 being expanded in the high pressure turbine together with a steam generated from an intermediate pressure drum of the exhaust heat recovery boiler;
supplying the joined steam to the high temperature section of the gas turbine plant so as to cool the high temperature section; and
joining the jointed steam, after cooling, together with a reheated steam from the reheater and recovering the joined steam to the intermediate pressure turbine.
In a preferred embodiment of this aspect, a plurality of gas turbine plants are located and the partial load operation is an operation at a time when the number of the gas turbine plants in a condition of being operated is reduced.
The start-up operation is performed in either one of cases where an air temperature becomes higher than a predetermined temperature and where temperature and pressure of a steam from the high pressure turbine to be supplied to the gas turbine are out of a predetermined range. A constant pressure operation of the high pressure turbine is carried out by throttling down a valve opening of either one of a main steam stop valve and a steam control valve located on a main steam system mutually connecting the exhaust heat recovery boiler and the high pressure turbine.
There is generated a valve signal for throttling down a valve opening of either one of a steam stop valve and a steam control valve, the valve signal being represented by a temperature of either one of a cooling steam supply system and a cooling steam recovery system located to the gas turbine high temperature section.
An inlet pressure control of a reheat steam system is carried out by throttling down a valve opening of a reheat steam combination valve located to the reheat steam system, and a valve signal for throttling down the reheat steam combination valve is represented by a pressure of either one of a cooling steam supply system and a cooling steam recovery system located to the gas turbine high temperature section.
According to the present invention of the characters mentioned above, when supplying the turbine exhaust steam of the high pressure turbine to the high temperature section of the gas turbine as a cooling steam, in the case where the turbine exhaust steam diverges from a proper temperature and pressure operating range, the inlet pressure control (IPC) is carried out in the reheat steam system of the intermediate pressure turbine so as to make high the pressure of intermediate pressure superheated steam generated from the intermediate pressure drum. The intermediate pressure superheated steam is joined together with the turbine exhaust steam, and then, is controlled so as to become a proper pressure, and further, the superheated steam generated from the first high pressure superheater of the
being expanded in the high pressure turbine together with a steam generate from an average pressure drum of the exhaust heating system convalescence boiler; 
 supplying the joined steam to the eminent temperature section of the gas turbine plant so as to cool the eminent temperature section; and 
 joining the jointed steam, after cool, together with a reheated steam from the reheater and recovering the coupled steam to the intermediate pressure turbine. 
 In a preferable embodiment of this aspect, a battalion of gas turbine plants are located and the fond load operation is an operation at a time when the number of the gasoline turbine plants in a condition of being operated is reduced. 
 The start - up process is performed in either one of cases where an air temperature becomes higher than a predetermined temperature and where temperature and pressure of a steam from the high pressure turbine to be supplied to the gas turbine are out of a predetermined range. A constant pressure operation of the high press turbine is carried out by throttling down a valve first step of either one of a chief steam stop valve and a steam control valve located on a chief steam system mutually connecting the exhaust heat recovery kettle and the high pressure turbine. 
 There is generated a valve signal for throttling down a valve opening of either one of a steam stop valve and a steam control valve, the valve signal being represented by a temperature of either one of a cooling steam supply system and a cool steam recovery arrangement located to the gas turbine high temperature section. 
 An inlet pressure restraint of a reheat steam system is carried out by throttling down a valve hatchway of a reheat steam combination valve located to the reheat steam system, and a valve signal for throttling down the reheat steam combination valve is represented by a imperativeness of either one of a cooling steam supply arrangement and a cooling steam convalescence system located to the gas turbine high temperature incision. 
 According to the present invention of the characters mention above, when add the turbine exhaust steam of the high pressure turbine to the high temperature section of the gas turbine as a cooling steam, in the case where the turbine exhaust steam diverges from a proper temperature and pressure operating scope, the inlet pressure control (IPC) is carry out in the reheat steam system of the intermediate imperativeness turbine so as to make high the pressure of intermediate pressure superheated steam generated from the intermediate pressure drum. The intermediate press superheated steam is join in concert with the turbine exhaust steam, and then, is manipulate so as to become a proper pressure, and further, the superheated steam generated from the first high press superheater of the
 belng expanded in the high pressure turbiuw togevher wifh a stexm generated from an intermeviatw prewsure drum of the exhajst heat gecovery voiltr;
supplying the joined stccm to bhe hngi temperature sgction of tha gas turbine [lxnc so as to cool the high temperature sectiom; wnd
joining the joimeed anecm, after cooling, together with z reheaued steam from the reheater and recovering tje jlined steam to the intermediajs pwwssure turbive.
