228608912 Shell and Tube Heat Exchanger

8/18/2019 228608912 Shell and Tube Heat Exchanger

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ABSTRACT

This experiment was conducted to evaluate and study the performanceof the shell and tube heat exchanger heat load and heat balance, LMTD,

overall heat transfer coe cient ,Reynolds shell side and tube side, heattransfer coe cient and pressure drop at shell side and tube side. Theexperiment will run in with ! sets each. "ach runs will be using di#erentnominal $ow rates for %& and '&. &e carried out for Run ((( and () only. The*%+*' that close to .-- will be chosen to use for calculation. "very runwill be using di#erent $ow rate. /rom the result, the pressure drop dependson the $ow rate not the temperature. 0s we can see that the pressure dropfor Run ((( which used - 123M and 4 123M was higher than pressure atRun () which used - 123M. /rom the calculation, we conclude that thenumber of *% is decreasing from Run ((( to Run () and same pattern goes to*' and -.45*%6*'7.8ther than that, is also decreasing from R 9 ((( to Run(). The overall heat transfer coe cient, , Reynolds number and $ow ratesof hot water are also decreasing from Run ((( to Run ().


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INTRODUCTION

1hell:and:tube heat exchangers are commonly used in oil re;neriesand other large:scale chemical processes. 0 heat exchanger is a device thatis used to transfer thermal energy between transfer thermal energy betweentwo or more $uids, between a solid surface and a $uid a $uid, or betweensolid particulates and a $uid at di#erent temperatures and in thermal contact(n this model, two separated $uids at di#erent temperatures $ow through theheat exchanger< one through the tubes 5tube side7 and the other through the

shell around the tubes 5shell side7. 1everal design parameters and operatingconditions in$uence the optimal performance of a shell:and:tube heatexchanger. The main purpose of this model is to show the basic principles forsetting up a heat exchanger model. (t can also serve as a starting point formore sophisticated applications, such as parameter studies or addingadditional e#ects li=e corrosion, thermal stress, and vibration.

The heat exchanger is made of structural steel. The participating $uids

are water $owing through the tube side and air $owing through the shellside. The ba>es introduce some cross:$ow to the air and such increasing thearea of heat exchange. 0nother advantage is that ba>es reduce vibrationdue to the $uid motion.5%omsol, - !7.


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/igure < 2eometry of shell and tube heat exchanger

The scope of shell and tube heat exchanger

Maximum pressure• 1hell !-- bar 5?4-- psia7• Tube ?-- bar 5 ---- psia7

Temperature range• Maximum @-- o% 5 -- o/7 or even @4- o%• Minimum : -- o% 5: 4-o/7

/luids• 1ubAect to materials• 0vailable in a wide range of materials

1iBe per unit -- : ---- ft 5 - : --- m 7

'owever shell and tube heat exchanger can be extended with specialdesigns and materials.

'eat "xchangers are classi;ed according to

Transfer process9umber of $uidsDegree of surface contactDesign features/low arrangements'eat transfer mechanisms


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1hell and tube heat exchanger is the most common type of heatexchanger in industrial applications.(t contain a large number of tubes5sometimes several hundred7 pac=ed in a shell with their axes parallel to thatof the shell. 'eat transfer ta=es place as one $uid $ows inside the tubeswhile the other $uid $ows outside the tubes through the shell. 1hell:and:tubeheat exchangers are further classi;ed according to the number of shell andtube passes involved.5%engel, - 7.

/igure < 1chematic shell and tube heat exchanger5open shell pass and onetube pass7.

• Regenerative heat exchanger< (nvolve the alternate passage of the hot

and cold $uid streams through the same $ow area.• Dynamic:type regenerator< (nvolve a rotating drum and continuous

$ow of the hot and cold $uid through di#erent portions of the drum sothat any portion of the drum passes periodically through the hot


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stream, storing heat, and then through the cold stream, reAecting thisstored heat.

• %ondenser< 8ne of the $uids is cooled and condenses as it $ows

through the heat exchanger.• Coiler< 8ne of the $uids absorbs heat and vaporiBes.

OBJECTIVE

• To evaluate and study the performance of shell and tube heatexchanger at various operating condition.

• To evaluate and study the heat balance, LMTD and overall heattransfer coe cient.

• To calculate Reynolds s number at the shell and tube heatexchanger.

• To measure and determine the shell and tube side pressure drop.

THEORY

(n most heat exchangers, two $uids are exchanging their heat withoutdirect physical contact to avoid mixing. This is called indirect heat transfer.%ooling water temperature in a hot area is normally above 4 degreescentigrade, and it depends on the atmospheric and climate condition. To

reach the range of to 4 degrees centigrade, we need to use chilled water,which is already cooled by a refrigerant. /or heating purposes, themechanism is similar to the cooling. &e can use hot intermediate $uid suchas hot water or steam and even other hot process streams.


