Project
Project
Project
At
KANCHAN INDIA LIMITED
(DURING 15TH JUNE 2023 TO 14TH AUGUST 2023)
Submitted to
Mewar University, Chittorgarh
(SESSION: 2023-2024)
In accordance with the requirement for the Diploma Programme in the Mechanical
Engineering in the Department of Mechanical Engineering, Faculty of Engineering &
Technology. I present this Short Term Industrial Training Report at KANCHAN INDIA
LIMITED CHITTORGARH .
declare that the work presented in the report is my own work except as acknowledged in
the text and footnotes, and that to my knowledge this material has not been submitted
either in whole or in part, for a degree at this University or at any other such Institution.
i
RECOMMENDATIONS
This Industrial training project report conducted at Short Term Industrial Training Report
at KANCHAN INDIA LIMETEDM, BHILWARA submitted by Mr. POLURAM JAT
towards the the partial fulfillment of the Diploma in Mechanical Engineering in the
Department of Mechanical Engineering, Mewar University, Chittorgarh is a satisfactory
account of his dissertation work and is recommended for the award of degree.
Head of Department
Mr. Dinesh Kumar
Assistant Professor, HOD
Department of Mechanical Engineering
Mewar University, Chittorgarh (Raj.)
Date:-
ii
CERTIFICATE BY THE INSTITUTION
This is certify that Mr. POLURAM JAT bearing MUR2104981 is a bonafide student of
Diploma of our institution during 2023-2024 batch.
The Short Term Industrial Training project report conducted at KANCHAN INIDA
LIMETED is prepared by him to partial fulfilment of the requirement for award of the
degree of Diploma in Mechanical Engineering, affiliated for the Mewar University of
Gangrar, Chittorgarh, Rajasthan.
Head of Department
Mr. Dinesh Kumar
Assistant Professor, HOD
Department of Mechanical Engineering
Mewar University, Chittorgarh (Raj.)
iii
ABSTRACT
An initial design of chimney heat recovery heat exchanger was provided. The design had a
completely fabricated exchange core but an incomplete ducting system .
This report is based on the work undertaken to complete and test the gas to gas heat recovery
system. This system was specifically designed for boiler chimney and therefore the systems
ducting was designed to conform to the general boiler stack.
In the completion of the design, the major factor to consider was to design against fouling. The
system was therefore designed with means of reducing fouling such as provision for easily
replaceable particulate filter and quick washing system.
The project was hence done in the following manner.
1. Completing of the fabrication.
2. Research on ways of minimizing fouling .
3. Incorporating the ways arrived at in 1 above into the system design.
4. Testing of the model under forced convection condition.
The gases from a furnace were used to simulate industrial flue gases. The performance of the
model was used to project the optimum of prototype.
LIST OF TABLES
Table 4: Design parameters…………………………………………………………………..12
LIST OF GRAPHS
r: Radius.
T g in :Gasinlet temperature.
t : Plate thickness.
α:Ratio of heat transfer area on one side of a plate exchanger to total volume between the plate
on that side.
θ: Time.
ε :Effectiveness .
ρ: Fluid density.
∆Tm.: The log mean temperature difference.
OBJECTIVE STATEMENT
The aim of this project was to recover heat lost through flue gases exhaust at the chimney stage
taking a keen consideration of the effect of fouling especially at the core of the heat exchanger.
Some research was done and the exchanger system designed and fabricated though not to
completion. It was nevertheless tested specifically to determine its heat exchange effectiveness.
However critical factors such as fouling were not keenly observed. The small plate spacing of the
exchange core will allow for a substantial heat recovery. This obviously means the core will
undergo fouling at a higher rate as compared to boiler tubes. This makes the exchanger to require
more frequent maintenance than the normal boiler maintenance.
The objective was to review the design ensuring that fouling was reduced and that the
maintenance practice on the exchanger does not adversely interfere with the normal operation of
the boiler.
It was projected that the project will maintain its goal of recovering heat and hence its benefits
towards energy management and at the same time maintain the smooth operation of the boiler.
The aim of this project can therefore be summarized as
1. Complete the fabrication of the heat recovery system and test.
2. Research on fouling effects for different fuels used in boilers.
3. Minimizing fouling and reduce maintenance requirements to avoid interference with the
normal operations of the boiler.
