Optimization on fuel gas operation for combined cycle power plant

Abstract

Fuel gas system for 13E2 gas turbine is designed to optimize the fuel gas consumption and reduce nitrogen oxide gas emission. This system consists of closed loop controller, control valves, shut off valves, and burners. Due to long running operation, the hardware of gas turbine efficiency will deteriorate. During major outage, all hardware will be replaced or repaired. Since the characteristic of gas turbine changed, it is not matching with the existing fuel gas system setting. Hence the fuel gas system has to be calibrated. In this project thesis, one of the main targets is to explain the CCGT fundamentals. In the CCGT system, there is a subsystem named as fuel gas control system. This system is selected for improvement purposes. The next main target is to prove that the proposed improvement is possible. The calibration work is focused on the 3 main control valves (MBP 41, 42, and 43). A step by step working instruction is indicated and the trending for relevant signals are displayed and recorded. On top of that, the details of fuel gas system, components, and its operation have been explained. Each protection measurements available in the controller have to be monitored in advance to avoid any tripping during testing. Any tripping at certain load may incur certain amount of equivalent operating hour. The final result from this project proved that there is an improvement in the operation of fuel gas system. The reduction is mass flow at certain loads are visible. Besides, there is no potential of tripping on GT due to current gas composition