DESIGN_OF_A_SHELL_AND_2_TUBE_HEAT_EXCHAN.pdf

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DURBAN UNIVERSITY OF TECHNOLOGY
DEPARTMENT OF CHEMICAL ENGINEERING
CHEMICAL ENGINEERING DESIGN 2B – 2019
Design Project 2: Design of a Shell and Tube Heat
Exchanger
Authors: Tasmiyah Ismail
Student Number: 21807952
This report is submitted in partial fulfilment of the requirements for Chemical
Engineering Design 2B in the Department of Chemical Engineering, Durban
University of Technology.

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PREFACE
This compilation entails multiple sections of consideration. This project aims at designing a
shell and tube heat exchanger to fulfil certain parameters. These parameters are to be identified
from the problem statement issued.
Independent study and research were carried out in private facilities and at the Durban
University of Technology Computer Laboratory. Assistance and input from colleagues were
accepted through group discussions on how to tackle this project and possible techniques that
may be implemented.
The use of software such as Word, Excel, AutoCad and Aspen have assisted in comprising this
compilation.
Due to unforeseen circumstances this assignment submission was prolonged to more than five
weeks, from the date which the project was received.

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DECLARATION
I Tasmiyah Ismail, hereby declare that all work presented in this compilation was of an original
effort and was not a subject of plagiarism. All work sourced from external I have done this task
on my own accord with sincere dedication and utmost potential.
Signature: ……………………………………….
Date: ……………………………………………….

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ACKNOWLEDGEMENTS
Special thanks go out to my colleagues for their efforts and inputs with regards to different
perspectives of how to undertake this project. Knowledge shared was highly appreciated.
Assistance, guidance and clarification of this assignment from the assigned lecture was highly
appreciated.

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ABSTRACT
This project aims at designing a Shell and Tube heat exchanger to service a supercomputer
circuit. This circuit comprises of 100 supercomputers through which liquid propylene flows at
40 kg/hr. Liquid propylene is a heat transfer fluid aimed at removing heat from the
supercomputers to restore optimum functioning.in exchanger the liquid propylene is cooled
from 27°C - 15°C by chilled water through a shell and tube heat exchanger. The cooling water
is available at 5°C and at 10 000 kg/hr.
The design aspect is based on the Kern method of design. This incorporates reasonable
assumptions within a justified range. The thermal design is first calculated followed by the
geometric collaborating. The selected type of heat exchanger is a one-shell, two-tube pass heat
exchanger.
Two methods of approach are investigated for the presumed design. The theoretical design
calculated using the EXCEL software and the simulation using ASPEN software. These two
approaches are used in comparison to each other, to determine close to ideal results. However
due to geometric design specifications not all the final results correspond. Minor error is
evaluated in some while a range of error is view on others due to a difference in the geometric
design specification and type of heat exchanger.
A safety and operability study are done on the designed heat exchanger to analyse its efficiency
and reliability in a process unit. Hazards and mitigation are determined for the heat exchanger,
its operability and the impact on the process and employees.
Financial analysis is done for the cost of the heat exchanger as well as the payback period
involved to see if the presumed design is cost efficient. A payback period of approximately 2
years is determined making the production of heat exchangers viable. The costing is dependant
and the stock market and currency thus the prices may change over a period of time.
Investigation and research are recommended in the variety of heat exchangers available. This
may result in a suitable style for the desired process. Investigation into eco-friendly and cost-
efficient materials are also recommended to stand by codes that abide by environmental impact.

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NOMENCLATURE
𝑚
̇ 𝑖𝑛, 𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒 = mass flowrate in-propylene
𝑚
̇ 𝑜𝑢𝑡, 𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒 = mass flowrate out-propylene
𝑚
̇ 𝑖𝑛, 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑤𝑎𝑡𝑒𝑟 = mass flowrate in-cooling water
𝑚
̇ 𝑜𝑢𝑡, 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑤𝑎𝑡𝑒𝑟 = mass flowrate out-cooling water
𝐶𝑝𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒 = specific heat of propylene
𝑄𝑙𝑜𝑠𝑠 = heat duty lost
𝑄𝑔𝑎𝑖𝑛 = heat duty gained
𝑡𝑖𝑛 = inlet temperature tube-propylene
𝑡𝑜𝑢𝑡 = outlet temperature tube-propylene
𝑚
̇ 𝑠ℎ𝑒𝑙𝑙 = mass flowrate shell side-water
𝑇𝑖𝑛 = inlet temperature tube-water
𝑇𝑜𝑢𝑡 = outlet temperature tube-water
𝐶𝑝𝑤𝑎𝑡𝑒𝑟 = specific heat of water
∆𝑇𝑙𝑚= log mean temperature difference = LMTD
ht = heat transfer coefficient of the tube side
Nu = Nusselts number
k = fluid thermal conductivity
𝜌 = density
𝜇 = dynamic viscosity
𝑗ℎ= heat transfer factor
Re = Reynolds number
Pr = Prandtls number

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Uo = the overall heat transfer coefficient
ho = outside fluid film coefficient
hi = inside fluid film coefficient
hod = outside dirt coefficient (fouling factor)
hid = inside dirt coefficient
kw = thermal conductivity of the tube wall material
di = tube inside diameter
do= tube outside diameter
𝑁𝑝 = number of tube passes
𝑗𝑓 = friction factor
𝐿
𝑑𝑖
= length diameter ratio
𝑣 = tube side velocity
𝐷𝑠 = shell diameter
𝑑𝑒 = equivalent diameter
𝐿
𝐼𝐵
= length baffle spacing ratio

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GLOSSARY
STHE: Shell and tube heat exchanger
LMTD: Log mean temperature difference
PNID: Piping and instrumentation diagram
PFD: Process flow diagram
ASPEN: Advanced system for process engineering
Geometric: Arithmetic design quantities
Mitigation: Solutions to hazards

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LIST OF TABLES
Table 1 Material of construction of heat exchanger Page 18
Table 2 Shows the heat transfer coefficients of hot and cold fluids of
shell and tube heat exchanger
Page 21
Table 3 Constant used to calculate bundle diameter Page 26
Table 4 Shows shell wall thickness for different materials and shell
diameter
Page 27
Table 5 Conductivity of metals Page 29
Table 6 Estimated material cost Page 38
Table 7 Labour costing Page 38
Table 8 Total cost of one heat exchanger Page 39
Table 9 Payback period of investment Page 40
Table 10 Showing input parameters entered into the simulation Page 45
Table 11 Showing results obtained from Aspen simulation Page 46
Table 12 Comparison of Excel and Aspen simulation Page 47
Table 13 Showing stream composition- generated by Aspen simulation Page 54

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LIST OF FIGURES
Figure 1 Flow diagram of the heat exchanging system Page 15
Figure 2 Closed flow system in which the heat exchanger operates Page 17
Figure 3 Overall heat transfer coefficients Page 20
Figure 4 Graph showing values for temperature correction factor Page 22
Figure 5 Approximate bundle diameter for selected heat exchanger Page 26
Figure 6 Tube side heat transfer factor Page 30
Figure 7 Cross-sectional area of the designed shell and tube heat
exchanger
Page 35
Figure 8 Temperature profile graph generated by the Aspen simulation Page 48

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TABLE OF CONTENTS
PREFACE......................................................................................................................................... 2
DECLARATION .............................................................................................................................. 3
ACKNOWLEDGEMENTS............................................................................................................... 4
ABSTRACT...................................................................................................................................... 5
NOMENCLATURE.......................................................................................................................... 6
GLOSSARY ..................................................................................................................................... 8
LIST OF TABLES ............................................................................................................................ 9
LIST OF FIGURES......................................................................................................................... 10
TABLE OF CONTENTS................................................................................................................. 11
INTRODUCTION........................................................................................................................... 13
PART A: MECHANICAL THERMAL DESIGN OF SHELL AND TUBE HEAT EXCHANGER.. 14
DESIGN OF SHELL AND TUBE HEAT EXCHANGER ........................................................... 14
Material and energy balance for the heat exchanger.................................................................. 14
Material of construction used for the design............................................................................. 18
Geometric design specifications............................................................................................... 19
Estimation of overall heat transfer coefficient: ......................................................................... 20
Calculation of overall heat transfer coefficient: ............................................................................ 21
Log mean temperature difference:............................................................................................ 21
Average temperature:............................................................................................................... 22
Provisional area: ...................................................................................................................... 23
Area of one tube: ..................................................................................................................... 24
Number of tubes:..................................................................................................................... 24
Number of tubes per pass:........................................................................................................ 24
Cross sectional area – Tube:..................................................................................................... 25
Tube cross sectional are per pass:............................................................................................. 25
Tube side velocity:................................................................................................................... 25
Bundle diameter: ..................................................................................................................... 25
Shell inner diameter:................................................................................................................ 26
Heat transfer coefficient – Tube side:....................................................................................... 27
Length diameter ratio:.............................................................................................................. 29
Thermal conductivity:.............................................................................................................. 29
Heat transfer factor: ................................................................................................................. 30
Baffle spacing and shell side velocity:...................................................................................... 31

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Equivalent diameter:................................................................................................................ 31
Volumetric flowrate – shell side:.............................................................................................. 32
Heat transfer area – shell side:.................................................................................................. 32
Number of baffles:................................................................................................................... 32
Shell side heat transfer coefficient............................................................................................ 33
Heat transfer coefficient of shell side fluid: .............................................................................. 33
Calculated overall heat transfer coefficient:.............................................................................. 34
Cross sectional area of the designed heat exchanger..................................................................... 35
Pressure drop on tube side and shell side required........................................................................ 36
Tube-side pressure drop:.......................................................................................................... 36
Shell-side pressure drop:.......................................................................................................... 37
CAPITAL COST OF THE CONSTRUCTED SHELL AND TUBE HEAT EXCHANGER ......... 38
Estimated cost of shell and tube heat exchanger: ...................................................................... 38
THE EXPECTED PAYBACK PERIOD FOR THE PROJECT.................................................... 40
OCCUPATIONAL HEALTH AND PROCESS SAFETY ASPECTS .......................................... 41
All potential occupational health and process hazards identified:.............................................. 41
Mitigation of all hazards are proposed:..................................................................................... 43
Determine the safety impact of the installation of the Shell and Tube Heat Exchanger:............. 44
PART B: DESIGN OF SHELL AND TUBE HEAT EXCHANGER USING ASPEN SIMULATION
........................................................................................................................................................ 45
PART C: COMPARE THERMAL DESIGN AND ASPEN SIMULATION OF SHELL AND TUBE
HEAT EXCHANGER..................................................................................................................... 47
Data Comparison:........................................................................................................................ 47
Associated graphs:....................................................................................................................... 47
Discussion of ASPEN Simulation:............................................................................................... 49
Discussion of Theoretical Design:................................................................................................ 49
CONCLUSION AND RECOMMENDATIONS.............................................................................. 50
REFERENCES................................................................................................................................ 51
APPENDICIES............................................................................................................................... 52
Isometric drawing:....................................................................................................................... 52
Isometric Drawing of STHE- AutoCad: ....................................................................................... 53
Design Aspects-EXCEL: ............................................................................................................. 54
Costing-EXCEL: ......................................................................................................................... 58
Stream compositions- Aspen:....................................................................................................... 59
Aspen Plus Calculation Report: ................................................................................................... 60

