Process HEAT PROGR ESS REPOR T

Laur en Ay er s Sarah Lade rman Adit i Ver ma Anonym ous stude nt

• System Diag ram

• Heat Exc ha ng ers

• Com pre ssors

• Heat Tran sport

• Hea t Sto rag e

• Requ ired Inp uts

Outline

System Diag ram

Printed Circ uit Heat Exc hangers (PCHE s)

Fi g . 1 (pg . 2 1 8 ) f ro m D. S o u t h al l , an d S . J. De w so n , I n n o v at i v e C o mp act H e at E x ch an g e rs. Published in ICAPP 2010, San Diego, CA, June 13-17, 2010. © Ame rican Nuclear Society and the authors. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse .

T hig h = 800 ° C P hig h =20 MPa

PCHEs chosen for t heir :

• Hig h opera ting temperatures

• Small volum es

• High ef fect iveness

Sys tem Diag ram - Ini tia l Design

PC HE lo ca tio n s

Process Hea t System

• Eli min ate d a PC HE, F -He he ate r an d

• iso la ted a PC HE

• red uce d the nu mbe r of de pe nd en t vari ab le s in t he Proce ss he at lo op

PCH E lo catio ns

So urce : w eb bo ok.n ist.go v/che mistr y /f lu i d

C hoice of Heat Exchanger Material

• T ens il e stre ngth

Con side ratio ns incl ud ed :

• The rmal co ndu ct ivity

• The rmal expans io n

• Corros io n res is tan ce

• Eas e o f manu fac turi ng pro ce ss

• Des ig n l ife of u p to 6 0 years

Allo y 61 7

nic kel -chro m ium -cob alt -m olybdenu m

Ulti mate T ens il e Stren gth at 6 50C = 62 7 MPa Coef fic ie nt of the rmal expans io n, [20 -760 ]C = 15 .1u m/m -C

The rmal co ndu ct ivity at 65 0C = 23 W/m -K

All oy 617 Stress es

Pmax = 2 0 M Pa a t core HX, T=630C Tmax =800C at h ydrogen HX , P = 3MP a

He at Ex chan gers wo uld be operatin g we ll bel ow desi gn str ess at all poi nts in system

Source: Li, Xiqing., et al. "Alloy 617 for the High Temperature Diffusion-Bonded Compact He a t E x ch an g e rs. " P u bl i sh ed i n I C A P P 2008, A n a h ei m , C A , J u n e 8 - 12, 2008 . © A m er i ca n Nuclear Society and the authors. All rights reserved. This cont ent is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse .

PCH E no da l mo de l

Mo d e l a ssu mp tio n s:

• T he total mass f lo w rate is un iforml y di stribu ted amo ng the cha nn el s

• T he w al l cha nn el temp era ture is un iform at eve ry ax ia l no de

• Co ld an d ho t pl ate s ha ve the same nu mbe r of f lo w cha nn el s

Co d e d ivi d e s a sin g le ch a n n e l in to n o d e s o f e q u a l le n g th a n d itera tes to o p timi ze the

cha nn el le ng th

V . Dostal , " A Supercritical Carbon Diox ide Cy cle for Nex t Generation Nuclear Reactors" , M IT PhD thesis (2004)

35 MW I nte rmed iat e Heat Exc ha ng er

Re y no ld s nu m ber

25 00 0

ho t flui d: S -CO2 col d flui d: He

20 00 0

15 00 0

d =5mm

10 00 0

hot

d co ld = 6 m m cou nte rflow Zigza g cha nn el s

θ=45 C

T h ot in = 6 30 ° C

T cold out =60 6 .5 ° C

m flow col d =22 kg/s (con strain ed by T cold out )

• Re y no ld s nu mbe r an d p ressu re dro ps as a f un ction of the mass f lo w rate of the ho t flui d

• Ho t flu id is i n t h e t u rb u le n t flo w

reg ime

• Co ld flui d is in t he lami na r flow reg ime

50 00

0

45 00 0

40 00 0

35 00 0

30 00 0

25 00 0

20 00 0

15 00 0

10 00 0

50 00

0

0 50 10 0 15 0 20 0 25 0

CO 2 mass f low r ate ( kg/s)

C o l d F l ui d r e y no l d s n um b er Ho t fl u i d rey n o l d s n u m b e r

Pre ss ure drop

0 50 10 0 15 0 20 0 25 0

CO 2 mass f low r ate ( kg/s)

C o l d s i de pr es s u r e d r op ( P a) H o t s i de p r es s ur e d r o p ( P a )

PCH E volum e

He at tra nsfer coe fficient

35 00

30 00

25 00

20 00

15 00

10 00

50 0

0

8

7

6

5

4

3

2

1

0

0 50 10 0 15 0 20 0 25 0

CO 2 mass f low r ate ( kg/s)

Co l d fl u i d he a t trans fe r c o eff i c i en t Ho t fl ui d he at tr an s f er c oe ff i c i e nt

PCH E v ol ume

0 50 10 0 15 0 20 0 25 0

CO 2 mass f low r ate ( kg/s)

• He at ex cha ng er vol ume de crea ses w ith an in crea se in the CO 2 mass flow rate

• Smal le st po ssib le vol ume is de sira bl e du e to hi gh costs of materi al s an d fab rica tion

• PCH Es cost up w ard s of $ 50 0,0 00 /un it an d cost is pro po rtion al to vol ume

• A straig ht cha nn el PCH E w ith a CO 2 mass flo w ra te o f 9 0 kg/s h a s a vo lu me o f 15 .36 7m 3. For t he same mass f lo w rate , a zig zag cha nn el PCH E is 54 .4% smal le r .

