flow meter

Abstract

The invention relates to a flow meter (100) for determining a flow rate of a fluid in a medium conduit (200), comprising: - a sensor base (101) comprising an obstruction body (102) and a sensor main body (103), - an electronics unit (300) and - a signal interface (400), wherein - the obstruction body (102) is arranged essentially upstream of the sensor main body (103) in a flow direction, - the sensor main body (103) comprises a support body piece (110) and a substrate assembly (111) having at least one ceramic substrate (108, 109), and - a gas flow meter - sensor unit (104) and a vortex counter - sensor unit (105) are arranged on the substrate assembly (111).

Description

Technical Field

[0001] This invention relates to a flow meter for determining the flow velocity of fluid in a medium pipeline.

[0002] The present invention also relates to a method for installing such a flow meter in a medium pipeline. Background Technology

[0003] In the field of flow measurement, there are already measuring devices used to determine the flow velocity of liquid or gaseous fluids in pipelines. These measuring devices will be referred to as flow meters below.

[0004] Flow meters in the prior art utilize different working principles, each of which is advantageous in specific applications.

[0005] Furthermore, the so-called vortex flow meter, also known as a vortex counter, is useful because the boundary layer, on a flow barrier also called an obstruction, detaches from the flow at a specific velocity, changing direction of rotation, forming a so-called Karman vortex street. With the aid of a suitable sensor, the frequency of this vortex shedding can be detected. This frequency allows for the determination of the flow velocity.

[0006] The purpose of heat flow measurement is to measure the removal of heat from a heat source by a flowing fluid. This heat removal is particularly relevant to flow velocity in lower velocity regions. A variation of heat flow measurement is hot gas measurement. A heating element, typically a hot wire or film resistor, is distributed here to carry the heat flow. The flowing fluid causes heat removal, thereby cooling the heating element. The heat flow is adjusted so that the heating element is maintained at a constant, elevated temperature relative to the fluid temperature. The necessary heating power can be derived from the fluid flow rate. To determine the real-time temperature of the fluid, the gas flow meter typically also includes an unheated temperature sensor, allowing for the consideration of fluid temperature variations when controlling the heating power.

[0007] For example, an air flow meter is known from DE3732856A1 that combines vortex flow measurement technology (i.e., a vortex counter) with hot-wire gas flow measurement technology (i.e., a hot gas flow meter). This combination of two measurement principles should enable reliable measurement over a wide velocity range. While hot-wire flow measurement technology provides high accuracy in low velocity ranges but becomes increasingly inaccurate at higher velocities, vortex flow measurement technology provides more accurate measurements at higher velocities. A significant drawback of the described measurement system is that, due to the use of a hot wire, it can only be applied to gaseous fluids such as air.

[0008] For example, a vortex flowmeter with a MEMS sensor mechanism (MEMS = Microelectromechanical System) is known from US10066976. This flowmeter includes an obstruction body in which a small channel is embedded. A MEMS sensor mechanism unit is disposed within the channel, the MEMS sensor mechanism unit including sensors for measuring flow rate using at least two different measurement principles. As mentioned in the aforementioned literature, this should cover an expanded measurement range. However, the sophisticated channel structure with an integrated MEMS sensor mechanism is susceptible to contamination buildup, thus such a flowmeter is practically only suitable for use with relatively clean gaseous media. Summary of the Invention

[0009] The objective of this invention is to provide a flow meter that is more improved than the prior art, especially one that can be manufactured at low cost and used flexibly, and to provide a simple and low-cost method for installing such a flow meter.

[0010] The task of the flow meter is solved by the features given in Embodiment 1. Dependent embodiments describe advantageous variations of the flow meter.

[0011] The task of the method is solved by the features given in Implementation 23.

[0012] A flow meter according to the present invention for determining the flow velocity of a fluid in a medium pipeline includes at least one sensor base, the sensor base comprising an obstruction and a sensor body. Furthermore, the flow meter includes an electronic unit and a signal interface. The obstruction is disposed substantially upstream of the sensor body in the flow direction. The sensor body includes a support member and a base assembly. The base assembly further includes at least one ceramic substrate. Additionally, a gas flow meter-sensor unit and a vortex counter-sensor unit are disposed on the base assembly, i.e., on the at least one ceramic substrate.

[0013] In this context, "medium conduit" refers to any type of guide or spatial limitation for the flow of a medium, such as a channel, pipe, or surface through which the fluid flows. Due to its structure or components, the flow meter according to the invention is suitable for use in any of the exemplary media conduits described.

[0014] In the context of this invention, the sensor base refers to an element of the flow meter that connects the flow meter to a portion of the media conduit. This sensor base enables flexible use of the flow meter at many measurement locations, allowing for a sealed and stable installation. The installation location of the flow meter is called the measurement location. When the measurement location is, for example, constructed as an opening in the pipe wall, the sensor base can be constructed, for example, as a flange or a plug-like insert.

[0015] The obstruction can be constructed as part of a sensor base or as a separate component held by the sensor base. These variations enable low-cost structures that can be flexibly adapted to many applications. The obstruction can be constructed as a rod-shaped element. The obstruction has a longitudinal axis that extends, for example, from the sensor base into the flowing fluid. Many suitable cross-sectional shapes exist in the prior art for the obstruction. The cross-sectional shape can be, for example, triangular, wherein the triangular sides are oriented perpendicular to and opposite to the flow direction, and the triangle is constructed symmetrically about an axis parallel to the flow direction.

[0016] The sensor body can also be constructed as part of a sensor base, or as a separate component held by the sensor base. These variations enable a low-cost structure that can be flexibly adapted to many applications. The sensor body can be constructed, for example, as a paddle-shaped or plate-shaped body with a longitudinal axis that extends from the sensor base into the flowing fluid.

[0017] The obstruction is positioned substantially upstream of the sensor body in the flow direction. In this context, this means, for example, that the volume element of the flowing fluid passes through the obstruction before passing through the sensor body. Here, for example, the obstruction and sensor body can be positioned along a line parallel to the flow direction. However, according to the invention, an obstruction positioned off-center, outside that line and before the sensor body, is also essentially defined as upstream, provided that the sensor body is not excluded from the influence of vortices formed behind the obstruction due to this arrangement. This arrangement enables reliable measurement over a wider flow velocity range.

[0018] According to the present invention, the electronic unit includes, for example, any type of circuit board, conductor channel, microelectronic component, and electronic component, which are suitable for performing control and measurement tasks individually or in combination, which are necessary to achieve the features of the present invention. The corresponding components can be mounted on one or more circuit boards, for example, on one or more packaged units, and can be electrically connected to each other. The electronic unit can be connected to the gas flow meter-sensor unit and the vortex counter-sensor unit via the conductor channel, and can receive and analyze the electrical sensor signals of these units. The sensor signals can be measurable voltage, current, capacitance, or frequency. The electronic unit may have short-time memory or non-short-time memory. The power supply of the flow meter can be provided to the electronic unit through electrical lines or an electromagnetic field from an external power source. Alternatively, the electronic unit can also have its own power source, such as a battery or battery pack. The electronic unit can be disposed within the internal space of the sensor base or within the housing of the flow meter. Here, the housing of the flow meter can be connected to the sensor base and disposed outside the medium conduit.

[0019] According to the invention, the signal interface is, for example, any medium for transmitting electrical or electromagnetic signals. Such a signal interface advantageously enables the flexible transmission of measured values, error signals, and other information from the flow meter to many different receivers. Data from external transmitters, such as calibration and configuration data, can also be received via the signal interface. The signal interface can be constructed, for example, via an electrical plug connector or a radio interface conforming to known wireless standards. The signal interface can be located within or adjacent to the internal space of the sensor base, or within or adjacent to the flow meter housing.

[0020] According to the invention, the support member is configured, for example, to accommodate or hold the base assembly. The support member can also be used to shape the external form of the sensor body. Such a support member enables a simple, modular structure and low-cost manufacturing of the flow meter.

[0021] The substrate assembly includes at least one ceramic substrate or an assembly of multiple ceramic substrates, which are interconnected, bonded, stacked, or separated from each other by other elements. The ceramic substrate is, for example, a thin plate made of ceramic material. According to the invention, the ceramic substrate serves, for example, as a support for a sensor unit. Such a substrate assembly enables a simple, low-cost structure and allows the element to have high resistance to environmental impacts.

[0022] In the context of this invention, a gas flow meter-sensor unit refers to any characteristic of a measuring element, or any combination of characteristics of measuring elements, such as resistance or a thermistor, and the gas flow meter-sensor unit is suitable for implementing the measurement principle of hot air force measurement.

