Gas Turbine Combustor Casing Segmentation for Cost Reduction
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Solution Overview
Problem
Conventional gas turbine facilities require expensive Ni-based alloys for components exposed to high-temperature carbon dioxide, increasing manufacturing costs due to the need for materials that can withstand extreme temperatures.
Innovation Solution
The design incorporates a dual carbon dioxide flow system where high-temperature and low-temperature carbon dioxide are used separately to cool different parts of the combustor casing, allowing the use of less expensive Fe-based heat-resistant steel for the downstream-side casing and potentially the upstream-side casing, reducing material costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the combustor casing is exposed to high-temperature carbon dioxide, then the casing can withstand the high temperature, but expensive Ni-based alloys must be used
Solution Approach 1:
The combustor casing is divided into upstream-side casing and downstream-side casing. The downstream-side casing is shielded from high-temperature carbon dioxide by the cylinder, allowing the use of inexpensive Fe-based heat-resistant steel, while the upstream-side casing that is exposed to high temperature uses expensive Ni-based alloy. This segmentation resolves the contradiction by applying expensive materials only where absolutely necessary.
Solution Approach 2:
Different materials are used for different parts of the combustor casing based on their exposure to high-temperature carbon dioxide. The downstream-side casing uses Fe-based heat-resistant steel while the upstream-side casing uses Ni-based alloy. This local differentiation of material quality resolves the contradiction between temperature resistance and manufacturing cost.
2Temperature
If carbon dioxide is used to cool the combustor liner and transition piece, then cooling efficiency is improved, but the casing is exposed to high-temperature carbon dioxide requiring expensive materials
Solution Approach 1:
The space between the combustor casing and combustor is divided into a high-temperature region (upstream) and a low-temperature region (downstream) by the cylinder. This segmentation allows carbon dioxide cooling to be effective in the combustor liner and transition piece while preventing high-temperature carbon dioxide from exposing the entire casing to extreme heat, thereby reducing material costs.
Solution Approach 2:
The cylinder acts as an intermediary barrier that separates high-temperature carbon dioxide from the downstream-side casing. This intermediary structure enables the casing to be made of inexpensive Fe-based heat-resistant steel while still allowing carbon dioxide to cool the combustor liner and transition piece effectively.
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 approach reduces manufacturing costs by utilizing more affordable Fe-based heat-resistant steel for the combustor casing components, maintaining efficiency and preventing exposure to high-temperature carbon dioxide, thus optimizing the gas turbine facility's operational performance.
Implementation Method 1
the oxygen having passed through the flow rate regulating valve 311 is heated by receiving a heat quantity from a later-described combustion gas in a heat exchanger 312
Implementation Method 2
The combustion gas having passed through the heat exchanger 312 passes through a heat exchanger 316 further. When the combustion gas passes through the heat exchanger 316, the water vapor in the combustion gas condenses into water.
Implementation Method 3
When the combustion gas passes through the heat exchanger 316, the water vapor in the combustion gas condenses into water.
Implementation Method 4
The carbon dioxide guided into the upstream-side casing 351a flows toward the turbine 315 between the downstream-side casing 351b and, a combustor liner 352 and a transition piece 353 (tail pipe). Thus, the carbon dioxide other than the one exhausted from the pipe 344 circulates in the system. When the carbon dioxide flows between the downstream-side casing 351b and, the combustor liner 352 and the transition piece 353, the carbon dioxide cools the combustor liner 352 and the transition piece 353.
Implementation Method 5
The above cooling is performed by porous film cooling and the like, for example. A part of the carbon dioxide is introduced into the combustor liner 352 and the transition piece 353 from holes 354, 356 of a porous film cooling part, dilution holes 355, and the like
Data Source
AI summary
A gas turbine facility 10 of an embodiment includes: a combustor 20; a cylinder 80 dividing a space between a combustor casing 70 and the combustor 20; and a turbine 25 rotated by a combustion gas exhausted from the combustor 20. The gas turbine facility 10 includes: a heat exchanger 24 which cools the combustion gas; a pipe 42 through which a part of the combustion gas cooled in the heat exchanger 24 passes in the heat exchanger 24 to be heated and is guided to a space between the combustor 20 and the cylinder 80; a pipe 44 which guides another part of the combustion gas cooled in the heat exchanger 24 to a space between the combustor casing 70 and the cylinder 80; and a pipe 45 which exhausts a remaining part of the combustion gas cooled in the heat exchanger 24 to the outside.