Effect of Alternative Diesel Fuels on Heat Release Curvesfor Cummins N14-410 Diesel Engine’

Yusuf Ali, Milford A. Hanna and Joseph E. Borg’SNDENT MEMBERMEM8ER

ABSTRACT

A Cummins N14-410 engine was operated on twelve fuels produced by blending

methyl tallowate, methyl soyate and fuel ethanol with No.2 diesel fuel. Engine in-cylinder

pressure data were collected and used to evaluate the rate of heat release, mass fraction

of fuel burned and charge temperature with respect to crank angle. It was observed that

the rate of heat release decreased with increasing engine speed. Peak rates of heat

release for a// fuel blends were less than for No.2 diesel fuel. When methyl tallowate was

blended with No.2 diesel fuel, the shift in the location of peak heat release was away from

top dead center (TDC) whereas the addition of ethanol to the blend shifted the location

towards TDC. Ignition delay sltghtly decreased when methyl tallowate was blended with

diesel fuel. However, ignition delays were not Acted by the methyl tallowate content of

the blend. The addition of ethanol to the fuel blends did not affect ignition delay. The

charge temperature decreased with decrease in diesel content of the fuel blends. A

reduction in charge temperature can reduce NO, emissions.

KEYWORDS: Methyl tallowate, methyl soyate, biodiesel, ethanol, Cummins engine,peak pressure, indicated mean effective pressure, rate of pressure change.

‘Journal Series Number 11128 of the University of Nebraska Agricultural Research Division.

‘The authors are: Yusuf Ali. Graduate Research Assistant, Milford A. Hanna. Professor and Director,Industrial Agricultural Products Center. and Joseph E. Borg, Graduate Research Assistant. Department OfGnlogical Systems Engineering. University of Nebraska-Lincoln, Lincoln, NE 685830726.

2

INTRODUCTION

The use of alternative fuels in compression ignition (Cl) engines to reduce exhaust

gas emissions has, in the past few years, become a popular topic of research. Much of

this research has centered on minimizing exhaust gas emissions while at the same time

optimizing power output. Most Cl engines are designed to operate on diesel fuel and

therefore, perform best while operating on that fuel. During the engine design and

optimization process, an engine manufacturer will perform in-cylinder pressure

measurements to determine cylinder pressure, rate of change in pressure, estimated rate

of heat release, mass-burned fraction and charge temperature.

High speed data acquisition systems are used by performance development

engineers and are found to be of practical value. Algorithms and techniques that provide

for an accurate representation of heat transfer and a means of very accurately determining

top dead center (TDC) have been developed. Engine cycle analysis (ECA) and fuel

injection analysis (FIA) software can be used to obtain steady state engine performance

characteristics (Gill, 1988). The combustion process in a diesel engine is usually

considered to occur in four phases according to heat release rate (Barbell et al., 1989).

Those phases are the ignition delay period, premixed burning phase, diffusion burning

phase and oxidation phase. These phases are used to follow the transformation of fuel

in the combustion cycle.

Kittelson et al. (1988) observed that soot concentration, heat release and fuel

injection data were related to one another. There was a longer delay between the start of

combustion and the start of soot formation for high equivalence ratio which was due to a

3

slightly longer premixed burning phase at high load. The increase in length of the

premixed burning period was much smaller than the increase in the formation lag time.

Shundoh et al. (1991) observed that low (1000 rev/min) and high (2000 rev/min)

engine speeds had no effect on heat release rate because the injection rates were the

same, and heat release closely followed the injection rate in type C combustion. The gas

temperature in the case of the low speed condition was higher than that at high speed and

was the reason for higher NOx and lower smoke levels at low speeds.

Alternative fuels also have been tried in direct injection compression ignition engines

and have been found to work satisfactorily. In-cylinder pressure measurements have been

performed using alternative fuels to compare with diesel fuel. Niehaus et al. (1986)

observed that diesel fuel produced more premixed burning than thermally cracked soybean

oil (TCSBO) at brake mean effective pressures (BMEP) of 100 kPa and 300 kPa.

However, premixed burning for TCSBO was greater than that for diesel fuel at a higher

BMEP of 500 kPa

Czerwinski (1994) used a rapeseed oil, ethanol and diesel fuel blend and compared

the heat release curves with diesel fuel. He observed that the addition of ethanol caused

longer ignition lag at all operating conditions. At higher and full loads, the combustion

speeds were high with strong premixed phases. The addition of rapeseed oil gave a little

lower combustion speed and lower combustion temperature as compared to diesel fuel.

