Refrigerator

We offer the best product range of Vapour Absorption Refrigerator.

Vapour Absorption Refrigerator

We manufacture Vapor Absorption Refrigerator with advanced working and easy operational features. These are self contained Refrigerators working on absorption technology. In the absence of a compressor or pump, the circulation takes place by density difference. The Vapor Absorption Refrigerator absorbs the vapor emitted in the industries and laboratories, and prevents the heating of the place.

Attributes

Consumes less electricity
Does effective cooling
Long service life
Low maintenance

How It Operates?

The system is pre-charged with three fluids namely water, ammonia and hydrogen. Hydrogen is used as an inert gas and does not undergo any phase change and heat transfer processes. Its purpose is to keep the pressure of the system constant
It uses an electrically operated generator, where, the ammonia vapors dissolved in water are separated and pure ammonia vapors enter the condenser
In the condenser, the high pressure vapors reject its latent heat to the surroundings and get liquefied
The liquid ammoniaexpands through expansion device where its pressure and temperature is reduced and cold low pressure vapor enters the evaporator where it absorbs heat from the space to be cooled and then vaporized ammonia absorbs in water
This strong solution then enters the generator and the cycle repeats

List of Experiments

To study construction and working of a vapour absorption refrigerator
To evaluate performance of the refrigerator by calculating the C.O.P of the system

Principle of OperationElectrolux principle works on 3-fluid system. There is solution circulation pump. Total pressure is the same throughout the system. The third fluid remains mainly in the evaporator thus reducing partial pressure of refrigerant to enable it to evaporate at low pressure and hence low temperature. The schematic diagram of the Electrolux refrigerator working on NH₃-H₂O system with H₂ as the third fluid is shown in figure. Liquid NH₃ evaporates in the evaporator in the pressure of H₂. Hydrogen is chosen as it is non corrosive and insoluble in water. A thermosyphon bubble pump is used to lift the weak aqua from the generator to the separator. The discharge tube from the evaporator the generator is extended down below the liquid level in the generator. The bubbles rise and carry slugs of weak NH₃-H₂O solution into the separator. Two U-bends are provided as vapour- locks to prevent H₂ from getting into the high side or solution circuit. Partial pressure of H2 provides the pressure difference of NH₃ between the condenser and evaporator. Accordingly, we have:

In condenser pure NH₃ vapour pressure = Total pressure
In evaporator NH₃ vapour pressure = Total pressure - partial pressure H₂

For example, Consider the condenser temperature at 50 C and evaporator temperature as -15 CThe corresponding vapour pressures of NH₃ are :

Condenser, Pk = 20.33bar
Evaporator outlet Po2 = 2.6bar

The approximate pressures in various parts of the system, then will be as given in the table.

Section	NH₃	H₂O	H₂	Total
Condenser	20.33	0	0	20.33
Evaporator inlet	1.516	0	18.814	20.33
Evaporator outlet	2.36	0	17.97	20.33
Generator top	15.54	4.79	0	20.33

It has been assumed that vapours leaving generator top are in equilibrium with entering rich solution at 40 C, at which temperature saturation pressure of NH₃ is 15.45bar. It has also been assumed that the temperature at evaporator inlet is -25 C at which temperature saturation pressure of NH₃ is 1.516 bar.

Technical Specifications

Sub Title	Parameter
Model	NAEVM-01
Gross Volume	41 Liters
Refrigerant	Water, Ammonia, Hydrogen
Generator	Electrically Heated
Condenser	Natural Convection Type
Evaporator	Natural Convection Type
Material of Construction	M.S.
Supply	230 Volts, 50 HZ, 1 PH
Energy Consumption	1.07 KWH Per 24 Hrs
Energymeter	Provided
Temperature Indicator	Digital Indicator at the Salient Points