2. Wärtsilä Seminar
International Standard ISO 3046/1…7 (1995)
Reciprocating internal combustion engines - performance
Part 1: Standard reference conditions and declarations
of power, fuel and lubricating oil consumption and
test method
Part 3: Test measurements
Part 4: Speed governing
Part 5: Torsional vibrations
Part 6: Over-speed protection
Part 7: Codes for engine power
3. Wärtsilä Seminar
International Standard ISO 3046/1 (1995)
STANDARD REFERENCE CONDITIONS:
- Total barometric pressure : 100 kPa. (1,0 bar)
- Air temperature: 298 K (25 ºC)
- Relative humidity: 30 %
- Charge Air coolant temperature: 298 K (25 ºC)
note! Relative humidity of 30% @temp 298 K corresponds to water vapour
of 1kPa. Hence the corresponding dry barometric pressure is 99 kPa
4. Wärtsilä Seminar
Power:
- Declared power “rated power/ output”
SI in kilowatt
Metric horse power (hp) = 0,736 kW
Engine horse power (HP) = 0,746 kW
Note! When stating the Output, the revolution, the ambient conditions
and load should be mentioned!
5. Wärtsilä Seminar
Type of power?:
- Declared power
- Indicated power
- Brake power /shaft
- Continuous power
- Overload power
- Fuel stop power
- ISO power
- ISO standard power
- Service power
- Service standard power
- Power adjustment
- Power correction
6. Wärtsilä Seminar
Auxiliaries?:
It is necessary to distinguish those auxiliaries which
affect the final shaft output
- dependent auxiliary (engine-driven)
- independent auxiliary (separately-driven)
- non-essential auxiliary (far auxiliary)
7. Wärtsilä Seminar
Fuel oil consumption?:
=is the quantity of fuel consumed by an engine per
unit of time at a stated power, under stated
ambient conditions, and full load
+ lower heating values of the fuel
+ tolerance
+ auxiliary
+ power factor
+ measurement point (Shaft, generators)
note! in general the used SI Unit = g/kWh
8. Wärtsilä Seminar
Lubricating oil consumption?:
= is “the quantity of lubricating oil consumed
by an engine per unit of time at a stated power,
and load”
+ the oil discarded during an engine oil change shall not be
included into the lube oil declaration
+ a stated period of running shall be declared
note! in general the used SI Unit = litre/ or g/kWh
Note! First 500 Opr-hours is standard period test
9. Wärtsilä Seminar Turkey
Calorific value of fuels?:
liquid fuel engines
“any declared specific fuel consumption of a liquid fuel engine shall
be related to a reference distillate type fuel of lower calorific value
of 42 700 kJ/kg.”
gas engines
“any declared specific fuel consumption of a gas engine shall be
related to a stated lower calorific value of the gas. The type of the
gas shall be declared”
The (MN) Methane number is concedered to be >80
12. Wärtsilä Seminar
Heat balance?:
fuel input Fi = B * Q
where:
B = gross fuel oil consumption in (kg/s)
Q = net calorific value in (kJ/kg)
Cooling water Pcool = m * c * dt
where:
m = the massflow of the water (kg/s)
c = thermal conductivity for water (4,18 kJ/kgK)
dt= temperature rise (K)
13. Wärtsilä Seminar
Exhaust gases Pexh. = m * c * dt
where: m = the mass-flow of the exhaust gas in (kg/s)
c = thermal conductivity for gases (1,045 kJ/kgK)
dt= temperature difference of gases (K)
The “dt” is the exhaust gas temp. minus the ambient temperature.
Power output P = 1,31 * (D*D) * S * Na * Z * Pme
where: D = piston diameter (m)
S = stroke (m)
Z = number of cylinders
Pme = calculated mean effective pressure (bar)
Na = working cycle per minute (rpm/2)
14. Wärtsilä Seminar
Efficiency?:
In the diesel engine, injected fuel is not completely changed to mechanical
energy. The energy changed to useful work is named as total efficiency (ne)
ne = (P/be)*Q
Where: P = output , be = s.f.o.c and Q = fuel net H.V
the easiest way to calculated the efficiency is
(Efficiency) = Output / Input
measured in (%)
17. Wärtsilä Seminar
Operating data?
In case the engine power will be utilised under more difficult conditions
than those mentioned or stated in the sales documents. Otherwise, the
engine manufacturer can give advice about the correct output reduction.
As a guideline additional reduction may be calculated as follows:
Reduction factors = -(a + b + c)
where:
a = 0,5 % for every ºC on CA exceeds the I.S.O ref. conditions
b = 1 % for every 100 m level above I.S. O ref. conditions
c = 0,4 % for every ºC on CW exceeds the I.S.O ref. conditions
18. Wärtsilä Seminar Turkey
Wärtsilä 18V46/ Performance (kWe) @ 100 m.a.s.l (m)
17 024
7 000
8 000
9 000
10 000
11 000
12 000
13 000
14 000
15 000
16 000
17 000
18 000
10 15 20 25 30 35 40
Ambient Temperature, °C
GeneratorOutputinkWe
Derating according to ISO 3064
Derating according to Wartsilä
