WO2013037588A1

WO2013037588A1 - Method and sensor assembly for measuring the pressure in a pressure vessel

Info

Publication number: WO2013037588A1
Application number: PCT/EP2012/065952
Authority: WO
Inventors: Carl Udo Maier; Jochen Ostermaier; Benjamin Waldmann
Original assignee: Siemens Aktiengesellschaft
Priority date: 2011-09-12
Filing date: 2012-08-15
Publication date: 2013-03-21
Also published as: DE102011082487A1

Abstract

The invention relates to a sensor assembly for measuring the pressure in the interior (4) of a vessel (2) having a vessel wall (3) which has at least one ferromagnetic layer. The sensor assembly comprises at least one magnetoelastic measurement sensor (1), to be arranged on or in the proximity of the ferromagnetic layer, on the outside of the vessel wall (3), for detecting forces prevailing in the ferromagnetic layer with the aid of the magnetoelastic effect, which outputs a signal representing the detected forces. According to the invention, the sensor assembly additionally comprises a processing unit (11) connected to the magnetoelastic measurement sensor (1) which determines the pressure in the interior (4) of the vessel (2, 21) from the signal output by the magnetoelastic measurement sensor (1).

Description

description

Method and sensor arrangement for measuring the pressure in a pressure vessel

The present invention relates to a method for measuring the pressure in a pressure vessel. In addition, it relates to a sensor arrangement for carrying out the method and to a pressure vessel with a sensor arrangement for measuring the pressure in its interior.

At pressure vessels, so to pressure vessels or pressurized pipes such as pipelines, it is often necessary to measure the pressure prevailing inside the vessel pressure to possibly detect an overpressure or negative pressure can. Conventional pressure gauge devices need to measure the pressure ei ^¬ nen connection with a direct connection to the inside of the vessel. It is therefore necessary either a pressure-resistant passage through the vessel wall, or the vessel wall must be opened for the connection of a pressure gauge. This can usually only be done while the container is not being used.

The object of the present invention is therefore to provide a method and a sensor arrangement for measuring the pressure in the interior of a pressure vessel, in which a passage through the vessel wall or an opening of the vessel for attaching the pressure measuring device is not necessary.

It is a further object of the present invention to provide an advantageous pressure vessel.

The first object is achieved according to claim 1 by a method for measuring the pressure inside a vessel and according to claim 9 by a sensor arrangement for measuring the pressure inside a vessel. The second object is achieved by a vessel according to claim 14. The dependent claims contain advantageous embodiments of the invention. In the method according to the invention for measuring the pressure in the interior of a vessel which has a vessel wall with at least one ferromagnetic layer, the forces prevailing in the ferromagnetic layer are produced by means of at least one magnetoelastic one attached to the outside of the vessel wall at or in the vicinity of the ferromagnetic layer Measuring sensor detected. The pressure inside the vessel is then determined from the detected forces. The vessel wall may in particular be made entirely of the ferromagnetic material ^¬ rule. Alternatively, it may be made of another material having a ferromagnetic layer applied thereon. The ferromagnetic layer can be applied either to the entire surface of the vessel wall or only to those areas where a magnetoelastic measuring sensor is present. The vessel may, for example, be a pressure vessel, a pipe such as a pipeline, etc. As pressure, a static pressure or a flow pressure can be measured.

The method according to the invention is based on the fact that the pressure inside the vessel exerts forces on the vessel wall, which in turn lead to tensions in the vessel wall. Now, if the vessel wall is made of a ferromagnetic material or at least in the area of magnetoelastic measuring sensors has a ferromagnetic layer, the forces prevailing due to the stresses in the ferromagnetic material forces lead to a change in the magnetic permeability of the layer and these in turn to changes in passing through the layer magnetic fields. These changes can be detected with the magnetoelastic measuring sensor. May then be closed to ^¬ back to the forces in the ferromagnetic layer and therefrom to the pressure inside the vessel from the measured with the magneto-elastic sensor measuring magnetic field strengths. In this case, the pressure measurement can be carried out completely from outside the container, so that a passage of a pressure sensor through the container wall or an opening of the container for attaching a pressure sensor is not necessary. The magnetoelastic measuring sensor used in the method according to the invention needs le ^¬ diglich be placed on the vessel wall or arranged at a distance from the vessel wall. For example, it is also possible to monitor the pressure inside the vessel via thick paint coatings or wraps.