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To proceed on the heat exchanger theory we need to =now that the meaningof the following terminologies<

The overall heat transfer rate in a heat exchanger

The overall heat transfer coe cient can be used to calculate the totalheat transfer through a wall or heat exchanger construction. The overall heattransfer coe cient depends on the $uids and their properties on both sidesof the wall, and the properties of the wall and the transmission surface.

* E 0 FT

E 8verall heat transfer coe cient

0 E 0rea of the tube

FT E Logarithmic mean temperature di#erence

'eat load and heat balance

This part of the calculation is to use the data in Table to chec= the heat

load and and to select the set of values where is closest to .

'ot water $ow rate 5 7

E

%old water $ow rate 5 7

E

where


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E 'eat load for hot water $ow rate

E 'eat load for cold water $ow rate

'ot water mass $ow rate

%old water mass $ow rate

'ot water inlet temperature

'ot water outlet temperature

%old water inlet temperature

%old water outlet temperature

Log mean temperature di#erence 5LMTD7

The corrected LMTDE /T x LMTD calculated above


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8verall heat transfer coe cient,

8verall heat transfer coe cient at which eGuivalent to can be calculated

by using eGuation

&here<

'eat rate with respect to the $ow rate of water or

Theoretically * above is eGual to or

(f there any error in temperature collected, it is recommended to calculate

value based on eGuation of that will give an averagevalue.

Reynolds 9umber

1hell:side Re5s7 for % &


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&here<

3itch E -.H inch

Tube outside diameter, inch

)iscosity, ta=en at average $uid temperature in the shell, lbmft : hr :

5lbmft : hr : 7

/low rate in 5lbmhr : 7

Tube:side Re 5t7 for ' &

&here<

)iscosity, ta=en at average $uid temperature in the tube, lbmft : hr :

'eat Transfer %oe cient


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Coth values of internal heat transfer coe cient, and outside heat transfer

coe cient, obtained from eGuation below<

0nd

&here<

Thermal conductivity at mean temperature with respect to $uidposition

/luid viscosity at mean temperature with respect to $uid position

/luid viscosity for di#erent value of hot and cold water stream

"nergy being transfer in the system

Therefore, the dirt factor, value <

&here<

%lean overall heat transfer coe cient from both individual insideand outside $uids


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8verall heat transfer coe cient obtained from calculation in part

/rom the eGuation before, % value is calculated from heat transfercoe cients, the Reynolds number 5i.e $ow rates7, the $owing $uids

properties and the 'eat "xchanger diameters.

value however is determined from actual heat transfer experiments atthe 'eat "xchanger diameters.

(t is the dirty or design heat transfer coe cient. /ouling phenomenon would

reduce value. /ouling may get worse with operation, resulting in reducedheat transfer and increasing pressure drop 5and loss of $ow7.

3ressure drop

This part would determine the following<

< The measured tube:inside pressure drop D3 5tube7 which will becorrected and is expected to be more than calculated tube:side pressuredrop.

< The measured shell:inside pressure drop D3 5shell7 which will becorrected and is expected to be more than calculated tube:side pressuredrop.

3ressure drop measurement

The shell and tube:side pressure drop 5D37 are measured using the

di#erential pressure transmitter 5D3T7 and then indicated digitally at thepanel D3 5D3(I7. 0 selector switch with a set of 4 solenoid valves allows boththe shell and tube:sides pressure drop i.e. D3 5shell7, D3 5tube7, to bemeasured one at a time.


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APPARATUS

Summary List of Instrumentation

ie!"#$ount

/T 5'7 < /low Transmitter for '&. )ortex $ow meter, -:!-123M


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/T 5%7 < /low Transmitter for %&. Magnetic $ow meter, -:!- 123M.

D3T < Di#erential 3ressure Transmitter for 1hell+Tube side3ressure drop, -:4--- mm ' 8.

T" to T"4 < Temperature "lement Resistance Temperature Detector5RTD7, for t , t , T , T T(%4 respectively,-: -- - %.

32:', 32:% < 3ressure gauges, -:@- psig.

T2 < Temperature gauge, -: -- - %.

T1)!0, T1)!C < Temperature 1olenoid )alve.

Pane!#$ount

/( 5'7, /( 5%7 < /low (ndicator for '&, %&. Digital display, -:!-132M

T( , T( , T(?< Temperature (ndicator for T" , T" , T"?, displaying t , t and T respectively. Digital display, -: -- - %

T(! 5T 7+T(%! < Temperature (ndicator with 89+8// control for T"!i.e. T . Digital display, -: -- - %

T(%4 < Temperature (ndicator with 89+8// control for T"4.

