SMP - O2 Analyser

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The purpose of the SMP -Maintenance Of O2 Analyser is to train and guide

maintenance personnel to ensure safe and efficient maintenance of the

system.

Responsibility: Team Leader, C&I

Other Department To Be Intimated: (Main Plant Operation, WTP

Operation)

Details of Hazard Involved

1. Fall from Height

2. Dust

3. Heat

4. Electric shock

5. Injury while handling oxygen probe/ analyzer

6. Poor illumination

Safety Precautions Required

1. Ensure use of proper PPE while handling the probe in field

2. Ensure sufficient light in the working zone

3. Use hand gloves while handling the probe.

4. Stand firmly on the temporary platform while working with the probe.

SMP - Maintenance Of O2 Analyser

ORISSA POWER GENERATION CORPORATION LTD.

IB THERMAL POWER STATION, BANHARPALI

STANDARD MAINTENANCE PROCEDURE

MAINTENANCE OF O2 ANALYSER

Document No:SMP / C&I 27

Filed At: Control & Instrumentation Dept

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Permit Type: Permit To Work Order

Permit Approving Authority: Shift-in-Charge (Main Control Room)

Isolation Procedure

1. Power supply to be made off from the UPS end before dismantling

analyzer and probe.

2. Before making any connections ensure that the power supply and any

high voltage or power-operated control circuits are switched off.

T&P including special ones

1. Slide Wrench set

2. Multimeter

3. Screw Driver Set

4. Spanner set

5. Pipe wrench

6. PVC tape

Frequency of maintenance: Annual Outage / In case of failures.

WORK INSTRUCTION PROCEDURE

A) Calibration of O2 Analyser:

1. Zirconia oxygen probe is designed to measure oxygen concentration in

flue gas by an in situ method. The system comprises of a flue mounted

oxygen probe containing a zirconia cell and electronics unit which

provides the power and reference air supply necessary for probe

operation.

2. Zero calibration of analyzer is done by connecting its input to supply air.

Auto Calibration commands is enabled and waited. This procedure is

repeated two to three times.

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a) Analyser continuously monitors oxygen levels of flue gas at Air Heater

inlet, displays measured oxygen percentage, thermocouple and flues

temperature and other operational parameters.

b) There are 4 relay outputs and 3 retransmission outputs.

c) The unit is used for in-situ (wet analysis) measurement.

Accessories: Program Card, door Key, Cable entry bungs.

Individual tactile membrane switches are used as follows.

% O2 ----- Used for viewing the measured % O2.

Temp ------Used for accessing the Display Temperature Page.

Alarm -> Used for accessing alarms and Indication page.

Cal -> Used for accessing probe calibration page.

> -> Page advance switch.

< -> Parameter advance switch

/\ -> Raise Switch

\/ -> Lower Switch

Enter -> For storing the programmed parameters and values into

instruments nonvolatile memory.

A) Setting the Reference Air Flow -

1. For Probe type Z-FG and Pump / Regulator configuration, adjust the flow

rate to 150 to 200 ml/min.

2. Calibration of oxygen analyzer is done as per following steps.

a) Analyser is first switched ON, the upper and lower displays are

illuminated for 3 seconds as a check for failed segments.

b) After that the instrument automatically monitors the probe temperature

until it reaches 600 deg. C. During cell warm up all oxygen related

parameters are disabled to prevent erroneous result.



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c) Then uncontaminated air supply is connected to the probe by removing

the plug from the test gas connector on probe, ENTER push button is

pressed and automatic zero calibration is initiated.

d) After warming up of cell is complete, the cell gets stabilized. It takes

almost 15 minutes for stabilization of the cell.

e) After the cell gets stabilized it shows it shows the % of O2 on the display.

Then air supply is disconnected from the probe and the plug is refit to the

connector and suitable time is allowed for the cell output to stabilize.

f) After the cell gets re-stabilized it shows the correct % of O2

concentration in the flue gas.

3. During the calibration the following faults are encountered which are

displayed on the header and corrective actions are taken to eliminate the

fault.

-Reversal of cell T/C

- Breakage of cell T/C

- Breakage of flue T/C

- High/Low cell temperature

- High/Low flue temperature

B) CHECKING OF OXYGEN PROBE:

1. Check cleanliness of Filter assembly.

2. Check purge airline.

3. Check the Thermocouple of the probe.

4. While removing or installing it should be carried carefully by two to

three persons so that the tip of the Probe doesnt get damaged.



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Quality Check

1. At full load the O2 % should come as 2 ~ 4 %.

2. At no load condition the O2 % should be 20 ~ 22 %.

Trial and Test Procedure

1. Check and compare with the readings calculated at DM Plant and

confirm the results with MCR.

Checks before release of Permit

1. Before release of permit alarms if coming during testing should be reset.

2. All T & Ps and manpower are removed

Revision No& Date

Prepared By Verified ByTechnical Committee

Approved ByDirector (Operation)

B. B. Behera


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SMP - O2 Analyser