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Study of the U-25B MHD generator system in strong electric and magnetic fields

Description: The third and fourth tests of the U-25B facility have demonstrated that the MHD flow train has operated for over 50 h with little difficulty. Review of the data reveals no significant problems associated with vibration, stress, or fluctuation of the electrical and gasdynamic parameters of the system components. In Test 3, the MHD generator produced a maximum power of 575 kW, a maximum Hall voltage of 4240 V, and a maximum Hall field of 2100 V/m. Inverter loading characteristics indicated that the upstream portion of the channel operated at low conductivity compared to the two downstream sections. During Test 4, at a lower mass flow rate but with cesium seed and oxygen enrichment to 60%, a power level of about 400 kW was generated. Because of inadvertent water and air leakage into the combustion chamber, however, combustion temperatures were lower in Test 4 that anticipated. These factors had a detrimental effect on the generator performance. Analysis of the data obtained from Tests 3 and Test 4 illustrates that in order to increase the power of the U-25B channel, a number of steps should be taken to increase the effective plasma conductivity and channel mass flow. For example, increasing the mass flow rate to 5 kg/s and achieving a K/sub sigma/ of 0.7 to 0.8, a channel inlet temperature about 2950 K may produce an electrical power output up to 1.3 MW. Steps are being taken to increase the preheat temperature in the facility, as well as to eliminate all water and air leakage into the combustor and decrease other thermal losses in the combustor nozzle and generator.
Date: January 1, 1979
Creator: Iserov, A.D.; Maksimenko, V.I. & Maslennikov, G.I.
Partner: UNT Libraries Government Documents Department

US/USSR cooperative program in open-cycle MHD electrical power gneration. Joint test report No. 2: tests in the U-25B facility; MHD generator test No. 3

Description: The third joint test with a Soviet U-25B MHD generator and a US superconducting magnet system (SCMS) was conducted in the Soviet U-25B Facility. The primary objectives of the 3rd test were: (1) to operate the facility and MHD channel over a wider range of test parameters, and (2) to study the performance of all components and systems of the flow train at increased mass flow rates of combustion products (up to 4 kg/s), at high magnetic-field induction (up to 5 T), and high values of the electrical field in the MHD generator. The third test has demonstrated that all components and systems of the U-25B facility performed reliably. The electric power generated by the MHD generaor reached a maximum of 575 kW during this test. The MHD generator was operated under electrical loading conditions for 9 hours, and the combustor for a total of approximately 14 hours. Very high Hall fields (2.1 kV/m) were produced in the MHD channel, with a total Hall voltage of 4.24 kV. A detailed description is given of (1) performance of all components and systems of the U-25B facility, (2) analysis of the thermal, gasdynamic, and electrical characteristics of the MHD generator, (3) results of plasma diagnostic studies, (4) studies of vibrational characteristics of the flow train, (5) fluctuation of electrodynamic and gasdynamic parameters, (6) interaction of the MHD generator with the superconducting magnet, and (7) an operational problem, which terminated the test.
Date: April 1, 1979
Creator: Tempelmeyer, K E & Sokolov, Y N
Partner: UNT Libraries Government Documents Department

Oxygen enrichment for open cycle magnetohydrodynamic power systems

Description: Efficient coal fired, open cycle MHD power generation systems require a combustion flame temperature of approximately 4600 F to provide adequate electrical conductivity in the MHD gas. To achieve this high flame temperature, either highly preheated combustion air or oxygen enrichment of combustion air preheated to a lower temperature is required. Since directly and separately fired high temperature air preheaters are not sufficiently advanced in development to ensure their reliable operation in near term MHD systems, oxygen enrichment may be the practical alternative for obtaining required flame temperatures in the near future. The work presented is a preliminary evaluation of economic and performance effects due to oxygen enrichment of combustion air in open cycle MHD power systems. Studies were initiated with a literature search and a comprehensive review of previous studies of oxygen enrichment in MHD systems. Summaries of these studies and their conclusions are contained in Appendix A. Using selected references from the literature as a starting point, sets of ground rules and assumptions were established for conducting an updated study with subsonic MHD channels. A NASA-developed computer code for modeling of the combustion products and establishing plasma properties was utilized, with slight modification, to prepare a base of thermal properties. Assuming Montana Rosebud coal and combustion air enriched with oxygen from 0 to 50% (by mass), a series of Mollier diagrams was prepared for the complete range of oxygen enriched cases (Appendix B). (WHK)
Date: June 1, 1979
Partner: UNT Libraries Government Documents Department