The forces occurring in the ferromagnetic material depend, in addition to the pressure prevailing in the interior of the vessel, also on the ambient pressure and the ambient temperature. In the determination of the pressure inside the vessel is therefore advantageously the ambient pressure and / or the ambient temperature. In this case, the ambient pressure and / or the ambient temperature can be measured. In particular, when the ambient pressure or the ambient temperature are not subject to relevant fluctuations, it is also possible to dispense with measuring the ambient pressure or the ambient temperature. Instead, it can then rely on averages for pressure and / or temperature, on estimates of pressure

and / or the temperature, etc. are used. Pressure values can be derived, for example, from the geographical altitude of the container.

In a further development of the method according to the invention, the pressure in the interior of the vessel is a flow pressure. The flow velocity of a fluid flowing in the vessel can then be determined from the determined flow ^pressure . Measuring the flow pressure inside a vessel is of particular interest in tubular vessels such as pipelines. By this method it is also possible, the flow pressure and / or the Strömungsge ^¬ speed monitor in a vessel and the vessel to check the flow ^¬ hand pressure or calculated, the calculated flow rate for the presence of leaks over ^¬. Here, when the flow pressure and / or the flow velocity at a plurality inside the vessel (we ^¬ nigstens two) of different locations of the vascular wall by means arranged distributed magnetoelastic measurement sensors exceeds is monitored, there is the possibility of pre ^¬ chaise longue determine the location of the leak from the determined for the ver ^¬ different points flow pressures and flow rates upon detection of a leak. As already mentioned, the existing at the measuring sensors ferromagnetic layer may be either a common ferromagnetic layer or may comprise two separate ferromagnetic Schich ^¬ th. A sensor arrangement according to the invention for measuring the pressure in the interior of a vessel having a vessel wall which has at least one ferromagnetic layer comprises at least one magnetoelastic measurement sensor to be arranged at or in the vicinity of the ferromagnetic layer for detecting the forces prevailing in the ferromagnetic layer. The ferromagnetic measuring sensor outputs a signal representing the detected forces. Furthermore, the regulatory Sensoran ^¬ comprises means connected to the magneto-elastic measurement sensor processing unit that the pressure inside the vessel is determined from the output from the magneto-elastic measuring sensor signal. The pressure can be a static pressure or a flow pressure.

The sensor arrangement may in particular also comprise at least one pressure sensor measuring the ambient pressure and / or a temperature sensor measuring the ambient temperature.

With the sensor arrangement according to the invention, the method according to the invention can be realized, so that the advantages described with reference to the method according to the invention can be achieved.

If the vessel is traversed by a fluid, the processing unit can also be switched off to determine from the signal output by the magnetoelastic measuring sensor, the flow velocity of the flowing fluid. In a development of the sensor arrangement, the latter has at least two, preferably a multiplicity on the outside of the vessel wall at or in the vicinity of the ferromagnetic

Layer distributed to be arranged magnetoelastic measurement sensors. In this development, for example, the presence and the location of a leak in a vessel through which fluid flows, for example in a pipeline, can be determined.

According to a further aspect of the invention is also a vessel having a vessel wall is provided, the Wenig ^¬ least having a ferromagnetic layer. At or in the vicinity of the ferromagnetic layer, a sensor arrangement according to the invention is arranged. The vessel wall can either consist entirely of ferromagnetic material, have a ferromagnetic layer which extends over the entire vessel wall, or one or more ferromagnetic layers, which are located in the region of a ferromagnetic sensor. Such a vessel makes it possible to detect the pressure inside the vessel without the need for a passage or opening in the vessel wall. The vessel may in particular be configured as a tube, for example. As ^¬ pipe line. In this case, it is advantageous if there is a sensor arrangement with at least two, preferably with a multiplicity of measuring sensors arranged on the outside of the vessel wall, since then the presence of a leak and the position of the leak are identified by the detection of a pressure drop or a drop in the flow velocity Leaks can be determined.

Further features, properties and advantages of the present invention will become apparent from the following description of embodiments with reference to the accompanying figures.

FIG. 1 shows a block diagram for an inventive device

Sensor arrangement. FIG. 2 shows a magnetoelastic measuring sensor of the sensor arrangement from FIG. 1.

Figure 3 shows a second embodiment for the dung OF INVENTION ^¬ modern sensor array.

FIG. 4 shows the position of the magnetoelastic measuring sensors of the sensor arrangement from FIG. 3 on a pipe through which fluid flows.

