CN111089669A - Device and method for accurately measuring turbine stage efficiency - Google Patents

Device and method for accurately measuring turbine stage efficiency Download PDF

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Publication number
CN111089669A
CN111089669A CN202010065744.7A CN202010065744A CN111089669A CN 111089669 A CN111089669 A CN 111089669A CN 202010065744 A CN202010065744 A CN 202010065744A CN 111089669 A CN111089669 A CN 111089669A
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measuring
hole
pressure
temperature
turbine
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马宏伟
金也佳
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Beihang University
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Beihang University
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
    • G01L3/26—Devices for measuring efficiency, i.e. the ratio of power output to power input

Abstract

The invention discloses a device and a method for accurately measuring turbine stage efficiency. The head of the device is a cylinder, and a plurality of groups of pressure sensing holes and temperature sensing holes are formed in the same side of the surface of the cylinder. Each group of sensing holes consists of a row of three adjacent pressure sensing holes and a temperature sensing hole which is close to the upper part or the lower part of the middle measuring hole of the three pressure sensing holes, and each group of three pressure sensing holes and one temperature sensing hole form a combined measuring point. The invention can simultaneously measure the total temperature, total pressure, static temperature, static pressure, deflection angle, Mach number, speed and density of the air flow at a plurality of positions of the inlet, the outlet and the interstage of the turbine, along the blade height direction, the turbine casing boundary layer, the hub boundary layer and the main runner. And calculating the efficiency of the turbine by using the parameters through a mass weighted average method. The invention has small interference to the measured flow field, high parameter measurement precision and more accurate turbine efficiency measurement result.

Description

Device and method for accurately measuring turbine stage efficiency
Technical Field
The invention belongs to the technical field of impeller mechanical testing, and particularly relates to a device and a method for accurately measuring turbine stage efficiency, which can realize accurate measurement of turbine stage efficiency of an impeller under the premise of reducing interference on a turbine flow field to the maximum extent.
Background
The impeller machine is a complex power machine, a turbine is one of main components of the power machine, efficiency is a key index for measuring the performance of the turbine, therefore, the accurate measurement of the efficiency of the turbine is of great significance for performance evaluation of the turbine and design and improvement of the turbine, and the measurement error of the prior art is too large to exceed the improvement value of the efficiency of a turbine stage.
The isentropic stagnation efficiency of the turbine is defined as the ratio of the rim work of the gas flow flowing through the turbine to the isentropic stagnation enthalpy drop of the gas flowing through the turbine, and further the efficiency of the turbine stage can be calculated by the total temperature ratio, the expansion ratio and the specific heat ratio of the inlet and the outlet of the turbine, and the calculation formula is as follows:
Figure BDA0002375914530000011
where η -turbine stage efficiency
Figure BDA0002375914530000012
Inlet total temperature of turbine stage, K
Figure BDA0002375914530000013
-total pressure, Pa, at the inlet of the turbine stage
Figure BDA0002375914530000014
-turbine stage outlet total temperature, K
Figure BDA0002375914530000015
-total pressure, Pa, at the outlet of the turbine stage
Gamma-specific heat ratio of gas flowing through turbine
Therefore, how to accurately measure the turbine stage, the total outlet temperature and the total pressure becomes one of the keys for accurately measuring the efficiency of the turbine stage. When the existing measuring device is used for measuring turbine parameters, a pressure measuring device and a temperature measuring device are mostly used for measuring pressure and temperature respectively. On one hand, such a measurement scheme prevents the pressure and the temperature from being measured at the same time and the same point, and the measured parameters do not come from the same streamline, so that the spatial resolution of the measurement device is greatly reduced, and the flow in the turbine has strong non-stationarity and spatial non-uniformity, so that the measurement result generates errors. On the other hand, when the measuring device extends into the turbine flow field for measurement, the measured flow field is inevitably interfered, and in the existing measuring scheme, the single pressure measuring device and the single temperature measuring device are adopted for measurement respectively, so that the used measuring devices are excessive in number, the measured flow field is inevitably interfered greatly, and the accuracy of the final measuring result is influenced.
Most of the existing measuring devices are single-point measurement, and when turbine parameters are measured along the radial direction, a plurality of measuring devices are required to be used simultaneously or the measuring devices are driven by a displacement mechanism to move for measurement. And a plurality of measuring devices are used simultaneously, so that the flow field can be blocked, the measuring precision is influenced, and the measuring cost is increased. The displacement mechanism drives the measuring device to cause time difference between multi-point measuring results, and the measurement of a plurality of measuring points of the flow field at the same time cannot be realized.
When the total temperature of a turbine stage is measured by the conventional measuring method, a rake-shaped total temperature measuring device or a plurality of multipoint total temperature measuring devices are used for measuring, and the average value of the total temperature is calculated by an arithmetic average method. In the turbine flow field, the flow velocity of each point in the main flow channel is not uniform, the velocity distribution in the main flow channel and the boundary layer is greatly different, and therefore, the measurement error is increased by calculating the total temperature average value by adopting an arithmetic average method.
When the total pressure of a turbine stage is measured by the conventional measuring method, a rake-shaped total pressure measuring device or a multipoint total pressure measuring device is used for measuring, and an area average method is used for calculating a total pressure average value. Due to the nonuniformity of flow field flow velocity, the error is also brought by using an area averaging method to calculate the total pressure average value, and the measurement accuracy is reduced.
In addition, the existing measurement can only measure the parameters of the inlet and the outlet of the multi-stage turbine, but can not measure the parameters among stages of the multi-stage turbine, so that for the multi-stage turbine, the existing technology can only measure the overall efficiency of the multi-stage turbine, but can not measure the single-stage efficiency of the turbine.
Therefore, the existing measuring device and method cannot meet the requirement of accurately measuring the single-stage efficiency of the turbine, and an accurate measuring device and method for the turbine stage efficiency are urgently needed to realize accurate measurement of the turbine stage efficiency.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the problems that the existing turbine stage efficiency measurement and calculation schemes are difficult to measure parameters such as total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed, density and the like of a flow field at the same time and the same point by the existing measuring device; the problem that a plurality of different parameter measuring devices respectively extend into a turbine flow field to greatly interfere with the measured flow field; the invention discloses a device and a method for accurately measuring turbine stage efficiency, which solve the problem that temperature parameters are large in difference from actual turbine flow field velocity distribution by adopting an arithmetic average method or an area average method when the turbine stage efficiency is calculated.
The invention relates to a device and a method for accurately measuring turbine stage efficiency, wherein a measuring device is different from a pressure measuring device and a temperature measuring device which are respectively independent in the past.
The invention discloses a device and a method for accurately measuring the efficiency of a turbine stage, and the measuring method is different from the existing measuring method. The existing method uses a single temperature measuring device and a pressure measuring device to respectively measure the total temperature and the total pressure of the inlet and the outlet of the turbine, and the measuring method of the invention uses the measuring device of the invention to carry out multi-parameter synchronous measurement, thereby reducing the number of the measuring devices, reducing the interference to a measured flow field, simplifying the measuring process and reducing the measuring cost. In the existing method, after the total temperature and total pressure parameters of the test point are obtained, the average value of the total temperature and total pressure of the measured section is obtained by an arithmetic average or area average method. The invention uses the mass flow weighting mode to obtain the average value of the total temperature and the total pressure of the measuring section, thereby greatly reducing the turbine efficiency measuring error and improving the turbine efficiency measuring precision. For the multi-stage turbine, the existing measuring method can only measure the overall efficiency, and the measuring method can measure the single-stage efficiency of the multi-stage turbine through a new measuring section and measuring point layout.