[0023] In the context of this invention, a vortex counter-sensor unit refers to any characteristic of a measuring element, or any combination of characteristics of measuring elements, which is suitable for implementing the measurement principle of vortex counter flow measurement.

[0024] The combination of the aforementioned sensor units enables the flow meter to achieve high measurement accuracy over a wide range of flow velocities. Furthermore, constructing the sensor units on the substrate assembly allows for low-cost manufacturing and high resistance to environmental impacts.

[0025] The following description of advantageous variations, particularly the description of the geometric setup, is predicated on the premise that the flow direction of the fluid extends horizontally, while the flow meter or obstruction and sensor body are oriented in a direction at least substantially orthogonal to it, and thus perpendicular. Therefore, the flow direction setup defined as at least substantially orthogonal to each other and the orientation of the flow meter or obstruction and sensor body mean that the longitudinal axis of the obstruction and sensor body does not extend parallel to the flow direction. Each deviation from horizontal and vertical flow direction selection, or flow meter orientation, will be considered equivalent according to this definition.

[0026] In one possible variation of the flow meter, the gas flow meter-sensor unit includes a first thick-film resistor for determining the medium temperature and a heated thick-film resistor for determining fluid-related power losses. Here, the first thick-film resistor and the heated thick-film resistor are positioned a first distance apart from each other about the vertical longitudinal axis of the sensor body.

[0027] The gas flow meter-sensor unit, utilizing a thick-film resistor design, enables a low-cost and highly robust sensor unit construction when integrated with the substrate assembly. The thick-film material is chosen to achieve the highest possible temperature coefficient, thereby also achieving high measurement accuracy.

[0028] In this possible variant scenario, the medium temperature value refers to the temperature of the flowing fluid.

[0029] Furthermore, in this possible variant, the resistors are spaced a first distance apart, arranged about the longitudinal axis of the sensor body. This means that the resistors are not arranged sequentially in the flow direction and, for example, do not overlap. Advantageously, the localized heating of the flowing fluid by the heated thick-film resistor in the direct environment has no effect on the measurement of the medium temperature by means of the first thick-film resistor. This improves the measurement accuracy of the gas flow meter-sensor unit.

[0030] In this possible variant scenario, it is not important whether the thick-film resistors are constructed on a common ceramic substrate or on two separate ceramic substrates.

[0031] In another possible variation of the flow meter, the vortex counter-sensor unit and the gas flow meter-sensor unit are positioned a second distance apart from each other about the vertical longitudinal axis of the sensor body. Here, the vortex counter-sensor unit may be located on the end section of the sensor body furthest from the sensor base.

[0032] In this variant, the sensor units are spaced a second distance apart from each other. The arrangement about the longitudinal axis of the sensor body means that the sensor units are not arranged sequentially in the flow direction and, for example, do not overlap each other.

[0033] This allows for an advantageous outcome where the localized heating of the flowing fluid in the direct environment of the heated thick-film resistor in the gas flow meter-sensor unit has no practical impact on the measurements of the vortex counter-sensor unit. This, in turn, improves the measurement accuracy of the vortex counter-sensor unit.

[0034] The vortex counter-sensor unit is positioned at the end of the sensor body, meaning that, for example, it extends further into the fluid flow than a gas flow meter-sensor unit, originating from a sensor base at the edge of the medium pipe. This allows for a particularly stable structure because the sensor body only needs to be inserted into the medium pipe to such an extent that the vortex counter-sensor unit is located within a region of sufficiently strong vortices. Consequently, the sensor body is subjected to relatively low overall hydrodynamic forces.

[0035] In this possible variant scenario, it is not important whether the gas flow meter-sensor unit and the vortex counter-sensor unit are constructed on a common ceramic substrate or on multiple separate ceramic substrates.

[0036] In another possible variation of the flow meter, the heated thick-film resistor is disposed on a ceramic substrate of the substrate assembly, the ceramic substrate having a cross-sectional contraction. The cross-sectional contraction can be disposed about the vertical longitudinal axis of the sensor body, for example, in a region of a first distance between the heated thick-film resistor and a first thick-film resistor, and / or in a region of a second distance between the gas flow meter-sensor unit and the vortex counter-sensor unit.

[0037] By means of the cross-sectional contraction, heat conduction through the ceramic substrate away from the heated thick-film resistor is effectively reduced. By positioning the cross-sectional contraction at a suggested location—that is, between each resistor or sensor unit relative to the longitudinal axis of the sensor body—the heating of the first thick-film resistor and / or the vortex counter-sensor unit by the heat from the heated thick-film resistor can be significantly reduced. This improves measurement accuracy and its stability. In this case, the cross-sectional contraction can be achieved, for example, through a trapezoidal cross-section on the side.

[0038] In this variant, it is not important whether the heated thick-film resistor, the first thick-film resistor, and the vortex counter-sensor unit are constructed on a common ceramic substrate or on multiple separate ceramic substrates.

[0039] In another possible variation of the flow meter, the vortex counter-sensor unit includes a pressure sensor.

[0040] The pressure sensor is suitable for reliably and accurately identifying the frequency at which vortices detach from the obstruction. Furthermore, the pressure sensor can be fabricated and assembled in a low-cost and simple manner when combined with a substrate component. Here, the pressure sensor can be configured as a MEMS chip (MEMS = Microelectromechanical Systems). Alternatively, the pressure sensor can also be configured as a diaphragm equipped with at least one strain-sensitive measuring element, which is integrated directly into the ceramic substrate of the substrate component. For example, a strain gauge or a strain-sensitive resistive channel on the diaphragm is suitable as the strain-sensitive measuring element.

[0041] In another possible variation of the flow meter, the pressure sensor is disposed on a ceramic substrate of the base assembly, the ceramic substrate having a notch, with the pressure sensor positioned above the notch. Furthermore, the sensor body has a free position surrounding the location of the pressure sensor. Through this free position, the pressure sensor receives and withstands the pressure of the flowing fluid. The notch and / or the free position can be sealed, in particular, with an elastic filler.

[0042] According to this variant, a notch refers to a through opening from one side of the ceramic substrate to the other side. Such an opening can be, for example, rectangular or constructed as a circular hole.

[0043] By positioning the pressure sensor above the notch, the strain-sensitive element of the pressure sensor can detect the pressure difference and pressure changes between the two sides of the substrate and the sensor body. When there is no corresponding notch, for example, a pressure sensor configured as a MEMS pressure sensor with an integrated reference chamber can be positioned on a ceramic substrate, and the pressure sensor detects pressure changes on its surface.

[0044] In this variant scenario, the placement of the pressure sensor on the ceramic substrate refers to, for example, adhesion.

[0045] When the pressure sensor is constructed as a diaphragm integrated into a ceramic substrate, and the diaphragm has at least one strain-sensitive measuring element, then according to the aforementioned definition of a notch, the ceramic substrate no longer has a notch. Instead, the ceramic substrate has a weakened portion, for example, a milled hole, at the location of the diaphragm, or thereby constructs the diaphragm. Nevertheless, such an implementation of the pressure sensor can still be combined with the free positions described above and below for the sensor body.

[0046] According to this variant, the free position refers to the shaping of the sensor body, so that the pressure sensor is covered not through the sensor body, but, for example, through a support member. For example, when combined with a notch in a ceramic substrate or a weakened portion or milled section of the material constituting the diaphragm, it is possible to apply the pressure of the fluid flowing on both sides of the sensor body to the pressure sensor, while simultaneously achieving a simple and low-cost structure.

[0047] Resilient fillers can be used to fill free positions and / or gaps to advantageously protect the pressure sensor from direct contact with the fluid. This allows the flow meter to be applied to a wide variety of fluids, particularly liquid media. Thanks to the elasticity of the filler, pressure transmission to the strain-sensitive element of the pressure sensor is also unimpeded. Silicone can be used as an example of a resilient filler.

[0048] In another possible variation of the flow meter, the substrate assembly includes at least two ceramic substrates, namely a first ceramic substrate and a second ceramic substrate. Here, the heated thick-film resistor is disposed on the first ceramic substrate, and the first thick-film resistor and the vortex counter-sensor unit are disposed on the second ceramic substrate.

[0049] With such a distribution of the sensor unit and / or resistors on the first and second ceramic substrates, it is advantageous to reduce the heat transfer from the heated thick-film resistor to the first thick-film resistor and the eddy counter-sensor unit.

[0050] Furthermore, this variant can specify that the ceramic substrates are arranged at least substantially parallel to each other. Here, "at least substantially parallel" means that the two substrates lie in two planes that either extend truly parallel to each other or intersect at an angle of less than 90 degrees.

