58660 - The Development Problems of Two-Fuel Burner for the Gas Turbine Combustion Chamber 

THE DEVELOPMENT PROBLEMS OF TWO-FUEL BURNER FOR THE GAS TURBINE COMBUSTION CHAMBER

Ph.D. A.Yu. Vasiliev¹, Ph.D. O.G. Chelebyan¹, Ph.D. A.I. Mayorova¹, A.N. Tarasenko¹, V.M. Zakharov¹

Ph.D. D.S. Tarasov²

¹ Central Institute of Aviation Motors, Moscow, Russia

² JSC «Power Machines»

ayvasilev@ciam.ru

This paper is devoted to the implementation of work on the topic " A spraying device for the gas and liquid fuel gas turbine combustion chamber designing". The introduction of two fuel gas turbines is welcomed by the final consumer. Such an approach allows to reduce the consumable fuel cost and improve fuel independence from the supplier.

The purpose on this stage of work is to develop and manufacture a liquid fuel spraying burner model based on the design of a single-fuel combustion chamber (CC) burner that can use only natural gas as a fuel.

The under development burner should provide a number of modern concepts requirements for industrial gas turbine combustion chambers. One of the most complicated requirements to implement is the ecological characteristics of the combustion chamber, namely the provision of a nitrogen oxides emission (NOx) parameter. One of the methods to ensure a low level of NOx emission in the dry circuit gas-turbines combustion chambers is the use of the technology that could provide a maintaining stable combustion of premixed lean air-fuel mixture at α≥2.0. It should be noted that, in general, the harmful substances formation process in the exhaust gases depends on the uniformity of the oxidant-fuel mixture formed behind the combustion chamber front device and also on the residence time. Thus, the most important circumstance in the low-emission combustion chamber development is the development of a highly efficient atomization system and a fuel supply control system.

Considering the above, on the first stage a 3D calculations of the air channels characteristics for two burner types - pilot and main - were carried out. Data were obtained on the flow and pressure fields inside and at the burners outlet, and also the volumes of the reverse flow zones. A very small zone of reverse flows is formed on the main burner flow. This circumstance should have a positive effect on the NOx production in the future. A pronounced reverse flow zone is formed on the pilot burner flow axis.

The fuel channels of the main and pilot injectors were calculated for two burners types. Two variants of fuel injectors differ in the liquid fuel atomizing methods for the gas turbine combustion chamber front device main burner. In option No. 1 to provide a uniform liquid fuel and air mixture at the burner nozzle outlet and to ensure the NOx emission required level a pneumatic spray method was proposed. In option No. 2 to ensure efficient fuel spraying at low operating conditions of the gas turbine a method of combined centrifugal-pneumatic spraying was used. The values ​​of the droplet fineness and the spray cone angle, depending on the fuel injection pressure, were obtained for the main burner at a pressure of 5 MPa - the torch angle of about 90 ° and the average Sauter droplet diameter of about 25 μm, and for the pilot burner - the torch angle of more than 70 ° and the average Sauter the droplet diameter of about 21 microns.

Experimental studies with two burners types were carried out to obtain aerosol with desired properties to ensure uninterrupted operation of liquid-fueled gas turbine. The aerosol measurement results confirm the calculation results. At the next stage of the work, it is planned to introduce developments in the design of a full-size compressor station and to conduct its experimental studies.