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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Fiscalini Farms Biomass Energy Project

In this final report describes and documents research that was conducted by the Ecological Engineering Research Program (EERP) at the University of the Pacific (Stockton, CA) under subcontract to Fiscalini Farms LP for work under the Assistance Agreement DE-EE0001895 'Measurement and Evaluation of a Dairy Anaerobic Digestion/Power Generation System' from the United States Department of Energy, National Energy Technology Laboratory. Fiscalini Farms is operating a 710 kW biomass-energy power plant that uses bio-methane, generated from plant biomass, cheese whey, and cattle manure via mesophilic anaerobic digestion, to produce electricity using an internal combustion engine. The primary objectives of the project were to document baseline conditions for the anaerobic digester and the combined heat and power (CHP) system used for the dairy-based biomass-energy production. The baseline condition of the plant was evaluated in the context of regulatory and economic constraints. In this final report, the operation of the plant between start-up in 2009 and operation in 2010 are documented and an interpretation of the technical data is provided. An economic analysis of the biomass energy system was previously completed (Appendix A) and the results from that study are discussed briefly in this report. Results from the start-up and first year of operation indicate that mesophilic anaerobic digestion of agricultural biomass, combined with an internal combustion engine, is a reliable source of alternative electrical production. A major advantage of biomass energy facilities located on dairy farms appears to be their inherent stability and ability to produce a consistent, 24 hour supply of electricity. However, technical analysis indicated that the Fiscalini Farms system was operating below capacity and that economic sustainability would be improved by increasing loading of feedstocks to the digester. Additional operational modifications, such as increased utilization of waste heat and better documentation of potential of carbon credits, would also improve the economic outlook. Analysis of baseline operational conditions indicated that a reduction in methane emissions and other greenhouse gas savings resulted from implementation of the project. The project results indicate that using anaerobic digestion to produce bio-methane from agricultural biomass is a promising source of electricity, but that significant challenges need to be addressed before dairy-based biomass energy production can be fully integrated into an alternative energy economy. The biomass energy facility was found to be operating undercapacity. Economic analysis indicated a positive economic sustainability, even at the reduced power production levels demonstrated during the baseline period. However, increasing methane generation capacity (via the importation of biomass codigestate) will be critical for increasing electricity output and improving the long-term economic sustainability of the operation. Dairy-based biomass energy plants are operating under strict environmental regulations applicable to both power-production and confined animal facilities and novel approached are being applied to maintain minimal environmental impacts. The use of selective catalytic reduction (SCR) for nitrous oxide control and a biological hydrogen sulfide control system were tested at this facility. Results from this study suggest that biomass energy systems can be compliant with reasonable scientifically based air and water pollution control regulations. The most significant challenge for the development of biomass energy as a viable component of power production on a regional scale is likely to be the availability of energy-rich organic feedstocks. Additionally, there needs to be further development of regional expertise in digester and power plant operations. At the Fiscalini facility, power production was limited by the availability of biomass for methane generation, not the designed system capacity. During the baseline study period, feedstocks included manure, sudan grass silage, and refused-feed. The ability of the dairy to produce silage in excess of on-site feed requirements limited power production. The availability of biomass energy crops and alternative feedstocks, such as agricultural and food wastes, will be a major determinant to the economic and environmental sustainability of biomass based electricity production.

03 NATURAL GAS↗
DOE OSTI2025

Vehicle-Cycle Inventory for Type C School Buses & Intra-City Transit Buses

This report documents the new inventory incorporated into the Research and Development version of Greenhouse gases, Regulated Emissions, and Energy use in Technologies (R&D GREET) 2025 model for the vehicle cycle of Type C school buses and intracity transit buses. The transportation sector contributes significantly to the United States’ energy consumption and resultant emissions (EPA, 2025a). However, public transit plays an important role in mitigating these impacts because it consumes a relatively low amount of energy per passenger (Congressional Budget Office, 2022). Public transit is widely used in the United States; more than 500,000 school buses (EPA, 2025b) and ~75,000 service buses (American Public Transportation Association, 2025) operate in the nation. These are primarily internal combustion engine vehicles (ICEVs) powered by diesel. Original equipment manufacturers (OEMs) are making efforts to electrify U.S. bus fleets by using batteries as a propulsion system to replace internal combustion engines. Electrification can reduce tailpipe emissions, such as particulate matter (with a diameter ≤10 µm [PM 10 ] and with a diameter ≤2.5 µm [PM 2.5 ]) and nitrogen oxides (Jonas et al., 2025; Martinez and Samaras, 2024; EPA, 2025b; Wayne et al., 2009). Hence, any energy and emission impact analysis of public transit must consider both conventional ICEVs and upcoming electric vehicle (EV) options for the school and transit buses that dominate this landscape. To understand the detailed environmental impact profiles of ICEV and EV school and transit buses, it is necessary to conduct a thorough analysis covering both vehicle manufacturing and vehicle use stages. The current literature lacks a detailed vehicle-cycle inventory for school and transit buses, which makes this kind of comparison difficult. To overcome this gap, we developed a comprehensive vehicle-cycle model for school and transit buses in Argonne’s R&D GREET 2025 model. The model is flexible in handling user inputs for key assumptions, such as component weights and material compositions, upstream energy sources for material processing, and vehicle operating parameters, to understand their impacts on energy use and emissions for both school and transit buses. This report is organized as follows: Section 2 provides details on the modeling approach and vehicle specifications (weights and composition of different vehicle components, and vehicle operating parameters) for both school and transit buses. Section 3 provides details on vehicle assembly, disposal, and recycling (ADR) approaches for the two buses. Section 4 includes details about their incorporation into the R&D GREET model.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2011