Digital display, -: ---

%D3( < Di#erential 3ressure (ndicator for D3 51hell7 and D3 5Tube7of 'eat "xchanger. Digital display, -:4--- mm ' 8

Porta%!e

/TD3R < /low, Temperature, Deferential 3ressure Recorder, :

C&anne!s' (a(er!ess an" )an %e )onne)te" to PC#Data A)*uisitionSystem


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PROCEDURE

3reparation procedures1tart the following preparation procedures step:by:step.

i7 Tan=s T and T was ;lled with water to their maximum level de;ne by theirover$ow drain pipes D.

ii7 0t tan= T , the discharge valve 5')7 was shut fully, but open fully its by:passvalve 5C)'7. The '& pump 3' was start for the water to recirculate aroundits tan= T , via only C)'. The suction valve of pump 3' must remained

open at all times. The heaters at the front of the panel was switch on and the water was

allowed in tan= T to be heated to its maximum temperature J- ℃ + 4H

℉ 5see T %47, which will too= about - minutes. &hilst waiting, proceed

to 5iii7 below. The heaters in tan= T was automatically switch o# by theon+o# temperature controller T %4 when the heated water temperature

exceeds its preset 'igh Limit 5say J- ℃ 7, and when the temperature drops

below switch them on again, say of its preset 'igh Limit 5i.e. below @K.4

℃ 7.

iii7 %& 1ystem < 'eat "xchanger 1hell side


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Meanwhile got familiar with the eGuipment, instrumentation, piping systemand the various manual valves. The following preliminary procedures arerecommended for farmilariBation.a7 0ll the %& pumps 53% , 3% 7 by pass valves 5C)% , C)% 7 and discharge

valves 5%) , %) 7 was chec=ed that were opened. The suction valves of all the pumps 53% , 3% and 3'7 was noted that must remained openedat all times.

b7 The external water supply to tan= T was chec=ed that always availablebut was automatically shut by the mechanical $oat:level valve at highlevel in tan= T . The water availability was tested by pushing down the$oat:water must $ow into tan= T via the $oat:level valve to con;rm

water availability.c7 Ma=e sure the %& pumps 3% and 3% were o#. The '& pump 3' was

noted that still recirculating '& around its tan= T via its by:pass valve5C)'7, but its discharge valve 5')7 was still fully shut.

d7 8nly one %& pump was switch on, say 3% whose suction was from tan= T . (ts by:pass valve C)% was still fully opened. 3% was did notoperated. %) was shut fully. The %& recirculation was noted from 3%

bac= into tan= T via mainly its by:pass valve C)% and the 'eater"xchanger returned solenoid valve T1)!0.

e7 The by:pass valve 5 C)% 7 was parctise manipulated to set various$owrates of %& into the 'eat "xchanger from 3% as follows<

• Remain fully opened the manual discharge valve %) .• &ith C)% was fully opened, the %& $owrate /% at /(5%I7 was

noted,drop the pressure 532:%7 and shell:side 5at D3(I7. To read D3

5shell7, the signal to D3(I was selected used the D3 1elector 1witchprovided at the panel, to the D3 5shell7 position and wait till thereading at D3(I was almost steady.

• Manually adAusted C)% until /% at /(5%I7 reads almost - 123M. 0

D3 5shell7 and 32:% was noted.


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• The by:passvalve 5 C)% 7 was shut fully and the increase in /%, 32:%

and 5shell7 was noted. The %& temperatures was noted at the 'eat"xchanger inlet 5T at T(!I7 oulet 5T at T(?I7. The 'eat "xchangerpressure drop increases with $owrates was noted.

f7 3ump 3% was switch on whose suction was from tan= T . 8pened fullyits manual discharge valve %) and by:pass valve 5C)% 7. The %&$owrate /% at /(5%I7 was note, pressure 532:%7 and shell:sidepressured drop 5at D3(I7.

• 2radually shut only C)% until the %& $owrate /% is about --

123M. /c, 32:% and D35shell7 was noted which increased with the$owrate /%.

g7 C)% was opened fully but %) was shut fully so that pump 3% nowoperates only as be mixing pump for tan= T . The drop in /%, 32:% andD35shell7was noted. 8nly pump 3% was now pumped through the 'eat"xchanger. 1hut C)% fully maximum $ow from 3% through the 'eat"xchanger. Coth the %& pumps 3% and 3% was swith o#. The D31elector 1witch was switch to the eGualising 5vertical or N- 7 position.

iv7 'w system < 'eat "xchanger Tube side

a7 T(%4 was noted to chec=ed if the water temperature in tan= T was

about J- ℃ 5 4H ℉ ¿ before proceeding to the next procedure

5b7. The discharge valve 5'&7 was noted, the '& pump 3' was stillshut but its by:pass valve 5C)'7 was fully opened.

b7 The by:pass5C)'7 was gradually shut fully and simultaneously openedits discharge valve 5')7 sully so that the maximum '& $ows into the'eat "xchanger and return into tan= T . The '& $owrate /' at/(5'I7 was read, pressure 532:'7 and Tube:side pressure drop 5atD3(I7. 1elect the D3 signal to D3(I to read used the D3 1elector 1witchprovided at the panel, to the D3 5Tube7 position. &ait till the D3 5Tube7


