Cross-flame tube sensor mounting for combustion oscillation detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional combustion oscillation detecting systems require multiple expensive pressure sensors for each combustor, leading to high manufacturing and running costs due to short sensor lifespan under high-temperature conditions, and lack design commonality and maintainability due to variable attachment positions.

Innovation Solution

The attachment structure of a combustion oscillation detecting device is positioned on cross-flame tubes connecting multiple combustors, reducing the number of sensors needed by half, allowing for commonality in combustor basket design and flexible attachment positions, with pressure sensors attached to the cross-flame tubes and baffle plates for stable detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If one pressure sensor is provided for each combustor, then combustion oscillations can be monitored accurately, but manufacturing cost and running cost increase due to the large number of expensive sensors required

Engineering Contradiction:
Improvecombustion oscillation detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The combustor system is segmented into multiple combustor baskets, each connected to a common cross-flame tube. The pressure sensor is strategically positioned in the cross-flame tube to detect oscillations from multiple combustors simultaneously, effectively segmenting the monitoring function across a shared detection point rather than requiring individual sensors for each combustor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A single pressure sensor in the cross-flame tube serves multiple combustors, making the sensor multi-functional. The cross-flame tube acts as a universal collection point for pressure oscillations from all connected combustor baskets, allowing one sensor to perform the monitoring function that would otherwise require multiple sensors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If pressure sensors are used under high-temperature conditions, then combustion oscillations can be detected in real-time, but sensor service life becomes short requiring frequent replacement

Engineering Contradiction:
Improvereal-time detection capabilityVSAvoidsensor service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The cross-flame tube serves as an intermediary medium between the high-temperature combustor environment and the pressure sensor. It transmits pressure oscillations from the hot combustor gases to the sensor while providing thermal isolation, allowing the sensor to operate in a relatively cooler environment and extend its service life.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention accepts that the pressure sensor will operate in a demanding environment but mitigates the impact by reducing the total number of sensors required. The system design acknowledges sensor limitations and compensates through strategic placement and reduced quantity, making the system more cost-effective despite individual sensor replacement needs.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If pressure sensors are attached to combustor basket walls, then combustion oscillations can be detected, but attachment position varies depending on combustor basket positioning

Engineering Contradiction:
Improvecombustion oscillation detectionVSAvoidcombustor basket commonality
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The cross-flame tube serves as a universal attachment location for pressure sensors across all combustor configurations. Since all combustor baskets connect to this common tube, the sensor placement becomes standardized and interchangeable, achieving universality and adaptability in the monitoring system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The cross-flame tube creates an equipotential monitoring point where pressure oscillations from all combustors converge. By placing the sensor at this common junction point rather than on individual basket walls, the system achieves consistent detection conditions regardless of how the combustor baskets are positioned or configured.

Inventive Principle:
Principle #12Equipotentiality

4Ease of operation

If multiple combustor baskets are designed with variable attachment positions, then pressure sensors can be attached, but various combustor baskets must be designed and manufactured

Engineering Contradiction:
Improvepressure sensor attachmentVSAvoidcombustor basket variety
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cross-flame tube serves as a universal mounting structure for pressure sensors, eliminating the need for different combustor basket designs. All sensors attach to the same common tube structure, standardizing the attachment process and reducing combustor basket variety to a single common design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The pressure sensor attachment function is extracted from the combustor basket structure and relocated to the separate cross-flame tube. This separation allows the combustor baskets to be designed once with a standard interface, while the sensor mounting is handled independently on the common tube, reducing overall system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach significantly reduces manufacturing and running costs by halving the number of pressure sensors, extends sensor lifespan, and enhances maintainability and design flexibility while ensuring accurate detection of combustion oscillations.

Implementation Method 1

the pressure sensor detects pressure fluctuations caused by combustion oscillations

Methodology Applied
Scientific EffectPressure fluctuation detection:

Implementation Method 2

pressure fluctuations caused by combustion oscillations are transmitted to the combustion oscillation detecting device through the baffle plate

Methodology Applied
Scientific EffectPressure transmission:

Data Source

PatentEP2154434B1Combustion oscillation detecting arrangement
Publication Date: 2017.08.09 MITSUBISHI HITACHIPOWER SYST LTD
  • EP2154434B1 patent drawingFigure 1
  • EP2154434B1 patent drawingFigure 2
  • EP2154434B1 patent drawingFigure 3

AI summary

In order to reduce a manufacturing cost and a running cost, casings (22) each housing a combustion oscillation detecting device (21) are attached in an alternating manner to cross-flame tubes (17) by which a plurality of combustors arranged annularly in a combustor casing are connected to each other.