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Presentation on

Heat Pumps

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Submitted by

Submitted To

Group Member:101-23-1927101-23-1883101-23-1973101-23-1869

Raihan Tayeb Lecturer of Textile Engineering

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What is heat pump ?

  A heat pump is an electrical device that

extracts heat from one place and transfers it to another by using mechanical energy. Examples: air conditioner; refrigerator.

In modern time  heat pump is an essential part of a heating and cooling system.

Most heat pumps are driven by electrical power; natural gas or Liquefied Petroleum Gas (LPG) can power certain systems that drive an internal combustion engine in place of a conventional electric motor.

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 Types of heat pumps

The two main types of heat pumps are:

01)compression heat pumps 02) absorption heat pumps

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compression & absorption heat pumps

compression heat pumps: Compression heat pumps always operate on mechanical energy while absorption heat pumps may also run on heat as an energy source.

absorption heat pumps: An absorption heat pump may be fueled by natural gas or LP gas.

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compression & absorption heat pumps cycle

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compression & absorption heat pumps cycle

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Other types of heat pump

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Other types of heat pump

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Other types of heat pump

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HOW DOES A HEAT PUMP WORK?

Process stage 01: At the beginning of the cycle the refrigerant (such as Freon) is in a liquid form This liquid refrigerant is very cold.  It enters the evaporator coil 

Process stage 02: After the refrigerant leaves the indoor evaporator coil it has absorbed heat and become gas. The refrigerant enters the compressor which mechanically pressurizes the gas.  That process will increase its temperature so the refrigerant will leave the compressor as hot gas.

Process stage 03: The refrigerant next moves to the condenser coil located outside the house.  Because the temperature outside is lower than the temperature of the hot gas the heat is transferred or “rejected” from the refrigerant in the coil to the outside air.

Process stage 04: The refrigerant leaves the outdoor condenser coil as warm liquid.  Now we need to make the warm liquid refrigerant cold so that it can absorb more heat. Again to repeat the cycle.

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Four main components

Evaporator: contais work fluid at lower temperature than environment. Heat is extracted from ground, air or water. So the work fluid evaporators.

Compressor: brings gas to higher pressure , temperature rises.

Condenser: Gas temperature is higher than fluid temperature of heating system. Excess heat is transferred to fluid. The gas

cools and condenses.

Expansion valve: causes pressure reduction, the temperature dropes,and the cycle begins again.

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Heat sources and sinks

all heat sources for a heat pump must be colder in temperature than the space to be heated. Most commonly, heat pumps draw heat from the air (outside or inside air) or from the ground (groundwater or soil)

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HEAT PUMP APPLICATIONS

There are few heating and cooling applications:01) Domestic Applications:Many homes can now benefit from a variety

of installations, including ground source, most suitable for certain new-build properties and small split or multi systems applied to existing premises.

02) Commercial Applications:Air to Air and Air to Water heat pumps are frequently used in office and retails spaces, they are often installed in ceiling voids or alcoves and offer substantially favourable cost comparisons against conventional boiler systems when measured against installation and running costs.

03)Others:Heat pumps are used in many industries, to recover heat or as an integral part of the process. Swimming pools can use heat pumps as the primary source of heat for the water in the pool, showers or to augment an existing fossil fuel system. In enclosed swimming pools, dehumidification is necessary and the heat recovered from the vapour in the air by a de-humidifier is easily returned to heat incoming fresh air or through a heat exchanger.

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Have any Question…?

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