Device for power generation according to a rankine cycle

Abstract

A device for power generation according to a Rankine cycle, in particular according to an organic Rankine cycle (ORC), comprises a turbine ( 16 ), for expanding a vapour of a working fluid, and at least one heat exchanger ( 18, 20, 22 ), through which the expanded vapour has to flow. The turbine ( 16 ) and the heat exchanger(s) ( 18, 20, 22 ) are contained in a vapour tight container ( 10 ). The turbine ( 16 ) is a radial-outward-flow type turbine having a shaft that is led in a sealed manner out of said container ( 10 ), an axial vapour inlet port arranged opposite the shaft and located inside the container ( 10 ), and a stator exhaust ring with stator exhaust blades defining peripheral vapour exhaust openings for discharging the expanded vapour directly into the vapour tight container ( 10 ), in which the expanded vapour flows through the heat exchanger(s) ( 18, 20, 22 ).

1 . A device for power generation according to a Rankine cycle, in particular according to an organic Rankine cycle (ORC), comprising:
 a turbine ( 16 ) for expanding a vapour of a working fluid; and   at least one heat exchanger ( 18 ,  20 ,  22 ) through which the expanded vapour has to flow; and   a vapour tight container ( 10 ) containing said turbine ( 16 ) and said at least one heat exchanger ( 18 ,  20 ,  22 ),   wherein said turbine ( 16 ) has a shaft ( 66 ) that is led in a sealed manner out of said container ( 10 ) and discharges the expanded vapour directly into said vapour tight container ( 10 ), in which the expanded vapour flows through said at least one heat exchanger ( 18 ,  20 ,  22 );   characterized in that   said turbine ( 16 ) is a radial-outward-flow type turbine having:   an axial vapour inlet port ( 82 ) arranged opposite said shaft and located inside the container ( 10 ); and   a stator exhaust ring ( 56   4 ) with stator exhaust blades ( 58   4 ) defining peripheral vapour exhaust openings for discharging the expanded vapour directly into said vapour tight container ( 10 ).   
     
     
         2 . The device as claimed in  claim 1 , wherein:
 said container ( 10 ) has the form of a vertical cylinder with a top end and a bottom end;   said turbine ( 16 ) is centred in said top end of said container ( 10 ); and   said at least one heat exchanger ( 18 ,  20 ,  22 ) is located below said turbine.   
     
     
         3 . The device as claimed in  claim 1 , wherein:
 said turbine ( 16 ) is a radial-outward-flow type multi-stage turbine with vapour induction in at least one intermediary stage, with an annular vapour inlet port ( 84 ) surrounding said axial vapour inlet port ( 82 ), said annular vapour inlet port ( 84 ) being arranged in said turbine ( 16 ) so as to annularly induce, in an intermediary stage of said turbine ( 16 ), a vapour stream from a second evaporator ( 14 ) into an already partially expanded vapour stream from a first evaporator ( 12 ).   
     
     
         4 . The device as claimed in  claim 1 , including
 a first evaporator ( 12 ) and, optionally, a second evaporator ( 12 ), wherein:   said first evaporator ( 12 ) and, if present, said second evaporator ( 14 ) are arranged in said container ( 10 ), axially below said axial vapour inlet port ( 82 ) of said turbine ( 16 ); and   said at least one heat exchanger ( 18 ,  20 ,  22 ) is arranged annularly around said first evaporator ( 12 ) and, if said second evaporator ( 14 ) is present, annularly around said first and second evaporator ( 14 ).   
     
     
         5 . The device as claimed in  claim 1 , further comprising:
 a first vapour drum ( 46 ) that is located in axial extension of said axial vapour inlet port ( 82 ) and directly connected to the latter without any intermediate piping; and   if said turbine is a multi-stage turbine with vapour induction in an intermediary stage, a second vapour drum that is located in axial extension of said annular vapour inlet port ( 84 ) and directly connected to the latter without any intermediate piping, wherein said second vapour drum ( 48 ) is a compartment inside said first vapour drum ( 46 ), or said first vapour drum ( 46 ) is a compartment inside said second vapour drum ( 48 ).   
     
