Turbo machine and method for operating such turbo machine

Patent metadata

Field	Value
Publication number	US-2016108756-A1
Application number	US-201514887834-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Oct 20, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

A turbo machine, especially gas turbine, comprises a rotor, which rotates about a horizontal machine axis, and which is enclosed by a coaxial enclosure comprising a metal casing, whereby an electrical heating system is provided on the lower half of said metal casing. A safe operation is achieved by having said heating system configured as a redundant system.

First claim

1 . Turbo machine, especially gas turbine, comprising a rotor, which rotates about a horizontal machine axis, and which is enclosed by a coaxial enclosure comprising a metal casing, whereby an electrical heating system is provided on the lower half of said metal casing, wherein said heating system is configured as a redundant system.

2 . Turbo machine as claimed in claim 1 , wherein said heating system comprises at least one electrical heating module with two similar redundant lines running in parallel alongside each other.

3 . Turbo machine as claimed in claim 2 , wherein said at least one heating module is connected to a power supply unit such that either each of said redundant lines is supplied with 50% of the electrical power supplied to said heating module from the power supply unit or only one of said redundant lines is supplied with 100% of said electrical power.

4 . Turbo machine as claimed in claim 1 , wherein said heating system comprises measuring means for measuring temperatures and/or electrical properties within said heating system, and that said measuring means is configured as a redundant measuring means.

5 . Turbo machine as claimed in claim 4 , wherein said heating system comprises at least one heating cable, which is attached to said metal casing, and that said measuring means comprises at least one thermocouple box attached to said at least one heating cable to measure a temperature of said at least one heating cable.

6 . Turbo machine as claimed in claim 5 , wherein said at least one thermocouple box encloses a section of said at least one heating cable at a predetermined place of said at least one heating cable, that said at least one heating cable runs through said thermocouple box between an upper part and a lower part of said thermocouple box, and that at least three thermocouples for measuring the temperature of said thermocouple box are attached to said thermocouple box.

7 . Turbo machine as claimed in claim 5 , wherein said at least one thermocouple box is covered with a thermal insulation in order to increase the temperature of the thermocouple box.

8 . Turbo machine as claimed in claim 1 , wherein said heating system comprises at least one heating cable, which is attached to said metal casing by means of metal holding strips.

9 . Turbo machine as claimed in claim 8 , wherein said metal holding strips are placed between said metal casing and said at least one heating cable and hold said heating cable by means of hook elements.

10 . Turbo machine as claimed in claim 9 , wherein said at least one heating cable is provided with a bend between two distant holdings strips holding said heating cable.

11 . Turbo machine as claimed in claim 1 , wherein a plurality of heating modules are symmetrically arranged on said metal casing with regard to a vertical symmetry plane through the machine axis, and that said heating modules are individually and controllably supplied with electric power by means of a power supply unit.

12 . Method for operating a turbo machine according to claim 1 , wherein a control unit within said heating system decides on the electrical power supplied to said heating system based on measurements of the temperature of the metal casing and/or the clearance of the machine and/or electric parameters of the heating system and/or operating parameters of the machine.

13 . Method for operating a turbo machine according to claim 6 , wherein said at least one thermocouple box creates an artificial hot spot at said heating cable, and that said three thermocouples attached to said thermocouple box are evaluated by a control unit 33 with a 2-out-of-3 logic.

14 . Method for operating a turbo machine according to claim 11 , that wherein a heating module on one side of said vertical symmetry plane is turned off when its symmetric counterpart on the other side of said vertical symmetry plane fails.

15 . Method for operating a turbo machine according to claim 11 , wherein in case of an asymmetric cool-down with respect to said vertical symmetry plane the heating system is powered asymmetrically to counter said temperature asymmetry.

Assignees

• Alstom Technology Ltd

Inventors

• Farkas Janos
• Cataldi Giovanni
• Rocchi Matteo

Classifications

• F01D5/18

  Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades · CPC title

• F01D25/14 Primary

  Casings modified therefor (double casings F01D25/26) · CPC title

• F01D25/26

  Double casings; Measures against temperature strain in casings · CPC title

• F01D11/24

  by selectively cooling-heating stator or rotor components · CPC title

• F05D2270/094

  by using back-up controls · CPC title