India is on its way to become a ‘Net Zero’ country; according to the India’s ‘Panchamrit’ gift to the United Nations Conference of Climate Change (COP26), which says we have committed to meeting 50% of the country's energy demands with renewable energy sources by 2030. It is our responsibility to contribute in every way possible to demonstrate the nation's commitment.
Higher education institutions have been identified as a critical pillar in the growth of countries. RCOEM Nagpur, as one of Central India's most prestigious higher education institutes, has recognised the need for research and development as well as awareness regarding renewable energy technologies. As a result, the institution is working diligently to create renewable energy facilities on campus for utility, demonstration, training, and research. Our current focus is on the use of solar energy, including solar photovoltaic and solar thermal systems. RCOEM has established an excellent Concentrated Solar Thermal (CST) system research facility on campus, in addition to a 460 kWp solar photovoltaic plant.
Apart from harnessing solar energy for direct electricity generation, usage of solar heat for thermal applications is another promising option. Around 50% of total energy consumed in India is used for heating applications, which include community cooking, process heat, and space heating and cooling in industrial, institutional, and commercial establishments. The heating applications are mainly classified as low temperature (below 800C), medium temperature (up-to 3000C) and high temperature (above 300 0C). Solar collectors of the non-concentrating type are well suitable for low temperature applications, while solar concentrators are used for medium and high-temperature applications.
Recognizing the significance of future research and knowledge dissemination about medium temperature solar thermal systems a state-of-the-art IOT-enabled and completely automatic research facility for a Concentrated Solar Thermal (CST) system has recently been established on the RCOEM Campus.
The research facility consists of two parabolic-dish solar concentrators, each with a 16-square-meter aperture area and a carefully designed helical coil cavity receiver to maintain the concentration ratio above 300. The dish collectors, along with the tracking gears and motors, are positioned on the rooftop of the Hostel mess on campus, using a specifically designed tripod type foundation. The dish collectors are made of fibre reinforced plastic (FRP) material and highly reflective anodized aluminium sheets to reduce the total weight of the system and auxiliary power usage. As a result, the 4 x 40 W PMDC motors can balance the entire tracking system while providing enough torque and rpm. To reduce convective heat losses, the receiver and working medium circuit are insulated with light resin bonded (LRB) Rock wool material. The dish collectors have a fully automatic Aurdino-based two-axis tracking system that tracks the direction of the sunrays so that all captured solar radiation must concentrate at the collector's focal point.
The entire system is fully automatic and controlled via an IoT-enabled graphical user interface (GUI). There is adequate online data monitoring capability in place, which is used to monitor the plant's live performance via a specifically built data acquisition system and IoT interface. During non-cloudy weather, the temperature at the receiver comfortably rises up to 200 degrees Celsius.
A high temperature in line vertical pump, a 300 litre stainless steel accumulator with a built-in coiled tube heat exchanger, expansion tank, pressure switches, a 2 HP air compressor, and two direct sparged stainless steel cooking vessels are also included in the system. The installed system is set up in such a way that researchers can use the entire 32 square metre collecting area or each individual dish collector for any comparative study.
The project coordinators Dr. Sandeep Joshi and Dr. Vishal Shukla of Department of Mechanical Engineering further informed that the research facilities will benefit undergraduate, postgraduate, and doctoral research students on campus. Some of the current research efforts include using CST to generate pressurized hot water for cooking and other applications, using collected heat in vapour absorption refrigeration (VAR) system, development of efficient thermal storage units and more.
RCOEM Nagpur has self-funded the entire project. The project coordinators have expressed their heartfelt gratitude to the college management and Principal- RCOEM Nagpur for their thoughtfulness in fostering a sustainable research culture on campus.