The results of experimental elaboration of engineering approaches relating to environmental update of combustors for the GTK-10 10 MW, GTG-1500 1.5 MW and GT-100 100 MW gas turbine engines are presented. The combustor update was carried out by a technique of directed dosed air blow into the maximum temperature zone with in the fire space. The advantages of the technique are as follows: • feasibility of reduction of Nox concentration in waste gases to 50 ppm; • simplicity and adaptability to manufacture of the structure; • no need in changing the design of the engine components and systems; • short-time outage of the unit at update.

The results of research into development of engineering approaches to environmental update of the GTN-16 16 MW gas-pumping unit combustor are presented. The built-in “disc” combustor of the GTN-16 is noted for having a small length and very low hydraulic resistances. The multi-burner low-NOx combustor design was developed in a test rig. The “lean” fuel/air premix combustion was adopted as the basis for the design. The proposed environmental update of the GTN-16 combustor does not bring about any changes in the most costly material-intensive and labour-consuming components of the combustor, viz. casing, frame, liners. No changes were also made in the automatic control system. It is noteworthy that a similar approach is appropriate for the “Turbomotorny Zavod” (Ekaterinburg, Russia) GTN-25 type 25 MW unit.

Results of the environmental update of GT-750-6 (“Nevsky Zavod”, 6 MW), KWU VR-438 (“Siemens”, 10 MW), MS-3002 (“General Electric”, 10 MW) gas-turbine unit combustors were examined. On the basis of some specific features of design and operating process in the combustors, original engineering approaches of their update using a technique of localized air blow into the fire space extreme temperature zones were developed. The technique was demonstrated to be effective for a variety of combustors. Using the technique, one needs no considerable changes of the combustor design. The fuel system and gas turbine plant automatic control and governing systems remain virtually intact.

The environmentally friendly modification of gas turbine combustion chambers is a process for altering the structure of combustion, mainly in the primary zone in order to reduce the emission of NOx, CO, and solids into the atmosphere. The ecological modernization of gas turbines that are currently in operation is a continually topical subject because there are several thousand turbine units in Europe that do not meet current emission limits. At the same time, it can be expected that the emission limits for these turbines operating in the European Union will be reduced to NOx≤75 mg/m3, CO≤100 mg/m3 in working range of 40–100% of the gas turbine output after the year 2010. The authors have developed a new construction of a hybrid low-emission natural gas burner. Developmental work was performed both on one burner and also in a burner group consisting of seven hybrid burners. Results will be presented in this paper for model conditions for the atmospheric test rig and their re-calculation to the operational parameters on the real gas turbine. A conception with variable primary section combustion chamber geometry has been used to achieve low emissions in a wide range of gas turbine output allowing the organization of the combustion process with a constant gas/air mixing ratio coefficient. A prototype of a combustion chamber with a hybrid burner group with control of the primary air mass flow has been manufactured and tested in a 6 MW gas turbine operating in a gas pipeline compressor plant. The achieved emission characteristics will be presented and compared with precalculations. The experiments made on the real gas turbine have proven the possibility of meeting the target emission limit performance of NOx≤50 mg/m3, CO≤50 mg/m3. Other possibilities how to reduce harmful emissions for this burner type will be presented in this paper.

Some results of the NPP “EST” activities on improvement of the environmental record of the stationary gas turbines, viz.GTG-1500, FRAME 5, GTN-16, which are in use nowadays in Russia, are presented. Toxic emissions reduction is achieved through combustors update. The technique of directed dosed air blow-in into the maximum fire temperature zones allows to reduce the NOx emissions to 70–130 mg/Nm3 (converted to NO2 at 15% O2 concentration) via minimal combustor design modifications. Lower NOx emissions, amounting to 15–25 mg/Nm3, can be produced through combustion of lean premixed air and fuel in the 4-burner low-toxic module. When retrofitting the GTN-16 unit combustor, the standard dome was replaced with 20 such modules.