Correcting for two-phase flow in a digital flowmeter
First Claim
1. A flowmeter comprising:
- a vibratable conduit;
a driver connected to the conduit and operable to impart motion to the conduit;
a sensor connected to the conduit and operable to sense the motion of the conduit and generate a sensor signal; and
a controller connected to receive the sensor signal, the controller being operable to;
generate a raw mass-flow measurement from the sensor signal;
detect a single-phase flow condition and process the raw mass-flow measurement using a first process during the single-phase flow condition to generate a first mass-flow measurement; and
detect a two-phase flow condition and correct the raw mass-flow measurement using a second process during the two-phase flow condition to generate a second mass-flow measurement.
7 Assignments
0 Petitions
Accused Products
Abstract
A flowmeter is disclosed. The flowmeter includes a vibratable conduit, and a driver connected to the conduit that is operable to impart motion to the conduit. A sensor is connected to the conduit and is operable to sense the motion of the conduit and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement. The controller is also operable to detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.
193 Citations
55 Claims
-
1. A flowmeter comprising:
-
a vibratable conduit;
a driver connected to the conduit and operable to impart motion to the conduit;
a sensor connected to the conduit and operable to sense the motion of the conduit and generate a sensor signal; and
a controller connected to receive the sensor signal, the controller being operable to;
generate a raw mass-flow measurement from the sensor signal;
detect a single-phase flow condition and process the raw mass-flow measurement using a first process during the single-phase flow condition to generate a first mass-flow measurement; and
detect a two-phase flow condition and correct the raw mass-flow measurement using a second process during the two-phase flow condition to generate a second mass-flow measurement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
an input layer for receiving input parameters;
a hidden layer having processing nodes for applying the set of predetermined coefficients to the input parameters; and
an output layer that generates an output parameter.
-
-
5. The flowmeter of claim 4 wherein the input parameters include a temperature parameter, a damping parameter, a density parameter, and an apparent flow rate parameter.
-
6. The flowmeter of claim 4 further including a training module connected to the neural network processor to calculate an updated set of coefficients when supplied with training data.
-
7. The flowmeter of claim 2 wherein the neural network processor is a radial basis function network.
-
8. The flowmeter of claim 1 wherein the controller includes a processor to analyze a density drop parameter, to predict a mass-flow error, and to calculate an error correction factor used to generate the second mass-flow measurement.
-
9. The flowmeter of claim 8 wherein the processor executes a bubble model routine to analyze the density drop parameter.
-
10. The flowmeter of claim 1 wherein the first mass-flow measurement is a validated mass-flow measurement comprising the raw mass-flow measurement and an uncertainty parameter calculated by the controller.
-
11. The flowmeter of claim 1 wherein the second mass-flow measurement is a validated mass-flow measurement comprising a corrected mass-flow measurement generated from the raw mass-flow measurement and an uncertainty parameter calculated by the controller.
-
12. The flowmeter of claim 1 wherein the controller generates a measurement status parameter associated with the first mass-flow measurement.
-
13. The flowmeter of claim 1 wherein the controller generates a measurement status parameter associated with the second mass-flow measurement.
-
14. The flowmeter of claim 1 further including a memory for storing sensor signal data generated from the sensor signal, wherein the controller uses the stored sensor signal data.
-
15. The flowmeter of claim 14 wherein the controller includes a sensor parameter processing module to analyze the sensor signal data and generate sensor signal parameters.
-
16. The flowmeter of claim 15 further including a state machine that receives the raw mass-flow measurement and the sensor signal parameters and detects the single-phase flow condition and the two-phase flow condition.
-
17. The flowmeter of claim 15 wherein the controller further comprises an output signal generator, the output signal generator being operable to receive the sensor signal parameters from the sensor parameter processing module and to generate a drive signal for the driver based the sensor signal parameters.
-
18. The flowmeter of claim 1 wherein the controller further comprises circuitry to generate a drive signal based on the sensor signal.
-
19. The flowmeter of claim 18 wherein the drive signal is a digital drive signal for operating the driver.
-
20. The flowmeter of claim 18 wherein the drive signal is an analog drive signal for operating the driver.
-
21. The flowmeter of claim 18 further comprising a second sensor connected to the conduit, the second sensor being operable to sense the motion of the conduit and generate a second sensor signal, wherein the controller is connected to receive the second sensor signal and generate the drive signal based on the first sensor signal and the second sensor signal using digital signal processing, and
generate a measurement of a property of material flowing through the conduit based on the first and second sensor signals. -
22. The flowmeter of claim 21 further comprising a second driver, wherein the controller generates different drive signals for the two drivers.
