ME 415 Assignment 2

8/6/2019 ME 415 Assignment 2

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1.

ME 415: Refrigeration and Building Mechanical SystemsAssignment:02A space to be maintained at 23oC dbt and 18oC wbt has a sensible heat gain of 25 kW and arate of moisture gain of 9 kg1hr. Moist air enters the space at 15.5oC dbt. Outside air at 35oCdbt and 25.5'C wbt is supplied for ventilation purposes at a rate of 390L/s of standard air.The system to be used is elementary summer a/c system. Estimate:the dbt and wbt of the air entering the cooling coil,refrigeration load.A space is to be maintained at 27oC dbt has a sensible heat gain of 13 kW and a rate of latentheat gain of 8.5kW. The system to be used is the elementary summer a/c system with bypassof re-circulated air. The mass flow rate of air supplied to the space is 1.1 kg/s. Outside air at38oC and 17oC dew-point temperature is introduced into the system at a rate of 0.28 kg/s. Theair exiting from the cooling coil is saturated and at a temperature of 7oC. Clearly sketch andlabel all points and process lines on a psychrometric chart in addition to the schematicdiagram of the system. Estimate:dbt and rh of air supplied to the space.rh of the space.refrigeration load.A space to be maintained at 24"Cdbt and 18oC wbt has a sensible heat gain of 110 kW and amoisture gain of 150 kg/hr. The chilled air leaves the cooling coil at l2oc dbt and 90o/o rh.The system used is summer A/C system with reheat. Clearly sketch and label all points andprocess lines on a psychrometric chart in addition to the schematic diagram of the system.Estimate:dbt and rh of air supplied to the space.rh of the space.refrigeration load.Size the supply-duct system shown in figure below using equal friction method and roundduct. Specify the total pressure needed at location I for this system if the diffrrsers both haveatotal pressure loss of 15 Pa.

a)b)2.

a)b)c)tJ.

a)b)c)4.

+3000 l/s

CD3-f0 2ii nr


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5. Estimate the cooling load of rooms I and 4 of the figure below:EE

(1) (3)

(2) (4)10m 15m

Day l2M April, time 3PM and 5 PM.

Given that:r Floor height = 3 m'Oo

aaoaooaoaa

Roof = q/pe 3, 100 mm light weight concreteWalls : 101.6 mm face briclq 101.6 film common brick, 9.5 mm cement plaster sandaggregate, 6.4 mm plywood.Windows :25o/o of wall area,13 mm clear glass with U:3.0 WUm2 CACH :l/hrLight :25Wlmz of floor areaRoom (1) : glmrnasium, accommodating 5 peopleRoom (2) = instrumentation laboratory, at20"CRoom (3) = kitchen, at 35t dbtRoom (4) : oflice room, accommodating 10 people using 5 PCsNo heat transfer through floorUse design conditions recornmended by ASHRAEAssume any reasonable value.


3/24

Qs=)-5*,tJ Gr= G'-25 kNT66=2o*c 7Tt,b:lE"C

Pnoblem l

ZOs: maCp (C-11+ 2 e kN : //la-x t'O 2 k3/t'


4/24

AJ oatl, d b: azTltz+/)t< Mq - (tO.g*fout 2.b) + (16.+ 5zlo3- o'4G8)TIt2'tIfi4 :+ tib: tt.GSxtog

Fron, FugehromeVrie CharD, TOa 6: 24.7"CTub O: lg.2"C4e: 55 kil/txglua:4t'6UA\LA

RtE: nabftt"u- lrd - @s-ua)^ aru|: o.,ar,[(55- 41.6) - (t1.65*lou - lo'2x(ou)*4-r,6*E5J: 4g.g8 RtA

Ans Condi Fion of air enberirB bho e-ooling coilTdb: 24-7 o C-Tub: lg.2'C

l2te,frigeraAiort Load - 4g'Og kN


5/24

Ouicr)F$uG:uFloJ=&6

!9/oo

cO r"{nii()!E*\Lf,t:I'sychronre trics

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oi-t)()()qoa(,trd01!!{lul(.r.jf:uloIuJ()()2Ir

-J-' rrl(J>2uF.rt0a uJ ,,


6/24

ProbLem 2 es=t5k6 gL-*E.SM

O.zBkg/sTdb= eB"CTdp= I7"C

SH R,: 9s : 0.6@s+9r le+b.5Froyq, trs6ch romebric Charv .

