“ANALYSIS ON PERFORMANCE OF RADIANT HEAT EXCHANGER OF THERMIC FLUID HEATER BY CHANGING THE SUITABLE GRADE OF MATERIAL”

“ANALYSIS ON PERFORMANCE OF

RADIANT HEAT EXCHANGER OF

THERMIC FLUID HEATER BY

CHANGING THE SUITABLE GRADE OF

MATERIAL”

“Patel Ronak I.1, Tandel Shyamal N.2, Patel Miteshkumar H.3, Patel Jaykumar S.4, MominInayat Husain M.5”

1. UG student 2. UG student 3.UG student 4.UG student 5.UG student of Mechanical engineering Department, Shree Swami AtmanandSaraswati Institute of Technology, Surat-395006

+91-7567694094, [email protected]; +91-9638101863, [email protected]; +91-9824537696, [email protected];

+91-9429986699, [email protected]; +91-7405237847, [email protected]

Abbreviation

GTVA : Gujtex Thermic Vertical Annulus

HP : Horse Power

ASTM : American Society for Testing and Material

BS : British Standards

AISI : American Iron and Steel Industry

TTHE : Tube in Tube helical coil Heat Exchanger

CFD : Computational Fluid Dynamics

PCD : Pitch Circle Diameter (mm)

Str : Short tandem repeat

HHV : Higher Heating Value (kJ/kg or kJ/kmol)

HCV : Higher Calorific Value (kJ/kg or kJ/kmol)

GCV : Gross Calorific Value (kJ/kg or kJ/kmol)

LHV : Lower Heating Value (kJ/kg or kJ/kmol)

LCV : Lower Calorific Value (kJ/kg or kJ/kmol)

NCV : Net Calorific Value (kJ/kg or kJ/kmol)

PMCC : Pensky Martens Closed Cup (0

C

)

COC : Cleveland Open Cup (0

C

)

DAF : Dry Air Fraction

Nomenclature

Re : Reynolds Number

Nu : Nusselt Number

hi : Convective heat transfer co-efficient for inner side (W/ m20C)

d : Tube diameter (mm)

D : Coil diameter (mm)

δ : Curvature ratio

r : Tube radius (mm)

R : Coil radius (mm)

hs : Heat transfer coefficient of single phase ( 2 /

W m K )

H : Coil pitch (mm)

Dh : Hydraulic diameter (m)

De : Dean Number

QR : Heat absorbed by radiant tubes (kJ/hr)

σ : StefenBoltzman Constant (

kJ

_{2 4}

hrm K

)

Qrls : Combustion heat of fuel based on the net calorific value (kJ/hr) Qair : Sensible heat of combustion air (kJ/hr)

Qfuel : Sensible heat of fuel (kJ/hr)

Qfluid : Sensible heat of atomization fluid (kJ/hr) Qr : Radiant heat transfer (kJ/hr)

Qshield : Radiant heat of shield tubes (kJ/hr)

Qfluegases: Sensible heat of flue gases leaving radiant section (kJ/hr) Qlosses : Assumed radiation heat loss through furnace casing (kJ/hr) Mair : Molecular weight of air (kmol/kg of air)

Cpi : Molar specific heat of component (

kJ

kmolK

)

Cp : Molar specific heat (

kJ

kmolK

)

wi : Percentage weight of component

mfuel : Mass flow rate of fuel (kg/hr) Dcoil : Diameter of coil (m)

C : Centre to Centre distance (m)

do : Diameter of outer tube (m)

di : Diameter of inner tube (m)

N : Number of tubes

R0 : Universal gas constant (

J

kmolK

)

F : Exchange factor

α : Relative effectiveness

Tair : Temperature of air (K) Tdatum : Temperature at datum (K) Tin : Temperature of fluid inlet (K) Tout : Temperature of fluid outlet (K) Tfuel : Temperature of fuel (K) Twall : Temperature of wall (K) Tfluid : Temperature of fluid (K) mair : Mass flow rate of air (kg/hr) mfluegases: Mass flow rate of flue gases (kg/hr)

