DE202015100457U1 - Sensor for measuring a volume flow or a mass flow of a fluid - Google Patents

Abstract

Sensor device for measuring a volume flow or a mass flow of a gaseous fluid, comprising a main channel (8, 8 ') through which gaseous fluid flows in a main flow direction, with a sensor module (1) arranged in a secondary channel (4) and the secondary channel ( 4) is connected via an input connection (5) and via an output connection (6) to the fluid-flowed main channel (8, 8 ') such that both the input connection (5) and the output connection (6) form a wall of the main channel (8 , 8 ') has sweeping connection and the input port (5) and the output port (6) on the main channel (8, 8') are arranged spaced from each other in the main flow direction, characterized in that the sensor module (1) a traversed by gaseous fluid measuring section having a flow sensor (2), and the measuring section forms a portion of the secondary channel (4), so that the secondary channel (4) from its Eingangsansc flow (5) through to its outlet port (6) can be flowed through by the gaseous fluid.

Description

The invention relates to a sensor for measuring a volume flow or mass flow of a gaseous fluid according to the features of the preamble of claim 1.

In practice, it is necessary, for example in tubular systems through which fluids flow, to detect the respective prevailing pressure as promptly and precisely as possible. To measure the pressure, suitable sensors are used in practice for this purpose.

Such sensors that can make a pressure measurement in a pipe system, are from the DE 198 60 881 A1 known. The pressure measurement of a flowing fluid takes place by means of a plurality of spaced apart in the transverse and longitudinal direction electromechanical in the inner wall of a tube recessed pressure measuring cells. In this case, the received signals of the individual pressure measuring cells are evaluated and determined differential pressures by means of a signal acquisition and evaluation. A display device is calibrated so that on the basis of the determined differential pressures of the actual currently prevailing pressure or the flow rate can be displayed.

After DE 10 2011 110 061 A1 In a pipe system, a plurality of differential pressure sensors in a plurality of annular channels arranged one behind the other in the flow direction, which have pores / slots in the direction of the channel interior, are arranged in the manner of a matrix. These sensors can be used to measure minute flow inhomogeneities. A display device can be calibrated so that the volume flow is displayed.

All of these measuring devices require a high production cost, which must first be provided in order to achieve an accurate measurement result by means of pressure sensors. However, the measuring device should be designed so that only a small manufacturing effort is required.

Object of the present invention is to provide a sensor device for measuring a volume flow or a mass flow of a gaseous fluid, which allows to achieve an accurate and preferably timely measurement result, without operating a high production cost.

According to the invention, this object is achieved with a sensor device for measuring a volume flow or a mass flow of a fluid according to the features of claim 1.

The sensor device according to the invention is characterized in that a sensor module has a flow-through measuring section with a flow sensor, and the measuring section forms a portion of a secondary channel, so that the secondary channel having at least one input terminal and at least one output terminal, from its input terminal up to Its output port of fluid can be flowed through. The secondary channel can be tubular. In particular, it is provided that the sensor according to the invention is constructed as a sensor device and in addition to a sensor measuring element comprises further components.

In this case, the fluid flows through a main channel in a main flow direction in which a volume flow or a mass flow of the fluid is to be measured. The sensor module, which is arranged in the secondary channel, can be connected to the fluid-flowed main channel in such a way that both the input port and the output port each have at least one passage penetrating the wall of the main channel and the input port and the output port on the main channel in the main flow direction to each other spaced apart.

The fluid is preferably formed as a gaseous fluid, in particular as air.

In the case of a flowing gaseous fluid, a mass flow or a volume flow in one embodiment can take place, for example, by measuring a static pressure drop along a channel section. By having the input port spaced from the output port as viewed in the flow direction, a corresponding static pressure difference can be measured.

In one embodiment, it can be provided that the input connection has at least two connections to the main channel, which are connected to one another by a ring line.

Furthermore, it can be provided in one embodiment that the output terminal has at least two connections to the main channel, which are connected to one another by a ring line.

