ENGR4998U – CAPSTONE DESIGN PROJECT II Molten Salt Loop Heating System design Report
NDL-MSL-RPT-005
Prepared for: Dr. Glenn Harvel
Prepared by: Sungcheol (Eric) Choi (100406639)
Signature:
Date: April 10, 2015
EXECUTIVE SUMMARYThe purpose of the project is to create a design of the Molten Salt Loop (MSL) heating
system as per Capstone Design Project II under the Faculty of Energy System and
Nuclear Science. The project was performed under the supervision of Dr. Glenn Harvel
at the University of Ontario Institute of Technology. The project timeline was from
January 05, 2015 to April 10, 2015. The scope of the project is to design, procure, and
verify the MSL heating system. This report provides the design of the heating system to
melt FLiNaK and to create a natural circulation in the MSL. In order to melt the salt and
maintain the salt in a molten state, the heating system must provide high temperatures.
Furthermore, a natural circulation is created when there is a temperature difference
between the hot leg and the cold leg. High temperature heaters are required to achieve
the objective of the design project. The approach to procure high temperature heaters in
this project was to create design requirements and summarize advantages and
disadvantages of the heaters that meet the design requirements. A decision tree was
used to support selection of the MSL heaters. All components of the MSL heating
system was procured and the design was verified by experiments such as heating up
and cooling down after the procurement was arrived. This report includes a literature
review, design requirements, heater options, preliminary calculations, cost estimate,
heating system design, and verification to justify a design of the MSL heating system. In
addition, MATLAB codes for the preliminary calculations and experimental data are
attached in the appendix. The Capstone Design Project II was successfully completed.
ii
ACKNOWLEDGEMENTSThe success of the MSL heating system design would not have been possible without
the contributions and feedback of UOIT Faculty of Energy System and Nuclear Science
(FESNS) staff. I would like to thank Dr. Harvel for his support and direction throughout
the semester. I also thank Adam Lipchitz and Jeffrey Samuel for their support in
developing the MSL heating system design and Robert Ulrich for helping with the
procurement process. Moreover, without our group’s support and contributions, this
project would have been extremely difficult. I would like to give special thanks to
Sangeeth Ragunathan for his contribution to our group project, Regan Trolly for
constructing the MSL frame, and Kyle Watson for supporting the heating system design
verification. I would like to give the most thanks to my wife, Sarah, and her family for
their support and patience for the 7 years it took to complete the Capstone Design
Project which concludes the Bachelor of Engineering (Honours) - Nuclear Engineering
degree. Lastly, I would like to acknowledge Fiona, my 23 month old daughter, because
she is one of the most important reasons why I successfully completed this project.
iii
Table of ContentsEXECUTIVE SUMMARY.................................................................................................. ii
ACKNOWLEDGEMENTS................................................................................................ iii
TABLE OF FIGURES......................................................................................................vi
TABLE OF TABLES........................................................................................................vii
1. INTRODUCTION..........................................................................................................1
1.1 Objective.............................................................................................................1
1.2 Background.........................................................................................................1
1.3 Problem Statement.............................................................................................1
2 Literature Review.......................................................................................................2
2.1 Molten Salt Reactor............................................................................................2
2.2 Experimental Molten Salt Loop...........................................................................2
2.3 Steam Pipe.........................................................................................................4
3 DESIGN REQUIREMENTS.......................................................................................5
3.1 Vessel Heater.....................................................................................................5
3.1.1 Functional requirement.................................................................................5
3.1.2 Performance requirement.............................................................................5
3.1.3 Safety requirement.......................................................................................6
3.2 Pipe Heater.........................................................................................................6
3.2.1 Functional requirement.................................................................................6
3.2.2 Performance requirement.............................................................................6
3.2.3 Safety requirement.......................................................................................6
4 SUMMARY OF HEATERS AND INSULATION.........................................................7
4.1 Ultra-High Temperature Heating Tapes..............................................................7
iv
4.1.1 Advantages of high temperature heating tapes............................................8
4.1.2 Disadvantages of high temperature heating tapes.......................................8
4.2 Ceramic Fiber Heater..........................................................................................8
4.2.1 Advantages of ceramic fiber heater..............................................................9
4.2.2 Disadvantages of ceramic fiber heater.........................................................9
4.3 Cartridge heater..................................................................................................9
4.3.1 Advantages of cartridge heater....................................................................9
4.3.2 Disadvantages of cartridge heater................................................................9
4.4 Insulation...........................................................................................................10
4.4.1 Advantages of ceramic fiber blanket..........................................................10
5 PRELIMINARY CALCULATION..............................................................................12
5.1 Heat loss through an uninsulated pipe and insulated pipe................................12
5.2 Time to reach the operating temperature..........................................................13
6 COST ESTIMATION................................................................................................14
7 DESIGN OF HEATING SYSTEM............................................................................16
7.1 Vessel heater design........................................................................................16
7.2 Pipe heater design............................................................................................17
8 DESIGN VERIFICATION.........................................................................................18
9 CONCLUDING REMARKS......................................................................................24
10 REFERENCES.....................................................................................................25
11 APPENDIX...........................................................................................................28
11.1 Calculations...................................................................................................28
11.1.1 Heat loss of uninsulated pipe..................................................................28
11.1.2 Heat loss of insulated pipe......................................................................29
11.1.3 Time it require to heat up the pipe...........................................................30
v
11.1.4 Time it takes to cool down.......................................................................30
11.1.5 Extra calculation......................................................................................31
11.2 Matlab Code..................................................................................................31
11.2.1 Heat loss with insulation..........................................................................31
11.2.2 Heat loss without insulation.....................................................................33
11.2.3 Cooldown (15 minutes & 30 minutes).....................................................34
11.3 Matlab Result.................................................................................................35
11.3.1 Heat loss with insulation..........................................................................35
11.3.2 Heat loss without insulation.....................................................................36
11.3.3 Cool down (15 minutes & 30 minutes)....................................................36
11.4 Experiment Data............................................................................................37
TABLE OF FIGURESFigure 1: Molten Salt Loop layout [2]................................................................................3
Figure 2: Example of steam pipe.....................................................................................4
Figure 3: Decision tree for selecting heaters commercially available.............................11
Figure 4: A tape heater installed on the vessel..............................................................16
Figure 5: tape heater (0.5 inch wide and 8 inches long)................................................16
Figure 6: Molten Salt Loop.............................................................................................17
Figure 7: Pipe heater Design.........................................................................................17
Figure 8: Design verification experimental setup...........................................................18
Figure 9: Temperature increase chart for 15 minutes using 50% power of 627W.........19
Figure 10: Temperature decrease chart for 15 minutes.................................................19
Figure 11: Design verification experiment setup 2.........................................................20
Figure 12: Temperature increase in 30 minutes using 100% power of 627 W...............21
Figure 13: A temperature decrease chart for 30 minutes...............................................22
Figure 14: Surface temperature of the insulation (heating up experiment)....................23
vi
Figure 15: Surface temperature of the insulation (cool down)........................................23
Figure 16: Ultra-high temperature tape heater image after the experiments..................23
Figure 17: Insulation image after the experiment...........................................................23
Figure 18: insulated pipe example.................................................................................29
Figure 19: Heat loss with insulation................................................................................35
Figure 20: Heat loss without insulation...........................................................................36
Figure 21: Cool down (15 minutes & 30 minutes)..........................................................36
TABLE OF TABLESTable 1: Summary of heaters commercially available....................................................11
Table 2: The MSL heating system cost estimate...........................................................14
Table 3:Hastelloy properties..........................................................................................30
Table 4:50% power of 627 W heat up data....................................................................37
Table 5: Cool down for 15 minutes data.........................................................................38
Table 6: 100% power of 627 W heat up data.................................................................38
Table 7: Cool down for 30 minutes data.........................................................................40
vii
1. INTRODUCTION1.1 ObjectiveThe purpose of this report is to provide a detailed design of the Molten Salt Loop (MSL)
heating system. The objective of the design is to melt FLiNaK and to create a natural
circulation in the loop.
