MEASURING SYSTEM FOR MEASURING A FLOW PARAMETER OF A FLUID FLOWING IN A PIPELINE

Description

[0001] The invention relates to a measuring system for measuring at least one flow parameter of a fluid material flowing in a pipeline.

[0002] In process measurement and automation technology, vortex flowmeters are often used to measure the flow velocities of fluids flowing in pipelines, especially high-speed and / or hot gases and / or fluid flows with a high Reynolds number, or flow parameters corresponding to a given flow velocity, such as volumetric or mass flow rates or totalized volumetric or mass flow rates. Examples of such measurement systems include, among others...from DE-A 10 2005 003631, EP-A 666 467, US-A 2006 / 0230841, US-A 2008 / 0072686, US-A 2011 / 0154913, US-A 2011 / 0247430, US-A 2011 / 0314929, US-A 2013 / 0282309, US-A 2016 / 0041016, US-A 2017 / 0284841, US-A 60 03 384, US-A 61 01 885, US-B 63 52 000, US-B 69 10 387, US-B 69 38 496, US-B 80 10 312, US-B 82 00 450, US-B 83 70 098, US-B 84 47 536, WO-A 98 / 43051, WO-A 2011 / 043667, WO-A 2017 / 153124, WO-A 2019 / 245645, DE 102018 132311 A1 or WO-A 2020 / 120060 are known and are also offered by the applicant itself, for example under the trade name "PROWIRL D 200", "PROWIRL F 200", "PROWIRL O 200", "PROWIRL R 200".

[0003] The measuring systems shown each have a baffle body projecting into the lumen of the respective pipeline, for example as a component of a heat supply network or a turbine circuit, or into the lumen of a measuring tube inserted into the course of said pipeline, and thus being subjected to a flow of the measured medium, for example (liquid) water or (hot) steam, in order to generate vortices arranged in a so-called Kármán vortex street within the partial volume of the fluid flow flowing immediately downstream of the baffle body.The vortices are generated at the baffle body with a separation frequency (fV) that depends on the flow velocity of the fluid flowing through the measuring tube in a main flow direction. This frequency—with the Strouhal number (Sr ~ fV / u) as the proportionality factor—is proportional to the flow velocity (u) of the fluid flowing past the baffle body, at least for high Reynolds numbers (Re) above 20,000. Furthermore, the measuring systems exhibit a characteristic in the range of... Karman'schen Vortex street in the flow, and thus in the lumen of the vortex sensor projecting into it, for example, positioned downstream of the dam or integrated within it. This vortex sensor serves in particular to detect pressure fluctuations in the vortex formed in the flowing fluid. Karman'sto detect vortex street and convert it into a vortex sensor signal representing the pressure fluctuations - for example, electrical or optical - which corresponds to a pressure prevailing within the measured material, which is subject to periodic fluctuations as a result of opposing vortices downstream of the - typically prismatic or cylindrical - dam body, such that the vortex sensor signal contains a useful component, namely a spectral signal component representing the shedding frequency, which nevertheless has an amplitude that differs significantly from the signal noise.

[0004] In the measuring system shown in US-B 63 52 000, US-A 2006 / 0230841 or US-A 2017 / 0284841 respectively, the vortex sensor has a deformation body – usually designed as a thin and essentially flat membrane – and a deformation body extending from an essentially planar surface – usually plate-shaped orThe sensor assembly consists of a wedge-shaped sensor vane designed to detect pressure fluctuations in the Kármán vortex street acting in a detection direction perpendicular to the main flow direction. These fluctuations are then converted into movements of the deformation body corresponding to them. As a result of these pressure fluctuations, the sensor vane performs oscillatory movements in the detection direction, elastically deforming the deformation body. This causes the deformation body and sensor vane to be excited into forced, yet non-resonant oscillations around a common static equilibrium position – typically below the lowest mechanical resonance frequency of the vortex sensor. The deformation body also features an outer edge segment, usually annular, designed to be connected to the holder of the deformation body.The sensor thus formed is to be hermetically sealed, for example by a material bond, to the housing serving a pipe wall, such that the deformation body covers or hermetically seals an opening provided in the pipe wall and that the surface of the deformation body carrying the sensor flag faces the lumen of the measuring tube or pipeline carrying the measured material, thus the sensor flag projects into this lumen. For the purpose of generating the vortex sensor signal, the vortex sensor further comprises a corresponding transducer element, formed, for example, by means of a capacitor mechanically coupled to or integrated within the sensor assembly or by means of a piezoelectric stack serving as a piezoelectric transducer, which is designed to detect movements of the deformation body, including movements of the deformation body corresponding to pressure fluctuations, or of the possibly...to detect existing compensating elements and modulate them onto an electrical or optical carrier signal. As shown, among others, in US-B 63 52 000 and US-A 2017 / 0284841, the sensor assembly or the vortex sensor formed therewith can also have a compensating element, usually rod-, plate-, or sleeve-shaped, extending from a surface of the deformation body facing away from the surface supporting the sensor flag. This compensating element serves in particular to compensate for forces or moments resulting from movements of the sensor assembly, for example, due to vibrations of the pipeline, or to prevent resulting undesired movements of the sensor flag.

