CMC-Jacketed Piping for High-Temperature Applications: Concept, Laboratory Tests and Large-Scale Application Test

2019 ◽  
Vol 809 ◽  
pp. 547-552
Author(s):  
Maximilian Friedrich ◽  
Min Huang ◽  
Anne Jüngert ◽  
Andreas Klenk ◽  
Stefan Weihe ◽  
...  
Keyword(s):  
High Temperature ◽  
Power Plants ◽  
Large Scale ◽  
Cost Effective ◽  
Renewable Sources ◽  
Electrical Grid ◽  
Highly Efficient ◽  
Effective Option ◽  
Materials Used ◽  
Temperature Applications

The increasing market share of highly volatile electricity generated from renewable sources like wind or solar energy, leads to enormous challenges in the energy sector. Since large-scale storage systems are neither currently nor in the near future available, the gap between electricity from renewable sources and current electricity demand has to be closed with flexibly operated conventional power plants. In order to be a viable, cost-effective option in tomorrow’s energy market future power plants must be highly efficient while having low CO2 emissions. Furthermore, they have to be highly reactive to counter instabilities in the electrical grid due to fluctuations in renewable sources. Current materials used in power plants are only within limits suited to experience extreme changes in operational loads. However, extreme changes of operational loads will become increasingly severe with a growing share of renewables. Our project team has developed a new concept for CMC-jacketed pipes to alleviate these issues. Recently, this concept was further developed and tested in laboratory as well as a large-scale application test at Grosskraftwerk Mannheim (GKM). All tests are still ongoing. Additionally, to the use in modern highly efficient power plants such CMC-jacketed piping is also suitable for other high-temperature applications, like e.g. solar power plants or industrial chemical applications.

scholarly journals WS(1−x)Sex Nanoparticles Decorated Three-Dimensional Graphene on Nickel Foam: A Robust and Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 929 ◽  
Author(s):  
Sajjad Hussain ◽  
Kamran Akbar ◽  
Dhanasekaran Vikraman ◽  
Rana Afzal ◽  
Wooseok Song ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Large Scale ◽  
Nickel Foam ◽  
Transition Metal Dichalcogenides ◽  
Three Dimensional ◽  
Cost Effective ◽  
Highly Efficient ◽  
Highly Active ◽  
Earth Abundant

To find an effective alternative to scarce, high-cost noble platinum (Pt) electrocatalyst for hydrogen evolution reaction (HER), researchers are pursuing inexpensive and highly efficient materials as an electrocatalyst for large scale practical application. Layered transition metal dichalcogenides (TMDCs) are promising candidates for durable HER catalysts due to their cost-effective, highly active edges and Earth-abundant elements to replace Pt electrocatalysts. Herein, we design an active, stable earth-abundant TMDCs based catalyst, WS(1−x)Sex nanoparticles-decorated onto a 3D porous graphene/Ni foam. The WS(1−x)Sex/graphene/NF catalyst exhibits fast hydrogen evolution kinetics with a moderate overpotential of ~−93 mV to drive a current density of 10 mA cm−2, a small Tafel slope of ~51 mV dec−1, and a long cycling lifespan more than 20 h in 0.5 M sulfuric acid, which is much better than WS2/NF and WS2/graphene/NF catalysts. Our outcomes enabled a way to utilize the TMDCs decorated graphene and precious-metal-free electrocatalyst as mechanically robust and electrically conductive catalyst materials.

Mullite Whisker Reinforced Zirconia Toughened Alumina for High Temperature Applications

2014 ◽  
Author(s):  
Taylor Robertson ◽  
Xiao Huang ◽  
Richard Kearsey
Keyword(s):  
High Temperature ◽  
Cost Effective ◽  
Mechanical Tests ◽  
Processing Route ◽  
Molten Salt Method ◽  
The Matrix ◽  
Mullite Whiskers ◽  
Monolithic Ceramics ◽  
Zirconia Toughened Alumina ◽  
Temperature Applications

Particulate enhanced oxide ceramics are an attractive class of materials for high temperature applications because they possess many of the high temperature capabilities of monolithic ceramics but also have enhanced mechanical properties due to their multi-phase structure. High temperature structural ceramics have the potential to operate above at higher temperatures than current super alloys; however, processing costs and lack of reliability has prevented their commercialization. In this work a particulate reinforced ceramic composed entirely of oxides is proposed as a more oxidation resistant and cost effective structural ceramic which will have potentially improved resistance to environmental degradation. Zirconia Toughened Alumina (ZTA), as the matrix, has enhanced toughness, strength, and creep resistance over single phase alumina or zirconia. ZTA can further be strengthened by the incorporation of SiC type whiskers; however, these whiskers are prone to deterioration at temperatures above 1000°C through oxidation. In this work Mullite, in whisker form, is proposed as the reinforcement to ZTA due to its stability in oxidizing atmospheres at high temperatures. Mullite whiskers are grown through the molten salt method and incorporated into the ZTA matrix using a colloidal processing route in this study. The composition of the ZTA matrix is 15wt% Yttria stabilized Zirconia (YSZ), 85 wt% α-Alumina. The Mullite whiskers make up 20 vol% of the composite, yielding a final composition of 71.6 wt% Alumina, 12.7 wt% YSZ, and 15.6 wt% Mullite. The green compacts are fired in a two stage sintering process incorporating atmospheric pressure sintering to 92% density (seal the pore channels) and then hot isostatic pressure pressing (HIP) to increase the density. Samples have been tested for room temperature flexural strength using a three point bend test and fracture toughness through Gong’s Vickers indentation method. The results of microstructure study and mechanical tests are reported in this paper.

