Gas Turbine Reheat Combustor Heat Load Matching

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Solution Overview

Problem

Existing gas turbine engines for combined heat and power generation struggle to match heat and electric loads in quantity and timing, particularly due to limitations in variable heat load demands, as they often require either fixed nozzle guide vanes or lack the flexibility to adjust to varying heat requirements efficiently.

Innovation Solution

The use of a reheat combustor and a power turbine with either fixed or variable nozzle guide vanes, configured to adjust the real capacity at the power turbine inlet in proportion to the required exhaust temperature, allowing for matching of heat loads while maintaining a constant apparent capacity at the gas generator exit, thereby accommodating variable heat demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed nozzle guide vanes are used in the power turbine, then the structure is simple and reliable, but the heat load matching flexibility is poor

Engineering Contradiction:
Improveheat load matching flexibilityVSAvoidnozzle guide vane system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by implementing variable nozzle guide vanes (VNGVs) in the power turbine that can change their opening degree dynamically. This allows the turbine to adjust its real capacity in proportion to the required exhaust temperature, enabling flexible adaptation to varying heat load demands while maintaining operational simplicity through automated control

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the real capacity at power turbine inlet is increased to meet high heat load demands, then the heat load matching capability is improved, but the apparent capacity at gas generator exit becomes variable which affects system stability

Engineering Contradiction:
Improveheat load matching capabilityVSAvoidsystem operating parameters stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by coordinating two key parameters: the real capacity at power turbine inlet and the apparent capacity at gas generator exit. The control system adjusts these parameters in a coordinated manner where changes in real capacity are compensated by corresponding changes in apparent capacity, maintaining overall system stability while meeting varying heat load demands

Inventive Principle:
Principle #35Parameter changes

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 configuration enables the gas turbine engine to effectively match heat load requirements, ensuring efficient operation by adjusting real capacity in response to changing heat demands, thereby improving the efficiency and flexibility of combined cycle power plants.

Implementation Method 1

a reheat combustor disposed downstream of the gas generator and configured to increase a fuel flow so as to increase a temperature of the reheat combustor

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2964920B1Cogenerative heat load matching through reheat and capacity match
Publication Date: 2020.06.24 IND TURBINE COMPANY UK
  • EP2964920B1 patent drawingFigure 1~2
  • EP2964920B1 patent drawingFigure 3
  • EP2964920B1 patent drawingFigure 4~5

AI summary

One example of a gas turbine engine may include a gas generator, a reheat combustor that is disposed downstream of the gas generator, and a power turbine that is disposed downstream of the reheat combustor and includes a plurality of nozzle guide vanes. The reheat combustor is configured to increase a fuel flow so as to increase a temperature of the reheat combustor and match a required exhaust temperature. The nozzle guide vanes are configured to increase a real capacity at a power turbine inlet in proportion with the required exhaust temperature. A constant apparent capacity at a gas generator exit upstream of the reheat combustor remains constant, in response to proportionately increasing the temperature and the real capacity with respect to one another.