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# OAR Box 1818 Prepped byOllie Stewart



### Document

Number: 

# 52 ) ll-D-2 4 Docket Number: 

# A-87-1 1

Printed 11/6/20083:12:45PM

Sheet 52 of 79P. 2

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NISSA NRESEARC H& DEVELOPMENT , INC
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191 9 Pennsylvani aAvenue , N.W
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Suite70 7 P
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. Box57105 Washington , DC 2003 7 Telephone (202) 466-5284 Apri l 14 , 198 7 Ref : W-144- S Mr . Charle s Gra y Director , Emissio nContro l Technolog y Divisio n Environmenta l Protecxtio n Agenc y 256 5 Plymout hRoa d An n Arbor , M I 4810 5 Dea r Mr . Gray : Nissa n appreciate d th e opportunit yt o mee t wit hyo u o nApri l 1 fo r discussio no f ou r feasibilit ystudyo nonboar d controls . Althoug hyo u wer e bus ywit hothe r pressin g assignments , than k yo u fo r arrangin g t o mee t wit hus . Enclose d herei n ar e response s t o th e question s tha t yo u and you r staf f aske d a t th e Apri l 1 meeting . I hop e th e enclosur e full yanswer s you r questions . However , i f ther e ar e othe r item s yo u wis ht o discus s abou t Nissan' s analysis , pleas e cal l m e a t anytime . I n referenc e t o ou r discussio nconcernin g confidentia l treatmen t o f th e material s submitte d byNissa n durin g ou r meeting , w e reques t tha t suc hmaterial s b e availabl e fo r EPA' s us e and no t distribute d outsid e o f EPA . Accordin g t o ou r discussion , yo u indicate d tha t i t ma yb e mor e convenien t fo r EP At o us e th e material s unde r a reques t fo r restricte d use , rathe r tha n fo r busines s confidentia l treatment . W e reques t th e sam e restricte d us e fo r th e enclose d information , whic hi s labele d "confidential. " Than k yo u fo r you r consideration . Sincerely ,

L i Shinbar a Engineerin g Staf f Engin e & Emissio n Contro l end /P. 3

NISSANMOTO RCO. , LTD . SUPPLEMENTA L INFORMATIO NREQUESTE D B YEP AO NONBOAR D CONTROL S

1 . Activate d Performanc e and Temperatur e o f Caniste r Figur e 2-2(b ) (1 ) Effec t o f rapi d temperatur e increas e o ncaniste r durabilit y Durabilit ytestin g i s no wbein g conducted . W e expec t t o finis hi n June , 1987 . (2 ) Reaso n tha t th e activate d carbo ntemperature s ar e highe r i n th e 3. 4 lite r caniste r tha ni nth e 1. 3 lite r caniste r Th e temperatur e o f th e activate d carbo ni s determine d bybot hth e H C adsorptio n capacit ywher e th e temperatur e wa s measured , and hea t transfe r i nth e canister . Tabl e 1 show s tha t th e hea t transfe r o f th e caniste r casin g (steel ) i n th e 3. 4 lite r caniste r i s large r tha ntha t i n th e 1. 3 lite r caniste r (plastic) . However , Tabl e 1 als o show s tha t activate d performanc e (absorbe d H C amoun t pe r lite r o f carbo n a t a certai n chargin g rate ) o f th e 3. 4 lite r caniste r i s large r tha n tha t o f th e 1. 3 lite r canister , and thus , tha t th e hea t generatio ncause d byH C adsorptio ni s highe r i nth e 3. 4 lite r caniste r tha n i n th e 1. 3 lite r canister . Fro mTabl e 1 , w e predicte d tha t th e temperatur e increase d no t becaus e o f a larg e hea t transfe r throug hth e caniste r casin g material , bu t becaus e th e activate d performanc e i s highe r i n th e 3. 4 lite r canister , whic hresult s i n greate r hea t generation . Sinc e thi s dat a wa s measure d up t o caniste r breakthrough , w e dee mi t necessar yt o study temperatur e difference s du e t o bot hlocatio no f th e temperatur e measurin g devic e and adsorptio n distribution . Th e horizonta l axi s o f Fig . 2-2(b ) indicate s th e tim e afte r th e temperatur e a t th e cente r o f th e carbo n caniste r start s t o rise . Actually , thi s tim e doe s no t reflec t th e adsorptio n time . Th e commencemen t o f adsorptio n i nth e caniste r wa s approximatel yon e minut e befor e th e temperatur e bega nt o ris e fo r th e 1. 3 lite r canister , and wa s approximatel ytwelv e minute s befor e th e temperatur e bega nt o ris e i nth e 3. 4 lite r canister . Th e chargin g rate s fo r bot h canister s wa s 5 g/minute .P. 4