[0051] Furthermore, in this variant, the support member can be disposed between the two ceramic substrates, for example, partially between the ceramic substrates. In this way, the support member can advantageously contribute to further reducing heat transfer from the thick-film resistance heated on the first ceramic substrate to the elements disposed on the second ceramic substrate. Moreover, the structure can be implemented in this manner in a particularly compact, low-cost, and robust manner because the support member supports, holds, and / or stabilizes the ceramic substrates.

[0052] Furthermore, this variant of the flow meter can be advantageously combined with the aforementioned possible variants. For example, it can be specified that the first ceramic substrate has a cross-sectional contraction located in a region relative to the first distance along a vertical longitudinal axis. The second ceramic substrate can have, for example, a notch, above which a vortex counter-sensor unit, implemented as a pressure sensor, is disposed.

[0053] In another possible variation of the flow meter, the ceramic substrate of the base assembly and the elements disposed on the ceramic substrate are coated with a protective layer. This protective layer can be constructed as a thick-film glaze and / or applied using a so-called sol-gel process.

[0054] By utilizing such a protective layer, it is possible to protect the flow meter from the effects of liquid media, especially at a much lower cost.

[0055] In another possible variation of the flow meter, the support member has a recess on its side that is oriented at least substantially orthogonal to the flow direction, wherein the ceramic substrate of the base assembly is placed or inserted into the recess.

[0056] In the context of this variant, "at least substantially orthogonal to the flow direction" means that the ceramic substrate placed or inserted into the recess is oriented such that it is at least not perpendicular to the flow direction, and the ceramic substrate in particular has a surface parallel to the flow direction.

[0057] This variant allows for an advantageous outcome: the sensor body structure is particularly robust while simultaneously being easily and cost-effectively molded. In this variant, the support member stably holds or supports the ceramic substrate, thus improving the mechanical stability of the structure. Furthermore, when combined, for example, with the aforementioned possible variants having a first ceramic substrate and a second ceramic substrate, only three components are required to construct the sensor body: the first ceramic substrate, the second ceramic substrate, and the support member. This enables low-cost production.

[0058] The recess is configured, for example, as a concave shape adapted to the contour of the ceramic substrate. This allows the ceramic substrate to be easily placed into the recess. Optional retaining elements, such as stop protrusions, can securely hold the ceramic substrate in the recess. Alternatively, the recess can also be implemented with an undercut, allowing the ceramic substrate to be inserted into the... Undercut Furthermore, the recess can also be, for example, locally bag-shaped, so that the ceramic substrate contained therein is held particularly stably, and is also protected from direct contact with flowing fluids.

[0059] In another possible variation of the flow meter, the sensor base and / or obstruction and / or support components are made of plastic in an injection molding process. The plastic is particularly capable of being constructed to be non-thermally and non-electrically conductive, and / or selected from a variety of fiber composite materials.

[0060] This variant enables manufacturing at exceptionally low cost. Furthermore, the components can be implemented in an advantageous manner, exhibiting resistance to environmental impacts while maintaining a relatively low weight. When combined with the aforementioned variant, the support structure according to this variant is particularly effective in fulfilling its thermal insulation function between the first and second ceramic substrates (with heated thick-film resistors).

[0061] The fiber composite material also offers high mechanical stability and resistance, which can be advantageously utilized in flow meters.

[0062] In another possible variation of the flow meter, the sensor body has at least a partially elliptical cross-sectional profile on at least the surface opposite to the flow direction, wherein the profile is constructed, for example, as an ellipse or a circle.

[0063] In this variant, the cross-sectional profile refers to a cross-section that passes through the sensor body perpendicular to its vertical longitudinal axis. Furthermore, the described surface can be any surface facing an obstruction. For example, it is the surface of the sensor body that is first passed through or first contacted by the volumetric segment of the flowing fluid.

[0064] The cross-sectional profile is at least partially constructed as an ellipse. Furthermore, this elliptical profile does not extend along the entire vertical longitudinal axis of the sensor body, or its shape changes along that axis. For example, the elliptical cross-sectional profile can have a radius of curvature that decreases from the sensor base towards the lower end section of the sensor body. Additionally, the surface opposite to the described surface can be constructed symmetrically with respect to the described surface, or similarly have a different cross-sectional profile, such as a rectangle.

[0065] This shape induces less eddy currents and turbulence in the fluid by the sensor body. This, in turn, contributes to the sensor body experiencing less flow-induced high pressure and less vibration from vortices that dissipate with changing rotational directions. Through the last possible variation, the flow resistance of the sensor body can be significantly reduced.

[0066] In another possible variation of the flow meter, the sensor base, the obstruction body, and the sensor body are integrally formed. That is, they are constructed from a single block and are integrally or permanently connected to each other.

[0067] The flow meter can thus be manufactured at a particularly low cost, and its structure can be easily formed. This variant is especially advantageous when combined with component manufacturing using the aforementioned injection molding process.

[0068] Regarding the alternative flow meter variant mentioned at the end above, the flow meter can also be constructed in another possible variant in which the sensor base, the obstruction body, and the sensor body are separate parts, and the sensor base has a support frame for accommodating and holding the obstruction body and / or the sensor body.

[0069] For example, the sensor base has two brackets, in which the obstruction is accommodated and held in the first bracket, and the sensor body is accommodated and held in the second bracket.

[0070] Alternatively, the sensor base may have only one support frame to receive and hold the obstruction. The obstruction may also have its own support frame to receive and hold the sensor body.

[0071] According to this variant, the support frame fits into the opening between the internal space of the medium pipe and the internal space of the sensor base, or the space surrounding the medium pipe. By accommodating and holding the obstruction and / or sensor body within the support frame, the frame is sealed, thus preventing medium penetration.

[0072] According to this variant, the support frame can be sealed, for example, by an O-ring or a shaped seal, or by a form-fitting seal towards the obstruction and / or the sensor body. This prevents fluid from escaping from the media conduit and entering the sensor base. Furthermore, it allows for a stable structure.

[0073] In another possible variation of the flow meter, the obstruction and / or sensor body is movably supported in a support frame. Here, the obstruction and sensor body can, for example, be movable relative to the sensor base at least substantially orthogonal to the flow direction and at least substantially parallel to the longitudinal axis of the sensor body and / or the longitudinal axis of the obstruction.

[0074] With such a support, it is advantageous to achieve that the immersion depth of the barrier and / or the immersion depth of the sensor body can be flexibly adjusted, for example, to adapt to the geometry of the medium conduit.

[0075] In this variant, the immersion depth describes the extent to which the obstruction and / or sensor body is inserted from the sensor base into the flowing fluid and / or media conduit. For example, it may be specified that the immersion depth of the obstruction is proportionate to the diameter of the media conduit in order to facilitate the most uniform flow possible. The immersion depth of the sensor body may, for example, be proportionate to the distance to the center of the fluid, i.e., proportionate to the radius of the media conduit.

[0076] Furthermore, the flow meter may have a fixing device arranged to securely connect the movable support obstruction and / or the movable support sensor body to the sensor base. In this secure connection, the obstruction and / or the sensor body can no longer move.

[0077] This allows for advantageous adjustment of the immersion depth of the obstruction and / or sensor body via the movable support. When the immersion depth is properly adjusted, the relative position of the obstruction and / or sensor to the sensor base can be fixed, thus providing a stable flowmeter structure. This fixing is reversible, allowing for constant readjustment of the immersion depth.

[0078] In another possible variation of the flow meter, the fixing device includes a reservoir filled with a castable, for example, a two-component castable. Here, the reservoir can be configured such that the castable flows automatically, for example by gravity, into the support frame when the reservoir is opened, and solidifies within the support frame in a sealing manner. This solidification can be achieved through contact and reaction with ambient air, or, when the castable is a two-component castable, through the mixing and reaction of the components. This design of the fixing device enables permanent, particularly resistant fixing and simultaneous sealing of the support frame.

[0079] According to this variant, the storage compartment is, for example, a closed plastic bag or pouch with thin walls. The thin walls can be opened, for example, using a tool such as a screwdriver.

[0080] In another possible variation of the flow meter, an electronic unit is arranged to acquire sensor signals from the gas flow meter-sensor unit and the vortex counter-sensor unit, and, depending on the sensor signals, assign the sensor signals to a low-speed measurement zone, an overlapping measurement zone, or a high-speed measurement zone.

