Cooling

Features

Petroleum gas is stored in liquefied state before its utilisation as fuel. The energy spent for pressurizing and liquefying is not recovered afterwards. If it is expanded in an evaporator, it will vaporise and absorb heat to produce cooling.

This property has been used for cooling so that the liquefied form of LPG can be utilised and then the expanded gas (LPG) can be further used for combustion as a fuel.

Concept (Evaporator)

• LPG is extracted at high pressure in its liquefied state from the storage unit. The pressure and flow rate is controlled by a valve connecting to the evaporator at a specified pressure and in requisite quantities.
• An evaporator is housed through which LPG flows. It is converted from liquefied state to gaseous state and expands. So it absorbs heat in the form of latent heat. Due to this process, heat from surrounding is absorbed so cooling effect is produced. 
• This effect is magnified by an evaporator. A network of pipes containing gas is covered by thin and closely spaced fins which help in effective and fast cooling. The insulating material helps in storing the cooling effect for a longer period of time.
• The LPG leaves the evaporator in gaseous form; it can be then directed towards the burner, engine, or any other application where it is to be used. Thus, no LPG is consumed for cooling purposes.

Concept (Heat Pump):
See Heat Pump