Currently, the priority for improvement of the combustion chambers of aircraft gas turbine engines and ground-based gas turbine plants is associated with a decrease in the concentration of harmful substances in the exhaust gases while ensuring fuel economy and operational efficiency. Pride of place in the design of a gas turbine power plant goes to solving the problem of organizing the combustion process, i.e. the development of a low-emission combustion system that provides high efficiency and environmental safety. Thus, ecology today determines not only the appearance of a combustion chamber, but also that of a gas turbine power plant as a whole. Below, an attempt is made to summarize the results of developing a low-emission combustion system for various types of combustion chambers of convertible gas turbine power plants and to present a unified approach to the problem of designing a conceptual structure of a low-emission combustion chamber.

The paper deals with the questions of introducing the additive technology of selective laser melting (SLM) into the production of the main structural elements of a combustion chamber for ground-based gas pumping, power and transport gas turbines. A fundamentally new design of a low-emission two-circuit burner was developed, adapted for the manufacture of products with a complex geometry through the use of selective laser melting (SLM) of metal powders according to mathematical CAD-models with the help of an advanced production technology. Technical difficulties associated with the implementation of additive manufacturing technology were overcome. The process chain was tried out from design to manufacturing and quality control of finished structural elements under conditions of mass production. The deficiencies of the parts manufactured by the additive technology were revealed and ultimately eliminated. Successful development of burners for a low-emission combustion chamber using a new technology significantly reduces labor intensity and time of production while maintaining high quality.

Metallist-Samara JSC has developed a fundamentally new design of a unified double-circuit burner of a low-emission combustion chamber (LECC) of a ground-based gas turbine unit (GTU), adapted for manufacturing with the help of an innovative technology by selective laser melting (SLM) of metal powders using CAD models. Several batches of burners were made and control studies were carried out characterizing the quality of manufacturing according to the established procedure. Deficiencies inherent in the SLM process were discovered, the main of which are: raised roughness, in particular, of the fuel channels of the main and duty zones; microporosity, microalloying; microcracks; instability of flow characteristics; local non-sintering zones of the layers grown on the burner body. As a result of the analysis of the state of the manufactured burners, research and refinements, it was found that most of the identified shortcomings can be eliminated during further development of the modes and parameters of the technological process. Currently, difficult engineering problems associated with the implementation of additive manufacturing technologies have been overcome.

Environmental safety issues are a priority in the modernization development of aviation or ground-based combustion chambers of gas turbine engines. In order to reduce the emission of harmful substances from combustion products, a low-emission combustion system, which is based on the concept of LPP (Lean-premixed and prevaporised), is being used today. This concept implements the principle of burning “ultra-poor” premixed air-fuel mixtures. The operational experience of combustion chambers developed in accordance with the indicated concept shows that one of the implementation problems is the difficulty in ensuring a good start. This paper presents the results of adjusting the operating process of a modern combustion chamber, launching a gas turbine unit, including drawing up a fuel supply control algorithm, experiments with igniting ignition devices and setting the gas turbine on idle mode. A feature of the commissioning work is the debugging of the operating process of the combustion chamber directly as part of the gas turbine unit, bypassing the traditional pilot-testing on the rig.

Today, more and more “stringent” requirements are established in the world for the emission of harmful substances in the combustion products of gas turbines operated and newly developed, which is why the issue of ensuring environmental safety is relevant. The article presents the basic principles of organizing low - emission fuel combustion based on a generalization of experience in the successful operation of gas turbines of the NK family, which ensured that modern requirements for reliability and environmental safety are met. An example is given of the modernization of the gas turbine combustion chamber in order to reduce the levels of emissions of harmful substances. The experience of introducing into serial production of additive technology for the manufacture of basic elements of low-emission combustion chamber using selective laser melting technology is described.