a study of dimethyl ether flow(dme) in diesel nozzle
TRANSCRIPT
1/21
Masaaki KATO
Hisaharu TAKEUCHI, Yuuji SAKURAI (DENSO CORP. )
Shuichi KAJITANI, Yuko SHIBASAKI (Ibaraki University)
Masahiro TAMAKI (TOYOTSU CHEMIPLAS CORP.)
The seventh Asian DME Conference,
Niigata Japan, 16-18 November 2011
A Study of Diesel Nozzle Tip Wear
in the Fuel DME
2/21
Outline of presentation
1. What is DME? DME (Dimethyl Ether) properties and
concern for diesel fuel injection system
2. Compare the nozzle wear test rigs with the real engine conditions
3. Evaluate the effect of several lubricant additives on decrease the wear of nozzle by the new Rig
4. Evaluate the corrosion effect of impurity water in DME on nozzle
Aim: To study and overcome the nozzle wear
in use of engine fueled DME
3/21
1. What is DME?
4/21
Characteristics
① Gaseous fuel easy to liquefy
② High cetan number suits for Diesel engine
③ Contain no sulphur →Creates no SOx
④ NOx is less than Diesel fuel
⑤ PM≒0 (Oxygenated fuel no C-C bond)
⑥ Can be manufactured various sources
( NG, coal, biomass ・・・)
DME(Dimethylether)?
Promising alternative fuel for Diesel engine
CH3OCH3
5/21
DME Physical Properties and Concerns for FIS
Lots of Subjects for fuel injection system
Property
Viscosity@25-80℃
Diesel oil DME
Bulk modulus of elasticity
Vapor pressure @25°C
Density@20°C
Calorific value
0.25-0.15cSt 3cSt
100MPa~1000MPa Depend on Temp. & Pressure
610kPa (3MPa@90℃) Depend on Temp.
1400MPa
840kg/m3 667kg/m3
42.7(MJ/kg) 28.8(MJ/kg)
-
Critical point 127℃, 5.3MPa ー
Specific heat @80°C 2090J/kg/K 2247
6/21
2. Nozzle wear test rigs
7/21
Diesel Fuel Injection System(FIS)
and Nozzle Tip
Fuel spray and
flame
Combustion
chamber Engine piston
Nozzle Tip
High Pressure
Supply Pump
Fuel Tank
Leak line
Injector
Common Rail & high pressure line
Leak line
Common Rail FIS
8/21
Fuel Temperature in Nozzle Sac on Engine
DME shows higher temperature and larger drop in sac than diesel fuel
Injector
Thermocouples’
leading wires
0
100
200
300
400
500
-40 -20 0 20 40 600
0.2
0.4
0.6
0.8
1
1.2
Crank angle [deg.]
Pme=0.6[MPa]
Injection pressure=20[MPa]
Static injection timing=-10[deg.]
Sac temp.
Tip temp.
DME
DME 50%,
Diesel fuel 50%
Diesel Fuel
DME
DME 50%,
Diesel fuel 50%
Diesel Fuel
Diesel Fuel
Tem
per
atu
re[℃
]
Nee
dle
lif
t [m
m]
Needle lift
TDC
Critical temp.
Nozzle
Sac thermocouple
150μm
Tip thermocouple
250μm
Body
Needle
9/21
Nozzle temperature with
Diesel Fuel Operation
Nozzle temperature with
DME Operation
Test Engine: Yanmer NFD13-K
Single cylinder
BorexStroke:φ92x96
Swept volume:638cm3
Nozzle hole dia.xNo.:φ0.175x4
Test condition:
Ne=960rpm
BMEP=0.6MPa
Numbers in figures show
Temperature [degree Celsius].
Temperature of Nozzle Body during
Engine Test
200℃<seat temp. & Diesel fuel≒ DME
10/21
FIE Wear Test Rig with Diesel Fuel
Motor
Injector
Supply pump
Argon Gas
(against ignition)
Injector Holder
w/heater
Common
rail
Fuel tank
:atoms. press. Mist filter
Oil cooler
Release to air
Heated up nozzle to engine condition with diesel fuel
Temperature of nozzle:up to 240℃
Source:[3]
11/21
HFRR:High Frequency Reciprocating Rig
Examination on actual nozzle is necessary
Outline of equipment Result of test
HFRR cannot predict real wear
Wear comparison: HFRR vs FIE rig
WSD<460〔μm〕・・・Japan&EU
Test Fuel
x
y
Lubricity evaluation equipment
decided by ISO
Consider
from wear of
ball 0
0.5
1
1.5
2
2.5
3
0 100 200 300 400 500 600 N
ozzle
seat
wear
on
FIE
rig
Wd (
μm
)
Lubricity improvement additive
No additive
Fuel : Diesel fuel
Prediction
Result
WSD by HFRR(μm)
12/21
NEW DME Nozzle Wear TEST RIG
3600[ rpm] 1000[ N]
Impact load=1kN
3600[ rpm]
Motor
Pump
Nozzle
1000[ N] Stepper
motor
DME circulate
3600[rpm]
Nozzle Inlet
pressure
RIG Fuel circulation part
Revolution speed
Fuel tank
Control Unit
Load control part
Concept
Patented: Japan, China , USA
・Circulation of Liquefied DME
・Use actual nozzle ・Improve experiments accuracy, small and compact
13/21 Test Area of Pressure & Temperature of Engine
& Wear Test Rigs, and DME phase
Temperature [degree Celsius]
Pre
ssu
re
[MP
a]
0
127
5
DME
Critical point
127C,5MPa
DME Super critical phase DME
liquid phase
DME in nozzle sac in eng.
