Oil Filled Tanks - Heat Loss
Heat loss from insulated and uninsulated, sheltered and exposed heated oil tanks.
Heat transfer rates - α - for heated oil filled tanks.
Sheltered Tank
| Tank Temperature | Heat Transfer Rate - α - | ||||
|---|---|---|---|---|---|
| Uninsulated | Insulated | ||||
| (oC) | (oF) | (W/(m2 oC)) | (Btu/(hr ft2 oF)) | (W/(m2 oC)) | (Btu/(hr ft2 oF)) |
| 10 | 50 | 6.8 | 1.2 | 1.7 | 0.3 |
| 27 | 80 | 7.4 | 1.3 | 1.8 | 0.33 |
| 38 | 100 | 8.0 | 1.4 | 2.0 | 0.35 |
Exposed Tank
| Tank Temperature | Heat Transfer Rate - α - | ||||
|---|---|---|---|---|---|
| Uninsulated | Insulated | ||||
| (oC) | (oF) | (W/(m2 oC)) | (Btu/(hr ft2 oF)) | (W/(m2 oC)) | (Btu/(hr ft2 oF)) |
| 10 | 50 | 8.0 | 1.4 | 2.0 | 0.35 |
| 27 | 80 | 8.5 | 1.5 | 2.1 | 0.38 |
| 38 | 100 | 9.0 | 1.6 | 2.3 | 0.4 |
Heat loss transfer rate depends heavily on
- the ambient conditions - whether it is wind, sun or raining or snowing on the external surface
- the internal conditions in the tank - the viscosity of the oil and the internal circulation in the tank
The total heat loss from an application can in general (in SI-units) be expressed as:
Q = α A dt (1)
where
Q = heat loss (W)
α = heat transfer rate (W/(m2oC))
A = area (m2)
dt = temperature difference (oC)
Example - Heat Loss from an Exposed Insulated Oil Tank
The total heat loss from an insulated tank with 1000 m2 exposed surface, filled with heated oil at 38 oC, surrounding temperature of 0 oC and a heat transfer rate of 2.27 W/m2 oC - can be calculated as:
Q = (2.27 W/(m2oC)) (1000 m2) ((38 oC) - (0 oC))
= 86260 W
= 86.3 kW
