Refrigerator is a kind of refrigeration equipment to maintain a constant low temperature, and it is also a civil product to keep food or other items in a constant low temperature cold state. Why can only refrigerators? Here are the reasons I sorted out about refrigerator refrigeration. Welcome to read and refer to.
Why can refrigerators cool?
The refrigeration system of refrigerator is composed of compressor, evaporator, condenser, capillary and drying filter. The compressor is a power machine that changes the state of refrigerant, which adopts fully enclosed type; The function of the evaporator is to absorb the heat of the items in the refrigerator and make the liquid refrigerant evaporate into gaseous state through endothermic evaporation; The function of the condenser is to release the heat brought by the refrigerant. At the same time, it can also make the gaseous refrigerant condense into liquid through heat dissipation; The function of capillaries is to control the flow of refrigerant to reduce pressure and throttle.
In the refrigeration process of the refrigerator, firstly, the heat absorbed by the evaporator is transformed into gaseous state, and then compressed into high-temperature and high-pressure gas through the compressor, which is transmitted to the condenser, and then the gas is emitted through the pipe wall, so as to reduce the temperature inside the refrigerator. In this cycle, the heat inside the refrigerator will be continuously transferred to the outside of the refrigerator, so as to achieve the purpose of refrigeration.
Introduction to the origin of refrigerator
Human beings have known for a long time that food preserved at a lower temperature is not easy to decay. More than 2000 BC, ancient residents of the Euphrates and Tigris River Basins in Babylon, Cuba, in West Asia began to pile ice blocks in pits to refrigerate meat. China also knew how to preserve food with ice in the Shang Dynasty (the early 17th century BC to the 11th century BC). In the middle ages, many countries also appeared in the original refrigerator that put ice cubes in special water cabinets or stone cabinets to preserve food. Until the 1850s, this kind of refrigerator was still on sale in the United States.
In 1822, Faraday, a famous British physicist, discovered the phenomenon that gases such as th oxidized carbon, ammonia and chlorine will become liquid under pressure and gas when the pressure decreases. In the process of changing from liquid to gas, it will absorb a lot of heat and make the surrounding temperature drop rapidly. Faraday's discovery provides a theoretical basis for future generations to invent artificial refrigeration technologies such as compressors. The first artificial refrigeration compressor was invented by Harrison in 1851. Harrison is the owner of the Australian "Keelung advertising newspaper". When cleaning the type with ether, he found that the ether had a strong cooling effect on the metal. Ether is a liquid with low boiling point, which is prone to evaporation and endothermic phenomenon. After research, Harrison developed a refrigerator using ether and refrigerator pressure pump, and applied it to a brewery in Victoria, Australia for refrigeration and cooling during brewing.
In 1873, German chemist and engineer Karl Feng Linde invented a refrigerator with ammonia as the refrigerant. Linde uses a small steam engine to drive the compression system, so that ammonia is repeatedly compressed and evaporated to produce refrigeration. Linde first applied his invention to the sedumar brewery in Wiesbaden to design and manufacture an industrial refrigerator. Later, he improved the industrial refrigerator. It was miniaturized and the world's first artificial refrigeration household refrigerator was manufactured in 1879. The steam powered refrigerator was soon put into production, and 12000 units had been sold in Germany and the United States by 1891.
The first refrigerator with a compressor driven by an electric motor was invented by Swedish engineers Brighton and Mendes in 1923. Later, an American company bought their patent and produced the first batch of household refrigerators in 1925. At first, the electric compressor of the refrigerator was separated from the refrigerator. The latter was usually placed in the ground kiln or storage room of the family and connected with the electric compressor through pipeline. Later, it was combined into one. Before the 1930s, most refrigerants used in refrigerators were unsafe, such as ether, ammonia, sulfuric acid, etc., or flammable, corrosive, or irritating. Later, he began to explore safer refrigerants and found Freon. Freon is a non-toxic, non corrosive and non combustible fluorine compound. It soon became the refrigerant of various refrigeration equipment and has been used for more than 50 years. However, it was found that Freon had a destructive effect on the ozone layer of the earth's atmosphere. So people began to look for new and better refrigerants.