In recent years they are endeavouring to develop and use natural energy including solar, wind, geothermal and tidal powers in the Democratic People’s Republic of Korea.
The electrotechnology faculty of the Kim Chaek University of Technology has achieved a number of successes in the work of developing highly efficient wind-driven generators of various types. In August last year they presented an involute wind-driven generator to a national sci-tech exhibition dedicated to the field of developing and using natural energy and economizing energy. The generator came as one of the top three exhibits. And at a national IT achievement exhibition held in November that year a highly efficient windmill flier designing support program the faculty had developed was awarded a prize, attracting the interest of visitors.
Kim Yong San, head of the research team, says, “The involute wind-driven generator we have developed is convenient for families to use as the flier is much more efficient with less noise and greater reliability, stability and aesthetic quality.” And he tells a story:
One day in February last year the research team had a discussion to introduce high-performance wind-driven generators across the country. To the surprise of the participants, researcher Kim Mun Hui made an unexpected suggestion. She said that since the horizontal-axis wind-driven generator with three fliers was scarcely installed in dwellings and streets because of a number of defects, they had to develop a new type of generator which would be attractive, economical and easy to install. Then, she produced an idea on a new type of involute winddriven generator
Thus a relevant research work began. An important problem was to apply an involute curve to the flier designing. To raise the efficiency of wind energy to the maximum, it was important to set a reasonable ratio of diameter to length of a flier, make a flier model based on the principle of involute curve and screw and figure out the flier shape ensuring a broader flier surface hit by wind.
Mun Hui worked day and night. Though they failed over again in computer simulations while studying science and reference books, they finally succeeded in acquiring reasonable values in the third test. Now they entered the stage of properly arranging and fixing the generator and the turning device. The bottleneck was that the centroid as a whole was unstable, for the generator itself was too heavy, thus the generator’s turning to the wind direction was awfully awkward. When they were anxiously groping for a solution researcher Kim Kwang Il blurted, “Why do you put the generator at the back always? Fix it in the front, and that will do.” Everybody approved his idea.
In this way many scientific and technological problems were solved through the pool of collective knowledge and zeal, and the involute wind-driven generator took shape after the ninth test.
Kim Mun Hui explained the advantages of the new generator. “This generator has a good mobile quality as the fliers tap energy all about their surface. And the fliers catch the whole energy of the wind blowing against them, thus increasing the generation efficiency. The noise has become less by more than a half compared to older generators. The fliers resemble a flower in their shape.”
Kim Yong San says, “There are still quite a few sci-tech problems to solve to make use of the wind force. We will produce new types of wind-driven generators of higher efficiency by intensifying the research in the use of wind energy with our efforts and knowledge.”
Now they are pushing ahead with a research project in the final stage to develop a new model of wind-driven generator by building on their achievement.
An article by Mun Il Jin
