MEASURING SYSTEM FOR ASCERTAINING A VOLUME FLOW AND/OR A VOLUME FLOW RATE OF A MEDIUM FLOWING IN A PIPELINE

• US 20150268082A1
• Filed: 09/23/2013
• Published: 09/24/2015
• Est. Priority Date: 10/11/2012
• Status: Active Grant

• Current Assignee: Endress+Hauser Flowtec AG (Endress+Hauser AG)
• Original Assignee: Endress+Hauser Flowtec AG (Endress+Hauser AG)
• Inventors: Kirst, Michael, Rieder, Alfred
• Granted Patent: US 9,372,107 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/849 having straight measuring conduits
• CPC Class Codes: G01F 1/8495 with multiple measuring conduits
• CPC Class Codes: G01F 15/02 Compensating or correcting for variations in pressure, density or temperature
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

The measuring system comprises: a vibration element for guiding flowing medium and having a lumen; and a vibration element, which is adapted to be contacted, at least at times, by a part of the medium. Additionally, the measuring system includes at least two oscillation exciters for exciting resonant oscillations of the respective vibration elements, two mutually spaced oscillation sensors for registering vibrations of the vibration element, each of which generates an oscillatory signal dependent on vibrations of the vibration element, as well as at least one oscillation sensor for registering vibrations of the vibration element and generating, dependent on vibrations of the vibration element, an oscillatory signal, which has a signal frequency corresponding to a resonant frequency, of the vibration element. Moreover, the measuring system also comprises a measuring and operating electronics, which based on a phase difference, existing between the oscillation signals and based on the signal frequency of the oscillation signal generates a measured value representing the volume flow rate, respectively the volume flow.

Claims

1-27. -27. (canceled)

28. A measuring system for ascertaining a volume flow, namely a total volume flowed during a measurement interval, and/or a volume flow rate, of a medium, especially a liquid or a gas, flowing in a pipeline, which measuring system, comprises:

a first vibration element having a lumen and formed, especially, by means of at least one straight measuring tube and/or a measuring tube insertable into the course of the pipeline, which first vibration element is adapted to guide in said lumen a part of the medium flowing with a first mass flow rate, and, while that is happening, to be caused to vibrate, especially with a resonant frequency;

at least a first oscillation exciter for exciting vibrations of said first vibration element in such a manner that said vibration element executes at least partially resonant oscillations, namely mechanical oscillations with a first resonant frequency, especially a first resonant frequency, dependent on a density of the medium;

a first oscillation sensor for registering vibrations of said first vibration element, especially resonant oscillations excited by means of the first oscillation exciter, which first oscillation sensor is adapted to generate, dependent on vibrations of said first vibration element, a first oscillatory signal, which has a signal frequency corresponding to said first resonant frequency;

at least a second oscillation sensor spaced from said first oscillation sensor for registering vibrations of said first vibration element, which second oscillation sensor is adapted to generate a second oscillatory signal dependent on vibrations of said first vibration element in such a manner that said second oscillatory signal has a signal frequency equal to the signal frequency of the signal component of said first oscillation signal, consequently corresponding to said first resonant frequency, as well as relative to said first oscillatory signal a phase difference, dependent on the first mass flow rate;

a second vibration element, especially one formed by means of at least one oscillatably held measuring tube and/or by means of at least one oscillatory rod, which second vibration element is adapted to be contacted, at least at times, by a part of the medium, especially to be flowed through or around, and, while that is happening, to be caused to vibrate, especially with a resonant frequency;

at least a second oscillation exciter for exciting vibrations of said second vibration element in such a manner that said second vibration element executes at least partially resonant oscillations, namely mechanical oscillations with a second resonant frequency, especially a second resonant frequency, dependent on a density of the medium and/or differing from said first resonant frequency, by more than 10 Hz;

at least a third oscillation sensor for registering vibrations of said second vibration element, which third oscillation sensor is adapted to generate, dependent on vibrations of said second vibration element, a third oscillatory signal, which has a signal frequency corresponding to said second resonant frequency; and

a measuring and operating electronics, especially one formed by means of two mutually communicating electronics modules, wherein;

said measuring and operating electronics is adapted, by means of said first, second and third oscillation signals, namely based on the phase difference existing between said first and second oscillatory signal, and based on the signal frequency of said third oscillation signal, to generate a measured value representing the volume flow rate, and/or

which is adapted, by means of said first, second and third oscillation signals, namely based on the phase difference existing between said first and second oscillatory signals, and based on the signal frequency of said third oscillation signal, to generate a measured value representing the volume flow.

29. The measuring system as claimed in claim 28, wherein:

said second vibration element is adapted to be immersed in medium, respectively to be flowed on by medium.

