There is a saying about Yulin: Yulin, the pearl beyond the Great Wall, satisfies all your fantasies about the northern winds, the vast desert, and the ancient city.

It is on this remarkable land that all employees of the Shaanxi Zaokuang Hongdunjie Project Department of SEPCO1 worked tirelessly, sounding a song of triumph with wisdom and sweat, and on November 25, 2024, successfully completed the 168-hour full-load trial operation of Unit 2, writing a new chapter for the "Iron Army of Power Construction."

Ingenious Engineering, Interpreting Perfection with Data

The Shaanxi Zaokuang Hongdunjie Project is part of the implementation of the Air Pollution Prevention and Control Action Plan issued by the State Council to address the energy shortage in the Beijing-Tianjin-Hebei-Shandong region. The National Development and Reform Commission approved the Yuheng-Weifang 1000kV UHV AC power transmission and transformation project. As one of the 12 UHV transmission channels under the national air pollution prevention and control plan, it can effectively leverage the resource advantages of the northern Shaanxi coal-fired power base, transforming coal transmission into electricity transmission. It will further promote the development of the northern Shaanxi thermal power base and facilitate the development and utilization of northern Shaanxi's coal resources and the economic development of northern Shaanxi. At the same time, it will play a huge role in supporting the outward transmission of power from northern Shaanxi and improving the structure of grid power sources.

From the pouring of the first cubic meter of concrete for the main powerhouse to the completion of the 168-hour trial operation of the unit, after countless days and nights of hard work, the Shaanxi Zaokuang Hongdunjie Project of SEPCO1 delivered a perfect answer with its data.

The No. 2 boiler hydrostatic test inspected 45,435 pressure-bearing weld joints; the first-pass qualification rate of inspected boiler weld joints reached 99.8%; the first-pass flaw detection qualification rate of the four major steam turbine piping weld joints reached 100%; and none of the inspected pressure-bearing weld joints leaked or burst.

During the 168-hour full-load operation of Unit 2, the投入 rate of electrical and thermal protection and automatic devices of the unit was 100%; the maximum shaft vibration of the turbine-generator set was 48μm; the hydrogen leakage rate of the generator was 2.34m³/d; and the vacuum tightness test was 6.6Pa/min. All parameters and indicators were excellent.

Overcoming Difficulties, Improving Quality and Efficiency through Innovation

This project adopts 1000kV UHV outdoor GIS gas-insulated metal-enclosed switchgear, with the highest voltage level in China. The outdoor power distribution装置 is 61m high, the connecting corridor is 41m high and 53m long, and the installation area has soft geology, high terrain, severe winter cold, a complex installation environment, and great construction difficulty. To ensure smooth construction, the project established a QC research group, used BIM 3D modeling to simulate the hoisting scheme in an all-round way, and continuously optimized it. At the same time, it developed special hoisting tools for the ultra-long corridor to prevent deformation, significantly improving construction efficiency.

In the construction of the main powerhouse structure, the architectural discipline adopted new plastic formwork, reinforced the column sections, and controlled the dimensions of square columns by controlling the hollow grooves of four single-bend clamping plates. Wedge-shaped iron gauges were inserted into the hollow grooves so that the four single-bend clamping plates all fit tightly against the four sides of the square column formwork. The hollow grooves at the ends of the single-bend clamping plates, in cooperation with the wedge-shaped iron gauges, can reinforce square columns of various sizes. The four single-bend clamping plates interlock to form a horizontal whole to reinforce the square column formwork. While ensuring the fair-faced concrete process and improving construction quality, this technology also greatly improved construction efficiency, reduced construction difficulty, saved building materials, lowered project costs, and shortened the construction period. Under the condition of ensuring safety, the framework and equipment foundations were constructed simultaneously. The orderly construction of the architectural discipline created conditions for safe and civilized construction of the project and for the handover and installation of equipment foundations.

