Combustor Liner with Adjustable Air Inlet Covers
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Solution Overview
Problem
The existing combustor designs in gas turbines face challenges in efficiently controlling the amount of cooling air supplied to the liner and transition piece, due to their thin thickness and double-tube structure, which limits the formation of holes or slopes for guiding airflow effectively.
Innovation Solution
The combustor design includes a liner with an inner and outer structure featuring adjustable openings for cooling air, guided by annular partitions and slope-formed guides, allowing for controlled airflow distribution between the liner and transition piece, with sliding covers and elastic members to adjust opening degrees and airflow ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If impinging jet cooling is used to cool the liner and transition piece, then cooling effect is achieved, but the thin thickness of the tubular structure prevents formation of holes or slopes to guide airflow in a particular direction
Solution Approach 1:
The liner is divided into an inner liner and an outer liner with an annular space between them. The transition piece is similarly segmented with an inner transition piece and an outer transition piece. This segmentation allows independent cooling channels to be formed without requiring complex holes or slopes in thin-walled structures, as the annular spaces themselves serve as cooling passages.
Solution Approach 2:
Cooling air is introduced into the annular space between the inner and outer liners, and also into the annular space between the inner and outer transition pieces. This intermediary cooling air acts as a mediator to cool the structures from the inside out, eliminating the need for direct impinging jet holes in the thin walls.
2Ease of manufacture
If the liner and transition piece have fixed cooling structures, then manufacturing is simplified, but the amount of cooling air supplied to each component cannot be controlled independently
Solution Approach 1:
The first and second annular guides are made movable relative to the outer liner and outer transition piece, respectively. By adjusting the positions of these guides, the opening areas of the first and second openings can be dynamically controlled, enabling independent adjustment of cooling air supply to the liner and transition piece while maintaining a relatively simple overall structure.
Solution Approach 2:
The opening areas of the first and second openings are changed by adjusting the positions of the annular guides. This parameter change allows control over the amount of cooling air supplied to each component independently, transforming a fixed cooling system into an adjustable one without complex redesign.
3Measurement precision
If additional devices are added to control cooling air flow, then airflow control precision is improved, but device complexity increases
Solution Approach 1:
The first annular guide serves multiple functions: it guides cooling air to the fuel injector, forms a seal with the outer liner, and its position adjusts the opening area of the first opening. The second annular guide similarly performs multiple functions including guiding cooling air, sealing, and controlling the opening area of the second opening. This multi-functionality reduces the need for separate control devices.
Solution Approach 2:
The annular guides themselves perform the control function by their positioning relative to the outer liners and transition pieces. The guides' positions directly determine the opening areas, eliminating the need for separate valves or flow control devices. The system uses its own structural components to perform the control function.
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 design enables precise control of cooling air flow rates to the liner and transition piece, enhancing cooling efficiency and stable operation of the fuel injectors, without the need for additional devices, and allows for visual indication of airflow adjustments.
Implementation Method 1
an elastic member (which may include a coil spring) fixed at one end to the second slot and configured at the other end to elastically support the ball against the first slot
Implementation Method 2
Impinging jet cooling is representatively used to cool the liner and the transition piece. The impinging jet cooling is a method of indirectly lowering the temperature of the liner and the transition piece by injecting jets of cooling fluid onto their outer surfaces coming into direct contact with hot combustion gas.
Implementation Method 3
The liner and the transition piece each have a double-tube structure, and it is necessary to cool the inner side of the structure, which directly contacts the high-temperature combustion gas in the combustion chamber.
Implementation Method 4
a first annular guide having a first slope formed on one side to guide the cooling air introduced through the first opening to the fuel injector
Data Source
AI summary
A combustor has a structure enabling selective control of the amount of air supplied to the liner and the transition piece and includes a liner having one end connected to a fuel injector, the liner comprising an inner liner surrounded by an outer liner having a first opening that is elongated in a circumferential direction of the outer liner and is configured to introduce cooling air into an annular space between the inner liner and the outer liner; a liner sliding cover configured to adjust an opening degree of the first opening; and a transition piece connected at one end to the other end of the liner and connected to a turbine at the other end, the transition piece having an effusion hole configured to supply cooling air to a combustion chamber, the effusion hole having an opening area that is less than the opening degree of the first opening.