A device and method for accurately measuring turbine stage efficiency

Abstract

The present invention discloses a device and method for accurately measuring turbine stage efficiency, wherein the measuring device comprises a head and a support rod. The head of the device is a cylinder, and a plurality of groups of pressure sensing holes and temperature sensing holes are provided on the same side of the surface of the cylinder. Each group of sensing holes is composed of a row of three adjacent pressure sensing holes and a temperature sensing hole above or below the measuring hole near the middle of the three pressure sensing holes, and each group of three pressure sensing holes and one temperature sensing hole constitute a combined measuring point. The present invention can simultaneously measure the total temperature, total pressure, static temperature, static pressure, deflection angle, Mach number, speed, and density of the airflow at multiple positions of the turbine inlet, outlet, and interstage, along the blade height direction, turbine casing boundary layer, hub boundary layer, and main flow channel. Using the above parameters, the efficiency of the turbine is calculated by the mass-weighted average method. The present invention has little interference to the measured flow field, high parameter measurement accuracy, and more accurate turbine efficiency measurement results.

Description

Technical Field

[0001] The present invention belongs to the technical field of impeller machinery testing, and specifically relates to a device and method for accurately measuring turbine stage efficiency, which can achieve accurate measurement of the turbine stage efficiency of a turbomachine under the premise of minimizing interference with the turbine flow field. Background Art

[0002] Turbomachinery is a complex power machine, with the turbine being one of its main components. Efficiency is a key indicator for measuring turbine performance, so accurate measurement of turbine efficiency is of great significance to turbine performance evaluation and turbine design and improvement. However, the measurement error of existing technologies is too large, exceeding the value of turbine-stage efficiency improvement.

[0003] The isentropic stagnation efficiency of a turbine is defined as the ratio of the rim work of the airflow through the turbine to the isentropic stagnation enthalpy drop of the gas flowing through the turbine. The turbine stage efficiency can be further calculated using the total temperature ratio, expansion ratio, and specific heat ratio of the turbine inlet and outlet. The calculation formula is:

[0004]

[0005] Where: η——turbine stage efficiency

[0006] ——Turbine stage inlet total temperature, K

[0007] ——Total pressure at turbine stage inlet, Pa

[0008] ——Total temperature at turbine stage outlet, K

[0009] ——Total pressure at turbine stage outlet, Pa

[0010] γ——Specific heat ratio of the gas flowing through the turbine

[0011] Therefore, how to accurately measure the total temperature and total pressure at the inlet and outlet of the turbine stage has become one of the keys to accurately measure the efficiency of the turbine stage. When measuring turbine parameters, most existing measuring devices use separate pressure measuring devices and temperature measuring devices to measure pressure and temperature respectively. On the one hand, such a measurement scheme makes it impossible to measure pressure and temperature at the same time and at the same point, and the measured parameters do not come from the same streamline, which greatly reduces the spatial resolution of the measuring device. The flow in the turbine has strong non-stationary and spatial non-uniformity, which causes errors in the measurement results. On the other hand, when the measuring device is inserted into the turbine flow field for measurement, it will inevitably interfere with the measured flow field. In the existing measurement scheme, separate pressure measuring devices and temperature measuring devices are used for measurement respectively. The excessive number of measuring devices used will inevitably cause greater interference to the measured flow field and affect the accuracy of the final measurement results.

[0012] Most existing measuring devices are single-point measurements. When measuring turbine parameters along the radial direction, it is necessary to use multiple measuring devices at the same time or use a displacement mechanism to drive the measuring device to move for measurement. Using multiple measuring devices at the same time will not only block the flow field and affect the measurement accuracy, but also increase the measurement cost. Using a displacement mechanism to drive the measuring device will cause a time difference between the results of multi-point measurements, making it impossible to measure multiple measurement points of the flow field at the same time.

[0013] The existing measurement method uses a rake-shaped total temperature measuring device or a multi-branch multi-point total temperature measuring device to measure the total temperature of the turbine stage, and uses the arithmetic average method to calculate the total temperature average value. In the turbine flow field, the flow velocity at each point in the main channel is not uniform, and the velocity distribution in the main channel and the boundary layer is also very different. Therefore, using the arithmetic average method to calculate the total temperature average value will increase the measurement error.

[0014] The existing measurement method uses a rake-shaped total pressure measuring device or a multi-point total pressure measuring device to measure the total pressure of the turbine stage, and uses the area average method to calculate the total pressure average value. Due to the unevenness of the flow field velocity, using the area average method to calculate the total pressure average value will also cause errors and reduce the accuracy of the measurement.

[0015] In addition, existing measurements can only measure the parameters of the inlet and outlet of a multi-stage turbine, but cannot measure the parameters between stages of the multi-stage turbine. Therefore, for a multi-stage turbine, existing technology can only measure the overall efficiency of the multi-stage turbine, but cannot measure the efficiency of a single stage of the turbine.

[0016] Therefore, the existing measuring devices and methods can no longer meet the demand for accurately measuring the single-stage efficiency of the turbine, and there is an urgent need for a device and method for accurately measuring the turbine stage efficiency to achieve accurate measurement of the turbine stage efficiency. Summary of the invention

[0017] The technical problems to be solved by the present invention are: in view of the problems existing in the existing turbine stage efficiency measurement and calculation schemes, the existing measuring devices are difficult to measure the total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed, density and other parameters of the flow field at the same time and at the same point; the problem that multiple different parameter measurement devices are respectively extended into the turbine flow field and cause great interference to the measured flow field; the problem that when calculating the turbine stage efficiency, the temperature parameters adopt the arithmetic average method or the area average method, which is greatly different from the actual turbine flow field velocity distribution. A device and method for accurately measuring the turbine stage efficiency are invented.

[0018] The present invention discloses a device and method for accurately measuring turbine stage efficiency. The measuring device is different from the previous independent pressure measuring device and temperature measuring device. The measuring device in the present invention is a combined pressure and temperature measuring device, that is, the parameters of the total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed and density of the airflow can be measured through a single measuring device.

[0019] The present invention discloses a device and method for accurately measuring turbine stage efficiency, and the measuring method is different from the existing measuring method. The existing method uses a separate temperature measuring device and a pressure measuring device to measure the total temperature and total pressure of the turbine inlet and outlet respectively, while the measuring method of the present invention uses the measuring device of the present invention to perform multi-parameter synchronous measurement, which reduces the number of measuring devices used, reduces the interference to the measured flow field, simplifies the measurement process, and reduces the measurement cost. After obtaining the total temperature and total pressure parameters of the test point, the existing method obtains the average total temperature and total pressure of the measuring section by arithmetic average or area average. The present invention uses a mass flow weighted method to obtain the average total temperature and total pressure of the measuring section, which greatly reduces the error of turbine stage efficiency measurement and improves the accuracy of turbine stage efficiency measurement. For a multi-stage turbine, the existing measurement method can only measure its overall efficiency, while the measurement method of the present invention can measure the single-stage efficiency of a multi-stage turbine through a new measurement section and measurement point layout.

