The refrigerator generates cold to preserve food.
The refrigerator is an appliance that generates cold to allow the preservation of food and other products. It is an appliance in which the temperature inside is always kept low (generally, less than 6 ºC ).
Thermally insulated cabinet
A refrigerator is a kind of thermally insulated cabinet. It usually has a compartment with a constant temperature of between 2ºC and 6ºC and another special section ( freezer ) intended for freezing thanks to a temperature of between -6ºC and -20ºC .
Known as a refrigerator , fridge , or refrigerator depending on the country, this appliance is usually located in the kitchen of homes. There are also refrigerators in various commercial establishments, in laboratories and in industrial plants.
Operation
What a refrigerator does is refrigerate : make an environment colder through artificial means. Its operation is based on several physical properties, such as the transfer of heat from a hot body to a colder one; the condensation of compressed gases; and the removal of heat through evaporation.
In this context, the refrigerator uses a cyclic process to provide cooling. It has a gas that circulates inside a tube that, as it runs through the interior and external parts of the appliance, allows heat exchange.
In an external section of the path, the gas is compressed, which increases its temperature . It is then cooled in a condenser , releasing the heat into the environment. The cooled gas becomes a liquid that releases even more heat and then evaporates, continuing to remove heat so that the interior of the refrigerator cools. Finally, the gas returns to the outside for a new compression and to restart the cycle.
Types of refrigerators
- Single-door refrigerator : This is the most basic and common type. It has a single door that opens forward and contains both the refrigerator and freezer compartments;
- Two-door refrigerator : also known as a combi refrigerator , it consists of one door for the refrigerator compartment, at the top, and another for the freezer, at the bottom. It offers more storage space and is usually larger than a single-door refrigerator;
- Side-by-side refrigerator : has two vertical doors that open in opposite directions. One half is used as a refrigerator and the other half as a freezer. They are usually quite large and offer a more balanced distribution of space;
- French Door Refrigerator - Also called French door refrigerator , it combines the features of the side-by-side and combi refrigerators. It has two vertical doors at the top for the refrigerator compartment and a drawer-type freezer at the bottom.
History
The history of the refrigerator dates back centuries, when humans discovered the importance of preserving food and prolonging its shelf life . In ancient times, the most common way to preserve perishable foods was through the use of techniques such as salting, smoking or cooling in caves or underground pits. These practices allowed food to be kept fresh for longer.
One of the first significant advances in food preservation came in the 18th century . In 1748, Scottish inventor William Cullen demonstrated the process of artificial refrigeration using a steam-pumping apparatus. However, this technology was not widely used for practical purposes at the time.
In hot weather, we can cool drinks thanks to the refrigerator.
Between 1850 and 1900, several inventors and entrepreneurs contributed to the advancement of refrigeration technology. By the late 19th century, companies such as the Frigidaire Company and General Electric began manufacturing and marketing electric refrigerators for home use that used compressors and refrigerants to cool the air inside.
As the 20th century progressed, refrigerators became more accessible and popular in households around the world. Improvements were made to their design, energy efficiency and storage capacity.