Pressure compensation for fluid flow parameters

Abstract

A method for pressure compensation of a fluid flow parameter is provided that includes receiving a measured pipeline pressure value for a fluid in a pipeline and determining a pressure for determining a pressure-compensated fluid flow parameter value based on the measured pipeline pressure value.

Description

[Technical Field]

[0001] The embodiments described below relate to correcting fluid flow parameters measured by a vibration meter, and more specifically, to pressure compensation of fluid flow parameters. [Background technology]

[0002] For example, vibration meters such as Coriolis mass flow meters, liquid densimeters, gas densimeters, liquid viscometers, gas / liquid hydrometers, gas / liquid relative densimeters, and gas molecular weight meters are commonly known and used to measure fluid parameters. Generally, a vibration meter comprises a sensor assembly and meter electronics. The material in the sensor assembly may be flowing or stationary. A vibration meter can be used to measure one or more fluid parameters, such as mass flow rate, density, or other properties of the material in the sensor assembly.

[0003] A vibration meter, or more specifically, a sensor assembly, may be integrated in series with a pipeline. More specifically, the inlet of the sensor assembly may be fluidically coupled to the inlet pipeline, and the outlet of the sensor assembly may be fluidically coupled to the outlet pipeline. A sensor assembly typically includes one or more conduits, referred to as flow tubes, that vibrate to measure one or more fluid parameters. These conduits may have a smaller diameter than the diameter of the pipeline into which the vibration meter is integrated in series. As a result, the fluid velocity in the conduit may increase, leading to a corresponding reversible or dynamic pressure drop. Additionally, friction, turbulence, etc., may cause corresponding pressure loss or irreversible pressure drop.

[0004] Reversible and / or irreversible pressure drops can affect the measurement of fluid flow parameters. For example, the measured density error may increase as the fluid flow rate increases. Similar problems can also occur with mass flow rate or other fluid flow parameter values. The quantitative impact of these problems may be relatively small, and it may or may not have an adverse effect on the process using the vibrator. However, the purchaser of the vibrator may be aware that the fluid flow parameter values may be affected by pressure. The purchaser may also request information regarding whether there are specific positions (e.g., upstream, downstream, distance, etc.) for pipeline pressure measurement to determine the impact of pressure on the fluid flow parameter values. Therefore, pressure compensation for fluid flow parameters is required. SUMMARY OF THE INVENTION

[0005] A method for pressure compensation of fluid flow parameters is provided. In one embodiment, the method includes receiving a measured pipeline pressure value of the fluid in the pipeline and determining a pressure for determining a pressure-compensated fluid flow parameter value based on the measured pipeline pressure value. A meter electronics, a vibrator, and a system configured to perform the aforementioned method are also provided.

[0006] [ASPECTS] According to one aspect, a method for pressure compensation of fluid flow parameters includes receiving a measured pipeline pressure value of the fluid in the pipeline and determining a pressure for determining a pressure-compensated fluid flow parameter value based on the measured pipeline pressure value.

[0007] Preferably, the measured pipeline pressure value includes one of the measured inlet pipeline pressure value and the measured outlet pipeline pressure value.

[0008] Preferably, determining the pressure for determining the pressure compensation fluid flow parameter value based on the measured pipeline pressure value includes determining a pressure calculated based on one of the following equations. P C = (P1 + ρV1 2 / 2) - (permanent pressure loss) / 2 - (dynamic pressure drop) And P C = (P3 + ρV3 2 / 2)+(permanent pressure loss) / 2 - (dynamic pressure drop) Here, P1 is the measured inlet pipeline pressure value, V1 is the velocity of the fluid in the inlet pipeline, P3 is the measured outlet pipeline pressure value, V3 is the velocity of the fluid in the outlet pipeline, P C is the calculated pressure, ρ is the density of the fluid, (permanent pressure loss) is the permanent pressure loss value of the vibration meter connected to the pipeline, (dynamic pressure drop) is the dynamic pressure drop related to the diameter difference between the conduit of the vibration meter and the pipeline connected to the vibration meter.

[0009] Preferably, the pressure for determining the pressure compensation fluid flow parameter value is based on the pressure loss related to at least one of the conduit, the inlet manifold, and the outlet manifold.

[0010] Preferably, the pressure loss related to the conduit includes at least one of the frictional pressure loss and the bend pressure loss of the conduit.

[0011] Preferably, the pressure for determining the pressure compensation fluid flow parameter value includes one of the following equations.

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[0012] Preferably, determining the pressure for determining the pressure-compensated fluid flow parameter value based on the measured pipeline pressure value includes determining whether the pressure for determining the pressure-compensated fluid flow parameter value is one of the calculated pressure value and the measured pipeline pressure value.

[0013] Preferably, determining the pressure-compensated fluid flow parameter value based on the measured pipeline pressure value includes determining the error of the pressure-compensated fluid flow parameter value.

[0014] According to one embodiment, a meter electronic device configured for pressure compensation of fluid flow parameter values ​​comprises an interface configured to be communicatively coupled to a pressure sensor configured to measure the pipeline pressure of a fluid in a pipeline, and a processing system communicatively coupled to the interface, wherein the processing system is configured to perform the method described above.

[0015] According to one embodiment, a vibration meter configured to determine a pressure for pressure compensation of a fluid flow parameter value comprises a sensor assembly configured to provide a sensor signal and meter electronics communicatively coupled to the sensor assembly, the meter electronics being configured to receive the sensor signal and perform the aforementioned method.

[0016] According to one embodiment, a system for determining pressure for pressure compensation of a fluid flow parameter value, comprising a pressure sensor configured to measure pipeline pressure, and a vibration meter communicably connected to the pressure transducer, the vibration meter configured to perform the method described above. [Brief explanation of the drawing]

[0017] In all drawings, the same reference number represents the same element. [Figure 1] Figure 1 shows a vibration meter 5 configured to determine the pressure for pressure compensation of fluid flow parameter values. [Figure 2] Figure 2 shows a block diagram of the vibration meter 5, including a block diagram of the meter electronics 20 configured to perform pressure compensation for fluid flow parameter values. [Figure 3] Figure 3 shows the meter electronics 20 for pressure compensation of fluid flow parameter values. [Figure 4] Figure 4 shows system 400 for pressure compensation of flow meter parameters. [Figure 5] Figure 5 shows Graph 500, which illustrates the pressure compensation for fluid flow parameters. [Figure 6] Figure 6 shows a method 600 for pressure compensation of fluid flow parameters. [Modes for carrying out the invention]

[0018] Figures 1-6 and the following description illustrate specific examples to teach those skilled in the art how to construct and use the best mode of an embodiment for determining pressure for pressure compensation of fluid flow parameter values. Some conventional embodiments have been simplified or omitted for the purpose of teaching the principles of the present invention. Those skilled in the art will understand variations from these embodiments that fall within the scope of this specification. Those skilled in the art will understand that the features described below can be combined in various ways to form multiple variations for determining pressure for pressure compensation of fluid flow parameter values. Consequently, the embodiments described below are not limited to the specific examples described below, but are limited only by the claims and their equivalents.

