Analysis of motor vehicle engine performance using biogas from sorghum

Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW) (wood). The experimental measurement of syngas composition was done using a pilot scale gasifier. A numerical model was developed using Advanced System for Process ENgineering (Aspen) Plus software. Several Aspen Plus reactor blocks were used along with user defined FORTRAN and Excel code. The model was validated with experimental results. The study found very similar performance between simulation and experimental results, with a maximum variation of 3%. The validated model was used to study the effect of air-fuel and steam-fuel ratio on syngas composition. The model will be useful to predict the various operating parameters of a pilot scale SW gasification plant, such as temperature, pressure, air-fuel ratio and steam-fuel ratio. Therefore, the model can assist researchers, professionals and industries to identify optimized conditions for SW gasification.

<div class="htmlview paragraph"><b>T</b>HIS paper discusses first the theoretical relation between thermal efficiency and fuel-air ratio for assumed limited-pressure fuel-air cycles. Data on actual cycles are then presented showing the relation of indicated efficiency to fuel-air ratio. This and other relationships are then used in deriving equations for relating the power output of engines operated at constant speed and throttle setting to ambient conditions.</div> <div class="htmlview paragraph">The fundamental nature of the relation between thermal efficiency and fuel-air ratio is emphasized by showing the variation with fuel-air ratio of computed efficiency of assumed limited-pressure fuel-air cycles. This computed efficiency for a given cycle and compression ratio is determined solely by the thermodynamic properties of the fuel-air medium and is the maximum efficiency theoretically possible for the assumed conditions.</div> <div class="htmlview paragraph">The paper also includes an analysis of published data on compression-ignition engine performance showing the relation between actual indicated efficiency and fuel-air ratio. The data available indicate that this relation is not affected significantly by changes in ambient conditions, provided that the pressure at the intake equals the pressure at the final exhaust. Because this basic relation is independent of ambient conditions, it may be used in predicting the effect of changes in ambient conditions on the power output of compression-ignition engines operated at constant speed and throttle setting. This can be done only if the effect of changes in ambient conditions on fuel-air ratio is known or can be computed. Inasmuch as the quantity of fuel supplied to a compression-ignition engine depends only on the speed and throttle setting and is not affected by changes in ambient conditions, the effect on fuel-air ratio of such changes can be determined when the quantity of air entering the engine at each condition is known. This latter factor is determined by the density of the air and by the volumetric efficiency; both of these factors depend on ambient temperature and pressure. Equations relating all of these factors are presented herein. These equations furnish a rational basis for computing the power output of a compression-ignition engine at a given set of conditions from the power output at some other set of conditions. The precision with which the equations represent test results is shown.</div> <div class="htmlview paragraph">The effect of changes in ambient conditions on the power output of engines in which the fuel-air ratio is constant for operation at constant speed and throttle setting is discussed briefly. This discussion applies to the gasoline or more precisely the spark-ignition engine equipped with a carburetor. It is pointed out that knowledge of the relation between fuel-air ratio and indicated efficiency is not required in formulating equations for computing the effect of ambient conditions on the power output of gasoline engines because fuel-air ratio and, consequently, indicated efficiency are more or less constant, depending on the operating characteristics of the carburetor.</div>

Thermodynamic performance analysis of ramjet engine at wide working conditions

This article presents the actual AFR of the vehicular emission from the tailpipe data of motorcycles with petrol engine in Southwest Nigeria. It also presents the ratio between the actual air-fuel ratio (AFRactual) and the ideal/stoichiometric air-fuel ratio (AFRideal) known as the equivalence air-fuel ratio or lambda (λ). This was compared with the expected value for lambda by the catalytic technology for exhaust gases emission, which is 1 (± 5%). In this study, over 95% of the sampled motorcycles have higher lambda values than expected, thereby emitting very high concentrations of carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO2). The Portable, Hand-Held, battery-operated Kane automotive 4-gas analyser with detector tube (Model Auto 4-1) was used to measure the automobile emissions. The air-fuel ratio is a significant indicator and very important measure for gasoline engine performance controlling and tuning, and anti vehicles exhaust emissions pollution reasons [1]. Internal combustion (IC) gasoline fuelled engines exhaust gases emission depend heavily and mainly on the air-fuel ratio. For a gasoline fuelled engine, carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) exhaust gases emission are significantly influenced by air-fuel ratio. CO and HC are majorly generated or produced with rich air–fuel mixture, while NOx with lean air-fuel mixtures which mean that there is no fixed air-fuel mixture for which it can obtain the minimum for all exhaust gases emission [2]. This study can help in reducing fuel consumption, improving the quality of fuel combustion and reducing vehicle exhaust emissions in Nigeria.

