Post on 18-Aug-2018
Engine Testing and Instrumentation 1
Fuel Consumption Test for Hydrogen FCVs
Engine Testing and Instrumentation 2
The argument for an alternativeBut what are the snags !!
Engine Testing and Instrumentation 3
FUEL CELLS
Fuel cells generate electricity by combining oxygen and hydrogen without combustion.
The diagram below shows that, hydrogen fuel enters at the anode, oxygen (in the form of air) enters through the cathode. The hydrogen splits into a proton and electron, which move to the cathode and join with the oxygen to create water.
Engine Testing and Instrumentation 4
FUEL CELLS
• Fuel cells have short refuelling times and can travel further between refuelling than comparable battery powered electric vehicles (BEV). When fuelled by hydrogen, no emissions are produced and other fuels produce near zero emissions. The downside is that it is still a relatively young technology and thus requires time for costs to reduce to levels acceptable to the consumer.
Engine Testing and Instrumentation 5
FUEL CELLS
• Although hydrogen is a popular choice of fuel, it has a low density in liquid and gas phase. Methanol is the next choice as it can be readily derived from hydrogen but the reforming of methanol produces CO2, although only 10% of what ICE’s produce. The other advantage is that methanol can be handled as simply as gasoline and is easily produced from natural gas or biogas.
Engine Testing and Instrumentation 6
FUEL CELLS• Fuel cells have short refuelling times and can travel further
between refuelling than comparable battery powered electric vehicles (BEV). When fuelled by hydrogen, no emissions are produced and other fuels produce near zero emissions. The downside is that it is still a relatively young technology and thus requires time for costs to reduce to levels acceptable to the consumer.
• Although hydrogen is a popular choice of fuel, it has a low density in liquid and gas phase. Methanol is the next choice as it can be readily derived from hydrogen but the reforming of methanol produces CO2, although only 10% of what ICE’s produce. The other advantage is that methanol can be handled as simply as gasoline and is easily produced from natural gas or biogas.
Engine Testing and Instrumentation 7
skateboard-shaped
Fuel Cell VehiclesAlthough they are not expected to reach the mass market before 2010, fuel cell vehicles (FCVs) may someday revolutionize on-road transportation.
The potential to significantly reduce energy use and harmful emissions, as well as our dependence on foreign oil. No Greenhouse Gases No Air Pollutants (no smoke and harmful particulates)Helps Strengthen National Energy Security More Energy Efficient Design FlexibilityQuieter
Engine Testing and Instrumentation 8
One Example of FCV – Ford’s 3rd Generation
a Ni-MH high voltage battery with the hydrogen-powered fuel cell engine
Engine Testing and Instrumentation 9
Hydrogen FC System for Vehicle
Engine Testing and Instrumentation 10
How Fuel Cell Works
Engine Testing and Instrumentation 11
FC Stack
• Most fuel cells designed for use in vehicles produce less than 1.16 volts of electricity-far from enough to power a vehicle.
• Multiple cells must be assembled into a fuel cell stack.
• The potential power generated by a fuel cell stack depends on the number and size of the individual fuel cells that comprise the stack and the surface area of the PEM (Polymer Electrolyte Membrane, also called Proton Exchange Membrane).
Engine Testing and Instrumentation 12
Various FCs
• FCVs can be fueled with pure hydrogen gas stored onboard in high-pressure tanks.
• They also can be fueled with hydrogen-rich fuels; such as methanol, natural gas, or even gasoline; but these fuels must first be converted into hydrogen gas by an onboard device called a "reformer."
• Solid oxygen FC
Engine Testing and Instrumentation 13
H2-Rich Fuel FC
Engine Testing and Instrumentation 14
Solid Oxygen FC
• Because of the high operating temperature (between 700 and 1000 °C), the SOFC can be made of non-noble and therefore relatively cheap materials
• It can convert several fuels other than hydrogen.
