Method of correcting flow meter variable
A method for correcting a flow variable ( 509 ) based on an inner pressure inside a Coriolis flow meter ( 202 ) comprises the steps of receiving a first outside pressure ( 503 ) measured with a first pressure sensor ( 204 ) located in a first process conduit ( 208 a ) positioned on a first end ( 212 a ) of the Coriolis flow meter ( 202 ), determining a second outside pressure ( 505 ) in a second process conduit ( 208 b ) positioned on a second end ( 212 b ) opposing the first end ( 212 a ) of the Coriolis flow meter ( 202 ), determining an estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 ), receiving the flow variable ( 509 ), and generating a corrected flow variable ( 512 ) based on the estimated inner flow meter pressure ( 507 ), a pressure compensation factor ( 510 ), and the flow variable ( 509 ).
1. A method for correcting a flow variable ( 509 ) based on an inner pressure inside a Coriolis flow meter ( 202 ), the method comprising:
receiving a first outside pressure ( 503 ) measured with a first pressure sensor ( 204 ) located in a first process conduit ( 208 a ) positioned on a first end ( 212 a ) of the Coriolis flow meter ( 202 );
determining a second outside pressure ( 505 ) in a second process conduit ( 208 b ) positioned on a second end ( 212 b ) opposing the first end ( 212 a ) of the Coriolis flow meter ( 202 );
determining an estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 );
receiving the flow variable ( 509 ); and
generating a corrected flow variable ( 512 ) based on the estimated inner flow meter pressure ( 507 ), a pressure compensation factor ( 510 ), and the flow variable ( 509 ), wherein the pressure compensation factor is correlated to a pressure inside a flow tube of the Coriolis flow meter ( 5 ).
2. A method as claimed in claim 1 , wherein determining the second outside pressure ( 505 ) is based on a pressure loss coefficient, a fluid velocity, a fluid viscosity, and a density.
3. The method as claimed in claim 1 , wherein determining the second outside pressure ( 505 ) further comprises receiving a second outside pressure measurement from a second pressure sensor ( 206 ) located in the second process conduit ( 208 b ).
4. A method as claimed in claim 1 , wherein determining the estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 ) further comprises averaging the first outside pressure ( 503 ) and the second outside pressure ( 505 ).
5. A method as claimed in claim 1 , wherein determining the estimated inner pressure is further based on a cross-sectional area of a process conduit, a diameter of the process conduit, a cross-sectional area of the flow tube of the Coriolis flow meter ( 202 ), a measured density p, and a measured flow rate M.
6. A method as claimed in claim 1 , wherein the flow variable ( 509 ) is at least one of: a mass flow, a volume flow, or a density.
7. A method as claimed in claim 1 , wherein determining the estimated inner flow meter pressure ( 507 ) is further based on a flow meter direction.
8. An electronics for correcting a flow variable ( 509 ) based on an inner pressure inside a Coriolis flow meter ( 202 ), the electronics comprising an interface for receiving a first outside pressure ( 503 ) from a first pressure sensor ( 204 ), and a processing system in communication with the interface, with the processing system configured to:
receive a first outside pressure ( 503 ) measured with a first pressure sensor ( 204 ) located in a first process conduit ( 208 a ) positioned on a first end ( 212 a ) of the Coriolis flow meter ( 202 );
determine a second outside pressure ( 505 ) in a second process conduit ( 208 b ) positioned on a second end ( 212 b ) opposing the first end ( 212 a ) of the Coriolis flow meter ( 202 );
determine an estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 );
receive the flow variable ( 509 ); and
generate a corrected flow variable ( 512 ) based on the estimated inner flow meter pressure ( 507 ), a pressure compensation factor ( 510 ), and the flow variable ( 509 ), wherein the pressure compensation factor is correlated to a pressure inside a flow tube of the Coriolis flow meter.
9. An electronics as claimed in claim 8 , wherein the processing system is further configured to determine the second outside pressure ( 505 ) based on a pressure loss coefficient, a fluid velocity, a fluid viscosity, and a density.
10. An electronics as claimed in claim 8 , wherein the processing system is further configured to determine the second outside pressure ( 505 ) by receiving a second outside pressure measurement from a second pressure sensor ( 206 ) located in the second process conduit ( 208 b ).
11. An electronics as claimed in claim 8 , wherein the processing system is further configured to determine the estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 ) by averaging the first outside pressure ( 503 ) and the second outside pressure ( 505 ).
12. An electronics as claimed in claim 8 , wherein the processing system is further configured to determine the estimated inner pressure based on a cross-sectional area of a process conduit, a diameter of the process conduit, a cross-sectional area of a flow tube of the Coriolis flow meter ( 202 ), a measured density p, and a measured flow rate M.
13. An electronics as claimed in claim 8 , wherein the flow variable ( 509 ) is at least one of: a mass flow, a volume flow, or a density.
14. An electronics as claimed in claim 8 , wherein determining the estimated inner flow meter pressure ( 507 ) is further based on a flow meter direction.
15. A flow meter correction system configured to correct a flow variable ( 509 ) based on an inner pressure inside a Coriolis flow meter ( 202 ), the system comprising:
a first pressure receiving module configured to receive a first outside pressure ( 503 ) from a first pressure sensor ( 204 ) located in a first process conduit ( 208 a ) positioned on a first end ( 212 a ) of the Coriolis flow meter ( 202 );
a second pressure receiving module for determining a second outside pressure ( 505 ) in a second process conduit ( 208 b ) positioned on a second end ( 212 b ) opposing the first end ( 212 a ) of the Coriolis flow meter ( 202 );
an inner flow meter pressure estimation module configured to determine an estimated inner flow meter pressure ( 507 ) based on the first outside pressure ( 503 ) and the second outside pressure ( 505 );
a flow variable receiving module configured to receive a flow variable ( 509 ); and
a flow variable correction module configured to generate a corrected flow variable ( 512 ) based on the estimated inner flow meter pressure ( 507 ), a pressure compensation factor ( 510 ), and the flow variable ( 509 ), wherein the pressure compensation factor is correlated to a pressure inside a flow tube of the Coriolis flow meter ( 202 ).
16. A flow meter correction system as claimed in claim 15 , wherein the second pressure receiving module is further configured to determine the second outside pressure ( 505 ) based on a pressure loss coefficient, a fluid velocity, a fluid viscosity, and a density.
17. A flow meter correction system as claimed in claim 15 , wherein the second pressure receiving module is further configured to receive a second outside pressure measurement from a second pressure sensor ( 206 ) located in the second process conduit ( 208 b ).
18. A flow meter correction system as claimed in claim 15 , wherein the inner flow meter pressure estimation module is further configured to average the first outside pressure ( 503 ) and the second outside pressure ( 505 ).
19. A flow meter correction system as claimed in claim 15 , wherein the inner flow meter pressure estimation module is further configured to determine the estimated inner pressure based on a cross-sectional area of a process conduit, a diameter of the process conduit, a cross-sectional area of a flow tube of the Coriolis flow meter ( 202 ), a measured density p, and a measured flow rate M.
20. A flow meter correction system as claimed in claim 15 , wherein the flow variable ( 509 ) is at least one of: a mass flow, a volume flow, or a density.
21. A flow meter correction system as claimed in claim 15 , wherein the inner flow meter pressure estimation module is further configured to determine the estimated inner flow meter pressure ( 507 ) based on a flow meter direction.