<div class="htmlview paragraph">Visualization of in-cylinder reaction processes and performance analysis of a direct-injection Diesel engine equipped with a high injection pressure (HIP) unit were conducted. The study was directed towards evaluation of high-power-density (HPD) engine design strategies, which utilize more intake air operating at rich overall fuel-air ratios.</div> <div class="htmlview paragraph">Two separate engine apparatus were used in this study: a Cummins 903 engine and a single-cylinder optical engine equipped with the same family engine components including the cylinder head. The engines were mated with an intensifier-type HIP fuel system fabricated at Rutgers which can deliver fuel injection pressure of over 200 MPa (30,000psi).</div> <div class="htmlview paragraph">The one-of-a-kind high-speed four-band infrared (IR) imaging system was used to obtain over fifteen hundred sets of spectral digital movies under varied engine design and operating conditions for the present analysis. In order to analyze and present this large amount of results, a new data analysis and presentation method was developed (called Rutgers Animation Program, RAP for short). RAP is a computer program permitting simultaneous display of as many as twenty-eight (28) sets of digital movies over a single PC screen for mutual comparison in a controlled manner.</div> <div class="htmlview paragraph">Among the findings from the study is that the in-cylinder imaging performed within the first several cycles may not represent what is happening in a typical warm engine. In addition, the spray development and subsequent reactions of the HIP unit may not be comparable to those of low-pressure conventional injector units. In-cylinder processes and engine performance of an HPD engine affected by various factors are also described in the paper which include: the injection pressure, intake air temperature, and overall air-fuel ratio.</div>

In this study, a 1D model was created using the Ricardo-Wave program for a single-cylinder, spark ignition, four-stroke, direct injection engine with a stroke volume of 398 cc. Air-fuel ratio (AFR), mixture temperature (MT), and start of injection (SOI) were used as fuel injection parameters. Using these parameters, 343 different cases were created. Brake power, thermal efficiency, and fuel consumption were used as engine performance parameters. By holding one injection parameter constant, a contour plot was created to examine the effect of the other two parameters on the engine performance parameter. According to the results, the effect of MT and SOI on brake power is 1%, the effect of AFR on brake power is 9.6%, the effect of MT and SOI on thermal efficiency is 1%, and the effect of AFR on thermal efficiency is 12.8%. The effect of MT and SOI on fuel consumption is 0.04%, the effect of AFR on fuel consumption is 22.9%, and the effect of AFR on brake specific fuel consumption is 22.9%. These results indicate that the most significant effect is provided by AFR, while MT and SOI also have a slight impact on engine performance.

Transient Spark Advance Calibration Approach

<div class="section abstract"><div class="htmlview paragraph">This paper presents a study of the performance of a lean burn, natural gas-fuelled, naturally aspirated, spark ignition engine for an <i>E</i> class vehicle. Engine performance and exhaust emissions (<i>NO, CO,</i> and <i>UHC</i>) data are first discussed. An energy balance of the engine operating at different loads and air-fuel ratios is then presented, and used to explain why engine efficiency varies with air-fuel ratio. Finally, the hot start drive cycle <i>CO<sub>2e</sub></i> (<i>CO<sub>2</sub></i> equivalent) emissions are estimated for a vehicle with this engine. This shows a potential for significant reduction in vehicle greenhouse gas emissions compared to an equivalent gasoline-fuelled vehicle.</div></div>

