Dr. P. Muthukumar

Associate Professor

Department of Mechanical Engineering

Indian Institute of Technology Guwahati

Guwahati - 781039, INDIA

Email: pmkumar@iitg.ernet.in

Development of Porous Radiant

Burners for Domestic LPG Cooking

and Industrial Applications

2

About IITG

Located in the Gateway of

North – Eastern Part of India

Started 1995, established

during 2005.

Beautiful campus among

other IITS. Located on the

river bank on

Brahmaputra[Yarlung

Tsangpo-Siang-

Brahmaputra-Jamuna].

Campus is surrounded by

many Hills and Lakes.

Campus size about 700 acr.

8 Engg and 4 Science

Departments. About 6000

students, 425 faculty and

500 supporting staffs

Few thousands of

migratory birds, wild cats,

etc.

4

5

6

Indian LPG consumption pattern

Concept of porous medium combustion (PMC)

Advantages of PMC

Development of Porous Radiant Burner (PRB)

Performance testing

Concluding remarks

Out line of Presentation

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

.

7

India is the fourth largest consumer of LPG in the world

India is not self-sufficient in LPG – has to import a huge

amount of LPG.

India: 1.2 billion Number of LPG Consumers:246,692,667

LPG: Propane – 57-60% + Butane – 40- 43%

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Government

provides a huge

amount of subsidy

~ $7 Billion

For consumer

too the price is

increasing

From $16 to $ 6.8

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13R

up

ees

in C

rore

Total Subsidy by Government & Oil Companies on Domestic LPG

Years

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

9

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Flame propagation for:

65numberPecklet k

dcuP

mpL

e

uL : laminar flame velocity

dm : equivalent porous cavity diameter

cp : Heat capacity of gas mixture

: Density of gas mixture

K : Thermal conductivity of gas mixture

where

Heat production

Exhaust gas

Air-fuel mixture

Combustion zone

Preheating zone

Heat transport for

reaction zone

stabilization

Conduction and radiation manifest

65Pe

Heat removal

All three modes of heat

transfer become important

Solution: LPG/kerosene stoves with porous radiant burner

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

LPG stoves with conventional burners

Fre

e f

lam

e c

om

bu

sti

on

N

OT

eff

icie

nt

Combustion in porous

media is efficient

Burners based on

porous medium

combustion

Solution: LPG/kerosene stoves with porous radiant burner

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

12

Alumina matrix

Compressed

air

50 mm

90 mm

20 mm

SiC foam

Wire

mesh to

support

alumina

matrix

Burner

casing

Mixing tube

Coriolis

mass flow

meter

Coriolis

mass flow

meter

LPG

90 mm 1

2

3

4

5

6

7

Design details of Porous Radiant Burner

1.Burner casing 2. SiC foam 3.ZrO2 foam 4. Wire mesh

5.Alumina matrix 6.Alumina ball 7.Mixing tube

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

EXPERIMENTAL SET UP

13

Muthukumar and Shyamkumar, Fuel, 2013;112:562-566

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Flow

meter for

Air

Flow meter for

LPG

Red Hot

PRB

EXPERIMENTAL SET UP : A Picture Showing Red Hot PRB

14

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

15

Photographs of PMB and the conventional domestic burner

Porous radiant burner

Conventional burner

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Conventional BurnerEfficiency : 50-65%

CO Emission : 400 to 1050 mg/m3

NOx Emission : 160 to 220 mg/m3

Equivalence ratio,

Th

erm

ale

ffic

ien

cy,%

0.51 0.54 0.57 0.60 0.63 0.66 0.69 0.72 0.7568

69

70

71

72

73

74

75

76

77

78

79

801.3 kW

1.5 kW

1.5 kW

Porosity = 90%Ti = 30

0C

Mw = 4.02 kg

φ φEquivalence ratio,

Th

erm

ale

ffic

ien

cy,%

0.51 0.54 0.57 0.6 0.63 0.66 0.69 0.72 0.7568

69

70

71

72

73

74

75

76

77

78

79

801.3 kW

1.5 kW

1.7 kWPorosity = 85%Ti = 30

0C

Mw = 4.02 kg

φ

CZ: 85% porosity SiC

PZ: Ø90 mm Alumina matrix

CZ: 90% porosity SiC

PZ: Ø90 mm Alumina matrix

o Combustion Zone: SiC (different porosity) and ZrO2 (90%)

o Preheating Zone : Alumina Balls and Alumina Matrix (40%)

o Equivalence ratio : 0.5 – 0.7, Wattage: 1.3 kW – 1.7 kW.

2 1100

CV

w pw v pv

th

f

m C m C T T

m

/

/

Stoich

Actual

A F

A F

(BIS 4246:2002)

(BIS 4246:2002)

Muthukumar and Shyamkumar, Fuel, 2013;112:562-566

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

17

Emissions The flue gas sampling was done according

to the IS: 4246:2002

A portable flue gas analyser (TESTO) was

used for measuring CO and NOx

emissions.

