CN-115651720-B - Method for controlling resistance of negative pressure gas system

CN115651720BCN 115651720 BCN115651720 BCN 115651720BCN-115651720-B

Abstract

The invention relates to the technical field of gas purification, in particular to a method for controlling the resistance of a negative pressure gas system. The invention carries out technical analysis and research of the system in theory and production practice, and avoids cleaning a primary cooler, electric capturing, a gas pipeline and the like after the process. The control and treatment method breaks through the control and treatment method and thought of the resistance of the negative pressure gas system in the field of gas purification, adopts the process parameter monitoring and operation control of the daily negative pressure gas system, the resistance prediction and process cleaning of the daily negative pressure gas system, the emergency treatment scheme and response program of the negative pressure gas system. The system is applied to a gas purifying negative pressure gas system, can stabilize the resistance of the negative pressure gas system for a long time, and is used for protecting the production. The invention integrates daily control, resistance prejudgment, advanced cleaning operation and online cleaning operation, and keeps the resistance of the negative pressure gas system to stably run for a long time.

Inventors

GAO ZHANXIAN
YU ZHIXIAO
ZHANG BAOLEI
WANG ZHIJIANG
LI YUANYUAN
FENG ZHIQIANG
WANG ZHENGQIANG
YAN JINSONG
ZHANG YUFENG

Assignees

鞍钢化学科技有限公司

Dates

Publication Date: 20260505
Application Date: 20220923

Claims (1)