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INTRODUCTION
This compilation is a technical report on the design of a Shell and Tube Heat Exchanger to
satisfy the problem statement provided. The problem statement defines a design for the cooling
of 100 super computers. This is done through a heat exchanger whereby liquid propylene flows
through the supercomputer circuit. Heat is rejected by the supercomputers to the propylene.
The propylene is then cooled using chilled water through a designed heat exchanger. The aim
of this project is to design a heat exchanger fit to serve the specifications provided.
The flowrate of liquid propylene from each super computer is given to be 40kg/hr while the
flowrate of cooling water available to the heat exchanger is 10 000 kg/hr. Liquid propylene
exits the supercomputers at a temperature of 27°C it is then cooled through the heat exchanger
to a temperature of 15°C where it is recycled to the supercomputers. The cooling water is
maintained at 5°C as entrance temperature to the heat exchanger.
Amongst other specifications the design has to be calculated using Excel software and Aspen
simulation Software. A comparison of results is required to determine the irregularities of
design. A costing analysis using formula auditing is also required to give an estimated payback
period to the designed heat exchanger.

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PART A: MECHANICAL THERMAL DESIGN OF SHELL AND
TUBE HEAT EXCHANGER
In this compilation the kern method of investigation is used to calculate the thermal and
geometric properties of the specified heat exchanger. The heat exchanger in consideration is
the shell and tube heat exchanger. The selected type of shell and tube heat exchanger is a one
shell, two pass heat exchanger. Cooling water is selected to flow through the shell while liquid
propylene is chosen to flow through the tubes. Since it is suggested that the more fouling fluid
flows through the tubes. This is since it can be easily and economically replaced upon
maintenance.
DESIGN OF SHELL AND TUBE HEAT EXCHANGER
Material and energy balance for the heat exchanger
For this design it is assumed that the system in consideration is a closed system. Hence the law
of conservation of mass and energy is followed. The amount of heat lost is equal to the amount
of heat gained. Heat transfer occurs from the hot propylene to the cool chilled water. From this
energy is assumed to be conserved within the system and losses to the surroundings and
frictional forces are taken to be negligible. Since energy is conserved the thermal energy know
as heat duty is equal on both shell and tube side. From this the temperature out of the chilled
water can be calculated.
Material Balance:
Tube side:
𝑚
̇ 𝑖𝑛, 𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒 = 𝑚
̇ 𝑜𝑢𝑡, 𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒 = 4000 𝑘𝑔/ℎ𝑟
Shell side:
𝑚
̇ 𝑖𝑛, 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑤𝑎𝑡𝑒𝑟 = 𝑚
̇ 𝑜𝑢𝑡, 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑤𝑎𝑡𝑒𝑟 = 10 000 𝑘𝑔/ℎ𝑟

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SUPER
COMPUTER
SHELL AND
TUBE HEAT
EXCHANGER
COOLING
WATER IN
COOLING
WATER OUT
PROPYLENE
OUT
OF
SUPER
COMPUTER
PROPYLENE INTO
SUPER COMPUTER
PROPYLENE INTO SHELL
AND TUBE HEAT
EXCHANGER
PROPYLENE OUT OF SHELL AND
TUBE HEAT EXCHANGER
Figure 1: shows the flow diagram of the heat exchanging system
Energy Balance:
Tube side properties:
Fluid: Liquid propylene
Mass flowrate - 𝑚
̇ 𝑡𝑢𝑏𝑒 = 40 kg/hr per supercomputer x 100 supercomputers
=4000 kg/hr
= 1.11 kg/s
Temperature in - 𝑡𝑖𝑛 = 27°C
Temperature out - 𝑡𝑜𝑢𝑡 = 15°C
Specific heat of propylene – 𝐶𝑝𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒= 1.5 kJ/kg. K
*The specific heat is obtained from the Coulson and Richardson Handbook Volume 2 at an
average temperature of 25 °C

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Heat duty – 𝑄𝑙𝑜𝑠𝑠 = 𝑚
̇ 𝑡𝑢𝑏𝑒𝐶𝑝𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒(𝑡𝑖𝑛 − 𝑡𝑜𝑢𝑡)
Heat duty – 𝑄𝑙𝑜𝑠𝑠 = 1.11 × 1.5 × (27 − 15)
= 19.98 kW
≈ 20 kW
Shell side properties:
Fluid: Cooling water
Mass flowrate - 𝑚
̇ 𝑠ℎ𝑒𝑙𝑙 = 10 000 kg/hr
= 2.78 kg/s
Temperature in - 𝑇𝑖𝑛 = 5°C
Specific heat of water – 𝐶𝑝𝑤𝑎𝑡𝑒𝑟= 4.21 kJ/kg. K
*The specific heat is obtained from the Coulson and Richardson Handbook Volume 2 at an
average temperature of 25 °C
Since 𝑄𝑙𝑜𝑠𝑠 = 𝑄𝑔𝑎𝑖𝑛
Therefore 𝑄𝑙𝑜𝑠𝑠 = 𝑄𝑔𝑎𝑖𝑛 = 𝑚
̇ 𝑡𝑢𝑏𝑒𝐶𝑝𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒(𝑇𝑖𝑛 − 𝑇𝑜𝑢𝑡)
Hence Temperature out - 𝑇𝑜𝑢𝑡 = 𝑇𝑖𝑛 +
𝑄𝑙𝑜𝑠𝑠
𝑚
̇ 𝑡𝑢𝑏𝑒𝐶𝑝𝑝𝑟𝑜𝑝𝑦𝑙𝑒𝑛𝑒
Hence Temperature o - 𝑇𝑜𝑢𝑡 = 5 +
20
2.78×4.21
= 6.71 °C

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Figure 2: shows the closed flow system in which the heat exchanger operates.
100 supercomputers
high density circuits
Shell and tube heat
exchanger
Propylene feed stream
Propylene cooled out
of heat exchanger
Cooling water out
Cooling water in
Propylene out of
supercomputers
t2 = 15 degree Celsius
Mass flowrate 1 = 40 kg/h x 100 computers
t1 = 27 degrees
Celsius
T1 = 5 degrees Celsius
Mass flowrate 3 = 10000 kg/h
T2 = 6.71 degrees Celsius

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Material of construction used for the design
Table 1: Material of construction of heat exchanger
Part of heat exchanger Material of construction
Shell Carbon steel
Tube Carbon Steel
Baffles Galvanised coated stainless steel
Support brackets Carbon steel
Gaskets Carbon steel
Tie rods and spacers Galvanised coated stainless steel
Fixed head Carbon steel
Channel cover Carbon steel
Sealant Carbon graphite
Material of construction: Carbon Steel
Carbon steel is an alloy comprising of Iron and Carbon.
Suitability:
• Carbon steel is classified as a safe material of construction
• Can withstand a large temperature range
• Ideal when associated with a variety of materials and fluids
• It has a high durability
• Can withstand high stress and is unaffected by the changes in pressure to some extent
• Ability to withstand harsh weather conditions
• Shock resistant
• Does not encourage pests and insects
• Can be fairly cost effective
• Ductile and can be shaped within a certain range
• Available in various sizes, thickness and shapes on a commercial level
Material of construction: Galvanised coated Stainless Steel
Suitability:
• High corrosion resistance due to galvanisation
• Tough material
• Ductile
• Has a high strength capacity
• Low maintenance
• Material availability in production of tie rods and spacers

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Material of construction: Carbon Graphite
Suitability:
• Acts as a good sealant
• High strength capacity
• Relatively high modulus regarding elasticity, thus can withstand a range of
deformations
• Rigidity along with strength
• Compatible with high pressures
• Ability to seal off components effectively
Geometric design specifications
Tube side data:
*assumed outer and inner diameter in correlation to standard sizes
* assumed diameters are suggested in correlation to Coulson and Richardson handbook
Volume 2
Tube outer diameter = 20 mm
Tube inner diameter = 18 mm
Tube wall thickness = 20 mm – 18 mm
= 2 mm
Tube length = 3 m
Tube pitch = 1.25 × tube outer diameter
= 1.25 × 20
= 25 mm

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Estimation of overall heat transfer coefficient:
Figure 3: Overall heat transfer coefficients
From the above diagram the overall heat transfer coefficient is assumed to be 350 W/m2
.°C.This value
is based on the fluid flowing on the shell side and the fluid flowing ton the tube side of the shell
and tube heat exchenager.in this design the fluid propylene and water are investigated.
Propylene is the process fluid while water is the service fluid. Propylene is classified as a light
oil, hot fluid and water as cold fluid. From the table below the typical overall heat transfer
coefficient range for these two fluids is seen to be 350 - 900 W/m2
. °C. Hence the assumption
of 350 W/m2
. °C is justified accordingly. This assumption is further tested using an iteration
method by calculating the overall heat transfer coefficient. This is shown as follows.

