Voyage fuel cost to keep a heated cargo (HFO, asphalt, vegoil) above its discharge-pumpable temperature given ambient seawater and tank U-value.
Formula
$$ \dot Q = U \cdot A \cdot \Delta T, \quad \dot m_{fuel} = \frac{\dot Q}{\eta_b \cdot \text{NCV}} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $U$ | Tank overall heat-transfer coefficient | W/m²·K | insulation schedule |
| $A$ | Heat-loss area | m² | tank drawing |
| $\Delta T$ | Cargo-ambient ΔT | K | on-board RTDs |
| $\eta_b$ | Boiler efficiency | - | boiler maker data |
| $NCV$ | Net calorific value | MJ/kg | BDN / ISO 8217 |
Sources
- ISO 8217 - Marine fuel specifications.
- OCIMF ISGOTT 6th Ed..