It can be provided that the connections of the input terminal are arranged circumferentially around the main channel in a radial plane, and / or the connections of the output terminal are arranged circumferentially around the main channel in a radial plane.

Both the ring lines and their connections to the main channel can also be tubular.

In one embodiment, it is provided that the input terminal or the input terminals and / or the output terminal or the output terminals are formed flush with a main channel wall. The tap of the static pressure is thus directly on the main channel wall. As a result, fittings in the main channel and thus disturbing flow obstacles are avoided.

In an alternative embodiment it can be provided that the input terminal or the input terminals and / or the output terminal or the output terminals are formed extending into the main channel via a probe. The tap of the static pressure takes place in this embodiment at a distance from the main channel wall. As a result, disturbing influences of the main channel wall are largely minimized. The probe may be angled in an L-shape or be designed as a pitot probe or pitot tube.

An advantage of using a flow rate sensor in the sub-channel is precise detection of even the smallest static pressure differences. As a result, compared to a purely static pressure measurement, a more accurate measurement result and a temporally faster response are achieved.

In one embodiment, it may be provided that the connections of the input terminal are arranged equidistant from each other around the main channel and / or the connections of the output terminal are arranged to be circumferentially equidistant from each other around the main channel.

It can be provided that the secondary channel connects the two ring lines with each other.

In a further embodiment it can be provided that two or more secondary channels are provided for connecting the two ring lines, wherein in each case one sensor module is preferably arranged in each secondary channel.

It may further be provided that the connections of the secondary channels to a ring line along this ring line are arranged equidistant from each other.

It can be provided that the sensor module has a thermal flow sensor or a vortex flow sensor or a differential pressure flow sensor or an ultrasonic flow sensor. In this case, preferably commercially available sensors are to be used.

Ultrasonic flow sensors, also called ultrasonic flowmeters, are sensors that measure the velocity of a flowing fluid using acoustic waves. The measurements can be carried out by the Doppler method, by the stroboscopic method, by the drift method or by transit time difference measurement.

Differential pressure flow sensors, make a flow measurement according to the differential pressure method. In this case, a defined cross-sectional constriction is made by means of a diaphragm in a channel through which a fluid flows.

Thermal flow sensors, also called calorimetric flowmeters or thermal anemometric flow sensors, are sensors that operate on the thermal principle. This thermal principle can be implemented by the hot-wire method or by means of the heating process.

Vortex Flowmeters, also known as vortex flowmeters, are sensors used to determine volume flow or mass flow of fluids based on the Kármán vortex street. In this case, a disruptive body is introduced in a flow-through with a fluid channel, which is flowed around by a fluid.

It can be provided that the cross-sectional area of the secondary channel is in the range of at most 7% up to 0.1%, preferably 2% up to 0.3%, most preferably 1% up to 0.7% of the cross-sectional area of the main channel, or that the total of the cross-sectional areas of all secondary channels is a maximum of 7% to 0.1%, preferably 2% to 0.3%, most preferably 1% to 0.7% of the cross-sectional area of the main channel. Especially with a large cross-section of the main channel, the cross-sectional area of the secondary channel or the sum of the cross-sectional areas of all secondary channels can be significantly less than 1% of the cross-sectional area of the main channel.

It should be noted that the cross-sectional area of the secondary channel or the sum of the cross-sectional areas of all secondary channels does not exceed a total of 7% of the cross-sectional area of the main channel, since otherwise possible interference by the flow behavior of the fluid in the secondary channel or the secondary channels can lead to a falsification of a measurement result.

It can be provided that the main channel in the region between the input terminal and the output terminal has no impairment of the flow of the fluid internals.

It may further be provided that the main channel in the region between the input terminal and the output terminal is a constant Cross-sectional area and / or has a constant cross-sectional contour. As a result, in contrast to a measurement with dynamic pressure or a measurement according to the Venturi principle caused by the measurement pressure drop is avoided. In addition, a constant cross-sectional area or a constant cross-sectional contour is inexpensive to manufacture.