Engine Testing and Instrumentation 15
Challenges• Onboard Hydrogen Storage • Cold-weather Operation (Freezing, low T performance)• Getting Hydrogen to Consumers • Cost (the costs of the electrolyte membrane and catalyst - the catalyst is made
of platinum)• Safety• Competition with Other Technologies (Hybrid, Diesel, GDI, HCCI)
Engine Testing and Instrumentation 16
Accuracy Verification Testing System for Measurement Method
Engine Testing and Instrumentation 17
Electrical Current Method
W = Fuel consumption [g]n = Number of cells of fuel cell stackm = Molecular weight of hydrogen 2.016 [g/mol]
= Integrated current of fuel cell stack [A·sec]v = Valence number of hydrogen 2F = Faraday constant 9.6485×104 [C/mol]
-20
-15
-10
-5
0
5
10
0 100 200 300 400
Fuel Flow by Sonic Nozzle [NL/min]
Erro
r of E
lect
ric C
urre
nt M
erho
d [%
]
)/()( FvImnW ×Σ××=
IΣIΣ
IΣ
Engine Testing and Instrumentation 18
PRESSURE METHOD (P/T METHOD)
Engine Testing and Instrumentation 19
PRESSURE METHOD (P/T METHOD)
W = Fuel consumption [g]m = Molecular weight of hydrogen 2.016 [g/mol]V = Volume of hydrogen tank [m3]R = Gas constant 8.314 [J/mol·K]P1 = Hydrogen tank pressure before test [Pa]P2 = Hydrogen tank pressure after test [Pa]T1 = Hydrogen tank temperature before test [K]T2 = Hydrogen tank temperature after test [K]z1 = Compressibility factor at P1, T1z2 = Compressibility factor at P2, T2
)(22
2
11
1
TzP
TzP
RVmW
×−
×××=
Engine Testing and Instrumentation 20
Change in Inside Gas Temperature and Tank Surface Temperature during Gas Discharge
[℃][℃]Time fromgas discharge
100[sec]
300[sec]
H2 : 500NL/min
-5
0
5
10
15
20
25
0 1 2 3 4 5
Time [min]
Gas
tem
p. in
Fue
l Con
tain
er [℃
]
-5
0
5
10
15
20
25
0 1 2 3 4 5
Time [min]
Gas
tem
p. in
Fue
l Con
tain
er [℃
]
H2 : 500NL/min
⑦Upper
⑨Middle
⑪Lower
H2 : 50NL/min
PRESSURE METHOD (P/T METHOD)
Engine Testing and Instrumentation 21
Influence of Temperature Measuring Point on Pressure Method
-4
-2
0
2
4
①O
utle
t pip
e
②U
pper
③M
iddl
e-le
ft
④M
iddl
e
⑤M
iddl
e-rig
ht
⑥Lo
wer
⑦U
pper
⑧M
iddl
e-le
ft
⑨M
iddl
e
⑩M
iddl
e-rig
ht
⑪Lo
wer
Temperature Measuring Point
Erro
r of P
ress
ure
Met
hod
[%]W/O SoakW Soak
PRESSURE METHOD (P/T METHOD)
Engine Testing and Instrumentation 22
Gas Temperature Distribution in Vertical Cross-Section of Tank by Simulation
Tank volume: 34litersH2 flow rate: 200liters/minInitial pressure: 8MPaGGas releasing time: 180s
PRESSURE METHOD (P/T METHOD)
(a) Horizontal position
+2℃
+1℃
0℃
-1℃
-2℃
Tank volume: 34litersH2 flow rate: 500liters/minInitial pressure: 8MPaGGas releasing time: 180s
(b) Vertical position
Engine Testing and Instrumentation 23
Influence of Temperature Measuring Point and Soaking Time on Pressure Method (Tank Volume:20 liters)
-4
-2
0
2
4
6
0 500 1000 1500 2000 2500
Fuel Flow by Standard Method [NL/test]
Erro
r of P
ress
ure
Met
hod
[%]
W/O SoakSoak 5minSoak 30min
PRESSURE METHOD (P/T METHOD)
(a) Calculation from Inside Gas Temperature
(b) Calculation from Tank Surface Temperature
-4
-2
0
2
4
6
0 500 1000 1500 2000 2500
Fuel Flow by Standard Method [NL/test]
Erro
r of P
ress
ure
Met
hod
[%]
W/O SoakSoak 5minSoak 30min
Engine Testing and Instrumentation 24
Error of Weight Method using Ordinary H2 Tank and Full-wrapped H2 Tank: The full-wrapped tank is about 3.5 times larger in capacity than a conventional hydrogen tank and, therefore, it is adaptable to testing of even large vehicles.
