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:(Flow area ratio). Showing records 1 – 3 of 3 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


NSYSU

1. Hsiung, Szu-kai. The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2002, NSYSU

Abstract The experimental tests and analysis of single fuel cell unit are performance in this research, and the electrolyte in MEA(membrane and electrode assembly) we used Nafion 112.Accroding to change several design factors and operation conditions, we can find out how important the factors affect the PEMFC power output. The experimental conditions in this study are various of type of fasten torque, flow channels, oxidizers, catalyst type and loading in cathode side, materials of electron collector, inlet gas pressure and humidification of membrane. The results can provide us references to assemble a fuel cell stack in future. PEMFC can start quickly at low temperature and achieves stable output voltage. When the 4 N-m torque is applied to fasten the reaction chamber, the contact resistance between the electrode and electron collector reaches a minimum value. The results show that when the area ratio(Af /At)is 58.41%, we can have better ratio between channel areas and contact area, and the output can be larger. We found that increasing the loading of catalyst in the cathode, the power output rises up clearly, but the loading also has a limitation. By using gold to be the electron collector, the result shows that it has better performance than using graphite, but the price is also much higher. Our experiments display that use oxygen to be oxidizer can have better performance than use air. When we heated membrane in the water at 80â, it can resupply the water in the membrane, remain enough humidification of membrane can be clearly helpful to the PEMFC power output, because humidification can keep the proton conductivity of the membrane in good condition. And we also found while the hot press pressure at 160atm, the performance can be better than using other pressure. Key words : PEMFCãMEAãFlow area ratio Advisors/Committee Members: Long-Jeng Chen (committee member), Chin-Chia Su (chair), Shin-Min Chiang (chair), Ming-San Lee (chair).

Subjects/Keywords: PEMFC; MEA; Flow area ratio

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th Edition):

Hsiung, S. (2002). The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0625102-154628

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):

Hsiung, Szu-kai. “The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method.” 2002. Thesis, NSYSU. Accessed January 22, 2020. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0625102-154628.

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

MLA Handbook (7th Edition):

Hsiung, Szu-kai. “The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method.” 2002. Web. 22 Jan 2020.

Vancouver:

Hsiung S. The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method. [Internet] [Thesis]. NSYSU; 2002. [cited 2020 Jan 22]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0625102-154628.

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

Council of Science Editors:

Hsiung S. The research of using different experiments to develope the effect of PEMFC performance in changing different design conditions and manufacture method. [Thesis]. NSYSU; 2002. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0625102-154628

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


NSYSU

2. Hu, Yao-lun. The Effect of Deformation on the Efficiency of PEMFC.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2015, NSYSU

Energy crisis is a global issue, and many countries are eager to search or develop new energy resources. Fuel cell is one potential energy resource of new energy resources. In all kinds of fuel cells, proton exchange membrane fuel cell (PEMFC) is the most profitable one. However, many researches were focus on improving efficiency through chemical reactions, and rarely discussed the effect of structural deformations on efficiency. The purpose of this research was to build up a three dimensional and full PEMFC model through finite element method (FEM), and to investigate deformations caused by internal heat and bolt pre-loading under real operating condition. Furthermore, effects of variations of bolt pre-loadings, flow channel cross-sectional area designs and flow channel fillets on deformations of PEMFC, compression ratio of gas diffusion layers and intrusion rate of flow channels were studied. The results showed that deformation of PEMFC caused by bolt pre-loading could not be ignored, and average equivalent stress of graphite plates and gas diffusion layers increased linearly with increasing bolt pre-loadings which generated maximum equivalent stress at inlet or outlet of flow channels. With increasing bolt pre-loadings, compression ratio of gas diffusion layer increased linearly, and thus increased the efficiency of PEMFC. However, when bolt pre-loading reached 7 MPa, compression ratio of gas diffusion layer exceeded 15% and degraded the efficiency. The intrusion rate of flow channels increased non-linearly with increasing bolt pre-loading. When bolt pre-loading was 6 MPa, the cross-sectional area of flow channels was 92.54% of its original state and decreased the efficiency. In part of flow channel cross-sectional area designs, when bolt pre-loading was 6 MPa and if cross-sectional area increased 27%, the flow rate of reactants could be promoted 17.42%, and the fuel cell efficiency can be improved also. Advisors/Committee Members: Jung-Hung Sun (chair), Ting-Nung Shiau (chair), Chi-Hui Chien (committee member).

Subjects/Keywords: flow channel intrusion rate; gas diffusion layer compression ratio; fuel cell efficiency; finite element method; proton exchange membrane fuel cell; flow channel cross-sectional area; bolt pre-loading

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th Edition):

Hu, Y. (2015). The Effect of Deformation on the Efficiency of PEMFC. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0723115-031201

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):

Hu, Yao-lun. “The Effect of Deformation on the Efficiency of PEMFC.” 2015. Thesis, NSYSU. Accessed January 22, 2020. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0723115-031201.

