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Thermodynamic data for the computation of the performance of exhaust-gas turbines

Description: From Summary: "Information published in chemical journals from 1933 to 1939 on the thermodynamic properties of the component gases of exhaust gases based on spectroscopic measurements were used as data for computing the ideal values of work, mass flow, nozzle velocity, power, and temperature change involved in the thermodynamic properties of a gas turbine. Curves from which this information can conveniently be obtained are given. An additional curve is included from which the heat flow may be calculated for nonadiabatic processes."
Date: October 1945
Creator: Pinkel, Benjamin & Turner, L. Richard
Partner: UNT Libraries Government Documents Department

Real-Time Measurement of Vehicle Exhaust Gas Flow

Description: A flow measurement system was developed to measure, in real-time, the exhaust gas flow from vehicies. This new system was based on the vortex shedding principle using ultrasonic detectors for sensing the shed vortices. The flow meter was designed to measure flow over a range of 1 to 366 Ips with an inaccuracy of ~1o/0 of reading. Additionally, the meter was engineered to cause minimal pressure drop (less than 125mm of water), to function in a high temperature environment (up to 650oC) with thermal transients of 15 oC/s, and to have a response time of 0.1 seconds for a 10% to 90!40 step change. The flow meter was also configured to measure hi-directional flow. Several flow meter prototypes were fabricated, tested, and calibrated in air, simulated exhaust gas, and actual exhaust gas. Testing included gas temperatures to 600oC, step response experiments, and flow rates from O to 360 lps in air and exhaust gas. Two prototypes have been tested extensively at NIST and two additional meters have been installed in exhaust gas flow lines for over one year. This new flow meter design has shown to be accurate, durabIe, fast responding, and to have a wide rangeabi~ity.
Date: June 28, 1999
Creator: Hardy, J.E.; Hylton, J.O.; Joy, R.D. & McKnight, T.E.
Partner: UNT Libraries Government Documents Department

HEV dynamometer testing with state-of-charge corrections in the 1995 HEV challenge

Description: In the 1995 HEV Challenge competition, 17 prototype Hybrid Electric Vehicles (HEVs) were tested by using special HEV test procedures. The contribution of the batteries during the test, as measured by changes in battery state-of-charge (SOC), were accounted for by applying SOC corrections to the test data acquired from the results of the HEV test. The details of SOC corrections are described and two different HEV test methods are explained. The results of the HEV test methods are explained. The results of the HEV tests and the effects on the test outcome of varying HEV designs and control strategies are examined. Although many teams had technical problems with their vehicles, a few vehicles demonstrated high fuel economy and low emissions. One vehicle had emissions lower than California`s ultra-low emission vehicle (ULEV) emissions rates, and two vehicles demonstrated higher fuel economy and better acceleration than their stock counterparts.
Date: March 1, 1996
Creator: Duoba, M. & Larsen, R.
Partner: UNT Libraries Government Documents Department

Direct measurement of divertor exhaust neo enrichment in DIII-D

Description: We report first direct measurements of divertor exhaust gas impurity enrichment, {eta}{sub exh}=(exhaust impurity concentration){divided_by}(core impurity concentration), for both unpumped and D{sub 2} puff-with-divertor-pump conditions. The experiment was performed with neutral beam heated, ELMing H-mode, single-null diverted deuterium plasmas with matched core and exhaust parameters in the DIII-D tokamak. Neon gas impurity was puffed into the divertor. Neon density was measured in the exhaust by a specially modified Penning gauge and in the core by absolute charge exchange recombination spectroscopy. Neon particle accounting indicates that much of the puffed neon entered a temporary unmeasured reservoir, inferred to be the graphite divertor target, which makes direct measurements necessary to calculate divertor enrichments. D{sub 2} puff into the SOL (scrape-off layer) with pumping increased {eta}{sub exh} threefold over either unpumped conditions or D{sub 2} puff directly into the divertor with pumping. These results show that SOL flow plays an important role in divertor exhaust impurity enrichment.
Date: June 1, 1996
Creator: Schaffer, M.J.; Wade, M.R.; Maingi, R.; Monier-Garbet, P.; West, W.P.; Whyte, D.G. et al.
Partner: UNT Libraries Government Documents Department