     
         6 . The device as claimed in  claim 5 , wherein:
 said axial vapour inlet port is formed by a first tubular vapour inlet connection ( 82 ), which is engaged in a sliding and sealed manner by said first vapour drum ( 46 ); and   said annular vapour inlet port, if present, is formed by a second tubular vapour inlet connection ( 84 ) surrounding said first tubular vapour inlet connection;   said second tubular vapour inlet connection is engaged in a sliding and sealed manner by said second vapour drum ( 48 ), and, if said first evaporator ( 12 ) and second evaporator ( 14 ) are arranged axially below said axial vapour inlet port ( 82 ) of said turbine ( 16 ), said first vapour drum ( 46 ) and/or said second vapour drum ( 48 ) are supported by said first evaporator ( 12 ) and/or second evaporator ( 14 ) or by a support structure associated with said first evaporator ( 12 ) and/or second evaporator ( 14 ).   
     
     
         7 . The device as claimed in  claim 1 , said at least one heat exchanger ( 18 ,  20 ,  22 ) includes:
 a first regenerator ( 20 ) that is arranged in said container ( 10 ) so that the exhaust vapour of said turbine ( 16 ) flows directly through it, said first regenerator ( 20 ) being connected to a fluid inlet port of a first evaporator ( 12 ), so as to reheat said fluid with heat extracted from the exhaust vapour flowing through said first regenerator ( 20 ); and   optionally, a second regenerator ( 22 ) that is arranged in said container ( 10 ) so that the vapour having crossed said first regenerator ( 20 ) flows through it, said second regenerator ( 22 ) being connected to a fluid inlet port of a second evaporator ( 14 ), so as to reheat said fluid with heat extracted from the vapour flowing through said second regenerator ( 22 ); and/or   a condenser ( 18 ) in which said expanded vapour is condensed;   wherein, if present, said first regenerator ( 20 ), said second generator ( 22 ) and said condenser ( 18 ) are arranged below said turbine ( 16 ), vertically one above the other.   
     
     
         8 . The device as claimed in  claim 1 , further including:
 a first evaporator ( 12 ) connected to an axial vapour inlet port ( 82 ) of said turbine ( 16 );   a second evaporator ( 14 ) working at a lower evaporation pressure than said first evaporator ( 12 ) and connected to an annular vapour inlet port ( 84 ) of said turbine ( 16 ) for inducing lower pressure vapour into an intermediary stage of said turbine;   for said first evaporator ( 12 ), a first heat carrier fluid inlet port ( 30 ) and a first heat carrier fluid outlet port;   for said second evaporator ( 14 ), a second heat carrier fluid inlet port ( 32 ) and a second heat carrier fluid outlet port;   a connection pipe ( 44 ) connecting said first heat carrier fluid outlet port to said second heat carrier fluid inlet port ( 32 ); and   optionally, a bypass-valve ( 45 ) connected between said second heat carrier fluid inlet port ( 32 ) and said second heat carrier fluid outlet port, for adjusting the flow rate of the heat carrier fluid in said second evaporator ( 14 ).   
     
     
         9 . The device as claimed in  claim 8 , wherein:
 said at least one heat exchanger ( 18 ,  20 ,  22 ) includes a condenser ( 18 );   a condensate collector ( 158 ) is arranged under said condenser ( 18 ) in said container ( 10 );   a condensate outlet port ( 36 ) is connected to said condensate collector;   a first condensate inlet ( 38 ) is connected either directly or through a first regenerator ( 20 ) to a first evaporator ( 12 );   a second condensate inlet ( 40 ) is connected either directly or through a second regenerator ( 22 ) to a second evaporator ( 14 ); and   a condensate pump ( 24 ) is connected with its suction side to said condensate collector ( 36 ), and with its pressure side via a first valve ( 52 ) to said first condensate inlet ( 38 ) and via a second valve ( 54 ) to said second condensate inlet ( 40 ).   
     
     
         10 . The device as claimed in  claim 1 , including:
 an air-cooled condenser ( 170 ) arranged outside said container ( 10 ) and connected to said container ( 10 ) by means of a large diameter pipe ( 172 );   wherein said at least one heat exchanger ( 18 ,  20 ,  22 ) includes at least one regenerator ( 20 ,  22 ) arranged in said container ( 10 ) so that the expanded vapour flows through it before being channelled through said large diameter pipe ( 172 ) into said air-cooled condenser ( 170 ).   
     
