A short & updated review of nanofluids utilization in solar parabolic trough collector

Abstract

The world is facing a crisis of energy because fossil fuels are depleting day by day. The growth of any country mainly depends upon 3Es namely energy, economy and environment. These are the three pillars of sustainability also. The ejaculation of greenhouse gases is also the ultimatum for the world. The major constituent of greenhouse gas is CO2 and it increased rapidly in the last decade which increases the earth's temperature very rapidly. The problem of the energy crisis as well as greenhouse gas emissions from oil and coal-based energy sources can be overcome by the utilization of renewable sources of energy such as solar, wind, hydro, tidal and many more. The sun is the primary source of energy on earth since it is readily available, cost-free, and has no negative effects on the environment. Without emitting greenhouse gases, solar energy can be transformed directly into thermal energy in the form of heat and then into electrical energy. The main obstacle in the utilization of solar energy is the enhancement of heat transfer rate which can be overcome by utilizing a high thermal conductivity fluid known as nanofluid. In the present study progress of nanofluid utilization in solar parabolic trough collectors are reviewed. The effects of various variables such as volume fraction, the flow rate of mass, thermal conductivity and rate of heat transfer are reviewed. The effects of nanofluid utilization for enhancement of efficiency, exergy and pressure drop in PTC are also reviewed.