Another advantage results from the fact that the sensor device according to the invention has a higher dynamic range in flow measurements than conventional systems.

In a further embodiment, it can be provided that a ring line and / or a secondary channel has one or more sections consisting of a cut-to-length flexible hose piece or is formed from such.

It can be provided that the connection of the input connection and / or the connection of the output connection to the main channel are designed so that no components projecting into the main channel and / or throttling the flow of the fluid are provided in the region of a connection.

The sensor device according to the invention according to one or more of the preceding embodiments of the invention can be used in a heating and / or air conditioning device.

The sensor device can generally be used in buildings and / or industrial plants wherever fluid-flowed tubular systems are installed by fluids, in particular gases, in which a pressure, a volume flow or a mass flow has to be measured. These may, for example, also be ventilation systems, fluid conveyors, pipe systems for transporting fluids, and systems for producing fluids. The pipe systems or fluid channels can have a round cross-section or an angular, in particular rectangular, cross-section. A quadrangular or rectangular cross-sectional area with an aspect ratio of 1: 1 to 1: 7, preferably 1: 5, is preferred.

The invention will now be explained in more detail with reference to exemplary embodiments.

Showing:

1 Schematic representation of the sensor device according to the invention with a sensor module for measuring a volume flow or mass flow of a fluid according to the present invention;

2a Schematic representation of a measuring arrangement with a sensor on a main channel with a relatively large cross-sectional area of the main channel according to the present invention;

2 B Schematic representation of a measuring arrangement with a sensor on a main channel with a relatively small cross-sectional area of the main channel according to the present invention;

3a Schematic representation of a cross-sectional area of the main channel with probe tap;

3b Schematic representation of a probe

1 shows a schematic representation of the sensor device with a sensor module 1 for measuring a volume flow or mass flow, a calorimetric sensor 2 contains. The sensor module 1 has a housing 3 on, through which a flow channel 4 is guided here as a side channel 4 is designed. The secondary channel 4 has an input port 5 and an output terminal 6 , each with a main channel 8th . 8th' as in the 2a and 2 B shown connected. Inside the case 3 of the sensor module 1 is right in the side channel 4 a sensor 2 arranged. In the example shown, the sensor 2 designed as a calorimetric sensor. As an alternative, other suitable flow sensors may be used in alternative embodiments. In order to measure a volumetric flow or a mass flow of a gaseous fluid, flows into the input port 5 a fluid in the flow direction 7 through the secondary channel 4 , flows around the calorimetric sensor 2 and then exits the output port 6 out again. The electrically heated calorimetric sensor 2 changes during the recirculation as a result of a temperature change induced thereby in the calorimetric sensor 2 its electrical resistance, so that by means of a calorimetric sensor 2 connected electronic evaluation device, not in 1 represented, on the flow velocity of the fluid and thus on the volume flow or mass flow of the fluid can be closed.

The 2a and 2 B show a schematic representation of a measuring arrangement with a sensor 10 on a main canal 8th . 8th' , where the main channel 8th . 8th' in the flow direction 7 is traversed by a fluid. The sensor 10 consists of a sensor module 1 that on the main channel 8th . 8th' is mounted, a side channel 4 passing through the sensor module 1 is guided, a first ring line 11 . 11 ' , which have an input connection 5 on the input side with the secondary channel 4 is connected, and a second loop 12 . 12 ' that over one output port 6 on the output side with the secondary channel 4 connected is. The first ring line 11 . 11 ' and the second loop 12 . 12 ' include the main channel 8th . 8th' and each have four connections 13 . 13 ' with the main channel 8th . 8th' connected. The connections are taking effect 13 . 13 ' the main channel so that it does not enter the main channel 8th . 8th' protrude and thus with the inner wall of the main channel 8th . 8th' to lock. The respective four connections 13 . 13 ' between the main channel 8th . 8th' and the first loop 11 . 11 ' as well as between the main channel 8th . 8th' and the second loop 12 . 12 ' are radially around the main channel 8th . 8th' each perpendicular to the flow direction 7 of the fluid to each other at an angle of 90 °.

