Method of and apparatus for cooling a seal for machinery

• US 5,743,094 A
• Filed: 09/25/1996
• Issued: 04/28/1998
• Est. Priority Date: 02/22/1994
• Status: Expired due to Term

• Current Assignee: Ormat Technologies Incorporated (Ormat Industries Limited)
• Original Assignee: Ormat Industries Limited
• Inventors: Regal, Meir, Hatzir, Shimon, Amir, Nadav, Zimron, Ohad
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Basichas, Alfred
• Application Number:
  US08/720,172
• Time in Patent Office: 580 Days
• Field of Search: 60/646, 60/656, 277/3, 277/22, 277/81 R, 277/59, 277/65, 415/111, 415/112, 415/175, 415/176
• US Class Current: 60/646
• CPC Class Codes: F01D 11/00 Preventing or minimising internal leakage of working-fluid, e.g. between stages sealings in general F16J ; sealing arrangements for transition ducts of combustor cans F01D9/023
• CPC Class Codes: F01D 25/125 of bearings
• CPC Class Codes: F01D 5/02 Blade-carrying members, e.g. rotors rotors of non-bladed type F01D1/34; stators F01D9/00 ; selecting particular materials F01D5/28

Abstract

A seal heated by hot pressurized vapor is cooled by providing a chamber in which the seal is located and for containing vapor that leaks thereinto. The pressure in the chamber is reduced by connecting it to a source of low pressure; and liquid is supplied to the chamber at a pressure above the reduced pressure of the chamber and at a temperature below the temperature of vapor leaking into the chamber. The liquid is introduced into the chamber as droplets for contacting vapor that leaks thereinto thereby cooling the vapor and thus cooling the seal. The flow rate of the liquid is adjustable in accordance with the temperature of the liquid in the chamber.

Claims

1. A method for cooling the rotary seal of a turbine operating on vaporized working fluid that expands in the turbine producing expanded vaporized working fluid that is condensed in a condenser from which condensate is pumped into a vaporizer that produces said vaporized working fluid, said method comprising connecting the seal operating environment to the condenser, and pumping condensate into the seal operating environment.

27. A method according to claim 1 including controlling the rate at which condensate is pumped into said seal operating environment.

28. A method according to claim 27 including removing fluid from said seal operating environment, sensing the temperature of the removed fluid, and controlling the rate at which condensate is pumped into said seal operating environment in accordance with the sensed temperature.

2. Apparatus for cooling a mechanical seal heated by hot pressurized vapor comprising:

(a) a chamber for locating therein the seal and for containing vapor that leaks through said seal;

(b) a connection for connecting the chamber to a source of low pressure thereby reducing the pressure in the chamber to a level below the pressure of vapor that leaks into the chamber;

(c) a source of liquid for supplying liquid to the chamber at a pressure above the reduced pressure of the chamber; and

(d) apparatus for distributing the liquid throughout the chamber in the form of droplets that contact and cool vapors in the chamber, thus cooling the seal.

3. Apparatus according to claim 2 including flow conditioning apparatus for regulating the supply of said liquid to said chamber, including a flow control valve operable to adjust the flow rate of said liquid.

4. Apparatus according to claim 3 wherein said chamber includes means for venting said chamber, and including a conduit for conveying vented fluid to said source, and a temperature sensor for sensing the temperature of the vented fluid, said flow control valve being adjusted in accordance with the sensed temperature.

5. Apparatus according to claim 4 wherein said flow conditioning apparatus includes a filter serially connected with said flow control valve for filtering said liquid before it is introduced into said chamber.

6. Apparatus according to claim 5 wherein said flow conditioning apparatus includes a shut-off valve upstream of said filter, and a flow control valve for selectively disconnecting said liquid from said chamber to enable replacement of the filter.

7. Apparatus according to claim 6 including a turbine wheel mounted on a shaft in a pressure chamber containing hot pressurized, vaporized working fluid, said shaft passing through a labyrinth seal mounted on the shaft between the turbine wheel and the seal.

8. Apparatus according to claim 7 wherein said apparatus for distributing the liquid throughout the chamber includes a disc in the chamber mounted on the shaft and rotating therewith, and means for causing said liquid to impinge on said disc and produce droplets.

9. Apparatus according to claim 7 wherein said hot pressurized working fluid expands in said turbine producing power and expanded working fluid, and including a condenser for condensing said expanded working fluid, and said source of low pressure said the condenser.

10. Apparatus according to claim 9 wherein said flow conditioning apparatus includes an orifice device defining a fixed orifice downstream of said shut-off valve for isolating the rate of flow of said liquid from variations in flow through said condenser.

