bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Hydrogen and Hydrogen Mixtures in Gas Engines and Potentials of NOx Emissions
Authors: Herdin Gu¨nther , Gruber Friedrich , Klausner Johann , Robitschko Reinhard , Plohberger Diethard
Published: November 2008

In the utilization of gas mixtures with high amounts of H2 there is a great number of applications of such special gases, for example several gases that result from pyrolysis or the gasification of biomass or thermally utilizable waste substances. What is special about gases containing H2 is the shifting of the lean-burn limit towards greater amounts of excess air than is the case with natural gas. This effect causes the mean combustion chamber temperatures to sink and the NOx emissions are reduced to a very low level. Depending on the amount of hydrogen and other gas components it is possible to attain NOx values of under 5 ppm. Also very interesting is the property of these H2-rich gas mixtures to have a neutral influence on the degree of efficiency (even with extremely high amounts of excess air). The background of this property lies in the considerably higher laminar flame speed of hydrogen. Especially in the lower and medium load range this effect can be utilized directly; in this regard it was possible to measure an efficiency of up to 2% points better with operation using pure hydrogen compared with NG. Higher BMEPs are also only possible to a limited extent with extreme lean-burn operation because the knocking limit is reached. Furthermore, the dimensioning of the turbocharger is becoming more and more difficult because the exhaust gas temperature upstream from the turbine sinks and as a result also the thermal energy is available only to a limited degree. When dealing with high amounts of H2, from the standpoint of operational reliability it is necessary to modify the mixture formation before the TC position to the pressure side position upstream from the intake valve, because otherwise load fluctuations could lead to undesired rich mixtures in the inlet side. As a result, backfiring could occur that could also cause engine damage and that could be hazardous for personnel. From the viewpoint of GE Jenbacher H2 technology can be applied relatively quickly to reduce NOx emissions. Especially when considering the “life cycle costs”, this potential solution is superior to concepts functioning on the basis of stoichiometric combustion. The next step that can be mentioned is the concept of fuel-reforming integrated in the engine — here a part of the exhaust gas energy is used to reform a relatively small amount of natural gas to a CH4/H2/CO mixture. With this concept, alongside the dramatic reduction of NOx emissions to the level of fuel cells, the degree of efficiency can be improved by about 2 to 3% points by means of “energy shifting”.
The Effects of Oxygen Enrichment of Combustion Air for Spark-Ignition Engines Using a Thermodynamic Cycle Simulation
Authors: Caton Jerald A.
Published: November 2008

A thermodynamic cycle simulation was used to examine the effects of oxygen enriched combustion air on engine performance for a range of operating conditions and for different sized engines. The use of oxygen enriched combustion air will have a direct effect on the combustion process and on the overall engine thermodynamics. For example, for cases with higher inlet oxygen concentration (and hence less nitrogen dilution), for the same operating conditions, the combustion gas temperatures and engine cylinder heat losses will be higher. In addition, the engine using oxygen enriched combustion air will be smaller than an engine using normal air for the same power output. The major objective of this study was to quantify these expectations for a range of operating conditions. One special feature of a portion of the current study is the constant engine power output by decreasing engine size as the oxygen concentration increased in the combustion air. Results include detail thermodynamic results of temperatures, pressures and properties as functions of the oxygen concentration of the combustion air. Results also include engine performance parameters such as power, torque, fuel consumption, thermal efficiency, and exhaust temperatures. For one comparison, engine performance and fuel consumption were obtained for an equivalence ratio of 1.0, MBT spark timing, and 2500 rpm. For oxygen enriched combustion air with 32% oxygen, equal power output was obtained with 73% of the displaced volume (all else the same). For the higher oxygen case, the brake fuel consumption increased about 11% primarily due to higher heat losses and higher exhaust gas energy which were a consequence of the higher gas temperatures. For the MBT spark timing case, the nitric oxide emissions increased by about 11% as the oxygen concentration increases from 21% to 25%.
A Different Combustion Engine
Authors: Tort Oropeza Alejandro , Gonza´lez Oropeza Rogelio , Nu´n˜ez Orozco Fe´lix
Published: November 2008

This paper investigates the possibilities of an EXTERNAL COMBUSTION ENGINE (ECE) capable of attaining high thermodynamic efficiency and low emission of noxious gases. This ECE consists principally of an air compressor, a combustion chamber or combustor and an expansion or power cylinder. The compressed air is introduced into the combustor; the fuel is injected into the combustor, and a spark plug initiates the combustion. By performing the combustion in a combustor specially designed for that purpose, the combustion can be controlled and the generation of noxious gases can be reduced. The water that cools the jackets of the system is also injected into the combustor; by doing so, the temperature of the combustion products can be maintained at a value sufficiently low so as to minimize the formation of NOx, and at the same time, a significant part of the heat transmitted to the cooling water can be recuperated instead of being dissipated in a radiator. The water, already hot or evaporated, mixes with the combustion gases and expands in the power cylinder, participating in the generation of mechanical power. The efficiency of the cycle is increased.
Development and Application of a Complete Common-Rail Injection System Mathematical Model for Hydrodynamic Analysis and Diagnostics
Authors: Catania Andrea Emilio , Ferrari Alessandro , Manno Michele
Published: November 2008

