Geenrator Seal Oil PR Report

8/10/2019 Geenrator Seal Oil PR Report

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1#

Report on #1 generator sealing oil pressure differential of H2

side and air side high

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Generator sealing oil part has become the key element of H2 insidecooled generator seal because H2 cooled generator rotor shaft should gothrough the casing end of generator. Sealing oil is composed of air sideand H2 side, and it supplies the oil to the two annular oil distribution tank in bearing sealing pad, and the oil go through the gap between sealing padinternal diameter and shaft along the shaft in a ial direction.

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!he oil will not flow between the gap of two oil distribution tank if the supply oil pressure of the two oil pipe is e"ual in the sealing pad# ingeneral, if the sealing oil pressure maintain higher than the steam pressureof the turbine, it will pre$ent the H2 o$erflow from the generator.

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Oil supplied by air side oil pipe will flow to the bearing side alongthe gap between shaft and sealing pad, and flow into air side sealing oil

tank with bearing returning oil, therefore it pre$ent air and damper steamfrom going into the generator. H2 side sealing oil will flow into the


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generator along the gap between shaft and sealing pad, then fall into thedefoaming bo , and return to H2 side sealing oil tank at last.

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Differential pressure $al$e is connected with oil inlet and outlet inair side sealing oil pump, which ad(usts bypass pressure, and its signalseparately come from turbine inside pressure )transfer through oil

pressure* and sealing oil air side outlet oil pressure. !he $al$e couldad(ust bypass flow automatically, which will ensure air side sealing oilmaintaining higher than turbine pressure %&k'a.

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alancing $al$es are installed in H2 side outlet part, of which one isconnected with oil pipe flowing to e citation end, and the other isconnected with oil pipe flowing to turbine end, and their signalsseparately come from oil pressure of air side in e citation end and turbineend sealing pad. /d(ust the openness of balancing $al$e automaticallythrough changing air side oil pressure, which will maintain the oil

pressure differential of air side and H2 side within +& -'a. )!hefollowing is balancing $al$e picture.*


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01 QR &U %2k'a % k'a

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+& -'a ( od

/t present 01 generator air side sealing oil pressure maintain higher than turbine steam pressure with %2k'a % k'a, which shows pressuredifferential $al$e following generator H2 pressure is good. /nd thedifferential pressure of H2 oil and air side oil is far more than +& -'a.) or differential pressure data of recent days during unit operation, findthe following form*

Time Load Pressure differential

of air side sealing oil

and H2 pressure

Pressure differential of

excitation end H2 side

oil pressure and air side

oil pressure

Pressure differential of

turbine end H2 side oil

pressure and air side oil

pressure

2 th,

3une

&--45 %6.-0 k'a 0&.7- k'a 0- % k'a

0st 3uly 86-45 %9.9 k'a 0&.27 k'a 0- 99 k'a


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8rd 3uly - %2.09 k'a 00.7& k'a 0.77 k'a &th, 3uly - % .60 k'a 02.&% k'a 6.%% k'a7th, 3uly - % . 7 k'a 02.7- k'a 9.&7 k'a

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e U H($ *

+& -'a (

:f air side oil pressure is larger than H2 oil pressure, it will causesealing oil in the sealing pad flow from air side oil to H2 side, andgenerator H2 purity will decrease. !he causes of H2 side oil pressure and

air side oil pressure larger than +& - 'a are listed as follows;0 r "wwJF(


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!he lower part bolt has been ad(usted for se$eral times, but it hasnot changed the differential of H2 side oil and air side oil pressure high

problem.

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=o blockage and impurity is found after balancing $al$e dismantleand inspection.

8 1 (

=o defects are found in generator sealing pad.

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=o abnormality is found in sealing oil pipeline.

7 &? * (our set of meters all display oil pressure differential of H2 side

and air side is high.

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/t present 10 generator e citation end and turbine end all ha$e thedefects of oil pressure differential high problem, and the defects are noteliminated after se$eral measures, so the manufacturer andcommissioning team are needed to eliminate this defect.

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Geenrator Seal Oil PR Report