4. Give the recommendations based on the prototype performance
CONTENTS
CHAPTER ONE……………………………………………………………..1
2.4.1 Scaling/precipitation…………………………………………………..9
2.4.2 Particulate fouling……………………………………………………9
2.4.3 Chemical /corrosion fouling………………………………………….10
2.4.4 Solidificationfouling…………………………………………………10
3.2 DESIGNS AGAINST FOULING……………………………………………...10
3.2.1 Provision of particulate filters…………………………………........10
3.2.2 Introduction of turbulent flow upstream of the exchange core…….11
CHAPTER FOUR
4.0 THE HEAT EXCHANGER SYSTEM DESCRIPTION………………12
4.1 COMPONENTS AND PROPERTIES…………….………………………………..12
CHAPTER SIX
6.0. BILL OF QUANTITIES………………………………………………………………..30
CHAPTER SEVEN
7.0 DISCUSSION ………………………………………………………………….31
7.1 CONCLUSION…..……………………………………………………………..32
7.2 RECOMMENDATION…………………………………………………………33
7.3 REFERENCES………………………………………………………………….34
CHAPTER ONE
1.0 INTRODUCTION
1.1. INDUSTRIAL WASTE HEAT.
This is heat lost in industries through ways such as discharge of hot combustion gases to the
atmosphere through chimneys, discharge of hot waste water, heat transfer from hot surfaces.
This energy loss can be recovered through heat exchangers and be put to other use such as
preheating other industrial fluids such as water or air.
This project focuses on recovering heat that is lost through boiler chimney flue gas. The
advantages of heat recovery include:
i). Increasing the energy efficiency of the boiler.
ii). Decreasing thermal and air pollution dramatically.
2.0LITERATURE REVIEW
2.1 INTRODUCTION
Heat exchangers are devices that facilitate the exchange of heat between two fluids that are at
different temperatures while keeping them from mixing with each other. Heat transfer in heat
exchangers involves convection in each fluid and conduction through the wall separating the two
fluids. In order to account for the contribution of all the effects of convection and conduction, an
overall heat transfer coefficient, U, is used in the analysis. Heat transfer rate depends on the
temperature differences between the two fluids at the location and the velocity of the fluids (time
of interaction) between the fluids.
2.2TYPES OF HEAT EXCHANGERS
Due to the different types of applications for heat exchanges, different types of hardware and
different configurations of heat exchanges are required. This has resulted to different designs of
heart exchangers which includes and not limited to.
2.2.1Double pipe heat exchanger (simplest heat exchanger)
Consists of two concentric pipes of different diameter. In application, one fluid passes through
the pipe of smaller diameter while the other flows through the annular space between the two
pipes. The flow of fluids can be arranged into:-
i). Parallel flow.(Cengel, 2002)
Both fluids (hot fluid and cold fluid) enter the heat exchanger at the same end and move in the
same direction to leave at the other end as shown in the figure below.
Fig a. (i) shows the flow regimes while fig a (ii) shows the associated temperature profiles.
(ii). Counter flow(Cengel, 2002)
In these types of arrangement, the cold and hot fluids enter the exchanger at opposite ends and
flow in opposite directions as shown in the figure below:
Ross-flow
Cross-flow
(unmixed)
(mixed)
(Ozisk, 1985)
Flat tubes
Fig c. compact heat exchangers
2.2.3 Shell and tube heat exchanger
Contains a large number of tubes packed in a shell with their axes parallels to that of the shell.
One fluid flows through the tubes while the other flows through the shell but outside the tubes.
Baffles’ placed in the shell increases the flow time of the shell-side fluid by forcing it to flow
across the shell thereby enhancing heat transfer in addition to maintaining uniform spacing
between the tubes.These baffles are also used to increase the turbulence of the shell fluid. The
tubes open to some large flow areas called header at both ends of the shell. These types of heat
exchanger can accommodate a wide range of operating pressures and temperatures. They are
easier to manufacture and are available at low costs. Both the tube and shell fluids are pumped
into the heat exchanger and therefore heat transfer is by forced convection. Since the heat
transfer coefficient is high with the liquid flow, there is no need to use fins. They can also be
classified into parallel and counter flow types.
(Ozisk, 1985)
Tube
Tube
outlet
inlet baffles
Corrugations
(or fins)
Hot
air
inlet Parallel plates
A rotary heat exchanger consists of a circular honeycomb matrix of heat absorbing material
which is slowly rotating within the supply and exhaust air streams of an air handling system.
2.2.5.4 Economizer.
In case of process boilers, waste heat in the exhaust gas passed along a recuperator that carries
the inlet fluid for boiler and thus decrease energy intake of the inlet fluid.
2.2.5.5 Run around coil.
Comprises 2 or more multi-raw finned tube coils connected to each other by pumped pipe work
circuit.
