In the 21st century, the most competition among human beings is the competition about energy . The non-renewable nature of most natural resources tells us that human civilization will "stop" after human beings have exhausted everything. Because has no energy, we simply cannot develop technology, let alone realize the dream of interstellar immigration .
After the real problem of energy depletion is in front of us, scientists from all over the world are actively looking for a new energy source, intending to replace these old energy sources. nuclear fusion was born at this time, as a part of nuclear energy, it can easily turn waste into treasure, and it also has super benefits. How tempting is
nuclear fusion? Scientists once said that 0.6 tons of nuclear fusion fuel is equivalent to 2 million tons of high-quality coal , so what other advantages does nuclear fusion have? Why don't we take a look together.
tempting nuclear fusion
nuclear fusion is a way to utilize nuclear energy, it can also be called nuclear fusion. The nucleus in mainly refers to the atom with small mass, such as deuterium, helium-3 and so on. Use high temperature or high pressure to let the extranuclear electrons break free from the shackles of the nucleus , and then let the two nuclei attract each other to form a larger core. The loss of mass is accompanied by the release of huge energy. Like the hydrogen bomb explosion we are familiar with, it is the result of nuclear fusion.
The familiar sun has been doing nuclear fusion reaction inside , this reaction allows it to release a large amount of energy, for example 1 kilogram of deuterium fusion releases energy equivalent to the energy released by burning 11,000 tons of standard coal.
The aggregation of atomic nuclei sounds very easy, but it is actually very difficult to operate. Why do you say that? Because atomic nuclei are positively charged, they have the principle of same-sex repulsion between them, but it is worth mentioning that the lighter the atomic nucleus is, the smaller its electrostatic repulsion will be.
Common nuclear fusion reactions are: D+T→4He+n+17.6MeV, D+D→3He+n+3.0MeV, D+D→T+p+4.0 MeV.
nuclear fusion process
so what are the advantages of nuclear fusion? First of all, from the perspective of its raw materials, the lighter the nucleus used in nuclear fusion, the better, so its best fuel is deuterium and tritium. seawater happens to contain a large amount of this element. According to statistics, contains 0.03g of deuterium per liter of seawater. And 70% of the earth is ocean, so it is roughly estimated that the amount of deuterium in seawater is at least 45 trillion tons.
nuclear fusion production is extremely efficient. According to the fuel burned by a 1 million kwh power station in a year, if it is an oil-fired power plant, it will consume 1.3 million tons of fuel oil a year, and if it is a traditional coal-fired power plant that uses coal as fuel, it needs to burn 200 a year tons of high-quality coal. But Assuming that this power station uses nuclear fusion, it only needs to consume 0.6 tons of deuterium per year.
only needs 0.6 tons of deuterium for nuclear fusion, which can easily be equivalent to 2 million tons of high-quality coal , how many times higher this production capacity is self-evident.
Finally, nuclear fusion also has the characteristics of clean and pollution-free, safe and reliable. Some people may be confused, nuclear radiation is notA very serious pollution? This is because the word nuclear pollution has left a deep impression on us. Whether it is the explosion of the Chernobyl nuclear power plant or the leakage of the Fukushima nuclear power plant in Japan, it seems to prove to us that nuclear energy is unsafe.
Chernobyl
But nuclear fusion is different, the waste it produces after the reaction is a kind of inert gas, this gas is called "helium", it will not produce radioactive substances, so it is impossible to pollute the environment . In addition, the nuclear fusion reaction is a chain of rings, as long as any link in this chain is removed, the nuclear fusion can be completely stopped. Therefore, it is more stable and safer than nuclear fission , and is less affected by the outside world.
In summary, it can be seen that the advantages of nuclear fusion are very obvious, and any one of the advantages is particularly in line with the development needs of the current era. So since nuclear fusion is such a high-quality energy source, why hasn't it been widely used in our lives until now?
The difficult road of exploration of controllable nuclear fusion
Although nuclear fusion has many benefits, it is very difficult to realize it. In the previous article, when I introduced the principle of nuclear fusion, I mentioned that "same-sex repels each other" . It is true that in the experiment, there is a real limitation in trying to combine two atomic nuclei that are "inseparable from each other". It is too much. Although the hydrogen bomb explosion we are talking about is through nuclear fusion, it belongs to uncontrolled nuclear fusion.
If you want to use nuclear fusion to produce a large amount of efficient and cheap fuel, then must first make nuclear fusion "controllable". This is the controllable nuclear fusion that countries all over the world are now studying.
Controllable nuclear fusion
Controllable nuclear fusion experiments and research began as early as the 1950s, when China, the United States, EU, Russia and other seven countries jointly participated in the ITER project which cost 10 billion euros . But so long has passed, and there are still only a handful of substantive achievements about controllable nuclear fusion obtained by human beings.
The controllable nuclear fusion that modern humans can achieve is still in the first generation, which is based on deuterium-tritium fusion. However, tritium is produced by the reaction of neutrons and lithium-6 (6Li), that is, n+6Li→T+4He, which involves the issue of lithium resources.
So currently, controllable nuclear fusion is still in a research stage, and there is still a long way to go before it can be used as an energy source for human beings. After all, although its main raw material is a lot of deuterium, other raw materials for auxiliary synthesis are very scarce, which invisibly increases the cost of nuclear fusion. Besides, human has not mastered the method of safely realizing continuous and controllable nuclear fusion.