[0019] Figure 1 shows a vibration meter 5 configured to determine pressure for pressure compensation of fluid flow parameter values. As shown in Figure 1, the vibration meter 5 comprises a sensor assembly 10 and meter electronics 20. The sensor assembly 10 responds to the mass flow rate and density of the process material. The meter electronics 20 is connected to the sensor assembly 10 via lead wires 100 and provides density, mass flow rate, and temperature information, as well as other information, via port 26.

[0020] The sensor assembly 10 includes a pair of manifolds 150 and 150', flanges 103 and 103' with flange necks 110 and 110', a pair of parallel conduits 130 and 130', a driver 180, a resistance temperature detector (RTD) 190, and a pair of pick-off sensors 170l and 170r. The conduits 130 and 130' have two essentially straight inlet legs 131, 131' and outlet legs 134, 134', which converge toward each other at conduit mounting blocks 120 and 120'. The conduits 130 and 130' bend at two symmetrical positions along their length and are essentially parallel over their entire length. The brace bars 140 and 140' serve to define the axes W and W' around which each conduit 130 and 130' oscillates. The legs 131, 131' and 134, 134' of conduits 130, 130' are fixedly mounted to conduit mounting blocks 120 and 120', which are then fixedly mounted to manifolds 150 and 150'. This provides a continuous, closed material path through the sensor assembly 10.

[0021] When flanges 103 and 103', having holes 102 and 102', are connected via an inlet end 104 and an outlet end 104' to a process line (not shown) carrying the process material being measured, the material enters the inlet end 104 of the meter through an orifice 101 in flange 103 and is guided through a manifold 150 to a conduit mounting block 120 having a surface 121. Within the manifold 150, the material is split and fed through conduits 130 and 130'. Exiting conduits 130 and 130', the process material is recombined in a single flow within block 120', having a surface 121' and a manifold 150', and then fed to an outlet end 104' connected to a process line (not shown) by flange 103' having hole 102'.

[0022] Conduits 130 and 130' are selected to have substantially the same mass distribution, moment of inertia, and Young's modulus with respect to bending axes WW and W'-W', respectively, and are appropriately mounted on conduit mounting blocks 120 and 120'. These bending axes pass through brace bars 140 and 140'. Since the Young's modulus of the conduits changes with temperature, and this change affects the calculation of flow rate and density, an RTD 190 is attached to conduit 130' to continuously measure the temperature of conduit 130'. The temperature of conduit 130', and therefore the voltage appearing on the RTD 190 for a particular current passing through it, is determined by the temperature of the material passing through conduit 130'. The temperature-dependent voltage appearing on the RTD 190 is used in a well-known manner by meter electronics 20 to compensate for the change in the elastic modulus of conduits 130 and 130' due to the change in conduit temperature. The RTD 190 is connected to meter electronics 20 by lead wires 195.

[0023] Both conduits 130 and 130' are driven by a driver 180 in opposite directions around their respective bending axes W and W', and in what is called the first out-of-phase bending mode of the vibrometer. This driver 180 can comprise one of many well-known configurations, such as a magnet attached to conduit 130' and opposing coils attached to conduit 130 through which alternating current flows to vibrate both conduits 130 and 130'. An appropriate drive signal 185 is applied to the driver 180 via lead wires by the meter electronics 20.

[0024] The meter electronics 20 receives the RTD temperature signal on lead wire 195 and the sensor signal 165 appearing on lead wires 100 that carry the left and right sensor signals 165l and 165r, respectively. The meter electronics 20 generates a drive signal 185 appearing on the lead wires to the driver 180 and the vibrating conduits 130 and 130'. The meter electronics 20 processes the left and right sensor signals 165l and 165r and the RTD signal 195 to calculate the mass flow rate and density of the material passing through the sensor assembly 10. This information, along with other information, is applied by the meter electronics 20 as a signal via port 26. A more detailed description of the meter electronics 20 is as follows.

[0025] Figure 2 shows a block diagram of the vibrometer 5, including a block diagram of the meter electronics 20 configured to perform pressure compensation for fluid flow parameter values. As shown in Figure 2, the meter electronics 20 is communicatively connected to the sensor assembly 10. As previously mentioned with reference to Figure 2, the sensor assembly 10 includes left and right pick-off sensors 170l, 170r, a driver 180, and a temperature sensor 190, which are communicatively coupled to the meter electronics 20 via a set of lead wires 100 through a communication channel 112.

[0026] The meter electronics 20 supplies a drive signal 185 via lead wires 100. More specifically, the meter electronics 20 supplies the drive signal 185 to a driver 180 in the sensor assembly 10. Furthermore, a sensor signal 165, including a left sensor signal 165l and a right sensor signal 165r, is supplied by the sensor assembly 10. More specifically, in the illustrated embodiment, the sensor signal 165 is supplied by left and right pick-off sensors 170l and 170r in the sensor assembly 10. As understood, each sensor signal 165 is supplied to the meter electronics 20 through a communication channel 112.

[0027] The meter electronic equipment 20 includes a processor 210 communicatively coupled to one or more signal processors 220 and one or more memories 230. The processor 210 is also communicatively coupled to a user interface 30. The processor 210 is communicatively coupled to the host via a communication port through port 26 and receives power via a power port 250. The processor 210 may be a microprocessor, but any suitable processor can be used. For example, the processor 210 may consist of subprocessors such as a multicore processor, a serial communication port, a peripheral interface (e.g., a serial peripheral interface), on-chip memory, and I / O ports. In these and other embodiments, the processor 210 is configured to perform operations on received and processed signals, such as digitized signals.

[0028] The processor 210 can receive digitized sensor signals from one or more signal processors 220. The processor 210 is also configured to provide information such as phase difference and fluid characteristics within the sensor assembly 10. The processor 210 can provide information to the host via a communication port. The processor 210 can also communicate with one or more memories 230 and be configured to receive and / or store information in one or more memories 230. For example, the processor 210 can receive calibration coefficients and / or sensor assembly zeros (e.g., phase difference for zero flow rate) from one or more memories 230. Each of the calibration coefficients and / or sensor assembly zeros can be associated with the vibration meter 5 and / or sensor assembly 10, respectively. The processor 210 can use the calibration coefficients to process the digitized sensor signals received from one or more signal processors 220.

[0029] One or more signal processors 220 are shown to consist of an encoder / decoder (CODEC) 222 and an analog-to-digital converter (ADC) 226. One or more signal processors 220 can adjust analog signals, digitize the adjusted analog signals, and / or provide the digitized signals. The CODEC 222 is configured to receive sensor signals 165 from left and right pick-off sensors 170l, 170r. The CODEC 222 is also configured to provide drive signals 185 to a driver 180. In alternative embodiments, more or fewer signal processors may be used.

