Steam Blowing Procedure

ADHI KARYA KARYA - JEPOE JOINT OPERATION

COMMISSIONING COMMISSIONING PROCEDURE Document No. BOILER UNIT – 1 1 STEAM BLOWING PROCEDURE

PLG-100-CP-PS-0004

Rev. : 0 Page Number 1 of 15

OW NE NER

:

PT. P PL N ( N ((Per ser o)

PR OJECT NA NAME

:

PLTU L LAMPU NG NG ((2 X X 1 100 M MW)

PR OJECT T TITLE

:

PLG

JOB NUMBER

:

07908

LOCATIO N

:

TA NJ NJU NG NG S SELAK I, L LAMPU NG NG

0 REV

Juli 28,2011 DATE

Issued for Approval DESCRIPTION

SAS

FSB

KSN/BES

PREP’D

VER’D

CHK’D

PLN COMMISSIONING TEAM APP’D


COMMISSIONING COMMISSIONING PROCEDURE Document No. PLG-100-CP-PS-0004

BOILER UNIT – 1 1 STEAM BLOWING PROCEDURE


TABLE OF CONTENT

1.0

TITLE

2.0

SCOPE

3.0

REFERENCE

4.0

GENERAL DESCRIPTION OF THE SYSTEM

5.0

PREPARATIONS FOR STEAM BLOWING

6.0

EXTENT OF STEAM BLOWS

7.0

WAY OF STEAM BLOWING

8.0

RECORD OF THE RESULTS

9.0

DESCRIPTION OF STEAM BLOWS

10.0

PRECAUTIONS

11.0

APPENDICES

APPENDIX 1: SUMMARY TABLE APPENDIX 2: GUIDELINES FOR THE TARGET PLATE EVALUATION APPENDIX 3: CURVE; COLD START-UP PRESSURE RISE CURVE APPENDIX 4: CURVE; STEAM BLOWING APPENDIX 4: LAYOUT; STEAM BLOWING





1.0

TITLE

Procedure for steam blowing 2.0

SCOPE

This procedure covers the general requirements for steam st eam blowing.

3.0

REFERENCE

3.1 JINAN BOILER OPERATION MANUAL

4.0

GENERAL DESCRIPTION OF THE SYSTEM

4.1 Data of the boiler Boiler manufacturer

: Jinan Boiler

Type of the boiler

: CFB

Max steam capacity

: 420 t/h

Steam outlet temperature temperatur e

: 540 °C

Steam outlet pressure

: 9.8 MPa

4.2 Description of steam blowing

5.0

4.2.1

Holding pressure

: 3.9 MPa

4.2.2

Release pressure

: 6.3 MPa

PREPARATIONS FOR STEAM BLOWING

Steam blowing is a procedure used to clean boiler superheaters and other steam piping of loose dirt, welding bead deposits, pipe slag, iron oxides and other foreign material to minimize the possibility of damage to turbine, control valves, in line instruments, etc. Steam blowing of the boiler is performed after chemica l cleaning has carried out and magnetite film has been formed. Chemical cleaning and magnetite film formation are performed according to separate instructions.





Before steam blows are started, the following main systems must be in operating condition and commissioned: 

demineralized water system



feed water system



boiler water and steam system



oil firing system



air and flue gas system



boiler interlock and control system system

In addition:

6.0



the chemical cleaning connections have been restored and checked



the temporary blow-out piping has been insta lled and examined



the systems, with sufficient capacities, needed for feed water supply are available.

EXTENT OF STEAM BLOWING

Steam blow out of the boiler takes place p lace through boiler main steam piping until unt il steam turbine inlet piping (before main steam valve or DEH valve). For steam blowing temporary blow out pipe is installed at the main steam pipe in the pipe pipe bridge at the level +8.000. Steam blows will be controlled by a temporarily installed motor-operated steam valve located in blow out pipe (after ON/OFF motorize valve). The blow out pipe will cause high noise during the blow-outs, and this should be taken into account in order to avoid personal or material damages due to noise.

