System and flow sensor for measuring flow of fluid measurement medium
By designing movable closed components and multi-channel structures in the flow sensor, the problem of difficulty in adapting existing flow sensors within different flow ranges is solved, and flexible flow adaptation and high-precision measurement are achieved.
Patent Information
- Application Number
- CN202380079283.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-18
- Filing Date
- 2023-11-09
- Publication Date
- 2025-06-20
AI Technical Summary
The adaptation of existing flow sensors in different flow ranges is difficult, especially for small and medium-sized applications. The adaptation of flow channels is often omitted, resulting in limited measurement accuracy and application range.
A flow sensor including a housing, a sensor element and a movable closure element is designed. Through the combination of the main channel and the auxiliary channel, the flow ratio is adjusted using the movable closure element to achieve flexible adaptation to the flow range.
It realizes flexible adaptation within different flow ranges, reduces the demand for flow channel geometry, improves measurement accuracy and application range, and is cost-effective.
Smart Images
Figure CN120188004A_ABST
Abstract
Description
Field of the Invention
[0001] The present invention relates to a flow sensor for measuring the flow rate of a fluid measurement medium. Furthermore, the present invention relates to a system comprising a control / evaluation unit and a flow sensor according to the present invention. Background Art
[0002] Flow sensors are used to determine flow rates or flow velocities, volumetric flow rates, mass flow rates or relevant variables of the measurement medium, or of fluids, such as gases, gas mixtures or liquids. There are various types of flow sensors, such as thermal flow sensors, Coriolis flow sensors, ultrasonic flow sensors, microwave flow sensors, etc.
[0003] For example, thermal flow sensors utilize the fact that the (flowing) measurement medium transports heat away from a heated surface. Thermal flow sensors typically consist of several functional elements, usually at least one low-impedance heating element and one high-impedance resistance element serving as a temperature sensor. Alternatively, thermal flow sensors consist of several low-impedance heating elements serving as heaters and temperature sensors.
[0004] Flow sensors and modules are designed for specific flow rate ranges, which are usually defined by the geometry of the flow channel. Therefore, the sensor or the flow channel must be adjusted for each flow rate range. Depending on the application, for example because the market is too small to justify such an adaptation (which usually involves small or medium quantities), a separate adaptation of the channel geometry is not desired.
[0005] It is known from the prior art to use a so-called "bypass" channel in which the flow sensor is located and which is fluidly connected to the flow channel. The bypass channel allows the use of the same sensor type in different applications. For this purpose, not the entire flow channel, but only the bypass channel must be geometrically adapted to the desired flow rate range.
[0006] However, even the adaptation of the bypass channel often involves effort and development, which is why such an adaptation is often omitted, especially for smaller and medium-sized applications. Summary of the Invention
[0007] Starting from this problem, the object of the present invention is to provide a flow sensor that can be used for different flow rate ranges.
[0008] This object is achieved by the flow sensor according to claim 1 and the system according to claim 11.
[0009] Regarding the flow sensor, there is provided one for measuring the flow rate of a fluid measurement medium and comprising:
[0010] - A housing, wherein the housing has an inlet channel for receiving a fluid measurement medium, an outlet channel for discharging the fluid measurement medium, a measurement channel extending between the inlet channel and the outlet channel, and at least one auxiliary channel extending between the inlet channel and the outlet channel and more particularly connected parallel to the measurement channel, wherein a first fluid transfer for connecting the inlet channel and the auxiliary channel is provided, and wherein a second fluid transfer for connecting the auxiliary channel and the outlet channel is provided;
[0011] - A sensor element arranged in the measurement channel for sensing a physical measurement variable regarding the flow rate of the fluid measurement medium; and
[0012] - A first bolt-shaped closing element, wherein the first closing element is designed and attached to the housing such that the first closing element can be moved to at least a first position and a second position relative to the first fluid transfer or the second fluid transfer, wherein the first closing element closes the first fluid transfer or the fluid transfer in the first position, and wherein the first fluid transfer or the second fluid transfer is not closed in the second position of the first closing element.
[0013] The present invention consists of a housing that forms a variable bypass channel. According to the present invention, a main channel and at least one auxiliary channel are provided in the housing. The auxiliary channel can be closed at the first fluid transfer by at least one closing element (such as a piston, bolt, screw, etc.). This allows adjustment of the proportion of the flow rate passing through the measurement channel. This makes the adjustment of the flow channel very easy and cost-effective to implement. Therefore, the flow rate range can be defined according to the application and requirements.