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reading at D3(I almost steady to too= the reading.(n tan= T , the temperature of '& will drop due to heat being transferred tothe Nmetal body of the 'eat "xchanger,even if there was no %& $ow in the'eat "xchanger. The '& temperature at the 'eat "xchanger inlet 5t at

T I7 and oulet 5t at T I7c7 The '& pump 3' was stopped and the drop in /', 32:' and D3

5Tube7 ws noted. The D3 1elector 1witch to the eGualiBing 5verticalNo 7 position was switched. The heat from '& was noted and nowNstored in the 'eat "xchanger tubes. The heaters was switch o#.

d7 3roceed to 5% 7 3L099(92 T'" "O3"R(M"9T.5% 7 3lanning The "xperiment

Refer to table and plan out the experiment strategy as follows <i7 R 9a7 Run was done at the following recommended nominl $owrates. (t was

not necessary to operated at exactly the recommended nominal $owrates

below. 0deviation of ± 5 was acceptable for tested purposes.

%&, /% < - 123M '&, /' < 4 123Mb7 3lease refered to table , Three 5!7 sets of readings were ta=en for every

R 9.• "ach set of temperature readings consists of four readings to be ta=en

simultaneously <%& Temperature P inlet T at T(!I and outlet T at T(?I,'& temperatures P inlet T at T( I and oulet T at T( I

• "ach set of $owrate readings consists of two readings<

%& $owrate /% at /(5%I7'& $owrate /' at /(5'I7

• "ach set of pressure drop readings consists of two readings <

D3 5shell7 at D3(I, with the D3 1elector 1witch at the D3 5shell7position.

D3 5Tube7 at D3(I, with the D3 1elector 1witch at the D3 5Tube7


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position.• "ach set of 'eat "xchanger inlet gauge pressure readings consists of

two readings <32:% of %& pipeline, inlet to the 1hell side of the 'eat "xchanger.32:' of '& at the '& pipeline, inlet to the Tube side of the 'eat

"xchanger.

c7 The '& temperature in tan= T drops 5note T(%47 was noted when theheater input was inadeGuate to meet with the heat 5*%7 removed by %&.'ence the second and third sets of temperature readings may be ta=en atdecreasing heat load, but the water temperature at tan= T must be at

least @- ℃ .

d7 %oncentrated on ta=ing the three 5!7 sets of temperature, $owrate andpressure drop readings. The pressure drop readings D35 shell7 andD35Tube7 were ta=en at the panel:mount D3(I, used the D3 signal 1elector1witch provided. The pressure drop depends on the $owrate and not onthe temperature was noted.

e7 The above procedure for other R 91 5((, (((, etc7 was repeated at thefollowing %& and '& recommended nominal $owrates. 0 deviation of ±

4Q was acceptable. 0 summary list of the recommended nominal$owrates.

R 9 %&, /% '&, /'((( - 123M 4 123M() - 123M - 123M

5% 7 "xperimental 3rocedures&ith a good overview of the experiment plan detailed in % , proceed withR 9 ( as follows<i7

• 0ll the pump suction valves 5for 3', 3% , 3% 7 were chec=ed and fully


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opened all the time.• 8pened C)% fully but shut %) fully so chat that 3% shall operated as

a bac=:mixing pump for r tan= T in the next experiment. %) C)% wasopened fully. To pump %& into the 'eat "xchanger in the nextexperiment used 3% shall. Did not switch on any %& pumps 53% , 3% 7yet.

• 1hut ') fully but opened C)' fully.• To circulate around tan= T via only C)' was started pump 3' for '&.• The heaters was started and noted T(%4. &hen the '& in tan= T was

almost J- ℃ + 4H ℉ 5see T(%47, opened ') fully. The '& $owrate

was Guic=ly adAusted to abouat 4 123M by regulating its by:passvalve C)'.

• %& pumps 3% and 3% was switched on. The %& $owrate was Guic=ly

adAusted to about - 123M by regulating the by:pass valve C)% .• The D3 1elector 1witch to the D3 51hell7 position was switched.

ii7a7 /irst set of temperature and $owrate readings was too=<

%&< Temperature: inlet+oulet, T(!I 5T 7, T(?I 5T 7< /lowrate /% at /(5%I7.

'&< Temperature: inlet+oulet, T( I5t 7, Ti I 5t 7< /lowrate /' at /(5'I7

The %& inlet temperature 5T 7 was increased gradually was noted. The %&oulet temperature 5T 7 varies together with the '& inlet+oulet tenperaturet +t . 0ll the temperature and $owrate readings was important and be ta=en

almost simultaneously.Readings appropriately in table was recorded<

• The respective inlet pressure and pressure drop of the %& and '& $ow

streams was recorded. /or the pressure drop readings, D3 51hell7, D35Tube7 at the panel:mount D3(I, used the D3 signal 1elector 1witch


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appropriate=y as explained below.%&< 32:%, D3(I for D351hell7 with the D3 1elector 1witch at the D351hell7 position.'&< 32:' , D3(I for D3 5Tube7 with the D3 1elector 1witch at the D35Tube7 position.

