The document presents an experimental study on the effects of substituting Compressed Natural Gas (CNG) for diesel fuel in a compression ignition engine. Experiments were conducted at different CNG substitution levels of 2.5 LPM, 7.5 LPM, and 12.5 LPM and compression ratios of 16.5, 17.5, and 18.5. Performance parameters like brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, and brake specific energy consumption were calculated. The results showed that as CNG substitution increased, performance parameters like brake thermal efficiency and volumetric efficiency decreased while brake specific fuel consumption and brake specific energy consumption increased. The highest performance was achieved at a compression ratio of 17.5. Ex
Performance Study of Ethanol Blended Gasoline Fuel in Spark Ignition EngineIOSR Journals
Growing energy needs and environmental concern worldwide have propelled the interest for quest
and utilization of renewable and eco friendly fuels .Various substitutes are available to be used engines with the
possibility of reducing harmful emissions. In this work gasoline is taken as reference which is blended with
ethanol. Physical properties relevant to the fuel were determined for the four blends of gasoline and ethanol. A
four cylinder, four stroke, varying rpm, Petrol engine connected to eddy current type dynamometer was run on
blends containing 5%,10%,15%,20% ethanol and performance characteristics were evaluated. In this paper it
is shown that the higher blends can replace gasoline in a SI engine, results showed that there is a reduction in
exhaust gases and increase in Mechanical efficiency, Specific Fuel Consumption and air fuel ratio on blending.
We can conclude from the result that using 10% ethanol blend is most effective and we can utilize it for further
use in SI engines with little constraint on material used to sustain little increase in pressure
Natural gas engine combustion research based on bench testIJRES Journal
In this paper, mainly research on LNG(CNG) engine with outside-cylinder premixed combustion mode, the combustion mode can determine the gas engine emissions and power performance. There are three kinds of engine combustion -Lean combustion, Equivalent combustion and Mixed combustion mode by using equivalent combustion/lean burn combined. The innovation point lies in this paper is that this experiment adopts mixed combustion mode by burning strategy control, can be achieved in guarantee engine fuel economy, power performance , meet the requirements of Euro V combustion emissions regulations.
SIMULATION, EXERGY EFFICIENCY AND ENVIRONMENTAL IMPACT OF ELECTRICITY OF A 62...Zin Eddine Dadach
The first part of this study is to simulate a Natural Gas Combined Cycle (NGCC) for a production of about 620 MW of electricity using the commercial software Aspen Hysys V9.0 and the Soave-Redlich-Kwong (SRK) equation of state. The aim of the second part is to use exergy-based analyses in order to calculate its exergy efficiency and evaluate its environmental impact under standard conditions.
Experimental investigation of Methanol blends with gasoline on SI engineIJERA Editor
Automobile have become a very important part of our modern life style. And it runs on fossil fuel. But the excessive use of fossil fuels will very soon leads to the energy crises so the future of automobile based on fossil fuels has been badly affected by two major problems. That is less availability of fuel and environmental degradation. So it is very important to found some new renewable non polluting alternative fuels to ensure the proper and safe survival of internal combustion engines. In present study we evaluate the performance of two stroke single cylinder spark ignition engine with ratio of 10%, 20% and 30% of methanol and gasoline by volume. Performance parameters (brake thermal efficiency, brake specific energy consumption and brake specific fuel consumption) were determined at various loads on engine with methanol blended gasoline. The comparison was made on performance of conventional SI engine with pure gasoline operation. As a result, brake thermal efficiency and brake specific fuel consumption showed improved performance when compared with pure gasoline performances.
Performance Study of Ethanol Blended Gasoline Fuel in Spark Ignition EngineIOSR Journals
Growing energy needs and environmental concern worldwide have propelled the interest for quest
and utilization of renewable and eco friendly fuels .Various substitutes are available to be used engines with the
possibility of reducing harmful emissions. In this work gasoline is taken as reference which is blended with
ethanol. Physical properties relevant to the fuel were determined for the four blends of gasoline and ethanol. A
four cylinder, four stroke, varying rpm, Petrol engine connected to eddy current type dynamometer was run on
blends containing 5%,10%,15%,20% ethanol and performance characteristics were evaluated. In this paper it
is shown that the higher blends can replace gasoline in a SI engine, results showed that there is a reduction in
exhaust gases and increase in Mechanical efficiency, Specific Fuel Consumption and air fuel ratio on blending.
We can conclude from the result that using 10% ethanol blend is most effective and we can utilize it for further
use in SI engines with little constraint on material used to sustain little increase in pressure
Natural gas engine combustion research based on bench testIJRES Journal
In this paper, mainly research on LNG(CNG) engine with outside-cylinder premixed combustion mode, the combustion mode can determine the gas engine emissions and power performance. There are three kinds of engine combustion -Lean combustion, Equivalent combustion and Mixed combustion mode by using equivalent combustion/lean burn combined. The innovation point lies in this paper is that this experiment adopts mixed combustion mode by burning strategy control, can be achieved in guarantee engine fuel economy, power performance , meet the requirements of Euro V combustion emissions regulations.
SIMULATION, EXERGY EFFICIENCY AND ENVIRONMENTAL IMPACT OF ELECTRICITY OF A 62...Zin Eddine Dadach
The first part of this study is to simulate a Natural Gas Combined Cycle (NGCC) for a production of about 620 MW of electricity using the commercial software Aspen Hysys V9.0 and the Soave-Redlich-Kwong (SRK) equation of state. The aim of the second part is to use exergy-based analyses in order to calculate its exergy efficiency and evaluate its environmental impact under standard conditions.
Experimental investigation of Methanol blends with gasoline on SI engineIJERA Editor
Automobile have become a very important part of our modern life style. And it runs on fossil fuel. But the excessive use of fossil fuels will very soon leads to the energy crises so the future of automobile based on fossil fuels has been badly affected by two major problems. That is less availability of fuel and environmental degradation. So it is very important to found some new renewable non polluting alternative fuels to ensure the proper and safe survival of internal combustion engines. In present study we evaluate the performance of two stroke single cylinder spark ignition engine with ratio of 10%, 20% and 30% of methanol and gasoline by volume. Performance parameters (brake thermal efficiency, brake specific energy consumption and brake specific fuel consumption) were determined at various loads on engine with methanol blended gasoline. The comparison was made on performance of conventional SI engine with pure gasoline operation. As a result, brake thermal efficiency and brake specific fuel consumption showed improved performance when compared with pure gasoline performances.