The turbine discipline coordinated equipment arrival and hoisting sequence in an overall manner and actively coordinated multiple times with the general contractor and equipment manufacturers so that the deaerator and high- and low-pressure heaters were supplied in a centralized manner in the order required by the project department. It made full use of effective mechanical resources to complete hoisting work, saved material turnover time, greatly improved construction efficiency, and effectively reduced machinery shift costs, material costs, and labor costs. In the pipeline construction at the zero-meter level, 7.8-meter level, and operating floor of the turbine hall, hydraulic lifting platforms were adopted, and a new construction method of installing pipeline supports and hangers first was used, avoiding the old method of erecting scaffolding first in previous construction. This not only avoided the risk of working at height but also saved turnover materials, while also eliminating the risk of secondary pollution and damage to finished ground surfaces.

Before the construction of instrument piping, cable trays, and other works by the electrical and control discipline, members of the project department's BIM team displayed the layout and routing of pipelines and lines in 3D, avoiding collisions and crossings, optimizing the design, improving the process level, and greatly increasing work efficiency.

Advance Planning, Demonstrating the Strength of the Iron Army through Action

This project is located in the transition zone between the Mu Us Desert and the Loess Plateau. In northern Shaanxi, winters are severely cold and long, springs are windy and sandy, and autumns are rainy, leaving relatively little available construction time. The project also faced various difficulties and many unfavorable factors, such as high risk of epidemic prevention and control, narrow turnover sites, and delayed equipment arrival. At the beginning of the project, overall site planning was carried out for the assembly yard and boiler area, and factory prefabrication was carried out for the inter-story beams of the main powerhouse, steel roof trusses, and booster station frameworks, which were delivered to the site for installation in batches according to progress, alleviating on-site storage space. Fixed-position planning was carried out for the boiler area and turbine hall area. To reduce turnover sites and avoid material accumulation, good process connection and overall progress control were ensured, and measures were taken to submit material plans according to progress. At the same time, process coordination was strengthened, and the site always maintained a clean, tidy, and civilized construction environment.

Success is never smooth sailing. It can be said that from beginning to end, every process of the project was extremely arduous, and every step was extremely difficult. Due to various reasons, the general contractor required Unit #2 to be the first to start overall commissioning, which was pressure but also motivation for the project department. To ensure that the overall commissioning requirements were met at the scheduled time, Project Execution Manager Liu Jianyi organized carefully and planned in advance. Through reverse scheduling and holding daily evening coordination meetings, he led by example. Even during the 2024 Spring Festival, project department employees still stayed at their posts. During the project trial operation period, all disciplines worked in 24-hour rotation, and management personnel carried out inspections in place. Wherever there was a problem, management personnel were there. From lagging behind Unit 1 in the hydrostatic test to now perfectly overtaking in the 168-hour trial operation, all members of the project department perfectly interpreted the spirit of the "Iron Army of Power Construction" and further established the "Iron Army of Power Construction" brand within Shandong Energy Group.

Striving for Excellence, Building Quality Projects with Attitude

Quality is the lifeline of a project. By controlling the source of project construction quality, unit construction is set on the right starting line. At the beginning of the project, the Zaokuang Hongdunjie Project Department clearly defined the construction concept of "balanced construction and creating a dual-excellence project" and established the project construction goal of "winning the Electric Power Industry Quality Project Award and striving for the National Quality Project Award."

To ensure the sound and healthy operation of the project quality system, the project department planned in advance. By controlling the source, grasping the process, emphasizing inspection, strengthening process supervision, and moving checkpoints forward, it established strict systems for drawing review, equipment inspection, and regular quality supervision and inspection. It implemented full-process form-based management and pursued excellence through process control. To ensure clean construction of boiler heating surfaces, dedicated personnel were assigned to manage each link, including ball passing, assembly, welding, and inspection. After ball passing was completed, customized special sealing tape was used for sealing. If the previous process failed acceptance, entry into the next process was strictly prohibited, and violations would result in assessment of the responsible persons to ensure construction quality.