[0005] The vortex sensor is connected on a side facing away from the fluid-carrying lumen to a converter electronics unit – typically encapsulated to withstand pressure and impact, and optionally hermetically sealed to the outside. The converter electronics include a corresponding digital measuring circuit, electrically connected to the vortex sensor or its transducer element via connecting lines, possibly with the interposition of electrical barriers and / or galvanic isolation points. This circuit processes and evaluates the vortex sensor signal and generates digital measured values ​​for the respective flow parameter to be measured, such as flow velocity, volumetric flow rate, and / or mass flow rate.In particular, the converter electronics are designed to determine digital vortex frequency measurements representing the separation frequency based on at least one vortex sensor signal, and to calculate and output measured values ​​for at least one flow parameter using one or more vortex frequency measurements, for example to a corresponding display element provided in the measuring system. As well as other featuresAs also shown in the aforementioned US-B 6938496, US-B 6910387, US-B 8010312, US-B 8200450, US-B 8370098, or US-B 8447536, measuring systems of the type in question may further comprise a temperature sensor and / or a pressure sensor, for example, located downstream of or within the dam body. The converter electronics may also be configured to calculate measured values ​​for at least one flow parameter using a temperature sensor signal provided by the temperature sensor or a pressure sensor signal provided by the pressure sensor. The converter electronics, typically housed in a protective enclosure made of metal and / or impact-resistant plastic, are of industrial grade.Established measurement systems in industrial measurement technology also typically provide external interfaces compliant with an industry standard, such as DIN IEC 60381-1, for communication with higher-level measurement and / or control systems, for example, those implemented using programmable logic controllers (PLCs). Such an external interface can, for example, be designed as a two-wire connection that can be integrated into a current loop and / or be compatible with established industrial fieldbuses.

[0006] As discussed in the aforementioned US-A 2016 / 0041016, US-A 2013 / 0282309 and US-A 2011 / 0314929 respectively, the flow measurements obtained using measuring systems of the type in question can be significantly erroneous in the regularly unavoidable case that the measured substance also contains foreign substances; this is particularly true in the frequently occurring case that gas is carried along in the otherwise liquid measured substance, for example in the form of gas bubbles, or that the measured substance and foreign substance(s) form a bubble flow, and / or in such a way that the presence of foreign substances is not detected or is detected late by the converter electronics.

[0007] Starting from the aforementioned prior art, one object of the invention is to improve measuring systems of the aforementioned type in such a way that at least the occurrence of foreign substances causing increased measurement errors in a flowing medium can be detected at an early stage and / or that measurement errors caused by foreign substances in the medium can be reduced.

[0008] To solve this problem, the invention comprises a measuring system for measuring at least one flow parameter, for example a flow velocity and / or a volume flow and / or a mass flow, of a fluid substance flowing in a pipeline, for example at least occasionally single-phase and / or at least occasionally multi-phase, namely a gas, a liquid or a dispersion, which measuring system comprises: a pipe with a lumen, which can be inserted into the course of the aforementioned pipeline and is designed to guide the fluid flowing in the pipeline or to be flowed through by the fluid; a baffle, for example prismatic or cylindrical, arranged in the lumen of the pipe and designed to generate vortices in the fluid flowing past it with a separation frequency (f V ~ u) that depends on the instantaneous flow velocity (u) of the fluid, such that a Kärmän'schevortex street is formed; a vortex sensor arranged downstream of the baffle body, which has at least one, for example, lowest and / or always above the separation frequency, mechanical resonance frequency (f R ) and which is configured, excited by the flowing medium, to perform mechanical oscillations around a static equilibrium position and to provide at least one vortex sensor signal representing such oscillations, for example, electrical or optical, which contains a first useful component, namely a first spectral signal component (vortex component) representing oscillations of the vortex sensor with the separation frequency (f V ) - for example, having a signal level not below a predetermined threshold for signal noise - and which contains a second useful component,namely, a second spectral signal component (resonance component) representing the resonance oscillations of the vortex sensor with its mechanical resonance frequency (fR) – for example, a signal level not below a predetermined threshold for signal noise; and converter electronics, for example, formed by means of at least one microprocessor, for evaluating the at least one vortex sensor signal and for determining, for example, digital, measured values ​​for the at least one flow parameter; wherein the converter electronics are configured to receive and evaluate the at least one vortex sensor signal, namely, at least on the basis of the first useful component of the at least one vortex sensor signal, to determine, for example, digital,to determine vortex frequency measurements and, based on the second useful component of the at least one vortex sensor signal, to determine amplitude measurements representing the resonance oscillations of the vortex sensor, for example digitally; and wherein the converter electronics are configured to determine, using one or more amplitude measurements, whether and / or to what extent the measured substance contains foreign substances, for example gas inclusions (bubbles) carried in a liquid, and / or to determine whether the measured substance is single-phase or multi-phase, and to calculate flow parameter measurements, namely measured values ​​for the at least one flow parameter, using one or more vortex frequency measurements, for example digitally.

[0009] According to a first embodiment of the invention, it is further provided that the converter electronics are set up, and the flow parameter measured values ​​are also to be calculated using a Strouhal number (Sr ~ fv / u), namely a characteristic number representing a ratio of the separation frequency (f V ) to the flow velocity (u) of the fluid flowing past the baffle body.

[0010] According to a second embodiment of the invention, it is further provided that the converter electronics are configured to calculate the flow parameter measured values, at least in the case of a two-phase measured medium, also using one or more amplitude measured values.

[0011] According to a third embodiment of the invention, it is further provided that the converter electronics are configured to calculate, using at least one of the amplitude measurements, for example also using at least one of the vortex frequency measurements, a characteristic value for a flow characteristic that characterizes the ratio of a static pressure (p stat ) acting on the vortex sensor in a direction transverse to an imaginary longitudinal axis of the measuring tube to a dynamic pressure (p dyn ) acting on the vortex sensor in the direction of the imaginary longitudinal axis of the measuring tube, for example such that the flow characteristic corresponds to a pressure coefficient of the vortex sensor, an Euler number or a cavitation number of the measured medium.Further developing this embodiment of the invention, the converter electronics are also configured to compare the characteristic value with at least one threshold value, determined, for example, in advance under reference conditions and / or based on the vortex sensor signal, which represents a predefined, for example, maximum permissible and / or critical, foreign substance content for the measuring system and / or the measured substance. For example, the converter electronics can also be configured to determine the threshold value based on the vortex sensor signal, for example, using at least one of the vortex frequency measurements, and / or to output a message, for example, visually and / or audibly perceptible on-site and / or encoded in a data signal and / or declared as an alarm, if the characteristic value has exceeded the at least one threshold value.Alternatively or additionally, at least one threshold value can correspond to a characteristic value determined in advance under reference conditions, namely for a single-phase calibration fluid, such as water, flowing through the measuring transducer.