The technical solution of the invention is as follows:
the measuring device comprises a head (1), a support rod (2), a hub boundary layer pressure sensing hole (3), a hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5), a casing boundary layer temperature sensing hole (6), a main runner pressure sensing hole (7), a main runner 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 strut (2);
the pressure sensing device is characterized in that multiple rows of pressure sensing holes are formed in the same side surface of a cylinder (11) of the head (1) along the axial direction, each row of pressure sensing holes comprises three pressure sensing holes which are close to each other but are not communicated with each other, namely a left hole (12), a middle hole (13) and a right hole (14), the central lines of the three pressure sensing holes are located in the same plane, and the central lines of the left hole (12) and the right hole (14) are symmetrically distributed on the plane relative to the central line of the middle hole (13);
a plurality of rows of temperature sensing holes are formed in the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes comprises a temperature sensing hole (15), and the center line of each row of temperature sensing holes is parallel to the center line of the hole (13) in the pressure sensing hole;
the pressure sensing hole is communicated with one end of the pressure guide channel (9) which is encapsulated in the head part (1); the temperature sensing hole is only directly communicated with a temperature sensor (16), and the temperature sensor can be a bare wire thermocouple, an armored thermocouple, a thermal resistor, an optical fiber sensor and the like; the pressure guide channel (9) and a cable (10) of the temperature sensor are led out of the tail part through a pipeline in the support rod (2);
the pressure sensing hole (3) of the hub boundary layer is close to the end face of the head (1), the distance between the circle center 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 included 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 degrees to 60 degrees;
the hub boundary layer temperature sensing hole (4) is positioned below the center hole (13) of the hub boundary layer pressure sensing hole (3), the distance between the circle center and the center hole (13) of the hub boundary layer pressure sensing hole (3) is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the pressure sensing hole (5) of the casing boundary layer is close to the interface of the head (1) and the support rod (2), the distance from the interface of the head (1) and the support rod (2) is 0.5 mm to 5 mm, the diameter is 0.2 mm to 1.5 mm, and the circumferential included angle of 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 degrees to 60 degrees;
the temperature sensing hole (4) of the casing boundary layer is positioned above the center hole (13) of the pressure sensing hole (3) of the casing boundary layer, the distance between the circle center and the center hole (13) of the pressure sensing hole (3) of the casing boundary layer is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the main runner pressure sensing hole (7) is positioned between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), the diameter is 0.2 mm to 1.5 mm, and the circumferential included 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 degrees to 60 degrees;
the main runner temperature sensing hole (8) is positioned below a center hole (13) of the main runner pressure sensing hole (7), the distance between the center of the circle and the center of the center hole (13) of the main runner pressure sensing hole (3) is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the diameter of the head (1) cylinder (11) is 2 mm to 8 mm, and the length of the head (1) cylinder is 10 mm to 400 mm;
the measuring method comprises the steps of calibrating a device for accurately measuring the efficiency of a turbine stage, and enabling incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, speed and total temperature; recording the pressure of three pressure sensing holes in each row of a plurality of 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 the adjacent rows of pressure sensing holes and temperature sensing holes as a group of measuring points;
defining the left hole (12) as the measured pressure P1The mesopore (13) measuring pressure is P2The right hole (14) measures pressure P3The temperature sensor measures a temperature TpTotal pressure of incoming flow is PtIncoming static pressure of PsTotal temperature of incoming flow TtComing stream static temperature TsTherefore, the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient under different incoming flow Mach numbers can be obtained;
total pressure coefficient:
Figure BDA0002375914530000041
static pressure coefficient:
Figure BDA0002375914530000042
deflection angle coefficient:
Figure BDA0002375914530000043
total temperature recovery coefficient:
Figure BDA0002375914530000044
therefore, calibration curves of the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient of the device under different Mach numbers and different deflection angles can be obtained;
the first tested turbine stage inlet measuring point arrangement scheme is that a section of a tested turbine stage inlet front distance from the stator blade front edge by 0.05-1.5 times of blade chord length is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measuring areas according to the turbine stage single stator blade grid distance; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, different circumferential measuring positions are concentrated in a fan-shaped measuring area of a stator blade grid distance and are dense at positions close to blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and a measuring device is driven to walk through all circumferential measuring positions through a displacement mechanism;
the second turbine stage inlet measurement point arrangement scheme is that a section of a turbine stage inlet front distance between 0.05 and 1.5 times of blade chord length of a stator blade front edge is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to a single stator blade grid pitch of a turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, a plurality of measuring devices are used at the same time, the measuring devices are respectively distributed in fan-shaped measuring areas with a plurality of stator blade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas are rotated to the same fan-shaped measuring area by an integral multiple of the angle corresponding to a single stator blade grid distance by taking a turbine axis as a rotation center, the positions close to blades can still be ensured to be dense, parameters in a tail track can be ensured to be measured, and the parameters are sparse in the middle of a channel;
the first turbine stage outlet measurement point arrangement scheme is that a section, which is 0.05 to 1 time of the chord length of a blade from the tail edge of a rotor blade after the outlet of a turbine stage to be measured, is selected as an outlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of a single stator blade grid of the turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, different circumferential measuring positions are concentrated in a fan-shaped measuring area of a stator blade grid distance and are dense at positions close to blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and a measuring device is driven to walk through all circumferential measuring positions through a displacement mechanism;
the second turbine stage outlet measurement point arrangement scheme is that a section, which is 0.05 to 1 time of the chord length of the blade from the tail edge of the rotor blade after the outlet of the turbine stage to be measured, is selected as an outlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of the single stator blade grid of the turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, a plurality of measuring devices are used at the same time, the measuring devices are respectively distributed in fan-shaped measuring areas with a plurality of stator blade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas are rotated to the same fan-shaped measuring area by an integral multiple of the angle corresponding to a single stator blade grid distance by taking a turbine axis as a rotation center, the positions close to blades can still be ensured to be dense, parameters in a tail track can be ensured to be measured, and the parameters are sparse in the middle of a channel;
further, carrying out test measurement, mounting the measuring device at the initial position of the turbine stage and the outlet measuring section, adjusting the measured turbine part to enter a test state, measuring and recording pressure sensing hole data and temperature sensor data of each group of measuring points, driving the measuring device to enter the next circumferential position by using the displacement mechanism, and repeating the process until all circumferential measuring positions are reached; when a method of simultaneously measuring by a plurality of measuring devices is adopted, the measuring devices are arranged at respective measuring positions of the turbine stage and the outlet measuring section, the turbine part to be measured is adjusted to enter a test state, and the pressure sensing hole data and the temperature sensor data of each group of measuring points of all the measuring devices are directly recorded;
further, according to data of three pressure sensing holes of each group of measuring points and data of a temperature sensor, a deflection angle coefficient is worked out, and then a calibrated coefficient curve is combined to work out the deflection angle, total pressure, static pressure and Mach number of each measuring point through interpolation; and the incoming flow velocity and density are obtained by the following formulas:
Figure BDA0002375914530000051
Figure BDA0002375914530000052
Figure BDA0002375914530000053
c2＝γRTs
Ps＝ρRTs
wherein p istAnd psIs total pressure and static pressure of the flow field, gamma is adiabatic index of the flow field, TtAnd TsThe total temperature and the static temperature of the flow field, Ma is the Mach number of the flow field, v is the velocity of the flow field, c is the local sound velocity of the flow field, R is a gas constant, and rho is the gas density;
further, the total temperature of the turbine inlet is obtained by using a mass weighting method
Figure BDA0002375914530000061
Inlet total pressure
Figure BDA0002375914530000062
Total outlet temperature
Figure BDA0002375914530000063
Total pressure at the outlet
Figure BDA0002375914530000064
Average value of the parameters, formula is as follows:
Figure BDA0002375914530000065
wherein the content of the first and second substances,
Figure BDA0002375914530000066
is a mass-weighted average of the measured parameters, viIs the velocity value of the ith measurement point, AiIs the area value corresponding to the ith measurement point, αiIs the deflection angle, X, of the ith measurement pointiIs the parameter value of the ith measurement point, and j is the total number of measurement points;
further, the measured turbine stage efficiency is calculated using the following formula:
Figure BDA0002375914530000067
where η is the turbine stage efficiency,
Figure BDA0002375914530000068
and
Figure BDA0002375914530000069
is the total temperature and pressure at the inlet of the turbine stage,
Figure BDA00023759145300000610
and
Figure BDA00023759145300000611
is the total temperature and pressure at the outlet of the turbine stage and gamma is the specific heat ratio of the turbine gas flowing through.