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Table 2: Shows the heat transfer coefficients of hot and cold fluids of shell and tube heat exchanger
Calculation of overall heat transfer coefficient:
Log mean temperature difference:
𝑇𝑙𝑚 =
(𝑡1 − 𝑇2) − (𝑡2 − 𝑇1)
𝑙𝑛
(𝑡1 − 𝑇2)
(𝑡2 − 𝑇1)
Where:
Tlm = log mean temperature difference
T1 = chilled water inlet temperature
T2 = chilled water outlet temperature
t1 = propylene inlet temperature
t2 = propylene outlet temperature
𝑇𝑙𝑚 =
(𝑡1 − 𝑇2) − (𝑡2 − 𝑇1)
𝑙𝑛
(𝑡1 − 𝑇2)
(𝑡2 − 𝑇1)
𝑇𝑙𝑚 =
(27 − 6.71) − (15 − 5)
𝑙𝑛
(27 − 6.71)
(15 − 5)
= 14.54 °C

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Average temperature:
For a one shell two pass heat exchanger the average temperature is calculated as follows
using corresponding correlation graphs.
Figure 4: shows the cross-sectional area of the designed shell and tube heat exchanger
𝑅 =
𝑡1 − 𝑡2
𝑇2 − 𝑇1
𝑆 =
𝑇2 − 𝑇1
𝑡1 − 𝑇1
Where:
T1 = chilled water inlet temperature
T2 = chilled water outlet temperature
t1 = propylene inlet temperature
t2 = propylene outlet temperature

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𝑅 =
𝑡1 − 𝑡2
𝑇2 − 𝑇1
=
27 − 15
6.71 − 5
= 7.02
𝑆 =
𝑇2 − 𝑇1
𝑡1 − 𝑇1
=
6.71 − 5
27 − 5
= 0.078
*values vary slightly as compared to excel document due to rounding off
Fouling correction factor is read off to the above graph to be = 0.95
Average mean temperature = log mean temperature difference x fouling factor
= 14.54 x 0.95
=13.81 °C
Provisional area:
*provisional area is made subject of formula using estimated overall heat transfer coefficient.
𝑝𝑟𝑜𝑣𝑖𝑠𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 =
𝑄
𝑈𝑜∆𝑇𝑙𝑚
Where:
Q = heat duty of heat exchanger
Uo = estimated overall heat transfer coefficient
∆𝑇𝑙𝑚= log mean temperature difference

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𝑝𝑟𝑜𝑣𝑖𝑠𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 =
𝑄
𝑈𝑜∆𝑇𝑙𝑚
=
20 × 1000
350 × 13.81
= 4.14 m2
Area of one tube:
𝐴𝑟𝑒𝑎 = 𝜋 × 𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 × 𝑡𝑢𝑏𝑒 𝑙𝑒𝑛𝑔𝑡ℎ
𝐴𝑟𝑒𝑎 = 𝜋 × 20/1000 × 3
= 0.19 m2
Number of tubes:
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒𝑠 =
𝑝𝑟𝑜𝑣𝑖𝑠𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎
𝑎𝑟𝑒𝑎 𝑜𝑓 𝑜𝑛𝑒 𝑡𝑢𝑏𝑒
=
4.14
0.19
= 21.8 tubes
*an approximate of 24 tubes are used in order to compensate for tube layout
Number of tubes per pass:
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒𝑠 𝑝𝑒𝑟 𝑝𝑎𝑠𝑠 =
𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒𝑠
𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒 𝑝𝑎𝑠𝑠
=
24
2
= 12 tubes per pass

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Cross sectional area – Tube:
𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 =
𝜋 × 𝑖𝑛𝑛𝑒𝑟 𝑡𝑢𝑏𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟2
4
=
𝜋 × 182
4
= 254.5 mm2
= 0.00025 m2
Tube cross sectional are per pass:
Area per pass = cross sectional area x tubes per pass
= 0.00025 x 12
= 0.0031 m2
Tube side velocity:
𝑡𝑢𝑏𝑒 𝑠𝑖𝑑𝑒 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 =
𝑚𝑎𝑠𝑠 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 × 𝑎𝑟𝑒𝑎 𝑝𝑒𝑟 𝑝𝑎𝑠𝑠
=
4000
3600
×
1
511.28
×
1
0.0031
= 0.701 m/s
*thermal properties are averaged and extrapolated from engineering toolbox for
corresponding temperature
Bundle diameter:
𝑏𝑢𝑛𝑑𝑙𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 = 𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑠𝑖𝑑𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 × (
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒𝑠
𝐾1
)
1/𝑛1
*constants for 2 tube pass square pitch are used.

26 | P a g e
Table 3: Constant used to calculate bundle diameter
𝑏𝑢𝑛𝑑𝑙𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 = 𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑠𝑖𝑑𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 × (
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑏𝑒𝑠
𝐾1
)
1/𝑛1
𝑏𝑢𝑛𝑑𝑙𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 = 20 × (
24
0.156
)
1/2.291
≈ 180𝑚𝑚
Shell inner diameter:
Figure 5: shows approximate bundle diameter for selected heat exchanger

27 | P a g e
*the selected heat exchanger is the fixed heat exchanger and since the bundle diameter is
approximately 0.2 m the bundle-shell clearance is assumed to be 10 mm.
Shell inner diameter = bundle diameter + bundle-shell clearance
= 180 + 10
= 190 mm
Table 4: Shows shell wall thickness for different materials and shell diameter
From the above table it can be seen that the minimum wall thickness is 7.1 mm. It is thus
reasonable to assume a wall thickness of 10 mm.
Heat transfer coefficient – Tube side:
ℎ𝑡 =
𝑁𝑢 × 𝑘
𝑡𝑢𝑏𝑒 𝑖𝑛𝑛𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
Where:
ht = heat transfer coefficient of the tube side
Nu = Nusselts number
k = fluid thermal conductivity

28 | P a g e
*Nusselts number is calculated as follows:
Reynolds Number
𝑅𝑒 =
𝜌 × 𝑑 × 𝑢
𝜇
Where:
𝜌 = density of propylene
d = inner diameter
u = tube side velocity
𝜇 = dynamic viscosity of propylene
𝑅𝑒 =
𝜌 × 𝑑 × 𝑢
𝜇
𝑅𝑒 =
511.28 × 0.0018 × 0.71
9.38 × 10−5
= 69 795.25
Prandtls number:
𝑃𝑟 =
𝐶𝑝 × 𝜇
𝑘
Where:
Cp = specific heat
𝜇 = dynamic viscosity of propylene
k = thermal conductivity of propylene
𝑃𝑟 =
𝐶𝑝 × 𝜇
𝑘
𝑃𝑟 =
2.630 × 9.38 × 10−5
0.09243
= 2.67

29 | P a g e
Length diameter ratio:
𝑅𝑎𝑡𝑖𝑜 =
𝑡𝑢𝑏𝑒 𝑙𝑒𝑛𝑔𝑡ℎ
𝑅𝑎𝑡𝑖𝑜 =
3
0.018
= 166.67
Thermal conductivity:
The table below shows the thermal conductivity of different metals. For steel with standing
temperatures between 0-100 °C the thermal conductivity is 45 W/m. °C.
Table 5: Conductivity of metals

30 | P a g e
Heat transfer factor:
For the calculated Reynolds number, the heat transfer factor jh can be read off the graph below. The
heat transfer factor is taken to be 0.00667.
Figure 6: Tube side heat transfer factor
Nusselts number:
𝑁𝑢 = 𝑗ℎ × 𝑅𝑒 × 𝑃𝑟0.33
Where:
𝑗ℎ= heat transfer factor
Re = Reynolds number
Pr = Prandtls number
𝑁𝑢 = 𝑗ℎ × 𝑅𝑒 × 𝑃𝑟0.33
𝑁𝑢 = 0.00667 × 69 795.25 × 2.670.33
= 643,73

31 | P a g e
Hence the heat transfer coefficient of tube side is calculated as follows:
ℎ𝑡 =
𝑁𝑢 × 𝑘
ℎ𝑡 =
643.73 × 45
0.018
= 3305,58 W/m2
.°C
Baffle spacing and shell side velocity:
Baffle spacing:
*according to Coulson and Richardson volume 2 the baffle spacing can be 0.2 to 1 of the
shell inner diameter.
For this heat exchanger 0.5 was the selected value between the range.
Baffle spacing = shell inner diameter x 0.5
= 190 x 0.5
= 95 mm
Equivalent diameter:
For square pitch tube arrangement, the following equation is used as per Coulson and
Richardson volume 2.
𝑑𝑒 =
1.27
𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
× (𝑡𝑢𝑏𝑒 𝑝𝑖𝑡𝑐ℎ2
− 0.785(𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟2))
𝑑𝑒 =
1.27
20
× (252
− 0.785(202))
= 19.75 mm

32 | P a g e
Volumetric flowrate – shell side:
𝑣𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒 =
𝑚𝑎𝑠𝑠 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒
𝑑𝑒𝑛𝑠𝑖𝑡𝑦
=
10 000
3600
×
1
999.87
= 0,002778 m3
/s
Heat transfer area – shell side:
𝑎𝑟𝑒𝑎 =
𝑡𝑢𝑏𝑒 𝑝𝑖𝑡𝑐ℎ − 𝑡𝑢𝑏𝑒 𝑜𝑢𝑡𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
𝑡𝑢𝑏𝑒 𝑝𝑖𝑡𝑐ℎ
× 𝑠ℎ𝑒𝑙𝑙 𝑖𝑛𝑛𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 × 𝑏𝑎𝑓𝑓𝑙𝑒 𝑠𝑝𝑎𝑐𝑖𝑛𝑔
𝑎𝑟𝑒𝑎 =
25 − 20
25
× 190 × 95
= 3616,31 mm2
= 0,003616 m2
Shell side velocity:
𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 =
𝑣𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝑓𝑙𝑜𝑤𝑟𝑎𝑡𝑒
𝑎𝑟𝑒𝑎
𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 =
0,002778
0,003616
= 0.8 m/s
Number of baffles:
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑎𝑓𝑓𝑙𝑒𝑠 =
𝑡𝑢𝑏𝑒 𝑙𝑒𝑛𝑔𝑡ℎ
𝑏𝑎𝑓𝑓𝑙𝑒 𝑠𝑝𝑎𝑐𝑖𝑛𝑔
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑎𝑓𝑓𝑙𝑒𝑠 =
3
0.095
= 32 baffles
*assume baffle cut of 25%

33 | P a g e
Shell side heat transfer coefficient
𝑚𝑒𝑎𝑛 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 =
𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑤𝑎𝑡𝑒𝑟 𝑖𝑛 + 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑤𝑎𝑡𝑒𝑟 𝑜𝑢𝑡
2
=
5 + 6.71
2
= 5.86 °C
Heat transfer coefficient of shell side fluid:
*the following equation is used to calculate the heat transfer coefficient of water specifically,
as suggested in the Coulson and Richardson volume 2.
ℎ𝑡 = 4200 ×
1.35 + 0.02(𝑚𝑒𝑎𝑛 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒)
𝑒𝑞𝑢𝑖𝑣𝑎𝑙𝑒𝑛𝑡 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟0.2
× 𝑠ℎ𝑒𝑙𝑙 𝑠𝑖𝑑𝑒 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦0.8
ℎ𝑡 = 4200 ×
1.35 + 0.02(5.86)
19.750.2
× 0.770.8
= 2747,87 W/m2
. °C