30. The measuring system as claimed in claim 28, wherein:

said first vibration element has a flow cross section, which is greater than the flow cross section of said second vibration element; and

/or

said second vibration element has a flow resistance, which is greater than a flow resistance of said first vibration element; and

/or

said second vibration element has a lumen for guiding flowing medium and is adapted to guide in its lumen a part of the medium flowing with a second mass flow rate, and while that is happening, to be caused to vibrate, especially with the second resonant frequency, especially in such a manner that the second mass flow rate, with which the part of the medium guided in the lumen of said second vibration element flows, is less than the first mass flow rate, with which the part of the medium flows guided in the lumen of said first vibration element.

31. The measuring system as claimed in claim 28, further comprising:

at least a fourth oscillation sensor spaced from said third oscillation sensor for registering vibrations of said second vibration element, wherein;

said fourth oscillation sensor is adapted to generate a fourth oscillatory signal dependent on vibrations of said second vibration element, in such a manner that said fourth oscillatory signal has a signal frequency equal to the signal frequency of said third oscillation signal, consequently corresponding to said second resonant frequency, as well as relative to said third oscillatory signal a phase difference, dependent on said second mass flow rate.

32. The measuring system as claimed in claim 31, wherein:

said measuring and operating electronics is adapted to generate the measured value representing the volume flow rate also by means of the fourth oscillation signal, namely based on the phase difference, existing between the third and fourth oscillatory signals; and

/or

said measuring and operating electronics is adapted to generate the measured value representing the volume flow, also by means of the fourth oscillation signal, namely based on the phase difference, existing between the third and fourth oscillatory signals; and

/or

said measuring and operating electronics is adapted, by means of the third and fourth oscillation signals, namely based on the phase difference existing between the third and fourth oscillatory signals, to generate a measured value representing the second mass flow rate, and/or

said measuring and operating electronics is adapted, by means of the first and second oscillation signals, namely based on the phase difference, existing between the first oscillatory signal and the second oscillatory signal, to generate a measured value representing the first mass flow rate.

33. The measuring system as claimed in claim 28, wherein:

said measuring and operating electronics is adapted, by means of the third oscillation signal, namely based on the signal frequency of the third oscillation signal corresponding to the second resonant frequency, to generate a measured value representing a density of the medium.

34. The measuring system as claimed in claim 28, wherein:

said measuring and operating electronics is adapted to generate a first driver signal for said first oscillation exciter, which has a signal frequency corresponding to the first resonant frequency.

35. The measuring system as claimed in claim 34, wherein:

said measuring and operating electronics is adapted, especially at least at times and/or simultaneously with the first driver signal, to generate a second driver signal for said second oscillation exciter, which has a signal frequency corresponding to the second resonant frequency, especially in such a manner that the signal frequency of the second driver signal deviates by more than 10 Hz from the signal frequency of the first driver signal.

36. The measuring system as claimed in claim 35, wherein:

said measuring and operating electronics is adapted to generate the first and second driver signals simultaneously, in such a manner that the signal frequency of the second driver signal corresponding to the second resonant frequency, is less than the signal frequency of the first driver signal corresponding to the first resonant frequency, especially in such a manner that the signal frequency of the second driver signal is less than 90% of the signal frequency of the first driver signal.

37. The measuring system as claimed in claim 28, wherein:

said first vibration element is connectable to the pipeline, especially insertable into the course of the pipeline, in such a manner that the lumen of said vibration element communicates with a lumen of the pipeline; and

/or

said first and said second vibration elements are adapted to be flowed through simultaneously by medium.

38. The measuring system as claimed in claim 28, wherein:

said first vibration element is formed by means of at least one measuring tube, especially a straight measuring tube and/or a measuring tube insertable into the course of the pipeline and/or having a caliber greater than 20 mm; and

/or

said second vibration element forms a bypass of the lumen of said first vibration element.

39. The measuring system as claimed in claim 28, wherein:

said second vibration element is formed by means of at least one measuring tube, especially a curved measuring tube and/or one bypassing said first vibration element and/or one having a caliber of less than 50 mm.

40. The measuring system as claimed in claim 38, wherein:

said at least one measuring tube, by means of which said first vibration element is formed, has a caliber, which is greater than a caliber of said at least one measuring tube, by means of which said second vibration element is formed, especially in such a manner that the caliber of said at least one measuring tube, by means of which said first vibration element is formed, amounts to greater than 5-times the caliber of said at least one measuring tube, by means of which said second vibration element is formed.

41. The measuring system as claimed in claim 39, wherein:

said second vibration element is connectable to the pipeline in such a manner that its lumen communicates with a lumen of the pipeline; and

/or

said second vibration element is connectable to the pipeline by means of a first connection line, especially a flexible and/or bent, first connection line, and by means of a second connection line, especially a flexible and/or bent, second connection line.

42. The measuring system as claimed in claim 41, further comprising:

a fluid control system for control of the second mass flow rate, especially a fluid control system formed by means of an electromagnetically actuatable valve and/or a valve driven by said measuring and operating electronics and/or by means of a pump driven by said measuring and operating electronics.