Effect of gas composition on the NO<sub>x</sub> conversion chemistry in a plasma

Description: Much work has been done on the application of plasmas to the treatment of NO<sub>x</sub> from power plants. In power plant applications, the purpose of the plasma is to oxidize NO to NO<sub>x</sub>, and eventually to nitric acid. The desires products, in the form of ammonium salts, are then obtained by mixing ammonia with the formed acids. Some form of scrubbing is required to collect the final products. For applications to the treatment of exhausts from cars and trucks, it is very important to make a distinction between NO removal by chemical oxidation and NO removal by chemical reduction. To avoid the need for scrubbing of plasma processing products, the desired method of NO removal is by chemical reduction; i.e., the conversion of NO to benign gaseous products like N NO<sub>2</sub>. This paper will discuss the results of an extensive series of experiments aimed towards understanding the effect of gas composition on the NO<sub>x</sub> conversion chemistry in a plasma. The NO<sub>x</sub> conversion chemistry in the presence of the individual components, such as N<sub>2</sub>, O<sub>2</sub>, H<sub>2</sub>O, and CO<sub>2</sub>, as well as the mixture of these, will be presented. We will show that, in a lean-burn gasoline or diesel engine exhaust, the main effect of the gas-phase reactions in a plasma is the oxidation of NO to NO<sub>x</sub> and nitric acid. To implement the reduction of NO<sub>x</sub> to N<sub>2</sub> in the highly oxidizing environment of a lean-burn engine exhaust, it will be necessary to prevent the formation of acid products and combine the plasma with another process that can chemically reduce NO<sub>2</sub> to N<sub>x</sub>.
Date: August 24, 1998
Creator: McLarnon, C R & Penetrante, B M
Partner: UNT Libraries Government Documents Department

Multi-stage selection catalytic reduction of NO{sub x} in lean burn engine exhaust

Description: Recent studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. These studies have prompted the development of schemes that use an oxidation catalyst to convert NO to NO{sub 2}, followed by a reduction catalyst to convert NO{sub 2} to N{sub 2}. Multi-stage SCR offers high NO{sub x} reduction efficiency from catalysts that, separately, are not very active for reduction of NO, and alleviates the problem of selectivity between NO reduction and hydrocarbon oxidation. A plasma can also be used to oxidize NO to NO{sub 2}. This paper compares the multi-stage catalytic scheme with the plasma-assisted catalytic scheme for reduction of NO{sub x} in lean-bum engine exhausts. The advantages of plasma oxidation over catalytic oxidation are presented.
Date: January 26, 1998
Creator: Penetrante, B.M.; Hsiao, M.O.; Merritt, B.T. & Vogling, E.
Partner: UNT Libraries Government Documents Department

Oxidation of automotive primary reference fuels in a high pressure flow reactor

Description: Automotive engine knock limits the maximum operating compression ratio and ultimate thermodynamic efficiency of spark-ignition (SI) engines. In compression-ignition (CI) or diesel cycle engines the premixed urn phase, which occurs shortly after injection, determines the time it takes for autoignition to occur. In order to improve engine efficiency and to recommend more efficient, cleaner-burning alternative fuels, we must understand the chemical kinetic processes which lead to autoignition in both SI and CI engines. These engines burn large molecular-weight blended fuels, a class to which the primary reference fuels (PRF), n-heptane and isooctane belong. In this study, experiments were performed under engine-like conditions in a high pressure flow reactor using both the pure PRF fuels and their mixtures in the temperature range 550-880 K and at 12.5 atm pressure. These experiments not only provide information on the reactivity of each fuel but also identify the major intermediate products formed during the oxidation process. A detailed chemical kinetic mechanism is used to simulate these experiments and comparisons of experimentally measures and model predicted profiles for O{sub 2}, CO, CO{sub 2}, H{sub 2}O and temperature rise are presented. Intermediates identified in the flow reactor are compared with those present in the computations, and the kinetic pathways leading to their formation are discussed. In addition, autoignition delay times measured in a shock tube over the temperature range 690- 1220 K and at 40 atm pressure were simulated. Good agreement between experiment and simulation was obtained for both the pure fuels and their mixtures. Finally, quantitative values of major intermediates measured in the exhaust gas of a cooperative fuels research engine operating under motored engine conditions are presented together with those predicted by the detailed method.
Date: January 1, 1998
Creator: Curran, H.J.; Pitz, W.J.; Westbrook, C.K.; Callahan, C.V. & Dryer, F.L.
Partner: UNT Libraries Government Documents Department