A first embodiment of the inventive Sen ^¬ soranordnung will be described below with reference to FIG 1 and FIG. 2 While Figure 1 shows the sensor arrangement in the form of a block diagram, Figure 2 shows a magneto ^¬ elastic measuring sensor 1, which is positioned on the container wall 3. Although the first embodiment will be described with reference to a pressure vessel, it is also possible to apply the sensor array of the first embodiment to a flow-through vessel such as a pipeline or other pipe.

The sensor arrangement illustrated in the first ^exemplary embodiment comprises, in addition to a magnetoelastic measuring sensor 1 to be arranged on the container wall 3, a data acquisition unit 5 which detects a signal output by the magnetoelastic measuring sensor 1. In addition, it can also detect the signals of a pressure sensor 7 measuring the ambient pressure and / or a temperature sensor 9 measuring the ambient temperature. The presence of a pressure sensor 7 and / or a temperature sensor Tempe ^¬ 9 is advantageous, but not necessary, as will be explained later, so that these two sensors are only optionally available in the sensor array.

The sensor arrangement also comprises a processing unit 11, to which the data acquisition unit 5 forwards the acquired data. The result of the processing 11 is standardized held processing of the signals detected by the data detection unit 5, finally, to a connected to the processing unit 11 Interface 13 wei ^¬ tergegeben, from where the result can be retrieved.

Hereinafter, the measurement of the pressure in the inner space 4 of the container 2 will be described. The container wall 3 of the container 2 is made in the present embodiment of a ferromagnetic material. But it can also be made of a different material and coated with a ferromagnetic ^¬ rule material or be connected ver ^¬ otherwise. The coating is then present at least where the magnetoelastic measuring sensor 1 is positioned. Advantageously, however, such a coating is present over the entire container wall 3 in order to increase the freedom in positioning the magnetoelastic measuring sensor 1. In addition, a thick paint layer or lacquer layer or a cladding, for example a thermally insulating cladding or a protective cladding, can be applied over the ferromagnetic container wall 3 or over the ferromagnetic layer, without thereby ^destroying the subsequently described measurement.

A pressure in the interior 4 of the container 2 leads to stresses in the container wall 3, which in turn influence the magnetic Permeabi ^¬ lity of the ferromagnetic material of the container wall 3 and the ferromagnetic layer. Whether tensile or compressive stresses occur in the container wall depends on whether the pressure in the container is higher or lower than the ambient pressure on the outside of the container 2. If the pressure in the interior 4 is lower than the external pressure, compression takes place Container wall 3, which leads to compressive stresses. Conversely, if the ambient pressure is lower than the pressure in the interior 4 of the container, this leads to an expansion of the container wall 3 and thus to tensile stresses.

In the context of the method according to the invention, the change in the magnetic permeability occurring due to the stresses is stability of the ferromagnetic material by means of the magneto ^¬ elastic measuring sensor 1 detected. As a rule, such a sensor has an excitation coil 15, also called a transmitting coil, which generates a magnetic field. It is arranged on a leg of a U-shaped ferrite core 17 in the present embodiment. On the opposite leg of the ferrite core 17, a receiving coil is arranged. The magnetic field generated by the transmitting coil 15 passes through the ferromagnetic material of the container wall 3 to the receiving coil 19. About the ferrite core 17 of the magnetic field circuit is closed. By means of the receiving coil 19, the magnetic flux density of the magnetic field at the location of the transmitting coil is detected, which depends on the mag ^¬ genetic permeability in the ferromagnetic material. A change in the magnetic permeability due to stresses therefore leads to a change in the magnetic flux density passing through the receiving coil 19, which in turn determines the current induced in the receiving coil 19. The current signal generated by the receiving coil 19 is therefore representative of the voltages present in the ferromagnetic material of the container wall 3.