1. A method for controlling the resistance of a negative pressure gas system, which is characterized by comprising the following steps: 1. daily control of technological parameters of negative pressure gas system (1) Controlling the technological parameters of a transverse tube primary cooler, an electric tar precipitator, a blower system, a condensate system, a circulating water system and a low-temperature water system: The gas resistance of the transverse pipe primary cooler is less than 1KPa, and the gas outlet temperature is 18-22 ℃; the resistance of the electric tar precipitator is less than 1KPa, and the voltage is kept in a state of collecting tar at 4 ten thousand volts; The gas pipeline drain pipe at the inlet and outlet of the blower system and the body drain pipe are unblocked; The flow rate of condensate at the upper section of each transverse pipe primary cooler in the condensate system is not less than 30m 3 /h, the flow rate of condensate at the lower section is not less than 80m 3 /h, and the light tar content in the lower section spraying liquid is 10% -30%; the temperature of the circulating water inlet of the circulating water system is not lower than 26 ℃ in winter and not higher than 32 ℃ in summer; the low-temperature water inlet temperature of the low-temperature water system is not lower than 14 ℃ in winter and not higher than 16 ℃ in summer; (2) Controlling the output flow and pressure of the circulating ammonia water and the high-pressure ammonia water: the pressure of the circulating ammonia water sent to coking is kept above 0.4MPa, and the pressure sent by a high-pressure ammonia water pump is below 2.5 MPa; (3) Control the suction force and temperature of blower system before transverse tube primary cooler when low gas quantity When the gas quantity is low, the gas suction before the blower system and the gas suction before the transverse pipe primary cooler are reduced on the premise of ensuring the coking suction; the temperature of the gas outlet is kept within a reasonable range by adjusting the inlet temperature or flow of the low-temperature water and the circulating water; (4) Controlling technological operation parameters of transverse tube primary cooler during waste heat water supply in winter Controlling the inlet temperature of the circulating water to be not lower than 26 ℃ and the inlet temperature of the low-temperature water to be not lower than 14 ℃; 2. resistance prediction and cleaning of daily negative pressure gas system (1) Predicting the resistance of a negative pressure gas system, and determining a cleaning mode and frequency: When the resistance of the transverse pipe primary cooler is stable, cleaning the transverse pipe primary cooler once in 3-6 days, cleaning the electric tar precipitator once with steam every 3 months, cleaning each liquid discharge pipeline of the gas pipeline once every 12 hours, and cleaning the gas pipeline at the outlet of the blower system and the related liquid discharge pipeline and the body liquid discharge pipeline once every 6 hours; (2) The negative pressure gas system resistance cleaning is carried out daily, and the judgment result is that: 1) Cleaning condensate systems at the upper section and the lower section of a transverse tube primary cooler by daily hot ammonia water, steam and hot wash oil, and judging the result; A. the process for cleaning the transverse tube primary cooler by hot ammonia water comprises the following steps: a. Closing the gas valve at the outlet of the transverse tube primary cooler, and stopping running the transverse tube primary cooler; b. Closing a circulating water inlet valve and an outlet valve of the horizontal pipe primary cooler, closing a low-temperature water inlet valve and an outlet valve, and emptying circulating water and low-temperature water pipelines of the horizontal pipe primary cooler and water stored in the heat exchange pipe; c. stopping the upper condensate spraying and the lower condensate spraying of the transverse tube primary cooler; d. Switching the condensate outlets of the upper section and the lower section to a cleaning temporary tank; e. Opening an upper ammonia water cleaning valve, and opening the upper ammonia water cleaning valve when the condensate in the upper section enters the cleaning temporary tank through the first temporary water sealing tank to be unblocked; f. sending the cleaned condensate to a mechanical ammonia water clarifying tank by using a cleaning temporary pump; g. If the liquid at the outlet of the condensate liquid at the upper section after cleaning is in a light yellow oil-free state, judging that the cleaning of the upper section of the transverse tube primary cooler is finished; h. closing the upper ammonia water cleaning valve, opening the lower ammonia water cleaning valve, and opening the lower ammonia water cleaning valve when the condensate return pipeline at the lower section enters the cleaning temporary tank through the first temporary water sealing tank to be unblocked; i. if the liquid at the condensate outlet of the lower section is in a light yellow oil-free state, judging that the cleaning of the lower section of the transverse tube primary cooler is finished; j. Upper and lower sections of transverse tube primary cooler the condensate is restored to the initial state; k. The upper section of the horizontal pipe primary cooler is used for delivering circulating water through an adjusting circulating water inlet valve, the lower section of the horizontal pipe primary cooler is used for delivering low-temperature water through a low-temperature water inlet valve, and after the operation is normal, an outlet gas valve of the horizontal pipe primary cooler is opened; B. The steam cleaning transverse tube primary cooler process comprises the following steps: a. Cleaning the transverse tube