EDF TRAINING TO MNER CHARACTERISE AND MAINTAIN THE MEASUREMENT - PowerPoint PPT Presentation

EDF TRAINING TO MNER CHARACTERISE AND MAINTAIN THE MEASUREMENT CHAIN JULY 2017 EDF Thermal Generation & Engineering Division

Characterise and maintain the measurement chain 1. 1 Introduction 2 Characterise a measurement chain 3 Maintain a measurement chain 4 Example of organisation in a powerplant EDF I 07/2017 | 2

INTRODUCTION Cédric CHALAUD (cedric.chalaud@edf.fr)  5 years in a dispatching ~ 48 (1) GW  5 years Instrumentation and control in a Powerplant in Germany (EnBW)  5 years engineering and maintenance I&C for the nuclear powerplant  4 years Maintenance Instrumentation & Control (I&C) for the thermal powerplant EDF I 07/2017 | 3

INTRODUCTION Definition of a measurement chain I/O Card Monitoring Sensor EDF I 07/2017 | 4

INTRODUCTION How to define a measurement chain : Define a measurement chain = define the process which is followed  The hardware architecture of the measurement chain is a compromise between  Availability of the measurement (how long and how often is it acceptable to have a no “acceptable” data)  Easiness to maintain  Price (conception and maintenance) With this compromise, we can define the acceptable time to detect and solve a default (MTR)  For the process , determine the acceptable level of uncertainty for the measurement (Quality of the measurement). That’s mean the difference between the real value and the value read EDF I 07/2017 | 5

Characterise and maintain the measurement chain 2. 1 Introduction 2 Characterisation of a measurement chain 3 Maintain a measurement chain 4 Example of organisation in a powerplant EDF I 07/2017 | 6

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : one sensor for the measurement 0 sensor out OK Sensor => Repair OK 1 sensor out STOP Sensor Advantages : Inconveniences : - Easy to install - Bad rate of disponibility - Cheap - Not suitable for a safety system | 7

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : 2 sensors for the measurement 0 sensor out OK Sensors 1 sensor out => Priority availability OK => Repair OK => Priority security Sensors 2 sensors out STOP => Repair OK Sensors Advantage: Inconvenience : - Suitable for a best rate of - Not suitable for a best rate of disponibility or security disponibility and security | 8

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : 3 sensors for the measurement 0 sensor out => Priority availability => if 2003 values = => OK Sensors 1 sensor out => Priority security => if 2002 values = OK => Repair OK => if 2002 values ≠ Sensors => Repair OK STOP 2 sensors out Sensors Advantage: Inconvenience : - Suitable for a best rate of - Price disponibility and security EDF I 07/2017 | 9

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Process to follow - Temperature - Pressure - Flow - Level Parameters of the process - Temperature (normal, minimum, maximum) - Pressure (normal, minimum, maximum) - explosive atmosphere (yes / no) => ATEX - Security Level required (SIL) EDF I 07/2017 | 10

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Range - Difference between the maximum and minimum value of the sensed parameter Resolution - The smallest change the sensor can differentiate. - For digital sensors, it is related to number of bits used - For analog sensors, it is limited by low-level electrical noise Sensitivity - Ratio of change in output to a unit change of the input EDF I 07/2017 | 11

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Linearity - Percentage of deviation from the best-fit linear calibration curve Zero offset - A nonzero value output for no input Zero Drift -The departure of output from zero value over a period of time for no input Accuracy - Inversely proportional to the error - Sometimes related to the sensor’s linearity Precision - Ability to reproduce repeatedly with a given accuracy - Sometimes called repeatability EDF I 07/2017 | 12

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Accuracy and Precision ? Precise but not accurate Accurate but not precise Neither precise nor accurate Precise and accurate EDF I 07/2017 | 13

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Deadband - The range of input -for which there is no output Saturation - Maximum output capability, regardless of input EDF I 07/2017 | 14

CHARACTERISATION OF A MEASUREMENT CHAIN 1) Hardware Architecture : Important parameters for the sensors Availability - Cost - Size and available space - Ease of use - Ease of maintenance - Required signal processing - Environmental conditions - Power available for sensing Product to follow - Composition - Density - Viscosity - Concentration EDF I 07/2017 | 15

