Non-ideal fluid measurement and related methods for Coriolis flow meters

Abstract

A method for operating a flow meter is provided, comprising the steps of allowing a fluid to flow through the flow meter and measuring the uncorrected mass flow rate, temperature, and density of the fluid. [Solution] Meter electronics for a flow meter configured to receive process fluid include an interface configured to communicate with the flow meter assembly of the flow meter and receive vibration responses. The processing system includes a mass flow correction routine coupled to the interface and configured to measure the temperature of the process fluid in the flow meter, measure the density of the process fluid in the flow meter, calculate the sound velocity of the process fluid in the flow meter, calculate the mass flow error, and calculate the corrected mass flow of the process fluid in the flow meter.

Description

Technical Field

[0001] The present invention relates to a flowmeter device and method, and more particularly to a flowmeter device and method for measuring ethylene, carbon dioxide, ethane, and other fluids and fluid mixtures, which are difficult to measure by conventional means.

Background Art

[0002] Vibrating conduit sensors, such as Coriolis mass flowmeters and vibrating densitometers, typically operate by detecting the movement of a vibrating conduit containing a flowing material. Characteristics related to the material within the conduit, such as mass flow rate, density, etc., can be determined by processing measurement signals received from motion transducers associated with the conduit. The vibration modes of a system filled with a vibrating material are generally affected by the combined mass, stiffness, and damping characteristics of the containing conduit and the material therein.

[0003]

[0004]

[0005]

[0006] ​​It is supplied by an electromechanical device such as a tuner. Mass flow rate is supplied by the transducer position. This can be determined by measuring the time delay or phase difference of the motion at the location. Such transducers (or pick-off sensors) as shown above are typically found in flow conduits. Used to measure the vibration response, typically positioned upstream and downstream of the driver. The instrument is placed there. The instrument receives a signal from the pick-off sensor and processes this vibration to measure the mass flow rate. Derive the value.

[0005] Flow meters can be used to perform mass flow measurements for various fluid flows. One area where Rioli flowmeters may be useful is in processes involving ethylene.

[0006] Ethylene is the most common raw material in many plastic manufacturing processes. When ethylene is transported from one place to another (for example, from producer to user), It is then pumped under high pressure under those critical phase conditions. The critical phase ethylene is gaseous ethylene Because it has a much higher density than , its pumping cost is relatively low (high voltage transmission) Electricity is a good analogy. When measuring ethylene, mass flow rate measurement is the preferred unit. be.

[0007] Unfortunately, critical phase ethylene does not behave like an ideal gas, making accurate measurement difficult. It exhibits characteristics such as the density and sound velocity (VoS) characteristics, which are influenced by temperature and / or pressure. It shows a large change for relatively small changes. This is due to the total Coriolis-based meter. This technology makes flow rate measurement extremely difficult.

[0008] Critical phase ethylene is often transported at pressures of 50 bar or higher. The temperature is usually... The room temperature is approximately 20°C, but since pipelines are often located underground, the ground conditions... Temperature can fluctuate due to changes in pressure and / or temperature. The density changes dramatically. For example, a change of 1 psi in pressure corresponds to a change of 2 kg / m³. 3 Draw the density change This is an ideal gas whose density changes to less than 0.1 kg / m³ for the same pressure change. It is compared to this.

[0009] In addition to changes in density, the magnitude of changes in VoS is also sensitive to changes in pressure. (1 psi pressure change) While this causes a VoS change of 5 m / s, in an ideal gas, VoS remains unchanged even when the pressure changes. It does not transform. This can cause problems with Coriolis mass flowmeters. An example of a flowmeter. Therefore, a 1 psi change in ethylene pressure can cause a 5 m / s change in VoS, and this continues This causes a 0.03% change in the measurement. This is typical for a 100psi pipeline. In the case of pressure fluctuations, this example flow meter would exhibit an unacceptable 3% error. The specification is 0.35%, which is better than the common measurement requirement of 0.5%. Therefore, when ethylene is operated in the critical phase region, there is a possibility of large flow rate errors. It is clear that...

