Compact Fluid Flow Sensor

Abstract

A system and method for monitoring fluid flow through a conduit is described. The method includes conveying a fluid through the conduit such that the fluid impinges on an impingement portion within the conduit and sensing a temperature with a heated temperature sensor thermally coupled to the conduit to provide a heated temperature measurement. The method also includes heating the heated temperature sensor with a heater and sensing the temperature of the fluid at a location in the conduit that is thermally insulated from the heater to obtain a reference temperature measurement. An indication of the flow rate of the fluid is provided based on a temperature difference between the reference temperature measurement and the heated temperature measurement.

Description

[Technical Field]

[0001] Claiming priority under 35 U.S.C. § 119 This application claims priority to U.S. Non-Provisional Application No. 18 / 103,269, filed January 30, 2023, entitled "Compact Fluid Flow Sensor," which is incorporated herein by reference.

[0002] background Field FIELD OF THE DISCLOSURE The present disclosure relates generally to sensing technology, and more particularly to fluid flow sensing technology. [Background technology]

[0003] background Sensing fluid flow is an important technology. Fluid flow sensing often requires devices that are bulky and / or must be immersed within the fluid flow path. Common sensing technologies include mechanical displacement, pressure change, fluid level change, optical sensors, and sonar technology, among others. These technologies require the sensor to be immersed in the fluid flow path. Many problems are associated with these technologies, including, among others, fluid contamination, unreliability due to moving parts, high cost, and the opportunity for leak paths where the sensor is inserted into a conduit. Therefore, there is a need for a cost-effective, reliable, and non-invasive method of measuring fluid flow. Summary of the Invention [Means for solving the problem]

[0004] overview According to one aspect, a system for monitoring a fluid flow is disclosed. The system includes a conduit for conveying a fluid in a fluid flow direction, the conduit including an impingement portion for the fluid flow. A reference temperature sensor is configured to sense a temperature of the fluid to provide a reference temperature measurement, and a heating temperature sensor is thermally coupled to the conduit in close proximity to the impingement portion to provide a heating temperature measurement. A heater is attached to the conduit in thermal proximity to the heating temperature sensor to heat the heating temperature sensor, and a flow monitor is configured to provide an indication of a flow rate of the fluid based on a temperature difference between the reference temperature measurement and the heating temperature measurement.

[0005] According to another aspect, a method includes monitoring a fluid flow, the method including conveying a fluid in a conduit such that the fluid impacts an impingement site in the conduit. The method also includes sensing a temperature with a heated temperature sensor thermally coupled to the conduit in close proximity to the impingement site to provide a heated temperature measurement. The heated temperature sensor is heated by a heater, and the temperature of the fluid is sensed at a location in the conduit that is thermally insulated from the heater to obtain a reference temperature measurement, and providing an indication of a flow rate of the fluid based on a temperature difference between the reference temperature measurement and the heated temperature measurement. [Brief explanation of the drawings]

[0006] [Figure 1A] FIG. 1A is a block diagram illustrating a system for monitoring fluid flow.

[0007] [Figure 1B] FIG. 1B is a block diagram illustrating another system for monitoring fluid flow.

[0008] [Figure 1C] FIG. 1C is a block diagram illustrating yet another system for monitoring fluid flow.

[0009] [Figure 2-1] 2A, 2B, 2C, and 2D illustrate examples of asymmetric deformation shapes according to some implementations. [Figure 2-2] 2A, 2B, 2C, and 2D illustrate examples of asymmetric deformation shapes according to some implementations.

[0010] [Figure 3-1] 3A, 3B, 3C, and 3D illustrate an example of a symmetric deformation shape according to some embodiments. [Figure 3-2] 3A, 3B, 3C, and 3D illustrate an example of a symmetric deformation shape according to some embodiments.

[0011] [Figure 4] FIG. 4 illustrates another example of a system for monitoring a fluid.

[0012] [Figure 5] FIG. 5 is a block diagram illustrating an example of a flow monitor that may be used in the systems described herein.

[0013] [Figure 6] FIG. 6 is a flowchart illustrating a method that may be traversed in connection with the systems disclosed herein.

[0014] [Figure 7] FIG. 7 presents data obtained using a system according to some embodiments.

[0015] [Figure 8] FIG. 8 presents additional data obtained using a system according to another embodiment.