Where hi, ho= heat transfer coefficients for inside and outside flow respectively
k= Thermal conductivity of the exchanger material
R= Total thermal resistance from inside to outside flow
t= Thickness of the heat exchanger material
Am= = logarithmic mean area, m2
( )
Ai,Ao= Inside and outside surface areas of the heat exchanger surfaces respectively.
Expressing the thermal resistance R as an overall heat transfer coefficient based on either the
fluid inside or outside surface of the heat exchanger surface areas:-
U o= andUi=
If the wall thickness is small and its thermal conductivity is high the material resistance may be
neglected and hence the overall heat transfer coefficient becomes:-
Ut=
In applications of heat exchangers, accumulation of deposits mostly from combustion, on the
heat exchanger surface causes additional thermal resistance, a condition known as fouling.
Effects of fouling are introduced in the heat transfer coefficient in the form of a fouling factor.
The total thermal resistance then became:-
R= + + + +
Where Fi and Fo are the fouling factors on the inside and outside surfaces respectively.
Fouling is a general term that includes any kind of deposits of extraneous material that appears
on the heat transfer surface during the lifetime of the heat exchanger.
Fouling reduce heat transfer across the exchanger surface hence reduces efficiency of the heat
exchanger. The foulingdeposits also reduce flow cross-section area causing a pressure deferential
across the heat exchanger which in turn increasing on the fan power required. It might also
eventually block the heat exchanger.
Different kinds of fuel produce different degrees of fouling .most fuel produce just soft black
soot that get deposited on the exchanger surface.
This can easily be removed by brushing and sand washing. However lower grade fuel
oil(principally no.6.oil or resid)contain large quantities of alkaline sulfates and vanadium
pentoxide that causes scaling due to their lower fusion temperatures.
Particulate fouling.
Scaling/precipitation.
Chemical/corrosion fouling.
Solidification.
It was our duty to consider the effect of fouling upon the heat exchanger performance during the
desired operation lifetime and make provisions in our design for sufficient extra capacity to
ensure that the exchange will meet process specifications upto shut down for cleaning.
We were also to consider the mechanical arrangements that are necessary to permit easy
cleaning.
In our design, the following measures have been taken to reduce the rate of fouling.
At the entry of the flue gas duct is attached, a cone shaped duct to whose narrower end
can be attached diesel particulate filter. The particulate filter is designed to remove fuel
particulate matter (soot) from the fuel gases. The efficiency of the filter is inversely
proportional to the pressure that is build up due to resistance to gas flow. It is therefore
difficult to achieve 100 percent efficiency through filtration, as there must be a
compromise between efficiency and pressure buildup .the best filters are therefore broad
band filters that can filter particles of diameters between 0.2-150µm.
The filters can easily be removed through a door on the side of the side duct for cleaning.
3.2.2Introduction of turbulent flow upstream of the exchange core
The cone shape element at the gas-duct entry causes turbulence as it suddenly opens into
the larger gas duct .this causes turbulence. This turbulent flow of air picks with it some
of the particles that stick on the exchanger surface due to its drag effect. This helps to
reduce on fouling.
The above filtration and turbulence only minimizes rate of fouling. But the fouling still
takes place. This therefore implies that the exchanger will require maintenance
(cleaning). There are various ways that could be used in cleaning the exchanger. In the
design we consider using the following methods.
1. Blowing
2. Washing
The system was designed with a slit on the wall of the flue gases duct downstream of the
exchanger .This allows the overhead water washing.
Pressurized water mixed with abrasives e.g. fine sand is used to remove soot that cannot
be removed by blowing air past the exchanger. The abrasives help in scrubbing the
surface.
Before washing, the particulate filter is removed and replace with alid to prevent water
from entering the broiler.
During washing the waste water drains out of the system through the outlet ducts at the base of
the flue gas inlet duct.
CHAPTER FOUR
TABLE 4
DESIGN PARAMETERS OF THE HEAT EXCHANGER.
Core dimensions L1 0.3m
L2 0.2m
L3 0.3m
Plate spacing mm 3
Air temperature at inlet °C 26
Air temperature at °C 200
outlet
Gas temperature at inlet °C 450
Gas temperature at °c 200
outlet
Aft. m2 0.06
2
Afr m 0.09
3
Core volume m 0.018
Plate thickness b mm 1.83
-1
αa m 615.555
-1
αg m 613.888
2
Aa m 11.08
5
Ag m 11.05
Effectiveness 0.75
2
Ua W/m K 3.683
R 0.96
Number of passages Air side 23
Gas side 23
It provides an end that can be covered by alid during cleaning to prevent water from
entering the boiler. Small holes are left at its joint to the gas duct to allow water out.