The inflammation lag with rapeseed oil was slightly shorter and the combustion duration

was approximately equal to diesel fuel. The blend of diesel, rapeseed oil and ethanol had

lower heat values which diminished the power output at full load as well as the available

power during the transient operating conditions.

The overall objective of this project was to perform in-cylinder pressure

measurementson an engine to determine the rate of heat release, mass-burned fraction

of fuel and charge temperature curves on fuels produced by blending diesel, methyl

tallowate, methyl soyate and fuel ethanol in different ratios and comparing them with No.2

diesel fuel. It was expected that this study would help establish the fuel burning

characteristics needed to control exhaust emissions and engine coking

MATERIALS AND METHODS

Engine and Instrumentation: A 1991 Cummins N14-410 direct injection diesel engine

was used in this research. Specifications of the engine are presented in Table 1.

The engine was coupled to an Eaton 522 kW (700 hp) dynamatic eddy current dry

gap dynamometer. Engine torque was measured with a load cell and Daytronic system

10 integrator, and speed was measured using a 60 tooth sprocket and magnetic pickup.

Engine torque and speed were controlled with an Eaton Dynamatic dynamometer

controller in conjunction with a Jordan controls throttle controller.

In-cylinder pressure measurement was accomplished using an AVL QH32C quartz

pressure transducer connected to a KISTLER Model 5004 Dual Mode Charge Amplifier.

The pressure transducer was mounted in the head of cylinder No.1 as close as possible

to the center of the cylinder to minimize any induced measurement error. Crank angle was

measured using a Gurley Precision instruments Model 82253600-CDSD-KZ rotary shaft

encoder. The optical shaft encoder was rigidly mounted to the front of the engine and

connected to the crank shaft with a flexible coupler. The encoder was connected to a

5

SuperFlow Corp. SF-1815 Engine Cycle Analyzer Power Supply that supplied both power

and signal conditioning for the crank angle and top dead center signals. The charge

amplifier and power supply outputs were connected to a SuperFlow Corp. DAB 500 high

speed data acquisition board placed in a 66 MHZ 80486 based PC. The data were

collected using a software package ECA911 obtained from SuperFlow Corp.

Specifications for pressure transducer, charge amplifier and shaft encoder are presented

in Table 2.

Fuels : Blends of high sulfur (0.24 %) No.2 diesel fuel, methyl tallowate, methyl soyate and

fuel ethanol were made and tested. Specific blend compositions are given in Table 3. The

methyl tallowate and methyl soyate were produced by Proctor and Gamble Co. of Kansas

Cii, KS and purchased from Interchem, Inc. of Kansas City, MO. Physical properties of

methyl tallowate, methyl soyate and their blends with diesel fuel and ethanol were reported

by Ali et al. (1995).

Testing Procedures : The charge amplifier and the SuperFlow power supply were turned

on two hours before collecting data to allow the instruments to stabilize. The engine was

started and warmed-up, at low idle, long enough to establish correct oil pressure and was

checked for any fuel, oil, water and air leaks. The speed was then increased to 1600

rev/min and sufficient load was applied to raise the coolant temperature to with normal

operating range. After completion of the warm-up procedure, the intake and exhaust

restrictions were fixed at rated engine speed (1800 rev/min) and full load and from then on

were not adjusted for different speed or load changes. The test procedure consisted of an

6

eight mode steady state emissions test sequence followed by four full load test points at

different speeds to complete a full load torque and power map. Table 4 presents the

speed and load combinations used. The testing was done in the Nebraska Power

Laboratory at the University of Nebraska-Lincoln.

The engine was run at the specified speeds and loads for a minimum of 6 min and

data were collected during the last 2 min of operation. Pressure data were collected for

all speed and load combinations, but for the purpose of this paper, only data taken while

the engine was at its maximum constant load at a given speed were used. The points

were at engine speeds of 1100, 1200, 1400, 1600, 1800 and 1900 rev/min with full loads.

Engine cycle data were collected over 450 cycles at each point and averaged for analysis.

