# Optical Equivalence Ratio Measurement of a Dual Fuel Burner for Natural Gas and Kerosene

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Experimental Setup and Measurement Techniques

#### 2.1. Single Burner Test Rig

#### 2.2. Spectrally Resolved Chemiluminescence

#### 2.3. Bandpass-Filtered Chemiluminescence

- CO${}_{2}$*-filter with a centre wavelength (CWL) of 456.42 nm, a peak transmission of 68.18% and a full width at half maximum (FWHM) of 2.4 nm
- CH*-filter with a CWL of 431.39 nm, a peak transmission of 48.63% and a FWHM of 10.6 nm

## 3. Results

#### 3.1. Global Equivalence Ratio from Spectrally Resolved Chemiluminescence

#### 3.2. Bandpass-Filtered Chemiluminescence Results

## 4. Summary and Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**Schematic sketch of the single burner test rig with modular swirl burner system and measurement techniques.

**Figure 3.**The dependence of different normalized chemiluminescence ratios on the equivalence ratio $\Phi $ for the combustion of natural gas under atmospheric conditions. The intensities of CH* and OH* are uncorrected in (

**a**) and background corrected in (

**b**). Various thermal powers are marked with symbols (diamond: 40 kW, circle: 50 kW, and triangle: 60 kW).

**Figure 4.**The dependence of different normalized chemiluminescence ratios on the equivalence ratio $\Phi $ for the combustion of kerosene under atmospheric conditions. The intensities of CH* and OH* are uncorrected in (

**a**) and background corrected in (

**b**). Various thermal powers are marked with symbols (diamond: 40 kW, circle: 50 kW, and triangle: 60 kW).

**Figure 5.**The dependence of the CH*/${\mathrm{CO}}_{2}$* chemiluminescence ratio on the equivalence ratio $\Phi $ for the combustion of natural gas in (

**a**) and kerosene in (

**b**) under atmospheric conditions for different air mass flow rates. All values are normalized to the approximation at $\Phi $ = 0.8.

**Figure 6.**(

**Upper half:**) Locally resolved CH* chemiluminescence intensity for natural gas combustion at an air mass flow rate of ${\dot{\mathrm{m}}}_{\mathrm{air}}$ = 25 g/s. The solid black lines represent the 75%, 50% and 25% isolines of the chemiluminescence intensity. The dashed black line represents the 50% isoline of the corresponding CO${}_{2}$* chemiluminescence intensity. (

**Lower half:**) Locally resolved CH*/CO${}_{2}$* distribution. The values are normalized to the mean CH*/CO${}_{2}$* ratio at $\Phi $ = 0.8.

**Figure 7.**(

**Upper half:**) Locally resolved CH* chemiluminescence intensity for natural gas combustion for an equivalence ratio of $\Phi $ = 0.775. The solid black lines represent the 75%, 50% and 25% isolines of the chemiluminescence intensity. The dashed black line represents the 50% isoline of the corresponding CO${}_{2}$* chemiluminescence intensity. (

**Lower half:**) Locally resolved CH*/CO${}_{2}$* distribution. The values are normalized to the mean CH*/CO${}_{2}$* ratio with an air mass flow rate of ${\dot{\mathrm{m}}}_{\mathrm{air}}$ = 30 g/s.

**Figure 8.**The dependence of the CH*/${\mathrm{CO}}_{2}$* chemiluminescence ratio on the air mass flow rate ${\dot{\mathrm{m}}}_{\mathrm{air}}$ for the combustion of natural gas under atmospheric conditions for different equivalence ratios. All values are normalized to the respective ratio at ${\dot{\mathrm{m}}}_{\mathrm{air}}$ = 30 g/s.

**Figure 9.**The dependence of the CH*/${\mathrm{CO}}_{2}$* chemiluminescence ratio on the preheating temperature ${\mathrm{T}}_{\mathrm{pre}}$ for the combustion of natural gas under atmospheric conditions for different equivalence ratios. All values are normalized to the respective ratio at ${\mathrm{T}}_{\mathrm{pre}}$ = 300 °C.

**Figure 10.**(

**Upper half:**) Locally resolved CH* chemiluminescence intensity for kerosene combustion at an air mass flow rate of ${\dot{\mathrm{m}}}_{\mathrm{air}}$ = 25 g/s. The solid black lines represent the 75%, 50% and 25% isolines of the chemiluminescence intensity. The dashed black line represents the 50% isoline of the corresponding CO${}_{2}$* chemiluminescence intensity. (

**Lower half:**) Locally resolved CH*/CO${}_{2}$* distribution. The values are normalized to the mean CH*/CO${}_{2}$* ratio at $\Phi $ = 0.8.

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**MDPI and ACS Style**

Vogel, M.; Bachfischer, M.; Kaufmann, J.; Sattelmayer, T.
Optical Equivalence Ratio Measurement of a Dual Fuel Burner for Natural Gas and Kerosene. *Fluids* **2022**, *7*, 43.
https://doi.org/10.3390/fluids7020043

**AMA Style**

Vogel M, Bachfischer M, Kaufmann J, Sattelmayer T.
Optical Equivalence Ratio Measurement of a Dual Fuel Burner for Natural Gas and Kerosene. *Fluids*. 2022; 7(2):43.
https://doi.org/10.3390/fluids7020043

**Chicago/Turabian Style**

Vogel, Manuel, Michael Bachfischer, Jan Kaufmann, and Thomas Sattelmayer.
2022. "Optical Equivalence Ratio Measurement of a Dual Fuel Burner for Natural Gas and Kerosene" *Fluids* 7, no. 2: 43.
https://doi.org/10.3390/fluids7020043