Future Heat Ex changer Wor k

• Optimize the he at e xc han ger s g ive n in pu ts an d o utp uts fro m bi ofu el s, co re , and hy dr og en su bg ro up s; ch oo se be twee n st ra ig ht an d z ig za g PC HE ch ann els

• Dete rmin e ou r HX ‟ s de si gn li fet ime

• Plan mai nte na nc e an d re pa irs sc he du le – on lin e ma na ge men t po ss ib le ?

• Int ro du ce an eme rg en cy he at si nk , al ter na te „r e se rv e‟ wor ki ng flu id fo r rap id co oli ng?

Source: Li, Xiqing., et al. " Alloy 617 for the High Temperature Diffusion-Bonded Compact Hea t Exchangers." Published in ICAPP 2008, Anaheim, CA, June 8-12, 2008. © American Nuclear Society and the authors. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse .

Compres sors

 Nee de d to kee p he liu m flo wing

 Pressure rati o & th erma l e fficie ncy given by ma nu factu rer

 To fin d o utl et tem pe ratu re:

n = W i de al = = h out , i de al − − h i npu t

W r e a l h out − − h i npu t

Whe re:

h = = c p ∗ ∗ T

Compres sors II

 Spe cific comp ressor chose n af te r pre ssures are de term ine d

 Pap er by Hee Cheo n No, Ji Hwan Kim, an d Hyeun Min Kim comp are s ma ny hig h tem pe ratu re & pre ss ure comp ressors

 Pressure rat io s fro m 1. 7 – 2

 Ma chine eff icien cies from 90-98 %

No et al . “A Re vie w of He li um Gas T urb in e T ech no lo gy for Hig h - temp era ture Gas -coo le d Re acto rs.” Nu cle ar En gi ne eri ng an d T ech no lo gy , V ol . 3 9, No . 1 (2 00 7).

Transport

 All oy 6 17 fo r he liu m pip in g ma te ria l

 Stai nle ss steel he at pip e f or wa ter tran sport

 Nee d warm est po ssible at mo sphe ric tem pe ratu re

 Once site i s det ermi ne d, loo k a t h ea t lo ss an d de te rmi ne pi pe th ickness

 Equa tio ns fr om 2 2.0 6 n ote s, mod el in g ea ch s ec tio n as a r es is tor fr om q ' cen ter to T atmosp he ric

600

550

Area F

500

450

400

350

300

Area E

250

200

Area D

150

Area C

100

50

Area B

0

0

10

Area A

20 30

40

50

Siz e of cloud (tons of h y drocarbon equiv alent)

Safety Dis tance s

 Area F: no li mits

 Area E: no housing

 Area D: De sign buil dings for a peak incid ent gauge pres sur e bet ween 1.5 & 3 psi. Roof to be independently suppor ted & win dows protect ed. N o publi c roads.

 30 m i n bet ween plants

 175 m fr om p ubli c roads

 360 m fr om hou sing

Image by MIT OpenCourseWare.

R ef erenc e : Gas Ex plos ion H andbook, ht t p: / / w w w . gex c on. c om / ha ndb oo k / GEXH Bc h ap 1 1. ht m (af t er Klet z , 1988)

PCM: Lithium Chloride (LiCl)

P u b li c d o m a in (W iki p e d ia )

Containment Material: All oy 20

 Nickel -Chro mi um - Mo lybde nu m all oy

 Resistant to chlori d e io n corrosio n

 MP >13 80 ° C

 k = 1 8. 15 W/m -K

© Best Stainless & Alloys. All rights reserved. This content i s excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse .

http://www.beststainless.com/alloys/alloy-20.html

S ou r ce: htt p : / / w w w . r ol l ed al l oy s. com / products/ ni ck el - al l oy s/ al l oy - 20

Image by MIT OpenCourseWare.

Chargin g Lay out

Disc harging Layout

Storage – Heat Exchanger

Storage – Heat Exchanger

Ass umptions

 Heat stored in PCM a s l ate nt he at on ly

 No con vection withi n PCM

 L(p cm) ~= L(slab )

 t(pcm) << L(p cm)

 Heliu m t em pe ratu re isoth erma l fo r an y g iven “x”

Next Steps for Storage

 Dete rmin e ge om etry

 Dete rmin e ma ss of PCM n ee de d

 Calcula te Re, h of he liu m, Bio t n um be r

 The rmal an alysis of PCM a nd cont ain me nt

 Pressure dro p across HX

 Cha rgi ng an d di scharg in g da ta

Required inputs

• Mass flow rate of lead bismuth during shutdow n

• Temp lead bismuth should be heat ed to using stored heat

• Time between s hutdown and heating lead bismuth

• Maximum time for heating lead b ismuth

Questions?

MIT OpenCourseWare http://ocw.mit.edu

22.033 / 22.33 Nuclear Systems Design Project

Fa ll 2011

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