Influence of Regulator Noise on Ultrasonic Meters – A review · PDF fileInfluence of Regulator Noise on Ultrasonic Meters ... Regulator upstream of an ultrasonic meter flow flow

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:! Influence of Regulator Noise on Ultrasonic Meters – A review Toralf Dietz, Claus Girschik, Volker Herrmann, SICK AG

: SICK AG : Vertraulich

Intention of the paper Explain potential influence of regulator noise on USM -!What is regulator noise? -!How can it be reduced? -!What measures are implemented in the USMs? -!Some tests! -!Practical experiences

- platform - Underground storage - Terranet regulator station

-!Are USMs immun against noise? -!What kind of application security do we have?

: Dr. Volker Herrmann, March 2014 2

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: SICK AG : Vertraulich 4 4

Sonde A Sonde B

Disturbed signal ! SNR = 6dB

Noise interference – a potential problem

nois

e

sign

al

xdBLevelNoiseLevelSignalSNR ==

__

Signal-Noise-Level

: Dr. Volker Herrmann, March 2014

: SICK AG : Vertraulich 5

How can we get an appropriate signal noise ratio? Proper installation can reduce noise level Proper meter selection can provide strong signal and reduce noise influence



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Regulator noise at the meter is dependent on

-! The valve "! Type, design of pressure control

-! Installation

"! Distance between valve and meter "! Special noise dampers "! Potential elbows, tees, etc. between valve and meter. "! Postition of meter to valve: upstream or downstream

-! Operation conditions "! Pressure drop across the valve "! Velocity of gas

6 : Dr. Volker Herrmann, March 2014



Frequency spectrum of regulator

:! noise damper (audible noise!) -! -22dB(a) in 10inch downstream


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0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

0,1 1 10 100 1000 10000 100000

Frequenz

Pegel

fL 1!

Dcf 1,0 beiMax !2fL!

Noise spectrum – from literature

!!"

#

$$%

&''(

)**+

,

-+.-..+

5.2

21

222 61log10)log(1093~][

pppcQdBdBL mnoise



4,5

4,0

3,5

3,0

2,5

2,0

1,5

1,0

0,5

0 0 1 10 100 1000 10000 100000



Practical measurement of noise spectrum


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Noise measurement

Flow

Vortexmeter

USmeter

Mokveldregulator

Sensor US noise

110

120

130

140

150

160

170

10 100 1000Frequency [kHz]

Nois

e le

vel [

dB]

MP01 , dp [bar] 30,0 , Vgas [m/s] 3,3MP06 , dp [bar] 25,0 , Vgas [m/s] 15,4MP02 , dp [bar] 24,5 , Vgas [m/s] 14,4MP08 , dp [bar] 24,0 , Vgas [m/s] 13,6MP03 , dp [bar] 25,3 , Vgas [m/s] 12,1MP07 , dp [bar] 23,3 , Vgas [m/s] 6,8MP04 , dp [bar] 25,0 , Vgas [m/s] 6,8MP05 , dp [bar] 24,3 , Vgas [m/s] 4,2



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Pressure drop : 24,3 !. 30 bar Velocity 3,3 !15,4 m/sec


One or two bends between regulator and meter filter, heat exchanger dampen noise


Noise reduction by piping installation

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6


Traditional noise attenuation with tees


FLOW Conditioner as dampening element

16

PTB Flow Conditioner

Approx. 6 db


Noise reduction

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:! Dampener type „Kötter“ 6“/DN150

:! < 20 db

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Special dampening element


Noise reduction


"! Regulator upstream of an ultrasonic meter

flow

flow

US

US

Regulator

Regulator

noise

noise

"! Regulator downstream of an ultrasonic meter

Distance and direction of the meter with respect to regulator


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What can a good meter contribute? Provide a high signal Further reduce noise

Meter design



Meter design – transducer power

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A good measurement starts with a strong signal


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Signal attenuation increases with path length – the shorter the better is the signal

Signal Level Chart

0

0.2

0.4

0.6

0.8

1

0 1 2

rel. path length

rel.

sign

al le

vel [

dB]

direct path

single bounced path

noise level

Signal to Noise Ratiodirect path

Signal to Noise Ratiosingle bounced path

reflection loss

A

BC

D

E

[ ]dBLL

SNRN

S

!!"