Key contributions in MHD power generation. Quarterly report, 1 June 1979-31 August 1979

Description: Activities during the third quarter of the contract period are reported in detail. The tasks reported on include: (1) investigation of electrical behavior in the vicinity of electrode and insulating walls; (2) studies of critical performance issues in the development of combustion disk generators; (3) development and testing of electrode modules, including studies of insulator properties; and (4) determination of coal combustion kinetics and ash behavior relevant to two-stage MHD combustors, and investigation of the mixing and flow aerodynamics of a high swirl geometry second stage.
Date: November 1, 1979
Creator: Louis, J F
Partner: UNT Libraries Government Documents Department

US/USSR cooperative program in open-cycle MHD electrical power generation: joint test report No. 3. Tests in the U-25B facility: MHD generator tests No. 4 and 5

Description: A description of the modifications made to improve the plasma parameters of the U-25B Facility is presented. The oxygen enrichment system was modified to allow oxygen enrichment of up to 50% (by volume) ahead of the preheaters. Optimum design and operating conditions of the seed injection system were defined as a result of experimental investigations. An account of the extensive diagnostic studies performed and a description of the measurement techniques and of the new submillimeter laser interferometer are given. The performance of the MHD generator is analyzed for different operating modes. Studies of fluctuations and nonuniformities, current take-off distributions, local electrical analysis, overall heat transfer history of the MHD channel, and an extensive parametric study of the generator are presented. A detailed account of the complete disassembly and inspection of channel No. 1 after more than 100 hours of operation with the combustor, and of the condition of its various elements is also given.
Date: July 1, 1980
Creator: Picologlou, B F & Batenin, V M
Partner: UNT Libraries Government Documents Department

Characterization of open-cycle coal-fired MHD generators. 14th/15th quarterly technical progress report, February 1-July 31, 1980

Description: The successful design of full-scale, open-cycle, coal-fired MHD generators for baseload electrical production requires a detailed understanding of the plasma chemical and plasma dynamic characteristics of anticipated combustor and channel fluids. Progress in efforts to model the efficiency of an open-cycle, coal-fired MHD channel based on the characterization of the channel flow as well as laboratory experiments to validate the modeling effort as detailed. In addition, studies related to understanding arcing phenomena in the vicinity of an anode are reported.
Date: September 1, 1980
Creator: Wormhoudt, J.; Yousefian, V.; Weinberg, M.; Kolb, C.; Martinez-Sanchez, M.; Cheng, W. et al.
Partner: UNT Libraries Government Documents Department

System study of an MHD/gas turbine combined-cycle baseload power plant. HTGL report No. 134

Description: The MHD/gas turbine combined-cycle system has been designed specifically for applications where the availability of cooling water is very limited. The base case systems which were studied consisted of an MHD plant with a gas turbine bottoming plant, and required no cooling water. The gas turbine plant uses only air as its working fluid and receives its energy input from the MHD exhaust gases by means of metal tube heat exchangers. In addition to the base case systems, vapor cycle variation systems were considered which included the addition of a vapor cycle bottoming plant to improve the thermal efficiency. These systems required a small amount of cooling water. The MHD/gas turbine systems were modeled with sufficient detail, using realistic component specifications and costs, so that the thermal and economic performance of the system could be accurately determined. Three cases of MHD/gas turbine systems were studied, with Case I being similar to an MHD/steam system so that a direct comparison of the performances could be made, with Case II being representative of a second generation MHD system, and with Case III considering oxygen enrichment for early commercial applications. The systems are nominally 800 MW/sub e/ to 1000 MW/sub e/ in size. The results show that the MHD/gas turbine system has very good thermal and economic performances while requiring either little or no cooling water. Compared to the MHD/steam system which has a cooling tower heat load of 720 MW, the Base Case I MHD/gas turbine system has a heat rate which is 13% higher and a cost of electricity which is only 7% higher while requiring no cooling water. Case II results show that an improved performance can be expected from second generation MHD/gas turbine systems. Case III results show that an oxygen enriched MHD/gas turbine system may be attractive for ...
Date: August 1, 1981
Creator: Annen, K.D.
Partner: UNT Libraries Government Documents Department