A rather complete mathematical model for a Common Rail injection-system dynamics numerical simulation was developed to support experimentation, layout and control design, as well as performance optimization. The thermo-fluid dynamics of the hydraulic system components, including rail, connecting pipes and injectors was modeled in conjunction with the solenoid-circuit electromagnetics and the mechanics of mobile elements. Onedimensional flow equations in conservation form were used to simulate wave propagation phenomena throughout the high-pressure connecting pipes, including the feeding pipe of the injector nozzle. In order to simulate the temperature variations due to the fuel compressibility, the energy equation was used in addition to mass conservation and momentum balance equations. Besides, the possible cavitation phenomena effects on the mass flow rate through the injector bleed orifice and the nozzle holes were taken into account. A simple model of the electromagnetic driving circuit was used to predict the temporal distribution of the force acting on the pilot-valve anchor. It was based on the experimental time-histories of the current through the solenoid and of the associated voltage that is provided by the electronic control unit (ECU) to the solenoid valve. The numerical code was validated through the comparison of the prediction results with experimental data, that is, pressure, injected flow rate and needle lift time-histories, taken on a high performance test bench Moehwald-Bosch MEP2000-CA4000. The novel injection-system mathematical model was applied to the analysis of transient flows through the hydraulic circuit of a commercial multijet second-generation Common Rail system, paying specific attention to the wave propagation phenomena, to their dependence on solenoid energizing time and rail pressure, as well as to their effects on system performance. An insight was also given into the model capability of accurately predicting the wave dynamics effects on the rate and mass of fuel injected when the dwell time between two consecutive injections is varied.
Modeling the Effects of Variable Intake Valve Timing on Diesel HCCI Combustion at Varying Load, Speed and Boost Pressures
Authors: Dougan Caroline L. , Kong Song-Charng , Reitz Rolf D.
Published: November 2008

It is well known that homogeneous charge compression ignition (HCCI) operated engines have the potential to provide the efficiency of a typical diesel engine, but with very low NOx and Particulate Matter (PM) emissions. One of the main challenges with this type of engine, however, is that it can be difficult to control the combustion event, especially at high loads. The development of Variable Valve Timing (VVT) technology may offer an important advantage in the ability to control HCCI combustion. This work investigates the potential of using late intake valve closure times to delay auto-ignition and to expand the HCCI operation range through proper combustion control. A multi-dimensional KIVA/Chemkin model is used in conjunction with detailed chemical kinetics, based on an available n-heptane mechanism. The model is used to evaluate the effectiveness of late intake valve times as load, speed, and boost pressure conditions are varied. Furthermore, a larger understanding of diesel HCCI combustion is sought by investigating the major parameters affecting combustion control under these various operating conditions.
Cylinder Pressure Reconstruction From Crankshaft Speed Measurement in a Four-Stroke Single Cylinder Diesel Engine
Authors: Taraza Dinu , Henein Naeim A. , Gade Mangesh J. , Bryzik Walter
Published: November 2008

In a single cylinder engine, the speed fluctuation during steady state operation of the engine is influenced only by the cylinder pressure variation, the engine friction and the dynamics of the crankshaft. This dependency is used to explore the capacity of the lumped mass model of the crankshaft to correctly represent its dynamics. Based on this model, the paper establishes the relationship between the cylinder pressure variation and the crankshaft speed fluctuation for steady state operation of the single cylinder diesel engine. Correlations are determined between the harmonic components of the tangential gas-pressure and the harmonic components of the angular speed of the free end of the crankshaft. These correlations are used to predict the angular speed variation of the crankshaft, when the cylinder pressure variation is known, or to reconstruct the cylinder pressure when the crankshaft speed fluctuation is known. The reverse calculation of the pressure variation from the measured crankshaft speed is strongly influenced by the elastic characteristics of the crankshaft. If the stiffness of the crankshaft is not accurately determined, the results are significantly distorted.
Control of S.I. Engine Exhaust Emissions Using Non-Precious Catalyst (ZSM-5) Supported Bimetals and Noble Metals as Catalyst
Authors: Ghosh Bankim B. , Roy Prokash Chandra , Ghosh Mita , Bhattacharya Paritosh , Panua Rajsekhar , Santra Prasanta K.
Published: November 2008