primary cooler according to the process steps a-i of cleaning the transverse tube primary cooler by hot ammonia water, closing an inlet valve of the transverse tube primary cooler, introducing nitrogen into the transverse tube primary cooler, and opening a discharge tube of the transverse tube primary cooler after eliminating the negative pressure of the transverse tube primary cooler to keep normal pressure unblocked; b. opening a steam cleaning valve at the bottom of the transverse tube primary cooler, introducing direct steam into the transverse tube primary cooler, and enabling steam condensate to enter a first temporary water seal tank through an upper condensate return pipeline and a lower condensate return pipeline, finally entering a temporary cleaning tank, and pumping the steam condensate to a mechanical ammonia water clarifying tank through a cleaning temporary pump; c. when a large amount of steam is emitted from the top of the transverse tube primary cooler, observing the quality of liquid in the first temporary water seal tank, and when the transparent state has no obvious tar, closing the steam cleaning valve after the steam cleaning of the transverse tube primary cooler is finished; d. cleaning the transverse tube primary cooler by hot ammonia water according to the process steps j-k of cleaning the transverse tube primary cooler by hot ammonia water, and recovering the transverse tube primary cooler; C. the hot wash oil cleaning transverse tube primary cooler process comprises the following steps: a. c, cleaning the transverse tube primary cooler by hot ammonia water according to the process steps a-i, emptying ammonia water in a cleaning temporary tank, pouring wash oil into the cleaning temporary tank, closing an inlet valve of the transverse tube primary cooler, introducing nitrogen into the transverse tube primary cooler to eliminate negative pressure of the transverse tube primary cooler, and opening a diffusing tube of the transverse tube primary cooler to keep normal pressure unblocked; b. the cleaning temporary pump is used for conveying the wash oil to replace hot ammonia water, the wash oil is sprayed to the upper section and the lower section of the transverse tube primary cooler respectively, and the wash oil automatically flows to the cleaning temporary tank through the outlets of the upper section condensate return pipeline and the lower section condensate return pipeline, so that the wash oil cooling circulation is established; c. Indirectly heating wash oil by using steam through a heat exchange tube bundle of the transverse tube primary cooler, opening a steam valve to introduce steam into a circulating water outlet or a low-temperature water outlet pipeline of the transverse tube primary cooler, discharging steam condensate from a circulating water inlet or a low-temperature water inlet pipeline blow-down pipe, heating the wash oil to 80-85 ℃, detecting the density and viscosity of the wash oil, and determining whether the hot wash oil is cleaned by the transverse tube primary cooler; d. According to the change condition of the density and viscosity of the wash oil, if the density and viscosity of the wash oil are always increased, stopping to pump the wash oil into a mechanical ammonia water clarifying tank by using a temporary cleaning pump, and replacing the wash oil again for circulation until the density and viscosity of the wash oil are not increased any more, and completing cleaning of the hot wash oil; 2) Daily steam cleans the electrical tar precipitator and judges the result: A. Steam cleaning of single electric tar precipitator A. Powering off the electric tar precipitator; b. closing an inlet valve of the electric tar precipitator, closing an outlet valve of the electric tar precipitator, introducing nitrogen into the electric tar precipitator body, and opening a diffusing pipe of the electric tar precipitator when the internal pressure is positive pressure, wherein the electric tar precipitator is kept in a normal pressure state; c. opening a steam cleaning valve of the electric tar precipitator body, and enabling cleaned condensate to enter a blasting underground tank through a gas water seal tank of the electric tar precipitator; d. After a large amount of steam is emitted from the diffusing pipe of the electric tar precipitator, checking whether the cleaned condensate is clear, and if the condensate is clear and has no tar substances, recovering the electric tar precipitator; e. Closing a steam valve of the electric tar precipitator, opening a nitrogen purging valve, closing a diffusing pipe valve after a large amount of nitrogen is diffused, closing the nitrogen purging valve, controlling the pressure of the electric tar precipitator body in the nitrogen purging process to be less than 10KPa, opening an inlet gas valve of the electric tar precipitator to be fully opened, and opening an outlet gas valve of the electric tar precipitator to be fully opened; f. after the electric tar precipitator is filled with coal gas for 2 hours, the temperature of an insulating box of the electric tar precipitator is controlled to be 80-110 ℃, and after the electric tar precipitator is detected to be qualified in insulation, the electric tar precipitator is powered on; B. integral steam cleaning process of electric tar precipitator system A. C, cleaning all the electric tar precipitator one by one according to the steam cleaning process steps a-f of the single electric tar precipitator; b. All electrical tar precipitator are powered off; c. opening a large coal gas transportation pipeline of the electric tar precipitator, enabling all coal gas to directly enter a coal gas blower through the large transportation pipeline, and closing an inlet main valve and an outlet main valve of the electric tar precipitator; d. When nitrogen is introduced into the