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PERFORMANCES OF A SPARK IGNITION (SI) ENGINE
FUELLED WITH LIQUEFIED PETROLEUM GAS (LPG) USING
LIQUID SEQUENTIAL INJECTION (LSI) TECHNIQUE
MOHD MUSTAQIM BIN TUKIMAN
UNIVERSITI TUN HUSSEIN ONN MALAYSIA
PTTAPERP
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PERFORMANCES OF A SPARK IGNITION (SI) ENGINE FUELLED WITH
LIQUEFIED PETROLEUM GAS (LPG) USING
LIQUID SEQUENTIAL INJECTION (LSI) TECHNIQUE
MOHD MUSTAQIM BIN TUKIMAN
A thesis report submitted in partial fulfillment of requirement for the award of the
Master of Engineering (Mechanical)
Faculty of Mechanical and Manufacturing Engineering
Universiti Tun Hussein Onn Malaysia
MAY 2017
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To my beloved parents, friend,
for their endless love, support and tolerance
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ACKNOWLEDGEMENT
In the name of Allah, the Most Merciful and the Most Compassionate. I thank
Allah for giving me the understanding and strength I needed to finish this study.
I would like to thank my supervisor Assoc. Professor Dr Mas Fawzi
Mohd Ali and my co-supervisor Dr Shahrul Azmir Osman, for their support,
impulse, tutoring and motivation along my research journey. My special thank to
my parent, Mr. Tukiman Nadi and Madam Siti Mariam Rahmat for the spiritual
support and their pray for my completion of this project.
I would like to record my thanks to the members of Automotive Research
Group (ARG-UTHM) (Assoc. Professor Dr Mas Fawzi Mohd Ali, Dr Shahrul
Azmir Osman, Dr Azwan Sapit, Dr Mohd Faisal Hushim and Mr. Muammar
Mukhsin Ismail) and my study comrade Mr. Norrizal Mustaffa, Mr. Rais
Hanizam, Mr. Khairul Ilman Sarwani, and Mr. Fathul Hakim Zulkifli for their
unequivocal support and advice for me throughout this research which has given
me confidence and strength to face any problems.
I also appreciate the cooperation from the Departments of Energy
Engineering and Thermofluids (JKT) and the Department of Manufacturing and
Industrial Engineering (JKPI), especially from Mr. Mzahar Abd Jalal and Mr.
Nizam Jamat for providing me the technical support to finish this research.
Without them this project is impossible to be complete. Lastly, I would like to
thank who have directly and indirectly contributed to the success of my study.
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ABSTRACT
The increment of fuel cost and environmental pollutions from transportation sector has
created interest on alternative fuels particularly in spark ignition (SI) engines. One of the
seen potential of alternative fuel is Liquefied Petroleum Gas (LPG). LPG has a research
octane number higher than gasoline and low carbon to hydrogen ratio content, thus the
LPG has the potential to give more power in SI engines and to reduce exhaust
emissions. An experimental work was conducted on a 1.6 Liters, 4-cylinder engine from
a Proton Gen 2 (S4PH), equipped with gasoline Multi Point Port Injection (MPI)
system. The engine was retrofitted with LPG Liquid Sequential Injection (LSI) and a
piggy-back system emulated the stock Electronic Control Unit (ECU). The engine was
tested in steady state conditions, which are based on engine speed from 1500rpm to
4000rpm with increment of 500rpm. The Throttle Position (TP) was varied at four
different levels that were 25%, 50%, 75% and 100% for every engine speed tested. The
findings from the experiment showed that the liquid phase LPG increased brake power
(BP) and brake torque (BT) in the range of 3% to 7%. The brake specific fuel
consumption (BSFC) of LPG at low engine speed (1500rpm to 2500rpm) was reduced
in the range from 21% to 52%. Meanwhile, at higher engine speed (3000rpm to
4000rpm) the LPG BSFC increased in average between of 3% to 57%. The carbon
monoxide (CO) exhaust emission was reduced in the range of 2% to 19% when using
LPG. The carbon dioxide (CO2) is also lower than gasoline in average between 9% and
18%. The hydrocarbon (HC) emission from LPG was increased in the range of 40% to
70%, and concentration of NOx emission was increased in average of 60% in
comparison with gasoline. As a conclusion, the LPG LSI system used in S.I engine is
more effective than gasoline at low engine speed condition due to low fuel consumption
and emission.
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ABSTRAK
Peningkatan kos bahan api dan pencemaran alam sekitar yang terhasil daripada sektor
pengangkutan telah menarik minat terhadap penggunaan bahan api alternatif yang
digunakan pada sistem enjin pencucuhan percikan api (SI). Salah satu potensi yang di
lihat sebagai bahan api alternatif ialah gas petroleum cecair (LPG). LPG mempunyai
nombor penyelidikan oktana (RON) yang tinggi disamping kandungan nisbah karbon
yang rendah dibandingkan dengan hidrogen. Oleh itu LPG berpotensi untuk memberi
kuasa yang lebih pada enjin SI dan mengurangkan pencemaran pelepasan asap ekzos.
Pada kajian ini, eksperimen dijalankan pada enjin 1.6Liter, 4-silinder dari Proton Gen 2
(S4PH) dan sistem penghantaran bahan api dilengkapi oleh sistem multi suntikan (MPI).
Enjin ini telah dimodifikasi dengan suntikan turutan cecair (LSI) LPG dan sistem unit
kawalan eletronik (ECU) yang asal pula telah disambungkan kepada sistem LSI
tersebut. Enjin telah ditetapkan kepada mod keadaan kekal, di mana kelajuan putaran
enjin bermula dari 1500rpm hingga 4000rpm dengan peningkatan kelajuan putaran enjin
sebanyak 50rppm. Terdapat empat perbezaan kedudukan posisi injap pendikit (TP) iaitu
25%, 50%, 75% dan 100% untuk setiap ujikaji mod kekal dijalankan. Hasil dapatan
kajian menunjukkan pengunaan LPG pada fasa cecair telah meningkatkan kuasa brek
(BP) dan tork brek (BT) dalam lingkungan 3%-7%. Brek penggunaan bahan api khusus
(BSFC) bagi LPG telah berkurang sebanyak 21%-52% pada kelajuan rendah putaran
enjin (1500ppm-2500ppm). Manakala BSFC pada kelajuan tinggi putaran enjin
(3000rpm-4000rpm) menunjukkan peningkatan 3%-57%. Pencemaran CO telah
berkurang sebanyak 2%-19% dan CO2 juga berkurang dalam purata 9% dan18%
apabila LPG digunakan. Pencemaran HC mencatatkan peningkatan sebanyak 40%-70%
dan NOx juga meningkat kepada 60% apabila dibandingkan dengan gasoline.
Kesimpulannya, pengunaan sistem LPG LSI pada enjin S.I adalah lebih efektif
berbanding gasoline jika digunakan pada kelajuan rendah putaran enjin.