[0012] According to a fourth embodiment of the invention, it is further provided that the converter electronics have a first signal filter which is configured to receive the vortex sensor signal at a signal input and to provide a first, for example digital, useful signal containing the first useful component of the vortex sensor signal, for example always containing only an attenuated or not containing the second useful component, at a filter output and / or that the converter electronics have a second signal filter which is configured to receive the vortex sensor signal at a signal input and to provide a second, for example digital, useful signal containing the second useful component of the vortex sensor signal, for example always containing only an attenuated or not containing the first useful component.Further developing this embodiment of the invention, the converter electronics are also configured to determine the vortex frequency measurements using the first useful signal and / or the amplitude measurements using the second useful signal.

[0013] According to a fifth embodiment of the invention, it is further provided that the converter electronics are configured to generate a discrete Fourier transform (DFT) of the at least one vortex sensor signal and to determine the vortex frequency measurements and / or the amplitude measurements based on said discrete Fourier transform of the at least one vortex sensor signal.

[0014] According to a sixth embodiment of the invention, it is further provided that the converter electronics are configured to calculate an autocorrelation (ACF) of the at least one vortex sensor signal and to determine the vortex frequency measured values ​​based on the same autocorrelation of the at least one vortex sensor signal.

[0015] According to a seventh embodiment of the invention, it is further provided that the converter electronics have at least one converter circuit which is configured to receive and digitize the at least one vortex sensor signal, for example, to convert it into a digital vortex sensor signal and to provide the same digital vortex sensor signal at a digital output of the converter circuit.

[0016] According to an eighth embodiment of the invention, the vortex sensor further comprises a deformation body, for example, membrane-like and / or disc-shaped, with a first surface facing the lumen and an opposing second surface, for example, at least partially parallel to the first surface, as well as at least one transducer element arranged above and / or on the second surface of the deformation body, for example, attached to and / or positioned near the deformation body, which is configured to detect movements of the deformation body, for example, of its second surface, and convert them into the vortex sensor signal. Further developing this embodiment of the invention, the vortex sensor has a sensor flag, for example, plate-shaped or wedge-shaped, extending from the first surface of the deformation body to a distal end.

[0017] According to a further development of the invention, it is further provided that the measuring system comprises a display element coupled to the converter electronics for outputting measured values ​​provided by the converter electronics for the at least one flow parameter and / or messages generated by means of the converter electronics.

[0018] A fundamental concept of the invention is to detect the (vibrational) amplitude of the resonance oscillations of the vortex sensor, which are excited by the flowing, possibly contaminated, measuring medium, and to evaluate this amplitude for the detection of the foreign substance, and optionally also for a calculation that quantifies the foreign substance content. An advantage of the invention is, among other things, that the detection of foreign substances contained in the measuring medium can be implemented simply by modifying the calculation algorithm typically implemented as firmware and / or software in the converter electronics of modern measuring systems. For example, it can be easily retrofitted to already installed measuring systems by a corresponding firmware or software upgrade.

[0019] The invention and advantageous embodiments thereof are explained in more detail below with reference to exemplary embodiments illustrated in the figures of the drawing. Identical, equivalent, or similarly functioning parts are designated with the same reference numerals in all figures; where clarity requires it or it otherwise appears appropriate, previously mentioned reference numerals are omitted in subsequent figures. Further advantageous embodiments or developments, in particular combinations of aspects of the invention initially described only individually, will also become apparent from the figures of the drawing and / or from the claims themselves.

[0020] Specifically, we show: Fig. 1, 2 schematically shows in different views a measuring system – here designed as a vortex flow meter – with a vortex sensor and converter electronics for measuring at least one flow parameter of a fluid flowing in a pipeline; Fig. 3 shows exemplary power spectral spectra of a fluid using a measuring system according to the Fig. 1 or 2 vortex sensor signals generated at different loadings of the measured substance with foreign matter (gas bubbles carried in water); and Figs. 4a, 4b, 4c, 4d schematically, partly also in cutaway views, an embodiment of an embodiment for use in a measuring system according to the Fig. 1 or 2 suitable vortex sensors.

[0021] In Fig. 1 and 2Figure 1 shows an embodiment of a measuring system for measuring at least one flow parameter, which may also vary over time, such as a flow velocity u and / or a volume and / or mass flow rate, of a fluid medium flowing in a pipeline, for example, a liquid, a gas, or a dispersion. The pipeline can, for example, be a component of a drinking water network, a heat supply network, or a turbine circuit; thus, the fluid can be, for example, water or steam, especially saturated or superheated steam, or, for example, condensate discharged from a steam line. The fluid can also be, for example, cryogenic gas, petroleum, or (compressed) natural gas or biogas; thus, the pipeline can also be, for example, a component of a natural gas or biogas plant or a gas supply network.

