This document describes the design of high thermal efficiency gas burners. It aims to improve upon conventional domestic burners which typically have low thermal efficiencies below 50% due to incomplete combustion from insufficient residence time. The proposed design incorporates swirling flames and porous inserts to increase residence time and promote more complete combustion, improving thermal efficiency. A double ring swirl burner design is presented and its performance is evaluated using a Junker's calorimeter experiment to calculate thermal efficiency.

1. HIGH THERMAL EFFICIENCY GAS BURNERS
Under the guidance of
Dr.G.POSHAL
Department of Mechanical Engineering
Vignana Bharathi Institute Of Technology
Jawaharlal Nehru Technological University Hyderabad
By
D MANOJ KUMAR 15P61A0335
EBIN PRAKASH 15P61A0318
T AJAY KUMAR 15P61A0302
KAUSHIK YADAV 15P61A0328

2. CONTENTS
WHAT?
1. Problem Statement
2. Abstract
WHY?
1. LPG as a fuel
2. Existing model and drawbacks
HOW?
1. Methods to improve efficiency
2. Design and improvements

3. PROBLEM STATEMENT
Problem Statement: Liquefied Petroleum Gas (LPG) is extensively used in
domestic as well as industrial cooking. It is a precious and non-renewable energy
source. Therefore, it is highly essential to use it efficiently by employing energy-
efficient devices. With the objective of conserving LPG fuel,design and
development of energy-efficient devices for domestic & industrial cooking that
surpass the thermal efficiencies of devices available in the market.
1

4. ABSTRACT
Existing designs of most conventional domestic burners (CB) have typically relied
on open combustion flame, where a large amount of energy loss with the flue gas
arises, resulting in relatively low thermal efficiency (<50%). The project is aimed at
designing a swirl ring that will help in combustion of fuel to the maximum extent
via swirl effect. We aim at improving the residence time allowing complete
combustion of the fuel and as a result improve thermal efficiency.
2

5. LPG - LIQUEFIED PETROLEUM GAS AS A FUEL
In this modern era of globalisation where industrialization is growing rapidly, the
demand for energy is growing rapidly. To meet the demand, optimum use of
available sources or use of alternate sources is expected. Since the available
sources are limited, we need to give more emphasis on developing method and
devices to use these sources more efficiently. Presently 55.78 million households
of India, uses LPG for cooking purpose. The energy consumption for LPG is more
in domestic sector than industrial. Thus enhancing efficiency of the domestic gas
stove will contribute to the Indian economy.
3

6. EXISTING MODEL AND DRAWBACKS
Fig 1- common burner open flame
Fig 2- burner head bottom view
Fig 3- burner head top view
Fig 4- burner hobb
Less residence
time
Incomplete
combustion
4

7. METHODS TO IMPROVE EFFICIENCY
SWIRLING
FLAMES
POROUS
INSERTS
LOW
THERMAL
INERTIA
Porous Inserts
1. Angle of
pores
2. Control the
direction of
flame
3. Mixture of
secondary air
Low thermal & pan height
1. Increase in pan height
❖ Better flow of
secondary air
❖ Less fuel loss
❖ Less heat transfer
2. Decrease in pan height
❖ Better heat transfer
❖ More fuel loss
❖ Minimal flow of
secondary air 5

8. SWIRLING FLAME
Swirl is the spiral motion imparted to the gas stream.
Swirl flows can be generated by three principle methods
1. Tangential entry (axial plus tangential entry swirl generator).
2. Guided vanes (swirl vane pack or swirler).
3. Direct rotation (rotation pipe). 6

9. EFFECTS OF SWIRL
1. Effect of swirl on residence time
Due to the swirling motion, the path travelled by flame increases the residence time. Hence more time is
available for diffusion and the chemical reaction to get completed.
2. Effect on heat transfer
In case of impinging swirling flame as in case of domestic burner, it increases the heat transfer rate. In
non-swirl flames the flame takes a direct 90º turn at a flat impinging surface; whereas in cases of swirling
flame, it rotates on the surface of impinging target. This increases, the contact time thereby increasing
heat transfer efficiency.
3. Homogeneity of mixing
If the swirl is imparted prior to the combustion to the air/gas mixture, a homogenous mixture of air and
gas is generated. This is due to the swirling motion. Due to homogeneity of air fuel mixture, completeness
of the combustion can be achieved.
7

10. DESIGN

11. 9
1. Basic Burner
Outer Dia 65mm
Inner Dia 55mm
Angle with
vertical axis
0
Slot 2*5
No.Of Slot 24

12. 10
2. Swirl Burner
Outer Dia 65mm
Inner Dia 55mm
Angle with
vertical axis
30
Slot 2*5
No.Of Slot 24

13. 111
3. Double Ring Swirl Burner
Outer Dia 65mm
Inner Dia 55mm
Angle with
vertical axis
30
Slot 2*5
No.Of Slot 24

14. EXPERIMENTS AND CALCULATION
Junker’s Calorimeter
12
CV. gas X Vol. gas = Vol.water X Rise in T
Assumption : Heat capacity of
water is unity
CV of LPG = 46.1 MJ/kg
T1 = Initial Temperature
T2 = Final Temperature
V1 = Vol. of LPG
V2 = Vol of water