[0010] A Coriolis flow meter and a method for operating the Coriolis flow meter are provided, wherein the density measurement is This provides a correction for the speed of sound. This results in more accurate measurements across a wide range of ethylene operating conditions. This provides accurate flow rate measurement. [Overview of the Initiative]

[0011] A method of operating a flow meter according to an embodiment is provided. The method includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The method includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated.

[0012] A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter. A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter. A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter. A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter. A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter. A meter electronics for a flow meter configured to receive a process fluid according to an embodiment is provided. The meter electronics includes an interface configured to communicate with a flow meter assembly of the flow meter and receive a vibration response. A processing system is coupled to the interface and includes a mass flow correction routine configured to measure a temperature of the process fluid in the flow meter, determine a density of the process fluid in the flow meter, calculate a speed of sound of the process fluid in the flow meter, calculate a mass flow error, and calculate a corrected mass flow rate of the process fluid in the flow meter.

[0013] [Aspects of the Invention] According to one aspect, a method of operating a flow meter is provided that includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated. According to one aspect, a method of operating a flow meter is provided that includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated. According to one aspect, a method of operating a flow meter is provided that includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated. According to one aspect, a method of operating a flow meter is provided that includes flowing a fluid through the flow meter and measuring an uncorrected mass flow rate, temperature, and density of the fluid. The speed of sound (VoS) of the fluid is calculated. A mass flow error is calculated. A corrected mass flow rate of the fluid is calculated.

[0014] Preferably, the fluid includes a non-ideal fluid.

[0015] Preferably, the fluid consists of ethylene.

[0016] Preferably, the fluid includes ethylene.

[0017] Preferably, the fluid consists of ethane.

[0018] Preferably, the fluid contains ethane.

[0019] Preferably, the fluid consists of carbon dioxide.

[0020] Preferably, the fluid contains carbon dioxide.

[0021] Preferably, the fluid is one of Freon, sulfur hexafluoride, and uranium hexafluoride. Includes.

[0022] Preferably, the flow meter includes a Coriolis mass flow meter.

[0023] Preferably, the flow meter calculates the temperature of the fluid.

[0024] Preferably, the flow meter calculates the density of the fluid.

[0025] Preferably, the step of calculating the VoS of the fluid uses the temperature and density This includes doing so.

[0026] Preferably, the step of calculating the VoS of the fluid is to use the VoS table to determine the temperature This includes cross-referencing and interpolating the degree and the density.

[0027] Preferably, the VoS table includes extrapolated VoS values.

[0028] Preferably, in the step of calculating the mass flow error, the mass flow error is calculated using the following formula. It is calculated.

number

[0029] Preferably, the corrected mass flow rate is calculated using the mass flow rate.

[0030] Preferably, the corrected mass flow rate is calculated as follows:

number

[0031] According to one embodiment, meter electronic equipment for a flow meter configured to receive process fluid. The meter electronics are provided. The meter electronics communicate with the flow meter assembly of the flow meter and receive the vibration response. It has an interface configured to do so. The processing system is connected to the interface. The temperature of the process fluid in the flow meter is measured, and the density of the process fluid in the flow meter is measured. Then, the sound velocity of the process fluid in the flow meter is calculated, the mass flow error is calculated, and the process fluid in the flow meter Includes a mass flow correction routine configured to calculate the corrected mass flow rate of a fluid.

[0032] Preferably, the fluid includes a non-ideal fluid.

[0033] Preferably, the fluid consists of ethylene.

[0034] Preferably, the fluid contains ethylene.

[0035] Preferably, the fluid consists of ethane.

[0036] Preferably, the fluid contains ethane.

[0037] Preferably, the fluid consists of carbon dioxide.

[0038] Preferably, the fluid contains carbon dioxide.

[0039] Preferably, the fluid is one of Freon, sulfur hexafluoride, and uranium hexafluoride. Includes.

[0040] Preferably, the flow meter includes a Coriolis mass flow meter.