#$$%

&'=

2,

2,log20 Configuration for a direct path meter

Meter design – path length


: SICK AG : Vertraulich 22 : Dr. Volker Herrmann, March 2014

Meter design – path length

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Higher frequency transducers – right frequency reduces noise

210kHz 350kHz

Meter design – Transducer power



Comparison of SNR with different working frequencies of the transducer pressure drop 40bar to 10bar

Increase Immunity FLOWSIC600, DN200, HDV Lintorf

0

10

20

30

40

50

0 15 30 45Velocity [m/s]

SNR

[dB

]

outer path up outer path dow n

inner path up inner path dow n

0 15 30 45Velocity [m/s]

outer path up outer path dow n

inner path up inner path dow n

Transducer with 210 kHz Transducer with 350 kHz

SNR Limit


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Noise reduction by stacking

Signal with 4-time stacking

Stacking – summary: n signal before analysis n = 2, 4, 8, 16

Improvment of SNR Idea: only phase correlated signals are amplified Non correlated signals are dampened drawback: longer response time



Meter design - plausibility

measuring window

Samples

Max

Digits Limit MaxTop

Limit MinAmplitude Limit

MaxPosEarly

Limit MaxPosLate

Many strict plausibility

checks


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Practical examples

-! Offshore Platform

-! Underground storage facility

-! Terranet control station



Offshore-Plattform

: Name (Datum) 28

Platform -! Installation of a new ejector for gas lifting -! Ejectorpower is controlled via Gas Flow -! High reliability required -! Non custody transfer measurement

Location platform

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Offshore-Plattform Ejector-measuring line

-! Selection of FLOWSIC600 6“ due to good experience with reliability -! Application conditions have not been known in detail from the

beginning -! 4-path meter installed in 2011 -! Reading connected via 4!20 mA only!



Offshore-Plattform

Installation:

-! Installation with short, straight inlet piping -! No flow conditioner, no dampener -! 30 bar pressure drop -! Meter downstream of the regulator


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Offshore-Plattform Ejector-measuring distance

Layout of metering line -! Without flow conditioner or acoustic dampener -! Pressure drop approx. 90 bar ! 60 bar

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Pressure regulator USM

Inlet piping Approx 10 D/ 90° / 6D)



Offshore-Plattform Ejector-Measuring line

-! Stability of measurement not sufficient. -! Measurement signal part time dropped -! No status signal wired!

-! Platform runs uninterrupped, no service possible

-! Ejectorpower controlled via operating pressure

-! No immediate solution possible


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Offshore-Platform Ejector-Measuring section

Analysing Measurement -! Path failures at USM

-! Analysis of the log data of the ultrasonic flowmeter -! Criteria that led to the rejection of the measurement

"! Signal comparison (MSE) "! Zero crossing "! Maximum amplitude



Offshore-Platform Ejector-Measuring Section

USM adaption -! Activating the signal stackings

"! USM adds 16 digital signals before the evaluation

"! Improved performance up to 90%

"! SNR on average paths are still close to the limit (13 dB) recommendation: switch to transducers with 300kHz


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Offshore-Plattform Ejector-Measuring Section

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Flow rate

Operation pressure

70 bar

33 bar

64 bar

FT-760 USM Status / January 2014 -! Pressure change does not cause incorrect measurements -! Flow signal in the DCS shows no failures

Ultrasonic measurement is stable at pressure change : Dr. Volker Herrmann, March 2014


Offshore-Plattform

Lessons learned:

-! We didn‘t evaluate all relevant application data -! Measurement with standard configuration not possible -! Additional stacking allows stable measurement, but meter at its limit -! Higher frequency brings further improvement

Measure:

-! SICK will enforce more consequent work with TQ together with the customer


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: SICK AG : Vertraulich : Name (Datum) 37


Underground storage bidirectional operation

Metering -! Ultrasonic gas measurement with FLOWSIC600 -! nominal width 16“/DN400, ANSI Class 900 -! Ultrasonic Gas Meter with 4 measuring paths -! High-pressure ultrasonic probes 250 bar -! Design pressure not permit use of probes with higher working

frequency (300kHz) -! Standard transducer with 200kHz


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Injection phase Pressure regulator Mokveld RZD RQX S99

-!Pressure drop is 5 bar -!Sound propagation over medium and pipe run 39

in-/outlet pipe

Pressure control valve FC USZ

10D 5D



withdrawal phase Pressure regulator Mokveld RZD RQX S99

-!Pressure drop is 20 bar -!Sound propagation mainly via pipe run 40

In-/outlet pipe

Pressure control valve FC USZ

10D 5D



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Diagnostic data during commissioning -!Pressurized line no gas flow -!Performance at 100% -!SNR bei >= 36db, AGC bei <= 47db

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AGC

SNR




diagnostic data SNR in a storage facility -! Flow 100 Tsd. Nm!/h

5 bar 17 bar pressure drop

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diagnostic data SNR storage facility -! Flow 400 Tsd. Nm!/h

5 bar 17 bar pressure drop

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diagnostic data in storage facility


Underground storage Bidirectional operation

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diagnostic data

Result of sound measurement

-! Ultrasonic signal rises only slightly from the noise of the regulator

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Underground storage Bidirectional operation



Measures -! Change to 300 kHz transducers ?