11. Apparatus according to claim 2 including a turbine wheel mounted on a shaft in a pressure chamber containing hot pressurized, vaporized working fluid, said shaft passing through a labyrinth seal mounted on the shaft between the turbine wheel and the seal.

12. Apparatus according to claim 11 wherein the means for distributing the liquid throughout the chamber includes a disc in the chamber mounted on the shaft and rotating therewith, and means for causing said liquid to impinge on said disc and produce droplets.

13. Apparatus according to claim 12 wherein the means for connecting the chamber to a source of low pressure includes means for connecting the chamber to a condenser of an organic Rankine cycle power plant having a turbine operating on organic fluid.

14. Apparatus according to claim 13 wherein the means for supplying cool and pressurized liquid to the chamber at a pressure above the reduced pressure of the chamber includes means for supplying organic working fluid to the chamber after the condensed organic fluid exiting the condenser of the organic Rankine cycle power plant has been pressurized by the cycle power plant pump.

15. Apparatus according to claim 2 wherein said source of low pressure is the condenser of a power plant.

16. Apparatus according to claim 15 wherein the condenser comprises a condenser of a power plant having a steam turbine.

17. Apparatus according to claim 16 wherein the means for supplying cool and pressurized liquid to the chamber at a pressure above the reduced pressure of the chamber includes means for supplying condensate to the chamber after the condensate exiting the condenser of the steam turbine power plant has been pressurized by the cycle power plant pump.

18. Apparatus according to claim 16 wherein the means for supplying cool and pressurized liquid to the chamber at a pressure above the reduced pressure of the chamber includes means for supplying water to the chamber.

19. A method for cooling the seal associated with a turbine that receives vaporized working fluid from a vaporizer and within which the vaporized working fluid expands producing expanded working fluid, and where the expanded working fluid is condensed in a condenser to produce condensate that is returned to a vaporizer by a cycle pump, the method comprising connecting the chamber containing the seal to the condenser, and using the pump to furnish condensate supplied to the chamber.

20. Apparatus for use with a vaporizer for producing vaporized working fluid from liquid working fluid, and a condenser for producing liquid working fluid from expanded vaporized working fluid, and a pump for returning liquid working fluid from said condenser to said vaporizer, said apparatus comprising:

a) a first turbine having a shaft and being responsive to vaporized working fluid produced by said vaporizer for expanding the vaporized working fluid and producing work at the shaft of the first turbine, and expanded working fluid;

b) a second turbine having a shaft and being responsive to expanded working fluid produced by said first turbine for further expanding the expanded working fluid and producing work at the shaft of the second turbine, and further expanded working fluid;

c) an electric generator coupled to the shafts of the first and second turbines for generating electricity;

d) a seal operating environment associated with said one of the turbines including;

(1) a chamber in which a seal for the shaft of said one of the turbines is located and for containing vapor that leaks the thereinto;

(2) a connection for connecting the chamber to said condenser thereby reducing the pressure in the chamber to a level below the pressure of vapor that leaks into the chamber;

(3) said pump supplying liquid working fluid from the condenser to the chamber at a pressure above the reduced pressure of the chamber;

(4) apparatus for distributing the liquid throughout the chamber in the form of droplets that contact and cool vapors in the chamber, thus cooling the seal; and

(e) flow conditioning apparatus for regulating the supply of liquid to said chamber of the seal operating environment, and including a flow control valve operable to adjust the flow rate of said liquid.

21. A method for cooling a seal heated by hot pressurized vapor comprising the steps of:

(a) providing a chamber for locating therein the seal and for containing vapor that leaks through said seal;

(b) reducing the pressure of the chamber by connecting it to a source of low pressure;

(c) supplying liquid to the chamber at a pressure above the reduced pressure of the chamber and at a temperature below the temperature of vapor leaking into the chamber; and

(d) forming liquid in said chamber into droplets and distributing such droplets throughout the chamber for contacting vapor that leaks thereinto thereby cooling the vapor and thus cooling the seal.

22. A method according to claim 21 including adjusting the flow rate of said liquid.

23. A method according to claim 22 including the steps of:

(a) venting fluid from said chamber;

(b) sensing the temperature of the vented fluid; and

(c) adjusting the flow rate in accordance with the sensed temperature.

24. A method according to claim 23 including adjusting the flow rate in response to the sensed temperature.

25. A method according to claim 22 including filtering said liquid before it is introduced into said chamber.

26. A method according to claim 25 including selectively disconnecting said liquid from said chamber to enable replacement of the filter.

29. A method according to claim 21 wherein the hot pressurized vapor is contained in a pressure chamber within which a turbine wheel is mounted on a shaft, and vapor leaks past a labyrinth mounted on the shaft between the turbine wheel and the seal.