[0020] The technical solution of the present invention is:

[0021] The measuring device comprises a head (1), a support rod (2), a wheel hub boundary layer pressure sensing hole (3) and a wheel hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5) and a casing boundary layer temperature sensing hole (6), a main flow channel pressure sensing hole (7) and a main flow channel temperature sensing hole (8), a pressure guide channel (9), and a temperature sensor cable (10); the head (1) comprises a cylinder (11) coaxial with the support rod (2);

[0022] A plurality of rows of pressure sensing holes are provided on the same side surface of the cylindrical body (11) of the head (1) along the axial direction, each row of pressure sensing holes includes three adjacent but mutually incompatible pressure sensing holes, namely a left hole (12), a middle hole (13), and a right hole (14), the center lines of the three pressure sensing holes are located in the same plane, and the center line of the left hole (12) and the center line of the right hole (14) are symmetrically distributed in the plane with respect to the center line of the middle hole (13);

[0023] A plurality of rows of temperature sensing holes are provided on the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes includes a temperature sensing hole (15), the center line of which is parallel to the center line of the hole (13) in the pressure sensing hole;

[0024] The pressure sensing hole and the pressure-inducing channel (9) are respectively connected to one end encapsulated in the head (1); the temperature sensing hole is directly connected only to the temperature sensor (16), and the temperature sensor can be a bare wire thermocouple, an armored thermocouple, a thermal resistor, an optical fiber sensor, etc.; the cable (10) of the pressure-inducing channel (9) and the temperature sensor is led out of the tail through the pipeline in the support rod (2);

[0025] The hub boundary layer pressure sensing hole (3) is close to the end face of the head (1), the distance between the center of the circle and the end face of the head (1) is 0.5 mm to 5 mm, the diameter is 0.2 mm to 1.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylinder (11) of the head (1) is 15° to 60°;

[0026] The hub boundary layer temperature sensing hole (4) is located below the center hole (13) of the hub boundary layer pressure sensing hole (3), the center of the circle is 0.5 mm to 2 mm away from the center of the center hole (13) of the hub boundary layer pressure sensing hole (3), and the diameter is 0.5 mm to 2 mm;

[0027] The casing boundary layer pressure sensing hole (5) is close to the interface between the head (1) and the support rod (2), with a distance of 0.5 mm to 5 mm from the interface between the head (1) and the support rod (2), a diameter of 0.2 mm to 1.5 mm, and a circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylinder (11) of the head (1) is 15° to 60°;

[0028] The casing boundary layer temperature sensing hole (4) is located above the casing boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 0.5 mm to 2 mm away from the center of the casing boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm to 2 mm;

[0029] The main flow channel pressure sensing hole (7) is located between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), has a diameter of 0.2 mm to 1.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the head (1) cylinder (11) is 15° to 60°;

[0030] The main channel temperature sensing hole (8) is located below the middle hole (13) of the main channel pressure sensing hole (7), the center of the circle is 0.5 mm to 2 mm away from the center of the middle hole (13) of the main channel pressure sensing hole (3), and the diameter is 0.5 mm to 2 mm;

[0031] The cylindrical body (11) of the head (1) has a diameter of 2 mm to 8 mm and a length of 10 mm to 400 mm;

[0032] The measuring method comprises calibrating a device for accurately measuring turbine stage efficiency, allowing incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, velocity and total temperature; recording the pressure of three pressure sensing holes in each row of multiple rows of pressure sensing holes on the windward surface of the measuring device, recording the temperature of a temperature sensor of the measuring device, and regarding an adjacent row of pressure sensing holes and temperature sensing holes as a group of measuring points;

[0033] Define the pressure measured by the left hole (12) as P1, the pressure measured by the middle hole (13) as P2, the pressure measured by the right hole (14) as P3, and the temperature measured by the temperature sensor as T p , the total pressure of the incoming flow is P t , the static pressure of the incoming flow is P s , total temperature of incoming flow T t , static temperature of incoming flow T s , from which we can get the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient under different incoming flow Mach numbers;

[0034] Total pressure coefficient:

[0035] Static pressure coefficient:

[0036] Deflection angle coefficient:

[0037] Total temperature recovery coefficient:

[0038] Thus, the calibration curves of the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient of the device of the present invention at different Mach numbers and different deflection angles can be obtained;

[0039] The first scheme for arranging the measuring points at the inlet of the measured turbine stage is to select a section at 0.05 to 1.5 times the blade chord length from the leading edge of the stator blade in front of the measured turbine stage inlet as the inlet test section, and divide the test section into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 3 to 9 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 5 to 10 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0040] The second scheme for arranging the measuring points at the inlet of the measured turbine stage is to select a section at 0.05 to 1.5 times the blade chord length from the leading edge of the stator blade in front of the measured turbine stage inlet as the inlet test section, and divide the test section into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; arrange 3 to 9 groups of measuring points on a single test device of the present invention, densely packed near the hub and the casing, to ensure that the parameters in the boundary layer are measured; arrange 5 to 10 measuring positions circumferentially, and use multiple measuring devices at the same time, each of which is distributed in a number of sector-shaped measurement areas of the stator blade grid pitch, so that there is at most one circumferential measuring position in each measurement sector-shaped measurement area, and when the circumferential measuring positions in these different sector-shaped measurement areas are rotated by an angle corresponding to an integer multiple of the single stator blade grid pitch with the turbine axis as the rotation center to the same sector-shaped measurement area, it can still be guaranteed to be densely packed near the blades, to ensure that the parameters in the wake are measured, and sparse in the middle of the channel;

[0041] The first arrangement scheme of measuring points at the outlet of the measured turbine stage is to select a section at 0.05 to 1 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage as the outlet test section, and divide the test section into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 3 to 9 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 5 to 10 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0042] The second scheme for arranging the measuring points at the outlet of the measured turbine stage is to select the section at 0.05 to 1 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage as the outlet test section, and divide the test section into several sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; arrange 3 to 9 groups of measuring points on a single test device of the present invention, densely close to the hub and the casing, to ensure that the parameters in the boundary layer are measured; arrange 5 to 10 measuring positions circumferentially, and use multiple measuring devices at the same time, each of which is distributed in the sector-shaped measurement area of ​​several stator blade grid pitches, so that there is at most one circumferential measurement position in each measurement sector-shaped measurement area, and when the circumferential measurement positions in these different sector-shaped measurement areas are rotated by an angle corresponding to an integer multiple of the single stator blade grid pitch with the turbine axis as the rotation center to the same sector-shaped measurement area, it can still be ensured that they are densely close to the blades, to ensure that the parameters in the wake are measured, and sparse in the middle of the channel;

