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Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 1
Chapter-1 Introduction
A Heat Exchanger Is A Device That Is Used To Transfer Thermal Energy (Enthalpy)
Between Two Or More Fluids, Between A Solid Surface And A Fluid, Or Between Solid
Particulates And A Fluid, At Different Temperatures And In Thermal Contact. In Heat
Exchangers, There Are Usually No External Heat And Work Interactions. Typical Applications
Involve Heating Or Cooling Of A Fluid Stream Of Concern And Evaporation Or Condensation
Of Single- Or Multicomponent Fluid Streams.
In Other Applications, The Objective May Be To Recover Or Reject Heat, Or Sterilize,
Pasteurize, Fractionate, Distil, Concentrate, Crystallize, Or Control A Process Fluid. In A Few
Heat Exchangers, The Fluids Exchanging Heat Are In Direct Contact. In Most Heat Exchangers,
Heat Transfer Between Fluids Takes Place Through A Separating Wall Or Into And Out Of A
Wall In A Transient Manner. In Many Heat Exchangers, The Fluids Are Separated By A Heat
Transfer Surface, And Ideally They Do Not Mix Or Leak. Such Exchangers Are Referred To As
Direct Transfer Type, Or Simply Recuperates. In Contrast, Exchangers In Which There Is
Intermittent Heat Exchange Between The Hot And Cold Fluids—Via Thermal Energy Storage
And Release Through The Exchanger Surface Or Matrix Are Referred To As Indirect Transfer
Type, Or Simply Regenerators. Such Exchangers Usually Have Fluid Leakage From One Fluid
Stream To The Other, Due To Pressure Differences And Matrix Rotation/Valve Switching.
Common Examples Of Heat Exchangers Are Shell-And Tube Exchangers, Automobile
Radiators, Condensers, Evaporators, Air Preheaters, And Cooling Towers. If No Phase Change
Occurs In Any Of The Fluids In The Exchanger, It Is Sometimes Referred To As A Sensible
Heat Exchanger. There Could Be Internal Thermal Energy Sources In The Exchangers, Such As
In Electric Heaters And Nuclear Fuel Elements. Combustion And Chemical Reaction May Take
Place Within The Exchanger, Such As In Boilers, Fired Heaters, And Fluidized-Bed Exchangers.
Mechanical Devices May Be Used In Some Exchangers Such As In Scraped Surface Exchangers,
Agitated Vessels, And Stirred Tank Reactors.
Heat Transfer In The Separating Wall Of A Recuperate Generally Takes Place By
Conduction. However, In A Heat Pipe Heat Exchanger, The Heat Pipe Not Only Acts As A
Separating Wall, But Also Facilitates The Transfer Of Heat By Condensation, Evaporation, And
Conduction Of The Working Fluid Inside The Heat Pipe. In General, If The Fluids Are
Immiscible, The Separating Wall May Be Eliminated, And The Interface Between The Fluids
Replaces A Heat Transfer Surface, As In A Direct-Contact Heat Exchanger.
A Heat Exchanger Consists Of Heat Transfer Elements Such As A Core Or Matrix
Containing The Heat Transfer Surface, And Fluid Distribution Elements Such As Headers,
Manifolds, Tanks, Inlet And Outlet Nozzles Or Pipes, Or Seals. Usually, There Are No Moving
Parts In A Heat Exchanger; However, There Are Exceptions, Such As A Rotary Regenerative
Exchanger (In Which The Matrix Is Mechanically Driven To Rotate At Some Design Speed) Or
A Scraped Surface Heat Exchanger. The Heat Transfer Surface Is A Surface Of The Exchanger
Core That Is In Direct Contact With Fluids And Through Which Heat Is Transferred By
Conduction. That Portion Of The Surface That Is In Direct Contact With Both The Hot And Cold
Fluids And Transfers Heat Between Them Is Referred To As The Primary Or Direct Surface.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 2
To Increase The Heat Transfer Area, Appendages May Be Intimately Connected To The
Primary Surface To Provide An Extended, Secondary, Or Indirect Surface. These Extended
Surface Elements Are Referred To As Fins. Thus, Heat Is Conducted Through The Fin And
Convected (And/Or Radiated) From The Fin (Through The Surface Area) To The Surrounding
Fluid, Or Vice Versa, Depending On Whether The Fin Is Being Cooled Or Heated. As A Result,
The Addition Of Fins To The Primary Surface Reduces The Thermal Resistance On That Side
And Thereby Increases The Total Heat Transfer From The Surface For The Same Temperature
Difference. Fins May Form Flow Passages For The Individual Fluids But Do Not Separate The
Two (Or More) Fluids Of The Exchanger. These Secondary Surfaces Or Fins May Also Be
Introduced Primarily For Structural Strength Purposes Or To Provide Thorough Mixing Of A
Highly Viscous Liquid.
Not Only Are Heat Exchangers Often Used In The Process, Power, Petroleum,
Transportation, Air-Conditioning, Refrigeration, Cryogenic, Heat Recovery, Alternative Fuel,
And Manufacturing Industries, They Also Serve As Key Components Of Many Industrial
Products Available In The Marketplace. These Exchangers Can Be Classified In Many Different
Ways. We Will Classify Them According To Transfer Processes, Number Of Fluids, And Heat
Transfer Mechanisms. Conventional Heat Exchangers Are Further Classified According To
Construction Type And Flow Arrangements. Another Arbitrary Classification Can Be Made,
Based On The Heat Transfer Surface Area/Volume Ratio, Into Compact And Non-Compact Heat
Exchangers. This Classification Is Made Because The Type Of Equipment, Fields Of
Applications, And Design Techniques Generally Differ.
1.1 Problem Summery
We Have Defined Our I.D.P Project As Energy Conservation And Co Generation From
An Annealing Oil Furnace In Which The Furnace Is Working At 900 °C To 1100 °C. And The
Exhaust Flue Gasses Is Leaving From Furnace At 400 °C-500 °C.
The Phosphating Line Consist Of 13 Chemical Tanks and Water Rains In Which 5 Tanks
Require Certain Temperature For Working Condition Of Chemicals. To Heat Up That Tanks
Between 65-70 °C Each Tank Carry 12 Heater. Which Carry Huge Consumption Of Electricity
Of Overall Plant.
Fig.1 Process Layout of Cold Forging Plant
Raw Material
Softening Cutting Shot
Blasting
PhosphatingWater Rinse
Acid Rinse
Phosphate Neutralizer Soaping Drying
Cold Forging
Cold Forging
Heat Treatment
Annealing Normalizing Shot Blasting
Machining
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 3
To Overcome From This Situation We Are Designing Two Heat Exchanger One From
Hot Flue Gases To System Fluid And Another Heat Exchanger From System Fluid To Chemical
Tanks. Due To This Project We Can Utilize That Waste Flue Gases Heat Energy To Heat Up
That Chemical Tank.
1.2 Selection Of Project
We Define Our Project Definition In Our Summer Internship 2015. Over There We Have
Taken Our Industrial Training In Echjay Industries Pvt. Ltd. In Our Internship Over There We
Have Visited Whole Industries & We Find Different Departments. In There One Of The
Department Is “Cold Forging” Unit.
During The Visit Of Cold Forging Unit We Have Observed That In Phosphating Line
There Several Chemical Tanks Which Require A Certain Temperature To React With Object. So
To Heat Up That Tanks They Are Using Twelve Electric Heaters Per Tank Which Consume
More Amount Of Conductive Electricity. The Power Factor Of Electricity Is 0.67 To 0.7. And
We Observed That There Is An Annealing Furnace Which Is Situated Beside The Phosphating
Line. It Is Use For Heat Treatment Of Work Piece To Remove The Internal Stresses And Increase
Malleability & It Has A Temperature Range Of 900-1100 ͦC.
So We Have Suggested That Rather To Heating The Phosphating Line By Use Of Electric
Heater We Can Use Utilize The Temperature Of Flue Gases Coming From The Exhaust Of
Furnace. By Putting A Heat Exchanger We Will Transfer Exhaust Temperature To Phosphating
Tank. Due To This We Can Reduce The Electric Consumption And Increase The Plant
Efficiency.
Fig.2 Flow Process Of Cold Forging
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 4
1.3 Objectives & Aims.
1. Industry
As The Industry Is Using Electric Heater Its Overall Energy Cost Increases Due
To Which Production Cost Is Also Increases.
By Utilizing This Exhaust Heat Of Flue Gases Use Can Reduce The Energy Cost
& Increase The Profit.
By Doing This Energy Conservation Project And After The Implementation The
Market Value Of Industry Is Increase Due To Energy Saving Projects.
By Implementing This Kind Of Projects Industry Can Achieve Some Good
Environment Friendly Rewards And Good Quality Standards. I.E. Iso 14000, Iso
9000/4000.
2. Society
With The Help Of This Project We Can Utilize The Heat Which Is Directly
Emitted To Atmosphere Which Will Affect The Surrounding The Ecosystem.
By Utilizing That Heat In Place Of 12 Electric Heater Per Tank Which Will
Reduce The Power Consumption. So The Overall Total Consumption Load Of
Industry Is Reduce Due To Which The Government Can Utilize That In Different
Power Grid.
This Project Will Create An Awareness Of Power Saving To The Employer And
Worker.
