Hydrophobic Filtration for Gas Turbine Tempering Air

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Solution Overview

Problem

Heavy-duty gas turbine systems produce exhaust gases at temperatures exceeding the acceptable range for traditional SCR systems, requiring significant tempering air to cool them down, and ambient air contaminants can poison the SCR catalyst, necessitating a more effective filtering solution.

Innovation Solution

A tempering air system with a hydrophobic filter is used to remove hygroscopic and deliquescent materials from the tempering air, which is then injected into the exhaust gas to cool it to a suitable temperature for the SCR process, thereby protecting the catalyst from contaminants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional filtration is used for tempering air, then the system structure is simple, but hygroscopic and deliquescent materials pass through and poison the SCR catalyst

Engineering Contradiction:
Improvecatalyst protectionVSAvoidfilter system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a hydrophobic porous filter medium that allows water vapor to pass through while blocking hygroscopic and deliquescent materials. The porous structure provides sufficient surface area and pore volume to trap catalyst poisons effectively, resolving the contradiction between simple system structure and reliable catalyst protection.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The filter system uses a composite approach combining hydrophobic coating or material properties with porous substrate structure. This composite material configuration enables selective filtration that blocks harmful hygroscopic materials while permitting water vapor transmission, achieving both simplicity and effectiveness.

Inventive Principle:
Principle #40Composite materials

2Temperature

If tempering air is injected to cool exhaust gas, then the exhaust gas temperature is reduced to suitable range, but contaminants in tempering air poison the SCR catalyst

Engineering Contradiction:
Improveexhaust gas temperatureVSAvoidcatalyst poisoning
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The filter is positioned in the tempering air pathway before the tempering air is injected into the exhaust gas. This preliminary filtration action removes hygroscopic and deliquescent materials from the tempering air before it contacts the SCR catalyst, preventing catalyst poisoning while maintaining the temperature reduction benefit.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hydrophobic porous filter acts as an intermediary between the tempering air and the SCR catalyst. It selectively blocks harmful hygroscopic materials while allowing water vapor to pass, mediating the interaction between tempering air and catalyst to prevent poisoning while maintaining cooling function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The hydrophobic filter effectively reduces the concentration of catalyst poisons in the tempering air, extending the life of the SCR catalyst and improving the efficiency of NOx reduction in the exhaust gas.

Implementation Method 1

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

Methodology Applied
Scientific EffectHydrophobic filtration: Filter (physical)

Implementation Method 2

A tempering air system of the exhaust processing system is configured to introduce tempering air into the exhaust path to cool the exhaust gas

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3187701B1Hydrophobic filtration of tempering air
Publication Date: 2019.03.13 GENERAL ELECTRIC CO
  • EP3187701B1 patent drawingFigure 1
  • EP3187701B1 patent drawingFigure 2
  • EP3187701B1 patent drawingFigure 3

AI summary

A gas turbine system may include an exhaust gas processing system configured to process exhaust gas received from a gas turbine engine 12 of the system. An exhaust path of the exhaust processing system 22 is configured to flow the exhaust gas through the exhaust processing system. A tempering air system 50 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 96 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 90 of the tempering air system has a hydrophobic filter 100 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.