TURBOMACHINE WITH COOLING SYSTEM USING LUBRICATION OIL
A turbomachine ( 10 ) comprising: •—a turbine provided with an turbine wheel •—sealing means, designed to prevent lubrication oil from escaping towards the turbine wheel, •—a cooling system exclusively based on heat removal by the lubricating oil, which includes a main channel for feeding the lubricating oil to support means of the turbomachine, wherein •—the cooling system is provided with at least one spray-channel for cooling the sealing means, fluid-dynamically connected to the main channel and able to supply a flow of lubricating oil fed directly or indirectly, from the main channel; —the spray-channel is provided, in a distal position with respect to the main channel, with a spray nozzle ( 5 a ) facing the sealing means.
1 . A turbomachine ( 10 ) comprising: at least one turbine ( 2 ) provided with an impeller sealing means ( 7 ), designed to prevent lubrication oil from escaping towards the turbine wheel ( 2 ), a cooling system ( 11 ) exclusively based on heat removal by the lubricating oil which includes a main channel ( 4 ) for feeding the lubricating oil to support means ( 3 , 3 *, 8 , 8 *) of the turbomachine ( 10 ), the turbomachine ( 10 ) being characterized by the fact that—the cooling system ( 11 ) comprises at least one spray-channel ( 5 , 5 *) for cooling the sealing means ( 7 ), fluid-dynamically connected to the main channel ( 4 ) and able to supply a flow of lubricating oil fed directly or indirectly, from the main channel ( 4 ); the spray-channel ( 5 , 5 *) is provided, in a distal position with respect to the main channel ( 4 ), with a spray nozzle ( 5 a ) facing the sealing means ( 7 ).
2 . The turbomachine ( 10 ) according to claim 1 , wherein a diameter (f 5 ) of the spray-channel ( 5 , 5 *) is between 10% and 25% of a diameter (f 4 ) of the main channel ( 4 ).
3 . The turbomachine ( 10 ) according to claim 2 , wherein for values of the diameter (f 4 ) of the main channel ( 4 ) between 5 mm and 6 mm, corresponding values of the diameter (f 5 ) of the spray-channel ( 5 , 5 *) are between 0.7 mm and 1.3 mm.
4 . The turbomachine ( 10 ) according to claim 1 , wherein said spray nozzle ( 5 a ) has a distance (d) from the sealing means ( 7 ) between five and twelve times the diameter (f 5 ) of the spray-channel ( 5 , 5 *).
5 . The turbomachine ( 10 ) according to claim 1 , wherein the turbine ( 2 ) comprises a body provided with a deflector designed to protect sealing means ( 7 ) from direct contact with the lubricating oil.
6 . The turbomachine ( 10 ) according to claim 1 , further comprising a branch ( 6 ) fluid-dynamically connected to the main channel ( 4 ), containing a lubricating oil flow coming from the main channel ( 4 ) and fed to a thrust ring ( 8 , 8 *) of the turbomachine ( 10 ).
7 . The turbomachine ( 10 ) according to claim 6 , in which the main channel ( 4 ) is provided with further channels ( 4 *) for supplying lubricating oil to floating plain bearings ( 3 ) of the turbomachine ( 10 ).
8 . The turbomachine ( 10 ) according claim 4 , in which the main channel ( 4 ) is provided with further channels ( 4 *) for supplying lubricating oil to rolling bearings ( 3 *) of the turbomachine ( 10 ).
9 . The turbomachine ( 10 ) according to claim 1 , in which inside the spray-channel ( 5 , 5 *), the lubricating oil pressure assumes values not exceeding 10 bar.
10 . The turbomachine ( 10 ) according to claim 1 , further comprising: a compressor ( 1 ), a shaft ( 9 ), rotatable, connecting the turbine ( 2 ) and the compressor (D, support means ( 3 , 3 *, 8 , 8 *) of the shaft ( 9 ).