1 presented by prof. dr. tharwat messiha farag experimental study of lpg diffusion flame at elevated...

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Presented By

Prof. Dr. Tharwat Messiha Farag

Experimental Study of LPG Diffusion Flame at Elevated Preheated Air Temperatures

Mechanical Power Engineering Department Faculty of Engineering

Port Said University Port Said, Egypt

E-mail :faragtm@yahoo.com ++201222705234

Amer A. A., Gad H. M., IbrahimI. A., Abdel-Mageed S. I., Farag T. M.COMBUSTION GROUP

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PRESENTATION LAYOUT

INTRODUCTION

AIM OF THE PRESENT WORK

EXPERIMENTALTEST RIG

EXPERIMENTALRESULTS

CONCLUSIONS

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Combustion

Heat(useful energy)

Pollutants(NOx,CO and UHC)

Domestic heating

Power generation

Boilers

Furnaces

Transportation

Reduction by

A highly Preheated Air Temperature and low-oxygen concentration

Provide significant energy savings

Reduce pollution and equipment size

Uniform thermal characteristics within the combustion chamber

INTRODUCTION

Products

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Some of the previous investigator concerned with studying the combustion characteristics of gaseous fuel diffusion flame by changing air swirl number and air fuel mass ratio, .... (Mafra et al, Farag, T.M., Chigier, Merlo et al, Gassoumi and Said, Farag, A.I.)

Some of the previous investigator studied the effect of highly preheated air temperature with low

oxygen concentrations on the characteristics of combustion (Min Choi and Katsuki , Gupta, Yuan and Naruse , Lille et al , Seepana and Jayanti , Ishiguro et al )

Little of the previous researchers studied the preheated air with moderate temperature by using different air to fuel mass ratios and different air swirl numbers.

In the present study, the effect of the moderate preheated air temperature for different air fuel mass ratios and

different air swirl numbers are investigated.

INTRODUCTION

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The Studied Parameters are

Air to fuel mass ratio

A/F =15, 20, 30, 40, and 50

Air swirl number

Preheated Air Temperature

Excess Air Factor, λ =0.97, 1.23, 1.95, 2.60, and 3.25

S = 0.50, 0.87, and 1.50

Tpr = 300, 350, 400, 450, and 500 K

Used Fuel LPG

60% (Propane) C3H8 and 40%C4H10(Butane] …….

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The Measurements

Temperature distributions

Visible flame length

Volume of high temperatures region

Exhaust species concentrations

CO2, CO, O2, NOx

Region ofTemperatures larger than

1300K

InRadial & Axial

Directions

Temperature Contours&

Temperature Maps

Emission of Index, EI of CO2, CO, O2, NOx

Measured at the Combustor End Section

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Air line and air preheating unit

LPG fuel line

Burner head and its arrangement

Water cooled swirl type combustor

The experimental test rig consists of:

Experimental Test Rig

8Experimental test rig

Experimental Test Rig

9 Combustion Air Line and Preheating Air Unit

Experimental Test Rig

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Air Preheating Unit

1 -Steel pipe

3 -Electrical heaters

2 -Insulation

4 -Automatic electric switches

Experimental Test Rig

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A Photograph of Electrical heaters

A photograph of Air preheating unit with and without insulation

Experimental Test Rig

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Water-cooled combustor

Experimental Test Rig

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Burner head

Fuel Nozzle

Air Swirler

Fuel Nozzle Air Swirler

Experimental Test Rig

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Platinum and Platinum-Rhodium (13 %) bare wire thermocouple

Experimental Test Rig

15 A photograph of experimental test rig

Experimental Test Rig

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The Experimental Study

Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on

Temperature distributions

Visible flame length

Volume of high temperatures region

Exhaust species concentrations

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The Experimental Study

To clarify the effect of the studied parameters;

The inlet fuel thermal load and momentum are

kept constant for all the studied experimental runs

Air to Fuel Mass Ratio, AFR

Air Swirl Number, S

Preheating Air Temperature, Tpr

Mass Fuel Flow Rate = 1.0 g/s and Fuel Nozzle Diameter = 6 mm

Therefore

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Temperature Distributions

Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Temperature distributions

Experimental Results

S = 0.50, T=300 K

S = 1.50, T=300 K

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AFR = 20AFR = 30AFR = 40AFR = 50