1.4 Problem Specification
In Forging Industry, Particularly In Cold Working Process The Raw Material Are
Cleaned & Soaped By Chemicals Which Is Heated At Particular Temperature. The Heat Is
Supplied By Electric Heaters. The Furnace For Heat Treatment Process Is Situated Besides The
Phosphating Plant. By Utilizing The Heat Of The Exhaust Flue Gases Which Is Coming Outside
From The Furnace By Use Of The Heat Exchanger The Utilized Heat Can Be Supply To The
Phosphating Instead Of Electric Heaters. The Power Consumption Of The Electric Heater Will
Decrease. Thus Over All Energy Consumption Will Decrease.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 5
Fig.3 Layout Of Project
Particular Problem Specification Are Listed Under:-
I. Theoretical Design:-
1. Design Of Heat Exchanger From Furnace To System.
2. Design Of Heat Exchanger From System To Chemical Tank.
3. Distribution System.
4. Pumping System.
5. Valve Control System.
6. Temperature Control System.
II. Computational Design:-
1. Modelling.
2. Meshing And Boundary Condition.
3. Simulation.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 6
Chapter-2 Literature Review & Data Collection
2.1 Industrial Data Collection
In The Industry We Have Measured Flue Gases Exhaust Pipe Which Is Over Oil Furnace
And Get The Dimension And Temperature
Furnace Exhaust Pipe OD = 500mm
Furnace Exhaust Pipe ID = 470mm
Refractory Brick = 20mm
Temperature Range = 400-500°C
Flow Rate Of Flue Gases As Per Industrial Guide And As Per Reference Book Studied And
Calculated= 0.6106 Kg/S (Referring Velocity= 10m/S).
No Of Tanks To Be Heated = 5
Capacity Of Tanks = 2700 Litres
Temperature To Maintain In Tanks = 60-75 °C.
Electrical Heating Rods Per Tanks = 12
Capacity Of Each Electrical Heating Rods = 9 Kw 230/400 V
Overall Efficiency Of Pump (𝜂ℎ𝑝) = 80%
2.2 Material Selection
Stainless Steel Specification
The Rate Of Thermal Expansion Of Stainless Steel Remains Relatively Constant Up
To 1200°C Compared To Carbon Steel Because Stainless Steel Does Not Experience
Phase Transformation.
The Magnitude Of Thermal Expansion Of Stainless Steel Is Greater Than The
Thermal Expansion Of Carbon Steel.
The Specific Heat Of Stainless Steel Increases Slightly At Elevated Temperatures,
Compared To Carbon Steel, Which Has A Huge Increase In Specific Heat At 730°C
Due To A Chemical Transformation From Ferrite-Pearlite To Austenite.
At Ambient Temperature, Stainless Steel Has A Much Lower Thermal Conductivity
Compared To Carbon Steel. However, The Thermal Conductivity Of Stainless Steel
Increases At Elevated Temperatures Which Will Exceed The Value Of Carbon Steel
Above 1000°C.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 7
Graph No.1 Specific Heat Vs. Temp. Of Stainless Steel & Carbon Steel
Through This Graph We Can See That The Specific Heat Of Carbon Steel Will Vary With
Respect To Certain Temperature After 650°C The Specific Heat Increases Suddenly Then After
It Will Reduces So Sudden Fluctuation Is There In Carbon Steel While The Specific Heat Of
Stainless Steel Is Consistent In All Temperature Very Little Variation In Larger Temperature
Scale.
Graph No.2 Thermal Elongation Vs. Temp. Of Stainless Steel & Carbon Steel
The Above Graph Is The Representation Of Comparing The Thermal Elongation At
Different Temperature Of Two Different Material, As We Can See The Difference Of Elongation
In This Materials The Carbon Steel Has Less Elongation Compare To Stainless Steel But At The
Same Time The Stainless Steel Have More Strong Property Like Wear Resistance, Corrosion
0
1000
2000
3000
4000
5000
6000
SP
EC
IFIC
HE
AT
(
J/K
G.K
)
TEMPERATURE(℃)
carbon steel Stainless Steel
0
5
10
15
20
25
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Th
erm
al
Elo
ngati
on
Δ
L/
L (
×10
-3)
Temperature(℃)
Carbon Steel
Stainless Steel
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 8
Resistance, More Life Span So Compare To Carbon Steel We Selected Our Initial Material As
Stainless Steel.
Table No.1 Material and Its Thermal Conductivity
Material Thermal Conductivity (W/M.K)
AISI 302 15.1
AISI 304 14.9
AISI 316 46.8
AISI 347 14.1
201 Annealed Steel 16.3
AISI 1015 (Cold Drawn Ss) 52
AISI 4130 42.7
Alloy Steel (Ss) 50
Copper 345
Aluminium 234
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 9
Chapter-3 Theoretical Design Calculation
3.1 Theoretical Design Calculations
Theoretical Design Steps:-
Table No.2 Equations Require For Calculating The Heat Transfer Problems
The Overall Heat Transfer Co-Efficient
𝑈𝑜 = 1
𝐴𝑜
𝐴𝑖ℎ𝑖+
𝐴𝑜Ln(𝑟𝑜
𝑟𝑖)
2𝜋𝑘𝐿+
1ℎ𝑜
1
𝑈𝑖=
𝐷𝑜
ℎ𝑖𝐷𝑖+ (
𝐷𝑜
𝐷𝑖× 𝑅𝑓𝑖) +
𝐷𝑜 Ln(𝐷𝑜
𝐷𝑖)
2𝑘+
1
ℎ𝑜
𝑈 = 1
1ℎ𝑖
+ 1
ℎ𝑜
The Heat Transfer Rate
𝑞 = 𝑇𝐴 − 𝑇𝐵
1ℎ1𝐴
+∆𝑥𝑘𝐴
+1
ℎ2𝐴
𝑞 = 𝑈𝐴∆𝑇𝑜𝑣𝑒𝑟𝑎𝑙𝑙
𝑞 = 𝑇𝐴 − 𝑇𝐵
1ℎ𝑖𝐴𝑖
+Ln(
𝑟𝑜
𝑟𝑖)
2𝜋𝑘𝐿+
1ℎ𝑜𝐴𝑜
𝑄 = 𝑚𝐶𝑝∆𝑇
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 10
For Unit Length Basis The Thermal
Resistance Of The Steel 𝑅𝑠 = Ln(
𝑟𝑜
𝑟𝑖)
2𝜋𝐾𝐿
For Unit Length Basis The Thermal
Resistance On The Inside
𝑅𝑖 = 1
ℎ𝑖2𝜋𝑟𝑖𝐿
Reynolds’s No. 𝑅𝑒 =
𝜌 × 𝑉 × 𝑑
𝜇
Prandlt’s No. 𝑃𝑟 =
𝐶𝑝 × 𝜇
𝑘
Greyshollf’s No. 𝐺𝑟 =
𝛽 × 𝑔 × 𝐷3 × 𝜌2 × (𝑇𝑠 − 𝑇𝛼)
𝜇2
Logamathric Mean Temperature Difference 𝐿. 𝑀. 𝑇. 𝐷. =
(𝑇ℎ,𝑖 − 𝑇𝑐,𝑜) − (𝑇ℎ,𝑜 − 𝑇𝑐,𝑖)
Ln[ (𝑇ℎ,𝑖 − 𝑇𝑐,𝑜) ÷ (𝑇ℎ,𝑜 − 𝑇𝑐,𝑖)]
Heat Transfer Co-Efficient ℎ =
𝑁𝑢 × 𝐾
𝑑
Nusselt’s No.
𝑁𝑢 =
𝑓2 × (𝑅𝑒) × 𝑃𝑟
1 + 8.1 × 𝑓8
0.5
× [ 𝑃𝑟
23 − 1]
Required Length For Heat Exchanger 𝐿𝑒𝑛𝑔𝑡ℎ =
𝑄
𝜋 × 𝐷𝑖 × 𝑈 × 𝐿. 𝑀. 𝑇. 𝐷.
