Performance evaluation of a major thermal power plant in Nigeria

Electric power is the bedrock of sustainable development in modern society. The demand for its adequate and reliable supply at a very competitive price is continuously increasing with population increase and the industrial revolution. A significant limitation to meeting this demand, is the inefficient operation of several of the existing power plants, resulting in their inability to generate electricity equivalent to their installed capacity. In this study, the exergy based performance evaluation of a major power plant in Nigeria was conducted to identify opportunities for thermodynamic improvement. Historical data of the plant was fed into HYSYS 8.8 to simulate its operations and obtain necessary thermodynamic data for assessing its performance. With the aid of codes embedded in HYSYS and the use of Ms Excel, the synthesized plant’s thermodynamics data was used for its performance evaluation. Components-wise evaluation revealed that apart from the turbines, exergy efficiencies were lower than energy efficiencies. The overall energy efficiency of the plant was found to be 33.19% while the corresponding exergy efficiency was 31.94%. The boiler was identified as the unit with the highest irreversibility and most significant contributor to overall plant’s inefficiency. It is posited that adequate knowledge of the effect of changes in operating parameters and load variation on performances will be handy in addressing inefficiencies in the boiler and other components of the plant.