1.2 BackgroundIn the previous semester, the Capstone design project I focused on a conceptual design
of the MSL [1]. The MSL was designed due to our group’s interest in experimenting the
degradation methods of reactor components. In order to investigate the effects of aging
on reactor components and systems, an experimental apparatus such as the MSL was
required. It is expected that the MSL will provide a means to obtain experimental data
for the characteristics of molten salt. The conceptual design of the MSL was
successfully completed.
1.3 Problem StatementA Molten Salt Loop (MSL) is composed of heating, and piping systems including
instrumentation. It is important to maintain salt in the molten state when running the
MSL to conduct experiments. Also, the difference between the operating temperature of
the MSL, which is approximately 600 °C, and the ambient temperature, which is
approximately 24 °C, is very significant. Therefore, an adequate heating system is
required to provide heat to the MSL. In addition, the MSL heating system is required to
create a natural circulation in the loop. Currently, a conceptual design of the MSL is in
place [1]. However, a detailed design is proposed to complete the final design of the
heating system and procure the components for this project [2].
1
2 Literature Review2.1 Molten Salt ReactorA Molten Salt Reactor (MSR), which is one of the six Gen IV concepts, is unique
because its fuel is in a molten state of fluoride salt mixture of, typically lithium, beryllium
sodium or potassium fluorides [3]. The mixture is very stable under a highly radioactive
environment and has a low reactivity with air and water. More importantly, molten salt
mixtures provide high operating temperatures up to 1000 °C at near atmospheric
pressure [4]. In other words, molten salt mixtures offer higher thermal efficiency
compared to water. It is known that the Simple Brayton cycle is more effective than the
steam Rankine cycle when the temperature is above 600 °C. Not only does the molten
salt provide high efficiency, but also the size of the whole reactor system can be smaller
and more compact due to the homogenous structure in which high power density can
be achieved [4]. One of the advantages of using molten salt is that fuel, minor actinides
and the majority of fission products are dissolved in the carrier salt. In this way, Cesium-
137, which is a harmful fission product, is contained in the salt and Xenon-135 which
absorbs neutrons and causes problems, can be continuously filtered in a pump bowl
using on-line fuel reprocessing [4].
2.2 Experimental Molten Salt LoopThe MSR was developed in the 1950s at Oak Ridge National Laboratory (ORNL) in the
USA. ORNL has conducted various material studies on molten salt experiments and
identified that fluoride salts tend to be very corrosive in that even stainless steel cannot
withstand severe corrosion at high temperatures. Nickel based alloys such as Hastelloy
N alloy (composition: Ni- 71%, Mo-16%, Cr-7%) was determined to be more suitable for
molten salts [4]. Therefore, Hastelloy alloy was further developed in a few types of
testing loops with both natural and forced convection [4]. Numerous works of research,
including thermal hydraulic studies, development and evaluation of components (e.g.
pumps, seals, measuring devices, etc.), material compatibility studies and also
operating procedure proposals and verification, were performed using the molten salt
testing loops in which real operational condition (e.g. temperature and pressure flow) at
2
small scale arrangement were simulated [4]. Many experiments were completed in a
natural circulation loops because of its simplicity. A natural circulation occurs when
there is a temperature difference in a loop. Buoyancy force and gravity drive the molten
salt circulation due to the change of salt density at different temperatures. Heated salt
becomes less dense (thus lighter) and rises, whereas cooled salt becomes more dense
(thus heavier) and falls by gravity force. In order to ensure proper circulation, heat
source (hot leg) has to be lower than the heat sink (cold leg) as shown in Figure 1 and
the temperature difference between the hot leg and the cold leg must be at least 50 °C.
It is suggested that the whole loop was heated all the time above its melting point to
prevent the salt from solidifying [4].
Figure 1: ORNL Molten Salt Loop layout [2]
3
2.3 Steam PipeSteam pipes are commonly used in many industries. There are many applications for
steam pipes such as household boilers, industrial steam generating plants, locomotives,
and steam engines [5]. All applications include insulation to reduce energy loss which
will result in lower operating costs. By Insulation is the materials or combination of
materials which retard the flow of heat energy. An example of a steam pipe is provided
in Figure 2 below. There are many advantages in using insulation. First of all, insulation
reduces heat loss or gain [5]. As a result, energy in pipes will be conserved. This
increases operating efficiency of heating, ventilating and cooling processes [5]. The
surface temperature of pipes can be controlled by depending on the thickness and
material of the insulation. Moreover, insulation can facilitate temperature control of a
process in pipes. Due to the temperature difference between pipes and the surrounding
temperature, vapor flow and water condensation can be created on the cold surface of
the pipe. Insulation prevents this phenomena from occurring. Furthermore, insulation
protects workers from hazards such as heat, burn and provides comfort while working
and also prevents damage to equipment from corrosive environment.
Figure 2: Example of steam pipe
4
3 DESIGN REQUIREMENTSIn this section, design requirements are provided to create a MSL heating system
design. First of all requirements, Heaters and insulation must be commercially available
and reasonable cost within the project budget. This requirement applies for both vessel
and pipe heater. A Molten Salt Loop (MSL) requires a high temperature of 600 °C to
maintain the salt in a molten state. Therefore, heaters that provide high temperatures
and powers are required for the MSL. Considering the requirements mentioned earlier,
functional, performance and safety requirements for both vessel and pipe heaters are
developed to create a MSL heating system design.
