Micro Gas Turbine Cooling via Extracted Working Fluid
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Solution Overview
Problem
Conventional micro gas turbine systems face challenges in enhancing thermal efficiency due to insufficient cooling of turbines and low working fluid flow rates, which affect cycle efficiency and turbine inlet temperature.
Innovation Solution
A micro gas turbine system that utilizes a working fluid expanded by a second turbine to cool down at least a portion of the first turbine or the working fluid fed to the first compressor, allowing for increased turbine inlet temperature and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the turbine inlet temperature is increased to improve thermal efficiency, then the thermal efficiency is improved, but the turbine components may be damaged due to excessive temperature
Solution Approach 1:
The turbine cooling system is segmented into multiple independent cooling channels (first cooling passage and second cooling passage) that can be controlled separately. This allows selective cooling of different turbine regions to manage temperature distribution while maintaining high inlet temperature for efficiency.
Solution Approach 2:
Cooling passages are pre-established within the turbine structure during manufacturing, and cooling fluid is supplied in advance through these passages before the turbine operates at high inlet temperatures. This preliminary cooling infrastructure enables the turbine to withstand higher inlet temperatures without component damage.
2Reliability
If a cooling system is added to protect the turbine from overheating, then the turbine is protected, but the device complexity increases
Solution Approach 1:
The cooling function is merged with the turbine structure itself by integrating cooling passages directly into the turbine body. The turbine wheel and nozzle are designed with internal cooling channels, combining the structural and cooling functions into a single integrated component rather than adding separate external cooling systems.
Solution Approach 2:
The turbine cools itself through internally integrated cooling passages that are part of its structure. The cooling fluid flows through passages built into the turbine wheel and nozzle, allowing the turbine to perform its own cooling function without requiring external cooling equipment or complex additional systems.
3Use of energy by moving object
If the working fluid flow rate is increased to improve cycle efficiency, then the cycle efficiency is improved, but the power consumption of the compressor increases
Solution Approach 1:
The working fluid flow is distributed with different local qualities through separate pathways: one stream goes through the main turbine for power generation, while another stream is extracted for cooling purposes. This local differentiation allows the system to maintain high cycle efficiency while managing compressor power requirements through selective fluid utilization.
Data Source
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AI summary
A disclosed micro gas turbine system includes a micro gas turbine apparatus and an extracting cycle apparatus. The micro gas turbine apparatus includes a first compressor, a burner, and a first turbine. The first turbine expands a combustion gas generated by the burner. The extracting cycle apparatus includes a second compressor and a second turbine. The second compressor receives a flow of extracted air that is generated by extracting a part of a working fluid discharged from the first compressor. The second turbine expands the working fluid discharged from the second compressor. The working fluid discharged from the second turbine cools down the first turbine.