scholarly journals THERMAL PERFORMANCE COMPARISON OF GLASS MICROSPHERE AND PERLITE INSULATION SYSTEMS FOR LIQUID HYDROGEN STORAGE TANKS

2008 ◽  
Author(s):  
J. P. Sass ◽  
J. E. Fesmire ◽  
Z. F. Nagy ◽  
S. J. Sojourner ◽  
D. L. Morris ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Thermal Performance ◽  
Liquid Hydrogen ◽  
Performance Comparison ◽  
Glass Microsphere ◽  
Storage Tanks ◽  
Insulation Systems

Thermal stratification in ribbed liquid hydrogen storage tanks

2006 ◽  
Vol 31 (15) ◽  
pp. 2299-2309 ◽  
Author(s):  
T KHURANA ◽  
B PRASAD ◽  
K RAMAMURTHI ◽  
S MURTHY
Keyword(s):  
Hydrogen Storage ◽  
Thermal Stratification ◽  
Liquid Hydrogen ◽  
Storage Tanks

State of the Art: Hydrogen storage

2008 ◽  
Vol 5 (3) ◽  
Author(s):  
I. Cumalioglu ◽  
A. Ertas ◽  
Y. Ma ◽  
T. Maxwell
Keyword(s):  
Energy Source ◽  
Fuel Cell ◽  
Hydrogen Storage ◽  
State Of The Art ◽  
Storage Systems ◽  
Liquid Hydrogen ◽  
Storage Tanks

Hydrogen is often considered to be the ultimate energy source for vehicles. However, if hydrogen is to fuel practical vehicles, then the development of fuel cell and hydrogen fueled engine technology must be accompanied by significant improvements in hydrogen storage techniques. Compressed hydrogen storage tanks, liquid hydrogen storage tanks, and containment systems for hydrides are examined to compare their advantages, disadvantages, and potential for onboard and stationary hydrogen storage systems. Each technique reviewed possesses specific shortcomings; thus, none can adequately satisfy the requirements of a hydrogen based economy.

Generalized Equation for Thermal Conductivity of MLI at Temperatures From 20K to 300K

2003 ◽  
Author(s):  
Lixing Gu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Radiation ◽  
Thermal Performance ◽  
Ambient Air ◽  
Liquid Hydrogen ◽  
Heat Fluxes ◽  
Layer By Layer ◽  
Storage Tanks ◽  
Thermal Conductivities

Multilayer insulation (MLI) has the lowest thermal conductivity of any currently used insulation in high vacuum environments and is used in cryogenic insulation system to minimize heat leaks in liquid hydrogen storage tanks. MLI consists of highly reflective radiation shields separated by spacers or insulation. The thermal conductivity of MLI varies with both temperature and vacuum level. Most published apparent thermal conductivities were measured for temperatures between 80K and 300K; some of the published data were for temperatures between 20K and 80K. Since the temperature of liquid hydrogen is 20K and the storage tanks are exposed to ambient air, it is essential to know the thermal performance of MLI for the temperature range of 20K to 300K. In addition, in order to provide a detailed temperature distribution and to optimize insulation systems with respect to the number of layers of MLI, layer density, insulation weight, and separator configuration, the layer-by-layer thermal performance of MLI has to be established for efficient storage tank design. A general equation for thermal conductivity was developed based on heat transfer principles for a wide range of temperature differences and vacuum levels. The equation consists of four heat transfer modes: 1) thermal radiation between two adjacent reflectors, 2) thermal radiation absorbed by spacers 3) gas conduction, and 4) solid spacer conduction. The equation can be applied for the temperature ranges of liquid hydrogen up to ambient, and for pressure ranges between 1.33 mPa to 1.33 kPa (0.01 millitorr and 10 torr). The predicted layer-by-layer temperatures, heat fluxes and apparent thermal conductivities using the developed thermal conductivity equation show very good agreement with measured data between the temperatures of 80K and 300K at the various pressure levels. When the equation was applied for a temperature of 20K, heat fluxes increased due to the larger temperature difference, while apparent thermal conductivities decreased due to the lower cold side temperature.