An investigation of late-combustion soot burnout in a DI diesel engine using simultaneous planar imaging of soot and OH radical

Description: Diesel engine design continues to be driven by the need to improve performance while at the same time achieving further reductions in emissions. The development of new designs to accomplish these goals requires an understanding of how the emissions are produced in the engine. Laser-imaging diagnostics are uniquely capable of providing this information, and the understanding of diesel combustion and emissions formation has been advanced considerably in recent years by their application. However, previous studies have generally focused on the early and middle stages of diesel combustion. These previous laser-imaging studies do provide important insight into the soot formation and oxidation processes during the main combustion event. They indicate that prior to the end of injection, soot formation is initiated by fuel-rich premixed combustion (equivalence ratio &gt; 4) near the upstream limit of the luminous portion of the reacting fuel jet. The soot is then oxidized at the diffusion flame around the periphery of the luminous plume. Under typical diesel engine conditions, the diffusion flame does not burn the remaining fuel and soot as rapidly as it is supplied, resulting in an expanding region of rich combustion products and soot. This is evident in natural emission images by the increasing size of the luminous soot cloud prior to the end of injection. Hence, the amount of soot in the combustion chamber typically increases until shortly after the end of fuel injection, at which time the main soot formation period ends and the burnout phase begins. Sampling valve and two-color pyrometry data indicate that the vast majority (more than 90%) of the soot formed is oxidized before combustion ends; however, it is generally thought that a small fraction of this soot from the main combustion zones is not consumed and is the source of tail pipe soot emissions.
Date: October 1, 1999
Creator: Dec, John E. & Kelly-Zion, Peter L.
Partner: UNT Libraries Government Documents Department

Exhaust gas sensors

Description: The automotive industry needed a fast, reliable, under-the-hood method of determining nitrogen oxides in automobile exhaust. Several technologies were pursued concurrently. These sensing technologies were based on light absorption, electrochemical methods, and surface mass loading. The Y-12 plant was selected to study the methods based on light absorption. The first phase was defining the detailed technical objectives of the sensors--this was the role of the automobile companies. The second phase was to develop prototype sensors in the laboratories--the national laboratories. The final phase was testing of the prototype sensors by the automobile industries. This program was canceled a few months into what was to be a three-year effort.
Date: February 9, 1997
Creator: Hiller, J. & Miree, T.J.
Partner: UNT Libraries Government Documents Department

Standard-D hydrogen monitoring system acceptance test

Description: This document details the results of the field Acceptance Testing of the Standard-D Hydrogen Monitoring System on the waste tank exhaust stacks in 241-AW and 241-AN tank farm. The monitors will be used to measure hydrogen and ammonia from the exhaust stacks.
Date: May 24, 1996
Creator: Lott, D.T., Westinghouse Hanford
Partner: UNT Libraries Government Documents Department

A thyratron-based pulse generator for fundamental studies of NO{sub x} removal in nonthermal plasmas

Description: In collaboration with the Army Research Laboratory (ARL), the National Institute of Standards and Technology (NIST), and McMaster University, the authors are investigating the removal of NOx from engine exhaust streams using nonthermal plasmas (NTPs). The near-term experiments focus on measuring temperature distributions and reactive species concentrations in electric discharge NTP reactors using laser induced fluorescence (LIF) and tunable diode laser absorption spectroscopy (TDLAS), with first experiments on LIF measurements of OH in a pulsed dielectric-barrier discharge. Because the self extinguishing microdischarges in a conventional (low frequency driven) barrier discharge are both short lived (a few to a few tens of nanoseconds) and randomly distributed in the process volume, it is difficult to measure the time-varying properties of the species produced by the plasma. To synchronize the plasma ignition with the optical diagnostics, a thyratron switched, high voltage pulse generator has been constructed to drive a small dielectric-barrier plasma cell. A fast rise time thyratron tube is used in a low inductance geometry to deliver a negative high voltage pulse to the cell. The output voltage pulse has a rise time of 6.5 ns, a peak voltage of 40 kV, and a repetition rate of 20 Hz. A microdischarge streamer occurs between the pin electrode and the glass barrier during the rise time of the voltage pulse. The delay between the input signal and the microdischarge is 250 ns with a jitter of 4 ns, thus allowing repetitive initiation of a microdischarge with low temporal jitter. The energy per pulse is obtained from the voltage and current versus time, v(t) and i(t), measured at the cell. The fast rising pulse also produces a higher E/N at breakdown in the discharge than in conventional NTP cells, which may affect the removal efficiency of pollutants.
Date: September 1, 1997
Creator: Korzekwa, R.A. & Rosocha, L.A.
Partner: UNT Libraries Government Documents Department