[0043] Further, test measurements are performed, the measuring device is installed at the initial position of the turbine stage inlet and outlet measurement sections, the turbine component under test is adjusted to enter the test state, the pressure sensing hole data and the temperature sensor data of each group of measurement points are measured and recorded, the displacement mechanism is used to drive the measuring device to the next circumferential position and the above process is repeated until all circumferential measurement positions are reached; when a method of simultaneous measurement with multiple measuring devices is adopted, the measuring devices are installed at the respective measurement positions of the turbine stage inlet and outlet measurement sections, the turbine component under test is adjusted to enter the test state, and the pressure sensing hole data and the temperature sensor data of each group of measurement points of all measuring devices are directly recorded;

[0044] Furthermore, the deflection angle coefficient is calculated based on the data of the three pressure sensing holes and the temperature sensor of each group of measuring points. Then, the deflection angle, total pressure, static pressure and Mach number of each measuring point are interpolated and calculated by combining the calibrated coefficient curve. The incoming flow velocity and density are calculated using the following formula:

[0045]

[0046]

[0047]

[0048] c 2 =γRT s

[0049] P s = ρRT s

[0050] Among them, p t and p s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T sis the total temperature and static temperature of the flow field, Ma is the flow field Mach number, v is the flow field velocity, c is the local sound velocity of the flow field, R is the gas constant, and ρ is the gas density;

[0051] Furthermore, the total temperature of the turbine inlet is obtained by using the mass weighting method. Total inlet pressure Total outlet temperature Total outlet pressure The parameter average value is as follows:

[0052]

[0053] in, is the quality-weighted average of the measured parameters, v i is the velocity value of the i-th measurement point, A i is the area value corresponding to the i-th measurement point, α i is the deflection angle of the ith measurement point, X i is the parameter value of the ith measurement point, j is the total number of measurement points;

[0054] Furthermore, the efficiency of the measured turbine stage is calculated using the following formula:

[0055]

[0056] Where: η is the turbine stage efficiency, and is the total temperature and total pressure at the turbine stage inlet, and is the total temperature and total pressure at the turbine stage outlet, and γ is the specific heat ratio of the gas flowing through the turbine.

[0057] The present invention provides a device and method for accurately measuring turbine efficiency. After the measuring device is calibrated through a calibration wind tunnel, a calibration curve can be obtained. In actual measurement, based on the data measured by each group of three pressure sensing holes and a temperature sensor, and according to the calibration coefficient curve and formula obtained through the calibration wind tunnel, through data processing, the total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed, and density parameters of the measured two-dimensional steady-state flow field can be obtained simultaneously, thereby improving the measurement spatial resolution and measurement accuracy. The measurement method can accurately measure the efficiency of a single stage and multiple stages of a turbine by optimizing the measurement point layout and the mass-weighted averaging method.

[0058] The beneficial effects of the present invention are:

[0059] Beneficial effect 1:

[0060] The device for accurately measuring turbine stage efficiency of the present invention can realize the measurement of total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, pitch angle, speed and density of flow field between turbine stages by using a single device. It has a compact structure and small size, effectively reduces interference to the measured flow field and improves test accuracy; at the same time, it simplifies test operations and reduces test costs.

[0061] Beneficial effect 2:

[0062] The method for accurately measuring turbine stage efficiency of the present invention eliminates the system errors caused by arithmetic mean and area mean in previous methods through a mass weighted method, improves the measurement accuracy of the total temperature and total pressure at the inlet and outlet of the turbine stage, and further improves the accuracy of turbine stage efficiency measurement.

[0063] Beneficial effect three:

[0064] The device and method for accurately measuring turbine stage efficiency of the present invention can accurately measure the efficiency of a single stage of the turbine.

[0065] Beneficial effect 4:

[0066] The device for accurately measuring turbine stage efficiency of the present invention can measure total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, pitch angle, speed and density parameters in the turbine hub boundary layer and casing boundary layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a schematic diagram of the structure of the first-stage inlet measuring device of the high-pressure turbine of the first embodiment of the present invention.

[0068] Figure 2 yes Figure 1 Right view of .

[0069] Figure 3 yes Figure 1 Left view of .

[0070] Figure 4 yes Figure 1 A-direction view.

[0071] Figure 5 yes Figure 2 A partial cross-sectional view of .

[0072] Figure 6 It is a schematic diagram of the structure of the first-stage outlet measurement device of the high-pressure turbine of the first embodiment of the present invention.

[0073] Figure 7 yes Figure 6 Right view of .

[0074] Figure 8 yes Figure 6 Left view of .

[0075] Fig. 9 yes Figure 6 A-direction view.

[0076] Fig.10 yes Figure 7 A partial cross-sectional view of .

[0077] Among them: 1-head, 2-support rod, 3-wheel hub boundary layer pressure sensing hole, 4-wheel hub boundary layer temperature sensing hole, 5-casing boundary layer pressure sensing hole, 6-casing boundary layer temperature sensing hole, 7-main channel pressure sensing hole, 8-main channel temperature sensing hole, 9-pressure channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor

[0078] Fig.11 It is a schematic diagram of installation and use of the first embodiment of the present invention.

[0079] Among them: 1-wheel hub, 2-casing, 3-high-pressure turbine first-stage inlet, 4-high-pressure turbine first-stage stator, 5-high-pressure turbine first-stage rotor, 6-high-pressure turbine first-stage outlet.

[0080] Fig.12 It is a schematic diagram of the arrangement of measuring points at the first stage inlet of the high-pressure turbine of the first embodiment of the present invention.

[0081] Fig.13 It is a schematic diagram of the arrangement of measuring points at the first-stage outlet of the high-pressure turbine in Embodiment 1 of the present invention.

[0082] Among them: 1-wheel hub, 2-casing, 3-circumferential measurement position, 4-measuring device.

[0083] Fig.14 It is a schematic diagram of the structure of the turbine stage inlet measuring device of the second embodiment of the present invention.

[0084] Fig.15 yes Fig.14 Right view of .

[0085] Fig.16 yes Fig.14 Left view of .

[0086] Fig.17 yes Fig.14 A-direction view.

[0087] Fig.18 yes Fig.15 A partial cross-sectional view of .

[0088] Fig.19 It is a schematic diagram of the structure of the turbine stage outlet measurement device of the second embodiment of the present invention.

[0089] Fig. 20 yes Fig.19 Right view of .

[0090] Fig.21 yes Fig.19 Left view of .

