Power generation equipment using ocean wave energy is popular around the world but is not used much in Vietnam because these equipment is not suitable for our country's wave regime. Therefore, scientists at the Institute of Energy Sciences (Vietnam Academy of Science and Technology) have found a solution.
The device was tested on Nghi Son beach, Thanh Hoa.
According to research results of the Institute of Sea and Island Research conducted in 2018, Vietnam is a country with huge wave energy potential. Of which, the total wave energy along Vietnam's coast in the year reached about 247 TW. Coastal areas from Quang Ngai - Ninh Thuan, Quang Binh - Quang Nam, Binh Thuan - Bac Lieu are places with the best potential and wave energy in Vietnam.
Does not create waste and does not require high maintenance costs, so wave energy has long been exploited by many countries around the world. However, power generation equipment using ocean wave energy is usually only suitable for sea areas with an average wave height of (2-6)m. Meanwhile, the average wave height in Vietnam is from (0.3-2)m.
On behalf of the author group, Mr. Nguyen Binh Khanh - Institute of Energy Sciences said: "Through research, we have designed a model ocean wave power generation device suitable for Vietnam's ocean wave regime. Specifically, the model operates on the principle of a hydroelectric station with a reservoir by creating a difference in water head and flow through the turbine to generate electricity. With this principle, the device maintains a relatively stable water column and electricity generation flow. In addition, the turbine is designed according to the working principle of a hydroelectric turbine, helping to improve the efficiency of exploiting ocean wave energy."
The device body is box-shaped, forming a closed compartment, divided into 2 compartments: intake compartment and discharge compartment. The body has the ability to float and is kept above sea water by buoyancy. When the first part of the ocean wave cycle reaches the intake port of the loading chamber, the loading mechanism is opened, the sea water enters the loading chamber, rises, flows through the outlet into the discharge chamber and rises. When the second half of the ocean wave cycle reaches the side surface of the discharge chamber located under the inlet of the discharge chamber, the discharge mechanism is opened, the inward seawater flows through the open discharge mechanism, causing the turbine to rotate continuously in a cycle of ocean waves and continuous, relatively stable generation of electricity.
Prepare to test the device.
According to this design, the buoy is anchored to the seabed and can be adjusted up and down according to changes in sea level during the day. This helps the equipment to be positioned in the appropriate position at sea, operating at the highest efficiency.
The research team determined that this device is used to exploit wave energy in sea areas with low wave heights, ranging from 0.5m - 1m. In order for the device's power source to be continuous and relatively stable, the research team selected the optimal size of the device (intake chamber, discharge chamber and size of the inlet/discharge port, charge/discharge chamber to be able to receive maximize the potential energy of the wave and create a stable flow and water level difference between the intake and discharge compartments).
The author of the useful solution also added that because the wave characteristics of each sea area of Vietnam are different, the tidal regime and wind regime are also different. Therefore, when applying this model, it is necessary to re-measure the wave data and calculate and calibrate the most suitable model to achieve the highest performance.
The equipment has been tested in Nghi Son waters (Thanh Hoa). According to calculations by the research team at the time of implementing the project, the power generation equipment was designed and operated with a wave height range of (0.3 ÷ 1.5)m, capacity of about 300W, conversion efficiency Energy conversion η = (28÷40.43)%.
Notably, because the equipment works in a marine environment, the research team chose anti-corrosion equipment for the turbine part and water protection measures for the generator, and the equipment shell was painted to protect Anti-corrosion protection according to regulations for marine equipment and structures. The cost for 1kW is calculated to be about 30 million VND and the equipment can be used for up to 10 years if regularly maintained. In current conditions and technology, the price can be lower than 25 million VND for 1kW.
To apply this useful solution in practice, Mr. Nguyen Binh Khanh said, it is necessary to have a processing unit that meets the design. In fact, local processing facilities can also do it because the model is not too complicated and the details can be pre-set according to detailed drawings.
"The difficulty is to design and manufacture a turbine suitable for each model, because the device's turbine is not available" - Mr. Khanh added.
In addition, the research team also believes that the device will operate more efficiently when there is an additional energy storage solution (such as using batteries) because when there is a need to use electricity and when there are conditions The conditions for generating electricity (having waves) are not completely identical.
Also according to the research group representative, in recent times, the group has not been able to deploy this device widely due to lack of funding. In addition, if financial resources are found, the team will conduct research and further improve: The kinetic energy of the waves to increase the device's capacity; Fabricate the device's output and input ports to be more flexible to increase the ability to receive wave energy, thereby increasing the device's capacity: Use self-recording measuring devices to increase the accuracy of displayed data displayed on the device; Solutions to increase equipment lifespan; Manufacturing and installation solutions to be able to develop on an industrial scale and reduce equipment costs.
This useful solution has been granted a useful solution patent 2-0001903 by the National Office of Intellectual Property on December 25, 2018.
Bich Ngoc (Collaborative article between the Department of Intellectual Property and Science and Development)
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