Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(Multi layer insulation). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


North-West University

1. Hodgman, Jacobus Henry. The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H.

Degree: 2011, North-West University

A need was identified to test multi–layer vacuum super insulation (MLVSI) used in cryogenic applications for hydrogen storage. The study focuses on the application of commercially available MLVSI to a locally patented liquid hydrogen cryogenic storage system. This led to an investigation of different types of multi–layer vacuum insulation configurations, as well as further research on tank inlet coupling configurations. It includes the manufacturing of a liquid nitrogen testing cryostat to be able to test and evaluate the system performance. The first set of tests was based on the development of an inlet coupling configuration to limit heat transfer through the inner tank inlet, of a double cryogenic tank system in order to reduce gas boil–off. The couplings were manufactured in the form of a bellow to handle cryogenic vacuum levels, while ensuring low heat transfer rates between inner and outer tanks. It was found that various coupling designs can be considered to limit gas boil–off. The second set of tests was conducted on a specific MLVSI configuration to determine its effectiveness to insulate the spherical header surface of a typical hydrogen storage vessel. The installation procedure, to limit heat transfer and boil–off due to edge effects in this configuration was investigated. It was found that insulation–overlap–edge effects will always have an impact on insulation performance when a spherical header of a storage vessel is insulated, due to its specific geometry. A time efficient way to install MLVSI on such a spherical header is presented and evaluated. Further investigations were carried out by combining findings into one single system to determine the performance of an optimised insulated cryogenic system. It was found that copper plate discs installed between the vanes of a bellowed inlet/outlet nozzle is the most promising to limit heat transfer to the cryogenic fluid.

Subjects/Keywords: Multi-layer; Vacuum insulation; Super insulation; Cryogenic; Hydrogen storage

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hodgman, J. H. (2011). The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H. (Thesis). North-West University. Retrieved from http://hdl.handle.net/10394/7327

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Hodgman, Jacobus Henry. “The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H. ” 2011. Thesis, North-West University. Accessed September 30, 2020. http://hdl.handle.net/10394/7327.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Hodgman, Jacobus Henry. “The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H. ” 2011. Web. 30 Sep 2020.

Vancouver:

Hodgman JH. The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H. [Internet] [Thesis]. North-West University; 2011. [cited 2020 Sep 30]. Available from: http://hdl.handle.net/10394/7327.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hodgman JH. The feasibility and application of multi–layer vacuum insulation for cryogenic hydrogen storage / Hodgman J.H. [Thesis]. North-West University; 2011. Available from: http://hdl.handle.net/10394/7327

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of South Florida

2. Mukka, Santosh Kumar. Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement.

Degree: 2005, University of South Florida

The study presents a systematic single and two-phase analysis of fluid flow and heat transfer in a liquid hydrogen storage vessel for both earth and space applications.The study considered a cylindrical tank with elliptical top and bottom. The tank wall ismade of aluminum and a multi-layered blanket of cryogenic insulation (MLI) has been attached on the top of the aluminum. The tank is connected to a cryocooler to dissipate the heat leak through the insulation and tank wall into the fluid within the tank. The cryocooler has not been modeled; only the flow in and out of the tank to the cryocooler system has been included. The primary emphasis of this research has been the fluid circulation within the tank for different fluid distribution scenario and for different level of gravity to simulate all potential earth and space based applications. The equations solved in the liquid region included the conservation of mass, conservation of energy, and conservation of momentum. For the solid region only the heat conduction equation was solved. The steady-state velocity, temperature and pressure distributions were calculated for different inlet positions, inlet opening sizes, inlet velocities and for different gravity values. The above simulations were carried out for constant heat flux and constant wall temperature cases. It was observed from single-phase analysis that a good flow circulation can be obtained when the cold entering fluid was made to flow in radial direction and the inlet opening was placed close to the tank wall. For a two-phase analysis the mass and energy balance at the evaporating interface was taken into account by incorporating the change in specific volume and latent heat of evaporation. A good flow circulation in the liquid region was observed when the cold entering fluid was made to flow at an angle to the axis of the tank or aligned to the bottom surface of the tank. The fluid velocity in the vapor region was found to be higher compared to the liquid region. The focus of the study for the later part of the present investigation was the conjugate heat transfer during a confined liquid jet impingement on a uniform and discrete heating source. Equations governing the conservation of mass, momentum, and energy were solved in the fluid region. In the solid region, the heat conduction equation was solved. The solid-fluid interface temperature shows a strong dependence on several geometric, fluid flow, and heat transfer parameters. For uniform and discrete heat sources the Nusselt number increased with Reynolds number. For a given flow rate, a higher heat transfer coefficient was obtained with smaller slot width and lower impingement height.The average Nusselt number and average heat transfer coefficient are greater for a lower thermal conductivity substrate. A higher heat transfer coefficient at the impingement location was seen at a smaller thickness, whereas a thicker plate or a higher thermal conductivity plate material provided a more uniform distribution of heat transfer coefficient. Compared to…

Subjects/Keywords: Zero boil-off; Cryocooler; Multi-layer insulation; Ammonia; Uniform and discrete heating; American Studies; Arts and Humanities

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Mukka, S. K. (2005). Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement. (Thesis). University of South Florida. Retrieved from https://scholarcommons.usf.edu/etd/781

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Mukka, Santosh Kumar. “Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement.” 2005. Thesis, University of South Florida. Accessed September 30, 2020. https://scholarcommons.usf.edu/etd/781.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Mukka, Santosh Kumar. “Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement.” 2005. Web. 30 Sep 2020.

Vancouver:

Mukka SK. Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement. [Internet] [Thesis]. University of South Florida; 2005. [cited 2020 Sep 30]. Available from: https://scholarcommons.usf.edu/etd/781.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mukka SK. Computation Of Fluid Circulation In A Cryogenic Storage Tank And Heat Transfer Analysis During Jet Impingement. [Thesis]. University of South Florida; 2005. Available from: https://scholarcommons.usf.edu/etd/781

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.