Studies of performance and emission characteristics of compressed natural gas...IOSR Journals
In Bangladesh, petrol, diesel and octane are conventionally used as an engine fuel. Petrol and
octane are used only transport sector. Diesel is used in transport, agriculture and power generation among
them 45% of diesel is consumed in transport sector. Total demand of liquid fuel is rising day by day. The
country has no natural sources of liquid fuels. As a result a huge amount of money spent for importing fuel from
abroad. This expenditure will be massive amount within a few years. The gas could be compressed natural gas
(CNG) or bio methane. The advantage is that this reduces fuel costs and when local bio methane is used, it also
contributes to the use of a more sustainable fuel supply.
CNG system suppliers are currently developing dual-fuel technology and have already converted
trucks, using government grants. Furthermore, various exploratory studies into the dual-fuel principle are being
conducted under contract to various municipalities in the context of sustainable transportation (fermentation of
city waste to produce bio methane for use as engine fuel). According to World Health Organization (WHO), the
safe limit of dust particles in the atmosphere is 40 to 80 micrograms, whereas in Dhaka city, it is 1700 to 2200
micrograms. To minimize environmental pollution in Dhaka, CNG played a vital role now a day. To use CNG
on commercial basis, different programs are taken to use compressed natural gas (CNG). This program mainly
concentrated on road transport. These programs cannot spread throughout the country due to some difficulties.
But there is a huge potentiality in road, marine, railway and stationary engines to use CNG.
COMBUSTION OPTIMIZATION IN SPARK IGNITION ENGINESBarhm Mohamad
The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using special fuel manifold. However, the satisfactory engine performance of the dual alcohol–gasoline blends need to be proved. The test fuels were GF, blend M35g65 (35 % methanol, and 65% GF by volume), blend E40g60 (40% ethanol, and 6o% GF by volume). The blend M35g65 was selected to match the vapor pressure (VP) of GF. The test fuels were a lean mixture with excess-air ratio of λ=1.1. The reaction parameters are taken from literatures and fitting calculations. Mathematical model and Computer software AVL program were conducted on a naturally-aspirated, spark ignition engine. The results show that indicate thermal efficiency (ITE) improved whereas the exhaust gas temperature (EGT) of the blends reduced, which is a benefit that reduces compression work. The regulated emissions were also reported. The blend E40g60 was recommended in preference to use because the former had shortened combustion duration, high energy content and its VP was selectively matched to that of GF's.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Investigation on multi cylinder s.i engine using blends of hydrogen and cngeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Performance and emission analysis of four stroke twin spark single cylinder S...ijsrd.com
An internal combustion (IC) engine has a predominant role in a low power generation and a virtual monopoly in mobile applications today. One of the best methods to improve the engine performance and reduce the exhaust emission in a SI engine is by using introduction of twin spark into the combustion chamber. The main purpose of this study is to investigate the effects of twin spark using CNG fuel in SI engine. The performance and emission analysis of an engine are investigated by experiment with CNG kit and gas analyzer. From this study the fuel consumption is reduce in twin spark arrangement for the same power output as compare to single spark using both of the fuel gasoline as well as CNG. Engine emission is considerably reduced using twin spark plug.
Combined numerical experimental study of dual fuel diesel engine to discuss t...Shans Shakkeer
It is my m.tech seminar presentation,on the basis of a study carried out by Carmelina Abagnale a, Maria Cristina Cameretti a,Luigi De Simio b, Michele Gambino b, Sabatino Iannaccone b, Raffaele Tuccillo ( Dipartimento di Ingegneria Industriale, Università di Napoli Federico II, Italy b Istituto Motori, C.N.R., Napoli, Italy ) were presented in 68th Conference of the Italian Thermal Machines Engineering Association, ATI2013, and Published by Elsevier ltd. in 2013
Studies of performance and emission characteristics of compressed natural gas...IOSR Journals
In Bangladesh, petrol, diesel and octane are conventionally used as an engine fuel. Petrol and
octane are used only transport sector. Diesel is used in transport, agriculture and power generation among
them 45% of diesel is consumed in transport sector. Total demand of liquid fuel is rising day by day. The
country has no natural sources of liquid fuels. As a result a huge amount of money spent for importing fuel from
abroad. This expenditure will be massive amount within a few years. The gas could be compressed natural gas
(CNG) or bio methane. The advantage is that this reduces fuel costs and when local bio methane is used, it also
contributes to the use of a more sustainable fuel supply.
CNG system suppliers are currently developing dual-fuel technology and have already converted
trucks, using government grants. Furthermore, various exploratory studies into the dual-fuel principle are being
conducted under contract to various municipalities in the context of sustainable transportation (fermentation of
city waste to produce bio methane for use as engine fuel). According to World Health Organization (WHO), the
safe limit of dust particles in the atmosphere is 40 to 80 micrograms, whereas in Dhaka city, it is 1700 to 2200
micrograms. To minimize environmental pollution in Dhaka, CNG played a vital role now a day. To use CNG
on commercial basis, different programs are taken to use compressed natural gas (CNG). This program mainly
concentrated on road transport. These programs cannot spread throughout the country due to some difficulties.
But there is a huge potentiality in road, marine, railway and stationary engines to use CNG.
