How Refrigerator Works? Another Explanation

The refrigerator in your kitchen uses a cycle that is similar to the one described in the previous section. But in your refrigerator, the cycle is continuous. In the following example, we will assume that the refrigerant being used is pure ammonia, which boils at -27 degrees F. This is what happens to keep the refrigerator cool:

1. The compressor compresses the ammonia gas. The compressed gas heats up as it is pressurized (orange).
2. The coils on the back of the refrigerator let the hot ammonia gas dissipate its heat. The ammonia gas condenses into ammonia liquid (dark blue) at high pressure.
3. The high-pressure ammonia liquid flows through the expansion valve.

   You can think of the expansion valve as a small hole. On one side of the hole is high-pressure ammonia liquid. On the other side of the hole is a low-pressure area (because the compressor is sucking gas out of that side).

4. The liquid ammonia immediately boils and vaporizes (light blue), its temperature dropping to -27 F. This makes the inside of the refrigerator cold.
5. The cold ammonia gas is sucked up by the compressor, and the cycle repeats.

By the way, if you have ever turned your car off on a hot summer day when you have had the air conditioner running, you may have heard a hissing noise under the hood. That noise is the sound of high-pressure liquid refrigerant flowing through the expansion valve.

Pure ammonia gas is highly toxic to people and would pose a threat if the refrigerator were to leak, so all home refrigerators don't use pure ammonia. You may have heard of refrigerants know as CFCs (chlorofluorocarbons), originally developed by Du Pont in the 1930s as a non-toxic replacement for ammonia. CFC-12(dichlorodifluoromethane) has about the same boiling point as ammonia. However, CFC-12 is not toxic to humans, so it is safe to use in your kitchen. Many large industrial refrigerators still use ammonia.

In the 1970s, it was discovered that the CFCs then in use are harmful to the ozone layer, so as of the 1990s, all new refrigerators and air conditioners use refrigerants that are less harmful to the ozone layer.

Confused about the Refrigerator Parts-Here is a Clear Explanation

What is a refrigerator made of?
Here are the major components of a refrigerator:

Compressor

Heat-exchanging Pipes

Expansion Valve

Refrigerant

Confusing! What are those parts?

A Compressor is a mechanical device used to compress or compact something. In the case of the refrigerator it is the refrigerant.

The Heat-exchanging pipes are the coiled set of pipes inside and outside the refrigerator. You can usually see this by looking on the back of the fridge.

The expansion valve allows the refrigerant to change its pressure by expanding a small pipe into a big one.

The refrigerant the liquid that evaporates inside the refrigerator to create the cold temperatures. This liquid in the past was ammonia or a chlorofluorocarbons (CFCs).

Ammonia is used because of its extremely low boiling rate. It boils at -27 degrees Fahrenheit or -32 degrees Celsius.

Now days ammonia is no longer used because it stinks, and CFCs are no longer used because of ozone depletion. CFCs have been banned from use by the Kyoto protocol. 134A is now used in most fridges today.

Introduction to Refrigerator

In almost every home in America maybe even the world, there is a refrigerator. This marvelous machine that can keep many things cool and preserve food.

With out a refrigerator much of our food cooked and not cooked would go bad in a short while. On many refrigerators there is also a freezer to keep stuff frozen and preserved even longer then the refrigerator can.

Refrigerators these days are getting larger, more organized chock full of great features like water dispensers and ice machines.

We really can take a refrigerator for granted sometimes. Just take a look back and see what they had to do to keep food good. Meat had to be salted in-order to be kept it edible. Cold drinks on a hot summer day were a luxury for most people.

Freezer is the one who, or that which, cools or freezes, as a refrigerator, or the tub and can used in the process of freezing ice cream.

How Does a Refrigerator Works?????

Well first the compressor compresses the refrigerant gas. By doing this the gas temperature and pressure are raised, allowing the heat-exchanging pipes on the outside of the fridge to dispel the heat of pressurization.

As the refrigerant is cooled it condenses, turning into a liquid again, and moves into the expansion valve.

As the liquid refrigerant travels through the expansion valve it is allowed to move from a high-pressure are to a low-pressure area. The low-pressure area is the part that the compressor is hooked to.

When it is not pressurized it then expands and evaporates. When the refrigerant evaporates it instantely begins to boil and vaporize, and this is what makes it cold. It drops immediately drops to 27 degrees Fahrenheit.

The second set of heat-exchanging coils inside of the refrigerator allow the refrigerant to transfer the cold and this cools the inside. There is also a fans inside and out of your refrigerator.

The on the inside helps with defrosting and more even cooling, the one on the inside cools the compressor, and blows air on the heat-exchange pipes on the back. After this process is done it continually repeats.

About every 15 minutes you can hear the refrigerator turn on. It is completing this process.

Working Process:

A refrigerator consists of two storage compartments - one for frozen items and the other for items requiring refrigeration but not freezing. These compartments are surrounded by a series of heat-exchanging pipes. Near the bottom of the refrigerator unit is a heavy metal device called a compressor. The compressor is powered by an electric motor. More heat-exchanging pipes are coiled behind the refrigerator. Running through the entire system is pure ammonia, which evaporates at -27 degrees Fahrenheit (-32 Celsius). This system is closed, which means nothing is lost or added while it is operating. Because liquid ammonia is a powerful chemical, a leaking refrigerator should be repaired or replaced immediately.

The refrigeration process begins with the compressor. Ammonia gas is compressed until it becomes very hot from the increased pressure. This heated gas flows through the coils behind the refrigerator, which allow excess heat to be released into the surrounding air. This is why users sometimes feel warm air circulating around the fridge. Eventually the ammonia cools down to the point where it becomes a liquid. This liquid form of ammonia is then forced through a device called an expansion valve. Essentially, the expansion valve has such a small opening that the liquid ammonia is turned into a very cold, fast-moving mist, evaporating as it travels through the coils in the freezer. Since this evaporation occurs at -27 degrees F (-32 degrees Celsius), the ammonia draws heat from the surrounding area. This is the Second Law of Thermodynamics in effect. Cold material, such as the evaporating ammonia gas, tend to take heat from warmer materials, such as the water in the ice cube tray.

As the evaporating ammonia gas absorbs more heat, its temperature rises. Coils surrounding the lower refrigerator compartment are not as compact. The cool ammonia still draws heat from the warmer objects in the fridge, but not as much as the freezer section. The ammonia gas is drawn back into the compressor, where the entire cycle of pressurization, cooling and evaporation begins anew.