Systems and methods for dynamic balancing of steam turbine rotor thrust

Patent metadata

Field	Value
Publication number	US-10871072-B2
Application number	US-201715582832-A
Country	US
Kind code	B2
Filing date	May 1, 2017
Priority date	May 1, 2017
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

The present application provides a steam turbine system. The steam turbine system may include a rotor, a high pressure section positioned about the rotor, one or more high pressure extraction conduits extending from the high pressure section, a high pressure control valve positioned on each of the high pressure extraction conduits, an intermediate pressure section positioned about the rotor, one or more intermediate pressure extraction conduits extending from the intermediate pressure section, an intermediate pressure control valve positioned on each of the intermediate pressure extraction conduits, and a controller in communication with the high pressure control valves and the intermediate pressure control valves and operable to selectively adjust respective positions of the high pressure control valves and the intermediate pressure control valves to balance thrust acting on the rotor.

First claim

I claim:

1. A steam turbine system, comprising:
a rotor;
a high pressure section positioned about the rotor;
an overload valve positioned on a high pressure bypass conduit;
a plurality of high pressure extraction conduits extending from the high pressure section, wherein each of the high pressure extraction conduits is configured to direct a high pressure extraction flow of steam;
a plurality of high pressure control valves each positioned on a respective one of the high pressure extraction conduits, the high pressure control valves comprising a first high pressure control valve and a second high pressure control valve;
an intermediate pressure section positioned about the rotor;
a plurality of intermediate pressure extraction conduits extending from the intermediate pressure section, wherein each of the intermediate pressure extraction conduits is configured to direct an intermediate pressure extraction flow of steam;
a plurality of intermediate pressure control valves each positioned on a respective one of the intermediate pressure extraction, conduits, the intermediate pressure control valves comprising a first intermediate pressure control valve and a second intermediate pressure control valve; and
a controller in communication with the overload valve, the high pressure control valves, and the intermediate pressure control valves, wherein the controller is configured to:
direct the second high pressure control valve to an open position;
direct the first intermediate pressure control valve to an open position; and
direct the second intermediate pressure control valve to a closed position;
wherein the directing of the respective positions of the second high pressure control valve, the first intermediate pressure control valve, and the second intermediate control valve occurs when the overload valve is in a fully open position and the first high pressure control valve is in an open position, such that a net thrust of the steam turbine system is balanced within a predefined range.

2. The steam turbine system of claim 1 , further comprising a thrust bearing positioned about the rotor and configured to interact with a thrust piston of the rotor.

3. The steam turbine system of claim 1 , wherein the controller is operable to selectively adjust the respective positions of the high pressure control valves and the intermediate pressure control valves to maintain the thrust acting on the rotor within the predefined range.

4. The steam turbine system of claim 1 , further comprising:
a high pressure admission conduit extending from a steam source to an inlet of the high pressure section;
wherein the high pressure bypass conduit extends from the high pressure admission conduit to an intermediate stage of the high pressure section.

5. The steam turbine system of claim 4 , wherein the controller is operable to selectively adjust the position of one of the high pressure control valves and the intermediate pressure control valves based at least in part on the respective positions of a remainder of the high pressure control valves and the intermediate pressure control valves and a position of the overload valve.

6. The steam turbine system of claim 1 , wherein the high pressure extraction conduits comprise a first high pressure extraction conduit extending from an intermediate stage of the high pressure section and a second high pressure extraction conduit extending from a last stage of the high pressure section, wherein the first high pressure control valve is positioned on the first high pressure extraction conduit and the second high pressure control valve is positioned on the second high pressure extraction conduit.

7. The steam turbine system of claim 6 , wherein the intermediate pressure extraction conduits comprise a first intermediate pressure extraction conduit extending from a first intermediate stage of the intermediate pressure section and a second intermediate pressure extraction conduit extending from a second intermediate stage of the intermediate pressure section, wherein the first intermediate pressure control valve is positioned on the first intermediate pressure extraction conduit and the second intermediate pressure control valve is positioned on the second intermediate pressure extraction conduit.

8. The steam turbine system of claim 1 , wherein the controller is operable to direct the first intermediate pressure control valve to assume a closed position or a partially closed position when the second intermediate pressure control valve is in the closed position, and wherein the controller is operable to direct the second intermediate pressure control valve to assume the closed position or a partially closed position when the first intermediate pressure control valve is in the closed position.

9. The steam turbine system of claim 7 , wherein the first high pressure extraction conduit is configured to direct a first high pressure extraction flow of steam to a first pre-heater, wherein the second high pressure extraction conduit is configured to direct a second high pressure extraction flow of steam to a second pre-heater, wherein the first intermediate pressure extraction conduit is configured to direct a first intermediate pressure extraction flow of steam to a third pre-heater, and wherein the second intermediate pressure extraction conduit is configured to direct a second intermediate pressure extraction flow of steam to a fourth pre-heater.

10. The steam turbine system of claim 1 , wherein the controller is further operable to direct the second intermediate pressure control valve to assume the closed position or a partially closed position when the overload valve is in the fully open position, the first high pressure control valve is in the open position, the second high pressure control valve is in the open position, and the first intermediate pressure control valve is in the open position.

11. The steam turbine system of claim 1 , wherein the controller is operable to direct the second high pressure control valve to assume a closed position or a partially closed position, to direct the first intermediate pressure control valve to assume the open position, and to direct the second intermediate pressure control valve to assume the closed position or a partially closed position when the overload valve is in the fully open position and the first high pressure control valve is in the open position.

12. The steam turbine system of claim 1 , wherein the controller is operable to direct the second high pressure control valve to assume a closed position or a partially closed position and to direct the second intermediate pressure control valve to assume the closed position or a partially closed position when the overload valve is in the fully open position and the first high pressure control valve and the intermediate pressure control valve each are in the open position.

13. The steam turbine system of claim 1 , further comprising:
a low pressure section positioned about the rotor;
a low pressure extraction conduit extending from the low pressure section and configured to direct one or more low pressure extraction flows of steam; and
a low pressure control valve positioned on the low pressure extraction conduit;
wherein the controller is in communication with the overload valve and the low pressure control valve, and wherein the controller is operable to selectively adjust respective positions of the high pressure control valves, the one or more intermediate pressure control valves, and the low pressure control valve based at least in part on a respective position of the overload valve.

14. A steam turbine system, comprising:

Assignees

• Gen Electric

Inventors

• Mehra Mahendra Singh

Classifications

• F05D2270/301

  Pressure · CPC title

• F05D2240/52

  Axial thrust bearings · CPC title

• F01D25/16

  Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) · CPC title

• F01D17/145 Primary

  by means of valves, e.g. for steam turbines (valves in general F16K) · CPC title

• F01D3/04 Primary

  axial thrust being compensated by thrust-balancing dummy piston or the like · CPC title