International Journal of Engineering Trends and Technology (IJETT) – Volume 25 Number 4- July 2015
Hydrogen Technology in Dual Combustion IC Engines
Kavin Raja G1, Karthik R2, Santosh N3
1,2&3
Student, B.E Mechanical Engineering, Sri Krishna College of Engineering and Technology, Tamil Nadu,
India.
Abstract— In this paper, research on advanced engine
technology is discussed. This concept of engine uses two
different fuels at the same time to extract maximum work
from the engine. In this concept we are implementing the
idea of using hydrogen as the first fuel in addition to
secondary conventional fuels like gasoline and diesel. The
objective of this project is to provide a means for using
hydrogen in internal combustion engines. In this concept,
cylinder of the engine has two thermodynamic systems
which works on Otto Cycle or Diesel Cycle and are
separated by the moving boundary which is the piston. The
four strokes of the Otto Cycle or Diesel Cycle works
alternatively in the two systems. The two chambers of the
cylinder have their own intake, exhaust and fuel injection
systems. The hydrogen is injected by high pressure direct
injection and is ignited by compression ignition and direct
injection in turn will eliminate premature ignition of
hydrogen. The strokes in the lower chamber can be initiated
by just supplying heat energy to the cylinder block which is
sufficient to ignite the hydrogen. The high diffusivity of
hydrogen further increases the safety in case of a leak. This
concept of the engine can also run using one fuel in case of
absence of the other since both the systems work
independently. This engine can provide only reciprocating
motion as output and it must be converted to rotary motion
by suitable mechanisms. In today’s world of depleting
resources hydrogen seems to be a promising fuel and
because of its low emissions, it could be the most ideal one
to be used.
Keywords— Hydrogen Engine, Renewable Energy
Sources, Eco friendly Engine Dual Combustion Engine,
Hydrogen IC Engine.
I. INTRODUCTION
Today, the energy resources that we use mostly
are non-renewable and are depleting at a very
faster rate. So, why not use the available energy in
a wise manner giving Mother Nature enough time
to regenerate fossil fuels? This idea of engine
design extracts the maximum energy from the
engine. But, according to the below given data, the
current energy resources may not be available to us
for a long time.
One of the alternative fuels that are readily
available for use in automobiles is hydrogen. So,
the use of hydrogen which is a renewable energy
resource in this concept of engine design has been
proposed. There are two ways of using hydrogen
in automobiles: i) In internal combustion engines,
ii) In hydrogen fuel cell vehicles. The fuel cell
technology is currently in research progress while
the use of hydrogen in internal combustion engines
could be processed quickly.
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TABLE 1
FUEL RESERVES
Fuel
Reserves
Years left
1,386 billion barrels
187.1 trillion cubic
Gas
metres
Coal
860,938 million tonnes
Source: BP. Reserves calculated at current
using current technologies
Oil
46.2
58.6
118
price
Use of hydrogen in normal IC engines would not
produce sufficient amount of power as desired. On
the other hand, the conventional IC engines that
runs on gasoline or diesel has low efficiencies.
Using the concept explained in this paper, more
power can be generated by the conventional fuels
and the efficiency is improved by hydrogen.
Hydrogen is a cleanest form of fuel that is
available today. When hydrogen undergoes
combustion process with pure air, it results in the
formation of water as the by-product. Hydrogen is
available in nature in the form of water. Water
which is available in abundance forms a surplus
source for hydrogen. Since the fossil fuels are
depleting at a faster rate, hydrogen which is
available in abundance proves to be the fuel of
tomorrow.
II. BODY
Our concept of the engine design has two
combustion chambers in a single cylinder such that
the cylinder is completely enclosed at the bottom
and can only give a reciprocating motion as output.
