What i'm about to share is aimed at building an absorption refrigerator that uses kerosene as it's heat of source. The details of vapour absorption systems and their mode of operation were studied to form the basis of the work.

A refrigerator often called a fridge is a cooling appliance comprising a thermally insulated compartment and a mechanism to transfer heat it to external environment,cooling the content to temperature below ambient.
Rather than been dependent on electricity to run a compressor, kerosene absorption Refrigerators uses heat source to provide the adequate energy is refrigerator process is called Absorption Refrigerator. This refrigerator is popular where electricity is unreliable, costly, or unavailable e.g here in Africa where electricity is very very unreliable. An Absorption refrigerator is similar to a regular compressor i that the refrigeration takes place by evaporating a liquid with a very low boiling point. In both cases when the liquid evaporates or boils, it takes some heat away with it, and can continue to do so either until the liquid is all boiled, or until everything has become cold that the sub-zero boiling point has been reached. The difference between the two is how the gas is changed back to liquid so that it may be used again.

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The Aim of this writing is to tell you how an absorption refrigerator that uses kerosene as its heat source for the refrigeration of food stuff and drink and it can also be used for camping and in our various homes. The details of different vapour absorption system and their mode of operation will be studied to form the basis of the work. The use of absorption kerosene refrigerator will reduce the risk of toxic substance resulting from the conventional refrigerator (Ammonia NH₃).

SIGNIFICANCE

The kerosene powered refrigerator can be used for domestic purpose; in homes for food preservation and drink refrigeration.
And aslo for Camping outdoor.

METHODOLOGY

The refrigerator can be fabricated from locally available materials. The use of metal scraps will be considered where necessary to encourage the recycling process of scrap materials.

The absorption refrigerator has no moving part, but it uses two(2) working fluids to achieve its purpose

• Reducing the pressure of the refrigerant.
• Reducing the boiling point of the refrigerant.
• Remove the heat from the refrigerating compartment.

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THE TWO WORKING FLUIDS USED ARE:

AMMONIA: Ammonia is a compound with formula NH₃. It is normally encounter as a colourless gas with a characteristics pungent odour. Ammonia is used as a fluid in the kerosene refrigerator because of its thermodynamics properties. Because it is also lighter than air, its density is 0.589 times of that air. Liquid ammonia boils at -33 degree at Atmosphere pressure. Liquid ammonia has a very high standard enthalpy of vaporisation (23.35kl/mol). It is ready mix with water(a saturated solutions) has a density of 0.880g/cm.
Although ammonia is toxic,it can be used in this system because there are no moving part which reduce the change of the ammonia leaking out. The system is a closed system which reduce the probability of leaking.

WATER: Water is a universal solvent, it is compose of hydrogen and oxygen, it is odourless, colourless and tasteless. Water in system is used as an absorber, to absorb the vapour ammonia coming from the evaporator. Water is also used in the system because ammonia readily mixes it and the boiling point of water is far higher than the ammonia ,water has a boiling point point of 100 degree Celsius at as compared to ammonia which is -33degree Celsius, so the ammonia will evaporate before the boiling point of the water is reduced.

THE COMPONENTS OF THE KEROSENE REFRIGERATOR

The unit consist of four main components:

• Generator
• Condenser
• Evaporator
• Absorber

This diagram explains how the four components works.

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These units operates on kerosene, The heat is supplied by a burner, this element is fitted underneath the central tube.
The unit charge consists of quantity of ammonia and water. These are sufficient pressure to condense ammonia at room temperature. When heat is supplied to the generator system, bubbles of ammonia gas are produced. This ammonia gas carries within a minute of vapour, this mixtures then enters the separator. In the separator, the few water vapour that follows the ammonia condense and runs to the absorber,leaving dry ammonia vapour to pass to the condenser. Air circulations over the tins of the condenser removes the heat from the ammonia vapour. It condenses into liquid ammonia and then flows through the throttle valve from there to the evaporator.
The throttle valve reduces the pressure in the evaporator. This in turn extracts heat from the food storage space lowering the temperature inside the refrigerator. The mixture of ammonia passes from the evaporator to the absorber, a contineous drip of weak ammonia solutions enters the absorber which is fed by gravity from the separator.

The hydrogen is free to rise through the absorber coil and return to the evaporator, the hydrogen circulates continuously between the absorber and the evaporator. The strong ammonia solutions produced in the absorber flows down to the absorber vessel. It passes on to the boiler system, thus completing the full circle of operation. This cycle operates continuously as long as the generator is heated.
Since the refrigerant is ammonia it can produce quite low temperatures. The refrigerator should be carefully levelled before being placed in operation. The pressure differentiate the type of system that is created by hydrogen gas. It causes ammonia to change pressure and allow it to boil off the evaporator (flash off).

CONCLUSION

This refrigerator would ease the dependency on electricity, and also could be used outdoors like for camping.

It will also reduce the dependency of refrigeration on electricity which is inadequate in this part of the world.

It might be difficult to see everywhere or function due to the fact that ammonia gas is not found everywhere , and ammonia gas is the suitable refrigerant for absorption refrigerators.

References

1. Eastop and Mconkey, “Applied Themodynamics” Pearson education Ltd. fifth edition PP 531-536

2. Jones and Dugan “Engineering Thermodynamics “ Prentice hall of India private Limited, India reprint PP 827-850

3. Rajput, “Heat and Mass Transfer” S.Chand Multicolour Edition, First Editor PP64-655(2006)

4. Wikipedia: Refrigeration

5. Wikipedia: Refrigerator

Please check the post on #steemstem!

Thank you for reading through, i hope we can construct from it.. heheheh

@segunreus cares!