[0022] The measuring system comprises a pipe 3, which can be inserted into the aforementioned pipeline, with a lumen 3' enclosed by a wall 3* of the pipe (e.g., made of metal). The lumen extends from an inlet end 3+ to an outlet end 3# and is designed to guide the fluid flowing in the pipeline or to allow the fluid to flow through it in the direction of a (main) flow direction of the measuring system defined by an imaginary longitudinal axis of the measuring pipe. In the embodiment shown here, a flange connection is provided at both the inlet end 3+ and the outlet end 3#, each with a corresponding flange on an inlet-side and outlet-side pipe segment of the pipeline, respectively, to create a leak-free connection. Furthermore, the pipe 3 can be, as in Fig. 1 or 2The system is depicted as being essentially straight, for example as a hollow cylinder with at least a partially circular cross-section, such that the pipe 3 has an imaginary straight longitudinal axis L connecting the inlet end 3+ and the outlet end 3#. The measuring system further comprises a baffle 4 arranged within the lumen 3' – for example, prismatic or cylindrical – which is designed to generate vortices in the fluid flowing past it with a separation frequency fV (fV ~ u) that depends on an instantaneous flow velocity u of the fluid, such that a baffle is generated in the fluid flowing downstream of the baffle. Karmansche a vortex street is formed, as well as a vortex sensor 1 - arranged, for example, downstream of the dam body 4 or integrated therein - for detecting vortices of the KarmanscheVortex street, for example, namely the periodic pressure fluctuations in the flowing fluid that accompany it at a constant flow velocity u. Vortex sensor 1 is specifically designed to provide at least one vortex sensor signal s1, in particular electrical or optical, that changes over time and corresponds, for example, to the aforementioned pressure fluctuations; this is done in such a way that the vortex sensor signal s1 – as well as from Fig. 3without further ado - a first useful component s1 N1 (vortex component), namely a first spectral signal component representing the separation frequency f V - for example, one that is not below a predefined threshold TH1 for signal noise, namely exhibiting at least a minimum spectral power density or a corresponding minimum amplitude, and / or not above a threshold TH2 for signal noise, namely exhibiting at most a maximum spectral power density or a corresponding maximum amplitude, if the fluid flowing downstream of the dam contains a Karmansche A vortex street is formed. Since the vortex sensor 1 naturally also contains a multitude of natural vibration modes, one or more of which can be excited during operation of the measuring system, the vortex sensor signal contains – as also from Fig. 3It is readily apparent that the vortex sensor typically contains one or more spectral signal components corresponding to a respective resonance frequency (fR) of one of the aforementioned vibration modes. In particular, it has been shown that the vortex sensor 1 can also be excited to vibrations at one or more of the aforementioned resonance frequencies by the fluid flowing past it, or conversely, that at least one of the aforementioned vibrations is not significantly excited or not excited at all if no fluid flows past the vortex sensor. Accordingly, the vortex sensor signal contains—as also shown from… Fig. 3It is readily apparent that at least temporarily there is also a second useful component s1 N2 (resonance component), namely a second spectral signal component (@f R) that is not below a predefined threshold value (TH0) for signal noise and / or occasionally above a threshold value (TH1) for the measured substance formed as a dispersion or foreign substance carried in the measured substance, and which represents a mechanical resonance frequency f R of the vortex sensor – for example, a lowest resonance frequency and / or a resonance frequency always above the separation frequency f V and / or a resonance frequency of a natural vibration mode useful for the detection of the vortices; this is especially true if fluid flows past the vortex sensor and / or not if no fluid flows past the vortex sensor.

[0023] According to a further embodiment of the invention, the measuring system comprises a temperature sensor 5 configured to provide at least one temperature sensor signal θ1, which follows a change in the temperature of the flowing fluid with a change in at least one signal parameter, and / or the measuring system comprises a pressure sensor 6 configured to provide at least one pressure sensor signal p1, which follows a change in the pressure of the flowing fluid, in particular a static pressure, with a change in at least one signal parameter. The temperature sensor can be located, for example, downstream of the baffle, optionally also within the vortex sensor, or – as also in Fig. 2 schematically depicted - located within the reservoir. Furthermore, the pressure sensor can also be located, for example, downstream of the reservoir or within the reservoir.

[0024] According to a further embodiment of the invention, the vortex sensor 1, as also in Fig. 2 and the Fig. 4a, 4b, 4c, 4d As each figure shows, or as can be readily seen from a combination of the figures, the sensor is formed by means of a deformation body 111, in particular a membrane-like or disc-shaped one, and a sensor flag 112 having a first side surface 112+ on the left and a second side surface 112# on the right. The sensor flag extends from a first surface 111+ of the deformation body 111 to a distal (free) end, namely away from the deformation body 111 or its surface 111+, and is designed to be surrounded by flowing fluid. The vortex sensor and the dam are specifically dimensioned and arranged such that the sensor flag 112 projects into the lumen 3* of the tube or the fluid guided therein in a region that is regularly disturbed during operation of the measuring system. Karmanschenvortex street is occupied. The deformation body 111 further has a second surface 111# opposite the first surface 111+, for example at least partially parallel to the first surface 111+, as well as an outer edge segment 111a, for example annular and / or provided with a sealing surface. The outer edge segment 111a has a thickness which - as in the Fig. 2or indicated in 4a, 4b, 4c, 4d - is significantly larger compared to the minimum thickness of an inner segment 111b enclosed by the same outer segment 111a - namely, the segment 111b supporting the sensor flag 112. The deformation body 111 and the sensor flag 112 are specifically designed to be excited to forced oscillations around a common static equilibrium position, such that the sensor flag 112 performs oscillatory movements that elastically deform the deformation body 111 in a detection direction or oscillation movements that run essentially transversely to the aforementioned (main) flow direction or transversely to the aforementioned longitudinal axis of the measuring tube, according to a natural oscillation mode inherent in the vortex sensor.According to a further embodiment of the invention, the sensor vane 112 accordingly has a width b, measured as a maximum extent in the direction of the (main) flow direction, which is significantly greater than a thickness d of the sensor vane 112, measured as a maximum lateral extent in the direction of the detection direction. In the Fig. 4a, 4b, 4c, 4dIn the illustrated embodiment, the sensor vane 112 is essentially wedge-shaped; however, it can also be designed, for example, as is quite common with such vortex sensors, as a relatively thin, flat plate. According to a further embodiment of the invention, the vortex sensor 1 and the tube 3 are dimensioned such that the length I of the sensor vane 112, measured as the minimum distance between a proximal end of the sensor vane 112 (i.e., the end bordering the deformation body 111) and the distal end of the sensor vane 112, corresponds to more than half a diameter DN of the tube 3 or less than 95% of that diameter DN. The length I can, for example—as is quite common with a comparatively small diameter of less than 50 mm—also be selected such that the distal end of the sensor vane 112 has only a very small minimum distance to the wall 3* of the tube 3.For pipes with a comparatively large caliber of 50 mm or more, the sensor flag 112 can be used – as is quite common in measuring systems of the type in question, or as is also evident from the . Fig. 2The deformation body 111 and the sensor flag 112 can, for example, be significantly shorter than half the diameter of the tube 3. Furthermore, they can be components of one and the same monolithic molded part, which is cast or manufactured using an additive manufacturing process such as 3D laser melting. However, the deformation body and sensor flag can also be designed as separate parts initially separated or subsequently joined by a material bond, for example, by welding or soldering, and thus made of materials that can be joined together. The deformation body 111 can—as is quite common with such vortex sensors—consist at least partially, for example predominantly or completely, of a metal such as stainless steel or a nickel-based alloy.The sensor flag can also consist at least partially of a metal, for example, stainless steel or a nickel-based alloy; in particular, the deformation body 111 and the sensor flag 112 can also be made of the same material. Furthermore, the vortex sensor includes a transducer element 12 – designed, for example, as a piezoelectric transducer, as a component of a capacitor, a capacitive element, or, for example, as a component of a photodetector – for generating a signal representing time-varying – typically at least periodic – movements of the sensor flag or similarly time-varying deformations of the deformation body 111, which here also serves as a vortex sensor signal, for example, a variable electrical voltage modulated by the aforementioned movements or correspondingly modulated laser light.The vortex sensor 1 is also inserted into the tube 3 in such a way that the first surface of the deformation body 111 faces the lumen 3' of the tube, and thus the sensor flag protrudes into the same lumen.