To ta=e the D3 readings at D3(I, wait till they were fairly steady. Thentoo= the D3 reading at its highest reading 5i.e. pea= reading7 Aust whenit starts to decrease.

b7%ontinued and too= the second and third sets of the above readingsfor R 9 ( consecutively. &hen all the temperatures were fairly steady,the last 1et of temperature readings should be ta=en.

iii7• R 9 i was completed, with three sets of the above readings• 0ll the %& pumps 3% and 3% was stopped.• Seep the 'eaters on for the next R 9• &ith the '& pump 3' still running, shut fully the discharge valve ')

but opened fully the by:pass valve C)'.• The D8 1elector 1witch was switched to eGualiBing 5vertical or N- 7

position.v7 0nalyst the data by computing the *% and *' values for each of the three5!7

sets of readings for the previous R 9 ( whilst waited for the '& in tan= T

to be heated to about J- ℃ + 4H ℉ 5see T(%47 for R 9 (( as follows<

a7 /or each set of readings in R 9 (, the heat load *% and *' was

calculated for the %& and the '& as per the formula in section 5"7calculation.

b7 The three 5!7b calculated values of *% and *' for R 9 ( wascompared. 1elect the set of readings where *% was closest to *' andnoted them down in table and table , as the selected *% and *'for R 9 (. 0t the same time, noted down their corresponding


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temperatures, $owrates and pressure drops as the selected datas forR 9 (. The other two sets of data not selected can be reAected as theywere of no further used.

c7 The above selected set od data i.e. *%, *', temperatures, $owratesand pressure drops for R 9 ( shall be used to compute the LMTD, theoverall heat transfer coe cient, Reynolds numbers, individual heattransfer coe cient and the pressure drop, for R 9 (.

d7 Run (),) at di#erent recommended nominal $owrates of %&5i.e. /%7and '&5i.e. /'7 was repeated,used the following procedures chec=list<

• To continued with the next R 9

The '& pump 3' was running with C') fully opened but ')

fully shut was chec=ed.

&ith the heaters on, the '& in tan= T almost J- ℃ + 4H

℉ 5see T(%47 was heated

8pened ') fully. The '& $owrate was adAusted until /' at /(

5'I7 was almost at the recommended nominal $owrate for the

R 9. This was done by regulating the by:pass valve C)' with') fully opened. 5'owever, if the $owrate was still too higheven when its by:pass valve was fully opened, gradually shut itsdischarge valve, '), to got the reGuired '& $owrate7 The %& pumps 3% , 3% with %) +C)% +C)% was started fully

opened but %) fully shut. /c at /(5%I7 as noted. /c wasadAusted to the recommended nominal $owrates for the R 9 by

regulating the by:pass valve C)% with %) fully opened.5'owever, (f the %& $owrate 5/%7 from 3% was still inadeGuateeven when its by:pass valve C)% was fully shut, used thesecond %& pump 53% 7 by gradually opening %) andsimultaneouslt shutting C)% to got the reGuired cw $owrate7


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The D3 1elector 1witch to the D3 51hell7 position was switched

The various readings for the R 9 was too=. Refer to table of

the apptopriate R 9.

• To end a R 9 after got ! set of readings

0ll the %& pumps 3% , 3% was stopped.

The D3 1elector 1witch to the eGualising 5vertival or No 7 position

was switched. The '& pump 3' and the heaters still on, shut fully ') but

opened C)' fully.5%!7 3lant 1hut Down

(7 The heaters was switched o# ((7 %hec=ed all the pumps 53', 3% , 3% 7 were switched o# (((7 The D3 1elector 1witch to the eGualising 5vertical N- 7 position was

switched()7 The main power supply was switched o# to the plant at the front of

the panel+cubical. 0ll the pumps suction valves, discharge valves5'), %) , %) 7 and by:pass valves 5C)', C)% , C)% 7 was opened

RESULT

Table < experimental data for R 9 (((

R 9 ((( 1"T 1"T 1"T !%& '& %& '& %& '&

9ominal /low,123M

0ctual /low, 123M

Temp, %, (nlet

/%< -

/%< K.H

/'< 4

/'< 4.!

-

4

4.!

-

K.K

4

4.

3ressure, psig, (nlet32:%< .4

D3< 4KJ51'"LL7

32:'< ?.J

D3< ?4?5TC"7

.4

@

?.4 .4 ?.4


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I Temp change, %

I 0verage Temp, %

!.J

?-.?4

!.