3.1 Vessel Heater3.1.1 Functional requirement
1. The heater shall have sufficient margin of 100 °C beyond the operating
temperature of 600 °C to avoid solidification of FLiNaK which has a melting
point of 454 °C [6].
2. The heater shall provide uniform heat through the vessel to distribute heat to
the molten salt effectively.
3. The heater shall be external not to corrode the heater to prevent rapid
decrease of efficiency and failure rate.
4. The heater shall be flexible for the purpose of installation on the vessel.
3.1.2 Performance requirement1. The vessel heater shall be able to bring up to the operating temperature of
600 °C to conduct an experiment effectively in an 8 hours shift.
2. The vessel heater shall be controlled (on/off) by an operator to prevent them
operating temperature to fall below the melting point (454 °C) of the FLiNaK
or rise over the maximum temperature of heaters.
3. Insulation shall be installed along with the heater to increase the efficiency of
the heating and minimize the heat loss through the environment.
5
3.1.3 Safety requirement1. The heater must be covered by insulation and/or panel to keep operators from
contacting it to prevent burns from high temperature of 600 °C
2. The heater must not damage the MSL frame structures by using insulation.
3.2 Pipe Heater 3.2.1 Functional requirement
1. Pre-heater the pipe to reduce the thermal shock to preserve the pipe integrity
2. The heater shall provide uniform heat through the vessel to distribute heat to
the molten salt effectively.
3. The heater shall be external not to corrode the heater to prevent rapid
decrease of efficiency and failure rate.
4. The temperature of the pipe heater shall be controlled by a variac in order to
create a natural circulation in the loop
5. The heat must be flexible to the purpose of installation on the piping
3.2.2 Performance requirement1. The heater shall have sufficient margin of 100 °C beyond the operating
temperature of 550 °C to avoid solidification of FLiNaK which has a melting
point of 454 °C [6].
2. The heater shall be controlled (on/off) by an operator to prevent them
operating temperature to fall below the melting point (454 °C) of the FLiNaK
or rise over the maximum temperature of heaters.
3. Insulation shall be installed along with the heater to increase the efficiency of
the heating and minimize the heat loss through the environment.
3.2.3 Safety requirement1. The heater must be covered by insulation and/or panel to keep operators from
contacting it to prevent burns from high temperature of 600 °C
2. The heater must not damage the MSL frame structures by using insulation.
6
4 SUMMARY OF HEATERS AND INSULATIONIn this section, a summary of high temperature heaters commercially available is
provided. The challenge with an operating temperature of 600 °C is the significant gap
between the MSL operating temperature and an ambient temperature of 22 °C. Heat
loss through the surrounding environment is expected to be significant. As a result,
molten salt can be solidified and could cause problems during operation. Our team
decided to build a frame with panels to minimized heat loss through the environment.
However, this is not enough to prevent significant heat loss as shown in the
Calculations. Therefore, high temperature insulation is required to complete the design
of the MSL heating system.
4.1 Ultra-High Temperature Heating TapesThe first heater that was investigated is a high temperature tape heater. This was
inspired by Adam’s liquid metal loop heater that used heating tapes to heat up a
cylindrical vessel. It was challenging to procure a heater that fits the vessel because the
design the vessel was being developed at the same time. A tape heater is flexible and
can be shaped into any structure. Therefore, a tape heater was a very good candidate
for the MSL. However, the only downside of the tape heater is that the maximum
temperature is 760 °C [7]. Since the MSL operating temperature is approximately 600
°C, the temperature margin between the operating temperature and the maximum
temperature is 160C. However, this can be a fail-safe feature this means heater will be
failed before boil FLiNaK which has the boiling point of 1570 °C [8]. The DHT Series
heaters have a highly flexible and durable multi-stranded dual heating element that
provides even heat across the tape, which is reinforced with high temperature fiberglass
for added strength and durability [9]. A heavy insulated tape is made by taking a
standard tape and braiding it between layers of Samox yarn. Wide tapes are made from
two or more standard tapes that are sewn between two layers of Samox cloth. High
temperatures and rapid thermal response provide a maximum exposure temperature of
760 ºC (1400ºF). A summary of advantages and disadvantages is provided in the
following section.
7
4.1.1 Advantages of high temperature heating tapes 1. provides flexibility;
2. provides uniform heat distribution;
3. easy to install and remove;
4. is affordable and commercially available; and
5. comes with a standard 2-prone plug no extra electric work is required
4.1.2 Disadvantages of high temperature heating tapes 1. The maximum exposure temperature is at 760 °C which is close to the estimated
operating temperature of 600 °C.
2. Insulation is required due to the significant heat loss through the environment.
4.2 Ceramic Fiber HeaterA ceramic fiber heater by Fibercraft™ was one of the best candidates because it
provides heating element and insulation in one unit. Fibercraft™ low mass vacuum
formed ceramic fiber heaters are a heating element and insulation together in one
complete unit [10]. These heaters are manufactured using high quality, high purity
ceramic fiber with a low sodium inorganic binder. The ceramic fiber heater has a high
operating temperature range; it is offered with maximum operating temperatures of
1100 °C [10]. However, the ceramic fiber heater has many disadvantages. The heater
has to be customized and manufactured for both a vessel and a pipe size of 1 inch.
Customization and manufacturing lead time was about 2 - 3 weeks and delivered from
the USA which affects significantly procurement schedule. In addition to the
procurement process issues, it would be difficult to securely install the heater onto a
vessel since the vessel is designed to be vertically mounted. Another disadvantage is
that the insulation is made of ceramic which is extremely fragile. In addition, this heater
is significantly costly compared to other heaters commercially available. A summary of
advantages and disadvantages is provided in the following section.
8
4.2.1 Advantages of ceramic fiber heater1. The maximum operating temperature is 1100 °C which has a sufficient margin
beyond the operating temperature of the MSL.
2. The heating element and insulation is one complete unit. This feature enhances
performance requirement.
3. Because of the insulation, heat loss to the environment is minimized.
4. Operating cost will be reduced due to energy efficiency.
5. Operators are protected by insulation from high temperature.
4.2.2 Disadvantages of ceramic fiber heater1. The cost is higher than an alternative heating instruments.
2. Installation can be a challenge.
4.3 Cartridge heaterA cartridge heater is excellent to provide high wattage density in limited spaces and its
stainless steel sheaths provides maximum heat transfer, high temperature range and
faster heating. The price was very affordable compared to other high temperature
heaters. In order to create a natural circulation, at least 50 °C temperature difference
between hot leg and cold leg. This heater can provide the additional heat for the certain
sections of piping. However, it is difficult to achieve uniform heat distribution of a large
surface area. Installation of the heater on piping can be a challenge. A summary of
advantages and disadvantages of cartridge heater is provided in the following section.