Power, kW

CO

em

issio

ns,m

g/m

3

NO

xe

mis

sio

ns,m

g/m

3

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2200

400

600

800

0

1

2

3

4

5

6

7

8

9

10CO

NOx

Equivalence ratio,

CO

em

issio

ns,m

g/m

3

NO

xe

mis

sio

ns,m

g/m

3

0.51 0.54 0.57 0.6 0.63 0.66 0.69 0.72 0.750

20

40

60

80

100

120

140

160

180

200

0

0.3

0.6

0.9

1.2

1.5

1.81.3 kW

1.5 kW

1.7 kW

1.3 kW

1.5 kW

1.7 kW

Porosity = 90%Alumina matrx

φ

Conventional Burner

CO Emission : 300 to 1050 mg/m3

NOx Emission : 4 to 220 mg/m3

Efficiency : 50-65%

PRB with 90% porosity

CO Emission : 10 to 140 mg/m3

NOx Emission : 0.1 to 0.9 mg/m3

Efficiency : 70-75%

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

18

Axial Temperature Distribution

• Combustion zone (TC)

• Preheating zone (TP)

• Down side of the wire mesh (TD)

• Interface of the two zones (TI)

90% porosity burner (PPZ – Alumina matrix)

• Temperature at TI showing higher

than any other regions

Max. TI = 1170 °C

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

• A series of experiments were

carried out at wide range of

ambient temperatures from 13.5 C to 30 C

• Thermal efficiency of the PB is

directly proportional to ambient

temperature.

• The maximum thermal

efficiency was found to be 75%

at 30 °C and 63% at 13.5 °C.

19

Effect of Ambient Temperature on Thermal Efficiency

Φ =0.54

SiC,CZ-90% PZ Alumina matrix

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

20

Commercial burner available in

Indian market chosen for comparison

At the thermal load of 10 kW, the PRB

yielded the maximum improvement in

thermal efficiency of about 34.3 %.

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Energy Savings with Less Emissions

The newly developed porous radiant burner (PRB) for LPG

cooking stoves has been found to have the maximum thermal

efficiency of ~ 75 % which is 15% higher than the conventional

burner.

Measured CO and NOx emissions of the PRB were in the range of

25-150 mg/m3 and 0-2 mg/m3. While, the respective values of the

conventional burners are in the range of 400-1100 mg/m3 and 75-

260 mg/m3.

In terms of both thermal efficiency and emissions, the PRB has

been found to be better than its conventional counterparts.

Compared to a conventional burner, the newly developed PRB

saves about 2 kg of LPG per cylinder (14.5 kg capacity ).

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

Required modifications before commercialization

o PRB, the combustion is happening completely

within the porous matrix. The entrained air is NOT

enough to give flameless combustion.

o The porous matrices in the preheating zone and

combustion zone added to the flow resistance.

o To overcome the flow resistance offered by the

porous matrices, the air was supplied at 1.2 bar.

o For domestic cooking, it CANNOT be

commercialized unless it works without any

external air supply.

Bu

rne

r to

be m

ad

e f

ree f

rom

th

e

exte

rna

l a

ir s

up

ply

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

PRB Without External Air

23

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

24

o Modified pressure regulator,

nozzle diameter and mixing

chamber.

o Achieved flameless

combustion with natural

entrainment.

o Achieved 73-74 % thermal

efficiency and less emissions

o Showed stable operation

o Power modulation is being

investigated.

Dr. P. Muthukumar, Mechanical Engg., IIT Guwahati – October 2014

25

Brief Biography : Dr.P.Muthukumar

Ph.D Studies on Metal Hydride based Thermal Devices for Compression and Storage of

Hydrogen, IIT Madras, Dec.2004.

Teaching / Research ExperienceAssociate Professor : IIT Guwahati, from 9-01-2010 onwards

Assistant Professor : IIT Guwahati from 27-01-2006 to 8-01-2010

Senior Project Officer : IIT Madras from 1-07-2004 to 23-01-2006

Student GuidancePhD : 3-Awarded; 2 –Thesis submitted; 2- Advance stage; 4-Ongoing.

M.Tech : 25-Completed; 3-ongoing ; B.Tech : 15-Completed; Project staffs : 4

Research ContributionsInt Journals : 40 + 10 Communicated (citation = 431)

Int Conference / workshops : 56

National Conference : 6

Patents : 1 (Patent Number: 173/KOL/2013)

Completed Projects : 4 Sponsored (63.35 L) + 3 Consultancy (7 L)

Ongoing Projects : 1 Sponsored (128 L)

Projects under evaluation : 2 sponsored (337 L) + 1 consultancy (36 L)

Awards / Fellowships receivedReceived DAAD Research Fellowships 3 times (2008, 2010, 2012)

Young Engineer Award -2012, from Senior Engineers Forum of Greater Guwahati

Commission Member from India to work with the International Institute of Refrigeration (IIR)

Represented India in Spain at Indo-Spain joint Workshop on Renewable Energy during March-11.

IEI Young Engineer Award-2010 in Mechanical Engg., from Institute of Engineers (India)

DST-DAAD Project based Fellowship- 2000.

Thanks for your kind attention