According to the device and the method for accurately measuring the turbine efficiency, the measuring device can obtain a calibration curve after being calibrated through the calibration wind tunnel; in actual measurement, based on data measured by each group of three pressure sensing holes and temperature sensors, total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed and density parameters of a measured two-dimensional steady-state flow field can be simultaneously obtained through data processing according to a calibration coefficient curve and a formula obtained by calibrating a wind tunnel, and the measurement spatial resolution and measurement precision are improved; the measuring method can accurately measure the single-stage and multi-stage efficiency of the turbine by optimizing the measuring point layout and the quality weighting averaging method.
The invention has the beneficial effects that:
the beneficial effects are that:
the device for accurately measuring the efficiency of the turbine stage can realize measurement of total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, pitch angle, speed and density of a flow field between the turbine stages by using a single device, has a compact structure and small size, effectively reduces interference on the measured flow field, and improves test precision; meanwhile, the test operation is simplified, and the test cost is reduced.
The beneficial effects are that:
according to the method for accurately measuring the efficiency of the turbine stage, the system error caused by arithmetic mean and area mean in the conventional method is eliminated through a quality weighting method, the measurement precision of the turbine stage, the total outlet temperature and the total pressure is improved, and the accuracy of the efficiency measurement of the turbine stage is further improved.
The beneficial effects are three:
the device and the method for accurately measuring the efficiency of the turbine stage can accurately measure the efficiency of the turbine stage.
The beneficial effects are four:
the device for accurately measuring the efficiency of the turbine stage can measure the 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 the casing boundary layer.
Drawings
FIG. 1 is a schematic structural diagram of a first-stage inlet measurement device of a high-pressure turbine according to a first embodiment of the invention.
Fig. 2 is a right side view of fig. 1.
Fig. 3 is a left side view of fig. 1.
Fig. 4 is a view in the direction a of fig. 1.
Fig. 5 is a partial cross-sectional view of fig. 2.
Fig. 6 is a schematic structural diagram of a first-stage outlet measuring device of a high-pressure turbine according to a first embodiment of the invention.
Fig. 7 is a right side view of fig. 6.
Fig. 8 is a left side view of fig. 6.
Fig. 9 is a view from direction a of fig. 6.
Fig. 10 is a partial cross-sectional view of fig. 7.
Wherein: 1-head, 2-support rod, 3-hub boundary layer pressure sensing hole, 4-hub boundary layer temperature sensing hole, 5-case boundary layer pressure sensing hole, 6-case boundary layer temperature sensing hole, 7-main runner pressure sensing hole, 8-main runner temperature sensing hole, 9-pressure guiding channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor
Fig. 11 is a schematic view of installation and use of the first embodiment of the present invention.
Wherein: the high-pressure turbine comprises a hub 1, a casing 2, a high-pressure turbine first-stage inlet 3, a high-pressure turbine first-stage stator 4, a high-pressure turbine first-stage rotor 5 and a high-pressure turbine first-stage outlet 6.
FIG. 12 is a schematic view of the arrangement of the inlet test points of the first stage of the high pressure turbine according to the first embodiment of the present invention.
FIG. 13 is a schematic diagram of the arrangement of the first-stage outlet measuring points of the high-pressure turbine according to the first embodiment of the invention.
Wherein: 1-hub, 2-casing, 3-circumferential measuring position, 4-measuring device.
FIG. 14 is a schematic view of a turbine stage inlet measurement device according to a second embodiment of the present invention.
Fig. 15 is a right side view of fig. 14.
Fig. 16 is a left side view of fig. 14.
Fig. 17 is a view from direction a of fig. 14.
Fig. 18 is a partial cross-sectional view of fig. 15.
Fig. 19 is a schematic structural view of a turbine stage outlet measurement device according to a second embodiment of the present invention.
Fig. 20 is a right side view of fig. 19.
Fig. 21 is a left side view of fig. 19.
Fig. 22 is a view from direction a of fig. 19.
Fig. 23 is a partial cross-sectional view of fig. 20.
Wherein: 1-head, 2-support rod, 3-hub boundary layer pressure sensing hole, 4-hub boundary layer temperature sensing hole, 5-case boundary layer pressure sensing hole, 6-case boundary layer temperature sensing hole, 7-main runner pressure sensing hole, 8-main runner temperature sensing hole, 9-pressure guiding channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor
Fig. 24 is a schematic view of installation and use of the second embodiment of the present invention.
Wherein: 1-hub, 2-casing, 3-turbine stage inlet, 4-turbine stage stator, 5-turbine stage rotor, and 6-turbine stage outlet.
FIG. 25 is a schematic view of turbine stage inlet test point arrangement according to the second embodiment of the present invention.
FIG. 26 is a schematic view of the turbine stage outlet station arrangement according to the second embodiment of the present invention.
Wherein: 1-hub, 2-casing, 3-circumferential measuring position, 4-measuring device.
FIG. 27 is a schematic structural diagram of a first-stage inlet measurement device of a high-pressure turbine according to a third embodiment of the invention.
Fig. 28 is a right side view of fig. 27.
Fig. 29 is a left side view of fig. 27.
Fig. 30 is a view from direction a of fig. 27.
Fig. 31 is a partial cross-sectional view of fig. 28.
Fig. 32 is a schematic structural diagram of a first-stage outlet measuring device of a high-pressure turbine according to a third embodiment of the invention.
Fig. 33 is a right side view of fig. 32.
Fig. 34 is a left side view of fig. 32.
Fig. 35 is a view from direction a of fig. 32.
Fig. 36 is a partial cross-sectional view of fig. 33.
Wherein: 1-head, 2-support rod, 3-hub boundary layer pressure sensing hole, 4-hub boundary layer temperature sensing hole, 5-case boundary layer pressure sensing hole, 6-case boundary layer temperature sensing hole, 7-main runner pressure sensing hole, 8-main runner temperature sensing hole, 9-pressure guiding channel, 10-temperature sensor cable, 11-cylinder, 12-left hole, 13-middle hole, 14-right hole, 15-temperature sensing hole, 16-temperature sensor
Fig. 37 is a schematic view of installation and use of the third embodiment of the present invention.
