Experience Gained from Shifting the 225 MW Power Units at the Cherepet State-Owned District Power Plant Equipped with TPE-223 Drum Boilers for Operation in the Sliding Pressure Mode

• Published in: Thermal engineering Vol. 68; no. 8; pp. 630 - 639
• Main Authors: Fomenko, E. A., Ryzhii, I. A., Shtegman, A. V., Sosin, D. V., Stepanishin, D. V., Tochilin, D. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-08-2021; Springer Nature B.V
• Subjects: Boiler Auxiliary Equipment; Boilers; Burner Units; Engineering; Engineering Thermodynamics; Expenditures; Feasibility; Fuel consumption; Fuel oils; Heat and Mass Transfer; Natural gas; Power plants; Power-Plant Fuels; Sliding; Steam Boilers; Turbines; Russia; sliding pressure; reduction of specific reference fuel consumption; modeling; tests; steam boiler; improvement of energy efficiency; power unit load; power unit
• ISSN: 0040-6015; 1555-6301
• DOI: 10.1134/S0040601521070053

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The operation of a steam boiler in a sliding pressure mode is characterized by certain advantages in comparison with the usual mode of equipment operation: it becomes possible to reduce the power unit’s minimum allowable load, reduce the electric energy expenditures for driving the feed pump, and reduce the specific reference fuel consumption. Increasing the equipment energy efficiency is a priority task for all power plants. Shifting a power unit for operation in a sliding pressure mode is a universal way to solve this problem irrespectively of the boiler type (drum or once-through) and the kind of combusted fuel (coal, natural gas, or fuel oil). Up to date, practical implementation of boiler operation in a sliding pressure mode has not received wide application in Russia. The existing examples of a power unit’s operation at sliding pressure are mainly associated with the transient conditions of equipment operation and are only related to once-through boilers. In drum boilers, practical studies of their operation at sliding pressure were not carried out in view of certain difficulties connected with the change of heat transfer conditions in the waterwall heating surfaces. The article presents the results of activities aimed at shifting the Cherepet state-owned district power plant (SDPP) 225-MW power units equipped with Ep-630-13.8-565/570KT (the TPE-223 model) drum boilers for operation at sliding pressure. These boilers use grade D coal from the Kuznetsk field as the main fuel. The operation of the power units was modeled using the Boiler Designer computer program, and a procedure for estimating the economic feasibility of shifting the power units to operate at sliding pressure was elaborated. Based on the results of preliminary studies, operational and adjustment tests of the power units were carried out, which confirmed the possibility and economic feasibility of shifting them to operation in the sliding pressure mode. The study results are presented, and the possibility of extending such practices to a significant part of the operating boiler and turbine equipment at the power plants of Russia is evaluated.