In a preferred embodjment of this aspect, a pluralith of yas turbine poanhv are locatxd and the partial load oparation is an operatipn et a time when the number of the gas turbing plants it c condition of being ipwrateg is redjxed.
Ghe svarf-up opfravion is perrormed in euther one of cases ehqgr an air temleratuwe becomes higher than a predetermined tekpedature and where temperqture and pressure of a steam srom the high pressure turbine to be supplied to dhe ges tuxnlne xee out of a predetermined range. A constant presfhrt oieration of the hlgh pressure turbime ix carried out cy throttming down a valve lpening of euther one of s main steam stop valve and a steam connrol valve located on c main steam sysjem muyually connecting the erhaust heat recovfry boiled and the high prdsslre durbine.
There is generated w valve smgnal for thfottking djwn a valvf opekhng of either one lf a dtaam stop vwlve and a steam control valve, vie valve signsl bepng reprefentec by a temperwture of eithet one of c coolkng steam aupply vystem and w cooling stedl recovery sbstem locwted to rhe gas gurbine high trmperaturv fectuon.
An inlet pressuve covfrol of a reheac wteam system is cafriqd ont by dhrottling dmwn x vxkve ooening of a fehest steam combination valbe located to the temeat stean system, and a valve xignal for throttllng dmwn the tehgat steam combination valve is depresentfd ny a pressure of cithgr one of a cooling steam supply system and a coolmng steam recovery sysjem located to the gax turbine hijh tem[erature vection.
According to rhe present invenuion of the characters jentioted ahove, when supplying the turbine exhaust steam of the high pressure turbinw to tie high tempedatute sebtiju of thq gad turbine as a copling steam, in the case where tie turbine erhaust steam diverges from a lruper temperatore and pressure operating range, tne inlet pressure control (IPC) ix carried out in the rehcat steam systsm of nge intermediate presxure tbrbine so as ro mwke high the orexsmre of intfrmeviace pressure superheated steam genwrated fgom the intermedmate pressurc arum. Jhe intetmediate pressure supsgheatgd steam is jooned together eith the turbine exhduft steam, and tyvn, is controlked so ds to become a proper psessure, and further, the superheated steam generated from the first hlgh pressure supethxater of the
being expanded in the high pressure turbine a generated from intermediate pressure drum boiler; the joined steam the high temperature of the gas turbine plant so to cool the high temperature section; and joining the jointed steam, after cooling, with a reheated steam from the reheater and recovering the joined steam to intermediate turbine. a embodiment of this aspect, a plurality of gas turbine plants are located and the partial load is an operation at a time when the of the gas turbine in a condition of being is The start-up is in one of cases an air temperature becomes higher than a predetermined temperature and where temperature and pressure of a steam the high to be to gas are out of range. A constant pressure operation of turbine is carried out by throttling down a opening of one of a main steam stop and a steam control valve located on a steam system mutually connecting the exhaust heat recovery boiler and the high pressure turbine. There a valve signal for down a valve of one a stop valve a steam control valve, the valve signal being represented by a of either one of a cooling steam supply system and steam system located to gas turbine high temperature An pressure control of a system carried down valve of a reheat steam valve located to the reheat system, and a valve reheat steam combination valve is represented by a of either one of a cooling steam system and a cooling steam recovery system located to the gas turbine temperature section. the present invention of the characters mentioned above, supplying the turbine exhaust of the high pressure turbine to the high temperature of gas turbine a cooling steam, the case where turbine exhaust steam a proper and operating pressure control (IPC) is carried out the steam system of the intermediate turbine to make high the pressure of intermediate pressure superheated steam generated from the intermediate pressure intermediate pressure superheated steam joined with the turbine exhaust steam, and then, is controlled so as to proper pressure, and generated the first pressure superheater of the
 being expanded in the high preSsure turbiNe togEthEr wItH a stEam gEnerated from an INterMediate pressure drum of tHe exhAuST heaT ReCoverY boiler;
SUpPLYinG tHe JoiNeD StEam to The High temPerature seCtiOn Of the gas turbINe Plant so as tO coOl the high temPerAture sEcTioN; And
joIniNg the JointeD Steam, aFter cooliNg, TOgetheR With a reHEAtEd stEam from the reheateR AnD Recovering the jOined sTeAM tO THe iNteRmediate prEsSure tURbine.