The sensor 10 on the main canal 8th . 8th' is constructed so that after the first loop 11 . 11 ' in the flow direction 7 of the fluid in the main channel 8th . 8th' at a defined distance A, B, the second loop 12 . 12 ' is arranged. Between the first loop 11 . 11 ' and the second loop 12 . 12 ' is on the outer wall of the main channel 8th . 8th' in the longitudinal direction of the sensor module 1 positioned. In each case, the first ring line 11 . 11 ' with the input connector 5 of the secondary channel 4 , the sensor module 1 passes through, and the second loop 12 . 12 ' with the output connector 6 of the secondary channel 4 connected. It is the one with the first loop 11 . 11 ' connected input terminal 5 of the secondary channel 4 opposite to the second loop 12 . 12 ' connected output terminal 6 of the secondary channel 4 radially around the main channel 8th . 8th' each perpendicular to the flow direction 7 of the fluid to each other at an angle of 180 °.

The secondary channel 4 , the first loop 11 . 11 ' , the second loop 12 . 12 ' and the connections 13 . 13 ' are tubular. They can be easily manufactured from cut-to-length flexible hose pieces.

Thus, the measuring arrangement forms a bypass. It flows while a small part of the main channel 8th . 8th' flowing fluid in the same flow direction 7 about the connections 13 . 13 ' in the first ring line 11 . 11 ' , from there via the input connection 5 in the secondary channel 4 , then through the sensor module 1 and via the output connector 6 in the second ring channel 12 . 12 ' , Finally, the fluid flows from the second loop 12 . 12 ' about the connections 13 . 13 ' back to the main channel 8th . 8th' , During the passage of the bypass with a fluid, as in 1 represented by means of within the sensor module 1 in the secondary channel 4 located calorimetric sensor 2 a volume flow or mass flow of the secondary channel 4 to be measured by flowing fluid. Due to the proportional ratio of the volume flow or mass flow of the in the secondary channel 4 flowing fluid to that in the main channel 8th . 8th' flowing fluid can then affect the volume flow or mass flow of the main channel 8th . 8th' be closed flowing fluid.

Decisive parameter is the pressure drop between the first loop 11 . 11' and the second loop 12 . 12' , This pressure drop is proportional to the mass flow and the volume flow of the fluid flowing in the main channel.

That in the 2a and 2 B shown embodiment of the sensor device 1 has connections to the main channel 8th . 8th' on that with a main channel wall 81 finish flush. The connections between the loop 11 . 11' or the second ring line 12 . 12' and the main channel open flush in openings of the channel wall of the main channel. This disturbing installations in the main channel 8th . 8th' avoided.

In contrast to that in the case of 3a and 3b shown embodiment, that the connections to the main channel 8th . 8th' one probe each 14 respectively. 15 exhibit. This probe picks up the static pressure in the main channel main channel 8th . 8th' with distance to the channel wall 81 from. This causes the static pressure measurement as in 3a shown more to the center of the canal 8th . 8 ' shifted. Any disturbing influences in the region of the channel wall can thus be reduced.

The probe 15 is in 3b shown. It is a pitot probe 15 for measuring static pressure. The probe has an L-shaped body having a fluid conduit inside the probe. Over side openings 16 in the area of the probe tip, the static pressure in the main channel 8th . 8th' tapped and through the probe interior to the input port 5 or to the output terminal 6 guided.

Incidentally, this corresponds to the 3a and 3b shown embodiment of the sensor device as in the 1 and 2a respectively. 2 B described.