ZOs : majp Q;-n)4 te - l-lx t"o2*(zl-4 n -l5.4fc:q

Qz= 522

From, Pe6chromobric CharD, (pr:Q? :1AZAloat, m+Tz : frzbT-z


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Nloru, moTg: m "oT" + rn4Tz1=) O.6e x Tg : O-O5 x 2V t O.29xgA+ To: O2"c

Fron, Pstychr o meyric Char Ft&6:22-5 t


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t.ll'sychromctrics

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oUdfFau4EuFdlJf6u,oozoCu,L!7()

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I

rritlutootY.Ft!()d.{:rrl

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Qt=-''-t c;-,.rr = Ier'C

Problen ? 9s= / !Otxtnl

HcaL,c, C.Cl2 'cgo%

t509r: uuhot:26,o;^ 25OO: loqkl4gHp-: -=. 9*= : o-5@s*9e

F rom, P et6chro rneVr'tc Char D'CortdiTion af A\r SupP0ed,-IgU: lB.2oC,p,: 60T.Clondi hion of SVaco' Qr: 562

N oat, 9s : ma,Cp (f"-r)+ llo : rrlax ( -o2x (zt-t - L8'2)+ fr&: lA' 6 "ds

P'E :_-

fis L&u- t6)- (us- a:a)^A""1I a.6 [ ( gt - e2. 5) - (t o's^ lb3- v'7 5 ^be)04 t.5 kN (Ans )

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I 'oN t.nllJ J!.rtrurorrl:r,{s(l ilVlllSV I ':ltrt

(t,-nm-oaoIno?m-J4oo:cv-tzo

ot9;IT()a


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Problen 4

Bn/s IcD 3-10B5n 4zooo/s

--_--_.>.3ooo0./s

Leb, us Arssu-WO,VOlocivy ab lonvion I

V - 6n/s

ASD 5-ro

3lOooL/s

(^a

7.24.26.6"

Secbion- O (nuls) I Yt-AAB

3t I2lB-z 2AC Ie,-g

/s) De.au@rt aP/t t (n) Due.bLoss6go o.B8 20 tv.6252525

5Bo580

o.3Ao- 88_o_48

5 4.425 2Z

450 5 4.425 45o o.g8 25 22

To2al drcP loss : 7O"4 Pct


12/24

FihhnT Losees5o o-toSocvion' tnb +:o'g , X:oa2 , Cb: o'44

Pv: (#)': (#)': et.6Pa.AP, b: Cb Pv: lb.QPa-

Socaton: IAC +: o.B 4^" : o.44, cs - Q- 156'vo v'v AgPv= (hl': (?:3 )n: 2o.47 Pa.

AP,-c: Cs Pv: O.6GPaoD g-togenvior\: AOz P: 53Ofrn , %: o'o54

Pv= (+*)": :f,# : ot.GPo'APa-t-'= e.o Pv = l.A Pa

Soctzon: ACg D - 45O mm , CD = O-O 6P,r= (#)': 2b -47Pa-

APn-u: %P, : l"4PaToVat Fiukng Loss - 20.66 Pa Frooeure, reqwrOd-Tobal Duca Loss : ]o' 4 Pa aD lou.uion IDilf e:eer Loss:2x 15: eo Pa l2l " OOPa

Toaat Loss : l2t"oGPa&


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Problem 5

Nco I 32 +

l}m t5m

Floor l'1eig[t:: ernAeeumin& Td:25-5"Cf or taovh roDftl I & 4

IIld'r | -E=+ds

Dab : t2 APril , rimo; ?Pm and 5P^Hnb Con d ucuance Calcul6tvi on

fZ= b/X 0.01c + o' l4 +fovoYo': o' 282

R'oof : fbpn g, tOOmm lighV netBhb @ncrebQ(abte tza) AO+E2+ EetCl4+Eo(raua t'j) Q,: o.59+ o.ogg+o. O 5o+0.5 87+ o.l2| : O. 9|6