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

MLA Handbook (7th Edition):

Hu, Yao-lun. “The Effect of Deformation on the Efficiency of PEMFC.” 2015. Web. 22 Jan 2020.

Vancouver:

Hu Y. The Effect of Deformation on the Efficiency of PEMFC. [Internet] [Thesis]. NSYSU; 2015. [cited 2020 Jan 22]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0723115-031201.

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

Council of Science Editors:

Hu Y. The Effect of Deformation on the Efficiency of PEMFC. [Thesis]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0723115-031201

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


University of Alberta

3. Miller, Warren Gregory. Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings.

Degree: PhD, Department of Civil and Environmental Engineering, 2010, University of Alberta

A study was conducted to evaluate the properties and processes influencing the rate and magnitude of volume decrease and strength gain for oil sand fine tailings resulting from a change in bitumen extraction process (caustic versus non-caustic) and the effect of adding a coagulant to caustic fine tailings. Laboratory flume deposition tests were carried out with the objective to hydraulically deposit oil sand tailings and compare the effects of extraction processes on the nature of beach deposits in terms of geometry, particle size distribution, and density. A good correlation exists between flume deposition tests results using oil sand tailings and the various other tailings materials. These comparisons show the reliability and effectiveness of flume deposition tests in terms of establishing general relationships and can serve as a guide to predict beach slopes. Fine tailings were collected from the various flume tests and a comprehensive description of physical and chemical characteristics of the different fine tailings was carried out. The characteristics of the fine tailings is presented in terms of index properties, mineralogy, specific surface area, water chemistry, liquid limits, particle size distribution and structure. The influence of these fundamental properties on the compressibility, hydraulic conductivity and shear strength properties of the fine tailings was assessed. Fourteen two meter and one meter high standpipe tests were instrumented to monitor the rate and magnitude of self-weight consolidation of the different fine tailings materials. Consolidation tests using slurry consolidometers were carried out to determine consolidation properties, namely compressibility and hydraulic conductivity, as well as the effect of adding a coagulant (calcium sulphate [CaSO4]) to caustic fine tailings. The thixotropic strength of the fine tailings was examined by measuring shear strength over time using a vane shear apparatus. A difference in water chemistry during bitumen extraction was concluded to be the cause of substantial differences in particle size distributions and degree of dispersion of the comparable caustic and non-caustic fine tailings. The degree of dispersion was consistent with predictions for dispersed clays established by the sodium adsorption ratio (SAR) values for these materials. The biggest advantage of non-caustic fine tailings and treating caustic fine tailings with coagulant is an increased initial settlement rate and slightly increased hydraulic conductivity at higher void ratios. Thereafter, compressibility and hydraulic conductivity are governed by effective stress. The chemical characteristics of fine tailings (water chemistry, degree of dispersion) do not have a significant impact on their compressibility behaviour and have only a small influence at high void ratio (low effective stress). Fine tailings from a caustic based extraction process had relatively higher shear strengths than comparable non-caustic fine tailings at equivalent void ratios. However, shear strength differences…

Subjects/Keywords: settlement; dispersion; hydraulic deposition; effective stress; thixotropic strength; caustic; flow rate; thixotropy; compressibility; fines content; geoenvironmental properties; water chemistry; index properties; noncaustic; fine tailings; shear strength; void ratio; self weight consolidation; slurry concentration; particle size distribution; bitumen extraction; vane shear; hydraulic conductivity; coagulant; oil sands; structure; beach slope; flume tests; consolidation; specific surface area; sodium adsorption ratio; flocculation; large strain

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th Edition):

Miller, W. G. (2010). Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/v692t662v

Chicago Manual of Style (16th Edition):

Miller, Warren Gregory. “Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings.” 2010. Doctoral Dissertation, University of Alberta. Accessed January 22, 2020. https://era.library.ualberta.ca/files/v692t662v.

MLA Handbook (7th Edition):

Miller, Warren Gregory. “Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings.” 2010. Web. 22 Jan 2020.

Vancouver:

Miller WG. Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings. [Internet] [Doctoral dissertation]. University of Alberta; 2010. [cited 2020 Jan 22]. Available from: https://era.library.ualberta.ca/files/v692t662v.

Council of Science Editors:

Miller WG. Comparison of geoenvironmental properties of caustic and noncaustic oil sand fine tailings. [Doctoral Dissertation]. University of Alberta; 2010. Available from: https://era.library.ualberta.ca/files/v692t662v

.