34 | P a g e
Calculated overall heat transfer coefficient:
1
𝑈𝑂
=
1
ℎ𝑜
+
1
ℎ𝑜𝑑
+
𝑑𝑜𝑙𝑛
𝑑𝑜
𝑑𝑖
2𝑘𝑤
+
𝑑𝑜
𝑑𝑖
×
1
ℎ𝑖𝑑
+
𝑑𝑜
𝑑𝑖
×
1
ℎ𝑖
Where:
Uo = the overall coefficient based on the outside area of the tube
ho = outside fluid film coefficient
hi = inside fluid film coefficient
hod = outside dirt coefficient (fouling factor)
hid = inside dirt coefficient
kw = thermal conductivity of the tube wall material
di = tube inside diameter
do= tube outside diameter
1
𝑈𝑂
=
1
ℎ𝑜
+
1
ℎ𝑜𝑑
+
𝑑𝑜𝑙𝑛
𝑑𝑜
𝑑𝑖
2𝑘𝑤
+
𝑑𝑜
𝑑𝑖
×
1
ℎ𝑖𝑑
+
𝑑𝑜
𝑑𝑖
×
1
ℎ𝑖
1
𝑈𝑂
=
1
2747.87
+
1
700
+
0.02𝑙𝑛
0.02
0.018
2 × 45
+
0.02
0.018
×
1
3000
+
0.02
0.018
×
1
3305.58
= 0,00265 m2.
°C/W
Uo = 1/0.00265
= 377.36 W/m2
. °C

35 | P a g e
Cross sectional area of the designed heat exchanger
Figure 7: shows the cross-sectional area of the designed shell and tube heat exchanger
Above shows the inlet and outlets of both streams as well as the cross sectional of components
that make up the one shell and two tube heat exchangers. These are mainly the shell, the tubes
and the separating plate. The different passes are denoted by the blue and red highlight on the
cross-sectional diagram. Through each pass there are 12 tubes each. These are evenly spaced
with square pitch tube orientation. For this design the heat exchanger operates under a counter
current regime.
*Note: piping an instrumental diagram and isometric diagram are attached in the appendices.
Cooling water inlet
Propylene outlet
Shell
Tubes
Propylene inlet
Cooling water outlet
Separating plate

36 | P a g e
Pressure drop on tube side and shell side required
Tube-side pressure drop:
∆𝑃𝑡 = 𝑁𝑝 × (8 × 𝑗𝑓 ×
𝐿
𝑑𝑖
+ 2.5) (
𝜌 × 𝑣2
2
)
Where:
𝑁𝑝 = number of tube passes
𝐿
𝑑𝑖
= length diameter ratio
𝜌 =liquid density
∆𝑃𝑡 = 𝑁𝑝 × (8 × 𝑗𝑓 ×
𝐿
𝑑𝑖
+ 2.5) (
𝜌 × 𝑣2
2
)
∆𝑃𝑡 = 2 × (8 × 0.095 ×
3
0.018
+ 2.5) (
511.28 × 0.712
2
)
= 33448,32 N/m2
= 0.334 bar

37 | P a g e
Shell-side pressure drop:
∆𝑃𝑠 = 8 × 𝑗𝑓 ×
𝐷𝑠
𝑑𝑒
×
𝐿
𝐼𝐵
× (
𝜌 × 𝑣2
2
)
Where:
𝐷𝑠 = shell diameter
𝑑𝑒 = equivalent diameter
𝐿
𝐼𝐵
= length baffle spacing ratio
𝜌 =liquid density
∆𝑃𝑠 = 8 × 𝑗𝑓 ×
𝐷𝑠
𝑑𝑒
×
𝐿
𝐼𝐵
× (
𝜌 × 𝑣2
2
)
1 = 8 × 0.05 ×
0.19
0.02
×
3
0.095
× (
999.87 × 0.772
2
)
= 35856,63 N/m2
= 0,359 bar

38 | P a g e
CAPITAL COST OF THE CONSTRUCTED SHELL AND TUBE HEAT
EXCHANGER
Estimated cost of shell and tube heat exchanger:
Table 6: Estimated material cost
Estimated Material Costing
Materials Quantity Cost per heat exchanger Total Costing (Rands)
Carbon steel shell 1 R1 450,00 R145 000,00
Carbon steel tube 24 R3 672,00 R367 200,00
Baffles 32 R1 162,67 R116 266,67
Support brackets 12 R1 738,26 R173 826,00
Gaskets 2 R507,50 R50 750,00
Tie rod and Spacers 2 R260,71 R26 071,00
Fixed head 1 R115,71 R11 571,00
Channel cover 1 R278,26 R27 825,50
Sealant 1 R50,00 R5 000,00
Total Cost R9 235,10 R923 510,17
The above table shows quantities and pricing of the materials used to put together the designed
heat exchanger. The last column shows the total capital cost of materials required to start
production of 100 units. The above pricing of materials was obtained in reference to Incledon,
Alibaba.com, Gumtree and Shandong Vast Industry Co.Ltd .These companies and sales
platforms give an estimated costing of the materials, since the currency used in relation is US
Dollars as compared to South African Rands.

39 | P a g e
Table 7: Labour costing
Labour costing
Number of employees 50
Hourly wages R55,50
Hours worked per day 8
Labour cost per day R22 200,00
Labour cost per heat exchanger R222,00
Total per month R666 000,00
The above table shows an estimated costing of manual labour required to put together the heat
exchangers. An estimated 50 employees are to be employed which allocates one employee to
complete the build of 2 heat exchangers a day. The maximum working hours per employee is
8 hours a day. This suggests an approximate of 4 hours to assemble 1 heat exchanger. The
hourly wages per employee is estimated to be R55.50 per hour. It is calculated that the total
labour cost per day is R22 200.00 to build 100 heat exchangers. Thus, the labour cost to build
one heat exchanger is calculated to be R 222.00. The total labour cost for a 30-day month is
calculated to be R 666 000.00. the above costing is an estimate and is subject to change in
accordance to the number of employees employed, overtime working hours and annual bonuses
and incentives.
Table 8: Total cost of one heat exchanger
Total cost to produce one heat exchanger
Material cost per heat exchanger produced R9 235,10
Labour cost per heat exchanger produced R222,00
Total cost to produce 1 heat exchanger R9 457,10
The above table shows the total costing of the production of one heat exchanger. This is the
sum of material costs and labour cost. Material costs amount to R 9 235.10, while labour costs
amount to R222.00 this adds up to R 9 457.10. Cost of one unit can change due to exchange
rates since some materials are imported and the currency in consideration is US dollars as
compared to South African Rands. Availability of materials from a certain supplier can also
affect the costing of the materials in future.

40 | P a g e
THE EXPECTED PAYBACK PERIOD FOR THE PROJECT
Table 9: Payback period of investment
Payback period of 100 heat exchangers produced
Total cost 100 units R945 710,17
Selling price excl. vat 100 units R1 418 565,25
Selling price incl. vat 100 units R1 631 350,04
Investment into business 100 units R945 710,17
Annual sales 50 units R815 675,02
Payback period (years) 1,16
The above table shows the calculation of the payback period for an investment to produce 100
heat exchangers. The total cost of the heat exchangers is calculated to be R 945 710.17 for 100
units. The chosen mark-up for each unit is estimated to be 50%. This gives a selling price of R
1 418 565.25 for 100 units excluding VAT. The equation used to calculate mark-up is shown
below.
𝑠𝑒𝑙𝑙𝑖𝑛𝑔 𝑝𝑟𝑖𝑐𝑒 𝑒𝑥𝑐𝑙. 𝑉𝐴𝑇 = (𝑐𝑜𝑠𝑡 𝑝𝑟𝑖𝑐𝑒 × 𝑚𝑎𝑟𝑘 − 𝑢𝑝) + 𝑐𝑜𝑠𝑡 𝑝𝑟𝑖𝑐𝑒
According to South African Law in the new section 50(70) incorporated into the VAT Act No.
89 of 1991 the Value Added Tax on goods produced is 15%. This is a must to be added to the
selling price of goods produced. The equation used is shown below.
𝑠𝑒𝑙𝑙𝑖𝑛𝑔 𝑝𝑟𝑖𝑐𝑒 𝑖𝑛𝑐𝑙. 𝑉𝐴𝑇 = (𝑠𝑒𝑙𝑙𝑖𝑛𝑔 𝑝𝑟𝑖𝑐𝑒 𝑒𝑥𝑐𝑙. 𝑉𝐴𝑇 × 0.15) + 𝑠𝑒𝑙𝑙𝑖𝑛𝑔 𝑝𝑟𝑖𝑐𝑒 𝑒𝑥𝑐𝑙. 𝑉𝐴𝑇
Thus, the selling price including VAT is R 1 631 350.04 for 100 heat exchangers produced. It
is assumed that 50 units get sold in the first year. This amounts to a payback of 1.16 years or 1
year and 2 months. The equation used to calculate the payback period is shown below.
𝑃𝑎𝑦𝑏𝑎𝑐𝑘 𝑝𝑒𝑟𝑖𝑜𝑑 (𝑦𝑒𝑎𝑟𝑠) =
𝐼𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡
𝐴𝑛𝑢𝑎𝑙 𝑠𝑎𝑙𝑒𝑠

41 | P a g e
OCCUPATIONAL HEALTH AND PROCESS SAFETY ASPECTS
All potential occupational health and process hazards identified:
Safety health hazards are said to be dependent on two main factors, namely type of material an
associate is in contact with and its toxicity and the duration of contact or duration of time in
that region. The occupational health and safety study are done to determine possible risks
associated with a specific process, equipment or product. Certain scenarios in relation to the
plant, process or equipment are analysed. For the heat exchanger of consideration, the materials
of construction have an influence on the safety and hazard study. The hazards associated with
the specific materials are discussed below.
Material of construction: Carbon Steel and Galvanised Stainless Steel
Hazards posed:
• Carbon steel product do not generally pose a safety hazard as per OSHA regulation.
However small particles generated through welding, sawing and filing are produced.
These particles when in contact with skin or inhaled may cause irritation and/or become
a contact hazard.
• Particles may cause damage to respiratory organs as a result of prolonged exposure.
• Allergic reactions may occur due to metal composition
• Swallowing of small particles found in the air may result in a serious health hazard,
especially through the digestive tract.
Material of construction: Carbon Graphite
Hazards posed:
• Material does not contain any hazardous chemicals and elements that are known to be
hazardous as per the OSHA regulation. However small particles that become respirable
can cause coughing and difficulty in breathing if saturated in air.
• Extensive exposure over long periods can lead to chronic illness such as bronchitis,
pulmonary fibrosis and other respiratory disorders.
• If material comes in to contact with skin, it can cause an allergic reaction or skin
irritation.
• If material comes into contact with eyes can cause eye irritation or acute blindness.