[0016] [Figure 9] FIG. 9 is a block diagram illustrating a computing system that may be used to implement some aspects disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0017] Detailed Description The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0018] As used herein, reference numbers may refer to different variations of the same general structure. For example, the impingement portion 105 disclosed herein may have any of a variety of shapes. Unless otherwise limited by the claims, specific reference numbers may refer to various implementations.

[0019] It should be noted that as used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "layer" includes two or more layers, and the like.

[0020] The term "horizontal" as used herein is understood to be defined as any reference direction H. The term "vertical" refers to a direction V perpendicular to the horizontal direction H defined above. Terms such as "above," "below," "bottom," "top," "side" (e.g., a side wall), "higher," "lower," "upper," "over," and "under" are defined relative to a horizontal plane. The term "on" means that there is direct contact between elements. The term "over" allows for intervening elements.

[0021] Embodiments disclosed herein include novel systems and methods for measuring fluid flow. FIGS. 1A, 1B, and 1C are block diagrams depicting systems 100A, 100B, and 100C, respectively. As shown in FIGS. 1A, 1B, and 1C, a conduit 102 is adapted to carry a fluid (e.g., a liquid such as water) therein, and a reference temperature sensor 110 and a heating temperature sensor 115 are mounted on the outside of the conduit 102. The fluid flow direction 120 in FIG. 1 is arbitrarily depicted as a horizontal direction moving from left to right. In FIGS. 1A-3C, a collision constitutes a deformation in the conduit 102, while in FIG. 4, the deformation is formed by a change in the direction of the conduit 102.

[0022] Beneficially, the system disclosed herein provides a non-invasive flow sensing technique based on the temperature difference between a reference temperature (at the reference temperature sensor 110) and a heating temperature (at the heating temperature sensor 115). Some examples of the reference temperature sensor 110 and the heating temperature sensor 115 include thermistors, resistance temperature detectors (RTDs), thermocouples, semiconductor-type sensors, and infrared sensors, among others. The choice of which technology to use is application-based, taking into account factors such as cost, space requirements, temperature range, performance, and stability. Data from temperature sensing can be useful to those operating a system or process to obtain fluid flow information about an area of ​​interest. The data can indicate a variety of indicators that are important to a system operator, designer, or engineer.

[0023] Being able to monitor fluid flow has many benefits, such as noticing disturbances and unexpected losses of fluid flow within a system. One example of an application that benefits from fluid flow monitoring is the cooling of power supplies used to power manufacturing operations. These power supplies can be used to provide high power to equipment used in the production of items such as semiconductor chips, light-emitting diodes (LEDs), solar panels, and liquid crystal displays (LCDs), among others. Loss of cooling fluid to the power supply can result in damage to the power supply and subsequent loss of product. Benefits may depend on any custom application, and certain fluid flow sensing technologies may be limited in use if they are too restrictive. For example, while sensors inserted into the fluid can accurately measure fluid flow, this technology is invasive, expensive, and may not be practical for field use. Therefore, there is a need to provide custom, economically viable fluid flow sensors tailored to a variety of different needs.

[0024] In operation, the heated temperature sensor 115 is heated by the heater 108, and heat is removed from the heated temperature sensor 115 by the flow of fluid through the conduit 102. The temperature difference between the reference temperature measurement 111 provided by the reference temperature sensor 110 and the heated temperature measurement 116 provided by the heated temperature sensor 115 is inversely proportional to the fluid flow rate.

[0025] In systems 100A, 100B, and 100C, the deformation portion forming impingement portion 105 may be realized with a variety of different geometries (i.e., the geometry of impingement portion 105 may be different from the geometry depicted in FIGS. 1A, 1B, and 1C), but generally, impingement portion 105 comprises a portion of conduit 102 formed with a directional component perpendicular to fluid flow direction 120. In systems 100A, 100B, and 100C, conduit 102 is generally oriented with an axial component parallel to the horizontal direction such that the radial component of conduit 102 is parallel to the vertical direction. As shown, the deformation portion of impingement portion 105 comprises upstream wall 106 forming a sloped shape with radial and axial components, the radial component being perpendicular to fluid flow 120. Impingement portion 105 also comprises transition portion 109 and downstream wall 113. As discussed further herein, each of the upstream wall 106, transition portion 109, and downstream wall 113 may have a different geometry and orientation than those depicted in Figures 1A, 1B, and 1C. In contrast to conventional systems, the impingement portion 105 increases sensitivity and improves the useful flow range. It should also be noted that the illustrated systems 100A, 100B, and 100C are capable of measuring temperature differences without the use of electrically and mechanically complex components such as Wheatstone bridges, capillary tubes, or bypass tubes known to be used in gas measurement mass flow sensors.

