LNG Boil-Off Rate from Heat Ingress
Daily BOR from tank surface, U-value and temperature drop - useful cross-check against trial-measured BOR.
Heat leak
63.0kW
Boil-off gas rate
445kg/h
BOR (% of cargo / day)
0.014%
Formula, assumptions, and limits
Modern 174k m³ membrane LNG carriers spec 0.085–0.10 %/day BOR laden; 0.12–0.15 % ballast (lower heel, higher ΔT fraction of container cooled). Fugitive leaks, pipe-hangers and pump sumps add to the calculated number.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Tank outer surface area | m² | GA plan | |
| Insulation overall U-value | W/(m²·K) | insulation spec | |
| Outer − LNG temperature | K | typical 175 K in ambient air | |
| LNG latent heat | kJ/kg | thermodynamic table |