[0041] Preferably, the flow meter calculates the temperature of the fluid.

[0042] Preferably, the flow meter calculates the density of the fluid.

[0043] Preferably, the calculation of the VoS of the fluid uses the temperature and density. Includes.

[0044] Preferably, the calculation of the VoS of the fluid is performed using a VoS table with the temperature and This includes cross-referencing and interpolating densities.

[0045] Preferably, the VoS table includes extrapolated VoS values.

[0046] Preferably, the mass flow error is calculated using the following formula.

number

[0047] Preferably, the corrected mass flow rate is calculated using the mass flow rate.

[0048] Preferably, the corrected mass flow rate is calculated as follows:

number

[0049] [Figure 1] Figure 1 shows a flow meter equipped with a sensor assembly and meter electronics. [Figure 2] Figure 2 shows a block diagram of a meter electronic device according to one embodiment. [Figure 3] Figure 3 is a graph showing the ethylene-VoS pressure. [Figure 4] Figure 4 is a graph showing the ethylene VoS density. [Figure 5A] Figure 5A is a table showing ethylene VoS based on density and temperature. [Figure 5B] Figure 5B is a table showing ethylene VoS based on density and temperature, with some values ​​extrapolated within it. [Figure 6] Figure 6 is a flowchart showing the method for mass flow rate correction. [Figure 7] Figure 7 is a table showing ethane VoS based on density and temperature. [Figure 8] Figure 8 is a table showing carbon dioxide (VoS) based on density and temperature. [Modes for carrying out the invention]

[0050] Figures 1-8 and the following description illustrate how the best mode of the present invention is constructed and used. Specific examples are given for instruction to vendors. For the purpose of teaching the principles of the present invention, some conventional The details are simplified or omitted. Those skilled in the art will recognize variations from these examples that fall within the scope of the present invention. Those skilled in the art will understand this. Those skilled in the art will be able to combine the features described below in various ways. Therefore, it can be understood that multiple variations of the present invention can be formed. Not limited to the specified examples, but limited only by the claims and their equivalents.

[0051] Figure 1 shows a flow meter 5 according to one embodiment. The flow meter 5 consists of a sensor assembly 10 and a The meter electronic equipment 20 is provided. The meter electronic equipment 20 is connected to the sensor via lead wires 100. It is connected to the 10 and measures density, mass flow rate, volumetric flow rate, total mass flow rate, temperature, and It will provide one or more of the other measurements or pieces of information through the communication path 26. It is configured as follows. The flow meter 5 may include a Coriolis mass flow meter or other vibrating flow meter. Good. Flow meter 5 is the number of drivers, pick-off sensor, flow conduit, or vibration operating mode. It will be apparent to those skilled in the art that, regardless of the type, the flow meter 5 can be of any type. It is likely.

[0052] The sensor assembly 10 includes a pair of flanges 101 and 101', a manifold 102 and 102', driver 104, pick-off sensors 105 and 105', and flow conduit 1 Includes 03A and 103B. Driver 104 and pick-off sensors 105 and 105'. These are connected to flow conduits 103A and 103B.

[0053] Flanges 101 and 101' are attached to manifolds 102 and 102'. In some embodiments, the nifolds 102 and 102' are attached to both ends of the spacer 106. It can be attached. Spacer 106 is the gap between manifold 102 and 102'. Maintain the pipeline that carries the process fluid to be measured (Figure 10). When inserted (not shown), the process fluid passes through flange 101 to sensor assembly 10 The entire amount of process fluid enters the conduit 103, passes through the inlet manifold 102, and flows through the conduit 103. Guided into A and 103B, and passing through flow conduits 103A and 103B to the outlet manifold Returning to the ring 102', the sensor assembly 10 exits through the flange 101'.