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CONTENTS
CHAPTER TITLE PAGE
TITLE
DECLARATION
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
ABSTRAK
CONTENTS
LIST OF TABLES
LIST OF FIGURES
LIST OF SYMBOLS AND ABBREVIATIONS
LIST OF APPENDIX
i
ii
iii
iv
v
vi
vii
xii
xiii
xvi
xix
CHAPTER 1 INTRODUCTION 1
1.1 Background of Study
1.1.1 Demands of Fuel
1.1.2 Asian Fuel Price
1.1.3 Emission from Vehicle in The
Transport Sector
1.2 Problem statement
1.3 Objectives
1.4 Scopes
1.5 Significance of Study
1
2
3
4
6
7
8
9
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CHAPTER 2 LITERATURE REVIEW 10
2.1 Introduction
2.2 The Internal Combustion Engine System
2.3 Exhaust Gas Pollution
2.3.1 Carbon Monoxide - CO
2.3.2 Carbon Dioxide - CO2
2.3.3 Hydrocarbon - HC
2.3.4 Oxide of Nitrogen - NOx
2.4 Liquefied Petroleum Gas (LPG) Processed
from Oil Refining
2.5 Liquefied Petroleum Gas (LPG)
Manufacturing
2.6 Liquefied Petroleum Gas (LPG) as an
Alternative Fuel
2.7 Liquid and Gaseous Injection for S.I
Engine
2.7.1 Injector system
2.7.2 Indirect Injection
2.8 Liquefied Petroleum Gas (LPG) Engine
Technology
2.8.1 Bi-fuel Engine Technology
2.8.2 Dual-fuel Engine Technology
2.9 Liquefied Petroleum Gas (LPG) Conversion
System
2.9.1 Mechanically Control LPG
Carburetion System (First
Generation)
2.9.2 Electronically Controlled LPG
Carburetion System (Second
Generation)
2.9.3 LPG Injection System Electronically
10
10
14
15
15
15
16
16
18
20
22
23
23
26
26
27
27
28
30
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Controlled (Third generation)
2.9.4 Sequential Gaseous Stage LPG
Injection (Fourth Generation)
2.9.5 Sequential Liquid Stage LPG
Injection (Fifth Generation)
2.10 Liquefied Petroleum Gas (LPG) Liquid
Sequential Injection (LSI) as a Latest
Generation
2.10.1 Properties of Liquefied Petroleum
Gas (LPG) in Liquid phase
2.11 Advantage of Liquefied Petroleum Gas
(LPG) for Latest Technology
2.12 Disadvantage of Liquefied Petroleum Gas
(LPG) for Latest Technology
2.13 Performance and Emissions of LPG Vehicle
2.14 LPG Refueling Systems
2.15 Summary
32
34
36
39
39
40
41
41
48
51
CHAPTER 3 METHODOLOGY 52
3.1 Overview
3.1.1 Process flow chart
3.2 Retrofit Kits for the Latest LPG Liquid
Sequential Injection (LSI)
3.2.1 Conversion of Gasoline to LSI LPG-
Spark Ignition Engine
3.2.2 Liquid Sequential Injection LPG
Conversion System
3.2.3 LPG Storage
3.2.4 LPG Refueling System
3.3 Experimental Apparatus
3.3.1 Test Engine
3.3.2 Chassis Dynamometer
52
53
54
55
56
58
60
64
64
65
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3.3.3 Measurement of Fuel Consumption
3.3.4 Measurement of In-cylinder Pressure
3.3.5 Measurement of Air Fuel Ratio and
the Exhaust Gas Emissions
3.3.6 Bosch Scan Tool KTS 570 V1.2
Management Systems
3.4 Engine Test
3.4.1 Steady-state Test
3.4.2 Engine Test Parameters
3.5 Standard Experimental Procedures
3.5.1 Preparatory Experimental
3.5.2 Running the Engine
3.5.3 Steady-state Engine Speed Mode
3.6 Summary
66
67
69
70
71
72
72
73
73
74
75
76
CHAPTER 4 RESULT AND DISCUSSION 77
4.1 Introduction
4.2 The LPG Refueling process
4.3 Comparison of Gasoline and LPG
Effect on the Engine Performance and
Exhaust Emission
4.3.1 The Effects of Gasoline and LPG on
Brake Power (BP)
4.3.2 The Effect of Gasoline and LPG on
Brake Torque (BT)
4.3.3 Brake Specific Fuel Consumption
(BSFC) on Gasoline and LPG
4.3.4 Carbon Monoxide (CO) Emission
4.3.5 Carbon Dioxide (CO2) Emission
4.3.6 Hydrocarbon (HC) Emission
4.3.7 Nitrogen Oxide (NOx) Emission
77
77
79
79
81
83
85
87
89
91
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CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 94
5.1 Conclusion
5.2 Future Recommendation
94
96
REFERENCES
APPENDIX
97
103
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LIST OF TABLES
TABLE TITLE PAGE
2.1 Classification of reciprocating engine by application
2.2 Effects of contaminants in LPG
2.3 Composition of LPG by country
2.4 Specification of LPG and gasoline in United Kindom
2.5 Reviews on characterizing on LPG engine
2.6 Reviews on characterizing on LPG engine (continued)
2.7 Reviews on characterizing on LPG engine (continued)
2.8 Reviews on characterizing on LPG engine (continued)
2.9 Reviews on characterizing on LPG engine (continued)
2.10 Reviews on characterizing on LPG engine (continued)
3.1 The specification of the LPG toroidal tank
3.2 Specification of LPG fuel pump
3.3 Specification of the LPG diaphragm pump
3.4 Specification of the test engine
3.5 The specification of dynamometer
3.6 Specification of the fuel flow meter display unit
3.7 The spec of the fuel flow meter
3.8 Specification of spark plug in-cylinder pressure sensor
3.9 Specification detail of the emission gas analyzer
3.10 The specification of Bosch scan tool KTS 570 V1.2
3.11 The steady-state set value
4.1 Air-fuel mixture from stock ECU mapping
13
20
21
22
42
43
44
45
46
47
59
60
62
65
66
67
67
69
70
71
72
91
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LIST OF FIGURE
FIGURE TITLE PAGE
1.1 Total world demands of gasoline fuel
1.2 Price of fossil fuel from 2010 to 2016
1.3 Fuel price in Asia
1.4 Total vehicle registered in Malaysia from 2010 to
2014 according to type
1.5 Malaysia's total CO2 emission from consumption of
conventional fuel
2.1 Four stroke operating cycle in an internal
combustion engine
2.2 Block diagram of LPG manufacturing
2.3 Chart of the LPG Fuel system delivery
2.4 Method of LPG injection
2.5 Generations of LPG
2.6 Diagram of the LPG fuel delivery control in first
generation
2.7 Mechanically controlled LPG Carburetion system
2.8 Flow diagram for second generation of LPG
2.9 Electronically controlled LPG Carburetion system
for the second generation
2.10 Diagram of LPG delivery control system in third
generation
2.11 Electronically controlled LPG injection system
2
3
4
5
6
14
18
22
25
28
29
30
31
32
33
34
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2.12 Diagram for function of sequential delivery system
fuel LPG
2.13 Diagram for fourth generation LPG gaseous
2.14 Schematic diagram for fifth generations
2.15 Diagram for fifth generation LPG-liquid phase
2.16 Configuration of liquid and gaseous phase LPG
2.17 Method for LPG refueling system
2.18 The LPG refueling station (BOB)
2.19 The LPG refueling station (FSS)
35
36
37
38
40
48
49
50
3.1 Research flow chart
3.2 Diagram of retrofit Kits for the latest LPG LSI
system
3.3 The process flow diagram for process assembly
3.4 The wiring diagram for the LSI LPG system
3.5 Schematic diagram for process conversion fuel
delivery LPG system
3.6 The parts of LPG storage systems
3.7 The process flow diagram for refueling
3.8 Schematic diagram of the LPG refueling station
3.9 Dish type nozzle for refueling process
3.10 Test engine for LPG
3.11 Dynapack chassis dynamometer
3.12 Diagram of pressure sensor placed in a cylinder
head
3.13 The schematic diagram of engine test conditions
4.1 Time duration for LPG refueling process
4.2 Comparison of brake power between gasoline and
LPG at various throttle valve positions
4.3 BP improvement % of LPG at 100% throttle valve
position
4.4 Comparison of brake torque between gasoline and
53
55
56
57
58
60
61
63
63
64
66
68
71
78
80
81
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LPG at several throttle valve positions
4.5 BT improvement % of LPG at 100% throttle valve
position
4.6 Comparison of BSFC between gasoline and LPG
at various engine speeds
4.7 BSFC improvement % of LPG at 100% throttle
valve position
4.8 Comparison of CO between gasoline and LPG at
various engine speeds
4.9 CO % of LPG at 100% throttle valve position
4.10 Comparison of CO2 between gasoline and LPG at
various engine speeds
4.11 CO2 % of LPG at 100% throttle valve position
4.12 Comparison of HC between gasoline and LPG at
various throttle positions
4.13 HC % of LPG increased than gasoline at 100%
throttle valve position
4.14 Comparison of NOx between gasoline and LPG at
various engine speeds
4.15 Comparison of NOx % of LPG and gasoline at
100% throttle valve position
82
83
84
85
86
87
88
88
90
90
92
93
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LIST OF THE SYMBOLS AND ABBREVIATIONS
AFR
BP
BT
BDC
BOB
BSFC
BTDC
CEN
CI
CNG
CO
CO2
C3H8
C4H10
DI
ECU
EDU
EGR
EIA
FSS
GDI
GGE
HC
HCCI
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Air/fuel Ratio
Brake Power
Brake Torque
Bottom Dead Center
Bubbling on Board
Brake Specific Fuel Consumption