[0014] Applications that sometimes require very different flow rate values can even be achieved. The metering pump processes very small flow rates during metering, but requires a large flow rate for the cleaning cycle. This is made possible by adjusting the closing element.
[0015] The measurement variable regarding the flow rate is understood as a measure such as the flow velocity, volume flow rate, mass flow rate, etc. of the measurement medium.
[0016] An embodiment of the flow rate sensor provides a second bolt-shaped closing element that is designed and attached to the housing such that the second closing element can be moved to at least a first position and a second position relative to the first fluid transfer or the second fluid transfer independently of the first closing element, wherein the second closing element closes the corresponding fluid transfer in the first position, and wherein the corresponding fluid transfer is not closed in the second position of the second closing element. Here, the second closing element provides redundancy for the first closing element.
[0017] Advantageous embodiments of the flow sensor provide that the first closing element and / or the second closing element can be adjusted to an intermediate position between a first position and a second position. This means that the cross-section of the corresponding fluid conveyance can be not only completely closed, but also partially and stepwise closed. This allows for a more precise adjustment of the division of the flow into the measuring channel and the auxiliary channels, such that the scope of application can be increased. By using two closing elements, where at least one closing element is adjustable in an intermediate stage, the flow division can be further improved.
[0018] Advantageous embodiments of the flow sensor provide that the first closing element and / or the second closing element can be adjusted smoothly. This allows for the individual positioning of the corresponding closing element, such that the flow range can be finely adjusted as needed.
[0019] According to an advantageous embodiment of the flow sensor according to the invention, a housing is provided that includes one or more additional auxiliary channels extending between an inlet channel and an outlet channel and, in particular, connected parallel to the measuring channel, wherein for each additional auxiliary channel, at least one additional first fluid conveyance is provided for connecting the inlet channel and the corresponding additional auxiliary channel, and in each case, an additional second fluid conveyance is provided for connecting the corresponding auxiliary channel and the outlet channel. Thus, the flowing fluid is divided between the measuring channel and all the auxiliary channels. Here, the first closing element can be adjusted to at least one third position in which the first fluid conveyance is closed together with at least one additional first fluid conveyance and / or with all additional first fluid conveyances. An additional position is provided for each additional auxiliary channel so that all the auxiliary channels can be closed using the first closing element.
[0020] Furthermore, a second closing element is provided that is designed and attached to the housing such that the second closing element can be adjusted to at least one third position in which the second fluid conveyance is closed together with at least one additional second fluid conveyance and / or with all additional second fluid conveyances. An additional position is provided for each additional auxiliary channel so that all the auxiliary channels can be closed using the first closing element.
[0021] By providing the additional auxiliary channels and the corresponding additional positions of the closing elements, it is also possible to finely adjust the flow range.
[0022] A variant of the flow sensor provides that for each additional auxiliary channel, there is at least one additional bolt-shaped closing element for closing the corresponding additional first fluid conveyance and / or additional second fluid conveyance. Thus, in this variant, no common closing element is provided for the fluid conveyances between the inlet channel and the auxiliary channels, or for the fluid conveyances between the auxiliary channels and the outlet channel, but rather individual closing elements for each fluid conveyance.
[0023] In a favorable development, the flow sensor has an actuator which is designed and connected to the first closing element and / or the second closing element such that the actuator generates a movement of the first closing element or the second closing element for controlling the respective first position, second position, intermediate position and third position. Thus, the closing element is not adjusted manually but by the actuator. For this purpose, the actuator has a servo drive, in particular an electric motor.
[0024] The flow sensor according to any one of the preceding claims, wherein the flow sensor is a thermal flow sensor. Here, the type and measurement principle of the thermal flow sensor can be freely selected (for example, "constant temperature anemometer" (CTA), "constant power anemometer" (CPA), etc.).
[0025] Regarding the system, it is provided that it comprises a flow sensor according to the invention and a control / evaluation unit, wherein the control / evaluation unit is designed to query a measured value of a physical measurement variable regarding the flow rate of the fluid measurement medium from the flow sensor and / or to adjust at least one of the closing elements to at least one position by means of the actuator. The control / evaluation unit is, for example, a circuit having an ASIC or a microprocessor, or a PC or a mobile device, such as a smartphone or a tablet.