During normal boiler operation gas filler can be put at this narrow end to trap carbon
particles from reaching the exchanger core. It was constructed from mild steel sheet (16
gauge)
4.1.2Ducts
The system has four ducts which are
a) Air inlet duct made from galvanized iron sheet (32 gauge)
b) Air outlet duct also made from galvanized iron sheet (32gauge) and is connected to the
air fan.
c) Gas inlet duct constructed from mild steel sheet (16gauge) to be able to support the whole
system and the rest of the chimney above.
d) Gas outlet duct: also constructed from mild steel sheet (16gauge) so as to hold the rest of
the chimney above the exchange.
Air duct Flue gas duct
L2
L1
L3
Air side
Table 5b
Velocity near duct Velocity at duct Angle of air control Average velocity
wall (m/s) center (m/s) flap (m/s)
0.15 0.45 75 0.3
0.19 0.60 60 0.395
0.26 0.72 45 0.49
0.32 0.84 30 0.58
0.44 0.96 15 0.70
0.60 1.30 0 0.95
Other results.
Transient test
5.4Analysis.
5.4.1 Calculation of volume flow rate.
4.20 × 10-2 m2
As the air flow rate at fully open duct is still low compared to the flue gas flow rate, it
was decided that the subsequent test be carried out at flap angle of 00 in the air duct.
Taout&Tain- Temperatures of air at outlet and inlet of the heat exchanger respectively.
[(Taout+ Tain) ÷ 2]
Temperature=22.7 0C.=295.7
.
= 0.9743 / 3
∗ .
(2) Overall heat transfer coefficient (u)
( )
U= =;∆Tm=
∆ . ( )
(3) Effectiveness ε
Effectiveness =
( )
ε=
( )
Dwell time Ѳd
Normalized time Ѳ*
Dwell time is the time air is in contact with the heat transfer surface from entry to exit of
exchanger core. It is given by: Ѳd= where L= length of heat exchanger from inlet to
outlet to exit.
V=
×
ρ =density of air
Ac=Exchanger minimum free flow area.
The normalized time is the ratio of time the air temperature takes to reach a constant value to the
dwell time i.e.
Ѳ
Ѳ*=
=0.04724 kg/s
=ṁCp (Taout-Tain)
( ) ( )
R= , P=
( ) ( )
( ) ( . )
Hence R= = 1.5139, P== = 0.32
( . ) ( . )
( )
∆Tm=
( )
( ) ( . )
=
( .
)
=272.850C
.
U=
. × . × .
= 0.5369kW/m2 K
Effectiveness
( )
ε=
( )
Dwell time
.
Ѳd = = .
= 0.316 seconds, where L2 is the length of the exchanger core from air inlet to air
outlet.
Table 5d
Table 5e
DETERMINATION OF EFFECTIVENESS
Ta in Ta Mean Cp air Tg in Tg out Mean Cp gas ṁ of air ṁCp of ṁ of ṁ Cp Effecti-
0 0 0
C out temp. kJ/Kg C C temp kJ/Kg.K kg/s air gas kg/s veness,
0 K kW/K
C .K for gas ε
K
22.7 205 386.8 1.015 480 249 637.5 1.05995 0.01492 0.01515 0.03193 0.033842 0.3969
34
22.7 194 381.4 1.013 482 253 640.5 1.06066 0.01964 0.01990 0.03193 0.033864 0.3730
00
22.7 190 379.3 1.012 483 255 642.0 1.06101 0.02437 0.02467 0.03193 0.033876 0.3635
34
22.7 184 376.4 1.011 483 256 642.5 1.06113 0.02884 0.02912 0.03193 0.033879 0.3504
14
22.7 171 369.8 1.010 483 257 643.0 1.06125 0.03481 0.03516 0.03193 0.033883 0.3222
11
22.7 170 369.3 1.010 483 260 644.5 1.06160 0.04724 0.04772 0.03193 0.033894 0.3200
06
Table 5g
TABLE 5i
Transient test
GRAPH 5.1:
Graph of U vs Q.
0.78
0.775
OVER ALL HEAT TRANSFER COEFFIIENT U
0.77
0.765
0.76 GRAPH OF U VS Q
0.755
0.75
0.745
0 1 2 3 4 5 6
HEAT RECOVERED Q kW
GRAPH 5.2:
Graph of Q vsṁ.
5
Q kW
4
GRAPH OF HEAT RECOVERED
3 VS MASS FLOW RATE
0
0 0.01 0.02 0.03 0.04 0.05
ṁ kg/s
GRAPH 5.3:
Graph of ε vsṁ.
