DE102020200937A1 - MEASURING PROBE FOR A FLOW MACHINE - Google Patents

Abstract

The present invention relates to a measuring probe (20) for flow and / or pressure measurement, with a sensor (23) for flow and / or pressure measurement, a first probe part (31) which has a first and a second opening (31.1, 31.2 ), and a second probe part (32) which defines a fluidic access (32.3) to the sensor (23), the first and second probe parts (31, 32) being assembled so that they can be relatively displaced in such a way that in a first relative position the first The opening (31.1) of the first probe part (31) is fluidically connected to the sensor (23) via the second probe part (32); and in a second relative position the second opening (31.2) of the first probe part (31) is fluidically connected to the sensor (23) via the second probe part (32).

Description

Technical area

The present invention relates to a measuring probe for pressure and / or flow measurement, in particular in a turbo machine.

State of the art

An axial flow machine is functionally divided into a compressor, combustion chamber and turbine, whereby in the case of an aircraft engine, the air sucked in is compressed in the compressor and burned in the downstream combustion chamber with added kerosene. The resulting hot gas, a mixture of combustion gas and air, flows through the downstream turbine and is expanded in the process. As a rule, the turbine and the compressor each have a multi-stage design, each stage comprising a stator and a rotor. The stators and rotors are each made up of a plurality of blades following one another around the circumference, around which the gas channel flows, that is to say, depending on the area of application, the compressor or hot gas.

The present subject is directed to a measuring probe for pressure or flow measurement, in particular in the gas duct. For this purpose, the measuring probe can, for example, be introduced into the gas duct via a corresponding opening and measurements can then be made in different annular space positions. This is intended to illustrate the subject matter at hand, but not initially to limit its generality.

Presentation of the invention

The present invention is based on the technical problem of specifying an advantageous measuring probe.

• - in einer ersten Relativposition die erste Öffnung des ersten Sondenteils fluidisch mit dem Sensor verbinden; und
• - in einer zweiten Relativposition die zweite Öffnung des ersten Sondenteils fluidisch mit dem Sensor verbinden.

This is achieved according to the invention with the measuring probe according to claim 1. In addition to the sensor for flow and / or pressure measurement, it has a first probe part that forms a first and a second opening. As explained in detail below, the space to be measured (e.g. the gas duct) can optionally be measured via the first or second opening with the present measuring probe, i.e. a fluidic connection to the sensor can optionally be established via one of the openings. For this purpose, the measuring probe additionally has a second probe part, which defines the fluidic access to the sensor and is assembled with the first probe part so that it can be moved relative to one another. By moving the two parts of the probe relative to one another, the second part of the probe

• - in a first relative position fluidly connect the first opening of the first probe part to the sensor; and
• - Connect the second opening of the first probe part fluidly to the sensor in a second relative position.

In the first relative position, the sensor is connected to the measuring space exclusively via the first opening, and in the second relative position exclusively via the second opening. The possibility of measuring via different openings that are at a different angle to the flow can expand the information content accessible via the measurement. It is then also possible, for example, to determine flow velocities and angles. Due to the relative offset of the probe parts, this multi-point or multi-hole measurement can be implemented with the same sensor, which, for example, saves size compared to a two-sensor solution. With a view to the preferred arrangement in the gas duct, a small overall size can generally be of advantage; in addition, this can also reduce interaction with the flow and thus prevent falsification of the measurement.

Preferred refinements can be found in the dependent claims and the entire disclosure, with the representation of the features not always differentiating in detail between device and method or usage aspects; in any case, the disclosure is to be read implicitly with regard to all claim categories. If, for example, the advantages of the measurement in a specific application are described, this is to be read at the same time as a disclosure of a corresponding use or such a measurement method.

“A” and “an” are to be understood as indefinite articles and therefore always as “at least one” or “at least one”, respectively, unless expressly stated to the contrary. For example, there can also be more than two openings in the first probe part, see below in detail. Insofar as reference is made here to “first”, “second” etc. parts or components, this serves to differentiate the parts (and does not imply any numerical information); parts that are different from one another are referenced. In the context of this disclosure, the information “axial”, “radial” or “circumferential” relate to a longitudinal axis of the measuring probe without expressly specifying the contrary. This can, for example, be introduced or pushed axially into the volume to be measured, for example the gas duct.