[0026] Although the heating temperature sensor 115 and the heater 108 are located above or on the transition portion 109 of the impingement portion 105, the heating temperature sensor 115 and the heater 108 may be located in different portions of the impingement portion 105. For example, without limitation, the heater 108 may be located on the upstream wall 106 and the heating temperature sensor 115 may be located in the transition portion 109, or vice versa.

[0027] In some embodiments, the impingement portion 105 may be symmetrical about the axis of the conduit 102 (e.g., an annular deformation). In other embodiments, the impingement portion 105 may not be symmetrical about the axis of the conduit 102 (e.g., a deformation may be present in a single section of the conduit 102). As an example of an asymmetric case, the impingement portion 105 is illustrated as being formed at the "top" of the conduit 102. However, the impingement portion 105 may also be formed at the "bottom" or "side" of the conduit.

[0028] In systems 100A, 100B, and 100C, the heated temperature sensor 115 is attached to the conduit 102 within a recessed portion of the deformation of the impingement section 105, where the diameter of the conduit 102 is a compressed diameter d2 that is smaller than the general diameter d1 of the conduit 102. In systems 100A, 100B, and 100C, the impingement section 105 compresses the fluid flow, increasing the turbulence and velocity of the flow within the region of the deformation, as illustrated by arrows 112 and 121 within the restricted region, respectively. The compression and turbulence of the fluid in thermal proximity to the heated temperature sensor 115 enhances the extraction of heat from the heated temperature sensor 115. This results in greater sensitivity of the heated temperature sensor 115 measurement to flow rate, allowing for more accurate estimation of flow based on the difference between the reference temperature sensor 110 and the heated temperature sensor 115. The increased variation with changing flow rates gives systems 100A and 100B improved sensitivity and a larger useful flow rate range. This system configuration exhibits a sub-second response time to changes in fluid flow.

[0029] The size of the impingement region 105 may be established to enhance the sensitivity of the fluid flow measurement system. When the deformation region is implemented as a depression in the surface of the conduit 102, the depth of the impingement region 105 is such that 10% to 50% of the cross-sectional area of ​​the conduit is occluded. Preferably, the depth of the impingement region 105 in the implementations of FIGS. 1A, 1B, and 1C occludes approximately 30% of the cross-sectional area of ​​the conduit. The length of the deformation region along the length of the conduit 102 can be approximately 0.065 centimeters to approximately 2.5 centimeters, although the dimension is not critical and other dimensions are certainly contemplated. Preferably, the length of the deformation region along the length of the conduit is approximately 1.25 centimeters.

[0030] In many implementations (e.g., as shown in FIGS. 1A and 1C ), the heater 108 is separated as a separate component from the heating temperature sensor 115. In these implementations, the heater 108 may heat the heating temperature sensor 115 through the substrate 107 by conduction. In these implementations, noise from the power applied to the heater 108 is isolated from the heating temperature sensor 115 so that the noise does not interfere with the heating temperature measurement 116. The heater 108 may be physically, and therefore thermally, close to the heating temperature sensor 115. The spacing between the heater 108 and the heating temperature sensor 115 may be about 0.13 centimeters to about 0.38 centimeters, although it is contemplated that these dimensions may be scaled depending on the size of the conduit 102. In some implementations, the spacing is about 0.65 centimeters. When implemented as a separate heater, the heater 108 may be a resistive heater having a resistance of about 1 ohm to about 80 ohms. However, this range of values ​​is exemplary only, and the particular resistance utilized will depend on the voltage applied to the heater 108. In operation, power is supplied to the heater 108 to generate heat, which is conducted by the conduit 102 (and substrate 107, if a substrate is utilized), and the heat increases the temperature of the heated temperature sensor 115. The more power supplied to the heater 108, the more heat is generated, increasing the temperature of the heated temperature sensor 115. In some implementations, the substrate 107 may be, for example, without limitation, beryllium oxide or aluminum nitride.

[0031] FIG. 1B follows the same concept as FIGS. 1A and 1C, except that heater 108 is integrated with heating temperature sensor 115 to form heating sensing device 117.