Before Top Dead Center
European Committee for Standardization
Compression Ignition
Compress Natural Gas
Carbon Monoxide
Carbon Dioxide
Propane
Butane
Direct Injection
Electronic Control Unit
Engine Driver Unit
Exhaust Gas Recirculation
Energy Information Administration
Fast Fill Station
Gasoline Direct Injection
Gasoline Gallon Equivalent
Hydrocarbon
Homogeneous Charge Compression Ignition
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HP
H2O
H2S
ICE
LPG
LSI
MPI
MSDS
NA
NDIR
NOx
OBD
OEM
O2
PFI-G
RON
rpm
SAE
SI
TBI
TBI-G
TDC
TP
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Horsepower
Water Molecule
Hydrogen sulfide
Internal Combustion Engine
Liquefied Petroleum Gas
Liquid Sequential Injection
Multi Point Port Injection
Materials Safety Data Sheet
Naturally Aspirated
Non-disperse infrared
Oxide of Nitrogen
On-board Diagnostic
Original Equipment Manufacturer
Oxygen
Phase Port Injection - Gaseous
Research Octane Number
Rotation-Per-Minutes
Society Automotive Engineering
Spark Ignition
Throttle Body Injection
Throttle Body Injection - Gas
Top Dead Center
Throttle Position
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LIST OF APPENDIX
APPENDIX TITLE PAGE
A Apparatus calibration procedures and certificates 103
B Experimental data 109
C List of publications 117
D Photographic of retrofitted LPG LSI engine 119
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CHAPTER 1
INTRODUCTION
1.1 Background of Study
This ever-increasing consumption of fuel has led the world to face the twin challenge;
fuel scarcity and environment deterioration. The transportation sector has experienced
steady growth in the past 30 years, which almost entirely relies on fossil fuels, oil in
particular. This oil demand is projected to be increased around 60% of the growth and
expected to increase further in the future, where the current reserves-to-production ratios
are projected to stay in remaining 40 years (Leung, 2011). The numbers of demand is
directly proportional to the rate of production, which will affected the draining current
fossil fuel reserve levels at a faster rate. This has resulted in fluctuating oil prices and
supply disruptions. In form of the deterioration an environmental issues, the
transportation sector had also contributed to a huge and growing share of emissions that
affects global climate; namely Green House Gases (GHG) emissions. In additional, the
GHG emissions from the transportation sector were responsible for about 23% and keep
increasing from year to year (Khan et al., 2009). To overcome these limitations, the use
of an alternative fuel is the best option to be considered. Some of the promising
alternatives are Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), bio-
fuel, Hydrogen and others.
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1.1.1 Demands of Fuel
Figure 1.1 shows the demands of conventional fuel increase every year. This is because
the automotive and transportation industry has grown tremendously worldwide.
According to the Energy Information Administration (EIA, 2016), from 2010 until 2016
demands of a gasoline increased in the range of 30% to 40%. Meanwhile, the demands
of Liquefied Petroleum Gas (LPG) are drastic decrease in the range 5% to 10% in every
year. To avoid the demand and supply to become unstable, the introduction of
alternative fuel technology for consumers may be an answer. Alternative fuel such as
Liquefied Petroleum Gas (LPG), Compress Natural Gas (CNG), Biofuel, Hydrogen,
Fuel cell, Electric vehicle, methanol and ethanol need to be highlighted, as the societal
understanding how important alternative fuel. Consequently, introduce the alternative
fuel will be stable the demands of fuel for spark ignition (SI) and Compression Ignition
(CI) on the future.
Figure 1.1: Total world demands of conventional fuel (reproduced from EIA, 2016)
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1.1.2 Asian Fuel Price
Generally, the increasing demand of fossil fuel such as gasoline and diesel with respect
to fuel supply has created economy turmoil particularly in transportation sector. The
fluctuation of current fuel price depends on the demand of fuel in world wide. Figure 1.2
shows the trend of fuel price from 2010 to 2016. In sum, the fuel price increased from
2010 to 2011. The price for gasoline started at USD 2.75 to USD 3.48 per gasoline
gallon equivalent (GGE). Thus, fuel price for diesel increased from USD 2.67 to USD
3.42 per GGE, and for LPG increased from USD 4.02 to USD 4.28 per GGE. On 2012
until 2014, the gasoline shows a fluctuated trend which started from USD 3.65, USD
3.50 and USD 3.51 per GGE. Diesel fuel price was decrease from USD 3.56, USD 3.54
to USD 3.49 per GGE. The price of LPG declined steadily from USD 3.86 to USD 3.83
and increased to USD 4.34 per GGE. In 2015 to 2016, the fuel price for gasoline has
dropped from USD 2.47 to USD 2.10 per GGE. Meanwhile, diesel was dropped from
USD 2.64 to USD 2.03 per GGE and LPG fuel price has decreased from USD 4.00 to
USD 3.83.
2010 2011 2012 2013 2014 2015 20160.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
US
D/ G
aso
line
Ga
llon
Eq
uiv
ale
nt (G
GE
)
Years
GASOLINE
DIESEL
LPG
Figure 1.2: Price of fossil fuel from 2010 to 2016 (reproduced from EIA, 2016)
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Due to an increased demand and fluctuated fuel price in the world, the Asian fuel
prices also effected, especially in Malaysia. Until March 6, 2017, the fuel price was
trading at USD 0.52 per liters for gasoline and USD 0.5 for the diesel as shown in
Figure 1.3. The fuel price of gasoline is lower than other country in Asia and the diesel
fuel is the second lower price after Brunei due to the government subsidy. The subsidy
is invalid for the industrial and commercial purpose. Consequently, this has created a
burden on economy development, especially in the transportation sector, where
companies need to bear the higher costs of operating due to fluctuation in fuel price.
Malaysia*
Thailand
Singapore
Indonesia
Brunei
Philippines
Veitnam
Japan
China
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
* Price updated March 2017
1
0.9
1.12
0.93
0.84 0.65
0.95
0.62
0.51 0.32
0.61
0.68
1.42
0.98
0.98 0.76
0.52 0.5
Current Oil Prices in Asia (USD/Liters)
Co
un
trie
s
GASOLINE
DIESEL
Figure 1.3: Fuel price in Asia (reproduced from MyTravelCost, 2017)
1.1.3 Emission from Vehicle in the Transport Sector
Until 2014, the total number of registered road vehicle in Malaysia increased in the
range of 4% to 5% annually. Figure 1.4 shows the total of transport registered between
2010 and 2014. The figure was reproduced from the Road Trasport Department of
Malaysia., (2016). The trend indicated a sharp growth in the use of motorcycle, from
2011 to 2014 the motorcyclists was recorded from 9.442 million to 11.629 million. The
trend also same with the motorcar, the number of registered vehicle is increased from
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9.115 million to 11.028 million annually, followed by good vehicle, bus and taxi. The
increment of transportation industries and low price of vehicles have increased the
number of vehicles registered in Malaysia especially in the urban areas, has led to the
increment of environmental contamination.
The increasing the number of vehicles, contribute to the increasing overall
carbon dioxide (CO2) concentration emission in Malaysia. Figure 1.5 shows the trend of
the total CO2 emission from consumption of gasoline and diesel fuel. According to the
Natural Resources and Environment, (2014) the figure shows the increasing of CO2
emission from 1990 to 2010 annually. The CO2 emission from 1990 to 1995 was
recorded at an average of 102.6 million metric tons, meanwhile at 1995 to 2000 CO2
emission was increased by 116 million metric tons. Following from 2000 to 2005 the
increasing of total emission was at 127.4 million metric tons. Lastly, from 2005 to 2010
the CO2 emission reached at 130 million metric tons. The increase of CO2 is a very
critical problem because it affects the greenhouse gas and global warming. As an effort
to reduce the CO2 emission in Malaysia, alternative fuel, namely LPG in liquid phase
can be introduced. In addition, according to Myung et al., (2012) LPG produced more
power, less pollutant emitted and the demands still low compared to conventional fuel.
