Cable branch box - cable span mass body to create island "power accelerator

Under the cross-sea bridge connecting Beilun District and Meishan Island Free Trade Zone in Ningbo, Zhejiang Province, six "power silver snakes" meander along the bridge towards Meishan Island Port Area. In June this year, with the launch of the 110 kV Qixing power transmission and transformation project, this cross-sea power channel will send a steady stream of power to the port area.

In 2008, the State Council approved the establishment of Ningbo Meishan Bonded Port Area, which is the fifth bonded port area in China after Shanghai Yangshan, Tianjin Dongjiang, Dalian Dayaowan and Hainan Yangpu. In the same year, the Ningbo Municipal Party Committee and the Municipal Government made a decision on accelerating the construction of Meishan Island.

In September 2009, various construction projects known as "Meishan" speed were fully launched on the island, more than 400 mu of storage land began piling, more than 10 infrastructure projects were started on the whole line, and the only 35 kV Meishan substation on the island was in short supply, so the power construction was urgent. To this end, Ningbo Electric Power Bureau, adhering to the principle of special affairs, has been implementing a special plan for power construction tailored for Meishan Island to meet the long-term development needs of the port area.

Tailored island "electric accelerator"

Special power construction means that every link from feasibility study, design to construction will closely focus on the construction and development needs of the port area, which means more comprehensive, more detailed and more considerate construction and services. At the beginning of 2013, after nearly five years of efforts, the 110 kV seven-name power transmission and transformation project entered the construction phase. In the face of such a rapidly developing island, protecting the environment and saving resources have become the work of Ningbo Electric Power Bureau.

"Considering the overall environment of the long-term development of Meishan Island Port Area, the overhead lines in this area are undergoing" up-to-down "transformation," said the project design director. From the perspective of the long-term development of the port area, the conventional overhead lines are bound to have an impact on the landscape of the Meishan Bridge portal and the future development and construction of the area through which the lines pass.

For this reason, Ningbo Electric Power Bureau has advanced planning, on the one hand, to transform the overhead lines in the development area into the ground; On the one hand, 110 kV cables with a cross section of 1000 square millimeters are used for the extremely difficult cross-sea laying to improve the "regional quality" of Meishan Island with technical quality.

"In order to coordinate the development of the island and combine the load characteristics of the port area, we have selected the voltage level of the distribution network in the port area as 20 kV." The project design director said that at present, the distribution station project of Qixing power transmission and transformation on Meishan Island is under construction.

Previously, in order to save the island resources and achieve the best quality of power supply, Ningbo Electric Power Bureau mobilized technical forces, expanded the scope of research, increased the intensity of research, and fully combined with the characteristics of Meishan Island, which is "long from east to west and narrow from north to south", proposed to build a 20 kV smart distribution grid on Meishan Island, reducing the planned 110 kV substations in the island from 3 to 2, which saved the line channel resources and land resources to the maximum extent.

Cross-sea laying of the "energy artery" in the port area

In April, the transmission line project from 220 kV Xianxiang Gan'ao Line T to 110 kV Qixing substation entered the most critical cross-sea cable laying stage of the whole project. This short distance of 1.1 kilometers carries the three first steps of Ningbo 110 kV cable: the first step is to lay the cable with a section of 1000 square millimeters, the first step is to carry out the cable construction along with the cross-sea bridge, and the first step is to set the cable expansion joint device according to the bridge expansion joint. The construction of the project is faced with various difficulties and challenges from the beginning.

Both sides of Meishan Island Bridge are fast lanes, and the cable laying space in the middle of the bridge is very narrow. After each cable expansion device weighing up to 5 tons arrives at the construction site, it is faced with the dilemma that it cannot be put in place. "Brothers, dismantle them first, and then transport them to the bottom for assembly." Ye Meng, the leader of the cable team, cheered, and more than 20 hands immediately disassembled the cable expansion devices into parts that are easy to lift and move.

Hanger, shoulder, several times down, in this still slightly cool season, everyone has already been sweating. After the parts are transported to the designated location, in order not to affect the subsequent construction, the construction team simply "cat" in the narrow space for five days continuously, and carefully assembled the five telescopic devices like building blocks.

The equipment problem was solved, and new difficulties followed. On April 12, in the hunting sea breeze of Meishan Island Bridge, the cable straightening machine had just stopped, and Ye Meng and several construction workers laid out the construction plan again for discussion. According to previous work experience, the difference between the relative positions of cable straighteners can be used to realize the bending of cables. However, after field trial, it is found that the straightener is bulky and slow in effect, and can only be constructed for 100 meters per day. There are 6000 meters of cables to be laid in serpentine form on the bridge, which will take 60 days to complete, and the whole project must be put into operation in June. What should we do?

"We must try to finish the cable laying in the shortest time." In the fierce sea breeze, everyone heard the firm voice of Ye Meng. After more than ten hours, six solutions and dozens of tests, the construction scheme of using the chain block as the cable orthopedic tool was finally approved.

"One, two, three, get up!" Ten pairs of hands with blue tendons tightened the chain block along the cable path, and tried their best to pry the 9-ton cable. Six silver "giant snakes" gradually surfaced, and the simple and efficient construction also reduced the construction period to 10 days.

"Within a few years, Meishan Island has become a new" giant ship "on the southeast coast from a barren and barren saline land. The key is to rely on strong power support.".