A refrigerator is a home appliance, which cools and preserves the food in a thermally insulated cabin, with the help of a heat pump. It uses electricity to perform the desired operation, and preserves the food by keeping the temperature below ambient temperature. It can maintain the temperature at negative degrees values too. At very low temperatures bacterial growth is completely hindered, so, the food in the compartment can be maintained fresh for many days.
History of Refrigerator
Before invention of refrigerator, people used ice cages to preserve food. James Harrison, an Australian scientist, developed a refrigerator for the first time in 1987. At that time, the size of the developed machine was very small.
Working of a Refrigerator
Any refrigerator or air conditioning system has five standard parts; they are
• Heat-exchanging pipes,
• Compressor,
• Heat-exchanging pipes,
• Expansion valve, and
• Refrigerant.
With the help of Refrigerant, cool atmosphere in the refrigerator is created. This refrigerant evaporates in air of refrigerator and creates cooling weather inside it.
Most of the industries use pure ammonia as the refrigerant. The basic working principle of refrigerator is as follows.
First, the compressor inside the mechanism of refrigerator compresses gas of the refrigerant; consequently, temperature, and pressure of refrigerant increases. The heat exchanging springs outside the refrigerator permits the refrigerant to produce heat.
After it cools down, refrigerant compresses in liquid form (purple) and passes via expansion valve. When it passes via the expansion valve, the liquid form refrigerant is permitted to move from high-pressure area to a low-pressure area; as a result, it evaporates (turns light blue). While evaporating, it gets heated, and then the coil permits the refrigerant to absorb all the heat in turn reducing the internal temperature of the refrigerator. In this way, the cycle continues. For easier understanding, a diagram is given, which clearly explains the mechanism of refrigerator.
Types of Refrigerator
Generally, two compartments are included in a refrigerator. Temperature is maintained at a value slightly greater than freezing point in one compartment, whereas in other compartment, temperature is maintained at a value lower than freezing point of water. Considering the types of refrigerator, there are four types. They are
• Side-by-side refrigerators,
• Top-Mount freezer refrigerator,
• French door refrigerators, and
• Freezer on bottom refrigerators.
Side-by-side Mount refrigerators
These refrigerators are very expensive than top freezer refrigerator models. More advanced features are included in this refrigerator such as door cool water dispenser. In this, both fridge (ordinary cooling compartment) and freezer are adjacent to each other. But, one disadvantage associated with this refrigerator is that it takes lot of kitchen space.
Top-Mount Refrigerator
This refrigerator is quite common and inexpensive too. One benefit associated with this refrigerator is the fact that it has wider shelves in both the fridge and freezer compartment.
Freezer on Bottom or Bottom Mount Freezers
These are not easily available refrigerators in market. These models are most suitable for household purposes. Configuration of these models is just similar to that of Top Mounted Freezer Refrigerators. It doesn’t consume much energy to cool the section.
French Door Refrigerator
Design of this refrigerator is based on the style of Side-by-Side and Bottom Mount Refrigerators. It has a pull out freezer drawer and dual doors. This has same features of a Side-by-Side refrigerator and it overcomes all disadvantages associated with the Side-by-Side refrigerators.
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