Mfuel : Molecular weight of fuel (kmol /kg of fuel)

Mfluegases: Molecular weight of flue gases (kmol/ kg of flue gases)

M

air : Molecular flow rate of air (kmol/hr)

M

fuel : Molecular flow rate of fuel (kmol/hr)

Qcombution: Combustion heat of fuel based on the gross calorific value (kJ/hr) Qnet : Net heat of fuel after losses (kJ/hr)

Cpfluegases : Molar Specific Heat of Flue Gases (

kJ

kmolK

)

Tflame : Flame Temperature (K) Tfuegases : Flue Gases Temperature (K)

ρfluegases: Density of flue gases (kg/m3)

P : Atmospheric pressure (Pa)

Ainfluegases: Area of flue gases inlet (m2) vfluegases: velocity of flue gases (m/s)

μ : Dynamic viscosity of flue gases (kg/ms)

Kfluegases: Thermal conductivity of flue gases (

W mK

/

) cpfluegases: Specific heat of flue gases (kJ/kgK)

Pr : Prandtl number

hcoil : Heat transfer coefficient of coil (W m K/ 2 )

hconv : Convective heat transfer coefficient (W m K/ 2 )

L : Length of one coil turns (m)

A : Effective area (m2) Ashield : Shield area (m2) Ai : Area of fluid inlet (m2)

V

: Volumetric flow rate of fluid (lit/hr) vifluid : Velocity of fluid inlet (m/s)

Cpair : Molar specific heat of air (

kJ

kmolK

)

mfluid : Mass flow rate of fluid (kg/hr)

ρfluid : Density of fluid (kg/m3) cpfluid : Specific heat of fluid (kJ/kgK) Qin : Heat entering in radiant section (kJ/hr) Qout : Heat leaving in radiant section (kJ/hr)

ABSTRACT

To make the radiant heat exchanger of higher performance and efficiency at low manufacturing and maintenance cost in which maximum utilization of heat energy of flue gases is possible and also which is less expensive and easily accommodate by any process industries for their usual operation. Also to improve working condition and decrease the operating cost by changing the grade of material of tubes for required mechanical and thermal property for which the radiant heat exchanger is to be designed.

INTRODUCTION

A thermal fluid uses a liquid phase heat transfer medium to put heat energy into a process. Thermal oil, glycol or water are common heat mediums that are used by being heated and circulated to heat energy users within a closed loop system. Thermal oil heater is usually of the tube coil type. It can be heated electrically or fired by oil fuel or gas to raise temperature of the thermal oil [1].

Generally, it is said that around 45-55% of the total heat release in the furnace is transferred to the processfluid in the radiant section, leaving about 25-45% of the total heat release to be eithertransferred to the process fluid in the convection section or carried by the flue gases throughthe stack and is lost.

Heat transfer by radiation is governed by the Stefan-Boltzman’s law for black body radiation, QR = σ T4. In practice, the radiative heat transfer is more complicated however as it involves the calculation of heat exchange factors as a function of the furnace geometry and the calculation of the absorptivity and emissivity of the combustion gases. There are also other factors to be considered such as the emissivity of the surface.

Qfluid. Part of this heat input liberated in the radiant section is absorbed by the tubes in the radiant Qr and shield Qshield sections, while the remaining heat is either carried as sensible heat by the exiting flue gas Qfluegases or is lost by radiation through the furnace walls or casing Qlosses. The temperature of the flue gas can then be calculated by setting up a heat balance equation.

Radiation heat losses through furnace walls depend on the size of the furnace, where greater heat losses are to be expected in small furnaces as the ratio between the walls area and the volume of the radiation section decreases with furnace size increase. For furnaces of 10 MW or more, they range from 2 to 5% of the net calorific value [2].

In radiant section, heat transfer to the oil take place by means of different modes of heat transfer like radiation, conduction and convection.