-
23. The flowmeter of claim 21 wherein the controller generates the measurement of the property by:
-
estimating a frequency of the first sensor signal;
calculating a phase difference using the first sensor signal; and
generating the measurement using the calculated phase difference.
-
-
24. The flowmeter of claim 23 wherein the controller compensates for amplitude differences in the sensor signals by adjusting the amplitude of one of the sensor signals.
-
25. The flowmeter of claim 23 wherein the controller determines a frequency, amplitude and phase offsets for each sensor signal, and scales the phase offsets to an average of the frequencies of the sensor signals.
-
26. The flowmeter of claim 23 wherein the controller calculates the phase difference using multiple approaches and selects a result of one of the approaches as the calculated based difference.
-
27. The flowmeter of claim 21 wherein the controller combines the sensor signals to produce a combined signal and to generate the drive signal based on the combined signal.
-
28. The flowmeter of claim 27 wherein the controller generates the drive signal by applying a gain to the combined signal.
-
29. The flowmeter of claim 28 wherein the controller generates the drive signal by applying a large gain to the combined signal to initiate motion of the conduit and generates a periodic signal having a phase and frequency based on a phase and frequency of a sensor signal as the drive signal after motion has been initiated.
-
30. The flowmeter of claim 1 further comprising a second sensor connected to the conduit and operable sense the motion of the conduit, wherein the controller comprises:
-
a first signal processor to generate the measurement, a first analog to digital converter connected between the first sensor and the first signal processor to provide a first digital sensor signal to the first signal processor, and a second analog to digital converter connected between the second sensor and the first signal processor to provide a second digital sensor signal to the controller.
-
-
31. The flowmeter of claim 30 wherein the first signal processor combines the digital sensor signals to produce a combined signal and generates a gain signal based on the first and second digital sensor signals, and the controller further comprises a multiplying digital to analog converter connected to receive the combined signal and the gain signal from the first signal processor to generate the drive signal as a product of the combined signal and the gain signal.
-
32. The flowmeter of claim 1 further comprising circuitry for measuring current supplied to the driver.
-
33. The flowmeter of claim 1 wherein the controller determines a frequency of the sensor signal by detecting zero-crossings of the sensor signal and counting samples between zero crossings.
-
34. The flowmeter of claim 1 further comprising a connection to a control system, wherein the controller transmits the measurement and results of a uncertainty analysis to the control system.
-
35. A flowmeter comprising:
-
a vibratable conduit;
a driver connected to the conduit and operable to impart motion to the conduit;
a sensor connected to the conduit and operable to sense the motion of the conduit and generate a sensor signal; and
a controller connected to receive the sensor signal, the controller being operable to;
detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement; and
detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.
-
-
36. A digital flowmeter comprising:
-
a vibratable conduit;
a driver connected to the conduit and operable to impart motion to the conduit;
a sensor connected to the conduit and operable to sense the motion of the conduit and generate a sensor signal; and
a controller connected to receive the sensor signal and detect a single-phase flow condition and a two-phase flow condition, the controller further comprising;
a first processing module to analyze the sensor signal during the single-phase flow condition and to generate a first mass-flow measurement;
a second processing module to analyze the sensor signal during the two-phase flow condition and to generate a second mass-flow measurement, the second processing module having a neural network processor to predict a mass-flow error and to calculate an error correction factor used to generate the second mass-flow measurement; and
output circuitry to generate a drive signal to operate the driver. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
-
-
47. A method of generating a measurement of a property of material flowing through a conduit, the method comprising:
-
sensing motion of the conduit;
generating a measurement of a property of material flowing through the conduit based on the sensed motion;
detecting a flow condition based on the measurement of the property;
if the flow condition is a single-phase flow condition, applying a first analysis process to the measurement of the property using digital signal processing to generate a first measurement signal;
if the flow condition is a two-phase flow condition, applying a second analysis process to the measurement of the property using a neural network processor to;
predict a mass-flow error based on the measurement of the property, generate an error correction factor, apply the error correction factor to the measurement of the property to generate a second measurement signal;
generating a drive signal to impart motion in the conduit based on the measurement of the property; and
imparting motion to the conduit using the drive signal. - View Dependent Claims (48, 49, 50, 51, 52, 53, 54, 55)
-
Specification