U : l. og N/rrrn cNall: lOl.6nmFoco brie)< I z6xo.4g: $e6- oezN


19/24

,Air Exphanry, ACu-l/h.,l-t f2toom Ii---'' V: f;xexlO : 24OrngV : Z4O ,no//", - O. OOV mo/s9s: l2oo V (ro-Tl): t2OoxO.O6Vx@g-25 5)

:GOOn@L: OOOoxtl V (uo-/Ai): gOooxlos* o-oG7 x(zoxtbu- lr'a^r74): IA o8.5N

[tuoom 4V: l7x|x\: e6or"'i - oaoms/A"r: o-l ns/s9s: t2oox O.t x (e g-25.5): gooN@r: ,c;ooox { 06,- O, lx (zo^rbu-l l' 5 ,.tos)

2: 255ON


20/24

[?.toom I : G\mnnuiu^ - e, no O, n.9s: 2lOx5:lO5Ol4or : 9t ex 5 : t575 l,'J (toate z8)[Uoom 4: Offtc-a fuoom- (O peoVlq

0s : Texto :75oNAt-: loxo :: 5lDtA (raule 2e)Hen"b Gain due bo EqluipmenPs

H""? G.ain due bo occupanzs

flooml: 9e:ONR.nom 4'. gs: eooxo : lSooN

Hu.U Ctain due ao ti At'tus.Wom l: Os: Pt-*bFxDxCLF:!5x5Oxlxlxl

: 2C-0C.NlZoorn 4: 9s: z7x l2ox I xlxl: OOOON


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9* Q,t, Heab conduc?ion

a) tuoofb) shadded l,,Jall

uivh glassc) Sunli b LualtUlbh BlassSolar HaD Gainbhrough utindow

NorvhLlesv

2"

a. Act+4. Lighbs5. oe-cupanbs6. EquipmertPs

3lgt"52lOOs.ta2974.75

6 Oa.2o4 |It70g.a44lII600 Ilzoo o

t o50o

t7 O8.5

I 515

t o50 0 e2 ao.sToVat: t6785N- 4.8 bon


22/24

Coolin} Load QtculaVion for tuoom l: 5pm

l.Hena conducbiona) rzoofb) sha*ded H att

Uibh glas sc) San tip uattulvh glass%. Sotar Heab Gainbhroug,h Hingow

Nor vhNav3. Actt4. Ltghvs5. Occupanbs6-EqulpnexVs

3zl 8.7 2(398.t6o587. ss

5+ g. t52429.446-0c.

2000to 50ot4365

Totul: t 8l5ONo2ae.5- 5.2 bon

lvo 8.5


23/24

Coolin\ Load @lculahion tor Rtoom 4: Time g pm9* Oz-

l. Heab condtrcbiona) l7'oofb) shadded tActtt

uibh gtassc) S untib LnailUtbh g(ass2. 9olqr tieab G.ainbhroxgh uindout

EoeDSouph

3. Acu4. t-ighas5. OccatpanpsG. Equi p men7 e

41 A7.29t905.07

4 07 6.305

I I Oo.g3v e 5.gg9oogooo75ol 5c.0

2550550

tgl 56 etooTouat: 2t gO 5 N - 6.2 bon


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Coolin4Load QlcutcVicrn 'Por n'oofn 4: Qpry

l. Heab Conducbiona) Atoofb) suoadacl tuatt

ulvh ahsse) sunb Uatlwtvh $aes

Z.$olar Ha7 Gain

I v700Tobal: 2 OEOO N

eloo'-" 6 bon

bMo*gh NindouEosP9oubh

O. Acu\. Lighvs5. aecupan?s6. EqlwpnenVs

49tg.Oalgo5.o7b349.tzs

&s5.tg506.8e9oo30oo7501500

ME 415 Assignment 2

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