Dynamic static pressure measuring device for high-temperature airflow

Abstract

The invention belongs to the technical field of high-temperature pressure testing, and discloses a dynamic static pressure measuring device for high-temperature airflow, which is suitable for dynamic static pressure measurement of turbine inlets, turbine outlets and interstage wall surfaces. The device is characterized by comprising a pressure sensing hole, a supporting rod, a dynamic pressure sensor, a supporting rod and an internal cooling structure, the supporting rod is of a cylindrical structure, the pressure sensing hole is formed in the head of the supporting rod, and the central axis of the hole coincides with the central axis of the supporting rod and is communicated with the dynamic pressure sensor in a cavity. A sensor cable is led out through an internal channel of the supporting rod. The supporting rod is of a double-layer coaxial structure, an independent water inlet channel and an independent water outlet channel are arranged between the inner layer and the outer layer, and a chamfer structure design is introduced into the communicating corner of the water inlet channel and the water outlet channel, so that cooling water is effectively prevented from generating local boiling in a high-temperature area or a thermal ablation phenomenon caused by a cavity effect. Through circular flow of cooling water in the interlayer, the dynamic pressure sensor and the internal space of the supporting rod can be efficiently cooled, so that the device can still effectively control the temperature near the sensor to be below 500K under the condition that the external environment temperature is up to 2000K.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature pressure testing, and particularly relates to a dynamic static pressure measuring device for high-temperature airflows, which is applicable to the dynamic static pressure measurement of the turbine inlet, outlet, and inter-stage wall surfaces. Background Art

[0002] To further enhance the thermal efficiency and thrust output of turbine engines, the turbine inlet temperature of the new generation is getting higher and higher, even exceeding 2200K, which poses more stringent requirements on the accuracy, response speed, and long-term reliability of the flow field measurement device. In a high-temperature and high-speed aerodynamic environment, accurately measuring the hot airflow parameters is a key requirement for evaluating the health status and operating performance of engine components. To deeply analyze the pressure field distribution of the turbine inter-stage, turbine inlet, and outlet, it is necessary to perform high-precision static pressure measurement and record the continuous pressure-time series.

[0003] However, in a high-temperature and high-speed flow field, due to the intense airflow disturbance, the thermal expansion of the probe structure, and the limited temperature resistance of the material, traditional pressure probes have significant deficiencies in measurement accuracy and long-term stability, and it is difficult to achieve real-time monitoring of the wall static pressure. To cope with the severe heat load challenge, the static pressure measurement device must be equipped with an efficient cooling system to maintain the probe temperature below the temperature resistance limit of the material to ensure its continuous and reliable operation. Therefore, there is an urgent need to develop a high-temperature airflow dynamic static pressure measurement device with optimized structure, rapid response, high-temperature tolerance, and the ability to dynamically measure static pressure, so as to accurately capture the time-varying characteristics of static pressure in a high-temperature aerodynamic environment and provide reliable data support for the design optimization, operation evaluation, and engineering application of the turbine flow field of aeroengines. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: aiming at the problem that the surrounding environment temperature is too high during the pressure measurement of the turbine inter-stage, turbine inlet, and outlet flow fields, which is likely to damage the structure of the measurement device, to invent a high-temperature airflow dynamic static pressure measurement device with high-temperature tolerance. Compared with the existing pressure probes, it can be continuously exposed to high-temperature fluids, has a rapid response, can measure the dynamic static pressure of the casing wall, and provides a technical means for practically measuring the dynamic static pressure of the turbine inlet, outlet, and inter-stage wall surfaces in a high-temperature environment.