Pressure and volume data collected for each test were converted into rate of heat release,

mass burned fraction and charge temperature with respect to crank angle using a software

package EGA91 1 obtained from SuperFlow Corp. (Colorado Springs, CO).

RESULTS AND DISCUSSION

Engine in-cylinder pressure data were analyzed for rates of heat release, mass-

burned fractions and charge temperatures with respect to crank angle (CA) for different

fuel blends.

Rate of Heat Release vs. Crank Angle : This analysis shows the estimated rate of heat

release during the combustion process. The results provide a quantified assessment of

combustion rate and the means to diagnose combustion problems. The analysis was

based on pressure and volume measurements. Therefore, some assumptions were made

7

to calculate rate of heat release. The first assumption was that the trapped charge

remained in a uniform single zone of constant composition from intake valve closing to

exhaust valve opening. In actuality, large temperature gradients existed in the charge

during combustion and the chemical composition of the unburned gases was different from

the burned gases. The second assumption was that leakage and heat transfer to the wall

was negligible. The third assumption was that the charge mixture behaved as an ideal

gas. Based on these assumptions, the rate of heat release with respect to CA and location

of peak heat release for blends of diesel, methyl tallowate, methyl soyate and ethanol at

different engine speeds were calculated using ECA911, a standard engine cycle data

analysis package, and are presented in Table 5. Representative graphs showing the

development of change in rate of heat release with CA are shown in Figs. 1 and 2.

It was observed that peak rate of heat release decreased as engine speed

increased from 1100 rev/min to 1900 revlmin (Table 5). The location of peak rate of heat

release was delayed as the engine speed increased. Furthermore, as the diesel fuel

content of the blended fuel was reduced, the peak rate of heat release also was reduced.

The shapes of the rate of heat release curves for all fuel blends at all engine speeds were

similar to that of No.2 diesel fuel. No.2 diesel fuel had a peak rate of heat release of 0.287

W’CA at the engine’s peak torque producing speed of 1200 revlmin and 0.250 kJ/“CA at

the engine’s rated speed of 1800 rev/min. The trends of peak rates of heat release with

CA for all fuel blends at engine speeds of 1200 and 1800 revlmin are shown in Figs. 1 and

2, respectively.

8

At 1200 rev/min engine speed, peak rates of heat release for 80:20, 70:30 and

60:40 % (v/v) blends of dieseLmethyl tallowate were within 2% of that for No.2 diesel fuel.

The locations of peak rates of heat release were within 10.6 and 11.2 “CA after top dead

center (ATE) for the respective fuel blends as compared to 10.6 “CA ATDC for No.2

diesel fuel. When the methyl tallowate was replaced by fuel ethanol and methyl soyate the

peak rates of heat release were reduced by as much as 3.14% without affecting their

locations. A comparison of peak rate of heat release for No.2 diesel fuel with the 6535%

(v/v) blend of methyl tallowate:ethanol showed an 8.71 % reduction in peak rate of heat

release. A similar comparison for the 32.532.535 % (v/v) blend of methyl tallowate:methyl

soyate:ethanol showed a 6.27 % reduction. The locations of the peak rates of heat

release were 8.4 and 9.4 “CA ATDC for the respective fuel blends.

At rated engine speed of 1800 rev/min, the peak rates of heat release for the 80:20,

70:30 and 60:40 % (v/v) blends of diesel:methyl tallowate were within 1.2% Of that of No.2

diesel fuel. Locations of peak rates of heat release were within 0.4 “CA ATDC of that of

No.2 diesel fuel. When the methyl tallowate was replaced by fuel ethanol and methyl

soyate, the peak rates of heat release were reduced by as much as 2.8 % of that of No.2

diesel fuel and locations of peak rates of heat release were within 1 “CA ATDC of that of

No.2 diesel fuel. A comparison of No.2 diesel fuel with the 6535% (v/v) methyl

tallowate:ethanol showed an 11.2% reduction in peak rate of heat release. A similar

comparison for the 32.5:32.5:35% (v/v) blend of methyl tallowate:methyl soyate:ethanol

showed a 10.0% reduction. The locations of the peak rates of heat release were 15.8 and

16.8 “CA ATDC for the respective fuel blends.

