Adiabatic Flame Temperature Formula

Adiabatic Flame Temperature Formula:

\[ T_{ad} = \frac{\sum (n_i \times \Delta H_{f,i})}{\sum (n_j \times C_{p,j})} \]

Adiabatic Flame Temperature (T_ad):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Adiabatic Flame Temperature?

The adiabatic flame temperature is the theoretical temperature that combustion gases would reach if the process occurred without any heat loss to the surroundings. It represents the maximum possible temperature for a given fuel-oxidizer mixture under adiabatic conditions.

2. How Does the Calculator Work?

The calculator uses the adiabatic flame temperature formula:

\[ T_{ad} = \frac{\sum (n_i \times \Delta H_{f,i})}{\sum (n_j \times C_{p,j})} \]

Where:

\( T_{ad} \) — Adiabatic flame temperature (K)
\( n_i \) — Number of moles of product i
\( \Delta H_{f,i} \) — Standard enthalpy of formation of product i (kJ/mol)
\( n_j \) — Number of moles of product j
\( C_{p,j} \) — Heat capacity at constant pressure of product j (J/mol·K)

Explanation: The equation balances the heat released by combustion (numerator) with the heat absorbed by the combustion products (denominator) under adiabatic conditions.

3. Importance of Adiabatic Flame Temperature

Details: Adiabatic flame temperature is crucial for designing combustion systems, predicting pollutant formation, optimizing engine performance, and ensuring material compatibility in high-temperature applications.

4. Using the Calculator

Tips: Enter the sum of enthalpy products in kJ and the sum of heat capacity products in J/K. Ensure all values are positive and represent complete combustion data.

5. Frequently Asked Questions (FAQ)

Q1: Why is adiabatic flame temperature theoretical?
A: In real systems, heat losses to surroundings, incomplete combustion, and dissociation effects prevent reaching the theoretical maximum temperature.

Q2: What factors affect adiabatic flame temperature?
A: Fuel type, equivalence ratio, initial temperature and pressure, and the presence of inert gases all influence the final temperature.

Q3: How accurate is this calculation?
A: This provides a first-order approximation. More sophisticated calculations account for temperature-dependent heat capacities and chemical equilibrium.

Q4: What are typical adiabatic flame temperatures?
A: For common fuels in air: methane ~2220K, propane ~2260K, hydrogen ~2380K, gasoline ~2300K.

Q5: Why use constant heat capacity in this formula?
A: This simplification makes calculation easier, but more accurate methods use temperature-dependent heat capacities in iterative calculations.