Pressure Drop (Δp) ∆𝑃 =
4 × 𝑓 × 2 × 𝐿 × 𝜂ℎ𝑝 × 𝜌 × 𝜇𝑚2
𝑑𝑖 × 2
Pumping Work (P) 𝑃 =
1
𝜂𝑝×
�̇�𝑝 × ∆𝑃
𝜌
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 11
Theoretical Design Calculation For Heat Exchanger -1
1. Double Pipe Heat Exchanger (Connected In Series)
o Inner Pipe Dimensions
Outer Diameter = 0.12m
Inner Diameter = 0.10m
o Outer Pipe Dimensions
Inner Diameter (Di) = 0.470m
Outer Diameter (Do) = 0.50m
o Cold Fluid Inlet Temperature (Tci) = 40℃
o Cold Fluid Outlet Temperature (Tco) = 95℃
o Hot Fluid Inlet Temperature (Thi) = 300℃
o Inner Cold Fluid (Water) Properties At 65℃
Density 𝜌 = 980 𝐾𝑔
𝑚3
Specific Heat 𝐶𝑝= 4.191 𝐾𝐽
𝐾𝑔.𝐾
Thermal Conductivity K= 0.668 𝑊
𝑚.𝑘
Viscosity = 420 × 10−6 𝑃𝑎. 𝑠
Prandlt’s No. = 2.99
o Outer Hot Fluid (Dry Air) Properties At 200℃
Density 𝜌 = 0.774 𝐾𝑔
𝑚3
Specific Heat 𝐶𝑝= 1.021 𝐾𝐽
𝐾𝑔.𝐾
Thermal Conductivity K= 0.0386 𝑊
𝑚.𝑘
Viscosity = 25.07 × 10−6 𝑃𝑎. 𝑠
Prandlt’s No. = 0.686
o Required Heat Is
𝑄 = 𝑚𝐶𝑝∆𝑇
Q = 553.212 Kw (Kj/S)
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 12
Calculations For Hot Fluid (Dry Air)
o Heat Supplied = Heat Observed By Heat Exchanger
o 𝑸 = 𝒎𝒉̇ 𝑪𝒑𝒉∆𝑻 = 𝒎𝒄̇ 𝑪𝒑𝒄∆𝑻
o 𝒎𝒉̇ = 𝒎𝒄̇ 𝑪𝒑𝒄
𝑪𝒑𝒉∆𝑻= 𝟐. 𝟕𝟎𝟗𝟏
𝐾𝑔
𝑠
o Reynolds’s No. = 𝜌 𝑉 𝐷
𝜇 = 2,33,187.953 (∴ 𝑇ℎ𝑒 𝑓𝑙𝑜𝑤 𝑖𝑠 𝑡𝑢𝑟𝑏𝑢𝑙𝑒𝑛𝑡 )
By, Correlation For Fully Developed Turbulent Convection Through Circular Duct
(From Ref.No.3 ) Gnielinski’s Correlation
o 𝑁𝑢 =𝑓
2×(𝑅𝑒)×𝑃𝑟
1+8.1× 𝑓
8
0.5
×[ 𝑃𝑟
23−1]
Where 𝑓 = (1.58 × Ln 𝑅𝑒 − 3.28 )−2
o 𝑁𝑢 = 0.003787836
2×(233187.953)×0.686
1+8.1× 0.003787836
8
0.5
×[ 0.68623−1]
= 𝟑𝟒𝟑. 𝟖𝟒𝟐𝟏
Heat Transfer Co-Efficient Of Hot Fluid
o ℎ𝑜 = 𝑁𝑢 ×𝑘
𝐷 = 110.60
𝑾
𝒎𝟐𝒌
Calculations For Inner Cold Liquid
o Reynolds’s No. = 𝜌×𝑣×𝑑𝑜
𝜇= 𝟕𝟐, 𝟕𝟓𝟓. 𝟔𝟔𝟔 (∴ 𝑇ℎ𝑒 𝑓𝑙𝑜𝑤 𝑖𝑠 𝑡𝑢𝑟𝑏𝑢𝑙𝑒𝑛𝑡)
By, Correlation For Fully Developed Turbulent Convection Through Circular Duct
(From Ref.No.3 ) Gnielinski’s Correlation
o 𝑁𝑢 =𝑓
2×(𝑅𝑒)×𝑃𝑟
1+8.1× 𝑓
8
0.5
×[ 𝑃𝑟
23−1]
Where 𝑓 = (1.58 × Ln 𝑅𝑒 − 3.28 )−2
o 𝑁𝑢 0.004817256
2×(72755.666)×2.66
1+8.1× 0.004817256
8
0.5
×[ 2.6623−1]
= 𝟐𝟕𝟐. 𝟕𝟗𝟐𝟎
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 13
o Heat Transfer Co-Efficient Of Inner Fluid
ℎ𝑖 = 𝑁𝑢 ×𝑘
𝐷 = 1822.25
𝑾
𝒎𝟐𝒌
Rfi = 0.000176 𝑊
𝑚2℃ (From Ref.No.3)
Overall Heat Transfer Co-Efficient On The Outside Of The Inner Tubes
1
𝑈𝑓=
𝑑𝑖
𝑑𝑜 × ℎ𝑖+
𝑑𝑖
𝑑𝑜× 𝑅𝑓𝑖 +
𝑑𝑜 × Ln𝑑𝑖𝑑𝑜
2 × 𝑘+
1
ℎ𝑜= 𝟗𝟓. 𝟑𝟖𝟓𝟗
𝑊
𝑚2℃
𝐿. 𝑀. 𝑇. 𝐷. = (𝑇ℎ,𝑖 − 𝑇𝑐,𝑜) − (𝑇ℎ,𝑜 − 𝑇𝑐,𝑖)
Ln[ (𝑇ℎ,𝑖 − 𝑇𝑐,𝑜) ÷ (𝑇ℎ,𝑜 − 𝑇𝑐,𝑖)]= 𝟏𝟏𝟖. 𝟎𝟏𝟒 ℃
Overall Required Heat Transfer Area Can Be,
𝐿𝑒𝑛𝑔𝑡ℎ = 𝑄
𝜋 × 𝐷𝑖 × 𝑈 × 𝐿. 𝑀. 𝑇. 𝐷.= 𝟔𝟓. 𝟎𝟑𝟒𝟔 𝑚
Pressure Drop In Hot Fluid
∆𝑃 =4 × 𝑓 × 2 × 𝐿 × 𝜂ℎ𝑝 × 𝜌 × 𝜇𝑚
2
𝑑𝑖 × 2 = 𝟒𝟗𝟎𝟔. 𝟓𝟐 𝐏𝐚
Required Pumping Work
𝑃 =1
𝜂𝑝×
�̇�𝑝 × ∆𝑃
𝜌= 𝟒𝟖𝟐𝟏𝟖. 𝟓 𝑾
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 14
3.2 Making Of Excel Calculation Sheet & Heat Exchanger Parameters
Optimizations
As The Procedure To Calculate The Length Of Heat Exchanger Is Very Much Complex And
We Have Number Of Variable To Optimize The Length So To Reduce The Time Consumption
We Have Make A Type Of User Friendly Program In Excel, In This We Have Mentioned All
The Parameter So Once The User Will Enter The Required Parameter Directly The Software
Will Calculate All The Required Equation And Generate The Result Of Each And Every
Parameter.
The Given Below Table Shows The First Calculation Which We Perform Theoretically
As Above So At The End We Can See That The Value Of Both The Values Are Equal And
Accurate So With The Help Of This Excel Program We Can Generate The Result Easily And
Make Our Calculation Fast So By Trial And Error Method We Started Optimizing The Pipe
Length.
Table No.3 Calculation No.1 Minimum Hot Fluid Mass Flow Rate
Double Pipe Heat Exchanger (Water-Air) Cold Fluid Water Hot Fluid Air
Mass Flow
Rate(Kg/S)
2.4 Mass Flow Rate
(Kg/S)
2.7091
Inner Pipe Material
Thermal
Conductivity
(W/M.K)
19.841
(Stainless Steel)
Tci (℃) 40 Thi (℃) 300
Tco (℃) 95 Tco (℃) 100
(Tco-Tci) (℃) 55 (Tco-Tci) (℃) 200
Inner Pipe Dimensions Outer (Annulus) Pipe Dimensions
I.D. (M) 0.10 I.D. (M) 0.12
O.D. (M) 0.12 O.D. (M) 0.470
O.D/I.D. 1.2 O.D/I.D. 3.91666
Ln (O.D. /I.D.)
0.1823 Ln (O.D. /I.D.) 1.3652
O.D.-I.D. (M) 0.02 O.D.-I.D. (M) 0.350
Cross Sectional Area
(M2)
0.007853 Cross Sectional Area
(M2)
0.16225
Thermal Properties
Density (Kg/M3) 998 Density (Kg/M3) 0.774
Specific Heat
(Kj/Kg.K)
4.191 Specific Heat
(Kj/Kg.K)
1.021
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 15
Thermal
Conductivity
(W/M.K)
0.668 Thermal Conductivity
(W/M.K)
0.0386
Viscosity (Pa.S)
0.00042 Viscosity (Pa.S) 0.00002507
Prandlt's No. 2.66 Prandlt's No. 0.686
Heat Exchanger Calculations
Velocity (M/S)
0.311181 Velocity (M/S) 21.58
Reynold's No. 72755.666 Reynolds’s No. 233187.53
Fanning Friction
Factor (F)
0.004817526 Fanning Friction
Factor (F)
0.003787836
(F/2) 0.0024088 (F/2) 0.00189403
(F/2)^1/2 0.049 (F/2)^1/2 0.0435
Nusselt's No. 272.790250 Nusselt's No. 343.75258
Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
1822.25 Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
110.60
Fouling Factor (Rfi)
0.000176 Fouling Factor (Rfo) -
L.M.T.D. (℃) 118.1926
Required Heat Kw, Q Kw (Kj/S)
Q=(Mass Flow Rate)*(Specific
Heat)*(Tco-Tci)
553.212
Overall Heat Transfer Co-Efficient
(W/M2.K)
95.3859
Heat Transfer Area (Ao) M2 49.144
Required Heat Transfer Pipe Length For
1 Tube L (M) 65.0346
For Optimization We Studied About Heat Transfer Parameters E.G.
Hot Fluid Mass Flow Rate
Pipe Material (Thermal Conductivity, Specific Heat)
Hot Fluid Outlet Temperature
Inner Pipe Dimensions (Outer Diameter, Inner Pipe, Pipe Thickness)
Pressure Drop
Fouling Factor
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 16
In This We Have Increased The Mass Flow Rate Of The Hot Flue Gases As The Mass Flow
Rate Change The Temperature Of Flue Gases At Outlet Change And Due To That The L.M.T.D
And Overall Heat Transfer Rate Change And That Will Affect In Length Of Heat Exchanger
Pipe (No. Of Pass = 1)
Table No.4 Calculation No.2 Changing In Hot Fluid Mass Flow Rate & As Per That
Change In Hot Fluid Gases Outlet Temperature (Tho) With Other Constant Parameters
Double Pipe Heat Exchanger (Water-Air) Cold Fluid Water Hot Fluid Air
Mass Flow
Rate(Kg/S)
2.4 Mass Flow Rate
(Kg/S)
9
Inner Pipe Material
Thermal
Conductivity
(W/M.K)
19.841
(Stainless
Steel)
Tci (℃) 40 Thi (℃) 300
Tco (℃) 95 Tco (℃) 239.7963
(Tco-Tci) (℃) 55 (Tco-Tci) (℃) 61
Inner Pipe Dimensions Outer (Annulus) Pipe Dimensions
I.D. (M) 0.10 I.D. (M) 0.12
O.D. (M) 0.12 O.D. (M) 0.470
O.D/I.D. 1.2 O.D/I.D. 3.91666
Ln (O.D. /I.D.)
