
2/21

1

Summary

The objective of this experiment was to study a single pass shell and tube heat exchanger which

included the comparison between theoretical and experimental results of both individual and

overall heat transfer coefficients and tube side pressure drops. In this experiment, cooling water

was used to recover heat form saturated steam. The cooling water was flown through the pipe

and the saturated steam was flown through the annulus. The experiment was performed at

different steam pressure. The values of overall heat transfer coefficient found experimentally

vary from 173.7199- 290.2413 J/sec.m2.K where the theoretical values range from 1651.821-

2593.331 J/sec.m2.K. The tube side pressure drop were in between 8092.587-39451.36 Pa

experimentally, where the theoretical pressure drop range from 1987.478- 12326.29 Pa.

Colburn JH factor (JH) vs. Reynoldss number (Re) and pressure drop (P) vs. velocity (v)

graphs are plotted both for 2.5 and 5 psig. The graphs show deviation from the theoretical graphs.

The possible discrepancies are described in discussion.


3/21

1-1Shell

andTube

Heat

Exchanger

Manometer

SteamIn

Condensate

Out

WaterIn

WaterOut

WaterTank

Pump

Steam

Trapper

Thermometer

Guage

Pressure

Controller

Figure1:Schematicdiagramoftheexperimentalsetup

Experimental Setup

2


4/21

3

Figure 3: Temperature profile of the Shell and Tube Heat Exchanger

Figure 2: Schematic Diagram of a 1-1 Shell and Tube Heat Exchanger

T1Water Ts Steam

T2

Steam

Condensed

Cold Water

Hot Water


5/21

4

Observed Data

Weight of Bucket = 1.5 Kg

Heat Exchanger

Shell: Nominal Size 6

Schedule No. 40

Passes: Shell side=1

Tube side=1

Tubes: OD= 0.5 inch

BWG=16

Length=96 inch

Number= 19

Pump

Centrifugal pump

1.5 kW; 240 V; 50 Hz; 2900 rpm

Hmax =38m; Qmax = 250 l/h

Table 1: Table of observed data for the study of a single pass shell and tube heat exchanger

No.

of

Obs

Steam

pressure

Flow

meter

reading

Water

temperature

Weight of

Bucket

+

Condensate

Collection time Manometer

reading

Inlet Outlet Water Condensat

e

Left Right

psig Litre oC oC Kg sec sec inch inch

1

2.5 10 23

30 2.35 14.75 60 33.5 36

2 29 2.4 10.57 60 32.6 36.5

3 28.5 2.5 8.47 60 31.5 37.3

4 27.5 2.55 6.75 60 30 385 27 2.6 5.25 60 27.6 39.3

6

5 10 23

31 2.1 11.47 60 33.4 35.8

7 30.75 2.3 9.54 60 32.3 36.5

8 30.5 2.5 8.56 60 31.5 37

9 29.5 2.6 7.09 60 30 37.7

10 28.75 2.65 5.41 60 27.5 39


6/21

5

Calculated Data

Table 2: Table of different water bulk temperatures and flow rates of water and condensate

No.of

Obs

Steampressure

Waterbulk

temperature

(Tb)

Weight Flow rate

Water

(mw)

Condensat

e

(mc)

Water

(Ww)

Condensate

(Wc)

psia oC kg kg kg/sec kg/sec

1

17.2

26.5 9.96653 0.85 0.675697 0.014167

2 26 9.96787 0.9 0.943034 0.015

3 25.75 9.96853 1 1.176922 0.016667

4 25.25 9.96984 1.05 1.477013 0.0175

5 25 9.9705 1.1 1.899143 0.018333

6

19.7

27 9.96517 0.6 0.868803 0.017 26.875 9.9655 0.8 1.044602 0.013333

8 26.75 9.96585 1 1.164235 0.016667

9 26.25 9.9672 1.1 1.405811 0.018333

10 25.875 9.9682 1.15 1.842551 0.019167

Table 3: Properties of water at bulk temperature

No.of

Obs

Waterbulk

temperature(Tb)

Density

(w)

Viscosity() Heat Capacity(c) ThermalConductivity

(k)oC Kg/m3 Pa-sec KJ/Kg-Kelvin Watt/m-Kelvin

1 26.5 996.653 0.00086 4.181 0.60972 26 996.787 0.00087 4.181 0.60893 25.75 996.853 0.00088 4.182 0.6084 25.25 996.984 0.00089 4.182 0.6085 25 997.05 0.00089 4.182 0.607

6 27 996.517 0.00085 4.181 0.611

7 26.875 996.55 0.00085 4.181 0.618 26.75 996.585 0.00086 4.181 0.619 26.25 996.72 0.00087 4.181 0.609