[0054] The process fluid may contain a liquid. The process fluid may contain a gas. The flow fluid includes, for example, but is not limited to, contaminating gases and / or contaminating solids. It may contain a multiphase fluid such as a liquid. Flow conduits 103A and 103B are, respectively Substantially the same mass distribution, moment of inertia, and modulus of elasticity around the bending axes WW and W'-W'. Selected to have and suitable for the inlet manifold 102 and outlet manifold 102' The flow conduits 103A and 103B are attached to manifolds 102 and 102'. It extends outward in essentially parallel to it.

[0055] Flow conduits 103A and 103B are in opposite directions around their respective bending axes W and W'. In the so-called first phase-out bending mode of the flow meter 5, it is driven by the driver 104. The driver 104 is attached to the magnet in the flow conduit 103A and to the flow conduit 103B. It can be equipped with one of many well-known configurations, such as an attached opposing coil. The current flows into the opposing coil, causing both conduits to vibrate. A suitable drive signal is received by the meter electronics 2. 0 is applied to the driver 104 via lead wire 110. Other driver devices This can also be considered and is included within the scope of this specification and the claims.

[0056] The meter electronic equipment 20 receives sensor signals on lead wires 111 and 111' respectively. The meter electronic equipment 20 generates a drive signal on the lead wire 110, thereby driving driver 1 At point 04, the flow conduits 103A and 103B are vibrated. Other sensor devices can also be considered. This is included within the scope of this specification and the claims.

[0057] The meter electronic equipment 20, in particular, uses a pick-off sensor 105 and 1 to calculate the flow rate. Processes left and right speed signals from 05'. Communication path 26 is operated by meter electronic equipment 20. Input means and output that enable interfacing with a data controller or other electronic systems. To provide a means. The explanation in Figure 1 is provided only as an example of the operation of the flow meter. This is not intended to limit the teaching of the invention. One or more embodiments are provided. Single-tube and multi-tube flowmeters with drivers and pick-offs are conceivable.

[0058] In one embodiment, the meter electronic equipment 20 vibrates the flow conduits 103A and 103B. It is configured as follows. The vibration is performed by the driver 104. The meter electronic equipment 20 is Furthermore, vibration signals resulting from the pick-off sensors 105 and 105' are received. The vibration signal includes the vibration response of flow conduits 103A and 103B. The meter electronic equipment 20 vibrates The meter electronic equipment 20 processes the dynamic response and determines the response frequency and / or phase difference. The response is processed, and one or more flow measurements including the mass flow rate and / or density of the process fluid are performed. Determine the constant value. Other vibration response characteristics and / or flow measurements are possible, and these are described in this specification. It is within the scope of the book and the claims.

[0059] In one embodiment, the flow conduits 103A and 103B are substantially O It is equipped with a mega-type flow conduit. Alternatively, in other embodiments, the flow meter is substantially linear It may be equipped with flow conduits, U-shaped conduits, delta-shaped conduits, etc. The shape of additional flow meters and You may use and / or configurations, which are within the scope of this specification and the claims. That is the case.

[0060] Figure 2 is a block diagram of the meter electronic equipment 20 of a flow meter 5 according to one embodiment. The flow meter 5 measures mass flow rate, volumetric flow rate, the mass and volumetric flow rates of individual flow components, and, for example, body Including one or more measured or average values ​​of the total flow rate, which includes both the volumetric flow rate and the mass flow rate, It provides a variety of outputtable measurement values.

[0061] The flow meter 5 generates a vibration response. The vibration response is received by the meter electronic equipment 20. It is processed to generate one or more fluid measurements. These values ​​are monitored, recorded, stored, and totaled. , and / or output.

[0062] The meter electronic equipment 20 communicates with interface 201 and interface 201. It includes a processing system 203 and a storage system 204 that communicates with the processing system 203. Although these components are shown as separate blocks, the meter electronics 20 is integrated It should be understood that it can be composed of various combinations of the and / or separate components. .

[0063] Interface 201 is configured to communicate with the sensor assembly 10 of the flow meter 5. Interface 201 is connected to lead wire 100 (see Figure 1), for example, drive Iba 104, pick-off sensors 105 and 105', and a temperature sensor (not shown) and signal It can be configured to exchange numbers. Interface 201 has a communication path 26 It may be further configured to communicate with external devices, etc.

