State changes by combustion tuning in a gas turbine dry low NOx combustor

In this study, a 100-MW-class gas turbine dry low NOx combustor, which is widely used in power generation, was tested to analyze variations of the exhaust temperature and combustion dynamic pressure in relation to the pilot fuel fraction and combustion airflow rate. The results showed that the exhaust temperature was proportional to the pilot fuel fraction at no and low loads but had an inverse relationship with the combustion airflow rate. When the turbine rotor inlet temperature, which was calculated with an experimental formula using the exhaust temperature, exceeded 1,000°C, the concentration of the emissions reduced sharply. This also indicated the combustion dynamic pressure was proportional to the gas turbine load and airflow rate, whereas the pilot fuel fraction had reduced intensity except in the high-frequency band. © 2021 The Korean Society of Mechanical Engineers.