[0026] Advantageously, the control / evaluation unit is designed to compare the measured value with at least one limit value and, if the limit value is exceeded or reached, to adjust at least one of the closing elements by means of the actuator such that the measured value no longer drops below the limit value or exceeds the limit value. This results in a controller function that can be advantageously used, especially under conditions such as changing flow rates with strong fluctuations. Description of the Drawings
[0027] The invention is explained in more detail with reference to the following drawings. In the drawings:
[0028] Figure 1 : is a horizontal sectional view of the flow sensor described in the first exemplary embodiment;
[0029] Figure 2 : is a vertical sectional view of the flow sensor described in the first exemplary embodiment;
[0030] Figure 3 : is a horizontal sectional view of the flow sensor described in the second exemplary embodiment; and
[0031] Figure 4 : is an exemplary embodiment of the system according to the invention. Detailed Description
[0032] Figure 1 and Figure 2Shows a first exemplary embodiment of the flow sensor DS according to the present invention. Here, Figure 1 Shows a horizontal cross-section through the flow sensor 1, or a plan view of the flow sensor 1, where the workpiece 400 is omitted. Figure 2 Shows a cross-section through the flow sensor DS in a horizontal plane of the measurement channel 130.
[0033] The flow sensor consists of a one-piece or multi-piece housing 100. In the case of a one-piece housing 100, this is made of, for example, plastic and manufactured by means of an additive manufacturing process, for example by means of 3D printing. In the case of a multi-piece housing, this is made of plastic or metallic material.
[0034] A number of channels are formed in the housing:
[0035] An inlet channel 110 and an outlet channel 120 are provided, by means of which the fluid measurement medium can be introduced into and discharged from the housing 100. Here, the arrows show the flow rate of the measurement medium. In addition, a measurement channel 130 and two auxiliary channels 140 are provided. Here, a first fluid conveyance member 150 connects the inlet channel 110 and the auxiliary channel. Here, a second fluid conveyance member 160 connects the inlet channel 110 and the auxiliary channel. Additionally, fluid conveyance members are also provided between the inlet channel 110 and the measurement channel 130 and between the measurement channel 130 and the outlet channel 120. Here, the fluid conveyance members 150, 160 are provided as holes in the material of the housing 100, which form channels between the corresponding auxiliary channels 140, 170 and the inlet channel 110 or the outlet channel 120. In the present example, the auxiliary channels each share a hole, but still form separate fluid conveyance members 150, 160.
[0036] Thus, the flow sensor DS can be connected to a flow channel and used as, for example, a bypass channel to the flow channel.
[0037] A flow sensor 200, in particular a thermal flow sensor 200, is installed in the measurement channel 130. This senses a measurement variable of the measurement medium flowing through the measurement channel, such as a measure of the flow rate, volume flow rate, mass flow rate, etc.
[0038] The measured variable measured by the flow sensor 200 in the measurement channel 130 is a measure of the flow rate or volumetric flow and / or mass flow of the measurement medium present in the flow channel. For this purpose, the flow sensor 200 is calibrated accordingly. Depending on the application, there are flow states of different sizes in the flow channel. For this purpose, the geometry of the measurement channel 130 must be designed accordingly to avoid the following flow in the measurement channel 130: a flow that can no longer be sensed by the flow sensor 200 due to too high or too low a flow rate. The flow sensor DS according to the invention provides the possibility of adjusting the flow state in the measurement channel 130 without having to adapt the geometry of the measurement channel 130.
[0039] For this purpose, a first closing element 300 is provided. In the present case, this has a bolt-like shape and can be inserted into the housing 100. Depending on the position, i.e., the extent to which the closing element 300 penetrates into the housing 100, one or more auxiliary channels 140, 170 can be closed. This is done by the closing element 300 passing through the corresponding first fluid connectors 150 and closing their channel cross-sections. This changes the pressure drop, and the change in the pressure drop in turn changes the fluid distribution in the corresponding channels 130, 140, 170.
[0040] In the first position P1, the closing element 300 is inserted into the housing 100 such that the closing element 300 does not engage any fluid connectors. The measurement medium flowing through the flow sensor DS is distributed proportionally to the measurement and auxiliary channels 130, 140, 170 according to the geometry of these measurement and auxiliary channels 130, 140, 170.