4K.@

H.H

!J.J

.H

4?.

@.

!@.!4

K.K

4-.44

*%+*' . @H . . HH1elect *%+*'nearest to .- 1"L"%T"D 98T 1"L"%T"D 98T 1"L"%T"D

1elected set,

K?? K.?4

Table < experimental data for R 9 ()

R 9 () 1"T 1"T 1"T !%& '& %& '& %& '&

9ominal /low, 123M

0ctual /low, 123M

Temp, %, (nlet

Temp, %, 8utlet

/%< -

/%< K.H

/'< -

/'< -.4

-

K.H

-

-.?

-

K.H

-

-.?

3ressure, psig, (nlet32:%< .4

D3< @-451'"LL7

32:'< .-

D3<4@?5T C"7

.4

@ -

.- .4 .-


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( BTU hr.ft 2 .℉ ) ( BTU hr.ft 2 .℉ ) ( BTU hr.ft 2 .℉ ) ( BTU hr.ft 2 .℉ ) ( BTU hr.ft 2 .℉ ),78/ #9.((( 4KH.H J .@H 4J .4J ? .-4 4-?.H !.K?() @ -. H @-?.K4 ?JK. @!.@! !! .J- -.@@?

Ta%!e :6 %alculated 3ressure Drop

RUN

Pressure Dro(S&e!!#si"e ,mmH ; O. Tu%e#si"e ,mmH ; O.Ca!)u!ate"

$easure"

Corre)te"

Ca!)u!ate"

$easure"

Corre)te"

((( ?K!J.J! 4@- @4.-4 HK.HK -K! !4!.J() ??H?.HH 4@? @K.-4 H.JK 4@!.! K .HH

CALCULATION

Sam(!e )a!)u!ation

R 9 (((, 1et

'eat Load and 'eat Calance

/%E K.H 132M

/%E K.H 123M x m ! +'r U --- Sg U . -?@ (bm

?.? 123M m ! =g

/%E ?K -. K (bm+hr

%3E Ctu+(bmo

/*%E /% U %3 U 5T :T 7

%onvertion unit of temp.

T E ??.@ o% E ??.@5 .H7 6 ! E . H o/

T E K.? o% E K.?5 .H7 6 ! E H?.K o/


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E ?K -. K (bm+hr x Ctu+(bm o/ x 5 . H P H?.K o/

E -K?J .KJCtu+hr

/' E 4.! 132M

/' E 4.! 123M U m ! +'r U --- Sg U . -?@ (bm

?.? 123M m! =g

/' E J@@@.-@4(bm+hr

%3E Ctu+(bm o/

*'E /' O % 3 O 5t : t 7

%onversion unit of temp.

t E ?4.H o% E ?4.H5 .H7 6 ! E ?.?? o/

t E 4H.Ho% E 4H.H5 .H7 6 ! E !J.H? o/

EJ@@@.-@4 (bm+hr x Ctu+(bmo/ x 5 !J.H? P ?.??7 o/

E JK!H4.K Ctu+hr

Ratio *%+*' E209472.97

179385.92 E . @H

%alculations above were repeated for each set in R 9 (). The set whichgives the ratio of *%+*' nearest to is then used for the next part of thecalculation for each respective R 9.

LMTD 5R 9 (((, 1et 7


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LMTD E

(137.84 − 114.44 )−( 112.28 − 84.92 )

ln (137.84 − 114.44 )(112.28 − 84.92 )

E 4.!!

%orrection factor, / T is obtained from ;gure H 5appendices7 based on thevalue of R and 1, where / T E -.JK4

LMTD 5true7E -.JK4 x 4.!!

E -. ?

8verall 'eat Transfer %oe cient, 5R 9 (((, 1et 7

The total heat transfer area of the 'eat "xchanger, 0 E ! .4 ft* E -.45*%6*'7

* E -.4 5 -K?J .KJ 6 JK!H4.K 7

* E K?? K.?45CT +hr7

U ( BTU hr.ft 2 .℉ )= 194429.45 (BTU hr ) x 131.5 (ft 2 ) x 112.2271 ¿504.81 BTU

hr.ft 2.℉

0ll calculations involving LMTD and were repeated again for the selectedset on R 9 (). The results of calculation are tabulated in table .


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2iven, D E -.-? 4 ft

& t E J@@@.-@4 lbm+hr

0 t E -.- !K

V E . 4 lbm+ft.hr

2 t E J@@@.-@4+-.- !K E !4H!K?.H lbm+hr.ft

Re5t7 E -.-? 4 x 5!4H!K?.H + . 4 7 E H!!.


