Integrated Heat Transfer and Clearance Control in Turbine Systems
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Solution Overview
Problem
Existing engineering control systems for fluid-based systems, such as gas turbine engines, face challenges in accurately and efficiently controlling flow and heat transfer due to complex phenomena like heat transfer and clearance, which are often treated separately and result in unstable models, especially under low-flow and choked-flow conditions.
Innovation Solution
A control system for rotary apparatuses, including a processor with an output module, temperature modules, a thermodynamic module, a comparator, and an estimator, that integrates heat transfer and clearance analysis to minimize errors and control flow along the gas path, using a component-level dynamic mathematical model to provide real-time, robust, and accurate control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If heat transfer and clearance are treated separately using independent sets of temperature and thermal growth states, then the modeling approach is simpler, but the model fidelity and reliability deteriorate
Solution Approach 1:
The patent merges heat transfer and clearance modeling into a unified integrated model that uses a single set of temperature states to drive both thermal expansion calculations and heat transfer analysis. This integration eliminates the need for separate independent temperature and thermal growth state sets, thereby improving model fidelity and reliability while maintaining manageable complexity through coupled differential equations that simultaneously solve for temperature and clearance.
2Ease of manufacture
If existing flow parameter models are used, then the implementation is straightforward, but the model becomes unstable under low-flow and choked-flow conditions
Solution Approach 1:
The patent implements a robust flow parameter model that dynamically adjusts parameters based on operating conditions. The model uses dimensionless parameters and transforms flow equations to remain numerically stable across the entire operating range, including low-flow and choked-flow conditions. This is achieved through parameter transformations that prevent division by zero and maintain numerical precision without complicating the implementation.
3Reliability
If a more integrated and physics-based approach is used, then the reliability and fidelity of the model improve, but the device complexity increases
Solution Approach 1:
The patent segments the integrated model into distinct functional modules: a heat transfer module that calculates heat exchange between working fluid and turbine components, a thermal expansion module that computes clearance changes from temperature states, and a coupled solver module that simultaneously resolves both phenomena. This modular segmentation maintains high model fidelity through physics-based coupling while reducing overall complexity through organized, reusable code structures and clear interfaces between modules.
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 system achieves fast, accurate, and reliable control of fluid-based systems by integrating heat transfer and clearance analysis, improving model fidelity and stability across a wide range of conditions, enhancing operational efficiency and reducing maintenance costs.
Implementation Method 1
heat transfer between turbine components and the working fluid is an important aspect of system behavior
Implementation Method 2
tip clearance is related to heat transfer via the relative thermal expansion of adjacent turbine components
Data Source
AI summary
A system comprises a rotary apparatus, a control law and a processor. The rotary apparatus comprises a rotor and a housing forming a gas path therebetween, and the control law controls flow along the gas path. The processor comprises an output module, a plurality of temperature modules, a thermodynamic module, a comparator and an estimator. The output module generates an output signal as a function of a plurality of rotor and housing temperatures defined along the gas path, and the temperature modules determine time derivatives of the rotor and housing temperatures. The thermodynamic module models boundary conditions for the gas path, and the comparator determines errors in the boundary conditions. The estimator estimates the rotor and housing temperatures based on the time derivatives, such that the errors are minimized and the flow is controlled.