So, for changing the effect of heat transfer, following things can be modified:

1. Changing the fuel that generated the better heat due to having high calorific value.

2. Changing the tube material grade to check whether heat transferred through conduction is maximized or not.

In the radiant heat exchanger, first fuel (coal or other things) is burned at atmospheric pressure with necessary requisites which creates flue gases which passes in the vertical direction in the radiant section of thermic fluid heater. This flue gases radiate heat to the surroundings where as shown in figure 1 and also some amount of convective heat exchange also takes place in the same place. Now this transferred heat is passed to the tubes walls from outer to inner side through conduction and this heat is absorbed by fluid passing inside the tube by convection.

So, there is requirement of the proper heat transfer mechanism

OBJECTIVE

The objective of this work is to find out that new material grade which would have been used for making the tube of Thermic Fluid Heater having a comparative study against current material grade such that some of its characteristics and properties can be improved and results are imposed in it and in this study, approach is selected on thermal performances aspects and problem is properly defined in various steps. These steps include mathematical modelling, modelling of the radiant heat exchanger in CREO PARAMETRIC 2.0 and CFD thermal analysis in ANSYS FLUENT 14.0 is used to measure and compare the various aspects such as Outlet temperature and Thermal Efficiency.

METHODOLOGY

Modelling

Radiant heat exchanger is built in two phases of CREO parametric and ANSYS workbench design module as shown in figure 2 and 3.

The part details of the model with state type is given Table 1

Table 1 Naming of various parts of the model with state type

Part number Part of the model State type

1 Fluid Fluid

2 Flue gases Fluid

Initially, a relatively coarser mesh is generated. This mesh contained mixed shells having both triangular and quadrilateral faces at the boundaries. Later on, a fine mesh is generated. For this fine mesh, the edges and regions of high temperature and pressure gradients are finely meshed as shown in figure 4.

The analysis type is changed to Pressure Based type. The velocity formulation is changed to absolute and time to steady state. Gravity is defined as z = 9.81 m/s2.

Fig. 4 Named Section of the Geometry

In model option, different types of models are available which are required to define to solve the problem. Energy equation is set ON position. Viscous model is selected as “k-ε model (2 equations). Radiation model is changed to Discrete Ordinates. In Heat Exchanger, dual cell model is selected. In which, flue gases is selected as primary fluid zone and fluid is selected as auxiliary fluid zone

In species model, species Transport model is selected. Volumetric option is set on in reaction. Lignite volatile air is selected in mixture material. Then in coal calculator, different values are given

To analyse the problem, oil is selected as a fluid material and ASTM A53 and BS 3059 is selected as a solid material. The corresponding values of different properties of fluid and solid materials are given in below Table 2.

Table 2 Material Data as an Input in the ANSYS

Material

Specific heat

(j/kg-k)

Density

(kg/m3)

Thermal conductivity

(w/m-k)

Viscosity

(kg/m-s)

Oil 1882 863 0.134 0.065433581

BS 3059 465 7850 54.7 -

ASTM A53 461 7850 51 -

For flue gases zone, coal volatile air and for fluid zone, oil are selected as material name.

Boundary conditions are used according to the need of the model. There are different five zones like flue gases inlet, flue gases outlet, fluid inlet, fluid outlet and wall outer. In which different values of different parameters like inlet temperature, emissivity, mass flow rate, velocity etc. have to be defined. Velocity of fluid is taken as 6.714 m/s and mass flow rate of flue gases is taken as 1.324 kg/s. Different values of different parameters are given in Table 3 for which calculation has been shown.