Motorcycle Motorcar Bus Taxi Goods Vehicle Others
0
2
4
6
8
10
12
0.8
82
0.8
63
0.5
40
0.5
16
0.5
161.1
60
1.1
16
1.0
32
0.9
98
0.9
66
0.1
06
0.1
00
0.0
93
0.0
90
0.0
85
0.0
65
0.0
63
0.0
74
0.0
72
0.0
69
11
.02
81
0.5
36
10
.35
59
.72
1
9.1
15
11
.62
9
11
.08
81
0.5
90
9.9
85
9.4
42
Nu
mb
er
of V
eh
icle
(M
illio
n)
Type of Vechicles
2010
2011
2012
2013
2014
Figure 1.4: Total registered vehicle in Malaysia from 2010 to 2014 according to type
(reproduced from Road Trasport Department of Malaysia, 2016)
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1990 1995 2000 2005 2010
0
25
50
75
100
125
150
Gasoline and diesel emission
Mill
ion
Me
tric
To
ns o
f C
O2
Years
CO2
Figure 1.5: Malaysia's total CO2 emission from consumption of conventional fuel
(reproduced from Natural Resources and Environment, 2014)
1.2 Problem Statement
The CO2 pollution issue was elevated in this country, which caused from transportation
sector that has increased at an average of 118.6 million metric tons in every five years.
In addition, world crude oil demands and supplies are dwindling, this cause the cost of
gasoline becoming increasingly expensive. In this research, several steps were being
chosen wisely to resolve this problem, the vehicle was retrofitted with LPG liquid phase
system as a bi-fuel system. This is because the liquid phase LPG produced low emission
and lower fuel consumption than gasoline. The brake power (BP) and brake torque (BT)
are comparable with gasoline, but the modification leads to the discovery of several
technical problems was studies by Kang et al., (2001), Sobiesiak et al., (2003), Gumus,
(2011), Myung et al.,(2014) and Farrugia et al., (2014).
According to Kang et al.,(2001) in year 2000 more than 6 million uses LPG on
the vehicle in Korea. The LPG vehicle received a warm welcome in automotive
industry. The LPG conversion systems can be divided into five generations, where the
first to fourth generation used gas phase for the fuel delivery system, while the latest
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technology system uses LPG in liquid phase. Based on the latest technologies of the
LPG conversion system; the Liquid Sequential Injection (LSI) technique offers various
advantages in comparison with the previous generation system. This implementation of
retrofitted LPG-LSI in SI engine is still limited and has substantial research gaps.
However, the implementing barriers need to be solved are:-
i. Retrofitting LPG LSI system for S.I engine
ii. The methodologies of fuel refuelling for the system
iii. The unknown characteristics of LPG LSI system in local vehicle in terms of for
S.I. engine; engine performances and exhaust gas emissions
iv. The trade-off fuel consumption analysis for both gasoline and retrofitted LPG-
LSI engine
Therefore, it is desired to have a spark ignition (SI) engine from local vehicle to
install LPG LSI system is functioning in bi-fuel system for running the both of fuel in
experiments. By installing an LPG LSI system in the local vehicle, it may open up
alternative solutions to solve the current issue.
1.3 Objectives
The objectives of this research are:
a) To identify the influence of liquid sequential injection (LSI) system liquified
petroleum gas (LPG) system of a Spark-ignition (SI) engine
b) To establish an LPG refueling system for an LPG tank designed for LSI
application
c) To analyze the engine performance and exhaust emission of gasoline fuel and
LPG
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1.4 Scopes
The scopes of this study are:
a) The composition of LPG used in this study is; 60% butane and 40% propane,
according to the Materials Safety Data Sheet (MSDS, 2015) of LPG in Malaysia.
b) The research focused on the installation of the retrofitted kit liquid sequential
injection (LSI) liquefied petroleum gas (LPG) at large passenger car with a
capacity of 1.6 Liters (S4PH GEN2) multi point port injection (MPI) spark
ignition (SI) engine.
c) This experiment used unleaded gasoline (RON95) and LPG liquid phase. Where,
to compare the engine performance and exhaust emission on local vehicle.
d) The LPG refueling system should be able to perform:
i. A transfer from LPG industrial cylinder tank (50kg) to the toroidal
external tank (17 kg) in the test vehicle with using diaphragm pump,
which is the pump has specific features for the LPG transfer process.
e) Analysis in terms of:
i. Engine performance
Brake power (BP)
Brake torque (BT)
Brake Specific Fuel Consumption (BSFC)
ii. Exhaust emission
Carbon monoxide (CO)
Carbon dioxide (CO2)
Hydrocarbon (HC)
Oxides of nitrogen (NOx)
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f) The experimental work was conducted via chassis dynamometer at these
conditions:
i. Steady-state conditions with specific engine speed; 1500rpm, 2000rpm,
2500rpm, 3000rpm, 3500rpm and the 4000rpm.
ii. Four different throttle valve positions; 25%, 50%, 75% and 100% throttle
valve positions.
f) Analyze the efficiency of energy consumed between gasoline and LPG in term
of brake specific fuel consumption (BSFC) at the specific engine speed and
throttle valve opening in order to compare the fuel economy
1.5 Significance of Study
Based on the experiment, the installation of LPG LSI system will produced new
knowledge in this study and the future studies. This research will also open a new
opportunity to introduce the LPG as a new alternative fuel in Malaysia. On the other
hand, this research also compared gasoline and LPG in term of performance, exhaust
emission and fuel economy in the 1.6 Liters (S4PH GEN2) engine. These results may
contribute as a reference to establish another alternative fuel in our country.
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LITERATURE REVIEW
2.1 Introduction
This chapter presents a review of literature on the efforts related to conversion and
evaluation of the LPG system into a spark ignition (SI) engine. It is an attempt to
establish the parameters, modification and technologies etc., which are required to make
this project successful. It began with the concept of an internal combustion engine
followed by the automotive trends from the findings of previous research experiments.
2.2 The Internal Combustion Engine System
The internal combustion engine (ICE) was producing the mechanical power, where the
chemical energy contained in the fuel (Heywood, 1988). There are two ignition type of
the internal combustion engine which is spark ignition (SI) and compression ignition
(CI).
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Following to the standard of ICE engine, they were divided in some classified which
are:
1. Engine operating cycle
a. Four stroke cycles - Completed the sequence power stroke with two
revolutions of the crankshaft and has four piston movements.
b. Two stroke cycles - Completed the sequence power stroke with a single
revolution of the crankshaft and has two piston movements.
2. Types of ignition
a. Spark Ignition (SI) - Need spark plug as an igniter to initiate the air/fuel
mixture in the combustion chamber.
b. Compression Ignition (CI) - The combustion process starts when the
air/fuel mixture self-ignites due to high temperature in the combustion
chamber cause by high compression.
3. Air intake process
a. Naturally Aspirated (NA) - No forced air induction pressure system.
b. Supercharged - Forced air induction in the intake manifold to
combustion chamber and increased the air pressure with the compressor
driven by the engine crankshaft.
c. Turbocharged - Forced air induction in the intake manifold to the
combustion chamber and increased the air pressure with turbine-
compressor driven by engine exhaust gas.
4. Method of fuel delivery for (SI) engine
a. Carbureted
b. Multipoint Port Fuel Injection (MPI) - One or more fuel injector in the
each cylinder's intake.
c. Throttle Body Fuel Injection (TBI) - Fuel injector are mounted
upstream in the intake manifold.
d. Gasoline Direct Injection (GDI) - Fuel injector are mounted in the
combustion chamber with injected fuel directly into the cylinder.
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5. Method of fuel delivery for (CI) engine
a. Direct Injection (DI) - The fuel will inject into the main combustion
chamber.
b. Indirect Injection - The fuel will inject into the secondary combustion
chamber.
c. Homogeneous Charge Compression Ignition (HCCI) - Some of fuel
will add during the intake stroke.