4.3.1 Advantages of cartridge heater1. High temperature range (up to 760 °C sheath temperature)
2. High wattage in limited spaces
3. Fast heating
4. Affordable cost
4.3.2 Disadvantages of cartridge heater1. Non-uniform heat distribution
2. Difficult installation
9
4.4 InsulationAfter the discussion with Adam Lipchitz and Jeffrey Samuel, it became clear that
uninsulated pipe will lose heat very quickly which will result in solidification of FLiNaK. It
is critical to use insulation to bring the pipe temperature close to operating temperature
even the steam pipe uses insulation. The entire loop including the areas that are not
covered by the tape heaters should be wrapped with insulation to maintain high
operating temperature and to minimize heat loss from the pipe. Therefore, several
insulations were investigated. Since the MSL has a high operating temperature of 600
°C, one of the first criteria was that the insulation material must withstand high
temperature. First of all, fiberglass was investigated. However, it was found that the
temperature range of fiberglass is -30 °C to 540 °C [11]. Although fiberglass can be
easily obtained, it is not acceptable for the MSL. The next item that was investigated
was an insulation for home-building materials. It was difficult to find the temperature
range of the insulations but the temperature range for the home-building materials is
assumed to be significantly low compared to the MSL operating temperature. Moreover,
for the insulation of a high temperature heating system, a material that has low thermal
conductivity is desirable. it is known that a ceramic heater by Fibercraft has a high
temperature range. It is already proven safe to use ceramic material for the high
temperature ranges. Therefore, ceramic fiber blanket was chosen. A summary of
advantages is provided in the following section.
4.4.1 Advantages of ceramic fiber blanket1. Low thermal conductivity [12]
2. High temperature ranges (above 1100 °C)
3. Flexible
4. Commercially available and affordable
.As shown in Figure 3, a decision tree was used to describe the process of selecting the
MSL heaters.
10
Heaters commercially
available
External & high temperature
Tape heaterCeramic fiber heater
Cartridge heaterMicro heater
Internal & low maximum
temperature
Uniform heat distribution
Tape heaterCeramic fiber heater
Cartridge heaterMicro heater
Installation & cost
Tape heaterCartridge heater Ceramic fiber heater
Figure 3: Decision tree for selecting heaters commercially available
Based on the design requirements, the heaters that are suitable for our design project
purpose and commercially available are summarized in Table 1.
Table 1: Summary of heaters commercially available
Criteria of
Heaters
Ceramic Fiber [10] Tape heater [9] Cartridge heater
Maximum
exposure
temperature
Above 1100 °C 760 °C 760 °C
Power 300W – 1200W 313W -627W 75W - 350W
Insulation Ceramic Fiber Samox no
Approx. Cost $290 - $380 $100 - $200 $17.25 - $43
11
5 PRELIMINARY CALCULATIONIn this section, preliminary calculations are provided. Preliminary calculations are
performed to identify the heat loss on the pipe both with insulation and without
insulation, and the time to increase a Hastelloy pipe to the MSL operating temperature.
5.1 Heat loss through an uninsulated pipe and insulated pipeFirst of all, heat loss of uninsulated piping was calculated to identify the temperature
including both inside and outside of the pipe wall. Based on the temperature difference,
whether an insulation is required will be determined. Assuming that molten FLiNaK is at
600 °C and the ambient air temperature is 25 °C, and the Hastelloy pipe has an inner
diameter of 0.0133604 m and outer diameter of 0.021336 m, heat loss can be
calculated using the conduction and convection heat transfer equations as shown in the
section 11.1.1 Heat loss of uninsulated pipe. For a pipe without any insulation, the heat
loss isQ=467.5W . Heat loss for a pipe with ceramic insulation can be obtained using the
same equations. Assuming the thickness of the insulation is 0.0445 m, the heat loss is
Q=209.9W . The heat loss difference between the uninsulated pipe and the insulated is
significant. The heat loss more than doubles when the pipe is not insulated compared to
the pipe with insulation as shown below.
467.5W209.9W
=2.23( for the case of unit lengthof the pipe)
According to this preliminary calculation, high temperature heaters require insulation to
reduce heat loss by more than 50%. By decreasing the heat loss through the
environment, the temperature of the pipe wall increase more effectively and efficiently.
As a result, the heating system performance is expected to increase significantly.
12
5.2 Time to reach the operating temperatureIt is important to know how long it takes to heat up the MSL heating system. Based on
the estimated time to heat a pipe, whether the heating system meets the performance
requirements can be determined. Using Equation 1 provided below, the energy required
to heat up a pipe can be calculated. For a detailed calculation, please refer to the
section 11.1.3 Time it require to heat up the pipe.
Q=mC p∆T Equation 1
Assuming the density, specific heat, and thermal conductivity of Hastelloy at room
temperature are given as 8.22 g/cm3, 500 J/kg∙℃, and 19 W/m∙℃, respectively [13].
Using a 627W heater, 514500 J of energy is required to bring the pipe temperature to
600 °C from 24 °C. According to the calculation, the 627W heater will increase the room
temperature to 600 °C in 53.8 minutes.
13
6 COST ESTIMATION1. Vessel heater: Based on the design requirements and commercial availability,
Ultra-High Temperature Heating Tape (STH101-040) is best fit for the vessel
heater.
2. Pipe heater: based on the design requirements and preliminary calculations, the
Ultra-High Temperature Heating Tape (STH101-040) is the most suitable for the
piping. Moreover, the short cartridge heater (CSH-204350) is added to create a
hot leg on the pipe,
3. Insulation: based on the design requirements and preliminary calculations, the
ceramic blanket is the best candidate for the MSL heating system insulation.
Table 2: The MSL heating system cost estimate
Name ImageModel
No.Watts Volts
Qu
ant
ity
Delivery
time
Estimated
Cost
Short
Cartridge
heater from
OMEGA
(pipe heater)
CSH-
204350350W 120V 6 7 days
$29.5CAD
X 6 = $
177 CAD
Ultra-High
Temperature
Heating
Tapes from
OMEGA
(pipe heater)
STH10
1-040627 W
120
Volts2 7 days
$70CAD X
2 = $140
CAD
14
Ultra-High
Temperature
Heating
Tapes from
OMEGA
(Vessel
heater)
STH10
1-040627 W
120
Volts3 7 days
$70CAD X
3 = $210
CAD
Durablanket-
S. Ceramic
blanket
(insulation)
N/A N/A N/A 12-3
days
$119 CAD
X1 = $119
CAD
Aluminum foil N/A N/A N/A 2 N/A $10
Total $656 + 15% tax + shipping($25) 7 days$779.4
CAD
15
7 DESIGN OF HEATING SYSTEMIn this section, the design of the MSL heating system is described. Each heater is an
external heater design for both the MSL vessel and piping. The heaters are capable of
withstanding the maximum temperatures of 760 °C. As shown in Figure 6 in the pipe
heater design section, a natural circulation occurs when the operating temperature of
the hot leg (left section) and the cold leg (right section) are provided with 650 °C and
600 °C, respectively.