[0091] Fig. 22 yes Fig.19 A-direction view.

[0092] Fig.23 yes Fig. 20 A partial cross-sectional view of .

[0093] Among them: 1-head, 2-support rod, 3-wheel hub boundary layer pressure sensing hole, 4-wheel hub boundary layer temperature sensing hole, 5-casing boundary layer pressure sensing hole, 6-casing boundary layer temperature sensing hole, 7-main channel pressure sensing hole, 8-main channel temperature sensing hole, 9-pressure channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor

[0094] Fig.24 It is a schematic diagram of installation and use of the second embodiment of the present invention.

[0095] Among them: 1-wheel hub, 2-casing, 3-turbine stage inlet, 4-turbine stage stator, 5-turbine stage rotor, 6-turbine stage outlet.

[0096] Fig.25 It is a schematic diagram of the arrangement of measuring points at the turbine stage inlet of the second embodiment of the present invention.

[0097] Fig.26 It is a schematic diagram of the arrangement of measuring points at the turbine stage outlet of the second embodiment of the present invention.

[0098] Among them: 1-wheel hub, 2-casing, 3-circumferential measurement position, 4-measuring device.

[0099] Fig. 27 It is a schematic diagram of the structure of the first-stage inlet measuring device of the high-pressure turbine of the third embodiment of the present invention.

[0100] Fig.28 yes Fig. 27 Right view of .

[0101] Fig.29 yes Fig. 27 Left view of .

[0102] Fig.30 yes Fig. 27 A-direction view.

[0103] Fig.31 yes Fig.28 A partial cross-sectional view of .

[0104] Fig.32 It is a schematic diagram of the structure of the first-stage outlet measurement device of the high-pressure turbine of the third embodiment of the present invention.

[0105] Fig.33 yes Fig.32 Right view of .

[0106] Fig.34 yes Fig.32 Left view of .

[0107] Fig.35 yes Fig.32 A-direction view.

[0108] Fig.36 yes Fig.33 A partial cross-sectional view of .

[0109] Among them: 1-head, 2-support rod, 3-wheel hub boundary layer pressure sensing hole, 4-wheel hub boundary layer temperature sensing hole, 5-casing boundary layer pressure sensing hole, 6-casing boundary layer temperature sensing hole, 7-main channel pressure sensing hole, 8-main channel temperature sensing hole, 9-pressure channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor

[0110] Fig.37 It is a schematic diagram of the installation and use of the third embodiment of the present invention.

[0111] Among them: 1-wheel hub, 2-casing, 3-turbine stage inlet, 4-high-pressure turbine first-stage turbine stator, 5-high-pressure turbine first-stage turbine rotor, 6-turbine stage outlet.

[0112] Fig.38 It is a schematic diagram of the arrangement of measuring points at the first stage inlet of the high-pressure turbine of the third embodiment of the present invention.

[0113] Fig.39 It is a schematic diagram of the arrangement of measuring points at the first-stage outlet of the high-pressure turbine in the third embodiment of the present invention.

[0114] Among them: 1-wheel hub, 2-casing, 3-circumferential measurement position, 4-measuring device. DETAILED DESCRIPTION

[0115] The preferred embodiments of the present invention are described in detail below in conjunction with 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.

[0116] Embodiment 1

[0117] For the first-stage inlet and outlet of the high-pressure turbine, the axial and radial dimensions are small, the flow conditions are complex, and the incoming flow may contain impurities such as combustion products in the combustion chamber. The device head and support rod should be selected to be relatively small in size to minimize the blockage of the convection field. At the same time, the sensing hole should be selected to have a relatively large aperture to avoid impurity blockage while ensuring spatial resolution. Due to space limitations, fewer measuring points are selected. Therefore, the following implementation cases can be used when measuring the first-stage efficiency of the high-pressure turbine:

[0118] A device and method for accurately measuring turbine stage efficiency, characterized in that:

[0119] The measuring device comprises a head (1), a support rod (2), a wheel hub boundary layer pressure sensing hole (3) and a wheel hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5) and a casing boundary layer temperature sensing hole (6), a main flow channel pressure sensing hole (7) and a main flow channel temperature sensing hole (8), a pressure guide channel (9), and a temperature sensor cable (10); the head (1) comprises a cylinder (11) coaxial with the support rod (2);

[0120] A plurality of rows of pressure sensing holes are provided on the same side surface of the cylindrical body (11) of the head (1) along the axial direction, each row of pressure sensing holes includes three adjacent but mutually incompatible pressure sensing holes, namely a left hole (12), a middle hole (13), and a right hole (14), the center lines of the three pressure sensing holes are located in the same plane, and the center line of the left hole (12) and the center line of the right hole (14) are symmetrically distributed in the plane with respect to the center line of the middle hole (13);

[0121] A plurality of rows of temperature sensing holes are provided on the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes includes a temperature sensing hole (15), the center line of which is parallel to the center line of the hole (13) in the pressure sensing hole;

[0122] The pressure sensing hole and the pressure-inducing channel (9) are respectively connected to one end encapsulated in the head (1); the temperature sensing hole is directly connected only to the temperature sensor (16), and the temperature sensor is a Pt100 thermal resistor; the cable (10) of the pressure-inducing channel (9) and the temperature sensor is led out of the tail through the pipeline in the support rod (2);

[0123] The hub boundary layer pressure sensing hole (3) is close to the end face of the head (1), the distance between the center of the circle and the end face of the head (1) is 0.5 mm, the diameter is 0.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0124] The hub boundary layer temperature sensing hole (4) is located below the hub boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 0.6 mm away from the center of the hub boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm;

[0125] The casing boundary layer pressure sensing hole (5) is close to the interface between the head (1) and the support rod (2), with a distance of 0.5 mm from the interface between the head (1) and the support rod (2), a diameter of 0.5 mm, and a circumferential angle of 30° between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1);

[0126] The casing boundary layer temperature sensing hole (4) is located above the casing boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 0.6 mm away from the center of the casing boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm;

[0127] The main channel pressure sensing hole (7) is located between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), has a diameter of 0.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0128] The main channel temperature sensing hole (8) is located below the middle hole (13) of the main channel pressure sensing hole (7), the center of the circle is 0.6 mm away from the center of the middle hole (13) of the main channel pressure sensing hole (3), and the diameter is 0.5 mm;

[0129] The cylindrical body (11) of the head (1) has a diameter of 2.5 mm and a length of 20 mm;

[0130] The measuring method comprises calibrating a device for accurately measuring turbine stage efficiency, allowing incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, speed and temperature; recording the pressure of three pressure sensing holes in each row of multiple rows of pressure sensing holes on the windward surface of the measuring device, recording the temperature of a temperature sensor of the measuring device, and treating an adjacent row of pressure sensing holes and temperature sensing holes as a group of measuring points;

