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Preheating of secondary superheated steam pipelines when starting steam turbines of SCР power units

https://doi.org/10.24223/1999-5555-2022-15-1-4-11

Abstract

Specific features of the technology of preheating hot legs of steam pipelines of intermediate steam overheating at the start-up of SCР power units with single-bypass thermal circuits are presented, with the advantages and disadvantages of various previously used methods of preheating steam pipelines after intermediate steam overheating at the startup of power units at supercritical pressure with a capacity of 250–300 MW considered. The analysis of the conditions for the completion of the heating of these steam pipelines using various process heating arrangements, as well as the heating steam consumption necessary for heating and its sources (special kindling steam by-passes, steam by-passes of own needs, kindling expander and combined heating technology at various intermediate rotational speeds of the turbine rotor) is carried out. The results of computational and experimental studies of the heating processes of steam pipelines during the start-up of SCР power units from various thermal states are presented, nomograms for determining the duration of preheating of mono and double steam pipelines with a capacity of 250–300 MW, developed on the basis of solving the inverse problem of thermal conductivity, are presented. The basis for determining the duration of heating of steam pipelines is the assumption of limited cooling of the medium pressure rotor of the steam turbine as steam is supplied to the same, as well as the temperature of the end section of the steam pipeline, which excludes the formation of condensate and thereby reduces the risk of its removal into the flow part when steam is supplied to the medium pressure cylinder. Two criteria for the termination of heating are determined in the form of an average integral temperature of the middle part of the steam pipeline and the temperature of its end section upstream the steam inlet elements of the medium pressure part. 

About the Author

Yu. A. Radin
PJSC "Mosenergo"
Russian Federation

Avtozavodskaya str., 12, 115280, Moscow



References

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Review

For citations:


Radin Yu.A. Preheating of secondary superheated steam pipelines when starting steam turbines of SCР power units. Safety and Reliability of Power Industry. 2022;15(1):4-11. (In Russ.) https://doi.org/10.24223/1999-5555-2022-15-1-4-11

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ISSN 1999-5555 (Print)
ISSN 2542-2057 (Online)