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