Table 3 Flue Gases and Fluid Boundary Conditions [3]

Zone Type Inlet temperature (k) Internal emissivity

Flue gases inlet Mass flow rate 1428 0.6

Flue gases outlet Pressure outlet - 0.6

Fluid inlet Velocity inlet 405 0.6

Fluid outlet Pressure outlet - 0.6

Data Calculation

For coal calculation, following details of the coal are required as follows in Table 4

Table 4 Proximate and Ultimate Analysis of Coal with its Properties [3]

Proximate Analysis (mass fraction, dry) Value Ultimate Analysis (mass fraction) Value

Volatile Matter 37.4 % Carbon (C) 73.69 %

Fixed Carbon 54.3 % Hydrogen (H) 4.66 %

Moisture Content 0 % Nitrogen (N) 1.33 %

Ash 8.3 % Sulphur (S) 0.86 %

Total 100 % Oxygen (O) 19.46 %

Total 100 %

Physical Properties (Dry) Value

Raw Coal Density 1560

kg m

/

3

Raw Coal Specific Heat 1.225

kJ

kgK

From above Table 1 molecular weight of each constituent, Molecular weight of each constituent by ultimate analysis and proximate analysis, typical air requirement for combustion process, mole, and mass fraction. Dulong’s Formula is used to calculate the Higher Calorific Value and Lower Calorific Value of the fuel and which is calculated as follows[10]:

HHV/HCV/GCV = [33800 C + 144000 (H-O/8) + 9270S]/100 = 25298.792 kJ/kg = 276388.842 kJ/kmol (1)

LHV/LCV/NCV = HHV – (9*H*2442) = 24274.6172 kJ/kg = 265199.7509 kJ/kmol (2)

For heat generation from the flue gases with its necessary properties requirement are calculated by following tables

Table 5 Data Constant for Molar Specific Heat [2]

Molar Specific Heat A B C D

2

CO

43.2936 0.01147 0 -818558.5

2

N

27.2155 4.19



10

03 0 0

2

O

34.63 1.08



10

03 0 -785900

2

SO

32.24 0.0222 -3.48



10

06 0

2

H O

34.42 6.28



10

04 5.61



10

06 0

Molar Property of Component

A B T

C T

2

D

1

₂

T

    

 

, (3)

Molar Property





%

w

_i



Property of Component

(4)

Table 6 Data Constant for Thermal Conductivity [4]

Thermal Conductivity

(mW/m K)

A B C D

2

CO

14.146 0.084035 _-1.87



₁₀

05 _4.17



₁₀

09

2

N

24.6665 0.063338 _-1.83



₁₀

05 _3.92



₁₀

09

2

O

24.625 0.072635 _-1.34



₁₀

05

2.47



10

09

2

SO

14.146 0.084035 _-1.87



₁₀

05 _4.17



₁₀

09

2

H O

15.4632 0.087818 _2.68 05

10





-1.28



10

09

Table 7 Data Constant for Specific Heat [4]

Specific Heat

(kJ/kg K) A B C D

2

CO

0.819372 _5.25



₁₀

04 _-2.76



₁₀

07 _6.18



₁₀

11

2

N

1.03768 _1.41



₁₀

06 _1.20



₁₀

07 _-4.59



₁₀

11

2

O

0.908963 _1.42



₁₀

04 _-2.02



₁₀

09 _-1.40



₁₀

11

2

SO

0.594236 _3.23 04

10





-1.52



10

07 2.78



10

11

2

H O

1.85076 _1.33



₁₀

04 _2.39



₁₀

07 _-9.02



₁₀

11

Table 8 Data Constant for Dynamic Viscosity [4]

Dynamic Viscosity

(kg/ms)



10

06 A B C D

2

CO

13.7639 0.049807 _-2.10



₁₀

05 _5.70



₁₀

09

2

N

16.8846 0.044049 -1.86



10

05 5.89



10

09

2

O

19.269 0.054237 _-2.42



₁₀

05 _7.80



₁₀

09

2

SO

13.7639 0.049807 _-2.10



₁₀

05 _5.70



₁₀

09

2

H O

7.5245 0.044734 _-6.75



₁₀

06 _2.94



₁₀

09

BS – 3059 Part – 1 [5]

Density of Steel = 7850

kg m

/

3

Table 9 Properties Variation of BS 3059 Part 1 [5]

Temperature (0

C

) 20 100 200 300 400

Temperature (K) 293 373 473 573 673

Specific Heat Capacity from

20 0

C

(

J kgK

/

)