7.1 Vessel heater designOne ultra-high temperature tape heater which has power of 627W is used for the MSL
vessel. The heater is 120V, double insulated with braided Samox and knitted into flat
tapes for maximum flexibility. Each heater is 0.5 inch wide and 8 inches long. Ceramic
blanket insulation chosen as an insulation since the high temperature range of 1200 °C
and the very low thermal conductivity. The thickness of 2 inch of ceramic fiber blanket is
wrapped around the vessel. Aluminum foil is used to cover the ceramic blanket
insulation.
16
Figure 4: tape heater (0.5 inch wide and 8 inches long)
Figure 5: A tape heater installed on the vessel
7.2 Pipe heater designFor the piping, one 120V ultra-high temperature tape heater with power of 627W is
wrapped on the left side of the piping as shown in Figure 7 below. This is applies to the
right section of the piping. On the bottom section, three short cartridge heaters with
power of 350W will be added using thermal paste. These heaters provide additional
heat on the bottom section to create a temperature difference between the hot leg and
the cold leg. As a result, a natural circulation will be created in the loop.
Figure 6: Molten Salt Loop
17
Hot Leg650 ℃
Cold Leg550 ℃
Cartridge Heater Tape heater
Ceramic blanket
Figure 7: Pipe heater Design
1 inch of the ceramic blanket insulation will cover the short cartridge heaters as well as
any piping sections that are exposed to the ambient temperatures. Aluminum foil is
used to cover the ceramic blanket insulation.
8 DESIGN VERIFICATIONIn this section, a design verification experiment and its results are provided. The
purpose of the experiment is to verify the MSL heating system design. In order to
comfirm whether the tape heater and the insulation work, an experiment was set up as
shown in Figure 8 below. A pipe was wrapped with a ultra-high temperature heating
tape. On one end of the pipe, a sample ceramic blanket insulation covers the tape
heater on the pipe. A veriac was set up to control the power of the heater. The first
experiment was performed using 50% of the full power.
Figure 8: Design verification experimental setup
The initial pipe wall temperature was 23.5 °C for both thermometers. The surrounding
temperature was 24 °C. The temperature was measured inside the insulation and the
centre of the pipe. The temperature data was measured and recorded every minute for
15 minutes.
Time versus temperature charts are shown in Figure 9 and Figure 10 below. In the case
of the heating-up experiment, the temperature increases from 60.6 °C to 163.5 °C in 15
18
minutes. It should be noted that the pipe was pre-heated from the initial temperature.
Figure 9 shows that the insulated pipe increased the pipe wall temperature more
effectively and efficiently than the uninsulated pipe.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 150
20406080
100120140160180
Time vs. Temperature (50% power of 627W)
Thermal couple 1 (inside the insulation) Thermal couple 2 (center of the pipe)
Time (min)
Tem
pera
ture
()
Figure 9: Temperature increase chart for 15 minutes using 50% power of 627W
In the case of the cool down experiment, the insulated pipe wall temperature was
cooled down from 163.5 °C to 85.1 °C, as illustrated in Figure 10 below. This shows a
78.4 °C temperature decrease in 15 minutes, whereas the uninsulated pipe cooled
down from 131.5 °C to 6.4 °C, which is only a 64.1 °C temperature decrease. The
insulated pipe wall temperature decreases more than the uninsulated pipe in the same
period. However, the larger temperature decrease in the insulated pipe was due to the
initial temperature of the insulated pipe being higher than that of the uninsulated pipe.
19
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 150
20406080
100120140160180
Time vs. Temperature (Cool down)
Thermal couple 1 (inside the insulation) Thermal couple 2 (center of the pipe)
Time (min)
Tem
pera
ture
()
Figure 10: Temperature decrease chart for 15 minutes
Using the cool down data and Newton’s cooling law, a relationship between time and
temperature can be obtained. The initial temperature of the pipe with insulation was
163.5 °C, which cooled to 85.1 °C in 15 minutes. Given that the surrounding
temperature was 24 °C, an estimated time taken by the pipe to cool from 600 °C to 30
°C can be obtained. The equation to calculate the time it takes cool the MSL is
T (t )=24+(T i−24 )e−0.055t. Assuming the pipe wall temperature is 600 °C and the desired
temperature is 45 °C, it will take 60.2 minutes to cool down to 45 ℃. Based on the
calculation, it is expected that the time that it takes to heat up a 1 m long pipe to 600 °C,
using a tape heater with the power of 627 W, would be 60 minutes assuming that the
initial temperature of the pipe wall is 24 °C (see the section 11.1.3 for the calculation).
In order to further confirm the heating system design, an additional experiment
measuring the pipe wall temperature was conducted using 100% power of 627W heater
for 30 minutes. In this experiment, one temperature was measured inside the ceramic
fiber blanket insulation and the other temperatures were measured at two different
points of the centre pipe wall, which were exposed to the ambient temperature without
any insulation, as shown in Figure 11 below.
20
Figure 11: Design verification experiment setup 2
The uninsulated pipe wall temperatures were then averaged for the purpose of
comparing with the insulated pipe wall temperature. As shown in Figure 12 below, the
temperature of the insulated pipe wall increased from 23.5 °C to 524.9 °C in 30 minutes.
In theorietical calculations, it is calculated that it takes 44 minutes to increase the
temperature from 23.5 °C to 524.9 °C. The percent error is provided below.
% error=|Therorietical value−Expected value|T herorietical value
×100
¿|44−30|
44×100=31.8 %
This temperature increase rate is the expected value compared to preliminary
calculations with a percent error of 31.8%. However, this meets a functional design
requirement in which the heater will be able to heat up to an operating temperature of
600 °C. The uninsulated pipe was heated to 273.4 °C from the same intial temperature
of 23.5 °C. However, the pipe wall temperature at 30 minutes almost reaches an
equilibrium to the surrounding temperature. As shown in Figure 12 below, the
uninsulated pipe graph starts to flatten after 20 minutes. The temperature gap between
the insulated pipe and the uninsulated pipe is 251.5 °C, which is very significant. This
21
shows the importance and effectiveness of insulation and also meets performance
requirements.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 300
100
200
300
400
500
600
Time vs Temperature
Thermal couple 1 (inside the insulation) Average of uninsulated value
Time (min)
Tem
pera
ture
()
Figure 12: Temperature increase in 30 minutes using 100% power of 627 W
With regard to safety, the tempererature on the surface of the inulsation was only 105.3
°C when the pipe wall temperature was at 524.9 °C, as shown in Figure 14. This
indicates that the temperature on the outside of insulated panels of the MSL frame
would be low enough to enable safe contact.