[0081] Regarding the measurement zone, the vortex counter-sensor unit typically exhibits a unique measurement inaccuracy that decreases with increasing flow velocity. This indicates that the vortex counter-sensor unit measures very accurately at higher flow velocities. According to this variant, the high-velocity measurement zone can therefore be a measurement zone with higher flow velocities, in which the vortex counter-sensor unit has lower measurement inaccuracies. Conversely, the hot gas flow meter-sensor unit exhibits a typically opposite relationship. That is, the hot gas flow meter-sensor unit has very low measurement inaccuracies at lower flow velocities, which increase with increasing flow velocity at the end of the measurement zone. According to this variant, the low-velocity measurement zone can be a measurement zone with lower flow velocities, in which the gas flow meter-sensor unit has lower measurement inaccuracies. The medium-velocity measurement zone in which both the gas flow meter-sensor unit and the vortex counter-sensor unit have low measurement inaccuracies can be referred to as the overlapping measurement zone. By definition, the overlapping measurement zone can be the intersection of the low-velocity and high-velocity measurement zones. However, it is possible that if other zones do not overlap, then the overlapping measurement zone is defined as the zone between other zones, or if the low-speed measurement zone and the high-speed measurement zone intersect only at a boundary value, then the overlapping measurement zone is defined as a point value.

[0082] According to this variant, the electronic unit can assign sensor signals to the measurement zone or flow velocity zone based on the sensor signals, thereby determining which measurement inaccuracy the sensor unit is operating at. This advantageously opens up the possibility of intelligent control and optimization of the flow meter's operation through the electronic unit, which is the goal of the variant described later.

[0083] Here, the sensor signals can be assigned, particularly based on reference data and / or calibration data stored in the flow meter. This assignment can be based on a single sensor signal, on two sensor signals, or on the relationship between two sensor signals.

[0084] In another possible variation of the flow meter, the electronic unit is arranged to analyze the sensor signal of the gas flow meter-sensor unit in the low-speed measurement zone and provide it as a measured value signal through the signal interface, and to analyze the sensor signal of the vortex counter-sensor unit in the high-speed measurement zone and provide it as a measured value signal through the signal interface.

[0085] The analysis of sensor signals refers to calculating the measured value signal from the sensor signal according to specific analysis rules. The electronic unit can store its own analysis rules for the gas flow meter-sensor unit and the vortex counter-sensor unit, respectively, for example, the analysis rules are determined during calibration.

[0086] Because the signals of the sensor units are analyzed and emitted separately, this variant scheme can optimize the measurement accuracy of the flow meter. Due to their respective characteristics, the sensor units have minimal measurement inaccuracies in the existing flow velocity range.

[0087] In another possible variation of the flow meter, the electronic unit is arranged to analyze the sensor signals of the gas flow meter-sensor unit and the vortex counter-sensor unit simultaneously in the overlapping measurement area, and provide the resulting measured value signal through the signal interface.

[0088] In this variant, analyzing sensor signals together refers to acquiring two sensor signals and combining them to calculate the resulting measurement. This calculation can be done by deriving an intermediate value from the separately obtained measurements, for example, by weighted calculation. Here, a weighting factor wA can be assigned to the measurement determined from the sensor signal of the gas flow meter-sensor unit, and a weighting factor wW = (1-wA) can be assigned to the measurement determined from the sensor signal of the vortex counter-sensor unit. The weighting factor wA can be dynamically determined, for example, taking the value wA = 1 at the lower limit of the overlapping measurement region and wA = 0 at the upper limit of the overlapping measurement region, and following a function, for example, between the upper and lower limits, that is related to one or both sensor signals and takes values ​​between 1 and 0. In the simplest case, the function is a straight line that linearly falls from an initial value of 1 to a final value of 0 in the overlapping measurement region.

[0089] This modified scheme enables a smooth transition from low-speed to high-speed measurement zones in the overlapping measurement area, while achieving low measurement inaccuracies in all zones.

[0090] In another possible variation of the flow meter, the electronic unit is arranged to analyze the sensor signals of the gas flow meter-sensor unit and the vortex counter-sensor unit together in the overlapping measurement zone, and to balance the sensor signals of the gas flow meter-sensor unit with those of the vortex counter-sensor unit, and / or to adjust the signal deviation of the gas flow meter-sensor unit relative to the vortex counter-sensor unit in the overlapping measurement zone to suit the low-speed measurement zone.

[0091] Analyzing sensor signals together, in this variant context, means acquiring two sensor signals and, in particular, analyzing the sensor signals according to their respective analysis rules.

[0092] Balancing the sensor signal of the gas flow meter-sensor unit with the sensor signal of the vortex counter-sensor unit means that the electronic unit only analyzes the sensor signal of the vortex counter-sensor unit into a measured value signal and provides it through the signal interface. Conversely, the sensor signal of the gas flow meter-sensor unit is only compared with the sensor signal of the vortex counter-sensor unit, and / or the measured values ​​of the two sensor units are compared, and / or possible signal deviations or measured value deviations are determined.

[0093] Adjusting the signal deviation of the gas flow meter-sensor unit relative to the vortex counter-sensor unit in the overlapping measurement region to adapt to the low-speed measurement region refers to adjusting the analysis rules used to analyze the sensor signal of the gas flow meter-sensor unit into measured values ​​or measured value signals, so that these analysis rules are adapted to the real-time analyzed measured values ​​or measured value signals of the vortex counter-sensor unit in the overlapping region. This balances the long-term signal variations of the gas flow meter-sensor unit, i.e., the so-called drift, which can be caused, for example, by deposition on a thick-film resistor.

[0094] This adaptation adjustment process can, for example, be combined with the aforementioned sensor signal balancing, and / or initiated through the balancing. Here, the adaptation adjustment process is automatically implemented when the deviation of the gas flow meter-sensor unit relative to the vortex counter-sensor unit over a certain time interval is determined, and this deviation exceeds a preset threshold value. During this time interval, both signals are stable (and therefore signal deviation or measurement deviation is not attributed to inconsistent response times).

[0095] Therefore, the reliable function and measurement accuracy of the flow meter can be maintained in an advantageous manner throughout the measurement range, and the frequency of disassembling the flow meter for calibration, cleaning or correction is reduced.

[0096] In another possible variation of the flow meter, the electronic unit is arranged to simultaneously analyze the sensor signals from the gas flow meter-sensor unit and the vortex counter-sensor unit, and, using reasonably reliable data stored in the electronic unit, determine that one of the two sensor units is faulty. Once the fault is determined, a fault signal can be issued through the signal interface.

[0097] Analyzing sensor signals together, in this variant, refers to acquiring two sensor signals and, in particular, comparing them. According to this variant, reliable data includes data and limit values ​​stored in the electronic unit, especially tolerance ranges and numerical tables for the sensor signals, or the differences between the sensor signals. This reliable data can infer the normal functioning of the sensor unit.

[0098] This variant allows the flow meter to independently monitor its function and identify and signal faults, thus enabling rapid fault identification.

[0099] Specifically, it can be stipulated that the reasonable and reliable data is determined by the flow meter itself during the so-called learning phase, for example, when the flow meter starts up. Here, the electronic unit can enter the learning operation state via a signal interface through a corresponding control signal. In this learning operation state, the electronic unit continuously analyzes the sensor signals and derives the corresponding reasonable and reliable data from the analysis. When sufficient reasonable and reliable data has been accumulated, the electronic unit can switch to normal measurement operation. During the learning phase, the sensor signals and / or measured values ​​can be monitored by a control position to ensure that no malfunction occurs in one of the sensor units during the learning phase.

[0100] In another possible variation of the flow meter, the electronic unit is arranged to analyze the sensor signals from both the gas flow meter-sensor unit and the vortex counter-sensor unit, and to receive information about the fluid velocity via the signal interface. The electronic unit can calculate fluid properties from this information and the sensor signals from the gas flow meter-sensor unit and the vortex counter-sensor unit, and transmit these properties via the signal interface. These properties may include, for example, the fluid's density, viscosity, or thermal conductivity.

[0101] Therefore, flow meters are also flexible enough to measure quantities other than flow velocity, and can provide valuable information about the process medium, for example, when used in process industries. Here, if the flow velocity is not constant during the analysis of the sensor signal, but varies over a time interval, such as a time interval including an overlap region, then the calculated fluid properties can be given with particularly high accuracy.

[0102] In another possible variation of the flow meter, the electronic unit is arranged to temporarily increase the heating power on the heated thick-film resistor, so that the sensor body is at least partially free of organic deposits.

[0103] As explained in the preceding paragraphs, this method effectively prevents deposits on the heated thick-film resistor from affecting the sensor signal. Consequently, reliable function and measurement accuracy of the flow meter can be maintained for extended periods, and the frequency of disassembly for calibration, cleaning, or adjustment is reduced.

[0104] It can also be specified that the first thick film resistor is temporarily switched from the measurement working state to the heating working state through the electronic unit, and the first thick film resistor is also connected with increased heating power in the heating working state, so that the organic deposits can also be removed at least partially.

