The world’s compressor-free ultra-low temperature refrigerator with the lowest temperature of -80℃——Stirling ultra-low temperature refrigerator
The history of the refrigerator
The discovery of American Jacobi Perkins in 1834 led to the invention of the refrigerator. The Scot John Harrison discovered the cooling effect, and by 1862, his first refrigerators were on the market. And German engineer Karl von Linde made the first household refrigerator in 1879. But before the invention of the electric refrigerator in the 1920s, refrigerators did not enter households on a large scale, and they were popularized in the United States in 1920.
Household refrigeration equipment appeared in 1910. In 1913, Larsen produced the first manually operated household refrigerator. In 1918, the American company Kelvinator (Kelvinator) sold refrigerators on the market for the first time. 67 units were sold that year, 1926 In the United States, Qiqi Company produced the world's first refrigerator with a sealed refrigeration system. In 1927, the first household absorption refrigerator appeared in the American market and gradually became popular in the 1930s. In 1939, the double compartment was introduced for commercial use by General Electric.
The role of the refrigerator
In the last century, refrigerators were a luxury item in China. At that time, those who could afford refrigerators were afraid of being rich or expensive. With the rapid development of China's economy, people's living standards have generally risen. Now refrigerators are basically standard equipment in every family.
The role of the refrigerator
Household refrigerators are frozen and fresh to ensure that the ingredients will not spoil. If there is no refrigerator, in the summer, it can be said that the dishes will not survive the night, and the overnight dishes have many bacteria, even poisonous. You can't buy more fruits. If you buy too much, you can't eat them. The next day they won't be fresh or even deteriorate.
The working people in ancient China were very wise. In ancient times, there was a method of making ice with brine and a good method of storing ice. Therefore, ancient people could eat "popsicles". In addition, ancient people used well water or Iced watermelon in spring water and preserved tofu are also very good methods.
However, the above methods are also relatively limited. What really changes people's lives is the appearance of refrigerators.
Ultra-low temperature refrigerator-cold source cold chain Stirling refrigerator
Many people may not have a concept of ultra-low temperature refrigerators. This article is about Stirling refrigerators, which can cool to more than -80℃. Now ordinary refrigerators are cooled to -24℃.
The fundamental difference between a Stirling refrigerator and an ordinary refrigerator is that the ordinary refrigerator uses a compressor for cooling, while the Stirling refrigerator uses a Stirling engine for cooling.
The Stirling engine was invented by British physicist Robart Stirling in 1816, so it was named "Sterling Engine". The Stirling engine outputs power through a cycle of cooling, compression, heat absorption, and expansion of the working medium (hydrogen or helium) in the cylinder, so it is also called a heat engine. Stirling engine is a kind of external combustion engine, and its effective efficiency is generally between gasoline engine and diesel engine.
The advantages of Stirling engine are simple structure, high efficiency, high reliability and long life. The main application fields are aerospace, submarine, solar energy, etc. It has only been applied to the biological refrigeration industry in the past ten years. Because of the large noise, slow refrigeration efficiency, high power consumption, high voltage and environmental requirements of the ultra-low temperature refrigerator that overcomes the traditional compressor refrigeration, the industry or even the international industry cannot overcome it for nearly half a century. The problem, it can be said that the ultra-low temperature refrigerator using the Stirling engine has opened a new era of technological refrigeration.
Advantages of Stirling refrigerator
1. Temperature stability: The temperature fluctuation range of the refrigerator is within 1℃
2. High refrigeration efficiency: the volume is more than 700 liters, all doors are opened for about two minutes, and the temperature will return to -80°C within 35 minutes after closing the doors
3. No voltage requirement, no need to modify the circuit: the voltage range is wide to 100-256V
4. Noise: <45 decibels
5. Energy saving and environmental protection: Compared with traditional compressor refrigerators, energy consumption is reduced by 70%, and because of low heat dissipation and low carbon emissions, the cost of air conditioning is also reduced by 60%. Use 100% natural refrigerant, no pollution, no possibility of ozone depletion, no volatile organic compounds.
6. Stable performance, low maintenance cost, no compressor failure
Stirling refrigerators are now mostly used in the medical field, transporting vaccines, etc. During the COVID-19 period, many places used this kind of refrigerator to transport nucleic acid test reagents. There is one in the United States that has production capacity for this type of refrigerator, and China's Guangdong Cold Source Cold Chain is the second company in the world to produce this type of refrigerator.
The rapid development of China's science and technology, in the near future, Chinese medical field can also use this kind of ultra-low temperature refrigerator.