In the processing unit 11 by the magnetic ^¬ meabilität is determined in the ferromagnetic material on the basis of the induced in the receiving coil 19 current. From this, the stresses in the container wall 3 can then be calculated on the basis of the inverse magnetostrictive effect, from which in turn the pressure in the container interior 4 can be calculated. In this calculation, ambient temperature readings and / or ambient pressure readings may be taken when calculating the pressure inside the vessel. The pressure calculated in the processing unit 11 in the container ^interior 4 is finally output to the interface 13, from where the pressure value can be retrieved. As already mentioned, the hang occurring defects ^¬ Tenden in the container wall 3 voltages on the pressure difference between the pressure in the inner space 4 of the container 2 and the ambient pressure. For example, if at constant pressure in the interior of the 4 Ambient pressure decreases, this has an effect on the stresses occurring in the container wall 3. The same applies to thermal expansion of the container wall 3. This also influences the stresses occurring in the container wall 3. In particular, when greater fluctuations in the ambient pressure and / or the ambient temperature is to be expected, it is advantageous to measure the ambient pressure and / or the ambient temperature. On the basis of the measurement of the ambient pressure and / or the ambient temperature, their influence can then be calculated out of the signal obtained by the magnetoelastic measuring sensor 1.

If larger fluctuations in the other ^¬ ambient pressure and / or are afraid of not loading in the ambient temperature at the location of the container 2, there is also the option of not

Provide pressure sensor 7 and / or temperature sensor 9 in the sensor assembly. For example, a constant mean value for the ambient pressure and / or for the ambient temperature can then be set in the evaluation of the signal acquired with the magnetoelastic measuring sensor 1. Such an average may for example be determined from the altitude at the location of Behäl ^¬ ters 2 or from measured values of the past (for temperature and / or ambient pressure). A second embodiment of the inventive Sen ^¬ soranordnung is shown in Figure 3 and in FIG. 4 Elements corresponding to those of the first embodiment are denoted by the same reference numerals as in FIGS. 1 and 2 and will not be described again in order to avoid repetitions. The description of the second embodiment is therefore limited to the differences from the first embodiment.

The sensor arrangement of the second exemplary embodiment illustrated in FIG. 3 comprises a plurality of magnetoelastic measuring sensors 1, which are all connected to the data acquisition unit 5. As in the first embodiment ^¬ op tional to a pressure sensor 7 and / or a temperature sensor 9 for Measuring the ambient pressure or the ambient temperature be present.

The sensor arrangement shown in FIG. 3 is used in the present exemplary embodiment for measuring the flow pressure at different locations of a pipeline 21 (FIG. 4) whose outer wall consists of a ferromagnetic material or comprises a ferromagnetic layer. In the case of a ferromagnetic layer, this is present in particular where magnetoelastic measuring sensors 1 are arranged.

However, advantageously it extends over the entire wall of the pipeline 21 to allow free as possible Positionin ^¬ tion of the magneto-elastic measurement sensors 1 on the outside of the pipeline. In the present exemplary embodiment play three magnetoelastic measuring sensors 1 in regelmä ^¬ lar intervals along the axial direction of the pipeline 21 are arranged. The number of three electromagnetic measuring sensors 1 is hereby only owed for the sake of clarity. In fact, the number of magnetoelastic measuring sensors can also be considerably larger than shown in FIG. Moreover, there is also the possibility of electro-magnetic measuring sensors 1 ^¬ not only to distribute in the axial direction of the pipeline 21, but also processing in which the circumferential.

The fluid flowing in the pipeline medium influenced by the-carrying route due to the friction within the Me ^¬ diums itself and the friction of the medium on the tube wall the flow pressure in the pipeline 21. The flow pressures at the locations of the magneto-elastic measurement sensors 1 are of the prevailing Flow rate dependent. With ^{¬ means} of magnetoelastic measuring sensors 1, therefore, the flow velocity of the medium can be calculated at the respective Stel ^¬ len. An interpolation of the flow velocity can take place between the measuring points. In this ^¬ terpolation is more accurate the lower the distance between the magnetoelastic measuring sensors 1 are. From the information about the flow velocities at the measuring points, the presence of leaks can also be detected. A leak is noticeable by a changed flow flow of the medium. Is the network of distributed over the outside of the pipeline 21 magnetoelastic measuring sensors 1 corresponding to dense, it is also possible ^¬ ness, to determine the location of a leak from the determined speeds Strömungsge ^¬. With the aid of the sensor arrangement according to the invention, the flow velocity of the medium can be determined ^¬ next to the pressure in the pipeline 21 and the, in particular in a sufficiently dense network of magneto-elastic measurement sensors 1, and the presence of leaks. The sensor arrangement shown in FIG. 3 is therefore particularly suitable for monitoring pipelines or other pipes through which they flow.