[0105] In the method according to the invention for installing a flow meter at a measuring position in a medium pipeline, a sensor base is positioned at the measuring position. In this context, "positioning" refers, for example, to screwing in a threaded seat, attaching it, welding it, or forming a flange connection. Once the sensor base is stably and sealingly positioned at the measuring position, a retainer is inserted from outside the medium pipeline into the holder of the sensor base and guided into the medium pipeline. Here, the depth of insertion of the retainer is, for example, such that the retainer contacts the inner wall of the medium pipeline opposite the sensor base. In the next step, the sensor body is guided from outside the medium pipeline into the medium pipeline via another holder of the sensor base or another holder of the retainer. Here, the depth of insertion of the sensor body is, for example, such that the end portion of the sensor body is positioned in the center of the fluid, i.e., in the middle of, for example, the medium pipeline. In another step, the retainer and the sensor body are securely connected to the sensor base by a fixing device.

[0106] This method allows for very quick and therefore low-cost installation of flow meters. Furthermore, individual adjustments to the media piping dimensions, particularly the media piping diameter, are possible.

[0107] To determine the flow rate in generally flowing fluids, i.e., gaseous and liquid flowing media, the flow meter according to the invention and its variations have been described in the preceding paragraphs. The flow meter according to the invention and its possible variations can also be used in liquid media because its modular and stable structure enables high mechanical load capacity and high sealing performance. The flow meter can thus withstand greater forces, which are greater than those conducted by flowing liquids compared to flowing gases.

[0108] Furthermore, the flow meter according to the invention and its possible variations are also suitable for use in fluids that have both liquid and gaseous components. The flow meter can also be used in flow media that are predominantly gaseous, even when faced with short-duration, pulsating liquid flows. Conversely, such pulsating liquid flows can damage known flow meters for gases, particularly their sensitive measuring elements such as hot wires.

[0109] When faced with short-duration, pulsating gas flows or bubbles, the flow meter according to the invention and its possible variations can also be used in preferred liquid flow media. The stable structure of the flow meter can withstand the fluctuations in mechanical load. The sensor unit constructed on the base assembly can also operate reliably under such load fluctuations. According to various variations of the flow meter, the first thick-film resistor and the heated thick-film resistor of the gas flow meter-sensor unit can withstand the thermal delamination that occurs simultaneously with the change from liquid to gas phase, i.e., it will not cause burnout, as is possible in the case of hot wire applications.

[0110] The flow meter, variations thereof, and method for installing the flow meter according to the present invention are not limited to the embodiments described above. Without mutual exclusion, this specification particularly includes individual features or all combinations of features of the various variations. Attached Figure Description

[0111] The following description, with reference to the accompanying drawings, illustrates possible embodiments and variations of the present invention.

[0112] in

[0113] Figure 1 This diagram schematically illustrates a flow meter in a media pipeline.

[0114] Figure 2 A ceramic substrate is schematically shown.

[0115] Figures 3A to 3C The schematic diagram shows the support structure and the cross-section through the sensor body.

[0116] Figures 4A to 4CThe diagram illustrates three sub-steps of a method for installing a flow meter.

[0117] Figure 5 Two charts are shown schematically, and

[0118] Figure 6 A schematic cross-sectional view of two ceramic substrates of the base assembly is shown.

[0119] The same parts are labeled with the same reference numerals in all the accompanying drawings. Detailed Implementation

[0120] The foregoing description of the solution according to the invention thus includes, in particular, various combinations of features defined by the subsequently numbered embodiments:

[0121] 1. A flow meter (100) for determining the flow velocity of a fluid in a medium conduit (200), comprising - a sensor base (101) including an obstruction (102) and a sensor body (103), - an electronic unit (300) and

[0122] -Signal interface (400),

[0123] in

[0124] - The obstruction (102) is positioned at least substantially upstream of the sensor body (103) in the flow direction.

[0125] The sensor body (103) includes a support member (110) and a substrate assembly (111), the substrate assembly having at least one ceramic substrate (108, 109), and

[0126] The gas flow meter sensor unit (104) and the vortex counter sensor unit (105) are disposed on the base assembly (111).

[0127] 2. The flow meter (100) according to embodiment 1,

[0128] in

[0129] The gas flow meter-sensor unit (104) includes

[0130] - The first thick-film resistor (106) used to determine the medium temperature of the fluid, and

[0131] - Thick-film resistor (107) used to determine fluid-related power losses during heating, and

[0132] - The first thick-film resistor (106) and the heated thick-film resistor (107) are positioned apart from each other by a first distance (501) about the vertical longitudinal axis (500) of the sensor body (103).

[0133] 3. The flow meter (100) according to embodiment 2,

[0134] in

[0135] The vortex counter-sensor unit (105) and the gas flow meter-sensor unit (104) are arranged apart from each other by a second distance (502) about the vertical longitudinal axis (500) of the sensor body (103), and

[0136] The vortex counter-sensor unit (105) is particularly disposed on the end section (131) of the sensor body (103) away from the sensor base (101).

[0137] 4. The flow meter (100) according to embodiment 3,

[0138] in

[0139] The heated thick-film resistor (107) is disposed on a ceramic substrate (108, 109), the ceramic substrate having a cross-sectional contraction (112).

[0140] The cross-sectional contraction (112) is positioned about the vertical longitudinal axis (500) of the sensor body (103).

[0141] -In the region of the first distance (501), and / or

[0142] -The region of the second distance (502).

[0143] 5. The flow meter (100) according to any one of the foregoing embodiments,

[0144] in,

[0145] The vortex counter-sensor unit (105) includes a pressure sensor (113), wherein the pressure sensor (113) is particularly

[0146] - Constructed into a MEMS chip or

[0147] - A diaphragm (126) is constructed to be integrated in the ceramic substrate (108, 109), and at least one strain-sensitive measuring element (132) is disposed on the diaphragm.

[0148] 6. The flow meter (100) according to embodiment 5,

[0149] in,

[0150] - The pressure sensor (113) is disposed on the ceramic substrate (108, 109), the ceramic substrate having a notch (115), wherein the pressure sensor (113) is disposed above the notch (115), and / or

[0151] - The sensor body (103) has a free position (116), through which the pressure sensor (113) receives the pressure of the flowing fluid, and

[0152] - In particular, the notch (115) and / or free position (116) are sealed with an elastic filler (117).

[0153] 7. The flow meter (100) according to any one of embodiments 2 to 6,

[0154] in,

[0155] The substrate assembly (111) includes a first ceramic substrate (108) and a second ceramic substrate (109), wherein

[0156] The heated thick-film resistor (107) is disposed on the first ceramic substrate (108), and

[0157] The first thick-film resistor (106) and the vortex counter-sensor unit (105) are disposed on the second ceramic substrate (109).

[0158] -The ceramic substrates (108, 109) are arranged substantially parallel to each other, and / or

[0159] - The support member (110) is disposed between the ceramic substrates (108, 109).

[0160] 8. The flow meter (100) according to any one of the foregoing embodiments,

[0161] in,

[0162] The ceramic substrate (108, 109) and the elements disposed on the ceramic substrate are coated with a protective layer (118), wherein the protective layer (118) is particularly

[0163] - is a thick film glaze, and / or

[0164] -The protective layer (118) is applied in the sol-gel process.

[0165] 9. The flow meter (100) according to any one of the foregoing embodiments,

[0166] in,

[0167] -The support member (110) has a recess (120) on its side oriented at least substantially orthogonal to the flow direction, and

[0168] - A ceramic substrate (108, 109) is placed or inserted into the recess (120).

[0169] 10. The flow meter (100) according to any one of the foregoing embodiments,

[0170] in,

[0171] -The sensor base (101) and / or

[0172] -The obstruction (102) and / or

[0173] -The supporting component (110)

[0174] Made of plastic in the injection molding process.

[0175] Among them, the plastic is particularly

[0176] - Constructed to be neither thermally nor electrically conductive, and / or

[0177] - Select from the types of fiber composite materials.

[0178] 11. The flow meter (100) according to any one of the foregoing embodiments,

[0179] in,

[0180] -The sensor body (103) has at least a partially elliptical cross-sectional profile on at least the surface (119) opposite to the flow direction, and

[0181] - The cross-sectional profile is particularly constructed to be elliptical or circular.

[0182] 12. The flow meter (100) according to any one of the foregoing embodiments,

[0183] in,

[0184] The sensor base (101), the barrier (102), and the sensor body (103) are integrally formed, especially in the injection molding process.

