10.11.2013 12:15

How Refrigeration Compressors Work In A Cooling System

How Refrigeration Compressors Work In A Cooling System


Many people, even if they are not engineers, know that refrigeration systems rely on a substance that vaporises and condenses to lower the temperature of the device. This is a common way of working for fridges, air conditioning systems and other gadgets that rely on cooling, such as dehumidifiers. The liquid is often referred to as the systemís refrigerant and, in any such device, a compressor is needed to raise the level of its pressure.

When refrigerant passes through a cooling systemís compressor, in a gaseous state, the pressure of the refrigerant is raised according to the specifications of the compressor being used. After this, the refrigeration compressor moves on to a condenser. It is at this point in a systemís flow that it condenses Ė that is, alters state from gas to liquid. This process produces energy which we usually notice in the form of heat. That is why, if you ever reach around the back of your kitchenís fridge, that you can detect warmth.

Following on from the condensing process, the now liquid refrigerant moves on to an expansion valve. This works in the opposite way to the systemís compressor because it is here that the refrigerant experiences a pressure drop. At the final stage of the process, the refrigerant flows on to an evaporator. The refrigerant draws on heat energy from around the evaporator. This means that the refrigerant will vaporise once more to become a gas. This uses up the local heat energy. Just like when sweat vaporises from your skin, the effect is to use up heat energy and produce a cooling effect.

However, unlike sweat which is lost into the atmosphere, refrigerant lies in a sealed system and can be used again. It is at this point that the compressor is crucial. Returning to the start of the process, the refrigerant - once more operating as a gas - needs to be put under pressure so that it can be used again. It is, as before, the compressor which performs this task.

Different sorts of compressors do their job of pressuring refrigerant if differing ways. Some compressors are called reciprocating and others rotary. There are also centrifugal compressors. Nevertheless, in most domestic settings the most popular choice is for reciprocating ones. With this type of compressor, a piston - driven by a motor - causes the refrigerant to be sucked into a cylinder. As the piston moves through the cylinder, thereby increasing the space, it draws refrigerant from the evaporator to start the process over.

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