[0005] The technical solution of the present invention is:

[0006] A device for measuring the dynamic static pressure of high-temperature gas flow, characterized in that it includes a pressure sensing hole (1), a support rod (2), a dynamic pressure sensor (3), a pressure measurement channel (4), a water inlet channel (5), a water outlet channel (6), a partition plate (7), a cavity (8), a multi-functional positioning block (9), a fixing thread (10) and a cable (11). The support rod (2) is of a cylindrical structure. A pressure sensing hole (1) is opened at the head of the support rod (2) and is communicated with the dynamic pressure sensor (3) through the pressure measurement channel (4). The cable (11) of the dynamic pressure sensor (3) is communicated with the outside through the tail of the support rod (2). The inside of the support rod (2) adopts a double-layer coaxial structure. The water inlet channel (5) and the drainage channel (6) are separated by a vertically arranged partition plate (7) between the inner layer and the outer layer. A fixing thread (10) is provided at the lower end of the support rod for connecting and fixing with the casing wall surface. A pressure measurement channel (4), a water inlet channel (5) and a water outlet channel (6) are arranged axially inside the support rod, and the three are not communicated with each other. A multi-functional positioning block (9) is arranged at the rear end of the support rod (2). One side is for positioning, and the other side is a tightening device for fixedly connecting with the casing wall surface to ensure the accurate installation and stable positioning of the support rod. The whole support rod is made of stainless steel, and a high-temperature resistant and heat-insulating coating is sprayed on the outer surface. The measurement accuracy of the dynamic pressure sensor (3) is 0.1% - 1%, and the response frequency is 300Hz - 500kHz, so as to ensure high-frequency response and high-precision performance in a high-temperature gas flow environment;

[0007] Further, the aperture of the pressure sensing hole (1) is 0.8 mm - 2 mm, the distance from its center to the upper bottom surface of the inner cavity of the support rod (2) is 0.5 mm - 4 mm, the center of the pressure sensing hole (1) and the center line of the support rod (2) are on the same axis, and the water inlet channel (5) and the water outlet channel (6) are symmetrical along this axis;

[0008] Further, the support rod (2) is of a cylindrical structure, with a diameter of 3 mm - 6 mm and a length of 10 mm - 30 mm;

[0009] Further, the measurement accuracy of the dynamic pressure sensor (3) is 0.1% - 1%, and the response frequency is 300Hz - 500kHz;

[0010] Further, the water inlet channel (5) and the water outlet channel (6) and the support rod (2) adopt an integral processing structure, and chamfers are designed in the head corner area to effectively avoid the boiling phenomenon of cooling water in local areas and prevent structural damage caused by thermal stress concentration caused by high temperature;

[0011] Furthermore, the water inlet and outlet of the cooling water channel are designed to gradually and smoothly transition from a special cashew-shaped cross-section to a circular cross-section structure, with the flow area of each cross-section being equal, avoiding flow separation and vortex phenomena caused by cross-section mutations. The cashew-shaped cross-section can effectively guide the fluid to generate appropriate turbulence at the initial stage of entering the pipeline, increasing the local heat exchange efficiency and enhancing the cooling effect;

[0012] The cooling water is injected into the interior of the support rod (2) by a water pump through the water inlet channel (5). The cooling water flows along the length direction of the support rod in the channel and enters the water outlet channel (6) for discharge. During the whole process, the cooling water continuously circulates in a reflux manner in the sandwich layer of the support rod (2) and will not enter the inner cavity of the support rod (2) and leak through the pressure measuring channel (4) under the action of structural sealing, thereby effectively cooling the dynamic pressure sensor (3) and the internal space of the support rod (2). This design prevents the adverse effects caused by the high-temperature environment on the measurement accuracy of the sensor and the structural stability, and improves the long-term stable operation ability and service life of the device under high-temperature working conditions.

[0013] The high-temperature gas dynamic static pressure measurement device provided by the present invention can obtain accurate calibration coefficients through wind tunnel calibration. In practical applications, the pressure sensing holes at the head of the device are arranged perpendicular to the air flow direction, which is suitable for measuring the dynamic static pressure at the inlet, outlet and inter-stage wall surfaces of an aero-engine turbine and can obtain the dynamic static pressure data of the wall surface. This device can work stably in an air flow environment with a temperature up to 2000K, and the probe frequency response performance exceeds 80kHz, meeting the requirements for dynamic static pressure measurement in complex high-temperature and high-speed flow fields.