[0185] 13. The flow meter (100) according to any one of embodiments 1 to 11,

[0186] in,

[0187] - The sensor base (101) has a support frame (121) for accommodating and holding the obstruction (102) and / or the sensor body (103), and

[0188] -The bracket (121) is sealed, in particular, by means of a seal (122) or by a form fit toward the obstruction (102) and / or the sensor body (103).

[0189] 14. The flow meter (100) according to embodiment 13,

[0190] in,

[0191] The obstruction (102) and / or the sensor body (103) are in the bracket (121)

[0192] - Relative to the sensor base (101), and

[0193] -At least substantially orthogonal to the direction of flow, and

[0194] - At least substantially parallel to the longitudinal axis (500) of the sensor body (103).

[0195] Movable support, and in which

[0196] The flow meter (100) has a fixing device (123) that securely connects the obstruction body (102) and / or the sensor body (103) to the sensor base (101).

[0197] 15. The flow meter (100) according to embodiment 14,

[0198] in,

[0199] - The fixing device (123) includes a reservoir (124) filled with castable refractory (125), particularly a two-component castable refractory, and

[0200] - The reservoir (124) is configured such that the castable (125) flows into the support frame (121) when the reservoir (124) is opened, and solidifies in a sealing manner within the support frame.

[0201] 16. The flow meter (100) according to any one of the foregoing embodiments,

[0202] in,

[0203] The electronic unit (300) is arranged to acquire sensor signals from the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105), and, based on the sensor signals, assign the sensor signals to...

[0204] -Low speed measurement area (600) or

[0205] - Overlapping measurement area (700) or

[0206] - High-speed measurement zone (800).

[0207] 17. The flow meter (100) according to embodiment 16,

[0208] in,

[0209] The electronic unit (300) is arranged for

[0210] - The sensor signal of the gas flow meter-sensor unit (104) is analyzed in the low-speed measurement zone (600) and provided as a measured value signal through the signal interface (400).

[0211] - The sensor signal of the vortex counter-sensor unit (105) is analyzed in the high-speed measurement zone (800) and provided as a measurement value signal through the signal interface (400).

[0212] 18. The flow meter (100) according to embodiment 16 or 17,

[0213] in,

[0214] The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together in the overlapping measurement area (700), and to provide the measured value signal as a result through the signal interface (400).

[0215] 19. The flow meter (100) according to any one of embodiments 16 to 18,

[0216] in,

[0217] The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) simultaneously in the overlapping measurement area (700), and

[0218] - Balance the sensor signal of the gas flow meter-sensor unit (104) with the sensor signal of the vortex counter-sensor unit (105), and / or

[0219] - Adjustment to adapt the signal deviation of the gas flow meter-sensor unit (104) in the overlapping measurement area (700) relative to the vortex counter-sensor unit (105) to the low-speed measurement area (600).

[0220] 20. The flow meter (100) according to any one of the foregoing embodiments,

[0221] in,

[0222] The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together, and to determine, with the aid of reasonable and reliable data stored in the electronic unit (300),

[0223] -The gas flow meter-sensor unit (104) is faulty, or

[0224] -The vortex counter-sensor unit (105) is faulty.

[0225] And a fault signal is sent through the signal interface (400).

[0226] 21. The flow meter (100) according to any one of the foregoing embodiments,

[0227] in,

[0228] The electronic unit (300) is arranged for

[0229] -Analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together.

[0230] - Receive information about the fluid flow rate through the signal interface (400), and

[0231] - The fluid properties are calculated from the sensor signals and the information, and the properties are transmitted through the signal interface (400).

[0232] The properties mentioned here specifically refer to the fluid's density, viscosity, or thermal conductivity.

[0233] 22. The flow meter (100) according to any one of embodiments 2 to 22,

[0234] in,

[0235] The electronic unit (300) is arranged to temporarily increase the heating power on the heated thick film resistor (107), so that the sensor body (103) is at least partially free of organic deposits.

[0236] 23. A method for installing a flow meter (100) according to any one of embodiments 1 to 22 in a medium pipeline (200), characterized by the following steps

[0237] A) The sensor base (101) is set at the measurement position (201) of the medium pipeline (200).

[0238] B) Insert the obstruction (102) through the support frame (121), wherein the immersion depth of the obstruction (102) is at least substantially consistent with the diameter (D) of the medium conduit (200).

[0239] C) Insert the sensor body (103) through the support frame (121), wherein the immersion depth of the sensor body (103) is at least substantially consistent with the radius of the medium conduit (200), and

[0240] D) The obstruction (102) and the sensor body (103) are fixed to the sensor base (101) by means of the fixing device (123).

[0241] Figure 1 An exemplary embodiment of the flow meter 100 is shown, which combines features of a number of possible variations of the flow meter 100 described above according to the invention.

[0242] The flow meter 100 is installed at the measurement position 201 of the medium pipeline 200. The flow velocity curve of the fluid in the medium pipeline 200 is schematically shown by the arrow on the left side of the medium pipeline 200.

[0243] The flow meter 100 includes a sensor base 101, an obstruction 102, and a sensor body 103 having a support member 110, a base assembly 111, a gas flow meter-sensor unit 104, and a vortex counter-sensor unit 105. The immersion depth of the obstruction substantially corresponds to the diameter D of the medium pipe 200. Here, the vortex counter-sensor unit 105 is disposed in the region of the end section 131 of the sensor body 103. The immersion depth of the sensor body 103 substantially corresponds to at least half the diameter D of the medium pipe 200, wherein the sensor body 103 is disposed downstream of the obstruction 102 in the flow direction. The vertical longitudinal axis 500 of the sensor body 103 is shown as a dashed arrow.

[0244] Electronic unit 300 is connected to sensor units 104, 105 and signal interface 400 via electrical wiring. The signal interface 400 is exemplarily shown as a plug contact. Electronic unit 300 and signal interface 400 are disposed within housing 127 (indicated by dashed lines) of flowmeter 100. Obstruction 102 and sensor body 103 are received and held within support frame 121 of sensor base 101. This exemplary embodiment achieves the corresponding advantages of the invention described above through its features and components.

[0245] Figure 2 The left side shows an exemplary embodiment of a base assembly 111 having a first ceramic substrate 108. Figure 2 The right side shows the front and back of an exemplary embodiment of the substrate assembly 111 having a second ceramic substrate 109. The ceramic substrates 108 and 109 are shown at the same scale and relative to the longitudinal axis 500 of the common sensor body 103.

[0246] In the region of the lower end segment 114 of the first ceramic substrate 108, a heated thick-film resistor 107 is disposed on the first ceramic substrate 108. The heated thick-film resistor is connected to the contact portion 129 on the upper end of the first ceramic substrate 108 via a conductor channel 128.

[0247] Above the heated thick-film resistor 107, the first ceramic substrate 108 has a cross-sectional contraction 112. This cross-sectional contraction reduces the heat that can diffuse upwards from the heated thick-film resistor 107. Relative to the indicated vertical longitudinal axis 500 of the sensor body 103, the cross-sectional contraction 112 is disposed in a region of a first distance 501, located between the position of the heated thick-film resistor 107 and the position of the first thick-film resistor 106. A second distance 502 is constructed between the position of the heated thick-film resistor 107 and the position of the vortex counter-sensor unit 105.

[0248] As shown in the middle diagram, the second ceramic substrate 109 supports the vortex counter-sensor unit 105, exemplarily configured as a pressure sensor 113, on one side. The pressure sensor 113 is, for example, a MEMS chip. The pressure sensor 113 is attached to the second ceramic substrate 109 and above a notch 115 in the second ceramic substrate 109. The pressure sensor 113 is connected to a contact portion 129 provided for this purpose via a bonding wire 130. This contact portion is then connected to a conductor channel 128 having the contact portion 129 at the upper edge of the second ceramic substrate 109. This contact portion is also connected to the electronic unit 300.

[0249] As shown in the diagram on the right, on the other side of the second ceramic substrate 109, the second ceramic substrate 109 carries the first thick-film resistor 106, which is also electrically connected to the contact portion 129 at the upper end of the second ceramic substrate 109 via the conductor channel 128. The bottom portion of the pressure sensor 113 is exposed through the notch 115, allowing the pressure sensor 113 to receive pressure from both sides of the second ceramic substrate 109.

[0250] Figure 3A Two perspective views illustrate an exemplary embodiment of the support member 110.

[0251] The support member 110 forms the side surface 119 of the sensor body 103, which is oriented opposite to the fluid flow direction. The side surface 119 has an elliptical cross-sectional profile. Two surfaces perpendicular to the flow direction have recesses 120 into which ceramic substrates 108 and 109 can be placed or inserted. Furthermore, the support member 110 has a free position 116.