Wherein: the turbine comprises a hub 1, a casing 2, a turbine stage 3, a high-pressure turbine first-stage turbine stator 4, a high-pressure turbine first-stage turbine rotor 5 and a turbine stage 6.
FIG. 38 is a schematic view of the arrangement of the inlet test points of the first stage of the high pressure turbine according to the third embodiment of the present invention.
FIG. 39 is a schematic diagram of the arrangement of the first-stage outlet measuring points of the high-pressure turbine according to the third embodiment of the invention.
Wherein: 1-hub, 2-casing, 3-circumferential measuring position, 4-measuring device.
Detailed Description
The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the invention.
Example one
For the inlet and the outlet of the first stage of the high-pressure turbine, the axial and radial dimensions are small, the flow condition is complex, the incoming flow possibly contains impurities such as combustion products of a combustion chamber, the head and the support rod of the device are selected to have relatively small dimensions so as to reduce the blockage of a flow field as much as possible, but the sensing hole is selected to have relatively large aperture to avoid the blockage of the impurities on the premise of ensuring the spatial resolution, and less measuring point positions are selected due to the spatial limitation, so the following implementation case can be adopted when the efficiency of the first stage of the high-pressure turbine is measured:
an apparatus and method for accurately measuring turbine stage efficiency, characterized by:
the measuring device comprises a head (1), a support rod (2), a hub boundary layer pressure sensing hole (3), a hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5), a casing boundary layer temperature sensing hole (6), a main runner pressure sensing hole (7), a main runner 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 strut (2);
the pressure sensing device is characterized in that multiple rows of pressure sensing holes are formed in the same side surface of a cylinder (11) of the head (1) along the axial direction, each row of pressure sensing holes comprises three pressure sensing holes which are close to each other but are not communicated with each other, namely a left hole (12), a middle hole (13) and a right hole (14), the central lines of the three pressure sensing holes are located in the same plane, and the central lines of the left hole (12) and the right hole (14) are symmetrically distributed on the plane relative to the central line of the middle hole (13);
a plurality of rows of temperature sensing holes are formed in the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes comprises a temperature sensing hole (15), and the center line of each row of temperature sensing holes is parallel to the center line of the hole (13) in the pressure sensing hole;
the pressure sensing hole is communicated with one end of the pressure guide channel (9) which is encapsulated in the head part (1); the temperature sensing hole is only directly communicated with a temperature sensor (16), and the temperature sensor adopts a Pt100 thermal resistor; the pressure guide channel (9) and a cable (10) of the temperature sensor are led out of the tail part through a pipeline in the support rod (2);
the pressure sensing hole (3) of the hub boundary layer is close to the end face of the head (1), the distance between the circle center and the end face of the head (1) is 0.5 mm, the diameter is 0.5 mm, and the circumferential included angle of 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) of the measuring device is 30 degrees;
the hub boundary layer temperature sensing hole (4) is positioned below the center hole (13) of the hub boundary layer pressure sensing hole (3), the distance between the circle center and the center hole (13) of the hub boundary layer pressure sensing hole (3) is 0.6 mm, and the diameter is 0.5 mm;
the pressure sensing hole (5) of the casing boundary layer is close to the interface of the head (1) and the support rod (2), the distance between the pressure sensing hole and the interface of the head (1) and the support rod (2) is 0.5 mm, the diameter of the pressure sensing hole is 0.5 mm, and the circumferential included angle between the central line of the left hole (12) and the central line of the right hole (14) on the surface of the cylinder (11) of the head (1) of the measuring device is 30 degrees;
the temperature sensing hole (4) of the casing boundary layer is positioned above the center hole (13) of the pressure sensing hole (3) of the casing boundary layer, the distance between the circle center and the center hole (13) of the pressure sensing hole (3) of the casing boundary layer is 0.6 mm, and the diameter is 0.5 mm;
the main runner pressure sensing hole (7) is positioned between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), the diameter of the main runner pressure sensing hole is 0.5 mm, and the circumferential included 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) of the measuring device is 30 degrees;
the main runner temperature sensing hole (8) is positioned below the center hole (13) of the main runner pressure sensing hole (7), the distance between the center of the circle and the center hole (13) of the main runner pressure sensing hole (3) is 0.6 mm, and the diameter is 0.5 mm;
the diameter of the head (1) and the length of the cylinder (11) are 2.5 mm and 20 mm;
the measuring method comprises the steps of calibrating a device for accurately measuring the efficiency of a turbine stage, and enabling 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 3 pressure sensing holes in each row of a plurality of 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 one row of adjacent pressure sensing holes and one row of adjacent temperature sensing holes as a group of measuring points;
defining the left hole (12) as the measured pressure P1The mesopore (13) measuring pressure is P2The right hole (14) measures pressure P3The temperature sensor measures a temperature TpTotal pressure of incoming flow is PtIncoming static pressure of PsTotal temperature of incoming flow TtComing stream static temperature TsTherefore, the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient under different incoming flow Mach numbers can be obtained;
total pressure coefficient:
Figure BDA0002375914530000101
static pressure coefficient:
Figure BDA0002375914530000102
deflection angle coefficient:
Figure BDA0002375914530000103
total temperature recovery coefficient:
Figure BDA0002375914530000104
therefore, calibration curves of the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient of the device under different Mach numbers and different deflection angles can be obtained;
the turbine stage inlet measurement point arrangement scheme is that a section of a turbine stage inlet to be measured, which is 1 time of blade chord length from the front edge of a stator blade, is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of a single stator blade grid of a turbine stage; 4 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 7 measurement positions are circumferentially arranged, different circumferential measurement positions are concentrated in a fan-shaped measurement area of the grid pitch of the stator blade grids, the measurement positions are dense at positions close to the blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and the measurement device is driven to walk through all the circumferential measurement positions through a displacement mechanism;
the arrangement scheme of the measured turbine stage outlet measuring points is that a section, which is 0.2 times of the chord length of the blade from the tail edge of the rotor blade after the outlet of the measured turbine stage, is selected as an outlet testing section, and the testing section is divided into a plurality of fan-shaped measuring areas according to the grid pitch of the single stator blade grid of the turbine stage; 5 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 7 measurement positions are circumferentially arranged, different circumferential measurement positions are concentrated in a fan-shaped measurement area of the grid pitch of the stator blade grids, the measurement positions are dense at positions close to the blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and the measurement device is driven to walk through all the circumferential measurement positions through a displacement mechanism;
further, carrying out test measurement, mounting the measuring device at the initial position of the turbine stage and the outlet measuring section, adjusting the measured turbine part to enter a test state, measuring and recording pressure sensing hole data and temperature sensor data of each group of measuring points, driving the measuring device to enter the next circumferential position by using the displacement mechanism, and repeating the process until all circumferential measuring positions are reached;
further, according to data of three pressure sensing holes of each group of measuring points and data of a temperature sensor, a deflection angle coefficient is worked out, and then a calibrated coefficient curve is combined to work out the deflection angle, total pressure, static pressure and Mach number of each measuring point through interpolation; and the incoming flow velocity and density are obtained by the following formulas:
Figure BDA0002375914530000111
Figure BDA0002375914530000112
Figure BDA0002375914530000113
c2＝γRTs
Ps＝ρRTs
wherein p istAnd psIs total pressure and static pressure of the flow field, gamma is adiabatic index of the flow field, TtAnd TsThe total temperature and the static temperature of the flow field, Ma is the Mach number of the flow field, v is the velocity of the flow field, c is the local sound velocity of the flow field, R is a gas constant, and rho is the gas density;
further, the total temperature of the first-stage inlet of the high-pressure turbine is obtained by using a mass weighting method
Figure BDA0002375914530000114
Inlet total pressure
Figure BDA0002375914530000115
Total outlet temperature
Figure BDA0002375914530000121
Total pressure at the outlet
Figure BDA0002375914530000122
Average value of the parameters, formula is as follows:
Figure BDA0002375914530000123
wherein the content of the first and second substances,
Figure BDA0002375914530000124
is a mass-weighted average of the measured parameters, viIs the velocity value of the ith measurement point, AiIs the area value corresponding to the ith measurement point, αiIs the deflection angle, X, of the ith measurement pointiIs the parameter value of the ith measurement point, and j is the total number of measurement points;
further, the measured turbine stage efficiency is calculated using the following formula:
Figure BDA0002375914530000125
where η is the turbine stage efficiency,
Figure BDA0002375914530000126
and
Figure BDA0002375914530000127
is the total temperature and total pressure of the inlet of the first stage of the high-pressure turbine,
Figure BDA0002375914530000128
and
Figure BDA0002375914530000129
is the total temperature and pressure at the outlet of the first stage of the high pressure turbine, and gamma is the specific heat ratio of the gas flowing through the turbine.
