Burner for a gas turbine

Abstract

A burner for a gas turbine, wherein the burner has a combustion chamber, a preheating device adapted to preheat air before it enters the combustion chamber and a swirler adapted to guide a swirler air flow that has the preheated air to the combustion chamber, wherein the swirler has a base plate with a surface that confines the swirler air flow, wherein the surface has a hole adapted to inject a liquid fuel into the swirler air flow and the base plate has a channel for transporting the liquid fuel to the hole, wherein at least a part of the channel is oriented essentially parallel to the surface so that the liquid fuel streams essentially parallel to the surface and is preheated by the swirler air flow.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2016 / 066333 filed Jul. 8, 2016, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP15176506 filed Jul. 13, 2015. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention relates to a burner for a gas turbine.BACKGROUND OF INVENTION[0003]A burner for a gas turbine can be operated at certain operating conditions by injecting water into the combustion chamber in order to reduce the flame temperature and therefore reducing the emission of NOx. An alternative approach for reducing the emission of NOx lies in using dry low emission (DLE) burners that are operated without the injection of water and are based on premixing fuel and air prior to combustion. DLE burners emit low concentrations of NOx and produce compact flames. However, the DLE burners...

AI Technical Summary

Benefits of technology

The invention is a burner for gas turbines that can operate efficiently over a range of load ranges. It has a swirler with a wall that has a hole for injecting liquid fuel and a channel for transporting the fuel to the hole. The fuel is preheated by the swirler air flow and atomized efficiently. The burner has a step that causes a vortex, which helps mix the fuel and air effectively. The combustion chamber is rotationally symmetric, and the step is located at a radial distance from the burner axis to ensure efficient interaction with the fuel. The technical effects of the invention include efficient atomization and mixing of liquid fuel and air, reduced viscosity of the fuel, and improved performance at part load operations.

Problems solved by technology

However, when the burner is operated at a part load operation, the pressure drop over the lances is lower in comparison to the full load operation, which results in a less efficient atomisation than at the full load operation.

This leads to a less efficient mixing of the fuel with air and can lead to the formation of fuel ligaments that are deposited on surfaces of the burner where it leads to the formation of a carbon build-up.

When the carbon build-up is formed on the lances it can lead to an obstruction of the fuel and when this carbon build-up is formed at an igniter-port it can lead to a reduction in the efficiency of ignition.

Furthermore, the less efficient mixing of the fuel with air can lead to the formation of soot that is emitted into the atmosphere.

However, this operation is disadvantageous since it reduces the efficiency of the gas turbine and can not be performed at a part load of less than 40% of the full load.

Images