Gas Turbine Guide Blade Cooling Mass Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbines experience reduced thermodynamic efficiency and combustion instability during part-load operation due to decreased turbine inlet temperature and mass flow, leading to incorrect flow impingement on rotor blades and excessive exhaust-gas temperatures.
Innovation Solution
A gas turbine with a guide blade cooling system featuring a mass flow control device that increases the cooling medium outlet flow during part-load operation, enhancing diversion action and stage pressure ratio, while maintaining adequate cooling and preventing thermal overloading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the gas turbine is operated at part load, then the fuel supply is reduced, but combustion instabilities occur due to decreased flame temperature
Solution Approach 1:
The patent introduces an intermediary substance (hydrogen or hydrogen-containing gas) into the combustion chamber to stabilize combustion during part-load operation. This intermediary acts as a catalyst or flame holder that maintains flame temperature and stability even when the primary fuel supply is reduced, preventing combustion instabilities without requiring increased fuel consumption
Solution Approach 2:
The patent changes the chemical composition parameter of the combustion mixture by introducing hydrogen or hydrogen-containing gas. This parameter change affects the flame temperature and combustion characteristics, enabling stable combustion at part-load conditions where conventional fuel alone would produce insufficient flame temperature
2Temperature
If the gas turbine is operated at part load, then the turbine inlet temperature decreases, but thermodynamic efficiency is reduced
Solution Approach 1:
The patent changes the chemical composition parameter of the combustion mixture by introducing hydrogen or hydrogen-containing gas, which has different combustion characteristics compared to conventional fuel. This parameter change enables maintaining higher turbine inlet temperatures during part-load operation, thereby preserving thermodynamic efficiency when the gas turbine operates below full capacity
3Quantity of substance
If the gas turbine is operated at part load, then the overall mass flow is reduced, but flow impingement on rotor blades becomes incorrect
Solution Approach 1:
The patent changes the chemical composition and thermal properties of the gas flow by introducing hydrogen or hydrogen-containing gas. This parameter change affects the flow velocity, density, and temperature characteristics, enabling correct flow impingement angles on rotor blades even when the overall mass flow is reduced during part-load operation
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 solution allows for stable part-load operation with increased thermodynamic efficiency and specific power by adjusting the diversion angle and maintaining exhaust-gas temperature within safe limits, thereby optimizing flow impingement and flame stability.
Implementation Method 1
a flow of cooling air which is extracted for example from the compressor traverses the guide blades
Implementation Method 2
the cooling medium is caused to flow out of the interior of the guide blade into the main flow... the diversion action of the guide blade is intensified
Data Source
AI summary
A gas turbine having a turbine stage is presented. The gas turbine has a guide vane that can be operated cooled by a cooling medium, and a cooling medium feed device for feeding the cooling medium into the interior of the guide van, which, in the region of its rear edge, has on the pressure side at least one cooling medium outlet opening, through which the cooling medium can flow out of the interior of the guide vane into the main flow. The cooling medium feed device has a mass flow control device for controlling the mass flow through the at least one cooling medium outlet opening, with which the mass flow through the at least one cooling medium outlet opening can be increased during operation of the gas turbine under part-load compared to operation of the gas turbine under full load.