[0064] Processing system 203 may include any type of processing system. 203 reads and executes a stored routine in order to operate the flow meter 5. It is configured as follows: The memory system 204 contains the flow meter routine 205, the mass weighted density / viscosity routine. Chin 209, mass weighting temperature routine 211, sound velocity routine 213, and mass flow rate correction routine Routines including Chin 215 can be stored. Other measurement / processing routines can be considered. This falls within the scope of this specification and the claims. The storage system 204 receives the measured values, received Values, working values, and other information can be stored. In some embodiments, the storage system Tem,

number

[0065] The flow meter routine 205 can generate and store fluid quantification values ​​and flow rate measurements. These values ​​may include essentially instantaneous measurements, or sums or cumulative values. It can contain values. For example, the flow meter routine 205 generates a mass flow measurement, and These can be stored, for example, in the memory of the mass flow rate 221 of the memory system 204. Flow meter routine 205 generates, for example, measurements of density 225, and these are used for density 225 It can be stored in the memory. The values ​​of mass flow rate 221 and density 225 are as described above. And, as is known in the art, it is determined from the vibration response. Mass flow rate and other measurements The values ​​can include essentially instantaneous values, samples, and time intervals. It can include a barrel average value or a cumulative value over a time interval. The interval is defined as a specific fluid state, for example, a liquid-only fluid state, or a liquid and mixed gas state. It can be selected to correspond to the time block in which the fluid state is detected. Other mass flow rates and related quantifications are possible, and these are within the scope of the description and claims. It is included in.

[0066] As mentioned above, ethylene is particularly susceptible to operating conditions when operating near critical pressure and / or temperature. Because density and VoS undergo large changes based on small differences, measurement is particularly difficult. It is a difficult fluid. In one embodiment, the mass flow rate correction routine 215 is the state of ethylene. By using the formula, a correction means is provided that facilitates accurate flow meter measurements. The temperature and pressure of the Lenn are necessary for this embodiment, and the methodology disclosed herein is It provides flow rate correction.

[0067] Referring to Figure 3, the VoS-pressure behavior of ethylene is highly nonlinear and difficult to characterize. It will be clear that this is difficult.

[0068] According to one embodiment, the relationship between VoS and density at various temperatures is used to perform flow rate correction. It is used for this purpose. Referring to Figure 4, the relationship between VoS and density at various temperatures is illustrated. This relationship is observed in over 90% of the operating conditions (approximately 15-50°C and approximately 1-150 bar). It will become clear that this is quite predictable. Such a relationship can easily be expressed as a curve. It can be understood that fitting is possible. Unlike the data shown in Figure 3, The absence of large gradients makes modeling (or curve fitting) much easier. Furthermore, since density and temperature are used as independent variables, this requires additional equipment and External pressure measurement is not necessary.

[0069] To calculate the fluid properties, data is obtained from the NIST "Refprop" database. This is shown in the table in Figure 5A. In one embodiment, a table for calculating fluid properties is shown. This may have extrapolated values ​​within it, as shown in Figure 5B.

[0070] In one embodiment, the correction of the mass flow rate is based on equations (1) and (2), This is performed by the mass flow correction routine 215 of the electronic equipment 20.

number

number

[0071] Figure 6 shows a method for correcting mass flow errors using a Coriolis mass flowmeter containing ethylene. In step 600, the density of ethylene is measured by a flow meter. Temperature is also measured. In one embodiment, the operating frequency can also be measured.

[0072] In step 602, VoS is calculated using the measured temperature and density. In the embodiment, VoS is calculated using the table shown in Figure 5 or a similar table. In the application method, VoS is calculated from the table shown in Figure 5 or by interpolation from a similar table. It will be done.

[0073] In step 604, the mass flow error is calculated. In one embodiment, the mass flow error This is calculated using VoS. In one embodiment, the mass flow error is calculated using equation (1) It is calculated as follows.