In the case of the cool down temperature data for the insulated pipe wall, the
temperature decreased from 524.9 °C to 109 °C. The surface of the insulation
temperature was 35.1 °C when the pipe wall temperature was 109 °C, as shown in
Figure 15. The initial temperature of the pipe with insulation was 524.9 °C. Given that
the surrounding temperature was 24 °C, an estimated time taken by the pipe to cool
from 600 °C to 45 °C, which is safe skin contact temperature, can be calculated [13].
The equation to calculate the time it takes cool the MSL is T ( t )=24+(T i−24 )e−0.059t.
22
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 300
100
200
300
400
500
600
Time vs. Temperature (Cool down for 30 min)
Thermal couple 1 (inside the insulation) Average of uninsulated pipe temeprature
Time (min)
Tem
pera
ture
()
Figure 13: A temperature decrease chart for 30 minutes
Based on the calculation, it is expected that the time that it takes to heat up a 1 m long
pipe to 600 °C, using a tape heater with the power of 627 W, would be 56 minutes
assuming that the initial temperature of the pipe wall is 24 °C (see the section 11.1.3 for
the calculation). This result indicates that the MSL will be available for operator access
in one hour.
23
After the
experiment, a picture of the heater and the insulation were taken to investigate whether
they were demaged by high temperatures. The color of the heater was changed from
light brown to white. Howerever, the integrity of both the heater and the insulation was
not compromised as shown in Figure 17 and Figure 16below. Finally, the heating
system design was verified that it is suitable for the MSL.
24
Figure 14: Surface temperature of the insulation (heating up experiment)
Figure 15: Surface temperature of the insulation (cool down)
Figure 17: Ultra-high temperature tape heater image after the experiments Figure 16: Insulation image after the experiment
9 CONCLUDING REMARKSThe MSL heating system was designed, procured and verified through the design
verification experiments. Based on the design verification, it can be concluded that the
heaters designed and procured are not only capable of reaching an operating
temperature of 600 °C but achieve that temperature within an hour, using an ultra-high
temperature tape heater with a power of 627W and 1 inch thick ceramic blanket
insulation. The ceramic blanket insulation withstood highest temperature of 527.4 °C. A
hot leg and a cold leg of the piping can be created by heaters using variacs, which
control the power of the heaters, to create a natural circulation in the loop. Throughout
the report, it was identified that all other design requirements have been met for the
MSL heating system. In terms of safety, as shown in the experiment, the surface
temperature of the insulation while operating the heater indicates that the temperature is
much less than the melting point of Aluminum. Therefore, the MSL heating system will
not compromise the integrity of the MSL frame which is made of aluminum material.
More importantly, the MSL heating system is safe from burning hazards for those who
conduct experiments since it is contained in a MSL frame with insulated panels. The
MSL will be cooled down in less than an hour based on the experiment and the heat
transfer calculations. Finally, the objective of Capstone design project II was
successfully accomplished.
25
10 REFERENCES
[1] S. Ragunathan, R. Trolly, S. Choi and K. Watson, "CONCEPTUAL DESIGN OF A
MOLTEN SALT LOOP (MSL) FOR INVESTIGATING AGING RELATED
DEGRADATION," University of Ontario Institute of Technology, Oshawa, 2014.
[2] S. E. Choi, NOL-MSL-PPL-003 ENGR 4998U CAPSTONE 2: PROPOSAL,
Oshawa: University of Ontario Institute of Technology, 2015.
[3] M. S. Sohal , M. A. Ebner, P. Sabharwall and P. Sharpe, "Idaho National
Laboratory," 1 March 2010. [Online]. Available:
http://www5vip.inl.gov/technicalpublications/Documents/4502650.pdf. [Accessed 5
April 2015].
[4] R. Bican, "www.csvts.cz/cns/jb/doc/papers/ENYGF2011/04_15_Bican_paper.pdf,"
1 January 2014. [Online]. Available:
http://www.csvts.cz/cns/jb/doc/papers/ENYGF2011/04_15_Bican_paper.pdf.
[Accessed 5 April 2015].
[5] A. Stevens, "www.raeng.org.uk/publications/other/2-steam-pipe," 1 January 2015.
[Online]. Available: http://www.raeng.org.uk/publications/other/2-steam-pipe.
[Accessed 13 January 2015].
[6] P. Sabharwall , M. Ebner, M. Sohal, P. Sharpe, M. Anderson, K. Sridharan, J.
Ambrosek, L. Olson and P. Brooks, "Skyscrubber.com - Fixing the Fires that are
causing Climate Change," 1 March 2010. [Online]. Available:
www.skyscrubber.com/Molten Salts For High Temperature Reactors -
4502649.pdf. [Accessed 28 March 2015].
[7] OMEGA Engineering Inc., "High Temperature, Dual-Element Heating Tapes,"
OMEGA Engineering Inc., 1 January 2015. [Online]. Available:
http://www.omega.com/pptst/DHT.html. [Accessed 6 February 2015].
26
[8] K. H. Bang, "Our Work: COOL," 1 June 2010. [Online]. Available:
https://www.iaea.org/INPRO/CPs/COOL/3rd_Meeting/Korea_COOL_2010.pdf.
[Accessed 03 April 2015].
[9] OMEGA Engineering Inc., "Ultra-High Temperature Heating Tapes," OMEGA
Engineering Inc., 1 January 2015. [Online]. Available:
http://www.omega.com/pptst/STH_SST_SWH.html. [Accessed 6 February 2015].
[10] Thermcraft, Inc., "High Temperature Ceramic Electric Heaters for Sale |
Thermcraft," Thermcraft, Inc., 1 January 2015. [Online]. Available:
http://www.thermcraftinc.com/high-temperature-heaters.html. [Accessed 6
February 2015].
[11] The Engineering ToolBox, "Insulation Materials and Temperature Ranges," The
Engineering Tool Box, 1 January 2015. [Online]. Available:
http://www.engineeringtoolbox.com/insulation-temperatures-d_922.html.
[Accessed 1 March 2015].
[12] The Engineering Tool Box, "Thermal Conductivity of some common Materials and
Gases," The Engineering Tool Box, 1 January 2015. [Online]. Available:
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html. [Accessed
25 March 2015].
[13] Haynes International, Inc., "Haynes International, Inc. HASTELLOY® C-276 alloy,"
Haynes International, Inc., 11 February 2015. [Online]. Available:
http://www.haynesintl.com/HASTELLOYC276Alloy/HASTELLOYC276AlloyPP.htm
. [Accessed 5 April 2015].