COMBUSTION OPTIMIZATION IN SPARK IGNITION ENGINESBarhm Mohamad
The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using special fuel manifold. However, the satisfactory engine performance of the dual alcohol–gasoline blends need to be proved. The test fuels were GF, blend M35g65 (35 % methanol, and 65% GF by volume), blend E40g60 (40% ethanol, and 6o% GF by volume). The blend M35g65 was selected to match the vapor pressure (VP) of GF. The test fuels were a lean mixture with excess-air ratio of λ=1.1. The reaction parameters are taken from literatures and fitting calculations. Mathematical model and Computer software AVL program were conducted on a naturally-aspirated, spark ignition engine. The results show that indicate thermal efficiency (ITE) improved whereas the exhaust gas temperature (EGT) of the blends reduced, which is a benefit that reduces compression work. The regulated emissions were also reported. The blend E40g60 was recommended in preference to use because the former had shortened combustion duration, high energy content and its VP was selectively matched to that of GF's.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Investigation on multi cylinder s.i engine using blends of hydrogen and cngeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Performance and emission analysis of four stroke twin spark single cylinder S...ijsrd.com
An internal combustion (IC) engine has a predominant role in a low power generation and a virtual monopoly in mobile applications today. One of the best methods to improve the engine performance and reduce the exhaust emission in a SI engine is by using introduction of twin spark into the combustion chamber. The main purpose of this study is to investigate the effects of twin spark using CNG fuel in SI engine. The performance and emission analysis of an engine are investigated by experiment with CNG kit and gas analyzer. From this study the fuel consumption is reduce in twin spark arrangement for the same power output as compare to single spark using both of the fuel gasoline as well as CNG. Engine emission is considerably reduced using twin spark plug.
Combined numerical experimental study of dual fuel diesel engine to discuss t...Shans Shakkeer
It is my m.tech seminar presentation,on the basis of a study carried out by Carmelina Abagnale a, Maria Cristina Cameretti a,Luigi De Simio b, Michele Gambino b, Sabatino Iannaccone b, Raffaele Tuccillo ( Dipartimento di Ingegneria Industriale, Università di Napoli Federico II, Italy b Istituto Motori, C.N.R., Napoli, Italy ) were presented in 68th Conference of the Italian Thermal Machines Engineering Association, ATI2013, and Published by Elsevier ltd. in 2013
Realisor helps create the information and business conversations to deliver greater results. It is business software and a flexible and engaging process. See www.realisor.com for more info.
Use for benefits realisation/ management, business cases, assurance, governance and programs and portfolios.
WHY USE?
People are more engaged and effective plans are created with greater efficiency. Delivery has greater transparency and this enables people to make clearer and faster governance decisions.
This allows costs and risks to be reduced and greater benefits delivered. Reputation can be protected and customer, employee and stakeholder satisfaction can then be increased.
PERFORMANCE AND EMISSION ANALYSIS OF POROUS MEDIA COMBUSTION CHAMBER IN DIESE...IAEME Publication
Diesel engines, particularly direct injection types, have been an important choice as prime movers in heavy-duty applications such as on-road, off-road, marine and industrial usage due to their high brake thermal efficiency. The fuel economy and exhaust emission regulations, new technologies, development time and cost reduction require increasingly sophisticated solutions to improve the diesel engine performance and reduce exhaust emissions. In this paper we have analyzed the combustion and emission performance of a diesel engine with a porous media for different blends of fuel.
Performance and emission characteristics on glow plug hot surface ignition c....eSAT Journals
Abstract The concept of using alcohol fuels as alternative to diesel fuel in diesel engine is recent one. The scarcity of transportation petroleum fuels due to the fast depletion of the petroleum deposits and frequent rise in their costs in the international market have spurred many efforts to find alternatives. Alcohols were quickly recognized as prime candidates to displace or replace high octane petroleum fuels. Innovative thinking led to find varies techniques by which alcohol can be used as fuel in diesel engine. Amongst the fuel alternative proposed, the most favourest ones are methanol and ethanol. The specific tendency of alcohols to ignite easily from a hot surface makes it suitable to ignite in a diesel engine by different methods. The advantage of this property of alcohols enables to design and construct a new type of engine called surface ignition engine. Methanol and ethanol are very susceptible to surface ignition, this method is very suitable for these fuels. The hot surfaces which, can be used in surface ignition engine are electrically heated glow plug with hot surface. Hence present research work carries the experimental investigation on glow plug hot surface ignition engine, by adding different additives with methanol and ethanol as fuels, with an objective to find the best one performance, emission and compression parameters. Keywords: GHSI, Ethanol, Low Heat Rejection, PSZ, Additive (Iso amyl nitrate).
The Prevalence of Alcohol Consumption among Commercial Drivers in Uyo Local G...IOSR Journals
Abstract: The purpose of the study was to assess the prevalence of alcohol consumption among commercial
drivers in Uyo metropolis. Five research questions and three null hypothesis design was adopted, and the
instrument for the study was mainly interview schedules.
Due to the transitory nature of drivers in Uyo motor parks, convenient sampling was used to draw 160 drivers
who use Uyo motor parks.
The descriptive statistics percentage was used to answer the research questions, while chi – square statistics
was used to test the hypotheses at 0.05 level of significance. All the drivers interviewed drink alcohol for several
reasons. The sale of alcohol in the park and its environs has significant (P< 0.05) influence on their use. There
is no statistically significant difference (P>0.05) in the perceived influence of the use of alcohol on health with
respect to years of experience and age of drivers. The study was concluded with appropriate recommendation to
help the situation.
Key words: alcohol, drivers, prevalence and Uyo
“Relationship of Kinematic Variables with the Performance of Standing Broad J...IOSR Journals
Abstract: The purpose of investigation was to study the relationship of kinematics variables with the
performance of standing broad jump. Subjects were randomly selected from J.N.V. University, Jodhpur and
M.D.S. University, Ajmer. The criterion measure used for this study was the performance in standing broad
jump and selected kinematics variables. To analyze the raw data coefficient of correlation (r) were calculated
and results were compared with the help of Analysis of variance (ANOVA) technique where level of significance
was set at .05.
Effect of Pilot Fuel Quantity on the Performance and Emission Characteristics...IOSR Journals
The serious environmental pollution and the energy crisis all over the world has caused for
development of the lower pollution and lower energy consumption automobile to become major research goal.
