Flow sensor assembly having a hybrid sensor response
View Patent ↗A flow sensor system including a flow sensor assembly is provided. The sensor assembly may be configured to allow fluid flow through a flow conduit. A flow disrupter may be disposed in the flow conduit to impart disturbances to the fluid flow. A by-pass channel may be in fluid connection with the flow conduit and may be arranged to have a geometrical relationship relative to the flow conduit and the flow disrupter to affect flow characteristics in the bypass channel. One or more sensors may be disposed in the by-pass channel to generate a signal responsive to the flow characteristics in the bypass channel. In a first flow regime, the flow characteristics in the bypass channel may effect an amplitude response of the sensor, and in a second flow regime, the flow characteristics may effect a temporal response of the sensor.
1. A flow sensor system, comprising:
a flow sensor assembly comprising:
a flow conduit configured to allow fluid flow through the flow conduit;
a flow disrupter disposed in said flow conduit to impart disturbances to the fluid flow;
a by-pass channel in fluid connection with the flow conduit and arranged to have a geometrical relationship relative to the flow conduit and the flow disrupter to affect at least some flow characteristics in the bypass channel;
at least a first sensor disposed in the by-pass channel and arranged to generate a signal responsive to the flow characteristics in the bypass channel; and
a processor coupled to the first sensor to receive the generated signal and determine a flow rate for the fluid flow through the flow conduit, wherein in a first flow regime, the flow rate is determined based on an amplitude response of the sensor to the flow characteristics in the bypass channel, and wherein in a second flow regime, the flow rate is determined based on a temporal response of the sensor to the flow characteristics in the bypass channel.
2. The sensor system of claim 1 , wherein the first flow regime comprises a substantially laminar fluid flow through the by-pass channel.
3. The sensor system of claim 2 , wherein the second flow regime comprises fluid flow at a flow rate sufficiently high so that the flow disrupter imparts the disturbances to the fluid flow through the flow conduit.
4. The sensor system of claim 1 , wherein the first flow regime comprises fluid flow having a substantially steady pressure at least at an entrance of the by-pass channel, and the second flow regime comprises fluid flow having oscillatory pressure fluctuations at the entrance of the by-pass channel.
5. The sensor system of claim 3 , wherein the processor comprises a calibration module configured to estimate a calibration function in a flow regime comprising an overlap of the amplitude response and the temporal response of the sensor.
6. The sensor system of claim 5 , wherein the calibration function is adapted to transform amplitude values obtained in the first flow regime to a volumetric flow measurement.
7. The sensor system of claim 1 , wherein in the first flow regime, a calibration function is applied to the amplitude response of the sensor to transform the amplitude response of the sensor to a volumetric flow measurement for the fluid flow through the flow conduit.
8. The sensor system of claim 1 , wherein the geometrical relationship is selected to effect a cross-correlation between a flow pressure at an entrance of the by-pass channel and a flow pressure at an exit of the by-pass channel.
9. The sensor system of claim 8 , wherein the cross-correlation effects a suppression of common mode noise effects in the signal supplied by the first sensor.
10. The sensor system of claim 1 , wherein the geometrical relationship is selected to affect a phase difference between a flow pressure at an entrance of the by-pass channel and a flow pressure at an exit of the by-pass channel.
11. The sensor system of claim 10 , wherein the phase difference is selected to increase a signal-to-noise ratio of the signal supplied by the first sensor.
12. The sensor system of claim 1 , wherein the fluid comprises a gas or a gas mixture and wherein the flow rate determined during the first and second flow regimes comprises a flow rate determination substantially free from effects selected from the group consisting of gas density fluctuations, gas mixture fluctuations and moisture fluctuations.
13. The sensor system of claim 1 , wherein said at least first sensor comprises a mass flow sensor.
14. The sensor system of claim 13 , wherein the mass flow sensor comprises a sensor selected from the group consisting of a thermo-electric sensor, a microelectromechanical (MEMS) sensor, a thermopile, a temperature sensor, a calorimetric flow sensor, and a hot wire anemometer.
15. The sensor system of claim 1 , wherein said at least first sensor comprises at plurality of temperature sensors and at least one heater.
16. The sensor system of claim 15 , wherein the heater is operated in a mode selected from the group consisting of a constant current mode, a constant power mode and a constant temperature mode.
17. The sensor system of claim 1 , further comprising a second sensor disposed within the by-pass channel at a location spaced-apart from the first sensor.
18. The sensor system of claim 1 , wherein the flow disrupter comprises a flow disrupter selected from the group consisting of a blunt flow disrupter, a rectangular flow disrupter, or combinations thereof.
19. The sensor system of claim 1 , wherein the flow disrupter comprises a blunt flow disrupter comprising a first part separated from a second part by a flow separator.
20. The sensor system of claim 1 , further comprising a second flow disrupter.
21. The sensor system of claim 2 , wherein the second flow regime comprises fluid flow at a flow rate sufficiently high so that the flow disrupter imparts the disturbances to the fluid flow through at least one of the flow conduit and the by-pass channel.
22. The sensor system of claim 1 , wherein the first flow regime comprises a flow rate value which is less than a flow rate value in the second flow regime.
23. The sensor system of claim 1 , wherein the processor comprises a signal processor module configured to perform a spectral analysis on the signal received from the sensor.
24. The sensor system of claim 23 , wherein the signal processor module performs the spectral analysis based on a signal processing selected from the group consisting of a Fast Fourier Transform, a signal processing based on a heterodyne principle, and a signal processing utilizing a phase-locked loop.
25. A flow sensor assembly comprising:
a flow conduit configured to allow fluid flow through the flow conduit;
a flow disrupter disposed in said flow conduit to impart disturbances to the fluid flow;
a by-pass channel in fluid connection with the flow conduit and arranged to have a geometrical relationship relative to the flow conduit and the flow disrupter to affect at least some flow characteristics in the bypass channel;
at least a first sensor disposed in the by-pass channel and arranged to generate a signal responsive to the flow characteristics in the bypass channel, wherein in a first flow regime, the flow characteristics in the bypass channel effect an amplitude response of the sensor, and wherein in a second flow regime, the flow characteristics effect a temporal response of the sensor.
26. The sensor assembly of claim 25 , further comprising a processor coupled to the first sensor to receive the generated signal and determine a flow rate for the fluid flow through the flow conduit.
27. The sensor assembly of claim 25 , wherein the first flow regime comprises a substantially laminar fluid flow through the by-pass channel.
28. The sensor system of claim 1 , wherein the first flow regime comprises fluid flow having a substantially steady pressure at least at an entrance of the by-pass channel, and the second flow regime comprises fluid flow having oscillatory pressure fluctuations at the entrance of the by-pass channel.
29. The sensor assembly of claim 27 , wherein the second flow regime comprises fluid flow at a flow rate sufficiently high so that the flow disrupter imparts the disturbances to the fluid flow through the flow conduit.
30. The sensor assembly of claim 26 , wherein the processor comprises a calibration module configured to estimate a calibration function in a flow regime comprising an overlap of the amplitude response and the temporal response of the sensor.
31. The sensor assembly of claim 30 , wherein the calibration function is adapted to transform amplitude values obtained in the first flow regime to a volumetric flow measurement of a gas or gas mixture, wherein the volumetric flow measurement is substantially free from effects selected from the group consisting of gas density fluctuations, gas mixture fluctuations and moisture fluctuations.