Example two
For the turbine stage rear stage and the turbine stage rear outlet, the axial and radial sizes are larger, the incoming flow velocity is faster, the difference of the flow state between different positions is large, therefore, more measuring positions can be selected to improve the overall accuracy of the test, in addition, the head and the support rod of the device need to ensure the strength and the rigidity when the sizes are selected, and the pressure sensing hole selects a larger aperture to avoid the blockage of impurities from a combustion chamber, therefore, the following implementation case can be adopted when the turbine efficiency of the whole machine is measured:
an apparatus and method for accurately measuring turbine stage efficiency, characterized by:
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 runner pressure sensing hole (7) and a 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 strut (2);
the pressure sensing device is characterized in that multiple rows of pressure sensing holes are formed in the same side surface of a cylinder (11) of the head (1) along the axial direction, each row of pressure sensing holes comprises three pressure sensing holes which are close to each other but are not communicated with each other, namely a left hole (12), a middle hole (13) and a right hole (14), the central lines of the three pressure sensing holes are located in the same plane, the central lines of the left hole (12) and the right hole (14) are symmetrically distributed on the plane relative to the central line of the middle hole (13), and the intersection point of the central lines is located on the axial line of the head (1);
a plurality of rows of temperature sensing holes are formed in the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes comprises a temperature sensing hole (15), and the center line of each row of temperature sensing holes is parallel to the center line of the hole (13) in the pressure sensing hole;
the pressure sensing hole is communicated with one end of the pressure guide channel (9) which is encapsulated in the head part (1); the temperature sensing hole is only directly communicated with a temperature sensor, and the temperature sensor is a Pt100 thermal resistor; the pressure guide channel (9) and a cable (10) of the temperature sensor are led out of the tail part through a pipeline in the support rod (2);
the pressure sensing hole (3) of the hub boundary layer is close to the end face of the head (1), the distance between the circle center and the end face of the head (1) is 0.8 mm, the diameter is 0.8 mm, and the circumferential included angle of 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) of the measuring device is 30 degrees;
the hub boundary layer temperature sensing hole (4) is positioned below the center hole (13) of the hub boundary layer pressure sensing hole (3), the distance between the circle center and the center hole (13) of the hub boundary layer pressure sensing hole (3) is 1 mm, and the diameter is 0.8 mm;
the pressure sensing hole (5) of the casing boundary layer is close to the interface of the head (1) and the support rod (2), the distance between the pressure sensing hole and the interface of the head (1) and the support rod (2) is 0.8 mm, the diameter of the pressure sensing hole is 0.8 mm, and the circumferential included 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) of the measuring device is 30 degrees;
the temperature sensing hole (4) of the casing boundary layer is positioned above the center hole (13) of the pressure sensing hole (3) of the casing boundary layer, the distance between the circle center and the center hole (13) of the pressure sensing hole (3) of the casing boundary layer is 1 mm, and the diameter is 0.8 mm;
the main runner pressure sensing hole (7) is positioned between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), the diameter of the main runner pressure sensing hole is 0.8 mm, and the circumferential included 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) of the measuring device is 30 degrees;
the main runner temperature sensing hole (8) is positioned below a center hole (13) of the main runner pressure sensing hole (7), the distance between the center of the circle and the center of the center hole (13) of the main runner pressure sensing hole (3) is 1 mm, and the diameter is 0.8 mm;
the diameter of the head (1) and the cylinder (11) is 4 mm, and the length of the head (1) and the cylinder (11) is 200 mm;
the measuring method comprises the steps of calibrating a device for accurately measuring the efficiency of a turbine stage, and enabling incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, speed and total temperature; recording the pressure of 3 pressure sensing holes in each row of a plurality of 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 one row of adjacent pressure sensing holes and one row of adjacent temperature sensing holes as a group of measuring points;
defining the left hole (12) as the measured pressure P1The mesopore (13) measuring pressure is P2The right hole (14) measures pressure P3Temperature sensor measuring temperatureDegree of TpTotal pressure of incoming flow is PtIncoming static pressure of PsTotal temperature of incoming flow TtComing stream static temperature TsTherefore, the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient under different incoming flow Mach numbers can be obtained;
total pressure coefficient:
Figure BDA0002375914530000131
static pressure coefficient:
Figure BDA0002375914530000132
deflection angle coefficient:
Figure BDA0002375914530000133
total temperature recovery coefficient:
Figure BDA0002375914530000141
therefore, calibration curves of the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient of the device under different Mach numbers and different deflection angles can be obtained;
the turbine stage inlet measurement point arrangement scheme is that a section of a turbine stage inlet front distance of 0.3 times of blade chord length of a stator blade front edge is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to a turbine stage single stator blade grid distance; 5 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 9 measurement positions are circumferentially arranged, different circumferential measurement positions are concentrated in a fan-shaped measurement area of the grid pitch of the stator blade grids and are dense at positions close to the blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and the measurement device is driven to walk through all the circumferential measurement positions through a displacement mechanism;
the arrangement scheme of the measured turbine stage outlet measuring points is that a section, which is 0.5 times of the chord length of the blade from the tail edge of the rotor blade after the outlet of the measured turbine stage is selected as an outlet testing section, and the testing section is divided into a plurality of fan-shaped measuring areas according to the grid pitch of the single stator blade grid of the turbine stage; 7 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 9 measurement positions are circumferentially arranged, different circumferential measurement positions are concentrated in a fan-shaped measurement area of the grid pitch of the stator blade grids and are dense at positions close to the blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and the measurement device is driven to walk through all the circumferential measurement positions through a displacement mechanism;
further, carrying out test measurement, mounting the measuring device at the initial position of the turbine stage and the outlet measuring section, adjusting the measured turbine part to enter a test state, measuring and recording pressure sensing hole data and temperature sensor data of each group of measuring points, driving the measuring device to enter the next circumferential position by using the displacement mechanism, and repeating the process until all circumferential measuring positions are reached;
further, according to data of three pressure sensing holes of each group of measuring points and data of a temperature sensor, a deflection angle coefficient is worked out, and then a calibrated coefficient curve is combined to work out the deflection angle, total pressure, static pressure and Mach number of each measuring point through interpolation; the incoming flow velocity and density are obtained by the following formulas:
Figure BDA0002375914530000142
Figure BDA0002375914530000143
Figure BDA0002375914530000144
c2＝γRTs
Ps＝ρRTs
wherein p istAnd psIs total pressure and static pressure of the flow field, gamma is adiabatic index of the flow field, TtAnd TsIs the total temperature and static temperature of the flow field, Ma is the Mach number of the flow field, v is the flowThe field velocity, c is the local acoustic velocity of the flow field, R is the gas constant, and ρ is the gas density;
further, the total temperature of the inlet of the turbine stage is obtained by using a mass weighting method
Figure BDA0002375914530000151
Inlet total pressure
Figure BDA0002375914530000152
Total outlet temperature
Figure BDA0002375914530000153
Total pressure at the outlet
Figure BDA0002375914530000154
Average value of the parameters, formula is as follows:
Figure BDA0002375914530000155
wherein the content of the first and second substances,
Figure BDA0002375914530000156
is a mass-weighted average of the measured parameters, viIs the velocity value of the ith measurement point, AiIs the area value corresponding to the ith measurement point, αiIs the deflection angle, X, of the ith measurement pointiIs the parameter value of the ith measurement point, and j is the total number of measurement points;
further, the measured turbine stage efficiency is calculated using the following formula:
Figure BDA0002375914530000157
where η is the turbine stage efficiency,
Figure BDA0002375914530000158
and
Figure BDA0002375914530000159
is the total temperature and pressure at the inlet of the turbine stage,
Figure BDA00023759145300001510
and
Figure BDA00023759145300001511
is the total temperature and pressure at the outlet of the turbine stage and gamma is the specific heat ratio of the turbine gas flowing through.