- 468 492 516 541

Thermal Conductivity

(

W mK

/

)

54.7 53.8 50.5 47.0 43.5

ASTM A-53 Grade A [11]

Density of Steel = 7850

kg m

/

3

Thermal Conductivity at 200

C

= 51

W mK

/

Specific Thermal Capacity at 200

C

= 461

J kgK

/

Table 10 Property Variation of ASTM A53 Grade A [6]

Temperature

(0

C

)

21 93 204 316 399 510

Temperature (K) 294 366 477 589 672 783

Thermal Conductivity

(

W mK

/

)

46.9 44.6 41.8 38.9 37.0 34.1

After the conduction, heat is passed inside the fluid and it is heated due to convective heat transfer and for that condition,In this work following fluid is selected for analysis and its details mentioned as follows:

- Fluid Name: Shell Heat Transfer Oil S2

- Previous Name: Shell Thermia B

- Manufacturer: Shell Lubricants [7] Typical fluid properties are as follows:

Table 11 Typical Fluid Properties [7]

Property Unit Value

Density at 15 0

C

kg m

/

3 866

Flash Point PMCC 0

C

210

Flash Point COC 0

C

220

Fire Point COC 0

C

255

Pour Point 0

C

-12

Initial Boiling Point 0

C

355

Auto ignition Temperature 0

Fluid properties which are required for the further calculations are as follows:

Table 12 Fluid Properties Data [7]

Temperature K

Temperature

0

C

Density

3

/

kg m

Specific Heat

/

kJ kgK

Prandlt No

Dynamic Viscosity

/

kg ms

Kinematic Viscosity

2

/

m

s

Thermal Conductivity

/

W mK

273 0 876 1.809 3375 0.2537313 0.00028964 0.136

293 20 863 1.882 919 0.0654335 7.8521105

10





0.134

323 40 850 1.954 375 0.0255245 3.0028905

10





0.133

373 100 811 2.173 69 0.0040644 5.0116506

10





0.128

423 150 778 2.355 32 0.0016985 2.1831806

10





0.125

473 200 746 2.538 20 0.0009535 1.2781606

10





0.121

523 250 713 2.72 14 0.000607 _8.52



₁₀

07 0.118

573 300 681 2.902 11 0.000432 6.35



10

07 0.114

613 340 655 3.048 9 0.000328 ₅



₁₀

07 _0.111

From above Table 12, equations are generated for further procedure with the help of Newton- Raphson method Heat Transfer Calculation and its Balance

Available Data from previous calculations

Mass flow rate of coal m_fuel= 380 kg/hr =0.105555556 kg/s [8]

Table 13 Geometry Data Available [8]

Geometry Name Geometry Symbol Value Unit

Diameter of coil

D

coil 1.95 m

Pitch of coil / Centre to Centre distance C 0.064 m

Diameter of outer tube

d

o 0.0635 m

Diameter of inner tube

d

i 0.05618 m

Number of tubes N 22 -

Table 14 Constant Properties to be used [2, 9]

Constant Property Name Value Unit

Universal Gas Constant

R

_{0 8.314}

J

kmolK

StefenBoltzman Constant



_2.04 07

10





2 4

kJ

hrm K

Exchange Factor F 0.97 -

Relative Effectiveness



0.9 -

Various Temperatures available for analysis procedure

Table 15Various Temperatures Required [2, 8]

Temperature _In 0

_C

In K

air

T

30 303

datum

T

25 298

in

T

132 405

out

T

162 435

fuel

T 30 303

wall

T

247 520

fluid

T 30 303

For wall temperature [2];

wall

T

100 (

)

2

in out

T



T





(5)