[14] E. Ungar and K. Stroud, "P13038 / Benchmarking and Research Store - Directory
contents," 19 February 2013. [Online]. Available:
http://edge.rit.edu/edge/P13038/public/Benchmarking%20and%20Research
%20Store/Approach%20to%20Human%20Touch%20Temperature
%20Standards.pdf. [Accessed 5 April 2015].
27
28
11 APPENDIX11.1 Calculations11.1.1 Heat loss of uninsulated pipe
T∞1=600℃ (OperatingTemperature )
T∞2=25℃(Ambient Temperature)k1=19W /(m ∙℃) (thermal conductivity of hastloy )
L=1m(Lengthof the pipe)D1=0.0133604 m(inner diameter of the pipe)
D2=0.021336m(inner diameterof the pipe)
A1=2π r1L=2π (0.0066802m ) (1m)=0.04197m2
A2=2π r2L=2π (0.010668m ) (1m )=0.06724m2
h1=60W /m2 , h2=18W /m2
Ri=R conv, 1=1
h1 A1= 1
(60 Wm2∙℃ ) (0.04197m2 )
=0.04197℃ /W
R1=R pipe=
ln( r2
r1)
2 π k2L=
ln (1.59696)
2π (19 Wm∙℃ )(1m)
=0.003921℃ /W
Ro=Rconv ,2=1
h1 A1= 1
(18 Wm2 ∙℃ )( 0.067029m2 )
=0.8288℃ /W
Rtotal=R i+R1+Ro=0.04197+0.003921+0.8288=0.87472℃/W
Q=T ∞1−T∞2
Rtotal=600℃−25℃
0.87472℃/W=657.4W
T 1=T ∞1−Q R conv , 1=600−(657.4W ) (0.04197℃/W )=572.4℃
T 2=T 1−Q R pipe=572.4℃−(657.4W ) (0.003921℃ /W )=569.8℃
29
11.1.2 Heat loss of insulated pipe
Figure 18: insulated pipe example
T ∞1=600℃ (OperatingTemperature )
T ∞2=25℃(Ambient Temperature)k1=19W /(m ∙℃) (thermal conductivity of hastloy )
L=1m(Lengthof the pipe)D1=0.0133604 m(inner diameter of the pipe)
D2=0.021336m(inner diameter of the pipe)
h1=60W /(m2 ∙℃)
h1=18W /(m2 ∙℃)
A1=2π r1L=2π (0.0066802m ) (1m)=0.04197m2
A2=2π r2L=2π (0.010668m ) (1m )=0.06724m2
h1=60W /m2 , h2=18W /m2
Ri=R conv, 1=1
h1 A1= 1
(60 Wm2∙℃ ) (0.04197m2 )
=0.04197℃ /W
30
R1=R pipe=
ln( r2
r1)
2 π k2L=
ln (1.59696)
2π (19 Wm∙℃ )(1m)
=0.003921℃ /W
Ro=Rconv ,2=1
h2 A1= 1
(18 Wm2 ∙℃ )( 0.067029m2 )
=0.8288℃ /W
Rtotal=R i+R1+Ro=0.04197+0.003921+0.8288=0.87472℃/W
Q=T ∞1−T ∞2
Rtotal=600℃−25℃
0.87472℃/W=657.4W
T 1=T∞1−Q R conv, 1=600−(657.4W ) (0.04197℃/W )=572.4℃
T 2=T 1−Q R pipe=572.4℃−(657.4W ) (0.003921℃ /W )=569.8℃
11.1.3 Time it require to heat up the pipeTable 3:Hastelloy properties
Properties Values
Density 8.22 g/cm3
Specific Heat 500 J/kg∙℃
Thermal Conductivity 19 W/m∙℃m=ρV
¿(8.22 gc m3 )(π (1.06682−0.668022))cm2 (100 cm)
¿1786.5g
Q=mC p∆T ¿ (1786.5g )(0.5 Jg∙℃) (600−24℃ )
¿514519.7 J
t ( time )=Q /(heat gain−heat loss)514519.7 J
627 Js−467.5 J
s
=3225.8 s=53.76min
31
11.1.4 Time it takes to cool downUsing Newton’s cooling law
dTdt
=−k (T i−T s )
T (t )=T s+(T i−T s )e−kt
T ( t )−T s
T i−T s=e−kt
85.1−24163.5−24
=e−k (15min )
k=0.055037
11.1.5 Extra calculationQ=mC p∆T
D¿=0.0133604m→A¿=π D2
4=
π (0.0133604 m)2
4=4.40043×10−4m2
ρ=2.02 gcm3 =2020 kg
m3 m=ρVA=(2020 kgm3 )(1 m
s ) (4.40043×10−4m2 )=0.88889 kgs
11.2 Matlab Code11.2.1 Heat loss with insulation%Heat loss with insulation T_fluid = 600 ; % C, bulk fluid temperature of the molten salt T_room = 25 ; % C, room temperature k1 = 19 ; % W/m*k, thermal conductivity of hastelloy k2 = 0.12 ; % W/m*k, thermal conductivity of ceramic insulation D1 = 0.0133604 ; % m, inner diameter of the pipe D2 = 0.021336 ; % m, outter diameter of the pipe t_ceramic = 0.04445 ; % m, thickness of ceramic insulation
32
D3 = (t_ceramic*2 + D2) ; % m, diameter of the pipe and insulation L = 1:0.05: 2 ; % length of the pipe every 5 cm h1 = 60 ; % W/m^2, heat transfer coefficient of the molten salt h2 = 18 ; % W/m^2, heat transfer coefficient of the ambient air A1 = 2*pi*(D1/2).*L ; % m^2, the area of the pipe inner surface for the unit length A2 = 2*pi*(D3/2).*L ; % m^2, the area of the pipe outter surface for the unit lengt R_i = 1./(h1.*A1) ; % C/W, convection resistance of the molten salt R1 = log(D2/D1)./(2*pi*k1.*L) ; % C/W, conduction resistance of the pipe R2 = log(D3/D2)./(2*pi*k2.*L) ; % C/W, condction resistance of the insulation R_f = 1./(h2.*A2) ; % C/W, convection resistance of the air R_total = R_i + R1 + R2+ R_f ; % C/W, total resistance Q_loss = (T_fluid - T_room)./R_total ; % W, heat loss per m pipe length delta_T_pipe = Q_loss.*R1 ; % C, temperature drop between the pipe delta_T_insulation = Q_loss.*R2 ; % C, temperature drop between the insulation T1 = T_fluid - Q_loss.*R_i ; % C, temperature of inner pipe surface T2 = T1 - delta_T_pipe ; % C, temperature of outter pipe surface T3 = T2 - delta_T_insulation ; % C, temperature of the ouuter insulation surface plot(L,Q_loss) ; % plot Heat loss versus pipe length legend('Heat loss versus pipe length') ;title('Heat loss versus pipe length') ;xlabel('Pipe Length','FontSize',12,'FontWeight','bold','Color','b') ;ylabel('Heat Loss','FontSize',12,'FontWeight','bold','Color','b') ;
33