42 | P a g e
Apart from materials of construction the designed shell and tube heat exchanger may have
hazards that could occur during production of the product and during operation of the product.
These potential hazards are presented as follows:
• Exceeding flowrates through the heat exchanger may cause an increase in pressure and
thus pressurise the equipment. The equipment may burst if this highly pressurised state
is maintained.
• Excessive fouling may occur and cause blockages if unit is not maintained and cleaned
at adequate intervals.
• Inadequate training of employees can lead to self-injury during assembly of heat
exchanger unit.
• Inadequate use of machinery can cause mishaps in the factory and injury to employees.
• Steel is a good heat and electricity conductor; this implies that the heat exchanger may
reach high temperature. As a safety consideration unknowledgeable persons or
employees that come into contact with this may receive burns depending on
temperature variations. This is in the even that insulation wares off due to ware and
tare.

43 | P a g e
Mitigation of all hazards are proposed:
Migration of hazards refer to the long-term prohibition of injury. Thus, increasing safety of an
environment. The following are mitigation methods to proposed hazards associated with the
shell and tube heat exchanger:
• During the production process it is advised to use protective gear such as gloves, dust
masks and overalls. This is to prevent particles from being inhaled or contact of
particles on the skin that may cause irritation.
• Use of thermal insulation gear when working with the heat exchanger at high
temperatures this prevents possible burning to the skin.
• Strict regulations that prevent eating and drinking are implemented to avoid ingestion
of particles that can cause injury.
• Installation of ventilation systems and fume hoods remove excess fumes that may be
caused due to cutting and welding.
• Goggles are used to prevent irritation caused to the eyes by dust particles and welding
sparks.
• With regards to the heat exchanger unit, meters are to be used to monitor flowrates,
pressures and temperatures. These properties are monitored by the following meters
respectively: flowmeter, pressure gauge and thermocouple. These meters help maintain
safe operation of the unit.
• The installation of valves also helps control the flow through the system.
• Timeous maintenance of the heat exchanger unit will prevent excessive fouling through
the heat exchanger.
• Adequate training of staff before they can operate equipment can prevent any mishaps
during the process operation.
• Testing of equipment before sale can help correct any future hazards or discrepancies.

44 | P a g e
Determine the safety impact of the installation of the Shell and Tube Heat Exchanger:
The designed Shell and Tube heat exchanger is associated with high pressures and
temperatures. With these parameters are associated safety measures. This is certain with or
without the operation of the shell and tube heat exchanger. Upon installation of the STHE the
process stream pressures, temperatures and flowrates will be affected.
An analysis on the entire process is to be done to ensure these parameters are correctly
determined. Miscalculated parameters may affect the process operation as well as the operation
of the STHE. Improper variables pose a safety hazard. This is since the process variables may
exceed or precede the variable range suitable for operation by the designed STHE. Operating
the STHE out of the suitable range inhibits safety and operability issues. These include higher
or lower pressures and temperatures. These affect the material of construction and can cause
fracturing or worst case exploding or igniting of the STHE.
Shell and tube side streams also affect the ignition of any proposed explosions. High or low
flowrates of the streams may inhibit blockages or fractures of the STHE. High pressures and
flowrates may cause leakages at input and exit points on the heat exchanger. Unconcise variable
parameters may result in ware and tare of the STHE at a faster rate. This means that the STHE
is required to be maintained more often than required.
Apart from damage to the STHE these irregularities may affect the safety of operators and
employees. Thus, it is advised to provide adequate training to staff on the operability of the
STHE and the safety measures and precautions to take during its operation. When the STHE is
not in operation it is advised that the unit be drained of all process streams. This prevents any
excess fouling through the STHE and reduces the maintenance cycle.it is also advised to store
the STHE in a low or atmospheric pressurised environment and medium to low temperature
environment to prevent fracturing of materials of construction.
Safety features such as gauges and computer monitoring systems are advised to control the
operability parameters of the STHE. Although computerised systems are advised it is also
encouraged that occasional manual checks be done in the event of faulty equipment. In the
event a safety breach occurs this may cause injury and bodily harm to staff, may impact the
environment (toxic fumes released into the atmosphere) and associated process as well as cause
monetary loss to the business.

45 | P a g e
PART B: DESIGN OF SHELL AND TUBE HEAT EXCHANGER
USING ASPEN SIMULATION
Table 10: Showing input parameters entered into the simulation
HeatX
Name STHE
Hot side property method NRTL
Hot side use true species approach for electrolytes YES
Hot side free-water phase properties method STEAM-TA
Hot side water solubility method 3
Cold side property method NRTL
Cold side use true species approach for electrolytes YES
Cold side free-water phase properties method STEAM-TA
Cold side water solubility method 3
Exchanger specification 15
Units of exchanger specification C
Minimum temperature approach [C] 1
Hot side outlet pressure [bar] 0
Cold side outlet pressure [bar] 0
Inlet hot stream temperature [C] 27
Inlet hot stream pressure [bar] 1
Inlet hot stream vapor fraction 1
Outlet hot stream temperature [C] 15
Outlet hot stream pressure [bar] 1
Outlet hot stream vapor fraction 1
Inlet cold stream temperature [C] 5
Inlet cold stream pressure [bar] 1
Inlet cold stream vapor fraction 0
Outlet cold stream temperature [C] 6,80205318
Outlet cold stream pressure [bar] 1
Outlet cold stream vapor fraction 0
The above table shows all input variables entered into the Aspen simulation. These parameters
are the same as those used in the manual and excel calculation in the design process. All
parameters highlighted in grey are the input variables used in the manual calculation. These
are namely the inlet and out temperatures of propylene, 27°C and 15°C respectively and inlet
and outlet temperatures of cooling water, 5°C and 6.8°C respectively. These variables are stated
in the problem statement of the prospective design for the shell and tube heat exchanger. Thus,
it is justified to use these parameters. For hot stream inputs propylene properties was used and
for cold stream inputs water properties was used.

46 | P a g e
Table 11: showing results obtained from Aspen simulation
Thermal properties Results Units
Calculated heat duty 20,32149 kW
Required exchanger area 1,648076 sqm
Actual exchanger area 1,648076 sqm
Percent over (under) design 0
Average U (Dirty) 850 J/sec-sqm-K
UA 1400,864 J/sec-K
LMTD (Corrected) 14,50639 C
LMTD correction factor 1
Number of shells in series 1
The above table shows the results obtained from the aspen simulation these results calculated
are the heat duty, heat exchanger area, heat transfer coefficient and log mean temperature
difference. From the results obtained as compared to the results calculated, parameters such as
the overall heat transfer coefficient is quite different. This could be due to geometric properties
of the shell and tube heat exchanger which the simulation may not take into consideration.
Other factors include the one-shell, two-tube pass design selected. This simulation does not
account for changes through a two-tube pass shell and tube heat exchanger. The selected
rounded off values of baffles, baffle spacing and tube numbers for purposes of orientation may
have also been neglected in the simulated design. The geometric property of tube orientation
selected to be squared pitch may have not been considered during the simulation. Although
some variables are different, variables such as heat duty are similar in value with, he calculated
heat duty at 20 kW and the simulated heat duty at 20.32149 kW. The calculated log mean
temperature difference also is similar to that produced via the simulation. The calculated
LMTD is 14.54°C while the simulated LMTD is 14.509°C.

47 | P a g e
PART C: COMPARE THERMAL DESIGN AND ASPEN
SIMULATION OF SHELL AND TUBE HEAT EXCHANGER
Data Comparison:
Table 12: comparison of Excel and Aspen simulation
Variable Excel Manual Calculation Aspen Simulation Difference
Heat duty 20 kW 20.32149 kW 0.32149
Heat Exchanger Area 4.14 m2
1.648076 m2
2.49124
Overall heat transfer
coefficient
377.23 W/m2
. °C 850 W/m2
. °C 472.77
Log mean temperature
difference
14.54 °C 14.50639 °C 0.03361
From the above table of comparison of some of the main thermal properties calculated, a
difference of results is seen between Excel and Aspen calculations. For heat duty and LMTD
the difference in results is fairly small.in contrary the difference in results for the heat transfer
area and overall heat transfer coefficient is very high.
*Note: The Aspen simulation file can be found on the CD attached and the Aspen calculation
report can be found under the appendices.
Associated graphs:
The figure on the next page shows the temperature profile generated from the Aspen
simulation. The graph shows the change in temperature for counter current flow through the
heat exchanger. For this heat exchange design counter-current flow was selected, since this
type of flow allows for the a higher LMTD as compared to co-current flow. This type of flow
is also preferable when working with a one-shell two-tube pass heat exchanger.

48
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Block STHE:TQ Curves
Duty cal/sec
Temperatu
re
C
0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500 3750 4000 4250 4500 4750 5000
5.0
7.5
10.0
12.5
15.0
17.5
20.0
22.5
25.0
27.5
INLET Cold stream
INLET Hotstream
Figure 8: shows the temperature profile graph generated by the Aspen simulation

49 | P a g e
Discussion of ASPEN Simulation:
Aspen simulation has calculated a heat duty of 20.32 kW. This thermal energy is the required
amount to cool the hot propylene stream, coming from the 100 supercomputers, at 27°C. This
amount of energy cools the propylene to 15°C. The area through which this heat transfer takes
place is simulated to be 1.65 m2
. This value is different from the value calculated through excel
which is 4.14 m2
. The overall heat transfer coefficient is dependent upon the area of heat
transfer. Thus, the heat transfer coefficient simulated is different from the heat transfer
calculated on excel. The variance occurred through the geometric properties of the heat
exchanger. With regards to the LMTD the value simulated by Aspen is 14.506 °C, this is similar
to that calculated by Excel. The values show minimal difference since they are dependant only
on the input and output temperatures, as well as the type of flow (in this case counter current)
and not the geometric properties of the shell and tube heat exchanger. The overall heat transfer
coefficient is thus dependant on the three parameters namely, heat duty, area through which
heat transfer takes place and LMTD. It is justified as to why the overall heat transfer coefficient
is simulated to be 850 W/m2
. °C
Discussion of Theoretical Design:
The theoretical design for the STHE is based on the Kern method approach. The calculations
are iterated on Excel using formula auditing. This design is based on justified assumptions
which allowed for the calculation of required parameters. Assumed parameters are as follows:
overall heat transfer coefficient, tube inner diameter and outer diameter, shell thickness and
tube length. The type of STHE is also assumed to be one-shell pass and two-tube pass design.
The outlet cooling water temperature was determined by assuming the heat loss is equal to the
heat gain. This gives a value of 6.71°C. It is also assumed that the heat exchanger operates at
a counter current system. The log mean temperature is calculated to be 14.54°C. Which is fairly
similar to the value simulated through Aspen. The area of heat transfer calculated to be 14.4m2
by Excel is dependant on the assumed length and diameters.
The overall heat transfer is 350 W/m2
. °C and the iterated value calculated is 377.36 W/m2
. °C.
Thus, it is determined that the assumption is fairly correct and due to minor errors in rounding
off there is a 7.25% difference. The heat transfer coefficient is understood to be directly
dependent on the area of heat transfer and the LMTD.