43. The measuring system as claimed in claim 28, wherein:

the resonant frequency, with which said first vibration element is caused to vibrate, deviates from the resonant frequency, with which said second vibration element is caused to vibrate; and

/or

the second resonant frequency is less than a first resonant frequency, especially in such a manner that the second resonant frequency is less than 90% of the first resonant frequency; and

/or

said first and said second vibration elements are mechanically decoupled from one another in such a manner that each of the two vibration elements can vibrate independently of the respective other vibration element, and/or in such a manner that a lowest mechanical eigenfrequency of said first vibration element differs from a lowest mechanical eigenfrequency of said second vibration element, especially in such a manner that the lowest mechanical eigenfrequency of said first vibration element is less than the lowest mechanical eigenfrequency of said second vibration element; and

/or

said first vibration element is formed by means of at least two measuring tubes, especially straight measuring tubes and/or measuring tubes connected for parallel flow and/or equally constructed measuring tubes; and

/or

said second vibration element is formed by means of at least two curved measuring tubes, especially measuring tubes connected for parallel flow, especially in such a manner that each of the at least two measuring tubes is connected as a bypass of said first vibration element.

44. The measuring system as claimed in claim 28, further comprising:

a housing with a first housing end connectable to a first line segment of the pipeline and with a second housing end connectable to a second line segment of the pipeline, wherein;

at least said first vibration element is accommodated within a lumen of said housing.

45. The measuring system as claimed in claim 44, wherein:

both said first as well as also said second vibration element are accommodated within the same lumen of said housing.

46. The measuring system as claimed in claim 44, wherein:

said second vibration element is held on said housing, especially in such a manner that said second vibration element is accommodated within said housing, or that said second vibration element is arranged outside of said housing.

47. The measuring system as claimed in claim 44, wherein:

said second vibration element is held on said housing in such a manner that said second vibration element is arranged on an outside of said housing, especially an outside having at least one flow opening and adapted to be contacted by medium.

48. The measuring system as claimed in claim 44, wherein:

said first housing end has at least a first flow opening of first type, namely a first flow opening communicating with said first vibration element, and

said second housing end has at least a first flow opening of first type, namely a first flow opening communicating with said first vibration element.

49. The measuring system as claimed in claim 48, wherein:

said first housing end has at least a second flow opening of first type, namely a second flow opening communicating with said first vibration element; and

said second housing end has at least a second flow opening of first type, namely a second flow opening communicating with said first vibration element.

50. The measuring system as claimed in claim 49, wherein:

said first vibration element is formed by means of a first measuring tube, which communicates with a first tube end with the first flow opening of first type of said first housing end and with a second tube end with the first flow opening of first type of said second housing end, as well as by means of a second measuring tube, especially a second measuring tube constructed equally to the first measuring tube; and

said second measuring tube communicates with a first tube end with the second flow opening of first type of said first housing end and with a second tube end with the second flow opening of first type of said second housing end.

51. The measuring system as claimed in claim 48, wherein:

said first housing end has a flow opening of second type, namely a flow opening communicating with said second vibration element; and

said second housing end has a flow opening of second type, namely a flow opening communicating with said second vibration element.

52. The measuring system as claimed in claim 48, wherein:

said first housing end has a first flow opening of second type, namely a flow opening communicating with said second vibration element, as well as a second flow opening of second type, namely a flow opening likewise communicating with the second vibration element.

53. The measuring system as claimed in claim 28, further comprising:

a first temperature sensor, especially a first temperature sensor contacting said first vibration element on a side facing away from its lumen, for registering a temperature, of said first vibration element and adapted to generate a first temperature signal dependent on said temperature of said first vibration element, as well as

a second temperature sensor, especially a second temperature sensor placed on a side of said second vibration element not contactable by the medium, for registering a temperature, of said second vibration element and adapted to generate a second temperature signal dependent on said temperature of said second vibration element, wherein;

said measuring and operating electronics is adapted to generate the measured value representing the volume flow rate by means of the first temperature signal and/or by means of the second temperature signal; and

/or

said measuring and operating electronics is adapted to generate the measured value representing the volume flow by means of the first temperature signal and/or by means of the second temperature signal.

54. The measuring system as claimed in claim 28, further comprising:

at least one deformation sensor, especially a deformation sensor contacting said first vibration element on a side facing away from its lumen and/or formed by means of a strain gauge, for registering elastic deformation of said first vibration element, especially thermally related elastic deformation and/or elastic deformation effected by force introduced into the measuring system via the pipeline, which deformation sensor is adapted to generate a deformation signal dependent on said deformation of said first vibration element, wherein;

said measuring and operating electronics is adapted to generate the measured value representing the volume flow rate by means of the deformation signal; and

/or

said measuring and operating electronics, is adapted to generate the measured value representing the volume flow by means of the deformation signal.