High-Temperature Steam Supply: Configuration Design for Temperature Control Stability

1991 ◽  
Vol 113 (1) ◽  
pp. 12-19 ◽  
Author(s):  
J. P. Mumm ◽  
J. Orozco
Keyword(s):  
Extreme Temperature ◽  
Temperature Stability ◽  
Numerical Code ◽  
Operating Characteristics ◽  
Test Specifications ◽  
Process Operation ◽  
Temperature And Pressure ◽  
High Temperature Steam ◽  
Control Stability ◽  
Nominal Temperature

The main objective of this investigation is to report on the development and testing of a numerical code to simulate the operating characteristics of a steam-powered propulsion system. The test specifications permitted a temperature variation of 135 K (75°F) from the nominal temperature 1144 K (1600°F). Due to the extreme temperature and pressure involved, any overshoot would severly shorten the life of the facility. The predicted performance of the system was then evaluated for temperature stability. The code was also used to determine the modifications required to stabilize temperature variations. Testing was performed to better understand the dynamics of the process operation. The experimental data verified the predictions of the numerical code.

Improved Quality Assessment for Turbine Engine Components With Potential Applications to Ceramic Matrix Composite (CMC) Materials

2005 ◽  
Author(s):  
D. W. Akers ◽  
C. A. Rideout
Keyword(s):  
Positron Annihilation ◽  
Matrix Composite ◽  
Ceramic Matrix Composite ◽  
Extreme Temperature ◽  
Temperature Stability ◽  
Ceramic Matrix ◽  
Turbine Engines ◽  
Space Vehicles ◽  
Limited Information ◽  
Turbine Engine

Demand for improved power from turbine engines has resulted in the development of ceramic matrix composite (CMC) materials that can withstand extreme temperature environments and maintain the damage tolerance required for space vehicles and next generation turbine engines. CMC components allow higher temperature operation and increased power over nickel-based superalloy components due to their reduced weight and temperature stability. The use of CMCs allows a potential increase in turbine engine temperatures to above 1400°C. This temperature increase results in improved performance, which translates into increased efficiency, better power to weight ratios, and improved reliability with both significant fuel savings and reduced life cycle costs. Evaluating CMC component quality is difficult due to variations in the fiber/matrix properties and variations in fabrication related parameters. Further, there is limited information on operational and remaining life characteristics. These factors produce significant challenges to existing inspection methods. Determining the reliability of CMC components is a complex process and requires an understanding of both manufacturing variability and damage effects that can occur throughout the life of the component. Consequently, a nondestructive inspection capability is required that can reliably evaluate CMC components during manufacturing, provide acceptance/rejection criteria for determining “fitness for use” and be useful for assessing operational damage effects. New nondestructive testing capabilities, Photon Induced Positron Annihilation (PIPA) and Distributed Source Positron Annihilation (DSPA), have demonstrated the potential ability to detect and quantify fabrication flaws and manufacturing quality for metallic, composite and ceramic components that are used to improve performance and power to weight ratios in high temperature turbine engine applications.

Effect of Creep Load on Oxidation Behavior of Main Steam Pipes

2015 ◽  
Author(s):  
Bo Yang ◽  
Yi-chang Huang ◽  
Xiao-ying Tang ◽  
Yu-hui Huang
Keyword(s):  
High Temperature ◽  
Growth Characteristic ◽  
P92 Steel ◽  
Applied Loading ◽  
Long Time ◽  
Temperature And Pressure ◽  
High Temperature Steam ◽  
Main Steam ◽  
Creep Loading ◽  
Steam Pipes

Main steam pipelines work in the environment of high temperature and pressure steam and withstand double damage between oxidation and creep load for a long time. Creep-oxidation interrupt tests were used in high temperature steam conditions at different stress load to get P92 steel mechanochemical behavior date in the present study. Weight gain method was used to get the oxidation kinetics under different applied loading. Scanning electron microscopy (SEM) micro observation techniques was applied to obtain growth characteristic in the interaction between steam oxidation and creep loading.

