The ±1100 kV UHVAC engineering line from Zhudong to Weinan in Xinjiang has a total length of approximately 3,324 kilometers. It is the UHV transmission project with the highest voltage level in the world, the largest transmission capacity, the longest transmission distance, and the most advanced technology level. ' is the full line of 'throat'.
On May 3rd, the ±1100kV ultra-high voltage Yangtze River crossing project from Zhudong to Jinnan in Xinjiang entered the project acceptance stage.
Just over ten days ago, Gaogou Town, Wuwei County. With the final phase conductors successfully crossing the Yangtze River, the Zhundong-Weinan ±1100 kV ultra-high voltage Yangtze River Crossing Project penetrated.
This is the ±1100 kV transmission line crossing the Yangtze River for the first time. Among them, the main spanning tower is 225.2 meters high. The single base tower weighs 1259 tons. It spans a total length of 2900 meters. The tower height, tower weight and span distance are all the highest in the whole line. Crossing 'What high technology has been applied? Recently, the reporter interviewed the relevant person in charge of the project.
Wire-laying process 'Big Leap' : '2 pull 3' construction method increases efficiency by 1.5 times
In the past, in UHV and large span projects, the largest conductor cross-section for wireline construction was 720 square millimeters, and this project adopted a wire with a cross-section of 900 square millimeters.
'This is due to the consideration of the transmission capacity. The transmission capacity of this transmission line is 12 million kilowatts. With a small conductor cross-section, it will not be able to meet the established requirements. 'A few days ago, at the Transmission and Distribution Engineering Co., Ltd. Anhui transmission branch meeting In the room, Xu Pengfei, Chief Engineer of the Yangtze River Crossing Project explained.
The cross-section of the wire, span span, and vertical span increase, which leads to loosening of the thread tension, which increases the difficulty of construction.
'For this large cross-section conductor to cross the Yangtze River, we have no mature construction methods to learn from. We can only think for ourselves.' said Wang Yiwen, deputy manager of Anhui Transmission and Distribution Engineering Co., Ltd.'s transmission branch, and project manager of the Yangtze River Great Crossing Project.
At the beginning of the project construction, the technicians relied on the project to study the construction technology of the large-area cross-section of the 6-division 900 square millimetres of ±1100 kV high-voltage and large-span project, creatively carrying out the '2 pull 3' string test of the Yangtze River's large span, Line conditions, effectively solve the key technical problems such as take-off line construction and recycling rope selection.
'We cooperated with the relevant manufacturers of Hegong University and Jiangsu, Guizhou and other places to analyze the test results and finally formed a set of safe and reasonable construction methods.' Xu Pengfei said.
According to reports, the so-called '2 pull 3' construction method, which uses two devices to pull three wires at the same time. Compared with the previous 'a device to pull a wire', the work efficiency increased by 1.5 times, 'Yangtze River Leap' project It took 8 days to complete the wiring work, which was 2 days earlier than expected. 'For safety reasons, the conductors on the Yangtze River need to be sealed. The use of '2 lead 3' construction methods to spread the conductors can reduce the number of The second closure of the Yangtze River, thereby reducing the impact of engineering construction on the navigation of the Yangtze River. ' Wang Yiwen introduced.
As the chief engineer of the project, Xu Pengfei often checks with the quality control personnel at the construction site. 'Up to the time of the project, there are more than 200 workers. During the day, I have to check whether the workers perform the tasks as required and solve some technical problems at the scene; The office, we must pay close attention to doing some calculations and summary of the day. ' Xu Pengfei told reporters.
With a baby face, Xu Pengfei is a 'post-90' worker. Since arriving at the project site in August 2016, he has devoted himself wholeheartedly to his work. During the 2016 National Day, he took time to return to Hefei for a wedding ceremony. After the marriage leave, she returned to work on the construction site.
'Although the project has been completed, we still have to do some tail-ends to eliminate work.' Xu Pengfei said.
Safety Education 'Big Leap' : VR Technology Simulates Operational Immersion
After shaking for a while, it felt like falling down from high altitude.... Don't be nervous, this is not true, but it is simulated by VR technology.