0.45
0.4
0.35
0.3
EFFECTIVENESS ε
0.25
0.1
0.05
0
0 0.01 0.02 0.03 0.04 0.05
200
150
Ta out 0C
50
0
0 2 4 6 8 10 12
TIME θ S
GRAPH 5.5:
Graph of Ta out vs θ*.
250
200
AIR EXIT TEMPERATURE Ta out
150
50
0
0 500 1000 1500 2000
NORMALIZED TIME θ*
CHAPTER SIX
6.0. BILL OF QUANTITIES
TABLE 7.1
PRODUCTION COST OF THE EXCHANGER MODEL
ITEM QUANTITY UNIT PRICE TOTAL COST
(Ksh) (Ksh)
ALUMINIUM SHEET (32 GAUGE) m2 11.08 600 6648
SILICON SEAL (TUBES) 9 295 2655
GALVANIZED IRON SHEET (30 GAUGE) m2 1 550 550
MILD STEEL SHEET (16 GAUGE) m2 2.5 700 1750
BINDING WIRE (28 GAUGE) G1 m 3 30 90
MILD STEEL ANGLE LINE m 2 300 600
BOLTS NAD NUTS 62 10 620
DIESEL (litres) 15 105 1575
HOLTS GUN GUM 1 300 300
GROSS COST 14 788
LABOUR 2 220
TOTA PRODUCTION COST 17 008
CHAPTER SEVEN
7.0 DISCUSSION
From graph 5.1 the amount of heat recovered Q increased linearly with the overall heal transfer
coefficient from values of u and Q of 1.00 kW and 0.748 respectively. At a value of Q= 3.4kW,
the value of U reached its maximum and then remained constant for higher values of Q . The
optimum value of U was found to be 0.778 from Q=3.4kW and higher values of Q.
Q increased with increasein .As given in graph 5.2. optimum values was never reached due
to limited fan capacity.
For the mass flow rate of 0.02kg the corresponding effectiveness is 0.37 or 37% from graph 5.3.
The maximum effectiveness possible was taken as 40%.
TRANSIENT TEST
The air exit temperature rose sharply with time within the first two minutes from 22.70C to about
2000C. It then rose to a maximum of 2100C in the next one minute then dropped to 2050C at the
end of four minutes. This temperature then remained constant.
The maximum time to allow temperatures to reach maximum was 4 minutes.
Normalizing this time with the dwell time the maximum normalized time was found to be 750.
7.1 CONCLUSION
The objective of this project was completion and testing of boiler chimney heat recovery heat
exchanger system that could be used to recover heat lost through flue gases. A plate type heat
exchanger was used in the design. The systems model was completed and tested under forced
convection conditions. From the performance of the model the optimum operating conditions
were obtained as:
Overall heat transfer coefficient U= 0.778kW/m2 K
Amount of heat recovered Q =3.4 kW
Effectiveness ε = 40%
T air in = 22.70C, T air out = 1940C, T g in = 4820C, T g out 2530C
7.2 RECOMMENDATIONS
After completion, testing and analysis of the performance of the exchanger the following
recommendations were made:
1. The exchanger core plate spacing should be increased to improve on air flow. This will
also increase time required before maintenance as it will slow the rate of blockage due to
fouling on the gas side. The negative effect of this is that it will redue the number of
plates and hence the amount of heat recovered but it is still a worth change for the
lifetime of the plates.
2. An allowance for expansion of the plates should be provided at the ends of the plates.
This is to eliminate the slaking that was observed during testing of the exchanger. Slaking
of the plates increases resistance to flow.
3. The height, L2, of the heat exchanger should be increased to increase the time for the flue
gases to exchange heat with air.
4. The filters can be fabricated and installed and the model tested for fouling.
7.3 REFERENCES
1. YunusA.Cengel,HeatTransfer,second edition, McGraw-hill (2002), (Chapter
13)
2. M. NecatiOzisik, Heat Transfer: A Basic Approach , International students
edition, McGraw-hill, New York (1985) (chapter 11)
3. F. MakauLuti, University of Nairobi: Notes on Heat Transfer: An
Introduction, Lecture Notes(2012)
4. Rodgers G. F. C. and Mayhew Y. R., Thermodynamics and Transport
Properties of Fluids, 5thedition,Blackwell Publishing (1995).
5. Anthony F. Mills, Heat Transfer International,(1992, Paperback, Student
Edition of Text Book)
6. Hodge B. K. Robert P. Taylor, Analysis and design of energy systems ,3rd
edition, (paperback,1990)
7. Ongicha Hillary Buore, Ong’ondiMayaka Eugene, Design Fabrication and
Testing of Boiler Chimney Heat Recovery Unit roport, (2013)
PICTORIAL REPRESENTATIONS.