scholarly journals Alkanes increase the stability of early life membrane models under extreme pressure and temperature conditions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Loreto Misuraca ◽  
Bruno Demé ◽  
Philippe Oger ◽  
Judith Peters
Keyword(s):  
Early Life ◽  
Hydrothermal Vents ◽  
Time Window ◽  
Extreme Temperature ◽  
Adaptive Strategy ◽  
Multilamellar Vesicle ◽  
Chain Dynamics ◽  
Terrestrial Life ◽  
Temperature And Pressure ◽  
Membrane Components

AbstractTerrestrial life appeared on our planet within a time window of [4.4–3.5] billion years ago. During that time, it is suggested that the first proto-cellular forms developed in the surrounding of deep-sea hydrothermal vents, oceanic crust fractures that are still present nowadays. However, these environments are characterized by extreme temperature and pressure conditions that question the early membrane compartment’s capability to endure a stable structural state. Recent studies proposed an adaptive strategy employed by present-day extremophiles: the use of apolar molecules as structural membrane components in order to tune the bilayer dynamic response when needed. Here we extend this hypothesis on early life protomembrane models, using linear and branched alkanes as apolar stabilizing molecules of prebiotic relevance. The structural ordering and chain dynamics of these systems have been investigated as a function of temperature and pressure. We found that both types of alkanes studied, even the simplest linear ones, impact highly the multilamellar vesicle ordering and chain dynamics. Our data show that alkane-enriched membranes have a lower multilamellar vesicle swelling induced by the temperature increase and are significantly less affected by pressure variation as compared to alkane-free samples, suggesting a possible survival strategy for the first living forms.

Design Optimization of Compact Superalloy Heat Exchangers for Extreme Temperature and Pressure Conditions

2021 ◽  
Author(s):  
Kaiyuan Jin ◽  
Akshay Bharadwaj Krishna ◽  
Zachary Wong ◽  
Timothy Fisher ◽  
Ivan Catton ◽  
...  
Keyword(s):  
Design Optimization ◽  
Heat Exchangers ◽  
Extreme Temperature ◽  
Temperature And Pressure

Numerical Simulation and Experimental Investigation of Compression Processes of Two-Stage, very High Pressure Reciprocating Gas Compressors

1994 ◽  
Vol 208 (5) ◽  
pp. 287-298
Author(s):  
W H Hsieh ◽  
T T Wu
Keyword(s):  
High Pressure ◽  
Theoretical Model ◽  
Transient Flow ◽  
Numerical Code ◽  
Two Stage ◽  
Dead End ◽  
Compressor Performance ◽  
Phase Temperature ◽  
Temperature And Pressure ◽  
Very High

To help the design of more reliable and efficient two-stage, very high pressure reciprocating gas compressors, a theoretical model and a numerical code for simulating compression processes in the compressors were developed and validated. The theoretical model considers time-dependent conservation equations of species, mass and energy, the equation of state, kinematic relationships and various convective heat-transfer correlations The theoretical model was solved numerically. Experimentally, a 207 MPa (30 000 lb/in2) very high pressure gas compressor was instrumented for measurements of various transient flow properties. The experimental data were analysed to achieve a better understanding of the compression processes of the compressor as well as for model validation. A parametric study was conducted with the theoretical model and numerical code to investigate the effect of various compressor parameters on the compressor performance. Among the parameters studied, it was found that the dead-end volume had the strongest effect on the performance of the compressor. A reduced dead-end volume would increase the volumetric efficiency and the maximum gas-phase temperature and pressure in the first-stage cylinder.