With huge back ground, Compressed Natural Gas (CNG) is projected as the best alternative fuel for the country
like India. The properties of CNG make it an ideal fuel for direct use in spark ignition engines. Conversion of
any existing spark ignition engine to operate on natural gas is relatively simple with available equipment. Many
spark ignition engine vehicles are successfully operating in major cities of India with CNG fuel. However CNG
cannot be used as a fuel in diesel engines with ease. Since the maximum engines at present run on diesel, it will
be very much useful if a solution could be found to alter the existing diesel engine with minimum modifications
to run on CNG. Several researchers could attempt to run diesel engines with CNG. In the process three methods
were reported to be successful to use CNG as a fuel in diesel engines, they are (i) Spark ignited gas mode (ii)
Direct injection of CNG in dual fuel mode and (iii) Premixed CNG dual fuel mode. In the present work a
premixed dual fuel engine was developed which can perform well for the entire range of load and experiments
are carried out by varying the pilot fuel amount and studied the effect of pilot fuel amount on engine
performance and emissions characteristics and determined optimum fuel injection quantity for better
performance and lower emissions.
COMPARATIVE EMISSION ANALYSIS OF CNG AND OCTANE IN RETROFITTED CAR ENGINESIAEME Publication
Comparative emission analysis of octane and compressed natural gas (CNG) fueled retrofitted spark ignition car engine refers to exhaust emission (carbon monooxide, carbon di-oxide, Nitrogen Oxide) analysis and exhaust temperature on car engines which are operated with either gasoline or CNG using a solenoid actuated valve mechanism. The analysis was successfully carried out with the help of an exhaust gas analyzer (IMR 4000). Octane was used as the conventional fuels, whereas CNG was the alternative fuel. Comparative analysis of the experimental result showed the retrofitted engine produced higher exhaust gas temperature andNOx emission over different engines of different mileage when were used with CNG.
Other emission contents were significantly lower than those of the gasoline emissions.
ABSTRACT: In this paper, the control scheme of a Liquefied Petroleum Gas (LPG)–diesel dual-fuel engine with electronic
control is illustrated, the external characteristics and load characteristics of the LPG– diesel dual-fuel engine and the diesel
engine are compared and analyzed. The experimental results show that, compared with diesel, the output performance of
dual fuel is not reduced, while smoke emission of dual fuel is significantly reduced, NOx emission of dual fuel is hardly
changed, but HC emission and CO emission of dual fuel are increased and fuel consumption of dual fuel is reduced.
Keywords: LPG–Diesel dual fuel, electronic control, engine performance, pollutant emissions, fuel consumption
An Experimental Investigation of Performance and Emissions of LPG as Dual Fue...IJERA Editor
The usage of diesel engine generating set (Gen set) increasing day by day where the places without connection
to power grid or emergency power supply when the grid fails. Worldwide dual fuel engines are becoming
popular because of high performance and low emissions. LPG with diesel is a proven technology in case of
vehicles, but in diesel engine power plants it is far so.
The proposed work is concentrated on higher load of Diesel Engine Generator with LPG as dual fuel by keeping
environmental concern. A test is conducted on performance of engine along with emissions at different
proportions of Diesel and LPG including 100% diesel. An experimental set up is made with simple
modifications on existing genset to supply LPG as secondary fuel into Diesel.
PERFORMANCE AND EMISSION CHARACTERISTICS OF BIOGAS –PETROL DUAL FUEL IN SI EN...IAEME Publication
Towards the effort of reducing the dependency on petroleum fuel, one of the solutions is to use gaseous fuel as a partial supplement of liquid petrol fuel. In this experiment, four cylinder SI engine was tested with petrol as a fuel and petrol with partial substitution of biogas as fuel. Different percentages of biogas substitution in petrol were tested like B10 (90% Petrol +10% biogas), B20(80% Petrol +20% Biogas), B40(60%Petrol +40% Biogas). Test was conducted to study and compare the performance, emission and combustion characteristic of the engine for both the modes of engine operation. Biogas production was carried out using kitchen waste as a feedstock. Results clearly revealed that performance of the engine improved with the increases in amount of the gas substitution. Bsfc and brake thermal efficiency were found to improve. However emissions increased with the increases in the amount of gas substitution.
PERFORMANCE EVALUATION OF A CONVENTIONAL DIESEL ENGINE RUNNING IN DUAL FUEL M...IAEME Publication
Present study evaluates the performance of a compression ignition engine running in dual fuel mode with Liquefied Petroleum Gas and Petroleum Diesel. The LPG was inducted in the engine by Fumigation method at the rate of 0.094, 0.189 & 0.283 Kg/hr. Major performance parameters such as Brake power, Brake thermal efficiency, Brake specific fuel consumption etc. were evaluated at different load & different fuel combinations.
Performance Optimization of Diesel Engine with Chicken Waste Bio-diesel Blend...IJERD Editor
This paper presents an experimental study that include an application of the grey relational analysis
to determine the optimum factor level to obtain optimum multiple-performance characteristics of a diesel engine
run with different low-percentage chicken waste biodiesel-diesel blends. Grey relational analysis is used for data
analysis and four factors, namely, low-percentage chicken waste biodiesel-diesel blend, compression ratio,
injection timing and injection pressure were each considered at four levels. An L16 orthogonal array was used to
collect data for various engine performance related responses under constant engine loads. Results of
confirmation tests showed good agreement with predicted quantities. The results of the study revealed that the
combination of a blend consisting of 10% chicken waste biodiesel (B10), a compression ratio of 18, an injection
pressure of 220 bar and an injection timing of 19° bTDC produces maximum multiple performance of the diesel
engine.
Optimization of performance and emission characteristics of dual flow diesel ...eSAT Journals
Abstract
Depleting sources of fossil fuels coupled with after effects of exhaust gases on environment i.e. global warming and climate change has necessitated the need for development and use of alternate biodegradable fuels. In this present study optimization of performance and emission characteristics has been carried out using dual flow of CNG and Diesel with varying EGR under varying load by Taguchi method. Optimum values of output response parameters have been calculated with the help of regression equation and influence of various factors on output response has carried out with the help of analysis of variance.
