§ 18
How many litres of diesel per hour does a 150 kW motor use at 60% load?
Answer: Engine manufacturers specify specific fuel consumption in grams per kWh in the datasheet and consumption curves. If you multiply it by the power the engine actually delivers at cruising speed and divide by the fuel's density, you get litres per hour. The calculator is used when a customer asks what a new engine or a different cruising speed costs in fuel, or when you want to compare it with the consumption the customer has measured. The number can be entered directly into the calculator for range.
Effekt ved marchfart = nominel effekt × belastning
Forbrug (kg/t) = effekt (kW) × specifikt forbrug (g/kWh) ÷ 1000
Forbrug (l/t) = forbrug i kg ÷ densitet
Diesel according to EN 590 has a density of 0.820-0.845 kg/l at 15°C
| Symbol | Meaning | Unit |
|---|---|---|
| effekt_kw | Motor's nominal power | kW |
| belastning_pct | Load during march speed (% of rated power) | % |
| sfc | Specific consumption at that load (motor's datasheet) | g/kWh |
| densitet | Fuel density (diesel approx. 0.82-0.845, petrol approx. 0.74) | kg/l |
| = | Consumption | l/time |
| = | Consumption in kg | kg/time |
| = | Power at cruise speed | kW |
Does not apply when
The calculator's own default values inserted. The figures are calculated with exactly the formula the tool uses.
Substituted
Giver
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Når en kunde spørger hvad en ny motor eller en anden marchfart koster i brændstof, kan du regne forbruget ud fra effekten og motorens specifikke forbrug. Tallet kan sættes ind i aktionsradius-beregneren.
En motorbåd har en 150 kW diesel. Ved marchfart yder den ca. 60 %, og databladet giver 230 g/kWh.
It means: Motoren yder 90 kW og bruger ca. 24.6 l/time, altså 20.7 kg/time.
En sejlbåd har en 30 kW diesel, der kører på ca. 35 % ved 6 knob. Ved den lave belastning er det specifikke forbrug ca. 260 g/kWh.
It means: Forbruget er ca. 3.3 l/time. Det passer med det, sejlere typisk ser ved marchfart for motor.
En diesel bruger ca. 0,25-0,3 liter pr. kWh den yder.
Liter × densitet skal give kg.