Use of heat-resistant chromium-aluminum steel for tube spacers in superheaters of boiler units

Results of investigations and industrial testing of heat-resistant chromium-aluminum steel 03Kh18Yu3BT are presented; from these results, this steel can be recommended for the fabrication of spacers, mounting hardware for the heating surfaces of the superheaters of boiler units, and other lightly loaded articles operating at high temperatures during the burning of all types of fuels used in the firing of thermoelectric power plants. __________ Translated from élektricheskie Stantsii, No. 9, September 2007, pp. 34–37.     

Optimization of regimes for the feed of highly concentrated culm-anthracite coal dust for burning in a TPP-210A boiler

Results are presented for regime adjustment of feed systems for a TPP-210A boiler for the burning of highly concentrated culm-anthracite coal dust. As compared with nonoptimal regimes, optimal regimes of high-concentration-feed systems improve the economy of the boiler by 1.7% on average. __________ Translated from élektricheskie Stantsii, No. 3, March 2007, pp. 34–38.     

Asynchronous nonsalient-pole compensators with total air cooling1

The fundamental parameters and construction of asynchronous compensators, soon to be produced by the “Silovye Mashiny” — “élektrosila” Joint Stock Company in 2008, are considered. The compensator has a massive nonsalient-pole rotor with two excitation windings, shifted by 90° (in electrical angles), supplied from controlled reversible power sources. The compensators provide delivery-consumption of reactive power in the ±100 Mvar range with the possibility of short-term double forcing of the power output and improved dynamic characteristics compared with synchronous compensators. ¹ This paper is based on material presented at the conference “Russia Power 2008” (Moscow, April 2008). Translated from élektricheskie Stantsii, No. 11, November 2008, pp. 62–65.     

Automatic system for regulating the frequency and power of the 500 MW coal-dust power generating units at the Reftinskaya GRÉS

The monitoring and control systems at the 500 MW coal-dust power generating units No. 7, 8, and 9 at the Reftinskaya GRéS have been modernized using information-regulator systems. Layouts for instrumental construction of these systems and expanded algorithmic schemes for the automatic frequency and power control system and for the boiler supply and fuelling are discussed. Results from tests and normal operation of the automatic frequency and power control system are presented. Translated from élektricheskie Stantsii, February 2009, No. 2, pp. 47–53.     

Behavior of phosphates in a high pressure drum boiler with frequent loading

The overall contamination of the baffle pipes in a high pressure drum boiler in the phosphate water-chemical regime is estimated based on the increase in the concentration of phosphates in the boiler water during unloading of the boiler to approximately 50% of nominal. Translated from élektricheskie stantsii, No. 6, June 2008, pp. 29–33.     

Technical solutions for a modernized TPE-216M boiler in a highly efficient unit

A design is presented for a modernized lignite-fired TPE-216M boiler for a highly efficient 225-MW power-generating unit, which can be installed at the Kharanorskaya state area power plant (Station No. 3). The boiler has a guaranteed gross efficiency of 92.5%, and satisfies modern ecological requirements: NO_x concentration of less then 300 mg/m³ in the flue gases, owing to the high gross efficiency of the unit, which is no less than 40%, NO_x emissions computed per 1 kW · h are reduced additionally by 10%, and the same applies to CO₂ emissions. The temperature of the steam is raised from 545 to 565°C. A low-pressure water economizer, which is included in the heat diagram of the unit, is installed to lower the temperature of the exiting gases. __________ Translated from élektricheskie Stantsii, No. 6, pp. 8–13, June, 2006.     

Slagging properties of coals and allowance for them in the analysis of the possibility of using out-of-design fuel

It is shown that out-of-design coal should be used only after computational analysis of slagging of the boiler. The use of ash fusibility as a criterion for the analysis should be avoided because this property does not reflect the slagging properties of coal to an acceptable degree. Parameters characterizing the properties more appropriately are presented. It is shown that slagging of an actual furnace depends on many factors and the condition that “the thermal stresses should be lower than the limiting value” is insufficient. An algorithm for the analysis is suggested on the basis of the slagging conditions arising upon transition from one kind of fuel to another with allowance for the actual slagging situation. __________ Translated from élektricheskie Stantsii, No. 3, March 2006, pp. 18–23.     

Complex efficiency indicator for separators in dust-preparation plants

A relationship for determination of the complex efficiency hcom of a separator, which graphically reflects the effectiveness of its operation from the standpoint of both output of prepared dust with an assigned amount retained on a sieve, and also with consideration of the extent to which fine fractions of final dust are excluded from the return, is presented on the basis of analysis of existing methods of determining classifier efficiency, experience with their use in power engineering, and the function of dust separators of coal-pulverizing mills in the production process of boiler plants at TPP. A procedure is proposed for determination of the value of hcom when an assigned amount of final dust is retained on a sieve during operation. The possibility of determining complex separator efficiency for mills with a built-in separator is analyzed. __________ Translated from élektricheskie Stantsii, No. 6, July 2007, pp. 6–10.     

Results of heat tests of the TGE-435 main boiler in the PGU-190/220 combined-cycle plant of the Tyumen’ TÉTs-2 cogeneration plant

Special features of operation of a boiler operating as a combined-cycle plant and having its own furnace and burner unit are descried. The flow of flue gases on the boiler is increased due to feeding of exhaust gases of the GTU into the furnace, which intensifies the convective heat exchange. In addition, it is not necessary to preheat air in the convective heating surfaces (the boiler has no air preheater). The convective heating surfaces of the boiler are used for heating the feed water, thus replacing the regeneration extractions of the steam turbine (HPP are absent in the circuit) and partially replacing the preheating of condensate (the LPP in the circuit of the unit are combined with preheaters of delivery water). Regeneration of the steam turbine is primarily used for the district cogeneration heating purposes. The furnace and burner unit of the exhaust-heat boiler (which is a new engineering solution for the given project) ensures utilization of not only the heat of the exhaust gases of the GTU but also of their excess volume, because the latter contains up to 15% oxygen that oxidizes the combustion process in the boiler. Thus, the gas temperature at the inlet to the boiler amounts to 580°C at an excess air factor α = 3.50; at the outlet these parameters are utilized to T _out = 139°C and α_out = 1.17. The proportions of the GTU/boiler loads that can actually be organized at the generating unit (and have been checked by testing) are presented and the proportions of loads recommended for the most efficient operation of the boiler are determined. The performance characteristics of the boiler are presented for various proportions of GTU/boiler loads. The operating conditions of the superheater and of the convective trailing heating surfaces are presented as well as the ecological parameters of the generating unit. __________ Translated from élektricheskie Stantsii, No. 12, December 2006, pp. 26–32.     

Design study of boiler furnaces

It is shown that the standard method of design of boiler furnaces is not suitable for nonstandard operating conditions. A physicomathematical model of the furnace process is suggested for design studies of promising furnace devices and of conditions of flame extinction. An example of engineering design of a furnace with controlled process is presented. __________ Translated from élektricheskie Stantsii, No. 4, April 2006, pp. 5–10.