Steam turbine seal packing performance monitoring system using magnetic field communication

Patent metadata

Field	Value
Publication number	US-11098610-B2
Application number	US-201916265968-A
Country	US
Kind code	B2
Filing date	Feb 1, 2019
Priority date	Feb 26, 2018
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

In a steam turbine seal packing performance monitoring system, steam pressure is measured by installing a pressure sensor inside a seal packing for preventing steam from leaking, so that pressure information can be transmitted using magnetic field communication in order to externally monitor seal packing performance. The system includes a seal packing unit that is installed on a rotor shaft and has a plurality of seal packs disposed along an axial direction of the rotor shaft; a pressure sensor installed inside the seal packing unit to detect a pressure of steam leaked from inside the seal packing unit and to transmit a magnetic field signal by converting a detection signal indicative of the detected pressure into the magnetic field signal; and an adapter for receiving the magnetic field signal, converting the received magnetic field signal into pressure data, and calculating a leakage amount of steam based on the pressure data.

First claim

What is claimed is:

1. A system for monitoring performance of a seal packing in a steam turbine, the system comprising:
a seal packing unit installed on a rotor shaft of the steam turbine, the seal packing unit including a plurality of seal packs disposed along an outer surface of the rotor shaft;
a pressure detection unit installed inside the seal packing unit between adjacent seal packs among the plurality of seal packs and configured to detect a pressure of steam leaked from inside the seal packing unit and to transmit a magnetic field signal outside the seal packing unit by converting a detection signal indicative of the detected pressure into the magnetic field signal; and
an adapter for receiving the magnetic field signal, converting the received magnetic field signal into pressure data, and calculating a leakage amount of steam based on the pressure data.

2. The system of claim 1 , wherein the pressure detection unit is installed in a steam passage through which the steam is discharged from the inside of the seal packing unit.

3. The system of claim 1 , wherein the pressure detection unit is installed in an air passage through which air flows into the seal packing unit.

4. The system of claim 1 , wherein the pressure detection unit comprises:
a pressure sensor for detecting a pressure of the leaked steam and outputting the detection signal; and
an interface for transmitting the magnetic field signal outside the seal packing unit by converting the detection signal into the magnetic field signal.

5. The system of claim 4 , wherein the pressure detection unit consists of one or more pressure detection units installed inside the seal packing unit and configured to detect the pressure of the leaked steam of at least one seal pack.

6. The system of claim 4 , wherein the interface comprises:
a signal conversion unit for converting the detection signal into the magnetic field signal; and
a magnetic field transmission unit for transmitting the magnetic field signal outside the seal packing unit.

7. The system of claim 1 , wherein the adapter is installed outside the seal packing unit.

8. The system of claim 1 , wherein the adapter comprises:
an antenna for receiving the magnetic field signal;
a data conversion unit for converting the received magnetic field signal into the pressure data;
a control unit for calculating the leakage amount of the steam based on the pressure data to determine a performance of the seal packing unit; and
a communication unit for transmitting warning data generated by the control unit.

9. The system of claim 8 , wherein the control unit is configured to determine that steam is leaking from the seal packing unit when a difference between pressure data detected in a previous stage and currently detected pressure data is greater than or equal to a reference value with respect to the determined performance of the seal packing unit.

10. The system of claim 9 , wherein the control unit is further configured to control the communication unit to transmit the warning data when it is determined that steam is leaking from the seal packing unit, and wherein the warning data indicates a deterioration in the performance of the seal packing unit.

11. The system of claim 9 , wherein the control unit is further configured to determine a replacement cycle of the seal packing unit by comparing the leakage amount of steam with a predetermined reference steam amount.

12. The system of claim 8 ,
wherein the control unit is configured to determine that steam is leaking from at least one seal pack of a first seal pack and a second seal pack when first pressure data is greater than or equal to a reference value;
wherein the first pressure data is detected through a first pressure sensor of one or more pressure sensors respectively attached to downstream sides of the plurality of seal packs; and
wherein the first pressure sensor is provided between the first seal pack and the second seal pack.

13. The system of claim 12 , wherein the control unit is further configured to determine that steam is leaking from one seal pack of the first seal pack and the second seal pack when the pressure data detected through pressure sensors other than the first pressure sensor is less than the reference value.

14. The system of claim 12 , wherein the control unit is further configured to control the communication unit to transmit a warning message indicating a need to replace the seal pack determined as a seal pack from which the steam is leaking.

15. The system of claim 8 , wherein the adapter further comprises a storage unit for storing steam amount data matched to the pressure data.

16. A method for monitoring performance of a seal packing in a steam turbine, the steam turbine including a seal packing unit installed on a rotor shaft of the steam turbine, the seal packing unit having a plurality of seal packs disposed along an outer surface of the rotor shaft, the method comprising:
detecting a pressure of steam leaked from the steam turbine between adjacent seal packs among the plurality of seal packs;
transmitting a magnetic field signal outside the seal packing unit by converting a detection signal for the detected pressure into the magnetic field signal;
receiving the magnetic field signal; and
converting the magnetic field signal into pressure data, and determining a leakage amount of steam based on the pressure data.

17. The method of claim 16 , further comprising determining a replacement cycle of the seal packing unit by comparing the leakage amount with a predetermined reference steam amount.

18. The method of claim 16 , further comprising:
determining that steam is leaking from at least one seal pack of a first seal pack and a second seal pack when first pressure data is greater than or equal to a reference value,
wherein the first pressure data is detected through a first pressure sensor of one or more pressure sensors respectively attached to downstream sides of the plurality of seal packs, and
wherein the first pressure sensor is provided between the first seal pack and the second seal pack.

19. The method of claim 18 , further comprising determining that steam is leaking from one seal pack of the first seal pack and the second seal pack when the pressure data detected through pressure sensors other than the first pressure sensor is less than the reference value.

20. The method of claim 18 , further comprising transmitting a warning message indicating a need to replace the seal pack determined as a seal pack from which the steam is leaking.

Assignees

• Doosan Heavy Ind & Construction Co Ltd

Inventors

• Lee Seung Chul
• Choi Jong Min
• Son Hyun Woo

Classifications

• F01D21/003 Primary

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• F05D2240/55

  Seals · CPC title

• F01D17/08

  responsive to condition of working-fluid, e.g. pressure · CPC title

• F05D2220/31

  in steam turbines · CPC title

• F01D11/003

  by packing rings; Mechanical seals · CPC title