Prof. M.V. Rane and his team of Department of Mechanical Engineering have
chalked up a design of low cost, efficient, compact refrigeration cum water
heating system that is based on refrigeration cycles and can be powered by
a low-grade heat source such as solar collector.
The system devised has heat beds used to store heat which operates out of
phase giving continuos refrigeration as well as heating. The COP is increased
as system is not complicated and has separate circulating groups to transfer
the heated fluid. The heat storage and adsorption beds have better conductivity
and have a reduced cycle time which gives better heating and continuos refrigeration.
The system devised can operate with any low-grade heat source, for example
a very common system will be an adsorption system with solar source of
heat. This is called solar refrigeration. Solar powered has become a very
popular product these days as it is green and does not pollute the environment.
Solar refrigeration is an important use of solar energy because the supply
of solar energy and demand for cooling are great during the summer when
it is amply available. It has the potential to improve the quality of life
of people who live in areas where the supply of electricity is far sufficient.
Most people in rural areas depend on kerosene and wood to heat. This pollutes
the environment and is a health hazard.
Until now, for use with most cooling technologies, temperatures of around
100 degrees celcius were required. The success of solar cooling is dependent
on the availability of low cost and high performance solar collectors. The
system devised at IIT uses a solar collector which about 80% of the cost
of the system. The cost to refrigerate has been brought down by COP’s
of around 40% with low cycle time, which brings down the cost to make a kilogram
of ice per day. Scientists feel the cost will go down further after optimizing
the system to minimize the system costs. The system will cost one-third of
the current commercially available solar refrigeration system. The added
advantage of this system is that you not only get refrigeration using a low-grade
heat source but one also gets bonus-heated water. Thus saving on heating
needs in rural setting and dependence on fossil fuel consumption to heat
and cool.
Indian patent application no. 151/MUM/2002 Patent grant no. 203742
Inventors: M V Rane and Akhil Agarwal
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