[0025] The vortex sensor 1 is located in the Fig. 1In the embodiment shown in Figure 2, the sensor 1 is inserted from the outside through an opening 3 formed in the wall into the lumen of the tube and fixed to the wall 3* from the outside in the area of ​​this opening – for example, releasably – such that the surface 111+ of the deformation body 111 faces the lumen 3' of the tube 3, and thus the sensor flag 112 projects into this lumen. In particular, the sensor 1 is inserted into the opening 3" such that the deformation body 111 covers or hermetically seals the opening 3". This opening can, for example, be designed such that – as is quite common in measuring systems of the type in question – it has an (inner) diameter in a range between 10 mm and approximately 50 mm. According to a further embodiment of the invention, a receptacle for holding the deformation body on the wall 3* is provided in the opening 3" 3a trained.The vortex sensor 1 can be fixed to the tube 3, for example, by a material-bonded connection, in particular by welding or soldering, between the deformation body 111 and the wall 3*; however, it can also be detachably connected to the tube 3, for example, by being screwed to it or attached to it. Furthermore, at least one sealing surface, for example, circumferential or annular, can be formed in the housing 3a, which is designed to seal the opening 3" accordingly in conjunction with the deformation body 111 and an optional sealing element, for example, annular or disc-shaped. Finally, if the vortex sensor is to be inserted into the aforementioned housing 3a and detachably connected to the tube 3, the edge segment 111a of the deformation body 111 can also advantageously be provided with a sealing element, for example, one that may be located in the opening 3".The intended sealing surface must be provided with a sealing surface corresponding to and / or annular in shape.

[0026] To compensate for any movements of the vortex sensor – for example, due to vibration of the aforementioned pipeline connected to the pipe – and to prevent resulting undesirable movements of the sensor flag or the deformation body 111 that would distort the sensor signal s1, the vortex sensor 1, according to a further embodiment of the invention, also has a compensating body 114 extending from the second surface 111# of the deformation body 111, which may be, for example, rod-, plate-, or sleeve-shaped. This compensating body 114 can also serve as a holder for the transducer element 12 or as a component of the transducer element 12, for example, as a movable electrode of a capacitor forming the transducer element (capacitive).The compensating body 114 can, for example, be made of the same material as the deformation body and / or the sensor flag, such as a metal. For example, the compensating body 114 can be made of stainless steel or a nickel-based alloy. According to a further embodiment of the invention, the deformation body 111 and the compensating body 114 are materially bonded to one another, for example, by welding or soldering. Thus, it is provided that the compensating body 114 and the deformation body 111 are manufactured from materials that can be materially bonded to one another. Alternatively, the deformation body 111 and the compensating body 114 can also be components of one and the same monolithic molded part, for example, such that the sensor flag 111, the deformation body 112, and the compensating body 114 are components of the same molded part.Sensor flag 112 and compensating body 114 can further - as can also be seen from a summary of the . Fig. 4c and 4d The sensor flag 112 and the deformation body 111 can be arranged in a way that is aligned with each other, such that a principal axis of inertia of the sensor flag 112 coincides with a principal axis of inertia of the compensating body 114. Alternatively or additionally, the compensating body 114 and the deformation body 111 can also be positioned and aligned with each other such that a principal axis of inertia of the deformation body 111 coincides with a principal axis of inertia of the compensating body 114. Furthermore, the sensor flag 112, compensating body 114, and deformation body 111 can also be positioned and aligned with each other such that—as can also be seen, for example, from a combined view of the Fig. 2 , 4a, 4b, 4c and 4devident - a principal axis of inertia of the vortex sensor 11 runs parallel to a principal axis of inertia of the sensor flag 112 as well as to a principal axis of inertia of the compensating body 114 as well as to a principal axis of inertia of the deformation body 111 or coincides with the same principal axis of inertia of the sensor flag as well as with the same principal axis of inertia of the compensating body as well as with the same principal axis of inertia of the deformation body.

