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

2021 ◽  
pp. 146808742110583
Author(s):  
Ioannis Nikiforakis ◽  
Zhongnan Ran ◽  
Michael Sprengel ◽  
John Brackett ◽  
Guy Babbit ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
High Energy ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Case Scenario ◽  
Gas Combustion ◽  
Thermodynamic Conditions ◽  
Decentralized Energy

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 (H2: 33.9%, CO: 15.6%, CO2: 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 NOx 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.

scholarly journals A Review of Comparative Study on The Effect of Hydroxyl Gas in Internal Combustion Engine (ICE) On Engine Performance and Exhaust Emission

2021 ◽  
Vol 87 (2) ◽  
pp. 1-16
Author(s):  
Amir Ridhuan ◽  
Shahrul Azmir Osman ◽  
Mas Fawzi ◽  
Ahmad Jais Alimin ◽  
Saliza Azlina Osman
Keyword(s):  
Fuel Consumption ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Internal Combustion ◽  
Exhaust Emission ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Complete Combustion ◽  
Brake Power

This introductory study comes up with an innovative idea of using Hydroxyl gas as a fuel performance enhancer to reduce the natural sources and the overuse of fossil fuel resulting in increased pollution levels. Many researchers have used HHO gas to analyze gasoline and diesel in internal combustion engines. The main challenges of using HHO gas in engines have been identified as system complexity, safety, cost, and electrolysis efficiency. This article focuses on different performance reports and the emission characteristics of a compression ignition engine. As opposed to general diesel, this study found that using HHO gas improved brake power and torque. In all cases, an increase in braking thermal efficiency can be observed. This was due to the presence of hydrogen in HHO gas with higher calorific value than fossil fuels. At the same time, the fuel consumption unit of the engine was reduced, and the combined impact of hydrogen and oxygen helped to achieve complete combustion and improved the combustion capacity of the fuel when HHO gas was injected. The addition of HHO gas also improved the Brake Power (BP), Brake Torque (BT), Brake Specific Fuel Consumption (BSFC), and thermal efficiency while simultaneously reducing CO and HC formation. The rise in CO2 emissions represented the completion of combustion. Therefore, the usage of HHO gas in the Compression Ignition (CI) engine improved the engine performance and exhaust emissions.

Experimental Evaluation of Turbo-Matching Appropriateness of B60J67, B60J68, A58N70 and A58N72 Turbo-Chargers for a Commercial Vehicle Engine

2018 ◽  
Vol 6 (11) ◽  
pp. 71
Author(s):  
Badal Dev Roy ◽  
R. Saravanan
Keyword(s):  
Internal Combustion Engines ◽  
Perfect Match ◽  
Engine Performance ◽  
Operating Conditions ◽  
Data Logger ◽  
Negative Effects ◽  
Road Test ◽  
The Road ◽  
A Charge ◽  
All Speeds

The Turbocharger is a charge booster for internal combustion engines to ensure best engine performance at all speeds and road conditions especially at the higher load.  Random selection of turbocharger may lead to negative effects like surge and choke in the breathing of the engine. Appropriate selection or match of the turbocharger (Turbomatching) is a tedious task and expensive. But perfect match gives many distinguished advantages and it is a one time task per the engine kind. This study focuses to match the turbocharger to desired engine by simulation and on road test. The objective of work is to find the appropriateness of matching of turbochargers with trim 67 (B60J67), trim 68 (B60J68),  trim 70 (A58N70) and trim 72 (A58N72) for the TATA 497 TCIC -BS III engine. In the road-test (data-logger method) the road routes like highway and slope up were considered for evaluation. The operating conditions with respect various speeds, routes and simulated outputs were compared with the help of compressor map.

scholarly journals Octane Index Applicability over the Pressure-Temperature Domain

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Tommy R. Powell ◽  
James P. Szybist ◽  
Flavio Dal Forno Chuahy ◽  
Scott J. Curran ◽  
John Mengwasser ◽  
...  
Keyword(s):  
High Efficiency ◽  
National Laboratory ◽  
Operating Conditions ◽  
Dominant Factor ◽  
Compression Ignition ◽  
Oak Ridge ◽  
Operating Modes ◽  
Wide Range ◽  
Thermodynamic Conditions ◽  
Si Engines

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.

