Flat Plate Collector (FPC)

The utilization of affordable, clean and sustainable energy are the main factors for social and economic development. Due to this fact that solar energy has all of the mentioned factors, so recently has been paid attention intensely in various applications such as space heating, electricity generation, and drying applications. The performance of solar heat exchangers is enhanced by a better thermal transfer rate. Recently, numerous investigations have carried out in order to evaluation of solar efficiency through thermal transfer increment methods. One of such methods is the use of fins or turbulators. Turbulators increase the surface of thermal transfer as the same of fins that are led to better convection between the air and absorber. Hence, the channel performance is enhanced. Another technique for the evaluation of solar unit’s performance is the utilization of nanofluid as a carrier liquid. Heat transfer liquid has the main role to improve the efficiency in various applications and system size as well. The basic testing liquids like water have an inadequate thermal conductivity in many applications. Nanofluids due to having suspended nanoparticles enhance the thermal characteristics in comparison with the basic fluids. Nano-sized materials have created a revolutionary in science because of their small size and key properties including the increase of surface area than volume ratio as well as their diverse physicochemical properties in comparison with their mass counterparts. Nanofluids are the suspension of pure liquid and nanoparticles so that one of the main dimensions of nanoparticles is lower than 100 nm. From past researches, nanofluids have the capability to increase thermal features such as viscosity, convective thermal transfer and thermal conductivity which are related to basic liquids like ethylene glycol, water, and oil. Due to novel and beneficial properties of nanofluids they have found numerous usages such as refrigerator, pharmaceutical processes, heat exchanger, and chiller.

Passive technique has been absorbed many attentions because of its cost saving and easy operation/installation. Swirl stream systems generating secondary recirculation on the axial stream is a significant group of systems employed in passive technique. That causes higher mixing of fluid and then reaching thinner boundary layer. Twisted tape has obtained more attentions among the swirl generators because it has low price, acceptable thermal efficiency and easy installation.

Flat Plate Solar Collectors

Particular kind of heat exchangers which can convert solar radiation to heat energy is solar collector. Many kinds of such collectors were applied to collect radiation. The most typical system of thermal system is flat plate collector which is beneficial for thermal generation at low ranges of temperatures. This type of collector contains an absorber plate with pipes in its downward section that is placed in an adiabatic box, whereas there is a glass cover in the above region.

Generally, FPSC are designed for uses with usual operant temperatures between 40C and 60 C that is the instance of domestic hot water mechanisms. Also, many industrial use potentials exist for solar thermal systems at medium ranges of temperatures (80-160C).