This classification is very important basic to understand internal combustion
engine. In addition, it helps to understand how the engine operates with a LPG LSI
system. According to Heywood (1988), the reciprocating engine from SI engine was
classified into four engine group as shown in Table 2.1 based on the power output; small
passenger cars, light commercial, large passenger cars and heavy engines commercial.
The small passenger car engine normally has the power output in the range of 15
kilowatts (kW) or 20 horsepower (HP) to 75kW or 100 HP. Followed by light
commercial engine has the power output in the range of 35 kW or 46 HP to 150 kW or
200HP. Meanwhile, for large passenger cars capable of producing power output in the
range of 75kW to 200kW and equivalent between 100HP to 268HP. Lastly, for the
heavy commercial has potential to generate power output in the range of 120kW or 160
HP to 400kW or 536 HP. These engines were categorized in the class road vehicle,
normally using for transportation sector.
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Table 2.1: Classification of reciprocating engine by application (Heywood, 1988)
Class
Service
Approximate
engine power range
Predominant
type
Road
vehicle
Small
passenger cars
15 kW - 75 kW
20HP -100 HP
Spark Ignition
(SI)
Light
commercial
35 kW - 150 kW
46 HP - 200 HP
Large
passenger cars
75 kW-200 kW
100 HP - 268 HP
Heavy
commercial
120 kW - 400 kW
160 HP - 536 HP
Generally, the reciprocating SI and CI engine for four stroke cycle engine
requires four operating cycles, which are intake stroke, compression stroke, power
stroke and exhaust stroke. Figure 2.1 shows the four-stroke operating cycle for a
complete combustion.
Firstly, the intake stroke, which the piston starts from Top Dead Centre (TDC)
and the piston travel downward to Bottom Dead Centre (BDC). At the same time, the
intake valve is open to draw fresh mixture air into the cylinder and the exhaust valve is
closed. The traveling was produced a pressure differential, where the vacuum was
created in the cylinder.
Secondly, the compression stroke process, the piston upward from BDC to TDC
and the both of the valves are closed. Compression process produced higher pressure
and temperature in the cylinder. Meanwhile, the injector start to inject the fuel and
followed by the spark plug start ignite in the combustion chamber. These processes
happen at a certain degree Before Top Dead Centre (BTDC). For the CI engine the
combustion starts from evaporate of fuel mixture, higher pressure and temperature in the
cylinder this due the self ignite and producing combustion in the combustion chamber.
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The next process is power stroke or expansion stroke, where the piston travels
downward from TDC to BDC. At this time, the high pressure and temperature forced the
piston downwards and rotate the crankshaft. Before the piston reach BDC the exhaust
valve starts to open and drop the cylinder pressure.
Lastly, exhaust stroke process, where piston starts to upwards from BDC to
TDC. Meanwhile, the exhaust valve opens until certain degree BTDC and the exhaust
valve fully closed at TDC. During exhaust valve open, the piston force out the burned
gases exit from the cylinder. The new operating cycle will be happening in the ICE.
Intake Compression Power Exhaust
Crankshaft
Connecting rod
Piston
Combustion
Chamber
Air-fuel
mixture
Intake valve
open
Spark plug
Exhaust
valve
closed
Valve closed Valve closed
Intake valve
closed
Exhaust valve
open
Exhaust gases
Spark
plug
firing
Figure 2.1: Four stroke operating cycle in an internal combustion engine (reproduced
from Britanicca, 2007)
2.3 Exhaust gas pollution
The automotive industry and transportation has grown tremendously in the world wide.
This gives challenges of environmental pollution, such as CO, CO2, HC and NOx
exhaust emissions produced from internal combustion engine. The effects of the
emission are contributing to global warming, acid rain, smog odors and other health
problem (Pulkrabek, 2004 ; Costa et al.,2012).
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2.3.1 Carbon Monoxide - CO
Carbon monoxide is colorless, odorless and tasteless, but the high toxic. This gas is one
of the byproducts and produced from incomplete combustion when the fuel burned. The
production rate of CO in the engine depends on the value of the air/fuel ratio (AFR). If
the air/fuel ratio in richer conditions, the oxygen is insufficient to react with the entire
carbon bond and produce higher carbon monoxide (CO) (Toyota, 2012).
In the fact that CO emission has high toxic gas, direct exposures will cause
headache, dizziness, vomiting and nausea. Meanwhile, when the exposes over in a long
period of time also cause risks of heart disease and death (Pulkrabek, 2004).
2.3.2 Carbon Dioxide - CO2
Generally, carbon dioxide consists of greenhouse gas (GHG). However the combustion
of hydrocarbon (HC) in fuel produced water vapor H2O and carbon dioxide CO2. The
use of fuel in lower carbon content per unit energy its gives positive effect of reducing
the CO2 emission (Gumus, 2011).
The increased of CO2 gas emissions is a critical issue, because the GHG was
increased and the effect is higher thermal radiation. Thus, the average of earth
temperature also increased and bring the phenomenon of "global warming" (Pulkrabek,
2004; Heywood, 1988; Osman, 2014).
2.3.3 Hydrocarbon - HC
Hydrocarbon (HC) emission produced from raw unburned fuel and the increasing of HC
had showed incomplete combustion in the engine. Other than that, the engine was
affected towards misfire when the large amount of HC. The factor increased of HC
emission is the delay of ignition timing, fuel delivery system problem and air induction
problem. To avoid from this problem the air/fuel mixture need to control in the
stoichiometric range and the ignition timing need to set as to follow the ideal ignition
timing as follows engine requirement (Toyota, 2012).
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2.3.4 Oxides of Nitrogen - NOx
Oxides of nitrogen (NOx) consists of nitric oxide (NO), with small amount of nitrogen
dioxide (NO2) and other nitrogen-oxygen combination (Pulkrabek, 2004).During the
combustion process the nitrogen was reacted with oxygen to form oxides of nitrogen
(NOx). According to Heywood (1988), the amount of NOx emission depends upon:
i. Temperature of the cylinder
ii. Pressure of cylinder
iii. Exhaust Gas Recirculation (EGR) system
iv. Injection timing
v. The properties of fuel
Effects NOx for the environments is acid rain, where the hazard to the ecosystem
by increasing irritation and effects of ozone. Meanwhile, the effects of human are
harmful to the lungs and other biological tissue (Pulkrabek, 2004; Heywood, 1988;
Osman, 2014).
2.4 Liquefied Petroleum Gas (LPG) Processed from Oil Refining
According to Bahadori (2014), LPG is produced from crude oil, where the LPG has
been produced by distillation process. LPG contains propane (C3H8), butane (C4H10) and
small amounts of propylene and butylenes. Mainly, the LPG gas is odorless, but for
safety precaution the LPG was added with pungent gas such as ethanethiol. This is
because to easy detect any leakage if it happen.
Production of the LPG gas from crude oil started from fractionation of natural
gas liquid by distillation, catalytic cracking, delays cookers and hydrocrackers process.
After all process done, the heated crude oil is pumped into the distillation tower and all
petroleum products are extracted a specific fraction including gasoline, naphtha,
kerosene, diesel, fuel oil oil and residue. In the extraction process for producing
petroleum products, the temperature of distillation tower was controlled as follows the
extraction point respectively. Therefore, the LPG gas product was flowing at the top of
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the distillation tower to the lowest boiling point. In this stage the LPG gas still in raw
natural gas condition because has methane, ethane, propane, isobutane, buddiene,
pentane and pentene. To extract of these gases from raw natural gas to LPG gas, various
techniques are used to recover LPG from natural gas:
i. Recontacting-compression
The raw natural gas stream in the top distillation tower will be compressed,
combined, cooled and fed up to separator. From these processes, the
separator will isolate the liquid phase passed through the de-ethanizer and
the vapor phase is used as fuel gas.
ii. Refrigeration
This method is common for recovery of LPG from gas streams. Where,
the gas streams will be refrigerate to obtain LPG fractions and producing
LPG components.
iii. Adsorption
By using silica gel, activated carbon and alumina the molecules are
bonded to the surface and the natural gas will be separated as follows the
LPG molecules.