[0014] The beneficial effects of the present invention are as follows:

[0015] Beneficial effect one: Compared with the existing pressure measurement devices, the present invention adopts a double-layer coaxial structure of the support rod and sets independent water inlet channel (5) and water outlet channel (6) between the inner and outer layers, and realizes the efficient cooling of the dynamic pressure sensor (3) and the internal space of the support rod (2) through the circulating flow of the cooling water in the sandwich layer. The cooling water can quickly conduct and carry away the heat accumulated by the head shell, significantly improving the overall heat dissipation performance of the probe head. The contact area between the water inlet channel and the cooling water is large, and the heat conduction path is short, and the heat can be quickly released through the way of efficient convective heat transfer, realizing the combination of structural reinforcement and cooling heat transfer functions, and greatly improving the heat dissipation efficiency and structural reliability of the measurement device. When the external environmental temperature is as high as 2000K, the temperature near the sensor can be effectively controlled below 500K.

[0016] Beneficial effect two: The present invention introduces a chamfer structure design at the connecting corner between the cooling water inlet channel (5) and the outlet channel (6), effectively alleviating the problem of thermal stress concentration caused by local structural mutation, and preventing local boiling of the cooling water in the high-temperature area or thermal ablation phenomenon caused by cavity effect, further enhancing the safety of the measuring device in the extreme thermal environment.

[0017] Beneficial effect three: The water inlet and outlet of the cooling water channel are designed to gradually and smoothly transition from a special cashew-shaped cross-section to a circular cross-section structure, and the flow areas of each cross-section are equal, avoiding flow separation and vortex phenomena caused by cross-section mutation. The cashew-shaped cross-section can effectively guide the fluid to generate appropriate turbulence at the initial stage of entering the pipeline, increasing the local heat exchange efficiency and enhancing the cooling effect.

[0018] Beneficial effect four: The present invention is closely attached to the casing wall surface without interfering with the flow field. After being calibrated by a calibration wind tunnel, it can realize the dynamic static pressure measurement of the inlet, outlet and inter-stage wall surfaces of the aero-engine turbine, with a frequency response up to 80 kHz, meeting the requirements of high-speed dynamic measurement. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a device for measuring the dynamic static pressure of high-temperature gas flow in an embodiment of the present invention.

[0020] Figure 2 is Figure 1 front view of

[0021] Figure 3 is Figure 1 left view of

[0022] Figure 4 is Figure 1 bottom view of

[0023] Figure 5 is Figure 2 A-A cross-sectional view of

[0024] Figure 6 is Figure 2 B-B cross-sectional view of

[0025] Figure 7 is Figure 4 C-C cross-sectional view of

[0026] Figure 8 is Figure 5 D-D cross-sectional view of

[0027] Figure 9 It is a sectional view of the changing shape of the water inlet and outlet cross-sections.

[0028] Figure 10 It is a schematic diagram of a specific implementation.

[0029] Wherein: 1 - pressure sensing hole, 2 - support rod, 3 - pressure sensor, 4 - pressure measurement channel, 5 - water inlet channel, 6 - water outlet channel, 7 - partition board, 8 - cavity, 9 - multi-functional positioning block, 10 - fixing thread, 11 - cable. Specific embodiments