50 | P a g e
CONCLUSION AND RECOMMENDATIONS
This project aimed at designing a shell and tube heat exchanger for the purpose of cooling a
100 supercomputers circuits. The selected method of approach was the kerns method of design.
The type of STHE selected is the one-shell two-tube pass heat exchanger. From the design of
this heat exchanger it is clear that there is a wealth of information on how to design and simulate
design a heat exchanger. Much of the method was done by reasonable assumption and as a
result may be subject to error.
The selected fluid for shell side flow was cooling water while the selected fluid for tube side
flow was liquid propylene. Heat transfer occurs at two phases on the liquid propylene. Phase
one heat is transferred from the supercomputers to the propylene while the second is heat
transfer from propylene to the cooling water. The cooled propylene is then recycled into the
system.
With regards to software analysis, multiple obstacles were faced throughout the project. This
is since there a various perspectives in which this design may be foreseen. The use of Aspen
was a particularly difficult task as there were multiple parameters to standardize as well as a
variety of simulations to choose from. The method of costing subject to Excel was through
standardizing and quantifying of prices and as a result involved multiple assumptions of its
own. Costing is affected by markets and exchange rates thus increasing dependency of currency
on the cost and payback period calculated. The construction of the STHE is largely dependent
on the figures of costing determined.
The implications associated with the STHE have been investigated trough a safety and hazard
analysis. These assist in the safety of the unit without any implications during construction. A
safety analysis is important in designing any unit this allows for smooth operation and the
ability for the unit to fulfil its required task.
It is recommended that this design have more given parameters since multiple assumptions
may result in design failure. Converging of assumptions do not generally correlate with the
final result hence causing a loop in defined geometric and thermal properties. Multiple designs
are suggested to be tested for the given scenario thus increasing the chances of operability
through safety. Investigation into eco-friendly and cost-efficient materials are also
recommended to stand by codes that abide by environmental impact.

51 | P a g e
REFERENCES
Anon.2019.
Available: https://www.pdhonline.com
(Accessed: 20 October 2019)
Anon.2019.
Available: https://www.erpublication.org
(Accessed: 15 October 2019)
Anon. 2009.
Available: http://www.oocities.org/ucoproject/info.htm
(Accessed 26 October 2019)
Anon. 2019. Pricing-a-product.
Available: https://www.entrepreneur.com/encyclopedia/pricing-a-product
Cengal,Y.A. 2006. Heat and mass transfer: Fundamentals and applications: Properties. 5th ed.
McGraw-Hill
Engineering toolbox. 2019.
Available: https://www.engineeringtoolbox.com
Gleeson, P. 2019. Calculating labour costs.
Available: https://smallbusiness.chron.com/calculate-labor-cost-661.html
Kenton, W. 2019. Capital cost.
Available: https://www.investopedia.com/terms/c/costofcapital.asp
(Accessed 28 September 2019)
Sinnott,R.K. 2005. Coulson and Richardson: Chemical Engineering Design. 4th ed. Oxford
weldit. 2013.
Available: https://weldit.com/wp-content/uploads/2013/01/ThermalConductivity-of-Metalts-Non-
Metals-and-Alloys.png

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APPENDICIES
Isometric
drawing:
PROPYLENE OUT
PROPYLENE IN
COOLING
WATER
IN
COOLING
WATER
OUT
10 000
kg/hr
5 Degrees
Celsius
10 000
kg/hr
6.71 Degrees
Celsius 4 000
kg/hr
27 Degrees
Celsius
4 000
kg/hr
15 Degrees
Celsius
Piping and Instrumentation Diagram
One-Shell pass, Two-Tube pass Shell and Tube
Heat Exchanger
Chemical Engineering Design 2B
Tasmiyah Ismail - 21807952

53 | P a g e
Isometric Drawing of STHE- AutoCad:
*AutoCad DWG file is attached on CD
KEY:
NAVY-COOLING
WATER
IN
RED-COOLING
WATER
OUT
TURQUISE-MIXING
FROM
TUBE
PASS
ONE
TO
TUBE
PASS
TWO

54 | P a g e
Design Aspects-EXCEL:
Mass Flowrate, ms 10000,00 kg/hr
2,78 kg/s
Inlet Temperature, T1 5,00 °C
Outlet Temperature, T2 6,71 °C
Specific heat of water, Cp 4,21 kJ/kg.K
Heat duty of water, Q 20,00 kW
Mass Flowrate, mt 4000,00 kg/hr
1,11 kg/s
Inlet Temperature, t1 27,00 °C
Outlet Temperature, t2 15,00 °C
Specific heat of propylene, Cp 1,50 kJ/kg.K
Heat duty of propylene ,Q 20,00 kW
INLET MEAN OUTLET
Temperature 5,00 5,86 6,71 °C
Specific Heat 4,205 4,203 4,201 kJ/kg,K
k 5,71E-01 5,73E-01 5,74E-01 W/m.K
Density 999,90 999,87 999,83 kg/m^3
Dynamic Viscosity 1,52E-03 1,48E-03 1,45E-03 kg/m.s
INLET MEAN OUTLET
Temperature 27 21 15 °C
Specific Heat 2,690 2,630 2,570 kJ/kg,K
k 9,09E-02 0,09243 9,40E-02 W/m.K
Density 501,2 511,28 521,36 kg/m^3
Dynamic Viscosity 9,03E-05 9,38E-05 9,74E-05 kg/m.s
Log mean temperature difference 14,54 °C
R 7,015 S 0,08431
Fouling correction factor (Ft) 0,95
Average Mean temperature 13,82 °C
AVERAGE TEMPERATURE
SHELL SIDE PROPERTIES
PHYSICAL PROPERTIES OF SHELL SIDE FLUID - CHILLED WATER
TUBE SIDE PROPERTIES
PHYSICAL PROPERTIES OF TUBE SIDE FLUID -PROPYLENE
LOG MEAN TEMPERATURE DIFFERENCE

55 | P a g e
Material use for Shell Carbon Steel
Material use for Tubes Carbon Steel
Tube Outer Diameter 20 mm
Tube Length 3 m
Square pitch 25 mm
Tube Inner Diameter 18 mm
Actual tube length 12 m
Tube wall thickness 2 mm
Shell pass 1 pass
Tube pass 2 pass
Estimated overall heat transfer coefficient - Uo 350 W/m^2°C
Provisional area 4,14 m^2
Area of One tube 0,19 m^2
Number of Tubes 21,94
*closest approximate for tube geometry 24 tubes
Number of Tubes per pass 12 tubes
Tube cross-section area 2,54E-04 m^2
Area per pass 3,05E-03 m^2
Volumetric Flowrate 2,17E-03 m^3/s
Tube Side Velocity 0,71 m/s
TUBE DATA
ESTIMATE LAYOUT
ESTIMATE OVERALL HEAT TRANSFER COEFFICIENT

56 | P a g e
K1 0,156 n1 2,291
Bundle Diameter 180 mm
Bundle-Shell Clearence 10 mm
Shell inner Diameter 190 mm
Wall thickness of shell 10 mm
Reynolds number, Re 69795,25
Prandtl number ,Pr 2,67012
Length diameter ratio, L/dt 166,6667
Heat transfer factor, Jh 0,00667
Nusselt number , Nu 643,7346
Heat transfer coefficient for the tube side fluid ,hi 3305,577 W/m^2.°C
Baffle Spacing ,IB 95 mm
Equivalent diameter , de 19,75 mm
Volumetric flowrate on shell-side 0,002778 m^3/s
Area of shell side heat transfer , As 3616,31 mm^2
0,003616 m^2
Shell-side velocity 0,77 m/s
0,8
Number of baffles 31,55
32
Mean temperature of water 5,86 °C
Equivalent diameter, de 19,75 mm
Shell-side velocity 0,77 m/s
Heat transfer coefficient for shell-side fluid 2747,87 W/m^2.°C
BUNDLE & SHELL DATA
TUBE SIDE HEAT TRANSFER COEFFICIENT
BAFFLE SPACING & SHELL SIDE VELOCITY
SHELL SIDE HEAT TRANSFER COEFFICIENT

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ho 2747,87 W/m^2.°C
hi 3305,58 W/m^2.°C SUM:
hod 700 W/m^2.°C 0,00199165
hid 3000 W/m^2.°C 2,3413E-05
kw 45 W/m.°C 0,00063585
0,00265092
di(tube) 18 mm
do(tube) 20 mm
ln ratio 1,11
1/Uo 0,00265 m^2.°C/W
Uo 377,23 W/m^2.°C
Length, L 3 m
Inner diameter, di 0,018 m
Density , ρ 511,28 kg/m^3
Velocity , v 0,712 m/s
jf 0,095
Np 2
∆Pt 33448,32 N/m^2
0,334 bar
Length , L 3 m
lB 0,095 m
Density, ρ 999,87 kg/m^3
Velocity, v 0,77 m/s
jf 0,05
Ds 0,190 m
de 0,020 m
∆Ps 35856,63 N/m^2
0,359 bar
SHELL SIDE PRESSURE DROP
∆Ps = 8 x jf x (Ds/de) x (L/lB) x (ρ x v^2/2)
CALCULATED OVERALL HEAT TRANSFER COEFFICIENT
TUBESIDE PRESSURE DROP
∆Pt = Np x (8 x jf x (L/di) + 2.5)(ρ x v^2/2)