electric tar precipitator system to confirm internal positive pressure, the diffusing pipes of all the electric tar precipitator are opened, normal pressure is kept smooth, steam is introduced into the inlet and outlet pipelines and the body of the electric tar precipitator, and condensate flows into the underground tank through the gas water seal tank of the electric tar precipitator; f. after a large amount of steam is emitted from the diffusing pipe of the electric tar precipitator, checking whether the cleaned condensate is clear, and if the condensate is clear and has no tar substances, recovering the electric tar precipitator; g. Closing a steam valve of the electric tar precipitator, opening a nitrogen purging valve, closing all the diffusion pipe valves of the electric tar precipitator after a large amount of nitrogen is emitted from diffusion, closing the nitrogen purging valve, controlling the pressure of the electric tar precipitator body in the nitrogen purging process to be less than 10KPa, opening a total gas valve at an inlet of the electric tar precipitator to be fully opened, and opening a total gas valve at an outlet of the electric tar precipitator to be fully opened; h. after the electric tar precipitator is filled with coal gas for 2 hours, the temperature of an insulating box of the electric tar precipitator is controlled to be 80-110 ℃, and then the electric tar precipitator is powered on; 3) Cleaning condensate spraying pipelines at the upper section and the lower section of the transverse tube primary cooler in daily life; Each spraying pipe is cleaned one by circulating ammonia water when the transverse pipe primary cooler is cleaned each time, and the spraying pipes are cleaned 1-2 times each year after being disassembled; 3. Condensate quality control for upper and lower sections of transverse tube primary cooler The content of the light tar in the upper and lower sections of the horizontal pipe primary cooler is controlled to be 10-30%, and the stable content of the light tar in the condensate in the lower section is maintained by dynamically adding the quantity of the light tar and continuously discharging the light tar into a mechanized ammonia water clarifying tank; 4. Emergency cleaning process of non-stop production negative pressure gas system (1) The production is not stopped, and a gas pipeline is cleaned between the outlet of the transverse pipe primary cooler and the electric tar precipitator: 1) The outlet gas pipeline of the transverse pipe primary cooler is provided with holes, 1 hole is formed every 3-6 meters, the lowest point of the lower part of the front gas pipeline of the electric tar precipitator is provided with a liquid discharging hole, the temporary liquid discharging pipeline of the electric tar precipitator is connected to a second temporary water seal groove, and the water seal outlet pipeline is connected to a cleaning temporary groove; 2) Opening an ammonia water valve close to an inlet of the electric tar precipitator, spraying circulating ammonia water into a negative pressure gas pipeline, flushing deposited substances at the lower part of the gas pipeline into a liquid discharge hole, entering the temporary cleaning tank along with the ammonia water through a second temporary water seal tank through the electric tar precipitator, determining whether liquid accumulation exists by checking the full flow of the second temporary water seal tank, and repeatedly cleaning after the liquid accumulation is processed if the liquid accumulation stops cleaning; 3) Checking whether the cleaned condensate is light yellow, and judging that no obvious tar is cleaned; 4) Sequentially replacing ammonia water spraying positions forwards, spraying circulating ammonia water into the negative pressure gas pipeline, repeating the steps 2) and 3), and cleaning the gas pipeline from the transverse pipe primary cooler to the inlet of the electric tar precipitator; (2) The production is not stopped, and a gas pipeline is cleaned between an outlet main pipe of the electric tar precipitator and an inlet of a blower: 1) The method comprises the steps of firstly, perforating an outlet main pipe of the electric tar precipitator to an inlet gas pipeline of a blower, perforating a hole every 4-6 meters, connecting the hole to a circulating ammonia water pipeline, perforating a drain hole at the lowest point of the lower part of the inlet gas pipeline of the blower, connecting a temporary drain pipeline of the blower inlet to a third temporary water seal tank, and connecting a water seal outlet pipeline to a cleaning temporary tank; 2) Opening an ammonia water valve close to an inlet of a blower, spraying circulating ammonia water into a negative pressure gas pipeline, flushing substances deposited at the lower part of the gas pipeline into a liquid discharge hole, discharging the ammonia water into a third temporary water seal groove through a temporary liquid discharge pipeline at the inlet of the blower, isolating air from entering a cleaning temporary groove, determining whether liquid accumulation exists by checking the full flow of the water seal grooves of other blowers, and repeatedly cleaning after the liquid accumulation is processed if the liquid accumulation stops cleaning; 3) The cleaned condensate is light yellow without obvious tar, and is regarded as being cleaned; 4) Sequentially replacing ammonia water spraying positions forwards, opening an ammonia water inlet valve to spray circulating ammonia water into the negative pressure gas pipeline, repeating the steps 2) and 3), and cleaning the gas pipeline from the main pipe of the electric tar precipitator outlet to the inlet of the blower; 5) And (3) sequentially opening an ammonia water spraying valve in front of an inlet valve of the blower, and cleaning according to the steps 2) and 3).