From air requirement Calculation;

air

m

= m_fuel



Air fuel ratio = 380



11.54434907 = 4386.852647 kg/hr = 1.21857018 kg/s

(6)

fluegases

m = m_fuel+

m

_air= 4766.852647 kg/hr = 1.324125735 kg/s (7)

fuel fuel

fuel

m

M

M



= 34.27866667 kmol/hr (8)

air air

air

m

M

M



= 151.6263185 kmol/hr (9)

fluegases fuel air

M  M M = 186.4089852 kmol/hr (10)

combustion

Q



M fuel



GCV

_{=9613540.96 kJ/hr} (11)

losses

net

Q



Q

combustion -

Q

losses= 9132863.912 kJ/hr (13)

net

q

=

Q

_net/M fluegases= 48993.68936 kJ/kmol (14)

From Table 5;

fluegases

p

C

= 30.83200934



T

+ 0.002225781



T

2 + 232555.3337



1

T

+ 9.02043

08

10







3

T

(15) Now to calculate flame temperature, function is made from below formula

net

Q



M fluegases



Fluegases

p

C



T_flame (16)

And function is

F (T) =

Fluegases

p

C

-

Q

_net/M fluegases = 30.83200934



T

+ 0.002225781



T

2 + 232555.3337



1

T

+ 9.02043

08

10







3

T

- 48993.68936 = 0 (17)

By solving above equation by newton-raphson formula, flame temperature is

flame

T = 1428 K [2]

And at above temperature, Molar specific heat is

Fluegases

p

C

= 37.85471121

kJ

kmolK

Atmospheric Pressure P = 101325 Pa

From Molar Mass Calculation;

fluegases

M = 31.42290134 kg/kmol

Temperature of fluegases = T_fluegases in K

fluegases



= 0 fluegases fluegases

P M

R

T





(18)

s

fluegase

in

A

= 2

4

D

coil



_

= 2.99066625

m

2 (19)

fluegases v = s fluegase fluegases in fluegases

m

A





= 0.001321462 m/s (20)

From Table 8;



06

10



= 16.41626922 + 0.046478878



T_fluegases- 1.92



10

05



2

fluegases

T

+6.03



10

09



3

fluegases

T

(21) From Table 6;

fluegases

K



10

03 = 22.8600805 + 0.068699826



T_fluegases- 1.53



10

05



T

_fluegases2+2.90



10

09



T

_fluegases3 (22)

From Table 7;

fluegases

p

c

= 1.028054065 + 9.79



10

05



T_fluegases+ 5.54



10

08



2

fluegases

T

-2.90



10

11



3

fluegases

T

(23)

Re =



fluegases

v

fluegases

D

coil







(24)

Pr = pfluegases

fluegases

c

K





Nusselt Number Correlation inside helical coil is given by [12];

Nu =

19.64 Re

0.513

Pr

0.129

(

)

0.938

2

coil

C

D









(26)

coil

h

= fluegases

coil

Nu K

D



(27) conv

h

=

h

_coil

L =





D

_coil=6.1347 m (28)

A = N



C



L = 8.789924

m

2 (29)

shield

A

= 2.5423

m

2 ₍₃₀₎

2

4

i i

A

 



d

_{= 0.002482345}

m

2 ₍₃₁₎

fluid

i

v

₌

i

V

A

= 6.714080638 m/s (32)

Molar Specific Heat of air [2];

air

p

C = 33.915 + 1.214



10

03



(

T

_air



T

_datum

)

kJ

kmolK

= 34.279807

kJ

kmolK

(33)

From Table 13;

fluid

m =

V





_fluidat T_fluid = 51390.978894 kg/hr (34)

fluid

p

c

=1.917685833

kJ

kgK

at Tfluid

in

Q

=

Q

_rls +

Q

_air + Q_fuel + Q_fluid (35)

rls

Q

= Mfuel



NCV (36)

air

Q

=

M

air



air

p

C



(

T

_air -

T

_datum) (37)

fuel

Q = Mfuel



fuel

p

C



(T_fuel -

T

_datum) (38)

fluid

Q = m_fluid



fluid

p

c



(T_fluid -

T

_datum) (39)

out

Q

=

Q

_R +

Q

_shield +

Q

_losses + Q_fluegases (40)