Numerical investigation of recirculation in the UTSI MHD combustor

Description: Numerical studies were carried out to investigate the gross structure of flow in cylindrical combustors. The combustor configurations studied are variations of a working design used at the University of Tennessee Space Institute to burn pulverized coal at temperatures in excess of 3000K for generation of a plasma feeding a magnetohydrodynamic channel. The numerical studies were conducted for an isothermal fluid; the main objective of the calculations was to study the effect of the oxidant injection pattern on the gross structure of recirculating flows within the combustor. The calculations illustrate the basic features of the flow in combustors of this type and suggest implications for the injection of coal and oxidizer in this type of combustor.
Date: September 1983
Creator: Schulz, R. J.; Lee, J. J. & Giel, T. V., Jr.
Partner: UNT Libraries Government Documents Department

Diesel cogeneration plant using oxygen enriched air and emulsified fuels

Description: The investigation of oxygen-enriched combustion of alternative fuels in diesel engines at Argonne National Laboratory (ANL) is based on information gathered from two previous Department of Energy programs. The first was the slow-speed diesel engine program which used fuels such as coal-water slurry and coal derived liquid fuels in a slow speed diesel engine. The second was the development of membrane oxygen separation equipment. The results of these programs indicated that using the new membrane oxygen enrichment technology with medium- and high-speed diesel engines would do two things. First, oxygen enrichment could reduce some emissions from stationary diesel engines, particularly smoke, particulates and hydrocarbons while significantly increasing power output. The second, was that it might be possible to use less expensive liquid fuels such as No. 4, No. 6 and residual oil emulsified with water in medium- to high-speed diesel engines. The water would (1) help to eliminate the undesirable increase in nitrogen oxide production when enriched oxygen is used, and (2) by reducing the viscosity of the heavier liquid fuels, make them easier to use in smaller industrial cogeneration applications. This program consists of four steps: preliminary feasibility study, exploratory experiments, system development, and demonstration and commercialization of an industrial cogeneration system. 3 refs., 13 figs.
Date: January 1, 1990
Creator: Marciniak, T.J.; Cole, R.L.; Sekar, R.R.; Stodolsky, F. (Argonne National Lab., IL (USA)) & Eustis, J.N. (USDOE, Washington, DC (USA))
Partner: UNT Libraries Government Documents Department

Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

Description: The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion air had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.
Date: January 1, 1990
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)) & Schaus, J.E. (Autoresearch Labs., Inc. (USA))
Partner: UNT Libraries Government Documents Department

Oxygen-enriched diesel engine performance: A comparison of analytical and experimental results

Description: Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NO{sub x} emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation -- and thus the prediction capability -- of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NO{sub x} emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported. 14 refs., 10 figs., 1 tab.
Date: January 1, 1990
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)); Assanis, D.N. (Illinois Univ., Urbana, IL (USA)) & Schaus, J.E. (Autoresearch Labs., Inc., Chicago, IL (USA))
Partner: UNT Libraries Government Documents Department

Simulation studies of diesel engine performance with oxygen enriched air and water emulsified fuels

Description: A computer simulation code of a turbocharged, turbocompound diesel engine was modified to study the effects of using oxygen-enriched combustion air and water-emulsified diesel fuels. Oxygen levels of 21 percent to 40 percent by volume in the combustion air were studied. Water content in the fuel was varied from 0 percent to 50 percent mass. Simulation studies and a review and analysis of previous work in this area led to the following conclusions about expected engine performance and emissions: the power density of the engine is significantly increased by oxygen enrichment. Ignition delay and particulate emissions are reduced. Combustion temperatures and No{sub x} emissions are increased with oxygen enrichment but could be brought back to the base levels by introducing water in the fuel. The peak cylinder pressure which increases with the power output level might result in mechanical problems with engine components. Oxygen enrichment also provides an opportunity to use cheaper fuel such as No. 6 diesel fuel. Overall, the adverse effects of oxygen enrichment could be countered by the addition of water and it appears that an optimum combination of water content, oxygen level, and base diesel fuel quality may exist. This could yield improved performance and emissions characteristics compared to a state-of-the-art diesel engine. 9 refs., 8 figs.
Date: January 1, 1990
Creator: Assanis, D.N.; Baker, D. (Illinois Univ., Urbana, IL (USA)); Sekar, R.R.; Siambekos, C.T.; Cole, R.L. & Marciniak, T.J. (Argonne National Lab., IL (USA))
Partner: UNT Libraries Government Documents Department