S = 0.50, T=300 K

Effect of air to fuel mass ratio on temperature distributions

AFR = 15

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AFR = 20AFR = 30AFR = 40AFR = 50

S = 1.50, T=300 K

AFR = 15

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Temperature Distributions

Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Temperature distributions

Experimental Results

AFR = 30, T=300 K

AFR = 30, T=400 K

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S = 0.87S = 1.5

Effect of swirl number on temperature distributions

AFR = 30, T=300 K

S = 0.50

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S = 0.87S = 1.5S = 0.50

AFR = 30, T=400 K

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Temperature Distributions

Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Temperature distributions

Experimental Results

AFR = 30, S=0.50

AFR = 30, S=1.50

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T=350 KT=400 KT=450 KT=500 K

AFR = 30, S=0.50

Effect of preheated air temperature on temperature distributions

T = 300 K

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T=350 KT=400 KT=450 KT=500 K

AFR = 30, S=1.50

T = 300 K

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Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Visible flame length

Experimental Results

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Effect of air to fuel mass ratio on the flame length for different air swirl numbers

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AFR=15 AFR=20 AFR=30 AFR=40 AFR=500

0.1

0.2

0.3

0.4

0.5

0.6

S=0.5 S=0.87 S=1.5

FL

/ L

C

T=300 K T=350 K T=410 K T=460 K T=500 K

-0.0999999999999994

5.82867087928207E-16

0.100000000000001

0.200000000000001

0.300000000000001

0.400000000000001

0.500000000000001

0.600000000000001

S = 0.5 S = 0.87 S = 1.5

FL /

LC

Effect of air swirl number on flame length for different air to fuel mass ratios

Effect of air swirl number on flame length for different preheated air temperature at AFR of 30

Effect of air swirl number on the flame length

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Effect of preheated air temperatures on flame length

Effect of preheated air temperature on flame length for different air swirl number and air to fuel mass ratio of 30

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Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Volume of high temperatures region

Experimental Results

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The volume of the high temperatures region is calculated for the temperature ranges of 1300 to 1600 K.

Volume of High Temperatures Region

Effect of preheated air temperature on the volume of the high temperatures region at different air swirl numbers and air to fuel mass ratio of 30

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Effect of

Air to fuel mass ratio (15, 20,30, 40,and50)

Air swirl number, S (0.5, 0.87, and 1.5)

Preheated air temperature (300, 350,

400, 450, 500K)

on Exhaust species concentrations

Experimental Results

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Effect of air to fuel mass ratio on the emission index for different air swirl numbers

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Effect of preheated air temperature on the emissions index 

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The flame size decreases and the high temperatures region shifts upstream and became very close to the

burner.

The flame length decreases by about 64, 62, and 60% for air swirl numbers of 0.50, 0.87, and 1.50,

respectively.

Effect of Air to Fuel Mass RatioConclusions

Effect of Air Swirl Number

The flame temperature levels increase and then consequently the volume of the high temperatures region also increases.

The highest value of the volume of the high temperatures region is about 9% of the

combustor volume for air swirl number of 1.50 and AFR=15.

Increasing the air to fuel mass ratio from 15 to 50:

Increasing the air swirl number from 0.50 to 1.50:

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Effect of Air Preheated Temperature

The chemical reaction rate increases and then the time of combustion reduces which consequently leading to increasing the flame temperature levels and then in turn increasing the volume of the high temperatures region, and decreasing in the flame length.

The flame length is decreased by about 45, 42, and 26% for air swirl numbers of 0.50, 0.87, and 1.50, respectively.

The volume of the high temperatures region is increased by about 432% for S = 0.50

The highest volume value of the high temperatures region is about 18% of the combustor volume for air swirl number of 1.50 and preheated air temperature of 500 K.

The EINOx, EICO2 and EIO2 increase, while EICO decreases.

The highest reduction in EICO is 92% for air swirl number, S = 0.50

The highest increase in EINOx is 141% for air swirl number, S = 0.87

Increasing the preheated air temperature from 300 to 500 K:

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