[0131] Define the pressure measured by the left hole (12) as P1, the pressure measured by the middle hole (13) as P2, the pressure measured by the right hole (14) as P3, and the temperature measured by the temperature sensor as T p , the total pressure of the incoming flow is P t , the static pressure of the incoming flow is P s , total temperature of incoming flow T t , static temperature of incoming flow T s , from which we can get the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient under different incoming flow Mach numbers;

[0132] Total pressure coefficient:

[0133] Static pressure coefficient:

[0134] Deflection angle coefficient:

[0135] Total temperature recovery coefficient:

[0136] Thus, the calibration curves of the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient of the device of the present invention at different Mach numbers and different deflection angles can be obtained;

[0137] The arrangement scheme of the measuring points at the inlet of the measured turbine stage is as follows: a section at a distance of 1 times the blade chord length from the leading edge of the stator blade in front of the inlet of the measured turbine stage is selected as the inlet test section, and the test section is divided into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 4 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 7 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0138] The arrangement scheme of the measuring points at the outlet of the measured turbine stage is as follows: the section at 0.2 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage is selected as the outlet test section, and the test section is divided into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 5 groups of measuring points are arranged on a single test device of the present invention, and they are densely packed near the hub and the casing to ensure that the parameters in the boundary layer are measured; 7 measuring positions are arranged circumferentially, and the different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely packed near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0139] Further, test measurements are carried out, the measuring device is installed at the initial positions of the turbine stage inlet and outlet measuring sections, the turbine component under test is adjusted to enter the test state, the pressure sensing hole data and the temperature sensor data of each group of measuring points are measured and recorded, the measuring device is driven to the next circumferential position by the displacement mechanism and the above process is repeated until all circumferential measuring positions are covered;

[0140] Furthermore, the deflection angle coefficient is calculated based on the data of the three pressure sensing holes and the temperature sensor of each group of measuring points. Then, the deflection angle, total pressure, static pressure and Mach number of each measuring point are interpolated and calculated by combining the calibrated coefficient curve. The incoming flow velocity and density are calculated using the following formula:

[0141]

[0142]

[0143]

[0144] c 2 =γRT s

[0145] P s = ρRT s

[0146] Among them, p t and p s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature and static temperature of the flow field, Ma is the flow field Mach number, v is the flow field velocity, c is the local sound velocity of the flow field, R is the gas constant, and ρ is the gas density;

[0147] Furthermore, the mass-weighted method is used to obtain the total temperature of the first-stage inlet of the high-pressure turbine. Total inlet pressure Total outlet temperature Total outlet pressure The parameter average value is as follows:

[0148]

[0149] in, is the quality-weighted average of the measured parameters, v i is the velocity value of the i-th measurement point, A i is the area value corresponding to the i-th measurement point, α i is the deflection angle of the ith measurement point, X i is the parameter value of the ith measurement point, j is the total number of measurement points;

[0150] Furthermore, the efficiency of the measured turbine stage is calculated using the following formula:

[0151]

[0152] Where: η is the turbine stage efficiency, and is the total temperature and total pressure at the first stage inlet of the high-pressure turbine, and is the total temperature and total pressure at the outlet of the first stage of the high-pressure turbine, and γ is the specific heat ratio of the gas flowing through the turbine.

[0153] Embodiment 2

[0154] For the inlet and outlet of the rear stage of the turbine, the axial and radial dimensions are large, the incoming flow velocity is fast, and the flow state between different positions is very different. Therefore, more measurement positions can be selected to improve the overall accuracy of the test. In addition, the head and support rod of the device should be selected to ensure strength and rigidity when selecting the size. The pressure sensing hole should be selected with a larger aperture to avoid clogging by impurities from the combustion chamber. Therefore, the following implementation cases can be used when measuring the efficiency of the whole turbine:

[0155] A device and method for accurately measuring turbine stage efficiency, characterized in that:

[0156] The measuring device comprises a head (1), a support rod (2), a hub boundary layer pressure sensing hole (3) and a temperature sensing hole (4), a casing boundary layer pressure sensing hole (5) and a temperature sensing hole (6), a main flow channel pressure sensing hole (7) and a temperature sensing hole (8), a pressure-inducing channel (9), and a temperature sensor cable (10); the head (1) comprises a cylinder (11) coaxial with the support rod (2);

[0157] A plurality of rows of pressure sensing holes are provided on the same side surface of the cylindrical body (11) of the head (1) along the axial direction, each row of pressure sensing holes includes three adjacent but mutually incompatible pressure sensing holes, namely a left hole (12), a middle hole (13), and a right hole (14), the center lines of the three pressure sensing holes are located in the same plane, the center line of the left hole (12) and the center line of the right hole (14) are symmetrically distributed in the plane about the center line of the middle hole (13), and the intersection of the center lines is located on the axis of the head (1);

[0158] A plurality of rows of temperature sensing holes are provided on the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes includes a temperature sensing hole (15), the center line of which is parallel to the center line of the hole (13) in the pressure sensing hole;

[0159] The pressure sensing hole and the pressure-inducing channel (9) are respectively connected to one end encapsulated in the head (1); the temperature sensing hole is directly connected only to the temperature sensor, and the temperature sensor is a Pt100 thermal resistor; the cable (10) of the pressure-inducing channel (9) and the temperature sensor is led out of the tail through the pipeline in the support rod (2);

[0160] The hub boundary layer pressure sensing hole (3) is close to the end face of the head (1), the distance between the center of the circle and the end face of the head (1) is 0.8 mm, the diameter is 0.8 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0161] The hub boundary layer temperature sensing hole (4) is located below the center hole (13) of the hub boundary layer pressure sensing hole (3), the center of the circle is 1 mm away from the center of the center hole (13) of the hub boundary layer pressure sensing hole (3), and the diameter is 0.8 mm;

[0162] The casing boundary layer pressure sensing hole (5) is close to the interface between the head (1) and the support rod (2), with a distance of 0.8 mm from the interface between the head (1) and the support rod (2), a diameter of 0.8 mm, and a circumferential angle of 30° between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1);

[0163] The casing boundary layer temperature sensing hole (4) is located above the casing boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 1 mm away from the center of the casing boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.8 mm;

[0164] The main channel pressure sensing hole (7) is located between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), has a diameter of 0.8 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0165] The main channel temperature sensing hole (8) is located below the middle hole (13) of the main channel pressure sensing hole (7), the center of the circle is 1 mm away from the center of the middle hole (13) of the main channel pressure sensing hole (3), and the diameter is 0.8 mm;

[0166] The cylindrical body (11) of the head (1) has a diameter of 4 mm and a length of 200 mm;

