Rehabilitation and Conversion of Coal-based Power Plants to Cogeneration Plants for Increased Efficiency

Abstract

The analyses of electric utility system operations and in resource planning are becoming more and more complicated since deregulation came to the power industries. The risk aversion strategy is leading generation planners toward minimum risk capacity planning decision and asset optimization.

Some of the most attractive alternatives, which result in scaled down capacity increments, include:

• Rehabilitation/upgrading

• Cogeneration or combined heat and power (CHP) generation

Power plant rehabilitation is a high ranged concept essentially aimed at continued operations of the generating unit at, or near rated capacities for an extended life of the plant. In many cases, conservatively designed older units with components that were speci.ed with margin can be upgraded to yield additional capacity. The capacity increases are usually rather small and would not by themselves compensate for growth in demand. In essence, the need to rehabilitate may arise due to reasons such as low availability factor, low efficiency, increasing operating and maintenance costs, loss of reliability, drop in safety of plant and personnel, poor maintainability or environmental requirements. The term rehabilitation is therefore normally used in the context to cover the range of activities including repairing components, replacing equipment, modifying systems, adding new systems and equipment and perhaps restoration to rated capacities. This exercise on an already complex power generation process will naturally require the application of various technologies in order to ensure a safe and efficient installation of electricity supply and to adapt thermal power plants to the new conditions of the energy market. This article covers general consideration, approach and methodology adopted by the Public Electric Power Company of Bosnia and Herzegovina for the implementation of the project – Rehabilitation and Conversion of Unit 4 (200 MW) in Thermal Power Plant (TPP) “Tuzla” to cogeneration unit, from the initial engineering studies through scoping of works, project viability analysis, anticipated targets and benefits, problems encountered and finally the achievements of the project.