0.1823 Ln (O.D. /I.D.)
1.3652
O.D.-I.D. (M) 0.02 O.D.-I.D. (M) 0.350
Cross Sectional
Area (M2)
0.007853 Cross Sectional
Area (M2)
0.16225
Thermal Properties
Density (Kg/M3) 998 Density (Kg/M3) 0.774
Specific Heat
(Kj/Kg.K)
4.191 Specific Heat
(Kj/Kg.K)
1.021
Thermal
Conductivity
(W/M.K)
0.668 Thermal
Conductivity
(W/M.K)
0.0386
Viscosity (Pa.S)
0.00042 Viscosity (Pa.S)
0.00002507
Prandlt's No. 2.66 Prandlt's No. 0.686
Heat Exchanger Calculations
Velocity (M/S)
0.311688312 Velocity (M/S)
71.66660694
Reynold's No. 72755.666 Reynolds’s No.
774411.002
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 17
Fanning Friction
Factor (F)
0.004817526 Fanning Friction
Factor (F)
0.003037431
(F/2) 0.0024088 (F/2) 0.001518715
(F/2)^1/2 0.049 (F/2)^1/2 0.038970698
Nusselt's No. 272.790250 Nusselt's No. 902.9383051
Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
1822.25 Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
290.4451548
Fouling Factor
(Rfi)
0.000176 Fouling Factor (Rfo)
-
L.M.T.D. (℃) 202.3870005
Required Heat Kw, Q Kw (Kj/S)
Q=(Mass Flow Rate)*(Specific
Heat)*(Tco-Tci)
553.212
Overall Heat Transfer Co-Efficient
(W/M2.K)
205.59
Heat Transfer Area (Ao) M2 13.29619282
Required Heat Transfer Pipe Length
For 1 Tube L (M) 17.62752835
As We Can See That By Changing The Hot Fluid Mass Flow Rate There Is Change In
The Length Of The Heat Exchanger -1 So We Have Make A Table Through Which We Can
Analysis That At Which Mass Flow Rate The Pipe Length Is More And Visa-Versa.
Table No.5 Changing In Length Of Heat Exchanger Pipe With Respect To Hot Fluid Mass
Flow Rate
Hot Mass Flow
Rate (Kg/S)
Hot Fluid Velocity
(M/S)
Hot Fluid Exhaust
Temperature
(Tho ℃)
Length Of Heat
Exchanger Pipe M
(No. Of Passes-1)
2.7091 21.57244 99.999 65.43
3 23.888 119.38 54.075
3.5 27.87034 145.19 43.1403713
4 31.8588 164.5416 36.5797
4.5 35.833 179.5416 32.1219
5 39.8147 191.6333 28.8226
5.5 43.7962 201.4848 26.36
6 47.77 209.6944 24.3696
6.5 50.96 216.641 22.96196
7 55.74 222.5952 21.38755
7.5 59.722 227.755 20.2369
8 63.7 232.2708 19.2469
8.5 67.68 236.2549 18.3852
9 71.666 239.7963 17.627
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 18
It Is Observed That The At Different Mass Flow Rate The Pipe Length Decreases But
The Value Of Hot Gases At Outlet Increases Which Can Create Higher Pumping Work & It Is
Necessary Not To Take The High Mass Flow Rate Due To Which The Outlet Temperature
Increases. So As Per The Observation It Is Advisable To Take The Average Value Of Mass Flow
Rate So We Have Decided 5 Kg/Sec For Further Calculation.
Graph No.3 Mass Flow Rate (Hot Fluid) Vs. Hot Fluid Outlet Temperature
Graph No.4 Mass Flow Rate (Hot Fluid) Vs. Hot Fluid Inlet Velocity
The Value Of The Inlet Velocity Is Directly Proportional To The Mass Flow Rate Of The
Hot Flue Gases The Increase In Mass Flow Rate Will Increase The Velocity. As The Velocity
Increases The Flow Will Be More Turbulent And The Reynolds Number Will Also Increases So
0
50
100
150
200
250
300
0 1 2 3 4 5 6 7 8 9 10
Hot
Flu
id O
utl
et T
emp
rtu
re (
℃)
Mass Flow Rate (Kg/s)
Mass Flow Rate (Hot Fluid) Vs. Hot Fluid Outlet
Temprature
0
10
20
30
40
50
60
70
80
0 1 2 3 4 5 6 7 8 9 10
Hot
Flu
e G
ase
s In
let
Vel
oci
ty
(m/s
)
Mass Flow Rate (Kg/S)
Mass Flow Rate (Hot Fluid) Vs. Hot Fluid Inlet Velocity
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 19
It Is Observed That We Cannot Increase More Mass Flow Rate So There By It Is Advisable To
Select The Correct Mass Flow Rate And As Per Above Selection Of Mass Flow Rate That Is 5
Kg/S, Is Favourable For The Calculation.
Graph No.5 Mass Flow Rate (Hot Fluid) Vs. Required Heat Transfer Pipe Length
As Per The Calculation It Is Observed That By Increasing The Mass Flow Rate The Pipe
Length Is Decreasing Initially By Changing The Mass Flow Rate There Is Waste Change In Pipe
Length But After Some Interval The Ratio Of Change In Mass Flow Rate To Pipe Length Will
Reduce So If We Still Increase The Mass Flow Rate The Pipe Length Will Change Very Less.
There Is One Another Parameter Through Which We Can Reduce The Pipe Length That
Is The Inner And Outer Diameter Of The Internal Pipe Passing From The Exhaust Pipe As We
Change The Pipe Diameter We Can Change The Heat Transfer Coefficient Of Outer Surface
Area As The Area Of Heat Transfer Change So We Have Taken The Standard Pipe Size That Is
50mm Internal Diameter And 58mm Of Outer Diameter Having A Thickness Of 4mm.
Table No.6 Changing In Inner Pipe Diameter With Other Constant Parameters
Double Pipe Heat Exchanger (Water-Air) Cold Fluid Water Hot Fluid Air
Mass Flow
Rate(Kg/S)
2.4 Mass Flow Rate
(Kg/S)
2.7091
Inner Pipe
Material
Thermal
345 (Copper)
0
10
20
30
40
50
60
70
0 1 2 3 4 5 6 7 8 9 10
Pip
e L
ength
(m
)
Mass Flow Rate (Kg/s)
Mass Flow Rate (Hot Fluid) Vs. Required Heat Transfer
Pipe Length
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 20
Conductivity
(W/M.K)
Tci (℃) 40 Thi (℃) 300
Tco (℃) 95 Tco (℃) 100
(Tco-Tci) (℃) 55 (Tco-Tci) (℃) 200
Inner Pipe Dimensions Outer (Annulus) Pipe Dimensions
I.D. (M) 0.05 I.D. (M) 0.058
O.D. (M) 0.058 O.D. (M) 0.470
O.D/I.D. 1.16 O.D/I.D. 8.103448236
Ln (O.D. /I.D.)
0.14852005 Ln (O.D. /I.D.)
2.092289684
O.D.-I.D. (M) 0.008 O.D.-I.D. (M) 0.412
Cross Sectional
Area (M2)
0.001964286 Cross Sectional
Area (M2)
0.170921143
Thermal Properties
Density
(Kg/M3)
998 Density
(Kg/M3)
0.774
Specific Heat
(Kj/Kg.K)
4.191 Specific Heat
(Kj/Kg.K)
1.021
Thermal
Conductivity
(W/M.K)
0.668 Thermal
Conductivity
(W/M.K)
0.0386
Viscosity (Pa.S)
0.00042 Viscosity (Pa.S)
0.00002507
Prandlt's No. 2.66 Prandlt's No. 0.686
Heat Exchanger Calculations
Velocity (M/S)
1.246753247 Velocity (M/S)
20.47803531
Reynold's No. 145454.5455 Reynolds’s No.