Three Way Catalysts (TWC) are extensively used for simultaneous control of three principal automotive pollutants, namely carbon monoxide (CO), Oxides of nitrogen (NOx), and hydrocarbon (HC). Most of works on three way catalytic converter have been carried out with noble metals such as Platinum, Rhodium, and Iridium have been tried individually and in different combinations and proportions. Noble metal catalysts give very good performance of reduction of (NOx), CO and HC in the narrow range of stoichiometric Air Fuel ratio. Noble metals are costly and not abundantly available. These draw backs of the noble metal catalysts have inspired to search for the alternative catalysts, which will perform well over the wide range of A/F ratio and are economical and abundantly available. This paper discusses the processing of ZSM-5 to Cu-Ion- Exchanged ZSM-5, ZSM-5 supported Cu-Pt bimetallic catalyst and Cu-Rh bimetallic catalyst and placing them in a three staged converter to study the reduction efficiencies of exhaust emissions CO, NOx, and HC in a 800 cc Maruti S. I. Engine. The experiments are carried out at 1500 rpm, 17.6 A/F ratio, different catalyst bed temperatures and different engine loads 0%, 17.5%, 35%, 52.5%, and 70% of full load. The results achieved are the maximum reduction of CO 90% at 375 °C NOx 90% at 375 °C and HC 61% at 380 °C. The same engine was also run for Noble metal converter (NMC) (EURO-II) purchased from an authorized Maruti distributor and the maximum reduction achieved were CO 89% at 375° C, NOx 91% at 375° C, and HC 70% at 390° C comparable to Zeolite Catalytic Converter (ZCC).
Simulating Diesel Injectors Based on Different Cavitation Modeling Approaches
Authors: Li Ming , Mulemane Aditya , Lai Ming-Chia , Poola Ramesh
Published: November 2008

Computational Fluid Dynamic (CFD) results of different diesel fuel injector nozzle configurations using commercially available CFD codes are presented in this paper. The emphasis of the study is on comparing various cavitation modeling approaches by means of single-phase and two-phases. Results are compared for various diesel injector nozzles and observed to substantiate some of the experimentally established facts such as nozzle efficiency improvements by using techniques like rounded orifice inlets and conical orifices. The effects of needle lift and injection pressure on forming cavatation are also investigated. These simulation results agree well with the experimental results. Parameters like discharge coefficient, Cd and initial amplitude factor, amp0 are used to characterize the internal flow through the nozzle orifices.
Development of a Torsional Behavior Powertrain Model for Multiple Misfire Detection
Authors: Ponti Fabrizio
Published: November 2008

Many methodologies have been developed in the past for misfire detection purposes based on the analysis of the instantaneous engine speed. The missing combustion is usually detected thanks to the sudden engine speed decrease that takes place after a misfire event. Misfire detection and in particular cylinder isolation is anyhow still a challenging issue for engines with a high number of cylinders, for engine operating conditions at low load or high engine speed and for multiple misfire events. When a misfire event takes place in fact a torsional vibration is excited and shows up in the instantaneous engine speed waveform. If a multiple misfire occurs this torsional vibration is excited more than once in a very short time interval. The interaction among these successive vibrations can generate false alarms or misdetection, and an increased complexity when dealing with cylinder isolation. The paper presents the development of a powertrain torsional behavior model in order to identify the effects of a misfire event on the instantaneous engine speed signal. The identified waveform has then been used to filter out the torsional vibration effects in order to enlighten the missing combustions even in the case of multiple misfire events. The model response is also used to quicken the setup process for the detection algorithm employed, evaluating before running specific experimental tests on a test bench facility, the values for the threshold and the optimal setup of the procedure. The proposed algorithm is developed in this paper for an SI L4 engine; Its application to other engine configurations is possible, as it is also discussed in the paper.
Experimental Investigations on a Jatropha Oil Methyl Ester Fuelled Diesel Engine
Authors: Suryawanshi J. G. , Deshpande N. V.
Published: November 2008

Biodiesel is a non-toxic, biodegradable and renewable fuel with the potential to reduce engine exhaust emissions. The methyl ester of jatropha oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engines. The biodiesel is obtained through transesterification process. Various properties of the biodiesel thus developed are evaluated and compared in relation to that of conventional diesel oil. In the present investigation neat jatropha oil methyl ester (JME) as well as the blends of varying proportions of jatropha oil methyl ester (JME) and diesel were used to run a CI engine. A four stroke diesel engine having compression ratio of 17.5: 1 and developing 5.2 kW at 1500 rpm was used. Experiments were initially carried out on the engine at all loads using diesel to provide baseline data. Significant improvements in engine performance and emission characteristics were observed for JME fuel. The addition of jatropha methyl ester (JME) to diesel fuel has significantly reduced HC, CO, CO2 and smoke emissions but it increases the NOx emission slightly. The maximum reduction in smoke emission was observed by 35% in case of neat biodiesel operation as compared to diesel. The unburned hydrocarbon emission was drastically reduced by 53% for neat biodiesel operation.
Experimental and Numerical Study on Auto-Ignition and Combustion of Homogeneous Charge Compression Ignition Fueled With Dimethyl Ether
Authors: Luo Ma-Ji , Huang Zhen , Li De-Gang
Published: November 2008