10 25.875 996.82 0.00087 4.181 0.609


7/21

6

Table 4: Properties of condensate at film temperature

Table 5: Table of heat balances, LMTD and experimental overall heat transfer coefficient

No.

of

Obs

Heat absorbed

by water

(Qw)

Heat released

by steam

(Qc)

Average heat

transfer

(Qavg)

LMTD Overall heattransfer co-

efficient

(Experimental)

(UOE)

KJ/sec KJ/sec KJ/sec oC J/sec.m2. K

1 19.77562261 31.25350833 25.51456547 77.64741898 177.7150635

2 23.6569524 33.09195 28.3744512 78.16162176 196.3346702

3 27.07038471 36.76883333 31.91960902 78.41785647 220.1434079

4 27.79591392 38.607275 33.20159446 78.92862108 227.5032022

5 31.76886171 40.44571667 36.10728919 79.18316212 246.6182049

6 29.05972155 22.355 25.70736077 80.03337223 173.7198577

7 33.84796699 29.80666667 31.82731683 80.1625715 214.7293829

8 36.50749315 37.25833333 36.88291324 80.29162756 248.4380115

9 38.20502268 40.98416667 39.59459467 80.8064335 265.0043796

10 44.29630391 42.84708333 43.57169362 81.19106797 290.2413437

No. of

Obs

Film

temperature

(Tf)

Viscosity

()

Density

(w)

Thermal

Conductivity

(k)oC Kg/m3 Pa-sec Watt/m-Kelvin

1 75.0625 0.00037 974.82 0.667

2 74.875 0.00038 974.93 0.667

3 74.78125 0.00038 974.99 0.667

4 74.59375 0.00038 995.1 0.667

5 74.5 0.00038 975.15 0.666

6 77.0625 0.00037 973.61 0.668

7 77.015625 0.00036 973.64 0.668

8 76.96875 0.00037 973.67 0.668

9 76.78125 0.00037 973.78 0.66810 76.640625 0.00037 973.87 0.668


8/21

7

Table 6: Table of nusselt number, prandtl number, shell and tube side heat transfer co-

efficients and theoretical overall heat transfer coefficient

No.

of

Obs

Nusselt

number

(Nu)

Prandtl

number

(Pr)

Heat transfer

co-efficient

(Tube side)hi

Heat transfer

co-efficient

(Shell side)

ho

Overall heat

transfer co-

efficient(Theoretical)

(UOT)

J/sec.m2. K J/sec.m2. K J/sec.m2. K

1 53.08764109 5.897424963 3443.354763 4694.305766 1651.820895

2 69.72368795 5.973838069 4516.463148 4655.903542 1945.816467

3 83.74419646 6.052894737 5416.645899 4652.332961 2153.43645

4 100.968729 6.121677632 6530.743325 4692.60798 2381.073628

5 123.1305926 6.131762768 7951.092521 4636.44016 2593.330737

6 64.72125544 5.816448445 4206.881604 4676.51856 1869.194017

7 75.04255252 5.825983607 4869.782664 4706.898753 2041.264854

8 82.29696073 5.89452459 5340.547451 4673.020676 2141.4348439 96.27353274 5.972857143 6237.295898 4666.042579 2320.590061

10 119.5366115 5.972857143 7744.446425 4660.863049 2570.638783

Table 7: Table of Reynolds number, friction factor, jh, velocity, and mass velocity of water

No.

of

Obs

Reynolds

number

(Re)

Friction

factor

(f)

Velocity of water

(Vw)

Mass velocity

(Gt)

jH

ft2/in2 m/sec Kg/sec.m2

1 5536.655319 0.00033 0.514156 512.4351199 26.6662382

2 7727.213425 0.0003 0.717483538 715.1782638 34.81625786

3 9643.689957 0.00028 0.895372019 892.5542833 41.56792595

4 12102.63527 0.00027 1.123526074 1120.13752 49.8502936

5 15561.56116 0.00025 1.444533524 1440.27215 60.95457329

6 7118.96444 0.00031 0.661185789 658.882879 32.60597739

7 8559.457667 0.00029 0.794947694 792.2051245 37.78511626

8 9539.730612 0.00028 0.885958061 882.9325141 41.20905477

9 11519.20394 0.00027 1.069647532 1066.139088 47.91833705

10 15097.84657 0.00025 1.401811645 1397.353884 59.49709619


9/21

8

Table 8: Table of tube side experimental and theoretical pressure drops

No.

of

Obs

Diff. in manometer

reading

Pressure drop

(Experimental)

(p)

Pressure drop

(Theoretical)