R

Q

=

Q

_r+

Q

_conv =



   

F



A

(

T

_fluegases4



T

_wall4

)



h

_conv

 

A

(

T

_fluegases



T

_wall

)

(41)

shield

Q

=



  

F



A

_shield



(

T

_fluegases4



T

_wall4

)

(42)

losses

Q

= 0.05



Q

_rlskJ/hr (43)

fluegases

Q = M fluegases



fluegases

p

C



(T_fluegasesT_datum) (44)

By rearranging the above equations,

[



  

F



(

A

+

A

_shield)]



T

_fluegases4 + [(

h

_conv



A

+M fluegases



fluegases

p

C

)]



T_fluegases- [0.95



Mfuel



NCV +

M

air



air

p

fluegases

p

C



T

_datum -

M

air



air

p

C



T

_datum- Mfuel



fuel

p

C



T

_datum +



  

F



(

A

+

A

_shield)



T_wall4 +

conv

h

 

A

T

_wall] = 0 (45)

Now, by solving above equations with Newton Raphson Formula,

fluegases

T = 1146 K [2]

Table 16 Flue Gases Properties and Values

Parameter Value Unit

fluegases



334.1706139

kg m

/

3



_5.35 05

10





kg

ms

fluegases

K _8.58 02

10





W

mK

fluegases

p

c

1.17

kJ

kgK

Re _1.61



₁₀

04 -

Pr _7.29



₁₀

01 -

Nu 57.52408573 -

conv

h

=

h

_coil 2.53

W

₂

m K

Table 17 Heat Balance Sheet, kJ/hr

Parameter Value Parameter Value

in

Q

9745429.402

Q

out 9721710.198

rls

Q

9224354.536

Q

R 2528407.404

air

Q

25988.60467

Q

shield 748208.4287

fuel

Q 2327.5

Q

losses 461217.7268

fluid

Q 492758.761 Qfluegases 5983876.638

Above Values and the Parameters are shows that the heat balance and the other details which generates and provides proper amount of heat to the radiant heat exchanger wall and from that data CFD analysis would done on the ANSYS 14.0 Fluent (Non-Commercial Use Only) would give how much amount of heat can be carried by the fluid and the further results would obtained.

RESULTS

Table 18 Mass Flow Rate

Mass flow Rate (kg/s)

BS 3059 Part 1 ASTM A53 Grade A

Fluid Fixed property

Fluid Variable Property

Fluid Fixed Property

Fluid Variable Property

Fluid Inlet 12.796662 11.710684 12.796662 11.710685

Fluid Outlet -12.763357 -11.699321 -12.803849 -10.350078

Flue Gases Inlet 1.324 1.324 1.324 1.324

Flue Gases Outlet -1.2503964 -0.98158332 -1.2932405 -1.3236992

Table 19 Total Heat Transfer Rate

Total Heat Transfer Rate (w)

BS 3059 Part 1 ASTM A53 Grade A

Fluid Fixed property

Fluid Variable Property

Fluid Fixed Property

Fluid Variable Property

Fluid Inlet 2697325.9 2734787 2697325.9 2734819.9

Fluid Outlet -3944798.4 -3697056.4 -3953362.9 -3710175.4

Net -1247472.5 -962269.46 -1256037 -975355.53

Wall 1240136.8 835037.23 1240224.7 1270089.9

Table 20 Temperature Data for Various Conditions

Temperature

(K)

BS 3059 Part 1 ASTM A53 Grade A

Fluid Fixed property

Fluid Variable Property

Fluid Fixed property

Fluid Variable Property

Fluid Inlet 405 405 405 405

Fluid Outlet 457.23126 440.04703 457.06729 457.39188

Vectors of Static Temperature

Table 21 Result Table Comparison

Material BS 3059 Part 1 ASTM A53 Grade A

Fluid Condition Fixed Value Variable Value Fixed Value Variable Value

Outlet Temperature

(K) 457.23126 440.04703 457.06729 457.39188

Heat generated by

fuel (kcal/hr) 2204620.734 (for 10,00,000 Capacity)

