The ethylene power station of the thermal power plant is responsible for providing continuous steam for the ethylene plant. After two pulverized coal boilers were put into use, not only the production cost was greatly reduced, but also the safe steam supply was ensured.
With the continuous operation of pulverized coal boiler, due to the superposition of many factors, the water wall of boiler equipment has problems, the wall thickness is reduced, and it may leak at any time, which has a potential impact on production. Therefore, the damaged water wall must be repaired and replaced as soon as possible.
In order to ensure the high-quality overhaul of No.2 boiler, the thermal power plant attached great importance to it, and set up a project overhaul team composed of motor engineering department, production scheduling department, technical quality department, safety and environmental protection department and technical backbone of ethylene power station, with Zhang Shiwen, the former engineering minister with rich engineering experience, as the project leader to fully organize the overhaul work.
On July 1 1 day, No.2 pulverized coal boiler stopped as planned and entered the cooling and isolation stage before maintenance. On July 16, the public system was isolated and officially delivered for maintenance.
This overhaul focuses on replacing 992 tubes on the 6-meter water wall above and below the boiler burner. The long water wall pipe is too long, so a new pipe must be prefabricated on site before the second welding and installation. The difficulty of this overhaul is the disassembly and installation of the boiler four-corner burner. When disassembling, each burner should be marked, and the installation angle should not be changed at all. When installing, carefully adjust the previous angle to ensure the stability of combustion power field.
In the middle period of boiler overhaul, Qilu petrochemical area ushered in the continuous high temperature weather that has not been seen for many years. In addition, the maintenance site is close to other high-temperature steam pipelines, and the working environment temperature of maintenance reaches more than 40 degrees Celsius. The maintenance team braved the heat to stick to the maintenance site.
Welders work at high temperature, but also endure the searing heat of welding arc. Before long, they were soaked to the skin and sweat ran down the corner of their eyes. Sweat blocked their sight, so they could only touch it quickly with their hands and then continue to stick to the welding work.
The party and the masses in the thermal power plant overcame the shortage of personnel all the way and shouted the slogan of all services and all maintenance. According to the weather conditions, they organized the theme activity of "sending coolness in summer, keeping physical and mental health" in time, and sent sorbet, drinks and other heatstroke prevention and cooling foods to the workers on duty and field workers for organizational care.
Han Feng, the general manager of the company, braved the heat many times and went into battle lightly to visit the workers at the maintenance site. He asked the thermal power plant to completely eliminate the bottleneck affecting the long-term operation of the boiler through this overhaul, provide stable and reliable power for the ethylene plant, and boost the ethylene output to a new high. Zhang Shaoguang, secretary of the Party Committee of the company, also visited the workers at the maintenance site, hoping that party member, the cadre of the thermal power plant, would play the leading role of party member, overcome the hot summer weather, and chew this hard bone with high quality.
At the same time, the thermal power plant pays attention to maintenance and safe production, and needs to ensure the stable operation of another pulverized coal boiler and natural gas boiler.
Thermal power plants and workshops strictly implement the leadership shift system, and the factory duty must go to the maintenance site to check the work, solve problems on the spot, and ensure that the maintenance production is correct.
In order to ensure that the ethylene plant has enough steam, the ethylene station requires that the pulverized coal boiler 1 has more load, and the natural gas boiler operates under a stable load to supply the steam used in the ethylene plant.
At 20 o'clock on August 9, the staff found that the PH value and conductivity of boiler water of natural gas boiler continued to decline. If it is not handled in time, it will affect the safe operation of the water wall. After a detailed investigation of the system, it was finally confirmed that the cause of the failure was pipeline blockage. They took measures such as "flushing the drain, knocking on the valves in the system one by one, and repeatedly opening and closing" to continue the treatment. After 6 hours' treatment, the process was restarted, and the boiler dosing resumed, and the PH value of boiler water began to rise, tending to normal, which ensured the safe operation of natural gas boiler.
In August, the ethylene power station realized the stable operation of "1 1 1" mode, and there was no switching all month, which also helped the olefin plant to create a new level of ethylene hourly output in the past nine years.
After the overhaul on August 26th, the pickling and hydrostatic test of No.2 pulverized coal boiler began.
At 8: 50 on September 5, boiler No.2 met the start-up conditions and the boiler was successfully ignited. After more than 7 hours of boosting, heating and various tests, qualified steam was produced at 16: 30, and the operation mode of "2 1 1" was restored, and the No.2 boiler was revitalized again.