30. A method according to claim 29 wherein the step of forming the liquid into droplets is carried out by spraying the liquid onto a disc mounted in the chamber, said disc being mounted on the shaft on which the turbine wheel is mounted.

31. A method according to claim 21 wherein reducing the pressure of the chamber is achieved by connecting the chamber to a condenser of a power plant.

32. A method according to claim 31 wherein the power plant includes a vaporizer for vaporizing a working fluid, a turbine for expanding the working fluid, a condenser for condensing expanded working fluid, and a cycle pump for returning condensate from the condenser to the vaporizer.

33. A method according to claim 32 wherein the liquid supplied to the chamber is derived from the output of the cycle pump.

34. A method according to claim 32 wherein the working fluid is water.

35. A method according to claim 32 wherein the working fluid is an organic fluid.

36. Apparatus for use with a vaporizer for producing vaporized working fluid from liquid working fluid, and a condenser for producing liquid working fluid from expanded vaporized working fluid, and a pump for returning liquid working fluid from said condenser to said vaporizer, said apparatus comprising:

a) a first turbine having a shaft and being responsive to vaporized working fluid produced by said vaporizer for expanding the vaporized working fluid and producing work at the shaft of the first turbine, and expanded working fluid;

b) a second turbine having a shaft and being responsive to expanded working fluid produced by said first turbine for further expanding the expanded working fluid and producing work at the shaft of the second turbine, and further expanded working fluid;

c) an electric generator interposed between the first and second turbines and directly connected to the shafts thereof for generating electricity;

d) a seal operating environment associated with each turbine, each seal operating environment including;

(1) a chamber in which a seal for the shaft of the turbine is located and for containing vapor that leaks thereinto;

(2) a connection for connecting the chamber to said condenser thereby reducing the pressure in the chamber to a level below the pressure of vapor that leaks into the chamber;

(3) said pump supplying liquid working fluid from the condenser to the chamber at a pressure above the reduced pressure of the chamber;

(4) apparatus for distributing the liquid throughout the chamber in the form of droplets that contact and cool vapors in the chamber, thus cooling the seal; and

(e) flow conditioning apparatus associated with each turbine for regulating the supply of liquid to the chamber of the seal operating environment associated with the turbine, each flow conditioning apparatus including a flow control valve operable to adjust the flow rate of said liquid.

37. Apparatus according to claim 36 wherein each seal operating environment includes means for venting fluid in the chamber of said operating environment to said condenser, and a temperature sensor associated with each turbine for sensing the temperature of the fluid vented from the chamber of the seal operating environment associated with the turbine, the flow control valve associated with each turbine being adjusted in accordance with the sensed temperature of the fluid vented from the chamber of the seal operating environment associated with the turbine.

38. Apparatus according to claim 37 wherein each flow conditioning apparatus includes a filter serially connected with the flow control valve for filtering said liquid before it is introduced into said chamber, and a shut-off valve upstream of said filter and flow control valve for selectively disconnecting said liquid from said chamber to enable replacement of the filter.

39. An organic Rankine cycle power plant having a vaporizer for producing vaporized organic fluid, a turbine receiving said vaporized organic fluid, and having at least one wheel contained in a housing for producing power and expanding hot organic fluid vapor, a condenser for condensing expanded organic vapor, a cycle pump for supplying the condensed organic liquid from the outlet of the condenser to said vaporizer, said power plant comprising:

(a) a seal for sealing the turbine wheel housing;

(b) a chamber for locating therein the seal and for containing hot organic fluid vapors;

(c) means for reducing the pressure of the chamber by connecting it to the condenser of the power plant;

(d) means for supplying cool and pressurized liquid to the chamber from the outlet of the cycle pump at a pressure above the reduced pressure of the chamber;

(e) means for distributing the liquid throughout the chamber by forming droplets of the liquid for contacting the hot vapors and cooling them, thus cooling the seal.

40. A method for cooling a seal heated by hot pressurized vapor comprising the steps of:

(a) providing a chamber for locating therein the seal and for containing vapor that leaks through said seal;

(b) supplying liquid to the chamber at a temperature below the temperature of vapor leaking into the chamber; and

(c) causing liquid in said chamber to form into droplets and distributing such droplets throughout the chamber for contacting vapor that leaks thereinto thereby cooling the vapor and thus cooling the seal.

41. A method for cooling a hot seal comprising the steps of:

(a) providing a chamber for locating therein the seal;

(b) reducing the pressure of the chamber by connecting it to a source of low pressure;

(c) supplying cool and pressurized liquid to the chamber at a pressure above the reduced pressure of the chamber;

(d) distributing the liquid throughout the chamber by forming droplets of the liquid for contacting the gas in the chamber and cooling it, thus cooling the seal.