Hence there form two thermodynamic systems
with piston as a common moving boundary
between them. The rod which reciprocates takes
the reciprocatory motion as the output from the
engine and is converted into rotary motion by
suitable mechanisms. Both the upper and the lower
chamber have their own intake, exhaust and
ignition systems.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 25 Number 4- July 2015
TABLE 2
COMPARISON OF DIFFERENT VEHICLE TYPES
Gasoline
ICE
H2 ICE
H2 Fuel
Cell
Spark-ignition
Fuel cell &
CI (with
& electric
electric
electric motor)
motor
motor
Engine Type
Sparkignition
Average
engine
efficiency
~30%
~30%
~40%
~55%
Max engine
efficiency
32.5%
32.5%
~40%
~65%
Transmission
Standard
Type
CVT/hybrid
CVT/likely CVT/likely
hybrid
hybrid
Transmission
efficiency
~40%
~60%
~60%
~60%
Fuel
economy
(mpg
equivalent)
21
31
41
51
Increasing
Efficiency
Efficiency power may
improvements
losses or higher
be
over gas ICEs
emission
expensive,
are mostly lost
control costs to requiring
with increased
increase power additional
power
FCs
Large:
Fuel Tank
smaller
Small
Large
Size(constant Moderate
than H2
range)
ICE
Currently high:
Currently
but may be Currently
Currently low
Cost of Fuel
low
slightly lower
high
than FCVs
As much
power as
Sizeability needed, at
the cost of
mpg
Fig 1. Cross-section view of two-chambered engine
The primary fuel in this concept is hydrogen, which is
used at the lower chamber of the cylinder and the
secondary fuel can be any conventional fuels like
petrol and diesel. Hydrogen can be ignited by both
spark ignition and compression ignition. The strokes
of the engine are designed in such a way that
compression and expansion of the systems takes place
alternatively. The piston is made of suitable alloy such
that it withstands the temperatures produced on both
the chambers. The engine can produce two power
strokes in a single cycle and use of hydrogen improves
the efficiency of the engine. Thus it overcomes the
disadvantages of gasoline engine which has less
efficiency and hydrogen internal combustion engines
which has less power output.
A. Why Use Hydrogen in IC Engines
Hydrogen can burn in a lean mixture, but the
power produced by the combustion process
depends on the amount of hydrogen that is fed in
the combustion process. The wide range of
flammability of hydrogen can be used to produce
different amount of powers. Hydrogen can ignite
at very low temperatures, so the heat of the piston
and the cylinder due to the previous combustion
reactions is sufficient to ignite the hydrogen and
to start the cycles [2][3].
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Gasoline
Hybrid
Criteria
Pollutant
Emissions
Meets
Lower than
emission
gasoline ICE
standards
Developed and
State of
Developed in diffusion
technology
stage
Likely low,
some NOx
Very low
or none
Could be
developed
quickly
Earlier in
the
research
process
B. Piston Design
The piston is made of a suitable alloy such that it
can withstand the high temperatures produced in
both the chambers. The piston used in this
concept is a solid piston. Due to high
temperatures that are generated on both the
chambers, the piston must be cooled by
circulating suitable coolant by means of holes
inside the piston. To completely seal off both the
chambers, apart from the piston rings that are
generally available, a special type of ring which is
designed in a suitable shape so that it collects the
fuels and oils that get leaked from the upper
chamber and it is drained by means of drain hole
provided in the reciprocating rod. The draining is
vacuum assisted for easier drain. In such a way
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International Journal of Engineering Trends and Technology (IJETT) – Volume 25 Number 4- July 2015
the two systems or the chambers are completely
sealed off so that they don’t interfere with each
other’s reaction. In this case the absence of one
fuel does not affect the functioning of the engine
and the engine can run using only one fuel. It acts
like normal petrol or a hydrogen engine in the
previous case.
C. Stroke Sequence
We have made the corresponding changes in the
strokes of the engine to get the maximum
efficiency:
1.
2.
3.
The compression ratio of hydrogen is
higher than that of petrol, so the strokes
are altered in such a way that the power
produced in the upper chamber running
on petrol aids in compressing the air in
the lower chamber that must undergo
combustion reaction with hydrogen.
Similarly, in case of diesel as the
secondary fuel the inverse situation is
applied since the compression ratio in a
diesel engine is higher than that of
hydrogen engine.
Let us consider the case of petrol –
hydrogen engine, the stroke takes place
in continuous operation as given in the
following sequence below:
TABLE 3
WORKING STROKES
PETROL
CHAMBER
HYDROGEN
CHAMBER
Intake
Compression
Power
Exhaust
Intake
Compression
Exhaust
Power
The above table can be made for a diesel –
hydrogen engine also; but the sequence will be in
the opposite way.
D. Working
Let us consider petrol as the conventional fuel in
the upper chamber and hydrogen in the lower.
The working is as follows:
1.
Intake takes place in the upper chamber
and the air – fuel mixture from the
carburettor flows into the cylinder thus
lowering the piston. Simultaneously in
the lower chamber the exhaust gases
from the previous combustion reaction
of hydrogen goes out through the
exhaust valve.
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2.
3.
4.
Compression takes place in the petrol
chamber and the piston goes up. As the
piston moves up, a partial vacuum is
created in the lower chamber and thus
intake of air takes place in the lower
chamber.
The compressed air – fuel mixture in the
upper chamber gets ignited by the spark
plug and power is produced in the upper
chamber. The piston is forced down by
combustion of petrol and the air in the
lower chamber gets compressed.