"! Excluded because of a technical design pressure -! Increase damping with additional damper plate?

"! installation, no change possible -! signal processing ?

"! Activating the signal averaging possible!

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Stackings 0x 4x 8x 16x

theoretic [db] 0 6 9 12

SNR inner [db] 5 11 14 17

SNR outer [db] 10 16 20 22



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Implementation of signal averaging on USZ at dp = 20 bar

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0x 4x

8x 16x




Implementation of signal averaging on USZ -! Final on setting:

"! 8x Signal averaging "! Limit SNR = 10db "! Good compromise between SNR and dynamic behaviour



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Underground storage

Lessons Learned

-! FLOWSIC600 works upstream and downstream the regulator -! Using a flow conditioner helps, but is not a dampener -! Would be good to have 350 kHz at@250 bar -! Stable measurement with 200 kHz but stacking required -! Stacking parameter work as in theory.



Transport network and key numbers of terranets bw GmbH

gas reference points High-pressure gas network

business locations gas export points

Performance of compressor stations (in MW)1)

peak power (in MWh/h)

Transported amount of natural gas (in TWh)

Max. permitted operating pressure (in bar)

Pipeline diameter (in mm)

Length of high-pressure gas network (in km) 2012

1.965

50 - 80

76,7

80 bis 700

23.059

33 1) an zwei Standorten

MBDA-Station Nenzingen

Quelle: terranets bw GmbH, 2014


terranets – Control station „Nenzingen“ Projectdetails

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terranets – Control station „Nenzingen“ Projectdetails Modernization station

-! Exchange vortex meter against USM 2 measuring rails

-! Pressure regulator according to the meter at a distance < 20D Typ Mokveld RZD-REOX, DN200, ANSI CL600

-! Pressure drop across the regulators in regular at 40 bar

requirements -! High reliability of the US- flow measurement ! Measurement is used in network control

-! Design of the system for maximum immunity to noise ! no more adjustments after commissioning 51 : Dr. Volker Herrmann, March 2014


terranets – Control station „Nenzingen“ Project details

View at measuring station before renovation

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WBZ

inlet

Outlet with p&T Measuring


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View at station before renovation


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Pressure control valve Mokveld 8

Vortex Meter



realization -! Gas meter FLOWSIC600, DN150, ANSI CL600, 4 path

! Transducer with 300 kHz

-! Meter downstream < 20D "! Sound-absorbing measures

! PTB rectifier and Kötter dampener plate between US-meter and pressure regulator

commissioning

-! June 2013

54



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terranets – Control station „Nenzingen“ measurement line

:! Installation -! limited space available -! Distance to pressure regulator = 15D

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USM

Outlet pipe Pressure regulater valve

dampener

15D

rectifier



terranets – Control station „Nenzingen“ Measureperformance

Operating and diagnostic data -! Time 12.12.13 – 25.12.13

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0 10 20 30 40 50 60 70 80 90 100

0 5

10 15 20 25 30 35 40 45 50

10/1

2/13

12/1

2/13

14/1

2/13

16/1

2/13

18/1

2/13

20/1

2/13

22/1

2/13

24/1

2/13

26/1

2/13

Limit SNR

VO

G +

Dru

ck

Per

form

ance

+ S

NR

VOG

pressure drop

SNR

Perform.

case 1 case 2


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Operating and diagnostic data – case 2 -! Time 12.12.13 – 25.12.13

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VOG

Druck-abfall

SNR

•! SNR clearly stable with values > 25 dB

•! High pressure drop across the regulator of 30 bar does not change the SNR at the gas meter

terranets – Control station „Nenzingen“ Measureperformance



Lessons learned -! Distance between regulator and meter of 15 D is enough when additional

measures are taken. -! Having an Flow condition and an dampener improves situation -! Using 300 kHZ is a good idea -! === > Nearly ideal conditions for metering close to a regulator -! Cooperation between operator and meter supplier gives best results.

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terranets – Control station „Nenzingen“


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: SICK AG : Vertraulich : Name (Datum) 59

FLOWSIC500 Innovation

Meter size: DN80 / 3”

Meter cartridge

Meter body


Application – Dumas, Texas FLOWSIC500

July 2013

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Conclusions

The use of Ultrasonic Meters in the close environment of a regulator can give realiable results

It is necessary to plan the installation right

Modern transducer technology, software technology and application know how is required

A good measurement is mostly a result of a good meter and a proper installation. Good cooperation beetween supplier and customer is favourable



Thank for you attention !


Documents

Influence of Regulator Noise on Ultrasonic Meters – A review · PDF fileInfluence of Regulator Noise on Ultrasonic Meters ... Regulator upstream of an ultrasonic meter flow flow