-4
-2
0
2
4
0 500 1000 1500 2000 2500
Fuel Flow by Sonic Nozzle [NL/test]
Erro
r of W
eigh
t Met
hod
[%]
WEIGHT METHOD
(a) Ordinary H2 Tank (Cr-Mo steel, Volume:47liter, Maximum Pressure:14.7MPa)
-4
-2
0
2
4
0 500 1000 1500 2000 2500
Fuel Flow by Sonic Nozzle [NL/test]
Erro
r of W
eigh
t Met
hod
[%]
(b) Full-wrapped H2 Tank (Type3, Volume:74liter, Maximum Pressure:35MPa)
Engine Testing and Instrumentation 25
Flowmeter Methods
Characteristics of Flowmeter under Steady Flow Condition
-30-25-20-15-10
-50
0 100 200 300 400 500H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD
]
- 5%RD @50L/min
-30-25-20-15-10
-50
0 100 200 300 400 500H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD
]
- 5%RD @50L/min
-20
-10
0
10
20
0 100 200 300 400 500H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD
]
±2.5%RD @50L/min
-20
-10
0
10
20
0 100 200 300 400 500H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD
]
±2.5%RD @50L/min
-2
-1
0
1
2
0 50 100 150H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD
]
-8-6-4-2024
0 100 200 300 400 500H2 consumption by Standard method [NL/min]
Erro
r of f
low
met
er [%
RD]
(a) Thermal Mass Flowmeter (b) Coriolis Flowmeter
(c) Volumetric Flowmeter (d) Ultrasonic Flowmeter
Engine Testing and Instrumentation 26
Characteristics of Flowmeter under Transient Flow Condition
20
30
40
50
60
70
80
0 100 200 300 400SampleTime [sec]
Flow
rate
[NL/
min
]
Thermal CoriolisVolumetric Sonic Nozzle
CoriolisThermal
Volumetric
-6
-4
-2
0
2
4
6
Erro
r of
Inte
grat
ed fl
ow [%
](a) Trend Data of Instant Flow (b) Error of Integrated Flow for
Weight Method
Flowmeter Methods
Engine Testing and Instrumentation 27
Thermal Mass Flowmeter: Effect of Calibration using Sonic Nozzle and Hydrogen
-10
-5
0
5
10
0 200 400 600
Flowrate by Sonic Nozzle [NL/min]
Erro
r of I
nsta
nt F
low
[%R
D]
Before Calibration
After Calibration
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
Erro
r of I
nteg
rate
d flo
w [%
]
Before caribration
After caribration(a) Error of Instant Flow
(b) Error of Integrated Flow for Weight Method
Flowmeter Methods
Engine Testing and Instrumentation 28
Calibration Results of Thermal Mass Flowmeter using Sonic Nozzles with Hydrogen
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0 50 100 150 200 250Flowrate [NL/min]
Err
or
(vs.
Sonic
nozz
le)
[% o
f re
adin
g]
First cal.
Second cal.
lower flow range
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0 500 1000 1500 2000
Flowrate [NL/min]
Err
or
(vs.
Sonic
nozz
le)
[% o
f re
adi
ng]
First cal.
Second cal.
Higher flow range
Flowmeter Methods
Engine Testing and Instrumentation 29
Pressure Method, Weight Method and Flow Method
Engine Testing and Instrumentation 30
PRESSURE METHOD MEASUREMENT
Specification of Sensor for Pressure Method
1kPa(eq. to H2 0.2liters)
Min. Graduation
(0.05% F.S.Accuracy0-16 MPa absRange
Pressure sensor
0.01(CMin. Graduation0.01-0.03(CAccuracy
0-50(CRangeTemperature sensor (thermistor)
660mm
198mm(30%)
Temp.sensor
Engine Testing and Instrumentation 31
W = Fuel consumption [g]g1 = Weight of hydrogen tank before test [g]g2 = Weight of hydrogen tank after test [g]
WEIGHT METHOD
21 ggW −=
Vibration-Proof Stand
WindshieldPrecisionbalance
Vibration-Proof Stand
WindshieldPrecisionbalance
Engine Testing and Instrumentation 32
Specification of Thermal Mass Flowmeter for Flow Method
16kPa@2000liters/min(nor.)Pressure drop
5msSampling time
±1% of readingAccuracy
10-2000NL/minRange
Flowmeter Methods Measurement
Engine Testing and Instrumentation 33
Hydrogen Supply Device for FCV Test
To vent
Pressuresensor
Temp.sensorPressure
regulatorPT
Flowmeter
N2 Supplyfor Purge
H2 tankfor test
P
H2 Supplyfor Warm-up
H2 tankselect valve
To FCV
Purgevalve
Checkvalve
Safetyvalve
Supplyvalve
To vent
Pressuresensor
Temp.sensorPressure
regulatorPT
Flowmeter
N2 Supplyfor Purge
H2 tankfor test
P
H2 Supplyfor Warm-up
H2 tankselect valve
To FCV
Purgevalve
Checkvalve
Safetyvalve
Supplyvalve
Engine Testing and Instrumentation 34
Test Result of Fuel Consumption Test
Test Vehicle(no special order):1. Toyota FCHV(Toyota Motor Corp.)2. X-TRAIL FCV(Nissan Motor Co., Ltd.)3. Honda FCX(Honda Motor Co., Ltd.)4. F-Cell(DaimlerChrysler Japan Co., Ltd.)5. HydroGen3(GM Asia Pacific Japan Ltd.)
Engine Testing and Instrumentation 35
Test Result of Fuel Consumption Test
(10・15mode, Test vehicle in FY2004)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
A B C D E
Vehicle_
Err
or
(vs
Weig
ht
meth
od)
[%]
Pressure methodFlow method
(12) (16) (13)(5) (15)
( ):Test number