(p)

Wall

temperature

(Tw)

Viscosity at

wall

temperature

()m Pa Pa oC Kg/m3

1 0.063500772 8429.778306 1987.477737 65.35 0.00043

2 0.099061205 13150.45416 3496.852602 65.1 0.00043

3 0.147321791 19557.08567 5133.144374 64.975 0.00043

4 0.203202471 26975.29058 7953.500684 64.725 0.00043

5 0.297183614 39451.36247 12326.28535 64.6 0.00044

6 0.060960741 8092.587174 3096.933688 67.05 0.00042

7 0.106681297 14162.02755 4227.592083 66.9875 0.00042

8 0.139701699 18545.51227 5109.137718 66.925 0.00042

9 0.195582378 25963.71718 7364.585232 66.675 0.00042

10 0.292103552 38776.98021 11789.0593 66.4875 0.00042


10/21

9

Sample Calculation

Sample calculation for observation no. 6

Water inlet temperature, T1 = 23oC

Water outlet temperature, T2 = 31oC

Water Mean temperature, Tm =2

TT21

=

2

3123= 27 oC

Properties of water at mean temperature (27 oC),

Density, = 996.517 Kg/m3

Heat capacity, Cp = 4.181 KJ/Kg-kelvin

Viscosity, =0 .00085 Pa-sec

Thermal conductivity, k = .611 Watt/m-kelvin

Weight of bucket and condensate = 2.1 kg

Weight of bucket = 1.5 kg

Weight of condensate = (2.1-1.5) kg

= 0.6 kg

Flow rate of condensate, mc =sec60

Kg0.6

= 0.01 Kg/sec

Heat of condensation, c = 2235.5 KJ/Kg

Heat released by condensation, Qc= mcc

= (0.012235.5) KJ/sec

= 22.355 KJ/sec

Volume of water = 10 L

Weight of water = 10996.517/1000 = 9.96517 Kg

Flow rate of water, mw = (9.96517/11.47) Kg/sec

= 0.868802964 Kg/sec


11/21

10

Heat absorbed by water, Qw = mwCp(T2-T1)

= 0.868802964 4.181(31-23)

= 29.05972155KJ/ sec

Average heat transfer, Qavg =2

QQ cw

=2

29.05972355.22

= 25.70736077 KJ/sec

Saturation temperature at 5 psig (=19.7 psia), Ts= 107.1oC

Logarithmic Mean Temperature Difference,

LMTD =

2s

1s

2s1s

TT

TTln

)T(T)T(T

=

2s

1s

12

TT

TTln

TT

=

131.071

321.071ln

3213

= 80.03337223 K

The outside area of a 0.5 inch 16 BWG tube = 0.03991 m2/ lin m

Length of each tube = 96 inch = 2.438 m

Number of tubes = 19

Total outside area, A0 = 19 2.4384 0.03991

= 1.849 m2

Experimental overall heat transfer co-efficient,

UOE =LMTDA

Q

0

avg

= 3600143.3259849.1

35.23095


12/21

11

= 173.72 J/sec.m2. K

Prandtl Number, Pr =kCp

= 5.81645

Flow area of tube, Ai = 0.0000694 m2

Velocity of water, Vw =i

w

A

m

=190.0000694996.517

0.868803

= 0.66119 m/sec

Reynolds number, Re =

vD wi

= 7118.96

Tube wall temperature (steam side),

Tw =2

)]TT(0.5[Ts 21

=2

)]3132(0.5[107.1

= 67.07 oC


13/21

12

Using Seider-Tate equation,

Nu =0.027 Re0.8 Pr1/3(f/ w)0.14

= 0.027(7118.96)0.8 (5.81645)1/3(0 .00085/0.00042)0.14

= 32.606

Water side heat transfer co-efficient for turbulent flow,

hi = Nu i

D

k

= 4206.88 J/ sec. m2. K

Film temperature, Tf = Ts 0.75(Ts-Tw)

= 107.1 0.75 (107.1- 67.05)

= 77.0625 oC

Properties of condensate at film temperature (77.0625 oC),

Density, f = 973.61 Kg/m3

Viscosity, f = 0.00037 Pa-sec

Thermal conductivity, kf= 0.668 Watt/ m-kelvin

Heat of condensation, hfg = c= 2235500 J/Kg

Density of steam, v 0

Saturation temperature, Tg =Ts = 107.1oC = 380.1 K

Using Nusselt equation, steam side heat transfer co-efficient,

ho = 0.725

25.0

wgf

3ffgvff

)Tnd(T

kgh)(

= 0.725

25.0

wgof

3ffg

2f

)T(TD

kgh

= 4676.52 J/ sec. m2.oC


14/21

13

Theoretical overall heat transfer co-efficient,

UOT =

-1

ii

o

0 hD

D

h

1

= 1869.19 J/ sec. m2.K

jH factor calculation, jH = Nu .Pr-1/3.