<div class="section abstract"><div class="htmlview paragraph">The air pollution is increasing at an alarming rate now a day mainly due to emissions coming out of automotive vehicles. The exhaust emissions gases are hazardous to human health. The increased number of vehicles on road will make the scenario even worse. In order to control the pollution level, the regulatory bodies are now implementing stringent emission norms. In India, the regulatory authorities has framed the transition of BS IV to BS VI emission norms in 2020 by skipping the BS V emission norms which makes the automotive industries to work on more advanced fuel management technologies. It is more tedious to control the tail pipe emissions beyond BS IV emission norms with the conventional carburetor system since it is operating on open loop system. It is evident that in order to meet the stringent emission norms we need to have a closed loop system which controls the Air Fuel Ratio (AFR) close to stoichiometric to increase the conversion efficiency of the catalytic converter. The vehicle with fuel injection system can able to work on closed loop system, but the fuel injection system is not cost effective.</div><div class="htmlview paragraph">This paper illustrates the development of a cost effective smart engine management system for two wheeler application to meet the upcoming emission norms with some modification from the conventional carburetor system. Instead of controlling the fuel flow to keep the AFR close to the stoichiometric as in fuel injection system, the smart engine management system has a sophisticated air control mechanism to make the AFR close to stoichiometric. The carburetor was modified to incorporate an air control solenoid which is operated on the pulse width modulation to vary the air flow according to our requirement. The lambda sensor measures the AFR from the exhaust pipe and provides information to the ECU.</div><div class="htmlview paragraph">Based on the feedback from the lambda sensor, TPS, CPS, etc., the ECU maintains the AFR stoichiometric by controlling the flow through the air control solenoid with varying duty cycles. The vehicle performance test was carried out with vehicle having smart engine management system (Electronic carburetor) and also with fuel injection equipped vehicle on the chassis dynamometer. The test results show that the air fuel ratio of the electronic carburetor vehicle was maintained close to stoichiometric as in fuel injection vehicle which in turn reduce the emission to a considerable extent. Hence the smart engine management system caters a new way for an efficient low cost fuel management system.</div></div>

This paper presents the experimental results on brake power enhancement of a modified natural gas engine. Conventional natural gas engine produces 15 to 20% less brake power than that of gasoline fired engine. This lacking in compressed natural gas (CNG) engine needs to be recovered through modifications and optimization of fuel injection system to provide complete gas combustion in the engine cylinder. A multi-cylinder gasoline engine was modified to bi-fuel engine for operating in several test conditions, such as constant full and half throttle condition. Variation in power production with corresponding fuel flow rate and emission gases (such as carbon monoxides, CO; unburnt hydrocarbon, HC and nitrogen oxides, NOx) were studied by using two fuels (gasoline and CNG). Engine tune up information like variation in air fuel ratio (AFR) for lean burn operation can be known from those tests. Performance of engine was studied with both the fuels at fixed load and the corresponding fuel flow rate and emissions were measured for evaluation and optimization. The engine produced 10% higher brake power with CNG fuel as compared to that produced with gasoline fuel at full load, but at partial load gasoline fuel produced more brake power than CNG. Emission results revealed that CNG fuelled engine emits less CO and HC, showing more complete combustion than gasoline fuel. On the contrary, higher combustion temperature of CNG fuel produced more NOx than gasoline. The results of these investigations can be used to develop a new compressed natural gas (CNG), direct injection (DI) and higher efficiency engine in the near future to build an environment friendly fuel economic clean burning automotive vehicle with less emission and similar power rating like gasoline engine. Key words: Brake power, compressed natural gas-direct injection (CNG-DI), bi-fuel engine, fuel consumption, emission.