[0032] 1A and 1B, except that the reference temperature sensor 110 is not directly coupled to the conduit 102. Instead, the reference temperature sensor 110 is positioned to sense the temperature of the fluid in relation to another form of piping (e.g., a supply pipe) that is not part of the conduit 102. In some implementations, the reference temperature sensor 110 may be applied anywhere where the temperature of the fluid can be measured.

[0033] 2A-2D illustrate examples of asymmetric deformation section geometries according to some embodiments. In FIG. 2A, the impingement section 105 is illustrated as having a sloped upstream wall 106 and a sloped downstream wall 113 penetrating the fluid flow 120. In FIG. 2B, the impingement section 105 is illustrated as having both an upstream wall 106 and a downstream wall 113 with steep sides penetrating the fluid flow 120. In FIG. 2C, the impingement section 105 is illustrated as having an upstream wall 106 with a gradual slope penetrating the fluid flow 120 and terminating at the downstream wall 113, which begins with an abrupt transition 109 at the downstream edge of the impingement section 105. In FIG. 2D, the impingement section 105 is illustrated as having an upstream wall 106 that is steep, perpendicular to the direction of the fluid flow 120, and terminates at the sloped downstream wall 113 at the downstream portion of the impingement section 105.

[0034] 3A-3D illustrate examples of impingement sections 105 formed by symmetrical deformation section shapes (e.g., annular deformation sections) according to several variations. In FIG. 3A, the impingement section 105 is illustrated as having an upstream wall 106 with a sloped shape, which penetrates the fluid flow 120 with a radial component that causes the fluid flow 120 to impinge on the deformation section of the upstream wall 106 at approximately 45 degrees. In FIG. 3B, the impingement section 105 is illustrated as having an upstream wall 106 with a radial component that is perpendicular to the direction of the fluid flow 120. In FIG. 3C, the impingement section 105 is illustrated with an upstream wall 106 with a gentle slope that penetrates the fluid flow 120 and a downstream wall 113 at the downstream edge of the impingement section 105 that is perpendicular to the fluid flow 120. In FIG. 3D, the impingement section 105 is illustrated as having an upstream wall 106 that is perpendicular to the fluid flow 120, and the impingement section 105 terminates in a downstream wall 113 that has a gentle slope.

[0035] Referring now to FIG. 4 , another variation of the conduit 102 is shown in which the conduit 102 is redirected to form the impingement region 105. For example, the conduit may be redirected 90 degrees to form the impingement region 105, as shown in FIG. 4 . In the example depicted in FIG. 4 , the conduit is U-shaped to form the impingement region 105 with an upstream wall 106 perpendicular to the direction of the fluid flow 120. More specifically, the conduit 102 has an upstream vertical component 440, a horizontal component 442, and a downstream vertical component 446, with the upstream wall 106 formed by a portion of the horizontal component 442 exposed to the vertical portion of the fluid flow 120 such that the fluid flow 120 directly impinges on the upstream wall 106. As shown, a substrate 107 is located on the outer portion of the wall of the conduit 102 that forms the upstream wall 106, and the heater 108 and heating temperature sensor 115 are located on the substrate 107. It should also be noted that the transition section 109 and downstream wall 113 (which are present in other implementations) are not separate components of the impingement section 105 in FIG.

[0036] It should be appreciated that the positions of the heated temperature sensor 115 and the reference temperature sensor 110 may be switched so that the reference temperature sensor 110 is upstream of the heated temperature sensor 115. It should also be appreciated that the substrate 107 is not required in the variation depicted in FIG. 4 (or other variations discussed herein), but that the substrate 107 may provide a substantial increase in sensitivity, as discussed further herein. It should also be appreciated that the conduit 102 may change direction by more or less than 90 degrees to form the impingement region 105. For example, the conduit 102 of FIG. 4 may be modified to replace the horizontal section 442 with a triangular section to form an upstream wall 106 with components both parallel and perpendicular to the direction of fluid flow 120. For clarity, the flow monitor 122 is not shown in FIG. 4, but the flow monitor 122 may be utilized in the same manner as described in FIGS. 1B, 1C, and 1D. It should also be appreciated that the system described in FIG. 4 may be made up of any number of conduit components, not necessarily one continuous piece as depicted in FIG.