[0252] Figure 3B A cross-section of an exemplary embodiment of the sensor body 103 is shown, perpendicular to the vertical longitudinal axis 500 of the sensor body 103, the cross-section having a support member 110 and a base assembly 111.

[0253] The support member 110 has a side surface 119 oriented opposite to the flow direction, the side surface 119 being configured with an elliptical cross-sectional profile. An adjacent side surface has a recess 120 into which a first ceramic substrate 108 and a second ceramic substrate 109 are placed or inserted.

[0254] like Figure 3B As shown in the figure, Figure 3C A cross-section X along the vertical longitudinal axis 500 of an exemplary embodiment of the sensor body 103 is shown.

[0255] The first ceramic substrate 108 and the second ceramic substrate 109 are accommodated or inserted into the recess 120 of the support member 110 of the sensor body 103.

[0256] A heated thick-film resistor 107 is disposed on the first ceramic substrate 108. On the second ceramic substrate 109, a first thick-film resistor 106 is disposed on the outward-facing surface of the ceramic substrate 109 towards the fluid.

[0257] On the end section 131 of the sensor body 103, a pressure sensor 113 is disposed in the region of the free position 116 of the support member 110 on the other side of the second ceramic substrate 109. The pressure sensor is connected to a bonding line 130 having a contact portion 129 (not shown) on the substrate.

[0258] Furthermore, the second ceramic substrate 109 has a notch 115 in a surface section on which the pressure sensor 113 is disposed. The free position 116 and the notch 115 are filled with an elastic filler 117, which protects the sides of the pressure sensor 113 from direct contact with the fluid without hindering the receiving of pressure from the sides of the sensor body 103.

[0259] Figures 4A to 4C Three sub-steps of an exemplary design for an installation method are shown, the method being used to install an exemplary embodiment of a flow meter 100 at a measuring position 201 of a media conduit 200. The media conduit 200 and measuring position 201 are not shown for overview purposes.

[0260] Figure 4A A sensor base 101 is provided at measurement position 201. An obstruction 102 and a sensor body 103 are inserted into a support frame 121 of the sensor base 101 and move vertically therein until they reach their respective desired immersion depths. The support frame 121 is equipped with a seal 122. The fixing device 123 includes two reservoirs 124 filled with liquid castable 125. The castable 125 can be, for example, a two-component castable, such that each reservoir 124 prepares one component of the two components respectively.

[0261] Figure 4B In the process, the storage section 124 is broken open by means of tool 202. The casting material 125 of the fixing device 123 is released and flows into the support frame 121, the obstruction 102 and the sensor body 103 are held in the support frame and sealed by means of the seal 122.

[0262] Figure 4C This illustrates how the castable 125 hardens within the support frame 121. The obstruction 102 and sensor body 103 are thus securely connected to the sensor base 101, while the support frame 121 is simultaneously sealed in a hermetically sealed manner.

[0263] Figure 5 Two graphs are shown. In the upper graph, the measurement uncertainties 902 and 903 on the vertical axis 901 are shown above the horizontal axis 900, which represents the flow velocity. In the lower graph, the sensor signal on the vertical axis 904 is shown above the horizontal axis 900, which also represents the flow velocity.

[0264] In the diagram above, the relative measurement uncertainty 902 of the gas flow meter-sensor unit 104 is shown together with the relative measurement uncertainty 903 of the vortex counter-sensor unit 105. The gas flow meter-sensor unit 104 has a constant relative measurement uncertainty 902; in other words, the gas flow meter-sensor unit has the same relative accuracy relative to the real-time measurement value across its entire measurement range. Conversely, the vortex counter-sensor unit 105 has a constant measurement uncertainty 903 related to the final value of the measurement range across its entire measurement range.

[0265] The larger the real-time measured value, i.e., the greater the flow rate, the smaller the measurement uncertainty 903 becomes relative to each real-time measured value. It can be seen that it is advantageous to use the sensor signal of the gas flow meter-sensor unit 104 for analyzing the measured value in the first low-speed measurement zone 600, while in the high-speed measurement zone 800, the sensor signal of the vortex counter-sensor unit 105 is more suitable. In the overlapping measurement zone 700, the relative measurement uncertainties 902 and 903 of the two sensor units are almost identical.

[0266] The graphs below show the signal characteristic curve 905 of the gas flow meter-sensor unit 104 and the signal characteristic curve 906 of the vortex counter-sensor unit 105.

[0267] In the low-speed measurement zone 600, the signal characteristic curve 905 of the gas flow meter-sensor unit 104 initially rises sharply, then flattens out at higher flow rates. The signal characteristic curve 906 of the vortex counter-sensor unit 105 can only be reliably used starting from a certain minimum flow rate, and from that point it exhibits a continuous upward trend. In the overlapping measurement zone 700, both signal characteristic curves 905 and 906 show a still usable upward trend, but in the high-speed measurement zone 800, the signal characteristic curve 905 of the gas flow meter-sensor unit 104 becomes noticeably flattened.

[0268] Figure 6 The middle shows with Figure 3C A cross-sectional view similar to that in the previous section is a cross-sectional view of a possible embodiment of the second ceramic substrate 109 of the substrate component 111.

[0269] The first thick-film resistor 106 is disposed on the upper section of the second ceramic substrate 109. The vortex counter-sensor unit 105 is disposed on the lower section of the second ceramic substrate 109.

[0270] Different from Figure 3CIn the implementation scheme described above, the vortex counter-sensor unit 105 is constructed by itself using the ceramic substrate 109 in this example. Figure 3C In one embodiment, a pressure sensor 113 is disposed above a notch 115 in the ceramic substrate 109. Here, a material weakening portion 133 creates a thin diaphragm 126, which is easily elastically deformed by pressure fluctuations caused by passing vortices. A strain-sensitive measuring element 132 disposed on the diaphragm 126 converts this deformation into an electrically measurable sensor signal; the measuring element is, for example, a bonded strain gauge or a resistor applied in a thick-film process. Lane .

[0271] This invention is not limited to the specific embodiments described above. Modifications can be made within the scope of the embodiments. Various aspects of the dependent embodiments can also be combined with each other.

[0272] List of reference signs

[0273] 100 Flow Meter

[0274] 101 Sensor Base

[0275] 102 Obstacles

[0276] 103 Sensor Body

[0277] 104 Gas Flow Meter - Sensor Unit

[0278] 105 Vortex Counter - Sensor Unit

[0279] 106 First Thick Film Resistor

[0280] 107 Heated Thick Film Resistor

[0281] 108 First ceramic substrate

[0282] 109 Second ceramic substrate

[0283] 110 Supporting components

[0284] 111 Base Component

[0285] 112 Cross-sectional contraction

[0286] 113 Pressure sensor

[0287] 114 The end section of the first ceramic substrate

[0288] 115 Gap

[0289] 116 Free position

[0290] 117 Filler

[0291] 119 The side opposite to the flow direction

[0292] 120 recess

[0293] 121 Support frame

[0294] 122 Seals

[0295] 123 Fixing device

[0296] 124 Reserve Department

[0297] 125 Castable Refractories

[0298] 126 membrane

[0299] 127 Housing

[0300] 128 Conductor Channel

[0301] 129 Contact Department

[0302] 130 bond wire

[0303] 131 End section

[0304] 132 Strain-sensitive measuring element

[0305] 133 Material Weakening Section

[0306] 200 Medium Pipeline

[0307] 201 Measurement location

[0308] 202 Tools

[0309] 300 electronic units

[0310] 400 signal interface

[0311] 500 Longitudinal axis of the sensor body

[0312] 501 First Distance

[0313] 502 Second Distance

[0314] 600 Low-speed measurement area

[0315] 700 Overlap Measurement Area

[0316] 800 High-speed measurement area

[0317] 900 x-axis

[0318] 901 ordinate

[0319] Measurement uncertainty of the 902 gas flow meter sensor unit

[0320] Measurement uncertainty of 903 vortex counter-sensor unit

[0321] 904 ordinate

[0322] Signal characteristic curve of 905 gas flow meter - sensor unit

[0323] Signal characteristic curve of 906 vortex counter-sensor unit

[0324] D. Diameter of the medium pipeline

Claims

1. A flow meter (100) for determining the flow velocity of a fluid in a medium conduit (200), having - Sensor base (101), the sensor base includes an obstruction (102) and a sensor body (103). - Electronic unit (300) and -Signal interface (400). in - The obstruction (102) is positioned at least substantially upstream of the sensor body (103) in the flow direction. - The sensor body (103) includes a support member (110) and a substrate assembly (111), the substrate assembly having at least one ceramic substrate (108, 109), and The gas flow meter sensor unit (104) and the vortex counter sensor unit (105) are mounted on the base assembly (111). The gas flow meter-sensor unit (104) includes - A first thick-film resistor (106) used to determine the medium temperature of the fluid, and - Thick-film resistor (107) used to determine fluid-related power losses during heating, and The first thick-film resistor (106) and the heated thick-film resistor (107) are positioned apart from each other by a first distance (501) about the vertical longitudinal axis (500) of the sensor body (103). in, The substrate assembly (111) includes a first ceramic substrate (108) and a second ceramic substrate (109), wherein The heated thick-film resistor (107) is disposed on the first ceramic substrate (108), and The first thick-film resistor (106) and the vortex counter-sensor unit (105) are disposed on the second ceramic substrate (109). - The first ceramic substrate (108) and the second ceramic substrate (109) are disposed substantially parallel to each other, and / or - The support member (110) is disposed between the first ceramic substrate (108) and the second ceramic substrate (109).