[0167] The measuring method comprises calibrating a device for accurately measuring turbine stage efficiency, allowing incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, velocity and total temperature; recording the pressure of three pressure sensing holes in each row of multiple rows of pressure sensing holes on the windward surface of the measuring device, recording the temperature of a temperature sensor of the measuring device, and treating an adjacent row of pressure sensing holes and temperature sensing holes as a group of measuring points;

[0168] Define the pressure measured by the left hole (12) as P1, the pressure measured by the middle hole (13) as P2, the pressure measured by the right hole (14) as P3, and the temperature measured by the temperature sensor as T p , the total pressure of the incoming flow is P t , the static pressure of the incoming flow is P s , total temperature of incoming flow T t , static temperature of incoming flow T s , from which we can get the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient under different incoming flow Mach numbers;

[0169] Total pressure coefficient:

[0170] Static pressure coefficient:

[0171] Deflection angle coefficient:

[0172] Total temperature recovery coefficient:

[0173] Thus, the calibration curves of the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient of the device of the present invention at different Mach numbers and different deflection angles can be obtained;

[0174] The arrangement scheme of the measuring points at the inlet of the measured turbine stage is as follows: a section at 0.3 times the blade chord length from the leading edge of the stator blade in front of the inlet of the measured turbine stage is selected as the inlet test section, and the test section is divided into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 5 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 9 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0175] The arrangement scheme of the measuring points at the outlet of the measured turbine stage is as follows: a section at 0.5 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage is selected as the outlet test section, and the test section is divided into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 7 groups of measuring points are arranged on a single test device of the present invention, which are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 9 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, which are densely arranged near the blades to ensure that the parameters in the wake are measured, and sparsely arranged in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism;

[0176] Further, test measurements are carried out, the measuring device is installed at the initial positions of the turbine stage inlet and outlet measuring sections, the turbine component under test is adjusted to enter the test state, the pressure sensing hole data and the temperature sensor data of each group of measuring points are measured and recorded, the measuring device is driven to the next circumferential position by the displacement mechanism and the above process is repeated until all circumferential measuring positions are covered;

[0177] Furthermore, the deflection angle coefficient is calculated based on the data of the three pressure sensing holes and the temperature sensor of each group of measuring points. Then, the deflection angle, total pressure, static pressure and Mach number of each measuring point are interpolated and calculated by combining the calibrated coefficient curve. The incoming flow velocity and density are calculated using the following formula:

[0178]

[0179]

[0180]

[0181] c 2 =γRT s

[0182] P s = ρRT s

[0183] Among them, p t and p s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature and static temperature of the flow field, Ma is the flow field Mach number, v is the flow field velocity, c is the local sound velocity of the flow field, R is the gas constant, and ρ is the gas density;

[0184] Furthermore, the total temperature at the turbine stage inlet is obtained by using the mass weighting method. Total inlet pressure Total outlet temperature Total outlet pressure The parameter average value is as follows:

[0185]

[0186] in, is the quality-weighted average of the measured parameters, v i is the velocity value of the i-th measurement point, A i is the area value corresponding to the i-th measurement point, α i is the deflection angle of the ith measurement point, X i is the parameter value of the ith measurement point, j is the total number of measurement points;

[0187] Furthermore, the efficiency of the measured turbine stage is calculated using the following formula:

[0188]

[0189] Where: η is the turbine stage efficiency, and is the total temperature and total pressure at the turbine stage inlet, and is the total temperature and total pressure at the turbine stage outlet, and γ is the specific heat ratio of the gas flowing through the turbine.

[0190] Embodiment 3

[0191] For the first-stage inlet and outlet of the high-pressure turbine, the axial and radial dimensions are small, the flow conditions are complex, and the incoming flow may contain impurities such as combustion products in the combustion chamber. The device head and support rod should be selected to be relatively small in size to minimize the blockage of the convection field. At the same time, the sensing hole should be selected to have a relatively large aperture to avoid impurity blockage while ensuring spatial resolution. Due to space limitations, fewer measuring points are selected. Therefore, the following implementation cases can be used when measuring the first-stage efficiency of the high-pressure turbine:

[0192] A device and method for accurately measuring turbine stage efficiency, characterized in that:

[0193] The measuring device comprises a head (1), a support rod (2), a wheel hub boundary layer pressure sensing hole (3) and a wheel hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5) and a casing boundary layer temperature sensing hole (6), a main flow channel pressure sensing hole (7) and a main flow channel temperature sensing hole (8), a pressure guide channel (9), and a temperature sensor cable (10); the head (1) comprises a cylinder (11) coaxial with the support rod (2);

[0194] A plurality of rows of pressure sensing holes are provided on the same side surface of the cylindrical body (11) of the head (1) along the axial direction, each row of pressure sensing holes includes three adjacent but mutually incompatible pressure sensing holes, namely a left hole (12), a middle hole (13), and a right hole (14), the center lines of the three pressure sensing holes are located in the same plane, and the center line of the left hole (12) and the center line of the right hole (14) are symmetrically distributed in the plane with respect to the center line of the middle hole (13);

[0195] A plurality of rows of temperature sensing holes are provided on the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes includes a temperature sensing hole (15), the center line of which is parallel to the center line of the hole (13) in the pressure sensing hole;

[0196] The pressure sensing hole and the pressure-inducing channel (9) are respectively connected to one end encapsulated in the head (1); the temperature sensing hole is directly connected only to the temperature sensor (16), and the temperature sensor is a Pt100 thermal resistor; the cable (10) of the pressure-inducing channel (9) and the temperature sensor is led out of the tail through the pipeline in the support rod (2);

[0197] The hub boundary layer pressure sensing hole (3) is close to the end face of the head (1), the distance between the center of the circle and the end face of the head (1) is 0.5 mm, the diameter is 0.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0198] The hub boundary layer temperature sensing hole (4) is located below the hub boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 0.6 mm away from the center of the hub boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm;

[0199] The casing boundary layer pressure sensing hole (5) is close to the interface between the head (1) and the support rod (2), with a distance of 0.5 mm from the interface between the head (1) and the support rod (2), a diameter of 0.5 mm, and a circumferential angle of 30° between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1);

[0200] The casing boundary layer temperature sensing hole (4) is located above the casing boundary layer pressure sensing hole (3) middle hole (13), the center of the circle is 0.6 mm away from the center of the casing boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm;

[0201] The main channel pressure sensing hole (7) is located between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), has a diameter of 0.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylindrical body (11) of the measuring device head (1) is 30°;

[0202] The main channel temperature sensing hole (8) is located below the middle hole (13) of the main channel pressure sensing hole (7), the center of the circle is 0.6 mm away from the center of the middle hole (13) of the main channel pressure sensing hole (3), and the diameter is 0.5 mm;

