Symbol
|
Term
|
Unit
|
A/Fst
|
Stoichiometric air to fuel
ratio
|
1
|
c
x
|
Concentration in the exhaust (with
suffix of the component nominating, d=dry or w=wet)
|
ppm/% (V/V)
|
E
CO2
|
CO2 quench of
NOx analyser
|
%
|
E
H2O
|
Water quench of NOx
analyser
|
%
|
E
NOx
|
Efficiency of NOx
converter
|
%
|
E
O2
|
Oxygen analyser correction
factor
|
1
|
λ
|
Excess air factor: kg dry air/(kg
fuel · A/Fst)
|
1
|
f
a
|
Test condition parameter
|
1
|
f
c
|
Carbon factor
|
1
|
f
fd
|
Fuel-specific factor for exhaust flow
calculation on dry basis
|
1
|
f
fw
|
Fuel-specific factor for exhaust flow
calculation on wet basis
|
1
|
H
a
|
Absolute humidity of the intake air
(g water / kg dry air)
|
g/kg
|
H
sc
|
Humidity of the charge air
|
g/kg
|
i
|
Subscript denoting an individual
mode
|
1
|
k
hd
|
Humidity correction factor for
NOx for diesel engines
|
1
|
k
wa
|
Dry to wet correction factor for the
intake air
|
1
|
k
wr
|
Dry to wet correction factor for the
raw exhaust gas
|
1
|
n
d
|
Engine speed
|
min-1
|
n
turb
|
Turbocharger speed
|
min-1
|
%O2I
|
HC analyser percentage oxygen
interference
|
%
|
p
a
|
Saturation vapour pressure of the
engine intake air determined using a temperature value for the intake air
measured at the same physical location as the measurements for pb
and Ra
|
kPa
|
p
b
|
Total barometric pressure
|
kPa
|
p
c
|
Charge air pressure
|
kPa
|
p
r
|
Water vapour pressure after cooling
bath of the analysis system
|
kPa
|
p
s
|
Dry atmospheric pressure calculated by
the following formula: p
s = p
b - R
a· p
a /100
|
kPa
|
p
sc
|
Saturation vapour pressure of the
charge air
|
kPa
|
P
|
Uncorrected brake power
|
kW
|
P
aux
|
Declared total power absorbed by
auxiliaries fitted for the test and not required by ISO 14396
|
kW
|
P
m
|
Maximum measured or declared power at
the test engine speed under test conditions
|
kW
|
q
m
ad
|
Intake air mass flow rate on dry
basis
|
kg/h
|
q
m
aw
|
Intake air mass flow rate
on wet basis
|
kg/h
|
q
m
ew
|
Exhaust gas mass flow
rate on wet basis
|
kg/h
|
q
m
f
|
Fuel mass flow
rate
|
kg/h
|
q
m
gas
|
Emission mass flow rate
of individual gas
|
g/h
|
R
a
|
Relative humidity of the
intake air
|
%
|
r
h
|
Hydrocarbon response
factor
|
1
|
ρ
|
Density
|
kg/m3
|
s
|
Fuel rack
position
|
|
T
a
|
Intake air temperature
determined at the engine intake
|
K
|
T
caclin
|
Charge air cooler,
coolant inlet temperature
|
0C
|
T
caclout
|
Charge air cooler,
coolant outlet temperature
|
0C
|
T
Exh
|
Exhaust gas
temperature
|
0C
|
T
Fuel
|
Fuel oil
temperature
|
0C
|
T
Sea
|
Seawater
temperature
|
0C
|
T
SC
|
Charge air
temperature
|
K
|
T
SCRef
|
Charge air reference
temperature
|
K
|
u
|
Ratio of exhaust
component and exhaust gas densities
|
1
|
W
F
|
Weighting factor
|
1
|