Respected Sir,
Sir I Moin (B.E.MECH Student),working on project cooling effect from LPG. Sir I am confused how to do the calculations like e.g.-for achieving 't' deg.celcius temparature mass/mass flow rate of LPG required like that. From Internet I came to know that some formulaes like gas law may not be applicable for this LPG refrigerator.This calculations are required for project report. So please help me to solve this,and also suggest any idea which will be helpful to implement in this to th[/font]is project.
Cold water and cold air are utilised in industrial processes to control temperatures, pressures, chemical reactions as well as solubility relationships in precipitation process amongst others functions. The two most common ways of producing cold water and cold air using LPG is with the use of evaporators as well as heat pumps.
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.