260478.6488
Fanning
Friction Factor
(F)
0.004161022 Fanning
Friction Factor
(F)
0.003707602
(F/2) 0.002080511 (F/2) 0.001853801
(F/2)^1/2 0.045612618 (F/2)^1/2 0.043055789
Nusselt's No. 485.2899452 Nusselt's No. 375.4080569
Heat Transfer
Co-Efficient
(Hi)
(W/M2.K)
6483.473668 Heat Transfer
Co-Efficient
(Hi)
(W/M2.K)
249.8405344
Fouling Factor
(Rfi)
0.000176 Fouling Factor
(Rfo)
-
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 21
L.M.T.D. (℃) 118.0142275
Required Heat Kw, Q Kw (Kj/S)
Q=(Mass Flow Rate)*(Specific Heat)*(Tco-
Tci)
553.212
Overall Heat Transfer Co-Efficient
(W/M2.K)
217.2702403
Heat Transfer Area (Ao) M2 21.57530677
Required Heat Transfer Pipe Length For 1
Tube L (M) 59.1799167
It Is Observed From The Above Calculations That By Changing The Different Parameter
We Can Reduce The Pile Length So As Per The Sight Constrain At Industry We Are Going With
Following Parameter Inner Pipe I.D.-50mm & O.D.-58mm, Hot Fluid Mass Flow Rate – 5 Kg./S,
Hot Outlet Temperature(Tho)-191.633℃, Inner Pipe Material – Copper (Thermal Conductivity-
345 W/M.K) )
Table No.7 At Inner Pipe I.D.-50mm & O.D.-58mm, Hot Fluid Mass Flow Rate – 5
Kg./S, Hot Outlet Temperature(Tho)-191.633℃, Inner Pipe Material – Copper
Double Pipe Heat Exchanger (Water-Air) Cold Fluid Water Hot Fluid Air
Mass Flow
Rate(Kg/S)
2.4 Mass Flow Rate
(Kg/S)
5
Inner Pipe Material
Thermal
Conductivity
(W/M.K)
345 (Copper)
Tci (℃) 40 Thi (℃) 300
Tco (℃) 95 Tco (℃) 191.633
(Tco-Tci) (℃) 55 (Tco-Tci) (℃) 108.37
Inner Pipe Dimensions Outer (Annulus) Pipe Dimensions
I.D. (M) 0.05 I.D. (M) 0.058
O.D. (M) 0.058 O.D. (M) 0.470
O.D/I.D. 1.16 O.D/I.D. 8.103448236
Ln (O.D. /I.D.)
0.14852005 Ln (O.D. /I.D.)
2.092289684
O.D.-I.D. (M) 0.008 O.D.-I.D. (M) 0.412
Cross Sectional
Area (M2)
0.001964286 Cross Sectional
Area (M2)
0.170921143
Thermal Properties
Density (Kg/M3) 998 Density (Kg/M3) 0.774
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 22
Specific Heat
(Kj/Kg.K)
4.191 Specific Heat
(Kj/Kg.K)
1.021
Thermal
Conductivity
(W/M.K)
0.668 Thermal
Conductivity
(W/M.K)
0.0386
Viscosity (Pa.S)
0.00042 Viscosity (Pa.S)
0.00002507
Prandlt's No. 2.66 Prandlt's No. 0.686
Heat Exchanger Calculations
Velocity (M/S)
1.246753247 Velocity (M/S)
37.79490479
Reynold's No. 145454.5455 Reynolds’s No.
480747.5707
Fanning Friction
Factor (F)
0.004161022 Fanning Friction
Factor (F)
0.003306254
(F/2) 0.002080511 (F/2) 0.001653127
(F/2)^1/2 0.045612618 (F/2)^1/2 0.040658664
Nusselt's No. 485.2899452 Nusselt's No. 613.3106462
Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
6483.473668 Heat Transfer Co-
Efficient (Hi)
(W/M2.K)
408.1688094
Fouling Factor
(Rfi)
0.000176 Fouling Factor (Rfo)
-
L.M.T.D. (℃) 176.9758109
Required Heat Kw, Q Kw (Kj/S)
Q=(Mass Flow Rate)*(Specific
Heat)*(Tco-Tci)
553.212
Overall Heat Transfer Co-Efficient
(W/M2.K)
351.4297339
Heat Transfer Area (Ao) M2 8.894861239
Required Heat Transfer Pipe Length
L (M) 24.39813036
As Per The Optimised Calculation There Is The Calculation For Pump Work As We
Change The Mass Flow Rate We Have To Change The Pump Work So At Different Mass Flow
Rate The Pump Work Will Also Be Different This Are The Different Pump Work At Different
Mass Flow Rate.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 23
Table No.8 Changing In Pump Work, Pressure Drop With Respect To Hot Fluid
Mass Flow Rate
Mass
Flow Rate
(Kg/S)
Tho (℃) Reynold's
No.
Hot Fluid
Friction
Factor ( F
)
Hot
Fluid
Mass
Velocity
(M/S)
Overall Heat
Transfer So-
Efficient
U(W/M2.K)
Hot Fluid
Pressure
Drop (Δp)
Pump
Work (W)
2.7091 99.099
233114.92
07 0.00379 21.57 95.55 4906.52 20204.36
3 119.38 258137 0.00374 23.888 102.43 4956.41 22601.5
3.5 145.19 301159 0.00361 27.87 113.653 5167.436 27490.65
4 164.5416 344182.26 0.00352 31.85 124.19 5571.326 33873.42
4.5 179.5416 387205.3 0.00344 35.833 134.14 6060.873 41456.82
5 191.6333 430228 0.00337 39.8417 134.58 6344.589 48218.5
5.5 201.4848 473251 0.00331 43.762 152.55 7153.651 59804.04
6 209.6944 516274 0.00326 47.77 161.11 7754.269 64825.18
6.5 216.641 559296 0.00322 50.96 169.304 8356.113 82557.51
7 222.5952 602319 0.00317 55.74 179 8979.431 95440.27
7.5 227.755 645342 0.00314 59.722 184.67 9640.779 109904
8 232.2708 688365 0.0031 63.7 184.07 10310.25 125372.2
8.5 236.2549 731388 0.00306 67.8 198.86 10993.61 142036.2
9 239.7963 774411.02 0.00303 71.666 205.58 11700.13 160056.1
Graph No.6 Reynold's No. Vs. Overall Heat Transfer Co-Efficient
0
50
100
150
200
250
0 100000 200000 300000 400000 500000 600000 700000 800000 900000
Over
all
Hea
t T
ran
sfer
Co
-
Eff
icie
nt(
W/m
2.K
)
Reynold's No.
Reynold's No. Vs. Oveall Heat Transfer Co-Efficient
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 24
Graph No.7 Hot Fluid Mass Flow Rate (Kg/S) Vs. Hot Fluid Pressure Drop (Pa)
It Is Observed From The Above Graph That Increase In Mass Flow Rate Will Increase
The Pressure Drop Of Hot Fluid As The Mass Flow Rate Increases The Pressure At Outlet Will
Also Increases So The Pressure Difference Of Both The End Will Increases This Will Reduces
The Efficiency Of The System But For Proper Heat Transfer We Have Selected 5 Kg/S. So As
Per That The Pressure Drop Will Be There And For Same There Is Calculation We Have Taken
The Pump Work.
Graph No.8 Velocity (Hot Fluid) M/S Vs. Pressure Drop (Hot Fluid) Pa
0
2000
4000
6000
8000
10000
12000
14000
0 1 2 3 4 5 6 7 8 9 10
Pre
ssu
re D
rop
(H
ot
Flu
id)
(Pa)
Mass Flow Rate (Hot Fluid) Kg/s
Hot Fluid Mass Flow Rate (Kg/s) Vs. Hot Fluid Pressure
Drop (Pa)
0
2000
4000
6000
8000
10000
12000
14000
0 10 20 30 40 50 60 70 80
Pre
ssu
re D
rop
(H
ot
Flu
id)
Pa
Velocity (Hot Fluid) m/s
Velocity (Hot Fluid) m/s Vs. Pressure Drop (Hot Fluid) Pa
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 25
In The Above Graph We Can Observe That As The Velocity Increases The Pressure Drop
Will Also Increases As The Velocity Is Directly Co-Relate With The Mass Flow Rate So It Can
Be Understood That The Value Of Mass Flow Rate And Velocity Both Are Similar So More The
Mass Flow Rate Higher The Pressure Drop.
Graph No.9 Reynolds No. Vs. Friction Factor
This Graph Shows Us That By Increasing The Reynolds Number We Can Reduce The
Friction Factor As The Friction Factor Reduces The Overall Heat Transfer Efficiency Increases
So We Can Increases The Mass Flow Rate And Velocity As It Increases It Will Increase The
Reynolds Number So For That We Have Calculated Reynolds Number At Mass Flow Rate Of
5 Kg/S.
Graph No.10 Reynold's No. Vs. Pressure Drop (Pa)
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0 100000 200000 300000 400000 500000 600000 700000 800000 900000
Fri
ctio
n F
act
or
Reynold's No.
Reynold's No. Vs. Friction Factor
0
2000
4000
6000
8000
10000
12000
14000
0 100000 200000 300000 400000 500000 600000 700000 800000 900000
Pre
ssu
re D
rop
(P
a)
Reynold's No.
Reynold's No. Vs. Presure Drop (Pa)
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 26
There Are Multiple Factors Which Is Affected By A Single Parameter So We Cannot
Increase Or Decrease The Value Of Any Parameter Because Other Parameter Are Also
Connected To That Same Value As We Have Seen Above The Increase In Reynolds Number
Will Reduce The Pressure Drop But At The Same Time If The Reynolds Number Increases The
Pressure Drop Will Also Increases So It Is Advisable That Pressure Drop Should Not Be
Increased Very Much And Every Parameter Are Balanced Properly.
3.3 Calculation For Heat Exchanger 2
Data:
o Pipe Inner Diameter: 0.05m
o Pipe Outer Diameter: 0.058m
o Hot Water Outlet From Heat Exchanger – 1 : 95℃
o Hot Water Inlet To Heat Exchanger - 2 : 40℃
o Heat Supplied From Heat Exchanger : 553.212 Kw
o No. Of Tanks To Be Heated Required : 5
o Heat Required For Each Tank : 110.6524 Kw
o Mass Flow Rate Of Hot Water From Heat Exchanger : 2.4 Kg/S
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 27
Chapter-4 Modelling And Simulation
4.1 Rough Model For Conceptualization & Imagination
Figure No.4 Rough Model For Imagination
For The Understanding Of The Design And Its Surrounding Environment The Rough
Model Has Been Prepared By Us In Which We Have Prepared A Scale Model Of Gas
Furnace And The Chemical Line Passing Near The Furnace. We Also Have Design The
Exhaust Same As The Current Plant, But The Things Are Modified As We Have To Design
And Utilize That Exhaust Heat Of The Flue Gases.