Therefore, the natural gas liquid and associated heavy hydrocarbon such as
ethane, propane and butane must be through the recovery process in order to separate
the heavy hydrocarbon from the raw natural gas and to control dew point of the natural
gas stream. The other reason, components of the product will be sold as high as the
demands of the industries.
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2.5 Liquefied Petroleum Gas (LPG) Manufacturing
After LPG gas passed the recovery process, the LPG gas need to go through the
manufacturing process, to purify the LPG gas. The process manufacturing is shown in
Figure 2.2.
Raw natural gas stream
from distillation tower
Acid gas removal
Extraction unit
Fractionation unit
Product treatment unit
Finished product LPG
De-ethanizer section
Depropanizer section
Debutanizer section
Figure 2.2: Block diagram of LPG manufacturing
i. Acid gas removal
To remove gases contain corrosive acid such as carbon dioxide (CO2)
and hydrogen sulfide (H2S). The acid gas removal by using amine or
Benfield process. Removal acid gas is a compulsory process to produce
free natural gas.
ii. Extraction unit
The petroleum product stream was divided into two processes. The first
process has the liquid stream rich in propane, butane and gasoline will be
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sent to the fractionation tower as producing LPG product. The second
stream will be sent to the product gas unit for further processing.
iii. Fractionation unit
In the liquid stream consisted of ethane, propane, butane and pentane.
This product will be separate in the fractionator train and LPG ready to
sold. Generally, the fractionation tower has three columns to produce
LPG gas. There are:
De-ethanizer section- This process separated out ethane from this
column. The ethane was condensed in the condenser by using
propane at -7 ̊C and the gas was collected in the reflex drum.
Next, the non-condensed vapors (pure ethane) are sent to the fuel
gas system.
Depropanizer section- The pressure bottom product of De-
ethanizer is reduced and the product was entered the depropanizer
column. This product was condensed in the condenser and
produce propane. The condensed product (pure propane) was
collected into the reflex drum and flow to the fuel gas system
Debutanizer section- The bottom product from depropanizer is
expanding the pressure and fed to top of the tower. The product
will be condensed in the condenser and produce butane.
iv. Product treatment unit
After producing propane and butane from the fractionation plant, the
products need to go through the treatment process unit. The purpose of
this process is to remove some impurities such as water, hydrogen
sulfide, carbon disulfide and sulfur compound. The reason for removing
these compounds is shown in Table 2.2.
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Table 2.2: Effects of contaminants in LPG
Contaminates Reason for removal
Hydrogen sulfide Safety and environmental
Carbon dioxide Corrosion control
Carbon disulfide Avoid from freeze-out at
low temperature
Nitrogen Poisoning in downstream
facilities
Water Hydrate formation and
corrosion
LPG is considerable as flammable nontoxic gases. Therefore LPG was
commercial used for cooking in the common household. In the other hand, LPG also
used for aerosol propellant and hydrocarbon refrigerant. The advantage of LPG is it can
avoid from the damage ozone and uses of hydrocarbon refrigerant is more energy
efficient and cheaper than others chemicals. LPG also used as fuel, especially for
medium class vehicle such as a car. It is an advantage to use LPG as fuel, because it
burns cleaner than gasoline and diesel.
2.6 Liquefied Petroleum Gas (LPG) as an Alternative Fuel
Liquefied petroleum gas (LPG) is one of the clean alternative fuel and has low emission
of carbon dioxide (CO2) and high octane number. The uses of LPG in heavy duty engine
industries such as diesel, gasoline engine have potential to control the emission exhaust
(Khan & Watson, 2010 ; Oprešnik et al., 2012)
In year 2000, more than 6 million vehicle used LPG (Kang et al.,2001). It shows
that LPG is getting good acceptance in automotive industries. The composition of LPG
is mainly propane (C3H8) and butane (C4H10). This composition varies slightly by
season, country and the characteristics of supply crude oil, the refining process and cost
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refined product. Therefore, there is no specific standard value for compositions of LPG.
Table 2.3 shows the composition of LPG fuel in several countries.
Table 2.3: Composition of LPG by country (Saleh, 2008; Mustafa & Gitano-Briggs,
2009; MSDS, 2015)
Country Propane (%) Butane (%)
Malaysia 40 60
Austria 50 50
Australia 70 30
Belgium 50 50
France 35 65
German 90 10
Italy 25 75
United Kingdom 100 0
Netherland 50 50
In previous studies, LPG as fuel also reduce exhaust emission of oxide of
nitrogen (NOx) by decreasing the peak combustion temperature, anti-knock properties,
increase the volumetric efficiency and increase torque output (Kang et al., 2001;
Pundkar et al.,2012; Genchi et al., 2013). As shown in Table 2.4, the LPG has the
higher Research Octane Number (RON) as comparable with gasoline, where the value
of RON is in the range 106-111. Besides that, in term of performance the energy content
produced from LPG is higher, thus the power output from LPG is higher than gasoline.
In terms of CO2 emission, the LPG more advantage as the content of CO2 is lower. Thus,
LPG was promoted as superiority fuel than gasoline as follow the advantages.
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Table 2.4: Specification of LPG and gasoline in United Kingdom (Khan et al., 2006)
2.7 Liquid and Gaseous Injection for S.I Engine
The fuel delivery system is important for the engine, which is the process to supply fuel
in the combustion chamber and produce the combustion. Before the fuel through into the
combustion chamber the fuel has been mixed with air in the air intake manifold. Figure
2.3 shows the method for the fuel system delivery.
Injector System
Indirect Injection
Single Point Throttle
Body Injection (TBI)
Sequential Injection Banked Injection
Multi Point Port
Injection (MPI)
Figure 2.3: Chart of the LPG Fuel system delivery
Characteristics Liquified Petroleum Gas
(LPG) Gasoline
Chemical formula Butane C4H10 and
Propane C3H8 C8H18
Lower Heating Value (MJ/kg) 46.33 42.4
Research Octane Number (RON) 106-111 92-95
Relative Density at 25 ̊ C 0.51 0.74
Stoichiometries A/F ratio
(mass basic) 15.7 14.7
Relative CO2 per kJ 0.885 1
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2.7.1 Injector system
The fuel injector should be capable to control the amount of fuel injection into a
cylinder depending on the engine condition such as load and engine speed (Phuong,
2006; Roberto Cipollone, 2000). Generally, the LPG injector was divided into two types
(LPG liquid injector and LPG gaseous injector). The practicality of injector type
depends from the fuel condition. The LPG liquid injector can inject fuel at high pressure
in the range of 12 to 20 bar compared with the LPG gaseous injector that has a lower
pressure range of 3 to 4 bar. Meanwhile, the size of liquid injector is smaller than
gaseous injector because the higher density of the liquid (Watson & Phuong, 2007;
Mitukiewicz et al, 2015)
On the contrary, the uses of LPG liquid are capable to increase the torque output,
higher volumetric efficiency, reduced the backfire and reduce the exhaust gas emission.
Theoretically, the LPG in liquid phase will be vaporized in the surrounding intake air
manifold. Consequently, the temperature will be reduced and give effect to cooler air
intake. As a result, the density and mass of the fuel/air mixture will be greater. Hence, it
contribute for performance engine (Lutz et al, 1998; Szpica, 2016).
2.7.2 Indirect Injection
Indirect injection as shown in Figure 2.4 is divided into two types:
i. Throttle Body Injection (TBI)
ii. Multi Point Port Injection (MPI)
The throttle body injection (TBI) system has one or two fuel injectors, which the
injectors were mounted on the upstream of the throttle. For this system the air and fuel
were mixed before the throttle body, the process is similar to the carburetor systems,
but this injector is capable control the air/fuel ratio and the system offer a better
volumetric efficiency of the internal combustion engine. TBI system can increase the
performance by setting the electronic fuel schedule. However, the port injection spray is
more precise and gives a faster response time than the gas mixer system. The TBI
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system has weakness because the unequal division in terms of routes of travel during
air/fuel mixing induct in the intake manifold. According to Baker & Watson (2005) and
Masi (2012) the liquid phase LPG is not suitable for this system because the long
travelling process between the throttle body to the intake valve and the liquid phase
quickly vaporized to gas before the supply in the intake valve.
