HEAT PUMP

Hassan SarwarHassan SarwarME1004M-10C

Nov 1st, 2005

Objective

• Objective of this presentation is to relate heat pump to mechanical engineering and how it works.

What is it?

• A heat pump is a machine which takes heat from a low temperature reservoir to high temperature reservoir.

Common examples of Heat Pump

• Gas compression heat pumps

• Phase change heat pumps

• Geothermal exchange heat pumps

• Vortex Tubes

Gas Compression Heat Pumps

• Gas compression heat pumps are used to liquefy air to produce gases such as nitrogen, oxygen, argon for industrial purposes.

Phase Change Heat Pumps

• The most common type of Heat pumps• It is commonly used in refrigerators and air

conditioners• It takes a liquid, refrigerant, which has a

low boiling point. The liquid requires energy to evaporate and it then drains that energy from surrounding in the form of heat. When the vapour condenses, it release that energy back in form of heat.

Phase Change Heat Pumps

• This pump has two cycles.• In first cycle, it changes to vapour form• In next cycle, it changes back to liquid form• This process is called refrigeration cycle.• The liquid,used is used to be CFC, but due

to damage to ozone layer by CFC, now the liquid is R-13a but sometimes ammonia is also used.

Geothermal Exchange Heat Pumps

• Geothermal exchange heat pumps is also known as a ground source heat pump.

• It is a heat pump that uses Earth as either the heat source or heat sink, depends on the mode of operation.

• This type of heat pumps are either closed or open system and consisted of a loop, a compressor and a pump.

Geothermal Exchange Heat Pumps

• In closed system, a fluid is circulated and this fluid is never able to leave the system.

• This fluid is usually the water but it could be an antifreeze such as denatured ethanol, or methanol.

• In open system, the fluid moves one place to another and it either removes the heat or add the heat

Vortex Tubes

• Vortex Tubes are special kind of heat pumps with no moving parts

• A special type of gas is injected into the heat pump, where the internal shape of the chamber and the pressure of the gas accelerates the heat pump to high rate of rotation, over 1,000,000 rpm.

Vortex Tubes

• Vortex tubes are commonly used for inexpensive cooling, where compressed gas is available.

• Industry uses vortex tubes to produce a temperature drop of about 45 celsius

• Vortex tubes are also used in uranium enrichment.

Sources

• http://en.wikipedia.org/wiki/Heat_pumps