According to a preferred embodiment, the first and the second opening are tilted differently in relation to the longitudinal axis of the measuring probe, that is to say at different azimuthal angles (if a polar coordinate system is used as the basis) the longitudinal axis of the measuring probe is the polar axis). In this way, for example, pitch angles can also be measured, for example a virtual 4-hole probe can be implemented. In general, two further openings, which are at the same azimuthal angle but at different polar angles with the first opening, could also be implemented or scanned as a whole by rotating the measuring probe. In general, the angle at which a respective opening is located (azimuthal and / or polar angle) is taken along a central axis of the channel system formed by the probe parts where the respective channel system with the respective opening opens into the measuring space, e.g. B. in the gas duct. An arrangement can particularly preferably be such that the first opening is at an azimuthal angle of 90 ° and the second opening is at an azimuthal angle of 45 °.

In a preferred embodiment, the first probe part additionally has a third opening, which is connected to the sensor by pressure fluid in a third relative position of the first and second probe part, that is to say with the same sensor as the first and second opening in the other relative positions. In the third relative position, only the third opening is connected to the sensor. The first and third openings are preferably at different polar angles, but particularly preferably at the same azimuthal angle (e.g. 90 °). A polar angle offset of the first and third openings of 45 ° or 90 ° can be particularly preferred.

More preferably, there can also be a fourth opening, wherein in a fourth relative position of the first and second probe parts only the fourth opening is then connected to the sensor by pressure fluid. The fourth opening can preferably be at a different polar angle than the first and third openings, but particularly preferably at the same azimuthal angle (in particular 90 °). The first, third and fourth openings can particularly preferably be arranged next to one another with a polar angle offset of 45 ° each in such a way that they cover an angular range of 90 ° overall.

In general, the respective opening assigned to the sensor can also be selected by axially displacing the probe parts. In a preferred embodiment, however, the probe parts are brought into the different relative positions by relative rotation about the longitudinal axis. As a result of the relative rotation about the longitudinal axis, it is possible to choose between openings associated with different azimuthal and / or polar angles.

According to a preferred embodiment, the second probe part is provided with a first and a second channel, the channels each opening into the fluidic access to the sensor. In the first relative position, the first opening of the first probe part is then connected to the sensor via the first channel of the second probe part, whereas in the second relative position the second opening of the first probe part is connected via the second channel. In this case, the first probe part covers the inlet into the second channel in the first relative position, whereas it covers the inlet into the first channel in the second relative position.

The first and second channels of the second probe part are preferably at different azimuthal angles. The respective angle of the respective channel is taken on its center axis where the respective channel merges into the respective opening of the first probe part. The first channel is preferably at an azimuthal angle of 90 ° and the second at an azimuthal angle of 45 °.

According to a preferred embodiment, in the third relative position, the third opening of the first probe part is connected to the sensor via the first channel of the second probe part. In other words, the first channel connects a different opening to the sensor in each of the first and third relative positions. In a respective relative position, the first channel preferably connects all openings which are at the same azimuthal angle, but at a respective different polar angle.

In a preferred embodiment, the second probe part is a cap which is placed at the end on a rod-shaped pressure transducer. The sensor is arranged or encapsulated in the pressure transducer; the cap can be attached to the pressure transducer in a non-positive or, preferably, materially bonded manner, for example glued on. This can enable a commercially available pressure transducer to be retrofitted in a comparatively simple manner. As an alternative to an attached cap, further integration, for example, is generally also possible in that the second probe part is a housing of the sensor (that is, it is part of the pressure transducer).

According to a preferred embodiment, the first probe part is a housing, in the interior of which the second probe part is arranged, that is to say, for example, it is enclosed axially and radially. This housing is preferably closed apart from these at the axial end at which the openings are provided.

Preferably, not only the second probe part, but also the sensor is arranged in the housing interior formed by the first probe part. In particular, a rod-shaped pressure transducer can be inserted into which the sensor is seated axially at the end. The sensor will thus placed comparatively close to the measuring room, which can be an advantage in terms of measuring accuracy. Even independently of this positioning in detail, the sensor can be, for example, a semiconductor component, for example a piezoresistive sensor.

As already mentioned, one advantage of multiple use of the same sensor can lie in a compact design via the relative offset of the probe parts. In any case, the measuring probe preferably has a diameter of at most 3 mm, more preferably at most 2.5 mm and particularly preferably at most 2 mm, perpendicular to the longitudinal axis, in that section in which the openings are arranged. Possible lower limits can be, for example, 1 mm, 1.2 mm, 1.4 mm or 1.5 mm. The diameter is generally taken as the mean value of the smallest and largest extension perpendicular to the longitudinal axis, which in the preferred case of the circular cross section corresponds to the circle diameter.