Methodology for Calculating Cost-per-Mile for Current and Future Vehicle Powertrain Technologies, with Projections to 2024: Preprint

Currently, several cost-per-mile calculators exist that can provide estimates of acquisition and operating costs for consumers and fleets. However, these calculators are limited in their ability to determine the difference in cost per mile for consumer versus fleet ownership, to calculate the costs beyond one ownership period, to show the sensitivity of the cost per mile to the annual vehiclemiles traveled (VMT), and to estimate future increases in operating and ownership costs. Oftentimes, these tools apply a constant percentage increase over the time period of vehicle operation, or in some cases, no increase in direct costs at all over time. A more accurate cost-per-mile calculator has been developed that allows the user to analyze these costs for both consumers and fleets. Thecalculator was developed to allow simultaneous comparisons of conventional light-duty internal combustion engine (ICE) vehicles, mild and full hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs). This paper is a summary of the development by the authors of a more accurate cost-per-mile calculator that allows the user to analyze vehicle acquisition and operating costs for both consumerand fleets. Cost-per-mile results are reported for consumer-operated vehicles travelling 15,000 miles per year and for fleets travelling 25,000 miles per year.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2020

Assessment of turbulent combustion models for simulating pre-chamber ignition in a natural gas engine

Lean combustion in an internal combustion engine is a promising strategy to increase thermal efficiency by leveraging a more favorable specific heat ratio of the fresh mixture and simultaneously suppressing the heat losses to the cylinder wall. However, unstable ignition events and slow flame propagation at fuel-lean condition lead to high cycle-to-cycle variability and hence limit the high-efficiency engine operating range. Pre-chamber ignition is considered an effective concept to extend the lean operating limit, by providing spatially distributed ignition with multiple turbulent flame-jets and enabling faster combustion rate compared to the conventional spark ignition approach. From a numerical modeling perspective, to date, still the science base and available simulation tools are inadequate for understanding and predicting the combustion processes in pre-chamber ignited engines. In this paper, conceptually different RANS combustion models widely adopted in the engine modeling community were used to simulate the ignition and combustion processes in a medium-duty natural gas engine with a pre-chamber spark-ignition system. A flamelet-based turbulent combustion model, i.e., G-equation, and a multi-zone well-stirred reactor model were employed for the multi-dimensional study. Simulation results were compared with experimental data in terms of in-cylinder pressure and heat release rate. Finally, the analysis of the performance of the two models is carried out to highlight the strengths and limitations of the two formulations respectively.

combustion model evaluation↗
DOE OSTI2017

Laser modification of frictional surfaces

Improvement in the physicomechanical properties and frictional characteristics of cylinder and piston surfaces in airplane internal-combustion engines is considered. A method of developing recommendations regarding the optimization of laser treatment is proposed on the basis of experiments and a model of surface wear.

42 ENGINEERING↗
DOE OSTI2017

System for cooling hybrid vehicle electronics, method for cooling hybrid vehicle electronics

The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175.degree. C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

System for cooling hybrid vehicle electronics, method for cooling hybrid vehicle electronics

The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175° C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

France, David M.↗
DOE OSTI2011

Application of accelerometers for sensing combustion phasing of an advanced combustion engine