[0037] Referring now to FIG. 5, a block diagram illustrating one embodiment of the flow monitor 122 is shown. As shown, the flow monitor 122 may include a temperature difference calculator 560, a calibration data data store 562, and a determination module 564 coupled to both the temperature difference calculator 560 and the calibration data data store 562. Also shown is a power supply 566 configured to apply power to the heater 108. The temperature difference calculator 560 and the determination module 564 may be implemented by hardware or hardware in association with software, and the calibration data data store 562 may be implemented by memory, such as non-volatile memory. The power supply may also be implemented by a DC power supply that may be controlled by hardware or hardware in association with software. Referring to FIG. 5, reference is made simultaneously to FIG. 6, which is a flowchart illustrating a method that may be traversed in connection with the operation of the flow monitor 122. It should be appreciated that the method and corresponding claims are not limited by the order of operations presented in FIG. 6. In other words, the order of operations in FIG. 6 may be changed without departing from the scope of the claims.

[0038] As shown, a fluid is conveyed through a conduit 102 such that the fluid impinges upon an impingement portion 105 within the conduit 102 (block 600), and a heated temperature sensor 115 is heated by a heater 108 (block 602). The temperature of the fluid is sensed by a heated temperature sensor 115 that is thermally coupled to the conduit 102 in close proximity to the impingement portion 105 to provide a heated temperature measurement 116 (block 604). As previously described, the heater 108 may be a resistor that is heated by applying a voltage to the resistor via a power source 566 that causes a current to flow through the resistor, causing heating. The temperature of the fluid is sensed by a reference temperature sensor 110 at a location thermally isolated from the heater 108 to obtain a reference temperature measurement 111 (block 606). As previously described, the reference temperature sensor 110 may be located upstream or downstream of the heated temperature sensor 115, so long as the reference temperature sensor 110 is positioned to measure the temperature of the fluid without being measurably heated by the heater 108. Those skilled in the art will readily understand how far the reference temperature sensor 110 must be located from the heater 108 to achieve thermal isolation so that heat from the heater 108 does not adversely affect the fluid temperature reading of the reference temperature sensor 110.

[0039] As shown, an indication of the fluid flow rate is provided based on the temperature difference between the reference temperature measurement 111 and the heating temperature measurement 116 (block 608). More specifically, a temperature difference calculator 560 generates a temperature difference indicator 580 representing the temperature difference between the reference temperature measurement 111 and the heating temperature measurement 116, and a determination module 564 accesses calibration data from a calibration data store 562 relating the temperature difference to the flow rate.

[0040] As will be appreciated by those skilled in the art, calibration data may be created during a calibration mode by measuring the flow rate of fluid flow 120 using a precision flow meter (very well known in the art) to obtain a flow rate value at each of a plurality of temperature difference values, where each temperature difference value corresponds to the difference between the reference temperature measurement 111 and the heating temperature measurement 116. More specifically, during calibration, heater 108 may be heated at a particular power level, and the flow rate of fluid through the conduit may be varied to each of a plurality of different flow rates. For each flow rate, the precision flow meter obtains a flow reading, and a temperature difference between the reference temperature measurement 111 and the heating temperature measurement 116 is obtained.

[0041] During operation, the heater 108 is heated at the same power level used during calibration, and the temperature difference calculator 560 generates a temperature difference indicator 580 representing the temperature difference between the reference temperature measurement 111 and the heated temperature measurement 116. The determination module 564 utilizes the value of the temperature difference indicator 580 and accesses calibration data from the calibration data store 562, which associates the value of the temperature difference indicator 580 with a stored flow rate value. The determination module 564 may utilize the flow rate value to provide a flow indication 568. The flow indication may simply be a flow value (e.g., in liters / minute), a visual indication of the flow rate (e.g., green for significant flow, yellow for marginally significant flow, red for low flow), or an audible alarm when the flow rate drops below a certain flow threshold. It is also contemplated that the flow indication 568 may be used to automatically shut off power to a device (e.g., a power supply) cooled by the fluid.

[0042] Referring to FIG. 7, an example of calibration data depicted in graphical form that may be stored in the calibration data data store 562 is shown. FIG. 7 illustrates calibration data depicting the effect of different power levels without the use of a substrate 107. Data was collected at four different dissipation ranges (e.g., power levels) of the heater 108 and fluid flow rates ranging from 0 liters per minute (lpm) to 10 lpm. Water at nominal room temperature was used as the fluid in the data illustrated in FIG. 7. Data set 705 corresponds to a dissipation level of 1,050 mW, with the fluid flowing between 0 lpm and 10 lpm. Data set 710 corresponds to a dissipation level of 847 mW, with the fluid flowing between 0 lpm and 10 lpm. Data set 715 corresponds to a dissipation level of 667 mW, with the fluid flowing between 0 lpm and 10 lpm. Data set 720 corresponds to a dissipation level of 365 mW, with the fluid flowing between 0 lpm and 10 lpm. The data presented in FIG. 7 shows that the temperature difference between the reference temperature sensor 110 and the heated temperature sensor 115 is higher at higher dissipation levels.

