Design and Fabrication of Parabolic Trough Collector

Abstract

Industries in Pakistan are currently using natural gas and diesel for steam and hot water production which results in shortfall of energy(resources) along with adverse impact on environment due to carbon emissions. The solution to these problems is the use of Solar Thermal Energy (STE). The purpose of this project is to the design and manufacture Parabolic Trough Collector (PTC), a type of solar thermal collector, to harness the solar energy for industrial water heating applications in Pakistan. Parabolic Trough Collector (PTC) are devices which consist of mirror of parabolic shape and an absorber on its focus through which fluid to be heated pass. The reflector used for this project is polished stainless steel, absorber is vacuum tube and fluid is water. One Dimensional tracking is used to follow the sun which is done by a belt pulley mechanism, a stepper motor and solar equations programmed in Arduino using LabVIEW. Design calculations are performed using modern software and they are validated with experimental results. Analytical solutions are obtained by solving mathematical equations on MATLAB and the results are compared with CFD results which are found by simulating vacuum tube model in COMSOL. Both analytical and CFD results are in close agreement with the experimental results obtained by testing the prototype. CAD modelling software SOLIDWORKS was used to design the prototype. Manufacturing the prototype made use of conventional machining processes such as turning, boring, drilling, milling and non-conventional machining processes such as CNC laser cutting as well as Sheet metal forming and joining operations. The prototype fabricated is 2.8m2 in area and it is up to 67% efficient giving the temperature rise of about 40 oC. Keywords: Parabolic Trough Collector (PTC), Solar Tracking, Solar Radiation, CFD, COMSOL, MATLAB