Turbine blade tip clearance control method and system and medium

Abstract

The invention relates to a gas turbine engine, a turbine tip clearance control method and system thereof and a medium. The control method comprises the steps that S1, the steady-state wall temperature of a casing, the total pressure of an ACC pipeline inlet, the total temperature of the ACC pipeline inlet, the environment pressure of an engine, the total temperature of a gas compressor outlet and the flow of the gas compressor inlet when the ACC is closed are obtained; s2, according to the data obtained in the step S1, the temperature drop and the cooling flow of the casing are obtained; and S3, according to the data obtained in the S2, the ACC valve angle is obtained.

Description

Technical Field

[0001] This invention relates to the field of gas turbine engines, and more particularly to a gas turbine engine and its turbine tip clearance control method, control system, and computer-readable medium. Background Technology

[0002] In gas turbine engines, such as aero engines, the turbine tip clearance between the turbine blades and the turbine outer ring is a key parameter affecting turbine efficiency and propulsive efficiency. Because the temperature of the combustion gases after combustion in the combustion chamber can exceed 2000K, this causes the turbine blades and turbine casing to expand, increasing the turbine tip clearance and resulting in turbine efficiency loss. Therefore, during engine operation, it is essential to control the thermal expansion of the casing, maintain minimal turbine tip clearance, improve turbine efficiency, and reduce fuel consumption.

[0003] Currently, most aero engines employ a thermodynamic active clearance control system (ACC) to control turbine tip clearance. Cooling gas is typically drawn from the fan bypass, and its flow rate is regulated by active clearance control valves. The gas flows through cooling pipes surrounding the turbine casing, undergoing impact cooling via cooling holes in the pipes. This impact cooling controls the thermal expansion of the casing, thereby controlling the turbine tip clearance. The impact-cooled gas is then discharged into the engine's core nacelle and subsequently into the environment through exhaust slits at the rear of the core.

[0004] During engine operation, it is necessary to obtain the real-time clearance and clearance adjustment requirements of the engine under its current state based on relevant engine operating parameters, and send adjustment commands to the EEC (Electronic Engine Control). Complete turbine tip clearance prediction consists of three parts: turbine rotor deformation, blade deformation, and casing deformation. It is mainly obtained through two-dimensional or three-dimensional finite element simulation calculations of the turbine, which is time-consuming and difficult to apply to scenarios that require real-time data evaluation, such as core engine, whole engine testing, or actual on-wing engine operation. Summary of the Invention

[0005] One object of the present invention is to provide a method for controlling turbine blade tip clearance.

[0006] One object of the present invention is to provide a turbine blade tip clearance control system.

[0007] One object of the present invention is to provide a gas turbine engine.

[0008] One object of the present invention is to provide a computer-readable medium.

[0009] According to a first aspect of the present invention, a turbine tip clearance control method includes: S1. obtaining the casing steady-state wall temperature, ACC inlet total pressure, ACC inlet total temperature, engine ambient pressure, compressor outlet total temperature, and compressor inlet flow rate when the ACC is closed; S2. obtaining the casing temperature drop and cooling flow rate based on the data obtained in S1; S3. obtaining the ACC valve angle based on the data obtained in S2.

[0010] In one or more embodiments of the blade tip clearance control method, S2 includes:

[0011] The casing temperature drop ΔT can be obtained using the following formula. wtc

[0012]

[0013] Among them, T wtc_ACC_Off and T wtc_ACC_On ε and D represent the steady-state wall temperatures of the casing when ACC is off and on, respectively. case These are the coefficient of thermal expansion of the casing material and the outer diameter of the casing, respectively. C1 is a correction factor that can be determined by experiment.

[0014] In one or more embodiments of the blade tip clearance control method, S2 includes:

[0015] Define the cooling effect of the casing as:

[0016]

[0017] according to

[0018]

[0019] Able to obtain the corresponding η c The corresponding cooling flow rate ratio Thus, the corresponding ACC cooling flow rate W is obtained. ACC .

