Fuel Oil Density Temperature Gravity Volume Correction ASTM D1250

Overview

Engineering reference data for Fuel Oil Density Temperature Gravity Volume Correction ASTM D1250 in combustion engineering.

Key Formulas

Heat Release

$Q = \dot{m} \cdot HV$

Fuel energy release rate.

Air-Fuel Ratio

$AF = \frac{m_{air}}{m_{fuel}}$

Mass of air per mass of fuel.

Excess Air

$EA = \frac{O_2}{21 - O_2} \times 100\%$

From flue gas oxygen measurement.

Variables

Symbol	Description	Unit
$Q$	Heat release rate	W
$\dot{m}$	Mass flow rate	kg/s
$HV$	Heating value	J/kg
$AF$	Air-fuel ratio	—

Volume Correction Factors

Volume correction factors (VCF) adjust fuel oil volumes to a standard reference temperature, typically 15°C (59°F). The relationship is based on thermal expansion principles.

The volume at the observed temperature ($V_T$) relates to the volume at the reference temperature ($V_{15}$) via: $V_{15} = V_T \times \text{VCF}_{(T \to 15)}$ or conversely: $V_T = V_{15} \times \text{VCF}_{(15 \to T)}$

Applying Correction Factors: Examples

Example 1: Volume at Reference Temperature

1. Given: $V_T = 100$ L, $\rho_{15} = 800$ kg/m³, $T = 200$°C.
2. Find VCF: From the "Fuel oils volume correction figure (Density@Observed T/Density@15°C)" for $\rho_{15} = 800$ kg/m³, $\text{VCF}_{(200°C \to 15°C)} \approx 0.859$.
3. Calculate: $V_{15} = 100 \text{ L} \times 0.859 = 86$ L.
4. Check: Volume should be lower at lower temperature. ✓

Example 2: Volume at Observed Temperature

1. Given: $V_{15} = 1000$ m³, $\rho_{15} = 960$ kg/m³, $T = 100$°C.
2. Find VCF: From the "Fuel oils volume correction figure (Density@15°C/Density@observed T)" for $\rho_{15} = 960$ kg/m³, $\text{VCF}_{(15°C \to 100°C)} \approx 1.065$.
3. Calculate: $V_{100} = 1000 \text{ m³} \times 1.065 = 1065$ m³.
4. Check: Volume should be higher at higher temperature. ✓

Interpreting the Diagrams

The referenced figures plot fuel oil density against temperature. To use them:

1. Locate your fuel's density at a known temperature on the Density vs. Temperature diagram to identify the correct line (color).
2. Follow that same line to the desired temperature to find the new density.
3. Use the same line on the Volume Correction Factor diagram to read the VCF corresponding to your temperature interval. The factor greater than 1 indicates volume increase with temperature.

API Gravity Conversion

If the fuel oil density is given in degrees API (°API), convert it to density at 15°C (kg/m³) using: $\rho_{15} = \frac{141.5}{\text{°API} + 131.5} \times 999.016$ (where 999.016 kg/m³ is the density of water at 15°C)

References

• Original Source