Description

Method for controlling resistance of negative pressure gas system Technical Field The invention relates to the technical field of gas purification, in particular to a method for controlling the resistance of a negative pressure gas system. Background In the coking production and gas purification gas system, a gas blower is a heart of the whole system, and the resistance of the negative pressure gas system is a key index of the heart to run well or not, so that whether the whole coking and gas purification system can run normally and stably is determined. The whole system for purifying the domestic and foreign gas has the phenomenon that after a few years of operation, even a few months of operation, the negative pressure gas pipeline has large resistance and is very unstable in operation, and the resistance of the primary cooler and the electric tar precipitator needs to be maintained stable by high-frequency cleaning. The problems of negative pressure gas resistance are solved, the problems of blockage and the like are solved by adopting a method of stopping production and clearing or replacing blocked pipelines, the problems of blockage of a primary cooler by adopting a method of replacing a transverse tube bundle are solved, the problems of blockage of various pipelines and equipment are solved by adopting a method of replacing a transverse tube bundle, various measures suitable for own working conditions are tried to be found by each coking plant, various serious accidents such as coke oven diffusion, ignition and the like are caused in the trying process, technical blockage is not performed on the outside, a general rule suitable for negative pressure gas pipelines of each coking plant is not adopted, the trend of large models of coke ovens is changed into a normal state along with continuous updating of the negative pressure gas purifying devices at home and abroad, the requirements on the stability of the negative pressure gas system of the gas purifying devices are more and more strict, and the root cause of various resistance is not formed in the system analysis. Because of the particularity of the gas purification process, pipelines and equipment need to continuously run throughout the year, maintenance and cleaning time is not stopped, and once the blockage problem occurs, the blockage problem cannot be cleaned on line, so that the blockage problem becomes more serious, the treatment is not started until the transportation of the whole gas system is influenced, and even the negative pressure gas system cannot normally run to threaten production and is only important. The existing three primary cooler cleaning methods are all post-treatment methods, and the primary cooler is cleaned only when the resistance of the primary cooler is high, and all the three methods have respective defects that the technology of cleaning the primary cooler by hot ammonia water is required to ensure that the temperature of the hot ammonia water is above 70 ℃, the temperature of gas purifying circulating ammonia water of the upper section process of spraying the emulsion of an ammonia water separating tank on the primary cooler is lower, particularly the temperature of circulating ammonia water in winter is about 60 ℃, the primary cooler is cleaned by the hot ammonia water and cannot achieve the expected effect, the primary cooler cleaning time is longer, a large amount of steam condensate water enters condensate during cleaning, so that the primary cooler temperature exceeds the standard, particularly the primary cooler cannot be cleaned at all in summer, and the high-temperature steam of the primary cooler is used for long time to gasify the separated tar hung outside a heat exchange tube bundle of the primary cooler into asphalt on the outer surface of the tube bundle, so that the heat exchange efficiency of the primary cooler is affected. The hot wash oil cleaning technology is a better cleaning technology at present, each gas purifying operation area is used, and when the technology is suitable for a primary cooler and is not too serious in blockage, the primary cooler tube bundle is easy to leak due to the fact that the hot wash oil solubility Jiang Qing is washed, and when cleaning, the rubber gasket of a pipe box cover is aged and easy to leak due to the fact that steam is introduced into a waterway of the primary cooler. The resistances of the transverse pipe primary cooler, the electric tar precipitator, the blower and the gas pipeline connected with the blower under the negative pressure system must be kept stable, corresponding countermeasures and treatment measures are adopted to control the system resistance under the condition of abnormal resistance, and the production operation of the negative pressure gas system is necessary to be stabilized. Meanwhile, the negative pressure gas system is stable, so that the load of a refrigerator can be greatly reduced, the consumption of electricity of a gas blower i