【正文】 re of the superheated steam at low excess air, and produce minimal emissions of harmful substances, standard schemes for organizing the highly efficient, lowtoxicity bustion of fuel have been developed at the firm NPO TsKTI, including the following:— use of a new generation of specialized lowemission burners?！?bustion with low excesses of air?！?multistage supply of the oxidizing medium (when burning natural gas)。 and— flue gas recirculation. The new generation of specialized lowemission burners (Table 1) have considerable advantages over those in prior use and are more plicated devices (designed on the basis of recent studies in the field and using numerical simulation techniques) which require a higher quality of manufacture and are able to operate with greater reliability and safety. The burners offer the possibility of controlling the flare by redistributing the fuel over the burner cross section and feeding air in along the channel. As a rule, all the adjustments in the parameters of the fuel and air are conducted on bustion test stands at NPO TsKTI, as well as during the boiler regime setup stage for fullscale boiler assemblies in the field. With the new generation of burners, it is possible, not only to solve the problem of pletely burning the fuel, but, because of the organization of the bustion process in the boiler, the configuration of the burners, and the specified length of the flare, to maintain the required temperature levelfor the superheated steam, organize more economical bustion,and enhance the efficiency of the unit as a whole. In addition, in many cases it is possible to avoid having to reconstruct the steam and water loop of the boiler. The new generation of burners has been used to refit a variety of boiler types: TGM84, TGMP314Ts, TGME464,BKZ420, BKZ320, BKZ220, BKZ210, TP230, TP170,TP80, TP87, BKZ75, etc.Burners with a central gas distribution nozzle (Fig. 1) are used for various types of boilers with a wide range of powers. Burners of this type with powers of 4 – 20 MW are mounted on the walls of the boiler chamber (in single front, counterflow, multiple stage, and other configurations). They are reliable and simple to use and have good performance characteristics in terms of pleteness of bustion and moderate levels of harmful emissions.In some cases, burners of another type — with regulated pipe gas feed (Fig. 2) — can be used in low power boilers. These burners are mostly installed in boilers with a steam production rate greater than 75 tons
h. The presence of the regulated gas feed section, as well as the possibility of “regulating”the air supply regime (redistributing air over the individual burner channels), makes it possible to vary the length and configuration of the flare (., the character of the temperature distribution in the burning core) and to influence the emission characteristics of the flame. Regulation (numerous binations of the positions of the three sizes of gas feed nozzles) makes it possible to reduce the emissions of NOx, CO, and soot significantly, and also to affect the temperature of the superheated steam. Technical remendations have been developed for the angles at which the gas nozzles should be installed and this aids in obtaining a given flare configuration.The regulation modes can be set by specialists from the JSC “NPO TsKTI” during startup adjustment operations。Burners of a third type (Fig. 3) are furnished for boilers with tangentially mounted burners, as used for conversion of boilers with an angular distribution of burners from coaldust to natural gas bustion. These burners are also used for modernizing worn and obsolescent gasoil boilers. A tangential configuration (one or two vortex) makes it possible to reduce greatly the emissions of nitrogen oxides by staged bustion of the fuel. (The first stage involves burning as such in the burner, the second, vortical bustion in the boiler,and the third, burning with “tertiary” air feed through discharge nozzles mounted on the side walls above the level of the burners.) This arrangement has a number of other advantages,but it requires large capital expenditure for reconstruction of the boiler unit.Yet another important approach to modernizing gas fuelled systems is the development of afterburner systems, which are used to ensure efficient utilization of the heat in the flue gases from gas turbines and engineering systems. Afterburner systems consist of a structure (part of the boiler recovery system) with afterburner device sections mounted inside it (Fig. 4).The main fuel for an afterburner system is natural oxidant consists of bustion products from a gas turbine or industrial device. Natural gas is fed through gas feed pipes, is distributed over gas distribution pipes, and then enters the bustion zone through apertures in these of the hot gases and the stability of the bustion process are ensured by a special design for the pylons.A design and parameters for the afterburner system are determined for each individual project.The afterburner units developed and manufactured by the JSC “NPO TsKTI” differ in the following respects:— pactness and simplicity of design。— low aerodynamic drag?！?reliability of ignition, flame changeover, and bustion stabilization?！?elimination of the possibility of flame detachment。— operational reliability and safety。 and,— long service life owing to provision of sufficient cooling for the apparatus. One example of the reconstruction of medium power coaldust boilers using burners of the first type is the refitting of the TsKTI7539F2 boilers at the JSC “Chepetskii Mechanical Factory” heating and electric power plant, converting them to separate bustion of natural gas and oil. The following technical solutions were applied during therefitting: coaldust burners were replaced by GMU20m gasoil burners built by JSC “NPO TsKTI,” in the same numbers and at the same positions as before in the front w