EXAMPLE III
For the inlet and the outlet of the first stage of the high-pressure turbine, the axial and radial dimensions are small, the flow condition is complex, the incoming flow possibly contains impurities such as combustion products of a combustion chamber, the head and the support rod of the device are selected to have relatively small dimensions so as to reduce the blockage of a flow field as much as possible, but the sensing hole is selected to have relatively large aperture to avoid the blockage of the impurities on the premise of ensuring the spatial resolution, and less measuring point positions are selected due to the spatial limitation, so the following implementation case can be adopted when the efficiency of the first stage of the high-pressure turbine is measured:
an apparatus and method for accurately measuring turbine stage efficiency, characterized by:
the measuring device comprises a head (1), a support rod (2), a hub boundary layer pressure sensing hole (3), a hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5), a casing boundary layer temperature sensing hole (6), a main runner pressure sensing hole (7), a main runner 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 strut (2);
the pressure sensing device is characterized in that multiple rows of pressure sensing holes are formed in the same side surface of a cylinder (11) of the head (1) along the axial direction, each row of pressure sensing holes comprises three pressure sensing holes which are close to each other but are not communicated with each other, namely a left hole (12), a middle hole (13) and a right hole (14), the central lines of the three pressure sensing holes are located in the same plane, and the central lines of the left hole (12) and the right hole (14) are symmetrically distributed on the plane relative to the central line of the middle hole (13);
a plurality of rows of temperature sensing holes are formed in the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes comprises a temperature sensing hole (15), and the center line of each row of temperature sensing holes is parallel to the center line of the hole (13) in the pressure sensing hole;
the pressure sensing hole is communicated with one end of the pressure guide channel (9) which is encapsulated in the head part (1); the temperature sensing hole is only directly communicated with a temperature sensor (16), and the temperature sensor adopts a Pt100 thermal resistor; the pressure guide channel (9) and a cable (10) of the temperature sensor are led out of the tail part through a pipeline in the support rod (2);
the pressure sensing hole (3) of the hub boundary layer is close to the end face of the head (1), the distance between the circle center and the end face of the head (1) is 0.5 mm, the diameter is 0.5 mm, and the circumferential included angle of 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) of the measuring device is 30 degrees;
the hub boundary layer temperature sensing hole (4) is positioned below the center hole (13) of the hub boundary layer pressure sensing hole (3), the distance between the circle center and the center hole (13) of the hub boundary layer pressure sensing hole (3) is 0.6 mm, and the diameter is 0.5 mm;
the pressure sensing hole (5) of the casing boundary layer is close to the interface of the head (1) and the support rod (2), the distance between the pressure sensing hole and the interface of the head (1) and the support rod (2) is 0.5 mm, the diameter of the pressure sensing hole is 0.5 mm, and the circumferential included angle between the central line of the left hole (12) and the central line of the right hole (14) on the surface of the cylinder (11) of the head (1) of the measuring device is 30 degrees;
the temperature sensing hole (4) of the casing boundary layer is positioned above the center hole (13) of the pressure sensing hole (3) of the casing boundary layer, the distance between the circle center and the center hole (13) of the pressure sensing hole (3) of the casing boundary layer is 0.6 mm, and the diameter is 0.5 mm;
the main runner pressure sensing hole (7) is positioned between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), the diameter of the main runner pressure sensing hole is 0.5 mm, and the circumferential included 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) of the measuring device is 30 degrees;
the main runner temperature sensing hole (8) is positioned below the center hole (13) of the main runner pressure sensing hole (7), the distance between the center of the circle and the center hole (13) of the main runner pressure sensing hole (3) is 0.6 mm, and the diameter is 0.5 mm;
the diameter of the head (1) and the length of the cylinder (11) are 2.5 mm and 20 mm;
the measuring method comprises the steps of calibrating a device for accurately measuring the efficiency of a turbine stage, and enabling 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 3 pressure sensing holes in each row of a plurality of 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 one row of adjacent pressure sensing holes and one row of adjacent temperature sensing holes as a group of measuring points;
defining the left hole (12) as the measured pressure P1The mesopore (13) measuring pressure is P2The right hole (14) measures pressure P3The temperature sensor measures a temperature TpTotal pressure of incoming flow is PtIncoming static pressure of PsTotal temperature of incoming flow TtComing stream static temperature TsTherefore, the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient under different incoming flow Mach numbers can be obtained;
total pressure coefficient:
Figure BDA0002375914530000161
static pressure coefficient:
Figure BDA0002375914530000162
deflection angle coefficient:
Figure BDA0002375914530000163
total temperature recovery coefficient:
Figure BDA0002375914530000171
therefore, calibration curves of the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient of the device under different Mach numbers and different deflection angles can be obtained;
the turbine stage inlet measurement point arrangement scheme is that a section of a turbine stage inlet to be measured, which is 1 time of blade chord length from the front edge of a stator blade, is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of a single stator blade grid of a turbine stage; 4 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 7 measuring positions are circumferentially arranged, a plurality of measuring devices are used simultaneously and are respectively distributed in a plurality of fan-shaped measuring areas with the stator blade cascade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas rotate to the same fan-shaped measuring area by taking the turbine axis as the rotation center by an integral multiple of the angle corresponding to the single stator blade cascade grid distance, the circumferential measuring positions can still be ensured to be dense at the positions close to the blades, the parameters in the measured trail can be ensured to be sparse in the middle of a channel;
the arrangement scheme of the measured turbine stage outlet measuring points is that a section, which is 0.2 times of the chord length of the blade from the tail edge of the rotor blade after the outlet of the measured turbine stage, is selected as an outlet testing section, and the testing section is divided into a plurality of fan-shaped measuring areas according to the grid pitch of the single stator blade grid of the turbine stage; 5 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; 7 measuring positions are circumferentially arranged, a plurality of measuring devices are used simultaneously and are respectively distributed in a plurality of fan-shaped measuring areas with the stator blade cascade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas rotate to the same fan-shaped measuring area by taking the turbine axis as the rotation center by an integral multiple of the angle corresponding to the single stator blade cascade grid distance, the circumferential measuring positions can still be ensured to be dense at the positions close to the blades, the parameters in the measured trail can be ensured to be sparse in the middle of a channel;
further, carrying out test measurement, mounting the measuring devices at respective measuring positions of the turbine stage and the outlet measuring section, adjusting the tested turbine part to enter a test state, and directly recording pressure sensing hole data and temperature sensor data of each group of measuring points of all the measuring devices;