scholarly journals GLASS BUBBLES INSULATION FOR LIQUID HYDROGEN STORAGE TANKS

2010 ◽  
Author(s):  
J. P. Sass ◽  
W. W. St. Cyr ◽  
T. M. Barrett ◽  
R. G. Baumgartner ◽  
J. W. Lott ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Liquid Hydrogen ◽  
Storage Tanks

Thermal performance comparison of different sun tracking configurations

2019 ◽  
Vol 88 (2) ◽  
pp. 20902
Author(s):  
O. Achkari ◽  
A. El Fadar
Keyword(s):  
Thermal Performance ◽  
Electricity Generation ◽  
Arid Regions ◽  
Performance Comparison ◽  
Water Desalination ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
The Impact ◽  
The Mathematical Model ◽  
Good Agreement

Parabolic trough collector (PTC) is one of the most widespread solar concentration technologies and represents the biggest share of the CSP market; it is currently used in various applications, such as electricity generation, heat production for industrial processes, water desalination in arid regions and industrial cooling. The current paper provides a synopsis of the commonly used sun trackers and investigates the impact of various sun tracking modes on thermal performance of a parabolic trough collector. Two sun-tracking configurations, full automatic and semi-automatic, and a stationary one have numerically been investigated. The simulation results have shown that, under the system conditions (design, operating and weather), the PTC's performance depends strongly on the kind of sun tracking technique and on how this technique is exploited. Furthermore, the current study has proven that there are some optimal semi-automatic configurations that are more efficient than one-axis sun tracking systems. The comparison of the mathematical model used in this paper with the thermal profile of some experimental data available in the literature has shown a good agreement with a remarkably low relative error (2.93%).

Hydrogen Storage in Magnesium-Based Alloys

MRS Bulletin ◽  
1999 ◽  
Vol 24 (11) ◽  
pp. 40-44 ◽  
Author(s):  
R.B. Schwarz
Keyword(s):  
Energy Density ◽  
Hydrogen Storage ◽  
Alternative Energy ◽  
Distribution Systems ◽  
Electrical Energy ◽  
Clean Energy ◽  
Energy System ◽  
Liquid Hydrogen ◽  
Rechargeable Batteries ◽  
Oil Crisis

Magnesium can reversibly store about 7.7 wt% hydrogen, equivalent to more than twice the density of liquid hydrogen. This high storage capacity, coupled with a low price, suggests that magnesium and magnesium alloys could be advantageous for use in battery electrodes and gaseous-hydrogen storage systems. The use of a hydrogen-storage medium based on magnesium, combined with a fuel cell to convert the hydrogen into electrical energy, is an attractive proposition for a clean transportation system. However, the advent of such a system will require further research into magnesium-based alloys that form less stable hydrides and proton-conducting membranes that can raise the operating temperature of the current fuel cells.Following the U.S. oil crisis of 1974, research into alternative energy-storage and distribution systems was vigorously pursued. The controlled oxidation of hydrogen to form water was proposed as a clean energy system, creating a need for light and safe hydrogen-storage media. Extensive research was done on inter-metallic alloys, which can store hydrogen at densities of about 1500 cm3-H2 gas/ cm3-hydride, higher than the storage density achieved in liquid hydrogen (784 cm3/cm3 at –273°C) or in pressure tanks (˜200 cm3/cm3 at 200 atm). The interest in metal hydrides accelerated following the development of portable electronic devices (video cameras, cellular phones, laptop computers, tools, etc.), which created a consumer market for compact, rechargeable batteries. Initially, nickel-cadmium batteries fulfilled this need, but their relatively low energy density and the toxicity of cadmium helped to drive the development of higher-energy-density, less toxic, rechargeable batteries.

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