[0030] As shown in the figure, the sensor signal 165 is supplied to the CODEC 222 via the signal conditioner 240. The drive signal 185 is supplied to the driver 180 via the signal conditioner 240. Although the signal conditioner 240 is shown as a single block, the signal conditioner 240 may consist of two or more signal conditioning components such as operational amplifiers, filters such as low-pass filters, and voltage-current amplifiers. For example, the sensor signal 165 may be amplified by the first amplifier and the drive signal 185 may be amplified by the voltage-current amplifier. Amplification can ensure that the amplitude of the sensor signal 165 is close to the full-scale range of the CODEC 222.

[0031] In the illustrated embodiment, one or more memories 230 consist of a read-only memory (ROM) 232, a random access memory (RAM) 234, and a ferroelectric random access memory (FRAM®) 236. However, in alternative embodiments, one or more memories 230 may consist of more or fewer memories. In addition, or alternatively, one or more memories 230 may consist of different types of memory (e.g., volatile, non-volatile, etc.). For example, another type of non-volatile memory, such as erasable programmable read-only memory (EPROM), can be used instead of the FRAM 236. One or more memories 230 can be storage devices configured to store process data such as drive signals or sensor signals, mass flow rate, or density measurements.

[0032] Mass flow rate measurements can be generated according to the following formula.

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[0033] Regarding density, the resonant frequency at which each conduit 130, 130' can vibrate can be expressed as a function of the square root of the spring constant of conduit 130, 130' divided by the total mass of conduit 130, 130' containing the material. The total mass of conduit 130, 130' containing the material can be expressed as the mass of conduit 130, 130' plus the mass of the material inside conduit 130, 130'. The mass of the material inside conduit 130, 130' is directly proportional to the density of the material. Therefore, the density of this material can be proportional to the product of the spring constant of conduit 130, 130' multiplied by the square of the period during which conduit 130, 130' vibrates. Thus, by determining the period during which conduit 130, 130' vibrates and appropriately scaling the result, an accurate measurement of the density of the material contained in conduit 130, 130' can be obtained. The meter electronic equipment 20 can determine the period or resonant frequency using the sensor signal 165 and / or the drive signal 185. The conduits 130, 130' can vibrate in multiple vibration modes.

[0034] As a result, measured fluid parameter values, such as the measured flow rate, can be obtained. However, the measured fluid parameter values ​​may contain errors due to various issues. One of these issues may be related to the pressure within conduits 130 and 130'. The pressure within conduits 130 and 130' can cause changes in structural properties such as the stiffness of the conduit. This change in stiffness can be compensated for by measuring the pipeline pressure and determining the pressure compensation for the measured fluid parameter values. However, under certain conditions, simply using the measured pipeline pressure will result in pressure-related errors due to pressure drops within conduits 130 and 130'. Pressure compensation for fluid flow parameters will be explained in more detail below.

[0035] Figure 3 shows a meter electronics unit 20 for pressure compensation of fluid flow parameter values. As shown in Figure 3, the meter electronics unit 20 includes an interface 301 and a processing system 302. The meter electronics unit 20 receives vibration responses from a sensor assembly, such as a sensor assembly 10. The meter electronics unit 20 processes the vibration responses to obtain the flow characteristics of the fluid material flowing through the sensor assembly 10. The meter electronics unit 20 can also perform check, verification, and calibration routines to ensure that the fluid flow parameters of the fluid material are measured accurately.

[0036] Interface 301 can receive a sensor signal 165 from one of the pick-off sensors 170l, 170r shown in Figures 2 and 3. Interface 301 can perform any necessary or desired signal adjustments, such as formatting, amplification, or buffering, in any manner. Alternatively, some or all of the signal adjustments can be performed by the processing system 302. Furthermore, interface 301 can enable communication between the meter electronic equipment 20 and an external device. Interface 301 can be any method of communication, such as electronic communication, optical communication, or wireless communication. Interface 301 can provide information based on vibration response. Interface 301 can be coupled with a digitizer such as the CODEC 222 shown in Figure 2, in which case the sensor signal includes an analog sensor signal. The digitizer samples the analog sensor signal and digitizes it to generate a digitized sensor signal.

[0037] The processing system 302 operates the meter electronic equipment 20 and processes the flow rate measurements from the sensor assembly 10. The processing system 302 executes one or more processing routines, thereby processing the flow rate measurements and generating one or more flow rate characteristics. The processing system 302 is communicatively coupled to interface 301 and configured to receive information from interface 301.

[0038] The processing system 302 may comprise a general-purpose computer, a microprocessing system, logic circuits, or any other general-purpose or customized processing device. In addition, or alternatively, the processing system 302 may be distributed across multiple processing devices. The processing system 302 may also include any kind of integrated or separate electronic storage medium, such as the storage system 304.

[0039] The memory system 304 can store vibration meter parameters and data, software routines, constant values, and variable values. In one embodiment, the memory system 304 includes routines executed by the processing system 302, such as the operation routine 310 of the vibration meter 5. The memory system can also store statistical values ​​such as mean, standard deviation, and confidence interval.

[0040] The operation routine 310 can determine the mass flow rate value 312, the density value 314, and the fluid velocity 316 based on the sensor signals received by the interface 301. The mass flow rate value 312 can be determined from the sensor signals, such as the time delay between the left pick-off sensor signal and the right pick-off sensor signal. The density value 314 can also be determined from the sensor signals, for example, by determining the frequency from one or both of the left and right pick-off sensor signals. Figure 3 also shows the pipeline pressure 318. The pipeline pressure 318 can be the measured fluid pressure of the process fluid in the pipeline mechanically coupled to flanges 103, 103'. The measured fluid pressure can be obtained by a pressure sensor mechanically coupled to the pipeline.

[0041] As shown in Figure 3, the memory system 304 may also include pipeline parameters 320. The pipeline parameters 320 can be any parameters related to the pipeline mechanically coupled to the flanges 103, 103' of the vibrometer 5. As shown in Figure 3, the pipeline parameters 320 include the inlet pipeline diameter 322, the outlet pipeline diameter 324, and the pressure sensor position 326. In addition, or alternatively, other pipeline parameters can be used. For example, if the pipeline does not have a circular cross-section, alternative cross-sectional dimensions such as radius or width can be used. In another example, internal surface characteristics may be used, and depending on the desired level of accuracy, surface roughness, curvature, etc., can also be stored.

[0042] The inlet pipeline diameter 322 and the outlet pipeline diameter 324 may have the same value. Therefore, an alternative storage system can store only the pipeline diameter. The inlet pipeline diameter 322 and the outlet pipeline diameter 324 may be manually entered by the user or provided by a computer, for example, via port 26. The pressure sensor position 326 can be a toggle value, for example, indicating whether the pressure sensor is located upstream or downstream. Alternatively, the pressure sensor position 326 may be located both upstream and downstream. Additional sensor position-related parameters can be used, for example, the distance from the pressure sensor to flange 103, 103'.

