scholarly journals A Study on the Effect of Ignition Timing on Residual Gas, Effective Release Energy, and Engine Emissions of a V-Twin Engine

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4523
Author(s):  
Quach-Nhu Yhcmute ◽  
Nguyen-Xuan Khoa ◽  
Ocktaeck Lim
Keyword(s):  
Energy Performance ◽  
Operating Conditions ◽  
Nitrogen Oxide Emission ◽  
Ignition Timing ◽  
Si Engine ◽  
Engine Emissions ◽  
Experiment System ◽  
Braking Torque ◽  
Residual Gas ◽  
Co Emission

The ignition timing of an SI engine is a critical parameter. The influence on residual gas, effective release energy, and emissions characteristics of ignition timing for the V-twin engine is investigated in this research. For this purpose, an experiment system was built with a dynamometer, and a model of the simulation was created. In this research, the ignition timing was varied from 10 to 45 degrees BTDC under full load operating conditions, with engine speeds ranging from 3000 to 10,000 rpm. Based on the output data, ignition timing has a major impact on the proportion of residual gas, efficient release energy, performance of the engine, and the emission characteristics. The smallest proportion of residual gas was 0.07% at 8000 rpm and ignition timing of 10 °CA. At 15 °CA of ignition timing, the highest efficient release energy was 0.817 kJ at 4000 rpm, while at 8000 rpm and 25 °CA of ignition timing, it was 0.8305 kJ. At 6000 rpm, the greatest braking torque of the engine was 21.57 Nm, while the minimal BSFC was 343.821 g/kWh. The nitrogen oxide emission and HC emission increase with the advanced ignition timing, but CO emission decreases.

scholarly journals Managing energy performance in buildings from design to operation using modelling and calibration

2021 ◽  
pp. 014362442110083
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Dejan Mumovic ◽  
Mike Davies
Keyword(s):  
Best Practice ◽  
Good Practice ◽  
Energy Performance ◽  
Operating Conditions ◽  
Design Stage ◽  
Performance Gap ◽  
Actual Performance ◽  
Simulation Tools ◽  
Calibration Protocol ◽  
Covering Design

To manage the concerns regarding the energy performance gap in buildings, a structured and longitudinal performance assessment of buildings, covering design through to operation, is necessary. Modelling can form an integral part of this process by ensuring that a good practice design stage modelling is followed by an ongoing evaluation of operational stage performance using a robust calibration protocol. In this paper, we demonstrate, via a case study of an office building, how a good practice design stage model can be fine-tuned for operational stage using a new framework that helps validate the causes for deviations of actual performance from design intents. This paper maps the modelling based process of tracking building performance from design to operation, identifying the various types of performance gaps. Further, during the operational stage, the framework provides a systematic way to separate the effect of (i) operating conditions that are driven by the building’s actual function and occupancy as compared with the design assumptions, and (ii) the effect of potential technical issues that cause underperformance. As the identification of issues is based on energy modelling, the process requires use of advanced and well-documented simulation tools. The paper concludes with providing an outline of the software platform requirements needed to generate robust design models and their calibration for operational performance assessments. Practical application The paper’s findings are a useful guide for building industry professionals to manage the performance gap with appropriate accuracy through a robust methodology in an easy to use workflow. The methodological framework to analyse building energy performance in-use links best practice design stage modelling guidance with a robust operational stage investigation. It helps designers, contractors, building managers and other stakeholders with an understanding of procedures to follow to undertake an effective measurement and verification exercise.

scholarly journals Improvement Effect of Green Remodeling and Building Value Assessment Criteria for Aging Public Buildings

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1200
Author(s):  
Yong-Joon Jun ◽  
Seung-ho Ahn ◽  
Kyung-Soon Park
Keyword(s):  
High Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Energy Usage ◽  
Public Buildings ◽  
Value Judgment ◽  
Relationship Analysis ◽  
Improvement Effect ◽  
The Relationship ◽  
Usage Data

