Introduction
Refrigeration is the process of removing heat to lower the temperature within a closed space, which can be either a room or a small chamber. In the modern world, refrigeration technology is mainly used in domestic life to cool food and preserve the product’s properties for as long as possible. The refrigeration technology suppresses the effects of bacteria and prevents mold formation, helping to maintain the original nutritional quality. In addition, refrigeration technology is used to cool the rooms, which allows people to create a comfortable temperature regardless of the weather outside. Refrigeration technology, which has become widespread since the 19th century, has changed significantly, and in the 21st century, it is an integral part of most people’s daily lives.
The Principle of Work
Modern refrigeration devices most often use the principle of vapor compression in their work. A compressor, evaporator, condenser, expansion device, tube, and motor are required to operate such an installation successfully. Cooling also requires gas refrigerant, which is now mostly synthetic.
The refrigerant is compressed by a piston and forced through a tube into a condenser, where the tube, winding with steam, passes through air or water. The cooled steam enters a low-pressure area where the steam expands and draws expansion energy from the environment. In domestic refrigeration systems, the coil that contains the evaporator comes into contact with air and cools the enclosed space containing the food. Thus, when the compressor is turned on, the refrigerant is sucked from the evaporator, compressed, condensed, and injected, after which the cycle is closed.
The basic principle of the refrigerator’s operation is to pump heat from the chamber into the environment. Commercial refrigeration is only possible due to the physical properties of synthetic refrigerants. Refrigerators can have either a different number of chambers or a different number of compressors, which determines the power and amount of electricity consumption. The simplest in terms of design are single-chamber devices, in which one temperature is maintained, and two-chamber ones, which involve the usual separation and freezing compartment. Multi-chamber refrigerators are also gaining domestic distribution; their distinctive feature is the ability to maintain different temperature conditions for various types of products.
Historical Context
The need to freeze food for longer preservation of its ability to be used has been known to people since ancient times. Ancient people, especially those living in mountainous areas, used natural ice for cooling. The technology of digging cellars in cool soil to store ice, or the products themselves, was also widespread.
The need to cool products was a particularly serious problem in countries with a year-round warm climate. In such regions, people resorted to cooling with water using the principle of evaporation. Controlled evaporation conditions allowed ice to form even if the temperature did not drop below freezing. In some developing countries and remote regions, ice-cooling technology is still used today.
Freezing technology, common in modern refrigeration systems, is based on the rapid expansion of gases. Despite the fact that the need to create artificial cooling conditions was recognized long ago, mechanical cooling was discovered in the 19th century. The first refrigeration machine was designed by explorer Oliver Evans in 1805, using steam instead of liquid. Commercial refrigeration began in the mid-19th century and is associated with businessman Alexander Twining.
Finally, in the second half of the 19th century, the French scientist Ferdinand Carre used ammonia as a refrigerant, and this technology became widespread. The use of ammonia for refrigeration was commercially viable, but ammonia had a toxicity that became its main disadvantage. An alternative to ammonia was the use of synthetic refrigerants, which did not pose a danger to humans and animals.
Commercial refrigeration has tried to optimize the technology to make the process faster and cheaper. In the middle of the 20th century, the properties of semiconductors began to be used for commercial cooling. The Peltier effect formed the basis of some devices, which involve cooling the connection by using currents passing through the connection of metals. The revealed pattern was sufficient for commercial use but difficult to manufacture. Vapor compression cooling is currently the main method incorporated in modern refrigeration devices.
Thus, despite the fact that the need for refrigeration and freezing of products has been known to humanity for a long time, a significant breakthrough in production is associated with commercial production for domestic needs. The history of the development of refrigeration technology demonstrates the search for the simplest and fastest ways of cooling that can be profitably sold. Modern people can enjoy the convenience of refrigerators due to the commercialization of both the machine itself and new synthetic refrigerants. In the future, the technology may be further developed as businesses often look for ways to speed up and make the technology cheaper.
Causes
The refrigerator can be called one of the most important inventions in the food industry. The reason for the appearance of this invention is the desire to simplify the domestic sphere of life and make it more comfortable, which humanity is constantly striving for. Natural ice is the simplest and most intuitive way to preserve food for centuries. The ice needed to freeze food was traded and transported all over the world, and it became one of the first profitable trading industries globally.
Despite the fact that the ice trade was a significant profit, storage, transportation, and use were fraught with significant difficulties in maintaining low temperatures at all times. Household refrigerators have become a commercially viable solution to this problem, allowing food to be kept fresher for longer periods of time. Now, almost every American family has a refrigerator at home. The popularity of this invention is caused by its importance for daily use, ease of operation, and clear household benefits.
Effects
Refrigerators have had a significant positive impact on the food industry, but this does not save them from the negative impact on the environment. Refrigeration equipment is ubiquitous, which explains the magnitude of climatic effects. However, the refrigeration industry, which includes household refrigerators, cold rooms and appliances, and air conditioners, is responsible for about 10% of CO2 emissions. At the same time, with rising temperatures due to global warming, the need for cooling devices will increase, which will lead to an even greater unsustainable impact.
Despite the popularity, ubiquity, and profits, refrigeration companies must make efforts to reduce negative climate impacts. Refrigerators and air conditioners use a lot of electricity, and their chemicals also absorb heat from the environment. This gives refrigerators the ability to warm the atmosphere much more than carbon dioxide.
The main problem for the environment is synthetic refrigerants, which, at this stage of technology development, need to be changed to a more natural and less toxic alternative. Despite the awareness of the need to search for natural analogs, this transition is hampered by large companies producing refrigerants, as well as the lack of regulatory laws in most countries. Natural coolants can be inconvenient to use or toxic to people.
Preventing refrigeration’s negative effects on the climate can also be the responsibility of residential users. Household refrigerators and air conditioners must be properly disposed of so that the refrigerant does not enter the environment when the device is destroyed. Developed countries offer opportunities for the proper disposal of such household appliances. In addition, customers can regulate demand for more environmentally friendly refrigerators and air conditioners by prioritizing sustainability in their purchase and later operation.
Conclusion
The invention of refrigerators revolutionized the organization of the everyday concept of domestic comfort. From natural ice refrigeration to modern freezers with multiple compartments and temperature control capabilities, refrigerators are a major invention in the food industry. The reasons for this popularity lie in the ease of use and the necessity for everyday needs. Air conditioners operating on a similar principle have also become widespread in recent years.
Modern refrigeration devices operate based on synthetic substances – refrigerants. Popularization and lack of proper disposal led to the release of these toxic substances into the atmosphere, causing even more severe climate change. The development and implementation of natural refrigerants, informed choice, and proper disposal are necessary steps to solve the problem of the negative impact of refrigeration on the environment.
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