Introduction:-        

When you take your cold drink for the next time in a very hot day then you are thankful to a machine which is know as refrigerator.Today we have a chilled cold drink and we got a lots of enjoyment by that drink but there was a time when there is no refrigerator.Many people use to make a large amount of ice cubes and they sell them at high price and become very rich,but today is a era of refrigerator.

When there is no existence of refrigerator then at that time food preserving is very difficult job.

Refrigeration is one of the great invention that changed our life to a larher exent .Now we are not worry about the presevation of food ,we can easily preserve it by using the refrigerator. The supply of the food is very much stable now a day.As vwe see that a gallon of milk can be easily preserve for about 14-15 days with the help of refrigerator.That means you does not need a cow or buffalo in the background of your house for the regular supply of milk.

In U.S it is expected that about 5 percentage of all all electrical energy is used to keep the homes cool.This was really a amazing thing to know that when we know that the princple behind most of the refrigerator are very simple as we comapre it to other home appliances.

Now the principle of refrigerator in a easy way is that when a liqid evaporates,then this process obsorb the heat and by a some process a liquid is convert into gaseous state.

Purpose of a refrigerator

Now we talk about refrigerator but what is the real purpose of a refrigerator lets us know about this.

The most important and the fundamental needs of a refrigerator is to keep our food cool so it can last for a long time.Refrigerator play a very important role in slowing down the activity of a bacteria on our food for that reason bacteria needs a bigger time to spoil the food kept in a refrigerator.

Supose we take a example of milk when the milk is kept in a room temperature during the hot summer then bacteria attack on them very easily and it will spoil the milk as soon as in 4-5 hours but when we keep the milk in a refrigerator temperature then activity of bacteria slow down and milk last for a long time.

Parts of a general refrigerator

You all heared about the alcohal when you take little bit of alcohal and spread over your hand you feel cold means very cold .How this was possible is it a refrigerator or something else.In case of a alchol it evaporate in a room temperature.When the alcohal evaporate it work is to obsord heat from your skin and feel your skin cool.As the alchol is act as a coolant in the same way there is a coolant in refrigerator known as a refrigerant.It function is same as a alcohal but it is different only in the aspect that it is trapped in a series of coils.

A refrigerator is a collection of five main parts that is as follow:-

1.Compressor

2.Heat exchanging pipes- It is a coiled set of pipes outside the component.

3.Expansion valve..

4. Heat exchanging pipes- It is a coiled set of pipes inside the component.

5.Refrigerent- It is a liquid inside the refrigerator that function is to evaporate and form a cool temperature inside the refrigerator.

Understanding the Refrigerator

To learn about what happen inside the refrigerator let us perform a small experient which elaborate more about the refrigertor workink.

Requirement:-

1.A glass container filled with water must be a oven protected.

2.A therometer that measure up to a 480 degree Fahrenheit.

Process :-

Add a thermometer to a glass container that is filled with a water and place both in a oven by seting the temperature of a oven is equivalent to 420 degree Fahrenheit.

As the temperature of the oven rises it rises the temperature of the water upto the 100 degree celcius or 212 degree Fahrenheit and water start boiling.The temperature of the water remain or stick to the 100 degree celcius even when the temperature of the oven rises upto the maximum of 420 Fahrenheit.The temperature of the thermometer reach the 420 degree Fahrenheit when all the water boils.

Now we take a case of liquid nitrogen.All human being is comfortable at a temperature of 70 degree Fahrenheit but the liquid nitrogen boils at a 320 degree Fahrenheit.If you place a liquid nitrogen container at a room temperature it will boils at a 320 degree Fahrenheit.

Today is the time when all refrigerator generating a cycle to reuse a refrigent again and again.You too could generating a cycle by follow the step discuss below.

1.Again take a example of oven water boil at a 100 degree celcius even a oven produce a steam at a 420 Degree Fahrenheit temperature .According to max he told that collect all the steam in a bag.

2.When all the water boils then you give pressure the steam into the steel container.Now when the temperature reach a 800 degree Fahrenheit then he think that the steel container become very hot as a tempertaure grow up to the 800 degree Fahrenheit.

3. when max releases the steel container then it give heat to the aior in that oven.Now at that moment he slow down the temperature to a 400 degree Fahrenheit. At that point the high pressure air is condenses and form a pressurized water.

4.After that max remove all the water that is pressurized and take in a another container and again boil the water at a 100 degree celcius.

5.Now he follow all the four step again and again to reuse the same water.

Real process in refrigerator

Now you use a refrigerator that uses a cycle as the same way as that explain above.In the refrigerator the cycle is continous and it cannot stop for a moment.

Let us take a another example which explain you how refrigerator works in brief.This time we take a ammonia thjat must be pure it boils at 27 degree fahrenheit.Now come and see what happen in a refrigerator that help the refrigerator to keep cool.

1. Now we take a one of the parts of refrigertor that is the compressor that compresses the ammonia gas. Now the ammonia gas that is compressed heats up as it is going to pressurized .
2. Now the coils which is situated at the back side of the refrigerator now the hot ammonia gas dissolve its heat. At high pressure the ammonia gas condenses and converted into ammonia liquid which is dark blue in color.
3. Now the ammonia liquid that is produce by a high pressure it flows through the expansion valve. Expansion valve is a type of a small hole. Now on the both side of the hole there is a difference in pressure due to the presence of high pressure ammonia on one side and the low pressure area on the other side.
4. Now it time to boil the liquid ammonia and get vaporized nad turn into light blue in color now the temperature fall upto the 27 degree fahrenheit That is the reason which makes the inside of the refrigerator cool.
5. This process repeat as the cold ammonia gas is going to be sucked by the compressor, and the above cycle repeat.

Gas or propane Refrigerator

Another type of refrigerator that is a Gas and Propane Refrigerators.This type of refrigerator use a gas as there primary source.These type of refrigerator use the heat to produce cold inside the refrigerator.

When we discuss about a gas refrigerator uses It uses ammonia as a coolant.water,ammoia and hydrogen produce a continous cycle of ammonia.This gas refrigerator have five main parts they are:-

1.Generator – It function is to creates ammonia gas.

2.Separator – It function is to separate the ammonia gas from water.

3.Condenser – It play a major function to create liquid ammonia when hot ammonia gas is cooled and condensed .

4.Evaporator – Now the evaporator it function is to convert liquid ammonia to a gas which create the cool temperature inside the refrigerator.

5.Absorber – It function is to absorb the ammonia gas in which is present in water.

How this gas refrigerator works :-

1.First of all we apply heat to the solution of ammonia and water in a generator

2.When the mixture of ammonia and water comes to the boiling point of ammonia, then it flow into the separator

3.Now the ammonia gas will flows toward the up into the condenser, and ammonia gas is converted into liquid

4.Now the liquid ammonia takes way to the evaporator and its mixes with hydrogen gas where its evaporates and produce a cool temperatures inside the cold box of refrigerator.

5.Now its time come when the ammonia and hydrogen gases flow and come to the absorber here water is collected in the separator now it follow the step 2 again and mixes with the ammonia and hydrogen gas.

6.At last the ammonia forms a solution with the help of water and produce the hydrogen gas, this hydrogen gas again flows back to the evaporator.

7.Now the solution form by the mixting of ammonia and water flows toward the generator which repeat the cycle again and again.