Experimental study of the autoignition and combustion characteristics of homogeneous charge compression ignition (HCCI) was carried out on a modified diesel engine fuelled with Dimethyl ether (DME) fuel. Numerical simulations were also performed by using the detailed chemical kinetic mechanism of DME oxidation proposed by American Lawrence Livermore National Laboratory (LLNL). The experimental results indicate that HCCI combustion with DME fuel can be realized in diesel engine with a few modifications, and it has a two-stage heat release characteristics. The emissions of HCCI combustion with DME fuel can be characterized by free of smoke and near zero NOx. The simulation results suggest that the single-zone model can accurately predict the ignition timings, including the low temperature ignition and high temperature ignition. The variations of key species (such as H2O2, CH2O, OH, HCO, CH, etc) with crank angle during fuel oxidation and the effects of engine operating parameters on HCCI combustion can also be analyzed by numerical simulation.
A Quasi-Direct 3D Simulation of the Atomization of High-Speed Liquid Jets
Authors: Bianchi Gian Marco , Pelloni Piero , Toninel Stefano , Scardovelli Ruben , Leboissetier Anthony , Zaleski Stephan
Published: November 2008

In this paper a quasi-direct solution of transient three-dimensional CFD calculations based on a finite volume approach has been adopted to simulate the atomization process of high velocity liquid jets issuing an injector-like nozzle. An accurate Volume-of-Fluid (VOF) method is used to reconstruct and advect the interface between the liquid and gas phases. An extended mesh which includes the injector nozzle and the upstream plenum has been considered in order to investigate accurately the effect of nozzle flow conditions on the liquid jet atomization. Cavitation modeling has not been included in the present computations. Two different mean injection velocities, 150 m/s and 270 m/s, respectively, have been considered in the calculations as representative of semi-turbulent and fully-turbulent nozzle flow conditions. The liquid-to-gas density ratio is kept fixed at 57. The calculations show that atomisation is directly linked to the temporally and spatially correlated turbulence of the liquid jet. The bulk flow perturbation and the relaxation of the boundary layer have been found to be the basic mechanisms that generate surface perturbations of the liquid jet.
Coupled Model of Partially Flooded Lubrication and Oil Vaporization in an Internal Combustion Engine
Authors: Chui Boon-Keat , Schock Harold J. , Fedewa Andrew M. , Richardson Dan E. , Shaw Terry
Published: November 2008

The cylinder-kit assembly of an internal combustion engine experiences severe conditions during engine operation. The top compression ring, in particular, undergoes extreme stress directly from cylinder gas pressure, inertial and thermal loads. The top compression ring is often the most significantly affected piston ring, and one of the common resultant phenomena is high wear on the ring/bore surfaces. In many previous studies, the modeling of tribological phenomena at the top compression ring/bore region involves hydrodynamic and boundary lubrication, friction and wear. This present work accounts for an additional factor that may affect the piston ring/bore lubrication — the lubricant evaporative effect. A three-dimensional oil evaporative analysis is coupled into the calculation of mixed lubrication in a cyclic engine computation. The presence of the evaporation analysis allows the study of the temperature influence on the piston ring/bore lubrication in addition to its effect on oil viscosity. A prospective application of this model is in diesel engine analysis. Considering the broad operating range of modern diesel fuel injection systems, the injection timing can be made throughout the compression/expansion process. It is well demonstrated that certain areas of fuel injection operation can result in potential adverse consequences such as increased bore wear. A well known example is “bore wall fuel wetting.” Given concerns around the potential for wear-inducing interactions between the fuel injection plumes and the bore wall, we have explored a particular interaction: bore wear in response to an imposed local heating of the bore wall. The simulation result provides valuable insights on this interaction, in which higher bore wear is predicted around bore wall area with locally imposed wall heating.
The Operational Mixture Limits in Engines Fueled With Alternative Gaseous Fuels
Authors: Bade Shrestha S. O. , Karim Ghazi A.
Published: November 2008

The operation of engines whether spark ignition or compression ignition on a wide range of alternative gaseous fuels when using lean mixtures, can offer in principle distinct advantages. These include better economy, reduced emissions and improved engine operational life. However, there are distinct operational mixture limits below which acceptable steady engine performance cannot be sustained. These mixture limits are usually described as the “lean operational limits”, or loosely as the ignition limits which are a function of various operational and design parameters for the engine and fuel used. Through experimental investigation and analytical simulation of engine performance, relatively simple approximate procedures are described for predicting the operational mixture limits for both spark ignition and dual fuel compression ignition engines when using a range of common gaseous fuels such as natural gas/methane, propane, hydrogen and some of their mixtures. It is to be shown that good agreement between the predicted and corresponding experimental values can be obtained for a range of operating conditions for both types of engines.
Analytic Evaluation of Engine NVH Robustness Due to Manufacturing Variations
Authors: Batteh John J. , Tiller Michael M.
Published: November 2008