[0203] The cylindrical body (11) of the head (1) has a diameter of 2.5 mm and a length of 20 mm;

[0204] The measuring method comprises calibrating a device for accurately measuring turbine stage efficiency, allowing incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, speed and temperature; recording the pressure of three pressure sensing holes in each row of multiple rows of pressure sensing holes on the windward surface of the measuring device, recording the temperature of a temperature sensor of the measuring device, and treating an adjacent row of pressure sensing holes and temperature sensing holes as a group of measuring points;

[0205] Define the pressure measured by the left hole (12) as P1, the pressure measured by the middle hole (13) as P2, the pressure measured by the right hole (14) as P3, and the temperature measured by the temperature sensor as T p , the total pressure of the incoming flow is P t , the static pressure of the incoming flow is P s , total temperature of incoming flow T t , static temperature of incoming flow T s , from which we can get the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient under different incoming flow Mach numbers;

[0206] Total pressure coefficient:

[0207] Static pressure coefficient:

[0208] Deflection angle coefficient:

[0209] Total temperature recovery coefficient:

[0210] Thus, the calibration curves of the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient of the device of the present invention at different Mach numbers and different deflection angles can be obtained;

[0211] The arrangement scheme of the measuring points at the inlet of the measured turbine stage is as follows: a section at a distance of 1 times the blade chord length from the leading edge of the stator blade in front of the inlet of the measured turbine stage is selected as the inlet test section, and the test section is divided into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 4 groups of measuring points are arranged on a single test device of the present invention, and they are densely packed near the hub and the casing to ensure that the parameters in the boundary layer are measured; 7 measuring positions are arranged circumferentially, and multiple measuring devices are used at the same time, and they are respectively distributed in the sector-shaped measurement areas of a number of stator blade grid pitches, so that there is at most one circumferential measuring position in each measuring sector-shaped measurement area, and when the circumferential measuring positions in these different sector-shaped measurement areas are rotated by an angle corresponding to an integer multiple of the pitch of a single stator blade grid with the turbine axis as the rotation center to the same sector-shaped measurement area, it can still be ensured that they are densely packed near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel;

[0212] The arrangement scheme of the measuring points at the outlet of the measured turbine stage is to select the section at 0.2 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage as the outlet test section, and divide the test section into several sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; arrange 5 groups of measuring points on a single test device of the present invention, densely close to the hub and the casing, to ensure that the parameters in the boundary layer are measured; arrange 7 measuring positions circumferentially, and use multiple measuring devices at the same time, each of which is distributed in the sector-shaped measurement area of ​​several stator blade grid pitches, so that there is at most one circumferential measuring position in each measurement sector-shaped measurement area, and when the circumferential measuring positions in these different sector-shaped measurement areas are rotated by an angle corresponding to an integer multiple of the single stator blade grid pitch with the turbine axis as the rotation center to the same sector-shaped measurement area, it can still be ensured that they are densely close to the blades, to ensure that the parameters in the wake are measured, and sparse in the middle of the channel;

[0213] Further, test measurements are performed, measuring devices are installed at respective measuring positions of the turbine stage inlet and outlet measuring sections, the turbine components to be measured are adjusted to enter a test state, and pressure sensing hole data and temperature sensor data of each group of measuring points of all measuring devices are directly recorded;

[0214] Furthermore, the deflection angle coefficient is calculated based on the data of the three pressure sensing holes and the temperature sensor of each group of measuring points. Then, the deflection angle, total pressure, static pressure and Mach number of each measuring point are interpolated and calculated by combining the calibrated coefficient curve. The incoming flow velocity and density are calculated using the following formula:

[0215]

[0216]

[0217]

[0218] c 2 =γRT s

[0219] P s = ρRT s

[0220] Among them, p t and p s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature and static temperature of the flow field, Ma is the flow field Mach number, v is the flow field velocity, c is the local sound velocity of the flow field, R is the gas constant, and ρ is the gas density;

[0221] Furthermore, the mass-weighted method is used to obtain the total temperature of the first-stage inlet of the high-pressure turbine. Total inlet pressure Total outlet temperature Total outlet pressure The parameter average value is as follows:

[0222]

[0223] in, is the quality-weighted average of the measured parameters, v i is the velocity value of the i-th measurement point, A i is the area value corresponding to the i-th measurement point, α i is the deflection angle of the ith measurement point, X i is the parameter value of the ith measurement point, j is the total number of measurement points;

[0224] Furthermore, the efficiency of the measured turbine stage is calculated using the following formula:

[0225]

[0226] Where: η is the turbine stage efficiency, and is the total temperature and total pressure at the first stage inlet of the high-pressure turbine, and is the total temperature and total pressure at the outlet of the first stage of the high-pressure turbine, and γ is the specific heat ratio of the gas flowing through the turbine.

Claims

1. A device for accurately measuring turbine stage efficiency, characterized in that: The measuring device comprises a head (1), a support rod (2), a wheel hub boundary layer pressure sensing hole (3) and a wheel hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5) and a casing boundary layer temperature sensing hole (6), a main flow channel pressure sensing hole (7) and a main flow channel temperature sensing hole (8), a pressure guide channel (9), and a temperature sensor cable (10); the head (1) comprises a cylinder (11) coaxial with the support rod (2); A plurality of rows of pressure sensing holes are provided on the same side surface of the cylindrical body (11) of the head (1) along the axial direction, each row of pressure sensing holes includes three adjacent but mutually incompatible pressure sensing holes, namely a left hole (12), a middle hole (13), and a right hole (14), the center lines of the three pressure sensing holes are located in the same plane, and the center line of the left hole (12) and the center line of the right hole (14) are symmetrically distributed in the plane with respect to the center line of the middle hole (13); A plurality of rows of temperature sensing holes are provided on the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes includes a temperature sensing hole (15), the center line of which is parallel to the center line of the hole (13) in the pressure sensing hole; the pressure sensing hole is connected to one end of the pressure induction channel (9) encapsulated in the head (1); the temperature sensing hole is directly connected only to the temperature sensor (16), and the temperature sensor can be selected from bare wire thermocouples, armored thermocouples, thermal resistors, optical fiber sensors, etc.; the cable (10) of the pressure induction channel (9) and the temperature sensor is led out of the tail through the pipeline in the support rod (2); The hub boundary layer pressure sensing hole (3) is close to the end face of the head (1), the distance between the center of the circle and the end face of the head (1) is 0.5 mm to 5 mm, the diameter is 0.2 mm to 1.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylinder (11) of the head (1) is 15° to 60°; The hub boundary layer temperature sensing hole (4) is located below the center hole (13) of the hub boundary layer pressure sensing hole (3), the center of the circle is 0.5 mm to 2 mm away from the center of the center hole (13) of the hub boundary layer pressure sensing hole (3), and the diameter is 0.5 mm to 2 mm; The casing boundary layer pressure sensing hole (5) is close to the interface between the head (1) and the support rod (2), with a distance of 0.5 mm to 5 mm from the interface between the head (1) and the support rod (2), a diameter of 0.2 mm to 1.5 mm, and a circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the cylinder (11) of the head (1) is 15° to 60°; The casing boundary layer temperature sensing hole (6) is located above the casing boundary layer pressure sensing hole (5) middle hole (13), the center of the circle is 0.5 mm to 2 mm away from the center of the casing boundary layer pressure sensing hole (3) middle hole (13), and the diameter is 0.5 mm to 2 mm; The main flow channel pressure sensing hole (7) is located between the hub boundary layer temperature sensing hole (4) and the casing boundary layer temperature sensing hole (6), has a diameter of 0.2 mm to 1.5 mm, and the circumferential angle between the center line of the left hole (12) and the center line of the right hole (14) on the surface of the head (1) cylinder (11) is 15° to 60°; The main channel temperature sensing hole (8) is located below the middle hole (13) of the main channel pressure sensing hole (7), the center of the circle is 0.5 mm to 2 mm away from the center of the middle hole (13) of the main channel pressure sensing hole (7), and the diameter is 0.5 mm to 2 mm; The diameter of the cylinder (11) of the head (1) is 2 mm to 8 mm, and the length is 10 mm to 400 mm.