CHARACTERISATION OF A MEASUREMENT CHAIN 2) Process : Quality assurance for a measurement chain  The quality assurance take into account the error of a part of the chain : Acquisition & Process Monitoring Sensor Processing 100.7 bar 100 bar 100.9 bar 101 bar Error Error Sensor Error Acquisition : 0.2% 0,7% Monitoring : 0,1%  The whole error is the sum of : Error sensor + Error acquisition + Error Monitoring  This method can be simplify by using only the error of the sensor (in the example, 70% of the whole error). EDF I 07/2017 | 16

CHARACTERISATION OF A MEASUREMENT CHAIN 2) Process : Define the acceptable error for the process Process Sensor I/O Card Supervision 101 bar 100 bar EDF I 07/2017 | 17

CHARACTERISATION OF A MEASUREMENT CHAIN After the characterisation of the measurement chain, we can define 4 groups for strategic chains: • Material Safety • Human • Intern Rules • Extern : atmospheric fumes emission • Invoice Contract • Protection of the material Material • Important chains for the process EDF I 07/2017 | 18

Characterise and maintain the measurement chain 3. 1 Introduction 2 Characterise a measurement chain 3 Maintain a measurement chain 4 Example of organisation in a powerplant EDF I 07/2017 | 19

MAINTAIN A MEASUREMENT CHAIN 1) Introduction : MTR Begin of Resolution of MTR = Time between the begin and the default the default the resolution of the default. Detection Call Reparation Test  Detection (Hardware or Process error) can be divided into two parts  Automatic detection with alarm  Human detection : a technician notices the default  Call : time for the skilled worker to be on site  Reparation : availability of the spare part and duration of the reparation  Test : guarantee that the default is solved EDF I 07/2017 | 20

MAINTAIN A MEASUREMENT CHAIN 1) Introduction : Requirement to maintain the chain Skilled workers Spare parts Human Organisation EDF I 07/2017 | 21

MAINTAIN A MEASUREMENT CHAIN 2) Process : Definitions Verification  Difference between a reference (calibrator) and the value given by the sensor. ~ 48 (1) GW Sensor read calibrator 50,5 bar indicates 50 bar If an error of 1 bar is accepted on the sensor, the sensor is OK . EDF I 07/2017 | 22

MAINTAIN A MEASUREMENT CHAIN 2) Process : Definitions Calibration  Take back the sensor in this original technical specifications. Sensor Calibrator read 50,5 indicates bar 52 bar The sensor error accepted ± 1 bar After calibration Sensor calibrator read 50 indicates bar 50 bar EDF I 07/2017 | 23

MAINTAIN A MEASUREMENT CHAIN Question : is it necessary to calibrate the sensor ? Value read on the sensor Acceptable error for the process Time Formation métrologie du 25 novembre 2016 | 24

CHARACTERISATION OF A MEASUREMENT CHAIN After the characterisation of the measurement chain, we can define 4 groups for strategic chains: • Material Safety • Human • Intern Rules • Extern : atmospheric fumes emission • Invoice Contract • Protection of the material Material • Important chains for the process EDF I 07/2017 | 25

MAINTAIN A MEASUREMENT CHAIN Define the check Frequency Strategic (example) Sensor ? Yes No ~ 48 (1) GW Contract Safety No or rules? (SIL) ? Yes Yes Follow contract Periodical test to No check or rules maintain the SIL See annex 1 See annex 2 EDF I 07/2017 | 26

MAINTAIN A MEASUREMENT CHAIN Define the check Frequency (example) ~ 48 (1) GW Important More Safety No for No than one No (SIL) ? process sensor ? Yes Yes Periodicity = f(sensor, Periodicity = No test process) f(sensor, process) EDF I 07/2017 | 27

MAINTAIN A MEASUREMENT CHAIN Example : Regulatory measurement chain Example : monitoring of atmospheric fumes emissions ~ 48 (1) GW Solution STOP Perimeter : - Gas analyser in the chimney (SO2, NO, CO, O2, CO2) We are not allowed to run. - Dust analyser Control every month : - Calibration of the sensor with a reference gas. - Control and send the sensor’s drift to the authorities - Preventive check (sensor’s temperature and seal) - Change if necessary the filters EDF I 07/2017 | 28