Keywords: Taguchi method, CNG, EGR, biodegradable fuels
Experimental Investigation of Performance and Emissions of a Compression Igni...J. Agricultural Machinery
This study presents the effects of compressed natural gas fuel on a four-cylinder compression ignition engine. Compressed natural gas as the main fuel and diesel fuel as the igniter were used to investigate performance and emissions from the dual fuel engine. According to the engine speed and load, the amount of diesel fuel as igniter was adjusted using mechanical changes in the governor, while no ignition system was used. The engine experimental tests were performed at engine speeds of 1200, 1400, 1600, 1800 and 2000 rpm, using diesel fuel and dual fuel. These data were collected in the Engine Research Center of Tabriz Motorsazan Company and experimental runs were repeated three times. The maximum torque of the engine in diesel mode was 360 N m at 1400 rpm. Compared to the diesel mode, the dual fuel mode showed the maximum torque by 334 N m at 1600 rpm, which is about 26 N m less than that gained from the diesel mode. Considering emissions analysis at 2000 rpm, it is seen that the amount of NOX, HC, CO2 and CO emissions in the dual fuel mode was 20, 53, 16 and 86% more than diesel mode, respectively. However, O2 and soot showed the highest reduction at 2000 rpm for dual fuel mode by 51% and 69% respectively. This study indicated that there was a considerable enhancement in exhausted emissions when the injection of the diesel fuel as igniter was done mechanically. In this regard, control the amount and time of the igniter injection could likely be helped for better control of emissions. Therefore, further research on the modification of the diesel injection system as igniter or CNG injection system is needed towards reducing emissions.
Prediction on Increasing the Efficiency of Single Cylinder DI Diesel Engine U...IJMER
Exhaust Gas Recirculation (EGR) System means to use the Exhaust Gas coming from
Exhaust Manifold to Inlet Manifold in order to reduce the Emission of NOX which is particularly very
harmful. Engine without EGR are more pollutant & uses more atmospherically air for combustion. By
Implementation of EGR system in Engine, the Partial Exhaust Gas is re-circulated again in Engine. The
aim of this work is to review the potential of exhaust gas recirculation (EGR) to reduce the exhaust
emissions, particularly NOX emissions, and to delimit the application range of this technique. The
system is very much Eco Friendly. Using Exhaust Gas Recirculation (EGR) Technique in engines, the
emissions are very much controlled. This method is very reliable in terms of fuel consumption.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 13, Issue 1 Ver. V (Jan. - Feb. 2016), PP 52-59
www.iosrjournals.org
DOI: 10.9790/1684-13155259 www.iosrjournals.org 52 | Page
Consequences Of CNG Substitutions On Performance And
Exhaust Emissions Of A Diesel Engine With Varying Compression
Ratios
Rentala Girish Srivatsa1*
, Sarap Raghavendra1
1
(Department of Mechanical Engineering, Lords Institute of Engineering & Technology, Hyderabad,
Telangana, India)
Abstract: Compressed Natural Gas (CNG) is a hopeful alternative fuel as well as fuel additive to improve
performance and emissions in CI engine, due to its lower carbon content and less knocking tendencies. CNG
and Diesel dual fuel operation is regarded as one of the best ways to control emissions from diesel engines and
simultaneously saving petroleum-based diesel fuel. Dual fuel engine is a conventional diesel engine which burn
either gaseous fuel or diesel or both at the same time. This paper presents an experimental study on the effects
of CNG substitutions on the performance and emission characteristics of CI engine. In the present work,
experimental investigations were carried out by inducting CNG into the combustion chamber in conjunction
with air as CNG –Diesel dual fuel mode. Experiments were conducted on different substitutions of CNG i.e. 2.5
LPM, 7.5 LPM, and 12.5 LPM at different compression ratios (CR) i.e. 16.5, 17.5, 18.5 respectively and the
performance characteristics were calculated. The effect of CNG substitutions on emissions was measured at
various CR’s and reported.
Keywords: Compressed Natural Gas, CI Engine, Compression Ratio, Performance, Exhaust Emissions.
I. Introduction
Internal Combustion Engines have become an integral part of our life without which the world would
stop moving and will not meet its daily necessities. These engines act like the hearts of the majority of the prime
movers. The fuel used by these engines are generally non-renewable, highly expensive and cause environmental
pollution. This calls for the search for an alternative fuel, which promises to be harmonious in correlation with
sustainable development, conservation, management, efficiency and environmental preservation. [1]. CNG is
one such fuel which has been used as a fuel for spark ignition engine [2] and also for evolving compression
ignition engine researchers as an alternative fuel.
Compressed Natural Gas (CNG) is a natural product. It improved from organic matter over millions of
years ago. CNG is used in its primary gasiform state. Since it does not have to be transformed into any
secondary fuel, it can be utilized directly without any occurrence of environmental pollution. Researchers have
been investigating on many alternate fuels and a wide range of fuels were reviewed to substitute the vehicular
fuels such as gasoline and diesel. In such a case, CNG becomes a candidate mainly because of its low
emissions and abundant availability in the world. Much interest has centred on CNG due to its potential for
low particulate and NOX emissions. CNG and Diesel dual fuel operation is regarded as one of the best ways to
control emissions from diesel engines and simultaneously saving petroleum-based diesel fuel. The introduction
of CNG along with intake air and diesel changes the thermodynamic and chemical properties of the mixture in
the cylinder and thus the dual fuel combustion has its own performance and emission characteristics. The
diesel fuel which acts as a source of ignition is often referred to as pilot diesel [3].
In the present scenario, the infrastructure system of supplying, refuelling and its cost are the main
problems for the commercialization of alternative fuels. When compared with other alternative fuels, CNG
may possibly overcome these aspects if there is an increase in the production facilities and distribution
networks, as they are available in most advanced countries.