At The Same Time We Have Also Done The Assembly Of The Additional Equipment
Used For The Project Like Distribution Piping Line, Heat Exchanger-1, Heat Exchanger-2,
And Its Coupling. This Will Work In Visualization Of The Design And With The Help Of
This We Can Easily Identify The Theoretical Design Dimension Are Possible Or Not.
The Model Is Also Near To The Original Scale So The Spacing Between The Furnace
And The Tank Is One Of The Critical Parameter For Design And Installation. Thus With
This Model We Can Easily Identify Whether The Design Is Feasible Or Not.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 28
4.2 Modelling & Assembly In Software
Figure No.5 Modelling Of Heat Exchanger-1
As We Have Calculated The Pipe Length And All Other Parameter Theoretically Then We
Started Modelling The Heat Exchanger – 1 As Per The Dimension Of The Theoretical
Calculation So We Started Making The Part File In Solidworks And Then After We Have
Assembled It. The Above Fig Is F Heat Exchanger – 1 Which Is A Tube In Tube Type Heat
Exchanger.
In This We Will Supply The Hot Flue Gases From The Large Section Of Pipe And
Simultaneously Cold Water Will Flow In Small Section Of Pipe Both The Flow Are In Counter
To Each Other So The Overall L.M.T.D. Is More Which Will Increase The Heat Transfer Rate.
Figure No.6 Sectional View Of Heat Exchanger-1
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 29
This Is The Sectional View Of The Above Model Of Heat Exchanger – 1 Which Shows
The Inner Sectional Side Of The Pipes This Gives A Brief View Of The Inner Side Of The
Pipe.
4.3 Meshing Of Heat Exchanger-1
Figure No.7 Fine Meshing Of Heat Exchanger – 1 In Ansys
Once The Modelling And Assembly Is Done The Modelling File Is Saved As Part Or
Assembly File Then After It Is Also Saved As The .Stp Or In .Igs Format For Analysis Purpose.
Then After We Have Done Our Analysis In Ansys Multi-Physics Which Gives Us The Wide
Range Of Analysis Platform, In That There Are Many Modules Of Analysis But As We Are
Dealing With Fluid As Well As The Temperature We Have Selected The Cfd(Fluent) Analysis
Module Which Gives The Flow As Well As The Temperature Distribution, Pressure Drop
Results.
In That We Have To Fill The Hollow Section By Capping The Surface And Making It A
Solid Section Which Act As A Fluid In The Pipe. So Both Of The Section Is To Be Filled By
The Different Capping And After That Name Section Is Provided To Each Of The Surface Of
The Model Which Will Be Useful At The Time Of Giving Boundary Condition. Once All This
Procedure Is Done We Have To Update The Module Then After We Have To Define Meshing
To Whole Body The Meshing Is First Done With Simple Predefined Selection, After Seeing The
Result Of The General Mesh We Will Optimize The Meshing And Make The Selection Very
Fine To Have More Accurate Answers, We Also Cross Check The Meshing By Different
Meshing Statistics Technique Like Aspect Ratio, Jacobean Ratio, Warping Factor, Skewness
Methods. Out Of All This Methods The Meshing Results Must Come Under The Boundary Of
Any Three Methods.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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4.4 Analysis & Simulation Of Heat Exchanger-1
As The Meshing Is Completed We Have To Run The Setup Module In This We Have To
Apply Different Boundary Conditions As We Want To Have The Real Time Situation Answer
We Have To Apply All The Parameter Acting On It That Is Gravity Which Is 9.81 M/S. As The
Flow Is Turbulent We Have To Select The Factor On Which The Turbulent Flow Is Working In
This Analysis We Have Taken The K- Epsilon. Then After We Have To Provide The Material
To The Section That Is Solid To The Tank And Pipeline And Liquid And Gas To The Fluid.
There After The Boundary Condition As Per The Requirement Of The Model. Then Initialize It
And Run The Number Of Iterations More The Iteration Good The Answer.
Figure No.8 Temperature Distribution In Water (Working Fluid)
As We Have Defined The Parameter As Per The Above Description Then The
Computational Work Will Start Solving The Iteration And After Few Time We Will Get The
Results Of The Module. In This Above Image We Can See The Colour Difference In The Pipe
Which Indicate That The Change In Temperature Take Place As The Flue Gases Pass The Heat
To The Cold Water It Will Start Heating The Water And The Exhaust Flue Gases Will Loses Its
Temperature So Due To This We Can See This Type Of Image.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Figure No.9 Stream Line With Water Particle At Different Temperature
Base On That Flow We Can Create The Stream Line And See How Actually The Inner
Pipe Fluid Will Flow And This Fig Shows The Result Of That Simultaneously We Can Also See
How Water Particles Gain The Heat And Flow Through Pipe.
4.5 Modelling & Assembly Of Heat Exchanger-2
Figure No.10 Model Of Heat Exchanger – 2
As We Have Calculated The Pipe Length And All Other Parameter Theoretically Then We
Started Modelling The Heat Exchanger – 2 As Per The Dimension Of The Theoretical
Calculation So We Started Making The Part File In Solidworks And Then After We Have
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Assembled It. The Above Fig Is F Heat Exchanger – 2 Which Is A Tube In Tube Type Heat
Exchanger.
In This We Will Supply The Hot Water Generated By The Heat Exchanger – 1, The U
Shape Pipe Will Carry That Hot Fluid And Flow From The Upper Side To Lower Side, Outside
The Small Pipe The Chemical Is Filled In Tank Which Is To Be Heated The Tank Contain 85%
Of Water And Remaining 15 % Chemical Mixture Thus We Have Taken The Heat Transfer
Coefficient Of Water As The Tank Contain Maximum Portion Of It.
The Hot Water Passes Stage By Stage In Tank And Supply Heat To Tank Chemical The
Chemical Temperature Will Rise And The Water Temperature Will Drop Down As It Will Be
Cooled Down The Naturally Its Density Will Increases And It Will Move In Down Direction, So
At The Bottom Part We Will Collect The Cold Fluid And Again Send It To The Heat Exchanger
– 1, After A Certain Period Of Time The Chemical Temperature Raises As Per The Required
Level.
Figure No.11 Sectional View Of Heat Exchanger – 2
This Is The Sectional View Of The Above Model Of Heat Exchanger – 1 Which Shows
The Inner Sectional Side Of The Pipes This Gives A Brief View Of The Inner Side Of The Pipe.
As In The Sectional View We Can Easily See That The Pipe Is Distributed In Whole Tank So It
Will Cover Up The Overall Tank Fluid And Heat Up The Chemical From All Direction Evenly
This Will Reduce The Heating Tie Of Chemical So We Can Achieve Our Desired Temperature
In Lesser Time, Which Will Be More Useful At The Time Of Production.
Once The Modelling And Assembly Is Done The Modelling File Is Saved As Part Or
Assembly File Then After It Is Also Saved As The .Stp Or In .Igs Format For Analysis Purpose.
Then After We Have Done Our Analysis In Ansys Multi-Physics Which Gives Us The Wide
Range Of Analysis Platform, In That There Are Many Modules Of Analysis But As We Are
Dealing With Fluid As Well As The Temperature We Have Selected The Cfd(Fluent) Analysis
Module Which Gives The Flow As Well As The Temperature Distribution, Pressure Drop
Results.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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In That We Have To Fill The Hollow Section By Capping The Surface And Making It A
Solid Section Which Act As A Fluid In The Pipe. So Both Of The Section Is To Be Filled By
The Different Capping And After That Name Section Is Provided To Each Of The Surface Of
The Model Which Will Be Useful At The Time Of Giving Boundary Condition.
4.6 Meshing Of Heat Exchanger-2
Once All This Procedure Is Done We Have To Update The Module Then After We Have To
Define Meshing To Whole Body The Meshing Is First Done With Simple Predefined Selection,
After Seeing The Result Of The General Mesh We Will Optimize The Meshing And Make The
Selection Very Fine To Have More Accurate Answers, We Also Cross Check The Meshing By
Different Meshing Statistics Technique Like Aspect Ratio, Jacobean Ratio, Warping Factor,
Skewness Methods. Out Of All This Methods The Meshing Results Must Come Under The
Boundary Of Any Three Methods.
Figure No.12 Fine Meshing Of Heat Exchanger – 2
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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4.7 Analysis & Simulation Of Heat Exchanger-2
As The Meshing Is Completed We Have To Run The Setup Module In This We Have To Apply
Different Boundary Conditions As We Want To Have The Real Time Situation Answer We Have
To Apply All The Parameter Acting On It That Is Gravity Which Is 9.81 M/S. As The Flow Is
Turbulent We Have To Select The Factor On Which The Turbulent Flow Is Working In This
Analysis We Have Taken The K- Epsilon. Then After We Have To Provide The Material To The
Section That Is Solid To The Tank And Pipeline And Liquid And Gas To The Fluid. There After
The Boundary Condition As Per The Requirement Of The Model. Then Initialize It And Run
The Number Of Iterations More The Iteration Good The Answer
Figure No.13 Temperature Distribution In Chemical
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Chapter-5 Canvas Activity
5.1 Aeiou Canvas
The Aeiou Stands For Activity, Environment, Interaction, Objective And Users. In This Canvas
All The Above Activities Are Included As Per The Project Aspect. This Canvas Is Helps Us To
Make Our Project Plan Clear And Use To Develop The Path For The Project.