### Th e charging ai r temperatur e rise s du e t o it s passag e throughthe hightemperatur e areas . Thos e area s ar e cause d b

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yadsorbe d HC . Therefore , the commencemen t o f the temperatur e ris e doe s no t correspond t o th e star t o f H C adsorptio na t th e cente r o f the carbo ncanister . If , however , the increasing temperatur e o f th e charging ai r i s neglected , an d w e assume tha t the charging ai r spread s uniforml ythroughou t the canister , the rat e o f temperatur e increas e fo r the large r caniste r mayb e lowe r thantha t fo r th e smalle r caniste r (whenthe charging rate s an d HC charging amount s ar e equal) . 2 . Tes t Conditio n o f Figur e 2-2(c ) Th e charging rat e i s no t 8 0 g/min , bu t 5 g/mi n a s listed . 3 . Cros s Sectio n o f Caniste r o f in Figur e 2-2(e ) Eacho f the canister s ar e rectangular , bu t the size s ar e different : Typ e A ; 29 8 m

mx11 2 m

m Typ e B ; 21 0 m

mx10 8 m

m Typ e C ; 26 3 m

mx7 8 m

m 4 . Influenc e o f RVP on Emissio n - Figure s 2-3(a)-(c) , Tabl e 2- 3 Figur e 1 show s the relationshi p betwee nRVP an d emissions . A s RVP increases , the caniste r capacit y mus t increas e becaus e mor e gasolin e vapo r i s produced . Also , the HC purg e mus t increas e t o maintai n adsorptio n performance . Therefore , the HC purg e increas e woul d caus e emission s t o worsen .P. 5

5 . Caniste r Installatio n (1 ) Wh yth e caniste r canno t b e installe d i na crus hzon e I t i s necessar yt o reinforc e th e bod ystructur e whe n placin g th e caniste r i n crus hzones . I nF F vehicles , i f th e caniste r i s installe d i n th e rea r crus hzone , fuelin g part s suc ha s th e fue l tank and fille r tub e woul d b e locate d i nfron t o f th e canister . I norde r t o preven t th e caniste r fro mdamagin g th e fuelin g syste mi n cas e o f impact , bodyreinforcemen t i s necessary . (2 ) Wh yth e caniste r canno t b e installe d i nth e bumpe r Installatio no f a caniste r i n th e bumpe r woul d b e difficul t becaus e o f spac e constraints . Ther e i s n o availabl e spac e fo r th e caniste r i n th e bumper s o f Nissan' s curren t LDV s (Fig . 2) . Th e curren t bumper s use d i nNissa n vehicle s consis t o f a plasti c cove r fille d wit ha foammaterial , a thi nstee l sheet , and a spac e fo r absorbin g impac t energy . Upo n impac t th e bumpe r deform s t o preven t vehicl e bodydeformation . Th e spac e insid e th e bumpe r i s neede d fo r bumpe r deformation . I f ther e i s les s spac e insid e th e bumper , o r i f th e spac e i s fille d bya stif f objec t suc ha s a canister , th e requirement s i n4 9 CF RPar t 58 1 (bumpe r standards ) woul d b e violated . Curren t Nissa n bumper s recove r afte r smal l impacts , thu s savin g th e consume r th e inconvenienc e o f bumpe r replacemen t afte r mino r accidents . Sinc e th e bumpe r deform s easily , th e caniste r i n th e bumpe r coul d b e damage d byeve nver ysmal l impacts . Th e bac k pressur e du e t o broke ncasing , ben t tubing , o r broke n carbo n ca nrende r refuelin g difficul t o r eve n impossible , necessitatin g caniste r replacement . Eve n i f refuelin g wer e no t hampere d byth e damage d canister , a cracke d casin g wil l lea k vapor s withou t th e consumer' s knowledge . I n th e cas e o f LDTs , rea r bumper s ar e no t installe d a s standar d equipment . I f th e caniste r wer e installe d i n th e fron t bumper , th e syste mwoul d b e susceptibl e t o vapo r lin e blockag e bycondense d vapors . (3 ) Wh yth e caniste r mus t no t b e damage d Ther e i s n o safet yproble munles s caniste r damag e result s i n fue l leakage .P. 6

