1Professor, Department of Hydro and Renewable Energy, Indian Institute of Technology, Roorkee
2M.Tech Student, Department of Hydro and Renewable Energy, Indian Institute of Technology, Roorkee
3Project Fellow, Department of Hydro and Renewable Energy, Indian Institute of Technology, Roorkee
Online Published on 01 December, 2022.
Trash racks are comprised of an array of metal bars used in irrigation canals, water intakes, pumping stations, penstock intake and other hydraulic structures to prevent the floating and submerged material that may cause damage and operational problems to the hydraulic turbine and its other components, and subsequently result in efficiency reduction of hydropower plants. When trash racks get clogged with trashes, it will lead to excessive head loss which results into loss of revenue. In case of large head loss, it will result into cavitation problem in pump. Thus, hydraulic head loss is one of the governing parameters in designing trash rack. Many past researchers have given their valuable contributions towards performance analysis of trash rack cleaning systems. In this study, Computational Fluid Mechanics (CFD) modelling of trash rack installed in the channel has been carried out and it has been concluded that as the blockage in trash rack increases, losses increase abruptly. Outcomes from the CFD modelling shows that about 10% blockage of trash rack can cause reduction of 4.3% in head. Similarly, for 19.75%, 28.89%, 37.53%, and 45.68%, blockage causes reduction in heads are 5.54%, 6.90%, 9.22%, and 11.94% respectively. Apart from these values of trash rack blockage, head loss can be calculated for any amount of blockage area using CFD modelling. So timely cleaning of trash rack should be done for better performance of trash rack.
Head loss, Trash rack, CFD, Blockage, Small hydropower