14.0

w

= 32.606

Tube side Pressure Drop Calculation,

Specific gravity, s = 1

Internal diameter, D = 0.37 inch = 0.031 ft

Length of the tube, L = 8 ft

No. of pass in tube side, n = 1

The factor, t =

14.0

w

=

14.0

0.00042

0.00085

= 1.10373

Mass velocity, Gt = 658.883 lb/hr.ft2

For this mass velocity,2g'

V 2

144

52.5= 0.03 psi

For Reynolds number of 7118.96,

Friction factor, f = 0.00031ft2/in2

Pressure drop, pi =t

10

2

t

Ds105.22

LnGf

= 0.3288 psi

Pressure drop due to velocity head,

p r=

2g'

V

s

4n 2

144

52.5

= 0.12042 psi


15/21

14

Total theoretical pressure drop, p = pi+ pr

= (0.3288 + 0.12042)

= .4493psi

Again,Manometer reading (left) = 33.4 in

Manometer reading (right) = 35.8 in

Difference = (35.8 33.4) in

= 2.4 in

Experimental pressure drop, p = 1.174 psi


16/21

15

Results and Discussions

The results are summarized bellows

Heat transfer co-efficient (Shell side), h0 4636.44016-4706.898753 J/sec.m2. K

Heat transfer co-efficient (Tube side), hi 3443.354763-7951.092521 J/sec.m2. K

Overall heat transfer co-efficient

(Theoretical), UOT

1651.821- 2593.331 J/sec.m2.K

Overall heat transfer co-efficient

(Experimental), UOE

173.7199- 290.2413 J/sec.m2.K

For the jHFactor vs. NReplotted on log-log coordinate

1. The slope for 2.5 psig = 0.8 is shown at figure 4

2. The slope for 5 psig = 0.8 is shown at figure 5

All the graphs had shown their expected characteristics. The slope for steam pressure 2.5 psig

is 0.8 and for steam pressure 5.0 is 0.8 whereas the theoretical value is 0.8. Thus, the graphs

establish the validity of Sieder-Tate equation.

The theoretical and experimental results shows some discrepancies. The possible causes are

discussed here-

1. The theoretical values obtained in this experiment are not wholly theoretical. Thesevalues are found based on some parameters that are determined experimentally in one

way or another. Hence, they cannot be said to be purely theoretical.

2. There might be some heat loss through the pipes and wall which was not accountedduring the calculation. This might have brought the discrepancy. The theoretical value

was not a pure literature value. It was calculated by manipulating some data or

parameters.

3. The apparatus was very old and proper maintenance is not taken for several years.Excess fouling may encounter in tube side which decrease the overall heat transfer co-

efficient.

4. Heat absorbed by water was greater than the heat released by the steam which isnormally impossible. Uses of steam trapper caused this.


17/21

16

5. We assumed that the convection heat transfer co-efficient are constant through the heatexchanger, but experimentally the heat transfer co-efficient were not constant while

operation.

6. The steam pressure was considered constant during operation, but, it was not constantwhile operation.


18/21

17

NuPr (-1/3)(u/uw) -.014 vs. Reynolds Number (2.5 psig)

Figure 4: Graph of NuPr (-1/3)(u/uw) -.014 vs. Reynolds Number at 2.5 psig pressure

y = 0.027x0.8

10

100

5000

NuPr^(-1/3)(u/uw)^-.014

Reynold's Number


19/21

18

NuPr (-1/3)(u/uw) -.014 vs. Reynolds Number (5 psig)

Figure 5: Graph of NuPr (-1/3)(u/uw) -.014 vs. Reynolds Number at 5 psig pressure

y = 0.027x0.8

10

100

5000

NuPr^(-1/3)(u/uw)^-.014

Reynold's Number


20/21

19

Pressure drop vs. Water velocity (2.5 psig)

Figure 6: Graph of Pressure drop vs. water velocity at 2.5 psig pressure

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0.4 0.6 0.8 1 1.2 1.4 1.6

Pressu

redrop

Water velocity

Theoretical

Experimental


21/21

20

Pressure drop vs. Water velocity (2.5 psig)

Figure 7: Graph of Pressure drop vs. water velocity at 2.5 psig pressure

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5

Pressuredrop

Water velocity

Theoretical

Experimental

Study of a Single Pass Shell and Tube Heat Exchanger

Documents