Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)最新文献_第2页

Evaluation of the overall efficiency of a low pressure proton exchange membrane fuel cell power unit 低压质子交换膜燃料电池动力装置整体效率评价

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870923

V. Naso, M. Lucentini, M. Aresti

{"title":"Evaluation of the overall efficiency of a low pressure proton exchange membrane fuel cell power unit","authors":"V. Naso, M. Lucentini, M. Aresti","doi":"10.1109/IECEC.2000.870923","DOIUrl":"https://doi.org/10.1109/IECEC.2000.870923","url":null,"abstract":"Polymer electrolyte membrane fuel cells (PEMFC) at present can be considered the best choices to set up the auxiliary power unit of an hybrid electric vehicle. This paper describes how it is possible and convenient to manage a PEMFC at low pressure, using a blower instead of a compressor/expander. The polarization curve obtained from experimental tests on the stack confirms a typical behaviour at different values of pressure; although high pressure brings best performance, in the balance of the plant the air compressor generally absorbs more then 40% of the power generated from the stack. As a matter of fact, the overall efficiency of the whole FC apparatus can be improved by managing it at low pressure. In an FC/batteries hybrid electric vehicle, the FC is asked to operate not at partial load, but only at full load by using an ON-OFF control. Consequently it is possible to arrange a very compact and reliable apparatus in which the dynamic mass flow and pressure controls are not required and the mechanical and electric hardware is very simple.","PeriodicalId":224191,"journal":{"name":"Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124200422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Energy transfer processes of working gas-in pulse tube 工作气体在脉冲管内的能量传递过程

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870721

V. Naso, W. Dong, M. Lucentini

{"title":"Energy transfer processes of working gas-in pulse tube","authors":"V. Naso, W. Dong, M. Lucentini","doi":"10.1109/IECEC.2000.870721","DOIUrl":"https://doi.org/10.1109/IECEC.2000.870721","url":null,"abstract":"The pulse tube cooler is a device for cooling to low temperatures. It runs on a modified Stirling cycle but has no cold moving parts and the gas flow in the pulse tube can carry heat energy away from a low temperature point under certain conditions. An orifice or other device controlling the flow at the end of the cooler provides the condition for cooling to occur. Pulse tube coolers have great commercial potential; offering low cost, low vibration and high reliability and they can be designed in variety of configurations including linear, U-tube (folded 180 in the middle) and concentric. They can be designed to cool to 200 K, to as low as 2 K, or to any temperature in between. The cooling power ranges from milliwatts to kilowatts depending on cooler size and operating temperature. In the development of pulse tube coolers, it is important to study the energy transfer process of the working fluid in the pulse tube. The enthalpy flow in the pulse tube is the gross cooling power of the cooler. Since the pulse tube section is nearly adiabatic, there are large temperature oscillations yielded by pressure oscillation. To evaluate the temperature oscillation, a mathematical model was developed. With this model, the analytical result is that the temperature ratio of the working fluid is the function of pressure ratio between hot and cold heat exchanges.","PeriodicalId":224191,"journal":{"name":"Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124245341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The X-ray Multi Mirror (XMM-Newton) power system [spacecraft power] x射线多镜(xmm -牛顿)动力系统[航天器动力]

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870690

J. Haines, B. Jackson, L. Gerlach

引用次数: 0

Sensitivity of performance and degradation measurements on AMTEC electrodes in sodium exposure test cells to experiment conditions 钠暴露试验电池中AMTEC电极性能和降解测量对实验条件的敏感性

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870856

M. Schuller, B. Fiebig, P. Hudson, A. Williams

引用次数: 0

Electron beam and Nd-YAG laser welding of niobium-1% zirconium and molybdenum-44.5% rhenium thin select material 电子束和Nd-YAG激光焊接铌-1%锆和钼-44.5%铼薄材