[0027] To process and evaluate the at least one vortex sensor signal, the measuring system further comprises a converter electronics unit 2 – housed, for example, in a pressure- and / or impact-resistant protective housing 20 – which is connected to the sensor 1 and communicates with the vortex sensor 1 during operation of the measuring system. The protective housing 20 for the converter electronics unit 2 can be made, for example, of a metal, such as stainless steel or aluminum, and / or manufactured by a casting process, such as investment casting or high-pressure die casting (HPDC); however, it can also be formed, for example, by means of a plastic part manufactured by an injection molding process. In the embodiment shown here, the measuring system is also designed as a compact vortex flowmeter, in which the protective housing 20 with the converter electronics unit 2 housed therein is held on the pipe – for example, by means of a neck-shaped connecting piece 30.The converter electronics 2 – formed, for example, by means of at least one microprocessor – are designed, among other things, to receive and evaluate the vortex sensor signal s1, namely, to determine, at least on the basis of its first useful component, vortex frequency measurements X f representing the separation frequency, for example, digital, and, using one or more vortex frequency measurements X f, for example, also digital, flow parameter measurements XM, namely, to calculate measured values ​​for the at least one flow parameter; this, for example, in such a way that the flow parameter measurements XM each represent a calculation rule, at least in the case of a single-phase measured medium. X M = k 1 ⋅ X f fulfill, wherein the coefficient k 1 contained in the aforementioned calculation rule corresponds to the one mentioned at the outset. StrouhalThe number (Sr) corresponds to a calibration factor of the converter electronics or the measurement system formed by it, which may also be specific to the measurement system type or series. The flow parameter measurements XM can also be visualized locally and / or transmitted – wired via a connected fieldbus and / or wirelessly via radio – to an electronic data processing system, such as a programmable logic controller (PLC) and / or a SCADA system. Accordingly, in a further embodiment, the measurement system has a display element coupled to its converter electronics 2 and / or at least one data output for outputting data provided by the converter electronics 2 – for example, the measurements XM for the at least one flow parameter – and / or messages generated by the converter electronics 2.Not least in the case that at least one microprocessor suitable for processing the vortex sensor signal and determining the digital measured values ​​representing at least one flow parameter is provided in the converter electronics 2, the converter electronics can, according to a further embodiment of the invention, have at least one A / D converter circuit which is configured to receive and digitize the at least one vortex sensor signal, in particular.namely to convert into a digital vortex sensor signal and to provide that same digital vortex sensor signal at a digital output of the A / D converter circuit, and / or according to another embodiment of the invention, converter electronics 2 can have at least one non-volatile (data) memory (EEPROM) for storing digital measurement and / or operating data, for example, programs implementing calculation rules and / or calibration constants (k1, k2) and / or threshold values. In the aforementioned case where the measuring system includes the temperature sensor and / or the pressure sensor, the converter electronics 2 are further configured to also process the at least one temperature sensor signal or the pressure sensor signal.The converter electronics 2 are configured to receive at least one pressure sensor signal and are also configured to determine temperature measurements Xθ representing the temperature of the fluid based on the at least one temperature sensor signal and / or to determine pressure measurements Xp representing the pressure of the fluid based on the at least one pressure sensor signal. Furthermore, the converter electronics 2 can also be configured to consider the temperature measurements Xθ and / or the pressure measurements Xp when calculating the flow parameter measurements XM, or to incorporate them into the calculation of the flow parameter measurements XM, for example, also in the aforementioned case where the flow parameter measurements XM represent a mass flow rate of the measured medium.

[0028] As already mentioned, the vortex sensor and the measuring system formed with it are specifically designed for use in applications or systems where the measured substance is at least occasionally a dispersion, particularly a two-phase one, for example, such that gas with a (volume) concentration β, which may also vary over time, is carried along in the otherwise liquid measured substance. For this purpose, the converter electronics 2 are further configured to evaluate the vortex sensor signal s1 with respect to its second useful component, namely to determine (resonance) amplitude measurements X s, representing an amplitude of the resonance oscillations of the vortex sensor 1, for example, also digitally, based on the second useful component, and to determine, at least qualitatively, whether the measured substance is single-phase or multi-phase, e.g., whether...to determine the extent to which gas inclusions (bubbles) are carried in a liquid, and / or to quantitatively determine the extent to which, for example, with what (volume) fraction or with what (volume) concentration β, foreign substances are contained in the measured substance.

[0029] According to a further embodiment of the invention, the converter electronics 2 are also configured to use at least one of the amplitude measurement values ​​X s to generate a characteristic value XK for a loading of the measured substance with at least one foreign substance, for example, a corresponding foreign substance content or a corresponding ratio of the (pulsating) static pressure p stat (p stat @fr ) acting on the vortex sensor in the detection direction or in the direction transverse to the aforementioned (main) flow direction to a pressure acting in the direction of the aforementioned longitudinal axis of the measuring tube orto determine the dynamic pressure p dyn (p dyn ~u 2< ~ f V 2< ) acting on the vortex sensor in the (main) flow direction (dependent on the flow velocity u), thus representing a dynamic pressure acting on the vortex sensor, and the flow characteristic SK1 (Eu, σ, cp ); this in particular also using at least one of the vortex frequency measurements X f and / or such that the characteristic value XK represents a calculation rule: . X K = k 2 ⋅ Xs . X f 2 The requirement is met, thus quantifying the aforementioned ratio (p stat / p dyn ) of the static pressure p stat acting on the vortex sensor to the dynamic pressure p dyn acting on the vortex sensor. The coefficient k 2 contained in the aforementioned calculation method (like the aforementioned coefficient k 1 ) is also a calibration factor of the converter electronics or the measuring system formed therewith, possibly specific to the measuring system type or series. Advantageously, the coefficient k 2 can also be chosen or set such that the resulting flow characteristic SK1 corresponds to a pressure coefficient (cp ) of the vortex sensor or an Euler number (Eu) or a cavitation number (σ) of the fluid flowing past the vortex sensor, in particular around the sensor vane 112.Furthermore, the converter electronics can advantageously be configured to compare one or more of the characteristic values ​​XK with at least one threshold value TH1, determined, for example, in advance under reference conditions or based on the vortex sensor signal s1, which represents a foreign substance fraction specified for the measuring system and / or the measured substance. The aforementioned threshold value TH1 can, for example, be determined in advance under reference conditions, namely for a fluid flowing through the transducer with a specified or known Reynolds number, in particular...The (reference) characteristic value Xk (Xk @ H2, 25°C) determined using a single-phase calibration fluid, for example (bubble-free) water, corresponds to this (reference) characteristic value Xk, or can be adapted to the current flow velocity during the operating time of the measuring system by multiplying such a (reference) characteristic value by a second power (Xf 2< ) of a current vortex frequency measurement Xf, and / or be selected such that it represents a maximum permissible and / or critical foreign matter content. Accordingly, the converter electronics 2 can also be configured to determine the threshold value TH1 based on the vortex sensor signal s1, for example also based on amplitude measurements Xs determined (under reference conditions) and, if necessary,The converter electronics 2 can also be calculated based on frequency measurements Xf determined under reference conditions, for example, during initial calibration at the manufacturer of the measuring system and / or on-site recalibration, and / or the threshold value TH1 in the aforementioned non-volatile memory (EEPROM). Alternatively or additionally, the converter electronics 2 can also be configured to output a message, for example, declared as an alarm, if one or more of the characteristic values ​​XK have exceeded at least one threshold value TH1. The message can be output locally in an audible and / or visual manner, for example, by means of the aforementioned display element, and / or be encoded in a data signal transmitted, for example, to the aforementioned data processing system.