As in the 2a and 2 B and 3a is shown, the first ring line 11 . 11 ' and second ring line 12 . 12 ' four connections respectively connections 13 . 13 ' to the main channel 8th . 8th' on, so by the multiplicity of between the ring lines and the main channel 8th . 8th' existing connections 13 . 13 ' ultimately, an average pressure of the by-pass 4 flowing fluid arises. A variety of connections 13 . 13 ' to the ring lines thus contributes to a better averaging of the by-channel 4 flowing fluid as if the input port 5 of the secondary channel 4 and the output terminal 6 directly with the main channel 8th . 8th' would be connected. In addition, the pressure in the bypass channel is compensated by the bypass 4 so that it allows faster and more accurate measurement. Furthermore, the sensor 10 through the bypass able to respond faster to pressure changes of the main channel 8th . 8th' Responding fluid or to measure such.

To a mechanically and electrically identically constructed sensor module 1 , which also has a similar flow sensor in its parameters 2 for measuring the volume flow or mass flow of a fluid in main channels 8th . 8th' to be able to use with different cross sections, is only the distance A, B of the first loop 11 . 11 ' or the input terminal 5 to the second ring line 12 . 12 ' or to the output terminal 6 adapt. It is, as in 2a shown, the distance A between the first loop 11 and the second loop 12 when using a main channel 8th with a relatively large cross-sectional area greater than, as in 2 B shown, the distance B between the first loop 11 ' and the second loop 12 ' when using a main channel 8th' with a relatively small cross-sectional area.

LIST OF REFERENCE NUMBERS

1

 sensor module

2

 calorimetric sensor / flow sensor

3

 casing

4

 Flow channel / side channel

5

 input port

6

 output port

7

 flow direction

8, 8 '

 main channel

81

 Main channel wall

10

 sensor

11, 11 '

 first ring line

12, 12 '

 second ring line

13, 13 '

 connection

14

 probe

15

 pitot tube

16

 probe opening

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19860881 A1 [0003]
• DE 102011110061 A1 [0004]

Claims (19)