Effects of catalytic mineral matter on CO/CO{sub 2} ratio, temperature and burning time for char combustion. Quarterly progress report No. 2, January--March 1990

Description: The importance of the CO{sub 2}/CO ratio of carbon oxidation products is illustrated by examination of the heats of reaction for formation of these two products. The heat released by formation of CO{sub 2} is a factor of 3.5 higher than for CO so the temperature of a particle will depend strongly on the CO{sub 2}/CO ratio produced. If gas diffusion through the boundary layer is fast, increased direct production Of CO{sub 2} produces a higher temperature and a higher burning rate. If the supply of oxygen to the surface is limited by diffusion through the boundary layer, production of CO{sub 2} consumes half as much carbon as production of CO so carbon consumption rate is reduced even though temperature may be somewhat higher. Models of these complex interactions have been developed; however the CO{sub 2}/CO ratio produced by the carbon-oxygen reaction must, at present be assumed or inferred from measurement of particle temperature. CO{sub 2}/CO ratios can be strongly influenced by catalytic material in the carbon and by the char temperature. In this program we are measuring the CO{sub 2}/CO ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates. Measurements of CO{sub 2}/CO ratio for an uncatalyzed char (spherocarb) were reported in the Oct-Dec 1989 progress report. This ratio varied from a maximum of 1.5 at 700 K and 100% oxygen to 0.06 at 1430 K and 5% oxygen.
Date: December 31, 1990
Creator: Longwell, J. P.; Sarofim, A. F.; Bar-Ziv, E.; Lee, Chun-Hyuk & Du, Z.
Partner: UNT Libraries Government Documents Department

Evaluation of Pure Oxygen Systems at the Umatilla Hatchery: Task 1-Review and Evaluation of Supplemental O2 Systems, Final Report.

Description: The Northwest Power Planning Council has established a goal of doubling the size of salmon runs in the Columbia River Basin. The achievement of this important goal is largely dependent upon expanding the production of hatchery fish. Pure oxygen has been commonly used to increase the carrying capacity of private sector salmonid hatcheries in the Pacific Northwest. The use of supplemental oxygen to increase hatchery production is significantly less expensive than the construction of new hatcheries and might save up to $500 million in construction costs.
Date: March 1991
Creator: Fish Factory
Partner: UNT Libraries Government Documents Department

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

Description: This report contains the data gathered from tests conducted on a single-cylinder diesel engine to study the benefits and problems of oxygen-enriched diesel combustion and the use of water-emulsified and low-grade diesel fuels. This research, funded by the Office of Industrial Technologies (OIT) in the United States Department of Energy, is being conducted in support of the Industrial Cogeneration Program. The report is made up of two volumes. Volume 1 contains the description of the experiments, selected data points, discussion of trends, and conclusions and recommendations; Volume 2 contains the data sets. With the two-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.
Date: November 1, 1991
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L. & Marciniak, T.J.
Partner: UNT Libraries Government Documents Department

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

Description: The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and cumulative heat-release rates to change measurably. Even at higher oxygen levels, NO{sub x} emissions decreased rapidly when the timing was retarded, and the amount of smoke and the level of particulate-matter emissions did not significantly increase. The single-cylinder engine tests confirmed the results of an earlier technical assessment and further indicated a need for a low-pressure-drop membrane specifically designed for oxygen enrichment. Extension data set indexed separately. 14 refs.
Date: November 1, 1991
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L. & Marciniak, T.J.
Partner: UNT Libraries Government Documents Department

Experimental Evaluation of Oxygen-Enriched Air and Emulsified Fuels in a Single-Cylinder Diesel Engine. Volume 1, Concept Evaluation

Description: The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and cumulative heat-release rates to change measurably. Even at higher oxygen levels, NO{sub x} emissions decreased rapidly when the timing was retarded, and the amount of smoke and the level of particulate-matter emissions did not significantly increase. The single-cylinder engine tests confirmed the results of an earlier technical assessment and further indicated a need for a low-pressure-drop membrane specifically designed for oxygen enrichment. Extension data set indexed separately. 14 refs.
Date: November 1, 1991
Creator: Sekar, R. R.; Marr, W. W.; Cole, R. L. & Marciniak, T. J.
Partner: UNT Libraries Government Documents Department