In short, no matter in terms of technology or demand for raw materials, controllable nuclear fusion still has to go through a long and difficult stage. According to the scientists, judging from the development of modern scientific and technological exploration, it is difficult to say how many years it will take to see the rainbow through the fog. Next, we may have to invest more financial resources and energy in this area. After all, enough quantitative changes can lead to qualitative changes. I believe that with continuous accumulation, controllable nuclear fusion research will meet our expectations and needs sooner or later. .
nuclear power generation
nuclear power generation was discovered and implemented very early, but "nuclear fission" power generation is mainly used. However, the energy of nuclear fission power generation does not seem to be very high. The current mainstream power generation method of is still coal power generation , so which one is better compared with nuclear fission power generation and nuclear fusion?
Let's first look at the history of the use of nuclear fission. As early as the 19th century, after Tom discovered electrons, there were concerns about the use of nuclear energyThe issue has been closely watched by countries. After Einstein put forward the intelligent conversion formula, it made everyone realize how much energy is contained in the small atomic nucleus. It was not until 1938 when Otto Hahn discovered the phenomenon of nuclear fission that humans really began to use nuclear energy.
nuclear fission
Until January 2005, a total of 439 nuclear power units in 30 countries around the world were in operation, with a total installed capacity of 360 million kilowatts and a total power generation of 2.5 trillion kWh. Among them, there are 9 units in mainland China, with an installed capacity of 6.6 million kilowatts and a power generation of 42 billion kWh. The advantage of
nuclear fission power station is that it is small in size and high in energy, which is more beneficial than traditional fossil fuels. and its pollution is much smaller than that of thermal power generation, at least it will not release carbon dioxide and other greenhouse gases. But the shortcomings are also obvious, such as the problem of how to properly dispose of the radioactive nuclear waste used in power generation. Because nuclear waste is still very radioactive, if it is discarded at random, it will affect people's lives and safety, which is why Japan's discharge of nuclear wastewater has caused public outrage.
Fukushima Daiichi Nuclear Power Plant
Fukushima nuclear fusion is much safer than . You already know that nuclear fusion does not produce radioactive substances, but only inert gas such as helium, which is not harmful to the environment and human beings. There is no harm. So if people can use nuclear fusion to generate electricity in the future, they don't have to worry about how to deal with nuclear waste as they do now. In addition, the production capacity of nuclear fusion is higher than that of nuclear fission, and then "electricity" will become the cheapest energy in life.
In general,nuclear power generation can effectively reduce the use of coal. According to statistics, in 2011, my country's coal production has exceeded 3.5 billion tons, of which about 1.8 billion tons are used for power generation and heating. In time, if we can widely promote nuclear power generation, it will not only increase production capacity but also reduce pollution and cost.
Mechanized coal mining
Nuclear fusion and interstellar travel
With the continuous deepening of cosmic exploration, human beings are full of infinite reverie for the world outside the solar system. But the cruel reality tells us that the limited lifespan of human beings is too short compared to the long distance. If you want to fly out of the solar system, you don’t know how many generations you will die on the spaceship . The speed and flight distance of the
spacecraft depend on the fuel it uses. In other words, as long as the fuel used is good enough, it will be easy to fly out of the solar system. For example, the Valkyrie space shuttle used in the movie Avatar, and the future human battleship described in the novel " three-body ". The fuel of these high-tech spacecraft all benefits from nuclear fusion reaction, so it can be seen that nuclear fusion is closely related to our dream of interstellar travel.
Space Shuttle in "Avatar"
This depends on the kinetic energy conversion efficiency of energy. The kinetic energy conversion rate of traditional chemical fuels is less than 35%, while the conversion rate of ion propulsion using electric energy can reach more than 90%. It can be seen that the energy conversion rates of these energy sources are different, and the higher the efficiency, the higher the benefit. Nuclear fusion can directly convert about 1% of the mass into energy, and the loss of mass is less than 1%.
Therefore, , the nuclear fusion propeller in an ideal state can make the spacecraft reach 30,000 km/s . Although it is still a long way behind the speed of light, it is much better than the current speed of the spacecraft. With the blessing of this speed, whether it is human beings to carry out interstellar immigration or interstellar travel, it has become much easier.
Designs of several kinds of nuclear fusion propulsion
China’s artificial sun
Controllable nuclear fusion as a kind of “future"Energy" has been valued by all countries in the world, and our country is no exception. If you have heard the nursery rhyme "Planting the Sun" and then check the current development status of China's controllable nuclear fusion, you will find that we are really silent
This man-made Chinese sun is exactly China's "China Circulator No. 2 M", which is a new generation of controllable nuclear fusion research experimental device developed by our country. The highest parameter magnetic confinement controllable nuclear fusion experimental device, the ion temperature can reach more than 100 million degrees Celsius.
China Circulator No. 2 M
Not only that, On September 30, 2019, ITER Host Installation No. 1 contract was officially concluded in Beijing, Chinese enterprises play an important role in this. Judging from China's current controllable nuclear fusion research results, China will have a greater say in this field in the future.
Chairman of China National Nuclear Corporation Yu Jianfeng summed up with pride:won the installation project of the core part of the ITER project through international bidding, which proves that our team is leading in the world.
The future prospect of nuclear fusion
Nuclear fusion has become a hot topic of discussion as soon as it appeared, it is no exaggeration It is said that if controllable nuclear fusion can be realized within the next 20 years, then will bring a leap to human society like the past " industrial revolution ". Wait until then, electric energy will be everywhere, cars , airplanes, etc. will no longer need to burn fossil fuels, and the earth will also recover ecologically due to the reduction of pollution by humans.
expects ITER to make greater progress and achieve more results under the joint research and efforts of scientists from all over the world. I hope that one day the long distance between the universes will no longer be a difficulty that hinders our exploration. By then, whether it is the Proxima Centauri or the Andromeda Galaxy will become the end that humans can easily reach.