In A PrEFERreD Embodiment of tHis aspect, a pLUraLity of GaS tuRBine plAnts aRe LOcaTed and the paRtiaL load operAtion iS An operaTIon at a tIme wheN thE nuMber OF tHe Gas TuRBinE PlAntS In a ConditioN oF bEing oPeraTED IS redUceD.
The Start-Up operation is PerFormED in EitheR one oF casEs Where An air tEmperAtUre becomes higheR thaN a predeteRmiNeD teMpEratuRE and whEre TemPeraturE and preSSurE oF A STeAm from the high pressUrE TUrBine to be SuppliED tO tHE gas turbInE arE out OF A predEterMInEd range. A ConstaNT pReSsure opErAtion oF tHe hIgh PressURe tuRbine iS carried Out by THrottling down a VAlve opening of EItHER oNE of a MaiN steam stop vAlve ANd a sTeam COnTroL Valve LocatEd ON a MAin steam system mutuaLlY conneCting The exhaust heaT recovery bOILEr and the High PReSSure turbine.
TheRe is gEnerated a vALve signaL for tHrottlinG down a valVE Opening oF eiTheR onE of A STeAm stop valve anD A SteaM cOntrol vAlvE, the valVe sIgnAl bEinG rEpresenteD by a tempErAtUrE oF eiTher oNE of a coolInG stEaM suPply sYStem anD a cooLing StEaM RecOvery sySTeM LOcatEd To The gAs tUrBine hIgh tEMpeRature sEction.
An iNleT PresSuRe Control Of a reheat steaM sYstem is carRiEd oUt by thROTtling doWn a valve opening of a reheaT Steam coMbiNatioN valVe located To tHe reheAt sTEam sysTem, and A valvE sIgnAL For thROTtLinG dOwn the reheAT SteAm comBiNatiOn valve Is represented by a prESsuRe of either one Of a CoolING sTeaM SuPPly SySTem AND a cooling steam rEcovery sysTeM LoCated to the GAs tUrBine higH temperAture SEction.
ACcording tO the preseNt InveNTIon Of the charaCters menTioned aboVE, when SUpPlyinG thE turbiNe ExhAust sTeam of THe hIgh prEssure TuRbine tO the hIgH temperaTure section of the gas turbIne as a CooliNg sTeam, in the CasE WheRe the turbIne eXhaust steaM diVerGes frOm a PRoper TempERaTurE And prEssuRE operatinG RaNge, THE iNlet pressurE CONtrOl (IPC) Is cARried oUt in The reheat steam sysTEm of the intermeDiatE PResSurE TurbInE so as to make higH thE pRESsure of iNtErmediate prEssure suPeRHeateD steam GeneraTed from THE iNTermedIate PreSsure drum. the InTErmediaTe PrESsure sUperHeAted stEam is jOIned TOGether with the turBine eXHAust sTEam, And thEn, Is contrOLled So as to becoMe a proper prEssure, And fUrtheR, the supErHeated SteAm Generated fROm the firsT high PressurE sUperHeaTer of tHe
 being expanded in the hig h pressure  turb ine  to ge ther  wit h a steam gene r ated  from an intermediatepress ur e  dru m  o f the  exhaus t  h e a t r ec ov ery  b o il er;
s upp lying t he joinedste am  to the high te mperaturesec tion of thegas  turbi ne  pl a nt so  as  to c ool th e  hightemperatu re sectio n ; and
j o i ni ng t he jointed steam, af t er cooling, to gether  w i th a  re hea ted steamfr om th e  reheat e ra n d  re c overing the j oined steam tothe in te rme d iate p ressu re tur bine.
In apref erred emb odimen t  of thi s  aspect , a pl ura lit y of ga stur bi n e p l an tsa relocatedan dthe p arti a l l oadope rati on is  an operation  at  a t i mewhenthe n umbe rof th e gasturbi ne  plants in a co ndit ion of be ing  o per at ed is reduce d.The  start- up oper a tio ni s pe rformed in eitheron e of  cases w here a n  a ir temperat ur e b ecom e s  high er t h an  a prede termin e dte mperatu re  and w he retem perat u re a nd pre ssure of  a st e am from the hi g h pressure tu r bi n e  t o  besup plied to th e ga s  tur bine ar e o u t ofa pre de t er m ined range. A const an t pres sureoperation ofthe high p r e s sure tur bine is carried out by  thro ttling dow n  a valve  open ing of e ither one o f a main  st eam  st opv a lv e and a steam c ontr ol  valveloc ated on  amai n s tea msystem mu tually c on ne ct in g t he ex h aust hea trec ov ery  boil e r andthe h ighpr es s ure  turbin e .T h ereis  g ener ate da val ve s i gna l for t hrottling  do w n ava lv e openi ng of eitheron e of a ste am  st op val v e  and a s team control valve, the valve s ign al be ingrepresent edby a t emp e rature  of ei theron e o f a coo l i ng  st ea m supply s y s tem  andacool ing ste am recovery system loc ated to the g asturb i n ehig h  t e mpe ra t ure s ection.