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870896

D. Kramer, J. McDougal, B.A. Booher, J.D. Ruhkamp, E. I. Howell, J. Kwiatkowski

{"title":"Electron beam and Nd-YAG laser welding of niobium-1% zirconium and molybdenum-44.5% rhenium thin select material","authors":"D. Kramer, J. McDougal, B.A. Booher, J.D. Ruhkamp, E. I. Howell, J. Kwiatkowski","doi":"10.1109/IECEC.2000.870896","DOIUrl":"https://doi.org/10.1109/IECEC.2000.870896","url":null,"abstract":"A development study has been completed on autogenous electron beam and Nd-YAG laser welding of niobium-1% zirconium (Nb-1% Zr) and molybdenum-44.5% rhenium (Mo-44.5% Re) thin sheet material. Specimens 0.5 mm thick were welded using both processes in a butt joint configuration. Mechanical tests were performed on welded specimens and their ultimate tensile strengths and percent elongation were determined. Metallographic cross-sections of sample welds showed that electron beam welding resulted in larger grains and an increased heat affected zone compared to laser welded samples. The Nd-YAG laser process yielded a more refined grain structure in the weld compared to the electron beam process due most likely to solidification mode and weld heat input differences. These preliminary studies show that the Nb-1% Zr material can be successfully welded using either welding process. The Mo-44.5% Re material was only successfully welded using the electron beam process. The Nd-YAG laser welded Mo-44.5% Re samples yielded some surface and sub-surface cracks and displayed brittle behavior during mechanical testing of the welds. Additional work will be required to determine the feasibility of obtaining optimum laser welds on the Mo-44.5% Re material.","PeriodicalId":224191,"journal":{"name":"Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131605832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Some technical aspects of fires 火灾的一些技术问题

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870887

D. Lilley

引用次数: 0

Evaluating alternatives for integrating distributed DC generation with AC power systems 评估分布式直流发电与交流电力系统集成的备选方案

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870872

F. Wicks

{"title":"Evaluating alternatives for integrating distributed DC generation with AC power systems","authors":"F. Wicks","doi":"10.1109/IECEC.2000.870872","DOIUrl":"https://doi.org/10.1109/IECEC.2000.870872","url":null,"abstract":"Distributed generation generally means on site electric power generation devices such as photovoltaics or fuel cells that are installed at the customer end of the electric power system. One complication is that the photovoltaic panel and the fuel cell generate direct current (DC) while the electric power system and thus existing end use equipment has been designed for alternating current (AC). This paper suggests a method which converts all AC power from the electric utility to DC with rectifiers at the distribution substation or at the point of building entry and then interfaces the DC distributed generation from the photovoltaics or fuel cells directly with the rectified DC from the electric power system. Some of the equipment in the house such as light bulbs and electric heating in stoves and clothes dryers can operate indifferently on DC. Equipment such as induction motors in refrigerators and air conditioners can operate from small dedicated nonsynchronous chord mounted DC to AC inverters until replaced with DC compatible equipment. Electronics such as televisions and computers can also operate from chord mounted DC to AC inverters until replaced by DC compatible equipment. Ultimately, the entire electric utility system should be converted from a transformer based multiple voltage AC system to a more efficient solid state converter based multiple voltage DC system. This type of system would not only be fundamentally more efficient. It would also be directly compatible with distributed DC generation.","PeriodicalId":224191,"journal":{"name":"Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131122887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

A flat plate solar collector with dual channels for air flows 具有双通道空气流动的平板太阳能集热器

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870657

S. Ito, M. Kashima, N. Miura

引用次数: 5

Impedance studies on cathodes in Li-ion cells 锂离子电池阴极阻抗研究

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870898

G. Nagasubramanian

{"title":"Impedance studies on cathodes in Li-ion cells","authors":"G. Nagasubramanian","doi":"10.1109/IECEC.2000.870898","DOIUrl":"https://doi.org/10.1109/IECEC.2000.870898","url":null,"abstract":"Li-ion batteries have generated widespread interest as batteries of choice for a number of applications, because of their attractive energy and power densities. However, the performance at sub-ambient temperatures is very limited due to the increase in cell impedance at sub-ambient temperatures. AC impedance measurements seem to indicate that the ohmic resistance-which includes electrolyte resistance, electrodes bulk resistance, current collector and tab resistances of the cells increases only marginally at sub-ambient temperatures. Most of the increase in cell impedance comes from the electrode/electrolyte interfacial impedance. Sandia National Laboratories and others have shown that the increase in impedance comes mostly from the cathode electrolyte interface and not from the anode electrolyte interface. The question then is \"where exactly does the increase in cathode impedance come from?\" Whether it comes from the interfacial resistance (charge transfer+the solid-electrolyte-interphase resistance) or from diffusion of Li/sup +/ inside the cathode. To answer the question, we are investigating the impedance characteristics of the LiCoO/sub 2/ and other metal oxide cathodes at different temperatures and cell voltage. The data seem to indicate that the interfacial impedance of the cathode/electrolyte interface mostly accounts for the cell impedance.","PeriodicalId":224191,"journal":{"name":"Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133057232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Cogeneration analysis considering efficiency of 1-8 MW turboengines class 考虑1- 8mw级涡轮发动机效率的热电联产分析

Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022) Pub Date : 2000-07-24 DOI: 10.1109/IECEC.2000.870867

C. Cârlănescu, R. Sălcianu, D. Ionescu

引用次数: 0