The Green Remodeling Project under South Korea’s Green New Deal policy is a government-led project intended to strengthen the performance sector directly correlated with energy performance among various elements of improvement applicable to building remodeling by replacing insulation materials, introducing new and renewable energy, introducing high-efficiency equipment, etc., with public buildings taking the lead in green remodeling in order to induce energy efficiency enhancement in private buildings. However, there is an ongoing policy that involves the application of a fragmentary value judgment criterion, i.e., whether to apply technical elements confined to the enhancement of the energy performance of target buildings and the prediction of improvement effects according thereto, thus resulting in the phenomenon of another important value criterion for green remodeling, i.e., the enhancement of the occupant (user) comfort performance of target buildings as one of its purposes, being neglected instead. In order to accurately grasp the current status of these problems and to promote ‘expansion of the value judgment criteria for green remodeling’ as an alternative, this study collected energy usage data of buildings actually used by public institutions and then conducted a total analysis. After that, the characteristics of energy usage were analyzed for each of the groups of buildings classified by year of completion, thereby carrying out an analysis of the correlation between the non-architectural elements affecting the actual energy usage and the actual energy usage data. The correlation between the improvement performance of each technical element and the actual improvement effect was also analyzed, thereby ascertaining the relationship between the direction of major policy strategies and the actual energy usage. As a result of the relationship analysis, it was confirmed that the actual energy usage is more affected by the operating conditions of the relevant building than the application of individual strategic elements such as the performance of the envelope insulation and the performance of the high-efficiency system. In addition, it was also confirmed that the usage of public buildings does not increase in proportion to their aging. The primary goal of reducing energy usage in target buildings can be achieved if public sector (government)-led green remodeling is pushed ahead with in accordance with biased value judgment criteria, just as in the case of a campaign to refrain from operating cooling facilities in aging public buildings. However, it was possible to grasp through the progress of this study that the remodeling may also result in the deterioration of environmental comfort and stability, such as the numerical value of the indoor thermal environment. The results of this study have the significance of providing basic data for pushing ahead with a green remodeling policy in which the value judgment criteria for aging existing public buildings are more expanded, and it is necessary to continue research in such a direction that the quantitative purpose of green remodeling, which is to reduce energy usage in aging public buildings, and its qualitative purpose, which is to enhance their environmental performance for occupants’ comfort, can be mutually balanced and secured at the same time.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira
Keyword(s):  
Energy Conversion ◽  
Fuel Consumption ◽  
Conversion Efficiency ◽  
Minimum Energy ◽  
Energy Conversion Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Lower Fuel Consumption ◽  
Performance Improvements ◽  
Aspect Ratios

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

Potential of the Variable Valve Actuation (VVA) Strategy on a Heavy Duty CNG Engine

2014 ◽  
Author(s):  
Mirko Baratta ◽  
Roberto Finesso ◽  
Daniela Misul ◽  
Ezio Spessa ◽  
Yifei Tong ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Operating Conditions ◽  
Intake Valve ◽  
Heavy Duty ◽  
Engine Emissions ◽  
Variable Valve Actuation ◽  
Cng Engine ◽  
Variable Valve ◽  
Working Point ◽  
Valve Actuation

The environmental concerns officially aroused in 1970s made the control of the engine emissions a major issue for the automotive industry. The corresponding reduction in fuel consumption has become a challenge so as to meet the current and future emission legislations. Given the increasing interest retained by the optimal use of a Variable Valve Actuation (VVA) technology, the present paper investigates into the potentials of combining the VVA solution to CNG fuelling. Experiments and simulations were carried out on a heavy duty 6-cylinders CNG engine equipped with a turbocharger displaying a twin-entry waste-gate-controlled turbine. The analysis aimed at exploring the potentials of the Early Intake Valve Closure (EIVC) mode and to identify advanced solutions for the combustion management as well as for the turbo-matching. The engine model was developed within the GT-Power environment and was finely tuned to reproduce the experimental readings under steady state operations. The 0D-1D model was hence run to reproduce the engine operating conditions at different speeds and loads and to highlight the effect of the VVA on the engine performance as well as on the fuel consumption and engine emissions. Pumping losses proved to reduce to a great extent, thus decreasing the brake specific fuel consumption (BSFC) with respect to the throttled engine. The exhaust temperature at the turbine inlet was kept to an almost constant value and minor variations were allowed. This was meant to avoid an excessive worsening in the TWC working conditions, as well as deterioration in the turbocharger performance during load transients. The numerical results also proved that full load torque increases can be achieved by reducing the spark advance so that a higher enthalpy is delivered to the turbocharger. Similar torque levels were also obtained by means of Early Intake Valve Closing strategy. For the latter case, negligible penalties in the fuel consumption were detected. Moreover, for a given combustion phasing, the IVC angle directly controls the mass-flow rate and thus the torque. On the other hand, a slight dependence on the combustion phasing can be detected at part load. Finally, the simulations assessed for almost constant fuel consumption for a wide range of IVC and SA values. Specific attention was also paid to the turbocharger group functioning and to its correct matching to the engine working point. The simulations showed that the working point on the compressor map can be optimized by properly setting the spark advance (SA) as referred to the adopted intake-valve closing angle. It is anyhow worth observing that the engine high loads set a constraint deriving from the need to meet the limits on the peak firing pressure (PFP), thus limiting the possibility to optimize the working point once the turbo-matching is defined.

scholarly journals Determining the environmental indicators for vehicles of different categories in relation to CO2 emission based on road tests

2017 ◽  
Vol 170 (3) ◽  
pp. 66-72
Author(s):  
Jerzy MERKISZ ◽  
Łukasz RYMANIAK
Keyword(s):  
Co2 Emissions ◽  
Operating Time ◽  
Environmental Indicators ◽  
Operating Conditions ◽  
Si Engine ◽  
Propulsion Systems ◽  
System A ◽  
In Series ◽  
Series Configuration ◽  
Ci Engine

The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO2 emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NOx. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm3 urban passenger car with a SI engine and a start-stop system, a 2.5 dm3 off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm3. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO2 emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.

scholarly journals Optimization for energy consumption in drying section of fluting paper machine