This paper evaluates the ability of accelerometers to detect combustion phasing of a single-cylinder air-cooled internal combustion engine undergoing homogeneous charge compression ignition. Metrics derived from the measured surface acceleration waveform, surface velocity, and the surface-specific kinetic energy were compared to the 50 per cent energy release location (CA50) on a cyclic basis for three different experimental test cases. The peak surface velocity location showed a robust ability to detect CA50 on a cyclic basis for short combustion durations. Finally, using a simple single-degree-of-freedom vibration model, it is shown the impulsive nature of the combustion load and the natural frequency of the engine structure governs when the peak velocity location will indeed robustly detect CA50 on a on a per-engine cycle basis.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2011

E85 Optimized Engine through Boosting, Spray-Optimized DIG, VCR and Variable Valvetrain

The use of biofuels for internal combustion engines has several well published advantages. The biofuels, made from biological sources such as corn or sugar cane, are renewable resources that reduce the dependence on fossil fuels. Fuels from agricultural sources can therefore reduce a countries energy dependency on other nations. Biofuels also have been shown to reduce CO2 emissions into the atmosphere compared to traditional fossil based fuels. Because of these benefits several countries have set targets for the use of biofuels, especially ethanol, in their transportation fuels. Small percentages of ethanol are common place in gasoline but are typically limited to 5 to 8% by volume. Greater benefits are possible from higher concentrations and some countries such as the US and Sweden have encouraged the production of vehicles capable of operating on E85 (85% denatured ethanol and 15% gasoline). E85 capable vehicles are normally equipped to run the higher levels of ethanol by employing modified fuel delivery systems that can withstand the highly corrosive nature of the alcohol. These vehicles are not however equipped to take full advantage of ethanol's properties during the combustion process. Ethanol has a much higher blend research octane number than gasoline. This allows the use of higher engine compression ratios and spark advance which result in more efficient engine operation. Ethanol's latent heat of vaporization is also much higher that gasoline. This higher heat of vaporization cools the engine intake charge which also allows the engine compression ratio to be increased even further. An engine that is optimized for operation on high concentrations of ethanol therefore will have compression ratios that are too high to avoid spark knock (pre-ignition) if run on gasoline or a gasoline/ethanol blend that has a low percentage alcohol. An engine was developed during this project to leverage the improved evaporative cooling and high octane of E85 to improve fuel economy and offset E85's lower energy content. A 2.0 L production Direct Injection gasoline, (DIg) engine employing Dual Independent Cam Phasing, (DICP) and turbo charging was used as the base engine. Modified pistons were used to increase the geometric compression ratio from 9.2:1 to 11.85:1 by modifying the pistons and adding advanced valvetrain to proved control of displacement and effective compression ratio through valve timing control. The advanced valvetrain utilized Delphi's two step valvetrain hardware and intake cam phaser with increased phasing authority of 80 crank angle degrees. Using this hardware the engine was capable of operating knock free on all fuels tested from E0-E85 by controlling effective compression ratio using a Late Intake Valve Closing, (LIVC) strategy. The LIVC strategy results in changes in the trapped displacement such that knock limited torque for gasoline is significantly lower than E85. The use of spark retard to control knock enables higher peak torque for knock limited fuels, however a loss in efficiency results. For gasoline and E10 fuels, full effective displacement could not be reached before spark retard produced a net loss in torque. The use of an Early Intake Valve Closing, (EIVC) strategy resulted in an improvement of engine efficiency at low to mid loads for all fuels tested from E0- E85. Further the use of valve deactivation, to a single intake valve, improved combustion stability and enabled throttle-less operation down to less than 2 bar BMEP. Slight throttling to trap internal residual provided additional reductions in fuel consumption. To fully leverage the benefits of E85, or ethanol blends above E10, would require a vehicle level approach that would take advantage of the improved low end torque that is possible with E85. Operating the engine at reduced speeds and using advanced transmissions (6 speeds or higher) would provide a responsive efficient driving experience to the customer. The vehicle shift and torque converter lockup points for high ethanol blends could take advantage of the significant efficiency advantage of down-speeding and operating at higher loads to deliver the required power.

02 PETROLEUM↗
DOE OSTI2022

A detailed experimental and modeling comparison of molecular radiative heat loss in a spark-ignition engine