[0074] In step 606, the corrected mass flow rate is calculated. In one embodiment, the corrected mass flow rate is: It is calculated using formula (2).

[0075] The error arises from both the mass flow rate and density readings of the Coriolis analyzer using VoS. Logically, if density measurements are used to correct mass flow measurements, this correction is inherent to the This means that an error exists. However, the behavior of ethylene is such that the error in density measurement is very small. The density measurement error is small, and typical errors, including VoS errors, are ±10 kg / m³.

[0076] In the examples described, the critical point of ethylene is approximately 60°F and 750 psia (15°C and 5°F). It is provided to understand weighing at 0 bar, but is not limited to these conditions. The density of ethylene is 110 kg / m3. See the graph in Figure 4 and the tables in Figures 5A and 5B. VoS is 259-233 over a density range of 75-125 kg / m3 at a temperature of 15°C. Please note that it changes to m / s. As an extreme example, if the density measurement has an error of 50 kg / m3 Assuming this, the calculation error for VoS is 26 m / s, and the mass flow rate correction error is The result is only 0.5%. A more realistic, slightly larger density error than usually expected. In the case of a difference of 10 kg / m³, the V ratio to mass flow rate appears in relation to the small difference in actual fluid density. Considering the small change in the effect of oS error, the mass flow correction error is not significant. It probably won't happen.

[0077] In the exemplary examples provided for understanding, the metering under conditions where VoS changes significantly Scenarios are provided, but are not limited to them. This is for densities in the range of 350 kg / m3. This can occur in the following scenario. Here, the VoS effect on the instrument is very small, 0 It is 0.5% to 0.4%. Here too, the density error of 10 kg / m3 is not significant, and The resulting mass flow rate error is not significant.

[0078] Therefore, errors in the methods disclosed herein do not affect reliable mass flow measurement. It is clear that it is small enough to be done.

[0079] It should be noted that the apparatus and methods described herein are not limited to ethylene only. Other common critical phase fluids include ethane, carbon dioxide, and argon. The descriptions in the specification apply similarly to these fluids with the necessary modifications. For example, see Figure 7. The VoS value derived by the meter electronic equipment 20 based on the temperature and density of ethane is... Similarly, Figure 8 shows the meter electronics based on the temperature and density of carbon dioxide (CO2). The VoS value derived from 20 is shown.

[0080] The above detailed description of the embodiments is an all-encompassing account of all embodiments that the inventors consider to be within the scope of the present invention. This is not an exhaustive description of the embodiments. In fact, those skilled in the art will be able to interpret the specific elements of the above embodiments in various ways. By combining or removing elements, further embodiments can be created, such Further embodiments will be recognized as being included within the scope and teachings of the present invention. Within the scope and teachings of the present invention, the embodiments described above may be combined in whole or in part to provide additional information. It will also be apparent to those skilled in the art that embodiments can be created. Therefore, the scope of the present invention is This should be determined from the following claims.

Claims

1. Steps to flow fluid into the flow meter, A step of measuring the uncorrected mass flow rate of the fluid, A step of measuring the temperature of the fluid, A step of measuring the density of the fluid, A step of calculating the speed of sound (VoS) of the fluid, Steps to calculate the mass flow error and The step of calculating the corrected mass flow rate of the fluid. A method for operating a flow meter, including [specific details omitted].

2. A method for operating a flow meter according to claim 1, wherein the fluid includes an unideal fluid.

3. A method for operating the flow meter according to claim 1, wherein the fluid is ethylene.

4. A method for operating the flow meter according to claim 1, wherein the fluid contains ethylene.

5. A method for operating the flow meter according to claim 1, wherein the fluid is ethane.

6. A method for operating the flow meter according to claim 1, wherein the fluid contains ethane.

7. A method for operating the flow meter according to claim 1, wherein the fluid is carbon dioxide.

8. A method for operating the flow meter according to claim 1, wherein the fluid contains carbon dioxide.

9. Claims that the fluid includes one of Freon, sulfur hexafluoride, and uranium hexafluoride. A method for operating the flow meter described in item 1.