[0043] Figure 3 also shows the sensor assembly parameters 330. As shown in Figure 3, the sensor assembly parameters 330 include conduit dimensions 332, friction coefficient 334, and manifold pressure loss coefficient 336. Conduit dimensions 332 may include the diameter and length of the conduit, such as the conduits 130, 130' described above. More specifically, the conduits 130, 130' may have a circular cross-section with an inner diameter, which is stored as a value in conduit dimensions 332. Similarly, the length of the conduits 130, 130' may be the axial length of the conduits 130, 130' extending between, for example, the surfaces 121, 121' of the mounting blocks 120, 120'. The friction coefficient 334 may be a measure of resistance to fluid flow, relating to the inner diameter of the conduits 130, 130' but not relating to the surface roughness of the interior or wet surface of the conduits 130, 130'. The manifold pressure loss coefficient 336 can quantify the pressure loss caused by the aforementioned manifolds 150, 150'. The manifold pressure loss coefficient 336 can be predetermined based on the dimensions of the manifolds 150, 150' and other parameters. In addition, or alternatively, other sensor assembly parameters may be employed.

[0044] The memory system 304 may also include an error evaluation 340. The error evaluation 340 can, for example, determine whether an error may exist in the fluid flow parameter value. The error evaluation 340 can also determine the error due to the pressure loss of the vibrometer 5 and the evaluation that can be performed using that error. As shown in Figure 3, the error evaluation 340 includes an error budget 342, an error value 344, and a pressure-compensated fluid flow parameter value 346. The error budget 342 can be used, for example, to determine whether pressure compensation of the fluid flow parameter may be necessary. For example, under some conditions, pressure loss may not result in a significant error in the fluid flow parameter value. The error value 344 can be an error value resulting not only from pressure loss but also from other causes such as temperature drift, zero drift, etc. Thus, the contribution of all errors to the total error of the fluid flow parameter value can be used to determine whether the error due to pressure loss, i.e., the pressure loss error, is significant. The pressure-compensated fluid flow parameter value 346 is, for example, a pressure-compensated density value, a pressure-compensated mass flow rate value, etc.

[0045] As will be explained in more detail below, the measured pressure, such as the pipeline pressure 318 described above, can be used to calculate the pressure used for pressure compensation of fluid flow parameter values, such as the fluid flow parameters described above. For example, the fluid flow parameters may be mass flow rate, density, or any other suitable fluid flow parameters that are affected by the pressure of the fluid in the conduit, such as conduits 130 and 130' discussed above. The calculated pressure may depend on various dimensional parameters of the pipeline, inlet and outlet manifolds, vibrator conduits, and the characteristics of the fluid flow, etc.

[0046] As you can see, these effects may or may not contribute significantly to the error in fluid flow parameters. For example, in a relatively low-density fluid with low fluid velocity measured in a conduit connected to a manifold with a diameter change rate of approximately 1, the conduit pressure will not differ significantly from the measured pressure in the inlet pipeline. Consequently, using the measured pressure in the inlet pipeline for pressure compensation of fluid flow parameters may not significantly affect the error in the fluid flow parameters. For instance, a mass flow rate value pressure-compensated with the measured pressure in the inlet pipeline may contribute less than 1 percent to the error of the total error in the mass flow rate value.

[0047] However, using the measured pressure of the inlet pipeline for pressure compensation of fluid flow parameters can, in some cases, significantly impact the error in the pressure-compensated fluid flow parameter values. Therefore, using the calculated pressure of the fluid flow in the conduit, rather than the measured pressure of the pipeline, may help reduce the error in the pressure-compensated fluid flow parameters. However, this reduction in the error of the pressure-compensated fluid flow parameters may only be achievable with limited computational resources. Thus, appropriate assumptions regarding the dimensions of the vibration meter pipeline, inlet and / or outlet manifolds, and / or conduits may help optimize the trade-off between computational resource requirements and the contribution to the error in the pressure-compensated fluid flow parameter values.

[0048] The following discussion describes how to determine when the use of calculated pressures, such as calculated conduit pressures, may help reduce errors in pressure-compensated fluid flow parameter values. The discussion also describes how assumptions can be made to achieve a desired error in pressure-compensated fluid flow parameter values ​​while optimally reducing the computational resources required to achieve the desired error in the pressure-compensated fluid flow parameters. The decision of when to use calculated pressures and / or assumptions can be made online by detecting one or more conditions and selecting or not using formulas, based on detected conditions for determining the calculated pressures used for pressure compensation of fluid flow parameters.

[0049] Bernoulli formula for a simplified model of a vibration meter As an initial introduction, we begin with Bernoulli's energy equation, which can be expressed in the form of a “head” whose height does not change, as shown in equation [2] below.

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[0050] The pressure loss term of friction loss or parasitic loss over the length of the conduit can be expressed as follows: Pressure loss = fL / d·V 2 C / 2·ρ [3] Here f is the friction coefficient, L is the length of the conduit of the vibration meter containing the fluid, d is the diameter of the conduit of the vibration meter.

[0051] Therefore, substituting Equation [3] into the pressure loss term of Equation [2] and arranging the resulting terms, Equation [2] can be rewritten as follows.

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[0052] The conduit fluid velocity V2 can be determined by a meter electronic device based on the mass flow rate, the calculated viscosity of the fluid, and one or more dimensions of the conduit, such as conduit 130, 130'. The meter electronic device may be the meter electronic device 20 described above, but any suitable meter electronic device can be used. The meter electronic device can also be configured to determine the fluid density ρ. The meter electronic device can also store and include the geometric parameters of a sensor assembly, such as the sensor assembly 10 described above. The geometric parameters may include the conduit length L and diameter d. The friction coefficient f can also be stored in the meter electronic device. Thus, the meter electronic device can be configured to use not only the conduit fluid velocity V2 and the fluid density ρ, but also fluid-related parameters of the sensor assembly that determine the sensor characteristic fL / d. In this way, the meter electronic device can be configured to calculate the pressure on a given sensor assembly, for example, the pressure conduit value, under various operating conditions.

[0053] For example, a particular flow meter may have an fL / d value that is approximately 1, although it may not be constant with respect to the Reynolds number (Re). As a result, 1 + fL / d in equation [7] above can be approximated as "2". As can be seen, equation [7] above depends only on density and conduit fluid velocity V2. Therefore, the calculated pressure can significantly reduce the error in the pressure-compensated fluid flow parameter value only when the conduit fluid velocity V2 is relatively high. Under such conditions, the value of fL / d may approach the asymptotic value of 1, so this can be a reasonable approximation.

[0054] Therefore, fluid flow parameters can be compensated by using the measured pressure value of the fluid in the pipeline at a given location. Pressure-compensated mass flow values ​​can be obtained, for example, using mass flow pressure effect values ​​and pressure loss values, but any suitable method using calculated conduit pressure can be employed. Although mass flow has been described above, fluid flow parameters may be mass flow, density, viscosity, or any other suitable fluid flow parameters. Furthermore, the pressure P calculated to determine the pressure-compensated fluid flow parameters C Any appropriate means can be used to employ [the appropriate method].