11.2.2 Heat loss without insulation%Heat loss without insulation T_fluid = 600 ; % C, bulk fluid temperature of the molten salt T_room = 25 ; % C, room temperature k1 = 19 ; % W/m*k, thermal conductivity of hastelloy k2 = 0.12 ; % W/m*k, thermal conductivity of ceramic insulation D1 = 0.0133604 ; % m, inner diameter of the pipe D2 = 0.021336 ; % m, outter diameter of the pipe L = 1:0.05: 2 ; % length of the pipe every 5 cm h1 = 60 ; % W/m^2, heat transfer coefficient of the molten salt h2 = 18 ; % W/m^2, heat transfer coefficient of the ambient air A1 = 2*pi*(D1/2).*L ; % m^2, the area of the pipe inner surface for the unit length A2 = 2*pi*(D2/2).*L ; % m^2, the area of the pipe outter surface for the unit lengt R_i = 1./(h1.*A1) ; % C/W, convection resistance of the molten salt R1 = log(D2/D1)./(2*pi*k1.*L) ; % C/W, conduction resistance of the pipe R_f = 1./(h2.*A2) ; % C/W, convection resistance of the air R_total = R_i + R1 + R_f ; % C/W, total resistance Q_loss = (T_fluid - T_room)./R_total ; % W, heat loss per m pipe length delta_T_pipe = Q_loss.*R1 ; % C, temperature drop between the pipe T1 = T_fluid - Q_loss.*R_i ; % C, temperature of inner pipe surface T2 = T1 - delta_T_pipe ; % C, temperature of outter pipe surface plot(L,Q_loss) ; % plot Heat loss versus pipe length legend('Heat loss versus pipe length') ;title('Heat loss versus pipe length') ;xlabel('Pipe Length','FontSize',12,'FontWeight','bold','Color','b') ;ylabel('Heat Loss','FontSize',12,'FontWeight','bold','Color','b') ;
34
11.2.3 Cooldown (15 minutes & 30 minutes)%Cool down experiment data into newton's cooling lawt1 = 15; % min, TimeT_i1 = 163.5; % C, initial temperatureT_f1 = 85.1; % C, final temperatureT_s = 24; % C, surrounding temperaturesyms k % assign veriablecoeff = solve(T_s+(T_i1-T_s)*exp(-k*t1)-T_f1 == 0); % solve for k %Assuming cool down from the operating temperature of 600Ck1 = double(coeff);T_i = 600; % C, initial temperatureT_f = 45; % C, final temperatureT_s = 24; % C, surrounding temperaturesyms ttime = solve(T_s+(T_i-T_s)*exp(-k1*t)-T_f == 0);cooldown1 = double(time); %Cool down experiment data into newton's cooling lawt2 = 30; % min, TimeT_i2 = 524.9; % C, initial temperatureT_f2 = 109.3; % C, final temperatureT_s = 24; % C, surrounding temperaturesyms k % assign veriablecoeff = solve(T_s+(T_i2-T_s)*exp(-k*t2)-T_f2 == 0); % solve for k %Assuming cool down from the operating temperature of 600Ck2 = double(coeff);T_i = 600; % C, initial temperatureT_f = 45; % C, final temperatureT_s = 24; % C, surrounding temperaturesyms ttime = solve(T_s+(T_i-T_s)*exp(-k2*t)-T_f == 0);cooldown2 = double(time);
35
11.3 Matlab Result11.3.1 Heat loss with insulation
Figure 19: Heat loss with insulation
36
11.3.2 Heat loss without insulation
Figure 20: Heat loss without insulation
11.3.3 Cool down (15 minutes & 30 minutes)
Figure 21: Cool down (15 minutes & 30 minutes)
37
11.4 Experiment DataTable 4:50% power of 627 W heat up data
50% power of 627 W heat up
Time(min)
Thermal couple 1
(inside the insulation)
Thermal couple 2
(center of the pipe)
0 60.6 39.3
1 66.6 46.7
2 75.5 59.1
3 86 69.4
4 96 78.5
5 104.7 85
6 112.9 90
7 120.5 95.4
8 127.5 101.9
9 133.9 107.3
10 139.3 112.4
11 145 118
12 150 120.8
13 154.3 125.2
14 158.4 128.2
15 163.5 131.5
38
Table 5: Cool down for 15 minutes data
Cool down data
Time(min)
Thermal couple 1 (inside the
insulation)
Thermal couple 2 (center of
the pipe)
0 163.5 131.5
1 161.2 125.2
2 152 116.3
3 143 109.4
4 136 104.5
5 129 99.2
6 123.2 95.7
7 117.3 90.5
8 112.4 86.8
9 107.8 83.9
10 103.2 80.4
11 99.1 77.4
12 95.4 75.3
13 91.6 72.2
14 88.2 69.9
15 85.1 67.4
Table 6: 100% power of 627 W heat up data
100% power of 627 W heat up
Time(min)Thermal couple 1 (inside the
insulation)Average of uninsulated points
0 23.5 23.5
1 - -
2 90 53.45
39
3 148 85.15
4 197 106.4
5 240.5 129.35
6 279.5 151.2
7 318.8 166.55
8 340 181.1
9 368.5 194
10 390 205.15
11 409.9 214.55
12 427 223.8
13 441.6 231.65
14 454.1 237.9
15 465.3 242.55
16 475 251.2
17 483 255.6
18 490 257.55
19 495.5 259.85
20 500 260.1
21 505.3 264.85
22 509.4 265.75
23 512.4 267.95
24 514.8 268.5
25 516.8 270.1
26 518.8 272
27 520.2 270.3
28 522 272.9
29 524 278.4
30 524.9 273.35
40
Table 7: Cool down for 30 minutes data
Cool down data
Time(min)Thermal couple 1 (inside
the insulation)
Average of uninsulated pipe
temeprature
0 524.9 273.35
1 486.3 245.6
2 450.3 222.6
3 417.5 207.1
4 389 196.15
5 363 188.45
6 338 174.5
7 319 165.8
8 301 155.45
9 284.8 147.25
10 269.8 141.9
11 255 133
12 242.1 126.2
13 230 120.4
14 219 113.05
15 208 108.1
16 198.3 100.7
17 189.1 96.25
18 180.5 91.45
19 172.3 90.35
20 164.3 88.85
21 157.8 85.3
22 151 83.25
41
23 144.5 77.6
24 138.7 77.75
25 133 75.6
26 128 73.9
27 123.1 70.25
28 118 66.8
29 113.5 64.3
30 109.3 63
42