Table 1. Typical Composition of Natural Gas [4]
Components Volume Percent (%) Mass Percent (%)
Methane 92.29 84.37
Ethane 3.60 6.23
Propane 0.80 2.06
Butane 0.29 0.99
Pentane 0.13 0.53
Hexane 0.08 0.39
Carbon Dioxide 1.00 2.52
Nitrogen 1.80 2.89
Water 0.01 0.01
2. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 53 | Page
II. CNG For CI Engines
There have been several fundamental studies on dual fuel engines. Abhishek Paul et al. [5] studied on
the diesel-CNG and diesel ethanol blends. They investigated on the emission reduction characteristics of a CI
engine fuelled with diesel-ethanol blends with CNG enrichment. The study revealed that the bio-ethanol blend
increases the indicated mean effective pressure with an extension of the ignition delay and HC emission
increased, CO emission decreased. The results of this study showed a great improvement in PM and NOx
emissions with an increase in thermal efficiency. Chandra et al. [6] researched on gaseous fuel. In this
experiment, CNG-Methane enriched biogas & raw biogas was used as gaseous fuels. For performing the
experiments, CI engine was converted to SI engine with few modifications in ignition timing and compression
ratio. They found that there is a power loss due to the conversion of the engine from CI to SI and are calculated
as 31.8%, 35.6% and 46.3% for CNG, methane enriched biogas and raw biogas respectively. It is found that the
power development rate in case of raw biogas was significantly decreasing when compared to CNG and
methane enriched biogas. The comparative study resulted that the speed of the engine operating on biogas was
low compared to CNG and methane enriched biogas. In case of diesel engine co-fuelling of diesel with LPG [7,
8], methane [9, 10], natural gas [11] and hydrogen–methane combination were studied. Most research in dual
fuel engine has concentrated on defining the extent of dual fuelling and its effect on emissions and performance
[12] use of additives to methane has been reported to be effective to promote combustion at homogeneous lean
operation.
Table 2. Thermodynamic Properties of Diesel and CNG [13]
Thermodynamic Properties Diesel CNG
Stoichiometric Ratio 14.5 15.7
Density @25o
C (kg/ m3
) 833-881 2.52
Flammability Limits (% vol. in air) 0.7-5 15.6
III. Experimental Method And Experimentation
The engine used in the present study is Kirloskar TV-1, single cylinder, water cooled, four stroke,
variable compression ratio (VCR), and compression ignition diesel engine with specifications given in Table 3,
while a schematic diagram of the test rig setup is shown in fig. 1. This engine is coupled to an eddy current
dynamometer. Air temperature, coolant temperature and throttle position are connected to open electronic
control unit which controls fuel injector, fuel pump and idle air. The load was varied from 0% to 100% at an
interval of 25%. A digital shaft encoder was used to measure crankshaft position. The signals from piezo
sensors and the crank encoder were acquired using national instruments logical card. Data acquisition was
made using National Instruments Lab VIEW acquisition system developed in-house. Several series of
experimental cycles were conducted with varying CNG substitutions at 2.5 LPM, 7.5 LPM, and 12.5 LPM. At
each cycle, the engine was operated at rated injection opening pressure of 200 bar and the exhaust emissions
was noted. All the experiments were carried out at full load with a constant speed of 1500 rpm and at different
compression ratios of 16.5, 17.5 and 18.5 respectively. The injection timing was set to a value of 23o
BTDC.
CNG flows were measured by using a specially designed flow meter. Initially, the CNG from the
cylinder enters into the mixing chamber with the desired flow rate by using the flow meter. Here the CNG mixes
with air. Because of the enrichment of CNG with air in the mixing chamber, proper atomization takes place with
the diesel fuel and peak pressure was observed inside the combustion chamber. The diesel is used as a pilot fuel.
When CNG supply was increased, the diesel injection was automatically decreased due to the governor
mechanism of the engine to maintain a constant speed.
The exhaust gas analyser used is MN-05 multi-gas analyser (5 gas version) is based on infrared
spectroscopy technology with signal inputs from an electrochemical cell. Non-dispersive infrared measurement
technique used for the measurement of CO, CO2, and HC gases. Each individual gas absorbs infra-red radiation
that can be used to calculate the concentration of sample gas. The Gas Analyser uses an electrochemical cell to
measure oxygen concentration. It consists of two electrodes separated by an electrically conducted liquid or
cell. The cell is mounted on a polytetrafluorethene membrane through which oxygen can diffuse. The device,
therefore, measures oxygen partial pressure. If a polarizing voltage is applied between the electrodes the
resultant current is proportional to the oxygen partial pressure.
3. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 54 | Page
Fig.1. Schematic layout of CNG-Diesel dual fuel engine test rig
Table 3. Specifications of Test Engine
Particulars Specifications
Type Vertical, 4-Stroke Cycle, Totally Enclosed, Water Cooled
Make Kirloskar Oil Engines
Model TV-1
Type of Ignition Compression Ignition
Rated Power (KW) 3.5
Constant Speed (rpm) 1500
Bore (mm) 87.5
Stroke (mm) 110
Connecting Rod Length (mm) 234
Variable Compression Ratio 12:1 to 18.5:1
Cylinder Capacity (cc) 661
Fuel Injection Direct Injection
Injection Timing 23o
BTDC
Dynamometer Eddy Current Type
Piston Bowl Hemispherical
Starting Auto Start
Injection Pressure (bar) 200
IV. Results And Discussions
An experimental investigation was carried out for performance and exhaust emissions of the engine by
inducting CNG at different flow rates and various performance parameters and emission graphs have been
drawn at full load with respect to compression ratio. The plotted graphs depict the comparative study of a diesel
engine operating under pure diesel mode and dual fuel mode.
4.1 Effect of CNG Substitution on Performance Parameters
4.1.1 Brake Thermal Efficiency
16.5 17.0 17.5 18.0 18.5
27.0
27.5
28.0
28.5
29.0
29.5
30.0
30.5
31.0
BTE(%)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
4. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 55 | Page
Fig. 2. Effect of CNG Substitutions on BTE at various Compression Ratios
Brake thermal efficiency is the measure of the performance of the engine calculated as the ratio of
brake power generated to the heat input. The above fig. 2 shows the variation of brake thermal efficiency with
respect to different compression ratios i.e. 16.5, 17.5 and 18.5 respectively. BTE was calculated at full load
conditions at 2.5, 7.5 and 12.5 LPM CNG substitutions. It was observed that as substitutions of CNG increased,
BTE decreased at all compression ratios because CNG possesses extreme low flame velocity. It was also noticed
that as the compression ratio increased from 16.5 to 17.5, BTE increased and then slightly decreased at 18.5 CR.
