Causes and Prevention of Cracks in Boiler Main Steam Pipeline

2021 ◽  
Keyword(s):  
Steam Pipeline ◽  
Main Steam

Optimization design of separators for removing solid particles from main steam pipeline of high-parameter steam turbine

2017 ◽  
Vol 111 ◽  
pp. 516-525 ◽  
Author(s):  
Liuxi Cai ◽  
Shunsen Wang ◽  
Shangfang Cheng ◽  
Junfeng Xiao ◽  
Song Gao ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Optimization Design ◽  
Solid Particles ◽  
Steam Pipeline ◽  
Main Steam

scholarly journals Residual life evaluation of 12Cr1MoVG steel for main steam pipeline

2021 ◽  
Vol 675 (1) ◽  
pp. 012193
Author(s):  
Ping Tang ◽  
Shengpeng Huang ◽  
Wei Tian ◽  
Zhangwei Ling ◽  
Nanhui Jin ◽  
...  
Keyword(s):  
Residual Life ◽  
Steam Pipeline ◽  
Life Evaluation ◽  
Main Steam

scholarly journals Microstructure of P92 Steel for Main Steam Pipeline of Ultra Supercritical Units after 50,000 h Service

2019 ◽  
Vol 358 ◽  
pp. 042021
Author(s):  
Li Xinmei ◽  
Zhongwen Zhang ◽  
Yong Zou ◽  
Du Baoshuai ◽  
Yuzhong Wei ◽  
...  
Keyword(s):  
P92 Steel ◽  
Steam Pipeline ◽  
Main Steam

scholarly journals Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 2213-2224
Author(s):  
Vladimir Stevanovic ◽  
Sanja Milivojevic ◽  
Milan Petrovic
Keyword(s):  
Power Plants ◽  
Fluid Dynamic ◽  
Thermal Power ◽  
Pressure Rise ◽  
Computer Code ◽  
Dynamic Force ◽  
Stop Valve ◽  
Steam Pipeline ◽  
Dynamic Forces ◽  
Main Steam

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.

Dynamic Simulation of a HRSG System for a Given Start-Up/Shut Down Curve

2011 ◽  
Author(s):  
Hun Cha ◽  
Yoo Seok Song ◽  
Kyu Jong Kim ◽  
Jung Rae Kim ◽  
Sung Min KIM
Keyword(s):  
Dynamic Analysis ◽  
Gas Turbine ◽  
Flow Rate ◽  
Exhaust Gas ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Start Up ◽  
Gas Turbine Exhaust ◽  
Main Steam ◽  
Duct Burner

An inappropriate design of HRSG (Heat Recovery Steam Generator) may lead to mechanical problems including the fatigue failure caused by rapid load change such as operating trip, start-up or shut down. The performance of HRSG with dynamic analysis should be investigated in case of start-up or shutdown. In this study, dynamic analysis for the HRSG system was carried out by commercial software. The HRSG system was modeled with HP, IP, LP evaporator, duct burner, superheater, reheater and economizer. The main variables for the analysis were the temperature and mass flow rate from gas turbine and fuel flow rate of duct burner for given start-up (cold/warm/hot) and shutdown curve. The results showed that the exhaust gas condition of gas turbine and fuel flow rate of duct burner were main factors controlling the performance of HRSG such as flow rate and temperature of main steam from final superheater and pressure of HP drum. The time delay at the change of steam temperature between gas turbine exhaust gas and HP steam was within 2 minutes at any analysis cases.

Optimization of a Sintering Waste Heat Power Unit

2014 ◽  
Vol 1008-1009 ◽  
pp. 897-900
Author(s):  
Xue Min Gong ◽  
Jiu Lin Yang ◽  
Chen Wang
Keyword(s):  
Power Generation ◽  
Power Unit ◽  
Waste Heat ◽  
Steam Pressure ◽  
Operating Conditions ◽  
Parameters Optimization ◽  
Heat Power ◽  
Optimal Value ◽  
Generation Capacity ◽  
Main Steam

An optimization was performed for a sintering waste heat power unit with all data obtained in the site and under the unit normal operating conditions. The physical and mathematical model for the process of cooling and generation is established, which makes the net power generation as an objective function of the cooling machine imported ventilation, the thickness of sinter and the main steam pressure. Optimizing for single parameter, we found that each parameter had an optimal value for the system. In order to further optimize the system's operating parameters, genetic algorithm was used to make the combinatorial optimization of the three parameters. Optimization results show that power generation capacity per ton is increased by13.10%, and net power generation is increased by 16.17%. The optimization is instructive to the operation of sintering waste heat power unit.

scholarly journals The thermal history and stress state of a fresh steam-pipeline influencing its remaining service life

2011 ◽  
Vol 15 (3) ◽  
pp. 691-704 ◽  
Author(s):  
Gordana Bakic ◽  
Vera Sijacki-Zeravcic ◽  
Milos Djukic ◽  
Stevan Maksimovic ◽  
Dusan Plesinac ◽  
...  
Keyword(s):  
Service Life ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Life Assessment ◽  
Temperature History ◽  
Significant Variable ◽  
Remaining Life ◽  
Pipe Bend ◽  
Steam Pipeline ◽  
Remaining Life Assessment

The service life of thick-walled power plant components exposed to creep, as is the case with pipelines of fresh- and re-heated steam, depend on the exhaustion rate of the material. Plant operation at elevated temperatures and at temperatures below designed temperatures all relates to the material exhaustion rate, thus complicating remaining life assessment, whereas the operating temperature variation is a most common cause in the mismatching of real service- and design life. Apart from temperature, the tube wall stress is a significant variable for remaining life assessment, whose calculation depends on the selected procedure, due to the complex pipeline configuration. In this paper, a remaining life assessment is performed according to the Larson-Miller parametric relation for a ?324?36 pipe bend element of a fresh steam-pipeline, made of steel class 1Cr0.3Mo0.25V, after 160 000 hours of operation. The temperature history of the pipeline, altogether with the pipe bend, is determined based on continuous temperature monitoring records. Compared results of remaining life assessment are displayed for monitored temperature records and for designed operating temperature in the same time period. The stress calculation in the pipe bend wall is performed by three methods that are usually applied so to emphasize the differences in the obtained results of remaining life assessment.

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