In an effort to improve quality, shorten engine development times, and reduce costly and time-consuming experimental work, analytic modeling is being used upstream in the product development process to evaluate engine robustness to noise factors. This paper describes a model-based method for evaluating engine NVH (Noise, Vibration, and Harshness) robustness due to manufacturing variations for a statistically significant engine population. A brief discussion of the cycle simulation model and its capabilities is included. The methodology consists of Monte Carlo simulations involving several noise factors to obtain the crank-angle resolved response of the combustion process and Fourier analysis of the resulting engine torque. Further analysis of the Fourier results leads to additional insights regarding the relative importance of and sensitivity to the individual noise factors. While the cost and resources required to experimentally evaluate a large engine population can be prohibitive, the analytical modeling proved to be a cost-effective way of analyzing the engine robustness taking into account manufacturing process capability.
HCCI Combustion With Various Fuels for Heavy and Light Duty Engines
Authors: Wagner Uwe , Anca Razvan , Velji Amin , Spicher Ulrich , Po¨ttker Sven , Merker Gu¨nter Peter
Published: November 2008

Single-cylinder engine tests were carried out to assess the influence of several engine operating parameters on HCCI combustion. For the experiments, single-cylinder engines with cylinder volumes of 0.5 and 2 liter were used to represent light and heavy duty application. Engine operation parameters like EGR-rate, air / fuel ratio and injection timing were varied to analyze their influence on the combustion while using different fuels such as Diesel, Gas to Liquid (GtL) and gasoline. Special emphasis was put on synthetic fuels as on the one hand these fuels offer the possibility to “design” them according to the combustion process requirement. On the other hand these GtL — or BtL (Biomass to Liquid) — fuels also lead to a higher independence from fossil fuels. Besides engine out emissions (CO2, CO, NOx, O2, HC, soot) and in-cylinder pressure indication for burning process analysis, optical measurement techniques were used for combustion analysis. With different optical probes in-cylinder soot concentration was measured with the Two-Color-Method. In addition UV radiation of OH-radicals was detected with an intensified camera. This procedure allows the differentiation between the beginning of combustion with OH-radical formation and a possible soot formation due to insufficient homogenization.
Performance and Emissions of Natural Gas and Hydrogen/Natural Gas Blended Fuels in Spark Ignition Engine
Authors: Anand G. , Ravi M. R. , Subrahmanyam J. P.
Published: November 2008

The basic intent of the present work is to evaluate the potential of using alternative gaseous fuels like compressed natural gas (CNG) and H2/CNG as a spark ignition (SI) engine (lean burn engines) fuel. Computer modeling of internal combustion engine is useful in understanding the complex processes that occur in the combustion chamber. This research deals with quasi-dimensional, two-zone thermodynamic simulation of four-stroke SI engine fueled with CNG and H2/CNG. The fraction of hydrogen in the H2/CNG blend, for simulation was varied from 0–60% by volume. The developed computer model has been used for the prediction of the combustion and emission characteristics of H2/CNG blended fuel in SI engines, which includes the power, thermal efficiency, cylinder pressure-crank angle history, exhaust emissions (NOx and CO), fuel consumption, combustion duration, ignition delay, etc. Predicted results indicate that the presence of hydrogen in H2/CNG blend can improve combustion duration as it has a higher flame speed. There are increases in oxides of nitrogen emissions, but decrease in carbon monoxide and hydrocarbon emissions, when comparing H2/CNG blended fuel to neat CNG. The validity of the model has been carried out by comparing the computed results with experimental data obtained under same engine setup and operating conditions. The results obtained from the theoretical model when compared with those from experimental ones show a good agreement. Also, the effects of the many operating parameters such as equivalence ratio, engine speed, and spark timing have been studied.
Split Injection Strategy for Prompt Cold Starting and Low White Smoke Emissions
Authors: Girotra Mukul , Zhong L. R. , Henein Naeim A. , Bryzik Walter
Published: November 2008

Progressing needs for prompt cold start of direct injection Diesel engines is the motivation behind this study. Authors have examined the autoignition and combustion processes in the early firing cycles of the engine and proposed a strategy to reduce the cranking period and the white smoke emissions. The concept is to accelerate the preparation of the combustible mixture during the cranking process. This is achieved by splitting the injected fuel in two parts and controlling its timing. The duration of the first injection is limited such that the spray penetrates through the combustion chamber and evaporates before it reaches the walls. The dwell between the two injections is adjusted to allow time for the first spray to mix with the fresh charge, form a combustible mixture and start producing the autoignition radicals. The second part would evaporate and autoignite by reacting with the radicals before it reaches the cool walls. The strategy is verified on a 1.2 L Ford Diata Diesel engine equipped with a first generation common rail fuel injection system. The cycle resolved hydrocarbons, and NOx emissions are measured by high response detectors. In addition, the mass and constituents of the white smoke are measured. All the experiments for this paper have been conducted after the engine has been soaked at the normal room temperature for at least eight hours. The results showed that there is an optimum strategy for the split injection that would minimize the cranking period and white smoke emissions.
Experimental Investigation of the Effect of EGR on Wear Performance of a Compression Ignition Engine
Authors: Singh Shrawan Kumar , Shrivastava Dhanajay Kumar , Agarwal Avinash Kumar , Sharma Mukesh
Published: November 2008

