Offshore wind power construction will move forward toward intertidal wind farm

At the first offshore wind farm in Shanghai, the 100,000-kilowatt offshore wind demonstration project of the Shanghai Donghai Bridge, a total of six technical achievements obtained during the foundation construction and installation process were granted national patents, and another six patent applications were accepted.

The China National Aviation and Aviation Administration (CAAC), which is responsible for the construction and installation of the fan foundation for the 100,000 kilowatt offshore wind demonstration project of the Shanghai Donghai Bridge, is currently the only company in the country that has had successful experience in the overall installation of offshore wind power and has solved 10 m of water depth through independent innovation. The offshore deep-water segment implemented the key issues such as cushioning and precise positioning when the complete machine of the offshore unit was docked with the base platform in the process of integral lifting of the sea, and possessed the complete set of installation technology and equipment for transporting and hoisting the entire machine of the wind turbine. In the future, China will also step forward to the more potential intertidal wind farms, break through technical difficulties and fill the gaps in the world.

-- China's offshore wind power construction has formed a series of patents

The 100,000-kilowatt offshore wind demonstration project of Shanghai Donghai Bridge is the first offshore wind farm in China, and even the first in Asia. This project, officially approved by the Development and Reform Commission and listed as a demonstration project, has become an opportunity for China to develop major offshore wind projects.

Offshore wind power project installation projects can still be said to be a blank in China. If breakthroughs are made through demonstration projects, it will promote China's overall progress in this major new energy field. The main business of CCCC-3A has long been mainly in hydraulic engineering such as docks, docks, and bridges, and has strong offshore construction capabilities. After investigations and studies on domestic and foreign markets, the CAAC believes that the development of new energy sources is rapidly heating up. With the gradual saturation of wind power on land, the small wind power noise limit, and large energy output, offshore wind power has broad prospects for development.

After more than one year of research and development, the China Aviation, Aviation, and Aviation Administration (CAAC), which is building offshore wind power projects, has developed a set of installation systems with its own characteristics on the basis of learning from foreign installation technologies. It is both reasonable and feasible and maneuverable.

At present, the balance beam structure for installation of offshore wind turbines used in the 100,000-kilowatt offshore wind demonstration project of Shanghai Donghai Bridge at the first offshore wind farm in China, the installation structure of the offshore wind turbine installation base, and the flexible installation system of offshore wind turbines The six technical achievements including the leveling structure of the tower foundation ring in the foundation construction of offshore wind turbines and the installation of special-purpose diving barges for shallow wind power generating units have obtained national patents, and 6 other patent applications have been accepted.

- Independent innovation technology overcomes world-class construction problems

On September 28, 2008, the Donghai Bridge offshore wind farm fan foundation project began to piling. On March 20, 2009, the first wind turbine called "Asia's No. 1 Crane" was successfully hoisted. On September 4th of the same year, the first three wind turbines were connected to the grid for power generation. On February 27, 2010, all 34 wind turbines were installed and all wind turbines were connected to the grid for power generation in July.

China's first offshore large-scale wind power project can be built on the grid quickly, mainly relying on technological innovation. In China, the installation of large-scale offshore wind turbines is still the first time, and there is no mature technology and experience to learn from. Offshore offshore wind power installations have two schemes, namely the use of offshore platforms to achieve split lifting and the use of special shipboard equipment for integral lifting. During the design of the Donghai Bridge offshore wind farm installation plan, the expert group considered that the offshore operations were affected by waves, wind direction, wind speed, tidal range, undercurrent, and passing ships. After the cost accounting comparison, the split lifting was excluded. Adopted a three-step installation plan for the overall assembly of the wind turbine on land, the overall transportation at sea, and the integral lifting at sea.

In terms of wind power infrastructure construction, based on the special case of deeper silt in the East China Sea, the high-pile platform design replaces the commonly used fixed scheme abroad, effectively solving the technical problems of high-rise turbine load bearing, anti-pulling, and horizontal displacement. The world's pioneering infrastructure for offshore wind turbines. This is not only in line with the actual conditions of the wind farm, but also gives full play to the core advantages of China Communications and the three aviation bureau, high pile cap as its "look-home skill", the technology is very mature. In addition, the company's own technology crane center GPS positioning system, so that the crane lifting crane can quickly and accurately reach the designated position, to achieve the lifting of the rough positioning.

In the process of integral lifting at sea, it is the key to solve the problem of buffering and precise positioning of the joint between the complete machine and the base platform. Through R&D, the construction party broke through the two key technical bottlenecks of “stability” and “precision” when lifting the fan in a short time. The wind turbine equipment of the Donghai Bridge offshore wind farm has precision instruments that are prone to damage. For this reason, the construction party has developed a soft landing device suitable for the overall lifting of offshore wind turbines, successfully conquered the technical difficulties of wind turbine installation under adverse natural conditions at sea, and achieved a stable, safe and reliable installation of the fan in place.

After the coarse positioning and buffering are realized, how to accurately position and dock the tower tower of the fan and the base tower is another problem. According to the technical requirements, the centering error of the bolt flange cannot be exceeded when the two tower sections are docked. 2 mm, compared with the huge fan equipment, the precision of the fan hoisting can be imagined, and the specially developed precision positioning device solves this problem.

--The input of the ship's machinery is of strategic significance to the future construction of offshore wind power. In the future, China will move forward toward intertidal wind farms.

If it has been to the East China Sea Bridge offshore wind power hoisting site, first of all to be able to leave a lasting impression is the crane ship that has extended two huge booms. This is why the three aviation bureaus have spent 300 million yuan to set a special requirement for installation of offshore wind power. The 2,400-ton crane vessel "San Air Style" was made. The whole machine of the wind turbine can be positioned by means of the GPS positioning of the lifting hook under the action of the double hooks of the lifting vessel, lifted, translated, aligned, completed rough positioning, and guided under the guidance of the soft landing system and the precise positioning device, accurately and steadily. The tower of the platform transition section is docked, and it takes only two and a half hours to complete this series of actions.

In addition to the "three aviation style" number, another ship machine equipment is the transformation of the 6000-ton special transport barge. The assembled fan has a huge size, with a stand height of 123 meters (including blade height). The fan blades have a length of 45 meters. After the hub is assembled, the rotating diameter is more than 90 meters. The journey takes 3-4 hours. Ships such as the Jinshan Waterway, which are in dense waters, can easily shift the center of gravity or tilt the wind turbine due to the shaking of the ship during sea transport. The dedicated transport barge can transport two sets of fan machines at a time, and the use of the company's own design of the well frame and balance beam device constitutes the “best partner” fixed fan upper part, which not only solves the problem of stability but also improves the transportation efficiency.

Compared to the offshore deep-water section of the Shanghai 100,000-kilowatt offshore wind demonstration project of the Donghai Bridge in Shanghai, the intertidal zone in China is vast, and the regional resources suitable for the construction of offshore wind farms are more abundant. However, due to the fluctuation of the tide, the average depth of water in the intertidal zone is only 1.5 meters, and the duration of the high water level in one day is only 2-3 hours. Due to the limitation of water depth and construction time, new requirements have been put forward for wind power infrastructure construction and installation technology, and new offshore engineering technologies are needed to solve a series of problems and expand the comprehensive strength of China's offshore new energy development.