Net Heat Carried by

fluid (kcal/hr) 1073325.339 827936.6434 1080694.235 839195.898

Thermal Efficiency

(%) 48.6852 37.5546 49.0195 38.0653

Analytical value of the heat that can be carried during the actual process from available data at relative temperature which is given by;

Heat Carried by the fluid =





2

2

pin pout

in out

out in

c

c

V



_











_





_





_



T



T



 



= 749086.0312 kcal/hr

CONCLUSION

From the analysis of the various results of BS 3059 and ASTM A53 in ANSYS, the following conclusions can be achieved:

1. The specific heat of ASTM A53 (461

J kgK

/

) is lower than BS 3059 (465

J kgK

/

). So, the amount of heat per unit mass required to raise the temperature by one Kelvin in ASTM A53 is lower than BS 3059. Therefore, the heat transfer of the ASTM A53 is slightly higher than BS 3059.

2. The number of alloying elements in ASTM A53 is higher than the BS 3059. As the alloying elements

increases, thermal conductivity decreases. Therefore, the thermal efficiency of ASTM A53 is not too much higher than the BS 3059.

3. From the available data, the cost of ASTM A53 is also lower compared to BS 3059. So, it is better option for industry.

4. The fluid outlet temperature is slightly reduced in ASTM A53 compared to BS 3059 which does not

affect the exactness of the working condition of the Thermic Fluid Heater.

5. The analysis also gives higher results compared to the actual analytical value. So, it indicates that predicted analyses can become basis for actual experiment.

REFERENCE

[1] Code of Practice for Thermal Oil Heaters (Issued under Section 18A of the Boiler and Pressure Vessels Ordinance), Boiler & Pressure Vessels Authority, Hong Kong, 1992, Chapter 2, Page no. 9-11

[2] Hasan Al-Haj Ibrahim (2010), “Fired Process Heater”, Matlab – Modelling, Programming and Simulations, Emilson Pereira Leite (Ed.), ISBN: 978-953-307-125-1, In Tech, Available From: http://www.intechopen .com/books/matlab-modelling-programming-and-simulation/fired-process-heaters

[3] Rajesh Holkar, Dr.Ompraksh. D. Hebbal (2013) , “CFD analysis of Pulverised Coal Combustion of Burner Used In Furnace with Different Radiation Models”, Department of mechanical Engineering, PDA college of Engineering, Gulbarga, IOSR Journal of mechanical and civil engineering (IOSR-JMCE), e-ISSN: 2278-684, Volume 5, Issue 2, pp 25-34.

[4] H. Verbanck (1997) , “Development of a Mathematical Model for Water-tube Boiler Heat Transfer Calculation”, Proc S AfrSugTechnol Ass -71, pp 161-171

[5] BRITISH STANDARD, BS 3059-1:1987, Steel boiler and super heater tubes - Part 1: Specification for low tensile carbon steel tubes without specified elevated temperature properties, UDC 621.184.2-034.14

[6] G. K. Sahu (1998), “Handbook of Piping Design”, New Age International (PVT) Limited, ISBN: 81-224-1141-X

[7] Technical Data Sheet of “Shell Heat Transfer Oil S2”, High Performance Heat Transfer fluid, Shell Lubricants, August 2010 Report [8] GUJTEX Catalogue, GUJTEX Engineering Company

[9] Dr.ReyedShawabkeh, “Steps for design of Furnace/ Fired Heater”, Department of Chemical Engineering, King Fahd University of Petroleum & Minerals

[10] R. K. Rajput (2007), “Engineering Thermodynamics”, Laxmi Publication (P) LTD, ISBN: 978-0-7637-8272-6, 3678

[11] ThyssenKrupp Materials International, ASTM A53, Grade A (P235TR1/2) and Grade B (P265TR1/2), Material Data Sheet applies for seamless and welded tubes of non-alloy steel with specified elevated temperature properties (October 2011)