This investigation was aimed to investigate the effect of Exhaust Gas Recirculation (EGR) on wear of in-cylinder engine parts. EGR setup was fabricated for a two cylinder, air cooled, constant speed direct injection CI engine. Test setup was run for 96 hours with fixed loading cycles in two phases; normally operating condition (i.e. without EGR) and with 25% EGR rate. Addition of wear metals in the lubricating oil was investigated. Higher wear metal concentrations were found in the lubricating oil of EGR operated engine, which indicates higher wear of various engine parts. Weight loss of piston rings used in both the phases was compared to quantify the amount of wear of piston rings. To quantify the amount of wear of surface of cylinder liners, surface roughness parameters were measured at three positions (TDC, mid stroke, and BDC) on thrust and anti-thrust side. A qualitative analysis was also carried out by surface profiling and Scanning Electron Microscopy (SEM) at same locations.
Transient Heat Transfer of Piston/Rings/Liner System in Diesel Engines
Authors: Xiong Daxi , Tian Tian , Wong Victor
Published: November 2008

In diesel engines, transient heat transfer in the piston/rings/liner system greatly affects the performance of the engine, such as in carbon deposit buildup, microwelding, lubricant degradation, and changing mechanical properties of the materials. The current work aims at studying the local piston/rings/liner transient heat-transfer process by incorporating real time dynamics of the rings in sufficient detail. In the present study, several techniques have been adopted to simulate the transient heat transfer process, with fully-incorporated ring dynamics. These techniques include using the model/submodel approach, local refined mesh approach, and the virtual thermal conductivity approach. The transient temperature and heat flux profiles in the piston and rings are illustrated. The results show that the relative movement of the rings greatly affects the temperature/heat flux distribution and the peak temperature in the top ring. The friction heating between the top ring and the liner is also evaluated. The analysis demonstrates that under some extreme conditions when frictional heating reaches its peak value, some heat flux directs back to enter the ring.
Corrosion Study and Modification of Superheater Tubes in a Large Mass Burn WTE Boiler (Abstract)
Authors: Epelbaum Greg
Published: November 2008

Essex County Resource Recovery Facility (one of American Ref-Fuel Company’s six operating plants) has processing MSW capacity of approximately 2700 TPD and about 60% of this waste comes from NY City. Therefore, availability of the Essex plant boilers is very important not only for the company’s financial performance, it is also critical for the overall garbage disposal situation in the NYC Metropolitan area. One of the main factors affecting plant availability is boiler unscheduled downtime. The most recent data show that approximately 85% of Essex boilers unscheduled downtime is caused by tube failures, the majority of which occur in the superheater tubes. These tube failures are almost exclusively caused by fireside tube metal wastage driven by complicated mechanisms of corrosion in combination with local erosion. The corrosion is caused by chloride salts in the slag that deposits on the boiler tubes, coupled with high temperatures of flue gas going through the boiler. Corrosion rates are known to be very sensitive to flue gas temperature, tube metal temperature, heat flux, flow distribution. Erosion is typically caused by high velocities and flyash particle loading and trajectories. Extensive research revealed that in addition to this typical to WTE boiler corrosion/erosion mechanism, Essex boiler superheater tubes experienced a unique problem, resulting in tube overheating, accelerated wastage, and ultimate failure. In order to address this problem a modification plan was developed, which comprised several redesign options. A specially developed Three-dimensional Computational Fluid Dynamics (3-D CFD) model was utilized for comprehensive technical evaluation of the considered design options and for predicted performance simulations of the selected design at different operating conditions. The economical analysis, conducted in conjunction with the superheater redesign, provided financial justification for this project. The project has been recently executed, and field data collection is still in progress. Some preliminary data analyses have been performed. They have shown that the boiler performance after superheater modification is very close to the predicted target simulated by the CFD model. The plant and the company are already measuring financial benefits as a result of this project, the initial phase of which is presented in this paper.
Converting Army Waste to Fuel: Mobile Integrated Sustainable Energy Recovery
Authors: Powell Lisa Marie
Published: November 2008

This technology could change the logistics of solid waste management in the Army. Successful completion of the Mobile Integrated Sustainable Energy Recovery (MISER) project will lead to dramatic logistics changes. Where petroleum is now used to fuel generators, waste may be used in the future, substantially reducing solid waste disposal and transportation requirements.
A New Model for Waste-to-Energy Project Development (Abstract)
Authors: Pytlar Theodore S.
Published: November 2008

This presentation will address what is required to develop new Waste-To-Energy (WTE) projects by examining the model for project development followed during the 1980s and early 1990s. The setbacks and successes for that approach will be discussed and a new model for project development will be proposed. The original model will be exemplified by the “Resource Recovery Management Model,” developed by the Mitre Corporation for USEPA in 1980. That original model will be revisited and key project development actions and milestones set forth therein will be reviewed and discussed with regard to how they should be revised in order to arrive at a new model appropriate to current conditions. WTE development and operational experience gained during the previous twenty (20) years will be the basis for the updated model.
Waste to Energy in the 21st Century: Getting New Projects/Expansions off the Ground — Key Ingredients to a Successful Action Plan (Abstract)
Authors: Worster Shawn
Published: November 2008