[0055] For example, pressure-compensated fluid flow parameters can be determined from pressure effect terms and pressure drop terms. The pressure drop term can consist of dynamic or recoverable pressure drop and / or permanent or irrecoverable pressure loss. Considering only the pressure loss term, fluid flow pressure compensation can be determined from fluid flow parameter pressure effect terms (e.g., fluid flow parameter changes in response to pressure changes) and fluid flow pressure loss terms (e.g., friction loss, impact loss, etc.).

[0056] Therefore, if a pressure-compensated mass flow rate value is required, the following equation [8] can be used. Mass flow-to-pressure compensation = Mass flow-to-pressure effect * Pressure loss [8] The pressure loss term is the calculated pressure P used to determine the pressure-compensated mass flow rate, such as those described herein. C The resulting equation may include this. Therefore, the compensated mass flow rate can be determined using a mass flow rate pressure compensation equation such as the following equation [9].

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[0057] A similar method can be used to determine the pressure-compensated density value. For example, density-pressure compensation can generally be expressed as depending on a density-pressure effect term and a pressure loss term, as shown in equation

[10] . Density-pressure compensation = Density-pressure effect * Pressure loss

[10] Here, The density-pressure effect is a value that compensates for the pressure effect on the rigidity of the conduit. The pressure loss is, for example, the pressure loss value related to the conduit, and can be determined, for example, using the above equation [5].

[0058] The pressure compensation density value of a fluid can be obtained by using a pressure compensation density equation such as the following equation

[11] . Pressure compensation density = (measured density) + (1 + K) pd *P C )

[11] Here, The measured density is the measured density value of the fluid. K pd This is the mass flow pressure effect, P C This is the calculated pressure of the fluid. The calculated pressure P used to determine the pressure-compensated fluid flow parameter C This may result in the aforementioned conduit pressure P2 value.

[0059] To make it easier to understand, various parameters are used in the equation for pressure-compensated fluid flow parameters, such as the calculated pressure P2, which is the measured pipeline pressure or conduit pressure. C It is possible to determine which of the two will be used. Furthermore, the calculated pressure P C If it is decided that it will be used, the calculated pressure P will be as shown in the following explanation. C Various assumptions can be made to minimize the computational resources required to achieve the desired error contribution by using the fluid flow parameter values.

[0060] Pressure loss of vibration meter Determining whether assumptions about pressure loss can be made can begin with understanding where pressure loss occurs in a vibration meter. Pressure loss, sometimes referred to as irrecoverable or permanent pressure drop, can result from frictional losses between the fluid flow and the conduit containing this fluid flow, turbulence caused by surface properties within the conduit, and vibrations caused by changes in the direction of fluid flow.

[0061] In vibration meters such as Coriolis meters, there can be four main factors contributing to pressure loss: the inlet manifold, the length of the conduit, the bends in the conduit, and the outlet manifold. The inlet and outlet manifolds contribute to pressure loss due to impact loss. Impact loss is pressure loss caused by non-smooth and / or significant changes in the diameter of the manifold. The length of the conduit contributes to pressure loss through parasitic loss. Bends in the conduit can contribute to pressure loss due to the fluid pressure gradient between the outer and inner bends of the fluid flow. This pressure gradient can cause non-laminar flow such as helical flow and vortex flow, resulting in pressure loss in addition to friction loss, which is related to the length of the bends in the conduit.

[0062] In the case of a double conduit vibrometer with a bend of approximately 90° in the pipe, the inlet manifold of the double conduit vibrometer can split the fluid flow into two conduits, reducing the cross-sectional area of ​​the fluid flow. The outlet manifold can combine the two fluid flows into a single flow, increasing the cross-sectional area of ​​the fluid flow. In some double conduit vibrometers, the inlet and outlet manifolds may also bend the fluid flow by 90 degrees. These large changes in the fluid flow can reduce the fluid pressure, some of which may be due to pressure loss, such as the pressure loss mentioned above. For similar reasons, a bend in the pipe causes pressure loss that is a function of the radius of the bend.

[0063] In a double-tube vibrometer, the length of the conduit is sometimes referred to as the straight length of the conduit, even if the conduit includes a 90-degree bend. The straight length of the conduit correlates with friction or parasitic pressure loss. Friction or parasitic pressure loss causes a pressure drop that is linearly related to the length of the conduit. It is important to note that friction or parasitic pressure loss should not be confused with the coefficient of friction, which is related to the diameter of the conduit. As the diameter of the conduit decreases, the coefficient of friction may increase, for example, according to Haarland's equation. The following equation

[12] outlines the contributors to these pressure losses.

number

[0064] Determination of calculated pressure values ​​for pressure compensation The pressure drop described above in many vibration meters may not significantly affect the fluid flow parameter values. Therefore, the estimated conduit pressure may simply be the measured pressure of the fluid flow in the inlet and / or outlet pipeline connected to the vibration meter. That is, the measured pipeline pressure can be used if the dynamic pressure drop and permanent pressure loss do not significantly affect the error in the pressure-compensated fluid flow parameter values. By adopting the measured pipeline pressure, a numerical offset, which is an approximation of the pressure drop in the sensor assembly, may be included, without estimating the conduit pressure by calculating the pressure in the conduit.

[0065] However, in some vibration meters, the pressure drop in the sensor assembly can significantly affect the fluid flow parameter values. For example, the pressure drop can be large in sensor assemblies with conduits having a considerably smaller cross-sectional area than the pipeline connected to the sensor assembly. In addition, or alternatively, the fluid flow velocity may be relatively high under certain circumstances. That is, for the same sensor assembly, the fluid velocity may determine whether the pressure loss significantly affects the measurement error of the fluid flow parameter values. These and other issues are discussed below when calculating the pressure for pressure compensation of fluid flow parameters.

[0066] If the inlet pipeline pressure P1 is measured, the calculated pressure P used to determine the pressure-compensated fluid flow parameter is... C The pressure drop may be proportional to both dynamic or recoverable pressure drop and pressure loss or non-recoverable pressure drop. Also, the calculated pressure P used to determine the pressure-compensated fluid flow parameters... C This may be based on a pre-selected position within the vibration meter. For example, the calculated pressure can be selected to be approximately half the length of the conduit. Thus, the pressure drop may include only the pressure drop that yields the conduit pressure P2 value, under appropriate assumptions that provide a meaningful estimate of the conduit's pressure midpoint.

[0067] Furthermore, the calculated pressure P C This can be based on either the measured inlet pipeline pressure P1 or outlet pipeline pressure P3. Assuming the calculated pressure is the pressure at the midpoint of the conduit, the following equations

[13] and

[14] can be used depending on where the pipeline pressure is measured. P C =(P1+ρV1 2 ( / 2) - (Permanent pressure loss) / 2 - (Dynamic pressure drop)

[13] P C =(P3+ρV3 2 ( / 2) + (Permanent pressure loss) / 2 - (Dynamic pressure drop)

[14] Here, each item is as described above.