[0043] Referring now to FIG. 8 , another example of calibration data mapping multiple temperature difference values ​​to flow rate is shown. In contrast to the calibration data in FIG. 7 , the calibration data in FIG. 8 was generated when a substrate 107 (e.g., beryllium oxide) was utilized. The substrate 107 advantageously allows the heater 108 to heat the heated temperature sensor 115 more than if the heated temperature sensor 115 were directly coupled to the conduit 102, resulting in the heated temperature sensor 115 cooling less rapidly. The addition of the substrate 107 layer adds another level of thermal resistance, which allows for more uniform heating of the area around the heated temperature sensor 115. In terms of performance, when the substrate 107 is utilized, there is a greater change in temperature difference value with respect to a change in flow rate; as a result, the use of the substrate 107 produces greater sensitivity, allowing for greater accuracy in measuring flow rate.

[0044] The methods described in connection with the embodiments disclosed herein may be embodied directly in hardware, in processor-executable instructions encoded on a non-transitory machine-readable medium, or as a combination of the two. For example, referring to FIG. 9 , a block diagram is shown depicting the physical components of an exemplary controller 900 that may be utilized to implement aspects of the flow monitor 122 according to an exemplary embodiment of this disclosure. As shown, in this embodiment, a display 512 and a non-volatile memory 520 are coupled to a bus 522, which is coupled to a random access memory (“RAM”) 524, a processing unit (including N processing components) 526, a field programmable gate array (FPGA) 527, and a transceiver component 528 that includes N transceivers. While the components depicted in FIG. 5 correspond to physical components, FIG. 5 is not intended to be a detailed hardware diagram; thus, many of the components depicted in FIG. 5 may be realized by common components or distributed among additional physical components. Furthermore, it is contemplated that other existing and yet-to-be-developed physical components and architectures may be utilized to implement the functional components described with reference to FIG. 5 .

[0045] The display 512 generally operates to provide a user interface to a user, and in some implementations, the display 512 is implemented by a touchscreen display. For example, the display 512 can be used to control and interact with the flow monitor 122. For example, the display 512 may display a flow indication 568, which may be a parameter value such as a temperature or fluid flow indication. Generally, the non-volatile memory 520 is non-transitory memory that functions to store (e.g., persistently store) data and machine-readable (e.g., processor-executable) code (including executable code related to performing the methods described herein). In some embodiments, for example, the non-volatile memory 520 includes boot loader code, operating system code, file system code, and non-transitory processor-executable code to facilitate execution of the methods described herein, including the method described with reference to FIG. 6 .

[0046] In many implementations, non-volatile memory 520 is implemented by flash memory (e.g., NAND or ONENAND memory), although it is contemplated that other memory types may also be utilized. While it may be possible to execute code from non-volatile memory 520, executable code in non-volatile memory is typically loaded into RAM 524 and executed by one or more of the N processing components in processing unit 526. Non-volatile memory 520 may also be used to implement calibration data data store 562, which stores calibration data as described with reference to FIGS. 8 and 9.

[0047] In operation, the N processing components associated with RAM 524 may generally operate to execute instructions stored in non-volatile memory 520 to implement aspects of temperature difference calculator 560 and determination module 564. For example, non-transitory processor-executable instructions for implementing methods described herein may be persistently stored in non-volatile memory 520 and executed by the N processing components associated with RAM 524. As will be appreciated by those skilled in the art, processing unit 526 may include a video processor, a digital signal processor (DSP), a graphics processing unit (GPU), and other processing components.

[0048] Additionally or alternatively, a field programmable gate array (FPGA) 527 may be configured to accomplish one or more aspects of the methodologies described herein. For example, non-transitory FPGA configuration instructions may be persistently stored in non-volatile memory 520 and accessed by FPGA 527 (e.g., during power-up) to configure FPGA 527 to implement the functionality of controller 114.