[0030] The following describes in detail the preferred embodiments of the present invention with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] As Figures 1 to 9 shown is a device for measuring the dynamic static pressure of high-temperature gas flow according to the present invention, Figure 10 which is a schematic diagram of the device of the present invention for measuring the dynamic static pressure of the second-stage stator wall of a multi-stage turbine. 1. It includes a pressure sensing hole (1), a support rod (2), a dynamic pressure sensor (3), a pressure measurement channel (4), a water inlet channel (5), a water outlet channel (6), a partition board (7), a cavity (8), a multi-functional positioning block (9), a fixing thread (10) and a cable (11). The support rod (2) is a cylindrical structure. A pressure sensing hole (1) is opened at the head of the support rod (2) and is communicated with the dynamic pressure sensor (3) through the pressure measurement channel (4). The cable (11) of the dynamic pressure sensor (3) is communicated with the outside through the tail of the support rod (2). The inside of the support rod (2) adopts a double-layer coaxial structure. The inner layer and the outer layer are separated by a vertically arranged partition board (7) to form a water inlet channel (5) and a drainage channel (6). The lower end of the support rod is provided with a fixing thread (10) for connecting and fixing with the casing wall. A pressure measurement channel (4), a water inlet channel (5) and a water outlet channel (6) are arranged axially inside the support rod, and the three are not communicated with each other. A multi-functional positioning block (9) is arranged at the rear end of the support rod (2) for fixedly connecting with the casing wall to ensure the accurate installation and stable positioning of the support rod. The whole support rod is made of stainless steel, and the outer surface is sprayed with a high-temperature heat-insulating coating;

[0033] The diameter of the pressure sensing hole (1) is 0.8 mm, and the distance from the center to the upper bottom surface of the inner cavity of the support rod (2) is 2 mm;

[0034] The support rod (2) is a cylindrical structure with a diameter of 5 mm and a length of 15 mm;

[0035] The measurement accuracy of the dynamic pressure sensor (3) is 1%, and the response frequency is 500 kHz;

[0036] The inlet channel (5) and the outlet channel (6) are designed with 90° chamfers near the corner area of the device head to avoid the generation of voids at the corners of the cooling water, which can effectively prevent the boiling phenomenon of the cooling water in the local area and prevent the structural damage caused by the thermal stress concentration caused by high temperature.

[0037] Figure 9 The inlet and outlet of the cooling water channel are designed to gradually and smoothly transition from a special cashew-shaped cross-section to a circular cross-section structure, and the flow areas of each cross-section are equal, avoiding the flow separation and vortex phenomena caused by sudden changes in the cross-section. The cashew-shaped cross-section can effectively guide the fluid to generate appropriate turbulence at the initial stage of entering the pipeline, increasing the local heat exchange efficiency and enhancing the cooling effect.

[0038] The cooling water is injected into the inside of the strut (2) through the inlet channel (5) by a water pump. The cooling water flows along the length direction of the strut in the channel, enters the outlet channel (6) and is discharged. During the whole process, the cooling water continuously circulates in a reflux manner in the sandwich of the strut (2), and under the action of the structural seal, it will not enter the inner cavity of the strut (2) and leak through the pressure measurement channel (4), so as to effectively cool the dynamic pressure sensor (3) and the inner space of the strut (2), prevent the adverse effects caused by the high temperature environment on the measurement accuracy of the sensor and the structural stability, and improve the long-term stable operation ability and service life of the device under high temperature conditions.

[0039] A high-temperature gas dynamic static pressure measurement device introduced in the embodiment of the present invention adopts a double-layer coaxial structure of the strut, and independent inlet channel (5) and outlet channel (6) are arranged between the inner and outer layers. Through the circulating flow of the cooling water in the sandwich, the dynamic pressure sensor (3) and the inner space of the strut (2) are efficiently cooled, so that under the condition that the external environmental temperature is as high as 2000K, the temperature near the sensor can be effectively controlled below 500K, greatly improving the working stability and service life of the measurement device under high temperature conditions. The present invention introduces a chamfer structure design at the connecting corner between the cooling water inlet channel (5) and the outlet channel (6), effectively alleviating the problem of thermal stress concentration caused by local structural mutation, and preventing the local boiling of the cooling water in the high temperature area or the thermal ablation phenomenon caused by the cavity effect, further enhancing the safety of the measurement device in the extreme thermal environment.

