed, the gas consumption, temperature and pressure systems are adjusted progressively according to the production resumption plan, ensuring good maturity of the coke during the scheduled maintenance process and the production resumption period, reducing the risk of difficult coke pushing caused by overcooking and undercooking, reducing the environmental protection risk caused by undercooked coke, reducing the damage to the coke oven masonry caused by undercooked coke and overcooked coke. At the same time, a reasonable temperature and pressure system can effectively reduce gas consumption and improve heating efficiency, solving the safety and environmental protection risks in the production after the scheduled maintenance of the coke oven and ensuring the safe control of coke oven production.

[0020] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the examination of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Detailed Embodiment

[0021] The following uses specific specific examples to illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0022] During the 4-hour scheduled repair under high-load production of the coke oven and using the coke oven gas heating mode, the coking time of the coke oven is extended by 4 hours, from the normal production coking time of 19 hours to 23 hours. The temperature and pressure regime is adjusted 6 hours before the scheduled repair. During the scheduled repair, precise control of the high-temperature number is carried out on the basis of the temperature and pressure regime adjustment. During the resumption of production after the scheduled repair, the temperature and pressure regime adjustment is completed in a timely manner according to the resumption plan, and precise control is carried out according to the valve signature to ensure that the coke is well matured during the scheduled repair process and the resumption of production, and improve the heating efficiency, solving the safety and environmental protection risks during the scheduled repair of the coke oven and the resumption of production, and ensuring the safe control of coke oven production.

[0023] In this embodiment, the specific operations are as follows:

[0024] 1. Determine the scheduled repair date and time period according to the coke oven scheduled repair plan. Taking the normal coking time of 19 hours (standard temperature on the machine side is 1255 °C, standard temperature on the coke side is 1305 °C, and coke oven gas consumption is 15000 Nm 3 / h) and a scheduled repair of 4 hours (9:00 - 13:00) as an example (the remaining scheduled repair durations can be fine-tuned on this basis);

[0025] 2. Prepare the coke pushing plan for the day of the scheduled repair. Before the scheduled repair, prepare the coke pushing plan according to the normal production rhythm, and after the scheduled repair, use the shortest coking time of 23 hours as the standard;

[0026] 3. Start reducing the heating gas consumption 6 hours before the scheduled repair (i.e., after the temperature measurement at 2:00), with a reduction of 3% - 4% (about 450 - 600 Nm 3 / h), and the suction on both the machine and coke sides is reduced by 1 Pa;

[0027] 4. Start reducing the heating gas consumption 2 hours before the scheduled repair (i.e., after the temperature measurement at 6:00), with a reduction of 10 - 11% (about 1500 - 1600 Nm 3 / h), and the suction on both the machine and coke sides is reduced by 3 Pa;

[0028] 5. After the scheduled maintenance starts, reduce the heating gas consumption again (i.e., at 9:00), with a reduction of 13 - 15% (about 2000 - 2200 Nm 3 / h). The suction on both the coke oven and machine sides is reduced by 4 Pa each, and the coke oven heating is basically in a heat preservation state to ensure that the standard temperature is controlled at 1230°C on the machine side and 1280°C on the coke side during the scheduled maintenance;

[0029] 6. During the scheduled maintenance, precise control is carried out according to the actually measured temperature. At the end of coking, the temperature of the combustion chambers on both sides of the furnace number is often higher than the standard temperature. For furnace numbers higher than 70°C, close half of the corresponding regulating cocks;

[0030] 7. After the scheduled maintenance ends, resume production according to the coke pushing plan. At the same time, according to the actual production furnace number, timely and specifically open the furnace numbers with the regulating cocks closed during the scheduled maintenance to ensure normal temperature during the resumption of production;

[0031] 8. After the scheduled maintenance ends and production resumes, according to the temperature situation after the first temperature measurement (i.e., after the 14:00 temperature measurement), increase the coke oven gas consumption by 5% - 6% (about 750 - 900 Nm 3 / h), and the suction on both the coke oven and machine sides is increased by 2 Pa each;