7.0

WAY OF STEAM BLOWING

Steam blows are performed periodically; maximum 3 stea m blows a day. During the steam blows, the impurities in the piping are exposed to an impulse of at least the same strength as the impulse they will be exposed to in normal operation when the boiler is operated at the maximum load. The quality of the steam blow is evaluated by the so- called disturbance coefficient R.



PLG-100-CP-PS-0004


2

R

mblow





vblow



vmax max

2

mmax

Where m blow mmax max v blow vmax max



steam massflow during blowing



steam massflow at full full load



specifi specificc volume of steam at steam blow condition



specifi specificc volume of steam at full full load condition

During the steam blow, the disturbance coefficient should reach a value > 1 .0. When R>1, the effective force during steam blow is greater than that during maximum continuous rating (MCR) operation and then any debris left behind after blowing will not be moved by momentum flow force alone during normal operating conditions. The steam blowing quality is sufficient when blowing at holding pressure 3.9 MPa and release pressure at 6.3 MPa of drum pressure.

8.0

RECORD OF THE RESULTS

The number/sufficiency of steam blows is determined by the number and size of the detected impacts on the target plate installed in the steam pipe after the temporary blowing valve. The criteria of successful steam blowing are to be jointly agreed on with the owner and ADHI KARYA prior to steam blows are commenced. The guideline for the target plate evaluation is att ached in APPENDIX APPENDIX 2.

9.0

DESCRIPTION OF STEAM BLOWING

Steam blows are started by heating the boiler and increasing the pressure at the rate given in the operating instructions. During the first two start-ups, however, the rate of increase is kept considerably lower than normally and steam blow out is carried out at about 6.3 MPa drum pressure 9.1

During Heating

9.1.1

Control the thermal expansion expansion of the boiler.

9.1.2

Control the combustion and the function of the automatic control systems of the boiler.





9.1.3

Check that steam pressure and temperature measurements, feed water and make-up water flow measurements, drum level measurements and other measurements essential for the safe start-up are in operation.

9.2

Start Up

9.2.1

Before start-up, reserve sufficient sufficient amount amount of water in the feed water and makeup water tanks and reserve sufficient amount of oil in the oil tank.

9.2.2

Start the boiler according to the start start-up -up curves by increasing increasing the oil firing firing rate.

9.2.3

By opening opening the start-up and steam blow out valves, valves, adjust the steam flow flow needed to cool the superheaters and, at the t he same time, heat the steam blow pipe.

9.2.4

Increase the oil firing rate until a pressure of 6.3 MPa and a steam temperature of approx. 430 °C are reached.

9.3

Steam Blow Procedure Procedure

9.3.1

Start steam blow blow out by opening the steam blow valve, close the start-up valve and increase the oil firing rate

9.3.2

Increase the oil firing rate to maximum and control steam flow. Blowing valve to be maintained open at boiler drum pressure at 6.3 MPa until pressure drops to 3.9 MPa along ± 10 minutes, and blowing valve has to be closed sequentially, corresponding steam flow flow estimated 250 t/hr.

9.3.3

After blowing time of about 5 minutes stop steam blow by stopping oil firing and let the pressure gradually decrease.

9.3.4

When the drum pressure has decreased to about about 3.0 MPa, close the steam blow blow valve and the main steam valve and control boiler pressure decrease by start-up valve.

