Hydrophobic filtration of tempering air

Patent metadata

Field	Value
Publication number	US-10005016-B2
Application number	US-201514980772-A
Country	US
Kind code	B2
Filing date	Dec 28, 2015
Priority date	Dec 28, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A gas turbine system may include an exhaust gas processing system configured to process exhaust gas received from a gas turbine engine of the system. An exhaust path of the exhaust processing system is configured to flow the exhaust gas through the exhaust processing system. A tempering air system of the exhaust processing system is configured to introduce tempering air into the exhaust path to cool the exhaust gas. The tempering air system includes a tempering air pathway extending from an air inlet of the tempering air system to a tempering air outlet where tempering air is introduced from the tempering air system and into the exhaust path. A filter system of the tempering air system has a hydrophobic filter positioned along the tempering air pathway, the hydrophobic filter being configured to remove hygroscopic and deliquescent materials from the air flowing through the tempering air pathway.

First claim

The invention claimed is:

1. A gas turbine system, comprising:
an exhaust processing system fluidly coupled to an outlet of a turbine of a gas turbine engine, the exhaust processing system being configured to receive an exhaust gas having products of combustion generated by the gas turbine engine, and to process the exhaust gas before the exhaust gas exits the gas turbine system;
an exhaust path of the exhaust processing system configured to flow the exhaust gas through the exhaust processing system;
a tempering air system of the exhaust processing system configured to introduce tempering air into the exhaust path to cool the exhaust gas, wherein the tempering air system comprises a tempering air pathway extending from an air inlet of the tempering air system to a tempering air outlet where tempering air is introduced from the tempering air system and into the exhaust path; and
a filter system of the tempering air system having a hydrophobic filter positioned along the tempering air pathway, the hydrophobic filter being configured to remove hygroscopic and deliquescent materials from the air flowing through the tempering air pathway.

2. The system of claim 1 , comprising a selective catalytic reduction (SCR) system of the exhaust processing system configured to reduce a concentration of nitrogen oxides (NO x ) in the exhaust gas, wherein the SCR system comprises a stationary catalyst positioned along the exhaust path and configured to catalyze a reaction between the NO x , in the exhaust gas and a reductant, and wherein the tempering air outlet is positioned to introduce the tempering air into the exhaust path upstream of the stationary catalyst.

3. The system of claim 2 , wherein the hydrophobic filter is configured to remove hygroscopic and deliquescent materials from the air flowing through the tempering air pathway that would otherwise alter active sites of the stationary catalyst.

4. The system of claim 1 , wherein the tempering air pathway is entirely separate from an air pathway configured to flow air to a compressor of the gas turbine engine.

5. The system of claim 4 , wherein the filter system is contained in a filter housing, and the system comprises an additional filter system contained in an additional filter housing positioned along the air pathway configured to flow air to the compressor of the gas turbine engine.

6. The system of claim 1 , comprising one or more sensors configured to monitor a pressure drop of the air across the filter system of the tempering air system, or a change in flow rate of the air across the filter system, or both, and to provide an external indication relating to the pressure drop or the change in flow rate, or both.

7. The system of claim 6 , comprising a tempering air control system having one or more processors and memory circuitry storing one or more sets of instructions that, when executed by the one or more processors, are configured to:
receive the external indication relating to the pressure drop of the air across the filter system or the change in flow rate of the air across the filter system, or both;
correlate the pressure drop or the change in flow rate to a state of the hydrophobic filter;
provide a user-perceivable indication, via a user interface, relating to the state of the hydrophobic filter.

8. The system of claim 7 , wherein the one or more sets of instructions, when executed by the one or more processors, are configured to estimate a time-in-use of the hydrophobic filter, or a remaining time of useful life of the hydrophobic filter, or a combination thereof.

9. The system of claim 1 , wherein the tempering air pathway comprises a plurality of air inlets including the air inlet, wherein the plurality of air inlets are configured to allow air to enter the tempering air pathway along parallel and independent flow paths leading to a tempering air header, and wherein the parallel and independent flow paths each include:
a respective filter system having a respective hydrophobic filter;
a respective fan positioned downstream of the respective filter system and configured to draw air into the respective air inlet and through the respective filter system, and to motivate the air through the respective parallel and independent flow path;
one or more respective sensors configured to detect a pressure drop across the respective filter system, a change in flow rate across the filter system, or both, and to provide an external indication relating to the pressure drop or the change in flow rate, or both; and
a respective air outlet leading to the tempering air header.

10. The system of claim 9 , wherein the tempering air header is configured to combine respective flows of air from the plurality of parallel and independent flow paths, and to direct the respective flows of air to the tempering air outlet where tempering air is introduced from the tempering air system and into the exhaust path.

11. The system of claim 9 , comprising a tempering air control system communicatively coupled to the one or more respective sensors and a respective actuator of the respective fan of the plurality of parallel and independent flow paths, the tempering air control system having one or more processors and memory circuitry storing one or more sets of instructions that, when executed by the one or more processors, are configured to:
receive the external indication relating to the pressure drop of the air across the respective filter system or the change in flow rate of the air across the respective filter system, or both;
correlate the pressure drop or the change in flow rate to a state of the respective hydrophobic filter;
provide an output to the respective actuator of at least one of the respective fan to adjust a flow of air along the respective parallel and independent flow path in response to determining that the state of the respective hydrophobic filter is such that the respective hydrophobic filter is not operating within a predetermined set of parameters.

12. The system of claim 1 , wherein the filter system is positioned at the air inlet and upstream of a fan configured to draw air into the air inlet and through the filter system, and to motivate the air through the tempering air pathway.

13. The system of claim 1 , wherein the filter system comprises a multi-stage filter module having the hydrophobic filter as one of multiple filtration stages.

14. The system of claim 13 , wherein the multi-stage filter module includes a prefilter configured to filter dry particles present within the air flowing through the tempering air pathway, and wherein the hydrophobic filter is positioned downstream of the particulate filter within the multi-stage filter module.

15. The system of claim 1 , wherein the hydrophobic filter includes a fluoropolymer-coated fiberglass filter medium, or an expanded polytetrafluoroethylene (ePTFE).

16. A simple cycle gas turbine system, comprising:
a compressor configured to draw air into a compressor air inlet and to produce compressed air;
a combustor configured to receive a flow of the compressed air and a flow of fuel, and to combust a mixture of the compressed air and fuel to produce combustion gases;
a turbine drivingly coupled to the compressor through a shaft and configured to receive the combustion gases from the combustor, and to extract work from the combustion gases to power a load and the compressor via the shaft; and
a duct configured to receive the combustion gases from the turbine as an exhaust gas, the duct having multiple sections, and wherein the duct is fluidly coupled to a stack configured to allow treated exha

Assignees

• Gen Electric

Inventors

• Kippel Bradly Aaron

Classifications

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• F02C7/055

  with intake grids, screens or guards · CPC title

• F05D2260/607

  Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles · CPC title

• B01D46/0086

  Filter condition indicators · CPC title

• B01D53/864

  Removing carbon monoxide or hydrocarbons · CPC title