[0030] Furthermore, the characteristic values ​​XK can also be taken into account when calculating the flow parameter measured values ​​XM, for example, by being included in the calculation. Accordingly, the converter electronics 2 are configured to calculate the flow parameter measured values ​​XM, at least in the case of a two-phase fluid or a fluid loaded with foreign matter, using one or more of the aforementioned characteristic values ​​XK, in particular such that the flow parameter measured values ​​XM follow a calculation formula: X M = X K ⋅ X f fulfill. Alternatively or additionally, the converter electronics 2 can also be configured to calculate the flow parameter measured values ​​XM directly using one or more amplitude measured values ​​X s, at least in the case of a two-phase or foreign substance-laden fluid, in particular such that the flow parameter measured values ​​XM provide a calculation rule: X M = k M ⋅ Xs . Xf fulfill.

[0031] To process the vortex sensor signal, the converter electronics 2, according to a further embodiment, includes a first signal filter, for example, designed as a component of the aforementioned A / D converter circuit. This filter is configured to receive the vortex sensor signal at a signal input and to provide a first useful signal at a filter output. This first useful signal contains the first useful component of the vortex sensor signal, and in particular, always contains only an attenuated or no second useful component. Furthermore, the converter electronics can also be configured to use this first useful signal—which may also be digital—to calculate the vortex frequency measurements Xf. to determine.Alternatively or additionally, the converter electronics 2 further comprises a second signal filter, for example, designed as a component of the aforementioned A / D converter circuit, which is configured to receive the vortex sensor signal at a signal input and to provide a second useful signal at a filter output containing the second useful component of the vortex sensor signal, in particular always containing only an attenuated or no first useful component. Using the second useful signal – for example, digital – it can also be configured to determine the (resonance) amplitude measurements Xs. Alternatively or additionally, the converter electronics 2 can also be configured to generate a discrete Fourier transform (DFT) and / or an autocorrelation (ACF) of the at least one vortex sensor signal in order to subsequently determine, based on said discrete Fourier transform of the at least one vortex sensor signal, or...to determine one or more of the vortex frequency measurements X f and / or one or more of the (resonance) amplitude measurements X s based on the autocorrelation (AKF) of the at least vortex sensor signal.

Claims

1. A measuring system for measuring at least one, in particular time-variable, flow parameter, in particular a flow velocity and / or a volume flow, and / or a mass flow, of a fluid measured substance flowing in a pipeline, in particular one which is at least occasionally single-phase and / or at least occasionally multi-phase, that is to say, in particular, a gas, a liquid, or a dispersion, said measuring system comprising: - A tube (3) which can be inserted into the path of said pipeline with a lumen (3'), which is configured to conduct the measured substance flowing in the pipeline, or to have said measured substance flow through it; - an, in particular prismatic or cylindrical, damming body (4) arranged in the lumen of the tube (3), which is configured to generate in the measured substance that flows past it vortices with a vortex shedding frequency, fV (fV ~ u), depending on a momentary flow velocity, u, of said measured substance, in such a way that a Kármán vortex street is formed in the fluid downstream of the damming body; - a vortex sensor (1) arranged downstream of the damming body, -- which has at least one mechanical resonant frequency, fR, in particular a lowest one and / or one which is always above the vortex shedding frequency, -- and which is configured to perform mechanical oscillations around a static resting position initiated by the flowing measured substance, and to supply at least one, in particular electrical or optical, vortex sensor signal (s1) representing said oscillations, -- which contains a first useful component (s1N1), that is to say a first spectral signal component (vortex component) representing oscillations of the vortex sensor (1) with the vortex shedding frequency, fV - in particular having a signal level which is not below a specified threshold value for signal noise, -- and which contains a second useful component (s1N2), that is to say a second spectral signal component (resonant component) representing resonant oscillations of the vortex sensor (1) with its mechanical resonant frequency, fR - in particular having a signal level which is not below a specified threshold value for signal noise; - and converter electronics (2), in particular formed by at least one microprocessor, for analyzing the at least one vortex sensor signal and for determining, in particular digital, measured values (XM) for the at least one flow parameter; - wherein the converter electronics (2) are configured to receive and analyze the at least one vortex sensor signal, that is to say, at least -- to determine, in particular digital, vortex shedding frequency measured values (Xf) representing the vortex shedding frequency using the first useful component of the at least one vortex sensor signal -- and to determine, in particular digital, amplitude measured values (Xs) representing an amplitude of the resonant oscillations of the vortex sensor (1) using the second useful component of the at least one vortex sensor signal; - and wherein the converter electronics (2) are configured, -- using one or more amplitude measured values (Xs), --- to determine whether and / or to what extent there are foreign substances in the measured substance, in particular in entrained gas (bubbles) transported in a liquid and / or --- to determine whether the measured substance is made up of a single phase or multiple phases, -- and to calculate, in particular digital, flow parameter measured values (XM), that is to say measured values for the at least one flow parameter, using one or more vortex shedding frequency measured values (Xf), in particular in such a way that each flow parameter measured value (XM) satisfies a calculation rule, at least in the case of a single-phase measured substance: X M = k M X f .