[0068] Applying the above equations

[13] and

[14] to the geometric shape of the vibration meter, the calculated pressure P used for pressure compensation of the fluid flow parameter estimates the pressure at approximately half the length of the conduit in the sensor assembly. C This can be expressed by the following equation

[15] P C =P1-(Inlet manifold + conduit length / 2+1bend)-(dynamic pressure drop)

[15] Here, P1 is the measured pressure of the inlet pipeline. The inlet manifold is the pressure loss in the inlet manifold of the vibration meter. The conduit length / 2 is the pressure loss related to half the length of the conduit in the vibration meter. 1 bend is the pressure loss associated with a single bend in a conduit.

[0069] Using the term from equation

[12] above, equation

[15] above can be expressed as follows: equation

[16] .

number

number

[0070] As shown in equation

[16] , the calculated pressure P used for pressure compensation CThe permanent pressure loss included is approximately half of the total permanent pressure loss in the vibration meter. However, this approximation may not be perfectly accurate because the pressure loss in the outlet manifold (where the flow area increases) is higher than in the inlet manifold. Furthermore, as will be shown after discussing the calculation of pressure from measured outlet pipeline pressure, the total permanent pressure loss is often sufficiently small, so the above calculated pressure estimate may not significantly affect the error in the fluid flow parameter values.

[0071] If pressure measurements are taken downstream of a conduit, such as an outlet pipeline, a pressure loss term is added to the dynamic pressure drop term. To calculate the pressure at the midpoint of the conduit, the following equation

[17] is used, which includes pressure losses associated with half the length of the conduit of the sensor assembly, one bend, and the outlet manifold. P C =P3+(Outlet manifold + conduit length / 2+1bend)-(dynamic pressure drop)

[17] Using the term from equation

[14] above, equation

[17] can be rewritten as the following equation

[18] .

number

[18] above can be used for the measured outlet pipeline pressure P3, where the manifold pressure loss coefficient K m This includes only the pressure loss in the outlet manifold.

[0072] To make it clear, the above formula can be used to determine the contribution of calculated pressure to errors in fluid flow parameters. Determining the contribution of calculated pressure to errors can be helpful in determining whether additional computational resources should be used to calculate conduit pressure under specific conditions. For example, for relatively low flow rates, calculated conduit pressure may not contribute significantly to errors in fluid flow parameters. That is, since using calculated or estimated conduit pressure may not result in a significant reduction of errors, measured inlet and / or outlet pipeline pressures can be used to determine pressure-compensated fluid flow parameters.

[0073] For example, consider a case where the process fluid includes hydrocracking base oil HC-4 flowing through a double-tube Coriolis flowmeter, such as the double-tube Coriolis flowmeter described above. The process parameters of the process fluid are 10,000 bbl / hour and a density of 850 kg / m³ in a double-tube Coriolis flowmeter with a known coefficient of friction and fluid flow cross-sectional area. 3 , and viscosity can be 5 centiposes (cP). Using the above assumptions related to equation

[12] , exemplary results are a total permanent pressure loss of 9 pounds per square inch (psi) and a fluid velocity of 14 meters per second (m / sec), but any appropriate assumptions, coefficient of friction, and fluid flow cross-sectional area can be used. In such a situation, the dynamic pressure loss can be calculated as follows: Dynamic pressure loss=ρV 2 / 2=(850kg / m 3 )14 2 / 2 = 83300 Pa = 0.8 bar = 12 psi The approximation of the conduit pressure is conduit pressure P C We can assume that this is half of the permanent loss and all of the dynamic loss. Therefore, the conduit pressure P C If P1 is calculated from the inlet pipeline pressure, P1 can be calculated as follows: P C =P1-9 / 2-12=P1-16.5psi When outlet pipeline pressure P3 is measured, conduit pressure P C This can be calculated as follows: P C =P3+9 / 2-12=P3-7.5psi

[0074] The typical pressure effect of hydrocracking base oil HC-4 can be approximately -0.0014% / psi. For example, due to the pressure effect, the mass flow rate measurement of hydrocracking base oil HC-4 may have an error of approximately -0.0014% per 1 psi of pressure. Therefore, the difference between 16.5 psi and 7.5 psi may result in an error contribution of approximately 9 * (-0.0014) = 0.01% due to the pressure effect on the mass flow rate value. This difference in error contribution is usually undetectable in many processes. Therefore, whether to use the inlet pipeline pressure P1 or the outlet pipeline pressure P3 may not significantly affect the error in the fluid flow parameter value.

[0075] Pipeline assumptions The inlet and outlet pipelines may have the same diameter. Therefore, when the inlet pipeline pressure is measured and the calculated pressure derived from the measured inlet pipeline pressure is used for pressure compensation of the fluid flow parameter values, the above example can be rewritten as equation

[19] below. P C =P1+ρV1 2 / 2-ρV2 2 / 2 - (Permanent pressure loss) / 2

[19] When the outlet pipeline pressure is measured and the calculated pressure derived from the measured outlet pipeline pressure is used for pressure compensation of the fluid flow parameter values, the above example can be rewritten as equation

[20] below. P C =P3+ρV3 2 / 2-ρV2 2 / 2 + (Permanent pressure loss) / 2

[20]

[0076] As can be understood, the assumption that the inlet pipeline diameter is equal to the outlet pipeline diameter is well known and may be contained in meter electronics such as the meter electronics 20 described above. This assumption may be made because flanges such as flanges 103, 103' described above are fitted during manufacturing. Thus, equation

[20] can be adopted. Also, as can be understood, the permanent pressure loss term can be simplified by making assumptions about which structures (e.g., manifolds, conduits, flanges, etc.) and / or features (e.g., bending, friction coefficient, etc.) have a significant impact on errors in the fluid flow parameters.

[0077] System for pressure compensation of fluid flow parameters Figure 4 shows a system 400 for pressure compensation of flow meter parameters. As shown in Figure 4, system 400 includes an upstream pressure sensor 410, mechanically coupled to the upstream pipeline that receives and carries the fluid indicated by the arrow. Also indicated by a dashed line (the dashed line indicates that it is optional) is a downstream pressure sensor 410', mechanically coupled to the downstream pipeline that carries and supplies the fluid indicated by the arrow. The aforementioned vibration meter 5 is located within the pipeline. More specifically, the sensor assembly 10 is located between the upstream and downstream pipelines and mechanically coupled to them. The meter electronics 20 is also communicatively coupled to the sensor assembly 10. The sensor assembly 10 is shown as including a conduit 130 and manifolds 150, 150', referred to as the inlet manifold and the outlet manifold, respectively. The manifolds 150, 150' are mechanically coupled to the conduit 130 and the upstream and downstream pipelines.

