CHENNAI: At a time when energy generation and conservation are the catchwords driving modern technological innovation, three third year engineering college students from the city have come up with a concept that takes solar energy usage one step further.
B R Vijay Prithiv, R Prabakaran and R Sukumar, who belong to the Department of Mechanical Engineering at the Sri Sairam Engineering College, have developed a solar water heater that not only uses captured energy to heat water to higher temperatures that the ones in the market do now, but also keeps water heated for a longer period of time. In fact, their modification to a stock solar water heater has made it 20 per cent more effective and secured them the first prize at the RENERGY 2014 conference conducted by the Tamil Nadu Energy Development Agency last month.
Using a Phase Change Material (PCM) called Paraffin Wax 6403, the team along with their guides from the mechanical department of the SSEC have developed a simple way to store extra heat and use it. According to B R Vijay Prithiv, the paraffin wax not only acts as insulation, but also stores an amount of energy when it changes from its solid to liquid phase — which it does at around 60°C. The energy stored as latent heat is then dissipated when the PCM reverts to its solid state when the temperature becomes cool enough.
The team proceeded to use this property of the PCM to increase the efficiency of the solar heater. They filled several copper tubes with paraffin wax, sealed them and fitted them inside the heater. Effectively enabling the melting PCM to store more energy when melting and using the dissipated energy when the reverse happens to heat water more and keep it hotter longer.
The modification to the heater has made it possible to heat water to nearly 80°C and keep it hot for almost seven to eight hours. An improvement of 20.86 per cent. And what’s more, the modification makes the heater only `500-`700 more expensive than water heaters in the current market. “Not only is it a lot more effective, it is also very marketable and cost effective,” added Prithiv.