"Kid" inventor

(Baonghean) - "We hope that solar energy, a clean natural energy source, will be exploited to serve more human life", that is also the idea that originated the scientific topic "Exploiting solar energy with external combustion engines" of two students Dau Van Thuan and Nguyen Ngoc Chinh (class 9B, Dien Hai Secondary School, Dien Chau) who excellently won Second Prize at the National Science and Technology Competition for high school students in the 2014 - 2015 school year.

Dau Van Thuan shared: “In my hometown, the electricity grid has not been extended to the fields, so the villagers still have a hard time. One time when I went to work in the fields, I saw my parents still having to work hard pulling the electric wires, waiting for the water pump to operate, under the scorching sun, I suddenly had an idea: “Why not turn solar energy into electricity for irrigation?”

From that idea, Thuan shared it with his close classmate Nguyen Ngoc Chinh. The common point of these two students is their passion for science. Thuan's family has a side business of making household carpentry, so the two often take advantage of carpentry tools such as wood and steel to satisfy their hobby of tinkering, assembling, and designing models.

Students Dau Van Thuan and Nguyen Ngoc Chinh introduced the topic "Exploiting solar energy using external combustion engines".

When the school launched a science and technology innovation contest, the students enthusiastically participated. The topic "Exploiting solar energy with an external combustion engine" is based on the principle of light convergence. The model is designed with tools, a concave mirror used to catch sunlight and convert the parallel beam of sunlight into a converging beam, which means converting light energy into heat energy, to convert it into mechanical energy, helping the engine to operate. However, from idea to model was a challenging process for the two 9th grade students.

To complete the project, Thuan and Chinh had to supplement their knowledge with physics documents and look up on the internet, build technical parameters for the model. That was the time when they explored and invented on their own. After school hours, Thuan and Chinh took advantage of the time to search for recycled materials such as beer cans, milk cartons, plastic bags, iron bars, etc. to cut and trim into engine parts such as pistons, cylinders, and flywheels. "There are parts that require precision with the technical parameters of the model's structure, such as the round, flat flywheel made of iron. It took us a long time to search in repair shops and forging and welding shops to find the right materials," Thuan shared.

After obtaining the necessary materials, the two students diligently practiced assembling with their instructor. The most difficult step was making a concave mirror, with a diameter of over 1 meter. The steel bars had to be cut evenly, then bent into a circle to make a base; the mica sheet was cut into dozens of small, even fan-shaped shapes to be glued into a concave mirror, requiring meticulousness with every detail. There were dozens of cuts and trimmings but they did not meet the requirements and had to be redone. But perhaps the most memorable was the time when the model was completed in the final stage, and the teacher and students took it out to test. Under the sunlight, the mirror converged light but reflected it upwards, and the heat-collecting position was not made correctly, so the concave mirror that the two students and the teacher had spent months making was scorched.

Awarding prizes to the children

The teacher and students had a headache calculating to find the errors to fix. Accompanying the two students for a long time, the special impression that teacher Nguyen Minh Dong had of his two young students was their diligence, hard work, constant learning and creativity. After each failure, the students were very determined and self-motivated to learn, find documents to come up with their own solutions without being discouraged. If Thuan excelled in intelligence and was good at discovering problems, Chinh was always persistent and meticulous, accurate to every detail, thanks to which the students complemented each other to build a successful topic.

After 6 months of hard work, the external combustion engine model exploiting solar energy was completed. With outstanding advantages such as: exploiting an endless source of clean energy (a new direction in today's era, natural resources are increasingly being exploited and depleted); at the same time contributing to protecting the living environment; using an external combustion engine can achieve the highest efficiency compared to other types of heat engines, reducing noise and reducing emissions into the environment; the device is attached to a storage unit to store electricity in case of lack of sunlight, the machine can still operate... thanks to that, the work of the "young scientists" won the Second Prize at the National Science and Technology Competition for high school students in the 2014 - 2015 school year.

The success of the recent competition is a great source of motivation for the students to strive harder to excel in their studies. At the same time, they also expressed the very simple wish of the two coastal students: "Hopefully in the future, the external combustion engine model exploiting solar energy can be widely applied to operate household machines such as water pumps, drills, rice threshers, fans... to save costs and effort, helping farmers in plowing, planting or days at sea, entering the fields in the countryside, contributing practically and usefully to the lives of people in places without electricity grid such as islands, remote areas...".

Dinh Nguyet