[0049] Generally, the input components function to receive analog and / or digital signals, such as, for example, the reference temperature measurement 111 and the heating temperature measurement 116. The input components may receive user input for controlling the power supply 566 (e.g., power level). It should be appreciated that the input components may be realized by several separate analog and / or digital input processing chains, but for simplicity, the input components are depicted as a single functional block. In an exemplary mode of operation, the input components may operate to receive output signals from the reference temperature sensor 110 and the heating temperature sensor 115, and processor-executable instructions (executing the temperature difference calculator 560 and the determination module 564) prompt accessing calibration data in the non-volatile memory 520 to obtain a parameter value corresponding to, for example, temperature. The output component may be used to provide a flow indication 568 in the form of one or more analog or digital signals.

[0050] It is also contemplated that the output component may provide a control signal for controlling the monitored environmental parameter (e.g., as a feedback signal). For example, the control signal may be coupled to a system used for fault detection under conditions of reduced fluid flow or loss of fluid flow.

[0051] The illustrated transceiver component 528 includes N transceiver chains that can be used to communicate with external devices over wireless or wired networks, each of which can correspond to a transceiver associated with a particular communication scheme (e.g., WiFi, Ethernet, Universal Serial Bus, Profibus, etc.).

[0052] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A system for monitoring a fluid flow, the system comprising: a conduit for conveying a fluid in a fluid flow direction, the conduit comprising an impingement portion for the fluid flow; a reference temperature sensor configured to sense a temperature of the fluid and provide a reference temperature measurement; a heating temperature sensor thermally coupled to the conduit in close proximity to the impingement portion to provide a heating temperature measurement; a heater attached to the conduit in thermal proximity to the heating temperature sensor such that the heater can heat the heating temperature sensor; a flow monitor configured to provide an indication of a flow rate of the fluid based on a temperature difference between the reference temperature measurement and the heating temperature measurement; A system comprising:

2. The system of claim 1 , wherein the reference temperature sensor is thermally coupled to the conduit at a location thermally isolated from the heater to sense the temperature of the fluid.

3. The system of claim 1 , wherein the impingement portion comprises a deformation in the conduit.

4. The system of claim 3 , wherein the deformation of the conduit is not symmetric about an axis of the conduit.

5. The system of claim 3 , wherein the deformation comprises a steep upstream wall that penetrates into the conduit.

6. The system of claim 3 , wherein the deformation of the conduit is symmetric about an axis of the conduit.

7. The system of claim 1 , wherein the impingement is formed by a change in direction of the conduit.

8. The system of claim 7 , wherein the change in direction is 90 degrees.

9. The system of claim 1 , wherein the reference temperature sensor and the heating temperature sensor are selected from the group consisting of a resistance temperature detector, a thermocouple, and a thermistor.

10. The system of claim 1 , wherein the heater is integrated with the heating temperature sensor in a heating sensing device.

11. The flow monitor a temperature difference calculator configured to provide a temperature difference indicator indicative of the temperature difference between the reference temperature measurement and the heating temperature measurement; a calibration data data store configured to store calibration data relating the temperature difference indicator to a flow rate; a flow determination module configured to access the calibration data from the calibration data store to obtain the flow rate and provide the indication of the flow rate; The system of claim 1 , comprising:

12. 1. A method for monitoring a fluid flow, the method comprising: conveying a fluid through a conduit such that the fluid impinges on an impingement portion within the conduit; sensing temperature with a heating temperature sensor thermally coupled to the conduit in close proximity to the impingement portion to provide a heating temperature measurement; Heating the heating temperature sensor using a heater; sensing the temperature of the fluid at a location in the conduit that is thermally isolated from the heater to obtain a reference temperature measurement; providing an indication of a flow rate of the fluid based on a temperature difference between the reference temperature measurement and the heated temperature measurement; and A method comprising:

13. generating calibration data during a calibration mode relating temperature difference indicators to flow rates, each temperature difference indicator being a difference between a reference temperature measurement and a heating temperature measurement; During operation, obtaining a temperature difference indicator, the temperature difference between the reference temperature measurement and the heating temperature measurement; accessing the calibration data using the temperature difference indicator to obtain a flow rate; providing the indication of the flow rate of the fluid based on the flow rate; and 13. The method of claim 12, comprising:

14. The method of claim 12 , wherein providing the indication of the flow rate of the fluid includes providing an alarm when the flow rate of the fluid falls below a threshold value.

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