(4 ) Ca n th e roll-ove r valv e preven t fue l leakag e eve n wit hcaniste r damage ? Nissan' s ven t cu t valv e ca n preven t fue l leakage , eve n wit hcaniste r damage . 6 . Bac k Pressur e Increas e Cause d byLiqui d Gasolin e Figur e 2- 5 (1 ) Condition s fo r gasolin e accumulatio ni nth e vapo r line . Ho wmuc hgasolin e vapo r condensat e ca n accumulat e i nth e vapo r lin e ? War mgasolin e vapo r condense s i n th e vapo r lin e whe n i t contact s col d pipin g surface s i nth e vapo r line . Fo r example , condensatio n occur s afte r hig hloa d o r rush-hou r drivin g i n th e winter . Ou r experiment s indicate d tha t 5- 6 c c o f gasolin e coul d condens e i n th e vapo r lin e wit ha nambien t temperatur e o f 5 degree s C and a fue l temperatur e o f 2 6 degree s C . Althoug hth e wors t condition s o f condense d gasolin e accumulatio nhav e s o fa r no t bee n identified , mor e gasolin e ma ycondens e i n th e vapo r lin e wit h condition s othe r tha nnote d above . (2 ) Ca n a vapo r liqui d separato r i nth e vapo r lin e preven t condensation ? W e predic t tha t gasolin e condense d i nth e vapo r liqui d separato r wil l no t evaporat e whe nth e temperatur e i s low , and ma yspil l int o th e vapo r line . (3 ) I s ther e gasolin e condensatio ni nth e existin g evaporativ e syste m? Ther e ma ybe , a s note d above . However,sinc e ther e ar e n o seal s i nth e existin g evaporativ e syste mwhe n refueling , gasolin e condensatio ndoe s no t affec t refuelin g performance . (4 ) Won' t highe r RV P fue l caus e les s gasolin e condensation ? W e hav e experimente d onl ywit h11. 5 RV P gasolin e and d o no t ye t hav e condensatio n dat a wit hdifferen t RV P levels .P. 7

7 . Effectivenes s o f th e submerge d liqui d sea l fo r th e gasolin e tank o f th e 300Z X—Figur e 2-1 5 Th e fille r tub e o f th e 300Z Xi s attache d t o th e lowe r portio no f th e ga s tank . I t wil l no t functio na s a liqui d sea l afte r th e fue l insid e th e tank decrease s t o th e half-wa ypoint . W e hav e no t confirme d it s effectivenes s a s a seal , bu t w e hav e no t found any proble mi n th e existin g design . AJ-tub e fille r pip e wil l probabl yb e use d i n Nissan' s onboar d system . 8 . Refuelin g Performanc e — Figur e 2-1 6 (1 ) Wha t i s th e maximum possibl e refuelin g rat e i n existin g vehicles ? I t i s possibl e t o hav e refuelin g rate s o f up t o 1 2 gallons/minut e fo r som e existin g vehicles . However , w e hav e neve r attempte d refuelin g a t rate s greate r tha n 1 0 gallons/minut e fo r onboar d systems . (2 ) I s i t possibl e t o refue l t o 95 % o f tank capacit ya t 1 0 gallons/minut e befor e shutoff ? I n existin g system s i t i s possibl e t o excee d 95 % o f tank capacit ybefor e shutof f i nsom e model s whil e refueling , bu t mos t model s fal l betwee n9 0 - 95% . Fo r th e onboar d liqui d sea l system , w e hav e no t ye t bee n abl e t o establis ha metho d whic hallow s eve n90 % refueling . (3 ) Woul d ther e b e a cos t increas e fo r refuelin g rate s greate r tha n1 0 gallons/minute ? Nissa nha s no t ye t conducte d researc ho nthi s issue . However , th e followin g change s ma yb e necessary : a ) I n orde r t o decreas e th e pressur e los s o f th e ventilatio n system , th e tub e diameter , th e ven t cu t valv e size , and th e over-fil l valv e siz e mus t b e increased . b ) I n orde r t o decreas e fille r tub e resistance , th e tub e syste mha s t o b e redesigned , and th e diamete r o f th e fille r tub e ha s t o b e increased .P. 8

(4 ) Wil l ther e b e a cos t increas e fo r 90 % refuelin g and 95 % refueling ? Thi s ha s no t ye t bee n calculated , bu t a cos t increas e i s likely . (5 ) Th e SA E refuelin g procedur e Accordin g t o ou r experiment s usin g a liqui d seal , vapo r generatio n decrease d a s the refuelingrat e decreased . However , emission s fro mth e fille r pip e increase d becaus e o f th e lowe r velocit yo f th e ai r enterin g th e fille r pip e (se e th e result s below) . Therefore , th e SA E refuelin g metho di s no t a favorabl e procedur e fo r satisfyin g th e refuelin g emissio nregulation . Refuelin g Spee d (gal/min) : 5. 3 10. 0 H C Vapo r Emissio n (g/gal) : 0.1 5 0.07 5 9 . Lambd a Contro l Unde r Hig hTemperatur e Condition s (Figur e 2-18(b) ) Th e dat a showni nFigure s 2-1 8 i nth e technica l documen t i s derive d fro mtestin g a saturate d caniste r i na nintegrate d system . Th e chang e i nth e air/fue l rati o i n th e purg e lin e jus t pas t th e saturate d caniste r wit ha tw o m mpurg e orific e i s show ni nFigur e 3 attached . Thes e figure s i n 2-1 8 sho wtha t th e tota l air/fue l rati o introduce d int o th e combustio nchambe r exceed s th e boundar ycontrolle d bylambda . 10 . Cos t Estimatio n—Tabl e 3- 1 a . Hos e and Tub e (se e tabl e 2 ) W e estimate d th e cos t fo r th e hos e and tub e wit h th e followin g specifications . •Diamete r Charg e Side : Fue l tank t o caniste r Caniste r t o ambien t ai r Th e externa l tub e diamete r i s 1 5 m m(interna l diameter : 13. 6 mm ) s o a s t o minimiz e th e bac k pressur e durin g refuelin g and t o ensur e refuelin g performance .P. 9



### Purg e side : Caniste r t o engin e Th e externa l tube diamete r i s 1 0 m m(interna l diameter : 8. 6 mm) , i n orde r t o handl e the differen t flowvolume s tha t a variabl e orific e contro l valv e cansupply . Thi s i s necessarybecaus e the vapo r flowvolume canris e t o mor e than thre e time s the volume o f the curren t evaporativ e system . *Tub e Materia l W e used single-woun d stee l tubing , whic hi s copper plate d on the inside , an d plate d on the outsid e wit h coppe r an

d zinc , an

d coate d wit hresin . *Hos e Materia l W e used non-reinforce d NBRhos e fo r the insid e an d CR fo r the outside . Adetaile d piping cos t estimat e fo r a Nissan300Z Xi s show n in Tabl e 2 . b . Variabl e Orific e Contro l Valv e Figur e 4 show s th e variabl e orific e contro l valv e structur e an

d the cos t fo r the uni t wit ha dut ycontro l valve . c . Caniste r Th e cos t estimat e fo r the caniste r i s show ninTabl e 3 . 11 . Time Schedul e fo r the Introductio no f the Onboard Contro l Tes t Facilit y— Figure s 3-3 , 3- 6 Th e standard time require d fo r onboard contro l tes t facilitie s i s ten months . Thi s time interva l cover s the facilit ydesign (includin g the fue l suppl ysystem) , necessarybudge t procedures , construction , an d complianc e wit hmunicipa l building regulations . A t leas t eigh t month s ar e required eveni f thi s schedul e i s shortene d t o the greates t degre e possible .P.1 0



### 12 . Cos t Increas e i n the Cas e o f Tw o Year s Lead Time an d Phase-I n Adoptio n —Appendi xII I Th e calculatio n result s ar e show n inTabl e 4 . Th e calculatio n metho d i s the same a s describe d i n Appendi x III . 13 . Sale s Volume Percentag e o f NewModel s Equippe d wit hthe Onboard Contro l Systemfor EachMode l Yea r —Appendi x II I Tabl e 5 show s the sale s volume percentage s o f newmodel s fo r eachmode l yea r whe n onboard control s ar e adopte d b y a phase-i n plan starting wit hthe 199 3 mode l yea r (fou r year s lea

d time) .P.1 1



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