Activities
This Category Is Use To Make Our Future Activities Clear And Also Generate
The Path And Flow Process So One Can Easily Get What To Do First.
Environment
The Nearby Area Surrounded By The Site Is Considered In The Environment As
We Are Working With High Temperature The Environment We Have Higher
Temperature.
Interaction
Each And Every Person Connected To This Project Comes Under This Word.
Start With H.R.People And Administrative And Then General Manager, Plant
Head, Supervisor, Operator, Worker.
And From College Internal Guide And Other Faculty Have Supported In This
Project Work.
Objective
The Main Objective Of Our Project Is To Utilize The Exhaust Flue Gas
Temperature To Heat Up The Nearby Phosphating Line. This Will Decrease The
Plant Energy Cost And Thus The Plant Efficiency Increases In Terms Of Energy
As The Company Is Using Energy Conservation To Eco-Friendly Plant The
Company Also Get Iso Standardization Which Create Good Market Value.
As The System Is Simple And Easy In Construction The Maintenance Is Very
Less Compare To Current Plant.
Users
The Key User Is Company Itself, And Its Employees.
The Stakeholder And The Other Vendor Are Also Part Of This User Indirectly.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Figure No.14 Aeiou Canvas
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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5.2 Empathy Canvas
This Canvas Is Based On To Show Our Project How Is Defined & To Present To Industrial Shodh
Yatra (Isy). The Objective Is To Adopt Systematic Approach Based On Design Thinking And
Articulate The Insights Derived From Empathization Process Including Observation, Interaction
Etc. During Isy (Industrial Shodh Yatra) And Finalise The Problem/Idp/Udp Definition And
Orient The Task As Their Final Year Project In Their 7th And 8th Semester.
Observation
In Observation Box We Put Notes & Bullets Of Our Idp Project In Which We
Include The Different Shops & Places Of Industries.
Our Project Is Based On Our Summer Internship In Echjay Industries Pvt. Ltd.
Scouted Challenges
In Scouted Challenges We Include The Challenges Or Problems Which Is
Facing By Industry.
In Canvas By Use Of Sticky Notes We Shows Many Challenges And
Problems Which We Shows In Our Summer Internship In Industry.
Top Five Problems On The Basis Of Desirability, Feasibility & Viability
In This Section We Define Top Problems For Our Final Year Project Which
Can Completed By Us In One Year.
We Define The Project On The Different Sectors Like Thermal, Material
Handling, And Manufacturing & Energy Conservation.
Final Problem
After Defining Top 5 Problems In Industry, We Focused On Main Problem
Which Is Basis On Thermal & Energy Conservation. Which Is “Design Of
Heat Exchanger For Waste Heat Utilization From Exhaust Gases Of
Furnace.”
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 38
Figure No.15 Empathy Canvas
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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5.3 Ideation Canvas
5.3.1 Ideation Canvas
To Adopt A Systematic Design Thinking Approach To Ideate And Approach Towards Solving
The Defined Challenge, Finalized In Canvas Exercise 1. This Effort Will Bring In Various
Heuristics For Solving A Challenge Using Multiple Ways.
The Team Needs To Pick Up The Best Optimized Path From The Whole Ideation Output
And Proceed For Product/Solution Design.
In This Canvas We Focused On This Project In Socially, Place & Related Activities.
o People
o In This Section We Mentioned The People Which Are Directly & Indirectly Is
Connected With This Project.
Our Project Is Related To Industry So Many Peoples, Stakeholders Are Connected
And These Project Is Inflected With Them.
o Activities
In This Section We Mentioned The Activities Which Is Going To Take In This
Project Which Are:
Literature Survey
Data Collection
Theoretical Design
Computational Design
Analysis
Material Availability
Optimization
Demo Model
o Situation/ Context / Location
In This Section We Mentioned The Parameters, Dimensions, Area Constraints
Which Is Inflected To The Project.
Some Of Are:
Annealing Oil Fire Furnace
Phosphating Plant
Material Crane
Material Tray
Human Ergonomics
Tank Size
Temperature Regulations
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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o Possible Solutions
In This Section We Mention Which Solution & Results Can Be Achieved By Us
During Project Phase.
Figure No.16 Ideation Canvas
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5.3.2 Ideation Funnel Canvas
Ideation Funnel Canvas Is Interconnected To Ideation Canvas But In The Detailed Way. In
This Canvas We Are Mainly Focused On The People, Activities And Problems.
o People
In This Section We Mentioned The People Which Are Mostly Connected
With This Project.
Our Project Is Related To Industry So Many Peoples, Stakeholders Are
Connected And These Project Is Inflected With Them.
o Activities
In This Section We Mentioned The Activities Which Is Going To Take In
This Project.
In This Canvas We Mentioned The Activity In Which Are Currently
Working On. Which Are :
Literature Survey
Data Collection
Theoretical Design
o Problems
In This Part We Mentioned The Few Parameters & Constraints Which We
Have To Deal With It.
Temperature And Water Flow Control
Area Constraints
Multiple Solutions In Theoretical Calculations
o Situation/ Context / Location
In This Section We Mentioned The Parameters, Dimensions, Area
Constraints Which Is Inflected To The Project.
Some Of Are:
Annealing Oil Fire Furnace
Phosphating Plant
Human Ergonomics
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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o Possible Solution
In This Section We Mention Which Solution & Results Can Be Achieved
By Us During Project Phase.
In Which We Are Directly Focusing On.
o Inputs
In This Section We Mentioned The Inputs Which Is Given By Us To This
Project By Which We Can Achieve Our Main Target.
Theoretical Calculations
o Mechanical Inputs
o Thermal Inputs
o Fluid-Flow Inputs
o Mathematical Equations
Figure No.17 Idea Funnel Canvas
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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5.4 Product Development Canvas
This Exercise Is Meant For Giving Strategic Orientation To The Project Of Each Team So That
It Achieves Its True Goal As Defined By The Previous Canvas Exercises. This Exercise Is More
About Developing Strategy For The Proposed Product/Solution Design, After The Team Has
Successfully Attempted The Ideation Process And Has Incorporated Inputs From All
Stakeholders.
o Purposes
In This Section We Mentioned The Purposes, Our Main Goal Of This
Project. In This Section We Mentions The Advantages Of This Project To
The Industry And Our Perspective. Which Are:
Waste Heat Utilization
Energy Conservation
Plant Efficiency Improvement
Overall Cost Reduction
ISO Environmental Standardization
Market Value.
o Product Function
In These Part We Mentioned The Product Function Of Our Components
Which Is Going To Be Part Of This Project.
o Product Features
In This Section We Mentioned The Features Of Our Components Which
Enhance The Value Of Our Project.
Compact Design
Temperature Sensors And Valve Controller
Effective Heat Transfer Material
Sensitive System
o Customer Revalidation
In These Section We Put Three Factors In Which Our Product Is Deal
With Our Customers.
Cost
Product Life Cycle
Problem In Generating Required Output
o Reject/Redesign/Retain
We Mentioned Over Here Factors Of Redesign If The Customers Are Not
Satisfying With Our Product.
Raw Material Change
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Redesigning Heat Exchanger By Providing Fin.
Figure No.18 Production Development Canvas
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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5.5 Business Canvas
Key Partners
This Are Few Of The Reputed Companies Working With Echjay
Industries Pvt. Ltd. Companies Like Larson And Toubro, Mahindra,
Cat, Godrej, Siap, Tafe, Bmw, Audi. Etc. As We Develop The Echjay
Plant We Can Also Encourage The Partner Company To Get The
Advantage Of The Production Technology.
Key Activities
The Company Is Mainly Based On Forging Which Contain Cold
Forging Having Capacity Of 2500 Kn Fully Automatic Four Stage
Forging Machine. The Company Also Have Hot Rolling Line (HRL),
Axial Closed Die Rolling (ACDR), Ring Rolling, And It Also Have
High-Tech Machine Shops Equipped With CNC VMC And Automatic
Robots.
Key Resources
The Company Is Highly Managed And Have Good Chain Of Upward
And Downward Communication Chain Which Lead To A Clear
Message To Each And Every Employee Of The Company Having
Good Executive And Hr Staff, General Manager, Design Team,
Maintenance Team, Production Manager, Supervisor, Worker,
Helpers. Which Provide Company A Good Structure.
Value Propositions
The Company Is Serving With Good Products So The Quality Of The
Product Will Definitely Be Good, As Quality Is Good And The
Company Is Following Many Standardization The Life Span Of The
Product Will Be Good.
Customer Relationship
Company Is Highly Ethical To The Customer Point Of View This
Itself Says That Company Is Maintaining A Very Good Image To The
Customer.
Customer Segments
80% Of The Company Production Is Of Automotive Segment, 15%
Of The Part Is Of Heavy Duty Piping And Refining Industries,
Remaining 5% Of The Products Are Heavy Duty Marine And
Aerospace Application
Channels
The Company Have A Good Media Advertising In Different Medium
Like Facebook, Twitter, LinkedIn, YouTube, Just Dial, Yellow Pages.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Cost Structure
The Main Cost Of The Plant Is The Running Cost, Then After The
Maintenance Cost, The Cost In Research And Development And
Promotional Events And Charity
Revenues Streams
The Project Will Help To Reduce The Production Cost This Will Lead
To Profit Increase The Advantage Is That Environmental Pollution
Will Also Be Reduced So The Company Can Have Iso Certification.
