Fuel Ratio Control in Combustion Apparatus for Overheating Prevention

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Solution Overview

Problem

Combustors in gas turbines and similar systems face overheating issues due to high temperatures, which can damage components and impair performance, and existing control systems struggle to maintain optimal fuel/air ratios and pressure oscillations within safe limits.

Innovation Solution

A control arrangement that varies the ratio of fuel supplies between main and pilot fuel lines in a combustion apparatus, using temperature and pressure sensors to monitor critical parameters and adjust the fuel split to prevent overheating and excessive pressure oscillations, while maintaining a constant total fuel supply or adjusting it across multiple burners to compensate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the fuel supply ratio is adjusted to prevent overheating, then the temperature control is improved, but the system complexity increases due to multiple fuel supply lines and control mechanisms

Engineering Contradiction:
Improvecombustor temperatureVSAvoidfuel supply system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The fuel supply system is segmented into multiple independent fuel supply lines (main fuel line and pilot fuel line) with separate control mechanisms. This allows independent adjustment of fuel ratios to different burners, enabling precise temperature control in specific combustor zones without affecting the entire system, thus resolving the contradiction between temperature control capability and system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs dynamic control of fuel supply ratios through controllable valves or flow controllers on each fuel line. The fuel distribution is continuously adjusted based on real-time temperature and pressure conditions, allowing the system to adaptively prevent overheating while maintaining optimal performance, balancing temperature control improvement with manageable system complexity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple sensors and control mechanisms are added to maintain optimal fuel/air ratios and pressure oscillations, then the operational reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Temperature sensors and pressure sensors are integrated into the system to provide real-time feedback on combustor conditions. This feedback is used by control mechanisms to automatically adjust fuel supply ratios, ensuring optimal fuel/air mixing and maintaining pressure oscillations within safe limits. The feedback loop improves operational reliability by continuously monitoring and correcting deviations, while the automated control reduces the need for manual intervention, balancing reliability improvement with acceptable system complexity.

Inventive Principle:
Principle #23Feedback

3Duration of action of stationary object

If the fuel split is dynamically adjusted to prevent overheating, then the component longevity is improved, but the loss of time for system response and adjustment increases

Engineering Contradiction:
Improvecomponent longevityVSAvoidsystem response time
Core Design Contradiction:
Duration of action of stationary objectVSLoss of time

Solution Approach 1:

The system is designed with pre-positioned temperature sensors and pressure sensors at critical locations, and controllable valves or flow controllers pre-configured on each fuel supply line. This preliminary arrangement of control elements enables rapid response to overheating conditions without requiring system reconfiguration, reducing the time loss while still achieving the goal of extended component longevity through preventive temperature control.

Inventive Principle:
Principle #10Preliminary action

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

Effectively prevents overheating and reduces dynamic pressure oscillations, ensuring the longevity and efficient operation of combustion systems by dynamically adjusting fuel ratios based on real-time sensor data, thereby maintaining safe operating conditions.

Implementation Method 1

A control arrangement that varies the ratio of fuel supplies between main and pilot fuel lines in a combustion apparatus, using temperature and pressure sensors to monitor critical parameters

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

A control arrangement that varies the ratio of fuel supplies between main and pilot fuel lines in a combustion apparatus, using temperature and pressure sensors to monitor critical parameters

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 3

Combustors in gas turbines and similar systems face overheating issues due to high temperatures

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP1974139B1Fuel ratio control in a combustion apparatus with multiple fuel supply lines
Publication Date: 2018.08.22 SIEMENS AG
  • EP1974139B1 patent drawingFigure 1
  • EP1974139B1 patent drawingFigure 2A
  • EP1974139B1 patent drawingFigure 2B

AI summary

A combustion apparatus includes an incoming fuel supply line (27), which supplies fuel in a plurality of fuel-supply lines (24, 25) to one or more burners (12), the burners being associated with a combustion volume. A temperature sensor (32) is located in the apparatus so as to yield temperature information relating to a component part (31) of the apparatus, which is to be prevented from overheating. The apparatus also includes a control arrangement (36), which detects the temperature-sensor output and, depending on that output, varies the fuel supplies to one or more of the burners in such a way as to maintain the temperature of the component part below a maximum value, while keeping the fuel in the incoming fuel supply line substantially constant. The control unit preferably also strives to adjust the operating conditions of the apparatus so that pressure oscillations are kept below a maximum value.