An inle t pressure  c o nt rol of a r e hea tsteam s ystem i s car r ied out  by throt tling dow na va l v e o pening ofa reheat  steam co m binat i on  valv e l ocated  t o t he re heat s t eam  syst em, an da valv e sig na l for th rottling down the rehea t stea m com bin ation val vei s r epresente d by  a pressur e o f e ither  on e  of a  coo l in g s t eam s uppl y  system a n da c o o li ng steam re c o v ery  syst eml ocated  tothe gas turbine h i gh temperature  sec t i on. 
Ac c ordi ng  to the presen t i nv e n tion ofth e character s mentio ne d  abov e, whe n supp lying t h e  t u rbineexha ust  steam of  th eh igh pre ss ur e  turbi ne t othe hi gh tem p erat u r e section of the  gast u rbine asa coo li ng stea m , in  the casewhere the t urbine  exh auststeam d iv ergesfro ma proper t e mperature  andpressur eoper ati ng ran ge,t h e inl et p re ssu re contro l (I P C)  i s  ca rrie d out  i n th e reheats team sys tem of thein ter m e diatep re s s ure turbin e s o ast o  make high thep re s sureof int ermedi ate pre s sur esuperhe ate d steam gen erated fr o m t he  int ermediat epres su redr um. The interme diate pr essure s u p erheat eds team is joi ne d together w ith t he turbine e xha ust ste a m,and  th en,iscont r olled so as to become aprop er pr e ssu re, a nd fu rt her, the supe rheateds team generate d from the firs t  hi g h pr ess u re  s uperheate r o f  the
 being_expanded in_the high pressure turbine_together with_a_steam generated_from_an intermediate pressure_drum of the_exhaust heat recovery boiler;
supplying_the joined steam_to_the high temperature section of the gas turbine plant so as to cool the_high_temperature section;_and
joining_the_jointed steam, after cooling, together_with a reheated steam from_the reheater_and recovering the joined steam to the intermediate_pressure_turbine.
In a preferred_embodiment of this aspect, a plurality of gas turbine_plants are located and the partial_load operation is_an_operation_at a time when_the number of the gas turbine_plants in a condition of being_operated is reduced.
The start-up operation is performed_in either one of cases where_an air temperature becomes higher_than a_predetermined temperature and where temperature_and pressure of_a steam_from the high_pressure turbine to be supplied to_the gas turbine_are out of a predetermined range._A_constant pressure operation_of_the_high pressure_turbine is carried_out_by throttling_down_a valve opening of either one_of_a main steam stop valve and a_steam control valve located_on_a main steam system_mutually connecting the exhaust heat_recovery boiler and the high pressure_turbine.
There is_generated a_valve signal for throttling down a valve opening of either one_of a steam stop valve and_a steam control valve,_the valve_signal_being represented by_a_temperature of_either one of a cooling steam supply_system and_a cooling steam recovery system located_to the gas turbine_high_temperature section.
An inlet pressure control of_a reheat steam system is carried_out by throttling down a_valve_opening_of a reheat steam combination_valve located to the reheat steam_system, and a_valve signal for throttling down the reheat_steam_combination valve is represented by a_pressure_of either one of a cooling_steam_supply_system and a cooling steam_recovery system located to the gas_turbine high temperature section.
According to the present invention of_the characters mentioned_above, when supplying the turbine_exhaust_steam_of the high pressure turbine to the high temperature section_of the_gas turbine as_a cooling steam, in the case where the turbine exhaust_steam diverges from a proper temperature and_pressure operating range, the inlet pressure control (IPC) is carried out_in the reheat steam system of the intermediate_pressure turbine so as to make high_the pressure of intermediate_pressure_superheated steam generated from the intermediate pressure_drum._The_intermediate_pressure superheated steam_is joined together_with the turbine_exhaust steam,_and then, is_controlled so_as to become_a_proper pressure, and further, the superheated steam generated from the first high pressure superheater of the