Perpustakaan Digital ITB

With record-high global CO2 emissions, transitioning to clean power generation is an urgent global priority, and scaling up renewable energy is vital in achieving that goal. However, its intermittent nature, such as those from solar and wind power, poses a challenge in its integration to the grid. Currently, this intermittency is resolved by peaker plants in the form of gas-fired power plants. While this method resolves the intermittency issue fairly well, its high operational cost motivates the implementation of other solutions to provide flexibility. One such proposed solution is to increase the flexibility of current coal-fired power plants. As of now, the ramp rates of most coal power plants are between 1.5 – 4% of their nominal capacity, reaching as low as 0.5% for power plants in underdeveloped countries. Compared to the ramp rate of modern simple cycle gas turbine power plants at 20%, and the fact that coal-fired power plants will still be in operation for a period of time before transitioning into cleaner methods of power generation, there is an incentive to develop a method to increase its operational flexibility. This research focuses on improving the flexibility of existing coal-fired power plants through the development of a dynamic simulation. The power plant model is simulated within Dymola using the Cla-Ra library. In this study, the integration of gas turbine feedwater repowering is done on the plant model to optimize its ramp rate. Results showed a successful optimization of plant flexibility, with an increase of ramp rate from 0.78% Pnom / minute to 1.69% Pnom / min through feedwater repowering during ramp-up operation. Consecutively, the water-gas heat exchanger to be used for the repowering was successfully designed, presenting a 1.02% error of fluid inlet and outlet conditions between the dynamic simulation and final design.