Radiative heat transfer has been chiefly considered negligible in internal combustion engines, except for Diesel engines where soot radiation was recognized as a significant radiative transfer source. Only more recently, detailed simulations have shown that molecular radiation can be substantial as well. In extension to this, molecular radiative heat transfer can reach detectable levels of about 5–10% of the total heat transfer in spark-ignited engines. The broadband radiative nature of the significant emitting molecules, carbon dioxide and water, makes it necessary to address whether radiative trapping plays a substantial role in either total heat loss or energy redistribution within the cylinder. An experimental setup that allows measurements of the infrared emissions at a 2-crank-angle-degree resolution was developed to determine the importance of radiative trapping by carbon dioxide and water. Measurements were conducted in the well-characterized and documented TCC-III engine at the University of Michigan. The engine operated on a stoichiometric propane/air mixture at a speed of 1,300 RPM. Large Eddy Simulations with added line-by-line photon Monte-Carlo simulations of the molecular radiation were an integral part of this study to plan and devise the measurements. Post-processing of the simulation data included an accurate representation of the experimental volume from where infrared signals are collected. Additionally, the experimental data were used for validation of the photon Monte-Carlo simulations. Joint analysis of experimental and simulated spectra allowed quantifying the significance of radiative trapping. Results show the significant role of radiative trapping when predicting radiative heat transfer in the TCC-III engine.

42 ENGINEERING↗
DOE OSTI2023

EVI-Pro for Bogota Columbia [Slides]

The transportation sector is one of the largest producers of greenhouse gas emissions globally, with 37% of global CO 2 emissions in 2021 according to the International Energy Agency. Transitioning from internal combustion engine vehicles powered by fossil fuels to electrified transportation is a critical component in reducing those emissions significantly over the coming decades and avoiding the worst consequences of climate change. With governments and automakers increasingly announcing electrification targets and a progression away from the production and sale of internal combustion engine vehicles, a robust network of charging infrastructure must be built to enable the widespread use of electric vehicles (EVs). Some of the greatest hurdles to EV deployment are linked to the buildout of the required charging infrastructure including where it should be built, what types and how much charging would be optimal given high costs of installation, and the impact on the electrical grid. To this end, the National Renewable Energy Laboratory (NREL) conducts extensive research on EV deployment, including the development of the EVI-Pro model used to plan the future buildout of charging infrastructure given the travel patterns in a region. This document summarizes work done by NREL in the Bogotá, Colombia region to help Colombia plan for its EV deployment goals.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2025

Multidimensional Modeling of Mixture Formation in a Hydrogen-Fueled Heavy-Duty Optical Engine With Direct Injection

Hydrogen (H 2 ), as a carbon-free fuel, is considered as one of the most promising solutions to reduce the carbon footprint of hard-to-decarbonize energy and transportation sectors. As such, hydrogen-fueled internal combustion engines (H 2 ICEs) have recently been receiving increasing attention, particularly in applications such as on-road/off-road heavy-duty transport and combined heat and power. The direct injection (DI) of gaseous hydrogen into the combustion chamber offers great potential for achieving high power density and high engine efficiency, while mitigating the risk of backfire and reducing pre-ignition. However, the numerical simulation of H 2 DI system remains a formidable challenge associated with the high computational cost of reproducing compressible supersonic flow and shocks in narrow injector passages and in near-nozzle regions. In general, there is a lack of well-established and validated practices for the modeling of high-pressure H 2 DI in large-bore engines. Here, to this end, this study focuses on computational fluid dynamics (CFD) modeling of the mixture formation process in a heavy-duty optical engine employing a medium-pressure H 2 DI system. Both large eddy simulations (LES) and Reynolds Averaged Navier–Stokes (RANS) simulations are performed and evaluated against optical data. Gaseous hydrogen is injected into the combustion chamber via a centrally located outward opening hollow-cone injector at a pressure of 40 bar. Simulations are carried out for two injection timings, namely, −120 and −60 °CA. The numerical predictions for H 2 distribution in different horizontal and vertical planes during the compression stroke are systematically compared against optical data obtained through planar laser-induced fluorescence (PLIF) measurements. Overall, the LES approach using the Dynamic Structure model is found to have good predictive capabilities for the early jet penetration in terms of length and shape, as well as the later H 2 distributions. However, the unsteady RANS approach with the renormalization group $k - ϵ$ model, which is widely used by industry to model heavy-duty ICEs, significantly underpredicts the H 2 mixing, even at similar mesh resolution to that used in LES. These results indicate that there is a need for the improvement of mixing submodels within the RANS approach when applied to H 2 DI simulations.

LES↗
DOE OSTI2014

Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis

Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel-economy. One new advanced engine strategy utilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.