Plasma technology for tail pipe reduction of NO{sub x} in diesel exhaust

Description: In the conventional application of plasmas to the treatment of power plant flue gases, the plasma is used to oxidize NO{sub x} to nitric acid; the final product us ammonium nitrate, which is obtained by addition of ammonia. A critical issue in the application of plasmas to cars and trucks is whether the plasma can remove the NO{sub x} by direct chemical reduction to N{sub 2}. We have found that gas-phase reactions in the plasma alone cannot lead to true chemical reduction of NO{sub x}. Any reduction of NO{sub x}to N{sub 2} can only be accomplished through heterogeneous reactions of NO{sub 2} with surfaces or particulates. This paper discusses how the plasma oxidation of NO to NO{sub 2} can be utilized to enhance the heterogeneous catalytic reduction of NO{sub x} to N{sub 2}. Plasma- assisted heterogeneous catalysis can enhance the NO{sub x} reduction under conditions that normally make it difficult for either the plasma or the catalyst to function by itself. The combination of a plasmas with a catalyst opens the opportunity for a new class of catalysts that are potentially more durable, more active, more selective and more sulfur-tolerant compared to conventional lean-NO{sub x} catalysts.
Date: March 1, 1998
Creator: Penetrante, B.M.; Vogtlin, G.E.; Merritt, B.T. & Brusasco, R.M.
Partner: UNT Libraries Government Documents Department

Particulate emission characteristics of a port-fuel-injected SI engine

Description: Particulate emissions from spark-ignited (SI) engines have come under close scrutiny as they tend to be smaller than 50 nm, are composed mainly of volatile organic compounds, and are emitted in significant numbers. To assess the impact of such emissions, measurements were performed in the exhaust of a current-technology port-fuel-injected SI engine, which was operated at various steady-state conditions. To gain further insights into the particulate formation mechanisms, measurements were also performed upstream of the catalytic converter. At all engine speeds, a general trend was observed in the number densities and mass concentrations: a moderate increase at low loads followed by a decrease at mid-range loads, which was followed by a steep increase at high loads. Within reasonable bounds, one could attribute such a trend to three different mechanisms. An unidentified mechanism at low loads results in particulate emissions monotonically increasing with load. At medium loads, wherein the engine operates close to stoichiometric conditions, high exhaust temperatures lead to particulate oxidation. At high loads, combustion occurs mostly under fuel-rich conditions, and the contribution from combustion soot becomes significant. Estimates of the number of particles emitted per kilometer by a vehicle carrying the current test engine were found to be lower than those from a comparable diesel vehicle by three orders of magnitude. Similar estimates for mass emissions (grams of particulates emitted per kilometer) were found to be two orders of magnitude lower than the future regulated emission value of 0.006 (g/km) for light-duty diesel vehicles. Moreover, considering the fact that these particles have typical lifetimes of 15 min, the health hazard from particulate emissions from SI engines appears to be low.
Date: March 2, 2000
Creator: Gupta, S.; Poola, R.; Lee, K. O. & Sekar, R.
Partner: UNT Libraries Government Documents Department

Removal of nitrogen oxides from a gas stream by using monatomic nitrogen induced by a pulsed arc