This is due to the fact that increase in compression ratio ensures a complete combustion due to injection of fuel
in higher temperature and pressure compressed air, better air-fuel mixing and faster evaporation. The highest
value of BTE was noticed at 17.5 CR for pure diesel i.e. 30.89% and then followed by CNG substitutions of 2.5,
7.5 and 12.5 LPM i.e. 30.3%, 29.56% and 28.78% respectively.
4.1.2 Brake Specific Fuel Consumption
16.5 17.0 17.5 18.0 18.5
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
0.36
0.38
0.40
0.42
0.44
BSFC(Kg/KWh)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 3. Effect of CNG Substitutions on BSFC at various Compression Ratios
Brake specific fuel consumption is defined as the fuel flow rate per unit power output. Fig. 3 shows the
variation of brake specific fuel consumption for different compression ratios and different substitutions of CNG
when compared to that of pure diesel. It was observed that as the substitutions of CNG increased, BSFC
increased at all compression ratios when compared to pure diesel mode. CNG when enriched with diesel fuel
droplets, the mixture becomes lean which results in lower cylinder temperature and increase in brake specific
fuel consumption. Also, the trend of BSFC decreased with increase in compression ratio for pure diesel as well
as CNG substitutions as shown in the figure. This is due to the fact that increase in compression ratio reduces
BSFC due to a reduction in dilution of charge by residual gases, which results in better BTE and lower BSFC.
However, an increase in BSFC is observed with lower compression ratio due to low combustion pressure and
temperature. The lowest value of BSFC was noticed at 18.5 CR for pure diesel i.e. 0.21 Kg/KWh and then
followed by CNG substitutions of 2.5, 7.5 and 12.5 LPM i.e. 0.24, 0.28 and 0.31 Kg/KWh respectively.
4.1.3 Volumetric Efficiency
16.5 17.0 17.5 18.0 18.5
71.5
72.0
72.5
73.0
73.5
74.0
74.5
75.0
75.5
76.0
76.5
77.0
77.5
78.0
78.5
79.0
79.5
VolumetricEfficiency(%)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 4. Effect of CNG Substitutions on Volumetric Efficiency at various Compression Ratios
5. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 56 | Page
Volumetric efficiency is defined as the ratio of actual air capacity to ideal air capacity. The above fig. 4
shows the variation of volumetric efficiency for various CNG substitutions and at different compression ratios.
It was noticed from the figure that as the substitutions of CNG increased, volumetric efficiency decreased at all
compression ratios when compared to pure diesel mode. This is because heating up of inlet manifold due to
higher exhaust gas temperatures and due to radiation heat transfer in VCR engine. Also, as the compression ratio
increased from 16.5 to 17.5, volumetric efficiency decreased and then mildly increased at 18.5 CR. This is
because the increase in compression ratio increases the cylinder pressure and inlet air temperature leading to less
volumetric efficiency. The highest volumetric efficiency was noticed at 16.5 CR for pure diesel i.e. 79.06% and
then followed by CNG substitutions of 2.5, 7.5 and 12.5 LPM i.e. 77.31%, 75.96% and 73.77% respectively.
4.1.4 Brake Specific Energy Consumption
16.5 17.0 17.5 18.0 18.5
11500
12000
12500
13000
13500
14000
14500
15000
15500
16000
16500
17000
17500
BSEC(KJ/KWh)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 5. Effect of CNG Substitutions on BSEC at various Compression Ratios
Brake specific energy consumption is an essential and ideal parameter for comparing engine
performance of the fuels having different calorific value and density. Brake specific energy consumption in dual
fuel mode is calculated from the brake specific fuel consumption and calorific value of the dual fuel. From fig. 5
it is clearly observed that as substitutions of CNG increased, BSEC also increased at all compression ratios
when compared to pure diesel. This is due to lean air-fuel mixture which results in poor combustion efficiency
leading to increasing in brake specific energy consumption. At a compression ratio of 16.5, BSEC was highest
for all CNG substitutions and pure diesel mode followed by 17.5 CR and 18.5 CR. For CNG substitutions of
2.5, 7.5 and 12.5 LPM and at 16.5 CR, BSEC was 15260, 16789 and 17440 KJ/KWh respectively and for pure
diesel, it was 14649 KJ/KWh.
4.2 Effect of CNG Substitution on Emission Parameters
4.2.1 CO Emissions
16.5 17.0 17.5 18.0 18.5
0.14
0.16
0.18
0.20
0.22
0.24
0.26
0.28
CO(%vol)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 6. Effect of CNG Substitutions on CO Emissions at various Compression Ratios
Exhaust emissions play a significant role to predict the engine behavior. Fig. 6 shows the variation of
carbon monoxide for different compression ratios and different CNG substitutions. It was noticed that as the
substitutions of CNG increased, CO emissions significantly decreased at all compression ratios when compared
with pure diesel mode. 17.5:1 of compression ratio gives lowest CO emission as compared to all other
compression ratios and pure diesel fuel. The lowest CO emission at 17.5 CR is observed for CNG substitution of
12.5 LPM i.e. 0.14% by volume whereas for pure diesel it is 0.18% by volume. This may be due to better
6. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 57 | Page
combustion and less dilution of charge by residual gases accelerates the carbon oxidation reaction. At a lower
compression ratio of 16.5 CR, the CO emissions are increased due to more dilution of fresh air with residual
gases, lower compression temperature and poor mixing of fuel and air.
