Active on-line protective tuning adjustment technique to achieve better availability and performance in pre-mix DLN combustion

摘要

Stable combustion of gas turbines is essential to ensure reliability, availability and achieve maximum component life capability. Combustor instabilities can trigger high-pressure fluctuations that are generally due to sudden changes in fuel calorific value or fuel quality, large ambient temperature swings, or sudden changes in operating load conditions. In order to protect against combustor instabilities, Mitsubishi developed an advanced monitoring and protection system known as the Advanced Combustor Pressure Fluctuation Monitoring (advanced CPFM) system. This on-line monitoring and protection system automatically tunes the air bypass valve, main and pilot fuel flows to maintain appropriate fuel / air ratio depending on the combustion chamber flame instability condition. The response to such actions successfully prevents flame out occurrence, combustion oscillation, and flame flash back under various modes while trying to maintain emissions within specified levels. This paper describes the operation and functionalities of the advanced CPFM system that has been tested at Mitsubishi's in-house combined cycle power plant under real operating conditions.