[0078] Figure 4 also shows a pressure graph 430 showing the fluid pressure in the upstream and downstream pipelines and the sensor assembly 10. In particular, the pressure graph 430 includes a position axis 432 and a pressure axis 434. The position axis 432 corresponds to the position in the upstream and downstream pipelines, conduit 130, and manifolds 150, 150'. The fluid pressure at the upstream pressure sensor 410 is indicated by the upstream pressure P1. The fluid pressure in the conduit is indicated by conduit pressures P2, P2', and P2'', including a first conduit pressure P2, a second conduit pressure P2', and a third conduit pressure P2''. The conduit pressures P2, P2', and P2'' are shown by three lines indicating that the pressure loss within the conduit 130 differs due to different parasitic loss terms. More specifically, the first conduit pressure P2 has a zero slope because the parasitic loss is zero, while the second and third conduit pressures P2' and P2'' have slopes due to the parasitic loss.

[0079] Furthermore, the downstream pressures P3, P3', and P3'' are shown in Figure 4. The downstream pressures P3, P3', and P3'' consist of the first downstream pressure P3, the second downstream pressure P3', and the third downstream pressure P3'' at the downstream pressure sensor 410'. The downstream pressures P3, P3', and P3'' differ from each other due to parasitic losses in the conduit 130. The downstream pressures P3, P3', and P3'' do not differ from each other due to non-parasitic pressure changes in the manifold. The downstream pressures P3, P3', and P3'' also do not differ due to parasitic losses in the pipeline, since the parasitic losses in the pipeline are zero or substantially near zero.

[0080] To make it clear, in other systems, there may be other parasitic losses in the alternative vibration sensor assembly, for example, in the manifold and / or pipeline of the sensor assembly. Therefore, the alternative pressure graph may include, for example, pipeline pressure drops or unrecovered pressure changes within the manifold.

[0081] The above description illustrates how the method can determine the pressure for pressure compensation of fluid flow parameters. This method considers various operating parameters such as pipeline diameter, fluid velocity, conduit diameter, and manifold coefficient to calculate the pressure and determine whether the calculated pressure can be used to determine the pressure-compensated fluid flow parameters. In other words, determining the pressure for pressure compensation of fluid flow parameters may involve calculating the pressure and determining whether the calculated pressure can be used for pressure compensation of the fluid flow parameters.

[0082] Pressure selection for pressure compensation Figure 5 shows graph 500, which illustrates pressure compensation for fluid flow parameters. As shown in Figure 5, graph 500 includes a flow rate axis 510 in barrels per hour (bbl / hr) and a density error axis 520 in grams per cubic centimeter (g / cm). A density error plot 530 is also shown. As can be seen from the figure, the density error plot 530 includes an uncompensated density error plot 530a, shown as a solid filled circle, and a pressure-compensated density error plot 530b, shown as an unfilled circle.

[0083] The uncompensated density error plot 530a and the pressure-compensated density error plot 530b may consist of the difference between the measured density value and the reference density value. For example, the uncompensated density error plot 530a may consist of the difference between the uncompensated measured density value and the reference density value of the fluid. Similarly, the pressure-compensated density error plot 530b may consist of the pressure-compensated measured density value and the reference density value.

[0084] The uncompensated density error plot 530a increases as the flow rate of the fluid flowing through the vibrometer increases. The increase in the uncompensated density error plot 530a suggests that the pressure drop due to the increasing flow rate of the fluid flowing through the vibrometer affects the vibration frequency of the vibrometer. More specifically, the greater the pressure drop through the length of the vibrometer conduit, the larger the uncompensated density error plot 530a. Similar results can be obtained for other fluid parameters, such as the measured mass or volumetric flow rate. Thus, while fluid flow parameter errors may be negligible at relatively low flow rates, at higher fluid flow rates where pressure losses are large, fluid flow parameter errors can significantly impact the error budget of the measured fluid flow parameters.

[0085] The above describes various embodiments of pressure compensation for fluid flow parameter values, including a vibration meter 5 and meter electronic equipment 20 capable of performing such compensation. Examples thereof are described below.

[0086] Pressure relief method Figure 6 shows method 600 for pressure compensation of fluid flow parameters. As shown in Figure 6, method 600 can receive a measured pipeline pressure value of the fluid in the pipeline in step 610. As an example, method 600 can be performed with the meter electronic equipment 20 described above, and therefore method 600 performed with the meter electronic equipment 20 is Upstream Pipeline pressure values ​​measured from pressure sensor 410 and / or downstream pressure sensor 410' can be received. However, any suitable vibration meter and meter electronic equipment can be used. In step 620, method 600 can determine the pressure for determining the pressure-compensated fluid flow parameter values ​​based on the measured pipeline pressure values.

[0087] In step 620, the pressure for determining the pressure-compensated fluid flow parameter value can be determined, for example, based on the aforementioned equations

[13] and

[14] , which are calculated for the fluid in the conduits such as conduits 130, 130' described above. C This relates the measured pressure, half of the permanent pressure loss, and the dynamic pressure loss. The pressure for determining the pressure-compensated fluid flow parameter values ​​can be based on the pressure losses associated with components in the vibrometer, such as conduits 130, 130' and manifolds 150, 150'. The pressure losses associated with the conduits may be the friction pressure loss and / or bending pressure loss of the conduits. For example, the pressure for determining the pressure-compensated fluid flow parameter values ​​can be determined using the aforementioned equations

[16] and / or

[18] .

[0088] Method 600 can also determine whether the calculated or measured pressure of the pipeline should be used to determine the pressure-compensated fluid flow parameter values. For example, Method 600 may determine that using the measured pressure of the pipeline may not significantly affect the error budget of the measured fluid flow parameter values. Method 600 can make such a determination by comparing one or more fluid properties, such as mass flow rate, fluid velocity, density, and frequency, with corresponding thresholds. For example, as mentioned above with reference to Figure 5, measured density may not have a large error at relatively low flow rates. Therefore, if the measured uncompensated mass flow rate is smaller than the pressure-compensated mass flow rate threshold, the measured pressure of the pipeline can be used to determine the pressure-compensated fluid flow parameter values. Similar thresholds can be used along with fluid velocity, volumetric flow rate, etc.

[0089] In addition, or alternatively, a comparison may be made between the calculated pressure value and the measured pressure value. For example, if the difference between the calculated pressure and the measured pressure is less than the pressure compensation pressure difference threshold, the measured pipeline pressure value can be used as the pressure for determining the pressure compensation fluid flow parameter. As can be understood, the above and additional comparisons may be used alone or in combination. For example, if both the measured mass flow rate and pressure difference are less than their respective thresholds, the measured pipeline pressure may be used as the pressure for determining the pressure compensation fluid flow parameter value.

[0090] In addition, or alternatively, Method 600 may determine the error of the pressure-compensated fluid flow parameter. For example, Method 600 can determine the error between an uncompensated density value and a reference density value for a fluid whose density value is known but whose mass flow rate is variable. As an example, the density value can be known because the fluid composition used by the process monitored by the vibrometer 5 is constant. Alternatively, the densimeter may be communicatively coupled with the meter electronics 20 to provide a measurement of the fluid density that is independent of the pressure drop at the vibrometer 5.