Hydrogen at high pressure is injected
into the lower chamber and due to
change in pressure, the hydrogen gets
ignited and power is produced due to
which the piston moves up and pushes
the exhaust gases through the outlet in
the upper chamber.
The cycle continues and thus two power
strokes are produced in single cycle.
E. Calculation
We have considered the Honda CBR 250R engine and
the values for the Petrol chamber are taken from it.
TABLE 4
PERFORMANCE PARAMETERS OF TWO CHAMBERS
Characteristics
Hydrogen
Petrol
Compression Ratio
12:1
10.7:1
Torque @7000 rpm
23.64 Nm
23 Nm
Power @ 8000 rpm
23.23 HP
25 HP
Efficiency
40.32%
30%
Hydrogen has a variety of compression ratios and
varying this ratio can result in improvement of
efficiency. Hence the combination of both petrol and
hydrogen will increase the power and efficiency of the
vehicle.
F. Cam
The engine is equipped with variable valve timing
mechanism by using electronic cam. This
mechanism has different cam profiles to adopt for
different conditions of the engine. In variable
valve timing, the valve operation is shifted to a
different cam profile according to the engine
running conditions. The electronic cam table is
determined such that suitable amount of air – fuel
mixture is fed in correct proportions to both the
chambers so power produced in both sides of the
piston is almost equal [5].
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International Journal of Engineering Trends and Technology (IJETT) – Volume 25 Number 4- July 2015
limited to 17:1, and this temperature was used in
the experiments reported in this paper[3][4].
G. Valve Operation
The valve operation sequences for both the
chambers are given below.
J. Auto- Ignition of Hydrogen Jet
TABLE 5
VALVE OPERATION SEQUENCES
PETROL
HYDROGEN
Inlet Valve Open
Exhaust Valve Close
Inlet Valve Close
Inlet Valve Open
Exhaust Valve Open
Inlet Valve Close
Exhaust Valve Close
Exhaust Valve Open
H. Hydrogen Injection
Hydrogen is injected by means of constant
volume injection which is a direct injection
method. From the following figure, it could be
seen that hydrogen injected by direct means at
high pressure improves the thermal efficiency of
the engine [1].
Fig 3.Ignition delay as a function of temperature
The figure illustrates the strong dependence of the
cylinder charge temperature on the auto ignition
delay of the hydrogen jets. It can be seen that for
temperatures below approximately 1100K, the
auto ignition delay increases rapidly and becomes
significantly longer than for higher temperatures.
The auto ignition delay is strongly dependent on
the ambient gas temperature, and the temperature
de- pendency follows an Arrhenius function. It
was found that for temperatures below 1100K, the
auto ignition delay is longer than that of
conventional diesel fuels, but much shorter delays
can be obtained if the cylinder charge temperature
is close to or above 1100K. The figure explains
the need for inlet air heating in the hydrogenfuelled engine in order to achieve acceptable
ignition delays. For conventional diesel fuels, the
ignition delay curve would be shifted to the left
due to the lower self-ignition temperatures, and
acceptable ignition delay values can be achieved
with
lower
end-of-compression
charge
temperatures.
Fig 2. Comparison of Injection methods
I. Inlet Air Heating System
Due to the high self-ignition temperature of
hydro- gen, heating of the inlet air may be
necessary to en- sure fuel auto ignition. A 3.5kW
electric inlet air heating system, capable of raising
the inlet air temperature to 120 degree Celsius,
was implemented in the intake system, and the air
inlet temperature was controlled using a PID
controller. The air heating control system ensures
that the correct compression temperature for fuel
auto ignition is reached, and allows investigations
into the influence of this operational variable on
the engine performance. The minimum air inlet
temperature was found to be 80 degree Celsius,
since this particular engine compression ratio was
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K. Engine Options
There is wide range of engines available by
classifying the engines according to the ignition
systems that are used in the two chambers. The
fuels in both the chambers are compression
ignited or the upper chamber can be compression
ignited and the lower can be spark ignited in case
of using diesel as the secondary fuel. When petrol
is used as the secondary fuel, both the chambers
can be spark ignited or the upper chamber can be
spark ignited and the lower chamber can be
compression ignited. Thus we have four options
of engine based on the ignition systems.
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L. Engine Performance
There are several possibilities to improve the
performance of an automobile internal combustion
engine. One is to increase the capacity of the engine.
The capacity of the engine can be increased in a single
cylinder or the engine can be made to have several
cylinders. A single large cylinder may be a more
convenient choice due to fewer parts to manufacture
and maintain, but the advantages are over-weighed by
the disadvantages. This concept of engine introduces a
new possibility to increase the performance of an
engine without increasing its capacity. The range of
power that can be produced in an engine with all the
fixed parameters is higher than in free piston engine.
