"Endeavour" tidal power generator set successfully launched into the sea, the sea "symphony orchestra" how to generate electricity?

East China Sea "Violin" and "Guzheng"

The tide is like a musician

On the coast of the East China Sea, on the southern channel of Xiushan Island, is located the world's first Marine tidal current power station, which is named "East China Sea Violin" because of its unique shape. This tidal power station, born in July 2016, is a friend of the tide and partners with the sea all day long, continuously sending clean energy from the sea to thousands of households through the national grid.

General view of early tidal current power station by Zhang Fan

Photo by Tang Zhicheng of the current ocean tidal current power station

On February 24, the tidal current power Station ushered in a new member "Guzheng", that is, the world's largest single capacity of 1.6 MW tidal current power generator "Endeavour", the addition of this unit and the original "violin" combined into a "clean energy symphony orchestra", the harvest of a large wave of fan attention.

The "Symphony Orchestra" lies between two small islands in the south of Xiushan Island, Zhoushan, where the current is swift and the tide energy resources are rich, which is the most suitable natural stage for performance.

The part of the surface of the sea is nearly 200 meters long, 35 meters wide, and an average height of 20 meters, equivalent to the height of an 8-story building, and technicians call this frame structure "assembly platform". There are different "rooms" on the platform, which contain the various modules that keep the equipment running.

The fourth generation unit "Endeavour" hoisting Zhang fan photo

The fourth generation unit "Endeavour" goes into the sea to install Zhang Fan photo

Like an iceberg, it's beneath the surface. In order not to drift with the tide, scientists nailed the bottom of the assembly platform into rock-socked piles, which firmly fixed them to the seabed, so as to fully withstand the impact of the current. Second, scientists hid their "strings" under the ocean.

Students should focus on their "string" - the turbine, which is composed of a number of horizontal or vertical blades of the unit, the main role is to convert the momentum of the water into the mechanical energy of the blade rotation, so as to drive the generator to generate electricity.

Evolution of four generation units of tidal current power station

So in the vast sea, how is the tidal current energy unit installed? The scientists tailor-made a "plug and play" design for them, first fixing the turbine separately in the inner frame, and then the whole module is slowly placed into the assembly platform by the lifting ship, just like loading the battery into the battery compartment. To put it simply, the generator is like a sound box, the water turbine is like a string, the tide is playing the musicians, "symphony orchestra" in accordance with the "morning tide to fall late tide, January flow sixty times" schedule, day after day in the East China Sea on the line "concert".

The musicians who play them -- currents -- derive from the movement of water caused by tides. To the time on the schedule, the tide will ride the mighty sea water to them, the way to accumulate a huge amount of energy, and finally strive to pluck the "strings", "strings" on the blade began to turn under the impact, at this time the generator has also been with the "playing" signal, the "concert" officially began.

Fashion can be punctual and keep promises, clean and renewable. Trends, however, often come and go, and with varying degrees of enthusiasm. In order to pursue high-quality "performance effects" in a limited time, scientists set the optimal "string combination" for them to "play". In order to spend more time with the tide, a two-way flow operation was developed, so that each high tide and low tide could be played together.

Students may ask, what is the difference between tidal current power generation and ordinary hydroelectric power generation? This brings us to the difference between tidal and tidal energy.

First of all, energy comes in different forms. Tidal energy uses the potential energy in the vertical direction of the tide, that is, the difference in water level; Tidal currents can use the kinetic energy of the tide in the horizontal direction, which is the impact force. Second, the power generation principle is different. Tidal power works in a similar way to the Three Gorges Dam, by storing seawater in a harbor reservoir at high tide and releasing it at low tide. The difference in water levels causes turbines to spin. Tidal flow energy uses the energy of the sea water flowing to push the turbine to spin.

"Endeavour" tidal power generator set, why cow

What is the difference between the fourth generation of the tidal current generator set "Endeavour" and the previous generation of the unit?

First of all, look at the following set of data: the capacity of the single unit is 5 times that of the previous generation, the power generation capacity is 8 times that of the previous generation, but the investment is less than 1.5 times that of the previous generation, in short, the power generation cost is greatly reduced, laying the foundation for the commercial development and operation of the future power station.

Secondly, the power generation efficiency is higher, the fourth generation unit uses two-way variable paddle to make the blade rotation Angle more flexible, the unit can change the direction of the blade in the two-way power flow, in order to fully capture the flow direction of the power flow, has achieved better power generation efficiency. Finally, the maintenance is more convenient, before the failure to use the lifting ship to lift the unit maintenance, it is very troublesome, now "Endeavour" has an independent maintenance channel, the staff can go directly to the underwater unit through the central vertical channel to carry out maintenance work.

No matter how many brothers there are, the "violin" and "Guzheng" were born in response to the development of Marine clean energy and the construction of Marine economic power, their mission is to continue to "play" clean energy and contribute to the "double carbon" goal in response to global warming and energy shortage.

With the sea as their home, "violin" and "guzheng" also have to face many problems brought by the complex Marine environment: weak alkaline seawater corroded and worn "violin strings" for a long time; Marine debris, Marine life will always wind "strings"; Fashion enthusiasm is always high and low. In order to optimize the "playing" effect, they are constantly upgraded. Scientists sealed the key parts of their bodies with rubber, coated the shell with special anti-marine life and seawater corrosion paint, and washed the equipment with the help of bearing water purification stamping technology, by adjusting the blade to achieve the best Angle... In this ever-changing era, they insist on arming themselves with high technology to get out of the sea.

After talking so much about the introduction of the power station itself, I believe you must be interested in the "ticket" of the concert. On June 20, 2019, the on-grid guidance price of the tidal current power generation project was officially approved by the issuance and reform department, which was 2.58 yuan per KWH. This settlement check for 2.56 million yuan marked the first settlement of the tidal current power generation in China. This ticket seems a little expensive, after all, the cost of holding a concert is too high, from "only this one, no other branch" pressure is too big. However, it is believed that with the continuous maturation of technology and the continuous upgrading of management, especially after large-scale commercialization, when there is no longer only this "violin", the ticket price of the concert will be further reduced.

China's coastline has 32,000 kilometers, especially the Zhejiang and Fujian seas have a very large potential to settle in, I believe that in the near future, they will become the true C position of clean energy symphony orchestra. In the future, there will be more "violins" and "guzheng" together with other members of the orchestra (such as wind power, photovoltaic, etc.) to play in the distant sea islands.