Ever since the technology came into existence, it has loaded man with a variety of technological machinery to make his work more comfortable and save time and effort.
Refrigerators are one such invention which now has a popular place in the world of advance and well equipped machinery.
Fundamental Principal of Refrigerator
A refrigerator works on the basic principle of three steps
- The cold refrigerant gas which is inside the refrigerator is made to pass around the items to keep them fresh.
- The refrigerator absorbs the heat released out of the food items.
- The heat absorbed from the food items is made to release out of the refrigerator to relatively cool surroundings outside.
History of Refrigerator
The process of refrigeration is quite an old process. It has a history of its own, and the School of Refrigeration is well known to explain its courses and the applications. The school named RSI located in Phoenix, Arizona teaches about the techniques and theories related to refrigeration, along with its maintenance and repair.
At the beginning of the training period, the classes involve teachings regarding the commercial and domestic refrigeration processes, and later on knowing the advanced high-level refrigeration technologies.
Moving deep into history, we see to it that salting the food used to be the conventional method of preserving the food until the time refrigerators came into existence.
A well-known fact suggests that bacteria cannot grow or survive in salt. So rubbing the dry salt on food or getting it covered in a salt solution (Known as Brine) helped in the preservation of meat and other foods from spoilage.
Some people in the early days do have the advantage to keep their food in an icehouse to preserve it. It proved to be the earliest form of a fridge.
General Electric discovered the first electric refrigerator in the year 1911. The invention was, however, affordable by super-wealthy Americans. On the other hand, iceboxes were used by ordinary people to store and preserve their food.
Affording an icebox was also; a bit expensive as the water had to be frozen, then ice was cut, stored and later delivered. Freon was used in the refrigerators till the early 1930s. After World War 2, refrigerators were produced in bulk quantities, thus making them affordable and easy to reach every individual’s house in the US.
The new technology-oriented refrigerators had features ice making and the automatic defrost system. The combination of refrigerators and freezer units became immensely popular during the era.
From the 1970s to 1980s and then finally in 1990s, there were debates and studies regarding the use of Freon as per the environmental issues were concerned. Due to its adverse effect on the environment, it was finally banned by the government to be used as refrigeration equipment.
World of Refrigerators
Today not just American households’ posses’ good and advanced technology refrigerators but the popularity of the machine is on a worldwide scale. Imagining life without a refrigerator seems to be a bad nightmare to the people in today’s era.
The machine has made it possible for people to preserve food for longer durations without compromising with the quality of the food. It is a convenient option to meet the requirements of growing and demanding lifestyles.
The growing demand for refrigerators globally has made it essential to have well-trained professionals to deal with problems of repair and maintenance of the unit.
They play a significant role even in businesses and transporting and supplies. The professionals offering the services to repair and maintain the refrigerator are well trained and well equipped and posse’s knowledge about every part of the system. They are well known to the refrigeration technologies as this cools and dehumidifies.
The right amount of theoretical and practical knowledge is necessary to mend various issues in a refrigerator.
Technologies that evolved the concept of refrigeration
The idea of artificial cooling has never been a new concept but has evolved broadly over the years. The advancements in the methods of refrigeration have improved people’s lifestyle in many ways. It changed their way of living and eating.
The concept of vapor-compression refrigeration has dominated the industry since the 20th century.
The process is a bit simple. It involves circulating a cold fluid around the food item to be cooled, thus making the fluid to absorb the heat from the eatables and carry them away. This principal continuously creates cooled fluid to generate refrigeration of the food items.
This is the nub of the entire vapor-compression cycle. A compressor is used by the system here to create pressure on a vaporized refrigerant. Now the refrigerant is made to pump through a condenser, where it gets converted into a high-pressure liquid from high pressure and high-temperature vapor. The heat here is generated from the phase change, dissipated by the condenser.
This high-pressure liquid is then made to run by means of an expansion valve, creating a pressure drop, which reduces the temperature of the refrigerant significantly.
The final step in the process is to send the cold refrigerant by the evaporator coils. Here the coolant will get converted into the vapor form, cooling the area of the surroundings by absorbing the heat from them.
House Hold Refrigerator Technologies
The household refrigerator technologies bring into light the refrigerators based in a vapor compression cycle. The cycle based on the concept of VCC is categorized into three classifications; namely
- Dual evaporator
- Expansion loss recovery cycles and
- Multi-stage cycles.
The evaporator with two trade-offs is first made to operate at cold temperature, keeping the food frozen. But this step removes the moisture content from the air. The cold and dry freezer air decreases the level of humidity in the refrigerator, which is not suitable for most of the food items.
In case of expansion loss recovery cycle, expander and ejector cycles are explained. For the multi-stage cycles, the dual-loop and the two-stage cycle are generally discussed. For instance, refrigerants are reviewed as a working fluid.
Technologies such as thermoelectric, magnetic, absorption, thermoacoustic, and thermoplastic work in relation to domestic refrigerators.
But these are not based on VCC and hence not used more precisely for the household refrigerators. Reason being insufficient reliability and uneven performance in their working, but still, their potential is taken into consideration.
To conclude, refrigerators are the most useful invention for mankind. There invention has led to standardization of people’s way of living. Adding more to it, is the change in the functionality and coming up of new techniques to uplift food safety standards and health of people.