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine. Volume 2, Data sets

Description: This report contains the data gathered from tests conducted on a single-cylinder diesel engine to study the benefits and problems of oxygen-enriched diesel combustion and the use of water-emulsified and low-grade diesel fuels. This research, funded by the Office of Industrial Technologies (OIT) in the United States Department of Energy, is being conducted in support of the Industrial Cogeneration Program. The report is made up of two volumes. Volume 1 contains the description of the experiments, selected data points, discussion of trends, and conclusions and recommendations; Volume 2 contains the data sets. With the two-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.
Date: November 1, 1991
Creator: Sekar, R. R.; Marr, W. W.; Cole, R. L. & Marciniak, T. J.
Partner: UNT Libraries Government Documents Department

Taguchi methods applied to oxygen-enriched diesel engine experiments

Description: This paper describes a test series conducted on a six-cylinder diesel engine to study the impacts of controlled factors (i.e., oxygen content of the combustion air, water content of the fuel, fuel rate, and fuel-injection timing) on engine emissions using Taguchi methods. Three levels of each factor were used in the tests. Only the main effects of the factors were examined; no attempt was made to analyze the interactions among the factors. It was found that, as in the case of the single-cylinder engine tests, oxygen in the combustion air was very effective in reducing particulate and smoke emissions. Increases in NO[sub x] due to the oxygen enrichment observed in the single-cylinder tests also occurred in the present six-cylinder tests. Water in the emulsified fuel was found to be much less effective in decreasing NO[sub x] emissions for the six-cylinder engine than it was for the single-cylinder engine.
Date: January 1, 1992
Creator: Marr, W. W.; Sekar, R. R.; Cole, R. L.; Marciniak, T. J. (Argonne National Lab., IL (United States)) & Longman, D. E. (Autoresearch Labs., Inc., Chicago, IL (United States))
Partner: UNT Libraries Government Documents Department

Forensic analyses of explosion debris from the January 2, 1992 Pd/D{sub 2}O electrochemistry incident at SRI International

Description: The January 2, 1992 explosion in an electrochemistry laboratory at SRI International (SRI) resulted in the death of scientist Andrew Riley, and gained some notoriety due to its association with experimental work in the controversial field of cold fusion research. Selected components of explosion debris were subjected to forensic analyses at LLNL to elucidate potential causes of, or contributing factors to, the explosion. Interrogation of the debris by LLNL encompassed nuclear, chemical, physical, and materials investigations. Nuclear studies for the determination of tritium and neutron-activation products in stainless steel and brass were negative. No evidence of signature species indicative of orthodox nuclear events was detected. The inorganic and particulate analyses were likewise negative with respect to residues of unexpected chemical species. Such target compounds included conventional explosives, accelerants, propellants, or any exceptional industrial chemicals. The GC-MS analyses of trace organic components in the explosion debris provided perhaps the most interesting results obtained at LLNL. Although no evidence of organic explosives, oxidizers, or other unusual compounds was detected, the presence of a hydrocarbon oil in the interior of the electrochemical cell was established. It is likely that its source was lubricating fluid from the machining of the metal cell components. If residues of organic oils are present during electrolysis experiments, the potential exists for an explosive reaction in the increasingly enriched oxygen atmosphere within the headspace of a metal cell.
Date: August 15, 1992
Creator: Andresen, B.; Whipple, R.; Vandervoort, D. & Grant, P.
Partner: UNT Libraries Government Documents Department

Taguchi methods applied to oxygen-enriched diesel engine experiments

Description: This paper describes a test series conducted on a six-cylinder diesel engine to study the impacts of controlled factors (i.e., oxygen content of the combustion air, water content of the fuel, fuel rate, and fuel-injection timing) on engine emissions using Taguchi methods. Three levels of each factor were used in the tests. Only the main effects of the factors were examined; no attempt was made to analyze the interactions among the factors. It was found that, as in the case of the single-cylinder engine tests, oxygen in the combustion air was very effective in reducing particulate and smoke emissions. Increases in NO{sub x} due to the oxygen enrichment observed in the single-cylinder tests also occurred in the present six-cylinder tests. Water in the emulsified fuel was found to be much less effective in decreasing NO{sub x} emissions for the six-cylinder engine than it was for the single-cylinder engine.
Date: December 1, 1992
Creator: Marr, W. W.; Sekar, R. R.; Cole, R. L.; Marciniak, T. J. & Longman, D. E.
Partner: UNT Libraries Government Documents Department