'In the wiring process, workers need to carry out aerial work on more than 200 meters of towers. This places high demands on safety education. ' Wang Yiwen said, 'In the past, we usually carried out safety education through pictures, animations, etc. There is no personal experience. Now that VR technology has been introduced, workers can feel the feeling on the tower while standing on the ground.
According to reports, the UHV Changjiang Great Crossing Project adopts virtual reality, 360-degree panoramic photography and other technologies, and uses civilized construction, risk management and control, and engineering training as research objects, constructs a virtual three-dimensional scene, and allows construction personnel using the training system to come to the end of their lives. The sense of immersion in the environment has led to a 'shocking' type of education.
'We use virtual reality technology to simulate the consequences of each illegal operation, allowing construction personnel to experience from the visual and auditory aspects, and play a better role in warning education. ' Xu Pengfei said, 'Construction personnel can use the handheld device for panoramic roaming , risk experience and engineering process training. '
Wang Yiwen claimed to be a 'old delivery electrician' with 28 years of service'.. Since 2008, he has been involved in the construction of 5 UHV projects for 10 years. 'In the wiring process, every critical node, I have to Going to the scene to see, both to cheer them up, but also urge them to pay attention to safety. Workers operating in the tower more than 200 meters high, we need to pay more attention to their safety and cooling and heating. 'Wang Yiwen said.
The Yangtze River Crossing Project has a complete safety and visualization monitoring system. In addition to boosting morale at the scene, many times, Wang Yiwen also pays close attention to the progress of engineering construction through video surveillance equipment.
According to reports, the ball-type monitoring equipment is installed on each base tower of the project, and the whole process of the construction, full-cycle, panoramic security monitoring, and the management personnel can carry out on-site video surveillance through the handheld terminal equipment. In addition, the construction The site also innovatively applied the 'line inspection robot' to monitor the position of the board in real-time and provide the basis for on-site command, effectively protecting the safety of the wire construction process.
Construction Quality 'Big Leap' : Continuous Technology Tackling Multiple Construction Difficulties
The UHV Yangtze River Crossing Project has a base of 225.2 meters high and a 66-meter-high anchor tower. The project has a large base concrete volume, a high height across the tower, and a single piece of material with long and heavy weight. It not only imposes higher requirements on line-laying technology and construction safety, but also faces a series of construction difficulties such as difficult basic quality control and high risk of tower construction.
'We can say that regardless of the construction quality or construction technology, we have encountered unprecedented challenges.' Xu Pengfei told reporters.
In the face of endless difficulties in construction, Xu Pengfei and the technical team of the project team launched a technical breakthrough.
During the construction process, some staff reported that in accordance with the traditional construction method, 2×16 tons of double-armed poles should be fixed with 40 anchor bolts set in advance on the derrick. It is difficult to lay the ground screw, and the post-processing workload is large. , The underlying surface has a poor perception.
'In response to the problem that the 2×16 tons of double-armed poles and the derrick foundation were not matched, the technicians immediately carried out a new round of optimization. We used the original foundation bolts of the derrick foundation and the conversion base to connect and fix the original. The integrated conversion base was changed to a distributed structure. ' Xu Pengfei told reporters that in order to ensure safety and reliability, the project team also conducted collision avoidance verification through 3D modeling, and it was applied to the site after trial assembly.
This kind of pole fixing method simplifies the process, reduces the cost, improves the construction efficiency, and has certain guiding significance for the construction of large-tonnage pole foundations in the future. ' Wang Yiwen said.
There are many similar innovations. In the project construction project, 'a shaped hoop applied to FRP formworks' was granted a utility model patent; '±1100 kV Yangtze River Great Leap Tower's key technology' won the CEC 2018 year. Second Prize for Technological Progress...
'In a time of self-challenge, the new generation of technical forces have grown up. 'Sui Yuzhu, Party branch secretary of Anhui Transmission and Distribution Engineering Co., Ltd.'s transmission branch, said with emotion: 'In order to do a good job of project management, we are still working on the site. A temporary party branch was established. Nine party members fought in key positions such as project manager, project leader, and civil coordinator. They really played a key role in the management team.