The sensor arrangements described in the exemplary embodiments make it possible to monitor pressure vessels without opening the vessel wall. It is only a simple mount for mounting the magnetoelastic measuring sensors needed. These can either be placed directly on the container wall or at a distance from the container wall, since the method also works when the transmitter coil and the receiver coil have a distance from the container wall, if this distance is not too large. Even thick color coatings or Umhül ^¬ lungs therefore not hinder the pressure measurement with the magnetoelastic pressure sensor significantly.

The present invention has been described with reference to the figures using exemplary embodiments. However, these are not intended to limit the invention to the arrangements and methods described therein, but are for illustrative purposes only. Deviations in the number of magnetoelastic measuring sensors or in the arrangement of the magneto-elastic measuring sensors on the container wall are possible, as one skilled in the art readily recognizes. In addition, the magnetoelastic measuring sensor 1 shown in FIG. 2 is merely an example of one usable within the scope of the sensor arrangement magnetoelastic measuring sensor. In principle, all sensors suitable for measuring the magnetic flux density can be used in the sensor arrangement within the scope of the sensor arrangement. In addition, the sensor arrangement ^{according to} the invention can be used in conjunction with any pressure vessel, whether it flows through or does not flow through.

Claims

claims

A method of measuring the pressure inside (4) a vessel (2, 21) having a vessel wall (3) with at least one ferromagnetic layer in which by means of at least one on the outside of the vessel wall (3) in the vicinity of the ferromagnetic layer attached magnetoelastic measuring sensor (1) the forces prevailing in the ferromagnetic layer forces are detected and from the pressure inside (4) of the vessel (2, 21) is determined.

2. The method of claim 1, in which also the ambient pressure and / or the ambient temperature in the determination of the pressure in the interior (4) of the vessel (2, 21) received.

3. The method of claim 3, in which the ambient pressure and / or the ambient temperature are measured.

4. The method according to any one of claims 1 to 3, in which the pressure in the interior (4) of the vessel (21) is a flow pressure and from the determined flow pressures, the flow velocity of a vessel (21) flowing fluid is determined.

5. The method of claim 4, in which the flow pressure and / or the flow velocity is monitored or be and the vessel (21) is checked on the basis of the determined flow ^¬ pressure and / or the determined flow velocity to the presence of a leak.

6. The method of claim 5, in which the flow pressure and / or the flow velocity in the interior (4) of Ge ^¬ fäßes (21) distributed at a plurality of different points of the vessel wall (3) by means arranged magnetoelastic measuring sensors (1) is monitored and if Determining the presence of a leak, the position of the leak is determined from the flow pressures or flow velocities determined for the ^different points.

A method according to any one of the preceding claims, wherein the pressure vessel is a pipeline (21).

8. The method according to any one of the preceding claims, in which the at least one magnetoelastic measuring sensor (1) has a Ab ^¬ stand to ferromagnetic layer.

Sensor arrangement for measuring the pressure in the interior (4) of a vessel (2, 21) with a vessel wall (3) having at least one ferromagnetic layer, comprising:

at least one magnetoelastic measuring sensor (1) to be arranged on or in the vicinity of the ferromagnetic layer on the outside of the vessel wall (3) for detecting forces in the ferromagnetic layer with the aid of the magnetoelastic effect, which outputs a signal representing the detected forces , and

- One with the magnetoelastic measuring sensor (1) connected to the processing unit (11), which determines the pressure in the interior (4) of the vessel (2, 21) from the signal output by the magnetoelastic measuring sensor (1).

10. Sensor arrangement according to claim 9, which also comprises at least one pressure sensor (7) measuring the ambient pressure and / or a temperature sensor (9) measuring the ambient temperature.

11. Sensor arrangement according to claim 9 or claim 10, in which the vessel (21) flows through the fluid and the processing unit (11) is switched off, from the magneto ^¬ elastic measuring sensor (1) output signal to the flow velocity of the flowing fluid determine.

12. Sensor arrangement according to one of claims 9 to 11, which at least two, on the outside of the vessel wall (3) at or in the vicinity of the ferromagnetic layer distributed anzuord ^¬ nende magnetoelastic measuring sensors (1).

13. The sensor assembly of claim 12, in which the processing unit (11) is adapted, from the signals of the magneto-elastic measuring sensor (1) or the magnetoelasti ^¬ rule measuring sensors (1) leaks in the vessel (21) to be detected.

14. A vessel having a vessel wall which has at least one ferromagnetic layer, and a sensor arrangement according to one of claims 9 to 13.

15. A vessel according to claim 14, which is ^{ausgestal ¬} tet as a tube (21).