9

A similar trend was observed at all other engine speeds. In general, as the amounts

of methyl tallowate/methyl soyate and ethanol were increased there were reductions in the

peak rates of heat release as compared to No.2 diesel fuel with the exception of the 70:30

and 60:40 % (v/v) blends of diesel:methyl tallowate blends, in which cases there were

slight increases at 1200 rev/min. Reductions in the peak rates of heat release were

expected as the energy contents of the blends were less than that of No.2 diesel fuel, (Ali

et al., 1995). To understand the process of heat release in detail, one must know the

mass-burned fraction of the fuel with respect to CA to determine the ignition delay and

burn duration.

Mass-Burned Fraction vs. Crank Angle : The mass burned fraction was obtained by

integrating the rate of heat release. The curve of mass-burned fraction with respect to CA

allowed for identification of ignition delay, the fully developed combustion period and the

combustion tail. Further, it gave information about how much fuel was unburned at any

point in the combustion cycle.

Representative curves for mass-burned fraction of the fuel with respect to CA at

1200 and 1800 rev/min engine speeds are shown in Figs. 3 and 4, respectively. The burn

duration and ignition delay in terms of CA for No.2 diesel fuel are quantified in those

figures. Three points defined in those curves are start of injection, start of combustion and

end of combustion. Technically, ignition delay is defined as the interval between start of

injection and start of combustion but to assess mass burned fraction from engine cycle

analysis, the 0 to 10 % burned range is often defined as the ignition delay and the 10 to

90% range is the burn duration (Anon. 1994). The last 10 % burned is not usually carefully

1 0

considered due to errors associated with the assumptions made in the heat-release

analysis. The quantification of these parameters is extremely useful in characterizing

combustion chamber and ignition system performance. The quantified parameters related

to ignition delay and burn duration are presented in Table 6.

It was observed that the ignition delay increased with increasing engine speed

(Table 6). The ignition delay at 1100 rev/min was in the range of 19 to 20 “CA and

increased to 26 to 27 “CA at 1900 rev/min for all fuel blends. On the other hand, the burn

duration decreased with increasing engine speed. Burn duration reduced from the range

of 50 to 52 “CA at 1100 rev/min to the range of 41 to 43 “CA at 1900 rev/min. The ignition

delay for No.2 diesel fuel was 20.8 “CA at 1200 rev/min and increased to 24.6 “CA at

rated speed of 1800 rev/min. Similarly, the burn duration was 49.4 ‘CA and 42.6 “CA at

1200 and 1800 rev/min, respectively.

At 1200 rev/min engine speed, the ignition delays for the 8020.70:30 and 60:40%

(v/v) blends of diesel:methyl tallowate were all within 0.6 “CA of that of No.2 diesel fuel.

When the engine speed was increased to 1800 rev/min, the ignition delays were found to

be 24.6 “CA, the same as No.2 diesel fuel. The burn durations at 1200 rev/min engine

speed were all within 1.8 “CA of that of No.2 diesel fuel. At 1800 rev/min the burn

durations were all within 0.4 “CA of that of No.2 diesel fuel. Thus, from the standpoint of

ignition delay and burn duration, the blends of diesel and methyl tallowate performed

similarly to No.2 diesel fuel.

When the methyl tallowate was replaced by fuel ethanol and methyl soyate, the

ignition delays at 1200 rev/min engine speed were all within 0.4 “CA and at 1800 rev/min

11

they were all within 0.2 “CA of that of No.2 diesel fuel. The burn durations at 1200 revlmin

engine speed were observed to be within 1 “CA and at a speed of 1800 rev/min the burn

durations wars observed to be within 0.4 “CA of that of No.2 diesel fuel. A comparison

of No.2 diesel fuel with the 65:35 % (v/v) blend of methyl tallowate:ethanol and

32.5:32.5:35 % (V/V) blend of methyl tallowate:methyl soyate:ethanol showed some

reduction in ignition delay as compared to No.2 diesel fuel. The ignition delays at 1200

revlmin for the 6535 and 32532.535 blends were 19.6 and 20 “CA, respectively, as

compared to 20.9 “CA for No.2 diesel fuel. At 1800 rev/min, the ignition delays were 23.6