The performance parameters of the two chambers add
up and it provides increased power and torque. It also
provides good overall efficiency theoretically.
diesel-fuelled mode. Figure 4 shows the measured
NOx emissions with varying engine load for the
engine running in hydrogen-fuelled and
conventional diesel mode. As expected, the
nitrogen oxides formation is low at low loads, for
which the cylinder charge is lean and in-cylinder
temperatures are lower, but increases sharply with
increasing load.
TABLE 6
EXPERIMENTAL RESULTS FOR ENGINE ENERGY BALANCE
Fig 4.Variation of NOx concentration with Indicated Mean
Effective Pressure
Table 6 shows the engine efficiency results in
different operating modes. Engine efficiency is
significantly high in hydrogen direct injection (DI)
mode, with the engine achieving a brake
efficiency of 42.8%, compared with 27.9% when
using diesel fuel. This is mainly due to lower
losses to the cooling system, which constitute
engine frictional losses and heat transfer losses,
mainly to the combustion chamber walls. The
frictional losses are not heavily influenced by the
choice of fuel, but the increased engine power
makes the relative influence of the mechanical
losses lower in hydrogen-fuelled mode. Reduced
in-cylinder heat transfer losses are expected in the
hydrogen-fuelled engine due to the properties of
the gaseous fuel, leading to enhanced fuel-air
mixing, thereby reducing peak gas temperatures,
and the lower inertia of the fuel, reducing the
problems associated with spray-wall impingement.
The data in the table are for operation on 20%
diesel fuel and 80% hydrogen (on an energy
basis). The improved performance when using
dual fuels and HCCI compared to conventional
diesel engine mode can be seen [4].
M. Reduction in Emission
The nitrogen oxides emissions from a direct
injection hydrogen engine are expected to be
lower than those of the engine in conventional,
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A clear NOx emissions advantage for the
hydrogen-fuelled engine can be seen over the full
load range, with the NOx levels being
approximately 20% lower than those obtained
under diesel-fuelled operation. Although the peak
gas pressures are higher in hydrogen-fuelled
mode due to the higher fuel burn rate, this is seen
not to have an adverse effect on NOx formation.
This suggests that the peak gas temperatures are
lower in hydrogen-fuelled mode due to enhanced
fuel-air mixing and more homogeneous
conditions within the combustion chamber. Hightemperature zones, such as those occurring in the
outer regions of the fuel spray in conventional
diesel operation are reduced [4].
III. CONCLUSION
This concept brings about a new dimension in
automotive technology and with research on fuel
cells still in progress; this idea seems to be a very
efficient way of utilising the resources that are
available. It also provides better power to weight
ratio, lesser emissions and better efficiency than
the conventional IC engines. Thus this concept
proves to be a better solution for a greener
tomorrow.
ACKNOWLEDGMENT
We have presented this paper "Concept of
Hydrogen Technology in Dual Combustion
Engines" in various reputed institutions such as
IITs (Indian Institute of Technology) and NITs
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International Journal of Engineering Trends and Technology (IJETT) – Volume 25 Number 4- July 2015
(National Institute of Technology). In these
competitions we were evaluated by technical
experts in this field of engineering. They gave us
positive reviews and also provided us with some
valuable inputs. We would like to thank them
whole heartedly for these inputs as it played a vital
role in the development of this concept.
We had presented this research paper in a student
convention in front of a panel of research experts.
Our novel concept of engine technology received
humongous applause from them. We got the 1st
place in the event and the KNIMBUS YOUNG
INNOVATOR AWARD for the year 2014.
In addition, we were also sanctioned an prize
amount of Rs.25000 in Indian money. We have
now started the prototyping of this project. It is
with great pleasure I acknowledge the KNIMBUS
organization for their enthusiastic support and
motivation.
REFERENCES
[1]
[2]
[3]
[4]
[5]
www.eere.energy.gov - U.S. Department of Energy web
site for information on energy efficiency and renewable
energy technologies.
Peter Van Blarigan, Advanced Internal Combustion
Engine Research, Sandia National Laboratories,
Livermore, California.
Kenneth Gillingham, “Hydrogen Internal Combustion
Engine Vehicles: A Prudent Intermediate Step or a Step
in the Wrong Direction?” Stanford University.
J.M. Gomes Antunes, R. Mikalsen, A.P. Roskilly, An
experimental study of a direct injection compression
ignition hydrogen engine, Sir
Joseph Swan Institute for Energy Research, Newcastle
University, Newcastle upon Tyne, NE1 7RU, England,
UK.
Mrdjan Jankovic and Stephen W. Magner, Variable cam
timing
Consequences to
automotive engine control design, Ford Research
Laboratory.
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