These are critical times for users and vendors of waste-to energy technologies in the US. Many of the existing long term contracts entered into during the early to mid 80’s are nearing their end. Communities are facing the need to decide what to do with that portion of their waste stream remaining after they reduce, reuse and recycle. That effort includes determining the role that waste-to-energy will play in their 21st Century integrated solid waste management program and the nature of the contractual relationships that will define how it is managed.
The Puzzle of Drastic Reduction of Point Source Emissions and Continuing High Deposition of Mercury in Florida
Authors: Themelis N. J.
Published: November 2008

This report shows that the combined emissions of mercury from major point sources of mercury in Florida decreased from about 4.8 short tons in 1994 to 1.3 tons in recent years. A similar reduction of mercury emissions was reported by Florida DEP for south Florida where the Everglades Park is located: Point sources of emissions decreased from a high of 3.4 short tons (3,100 kg) of mercury in 1991 to 0.22 tons (204 kg) in 2000. The Florida DEP study of the Everglades also showed that the mercury concentrations in largemouth bass and in great egret nestlings decreased by a factor of six between 1991 and 2000. On the other hand, our analysis of 330 sets of weekly mercury deposition data, obtained by the Everglades station of the national Mercury Deposition Network (MDN) showed that the annual average deposition in the Everglades did not change significantly from December 1995 to January 2004. Two other interesting findings were that 73% of the total mercury deposition during those eight years occurred in the high precipitation season, between May and October; and that 40% of the weekly samples taken during this eight-year period represented only 3.8 % of the recorded total deposition of mercury. This paper examines the reasons why the substantial decrease of local and regional point sources of mercury emission has not affected substantially the local deposition rates. A likely answer is that climatic conditions in Florida, associated mainly with the warmer months and higher rates of precipitation and evaporation, have a large effect on a) re-emission of previously deposited mercury and b) co-precipitation of global mercury from the atmosphere. This may also explain why Florida, where the present annual rate of mercury emissions from coal-fired power plants (in kilograms per square kilometer) is one fifth that of Pennsylvania, has mercury deposition rates that are twice those reported by MDN for Pennsylvania.
The Use of Data Quality Objective Procedures: To Control Complex Inter-Related Environmental Problems for Metal Matrix Encapsulation Fly Ash Management
Authors: Robertson Daniel , Barratt Rod
Published: November 2008

The Data Quality Objective Procedure (DQOP) method aids implementing environmental polices, as engineering solutions. Pollution control issues identified and addressed through new environmental legislation need to be implemented. The metal matrix encapsulation (MME) treatment works as a toxicity reduction exercise that can legally control disposal of fly ashes from waste-to-energy plants. The MME process aids with the implementation of European Union (EU) legislation such as the Waste Incineration Directive by allowing fly ashes to be disposed of in landfill sites. By using the DQOP, as shown with the MME fly ash treatment, complex issues can be clearly identified and effectively controlled. The method considers various steps into which different activities can be addressed, agreed upon and allows engineering, financial and legal teams to cooperate. The EU is the world’s second largest economy with many waste management requirements. The DQOP can aid entry into this complex but rich economic opportunity.
Improving Semi-Dry Scrubber Performance Through Gas Flow Modeling
Authors: Gorsky Nikita , Bowen C. F. Peter
Published: November 2008

Poor flue gas flow distribution in the semi-dry scrubbers used in Waste-to-Energy facilities can cause reduced residence time for lime slurry spray droplet evaporation and subsequent “wet carryover” resulting in solids deposits on the scrubber vessel walls and ductwork and also baghouse bag blinding. In addition to promoting corrosion, the removal of deposits during boiler outages is very labor intensive. This paper identifies how gas flow modeling conducted in conjunction with Nels Consulting Services, Inc. on several different types of scrubbers at Covanta Energy’s Waste-to-Energy facilities resulted in modifications which increased the actual flue gas residence time, considerably reduced the solids deposits (scale) and associated maintenance costs, and in some cases reduced the pressure drop across the scrubbers and baghouses. The data presented includes typical model study velocity distribution data (before and after the modifications), vessel sketches, and photographs. Associated work included in-field scrubber outlet duct temperature and velocity distribution testing. The results of the in-field scrubber outlet temperature distribution testing, done both before and after the scrubber modifications, confirmed the improvements numerically by showing reduced flue gas temperature variation in the scrubber outlet duct.
Evaluation of Chloride Corrosion Reduction With Chemical Additives at Maine Energy Recovery
Authors: Martin J. David , Robbins Ken
Published: November 2008