[0091] To understand this, the decision of whether to use the calculated pressure of the conduit or the measured pressure of the pipeline can be made in a cascaded manner to reduce the computational load on the metering electronics 20. For example, an initial assessment can be made to determine whether process parameters have errors. For instance, even if the density of the fluid flowing through the vibrometer 5 is known and constant, measured parameters such as the resonant frequency of the conduits 130, 130' may change. Furthermore, method 600 can also compare such changes with a predetermined correlation between the change in frequency (e.g., a slope similar to the slope of the uncompensated density error plot 530a in Figure 5) and the fluid flow rate. Thus, if method 600 detects an unexpected change or a process parameter error, method 600 can proceed to determine the calculated pressure of the fluid in the conduits 130, 130', the error in the fluid flow parameter values, and / or the pressure-compensated fluid flow parameter values.

[0092] The vibration meter 5, meter electronics 20, and method 600 described above provide pressure compensation for fluid flow parameters. Pressure compensation can be fluid flow parameters measured by a vibration meter, such as a Coriolis flow meter. The vibration meter 5, meter electronics 20, and method 600 can reduce the computational load on the meter electronics 20 by being able to determine whether the fluid flow parameters may have errors before performing the calculations. In addition, or alternatively, the vibration meter 5, meter electronics 20, and method 600 can determine whether the error is a significant factor in the error of the fluid flow parameter value. This may also help reduce the computational load on the meter electronics 20 by avoiding real-time calculations of pressure-compensated fluid flow parameters, such as pressure-compensated mass flow or density, as described earlier. In addition, or alternatively, the vibration meter 5, meter electronics 20, and method 600 can also reduce errors in fluid flow parameter values ​​by calculating pressure-compensated fluid flow parameters using the calculated pressure of the fluid in the conduit.

[0093] The vibration meter 5, the meter electronic equipment 20, and method 600 can also perform such determinations and calculations regardless of the location of one or more pressure sensors, such as the aforementioned upstream and downstream pressure sensors 410, 410'. More specifically, the user may only need to answer a question during the installation of the vibration meter 5 indicating that a pressure sensor is located upstream of the vibration meter 5. As a result, method 600 can use this input from the user to use an equation that uses the upstream measured pressure, for example, equation [4] above. In addition, or alternatively, a downstream pressure sensor can be used. The meter electronic equipment 20 can then inform the user that, under all fluid flow conditions, pressure loss due to friction loss is automatically compensated for by the fluid flow parameter value.

[0094] The detailed description of the embodiments described above is not an exhaustive description of all embodiments that the inventors consider to be within the scope of this specification. In fact, those skilled in the art will understand that further embodiments can be created by combining or omitting certain elements of the embodiments described above in various ways, and that such further embodiments fall within the scope and teachings of this specification. It will also be apparent to those skilled in the art that further embodiments can be created within the scope and teachings of this specification by combining the embodiments in whole or in part.

[0095] Therefore, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of this specification, as will be understood by those skilled in the art. The teachings provided herein are applicable not only to the embodiments described above and shown in the accompanying figures, but also to other vibration meters, meter electronics, and pressure compensation methods for fluid flow parameters. Accordingly, the scope of the above embodiments should be determined from the following claims.

Claims

1. A method for pressure compensation of the fluid flow parameter of a fluid in a conduit of a vibration meter, The vibration meter receives the measured pipeline pressure value of the fluid in the pipeline connected to the conduit, Based on the measured pipeline pressure values, determine the determination pressure for determining the pressure-compensated fluid flow parameter values. The determination pressure for determining the pressure-compensated fluid flow parameter value is selected from either the calculated pressure value or the measured pipeline pressure value. Methods that include...

2. The method according to claim 1, wherein the measured pipeline pressure value includes one of the measured pressure value in the inlet pipeline coupled to the inlet of the vibration meter and the measured pressure value in the outlet pipeline coupled to the outlet of the vibration meter.

3. The method according to claim 2, wherein determining the determination pressure for determining the pressure-compensated fluid flow parameter value based on the measured pipeline pressure value includes determining a pressure calculated based on one of the following formulas. P Ｃ = (P １ +ρV １ ２ / 2) - (Permanent pressure loss) / 2 - (Dynamic pressure drop) and P Ｃ = (P ３ +ρV ３ ２ ( / 2) + (Permanent pressure loss) / 2 - (Dynamic pressure drop) Here, P １ is the measured inlet pipeline pressure value, V １ This is the velocity of the fluid in the inlet pipeline. P ３ This is the measured outlet pipeline pressure value, V ３ This is the velocity of the fluid in the outlet pipeline, P Ｃ This is the calculated pressure, ρ is the density of the fluid, (Permanent pressure loss) is the permanent pressure loss value of a vibration meter connected to a pipeline. The dynamic pressure drop is the pressure drop related to the difference in diameter between the conduit of the vibration meter and the pipeline connected to the vibration meter.

4. The method according to claim 1, wherein the determination pressure for determining the pressure-compensated fluid flow parameter value is based on a pressure loss associated with at least one of the conduit, inlet manifold, and outlet manifold of the vibration meter.

5. The method according to claim 4, wherein the pressure loss related to the conduit includes at least one of the friction pressure loss and bending pressure loss of the conduit.

6. The method according to claim 4, wherein the determination pressure for determining the pressure-compensated fluid flow parameter value includes one of the following formulas. [Number 17] Here, P １ This is the pressure value in the inlet pipeline coupled to the inlet of the vibration meter, [Number 18] This is the permanent pressure loss term, ρV ２ ２ / 2 is the dynamic pressure loss term, ρ is the density of the fluid, V ２ This is the velocity of the fluid in the conduit, K ｍ ｉｎｌｅｔ This is the manifold pressure loss coefficient, f is the coefficient of friction of the conduit, L is the total length of the conduit, d is the diameter of the conduit, K ｂ is the bending pressure loss coefficient.

7. The method according to claim 1, wherein determining the determination pressure for determining the pressure-compensated fluid flow parameter value based on the measured pipeline pressure value includes determining the error of the pressure-compensated fluid flow parameter value in order to minimize the computational resources required to achieve a desired error contribution of the determination pressure.

8. A meter electronic device (20) configured for pressure compensation of fluid flow parameter values, An interface (301) configured to be communicatively coupled to a pressure sensor configured to measure the pipeline pressure of the fluid in the pipeline, A processing system (302) that is communicatively coupled to the interface (301), and is configured to perform the method described in any one of claims 1 to 7. A meter electronic device (20) is provided.

9. A vibration meter (5) configured to determine the pressure for pressure compensation of fluid flow parameter values, A sensor assembly (10) configured to provide sensor signals, A meter electronic device (20) communicatively coupled to the sensor assembly (10), wherein the meter electronic device (20) is configured to receive the sensor signal and perform the method according to any one of claims 1 to 7. A vibration meter (5) is provided.

10. A system (400) for determining pressure for pressure compensation of fluid flow parameter values, A pressure sensor (410) configured to measure pipeline pressure, A vibration meter (5) that is communicatively coupled to the pressure sensor (410), and is configured to perform the method described in any one of claims 1 to 7. A system (400) equipped with [this feature].

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