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%p E .-- btu+lbm.W/

= E -.!JHJ btu+hr.ft . W/+ft 5at Tavg E 4K.@ %7

V E . 4 lbm+ft.hr

/rom ;gure H5appendices7, when Re 5t7 E H!!. , A h E @

@ Ehi 0.04125

0.3734(1.001 x 1.152 )−1 /3

0.37871 − 1 / 31.152 − 0.14

2.412 − 0.14

h i E J .@H ( BTU hr.ft 2 .℉ )

%alculation of N%lean 8verall 'eat Transfer %oe cient, c 5R 9 (((, 1et 7

hio= 721.68 x 0.495

0.625 E 4J .4JBTU

hr. ft 2.℉

U c=hio x hoh io+ho E ? .-4

BTU hr. ft

2.℉

%alculation of Dirt /actor, R d 5R 9 (((, 1et 7

d E 4-?.HBTU

hr.ft 2.℉

c E ? .-4 BTU hr.ft 2 .℉

Rd E504.81 − 421.05504.81 X 421.05


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E !.K?x - :?

Pressure Dro(

%onversion<

psi E .!-HHft E J.J ins E J-!.J mm' 8 at @- /512E .-7

1hell side pressure drop 5R 9 (((, 1et 7

X3s Ef xGs

2 x D s( N +1 )

2 x g x ρ x De x∅s

2iven, D s E (D E @.-@4ins E -.4-4? ft

9 E !

g E ?. J x - H ft+hr

Y E @ .-!?H lbm+ft ! 5at Tavg E ?-.?4 %7

De E -.--!J!! ft

2 s E @K! -.!? lbm+ft .hr

12 E -.KK! 5at T avg E ?-.?4 %7

Z s E .- @J

[ E -.--4 5at Re5s7 E !HK.! 7

X3s E

0.0052 x169320.342 x0.50541 (23 +1 )

2 x(4.17 x10 8) x 62.0348 x 0.003733 x1.01167 E K. 44- psi


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1ince 12 E -.KK! ,

psi E J-!.J x -.KK! E @KH.H@ mm' 8

X3s E K. 44- psi x @KH.H@ mm' 8 + psi E ?K!J.J! mm' 8

%orrection to the measured pressure drop for 1hell side, %& 5R 9 (((, 1et 7

3ressure drop read at 4@- mm' 8 and $ow rate %& of K.H 123M,

%alculated piping pressure drop D35s7 E ?K?.K4 mm' 8

X3 5corrected7 E 4@-:?K?.K4 E @4.-4mm' 8

Tube side pressure drop, '& 5R 9 (((, 1et 7

X3 t Ef xGt

2 x L x n

2 x g x ρ x D x∅t

2iven, D E -.-? 4 ft

L x n E

Y E @ .!K lbm+ft! 5at Tavg E 4K.@ %7

2 t E !4H!K?.H lbm+hr.ft

12 E -.KH@J 5at T avg E 4K.@ %7

Z t E -.KHK! [ E -.--- 5at Re 5t7 E H!!. 7

X3 t E0.00012 x 358394.81

2 x12

2 x(4.17 x 10 8 ) x61.392 x0.04125 x 0.9893 E -. K4 psi


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1ince 12 E -.KH@J ,

psi E J-!.J x -.KHJ E @K?. ? mm' 8

X3 t E -. K4 psi x @K?. ? mm' 8 + psi E HK.HK mm' 8

X3r E ( 4 nSG)( V 2

2 g ' )(62.5144 ) ,

&here ( V 22 g ' )(62.5144 )E -.- 5at 2 t E !4H!K?.H from ;gure J in appendices7

X3r E ( 4 (2 )0.98671 ) x -.- E -. @ psi x @K?. ? mm' 8 + psi E .4@mm' 8

P t = ∆ P' t +∆ P r E HK.HK 6 .4@E - .?4mm' 8

%orrection to the measured pressure drop for Tube side, '& 5R 9 (((, 1et 7

3ressure drop read at -K! mm' 8 and $ow rate %& of 4.! 123M,

%alculated piping pressure drop, D3 5t7 E J!K. H mm' 8

X3 5corrected7 E -K!:J!K. H E !4!.J mm' 8


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DISCUSSION

The obAective of the experiment is to evaluate and study theperformance of shell and tube heat exchanger at various operating condition.Cesides that, evaluate and study the heat balance, LMTD and overall heattransfer coe cient. &e need also calculate Reynolds s number at the shelland tube heat exchanger and measure and determine the shell and tube sidepressure drop. During the experiment, we carried out Run ((( and Run ()experiment. "very run consist of three set of data which need to be

considered.

/irstly, set up eGuipment according to the variable we need toinvestigate which are pressure and temperature. The ideal temperature forthis heat exchanger is between 4- - % and J- - %. 1o that, experiment runwhen the ideal temperature is achieve. /or run ((( the $ow rate is set to the

- 123M cold water 5%&7 and 4 123M for hot water 5'&7.Theexperiment was run until the value of $ow rate was stable. Then, all the data

was record for set .The experiment were repeated three times to get bestresult. The calculation was made from data recorded to identify which set of Run ((( have better result.

