The Einstein-Szilard Refrigerator

Abdul Basit Ahmad1221ME02

The Eco Friendly Refrigerator.

Contents

• What is a refrigerator? • Einstein’s role before 1930• Einstein Refrigeration Process• Drawbacks in this process• Changes made in this design• Disadvantages of modern refrigeration

process• Advantages of Einstein’s process.

What is Refrigeration?

Refrigeration is the process whereby,work is done to move heat from one location to another.

This work is traditionally mechanical but can also be done by other meanssuch as magnetism.

Refrigeration finds use both in homes and in industry.

Einstein Role Before 1930s:

Contributed to a variety of fields of physical inquiry, including, but not limited to, Brownian motion, photoelectric effect and relativity.

Considered to be one of the greatest scientists of all time.

First Eco-Friendly Refrigeration Process

• Tragic Death of entire family in Berlin due to refrigerator fumes.

• Einstein got very concerned about refrigerators after that.

• Wanted to design a refrigerator that didn’t need such toxic materials for its operation.

• Joined hands with Szilard, who had completed his research in thermodynamics, to construct a better design than mechanical compressors.

Einstein And Szilard’s Eco Friendly Refrigerator

Drawbacks of Einstein’s Process

• Device was less durable.• Device was less efficient.• Device was expensive.

Malcolm McCulloch

In 2008, Mcculloch, an Oxford University researcher,attempted to revive the Einstein refrigerator as a green replacement for electrical units.

He felt that the Einstein-Szilard design was environmentally friendly and could prove especially useful in developing countries, where demand for energy and cooling appliances is rapidly increasing.

Changes Made to Einstein Refrigeration Process

• The refrigerator requires a source with which to heat liquids and McCulloch felt that a solar energy system would be more “green” than the small gas burner that Einstein used.

• As a lack of efficiency was the reason that Einstein refrigerators were replaced by Freon compressors, McCulloch thought that by tweaking the design he can increase the efficiency by a large factor.

Delano’s Improvement

Fig: Delano With his Prototype

Andy Delano, a researcher at Georgia Tech.has also worked at improving the design of the Einstein Refrigerator.

Delano’s version uses an electric resistance heater as the source of heat.

He has sold his patent to AB Electrolux in Sweden, a company famous for its refrigeration solutions.

Disadvantages of ModernRefrigeration Process.

Depletion of Ozone Layer

Emission of CFCs and HCFCs from modern refrigerators lead to wide range depletion of the Ozone layer as shown in the accompanying schematic.

Fig: Schematic Showing the Depletion of Ozone Layer.

Effects Due to Ozone Layer Depletion

Fig: Environmental Effect of Ozone layer depletion.

Effect on human health.

Effect on Plants and animals.

Effect on marine systems.

Electrical Appliances

Among household appliances, refrigerators and air conditioners consume the maximum energy.

They amount to 50-70% of our total electrical consumption.

Popular air conditioners have quantities of 1, 1.5 and 2 tons.

In this we mostly use 1.5 tons air conditioners.

Usage of Air Conditioners

• Consumption of power by 1.5 ton ac:• 1.5 ton consumes 1.45kW in 1 hour.• In domestic usage, air conditioners are used

intermittently in season. • In corporate settings however, high capacity

central air conditioning systems are used round the clock, all year.

Power Consumption

• Domestic Usage Monthly power consumption of one air conditioner: 261 kWhr(7 hrs of daily usage).For generation of this much energy approx. 94 kgs. of coal needs to be burnt.

For 1 single a.c.

Commercial Usage

• Monthly consumption is approx. 1044 kWh.

• For generation of this much energy, approx. 400 kg of coal has to be burnt.

• For one single a.c.!

Just Imagine!!!

• Just imagine how much coal needs to be burnt just so that the current generation air conditioning and refrigeration systems can remain working all year.

• These quantities of coal burning have their own negative effect on the environment and is a great contributor to the greenhouse effect and climate change.

Advantages of Einstein Refrigeration Process

• Uses heat energy, even waste heat energy.

• Load variations don’t effect the performance.

• Can be operated at reduced evaporator pressure and temperature by increasing the steam pressure to the generator.