“CA for both fuel blends as compared to 24.6 “CA for No.2 diesel fuel. When burn

durations for both fuel blends were compared with that of No.2 diesel fuel it was observed

that there were slight reductions in burn duration. At 1200 rev/min the burn durations for

the 65:35 and 32.532.535 % (v/v) blends were 48.2 and 47.6 “CA, respectively, as

compared to 49.4 “CA for No.2 diesel fuel. Similarly, at 1800 rev/min, the burn durations

were 41.2 and 39.8 “CA as compared to 42.6 “CA for No.2 diesel fuel. The reductions in

burn durations may have been caused by the presence of a high percentage of ethanol in

the blends. Since both fuel blends contained 35 % (v/v) ethanol and the ethanol was

highly flammable, the burn duration was reduced. From Fig. 4 it can be observed that

these two fuel blends did not follow the same path as No.2 diesel fuel. These two fuel

blends had an early start of combustion and an early end of combustion as compared to

all other fuel blends. Fosseen et al. (1993) also observed a reduction in ignition delay and

a shift in the peak pressure point towards TDC when they used blends of diesel fuel and

methyl soyate (from 0 to 40 %) in a Detroit Diesel Corp. 6V-92 TA engine.

12

Charge Temperature vs. Crank Angle : Charge temperature was estimated from the

measured pressure and volume data. This relationship estimated only the average

temperature.

Representative curves for charge temperature with CA at 1200 rev/min and 1800

rev/min engine speeds are shown in Figs. 5 and 6. The trends of temperature change for

all fuel blends were similar to that of No.2 diesel fuel. The locations of the peak charge

temperatures also were in a narrow range. Peak charge temperatures and locations of

peak charge temperatures for all fuels are presented in Table 7.

No.2 diesel fuel had the maximum charge temperature(Table 7). At 1200 and 1800

rev/min, the charge temperatures were 1359 “K and 1284 “K, respectively. The respective

locations of the peak charge temperatures were 28.8 and 34.8 “CA ATDC.

At 1200 rev/min the peak charge temperatures for the 8020,70:30 and 60:40 %

(viv) blends of aiesel:methyl tallowate were reduced by as much as 19 “K as compared to

No.2 diesel fuel The locations of these peak charge temperatures were within 2.6 “CA of

that of No.2 diesel fuel. The shifts in the locations of peak charge temperatures were

consistent with the locations of peak rates of heat release. When engine speed was

increased to 1800 rev/min, the peak charge temperatures were reduced by as much as

12 “K of that of No.2 diesel fuel and their locations were changed by as much as + 0.4

“CA. The reductions in peak charge temperatures were due to reductions in the total

energy contents of the fuel blends which also resulted in reduction in peak rates of heat

release.

1 3

When methyl tallowate was replaced by fuel ethanol and methyl soyate, the peak

charge temperatures at 1200 revlmin were reduced by as much as 40 “K of that of No.2

diesel fuel with no change in their locations. At 1800 rev/min, the values of peak charge

temperatures were reduced by as much as 38 “K, respectively with not much change in

their locations. These results were in agreement with the results obtained for peak rates

of heat release for similar fuel blends and engine speeds.

A comparison of peak charge temperatures for the 65:35 % (v/v) blend of methyl

tallowate:ethanol and the 32.5:32.5:35 % (v/v) blend of methyl tallowate:methyl

soyate:ethanol with No.2 diesel fuel at 1200 revlmin engine speed showed temperature

drops of as much as 100 “K. The locations of the peak charge temperatures were 30.2

“CA ATDC for both fuel blends as compared to 32.6 “CA ATDC for No.2 diesel fuel.

Similarly, at 1800 revlmin the peak charge temperatures were reduced by as much as

110°K with their locations at 31.6 and 31.8 “CA ATDC as compared to 34.8 “CA ATDC for

No.2 diesel fuel. A similar trend was observed when rates of heat release were analyzed

Fosseen.et al. (1993) also observed steady reductions in exhaust gas temperatures at

both rated speed and peak torque conditions when they used blends of diesel and methyl

soyate (0 to 40 %) in a Detroit Diesel Corp. 6V-92 engine.

Reductions in the charge temperatures with different fuel blends were expected as

the energy contents of the methyl tallowate, methyl soyate and ethanol blends were less

than that of No.2 diesel fuel (Ali et al., 1995). Reductions in charge temperature help

reduce NO, emissions from the engine.

1 4

CONCLUSIONS

A complete engine cycle analysis was conducted to analyze in-cylinder pressure

data to estimate rate of heat release, mass-burned fraction and charge temperature with

respect to crank angle. It was concluded that the rate of heat release was reduced with

increases in the amounts of methyl tallowate, methyl soyate and ethanol in the fuel blends.