The heat load was calculated for all sets of data. The ratio of * %+*'which nearest to .- is selected to continue the calculation. Then, for R 9 (((,set is selected. The * % is -K?J .KJ Ctu+hr ,* ' is JK!H4.K Ctu+hr and-.45*%6*'7 is K?? K.?4 Ctu+hr. 9ext, the corrected LMTD was -. ? - /

while the overall heat transfer coe cient is 4-?.H ( BTU hr.ft 2 .℉ ) 0 TheReynolds number for shell is !HK.! and for tube is H!!. .8ther than


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that, for part ((( value ho, h i and h i- are 4KH. ( BTU hr.ft 2 .℉ ) ' J .@H

( BTU

hr.ft 2.℉ ) and 4J .4J (

BTU hr.ft

2.℉ ) respectively. /or %the value is ? .-4

( BTU hr.ft 2 .℉ ) and D is 4-?.H ( BTU hr.ft 2 .℉ ) 0 The value of R D is !.K? x x - :! .9ext,for the pressure drop at shell:side the calculated value, measured andcorrected are ?KJ!.J! mm' 8,4@- mm' 8 and @4.-4 mm' 8 respectively.

/or the pressure drop at tube:side the calculated value, measured andcorrected are HK.HK mm' 8, -K! mm' 8 and !4!.J mm' 8 respectively.

/or R 9 (), the $ow rate was set up to - 123M for both cold water5%&7 and hot water 5'&7.The instrument is run for a while until the ideal

temperature is achieved. /or R 9 (), set ! is selected. This is because theratio of * %+*' is nearest to .- which is . - . The * %is !?!?4.4! Ctu+hr ,* 'is K!4.4! Ctu+hr and -.45*%6*'7 is H ?-.4! Ctu+hr. 9ext, thecorrected LMTD was 4.4 - / while the overall heat transfer coe cient is

!! .J ( BTU hr.ft 2 .℉ ) 0 The Reynolds number for shell is !@?.?@ and for tube is

JJ4!.K?.8ther than that, for part ((( the h o, h i and h i- are @ -. H ( BTU hr.ft 2 .℉ ) '

@-?.K4 ( BTU hr.ft 2 .℉ ) and ?JK. ( BTU hr.ft 2 .℉ ) respectively. /or % the value is


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@!.@! ( BTU hr.ft 2 .℉ ) and D is !! .J- ( BTU hr.ft 2 .℉ ) 0 The value of R D is -.@@-? xx - :! 09ext, for the pressure drop at shell:side the calculated value,

measured and corrected are ??H?.HHmm' 8,4@?mm' 8 and @K.-4 mm' 8respectively. /or the pressure drop at tube:side the calculated value,measured and corrected are H.JKmm' 8,4@!.! mm' 8 and K .HHmm' 8respectively.

/rom the result above, the pressure drop depends on the $ow rate notthe temperature. 0s we can see that the pressure drop for Run ((( which used

- 123M and 4 123M was higher than pressure at Run () which used

- 123M. /rom the calculation, we conclude that the number of *% isdecreasing from Run ((( to Run () and same pattern goes to *' and-.45*%6*'7.8ther than that, is also decreasing from R 9 ((( to Run (). Theoverall heat transfer coe cient, , Reynolds number and $ow rates of hotwater are also decreasing from Run ((( to Run ().

CONCLUSION The obAective is achieved for Run ((( and Run (). Cased on evaluate and

study the performance of shell and tube heat exchanger at various operatingcondition was determined. Cesides that, the heat balance, LMTD and overallheat transfer coe cient also determined. The Reynolds s number at the shell


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and tube heat exchanger was identi;ed. Moreover, the shell and tube sidepressure drop also determined. /rom the result , the pressure drop dependson the $ow rate not the temperature. 0s we can see that the pressure dropfor Run ((( which used - 123M and 4 123M was higher than pressure atRun () which used - 123M. /rom the calculation, we conclude that thenumber of *% is decreasing from Run ((( to Run () and same pattern goes to*' and -.45*%6*'7.8ther than that, is also decreasing from R 9 ((( to Run(). The overall heat transfer coe cient, , Reynolds number and $ow ratesof hot water are also decreasing from Run ((( to Run ().

RECO$$ENDATION

• The water to the tube side should be the ;rst and last $ow rate to beturned on.

The steam should be turned on only after the water is $owing throughthe tube side

and the water should be turned on only after the steam has beenturned on.

• /ully drain system after each use of water on tube side and steamcondensate on

shell side in order to avoid corrosion build:up during down:times.

• The eye position should be perpendicular to the meniscus and thescale.

• 0void any lea=age of the instrument, the instrument should be wor=ing

properly• 0void direct contact with water because it is hot

RE ERENCE


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%omsol.5 - !7. Shell and tube heat exchanger . Retrieved from<https


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228608912 Shell and Tube Heat Exchanger

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