     
         11 . The device as claimed in  claim 1 , wherein said turbine ( 16 ) comprises:
 a substantially plate-shaped first turbine housing part ( 80 ) including said axial vapour inlet port ( 82 );   a set of stator rings ( 56 ) with stator blades ( 58 ), said stator rings ( 56 ) having increasing diameters and being fixed with screws onto said first turbine housing part ( 80 );   said stator exhaust ring ( 56   4 ) radially surrounding the stator ring with the biggest diameter and being fixed with screws onto said first turbine housing part ( 80 ), said stator exhaust blades defining said vapour exhaust openings for discharging the expanded vapour into said container ( 10 );   a substantially plate-shaped second turbine housing part ( 100 ) including a shaft outlet neck ( 72 ); said second turbine housing part ( 100 ) being fixed with screws onto said stator exhaust ring ( 58 );   a turbine ( 16 ) shaft rotatably supported within said shaft outlet neck ( 72 );   a rotor disk ( 64 ) supported in a cantilever manner by said turbine ( 16 ) shaft between said first turbine housing part ( 80 ) and said second turbine housing part ( 100 );   for each stator ring ( 56 ), a rotor ring ( 60 ) with rotor blades ( 62 ), said rotor ring ( 60 ) radially surrounding the corresponding stator ring ( 56 ) and being fixed with screws onto said rotor disk ( 64 ).   
     
     
         12 . The device as claimed in  claim 11 , wherein:
 said turbine ( 16 ) includes an annular vapour inlet port ( 84 ) formed in said first turbine housing part ( 80 ) as a ring-zone ( 92 ) with through-holes ( 94 ), said ring-zone ( 92 ) separating a first ring-shaped flange ( 88 ), which supports a first set of stator rings ( 56 ), from a second ring-shaped flange ( 90 ), which supports a second set of stator rings ( 56 ).   
     
     
         13 . The device as claimed in  claim 1 , wherein said turbine ( 16 ) comprises:
 a first turbine housing part ( 80 ) including said axial vapour inlet port ( 82 );   a set of stator rings ( 56 ) with stator blades ( 58 ) supported by said first turbine housing part ( 80 );   a turbine ( 16 ) shaft supporting in a cantilever manner a rotor disk;   for each stator ring ( 56 ), a rotor ring ( 60 ) with rotor blades ( 62 ), said rotor ring ( 60 ) radially surrounding the corresponding stator ring ( 56 ) and being supported by said rotor disk ( 64 );   an annular vapour inlet port ( 84 ) formed in said first turbine housing part ( 80 ) as a ring-zone ( 92 ) with through-holes ( 94 );   wherein said through-holes ( 94 ) open onto an outer rim ( 104   2 ) of one of said rotor rings ( 60 ), said outer rim ( 104   2 ) having a width decreasing towards its periphery, and forming an annular, preferably concave, surface, which defines with an annular, preferably convex, surface on the next stator ring ( 56 ), a ring-shaped converging nozzle ( 114 ), for annularly inducing, into said next stator ring ( 56 ), a vapour stream from said through-holes ( 94 ) into a vapour stream flowing through the preceding rotor ring ( 60 ).   
     
     
         14 . The device as claimed in  claim 1 , wherein said first turbine housing part ( 80 ) supports an end-cap ( 96 ), which forms a vapour inlet deflection surface ( 98 ) opposite said axial vapour inlet port ( 82 ), said vapour inlet deflection surface ( 98 ) being a revolution surface centred on said central axis ( 74 ) of the turbine ( 16 ), wherein a first stator ring ( 56   1 ) is integrated into said end-cap ( 96 ). 
     
     
         15 . The device as claimed in  claim 1 , wherein said second turbine housing part ( 100 ) is mounted in a sealed manner in an opening of said container ( 10 ), so that a shaft outlet neck ( 72 ) of said second turbine housing part ( 100 ) is located outside said container ( 10 ), and said turbine ( 16 ) further includes:
 rolling contact bearings in said shaft outlet neck ( 72 ) for supporting and locating said turbine ( 16 ) shaft therein; and   a shaft sealing device located adjacent to said rolling contact bearings, so that said rolling contact bearings are sealed from the vapour in the turbine ( 16 ).