Solid Electrolytic Capacitors Designed for High Temperature Applications

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000142-000152 ◽  
Author(s):  
Randy Hahn ◽  
Kristin Tempel
Keyword(s):  
High Temperature ◽  
Operating Temperature ◽  
Tantalum Pentoxide ◽  
Passive Component ◽  
Surface Mount ◽  
Electrolytic Capacitors ◽  
Developed Surface ◽  
Design And Manufacturing ◽  
Materials Used ◽  
Temperature Applications

For decades the maximum recommended operating temperature of solid electrolytic capacitors was 125°C. Responding to needs in the automotive and downhole drilling industries passive component manufacturers developed surface mount tantalum capacitors rated at 150°C in 2002–2003. Since that time the industry has introduced high temperature capable tantalum capacitors generally in 25°C increments roughly every four years. Today multiple manufacturers have products rated at 230°C poised for market release. The tantalum anode, tantalum pentoxide dielectric and manganese dioxide primary cathode material stand up well to these temperatures, although some optimization of the design and manufacturing process for these materials have been required. The primary challenges encountered when developing solid electrolytic capacitors with high temperature capabilities are associated with the carbon, silver and epoxy encapsulant materials used in conventional surface mount tantalum capacitors. Capacitor manufacturers have taken different paths to overcome these challenges. We have developed a metallized plating process to avoid issues associated with silver paints utilized in conventional Ta capacitors. We have worked with suppliers, or developed in house capabilities, to manufacture the other materials required to withstand the rigors of high temperature applications. This paper will discuss these challenges and provide reliability test data on a recently developed tantalum surface mount series capable of continuous operation at 230°C.

scholarly journals Scope and costs of autorefraction and photoscreening for childhood amblyopia—a systematic narrative review in relation to the EUSCREEN project data

Eye ◽  
2020 ◽  
Author(s):  
Anna M. Horwood ◽  
◽  
Helen J. Griffiths ◽  
Jill Carlton ◽  
Paolo Mazzone ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Large Scale ◽  
English Language ◽  
Cost Effective ◽  
Original Data ◽  
Community Services ◽  
Narrative Review ◽  
Effective Option ◽  
Automated Screening ◽  
Project Data

Abstract Background Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally. Methods A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality. Results Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably. Discussion Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.

Elevated Temperature Behavior of Creep and Fatigue in Welded P92 Steel

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1621-1626 ◽  
Author(s):  
Byeongsoo Lim ◽  
Bumjoon Kim ◽  
Moonhee Park ◽  
Sungjoon Won
Keyword(s):  
High Temperature ◽  
Weld Metal ◽  
Base Metal ◽  
Power Plants ◽  
Test Method ◽  
P92 Steel ◽  
Creep Properties ◽  
High Temperature Materials ◽  
Materials Used ◽  
Small Punch Creep Test

Fatigue strength and life of weldment at high temperature is very important for high temperature materials used in power plants. In this study, creep properties of weld metal, HAZ and base metal of P92 steel were evaluated by SP (small punch) creep test method. Fatigue crack growth behaviors in weld metal, HAZ and base metal of P92 steel were investigated at high temperature. Microstructure and microhardness of the weldment were also investigated for better analysis.

The Possibility of Cr-Base Alloys for High-Temperature Applications

2005 ◽  
Vol 475-479 ◽  
pp. 627-630 ◽  
Author(s):  
Yue Feng Gu ◽  
Y. Ro ◽  
Hiroshi Harada
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Ambient Temperature ◽  
Base Alloy ◽  
Structural Materials ◽  
Scattered Data ◽  
Temperature Analysis ◽  
Materials Used ◽  
High Possibility ◽  
Temperature Applications

The mechanical properties of chromium (Cr) and Cr-base alloys are reviewed, with particular emphasis on the ductility at ambient temperature and the strengths at high temperature. Analysis of rather scattered data and our recent results suggest that Cr-base alloy can be ductilized greatly at ambient temperature and is quite capable of being strengthened to high levels at high temperature. New designs on composition would give high possibility to Cr-base alloys as structural materials used in high-temperature applications.

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