The multi port fuel injection (MPI) has many advantages over the TBI system
because the liquid phase LPG reduces the wettest in the intake air manifold wall and the
distance of travelling is near to the intake valve. The result is higher torque and power
output than the TBI system. The injector is mounted in every single air intake manifold
for the multi cylinder engine. The fuel injected in individual cylinder will follow the
firing order and the fuel injection quantity was controlled by the Electronic Control Unit
(ECU) depending on the engine speed and load. The injector for MPI has several types,
they are:
i. Bosch K-Jetronic; mechanical type and ability operate without the
Engine Driver Unit (EDU)
ii. Bosch L-Jetronic and LH-Jetronic; electronic type and the operation
depend on electronic controller
iii. Bosch KE-Jetronic; combine mechanical and electronic and operate
based on the mechanical MPI data acquisition
iv. Denso Disc type 297-2009; Welded seal construction and equipped with
fully electronic control. The finer fuel spray to reduce exhaust emission
v. Rochester ball type; These have excellent atomization and a wide spray
pattern. Mechanical and electronic controller with using EDU.
The MPI system was divided into two methods for injecting the fuel, firstly is
banked injection and second is sequential injection. Banked injection is one of the
method MPI systems to supply fuel in the engine. This system operates based on the
crank angle or cam angle sensor signal. In this system all injectors will spray with
simultaneously in a multi cylinder engine. Consequently, there has waste fuel when the
firing order still doesn't change for the next cycle duration. Secondly, the fuel delivery
MPI has optional system namely sequential injection. This system is more effective than
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REFERENCES
Bahadori. (2014). Natural Gas Processing Technology and Engineering Design (First
Edit). Gulf Professional Publishing is an imprint of Elsevier.
Baker, P. Watson, H. (2005). MPI Air / Fuel Mixing for Gaseous and Liquid LPG
Reprinted From : SI Combustion and Direct Injection SI Engine Technology. SAE
Technical Paper No. 2005-01-0246.
Bayraktar, H. &, & Durgun, O. (2005). Investigating the effects of LPG on spark
ignition engine combustion and performance. Energy Conversion and
Management, 46(13-14), 2317–2333.
Birch, B. J., & Jaeger, S. (2002). LPG Refueling Technology. SAE Technical Paper No.
2002-01-2739.
Boretti, A., & Watson, H. C. (2009). Development of a Direct Injection High Efficiency
Liquid Phase LPG Spark Ignition Engine. SAE Technical Paper No. 2009-01-1881.
Bosch. (2009). Premium Wireless Diagnostic Tester & Oscilloscope Series KTS 570
Scanner. (Bosch, Ed.) (1st Editio). Germany.
Britanicca. (2007). Encyclopedia Britannica Kids. Retrieved October 10, 2016, from
http://kids.britannica.com/elementary/art-89315/An-internal-combustion-engine-
goes-through-four-strokes-intake-compression
Campbell, M., Wyszyński, Ł. P., & Stone, R. (2004). Combustion of LPG in a Spark-
Ignition Engine. SAE Technical Paper No. 2004-01-0974.
Carter, N. (2013). Liquefied Petroleum Gas (LPG) Pump Control Systems and Methods.
Google Patents.
CEN. (2016). European Committee For Standardization. (CEN, Ed.) (2nd Editio).
Toronto. Retrieved from https://www.cen.eu
Ceviz, M. A., Kaleli, A., & Güner, E. (2015). Controlling LPG Temperature for SI
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98
Engine Applications. Applied Thermal Engineering, 82, 298–305.
Costa, M., Sorge, U., & Allocca, L. (2012). Increasing Energy Efficiency of a Gasoline
Direct Injection Engine Through Optimal Synchronization of Single or Double
Injection Strategies. Energy Conversion and Management, 60, 77–86.
Creative Engineer. (2015). LPG AC Diaphragm Pump Instruction Manual. Retrieved
December 23, 2015, from http://www.malharpumps.net/
Dynapack. (2000). Dynapack Dynamometer model 4022. (Dynapack, Ed.) (1st Editio).
New Zealand.
EIA. (2016). U.S Energy Information Administration. Retrieved November 20, 2016,
from http://www.eia.gov/environment/emissions/ghg_report/ghg_carbon.cfm
EMSD. (2007). Code of Practice for Liquefied Petroleum Gas Filling Stations in Hong
Kong, (2), 66. Retrieved from http://www.emsd.gov.hk
Erkus, B., Sürmen, A., & Karamangil, M. I. (2013). A Comparative Study of
Carburation and Injection Fuel Supply Methods in an LPG-Fuelled SI Engine.
Fuel, 107, 511–517.
Farrugia, M., Briffa, A., & Farrugia, M. (2014). Liquid State LPG Conversion of an
Older Vehicle. SAE Technical Paper No. 2014-01-2613.
Gas Italy. (2014). LPG Kit for LSI (Liquid Sequential Injection) System. (Gas Italy, Ed.)
(2nd Editio). Italy.
Genchi, G., Pipitone, E., Beccari, S., & Piacentino, A. (2013). Knock Resistance
Increase through the Addition of Natural Gas or LPG to Gasoline: An Experimental
Study. Sae (2013-24-0100).
Gumus, M. (2011). Effects of Volumetric Efficiency on The Performance and Emissions
Characteristics of a Dual Fueled (Gasoline and LPG) Spark Ignition Engine. Fuel
Processing Technology, 92, 1862–1867.
Heywood, J. B. (1988). Internal Combustion Engine Fundementals. McGrawHill series
in mechanical engineering.
Kang, K., Lee, D., Oh, S., & Kim, C. (2001). Performance of an Liquid Phase LPG
Injection Engine for Heavy Duty Vehicles. SAE Technical Paper No. 2001-01-
1958.
Khan, M. A., Watson, H., Baker, P., Liew, G., & Johnston, D. (2006). SI Engine Lean-
PTTAPERP
USTAKAAN TUNKU T
UN AMINAH
99
Limit Extension Through LPG Throttle-Body Injection for Low CO2 and NOX
Reprinted From : SI Combustion and Direct Injection SI Engine Technology. SAE
Technical Paper No. 2006-01-0495.
Khan, M. A., & Watson, H. C. (2010). 4 L Light Duty LPG Engine Evaluated for Heavy
Duty Application. SAE Technical Paper No. 2010-01-1463.
Khan, M. A., Watson, H. C., & Baker, P. (2009). Mixture Preparation Effects on
Gaseous Fuel Combustion in SI Engines. SAE Technical Paper No. 2009-01-0323.
Kim, J., Kim, K., & Oh, S. (2016). An Assessment of The Ultra-Lean Combustion
Direct-Injection LPG (Liquefied Petroleum Gas) Engine for Passenger-Car
Applications Under The FTP-75 Mode. Fuel Processing Technology, 154.
Kim, K., Kim, J., Oh, S., Kim, C., & Lee, Y. (2017). Evaluation of Injection and
Ignition Schemes for The Ultra-Lean Combustion Direct-Injection LPG Engine to
Control Particulate Emissions. Applied Energy, 194, 123–135.
Kim, T. Y., Park, C., Oh, S., & Cho, G. (2016). The effects of Stratified Lean
Combustion and Exhaust Gas Recirculation on Combustion and Emission
Characteristics of An LPG Direct Injection Engine. Energy, 115, 386–396.
Kistler. (2013). Combustion Analysis in Vehicles and The Test Bench. (Kistler, Ed.).
Switzerland. Retrieved from www.kistler.com
Krishnaiah, R., Ekambaram, P., & Jayapaul, P. B. (2016). Investigations on the effect of
Piston Squish Area on Performance and Emission Characteristics of LPG fuelled
Lean Burn SI Engine. SAE Technical Papers, 2016-Febru, 1051–1060.
Lera-López, F., Faulin, J., & Sánchez, M. (2012). Determinants of The Willingness-to-
Pay for Reducing the Environmental Impacts of Road Transportation.
Transportation Research Part D: Transport and Environment, 17(3), 215–220.
Leung, V. (2011). Slow Diffusion of LPG Vehicles in China-Lessons from Shanghai,
Guangzhou and Hong Kong. Energy Policy, 39(6), 3720–3731.