[0032] 9. After the scheduled maintenance ends, the first cycle all experiences a long furnace soaking process. The standard temperature is controlled at 1230°C on the machine side and 1280°C on the coke side. According to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the coke oven and machine sides;

[0033] 10. In the second cycle after the scheduled maintenance ends, the coking time is shortened by 1 h compared to the first cycle. The standard temperature is controlled at 1240°C on the machine side and 1290°C on the coke side. According to the actually measured temperature in the second cycle, increase the coke oven gas consumption by 5% - 6% (about 750 - 900 Nm 3 / h), and the suction on both the coke oven and machine sides is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the coke oven and machine sides;

[0034] 11. In the third cycle after the scheduled maintenance ends, the coking time is shortened by 1 h compared to the second cycle. The standard temperature is controlled at 1245°C on the machine side and 1295°C on the coke side. According to the actually measured temperature in the third cycle, increase the coke oven gas consumption by 5% - 6% (about 750 - 900 Nm 3 / h, which can be carried out in batches according to the actual temperature), and the suction on both the coke oven and machine sides is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the coke oven and machine sides;

[0035] 12. In the fourth cycle after the scheduled maintenance is completed, the coking time is shortened by 1 h compared to the third cycle. The standard temperature is controlled at 1,250 °C on the machine side and 1,300 °C on the coke side. According to the actually measured temperature in the fourth cycle, the consumption of coke oven gas is increased by 5% - 6% (about 750 - 900 Nm 3 / h, which can be implemented in batches according to the actual temperature), and the suction on both the machine and coke sides is increased by 2 Pa. During the production of this cycle, according to the actually measured temperature, the consumption of coke oven gas and the suction on both the machine and coke sides are adjusted in a timely manner;

[0036] 13. In the fifth cycle after the scheduled maintenance is completed, the normal production rhythm is restored. The standard temperature is controlled at 1,255 °C on the machine side and 1,305 °C on the coke side. The consumption of coke oven gas is increased by 5% - 6% (about 750 - 900 Nm 3 / h, which can be implemented in batches according to the actual temperature), and the suction on both the machine and coke sides is increased by 2 Pa. According to the actually measured temperature, the consumption of coke oven gas and the suction on both the machine and coke sides are adjusted in a timely manner;

[0037] 14. Observe the maturity of the coke cake through the machine and coke sides. The criterion is that the coke cake is rice yellow and three obvious shrinkage cracks appear on the coke cake. If the coke cake is black, it means the coke is undercooked. In this case, increase the heating amount of coke oven gas and the corresponding suction in a timely manner, and continuously monitor the temperature and coke cake until it returns to normal. If the coke cake is golden yellow and shiny, it means the coke is overcooked. In this case, reduce the heating amount of coke oven gas and the corresponding suction in a timely manner, and continuously monitor the temperature and coke cake until it returns to normal.