In quality management, the project department always adhered to high standards and strict requirements. During construction, methods such as the four responsibility systems of quality management, daily supervision, special inspections, and major quality inspections were used. When quality problems were found, rectification notices were issued promptly and reported in the quality management WeChat group. Quality problems were handled without delay for minor issues and without overnight delay for major issues, promoting rapid handling and rapid closure of quality problems.

Construction quality is important, and finished product protection is equally important. As the final process, protection was carried out to ensure the aesthetic installation of the outer protective plates of main equipment. After the outer protective plates were installed, the project department successively used tarpaulins to provide all-round protection for the outer protective plates of main equipment and pipelines such as the high- and low-pressure heaters and four major pipelines in the turbine hall. At the same time, on-site inspections were intensified, and stricter assessment was imposed on damage to finished products.

The project department held two labor competitions successively, promoting "three comparisons and three competitions": comparing technological innovation, safety production, and spiritual civilization, and competing in project management, project quality, and project progress. The project department actively organized training activities such as "Working Standards for Small-Diameter Pipe Installation," "Training on Working Standards for Boiler Body Installation," "Working Standards for Turbine Casing Closure," and "Working Standards for Panel Cabinet Wiring," enhancing construction personnel's quality awareness and operational level, with overall physical process quality reaching high standards. QC research groups were established for key parts, important parts, and parts prone to quality problems of the project to solve process and quality difficulties encountered during construction. Among them, the internal quality and appearance workmanship of boiler small-diameter pipelines, insulation outer protective plates, cable laying, and distribution room panel cabinet wiring won high praise and owner commendations from the general contractor, supervision unit, and owner, effectively enhancing the brand image of the Iron Army of Power Construction.

Joint Management, Building Safe Projects with Responsibility

The project department insisted on strictly supervising the performance of duties under the four safety responsibility systems and fully implementing safety responsibilities, forming a safety management system that extends horizontally to the edges and vertically to the bottom, continuously improving the on-site safety management level of the engineering construction project and innovating safety management models.

At the construction site of Unit 2 of the Zaokuang Hongdunjie Project, one can strongly feel the rigorous, orderly, and harmonious atmosphere of safe and green construction. The site layout is reasonable and neat, all roads are clean and flat, construction planning is scientific and standard, safety fences are bright and eye-catching, and construction materials are stacked neatly. It has repeatedly received praise from all parties and been visited by various units.

The project organized activities such as "Safety Operation Skills Competition," "Large Machinery Emergency Drill," and "Fire Emergency Drill," and also set up a large number of safety warning signs at the construction site, managing safety work with "novelty" and "practical results."

The "modular closed management of project areas" model was used effectively. The Hongdunjie Project Department divided the construction site into multiple closed safety management areas, adhered to the standardization of regional facilities, adopted closed management for the boiler, main powerhouse, and booster station areas, and clearly defined management personnel and management responsibilities.

The project manager signed safety production responsibility letters with heads of each department and cooperating teams respectively, putting on a "safety tight hoop." During construction, it is necessary not only to ensure one's own safety but also to ensure the safety of others. To make everyone firmly remember that safety responsibility is not a matter for one person but for the entire team, every construction point had safety officer supervision, so that safety supervision could achieve full coverage. The project department innovated safety management and implemented safety grid management, dividing the site into four major areas, arranging grid maps in each area, and implementing a project leadership guarantee system. Each safety officer and technician was responsible for one grid and stayed at the site to ensure safe on-site construction.

Since the start of the project, project construction safety has been fully controlled. The project has successively won awards such as the general contractor's and owner's Annual Best Management Award, Excellent Project Safety Management Team, and Excellent Subcontractor. Safety production work has repeatedly received commendations from the owner and supervision unit and has served as a demonstration sample for safe construction learning by other section units. It also successfully achieved the safety responsibility goal of "zero safety production accidents."

Success is never accidental; it is achieved step by step. The successful completion of the Hongdunjie Project is inseparable from the hard work and strenuous efforts of all employees of the project department and embodies the sweat and tears of people in every position. On this vast land of the northwest, SEPCO1 once again created its own glory and history, demonstrating the brand and influence of the "Iron Army of Power Construction"!