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.