[0038] Previously, our factory adopted the control method of directly restoring the normal production rhythm after the scheduled maintenance. However, a series of problems frequently occurred, such as difficult pushing of overcooked coke, undercooked coke, sticking of the coke pot in the dry quenching coke due to undercooked coke, large smoke and fire of the coke, etc., which brought many potential hazards to the stable production of the coke oven, and even damaged the coke oven masonry. With the application of this method in the process of resuming production after the scheduled maintenance of the coke oven, it can effectively solve the problems of overcooked and undercooked coke caused by directly restoring the normal production rhythm after the scheduled maintenance, reduce the environmental protection risks brought by undercooked coke, reduce the damage to the coke oven masonry caused by undercooked coke and overcooked coke. At the same time, a reasonable temperature and pressure system can effectively reduce the gas consumption and improve the heating efficiency, solve the safety and environmental protection risks in the production after the scheduled maintenance of the coke oven, ensure the control of coke oven production and safety, and is widely implemented in the 1# - 6# coke ovens of our factory.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A control method for resuming production after scheduled maintenance under the high-load production state of a coke oven, characterized in that, It includes the following steps: S1. Determine the scheduled repair date and time period according to the coke oven scheduled repair plan, compile the coke pushing plan for the day of the scheduled repair, compile the coke pushing plan according to the normal production rhythm before the scheduled repair, and take 23h as the shortest coking time after the scheduled repair; S2. Start reducing the heating gas consumption 6 hours before the scheduled repair, with a reduction of 3%-4%, and the suction on both the machine side and the coke side is reduced by 1 Pa each; start reducing the heating gas consumption 2 hours before the scheduled repair, with a reduction of 10-11%, and the suction on both the machine side and the coke side is reduced by 3 Pa each; S3. After the scheduled repair starts, reduce the heating gas consumption again, with a reduction of 13-15%, and the suction on both the machine side and the coke side is reduced by 4 Pa each. The coke oven heating is basically in a heat preservation state, ensuring that the standard temperature is controlled at 1230°C on the machine side and 1280°C on the coke side during the scheduled repair; S4. Resume production according to the coke pushing plan after the scheduled repair ends. At the same time, according to the actual production furnace numbers, timely and specifically open the furnace numbers of the regulating cocks closed during the scheduled repair to ensure normal temperature during the resumption of production; S5. After the scheduled repair ends, the first cycle all experiences a long-time soaking process. The standard temperature is controlled at 1230°C on the machine side and 1280°C on the coke side. According to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the machine side and the coke side; S6. In the second cycle after the scheduled repair ends, the coking time is shortened by 1h compared with the first cycle. The standard temperature is controlled at 1240°C on the machine side and 1290°C on the coke side. According to the actually measured temperature in the second cycle, increase the coke oven gas consumption by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the machine side and the coke side; S7. In the third cycle after the scheduled repair ends, the coking time is shortened by 1h compared with the second cycle. The standard temperature is controlled at 1245°C on the machine side and 1295°C on the coke side. According to the actually measured temperature in the third cycle, increase the coke oven gas consumption by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the machine side and the coke side; S8. In the fourth cycle after the scheduled repair ends, the coking time is shortened by 1h compared with the third cycle. The standard temperature is controlled at 1250°C on the machine side and 1300°C on the coke side. According to the actually measured temperature in the fourth cycle, increase the coke oven gas consumption by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. During the production of this cycle, according to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the machine side and the coke side; S9. Resume the normal production rhythm in the fifth cycle after the scheduled repair ends. The standard temperature is controlled at 1255°C on the machine side and 1305°C on the coke side. Increase the coke oven gas consumption by 5%-6%, and the suction on both the machine side and the coke side is increased by 2 Pa each. According to the actually measured temperature, timely fine-tune the coke oven gas consumption and the suction on both the machine side and the coke side; S10. Observe the maturity of the coke cake through the machine side and the coke side. Take the coke cake showing rice yellow color and three obvious shrinkage cracks as the standard. If the coke cake is black, it means the coke is undercooked. Timely increase the heating coke oven gas volume and the corresponding suction, and continuously track the temperature and the coke cake until it returns to normal; if the coke cake shows golden yellow and shiny, it means the coke is overcooked. Timely reduce the heating coke oven gas volume and the corresponding suction, and continuously track the temperature and the coke cake until it returns to normal.

2. The overhauled resumption control method after scheduled repair under the high-load production state of a coke oven according to claim 1, wherein: Precise control is carried out according to the actually measured temperature during the regular repair period. At the end of coking, the temperature of the combustion chambers on both sides of the furnace number is higher than the standard temperature. For the furnace numbers higher than 70 °C, close half of the corresponding regulating cock.

3. A control method for resuming production after scheduled maintenance in the high-load production state of a coke oven according to claim 1, characterized in that: After the resumption of production at the end of the regular repair, according to the temperature situation after the first temperature measurement, increase the consumption of coke oven gas by 5%-6%, and increase the suction on both the machine side and the coke side by 2 Pa.