Technical Issues of Non-Conservatism in Design of High-Temperature Piping Subjected to Long-Term Operation in Creep Range When Using ASME B31.1

2019 ◽  
Vol 43 (7) ◽  
pp. 475-482
Author(s):  
Hyeong-Yeon Lee ◽  
Seok-Kwon Son ◽  
Ji-Young Jeong
Keyword(s):  
High Temperature ◽  
Term Operation ◽  
Technical Issues

Influence of Creep on Low-Cycle Fatigue Life Assessment of Ultra-Supercritical Steam Turbine Rotor

2014 ◽  
Author(s):  
W. Z. Wang ◽  
J. H. Zhang ◽  
H. F. Liu ◽  
Y. Z. Liu
Keyword(s):  
High Temperature ◽  
Steam Turbine ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Turbine Rotor ◽  
High Temperature Creep ◽  
Cycle Fatigue ◽  
Term Operation ◽  
Start Up

Linear damage method is widely used to calculate low-cycle fatigue damage of turbine rotor in the long-term operation without fully considering the interaction between creep and low cycle fatigue. However, with the increase of steam turbine pressure and temperature, the influence of high-temperature creep on the strain distribution of turbine rotor becomes significant. Accordingly, the strain for each start-up or shut-down process is different. In the present study, the stress and strain during 21 iterations of continuous start-up, running and shut-down processes was numerically investigated by using the finite element analysis. The influence of high-temperature creep on low cycle fatigue was analyzed in terms of equivalent strain, Mises stress and low cycle fatigue damage. The results demonstrated that the life consumption of turbine rotor due to low cycle fatigue in the long-term operation of startup, running and shutdown should be determined from the full-time coverage of the load of turbine rotor.

Long Term Operation of Rechargeable High Temperature Solid Oxide Batteries

2014 ◽  
Vol 161 (9) ◽  
pp. A1297-A1301 ◽  
Author(s):  
André Leonide ◽  
Wolfgang Drenckhahn ◽  
Horst Greiner ◽  
Harald Landes
Keyword(s):  
High Temperature ◽  
Solid Oxide ◽  
Term Operation

Durability of bends in high-temperature steam lines under the conditions of long-term operation

2015 ◽  
Vol 62 (4) ◽  
pp. 260-270 ◽  
Author(s):  
N. A. Katanakha ◽  
A. S. Semenov ◽  
L. B. Getsov
Keyword(s):  
High Temperature ◽  
Term Operation ◽  
High Temperature Steam

Application of the Multi-Axial Creep Failure Method on Double Reheat Thermodynamic Cycle Turbine

2013 ◽  
Author(s):  
Gang Chen ◽  
Puning Jiang ◽  
Yuxiang Wang ◽  
Zhenzhen Hao
Keyword(s):  
High Temperature ◽  
Steam Turbine ◽  
Life Prediction ◽  
Thermodynamic Cycle ◽  
Critical Issue ◽  
Design Criteria ◽  
Creep Failure ◽  
Term Operation ◽  
High Temperature Components

With the development of higher efficiency and lower consumption plants, higher steam parameters to 600/620/620°C and 33/10.6/3.5MPa and double reheat thermodynamic cycle system are adopted for the power plant. Thus, it is believed that the safety of high temperature components in the steam turbine system is a critical issue that could not be circumvented in the period of modern industrial development. To achieve a reliable design, manufacture and the desired long-term operation of the high temperature components in steam turbine, many fundamental research concerning design criteria and life prediction has been studied. However, for the steam turbine original equipment manufacturer (OEM) which design criteria and life prediction model are suitable for their product and how to accurately assess the components’ life under long-term operation is still a critical issue. For all confronted problems, the multi-axial creep failure is one of the major problems in the life prediction for high temperature components, and it is an important factor to be considered in the high temperature components design. In this paper, the creep failure mechanisms of high temperature components in steam turbine which under multi-axial stress states are analyzed, and the design criteria for creep strain and stress are presented which are based on cavity growth theory. The application of the method and design criteria in a medium pressure turbine which is included in a double reheat thermodynamic cycle plant is presented.

Major Advances in Tribology for Low Heat Rejection Engines: A Ten-Year Overview

2005 ◽  
Author(s):  
Paul Sutor ◽  
Ernest E. Schwarz ◽  
Harold Pangilinan
Keyword(s):  
High Temperature ◽  
Diesel Engines ◽  
High Power Density ◽  
Group V ◽  
Heat Rejection ◽  
Term Operation ◽  
Engine Component ◽  
Engine Testing ◽  
Engine Coolant

In the last decade, Surfaces Research and the U.S. Army have made very significant advances in tribology for high-power-density, low-heat-rejection (LHR) diesel engines. High-temperature tribology issues, which had been major technological hurdles for LHR engine technology, have now been solved. We have developed totally new and economical Group V-based lubricants and self-lubricating coatings in our laboratories. These new lubricants enable reliable, long-term operation of diesel engines with oil sump and engine coolant more than 38°C (100°F) higher than conventional operating temperatures. Over 1300 hours of engine testing have provided detailed data on lubricant and engine component performance at high-temperature, high-BMEP LHR engine conditions.

Mechanical Properties of Newly Developed API X80 Grade HFW Linepipe for Long-Term Exposure at Elevated Temperature

2014 ◽  
Author(s):  
Shunsuke Toyoda ◽  
Sota Goto ◽  
Takatoshi Okabe ◽  
Yasushi Kato ◽  
Satoshi Igi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
High Temperature ◽  
Distribution System ◽  
Weld Seam ◽  
Fatigue Properties ◽  
Oil Sand ◽  
Creep Tests ◽  
Term Operation

API X80 grade UOE double submerged arc-welded pipe has been applied to steam injection oil sand recovery systems to increase the volume of steam to be injected and decrease the installation cost. The pipes for the systems are subjected to high temperature for a long period, such as 350 °C for 20 years. Therefore, it is important to ensure the reliability of the pipes during and after long-term operation. In this study, based on the recent development of high-frequency electric-resistance-welded (HFW) linepipe with a high-quality weld seam, the durability of newly developed API X80 grade HFW linepipe for long-term high-temperature operation was investigated. The change in the microstructure of the pipe body and weld seam was small after exposure to 400 °C and lower temperatures. The tensile strength of the base metal and weld seam after heat treatment with temperatures as high as 400 °C can be determined using the Larson-Miller parameter, which depends on the temperature and holding time of the heat treatment. The newly developed API X80 grade HFW linepipe was considered to have sufficient tensile strength during and after long-term operation at 350 °C for 20 years, similar to API X80 grade UOE pipe. No significant change in the Charpy absorbed energy during long-term heating was observed. Creep tests indicated that the time to rupture at 400 °C or lower exceeded 106 hours, and the creep effect was considered almost negligible at temperatures less than 400 °C. The rupture stress at approximately 350 °C was estimated to be far higher than the typical hoop stress of approximately 200 MPa on the steam distribution system. High-temperature fatigue properties were also measured to ensure reliability under varying stress conditions.

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