SYNGAS BURNER OPTIMISATION FOR FUELLING A HEAVY DUTY GAS TURBINE WITH VARIOUS SYNGAS BLENDS

摘要

The IGCC power plant of Ferrera Erbognone will be the first real commercial power plant in Italy to be operated without taking into account the high benefits once available according to the national law (CIP6/1992) specifically dealing with recovery fuel usage alternative to natural gas. The syngas will be provided by the nearby refinery using tar as main feedstock. Furthermore, according to the demands of the refinery it will be possible in the gasifier island to separate hydrogen in variable quantity from the syngas thus giving a high variability composition as output fuel. Also, if the maximum quantity of hydrogen will be separated, an integration with natural gas will be performed in order to get the maximum power output of the power plant. As a consequence, the syngas burner has been designed taking into account all the fuel characteristics depending on the different composition carried out. According to these, the burner has been optimised in order to fit the various syngas blends to be fuelled when running the engine. In order to verify the modifications carried out the burner has been tested both at atmospheric and full engine conditions since the NOx requirements for this project are the more stringent experienced with respect to the past projects (NOx to be below 25 ppm). During these test the main aspect to be investigated have been: a) Minimum load when feeding the gas turbine with syngas b) NOx emission from 60% load up to base load c) Change over from natural gas to syngas and vice versa. The tests have been performed successfully: commissioning on site will start on November 2005. The paper describe the design and the testing phase highlighting the main features of the burner and the fuel system with respect to the plant requirements.