Performance Implications of High Energy Density Welding of Corrosion Resistant Alloy Heat Exchanger Tubing

2010 ◽  
Author(s):  
Dave O’Donnell ◽  
Nicole Karlen ◽  
Carl Kettermann
Keyword(s):  
Stainless Steel ◽  
Heat Exchanger ◽  
Energy Density ◽  
Heat Input ◽  
Cold Work ◽  
Laser Beam Welding ◽  
High Energy ◽  
Total Heat ◽  
High Energy Density ◽  
Delta Ferrite

The advent of Laser Beam Welding (LBW) has had a significant impact on resultant metallurgical performance of stainless steel welded heat exchanger tubing. While productivity enhancements are well recognized the metallurgical benefits are not. The low total heat input combined with the very high energy density results in ultra-fast quenching of molten metal, super-cooling past normal primary ferrite solidification in common 304/304L and 316/316L grades directly to austenite resulting in weldments with no retained delta ferrite and some inherent corrosion advantages. The same low total heat input and high energy density generates dramatically smaller dendrite spacing making subsequent homogenization by the combined efforts of cold work and solution annealing dramatically more effective. It should be recognized that this paper deals with issues relating to tube production where welds are autogenous or made without filler metal addition and are subsequently cold worked and solution annealed. Resulting benefits of laser welding include a seamless metallographic appearance, and improved field performance. The benefits and limitations of these enhancements are explored relative to other common stainless steel grades, as are alloy characteristics affecting performance.

A Perspective: Could Carbon Current Collectors Improve the Energy Density of Aqueous Alkaline Symmetric Supercapacitors?

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Hemesh Avireddy ◽  
Joan Ramon Morante ◽  
Cristina Flox
Keyword(s):  
Stainless Steel ◽  
Energy Density ◽  
Current Collector ◽  
Cell Voltage ◽  
High Energy ◽  
High Energy Density ◽  
Electrochemical Characteristics ◽  
Current Collectors ◽  
Collector System ◽  
Symmetric Supercapacitor

AbstractThe present discussion shows a perspective about using graphite as a current collector in order to achieve high energy density in a symmetric supercapacitor system. Several electrochemical modes (such as rest potential analysis, CV, PEIS, GCPL) were carried out to evaluate the electrochemical characteristics of graphite in aqueous 6 mol/L KOH. And, the resulting performance was compared to an another conventional current collector system based on nickel-stainless steel. Interestingly, widening of cell voltage was observed for graphite when compared to nickel-stainless steel. The discussion reveals the reasonable influences and validations of widening in cell voltage towards the values in energy densities. This perspective also highlights some issues related to carbon (graphite) current collectors and encloses with some promising strategies in overcoming these issues, not limiting the domain of application (either micro or macro supercapacitor devices).

scholarly journals Low-cost flexible supercapacitors with high-energy density based on nanostructured MnO2 and Fe2O3 thin films directly fabricated onto stainless steel

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Girish S. Gund ◽  
Deepak P. Dubal ◽  
Nilesh R. Chodankar ◽  
Jun Y. Cho ◽  
Pedro Gomez-Romero ◽  
...  
Keyword(s):  
Thin Films ◽  
Stainless Steel ◽  
Energy Density ◽  
Low Cost ◽  
High Energy ◽  
High Energy Density ◽  
Flexible Supercapacitors

A HIGH ENERGY DENSITY ZINC/OXYGEN BATTERY SYSTEM

1966 ◽  
Author(s):  
S. CHODOSH ◽  
E. KATSOULIS ◽  
M. ROSANSKY
Keyword(s):  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Battery System

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Si Nanowire Anode Prepared by Chemical Etching for High Energy Density Lithium-ion Battery

2013 ◽  
Vol 28 (11) ◽  
pp. 1207-1212 ◽  
Author(s):  
Jian-Wen LI ◽  
Ai-Jun ZHOU ◽  
Xing-Quan LIU ◽  
Jing-Ze LI
Keyword(s):  
Energy Density ◽  
Lithium Ion Battery ◽  
Chemical Etching ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Si Nanowire
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