The operation of the low-pressure turbine part in variable condensing and extraction regimes is analyzed. The effect of steam parameters at the inlet to the low-pressure part (in the lower extraction chamber) and of operation of the regulating stage of the LPP on the level of wetness in the low-pressure stages is determined. It is shown that the moving blades of the last stages of cogeneration turbines operate under heavier erosion conditions than in condensing turbines. This is one of the main causes of their intense erosion wear.Experience of operation of cogeneration turbines has shown that the entrance edges of moving blades of low-pressure stages undergo considerable erosion wear. Blades of the last stages of T-250/300-240-type turbines, the height of which (940 mm) is the greatest of all operating cogeneration turbines, are no exception. Today partial or full replacement of these blades is performed in virtually any overhaul of turbines of the cogeneration plants of the Mosénergo Company. The cost of a new set of blades is quite high. Repair replacement of the blades also costs much. The expensed can be reduced by 30 -40% by facing metal on partially damaged blades. Such technologies have been developed by a joint effort of TsRMZ and VTI and by the "Turboénergoservis-ÉK" Company. However, they have not found wide application yet and require further study and gaining of reconditioning experience.At the same time, for the greater part of year, the turbines of type T-250/300-240 serve in a heating (extraction) mode with partial opening of regulating diaphragms and reduced passage of steam to the low-pressure part (LPP). Under these conditions during the heating season the last stages operate in a ventilating mode and do not produce net power. In the summer months these turbines supply some heat to the hot water supply system and do not serve in a purely condensing mode, though their regulating diaphragms are fully opened. Under these conditions the production of power by the last stages is substantially lower than the rated output due to reduced steam flows and elevated pressure in the condenser as compared to the design values, which are determined by the circulation water temperature.These considerations show that it would be expedient to update the low-pressure part of the T-250/300-240 turbine by mounting shorter blades in the last stages, which should not only lower the intensity of erosion processes but also increase the efficiency of the turbine unit operating in the heating mode. The possibility of operation of such turbines without moving blades of the last stages is also being considered.Enhanced erosion wear of moving blades of cogeneration turbines as compared to condensing turbines is a result of some objective factors, the most important of which will be considered below.Effect of regime factors on development of erosion wear of moving blades of T-250/300-240 turbine. In condensing turbines and in cogeneration turbines operating in a purely condensing mode the maximum moisture content of steam in...
Results of detailed computations (performed with the use of mathematical models of dual-purpose turbine plants) of the effect of the main operating factors on the energy and economic efficiency of the production of additional condensation power in the periods of power generation (at partially loaded heating extractions and flow of live steam below the rated value) are presented as applied to actual conditions of operation of turbines of different types. The results obtained show that the additional power can be quite competitive in the power market (at least in peak demand periods of the day) and that it is expedient to use dual-purpose turbines for managing electric demand.Keywords: dual-purpose turbine plant, additional condensation power, power characteristic, variable operating conditions, thermodynamic parameters and cost-performance ratio of a cogeneration plant, efficiency, mathematical models, management of electric demand.The steady growth in the consumption of electric and heat energy under conditions of scarceness of investment in the power industry makes it necessary to carefully estimate the production possibilities of enterprises of the power industry and their capability to satisfy reliably and efficiently the growing demand for electric energy and heat and to use these estimates for determining the scale of required updating and development of the power industry.In this connection it is important to raise the efficiency of operation of the active cogeneration plants and thus make them more competitive in the markets of heat and electric energy.In order to increase the heating efficiency of the active cogeneration plants (cogeneration-based district heating is a very significant power-saving technology in Russia and makes it possible to save up to 20 -30% fuel as compared to separate production of heat and electric energy) specialists resort to such inexpensive measures as development and analysis of methods for obtaining additional power and optimizing the operating conditions of individual turbine plants and cogeneration plants as a whole.The present work is devoted to studying the energy and economic efficiency of additional condensation power obtained at dual-purpose turbine plants, because the operation of power systems is often connected with the complex and multivariant problem of distribution of electric and heat loads among heat power plants, cogeneration plants, and boiler houses. The problem is difficult to solve due to the necessity for analyzing the permissible combinations of loads of different quality, operating factors, and limitations of fuel supply. Though the theoretical approaches to complex solution of the problem are known, the data for practical computations are far from being full.It is known that dual-purpose turbines at cogeneration plants operate with long periods of partial loading of the heating equipment and live steam flows below the rated value. Under these conditions additional electric power can be obtained (at the same level of heat output) by increasing the conde...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.