International Scientific Journal


A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-34028]
PAPER REVISED: 2019-10-03
PAPER ACCEPTED: 2019-10-10
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THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 3, PAGES [2213 - 2224]
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© 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