Sensor device for measuring a volume flow or a mass flow of a gaseous fluid, comprising a main channel through which gaseous fluid flows in a main flow direction ( 8th . 8th' ), with a sensor module ( 1 ), which in a secondary channel ( 4 ), and the secondary channel ( 4 ) via an input terminal ( 5 ) and via an output terminal ( 6 ) with the fluid-flowed main channel ( 8th . 8th' ) is connected so that both the input terminal ( 5 ) as well as the output terminal ( 6 ) one the wall of the main channel ( 8th . 8th' ) has a strong connection and the input terminal ( 5 ) and the output terminal ( 6 ) on the main channel ( 8th . 8th' ) are arranged spaced apart in the main flow direction, characterized in that the sensor module ( 1 ) a flow-through of gaseous fluid measuring section with a flow sensor ( 2 ), and the measuring section comprises a section of the secondary channel ( 4 ) forms, so that the secondary channel ( 4 ) from its input terminal ( 5 ) to its output terminal ( 6 ) can be flowed through by the gaseous fluid. Sensor device according to claim 1, characterized in that the input terminal ( 5 ) at least two compounds ( 13 . 13 ' ) to the main channel ( 8th . 8th' ), which are interconnected by a loop ( 11 . 11 ' ) are connected. Sensor device according to claim 1 or 2, characterized in that the output terminal ( 6 ) at least two compounds ( 13 . 13 ' ) to the main channel ( 8th . 8th' ), which are interconnected by a loop ( 12 . 12 ' ) are connected. Sensor device according to one of claims 1-3, characterized in that the connections ( 13 . 13 ' ) of the input terminal ( 5 ) in a radial plane around the main channel ( 8th . 8th' ) are arranged circumferentially, and / or the connections ( 13 . 13 ' ) of the output terminal ( 6 ) in a radial plane around the main channel ( 8th . 8th' ) are arranged circumferentially. Sensor device according to claim 4, characterized in that the connections ( 13 . 13 ' ) of the input terminal ( 5 ) equidistant to each other around the main channel ( 8th . 8th' ) are arranged circumferentially and / or the connections ( 13 . 13 ' ) of the output terminal ( 6 ) equidistant to each other around the main channel ( 8th . 8th' ) are arranged circumferentially. Sensor device according to one of the preceding claims, characterized in that the main channel ( 8th . 8th' ) in the area between the input terminal ( 5 ) and the output terminal ( 6 ) has a constant cross-section, preferably a constant cross-sectional area. Sensor device according to one of claims 2 to 6, characterized in that the secondary channel ( 4 ) the two ring lines ( 11 . 11 '; 12 . 12 ' ) connects to each other. Sensor device according to one of claims 2 to 7, characterized in that two or more secondary channels ( 4 ) for connecting the two ring lines ( 11 . 11 '; 12 . 12 ' ) are provided, preferably in each secondary channel ( 4 ) each have a sensor module ( 1 ) is arranged. Sensor device according to claim 8, characterized in that the connections ( 5 ; 6 ) of the secondary channels ( 4 ) to a loop ( 11 . 11 '; 12 . 12 ' ) along this loop ( 11 . 11 '; 12 . 12 ' ) are arranged equidistant from each other. Sensor device according to one of the preceding claims, characterized in that the connection or the connections of the input connection ( 5 ) to the main channel ( 8th . 8th' ) and / or that the connection or the connections of the output terminal ( 6 ) with a main channel wall ( 81 ) are designed to be flush. Sensor device according to one of claims 1 to 9, characterized in that the connection or the terminals of the input terminal ( 5 ) to the main channel ( 8th . 8th' ) and / or that the connection or the connections of the output terminal ( 6 ) via a probe ( 14 . 15 ) in the main channel ( 8th . 8th ) are formed in reaching. Sensor device according to claim 11, characterized in that the probe as Pitotrohr ( 15 ) is trained. Sensor device according to one of the preceding claims, characterized in that the sensor module ( 1 ) comprises an ultrasonic flow sensor or a differential pressure flow sensor or a thermal flow sensor or a vortex flow sensor. Sensor device according to one of the preceding claims, characterized in that the cross-sectional area of the secondary channel ( 4 ) in the range of at most 7% up to 0.1%, preferably 2% up to 0.3%, in particular 1% up to 0.7% of the cross-sectional area of the main channel ( 8th . 8th' ), or that the sum of the cross-sectional areas of all secondary channels ( 4 ) in the range of a maximum of 7% to 0.1%, preferably 2% to 0.3%, in particular 1% to 0.7% of the cross-sectional area of the main channel ( 8th . 8th' ) is. Sensor device according to one of the preceding claims, characterized in that the main channel ( 8th . 8th' ) in the area between the input terminal ( 5 ; 13 . 13 ' ) and the output terminal ( 6 ; 13 . 13 ' ) has no the flow of the fluid impairing internals. Sensor device according to one of the preceding claims, characterized in that the main channel ( 8th . 8th' ) in the area between input terminal ( 5 ; 13 . 13 ' ) and output terminal ( 6 ; 13 . 13 ' ) has a constant cross-sectional area and / or a constant cross-sectional contour. Sensor device according to one of the preceding claims, characterized in that a ring line ( 11 . 11 '; 12 . 12 ' ) and / or a secondary channel ( 4 ) has one or more of a cut-length flexible hose piece existing sections or is formed from such. Sensor device according to one of the preceding claims, characterized in that the connection ( 13 . 13 ' ) of the input terminal ( 5 ) and / or the compound ( 13 . 13 ' ) of the output terminal ( 6 ) to the main channel ( 8th . 8th' ) are designed such that in the area of a connection ( 13 . 13 ' ) none in the main channel ( 8th . 8th' ) and / or the flow of the fluid throttling components are provided. Heating and / or air conditioning device with a sensor device ( 10 ) according to any one of the preceding claims.

Images