[0020] In one or more embodiments of the blade tip clearance control method, step S3 includes:

[0021] The ACC valve angle θ satisfies the following formula:

[0022]

[0023] Among them, P t_in_ACC and T t_in_ACC These represent the total inlet pressure and total inlet temperature of the ACC gas supply line, respectively, while PR is the inlet-outlet pressure ratio of the ACC line. P0 is the engine ambient pressure, i.e., the back pressure at the ACC line outlet.

[0024] A turbine tip clearance control system according to a second aspect of the present invention includes: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the turbine tip clearance control method as described in the first aspect.

[0025] In one or more embodiments of the control system, the processor is integrated into the full authority digital engine controller.

[0026] A gas turbine engine according to a third aspect of the present invention includes a control system as described in the second aspect and a turbine, the control system being capable of actively controlling the tip clearance of the turbine.

[0027] According to a fourth aspect of the present invention, a computer-readable medium has a computer program thereon, which is executed by a processor to implement the steps of the blade tip clearance control method as described in the first aspect.

[0028] The beneficial effects of the present invention include, but are not limited to, one or a combination of the following:

[0029] 1) Based on engine-related measurement parameters, a turbine blade tip clearance adjustment model is established. This model includes the relationship between the active clearance control valve angle, casing cooling flow rate, casing temperature, and casing deformation, and can be used to predict blade tip clearance under different engine operating conditions.

[0030] 2) An active turbine clearance control method based on a turbine tip clearance adjustment model was established. This control method only requires a clearance adjustment command and can automatically calculate the ACC valve angle command based on the turbine tip clearance adjustment model according to relevant engine measurement parameters. Attached Figure Description

[0031] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0032] Figure 1 This is a schematic diagram of the High Pressure Turbine Active Clearance Control System (HPTACC).

[0033] Figure 2 This is a schematic diagram of an implementation of a high-pressure turbine active clearance control system.

[0034] Figure 3 This is a flowchart illustrating a method for controlling the tip clearance of a gas turbine engine.

[0035] Figure 4 This is a schematic diagram showing the relationship between casing temperature drop and clearance adjustment requirements.

[0036] Figure 5 For the casing flow ratio With the cooling effect of the casing η c A schematic diagram of the relationship curve.

[0037] Figure 6 This is a schematic diagram of the flow characteristics of the ACC pipeline. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0039] Furthermore, this application uses specific terms to describe embodiments of the application, such as "an embodiment," "one embodiment," and / or "some embodiments," which refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment" or "one embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0040] It should be noted that in the following embodiments, the gas turbine engine described in the embodiments is an example of an aircraft and its turbofan engine, but it is not limited thereto. For example, the turbine tip clearance control method described in the embodiments can also be applied to ships and their gas turbine engines.

[0041] like Figure 1 This is a schematic diagram of the High Pressure Turbine Active Clearance Control System (HPTACC, hereinafter referred to as ACC). The high pressure turbine mainly consists of a turbine casing assembly and a turbine rotor. The turbine casing assembly mainly consists of a high pressure turbine casing 14, a middle casing 15, a retaining ring 16, and a turbine outer ring 17. The turbine rotor assembly mainly consists of turbine blades 18 and a turbine disk 19. The combustion chamber outflow 103 flows into the turbine blade passage, driving the turbine blades to rotate at high speed and generate thrust for the engine. The compressor cooling airflow 102 passes through the middle casing 15 and the outer ring 17, cools the turbine outer ring, mixes with the mainstream 102, and is then discharged rearward. Similarly, a compressor cooling airflow 104 cools the turbine disk, mixes with the mainstream, and is then discharged rearward.

[0042] When the engine rotates at high speed, the high-pressure turbine casing assembly undergoes thermal deformation, and the high-pressure turbine rotor assembly undergoes both thermal and centrifugal deformation. Consequently, the turbine exhibits different tip clearances (BTC) during flight. To control the turbine tip clearance, an active turbine clearance control system (ATC) is employed to cool the high-pressure turbine casing. Cooling airflow 101 from the engine's outer bypass duct flows through the HPTACC valve 12 and the impact cooling assembly 13, finally exiting through circumferentially distributed orifices 51, 52, 53, and 54 in the impact cooling pipe. This impact cooling of the high-pressure turbine casing causes radial contraction, controlling the turbine tip clearance. The HPTACC valve regulates the cooling flow rate via electronic engine control (EEC) to maintain the turbine tip clearance at its optimal operating point.