Temp.=100~200C
Press.<100MPa
DME upstream nozzle seat in eng.
Temp.=40~100C
Press.<100MPa
HFRR
60C,1bar
FIE wear test rig
Temp.:Fuel(diesel) 40~60C
Nozzle120~240C
Press.:Inj.180MPa, back1bar
DME Nozzle
wear test rig
<40C,<1MPa
DME gaseous phase
300
Temp. of nozzle
body seat in engine
200~300C
10
-25
MPT-HFRR
60~100C
<10MPa
14/21
3. Effect of lubricant additives
15/21
Wear on Nozzle Wear Test Rig & Engine
Fuel:DME Impact number:1X107
Needle
seat
Shape before & after test Photo x50
Test condition
Wear
depth:2.4μm
5μm/div
0.2mm/div
After
Before
5μm/div
0.2mm/div
Wear
depth:
3.4μm
After
Before
Test time
46hr (1×107 )
1kN
93hr (1×107 )
Measuring path D
ME
No
zzle
Wea
r te
st r
ig
En
gin
e
Test rig simulates the wear of nozzle on engine
Ne=960rpm
BMEP=0.6MPa
A
C
B
16/21
Fuel Additive Effect of Wear Reduction
on Nozzle Seat
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 50 100 150 200 250 300
Fuel additive concentration(ppm)
Sea
t w
ear
dep
th(B
od
y+
nee
dle
)[μ
m] Diesel
Neat DME
DA03P
DA03P+H2O 200+1%
DA04F
DA04F+H2O 30+1%
DA04F+H2O 300+1%
Impact number10^7, Load1kN
Additive
ppm
+water%
Include H2O
No H2O
200~300ppm of additive is enough for wear reduction
Additive
DAxxP: Polymer type
DAyyF: Fatty acid type
17/21
4. Influence of water
18/21
Oxygen concentration on wear tested needle
02468
1012141618
DIESEL DA02F DA02F+H2O DA04F+H2O DA03P+H2O
(300ppm) (300ppm+1%) (30ppm+1%) (200ppm+1%)
10^7 10^7 10^7 10^7 10^7
Ox
yg
en c
on
cen
trat
ion(
%)
DA02F+H2O
(300ppm+1%)
Analyzer:EDX(Energy
Dispersive X-ray analyzer)
DIESEL fuel DA02F
(300ppm)
DA03P+H2O
(200ppm+1%)
DA04F+H2O
(30ppm+1%)
Impact number 10^7, Load
1kN
DME
Corrosion by water was shown even under low temperature
Needle seat portion Needle tip
19/21
0
1
2
3
4
5
6
7
0 0.5 1 1.5 2 2.5 3 3.5 4
Wear depth of needle[μm]
Wear
depth
of
body [
μm
]
Diesel
NeatDME
DA03P 200
DA03P+H2O 200+200
DA03P+H2O 200+0.03%
DA03P+H2O 200ppm+500ppm
DA03P+H2O 200ppm+1%
DA03P+H2O 300ppm+1%
DA04F 30ppm
DA04F+H2O 30+1%
DA04F+H2O 300+1%
DA04F 200ppm
DA04F+H2O 200+1%
DA03P 300ppm
DA03P 500ppm
Impurity & Temperature Effect on
Nozzle Seat Wear Symbol
②NEAT DME
④=③+water
① Diesel fuel (rig)
③=②+additives
Diesel fuel (FIE rig)
200℃
120℃
Test should be on Engine, high temperature condition
Water 300ppm
20/21
Conclusion
1) There is the large wear at the needle seat in case of fuel DME. Although HFRR cannot evaluate the wear at the seat, newly developed prototype wear test Rig can evaluate the seat wear.
2) Results of the new rig are some of the fatty and the polymer type additives is effective on wear resistance for nozzle seat.
3) The concentration of each additive is 300ppm enough to decrease the wear.
4) Impurity such as water brings nozzle more oxidized corrosion. The ratio of impurity water should be less than 300ppm
5) The effect of additives and impurities on engine should be studied, because the temperature of nozzle on engine is higher than the rig.
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