There was a slight shift in the location of the peak rate of heat release away from top dead

center (TDC) when only methyl tallowate was blended with No.2 diesel fuel. When 35 %

of the methyl tallowate was replaced by ethanol, there was a further decrease in the rate

of heat release and the location of peak rate of heat release was shifted towards TDC at

both peak torque and rated engine speeds. Ignition delay and burn duration were

determined from mass burned fraction data. There was a slight decrease in ignition delay

when methyl tallowate was blended with diesel fuel. However, ignition delays were not

affected by the amount of methyl tallowate in the blend. Further, replating 35 % of the

methyl tallowate/methyl soyate by ethanol did not affect ignition delay at either peak torque

or rated engine speeds. The burn duration was more or less the same for all fuel blends.

The charge temperature decreased with increases in amounts of methyl tallowate,

methyl soyate and ethanol of the fuel blends. Maximum charge temperature was observed

for No.2 diesel fuel at both peak torque and rated engine speeds. The peak charge

temperatures and their locations followed the same trends as the peak rates of heat

release for all fuel blends. Therefore, looking at the results of rate of heat release, mass

burned fraction, ignition delay, burn duration and charge temperature for all fuel blends it

was concluded that since the performance of the engine with all fuel blends was similar to

1 5

that of No.2 diesel fuel, they should have no effect on long term engine performance.

ACKNOWLEDGMENT

The authors gratefully acknowledge the assistance of Kevin G. Johnson, Lab

Technician, Nebraska Power Laboratory, University of Nebraska-Lincoln, with engine

operations and data collection.

1 6

REFERENCES

Anon. 1994. Engine cycle analyzer; Operator’s manual. SuperFlow Corp. ColoradoSprings, CO. pp 3: 94-105.

Ali, Y., Hanna, M.A. and Borg, J.E. 1996. In-cylinder pressure characteristics of a Clengine using blends of diesel fuel and methyl esters of beef tallow.Tf?ANSACT/ONS of the ASAE (accepted).

Barbella, R. Bertoli, C. Ciajolo, A. D’Anna, A. and Masi, S. 1989. In-cylinder sampling ofhigh molecular weight hydrocarbons from a D.I. light duty diesel engine. SAE paperNo. 890437. Society of Automotive Engineers, Warrendale, PA.

Czerwinski, J. 1994. Performance of HD-DI-diesel engine with addition of ethanol andrapeseed oil. SAE paper No. 940545. Society of Automotive Engineers,Warrendale, PA.

Fosseen, D., Manicom, B., Green, C. and Goetz, W. 1993. Methyl soyate evaluation ofvarious diesel blends in a DDC 6V-92 TA engine. Fosseen Manufacturing andDevelopment. Radcliff, IA. (Report prepared for National Soydiesel DevelopmentBoard, Jefferson City, MO.).

Gill, A.P. 1988. Design choices for 1990’s low emission diesel engines. SAEpaper No.880350. society of Automotive Engineers, Warrendale, PA.

Kittelson, D.B., Pipho, M.J., Ambs, J.L. and Luo, L. 1988. In-cylinder measurements ofsoot production in a direct injection diesel engine. SAE paper NO. 880344. Society

of Automotive Engineers, Warrendale, PA.

Niehaus, HA., Goering, C.E., Savage, L.D. and Sorenson, S.C. 1986. Cracked soybeanoil as a fuel for a diesel engine. TRANSACTIONS of the ASAE, 29(3):683-9.

Shundoh, S., Kakegawa, T., Tsujimura, K. and Kobauashi, S. 1991. The effect of injectionparameters and swirl on diesel combustion with high pressure fuel injection. SAEpaper No. 910489. Sobety of Automotive Engineers, Warrendale, PA.

1 7

‘able 1. Engine specifications.