Liu, J., Zhang, X., Wang, T., Zhang, J., & Wang, H. (2015). Experimental and
numerical study of the pollution formation in a diesel/CNG dual fuel engine. Fuel,
159, 418–429.
Lutz, B. R., Stanglmaier, R. H., Matthews, R. D., & Wicker, R. (1998). The Effects of
Fuel Composition , System Design , and Operating Conditions on In-System
PTTAPERP
USTAKAAN TUNKU T
UN AMINAH
100
Vaporization and Hot Start of a Liquid-Phase LPG Injection System. SAE
Technical Paper No. 981388.
M. Ihsan Karamangil. (2007). Development of The Auto Gas and LPG-Powered Vehicle
Sector in Turkey : A Statistical Case Study of The Sector for Bursa. Energy Policy,
35, 640–649.
Masi, M. (2012). Experimental Analysis on a Spark Ignition Petrol Engine Fuelled with
LPG (Liquefied Petroleum Gas ). Energy, 41, 252–260.
Mitukiewicz, G., Dychto, R., & Leyko, J. (2015). Relationship Between LPG Fuel and
Gasoline Injection Duration for Gasoline Direct Injection Engines. Fuel, 153, 526–
534.
Mizushima, N., Sato, S., Ogawa, Y., Yamamoto, T., Sawut, U., Takigawa, B., …
Konagai, G. (2009). Combustion Characteristics and Performance Increase of an
LPG-SI Engine with Liquid Fuel Injection System. SAE Technical Paper No. 2009-
01-2785.
MSDS. (2015). Materials Safety Data Sheet Lpg in Malaysia (1st Editio). Malaysia.
Mustafa, K. F., & Gitano-Briggs, H. (2009). Liquefied Petroleum Gas ( LPG ) as an
Alternative Fuel in Spark Ignition Engine : Performance and Emission
Characteristics. Proceedings of ICEE 2009 3rd International Conference on
Energy and Environment, (December), 7–8.
MyTravelCost. (2016). Petrol Prices Around the World. Retrieved from
http://www.mytravelcost.com/petrol-prices/
Myung, C. L., Choi, K., Kim, J., Lim, Y., Lee, J., & Park, S. (2012). Comparative Study
of Regulated and Unregulated Toxic Emissions Characteristics from a Spark
Ignition Direct Injection Light-Duty Vehicle Fueled with Gasoline and Liquid
Phase LPG (Liquefied Petroleum Gas). Energy, 44(1), 189–196.
Myung, C. L., Ko, A., Lim, Y., Kim, S., Lee, J., Choi, K., & Park, S. (2014). Mobile
Source Air Toxic Emissions from Direct Injection Spark Ignition Gasoline and
LPG Passenger Car Under Various In-Use Vehicle Driving Modes in Korea. Fuel
Processing Technology, 119, 19–31.
Natural Resources and Environment. (2014). Malaysia’s Total Carbon Dioxide
Emission (3rd Editio). Malaysia.
PTTAPERP
USTAKAAN TUNKU T
UN AMINAH
101
Nayak, V., Rashmi, G. S., Chitragar, P., & Mohanan, P. (2016). Combustion
Characteristics and Cyclic Variation of a LPG Fuelled MPFI Four Cylinder
Gasoline Engine. Energy Procedia, 90(December 2015), 470–480.
Nylund, N., & Kyto, M. (1993). Propane Fueled Heavy-Duty Vehicles. SAE Technical
Paper No. 932817, (412).
Onosokki. (2014). FZ-2000 Series Mass Flowmeter Instruction Manual. (Onosokki,
Ed.) (1st editio). Japan.
Oprešnik, S. R., Seljak, T., Bizjan, F., & Katrašnik, T. (2012). Exhaust Emissions and
Fuel Consumption of a Triple-Fuel Spark-Ignition Engine Powered Passenger Car.
Transportation Research Part D: Transport and Environment, 17(3), 221–227.
Osman, S. A. (2014). Characterization of a C.I Engine Operated Using Retrofit
Fuelling Concept. Universiti Tun Hussein Onn Malaysia.
Pecqueur, M., Ceustermans, K., Huyskens, P., & Savvidis, D. (2008). Emissions
Generated from a Suzuki Liane Running on Unleaded Gasoline and LPG under the
Same Load Conditions. SAE Technical Paper No. 2008-01-2637.
Phuong, P. X. (2006). Comparison of Liquid and Gaseous Liquefied Petroleum Gas
Injection in a Spark Ignition Engine. Degree of Master of Eng, (September).
University of Sydney.
Pradeep, V., Bakshi, S., & Ramesh, A. (2015). Direct Injection of Gaseous LPG in a
Two-Stroke SI Engine for Improved Performance. Applied Thermal Engineering,
89, 738–747.
Proton. (2004). Engine Overhaul Proton GEN 2 (S4PH). (Proton, Ed.) (1st editio).
Malaysia: 2004.
Pulkrabek. (2004). Engineering Fundamental of the Internal Combustion Engine (2nd
editio). Pearson Prentice-Hall.
Pundkar, A. H., Lawankar, S. M., & Deshmukh, S. (2012). Performance and Emissions
of LPG Fueled Internal Combustion Engine : A Review. International Journal of
Scientific & Engineering Research, 3(3), 1–7.
Raslavičius, L., Keršys, A., Mockus, S., Keršiene, N., & Starevičius, M. (2014).
Liquefied Petroleum Gas (LPG) as a Medium-Term Option in The Transition to
Sustainable Fuels and Transport. Renewable and Sustainable Energy Reviews, 32,
PTTAPERP
USTAKAAN TUNKU T
UN AMINAH
102
513–525.
Road Transport Department of Malaysia. (2016). Static of Transports Anually in
Malaysia. Retrieved November 21, 2016, from
http://www.mot.gov.my/my/sumber-maklumat/statistik-tahunan-pengangkutan
Roberto Cipollone, C. V. (2000). A/F and Liquid-Phase Control in LPG Injected Spark
Ignition ICE. SAE Technical Paper No. 2000-01-2974.
SAE International. (2004). Surface Vehicle Standard J1349, 4970, 1–9.
Saleh, H. E. (2008). Effect of variation in LPG composition on emissions and
performance in a dual fuel diesel engine, 87, 3031–3039.
Sánchez, M., Borrás, C., Hergenrether, D., Sutton, W. H., & Chandra, H. (2001). Super-
Gas Fueling Stations. SAE Technical Paper No. 2001- 01-2472.
Sendyka & Noga. (2013). Combustion Process in the Spark-Ignition Engine with Dual
Injection System. Advance in Internal Combustion Engines and Fuel Technology.
Sierens, R. (1992). An Experimental and Theoretical Study of Liquid LPG Injection.
SAE Technical Paper No. 922363.
Siriwardena, S., Hunt, G., Teisl, M. F., & Noblet, C. L. (2012). Effective Environmental
Marketing of Green Cars: A Nested-Logit Approach. Transportation Research Part
D: Transport and Environment, 17(3), 237–242.
Sobiesiak, A., Hoag, M. W., & Battoei-avarzaman, M. (2003). LPG Port Injected Spark
Ignition Engine. SAE Technical Paper Series, (724).
SPTC. Ltd. (2009). Automotive Exhaust Emission Gas Analyzer. (SPTCKorea, Ed.) (1st
Editio). Kyonggido.
Szpica. (2016). Testing the Parameters of LPG Injector Solenoids as a Function of the
Lift of the Working Component and the Frequency of Impulses. Proceeding of 20th
International Scientific Conference. Transport Means, (October).
Toyota. (2012). Combustion Chemistry. Emissions.
Tugra Makina. (2012). LPG Toraidal Tank for vehicle (1st editio). Italy.
Vialle. (2016). LPG PUMP for the Trasportation. (Vialle, Ed.) (1st Editio). Italy.
Watson, H. C., & Phuong, P. X. (2007). Why Liquid Phase LPG Port Injection has
Superior Power and Efficiency to Gas Phase Port Injection. SAE Technical Paper
No. 2007-01-3552.
PTTAPERP
USTAKAAN TUNKU T
UN AMINAH
