Exergy analysis of large and impounded hydropower plants: Case study El Roseires Dam (280 MW)

Abstract

Nowadays, one of the major and serious worldly concerns is the limitation of energy resources. Sudan, in specific, confronts a critical crisis in fossil fuel resources due to its separation science 2011, and mostly concerning the production of electricity energy. There are many sources of renewable energies in Sudan such as hydropower.Which it is widely used in Sudan, and one example is Elroseires hydropower plant.This research aims to conduct an exergy analysis of the performance of the Elroseires hydropower plant to identify areas for improvement using actual operation data. The exergy efficiency and exergy destruction rate of each unit in the plant were determined independently. The thermodynamic inefficiencies of all units of the plant were quantified for analysis to identify breakthrough points for further energy savings.Results indicated that the lowest exergy destruction rate occurs in August (20.6 MW) despite the lowest production of energy during this period. This outcome is due to the volumetric flow rate being less than those in other months, thereby leading to minimal flow turbulence that result in low exergy destruction. By contrast, the greatest exergy destruction occurs in December (106.1 MW) because of the high volumetric flow rate for the same pipe diameter. Such condition leads to turbulent flow and results in considerable exergy destruction. This study emphasizes that exergy analysis is useful in determining irreversibilities and losses in Elroseires hydropower plant to improve its thermodynamic performance. K E Y W O R D S electricity, exergy, hydropower plant, renewable energy 1 | INTRODUCTION The demand for energy has increased drastically since the middle of the last century due to industrial development and population growth.Consequently, many countries have started searching for and developing new and renewable sources of energy. Electricity is considered as the most multipurpose energy carrier in our modern global economy because it is primarily associated with human and economic development. Electricity, as a source of energy, is increasingly growing relative to other sources of energy. This trend is expected to increase for decades as large parts of the world population, especially those in developing countries, become connected to power grids. Electricity needs careful attention with regard to its contribution to global greenhouse gas (GHG) emissions. Energy integration is used to reduce the required energy for any process (power saving) and minimize environmental impact; examples include reheat and regenerative heaters in combined cycle power plants, heat recovery in organic Rankine cycle, and thermocoupling and heat pumping in distillation systems. [1][2][3][4][5][6][7][8][9][10][11]