further, according to data of three pressure sensing holes of each group of measuring points and data of a temperature sensor, a deflection angle coefficient is worked out, and then a calibrated coefficient curve is combined to work out the deflection angle, total pressure, static pressure and Mach number of each measuring point through interpolation; and the incoming flow velocity and density are obtained by the following formulas:
Figure BDA0002375914530000181
Figure BDA0002375914530000182
Figure BDA0002375914530000183
c2＝γRTs
Ps＝ρRTs
wherein p istAnd psIs total pressure and static pressure of the flow field, gamma is adiabatic index of the flow field, TtAnd TsThe total temperature and the static temperature of the flow field, Ma is the Mach number of the flow field, v is the velocity of the flow field, c is the local sound velocity of the flow field, R is a gas constant, and rho is the gas density;
further, the total temperature of the first-stage inlet of the high-pressure turbine is obtained by using a mass weighting method
Figure BDA0002375914530000184
Inlet total pressure
Figure BDA0002375914530000185
Total outlet temperature
Figure BDA0002375914530000186
Total pressure at the outlet
Figure BDA0002375914530000187
Average value of the parameters, formula is as follows:
Figure BDA0002375914530000188
wherein the content of the first and second substances,
Figure BDA0002375914530000189
is a mass-weighted average of the measured parameters, viIs the velocity value of the ith measurement point, AiIs the area corresponding to the ith measurement pointValue, αiIs the deflection angle, X, of the ith measurement pointiIs the parameter value of the ith measurement point, and j is the total number of measurement points;
further, the measured turbine stage efficiency is calculated using the following formula:
Figure BDA00023759145300001810
where η is the turbine stage efficiency,
Figure BDA00023759145300001811
and
Figure BDA00023759145300001812
is the total temperature and total pressure of the inlet of the first stage of the high-pressure turbine,
Figure BDA00023759145300001813
and
Figure BDA00023759145300001814
is the total temperature and pressure at the outlet of the first stage of the high pressure turbine, and gamma is the specific heat ratio of the gas flowing through the turbine.

Claims (1)

1. An apparatus and method for accurately measuring turbine stage efficiency, characterized by:
the measuring device comprises a head (1), a support rod (2), a hub boundary layer pressure sensing hole (3), a hub boundary layer temperature sensing hole (4), a casing boundary layer pressure sensing hole (5), a casing boundary layer temperature sensing hole (6), a main runner pressure sensing hole (7), a main runner 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 strut (2);
the pressure sensing device is characterized in that multiple rows of pressure sensing holes are formed in the same side surface of a cylinder (11) of the head (1) along the axial direction, each row of pressure sensing holes comprises three pressure sensing holes which are close to each other but are not communicated with each other, namely a left hole (12), a middle hole (13) and a right hole (14), the central lines of the three pressure sensing holes are located in the same plane, and the central lines of the left hole (12) and the right hole (14) are symmetrically distributed on the plane relative to the central line of the middle hole (13);
a plurality of rows of temperature sensing holes are formed in the same side surface of the cylinder (11) of the head (1) along the axial direction, each row of temperature sensing holes comprises a temperature sensing hole (15), and the center line of each row of temperature sensing holes is parallel to the center line of the hole (13) in the pressure sensing hole;
the pressure sensing hole is communicated with one end of the pressure guide channel (9) which is encapsulated in the head part (1); the temperature sensing hole is only directly communicated with a temperature sensor (16), and the temperature sensor can be a bare wire thermocouple, an armored thermocouple, a thermal resistor, an optical fiber sensor and the like; the pressure guide channel (9) and a cable (10) of the temperature sensor are led out of the tail part through a pipeline in the support rod (2);
the pressure sensing hole (3) of the hub boundary layer is close to the end face of the head (1), the distance between the circle center 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 included 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 degrees to 60 degrees;
the hub boundary layer temperature sensing hole (4) is positioned below the center hole (13) of the hub boundary layer pressure sensing hole (3), the distance between the circle center and the center hole (13) of the hub boundary layer pressure sensing hole (3) is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the pressure sensing hole (5) of the casing boundary layer is close to the interface of the head (1) and the support rod (2), the distance from the interface of the head (1) and the support rod (2) is 0.5 mm to 5 mm, the diameter is 0.2 mm to 1.5 mm, and the circumferential included angle of 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 degrees to 60 degrees;
the temperature sensing hole (4) of the casing boundary layer is positioned above the center hole (13) of the pressure sensing hole (3) of the casing boundary layer, the distance between the circle center and the center hole (13) of the pressure sensing hole (3) of the casing boundary layer is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the main runner pressure sensing hole (7) is positioned between the hub boundary layer temperature sensing hole (4) and the casing boundary layer pressure sensing hole (5), the diameter is 0.2 mm to 1.5 mm, and the circumferential included 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 degrees to 60 degrees;
the main runner temperature sensing hole (8) is positioned below a center hole (13) of the main runner pressure sensing hole (7), the distance between the center of the circle and the center of the center hole (13) of the main runner pressure sensing hole (3) is 0.5 mm to 2 mm, and the diameter is 0.5 mm to 2 mm;
the diameter of the head (1) cylinder (11) is 2 mm to 8 mm, and the length of the head (1) cylinder is 10 mm to 400 mm;
the measuring method comprises the steps of calibrating a device for accurately measuring the efficiency of a turbine stage, and enabling incoming flow to flow through the measuring device in a standard wind tunnel with known incoming flow Mach number, speed and total temperature; recording the pressure of three pressure sensing holes in each row of a plurality of 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 the adjacent rows of pressure sensing holes and temperature sensing holes as a group of measuring points;
defining the left hole (12) as the measured pressure P1The mesopore (13) measuring pressure is P2The right hole (14) measures pressure P3The temperature sensor measures a temperature TpTotal pressure of incoming flow is PtIncoming static pressure of PsTotal temperature of incoming flow TtComing stream static temperature TsTherefore, the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient under different incoming flow Mach numbers can be obtained;
total pressure coefficient:
Figure FDA0002375914520000021
static pressure coefficient:
Figure FDA0002375914520000022
deflection angle coefficient:
Figure FDA0002375914520000023
total temperature recovery coefficient:
Figure FDA0002375914520000024
therefore, calibration curves of the total pressure coefficient, the static pressure coefficient, the deflection angle coefficient and the total temperature recovery coefficient of the device under different Mach numbers and different deflection angles can be obtained;
the first tested turbine stage inlet measuring point arrangement scheme is that a section of a tested turbine stage inlet front distance from the stator blade front edge by 0.05-1.5 times of blade chord length is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measuring areas according to the turbine stage single stator blade grid distance; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, different circumferential measuring positions are concentrated in a fan-shaped measuring area of a stator blade grid distance and are dense at positions close to blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and a measuring device is driven to walk through all circumferential measuring positions through a displacement mechanism;
