Compared with other new energy power stations, the molten salt tower solar thermal power station not only looks modern, but also extremely spectacular. Its main project is composed of a high-rise building and many surrounding high-rise buildings. Made of mirrors, China also has one such building, and it was completed as early as 2018.
This molten salt tower solar thermal power station in China was built in the Dunhuang Gobi Desert. It is the first molten salt tower solar thermal power station in Asia. Although in terms of design power, It is much smaller than ours in Dubai, with only 1 million kilowatts, but it can still meet the power consumption requirements of more than 80,000 homes, and in terms of appearance, it is also full of technological beauty. It is undoubtedly the best model on the Qinghai-Tibet Plateau. A scene. The main project of this solar thermal power station consists of a 260-meter-long heat collecting tower and 12,000 mirrors. So how does this equipment use mirrors to develop power plants?
The basic principle of the molten salt tower solar thermal power station is actually very easy to explain, which is to convert solar energy into heat and store it for use in generating electricity.
At first glance, it seems similar to traditional solar power generation, but in fact it is very different and has great advantages. The mirror used in the molten salt tower solar thermal power station is not an ordinary mirror. It has a special name called "heliostat." The heliostat is spherical and can rotate following the movement of light. , and accurately reflect the light shining on the mirror to the heat collecting tower above.
So how does the heat collecting tower store the heat? This requires talking about the molten salt material in the heat collecting tower. This molten salt is not lava, but it is similar to lava. Its main components are potassium nitrate and sodium nitrite. The shape of this salt material is very It is stable and can maintain a movable molten state between 290 degrees and 565 degrees. In order to better distinguish the high-temperature molten salt material and the ultra-low-temperature molten salt material, an ultra-low temperature tank and a high-temperature tank are installed on both sides of the heat collecting tower.
The ultra-low temperature tank stores lava material with a temperature of 290 degrees. When the heliostat sends light to the heat collecting tower, the ultra-low temperature tank will send the molten salt material at 290 degrees to the heat collecting tower. These molten salt materials gradually increase in temperature during the process of absorbing heat. When the water temperature approaches 565 degrees, a compression pump will pump them into a high-temperature tank for storage.
When preparing to generate electricity, the molten salt material in the high-temperature tank will be sent to the steam chamber, and then the water will begin to boil. The water will absorb the heat to form steam, and the steam will drive the turbine generator Run, electricity is created. The molten salt material transfers heat to the water, and its own temperature drops to close to 290 degrees, so they are taken back to the cryopump and enter the heat collecting tower again to collect heat. This is the basic concept of the molten salt tower photothermal power station. If you understand its basic principles, you can see the difference between it and traditional solar power generation. This difference is solved by the photothermal power station. The storage problem of kinetic energy.
Because the molten salt tower solar thermal power station can store heat through molten salt substances, its power output is very stable and is not limited by changes in day and night and weather changes, and can replace Traditional power generation methods, while solar power generation is completely extensive and can only be used immediately, so it can only be used as a supplementary power project.
So why can’t solar power generation be used for power engineering storage? And the cost is too high. If you want to equip a solar power station with corresponding power storage equipment, the project cost will increase by at least 10 times. Are there any surprises? But there's nothing flashy about it. Because to store the electricity produced by solar power stations, batteries must be used, and the cost of lithium batteries corresponding to solar panels is about twice that of solar panels, but the problem is that lithium-ion batteries The service life is far inferior to that of solar panels. The service life of solar energy produced today is more than 25 years, and lithium batteries can last for 5 years which is already the limit.
The construction cost of lithium batteries is twice that of solar panels, and solar panels need to be replaced five times during their lifespan. Calculated in this way, the construction cost will increase by 10 times, and This is also a very traditional possibility.
Compared with traditional solar power stations, the advantages of molten salt tower solar power stations are clear at a glance. It uses molten salt material to store heat and when the electricity is received The amount of electricity generated depends on the quantity command, so it is not only better than solar photovoltaic power stations, but even better than geothermal power generation and hydropower generation. So why is such an excellent new energy technology not popularized on a large scale? Compared with traditional power generation methods, the construction cost of molten salt tower solar thermal power stations may be relatively high, which hinders its rapid popularization in the short term, but in the future as scientific research continues With the continuous innovation of development and technology, construction costs will be relatively reduced. Therefore, the molten salt tower photothermal power generation method has great potential to become a popular power generation method in the future.