9.3.5

Remove the target plate for evaluation and if steam blowing has to be continued replace the target with a new one (first two – three three blows are carried out without target plate)

9.3.6

Let the boiler to cool off at least 4 hours before next steam blowing





10.0

PRECAUTIONS

10.1 Since the steam blows are very noisy they are to be publicised in advance and the inhabitants of the neighbouring area has to be informed of the matter separately if necessary 10.2 During the steam blow (start-up, steam blow, shutdown), working in the danger area is not permitted and access to the area must be prevented, for example, with sealing-off lines. The danger area is considered to include the boiler house, the area of the temporary steam blow piping and the blow area of the whole steam blow pipe. 10.3 The start and the end of each steam blow is announced using a public addressing system or a buzzer. 10.4 Any malfunctions which might occur during the steam blow out shall be thoroughly clarified and if checking is necessary, it shall be done before the steam blow out is continued. 10.5 Before any work is done to install or remove the target plate, make sure that the steam blow out o ut valve and the main steam stop valve are closed and no firing is going on in the boiler. 10.6 During the steam blow outs, the instructions of the authorities, pressure vessels standards and safety regulations of the plant shall be followed. 10.7 Between the steam blow outs, the condition of the boiler, steam blow out piping and the temporary connections shall be followed



PLG-100-CP-PS-0004


11.

APPENDICES

APPENDIX 1: SUMMARY TABLE No. 1 2 3 4 5 6 7 8 9 10

Date/Time

Pressure

Temperature

Flow

(MPa)

(°C)

(kg/s)

Note



PLG-100-CP-PS-0004


APPENDIX 2: GUIDELINES FOR THE TARGET PLATE EVALUATION a)

Target plates During the steam blows target plates made of cupper brass with brushed surface are to be used. The steam cleanliness is confirmed with the polished cupper brass (Brinell hardness 110 - 120) target plate installed to piping after temporary steam blow valve. The 2

target area in the plate is determined to be 2500 mm .

b)

Acceptance criteria The cleaning is successfully completed when the target plate examination fulfils the following criteria: No impacts > 0.8 mm  in an area of 2500 mm

2

Max. 2 impacts >0.4 mm  in an area of 2500 mm 2 Max.10 impacts >0.2 mm  in an area of 2500 mm 2 Impacts < 0.2 mm  are well dispersed and nowhere present on concentr ation.  Indicates

maximum corner to corner measurement





c)

Analysis of the target plates The approximate analysis of impacts on target plate is to done in co-operation with client, turbine manufacturer, boiler manufacturer, and commissioning team, immediately after the steam blow. It is to be determined in co-operation at which point the plates are to be subject for more detail evaluation. During the detail evaluation the impacts on the target plate are to be counted and measured based on the following: Size of the impacts 

Impacts on each plate are classified based on impact size (diameter)



The diameter is equal to maximum corner to corner measurement



The measurement and calculation of the impacts are to be done by using magnifying

glass or microscope with mm-Raster as reference 

The distribution is presented according to the attached impact chart.

Concentration of the impacts  

d)

The target plate is to be divided to 4 sections. sect ions. Number of impacts impacts smaller s maller than 0.2 mm per section is not calculated

Presentation of the data The following data of inspected target plate is to be given: 

Identification of the target plate.



Number of impacts impacts per each diameter class



Number of impacts impacts at various var ious parts of plate





e)

Agreement The evaluation method of the target plates and the steam purity criteria presented in this paper are hereby agreed to be indisputable indisputable and valid. ___ - ___ - 2011 On behalf of Boiler Manufacturer ____________________ ______________________ __

On behalf of Steam Turbine Manufacturer ____________________ ______________________ __

On behalf of Commissioning Team ____________________ ______________________ __

On behalf of PT. PLN (Persero) ____________________ ______________________ __


COMMISSIONING COMMISSIONING PROCEDURE Document No.

Rev. : 0


PLG-100-CP-PS-0004

Page Number 12 of 15

f)

Presentation of impact size distribution PLATE No: _______ Size distribution Impact diameter

number of impact a1

 >

0,8 mm

0,8 mm >  > 0,4 mm 0,4 mm >  > 0,2 mm

TARGET PLATE Location of impacts

a1

b1

a2

b2

a2

b1

b2

total





APPENDIX 3: CURVE; COLD START-UP PRESSURE RISE CURVE





APPENDIX 4: CURVE; STEAM BLOWING





APPENDIX 5: LAYOUT; STEAM BLOWING

Steam Blowing Procedure

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