Specifications Cummins N14-410engine

Type of engine 6 cylinder, 4-stroke, direct injection

Horsepower (Rated) 4 1 0

Bore x stroke 140 mm x 152 mm

Displacement 14 liters

Compression ratio l&3:1

Valves per cylinder 4

Aspiration Turbocharged & charge air cooler

Turbocharger Holsett type BHT 38

able 2 : Pressure transducer, charge amplifier and shaft encoder specification’

1 8

Diezoelectric Pressure Transducer

Uodel

3ynamic measuring range, (FSO), Mpa

sverload, MPa

Sensitivity, pC/MPa’

Linearity, % FSO

IMEP reproducibility. % error

Lifetime, cycles to failure

Charge Amplifier

Model

me

-inearity, % FSO

kale setting

Shaft Encoder

Wodel

We

Signal pulse/revolution

Index pulse/revolution

C = micro Coulomb

AVL QH3’2C

0 - 20

3 0

2.673

< f 0.2

< 2.0

,3x107

KISTLER 5004

Duel Mode

< * 0.05

5 user selectable settings

82253600-CDSD-KZ

Optical

3600

1

19

Table 3. Fuel blends tested.

Blend No. 2Number Diesel Fuel

%

Methyl MethylTallowate Soyate

% %

Ethanol

%

1 100 0 0 0

2 80 13 0 7

3 70 19.5 0

4 60 26 0

5 80 6 . 5 6 . 5

6 70 9.75 9.75

7 60 13 13

8 80 20 0

9 70 30 0

10 6 0 40 0

1 1 0 6 5 0

12 0 32.5 32.5

10.5

14

7

10.5

14

0

0

0

35

35

20

Table 4. Engine speeds and loads used to determine

Load%

100

75

50

IO

100

75

50

0

100

100

100

100

21

Table 5 : Peak rate of heat release for each fuel blend at different speeds and location ofthe peak rate of heat release with respect to TDC.

T ==7

Fuel Blends

No.2 diesel fuel(1oo:o)

D : M T(80 : 20)

D:MT(70 : 30)

D:MT(60 : 40)

D:MT:E(80:13:7)

D:MT:E(70 : 19.5 : 10.5)

D:MT:E(60 : 26 : 14)

D : M T : M S : E(80 : 6.5 : 6.5 : 7)

D:MT:MS:E(70 : 9.75 : 9.75 : 10.5)

D : M T : M S : E(60:13:13:14)

MT:E(65 :35)

tiT:MS:E32.5 : 32.5 : 35)

= Diesel

1100revlmin

0.288(10.8)

0.286(9.8)

0.284(94

0.283(10.0)

0.282(10.4)

0.282(10.4)

0.276(9.0)

0.283(10.0)

0.275(10.4)

0.275(11.0)

0.248C3.6)

0.261(9.0)

Peakr-.-a

1200revlmin

0.287(10.6)

0.284(10.6)

0.291(10.6)

0.289(11.2)

0.285(10.0)

0.282(10.0)

0.276(9.6)

0.283(10.4)

0.278(10.4)

0.278(9.6)

0.262(8.4)

0.269(9.4)

of heat,rankAn

1400rev/min

0.285(14.0)

0.284(13.8)

0.284(13.8)

0.278(13.8)

0.281(13.8)

0.281(13.8)

0.272(13.4)

0.281(13.6)

0.273(13.4)

0.278(13.2)

0.253(12.2)

0.262(12.4)

!ase at eATDC)

1600revimin

0.271(15.8)

0.275(15.8)

0.268(16.0)

0.268(16.0)

0.269(15.6)

0.269(15.6)

0.261(15.0)

0.268(152)

0.263(152)

0.268(15.0)

0.242(13.8)

0.249(14.0)

-

speed) A

1800rev/min

0.250(18.6)

0.248(18.6)

0.248(19.0)

0.247(19.0)

0.247(18.6)

0.245(18.3

0.243(18.0)

0.247(18.0)

0.244(17.6)

0.246(17.8)

0.222(15.8)

0.225(16.8)

-

1900rev/min

0.224(21.2)

0.226(21.2)

0.227(21.4)

0.219(20.8)

0.221(21.2)

0221(21.0)

0.240(17.8)

0.223(204

0.219(19.8)

0.219(20.0)

0.199(20.0)

0.203(19.6)

-

MT = Methyl TallowateMS = Methyl SoyateE = Ethanol

22

Table 6 : Ignition delay (ID) and bum duration (BD) of each fuel blend at different enginespeeds.