In principle, more openings than those discussed so far (first, second, third and fourth opening) are possible in the first probe part. With a view to the simplest possible structure, however, a maximum of five openings can be preferred, particularly preferably a maximum of four openings. With the four openings at the azimuthal and polar angles described above, the flow field can be adequately covered and at the same time a compact structure can be realized.

The invention also relates to a measuring method in which a measuring probe described in the present case for pressure and / or flow measurement is arranged in the gas duct of a turbomachine, preferably an aircraft engine. The pressure or flow field is measured successively over the different openings, for which purpose the first and second probe parts are brought into the different relative positions one after the other, preferably by relative rotation (see above). With regard to further possible details, reference is made to the above disclosure.

Brief description of the drawings

The invention is explained in more detail below with the aid of an exemplary embodiment, with the individual features within the framework of the independent claims also being essential to the invention in other combinations and furthermore no individual distinction is made between the different claim categories.

• 1 eine Strömungsmaschine, nämlich ein Flugtriebwerk in einem schematischen Axialschnitt;
• 2 eine erfindungsgemäße Messsonde in einem schematischen Schnitt;
• 3 ein Sondenteil der Messsonde gemäß 2 in einer Schrägansicht.

Shows in detail

• 1 a flow machine, namely an aircraft engine in a schematic axial section;
• 2 a measuring probe according to the invention in a schematic section;
• 3 a probe part of the measuring probe according to 2 in an oblique view.

Preferred embodiment of the invention

1 shows a turbomachine 1 , specifically a turbofan engine, in an axial section. The turbo machine 1 is functionally divided into compressors 1a , Combustion chamber 1b and turbine 1c . Both the compressor 1a as well as the turbine 1c are each made up of several stages. Each of the stages consists of a stator and a rotor. The reference number 4th refers to the gas channel, i.e. the compressor gas channel in the case of the compressor 1a . The sucked in air is in the compressor gas duct 3 compressed, it is then in the downstream combustion chamber 1b burned with added kerosene. The hot gas flows through the hot gas duct and thereby drives the rotors, which rotate around the axis of rotation 2.

2 shows a measuring probe 20th in a section, with a longitudinal axis 21 the measuring probe 20th lies in the cutting plane. The measuring probe 20th has a rod-shaped pressure transducer 22nd on that with a sensor 23 Is provided. The present case is a piezoresistive sensor with which pressures can be measured. The measuring probe 20th also has a first probe part 31 and a second probe part 32 on. The first part of the probe 31 delimits a housing interior 35 (compare also 3 ), in this are the pressure transducers 22nd with the sensor 23 and the second probe part 32 arranged.

The second part of the probe 32 is on the end of the pressure transducer 22nd glued. The first part of the probe 32 forms a first channel 32.1 and a second channel 32.2 and defines a fluidic access 32.3 to the sensor 23 . The two channels 32.1 , 32.2 around a respective central axis 32.1.1 , 32.2.1 can be essentially rotationally symmetrical, each lead into the fluidic access 32.3 . Here is the first channel 32.1 at a first azimuthal angle 40.1 of around 90 °, and extends the second channel 32.2 at a second azimuthal angle 40.2 of around 45 °.

How out 3 visible is the first part of the probe 31 with multiple openings 31.1-31.4 provided, namely a first opening 31, second opening 31, third opening 31 and fourth opening 31. By appropriately positioning the in the first probe part 31 arranged second probe part 32 can each have one of the openings 31.1-31.4 selected, i.e. via the respective channel 32.1 , 32.2 and the fluidic access 32.3 with the sensor 23 get connected. In the situation according to 2 is the first opening 31 over the first channel 32.1 connected, the remaining openings 31-31.4 are from the second part of the probe 32 however, concealed. The latter is in 2 for the second opening 31 to be seen, the third and fourth opening 31, 31.4 lie in front of and behind the plane of the drawing.

The first and second openings 31, 31.2 lie like the channels 32.1 , 32.2 , at different azimuthal angles 40.1 , 40.2 , namely at 90 ° and 45 °. In contrast to this, the third and fourth openings 31, 31.4 with the first opening 31 at the same azimuthal angle 40.1 , the openings 31, 31.3 , 31.4 however, lie on different polar angles 45 . You can rotate the first and second probe parts accordingly 31 , 32 one after the other over the first channel 32.1 pressure fluid with the sensor 23 get connected.