58 | P a g e
Costing-EXCEL:
Materials Quantity Cost per heat exchanger Total costing rands
Carbon steel shell 1 R1 450,00 R145 000,00
Carbon steel tube 24 R3 672,00 R367 200,00
Baffles 32 R1 162,67 R116 266,67
Support brackets 12 R1 738,26 R173 826,00
Gaskets 2 R507,50 R50 750,00
Tie rod and Spacers 2 R260,71 R26 071,00
Fixed head 1 R115,71 R11 571,00
Channel cover 1 R278,26 R27 825,50
Sealant 1 R50,00 R5 000,00
Total Cost R9 235,10 R923 510,17
* costing was references from Incledon, Gumtree, Alibaba and Shandong Vast Industry Co.Ltd.
50
R55,50
8
R22 200,00
R222,00
R666 000,00
Material cost per heat exchanger produced R9 235,10
Labour cost per heat exchanger produced R222,00
R9 457,10
Total cost 100 units R945 710,17
Selling price excl vat 100 units R1 418 565,25
Selling price incl vat 100 units R1 631 350,04
Inestment into business 100 units R945 710,17
Annual sales 50 units R815 675,02
Payback period (years) 1,16
Total cost to produce 1 heat exchanger
Estimated Material Costing
Labour costing
Total cost to produce 1 heat exchanger
Payback period of 100 heat exchangers produced
Number of employees
Hourly wages
Hours worked per day
Labour cost per day
Labour cost per heat exchanger
Total per month

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Stream compositions- Aspen:
Table 13: showing stream composition- generated by Aspen simulation
From STHE STHE
To STHE STHE
Stream Class CONVEN CONVEN CONVEN CONVEN
MIXED Substream
Phase Liquid Phase Vapor Phase Liquid Phase Vapor Phase
Temperature C 5 27 6,802053 15
Pressure bar 1 1 1 1
Molar Vapor Fraction 0 1 0 1
Molar Liquid Fraction 1 0 1 0
Molar Solid Fraction 0 0 0 0
Mass Vapor Fraction 0 1 0 1
Mass Liquid Fraction 1 0 1 0
Mass Solid Fraction 0 0 0 0
Molar Enthalpy cal/mol -68613,9 4862,874 -68582,4 4679,052
Mass Enthalpy cal/gm -3808,65 115,5608 -3806,9 111,1925
Molar Entropy cal/mol-K -40,1789 -33,8445 -40,067 -34,4695
Mass Entropy cal/gm-K -2,23027 -0,80428 -2,22406 -0,81913
Molar Density mol/cc 0,056233 4,01E-05 0,056138 4,17E-05
Mass Density gm/cc 1,013048 0,001686 1,011344 0,001756
Enthalpy Flow cal/sec -1,1E+07 128400,9 -1,1E+07 123547,2
Average MW 18,01528 42,08064 18,01528 42,08064
Mole Flows kmol/hr 555,0844 95,05559 555,0844 95,05559
Mass Flows kg/hr 10000 4000 10000 4000
Volume Flow l/min 164,52 39535,93 164,7972 37955,29

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Aspen Plus Calculation Report:
ASPEN PLUS IS A TRADEMARK OF HOTLINE:
ASPEN TECHNOLOGY, INC. U.S.A. 888/996-7100
781/221-6400 EUROPE (44) 1189-226555
PLATFORM: WIN-X64 OCTOBER 31, 2019
VERSION: 37.0 Build 395 THURSDAY
INSTALLATION: 8:31:56 A.M.
ASPEN PLUS PLAT: WIN-X64 VER: 37.0 10/31/2019 PAGE I
ASPEN PLUS (R) IS A PROPRIETARY PRODUCT OF ASPEN TECHNOLOGY, INC.
(ASPENTECH), AND MAY BE USED ONLY UNDER AGREEMENT WITH ASPENTECH.
RESTRICTED RIGHTS LEGEND: USE, REPRODUCTION, OR DISCLOSURE BY THE
U.S. GOVERNMENT IS SUBJECT TO RESTRICTIONS SET FORTH IN
(i) FAR 52.227-14, Alt. III, (ii) FAR 52.227-19, (iii) DFARS
252.227-7013(c)(1)(ii), or (iv) THE ACCOMPANYING LICENSE AGREEMENT,
AS APPLICABLE. FOR PURPOSES OF THE FAR, THIS SOFTWARE SHALL BE DEEMED
TO BE "UNPUBLISHED" AND LICENSED WITH DISCLOSURE PROHIBITIONS.
CONTRACTOR/SUBCONTRACTOR: ASPEN TECHNOLOGY, INC. 20 CROSBY DRIVE,
BEDFORD, MA 01730.

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TABLE OF CONTENTS
RUN CONTROL SECTION.................................... 1
RUN CONTROL INFORMATION........................... 1
FLOWSHEET SECTION...................................... 2
FLOWSHEET CONNECTIVITY BY STREAMS................. 2
FLOWSHEET CONNECTIVITY BY BLOCKS.................. 2
COMPUTATIONAL SEQUENCE............................ 2
OVERALL FLOWSHEET BALANCE......................... 2
PHYSICAL PROPERTIES SECTION............................ 3
COMPONENTS........................................ 3
U-O-S BLOCK SECTION.................................... 4
BLOCK: STHE MODEL: HEATX..................... 4
HEATX COLD-TQCU STHE TQCURV INLET............. 7
HEATX HOT-TQCUR STHE TQCURV INLET............. 8
STREAM SECTION......................................... 9
COLD-IN COLD-OUT HOT-IN HOT-OUT................... 9
PROBLEM STATUS SECTION................................. 10
BLOCK STATUS...................................... 10

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ASPEN PLUS PLAT: WIN-X64 VER: 37.0 10/31/2019 PAGE 1
RUN CONTROL SECTION
RUN CONTROL INFORMATION
-----------------------
THIS COPY OF ASPEN PLUS LICENSED TO DURBAN UNIVERSITY OF TEC
TYPE OF RUN: NEW
INPUT FILE NAME: _2628phs.inm
OUTPUT PROBLEM DATA FILE NAME: _2628phs
LOCATED IN:
PDF SIZE USED FOR INPUT TRANSLATION:
NUMBER OF FILE RECORDS (PSIZE) = 0
NUMBER OF IN-CORE RECORDS = 256
PSIZE NEEDED FOR SIMULATION = 256
CALLING PROGRAM NAME: apmain
LOCATED IN: C:Program FilesAspenTechAspen Plus V11.0Enginexeq
SIMULATION REQUESTED FOR ENTIRE FLOWSHEET

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FLOWSHEET SECTION
FLOWSHEET CONNECTIVITY BY STREAMS
---------------------------------
STREAM SOURCE DEST STREAM SOURCE DEST
COLD-IN ---- STHE HOT-IN ---- STHE
HOT-OUT STHE ---- COLD-OUT STHE ----
FLOWSHEET CONNECTIVITY BY BLOCKS
--------------------------------
BLOCK INLETS OUTLETS
STHE HOT-IN COLD-IN HOT-OUT COLD-OUT
COMPUTATIONAL SEQUENCE
----------------------
SEQUENCE USED WAS:
STHE
OVERALL FLOWSHEET BALANCE
-------------------------
*** MASS AND ENERGY BALANCE ***
IN OUT RELATIVE DIFF.
CONVENTIONAL COMPONENTS (KMOL/HR )
WATER 555.084 555.084 0.00000
PROPY-01 95.0556 95.0556 0.00000

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TOTAL BALANCE
MOLE(KMOL/HR ) 650.140 650.140 0.00000
MASS(KG/HR ) 14000.0 14000.0 0.00000
ENTHALPY(CAL/SEC ) -0.104512E+08 -0.104512E+08 0.178223E-15
*** CO2 EQUIVALENT SUMMARY ***
FEED STREAMS CO2E 0.00000 KG/HR
PRODUCT STREAMS CO2E 0.00000 KG/HR
NET STREAMS CO2E PRODUCTION 0.00000 KG/HR
UTILITIES CO2E PRODUCTION 0.00000 KG/HR
TOTAL CO2E PRODUCTION 0.00000 KG/HR

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PHYSICAL PROPERTIES SECTION
COMPONENTS
----------
ID TYPE ALIAS NAME
WATER C H2O WATER
PROPY-01 C C3H6-2 PROPYLENE

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U-O-S BLOCK SECTION
BLOCK: STHE MODEL: HEATX
-----------------------------
HOT SIDE:
---------
INLET STREAM: HOT-IN
OUTLET STREAM: HOT-OUT
PROPERTY OPTION SET: NRTL RENON (NRTL) / IDEAL GAS
COLD SIDE:
----------
INLET STREAM: COLD-IN
OUTLET STREAM: COLD-OUT
*** MASS AND ENERGY BALANCE ***
IN OUT RELATIVE DIFF.
TOTAL BALANCE
MOLE(KMOL/HR ) 650.140 650.140 0.00000
MASS(KG/HR ) 14000.0 14000.0 0.00000
ENTHALPY(CAL/SEC ) -0.104512E+08 -0.104512E+08 0.178223E-15
*** CO2 EQUIVALENT SUMMARY ***
FEED STREAMS CO2E 0.00000 KG/HR
PRODUCT STREAMS CO2E 0.00000 KG/HR
NET STREAMS CO2E PRODUCTION 0.00000 KG/HR
UTILITIES CO2E PRODUCTION 0.00000 KG/HR
TOTAL CO2E PRODUCTION 0.00000 KG/HR

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*** INPUT DATA ***
FLASH SPECS FOR HOT SIDE:
TWO PHASE FLASH
MAXIMUM NO. ITERATIONS 30
CONVERGENCE TOLERANCE 0.000100000
FLASH SPECS FOR COLD SIDE:
TWO PHASE FLASH
MAXIMUM NO. ITERATIONS 30
CONVERGENCE TOLERANCE 0.000100000
FLOW DIRECTION AND SPECIFICATION:
COUNTERCURRENT HEAT EXCHANGER
SPECIFIED HOT OUTLET TEMP
SPECIFIED VALUE C 15.0000
LMTD CORRECTION FACTOR 1.00000