To examine the effect of torch jet direction on the combustion characteristics and engine performances, a spark-ignition engine with each divided chamber having a torch nozzle of different flow direction is used by changing the torch nozzle area, prechamber volume and air-fuel ratio, while keeping the engine speed of 1000 rpm. Typical pressure diagrams for different torch jet directions are analyzed to obtain such combustion characteristics as the crank angles of combustion start and finish, heat release rate and mass burned fraction. The engine performances, e.g. mean effective pressure and specific fuel consumption, are also measured. As a result, it can be made clear not only the effect of torch jet direction on the combustion characteristics, but also the relationship between the combustion characteristics and the engine performances for different torch jet directions.

Spark ignition engine performance and exhaust emissions are strongly affected by the fuel/air ratio used. A considerable amount of investigations have been carried out by engine manufacturers to control engine performance and meet exhaust emission standards of governmental agencies by developing control systems for some operating variables such as ignition timing(IT), Fuel Air Ratio(FAR), and Exhaust Gas Recirculation (EGR) This paper presents a fuzzy control system that measures exhaust temperature and operates a needle valve on the engine earburetor jet that enables the fuel to air ratio lo oscillate about a desired value. A group of experiments have been carried out to obtain the relationship between fuel to air ratio or (ɸ), Exhaust temperature and exhaust emissions. A group of fuzzy logic rules which relate exhaust temperature, to the desired speed with the position of a needle valve actuated by a stepping motor are prop osed. A beneficial of fuzzy control method was that the rules determined the characteristics of control system are interpreted by the operator. Experimental and simulated results show that the prop osed fuzzy system improves the fuel/air mixture quality.

Global regulations on vehicle emissions have compelled the automotive industry to undergo rapid advancements over the past decades, prioritizing strategies for developing engines with greater efficiency and lower emissions. While the market for electric vehicles continues to expand, internal combustion (IC) engines remain indispensable and constitute the majority of the global vehicle fleet. Among the critical parameters for controlling engine performance, emissions, and fuel economy, the air–fuel ratio (AFR) is a key determinant. Inadequate control or fluctuations in AFR, whether in steady-state or transient conditions, can lead to higher levels of pollutant emissions, increased fuel consumption, and engine instability. For more than a century, AFR control has progressed from carburetor-based systems to electronically controlled port fuel injection (PFI) or gasoline direct injection (GDI) systems. In PFI or GDI systems, the precision of AFR regulation depends heavily on the performance of the controller governing the actuation of fuel injectors. This article reviews recent advancements in AFR control techniques, categorizing them into feedback, model-based, parameter estimation, robust, fuzzy, adaptive, neural network (NN), and machine learning (ML) approaches. At the end of each section, a comparative discussion outlines the most appropriate use cases for each technique, their relative performance against alternative approaches, implementation limitations, and studies that have demonstrated their applicability in real-world scenarios. Furthermore, graphical representations are provided to illustrate the annual volume of published research on IC engine control using each technique. These figures offer valuable insights into prevailing research trends and support the identification of promising directions for the development and implementation of future control strategies.

Adaptive air-fuel ratio control of dual-injection engines under biofuel blends using extreme learning machine

Detailed hydrogen–air chemical reaction mechanisms were coupled with the three-dimensional grids of an experimental hydrogen internal combustion engine (HICE) to establish a computational fluid dynamics (CFD) combustion model based on the CONVERGE software. The effects of different combustion modes on the combustion and emission characteristics of HICE under low load were studied. The simulation results showed that, with the increase in excess hydrogen, the equivalent combustion and excessive hydrogen combustion modes with medium-cooled exhaust gas recirculation (EGR) dilution could improve the intensity of the in-cylinder combustion of HICE, increase the peak values of pressure and temperature in the cylinder, and then improve the indicated thermal efficiency of HICE under low load. However, larger excessive hydrogen combustion could weaken the improvement in performance; therefore, the performance of HICE could be comprehensively improved by the adoption of excessive hydrogen combustion with a fuel–air ratio below 1.2 under low load. The obtained conclusions indicate the research disadvantages in the power and emission performances of HICE under low load, and they are of great significance for the performance optimization of HICE. Furthermore, a control strategy was proposed to improve the stability of HICE under low load.