Claims

1. A device for measuring the dynamic static pressure of high-temperature gas flow, characterized in that: It includes a pressure sensing hole (1), a support rod (2), a dynamic pressure sensor (3), a pressure measurement channel (4), a water inlet channel (5), a water outlet channel (6), a partition (7), a cavity (8), a multi-functional positioning block (9), a fixing thread (10) and a cable (11). The support rod (2) is of a cylindrical structure. A pressure sensing hole (1) is opened at the head of the support rod (2) and is communicated with the dynamic pressure sensor (3) through the pressure measurement channel (4). The cable (11) of the dynamic pressure sensor (3) is communicated with the outside from the tail of the support rod (2). The inside of the support rod (2) adopts a double-layer coaxial structure. The inner layer and the outer layer are separated by a vertically arranged partition (7) to form a water inlet channel (5) and a drainage channel (6). The lower end of the support rod is provided with a fixing thread (10) for connecting and fixing with the casing wall surface. A pressure measurement channel (4), a water inlet channel (5) and a water outlet channel (6) are arranged axially inside the support rod, and the three are not communicated with each other. A multi-functional positioning block (9) is arranged at the rear end of the support rod (2). One side is for positioning, and the other side is a tightening device for fixedly connecting with the casing wall surface to ensure the accurate installation and stable positioning of the support rod. The whole support rod is made of stainless steel, and a high-temperature resistant and heat-insulating coating is sprayed on the outer surface. The measurement accuracy of the dynamic pressure sensor (3) is 0.1% - 1%, and the response frequency is 300Hz - 500kHz, so as to ensure high-frequency response and high-precision performance in a high-temperature gas flow environment; The aperture of the pressure sensing hole (1) is 0.8 mm - 2 mm, and the distance from its center to the upper bottom surface of the inner cavity of the support rod (2) is 0.5 mm - 4 mm. The center line of the pressure sensing hole (1) and the center line of the support rod (2) are on the same axis, and the water inlet channel (5) and the water outlet channel (6) are symmetric along this axis; The support rod (2) is of a cylindrical structure, with a diameter of 3 mm - 6 mm and a length of 10 mm - 30 mm; The measurement accuracy of the dynamic pressure sensor (3) is 0.1% - 1%, and the response frequency is 300Hz - 500kHz; The water inlet channel (5) and the water outlet channel (6) and the support rod (2) adopt an integral processing structure, and chamfers are designed in the head corner area to effectively avoid the boiling phenomenon of cooling water in a local area and prevent structural damage caused by heat stress concentration caused by high temperature; Furthermore, the water inlet and outlet of the cooling water channel are designed to gradually and smoothly transition from a special cashew-shaped cross-section to a circular cross-section structure, and the flow areas of each cross-section are equal to avoid flow separation and vortex phenomena caused by cross-section mutation. The cashew-shaped cross-section can effectively guide the fluid to generate appropriate turbulence at the initial stage of entering the pipeline, increase the local heat exchange efficiency, and improve the cooling effect; Cooling water is injected into the interior of the support rod (2) by a water pump through the water inlet passage (5). The cooling water flows along the length direction of the support rod in the passage and enters the water outlet passage (6) for discharge. During the whole process, the cooling water continuously circulates in a reflux manner in the sandwich layer of the support rod (2), and under the action of structural sealing, it will not enter the inner cavity of the support rod (2) and leak through the pressure measurement passage (4), thereby effectively cooling the dynamic pressure sensor (3) and the inner space of the support rod (2). This design prevents the adverse effects of the high-temperature environment on the measurement accuracy and structural stability of the sensor, and improves the long-term stable operation ability and service life of the device under high-temperature working conditions; The high-temperature gas flow dynamic static pressure measurement device provided by the present invention can obtain accurate calibration coefficients through wind tunnel calibration. In practical applications, the pressure sensing holes at the head of the device are arranged perpendicular to the gas flow direction, which is suitable for measuring the dynamic static pressure at the inlet, outlet and inter-stage wall surfaces of the turbine of an aeroengine, and can obtain the dynamic static pressure data of the wall surface. This device can work stably in a gas flow environment up to 2000K, and the probe frequency response performance exceeds 80kHz, meeting the requirements of dynamic static pressure measurement in complex high-temperature and high-speed flow fields.

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