Engine performance and emission characteristics of a compression ignition engine fuelled with diesel/dimethoxymethane blends

2005 ◽  
Vol 219 (7) ◽  
pp. 905-914 ◽  
Author(s):  
Y Ren ◽  
Z H Huang ◽  
D M Jiang ◽  
L X Liu ◽  
K Zeng ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Mass Fraction ◽  
Volume Fraction ◽  
Engine Performance ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Performance And Emission ◽  
Fuel Blends ◽  
Performance And Emissions ◽  
Combustion Phase

The performance and emissions of a compression ignition engine fuelled with diesel/dimethoxymethane (DMM) blends were studied. The results showed that the engine's thermal efficiency increased and the diesel equivalent brake specific fuel consumption (b.s.f.c.) decreased as the oxygen mass fraction (or DMM mass fraction) of the diesel/DMM blends increased. This change in the diesel/DMM blends was caused by an increased fraction of the premixed combustion phase, an oxygen enrichment, and an improvement in the diffusive combustion phase. A remarkable reduction in the exhaust CO and smoke can be achieved when operating on the diesel/DMM blend. Flat NO x/smoke and thermal efficiency/smoke curves are presented when operating on the diesel/DMM fuel blends, and a simultaneous reduction in both NO x and smoke can be realized at large DMM addition. Thermal efficiency and NO x give the highest value at 2 per cent oxygen mass fraction (or 5 per cent DMM volume fraction) for the combustion of diesel/DMM blends.

scholarly journals Control of Exhaust Emissions Using Piston Coating on Two-StrokeSI Engines with Gasoline Blends

2021 ◽  
Vol 8 (1) ◽  
pp. H16-H20
Author(s):  
A.V.N.S. Kiran ◽  
B. Ramanjaneyulu ◽  
M. Lokanath M. ◽  
S. Nagendra ◽  
G.E. Balachander
Keyword(s):  
Fuel Consumption ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Specific Fuel Consumption ◽  
Thermal Barrier ◽  
Piston Crown ◽  
Barrier Coating

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.

Experiments and modeling of a dual-mode, turbulent jet ignition engine

2019 ◽  
Vol 21 (6) ◽  
pp. 966-986 ◽  
Author(s):  
Sedigheh Tolou ◽  
Harold Schock
Keyword(s):  
Experimental Data ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Peak Pressure ◽  
Operating Conditions ◽  
Turbulent Jet ◽  
Engine Fuel ◽  
Main Chamber ◽  
Dual Mode ◽  
Ignition System

The dual-mode, turbulent jet ignition system is a promising combustion technology to achieve high diesel-like thermal efficiency at medium to high loads and potentially exceed diesel efficiency at low-load operating conditions. The dual-mode, turbulent jet ignition systems to date proved a high level of improvement in thermal efficiency compared to conventional internal combustion engines. However, some questions were still unanswered. The most frequent question regarded power requirements for delivering air to the pre-chamber of a dual-mode, turbulent jet ignition system. In addition, there was no study available to predict the expected efficiency of a dual-mode, turbulent jet ignition engine in a multi-cylinder configuration. This study, for the first time, predicts the ancillary work requirement to operate the dual-mode, turbulent jet ignition system. It also presents a novel, reduced order, and physics-based model of the dual-mode, turbulent jet ignition engine with a pre-chamber valve assembly. The developed model was calibrated based on experimental data from the Prototype II dual-mode, turbulent jet ignition engine. The simulation results were in good agreement with the experimental data. The validity of the model was observed based on the standard metric of the coefficient of determination as well as comparison plots for in-cylinder pressures. Numerical predictions were compared to experiments for three metrics of main chamber combustion: gross indicated mean effective pressure, main chamber peak pressure, and main chamber phasing for the peak pressure. Predictions were within 5% of experimental data, with one exception of 6%. In addition, the absolute root mean square errors of in-cylinder pressures for both pre- and main-combustion chambers were below 0.35. The calibrated model was further studied to introduce a predictive and generalized model for dual-mode, turbulent jet ignition engines. Such a model can project engine behavior in a multi-cylinder configuration over the entire engine fuel map.

Effect of Fuel Injection Pressure and Engine Speed on Performance, Emissions, Combustion, and Particulate Investigations of Gasohols Fuelled Gasoline Direct Injection Engine

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Nikhil Sharma ◽  
Avinash Kumar Agarwal
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Driving Forces ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Primary Alcohols ◽  
Renewable Fuel

Abstract Fuel availability, global warming, and energy security are the three main driving forces, which determine suitability and long-term implementation potential of a renewable fuel for internal combustion engines for a variety of applications. Comprehensive engine experiments were conducted in a single-cylinder gasoline direct injection (GDI) engine prototype having a compression ratio of 10.5, for gaining insights into application of mixtures of gasoline and primary alcohols. Performance, emissions, combustion, and particulate characteristics were determined at different engine speeds (1500, 2000, 2500, 3000 rpm), different fuel injection pressures (FIP: 40, 80, 120, 160 bars) and different test fuel blends namely 15% (v/v) butanol, ethanol, and methanol blended with gasoline, respectively (Bu15, E15, and M15) and baseline gasoline at a fixed (optimum) spark timing of 24 deg before top dead center (bTDC). For a majority of operating conditions, gasohols exhibited superior characteristics except minor engine performance penalty. Gasohols therefore emerged as serious candidate as a transitional renewable fuel for utilization in the existing GDI engines, without requirement of any major hardware changes.