List of reference symbols

1

Turbo machine

1a

compressor

1b

Combustion chamber

1c

turbine

3

Sucked in air

4th

Gas duct

20th

Measuring probe

21st

Longitudinal axis

22nd

Pressure transducer

23

sensor

31

First part of the probe

31.1-31.4

openings

32

Second part of the probe

32.1

First channel

32.2

Second channel

32.1.1, 32.2.1

Center axes

32.3

Fluidic access

35

Housing interior

40.1

First azimuthal angle

40.2

Second azimuthal angle

45

Polar angle

Claims (15)

Measuring probe (20) for a flow and / or pressure measurement, with a sensor (23) for flow and / or pressure measurement, a first probe part (31) which has a first and a second opening (31.1, 31.2), and a second probe part (32) which defines a fluidic access (32.3) to the sensor (23), wherein the first and the second probe part (31, 32) are assembled so that they can be relatively offset - In a first relative position, the first opening (31.1) of the first probe part (31) is fluidically connected to the sensor (23) via the second probe part (32); and - In a second relative position, the second opening (31.2) of the first probe part (31) is fluidically connected to the sensor (23) via the second probe part (32). Measuring probe (20) Claim 1 , in which the first and the second opening (31.1, 31.2), based on a longitudinal axis (21) of the measuring probe (20) as the polar axis, lie at different azimuthal angles (40.1, 40.2). Measuring probe (20) Claim 1 or 2 , in which the first probe part (31) has a third opening (31.3), wherein - in a third relative position of the first and second probe parts (31, 32) the third opening (31.3) of the first probe part (31) over the second probe part (32) is fluidically connected to the sensor (23). Measuring probe (20) Claim 3 , in which the first and the third opening (31.1, 31.3), based on a longitudinal axis (21) of the measuring probe (20) as the polar axis, are at different polar angles (45). Measuring probe (20) according to one of the preceding claims, in which the first probe part (31) has a fourth opening (31.4), wherein - In a fourth relative position of the first and second probe parts (31, 32), the fourth opening (31.4) of the first probe part (31) is fluidically connected to the sensor (23) via the second probe part (32). Measuring probe (20) according to one of the preceding claims, in which the first and second probe parts (31, 32), based on a longitudinal axis (21) of the measuring probe (20), are rotated relative to the longitudinal axis (21) into the different relative positions are bringable. Measuring probe (20) after the Claims 2 and 6th , in which the second probe part (32) delimits a first and a second channel (32.1, 32.2), which channels (32.1, 32.2) each open into the fluidic access (32.3) to the sensor (23), wherein - in the first relative position, the first opening (31.1) of the first probe part (31) via the first channel (32.1) of the second The probe part (32) is fluidically connected to the sensor (23); and - in the second relative position, the second opening (31.2) of the first probe part (31) is fluidically connected to the sensor (23) via the second channel (32.2) of the second probe part (32). Measuring probe (20) after the Claims 2 and 7th , in which the first channel (32.1) extends at a first azimuthal angle (40.1) and the second channel (32.2) extends at a second azimuthal angle (40.2). Measuring probe (20) after the Claims 5 and 8th in which - in the third relative position, the third opening (31.3) of the first probe part (31) is fluidically connected to the sensor (23) via the first channel (32.1) of the second probe part (32). Measuring probe (20) according to one of the preceding claims, in which the second probe part (32) is a cap which is placed at the end on a rod-shaped pressure transducer (22) with the sensor (23). Measuring probe (20) according to one of the preceding claims, in which the first probe part (31) is a housing which delimits a housing interior (35) in which the second probe part (32) is arranged. Measuring probe (20) Claim 11 , in which the sensor (23) is also arranged in the housing interior of the first probe part (31). Measuring probe (20) according to one of the preceding claims, which, at least in a section in which the openings (31.1, 31.2) are arranged, has a diameter of at most 3 mm taken perpendicular to a longitudinal axis (21) of the measuring probe (20). Measuring probe (20) according to one of the preceding claims, in which the first probe part (31) has a total of at most five openings (31.1, 31.2) which can be connected to the sensor (23) by pressure fluid via the second probe part (32). Method for measuring a pressure and / or a flow in a gas duct (4) of a turbomachine (1), wherein a measuring probe (20) according to one of the preceding claims is arranged in the gas duct (4) and - In the first relative position, in which the sensor (23) is fluidically connected to the gas channel (4) via the first opening (31.1) of the first probe part (31), a first pressure and / or flow value is measured; - In the second relative position, in which the sensor (23) is fluidically connected to the gas channel (4) via the second opening (31.2) of the first probe part (31), a second pressure and / or flow value is measured.

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