10. A method for operating a flow meter according to claim 1, wherein the flow meter includes a Coriolis mass flow meter.

11. A method for operating a flow meter according to claim 1, wherein the flow meter calculates the temperature of the fluid.

12. A method for operating the flow meter according to claim 1, wherein the flow meter calculates the density of the fluid.

13. The step of calculating the VoS of the fluid includes using the temperature and density. A method for operating the flow meter described in claim 1.

14. The step of calculating the VoS of the fluid involves using a VoS table to determine the temperature and the A method for operating the flow meter according to claim 1, comprising cross-referencing and interpolating densities.

15. The flow meter according to claim 14 is operated such that the VoS table includes extrapolated VoS values. method.

16. In the step of calculating the mass flow error, the mass flow error is calculated using the following formula: A method for operating the flow meter described in item 1. [Number 8] Here, C = Mehter constant (for example, 1 / 2), f = meter operating frequency, Hz, d = meter tube diameter, m a = Speed ​​of sound of the fluid (i.e., VoS), m / s That is the case.

17. The flow meter according to claim 1, wherein the corrected mass flow rate is calculated using the mass flow rate. How to make it work.

18. The corrected mass flow rate is calculated as follows, in the manner in which the flow meter described in claim 1 is operated. Law. [Number 9]

19. In a meter electronic device (20) for a flow meter (5) configured to receive process fluid It is configured to communicate with the flow meter assembly of the flow meter (5) and receive vibration responses. An interface (201) and a process coupled to the interface (201) The system (203) comprises a processing system (203), The temperature (224) of the process fluid in the flow meter (5) is measured. The density (225) of the process fluid in the flow meter (5) is measured. The sound velocity (VoS) (244) of the process fluid in the flow meter (5) is calculated. Mass flow error calculation, The corrected mass flow rate of the process fluid in the flow meter (5) is calculated. A meter electronic device (20) is provided with a mass flow correction routine (215) configured as such.

20. A method for operating a flow meter according to claim 19, wherein the fluid includes an unideal fluid.

21. A method for operating the flow meter according to claim 19, wherein the fluid is ethylene.

22. A method for operating a flow meter according to claim 19, wherein the fluid contains ethylene.

23. A method for operating the flow meter according to claim 19, wherein the fluid is ethane.

24. A method for operating the flow meter according to claim 19, wherein the fluid contains ethane.

25. A method for operating the flow meter according to claim 19, wherein the fluid is carbon dioxide.

26. A method for operating the flow meter according to claim 19, wherein the fluid contains carbon dioxide.

27. Claims that the fluid includes one of Freon, sulfur hexafluoride, and uranium hexafluoride. A method for operating the flow meter described in item 19.

28. The meter electronic equipment (20) according to claim 19, wherein the flow meter includes a Coriolis mass flow meter. 。

29. The flow meter (5) calculates the temperature of the fluid, according to the meter electronic equipment of claim 19. ２０）。

30. The flow meter (5) calculates the density of the fluid, according to the meter electronic equipment of claim 19. ２０）。

31. The calculation of the VoS of the fluid includes using the temperature and density, The meter electronic equipment (20) described in item 19.

32. The calculation of the VoS of the fluid involves using a VoS table to compare the temperature and density. Meter electronic equipment (20) according to claim 19, comprising illuminating and interpolating.

33. The meter electronic equipment according to claim 32, wherein the VoS table includes extrapolated VoS values ​​(2 ０）。

34. The meter electronic device (20) according to claim 19, wherein the mass flow error is calculated by the following formula. [Number 10] Here, C = Mehter constant (for example, 1 / 2), f = meter operating frequency, Hz, d = meter tube diameter, m a = Speed ​​of sound of the fluid (i.e., VoS), m / s That is the case.

35. The meter according to claim 19, wherein the corrected mass flow rate is calculated using the mass flow rate. Electronic equipment (20).

36. The corrected mass flow rate is calculated as follows, according to the meter electronic equipment (2) described in claim 19. ０）。 [Math 11]

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