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U-O-S BLOCK SECTION
BLOCK: STHE MODEL: HEATX (CONTINUED)
PRESSURE SPECIFICATION:
HOT SIDE PRESSURE DROP BAR 0.0000
COLD SIDE PRESSURE DROP BAR 0.0000
HEAT TRANSFER COEFFICIENT SPECIFICATION:
HOT LIQUID COLD LIQUID CAL/SEC-SQCM-K 0.0203
HOT 2-PHASE COLD LIQUID CAL/SEC-SQCM-K 0.0203
HOT VAPOR COLD LIQUID CAL/SEC-SQCM-K 0.0203
HOT LIQUID COLD 2-PHASE CAL/SEC-SQCM-K 0.0203
HOT 2-PHASE COLD 2-PHASE CAL/SEC-SQCM-K 0.0203
HOT VAPOR COLD 2-PHASE CAL/SEC-SQCM-K 0.0203
HOT LIQUID COLD VAPOR CAL/SEC-SQCM-K 0.0203
HOT 2-PHASE COLD VAPOR CAL/SEC-SQCM-K 0.0203
HOT VAPOR COLD VAPOR CAL/SEC-SQCM-K 0.0203
*** OVERALL RESULTS ***
STREAMS:
--------------------------------------
| |
HOT-IN ----->| HOT |-----> HOT-OUT
T= 2.7000D+01 | | T= 1.5000D+01
P= 1.0000D+00 | | P= 1.0000D+00
V= 1.0000D+00 | | V= 1.0000D+00
| |

69 | P a g e
COLD-OUT <-----| COLD |<----- COLD-IN
T= 6.8021D+00 | | T= 5.0000D+00
P= 1.0000D+00 | | P= 1.0000D+00
V= 0.0000D+00 | | V= 0.0000D+00
--------------------------------------
DUTY AND AREA:
CALCULATED HEAT DUTY CAL/SEC 4853.7036
CALCULATED (REQUIRED) AREA SQM 1.6481
ACTUAL EXCHANGER AREA SQM 1.6481
PER CENT OVER-DESIGN 0.0000
HEAT TRANSFER COEFFICIENT:
AVERAGE COEFFICIENT (DIRTY) CAL/SEC-SQCM-K 0.0203
UA (DIRTY) CAL/SEC-K 334.5907
LOG-MEAN TEMPERATURE DIFFERENCE:
LMTD CORRECTION FACTOR 1.0000
LMTD (CORRECTED) C 14.5064
NUMBER OF SHELLS IN SERIES 1
PRESSURE DROP:
HOTSIDE, TOTAL BAR 0.0000
COLDSIDE, TOTAL BAR 0.0000

70 | P a g e
U-O-S BLOCK SECTION
BLOCK: STHE MODEL: HEATX (CONTINUED)
*** ZONE RESULTS ***
TEMPERATURE LEAVING EACH ZONE:
HOT
-------------------------------------------------------------
| |
HOT IN | VAP | HOT OUT
------> | |------>
27.0 | | 15.0
| |
COLDOUT | LIQ | COLDIN
<------ | |<------
6.8 | | 5.0
| |
-------------------------------------------------------------
COLD
ZONE HEAT TRANSFER AND AREA:
ZONE HEAT DUTY AREA LMTD AVERAGE U UA
CAL/SEC SQM C CAL/SEC-SQCM-K CAL/SEC-K
1 4853.704 1.6481 14.5064 0.0203 334.5907

71 | P a g e
U-O-S BLOCK SECTION
HEATX COLD-TQCU STHE TQCURV INLET
-------------------------------------
PRESSURE PROFILE: CONSTANT2
PRESSURE DROP: 0.0 BAR
-----------------------------------------------------
! DUTY ! PRES ! TEMP ! VFRAC !
! ! ! ! !
! ! ! ! !
! ! ! ! !
! CAL/SEC ! BAR ! C ! !
! ! ! ! !
!============!============!============!============!
! 0.0 ! 1.0000 ! 6.8020 ! 0.0 !
! 231.1287 ! 1.0000 ! 6.7163 ! 0.0 !
! 462.2575 ! 1.0000 ! 6.6305 ! 0.0 !
! 693.3862 ! 1.0000 ! 6.5447 ! 0.0 !
! 924.5150 ! 1.0000 ! 6.4589 ! 0.0 !
!------------+------------+------------+------------!
! 1155.6437 ! 1.0000 ! 6.3732 ! 0.0 !
! 1386.7724 ! 1.0000 ! 6.2874 ! 0.0 !
! 1617.9012 ! 1.0000 ! 6.2016 ! 0.0 !
! 1849.0299 ! 1.0000 ! 6.1158 ! 0.0 !
! 2080.1587 ! 1.0000 ! 6.0300 ! 0.0 !
!------------+------------+------------+------------!
! 2311.2874 ! 1.0000 ! 5.9442 ! 0.0 !

72 | P a g e
! 2542.4162 ! 1.0000 ! 5.8584 ! 0.0 !
! 2773.5449 ! 1.0000 ! 5.7726 ! 0.0 !
! 3004.6736 ! 1.0000 ! 5.6867 ! 0.0 !
! 3235.8024 ! 1.0000 ! 5.6009 ! 0.0 !
!------------+------------+------------+------------!
! 3466.9311 ! 1.0000 ! 5.5151 ! 0.0 !
! 3698.0599 ! 1.0000 ! 5.4292 ! 0.0 !
! 3929.1886 ! 1.0000 ! 5.3434 ! 0.0 !
! 4160.3173 ! 1.0000 ! 5.2576 ! 0.0 !
! 4391.4461 ! 1.0000 ! 5.1717 ! 0.0 !
!------------+------------+------------+------------!
! 4622.5748 ! 1.0000 ! 5.0859 ! 0.0 !
! 4853.7036 ! 1.0000 ! 5.0000 ! 0.0 !
-----------------------------------------------------

73 | P a g e
U-O-S BLOCK SECTION
HEATX HOT-TQCUR STHE TQCURV INLET
-------------------------------------
PRESSURE PROFILE: CONSTANT2
PRESSURE DROP: 0.0 BAR
-----------------------------------------------------
! DUTY ! PRES ! TEMP ! VFRAC !
! ! ! ! !
! ! ! ! !
! ! ! ! !
! CAL/SEC ! BAR ! C ! !
! ! ! ! !
!============!============!============!============!
! 0.0 ! 1.0000 ! 27.0000 ! 1.0000 !
! 231.1287 ! 1.0000 ! 26.4367 ! 1.0000 !
! 462.2575 ! 1.0000 ! 25.8725 ! 1.0000 !
! 693.3862 ! 1.0000 ! 25.3076 ! 1.0000 !
! 924.5150 ! 1.0000 ! 24.7419 ! 1.0000 !
!------------+------------+------------+------------!
! 1155.6437 ! 1.0000 ! 24.1754 ! 1.0000 !
! 1386.7724 ! 1.0000 ! 23.6081 ! 1.0000 !
! 1617.9012 ! 1.0000 ! 23.0400 ! 1.0000 !
! 1849.0299 ! 1.0000 ! 22.4711 ! 1.0000 !
! 2080.1587 ! 1.0000 ! 21.9013 ! 1.0000 !
!------------+------------+------------+------------!
! 2311.2874 ! 1.0000 ! 21.3308 ! 1.0000 !

74 | P a g e
! 2542.4162 ! 1.0000 ! 20.7594 ! 1.0000 !
! 2773.5449 ! 1.0000 ! 20.1873 ! 1.0000 !
! 3004.6736 ! 1.0000 ! 19.6143 ! 1.0000 !
! 3235.8024 ! 1.0000 ! 19.0404 ! 1.0000 !
!------------+------------+------------+------------!
! 3466.9311 ! 1.0000 ! 18.4657 ! 1.0000 !
! 3698.0599 ! 1.0000 ! 17.8902 ! 1.0000 !
! 3929.1886 ! 1.0000 ! 17.3139 ! 1.0000 !
! 4160.3173 ! 1.0000 ! 16.7367 ! 1.0000 !
! 4391.4461 ! 1.0000 ! 16.1587 ! 1.0000 !
!------------+------------+------------+------------!
! 4622.5748 ! 1.0000 ! 15.5798 ! 1.0000 !
! 4853.7036 ! 1.0000 ! 15.0000 ! 1.0000 !
-----------------------------------------------------

75 | P a g e
STREAM SECTION
COLD-IN COLD-OUT HOT-IN HOT-OUT
-------------------------------
STREAM ID COLD-IN COLD-OUT HOT-IN HOT-OUT
FROM : ---- STHE ---- STHE
TO : STHE ---- STHE ----
SUBSTREAM: MIXED
PHASE: LIQUID LIQUID VAPOR VAPOR
COMPONENTS: KMOL/HR
WATER 555.0844 555.0844 0.0 0.0
PROPY-01 0.0 0.0 95.0556 95.0556
TOTAL FLOW:
KMOL/HR 555.0844 555.0844 95.0556 95.0556
KG/HR 1.0000+04 1.0000+04 4000.0000 4000.0000
L/MIN 164.5200 164.7972 3.9536+04 3.7955+04
STATE VARIABLES:
TEMP C 5.0000 6.8021 27.0000 15.0000
PRES BAR 1.0000 1.0000 1.0000 1.0000
VFRAC 0.0 0.0 1.0000 1.0000
LFRAC 1.0000 1.0000 0.0 0.0
SFRAC 0.0 0.0 0.0 0.0
ENTHALPY:
CAL/MOL -6.8614+04 -6.8582+04 4862.8742 4679.0520
CAL/GM -3808.6501 -3806.9027 115.5608 111.1925
CAL/SEC -1.0580+07 -1.0575+07 1.2840+05 1.2355+05
ENTROPY:

76 | P a g e
CAL/MOL-K -40.1789 -40.0670 -33.8445 -34.4695
CAL/GM-K -2.2303 -2.2241 -0.8043 -0.8191
DENSITY:
MOL/CC 5.6233-02 5.6138-02 4.0071-05 4.1740-05
GM/CC 1.0130 1.0113 1.6862-03 1.7565-03
AVG MW 18.0153 18.0153 42.0806 42.0806

77 | P a g e
PROBLEM STATUS SECTION
BLOCK STATUS
------------
****************************************************************************
* *
* Calculations were completed normally *
* *
* All Unit Operation blocks were completed normally *
* *
* All streams were flashed normally *
* *
****************************************************************************

DESIGN_OF_A_SHELL_AND_2_TUBE_HEAT_EXCHAN.pdf

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DESIGN_OF_A_SHELL_AND_2_TUBE_HEAT_EXCHAN.pdf