[0043] Figure 2 This describes an implementation of an active clearance control system for a high-pressure turbine. Once the engine reaches a suitable state and achieves thermal stability, the clearance adjustment requirement is input, and relevant engine parameters are measured. The ACC valve angle θ can be quickly calculated using the clearance adjustment model. The EEC sends the calculated ACC valve angle command to the ACC valve, triggering its operation and thereby controlling the active clearance to regulate the cooling flow.

[0044] Among the measured engine-related parameters are: 1) the steady-state wall temperature of the casing when ACC is off. 2) Total pressure at the ACC inlet (P) t_in_ACC ); 3) Total temperature at the ACC pipeline inlet (T) t_in_ACC 4) Engine ambient pressure (P0); 5) Compressor outlet total temperature (T3); 6) Compressor inlet flow rate (W) 25 Steady-state casing wall temperature T when ACC is off. wtc_ACC_Off It can also be obtained through thermal analysis simulation.

[0045] It is understood that flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that, depending on the actual situation, the preceding or following operations may not necessarily be performed precisely in sequence. Other operations may be added to these processes, or one or more steps may be removed from them.

[0046] like Figure 3 As shown, in some embodiments, the turbine tip clearance control method for a gas turbine engine may include the following steps:

[0047] S1. Obtain the steady-state casing wall temperature, ACC inlet total pressure, ACC inlet total temperature, engine ambient pressure, compressor outlet total temperature, and compressor inlet flow rate when ACC is closed. That is... Figure 2 The parameters related to each engine are shown.

[0048] S2. Based on the data obtained in S1, calculate the casing temperature drop and cooling flow rate;

[0049] S3. Based on the data obtained in S2, the ACC valve angle is obtained.

[0050] Given the clearance adjustment requirement ΔBTC, the calculation process for the ACC valve angle is as follows:

[0051] In some embodiments, the step of obtaining the casing temperature drop in S2 may be:

[0052] Computer box temperature drop ΔT wtc

[0053]

[0054] Among them, T wtc_ACC_Off and T wtc_ACC_On ε and D represent the steady-state wall temperatures of the casing when ACC is off and on, respectively. case These are the coefficient of thermal expansion of the casing material and the outer diameter of the casing, respectively. C1 is a correction factor that can be determined by testing.

[0055] refer to Figure 4 The specific steps for obtaining the cooling flow rate in S2 may include:

[0056] Figure 4 This is a schematic diagram showing the relationship between casing temperature drop and clearance adjustment requirements.

[0057] The casing wall temperature T when ACC is turned on can be calculated using the above formula. wtc_ACC_On .

[0058] Calculate cooling flow rate W ACC

[0059] Define the cooling effect of the casing as:

[0060]

[0061] according to

[0062]

[0063] The corresponding η can be obtained c The corresponding cooling flow rate ratio Thus, the corresponding ACC cooling flow rate W is obtained. ACC .

[0064] Figure 5 For the casing flow ratio With the cooling effect of the casing η c A schematic diagram of the relationship curve.

[0065] In some embodiments, the step of S3 calculating the ACC valve angle may include:

[0066] The ACC valve angle θ satisfies the following formula:

[0067]

[0068] Among them, P t_in_ACC and T t_in_ACC These represent the total inlet pressure and total inlet temperature of the ACC gas supply line, respectively, while PR is the inlet-outlet pressure ratio of the ACC line. P0 is the engine ambient pressure, i.e., the back pressure at the ACC line outlet.

[0069] The flow characteristics of ACC piping can be determined through experiments or simulations. For example... Figure 6 The diagram shows the flow characteristics of the ACC pipeline. The flow rate versus valve angle curves for five different pressure ratios, from PR(1) to PR(5), are given to determine the flow characteristics of the ACC pipeline.

[0070] It can be understood that by executing steps S1, S2, and S3 in the above order, the steps to obtain the ACC valve angle can be achieved by knowing the clearance adjustment requirement ΔBTC. Similarly, if the ACC valve angle is known, steps S3, S2, and S1 can be executed in order to obtain the blade tip clearance adjustment amount ΔBTC when the ACC is open.

