THERMAL SCIENCE

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Authors of this Paper

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Dušan Strušnik

,

Igor Kuštrin

,

Jurij Avsec

OFF-DESIGN FLOW ANALYSIS OF COGENERATION STEAM TURBINE WITH REAL PROCESS DATA

ABSTRACT
This paper presents the concept of reconstruction of the existing coal-fired combined heat and power plant to comply with new European environmental policies. The existing coal-fired boiler will be replaced by two new dual pressure heat recovery steam generators, which will utilize the exhaust gas heat from two new gas turbines. The steam from the heat recovery steam generators will be fed to the existing steam turbine. After the reconstruction, the nominal turbine inlet steam mass-flow of 40 kg/s will be reduced to 30 kg/s. During periods of low heat demand, only one gas turbine and one heat recovery steam generator will be in operation and the live steam mass-flow may drop even to 12 kg/s. Prior to the reconstruction, dedicated tests of the existing steam turbine were carried out using the steam from the existing coal-fired boiler. The goal of the test was to verify the viability of operation with such an extremely low mass-flow. The results of tests show that such operation is possible but inefficient from a power generation point of view. Besides this, the turbine control algorithm needs to be accommodated to this extreme operating regime and additional measures like displacement of the extraction points and steam cooling will be required to control the temperature of the steam extractions. The novelty of this paper is using real pre-reconstruction process data for the assessment of feasibility and efficiency of the post-reconstruction operation of a combined heat and power turbine.
KEYWORDS
cogeneration, control valves, exhaust gas, heat recovery, steam turbine
PAPER SUBMITTED: 2021-12-05
PAPER REVISED: 2022-05-16
PAPER ACCEPTED: 2022-07-14
PUBLISHED ONLINE: 2022-10-29
DOI REFERENCE: https://doi.org/10.2298/TSCI2205107S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 5, PAGES [4107 - 4117]
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Off-design flow analysis of cogeneration steam turbine with real process data

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence