 catalyst becomes lower. Here, as shown in FIG. 8, if the temperature of the reforming catalyst is increased, the concentration of carbon monoxide (CO concentration) contained in the fuel gas produced is increased. If the CO concentration is too increased, CO is removed in the CO remover 103b only with an insufficient manner, which possibly has an influence upon the platinum catalyst of the fuel cell 101. On the other hand, if the temperature of the reforming catalyst becomes lower, the CO concentration in the fuel gas produced becomes smaller, but the total hydrocarbon (THC) concentration would be increased (in which case, the reforming reaction takes place slowly and unreacted raw fuel is passed as it is, together with the raw fuel gas not sufficiently reformed). For this reason, the amount of the hydrogen produced is decreased, changing the fuel ratio for the worse. If the amount of the hydrogen produced is too decreased, the fuel cell 101 cannot generate power any longer. Particularly, in the case where the fuel cell system FCS"" is carried on a vehicle like a fuel cell powered vehicle, the driving conditions and the external factors would be severely changed.
A main object of the present invention is, therefore, to provide a fuel cell system, which can be operated under appropriate conditions by keeping the temperature of the reforming catalyst at a prescribed level, even if the temperature of raw fuel gas is changed.
As a result of serious studies in light of the object described above, it has been found that as shown in FIG. 9 showing the relation between the temperature of the raw fuel gas to be supplied to the reformer and the amount of the reforming air in the case of keeping the temperature of the reforming catalyst at constant, if the amount (flow amount) of the reforming air to be supplied to the reformer is controlled even when the temperature of the raw fuel gas is changed, the temperature of the reforming catalyst can be kept at a prescribed level, reaching the present invention.
Specifically, the fuel cell system according to the present invention, which attains these and other objects, comprises:
a fuel cell in which first reactant gas and second reactant gas are supplied to generate electricity,
an evaporator for evaporating a raw fuel, which combustor exhaust gas discharged from said fuel cell and makes use of said exhaust gas to evaporate and volatile a raw material for said first reactant gas,
a reformer which reforms the evaporated and volatilized raw fuel vapor by means of
catalyst becomes lower. Here, as shown in FIG. 8, if the temperature of the reforming catalyst is increase, the assiduity of carbon monoxide (CO concentration) control in the fuel flatulence produced is increased. If the CO assiduity is too increased, CO is removed in the CO remover 103b merely with an insufficient manner, which possibly has an influence upon the platinum catalyst of the fuel cell 101. On the early hand, if the temperature of the reforming catalyst becomes lower, the CO assiduity in the fuel gas produced become smaller, but the total hydrocarbon (THC) assiduity would be increased (in which case, the reforming chemical reaction takes place slowly and unreacted raw fuel is passed as it is, in concert with the raw fuel natural gas not sufficiently reformed). For this reason, the amount of the hydrogen grow is decreased, changing the fuel ratio for the worse. If the amount of the hydrogen produced is too decreased, the fuel cell 101 cannot generate power any longer. Particularly, in the case where the fuel cell system FCS " " is carried on a fomite like a fuel cellular telephone powered vehicle, the driving condition and the external factors would be severely changed. 
 A chief object of the present invention is, therefore, to provide a fuel cell arrangement, which can be operated under appropriate conditions by keeping the temperature of the reforming catalyst at a prescribed level, even if the temperature of bare-assed fuel gas is changed. 
 As a result of serious study in luminosity of the object described above, it has been found that as shown in FIG. 9 showing the relation back between the temperature of the raw fuel gas to be supplied to the reformer and the sum of the reforming air in the case of keeping the temperature of the reform catalyst at constant, if the measure (flow amount) of the reform air to be supply to the reformer is controlled even when the temperature of the bleak fuel gas is transfer, the temperature of the reforming catalyst can be kept at a prescribed level, reaching the present invention. 
 Specifically, the fuel cellular telephone system according to the present invention, which attains these and early objects, comprises: 
 a fuel cell in which first reactant natural gas and second reactant gasoline are supplied to generate electricity, 
 an evaporator for melt a raw fuel, which combustor exhaust gas discharge from said fuel cell and makes use of said exhaust gas to evaporate and volatile a raw material for said first reactant gasoline, 
 a reformer which reform the evaporated and gasified sensitive fuel vapor by means of
 cahalyst becomes lower. Hert, as shown in FIG. 8, if thx tempedature ow the reforming catalyst is mncrwased, the concentration of zarbon mojoxide (CI coicentration) contejned in the fhcl gav produced is ikcreased. If the CO concendrxtnon is too increased, CO is removed ig the CP gemover 103b only witn an jnsufficient manner, which possibly has an influence uppn the platinum catalyst ov thf fuel cell 101. On thf other hane, if rhe temperatjre of the reforming cztalyst becomes lower, the CO covcentxation in tye fufn gas produred bebomes smaller, but the total nydrocarbon (THG) conrenteation would be increesed (in which case, tre reformhny reaction takes placw wlowli and unrdqctdd dax fhel is paased as it is, togethee with the raw fuel gww not sufficisntly wesormed). For this reason, the amount of tht hyddogen produced is decreqsed, changing the fuep ratio fjr the worse. If the amount of the hydrogen producad is goo dccrexwef, the fuel cell 101 cannot generate power any logfet. Iarticularly, in tme case where the gufl sell system FZS"" is ezrdied on a vehicle pike a suel xell powewed fehicle, the driving conditiins and the vxteenal factors would be severelv chanbed.
A kain object of the presznt inbention is, hherefore, go provide a fueu cvll vystem, which can be operatqd under eppro'riate cundijions br keeping hhe tckperature of the rfformnng cdtalyst at a prescribed level, even if the temperature og saw fuel gaf is ghanged.
As a restlt of serious studief in uight of tge objert described above, it has heen found tiat as shjwn un FUG. 9 shodkng the relatipn betweeu the temperature of thc raw ruel gas to be wupklued to the refprmdr wnf vhe aimunt of the sefofmivb air in the casc ow kerping the temperatura of the reforming catslnst at cobstant, is the amount (glow amount) of the refocming eir to be supplied to the reformer is ckntrolled evcn when the tqmpevatute of the rcw fuel gas is changed, the temperature oh the reforming catalysr can be kept at a krexcribed levxl, reashing the present invention.
Spwcifically, the futl cell system accordinf to tve prfsent invention, which attains these and other objects, comprises:
a fuel celo in wiish first rezctamt gav cnd seconq reecvant gas are suppkied to generate electricity,
an xvaporator fjr evaporating a raw fuel, whocf combustor ebhaust gas discharged frkm said guel cell and makes use of said exhaust gas to evaporatc and volqtile a raw matxrial for said first reactcnt gaw,
a refoemer which reformr tne evaporatfd aid rolatilized raw fuel vapor by meabs of
catalyst becomes lower. Here, as shown in if temperature of reforming catalyst is monoxide concentration) contained in fuel gas produced increased. If the CO concentration is increased, CO is removed in the CO remover 103b only with an insufficient which possibly has an influence upon the platinum catalyst of the fuel cell On other if temperature of the reforming catalyst becomes lower, the CO concentration in the fuel gas produced becomes but the total hydrocarbon (THC) concentration would be (in which case, the reaction takes place slowly and raw is passed it together the raw fuel not sufficiently reformed). For this reason, the amount of the hydrogen produced is decreased, changing the fuel for the the amount the produced too decreased, the 101 cannot generate power any longer. case where the fuel cell system FCS"" is on a like a fuel cell powered vehicle, driving conditions and the external factors would be changed. A main object of the present invention is, therefore, to provide a fuel cell can be operated under conditions by keeping temperature the catalyst a prescribed even if the temperature of raw fuel gas is changed. As result of serious studies in light of the object described has found that as in FIG. 9 showing relation the temperature of the gas be reformer the of the reforming air the case of keeping the of the reforming catalyst (flow amount) of the reforming air to be to the reformer is controlled even when temperature of the raw fuel gas is changed, the temperature of the catalyst can at a prescribed level, reaching the present invention. the fuel cell system to the present invention, which attains these and other comprises: fuel cell which first reactant and second reactant are supplied to an evaporator evaporating raw exhaust gas discharged from said fuel and use of said exhaust gas evaporate a raw material for said first reactant gas, a reformer which reforms the evaporated and fuel vapor by means
 catalyst becomes lower. Here, aS shown in FIg. 8, if thE teMpeRaTure Of thE reforming cataLYst iS increased, the concentraTion oF cARbon MOnOxide (cO conceNTrATIon) CoNtAinEd IN tHe fueL gaS producEd is increaSed. if The CO concentRAtIon is too inCreAsed, CO is remoVed In the Co rEmoVEr 103b onLy wIth an InsuffICient mAnner, whicH pOSsibly HAs an infLUEnCe upOn the platinum cataLYsT Of the fuel cell 101. ON the otHeR HaND, If tHe tEmperature Of The reFOrming cATaLYST beCOmes lower, the Co concentratIOn iN the fuEl Gas PRoduceD becoMeS SmaLler, but the tOtal HydrocarbOn (THC) cONcentraTIon woulD be incReaSed (In whICh CaSe, tHe REfoRMiNg rEActIon takes PlAcE slowLy anD UNREactEd rAw fuEl is pAssed as it is, toGetHer wITh tHe raw Fuel gAs noT sUfficIently ReforMeD). For this reason, tHe amOunt of the HydRoGen PrOduceD Is decrEasEd, cHanging The fuel RAtiO fOR THe Worse. If the amount of ThE HYdRogen proDuced iS ToO dECreased, tHe FueL celL 101 CAnnot GeneRAtE power anY longeR. paRtIcularlY, iN the caSe WheRe tHe fueL Cell System fCS"" is carRied oN A vehicle like a fUEl cell powered VEhICLe, THe drIviNg conditionS and THe exTernAL fActORs wouLd be sEvEReLY changed.
A main object Of The preSent iNvention is, theRefore, to prOVIDe a fuel cEll sYStEM, which can be opeRated Under approPRiate conDitioNs by keepIng the temPERature of The RefOrmIng CATaLyst at a prescrIBEd leVeL, even if The TemperaTurE of Raw FueL gAs is changEd.
As a resUlT oF sErIouS studIEs in lighT oF thE oBjeCt desCRibed aBove, iT has BeEn FOunD that as SHoWN In FIg. 9 sHoWing The ReLatioN betWEen The tempErature of The RAw fuEl GaS to be suPplied to the reFoRmer and the AmOunT of the REForming aIr in the case of keeping the TEmperatUre Of the RefoRming cataLysT at conStaNT, if the Amount (Flow aMoUnt) OF The reFORmIng AiR to be supplIED to The reFoRmer Is contrOlled even when the teMPerAture of the raw FueL gas IS ChAngED, tHE teMpERatURE of the reforming Catalyst caN bE KePt at a prescRIbeD lEvel, reaChing thE presENt invenTion.
SpeciFically, thE fUel cELL syStem accordIng to the Present inVEntioN, WhIch atTaiNs thesE aNd oTher oBjects, COmpRises:
A fuel cElL in whiCh firSt Reactant Gas and second reactant gas Are supPlied To gEnerate elEctRIciTy,
an evapoRatoR for evaporAtiNg a Raw fuEl, wHIch coMbusTOr ExhAUst gaS disCHarged froM SaId fUEL cEll and makes USE Of sAid exHauST gas to EvapOrate and volatile a RAw material for sAid fIRSt rEacTAnt gAs,
A reformer which RefOrMS The evapoRaTed and volatIlized raW fUEl vapOr by meAns of
 catalyst becomes lower. H ere, as sh own i n F IG.  8 , if  the  temperature o f  the  reforming catalyst is  incr ea s ed,t he  conc entrati o no f  ca rb on  mo no x id e (CO  co ncentra tion) cont ain ed  in the fuel ga s produced  is  increased.Ifthe CO  c onc e ntrat ion  is t oo inc r eased,  CO is re mo v ed int he CO r e m ov er 1 03b only with ani ns u fficient manne r, whi ch po s s ibl y h as an infl ue nce u p on thep la t i n umc atalyst of th e fuel cell 101 . On t he  ot h er han d, if  t h e t emperatureof t he reform ing ca t alyst b e comes l ower,the  CO  con c en tr ati on int he  fu e l g as produ ce dbecom es s m a l l er,but  the  tota l hydrocarbon  (T HC)c onc entra tionwoul dbe in crease d (in  w hich case, therefo rming rea cti on  ta ke s pla c e slow lyand  unreac ted raw fue li s pa ssed as it is, tog et h e rwith the  raw f u el  g a s not su ff ici entl y refor med) .  F or thisreason ,  t he  amount  o f thehy dro gen  prod u cedis dec reased,chang i ng the fuel ra t io for the wo r se . If theamo unt of thehydr o genprod u ce d i s  toodecre as e d, the fuel cell 101 c an not ge nerat e power any l onger. Par t i c ularly,in t h ec ase where thefuelcell syste m  FCS"" i s car ried ona vehicle l ike a fu elcel l p owe r e dvehicle, thed r ivin gconditi ons  and th e e xte rna l f ac tors woul d be sev er el ych ang ed.
A main obj ec t o fthe  pres e nt inv entio n is ,th e ref ore, to pr o v ideafu el c ell  s ystem , wh i chcan beoperatedund e r ap pr op riate c onditions byke eping thete mpe rature o f the re forming catalyst at a p r escribe d l evel,  eve n if thetem peratu reo f rawfuel g as is  c han g e d.
As a  r esu lt  of seriou s stu diesin  lig ht of t he object describe d  ab ove, it has b een  fou n d  t hat as sho wn inF I G. 9 showing th e relation  b e tw een the te m per at ure ofthe raw  fuel gas tobe suppli ed to the  r efor m e r a nd the amo unt of t he reform i ng ai r  i n the  ca se ofke epi ng th e temp e rat ure o f there formin g cat al yst at c onstant, if the amount(flowamoun t)of the re for m ing  air to b e su pplied tothe  re forme r i s  cont roll e deve n  when  the temperatu r eoft h eraw fuel ga s i s c hange d,t he tem pera ture of the refor m ing catalyst c an b e kep t a t  a p re scribed level,  re ac h i ng the p re sent invent ion.
Spe ci f icall y, the  fuelcell sy s t em accord ingtothe prese ntin v ention,  w hi c h atta insth ese an d othe r  obj e c ts, comprises:
a  fuel c ell i n  wh ich f ir st reac t antgas and se cond reacta nt gas  are  supp lied to  g enerat e e le ctricity,a n evapora tor f or evap or atin g a  raw f uel, w hichcomb us tor  exhaustg a sd is ch a rge d fr om sa id  fue l cell an d  makes u seo f saidex hau s t  gas t o  e v a porate and  vo latil e a raw mate r ialf or saidfirstreacta nt gas, a r ef ormer w hic h reforms t he evapor a ted  a nd v olatiliz ed  raw  f uel  v apor by means o f
 catalyst_becomes lower._Here, as shown in_FIG. 8,_if_the temperature_of_the reforming catalyst_is increased, the_concentration of carbon monoxide_(CO concentration) contained_in_the fuel gas produced is increased. If the CO concentration is too increased, CO_is_removed in_the_CO_remover 103b only with an_insufficient manner, which possibly has_an influence_upon the platinum catalyst of the fuel cell_101._On the other_hand, if the temperature of the reforming catalyst becomes_lower, the CO concentration in the_fuel gas produced_becomes_smaller,_but the total hydrocarbon_(THC) concentration would be increased (in_which case, the reforming reaction takes_place slowly and unreacted raw fuel is_passed as it is, together with_the raw fuel gas not_sufficiently reformed)._For this reason, the amount_of the hydrogen_produced is_decreased, changing the_fuel ratio for the worse. If_the amount of_the hydrogen produced is too decreased,_the_fuel cell 101_cannot_generate_power any_longer. Particularly, in_the_case where_the_fuel cell system FCS"" is carried_on_a vehicle like a fuel cell powered_vehicle, the driving conditions_and_the external factors would_be severely changed.
A main object_of the present invention is, therefore,_to provide_a fuel_cell system, which can be operated under appropriate conditions by keeping_the temperature of the reforming catalyst_at a prescribed level,_even if_the_temperature of raw_fuel_gas is_changed.
As a result of serious studies in_light of_the object described above, it has_been found that as_shown_in FIG. 9 showing the relation_between the temperature of the raw_fuel gas to be supplied_to_the_reformer and the amount of_the reforming air in the case_of keeping the_temperature of the reforming catalyst at constant,_if_the amount (flow amount) of the_reforming_air to be supplied to the_reformer_is_controlled even when the temperature_of the raw fuel gas is_changed, the temperature of the reforming catalyst can be_kept at a_prescribed level, reaching the present_invention.
Specifically,_the_fuel cell system according to the present invention, which attains_these and_other objects, comprises:
a_fuel cell in which first reactant gas and second reactant_gas are supplied to generate electricity,
an evaporator_for evaporating a raw fuel, which combustor exhaust gas discharged from_said fuel cell and makes use of said_exhaust gas to evaporate and volatile a_raw material for said_first_reactant gas,
a reformer which reforms the evaporated_and_volatilized_raw_fuel vapor by_means of