the second turbine stage inlet measurement point arrangement scheme is that a section of a turbine stage inlet front distance between 0.05 and 1.5 times of blade chord length of a stator blade front edge is selected as an inlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to a single stator blade grid pitch of a turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, a plurality of measuring devices are used at the same time, the measuring devices are respectively distributed in fan-shaped measuring areas with a plurality of stator blade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas are rotated to the same fan-shaped measuring area by an integral multiple of the angle corresponding to a single stator blade grid distance by taking a turbine axis as a rotation center, the positions close to blades can still be ensured to be dense, parameters in a tail track can be ensured to be measured, and the parameters are sparse in the middle of a channel;
the first turbine stage outlet measurement point arrangement scheme is that a section, which is 0.05 to 1 time of the chord length of a blade from the tail edge of a rotor blade after the outlet of a turbine stage to be measured, is selected as an outlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of a single stator blade grid of the turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, different circumferential measuring positions are concentrated in a fan-shaped measuring area of a stator blade grid distance and are dense at positions close to blades, parameters in a measured trail are guaranteed to be sparse in the middle of a channel, and a measuring device is driven to walk through all circumferential measuring positions through a displacement mechanism;
the second turbine stage outlet measurement point arrangement scheme is that a section, which is 0.05 to 1 time of the chord length of the blade from the tail edge of the rotor blade after the outlet of the turbine stage to be measured, is selected as an outlet test section, and the test section is divided into a plurality of fan-shaped measurement areas according to the grid pitch of the single stator blade grid of the turbine stage; 3-9 groups of measuring points are arranged on a single testing device, and are densely arranged at positions close to a hub and a casing, so that parameters in a boundary layer are guaranteed to be measured; the method comprises the following steps that 5-10 measuring positions are arranged in the circumferential direction, a plurality of measuring devices are used at the same time, the measuring devices are respectively distributed in fan-shaped measuring areas with a plurality of stator blade grid distances, so that at most one circumferential measuring position exists in each measuring fan-shaped measuring area, and when the circumferential measuring positions in the different fan-shaped measuring areas are rotated to the same fan-shaped measuring area by an integral multiple of the angle corresponding to a single stator blade grid distance by taking a turbine axis as a rotation center, the positions close to blades can still be ensured to be dense, parameters in a tail track can be ensured to be measured, and the parameters are sparse in the middle of a channel;
further, carrying out test measurement, mounting the measuring device at the initial position of the turbine stage and the outlet measuring section, adjusting the measured turbine part to enter a test state, measuring and recording pressure sensing hole data and temperature sensor data of each group of measuring points, driving the measuring device to enter the next circumferential position by using the displacement mechanism, and repeating the process until all circumferential measuring positions are reached; when a method of simultaneously measuring by a plurality of measuring devices is adopted, the measuring devices are arranged at respective measuring positions of the turbine stage and the outlet measuring section, the turbine part to be measured is adjusted to enter a test state, and the pressure sensing hole data and the temperature sensor data of each group of measuring points of all the measuring devices are directly recorded;
further, according to data of three pressure sensing holes of each group of measuring points and data of a temperature sensor, a deflection angle coefficient is worked out, and then a calibrated coefficient curve is combined to work out the deflection angle, total pressure, static pressure and Mach number of each measuring point through interpolation; and the incoming flow velocity and density are obtained by the following formulas:
Figure FDA0002375914520000031
Figure FDA0002375914520000032
Figure FDA0002375914520000033
c2＝γRTs
Ps＝ρRTs
wherein p istAnd psIs total pressure and static pressure of the flow field, gamma is adiabatic index of the flow field, TtAnd TsThe total temperature and the static temperature of the flow field, Ma is the Mach number of the flow field, v is the velocity of the flow field, c is the local sound velocity of the flow field, R is a gas constant, and rho is the gas density;
further, the total temperature of the turbine inlet is obtained by using a mass weighting method
Figure FDA0002375914520000041
Inlet total pressure
Figure FDA0002375914520000042
Total outlet temperature
Figure FDA0002375914520000043
Total pressure at the outlet
Figure FDA0002375914520000044
Average value of the parameters, formula is as follows:
Figure FDA0002375914520000045
wherein the content of the first and second substances,
Figure FDA0002375914520000046
is a mass-weighted average of the measured parameters, viIs the velocity value of the ith measurement point, AiIs the area value corresponding to the ith measurement point, αiIs the deflection angle, X, of the ith measurement pointiIs the parameter value of the ith measurement point, and j is the total number of measurement points;
further, the measured turbine stage efficiency is calculated using the following formula:
Figure FDA0002375914520000047
where η is the turbine stage efficiency,
Figure FDA0002375914520000048
and
Figure FDA0002375914520000049
is the total temperature and pressure at the inlet of the turbine stage,
Figure FDA00023759145200000410
and
Figure FDA00023759145200000411
is the total temperature and total pressure at the outlet of the turbine stage, and γ is the specific heat ratio of the turbine gas flowing through;
according to the device and the method for accurately measuring the turbine efficiency, the measuring device can obtain a calibration curve after being calibrated through the calibration wind tunnel; in actual measurement, based on data measured by each group of three pressure sensing holes and temperature sensors, total temperature, total pressure, static temperature, static pressure, Mach number, deflection angle, speed and density parameters of a measured two-dimensional steady-state flow field can be simultaneously obtained through data processing according to a calibration coefficient curve and a formula obtained by calibrating a wind tunnel; the measurement spatial resolution and the measurement precision are improved; the measuring method can accurately measure the single-stage efficiency of the turbine by optimizing the measuring point layout and the quality weighting averaging method.
CN202010065744.7A 2020-01-20 2020-01-20 Device and method for accurately measuring turbine stage efficiency Pending CN111089669A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115356115A (en) * 2022-10-24 2022-11-18 中国航发四川燃气涡轮研究院 Layout method for mainstream flow field fine test in core machine environment
CN117521563A (en) * 2024-01-08 2024-02-06 中国空气动力研究与发展中心计算空气动力研究所 Pneumatic data processing method based on impeller mechanical turbulence wall distance calculation

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115356115A (en) * 2022-10-24 2022-11-18 中国航发四川燃气涡轮研究院 Layout method for mainstream flow field fine test in core machine environment
CN117521563A (en) * 2024-01-08 2024-02-06 中国空气动力研究与发展中心计算空气动力研究所 Pneumatic data processing method based on impeller mechanical turbulence wall distance calculation
CN117521563B (en) * 2024-01-08 2024-03-15 中国空气动力研究与发展中心计算空气动力研究所 Pneumatic data processing method based on impeller mechanical turbulence wall distance calculation

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