As The Design Is Simple The Maintenance Cost Will Also Be
Reduced So After Some Time We Can Easily Achieve The Payback
Period Of The Installation Product Which Lead To Net Increment In
Profit.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Figure No.19 Business Canvas
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Chapter-6 Results And Future Working Plan
6.1 Result And Conclusion
By This Theoretical Calculation We Got The Length Of Our 1st Heat Exchanger Which Is
25m. And On Basis Of That We Are Calculating The Remaining Few Parameter By This
Procedure We Have Define Many Different Possible Way To Find The Results.
We Have Find The Optimized Dimensions For Heat Exchanger-1 & Heat Exchanger-
2 With Respect To Available Heat From Exhaust Gas.
From This Research About Exchanger We Have Observed That By Changing The
Mass Flow Rate Of Hot Fluid Liquid, The Effective Heat Transfer Area Will
Decrease.
But Also The Pumping Work & Pressure Drop Increases Which Create More Energy
Consumption.
Table No.9 Changing In Pipe Lengths With Respect To Changes In Mass Flow Rate & Pipe
Material (Id 50mm & Od 58mm)
Mass Flow Rate (Hot
Fluid) 3 4 5 6 7 8 9
201 Annealed Steel Ss
(K=19.841 W/M.K)
49.171
8
33.194
7
26.1509
5
22.04
8
19.3
2
17.3
7 15.89
AISI 1015, Cold Drawn
Ss (K=52 W/M.K) 47.63 31.93 25 20.95
18.2
7
16.3
4 14.888
AISI 304 (K = 16.3
W/M.K) 55.78 41.018 26.55
22.43
1
19.6
9
18.1
8
16.247
7
AISI 4130 Steel ( K=42.7
W/M.K) 47.84 32.105 25.155
21.10
8
18.4
1
16.4
8 15.023
Copper (K=345 W/M.K) 46.82 31.27 24.39 20.39
17.7
2 15.8 14.36
Aluminium (K= 234
W/M.K) 46.88 31.32 24.42 20.43
17.7
6
15.8
5 14.4
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Graph No.11 Heat Transfer Pipe Length Vs. Mass Flow Rate With Respect To Different
Material
From This Graph We Observed That There Is Less Difference Between Pipe Lengths
With Respect To Material From Higher Thermal Conductive To Lower Thermal
Conductive.
Copper Is The High Thermal Conductive Material In All Of This Materials, So It Gives
High Transfer Rate For Heat Exchanger, But As Per Market Value Copper Is Costlier
Material In All Of This Material We Have Selected.
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10
Hea
t T
ran
sfer
Pip
e L
ength
m
Mass flow rate (Hot Fluid) Kg/s
Mass flow rate (Hot Fluid) Kg/s Vs. Heat transfer pipe m
201 Anneled Steel SS (K=19.841 W/m.K)
Aisi 1015, Cold Drawn SS (K=52 W/m.K) AISI 304 (K = 16.3 W/m.K)
AISI 4130 Steel ( K=42.7 W/m.K) Copper (K=345 W/m.K)
Aluminium (K= 234 W/m.K)
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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As Per Guidance Of Our Industrial Guide industry would recommend to use stainless
steel which is cheaper than copper & it’s maintainace cost is low.
After This Research We Can Determine The Dimensions Of Heat Exchanger-1.
1. Inner Pipe Diameter (Water) :- 50 Mm
2. Outer Pipe Diameter (Water) :- 58mm
3. Inner Pipe Diameter (Hot Air) :- 58mm
4. Outer Pipe Diameter (Hot Air) :- 470 Mm
5. Hot Fluid Inlet Temperature :- 300℃
6. Hot Fluid Outlet Temperature :- 191.633℃
7. Cold Fluid Inlet Temperature :- 40℃
8. Cold Fluid Outlet Temperature :- 90℃
9. Hot Fluid Mass Flow Rate :- 5 Kg/S
10. Cold Fluid Mass Flow Rate :- 2.4 Kg/S
11. Heat Exchanger-1 Length (No. Of Pass=1, Id=50mm, Od=58mm,
Material=Copper) :- 24.39813036 Meter
12. Logamathric Mean Temperature Difference :- 176.9758109℃
13. Generated Pressure Drop (In Hot Fluid) :- 6344.589 Pa
14. Generated Pressure Drop (In Cold Fluid) :- 12539.989 Pa
15. Required Pumping Work (In Hot Fluid) :- 48218.5 W
16. Required Pumping Work (In Cold Fluid) :- 38.3837 W
Future Working Plans:-
Theoretical Design Calculation For Heat Exchanger -2
Optimization Of Heat Exchanger-2
Application Of Heat Transfer Fin To Increase Heat Effectiveness
Butterfly Valve Control System To Control The Flow Rate Of Hot Flue Gases
Coming From The Furnace.
Use Of Baffle Plates To Increase The Heat Transfer Process.
Break Event Point Calculation For This Project.
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Appendix-1
Air Properties At Atmospheric Pressure As A Function Of Temperature
Temperature Conductivity Cp Prandlt’s Density Viscosity
[K] [W/M.K] [Kj/Kg.K] Number [Kg/M3] [N·S/M2]
200 0.0181 1.007 0.737 1.7458 0.00001325
250 0.0223 1.006 0.72 1.3947 0.00001596
300 0.0263 1.007 0.707 1.1614 0.00001846
350 0.03 1.009 0.7 0.995 0.00002082
400 0.0338 1.014 0.69 0.8711 0.00002301
450 0.0373 1.021 0.686 0.774 0.00002507
500 0.0407 1.03 0.684 0.6964 0.00002701
550 0.0439 1.04 0.683 0.6329 0.00002884
600 0.0469 1.051 0.685 0.5804 0.00003058
650 0.0497 1.063 0.69 0.5356 0.00003225
700 0.0524 1.075 0.695 0.4975 0.00003388
750 0.0549 1.087 0.702 0.4643 0.00003546
800 0.0573 1.099 0.709 0.4354 0.00003698
850 0.0596 1.11 0.716 0.4097 0.00003843
900 0.062 1.121 0.72 0.3868 0.00003981
950 0.0643 1.131 0.723 0.3666 0.00004113
1000 0.0667 1.141 0.726 0.3482 0.00004244
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Appendix-2
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
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Appendix-3
Saturated Water Properties
Temperature Conductivity Cp Hfg Prandlt’s Viscosity Vap. Sp.
Vol.
Liq. Sp.
Vol.
[K] [W/M.K] [Kj/Kg.K] [Kj/Kg] Number [N·S/M2] [M3/Kg] [M3/Kg]
273.15 0.569 4.217 2502 12.99 0.00175 206.3 0.001
275 0.574 4.211 2497 12.22 0.00165 181.7 0.001
280 0.582 4.198 2485 10.26 0.00142 130.4 0.001
285 0.590 4.189 2473 8.81 0.00123 99.4 0.001
290 0.598 4.184 2461 7.56 0.00108 69.7 0.001001
295 0.606 4.181 2449 6.62 0.00096 51.94 0.001002
300 0.613 4.179 2438 5.83 0.00086 39.13 0.001003
305 0.620 4.178 2426 5.20 0.00077 29.74 0.001005
310 0.628 4.178 2414 4.62 0.00070 22.93 0.001007
315 0.634 4.179 2402 4.16 0.00063 17.82 0.001009
320 0.640 4.180 2390 3.77 0.00058 13.98 0.001011
325 0.645 4.182 2378 3.42 0.00053 11.06 0.001013
330 0.650 4.184 2366 3.15 0.00049 8.82 0.001016
335 0.656 4.186 2354 2.88 0.00045 7.09 0.001018
340 0.660 4.188 2342 2.66 0.00042 5.74 0.001021
345 0.668 4.191 2329 2.45 0.00039 4.683 0.001024
350 0.668 4.195 2317 2.29 0.00037 3.846 0.001027
355 0.671 4.199 2304 2.14 0.00034 3.18 0.00103
360 0.674 4.203 2291 2.02 0.00032 2.645 0.001034
365 0.677 4.209 2278 1.91 0.00031 2.212 0.001038
370 0.679 4.214 2265 1.80 0.00029 1.861 0.001041
373.15 0.680 4.217 2257 1.76 0.00028 1.679 0.001044
375 0.681 4.220 2252 1.70 0.00027 1.574 0.001045
380 0.683 4.226 2239 1.61 0.00026 1.337 0.001049
385 0.685 4.232 2225 1.53 0.00025 1.142 0.001053
390 0.686 4.239 2212 1.47 0.00024 0.98 0.001058
400 0.688 4.256 2183 1.34 0.00022 0.731 0.001067
410 0.688 4.278 2153 1.24 0.00020 0.553 0.001077
420 0.688 4.302 2123 1.16 0.00019 0.425 0.001088
430 0.685 4.331 2091 1.09 0.00017 0.331 0.001099
440 0.682 4.360 2059 1.04 0.00016 0.261 0.00111
450 0.678 4.400 2024 0.99 0.00015 0.208 0.001123
460 0.673 4.440 1989 0.95 0.00014 0.167 0.001137
470 0.667 4.480 1951 0.92 0.00014 0.136 0.001152
480 0.660 4.530 1912 0.89 0.00013 0.111 0.001167
490 0.651 4.590 1870 0.87 0.00012 0.0922 0.001184
500 0.642 4.660 1825 0.86 0.00012 0.0766 0.001203
Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 54
References
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Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 55
Notes
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Design of Heat Exchanger for Waste Heat Utilization from Exhaust Gases of Furnace
B.H.GARDI COLLEGE OF ENGINEERING & TECHNOLOGY Page 56
Remarks