Mechanism of Refrigeration.

Q: What gases are used in a modern day refrigerator ?

1. Tetrafluoro-ethane (R-134A) 2. Freon aka ISCEON MO99 (R-438A)

Mechanism of refrigeration

Refrigerator

Introduction

All kinds refrigeration works as per the rules of Thermodynamics. Refrigeration does not let foods rot nor melt allowing us eat, stay and live healthy in our daily life.

What rule of Thermodynamics does a refrigerator follow ?

Refrigerator follows second rule of Thermodynamics. The rule is " Heat from a substance of high temperature passes to the substance of low temperature."

So what about cooling ? The thing lies in a term called "Latent heat".

What is latent heat ?

When a solid substance is turned into liquid or a liquid body is turned into vapor, the substance absorbs some heat from its ambient environment without changing its temperature. So where did the absorbed heat go? The absorbed heat remains latent in the substance. This absorbed heat is called Latent heat. Anyway the absorbed heat turns the ambient environment cool.

Why do we use liquid gas as refrigerant in a refrigerator?

We use liquid gas as refrigerant as it evaporates quickly cooling things quickly. For example- When we take some Alcohol on our hand palms, we feel some chilling sensation. Because Alcohol evaporates quickly chilling our hand palms. Just this is the phenomenon that helps understand refrigeration.

When the liquid gas used in a refrigerator turns into gas, then the gas absorbs heat from its ambient air making the air cool. The cool air is then let pass into all chambers of a refrigerator that cools all stuffs kept inside it.

How does a refrigerator work ?

Mechanism of refrigerator

In a refrigerator, liquid gases like Freon gas are used as a refrigerant. The gas is let pass through a coil of a pipe into which there is a low pressure environment. This coil of pipe is called evaporator. After entering a low pressure environment, the liquid gas turns into gas making its ambient air cool. This cool air is then let pass by a fan to all chambers of refrigerator causing all kept inside things to be cool.

What is the role of compressor used in a refrigerator ?

As to run on the refrigeration, the gas needs to be turned into liquid again. To do so, there is a compressor in the fridge that sucks gas and compresses it at high pressure. The gas gets hot while being compressed. Because molecules of a compressed gas collides hard with each other and gets hot.

What is the role of a condenser used in a refrigerator ?

Then this hot compressed gas is let pass through a coil of pipe being blown by a fan. This is called condenser. After entering the condenser, the gas turns into liquid. This liquid gas in then again turned into gas to start a new cycle of refrigeration.

What is the role of Thermostat used in a refrigerator ?

A device named thermostat monitors and controls the refrigeration.

How does a non frost refrigeration work ?

A sensor is there in the chamber of a refrigerator that senses humidity and sucks the humid air and pass through a condenser (a coil of hot pipe). The humidity then turns into water. The water is then evaporated by heating.

What gases are used in a refrigerator ?

What gases were used in refrigerator in earlier days ?

1. Ethylene glycol (inflammable)

2. Ammonia (toxic)

3. Sulfur dioxide (toxic)

4. Methyl chloride (toxic)

5. Water vapor (energy consuming)

6. Carbon dioxide ( safe but requires high pressure)

7. Hydrocarbons ( Safe but inflammable)

8. Chlorofluorocarbon (non-inflammable but depletes ozone layer. This gas is called Freon (R-22).