Atmospheric pressure fluctuations and oxygen enrichment in waste tanks

Description: During In-Tank Precipitation (ITP) processing radiolytic decomposition of tetraphenylborate and water can produce benzene and hydrogen, which, given sufficiently high oxygen concentrations, can deflagrate. To prevent accumulations of benzene and hydrogen and avoid deflagration, continuous nitrogen purging is maintained. If the nitrogen purging is interrupted by, for example, a power failure, outside air will begin to seep into the tank through vent holes and cracks. Eventually a flammable mixture of benzene, hydrogen, and oxygen will occur (deflagration). However, this process is slow under steady-state conditions (constant pressure) and mechanisms to increase the exchange rate with the outside atmosphere must be considered. The most important mechanism of this kind is from atmospheric pressure fluctuations in which an increase in atmospheric pressure forces air into the tank which then mixes with the hydrogen-benzene mixture. The subsequent decrease in atmospheric pressure causes venting from the tank of the mixture -- the net effect being an increase in the tank`s oxygen concentration. Thus, enrichment occurs when the atmospheric pressure increases but not when the pressure decreases. Moreover, this natural atmospheric {open_quotes}pumping{close_quotes} is only important if the pressure fluctuations take place on a time scale longer than the characteristic mixing time scale (CMT) of the tank. If pressure fluctuations have a significantly higher frequency than the CMT, outside air will be forced into the tank and then out again before any significant mixing can occur. The CMT is not known for certain, but is estimated to be between 8 and 24 hours. The purpose of this report is to analyze yearly pressure fluctuations for a five year period to determine their statistical properties over 8 and 24-hour periods. The analysis also includes a special breakdown into summer and winter seasons and an analysis of 15-minute data from the SRTC Climatology Site.
Date: July 1, 1993
Creator: Kurzeja, R. J. & Weber, A. H.
Partner: UNT Libraries Government Documents Department

Bus application of oxygen-enrichment technology and diesel-electric hybrid systems

Description: The amendments to the Clean Air Act (CAA) mandate very strict limits on particulate, smoke, and other emissions from city buses. The use of alternative fuels, such as compressed natural gas (CNG) or methanol, can help transit operators, such as the Chicago Transit Authority (CTA), meet the mandated limits. However, the capital investment needed to convert the fueling infrastructure and buses is large, as is the expense of training personnel. If a {open_quotes}clean diesel{close_quotes} bus can be implemented with the help of oxygen-enrichment technology or a diesel-electric hybrid system, this large investment could be postponed for many years. The Regional Transportation Authority (RTA) initiated this project to evaluate the possibility of applying these technologies to CTA buses. Argonne National Laboratory (ANL) conducted a limited number of engine tests and computer analyses and concluded that both concepts are practical and will help in a {open_quotes}clean diesel{close_quotes} bus that can meet the mandated limits of the CAA amendments. The oxygen enrichment of combustion air depends on the availability of a compact and economical membrane separator. Because the technology for this critical component is still under development, it is recommended that an actual bus demonstration be delayed until prototype membranes are available. The hybrid propulsion system is ready for the demonstration phase, and it is recommended that the CTA and RTA commence planning for a bus demonstration.
Date: October 1, 1993
Creator: Sekar, R. R. & Marr, W. W.
Partner: UNT Libraries Government Documents Department

Willamette Hatchery Oxygen Supplementation Studies : Annual Report 1993.

Description: Hydropower development and operations in the Columbia River basin have caused the loss of 5 million to 11 million salmonids. An interim goal of the Northwest Power Planning Council is to reestablish these historical numbers by doubling the present adult runs from 2.5 million to 5.0 million fish. This increase in production will be accomplished through comprehensive management of both wild and hatchery fish, but artificial propagation will play a major role in the augmentation process. The current husbandry techniques in existing hatcheries require improvements that may include changes in rearing densities, addition of oxygen, removal of excess nitrogen, and improvement in raceway design. Emphasis will be placed on the ability to increase the number of fish released from hatcheries that survive to return as adults.
Date: November 1, 1993
Creator: Ewing, R. D.; Ewing, S. K. & Sheahan, J. E.
Partner: UNT Libraries Government Documents Department