2. The flow meter (100) according to claim 1. in The vortex counter-sensor unit (105) and the gas flow meter-sensor unit (104) are arranged apart from each other by a second distance (502) about the vertical longitudinal axis (500) of the sensor body (103), and -The vortex counter-sensor unit (105) is disposed on the end section (131) of the sensor body (103) away from the sensor base (101).

3. The flow meter (100) according to claim 2. in The heated thick-film resistor (107) is disposed on a ceramic substrate (108, 109), the ceramic substrate having a cross-sectional contraction (112). The cross-sectional contraction (112) is positioned about the vertical longitudinal axis (500) of the sensor body (103). -In the region of the first distance (501), and / or -The region of the second distance (502).

4. The flow meter (100) according to any one of claims 1-3. Its features are, The vortex counter-sensor unit (105) includes a pressure sensor (113), wherein the pressure sensor (113) - Constructed into a MEMS chip or - A diaphragm (126) is constructed to be integrated in the ceramic substrate (108, 109), and at least one strain-sensitive measuring element (132) is disposed on the diaphragm.

5. The flow meter (100) according to claim 4. Its features are, - The pressure sensor (113) is disposed on the ceramic substrate (108, 109), the ceramic substrate having a notch (115), wherein the pressure sensor (113) is disposed above the notch (115), and / or - The sensor body (103) has a free position (116), through which the pressure sensor (113) receives the pressure of the flowing fluid, and - Seal the notch (115) and / or free position (116) with an elastic filler (117).

6. The flow meter (100) according to any one of claims 1-3. Its features are, The ceramic substrate (108, 109) and the components disposed on the ceramic substrate are coated with a protective layer (118). The protective layer (118) mentioned above - is a thick film glaze, and / or -The protective layer (118) is applied in the sol-gel process.

7. The flow meter (100) according to any one of claims 1-3. Its features are, -The support member (110) has a recess (120) on its side oriented at least substantially orthogonal to the flow direction, and - A ceramic substrate (108, 109) is placed or inserted into the recess (120).

8. The flow meter (100) according to any one of claims 1-3. Its features are, -The sensor base (101) and / or -The obstruction (102) and / or -The supporting component (110) Made of plastic in the injection molding process. Wherein, the plastic - Constructed to be neither thermally nor electrically conductive, and / or - Select from the types of fiber composite materials.

9. The flow meter (100) according to any one of claims 1-3. Its features are, - The sensor body (103) has at least a partially elliptical cross-sectional profile on at least the surface (119) opposite to the flow direction.

10. The flow meter (100) according to claim 9. Its features are, The cross-sectional profile is elliptical or circular.

11. The flow meter (100) according to any one of claims 1-3. Its features are, The sensor base (101), the barrier (102), and the sensor body (103) are integrally formed.

12. The flow meter (100) according to any one of claims 1-3. Its features are, The sensor base (101), the barrier (102), and the sensor body (103) are integrally formed in an injection molding process.

13. The flow meter (100) according to any one of claims 1-3. Its features are, - The sensor base (101) has a support frame (121) for accommodating and holding the obstruction (102) and / or the sensor body (103), and - The bracket (121) is sealed by a seal (122) or by a form fit toward the obstruction (102) and / or the sensor body (103).

14. The flow meter (100) according to claim 13. Its features are, The obstruction (102) and / or the sensor body (103) are in the bracket (121) - Relative to the sensor base (101), and -At least substantially orthogonal to the direction of flow, and - At least substantially parallel to the longitudinal axis (500) of the sensor body (103). Movable support, and in which The flow meter (100) has a fixing device (123) that securely connects the obstruction (102) and / or the sensor body (103) to the sensor base (101).

15. The flow meter (100) according to claim 14. Its features are, - The fixing device (123) includes a reservoir (124) filled with castable refractory (125), and - The reservoir (124) is configured such that the castable (125) flows into the support frame (121) when the reservoir (124) is opened, and solidifies in a sealing manner within the support frame.

16. The flow meter (100) according to claim 14. Its features are, - The fixing device (123) includes a reservoir (124) filled with a two-component castable refractory, and - The reservoir (124) is configured such that the castable (125) flows into the support frame (121) when the reservoir (124) is opened, and solidifies in a sealing manner within the support frame.

17. The flow meter (100) according to any one of claims 1-3. Its features are, The electronic unit (300) is arranged to acquire sensor signals from the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105), and, based on the sensor signals, assign the sensor signals to... -Low speed measurement area (600) or - Overlapping measurement area (700) or - High-speed measurement zone (800).

18. The flow meter (100) according to claim 17. Its features are, The electronic unit (300) is arranged for - The sensor signal of the gas flow meter-sensor unit (104) is analyzed in the low-speed measurement zone (600) and provided as a measured value signal through the signal interface (400), and - The sensor signal of the vortex counter-sensor unit (105) is analyzed in the high-speed measurement zone (800) and provided as a measurement value signal through the signal interface (400).

19. The flow meter (100) according to claim 17. Its features are, The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together in the overlapping measurement area (700), and to provide the measured value signal as a result through the signal interface (400).

20. The flow meter (100) according to claim 18. Its features are, The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together in the overlapping measurement area (700), and to provide the measured value signal as a result through the signal interface (400).

21. The flow meter (100) according to claim 17. Its features are, The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) simultaneously in the overlapping measurement area (700), and - Balance the sensor signal of the gas flow meter-sensor unit (104) with the sensor signal of the vortex counter-sensor unit (105), and / or - Adjustment to adapt the signal deviation of the gas flow meter-sensor unit (104) in the overlapping measurement area (700) relative to the vortex counter-sensor unit (105) to the low-speed measurement area (600).

22. The flow meter (100) according to any one of claims 18-20. Its features are, The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) simultaneously in the overlapping measurement area (700), and - Balance the sensor signal of the gas flow meter-sensor unit (104) with the sensor signal of the vortex counter-sensor unit (105), and / or - Adjustment to adapt the signal deviation of the gas flow meter-sensor unit (104) in the overlapping measurement area (700) relative to the vortex counter-sensor unit (105) to the low-speed measurement area (600).

23. The flow meter (100) according to any one of claims 1-3. Its features are, The electronic unit (300) is arranged to analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together, and to determine, with the aid of reasonable and reliable data stored in the electronic unit (300), -The gas flow meter-sensor unit (104) is faulty, or -The vortex counter-sensor unit (105) is faulty. And a fault signal is sent through the signal interface (400).

24. The flow meter (100) according to any one of claims 1-3. Its features are, The electronic unit (300) is arranged for -Analyze the sensor signals of the gas flow meter-sensor unit (104) and the vortex counter-sensor unit (105) together. - Receive information about the fluid flow rate through the signal interface (400), and - The fluid properties are calculated from the sensor signals and the information, and the properties are transmitted through the signal interface (400). The properties referred to here are the fluid's density, viscosity, or thermal conductivity.

25. The flow meter (100) according to any one of claims 1-3. Its features are, The electronic unit (300) is arranged to temporarily increase the heating power on the heated thick film resistor (107), so that the sensor body (103) is at least partially free of organic deposits.

26. A method for installing a flow meter (100) according to any one of claims 1 to 25 in a medium pipeline (200), characterized in that... Steps A) The sensor base (101) is set at the measurement position (201) of the medium pipeline (200). B) Insert the obstruction (102) through the bracket (121), wherein the immersion depth of the obstruction (102) is at least substantially consistent with the diameter (D) of the medium conduit (200). C) Insert the sensor body (103) through the support frame (121), wherein the immersion depth of the sensor body (103) is at least substantially consistent with the radius of the medium conduit (200), and D) The obstruction (102) and the sensor body (103) are fixed to the sensor base (101) by means of the fixing device (123).

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