[0041] In the second position P2, the closing element 300 is inserted into the housing 100 such that the closing element 300 strikes the fluid connector 150 connecting the inlet channel 110 to the auxiliary channel 140 and completely closes its cross-section. Thus, the measurement medium flowing through the flow sensor DS is only distributed to the measurement channel 130 and the additional auxiliary channel 170, whereby a higher flow rate exists in these channels 130, 170 compared to the position P1.
[0042] In the third position P3, the closing element 300 is inserted into the housing 100 such that the closing element 300 engages the fluid connectors 150 connecting the inlet channel 110 to the auxiliary channel 140 and connecting the inlet channel 110 to the auxiliary channel 170 and completely closes their cross-sections. Thus, the measurement medium flowing through the flow sensor DS only flows through the measurement channel 130, whereby a higher flow rate exists in this measurement channel 130 compared to the positions P1 and P2.
[0043] In the fourth position P4, the closing element 300 is inserted into the housing 100 such that the closing element closes the cross-sections of all fluid connections of the channels 130, 140, 170. No more measuring medium flows through the flow sensor DS.
[0044] Figure 3 A second exemplary embodiment of the flow sensor is shown. This differs from the first exemplary embodiment in that instead of two auxiliary channels, only a single large auxiliary channel 140 is provided.
[0045] The closing element 300 is movable in three positions:
[0046] In the first position P1', the closing element 300 is inserted into the housing 100 such that the closing element 300 does not engage any fluid connections. The measuring medium flowing through the flow sensor DS is distributed proportionally to the measuring channel 130 and the auxiliary channel 140 according to the geometry of the measuring channel 130 and the auxiliary channel 140'.
[0047] In the second position P2', the closing element 300 is inserted into the housing 100 such that the closing element 300 strikes the fluid connection 150 that connects the inlet channel 110 to the auxiliary channel 140 and completely closes its cross-section. Thus, the measuring medium flowing through the flow sensor DS only flows through the measuring channel 130, resulting in a higher flow rate in this measuring channel 130 compared to the position P1'.
[0048] In the third position P3', the closing element 300 is inserted into the housing 100 such that the closing element 300 closes the cross-sections of all fluid connections of the channels 130, 140'. No more measuring medium flows through the flow sensor DS.
[0049] The second embodiment additionally provides the possibility of smoothly reducing the cross-section of the fluid connection 150. For this purpose, the closing element 300 can be adjusted to an intermediate position between the positions P1' and P2'. This provides a certain degree of adaptability for different applications.
[0050] Figure 4 An exemplary embodiment of the system according to the invention is shown. Here, the flow sensor DS corresponds to the flow sensor DS of the first exemplary embodiment (see Figure 1 and Figure 2 ). Additionally, here, an actuator 500 is provided, which can move the closing element 300 in the housing 100 and set the positions P1, P2, P3, P4.
[0051] Furthermore, a control / evaluation unit 600 can be provided. This is used to query the measured values from the flow sensor 200 and to control the actuator to move the closing element 300 to positions P1 to P4. It is also possible to implement a controller function, in which the control / evaluation unit 600 moves the closing element 200 in accordance with the variable sensed by the flow sensor 200. For example, the position is controlled when a limit value is exceeded or reached such that the flow sensor will be "out of specification". By controlling the appropriate position, the flow sensor 200 is again within the desired specification range.
[0052] The invention is not limited to the listed exemplary embodiments and Figures 1 to 4 the shown embodiments. Combinations of the exemplary embodiments are also included. It is also possible to provide a second closing element which can close a second fluid connection (between the auxiliary channel and the outlet channel, or between the measurement channel and the outlet channel). It is also possible to provide a separate closing element for each fluid connection.