Over the last several years it has been reported extensively in the literature that chloride induced corrosion of high temperature surfaces in Waste to Energy (WTE) boilers is one of the most costly problems in the industry. This problem can result in replacement of superheater pendents as often as annually in some units or the costly use of higher alloyed materials to either shield the metal surfaces or serve as replacement tube material. The cost-effectiveness of the replacement alloys has not been proven in many cases and therefore the industry has been looking for alternative solutions to evaluate. This paper will address the evaluation of chemical solutions to the problem and also a novel method for measurement of corrosion rates in the high temperature flue gas near WTE superheater pendents.
Validation Study of FTIR-Based Emissions Measurements at a Municipal Waste Combustor
Authors: Aldina G. J. , Hahn Jeffrey L.
Published: November 2008

EPA Test Methods 301 and 320 include statistical techniques for validating sampling methods in specific gas matrices. Several of these techniques were used to analyze extractive FTIR data collected at a municipal solid waste incinerator and to validate the method for hydrogen chloride (HCl) measurements. FTIR results for carbon monoxide (CO), sulfur dioxide (SO2), and nitric oxide (NO) were also compared to measurements recorded by the facility’s continuous emissions monitors (CEMs). Presented are discussions of the equipment, spectral analyses, and statistical comparisons of the various test methods.
Ash Management and Metals Recovery in Broward County, FL
Authors: Tewari Ram , Gutner Sandy
Published: November 2008

Broward County (the County), which is located on the southeast coast of Florida, is currently faced with an ash management and metals recovery decision. The County has two mass burn resource recovery plants and they process a combined total of approximately 1.65 million tons of MSW. The ash residue from these two facilities is currently landfilled. At one facility, the South Broward Waste-to-Energy Facility (the South County Facility), ferrous was being recovered at the ash monofill using mobile equipment, as the plant was not equipped with metals recovery equipment. But as market prices dropped, so did the ferrous metals recovery. This has adversely affected the useful life of the ash monofill, owned by the County. The County is looking for a cost–effective alternative for an on–line metals (ferrous and non–ferrous) recovery system.
York Resource Recovery Center Control System Upgrade
Authors: Salsbury Edward
Published: November 2008

The York Resource Recovery Center was constructed and completed for the York County Solid Waste and Refuse Authority by Westinghouse Electric Corporation in October 1989. The design incorporated three Westinghouse O’Connor Rotary Combustors fitted with Deltak Boilers to provide a state-of-the art incineration system for the 400,000 residents of York County. Westinghouse incorporated many of their industrial products into the plant including their Westinghouse Data Processing Family Control System (WDPF) for control of the plant combustion and generation process.
Pinellas County Resource Recovery Facility Capital Replacement Project: One Year of Improved MSW Throughput and Electrical Generation
Authors: White Thomas M. , Castro Donald J. , Hauser Robert
Published: November 2008

In May of 2003, the 3,150 TPD Pinellas County Resource Recovery Facility (PCRRF), the largest waste-to-energy plant in the United States, reached its 20-year milestone. The PCRRF is located in St. Petersburg, Florida, on a 705 acre (1.1 square mile) site owned by Pinellas County and known as “Bridgeway Acres”. The PCRRF has been owned by Pinellas County, operated by Wheelabrator Pinellas, Inc. (WPI) and monitored by HDR Engineering, Inc. since its inception. In addition to the PCRRF, the County operates both Class I and Class III landfills on the site.
A New Non-Invasive Air-Cooled Condenser Monitoring Methodology to Increase Performance
Authors: Caillard Fred , Screve Francois
Published: November 2008

Air-Cooled Condenser performance can significantly affect WTE plants bottom-line. Most of the possible ACC performance improvement solutions require some important capital costs (fin tubes replacement, fans blades or motor upgrade, additional ACC cells, addition of preventive air re-circulation panels, etc…). A new low cost tool and methodology is now allowing to gain a very detailed understanding of ACC behaviours and to optimize ACC operations and cleaning schedules. This article is illustrated by the case-study of a WTE located in the south of France (equipped with a 5.5 MW GE condensing turbine), where the facility performance was strongly limited by its ACC, and where additional turbine generator output of more than 1 MW were achieved.
The Status of Waste-to-Energy in the U.S.
Authors: Kiser Jonathan V. L.
Published: November 2008

This paper provides an update on the status of waste-to-energy in the United States. It features a breakdown of operating plants by technology, the relative contribution each technology type makes in terms of managing municipal solid waste, and the role of waste-to-energy compared with other management options. The paper also provides a regional look at operating plants, some key insights at the state level, plus the type and amount of materials recovered on-site at waste-to-energy operations for subsequent recycling. Particular emphasis is placed on the use of combustion ash in various beneficial applications. In addition, the latest air pollution control trends relating to waste-to-energy operations are addressed. Also, waste-to-energy community recycling rates are examined and compared with national recycling statistics. Finally, a summary of States recognizing waste-to-energy as a renewable resource is provided. The paper demonstrates the ongoing vital role waste-to-energy plays in helping to manage waste in the U.S.