Description: The effectiveness of N atoms, nitrogen, induced by a pulsed electric arc, in reducing nitric oxide (NO) and nitrogen dioxide (NO{sub 2}) was studied. Goal is reduction of nitrogen oxides (NO{sub x}) from automobile emissions by this alternative technique, which can be cost-effective and has the potential to reduce NO{sub x} in exhaust containing up to 10% oxygen. Initial tests with 100, 500, and 1,000 ppM NO in pure nitrogen have shown that a greater than 50% reduction of NO/NO{sub x} is readily achievable. At an NO concentration of 100 ppM, a greater than 90% NO/NO{sub x} reduction was recorded. Different flow rates of the monatomic nitrogen and the gas stream were tested. The flow rate of the monatomic nitrogen did not have a significant effect on the reduction efficiency, unlike the flow rate of the gas stream. The cross-sectional flow area of the gas stream was varied in order to assess whether the proximity of the gas stream to the arc would affect NO/NO{sub x} reduction. Results of the tests revealed that the smallest cross-sectional area had the best reduction, but also the highest chance of contacting the arc. The composition of the gas stream was also varied to elucidate the effects of N0{sub 2} and 0{sub 2} on the NO/NO{sub x} reduction efficiency. When N0{sub 2} and 0{sub 2} are present in the gas stream, both gases lower the reduction efficiency significantly by creating more NO or N0{sub 2}. Experiments are continuing to improve the reduction efficiency. The electrical power, a function of pulse frequency, voltage, and current, was treated as a key parameter in the investigation. The power consumption of the high-voltage purser apparatus for a 100-kW engine was estimated to be 3 kW.
Date: January 1, 1995
Creator: Ng, H.K.; Novick, V.J.; Sekar, R.R.; Pierucci, K.A. & Geise, M.F.
Partner: UNT Libraries Government Documents Department

Second Generation Advanced Reburning for High Efficiency NOx Control

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+% NO{sub x} control in coal-fired boilers at a significantly lower cost than SCR. The twelfth reporting period in Phase II (July 3-October 15, 2000) included design validation AR-Lean tests (Task No.2.6) in the 10 x 10{sup 6} Btu/hr Tower Furnace. The objective of tests was to determine the efficiency of AR-Lean at higher than optimum OFA/N-Agent injection temperatures in large pilot-scale combustion facility. Tests demonstrated that co-injection of urea with overfire air resulted in NO{sub x} reduction. However, observed NO{sub x} reduction was smaller than that under optimum conditions.
Date: September 30, 2000
Creator: Payne, Roy; Swanson, Lary; Marquez, Antonio; Chang, Ary; Zamansky, Vladimir M.; Maly, Pete M. et al.
Partner: UNT Libraries Government Documents Department

Second Generation Advanced Reburning for High Efficiency NOx Control

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+ NO{sub x} control in coal-fired boilers at a significantly lower cost than SCR. The eleventh reporting period in Phase II (April 1-June 30, 2000) included design validation AR-Lean tests (Task 2.6) in the 10 x 10{sup 6} Btu/hr Tower Furnace. The objective of tests was to determine the efficiency of AR-Lean at higher than optimum OFA/N-Agent injection temperatures in large pilot-scale combustion facility. Tests demonstrated that co-injection of urea with overfire air resulted in NO{sub x} reduction. However, observed NO{sub x} reduction was smaller than that under optimum conditions.
Date: June 30, 2000
Creator: Zamansky, Vladimir
Partner: UNT Libraries Government Documents Department

Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

Description: This report highlights work done on a project intended to lower the cost of environmental compliance and expedite project permitting for Exploration and Production (E&amp;P) operators by identifying, developing, testing, and commercializing emissions control and monitoring technologies. Promising technologies have already been identified and developed. Current work focuses on testing these promising technologies. Specifically, several technologies are being tested in the laboratory for application to lean-burn engines or fully characterized on-site for use with rich-burn engines. Upon completion of these tests, the most cost-effective and robust technologies will be tested in the field and commercialization will ensue. During this quarter, progress in laboratory testing for lean-burn engines was limited by maintenance issues on the KSU Ajax DP-115. The difficulties that required maintenance to be performed will likely require that the 180 psig prototype valve be tested in the future, if possible. The maintenance was performed, and it is expected that the Ajax will be available for testing in the coming quarter. Although laboratory testing was slowed as a result of maintenance issues, progress in experimental characterization of technologies has been significant. NSCR systems will be characterized as applied to rich-burn engines on-site. This characterization will ensure high-quality data in final field testing on rich-burn engines and is considered to be essential, despite that the work requires the delay of official field testing until 2008. Many preliminary and administrative tasks have been completed, including initial site selection, official proposal submittal, and beginning a process to approve necessary changes to installed field engines.
Date: December 31, 2006
Creator: Chapman, Kirby S. & Nuss-Warren, Sarah R.
Partner: UNT Libraries Government Documents Department