[0053] List of reference numerals
[0054] 100 housing
[0055] 110 inlet channel
[0056] 120 outlet channel
[0057] 130 measurement channel
[0058] 140 auxiliary channel
[0059] 150 first fluid conveyance
[0060] 160 second fluid conveyance
[0061] 170 additional auxiliary channel
[0062] 200 sensor element
[0063] 300 closing element
[0064] 400 workpiece
[0065] 500 actuator
[0066] 600 control / evaluation unit
[0067] DS flow sensor
[0068] P1 first position of the closing element
[0069] P2 second position of the closing element
[0070] P3 third position of the closing element
Claims
1. A flow sensor (DS) for measuring the flow rate of a fluid measurement medium, comprising: - A housing (100), wherein the housing (100) has an inlet channel (110) for receiving the fluid measurement medium, an outlet channel (120) for discharging the fluid measurement medium, a measurement channel (130) extending between the inlet channel (110) and the outlet channel (120), and at least one auxiliary channel (140) extending between the inlet channel (110) and the outlet channel (120) and more particularly being connected in parallel to the measurement channel (130), wherein a first fluid conveying member (150) is provided for connecting the inlet channel (110) and the auxiliary channel (140), and wherein a second fluid conveying member (160) is provided for connecting the auxiliary channel (140) and the outlet channel (120); - A sensor element (200), the sensor element (200) being arranged in the measurement channel (130) for sensing a physical measurement variable regarding the flow rate of the fluid measurement medium; and - A first closing element (300), in particular in the shape of a bolt, wherein the first closing element (300) is designed and attached to the housing (100) such that the first closing element (300) can be moved to at least a first position (P1) and a second position (P2) relative to the first fluid conveying member (150) or the second fluid conveying member (160), wherein the first closing element (300) closes the first fluid conveying member (150) or the fluid conveying member (160) in the second position (P2), and wherein the first fluid conveying member (150) or the second fluid conveying member (160) is not closed in the first position (P1) of the first closing element (300).
2. The flow sensor according to claim 1, comprising in particular a second closing element in the form of a bolt, wherein, The second closing element is designed and attached to the housing (100) such that the second closing element can be moved to at least a first position and a second position relative to the first fluid conveying member (150) or the second fluid conveying member (160) independently of the first closing element, wherein the second closing element closes the corresponding fluid conveying member (150, 160) in the second position, and wherein the corresponding fluid conveying member (150, 160) is not closed in the first position of the second closing element.
3. The flow sensor according to claim 1 or claim 2, wherein, The first closing element (300) and / or the second closing element can be adjusted to an intermediate position between the first position (P1) and the second position (P2).
4. The flow sensor according to claim 3, wherein, The first closing element (300) and / or the second closing element can be adjusted smoothly.
5. The flow sensor according to any one of the preceding claims, wherein, The housing (100) includes one or more additional auxiliary channels (170) extending between the inlet channel (110) and the outlet channel (120) and connected, in particular, parallel to the measurement channel (130), wherein for each additional auxiliary channel (170), at least one additional first fluid conveyance is provided for connecting the inlet channel (110) and the corresponding additional auxiliary channel (170), and in each case, an additional second fluid conveyance is provided for connecting the corresponding additional auxiliary channel (170) and the outlet channel (120).
6. The flow sensor according to claim 5, wherein, The first closing element (300) is designed and attached to the housing (100) such that the first closing element (300) can be adjusted to at least a third position (P3) in which the first fluid conveyance (150) is closed together with at least one additional first fluid conveyance and / or with all additional first fluid conveyances.
7. The flow sensor according to claim 5 or 6, wherein, The second closing element is designed and attached to the housing (100) such that the second closing element can be adjusted to at least a third position in which the second fluid conveyance (160) is closed together with at least one additional second fluid conveyance and / or with all additional second fluid conveyances.
8. The flow sensor according to claim 5, wherein, For each additional auxiliary channel, the flow sensor (DS) has at least one additional bolt-shaped closing element for closing the respective corresponding additional first fluid conveyance and / or additional second fluid conveyance.
9. The flow sensor according to any one of the preceding claims, wherein, The sensor element (200) is a thermal flow sensor.
10. The flow sensor according to any one of the preceding claims, comprising an actuator (500), the actuator (500) being designed and connected to the first closing element (300) and / or the second closing element such that the actuator (500) generates a movement of the first closing element (300) or the second closing element for controlling the respective first position (P1), second position (P2), intermediate position and third position (P2).
11. A system comprising the flow sensor (DS) according to claim 10 and a control / evaluation unit (600), wherein, The control / evaluation unit (600) is designed to query from the flow sensor the measured value of the physical measurement variable of the flow of the fluid measurement medium and / or to adjust at least one of the closing elements (300) to at least one of the positions (P1, P2, P3) by means of the actuator (500).
12. The system according to claim 11, wherein, The control / evaluation unit (600) is designed to compare the measured value with at least one limit value and, if the limit value is exceeded or reached, to adjust at least one of the closing elements (300) by means of the actuator (500) such that the measured value no longer drops below the limit value or exceeds the limit value.