Analysis of Operational Effects on Cooled H-Class Gas Turbines

2019 ◽  
Author(s):  
Selcuk Can Uysal ◽  
James B. Black
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Cooling System ◽  
Engine Performance ◽  
Heat Rate ◽  
Operating Conditions ◽  
Performance Parameters

Abstract During the operation of an industrial gas turbine, the engine deviates from its new condition performance because of several effects including dirt build-up, compressor fouling, material erosion, oxidation, corrosion, turbine blade burning or warping, thermal barrier coating (TBC) degradation, and turbine blade cooling channel clogging. Once these problems cause a significant impact on engine performance, maintenance actions are taken by the operators to restore the engine to new performance levels. It is important to quantify the impacts of these operational effects on the key engine performance parameters such as power output, heat rate and thermal efficiency for industrial gas turbines during the design phase. This information can be used to determine an engine maintenance schedule, which is directly related to maintenance costs during the anticipated operational time. A cooled gas turbine performance analysis model is used in this study to determine the impacts of the TBC degradation and compressor fouling on the engine performance by using three different H-Class gas turbine scenarios. The analytical tool that is used in this analysis is the Cooled Gas Turbine Model (CGTM) that was previously developed in MATLAB Simulink®. The CGTM evaluates the engine performance using operating conditions, polytropic efficiencies, material properties and cooling system information. To investigate the negative impacts on engine performance due to structural changes in TBC material, compressor fouling, and their combined effect, CGTM is used in this study for three different H-Class engine scenarios that have various compressor pressure ratios, turbine inlet temperatures, and power and thermal efficiency outputs; each determined to represent different classes of recent H-Class gas turbines. Experimental data on the changes in TBC performance are used as an input to the CGTM as a change in the TBC Biot number to observe the impacts on engine performance. The effect of compressor fouling is studied by changing the compressor discharge pressures and polytropic compressor efficiencies within the expected reduction ranges. The individual and combined effects of compressor fouling and TBC degradation are presented for the shaft power output, thermal efficiency and heat rate performance parameters. Possible improvements for the designers to reduce these impacts, and comparison of the reductions in engine performance parameters of the studied H-Class engine scenarios are also provided.

Investigating the Origins of Cyclic Variability in Internal Combustion Engines Using Wall-Resolved Large Eddy Simulations

2021 ◽  
Author(s):  
Sicong Wu ◽  
Saumil S. Patel ◽  
Muhsin M. Ameen
Keyword(s):  
Energy Distribution ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Large Eddy Simulations ◽  
Combustion Engines ◽  
Large Eddy ◽  
Cylinder Flow

Abstract Modern internal combustion engines (ICE) operate at the ragged edge of stable operation characterized by high cycle-to-cycle variations (CCV). A key scientific challenge for ICE is the understanding, modeling, and control of CCV in engine performance, which can contribute to partial burns, misfire, and knock. The objective of the current study is to use high-fidelity numerical simulations to improve the understanding of the causes of CCV. Nek5000, a leading high-order spectral element, open source code, is used to simulate the turbulent flow in the engine combustion chamber. Multi-cycle, wall-resolved large-eddy simulations (LES) are performed for the General Motors (GM), Transparent Combustion Chamber (TCC-III) optical engine under motored operating conditions. The mean and root-mean-square (r.m.s.) of the in-cylinder flow fields at various piston positions are validated using PIV measurements during the intake and compression strokes. The large-scale flow structures, including the swirl and tumble flow patterns, are analyzed in detail and the causes for cyclic variabilities in these flow features are explained. The energy distribution across the different scales of the flow are quantified using one-dimensional energy spectra, and the effect of the tumble breakdown process on the energy distribution is examined. The insights from the current study can help us develop improved engine designs with reduced cyclic variabilities in the in-cylinder flow leading to enhanced engine performance.

scholarly journals Performance and Emission Characteristics of CI Engine with Modification in Fuel Injector

2020 ◽  
Vol 9 (3) ◽  
pp. 1604-1607
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Engine Performance ◽  
Injection Pressure ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Fuel Injector ◽  
Performance And Emission ◽  
Toxic Emission ◽  
Ci Engine

Work has been carried out using four stroke single cylinder diesel engine with retrofit attached with fuel injector and at optimum injection pressure 210 bar and 230 BTDC. The main purpose of using retrofit is to achieve HCCI (Homogeneous charge compression ignition) with which emissions can be reduced. Four Variants of retrofits were used and with V-cut type retrofit it was found that there is reduction in toxic emission like CO and NO but there was slight increase in HC emission when compared with normal fuel injector. Engine performance was compared with normal injector and injector with V-cut and it was found that Break thermal efficiency was increased by 0.25% at full load and 1.53% at 80% load and specific fuel consumption decreased by 0.01%.

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