[0071] According to another aspect of this application, a computer-readable medium is also provided. The aforementioned computer-readable medium provided in this disclosure has computer instructions thereon. When executed by a processor, these computer instructions can implement the steps performed by the program in the turbine tip clearance control method described in the above embodiments.

[0072] It is understood that the processor in the preceding embodiments may be one or more of the following combinations: System-on-a-Chip (SOC), microcontroller, microprocessor (e.g., microcontroller), Reduced Instruction Set Computer (RISC), Application-Specific Integrated Circuit (ASIC), Application-Specific Instruction Integrated Processor (ASIP), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Physical Processing Unit (PPU), Microcontroller Unit, Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), Advanced RISC Machine (ARM), Programmable Logic Device (PLD), or any circuit or processor capable of performing one or more functions.

[0073] According to another aspect of this application, a blade tip clearance control system is also provided. The control system includes a memory and a processor. The memory stores instructions executable by the processor; the processor executes the instructions to implement the blade tip clearance control method described above. Preferably, the processor is integrated into a Full Authority Digital Engine Control (FADEC).

[0074] According to another aspect of this case, a gas turbine engine is also provided, including a blade tip clearance control system as described above and a turbine, the control system being capable of actively controlling the blade tip clearance of the turbine.

[0075] The beneficial effects of the solutions described in the above embodiments include, but are not limited to, one or a combination of the following:

[0076] 1. Based on relevant engine measurement parameters, a turbine blade tip clearance adjustment model is established. This model includes the relationship between the active clearance control valve angle, casing cooling flow rate, casing temperature, and casing deformation, and can be used to predict blade tip clearance under different engine operating conditions.

[0077] 2. A turbine active clearance control method based on a turbine tip clearance adjustment model was established. This control method only requires a clearance adjustment command, and automatically calculates the ACC valve angle command based on relevant engine measurement parameters and the turbine tip clearance adjustment model.

[0078] The steps of the methods described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0079] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0080] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A method of turbine tip clearance control for a gas turbine engine, characterized by, Comprising: S1. obtaining the steady-state wall temperature of the case, the total pressure at the inlet of the ACC pipeline, the total temperature at the inlet of the ACC pipeline, the engine ambient pressure, the total temperature at the outlet of the compressor, and the flow rate at the inlet of the compressor when the ACC is closed; S2. obtaining the temperature drop of the case and the cooling flow rate according to the data obtained in S1; S3. obtaining the ACC valve angle according to the data obtained in S2.

2. The tip clearance control method of claim 1, wherein, The S2 comprises: The temperature drop ΔT of the cartridge is obtained by the following equation wtc Where, T wtc_ACC_Off and T wtc_ACC_On are the steady-state wall temperatures of the casing when the ACC is closed and opened, respectively. ε and D case are the thermal expansion coefficient and the outer diameter of the casing, respectively, and C1 is a correction coefficient which can be determined by experiment.

3. The tip clearance control method of claim 1, wherein, The S2 comprises: defining the cooling effect of the case as: According to The corresponding η c value can be obtained The corresponding ACC cooling flow rate W ACC is obtained.

4. The tip clearance control method of claim 1, wherein, The S3 comprises: The ACC valve angle θ satisfies the following formula: Wherein, P t_in_ACC and T t_in_ACC are the ACC supply line inlet total pressure and inlet total temperature, respectively, PR is the ACC line inlet to outlet pressure ratio, P0 is the engine ambient pressure, i.e. the ACC line outlet back pressure.

5. A tip clearance control system, characterized by Comprising: a memory for storing instructions executable by the processor; a processor for executing the instructions to implement the tip clearance control method according to any one of claims 1 to 4.

6. The control system of claim 5, wherein, The processor is integrated in a Full Authority Digital Engine Control (FADEC).

7. A gas turbine engine characterized by, The control system according to claim 5 or 6 is capable of actively controlling the tip clearance of the turbine.

8. A computer readable medium having a computer program thereon, characterized in that, The program is executed by the processor to implement the steps of the tip clearance control method according to any one of claims 1 to 4.

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