Fuel Blends

N o . 2 d i e s e l f u e l(100 :O)

D:MT

D:MT

D:MT

D:MT:E(80 : 13 : 7)

D:MT:E(70 : 19.5 : 10.5)

rl:MT:E(60:26:14)

D:MT:MS:E(80 : 6.5 : 6.5 : 7)

D:MT:MS:E(70 : 9.75 : 9.75 : 10.5)

D : M T : M S : E(60: 13 : 13 : 14)

MT:E(65 : 35)

MT:MS:E32.5 :32.5 : 35)

-

-

IDEm

1100revlmin

19.451.4

/ M eqreeS

1200 1400 1600revlmin .evlmin revimin

20.8 22.2 23.049.4 46.4 43.2

1800 1900revlmin revlmlr

24.6 26.842.6 43.6

I D 20.0 20.6 22.2 23.0 24.6 26.8BO 51.0 40.0 45.6 43.2 424 43.2

I D 20.2 20.4 22.2 22.8 24.6 26.680 50.6 47.6 45.2 43.0 43.2 43.4

I D 19.6 20.2 22.2 23.0 24.6 27.0B D 50.6 49.0 45.8 43.0 42.8 43.6

20.0 20.4 22.0 22.8 24.6 26.851.0 40.4 45.2 41.6 42.4 41.6

I D 20.0 20.6 220 22.8 24.4 26.8BD 51.0 48.2 45.2 41.6 42.6 41.6

19.8 20.4 21.6 22.6 24.4 24.449.8 48.0 44.6 41.8 42.6 42.0

I D 20.0 20.6 22.0 23.0 24.6 26.83D 50.8 49.4 45.4 43.4 42.6 43.2

I D 19.6 20.4 21.8BD 51.4 50.4 46.4

22.8 24.6 26.643.8 43.6 43.8

ID 19.8 20.4 21.8 22.8 24.6 26.6BD 51.0 48.8 45.2 42.6 42.2 42.6

I D 18.8 19.6 21.0B D 52.2 48.2 46.4

23.6 26.241.2 42.8

ID3D

19.250.8

-

20.0 21.047.6 42.8

21.841.4

22.039.8

-

23.6 26.239.8 41.6

Fuel Blends

No.2 diesel fuel(100 : 0)

D:MT(80 : 201

D:MT(70 :30)

D:MT(60 : 40)

D:MT:E(80:13:7)

D:MT:E(70.19.5 : 10.5)

D:MT:E(60:26:14)

D:MT:MS:E(60 : 6.5 : 6.5 : 7)

D:MT:MS:E(70 : 9.75 : 9.75 : 10.5)

D : M T : M S : E(60:13:13:14)

MT:E(65 :35)

tiT:MS:E32.5 :32.5 :35)

23

mature for each fuel blend at different speeds and its locationnL.

1100revlmin

1330(32.6)

1325(31 .O)

1324(30.4)

1329(31.2)

1313(31.8)

1313(31.6)

1293(30.6)

1305(31.0)

1286(32.2)

1295(33.0)

1204(30.2)

1236(30.2)

Peakch, argf atemoerature “K atI

1200revlmin

1359(28.8)

@

1400revlmin

1373(31.6)

gle

1600revlmin

1359(33.0)

1340(29.0)

1325(31.0)

1361(33.4)

1355(29.8)

1363(31.4)

1350(33.2)

1349(31.4)

1367(31.6)

1351(33.0)

1351(26.6)

1364(31.4)

1346(32.8)

1345(28.6)

1364(31.4)

1346(32.8)

1328(28.6)

1337(31.0)

1315(32.8)

1334(28.6)

1358(31.2)

1340(33.0)

1321(28.6)

1335(31.0)

1326(32.8)

1319(26.6)

1339(31.0)

1330(32.8)

1261ew

1255(30.0)

1240(31.8)

1293(26.4)

-

1282(30.4)

-

1263(31.8)

-

,hspeed,

1800revlmin

1284(34.6)

1281(34.4)

1272(34.4)

1275(35.2)

1273(34.4)

1269(34.4)

1254(34.4)

1262(35.0)

1246(34.8)

1259(34.8)

1170(31.6)

1194(31.8)

1900revlmir

1171(35.6)

1166(35.8)

1177(35.2)

1147(35.4)

1160(35.4)

1160(35.4)

1244(34.2)

1156(35.6)

1150(35.4)

1145(35.4)

1059(34.3

1079(34.0)

-

I I-

-

0