4.2.2 NOX Emissions
16.5 17.0 17.5 18.0 18.5
880
900
920
940
960
980
1000
1020
1040
1060
1080
1100
1120
1140
1160
1180
1200
NOx(ppm)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 7. Effect of CNG Substitutions on NOX Emissions at various Compression Ratios
The above fig. 7 depicts the behavior of NOX with respective compression ratios. It was observed that
as the CNG substitutions increased NOX emissions decreased. The addition of CNG to diesel causes a greater
reduction in NOX in comparison with pure diesel. This is because most of the dual fuel burnt under lean
premixed conditions result in low local temperatures. Also, as the compression ratio increased from 16.5 to 18.5
CR, NOX emissions gradually increased for all CNG substitutions as well as for pure diesel mode. The highest
NOX emission was noticed at 18.5 CR for pure diesel i.e. 1190 ppm and then followed by CNG substitutions of
2.5, 7.5 and 12.5 LPM i.e. 1110, 1085 and 1015 ppm respectively. This may be due to the fact that increase in
compression ratio increases the combustion pressure and temperature which accelerates the oxidation of
nitrogen to form NOX emissions. At lower compression ratio, the combustion temperature and pressure
decreases which leads to lower NOX emissions.
4.2.3 UHC Emissions
16.5 17.0 17.5 18.0 18.5
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
UHC(ppm)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 8. Effect of CNG Substitutions on UHC Emissions at various Compression Ratios
The formation of unburnt hydrocarbons inside the engine cylinder and top of the piston head and across
the piston rings was due to incomplete combustion. From the above fig. 8 it was depicted that as the CNG
substitutions increased, UHC emissions increased at all compression ratios when compared to pure diesel mode.
For CNG-diesel dual fuel mode, maximum brake thermal efficiency at all compression ratios was observed at
pure diesel mode. Hence, the formation of UHC content for pure diesel will be less than that of all substitutions
of CNG. The maximum UHC content was observed for 12.5 LPM of CNG substitution at 17.5 CR i.e. 88 ppm
followed by 7.5 LPM and 2.5 LPM i.e. 79 ppm and 72 ppm respectively. Also, increase in UHC emission is
observed with increase in compression ratio which is due to insufficient time for combustion process at higher
compression ratios.
7. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 58 | Page
4.2.4 CO2 Emissions
16.5 17.0 17.5 18.0 18.5
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
CO2(%vol)
Compression Ratio
PURE DIESEL
CNG 2.5LPM
CNG 7.5LPM
CNG 12.5LPM
Fig. 9. Effect of CNG Substitutions on CO2 Emissions at various Compression Ratios
The effect of carbon dioxide with compression ratio is explained in the above fig. 9. It was noticed that
the content of CO2 emissions was maximum under pure diesel mode compared to different substitutions of CNG
at all compression ratios. As the compression ratio increased from 16.5 to 17.5, the CO2 content decreased for
all substitutions of CNG and pure diesel because more amount of diesel was injected as the load was increased
for the same amount of CNG and from 17.5 to 18.5 CR, CO2 emission rapidly increased. The minimum CO2
content was observed at 17.5 CR when the engine was operating under pure diesel mode i.e. 4.48% by volume
followed by 2.5, 7.5, 12.5 LPM of CNG substitutions i.e. 4.13, 3.89 and 3.56% by volume.
V. Conclusions
Brake thermal efficiency decreased as the CNG substitutions increased because CNG possesses extreme
low flame velocity. Also as the compression ratio increased, BTE increased because increase in
compression ratio ensures a complete combustion due to injection of fuel at higher temperature and
pressure, better air-fuel mixing and faster evaporation.
Brake specific fuel consumption increased with increase in CNG substitutions because addition of CNG to
diesel results in lean mixture leading to lower cylinder temperature and hence higher BSFC. Increase in
compression ratio reduces BSFC due to a reduction in dilution of charge by residual gases, which results in
better BTE and lower BSFC.
Volumetric efficiency decreased with increase in CNG substitutions because of heating up of inlet manifold
due to higher exhaust gas temperatures and due to radiation heat transfer in VCR engine. Also, as the
compression ratio increased from 16.5 to 17.5, volumetric efficiency decreased and then mildly increased at
18.5 CR.
Brake specific energy consumption increased with increase in CNG substitutions. This is due to lean air-
fuel mixture which results in poor combustion efficiency leading to increasing in brake specific energy
consumption. Also, as the compression ratio increased from 16.5 to 18.5 CR, BSEC gradually decreased.
As the substitutions of CNG increased, CO emissions significantly decreased at all compression ratios.
Also, CO emissions decreased with increase in compression ratio due to better combustion and less dilution
of charge by residual gases that accelerates the carbon oxidation reaction.
NOX emissions decreased with increase in CNG substitutions because addition of CNG to diesel leads to
the burning of dual fuel under lean premixed conditions that result in low local temperatures and hence less
NOX content. Furthermore, increase in compression ratio increases NOX emissions due to increase in the
combustion pressure and temperature which accelerates the oxidation of nitrogen to form NOX emissions.
UHC content increased with increase in CNG substitutions because BTE was low for all CNG substitutions
when compared with pure diesel mode. Also, increase in UHC emission is observed with increase in
compression ratio which is due to insufficient time for combustion process at higher compression ratios.
It was noticed that the content of CO2 emissions was maximum under pure diesel mode compared to
different substitutions of CNG at all compression ratios. Also, as the compression ratio increased from 16.5
to 17.5, CO2 content decreased and increased rapidly with increase in compression ratio up to 18.5.
8. Consequences Of CNG Substitutions On Performance And Exhaust Emissions Of A Diesel Engine
DOI: 10.9790/1684-13155259 www.iosrjournals.org 59 | Page
Table 5. Nomenclature
CNG Compressed Natural Gas
CI Compression Ignition
CR Compression Ratio
LPM Liters per Minute
BTDC Before Top Dead Center
BTE (%) Brake Thermal Efficiency
BSFC (Kg/KWh) Brake Specific Fuel Consumption
BSEC (KJ/KWh) Brake Specific Energy Consumption
CO (% vol) Carbon Monoxide
CO2 (% vol) Carbon Dioxide
NOX (ppm) Oxides of Nitrogen
UHC (ppm) Unburnt Hydrocarbons
ppm Parts per Million
% vol Percentage by Volume
Acknowledgements
The authors express their sincere gratitude to the support of Lords Institute of Engineering &
Technology, Hyderabad for extending the laboratory facilities and continuing support to carry out the research
work in the Thermal Engineering Laboratory.
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