42 ENGINEERING↗
DOE OSTI2021

Investigating realistic anode off-gas combustion in SOFC/ICE hybrid systems: mini review and experimental evaluation

Solid oxide fuel cells (SOFCs) have been deployed in hybrid decentralized energy systems, in which they are directly coupled to internal combustion engines (ICEs). Prior research indicated that the anode tailgas exiting the SOFC stack should be additionally exploited due to its high energy value, with typical ICE operation favoring hybridization due to matching thermodynamic conditions during operation. Consequently, extensive research has been performed, in which engines are positioned downstream the SOFC subsystem, operating in several modes of combustion, with the most prevalent being homogeneous compression ignition (HCCI) and spark ignition (SI). Experiments were performed in a 3-cylinder ICE operating in the latter modus operandi, where the anode tailgas was assimilated by mixing syngas (H 2 : 33.9%, CO: 15.6%, CO 2 : 50.5%) with three different water vapor flowrates in the engine’s intake. While increased vapor content significantly undermined engine performance, brake thermal efficiency (BTE) surpassed 34% in the best case scenario, which outperformed the majority of engines operating under similar operating conditions, as determined from the conducted literature review. Nevertheless, the best performing application was identified operating under HCCI, in which diesel reformates assimilating SOFC anode tailgas, fueled a heavy duty ICE (17:1), and gross indicated thermal efficiency ([Formula: see text]) of 48.8% was achieved, with the same engine exhibiting identical performance when operating in reactivity-controlled compression ignition (RCCI). Overall, emissions in terms of NO x and CO were minimal, especially in SI engines, while unburned hydrocarbons (UHC) were non-existent due to the absence of hydrocarbons in the assessed reformates.

Engineering↗
DOE OSTI2012

KIVA-Update June 2012

Development of a fractional step, a Predictor-Corrector Split (PCS), or what is often known as a projection method combining hp-adaptive system in a Finite Element Method (FEM) for combustion modeling has been achieved. This model will advance the accuracy and range of applicability of the KIVA combustion model and software used typically for internal combustion engine modeling. This abstract describes a PCS hp-adaptive FEM model for turbulent reactive flow spanning all velocity regimes and fluids that is being developed for the new KIVA combustion algorithm, particularly for internal combustion engines. The method and general solver is applicable to Newtonian and non- Newtonian fluids and also for incompressible solids, porous media, solidification modeling, and fluid structure interaction problems. The fuel injection and injector modeling could easily benefit from the capability of solving the fluid structure interaction problem in an injector, helping to understand cycle to cycle variation and cavitation. This is just one example where the new algorithm differs from the old, in addition to handling Conjugate Heat Transfer (CHT), although there a numerous features that makes the new system more robust and accurate. In these ways, the PCS hp-adaptive algorithm does not compete with commercial software packages, those often used in conjunction with the currently distributed KIVA codes for engine combustion modeling. In addition, choosing a local ALE method on immersed moving parts represented by overset grid that is 2nd order spatially accurate, allows for easy grid generation from CAD to fluid grid while also provide for robustness in handling any possible moving parts configuration without any code modifications. The combined methods employed produce a minimal amount of computational effort as compared to fully resolved grids at the same accuracy. We demonstrate the solver on benchmark problems for the all flow regimes as follows: (1) 2-D backward-facing step using h-adaption, (2) 2-D driven cavity, (3) 2-D natural convection in a differentially heat cavity with h-adaptation, (4) NACA 0012 airfoil in 2-D, (5) supersonic flows over compression ramps, (6) 2-D natural convection in a differentially heat cavity with hp-adaptation, (7) 3-D natural convection in a differentially heat sphere with hp-adaptation. In addition, we show the new moving parts algorithm for working for a 2-D piston; the immersed moving parts method also for valves and pistons, vanes, etc... The movement is performed using an overset grid method and is 2nd order accurate in space, and never produces a tangle grid, that is, robust system at any resolution and any parts configuration. We also show CHT for the currently distributed KIVA-4mpi software and some fairly automatic grid generation using Sandia's Cubit unstructured grid generator. A new electronic web-based manual for KIVA-4 has been developed as well.

02 PETROLEUM↗
DOE OSTI2020

DICE-gas turbine compound reheat combined cycle

Coal-fired Direct Injection Carbon Engine – Gas Turbine (DICE-GT) Compound-Reheat Combined Cycle (CRCC), is a combined cycle power plant comprising a multiplicity of coal-fired reciprocating internal combustion engines (RICE), which is commonly referred to by the acronym DICE (Direct Injection Carbon Engine); a natural gas-fired gas turbine (turbine and combustor); a heat recovery steam generator (HRSG); a steam turbine generator; and an integrally geared and intercooled centrifugal air compressor. Finally, the concept uses coal-water slurry/fluid in the DICE and natural gas (or hydrogen) in the gas turbine for unmatched efficiency (well above 50% net LHV) and modularity (block sizes of 120, 240 and 360 MW) with easy adaptability to carbon capture and sequestration with minimal additional cost, complexity and performance hit.

42 ENGINEERING↗
DOE OSTI2011

Enabling High Efficiency Ethanol Engines

Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy is due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