2. A method for accurately measuring turbine stage efficiency based on the device of claim 1, characterized in that: The measuring method comprises calibrating a device for accurately measuring turbine stage efficiency, allowing incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, velocity and total temperature; recording the pressure of three pressure sensing holes in each row of multiple rows of pressure sensing holes on the windward surface of the measuring device, recording the temperature of a temperature sensor of the measuring device, and regarding an adjacent row of pressure sensing holes and temperature sensing holes as a group of measuring points; Define the pressure measured by the left hole (12) as P1, the pressure measured by the middle hole (13) as P2, the pressure measured by the right hole (14) as P3, and the temperature measured by the temperature sensor as T p , the total pressure of the incoming flow is P t , the static pressure of the incoming flow is P s , total temperature of incoming flow P t , static temperature of incoming flow T s , from which we can get the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient under different incoming flow Mach numbers; Total pressure coefficient: Static pressure coefficient: Deflection angle coefficient: Total temperature recovery coefficient: Thus, the calibration curves of the total pressure coefficient, static pressure coefficient, deflection angle coefficient and total temperature recovery coefficient of the device of the present invention at different Mach numbers and different deflection angles can be obtained; The first scheme for arranging the measuring points at the inlet of the measured turbine stage is to select a section at 0.05 to 1.5 times the blade chord length from the leading edge of the stator blade in front of the measured turbine stage inlet as the inlet test section, and divide the test section into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 3 to 9 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 5 to 10 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism; The first arrangement scheme of measuring points at the outlet of the measured turbine stage is to select a section at 0.05 to 1 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage as the outlet test section, and divide the test section into a number of sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; 3 to 9 groups of measuring points are arranged on a single test device of the present invention, and they are densely arranged near the hub and the casing to ensure that the parameters in the boundary layer are measured; 5 to 10 measuring positions are arranged circumferentially, and different circumferential measuring positions are concentrated in a sector-shaped measurement area of ​​a stator blade grid pitch, and they are densely arranged near the blades to ensure that the parameters in the wake are measured, and they are sparse in the middle of the channel, and the measuring device is driven through all circumferential measuring positions by a displacement mechanism; The second scheme for arranging the measuring points at the outlet of the measured turbine stage is to select the section at 0.05 to 1 times the blade chord length from the trailing edge of the rotor blade after the outlet of the measured turbine stage as the outlet test section, and divide the test section into several sector-shaped measurement areas according to the pitch of a single stator blade grid of the turbine stage; arrange 3 to 9 groups of measuring points on a single test device of the present invention, densely close to the hub and the casing, to ensure that the parameters in the boundary layer are measured; arrange 5 to 10 measuring positions circumferentially, and use multiple measuring devices at the same time, each of which is distributed in the sector-shaped measurement area of ​​several stator blade grid pitches, so that there is at most one circumferential measurement position in each measurement sector-shaped measurement area, and when the circumferential measurement positions in these different sector-shaped measurement areas are rotated by an angle corresponding to an integer multiple of the single stator blade grid pitch with the turbine axis as the rotation center to the same sector-shaped measurement area, it can still be ensured that they are densely close to the blades, to ensure that the parameters in the wake are measured, and sparse in the middle of the channel; Further, test measurements are performed, the measuring device is installed at the initial position of the turbine stage inlet and outlet measurement sections, the turbine component under test is adjusted to enter the test state, the pressure sensing hole data and the temperature sensor data of each group of measurement points are measured and recorded, the displacement mechanism is used to drive the measuring device to the next circumferential position and the above process is repeated until all circumferential measurement positions are reached; when a method of simultaneous measurement with multiple measuring devices is adopted, the measuring devices are installed at the respective measurement positions of the turbine stage inlet and outlet measurement sections, the turbine component under test is adjusted to enter the test state, and the pressure sensing hole data and the temperature sensor data of each group of measurement points of all measuring devices are directly recorded; Furthermore, the deflection angle coefficient is calculated based on the data of the three pressure sensing holes and the temperature sensor of each group of measuring points. Then, the deflection angle, total pressure, static pressure and Mach number of each measuring point are interpolated and calculated by combining the calibrated coefficient curve. The incoming flow velocity and density are calculated using the following formula: c 2 =γRT s P s =ρRT s Among them, P t and P s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature of the flow field and the static temperature, Ma is the Mach number of the flow field, v is the velocity of the flow field, is the local sound speed of the flow field, R is the gas constant, and ρ is the gas density; Furthermore, the total temperature of the turbine inlet is obtained by using the mass weighting method. Total inlet pressure Total outlet temperature Total outlet pressure The parameter average value is as follows: in, is the quality-weighted average of the measured parameters, v i is the velocity value of the i-th measurement point, A i is the area value corresponding to the i-th measurement point, α i is the deflection angle of the ith measurement point, X i is the parameter value of the ith measurement point, j is the total number of measurement points; Furthermore, the efficiency of the measured turbine stage is calculated using the following formula: Where: η is the turbine stage efficiency, and is the total temperature and total pressure at the turbine stage inlet, and is the total temperature and total pressure at the turbine stage outlet, and γ is the specific heat ratio of the gas flowing through the turbine.

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