2. The measuring system as claimed in one of the preceding claims, wherein the converter electronics (2) are configured to calculate the flow parameter measured values (XM), also using a Strouhal number, Sr (Sr ~ fV / u), that is to say a characterizing number representing a ratio of the vortex shedding frequency, fv, to the flow velocity, u, of the fluid flowing past the damming body.

3. The measuring system as claimed in one of the preceding claims, wherein the converter electronics (2) are configured to calculate the flow parameter measured values (XM) at least in the case of a two-phase measured substance, in each case also using one or more amplitude measured values (Xs), in particular in such a way that the flow parameter measured values (XM) satisfy a calculation rule: X M = k M Xs Xf .

4. The measuring system as claimed in one of the preceding claims, wherein the converter electronics (2) are configured to calculate, using at least of the amplitude measured values, in particular also using at least one of the vortex shedding frequency measured values (Xf), a characterizing number value (XK) for a flow characterizing number (SK1) characterizing a ratio of a static pressure (pstat) acting on the vortex sensor in a direction running perpendicular to an imaginary longitudinal axis of the measuring tube to a dynamic pressure (pdyn) acting on the vortex sensor in the direction of the imaginary longitudinal axis of the measuring tube, in particular in such a way that the characterizing number value (XK) satisfies a calculation rule: X K = k K Xs X f 2 and / or in such a way that the flow characterizing number (SK1) corresponds to a pressure coefficient of the vortex sensor, a Euler's number, or a cavitation number of the measured substance.

5. The measuring system as claimed in the preceding claim, wherein the converter electronics (2) are configured to compare the characterizing number value (XK) with at least one threshold value (TH1), in particular determined in advance under reference conditions and / or determined using the vortex sensor signal (s1), which represents a foreign substance content specified for the measuring system and / or the measured substance, in particular a maximum permissible and / or critical foreign substance content.

6. The measuring system as claimed in the preceding claim, - wherein the converter electronics (2) are configured to determine the threshold value based on the vortex sensor signal (s1), that is to say, in particular, using at least one of the vortex shedding frequency measured values (Xf); and / or - wherein the at least one threshold value (TH1) corresponds to a characterizing number value (Xk) determined in advance under reference conditions, in particular for a calibration fluid flowing through the measuring transducer and / or a single-phase calibration fluid, that is to say, in particular, is identical to said characterizing number value (XK); and / or - wherein the converter electronics (2) are configured to output a notification, in particular one which can be perceived visually and / or acoustically on site and / or one which is coded into a data signal and / or is declared as an alarm, in the event that the characterizing number value (XK) has exceeded the at least one threshold value (TH1).

7. The measuring system as claimed in one of the preceding claims, - wherein the converter electronics (2) have a first signal filter, which is configured to receive the vortex sensor signal at a signal input and to supply a first, in particular digital, useful signal containing the first useful component of the vortex sensor signal, that is to say, in particular, only ever containing the second useful component attenuated or not containing it at all, at a filter output; and / or - wherein the converter electronics (2) have a second signal filter, which is configured to receive the vortex sensor signal at a signal input and to supply a second, in particular digital, useful signal containing the second useful component vortex sensor signal, that is to say, in particular, only ever containing the first useful component attenuated or not containing it at all, at a filter output.

8. The measuring system as claimed in the preceding claim, - wherein the converter electronics (2) are configured to determine the vortex shedding frequency measured values (Xf) using the first useful signal; and / or - wherein the converter electronics (2) are configured to determine the amplitude measured values (Xs) using the second useful signal.

9. The measuring system as claimed in one of the preceding claims, - wherein the converter electronics (2) are configured to generate a discrete Fourier transform (DFT) of the at least one vortex sensor signal, - and wherein the converter electronics (2) are configured to determine the vortex shedding frequency measured values (Xf) and / or the amplitude measured values (Xs) based on said discrete Fourier transform (DFT) of the at least one vortex sensor signal.

10. The measuring system as claimed in one of the preceding claims, - wherein the converter electronics (2) are configured to calculate an autocorrelation (AKF) of the at least one vortex sensor signal, - and wherein the converter electronics (2) are configured to determine the vortex shedding frequency measured values (Xf) based on said autocorrelation (AKF) of the at least one vortex sensor signal.

11. The measuring system as claimed in one of the preceding claims, wherein the converter electronics (2) have at least one converter circuit (A / D), which is configured to receive the at least one vortex sensor signal and to digitize it, that is to say, in particular, to convert it into a digital vortex sensor signal and to supply said digital vortex sensor signal at a digital output of the converter circuit.

12. The measuring system as claimed in one of the preceding claims, - wherein the vortex sensor has an, in particular membrane-like and / or disk-shaped, deformation body with a first surface facing toward the lumen and a second surface opposite it, in particular at least partially parallel to the first surface, - and wherein the vortex sensor has at least one converter element arranged above and / or on the second surface of the deformation body, that is to say, in particular, attached to the deformation body and / or positioned near it, which is configured to detect movements of the deformation body, in particular of its second surface, and convert these into the vortex sensor signal.

13. The measuring system as claimed in the preceding claim, wherein the vortex sensor has an, in particular plate-shaped or wedge-shaped, sensor flag starting at the first surface of deformation body and extending to a distal end.

14. The measuring system as claimed in one of the preceding claims, further comprising: A display element coupled with the converter electronics (2) for outputting measured values (XM) supplied by the converter electronics (2) for the at least one flow parameter and / or notifications generated using the converter electronics (2).