Volume-translated cubic EoS and PC-SAFT density models and a free volume-based viscosity model for hydrocarbons at extreme temperature and pressure conditions

2013 ◽  
Vol 359 ◽  
pp. 38-44 ◽  
Author(s):  
Ward A. Burgess ◽  
Deepak Tapriyal ◽  
Bryan D. Morreale ◽  
Yee Soong ◽  
Hseen O. Baled ◽  
...  
Keyword(s):  
Free Volume ◽  
Extreme Temperature ◽  
Viscosity Model ◽  
Temperature And Pressure

The Effects of Wall Conductance on Torque of the MHD Viscous Coupler and Hydrostatic Thrust Bearing

1973 ◽  
Vol 95 (2) ◽  
pp. 181-186 ◽  
Author(s):  
S. Kamiyama ◽  
A. Sato
Keyword(s):  
Thrust Bearing ◽  
Extreme Temperature ◽  
Magnetohydrodynamic Flow ◽  
Approximate Analysis ◽  
Rotating Disks ◽  
Operating Characteristics

An approximate analysis of the magnetohydrodynamic flow between rotating disks shows that the torque of rotating disks is strongly affected by the wall conductance. Also, considering the application to a viscous coupler or a hydrostatic thrust bearing operating under the extreme temperature, the operating characteristics of such MHD devices are analyzed.

Effects of additives on marginal detonation in gases

1962 ◽  
Vol 269 (1337) ◽  
pp. 165-179 ◽  
Keyword(s):  
Shock Front ◽  
Binary Mixtures ◽  
Degrees Of Freedom ◽  
Cylindrical Tube ◽  
Energy Liberation ◽  
Time Intervals ◽  
Specific Chemical ◽  
Temperature And Pressure ◽  
Nominal Temperature ◽  
Internal Degrees Of Freedom

Detonation has been studied under marginal conditions in various mixtures of hydrogen with oxygen, with additions of argon, nitrogen or organic molecules as a third component. Propagation was studied in mixtures in a long cylindrical tube exposed to the initiating impact from a detonating mixture of 2H 2 + O 2 . Time intervals for the passage of detonation past successive probes were recorded to 0.01 /us accuracy. At 1 atm pressure and 20 °C, binary mixtures of hydrogen with oxygen showed limits of detonation at 15.3 % H 2 and 91.0% H 2 . These limits were narrowed by additions of argon, nitrogen or iodomethane. Additions of furan or of water vapour had complex effects. Benzene had little effect. From the results, the marginal conditions that determine whether detonation will be propagated in a mixture or whether it will decay into an explosion wave, can be correlated with thermodynamic and kinetic characteristics of the reactions whose energy liberation sustains the detonation wave. In binary mixtures of oxygen with hydrogen, it appears that the rate of liberation of energy becomes inadequate to sustain detonation, when the nominal temperature and pressure behind the shock front fall below critical values. Much of the effect of the additives studied can be attributed to their thermal properties, which modify the peak temperature and pressure and thereby influence the chemical reactions that liberate energy. There is evidence that internal degrees of freedom of additives such as nitrogen do not participate appreciably in energy exchange immediately behind the shock front. Specific chemical intervention of the additives in these reactions cannot be excluded on the basis of present evidence, but appears to be subsidiary to thermal effects inhibiting the propagation of detonation.

Thermo-Mechanical Coupling Analysis of Tubular C/C-Weaving Composite

2014 ◽  
Vol 494-495 ◽  
pp. 538-545
Author(s):  
Feng Qu ◽  
Dong Po Qu
Keyword(s):  
Temperature Stability ◽  
Stress And Strain ◽  
Analysis Software ◽  
Coupling Analysis ◽  
Element Analysis ◽  
Temperature Changes ◽  
Mechanical Coupling ◽  
The Finite Element Analysis ◽  
Sequential Coupling ◽  
Temperature And Pressure

For the tubular C/C-weaving composite is often loaded on thermotics and mechanics loads together in using, adopting the sequential coupling method, utilizing the finite element analysis software: firstly analyze the stress distribution on loading temperature and pressure loads together, the maximums and changing rules of displacement, stress and strain have been obtained. Based on the works above, further to analyze the thermo-mechanical coupling of different loads, the curves of displacement, stress and strain in the specified paths have been obtained, it shows that the influence from temperature on every parameters is little when loading on the larger loads. So come to the conclusion that the tubular C/C composite has good temperature stability and can be used in the condition of high temperature or temperature changes greatly.

Sign in / Sign up

Export Citation Format

Share Document