2017 ◽  
Vol 21 (3) ◽  
pp. 1419-1429
Author(s):  
Shaaban Ghodbanan ◽  
Reza Alizadeh ◽  
Sirous Shafiei
Keyword(s):  
Process Parameters ◽  
Heat Recovery ◽  
Production Capacity ◽  
Inequality Constraints ◽  
Optimization Method ◽  
Energy Performance ◽  
Operating Conditions ◽  
Paper Machine ◽  
Recovery Performance ◽  
Drying Section

Non-linear programming optimization method was used to optimize total steam and air consumption in the dryer section of multi-cylinder fluting paper machine. Equality constraints of the optimization model were obtained from specified process blocks considering mass and energy balance relationships in drying and heat recovery sections. Inequality constraints correspond to process parameters such as production capacity, operating conditions, and other limitations. Using the simulation, the process parameters can be optimized to improve the energy efficiency and heat recovery performance. For a corrugating machine, optimized parameters show the total steam use can be reduced by about 11% due to improvement of the heat recovery performance and optimization of the operating conditions such as inlet web dryness, evaporation rate, and exhaust air humidity, accordingly total steam consumption can be decreased from about 1.71 to 1.53 tonnes steam per tonne paper production. The humidity of the exhaust air should be kept as high as possible to optimize the energy performance and avoid condensation in the pocket dryers and hood exhaust air. So the simulation shows the supply air should be increased by about 10% to achieve optimal humidity level which was determined about 0.152 kgH2O/(kg dry air).

Fuzzy ignition timing control for a spark ignition engine

2000 ◽  
Vol 214 (3) ◽  
pp. 297-306 ◽  
Author(s):  
W Wang ◽  
E. C. Chirwa ◽  
E Zhou ◽  
K Holmes ◽  
C Nwagboso
Keyword(s):  
Fuzzy Logic ◽  
Detection System ◽  
Open Loop ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Coolant Temperature ◽  
Optimum Level ◽  
Ignition Timing ◽  
Timing Control ◽  
Engine Design

It is well known that the optimum ignition timing, which gives the maximum brake torque (MBT) for a given engine design, varies with the rate of flame development and propagation in the cylinder. This depends, among other factors, on engine design and operating conditions, and on the properties of the air-fuel mixture. In modern engines the ignition timing is generally controlled by fixed open-loop schedules as functions of engine speed, load and coolant temperature. It is desairable that this ignition timing can be adjusted to the optimum level producing the best torque to obtain minimum fuel consumption and maximum available power. This paper presents an ignition timing control system based on fuzzy logic theory. A pressure sensor system ws developed for the determination of combustion parameters and ignition control on a Ford 1600cm3 four-cylinder engine fuelled with natural gas. Several tests were carried out in optimizing the pressure detection system. The results obtained provide important information compatible with intelligent control of the engine using fuzzy logic technology. Moreover, tests carried out to date using this technology show good results that fit quite well with the original engine output torque characteristics.

scholarly journals Effect of Fuel and Air Dilution on Syngas Combustion in an Optical SI Engine

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1566 ◽  
Author(s):  
S.D. Martinez-Boggio ◽  
S.S. Merola ◽  
P. Teixeira Lacava ◽  
A. Irimescu ◽  
P.L. Curto-Risso
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Process ◽  
Visible Spectrum ◽  
Propagation Speed ◽  
Fuel Mixture ◽  
Operating Conditions ◽  
Inert Gases ◽  
Pollutant Emissions ◽  
Si Engine ◽  
Lean Burn

To mitigate the increasing concentration of carbon dioxide in the atmosphere, energy production processes must change from fossil to renewable resources. Bioenergy utilization from agricultural residues can be a step towards achieving this goal. Syngas (fuel obtained from biomass gasification) has been proved to have the potential of replacing fossil fuels in stationary internal combustion engines (ICEs). The processes associated with switching from traditional fuels to alternatives have always led to intense research efforts in order to have a broad understanding of the behavior of the engine in all operating conditions. In particular, attention needs to be focused on fuels containing relatively high concentrations of hydrogen, due to its faster propagation speed with respect to traditional fossil energy sources. Therefore, a combustion study was performed in a research optical SI engine, for a comparison between a well-established fuel such as methane (the main component of natural gas) and syngas. The main goal of this work is to study the effect of inert gases in the fuel mixture and that of air dilution during lean fuelling. Thus, two pure syngas blends (mixtures of CO and H2) and their respective diluted mixtures (CO and H2 with 50vol% of inert gases, CO2 and N2) were tested in several air-fuel ratios (stoichiometric to lean burn conditions). Initially, the combustion process was studied in detail by traditional thermodynamic analysis and then optical diagnostics were applied thanks to the optical access through the piston crown. Specifically, images were taken in the UV-visible spectrum of the entire cycle to follow the propagation of the flame front. The results show that hydrogen promotes flame propagation and reduces its distortion, as well as resulting in flames evolving closer to the spark plug. All syngas blends show a stable combustion process, even in conditions of high air and fuel dilution. In the leanest case, real syngas mixtures present a decrease in terms of performance due to significant reduction in volumetric efficiency. However, this condition strongly decreases pollutant emissions, with nitrogen oxide (NOx) concentrations almost negligible.

Sign in / Sign up

Export Citation Format

Share Document