More Thrust includes a lot of test material. It was released between FT1 and FT2. Most rules are included in FT2 rulebook or one of the fleet books. But there are some interesting rules and …Full description
Full description
Descripción: strainer
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Temperature mapping for the pharma warehouse
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Free space battle rules.
civil engineering and hydraulic works
Thrust-Block-Calculation
Thrust Block Design
Design of thrust block foundation for pipe lines
Thrust Block Design AWWA M45Descripción completa
22
APRIL
TS TIDINGS
2010
FEED BACK NO. 2 PROJECT: VIJAYAWADA THERMAL POWER STATION, UNIT 7, 500 MW PROBLEM: HIGH THRUST BEARING TEMPERATURE IN TDBFP-A
TDBFP –A was commissioned on 29.06.2009. Unit reached full load on 08/10/2009 for the first time with both TDBFPs in service .At that time it was observed that the Active pad top thrust bearing temperature reached 93deg C. It was found to be increasing with increase in speed of the pump. At 3000 rpm it was maintaining at 81deg C and steadily increased upto 95-98 deg C at 4800-5000 rpm. This pump had experienced jamming on 26.10.2009 and its cartridge had to be withdrawn for servicing the same .Rubbing/Scoring marks observed on balancing drum were polished. During that time, site along with BHEL, Hyderabad representatives had also inspected the thrust bearing, and minor polishing of the babbitt surface was done. The alarm and Trip values are originally set at 100 and 105 deg C respectively in MAX DNA. During loading of the pump the Active pad Top Temperature was seen to increase upto 103-104 degC. During trial operation of the Unit at Full load from 26.01.2010 to 28.01.2010 the temperature has has further raised to 105 deg C. The following were parameters at full load. Turbine Load BFP-A speed Active pad temperature (Top /Bottom) Inactive pads temp.(Top/Bottom) Oil pressure to BFP Thrust bearing Lo Header pressure LO supply temperature Bearing Return oil temp.
: : : : : : : :
510 MW 5440 rpm 105/84 Deg C 69/69 deg C 0.55KSC 2.7KSC 44 Deg C 65DegC
TECHNICAL SERVICES / PSSR
23
APRIL
2010
TS TIDINGS
After discussing with BHEL, Hyderabad, temporarily the alarm and trip limits were raised by site to 105deg C and 110 deg C respectively as it was felt that pump could be run in that condition since only one out of two active pad temperatures was going above alarm limits. (The other active thrust pad temperature has maintained at temperatures of 75 to 84 deg C in the same operating regime of the pump.). During continuous operation of the machine after COD, the thrust bearing temperature increased gradually beyond these limits too and reached 108Deg C. Hence matter was escalated to BHEL, Hyderabad for urgent resolution. On 13.03.2010, BHEL, Hyderabad Engineers visited site after shut down was taken on pump. The pump thrust bearing was opened and inspected. Scoring marks and discoloration of the affected pads was observed. The following corrective actions were taken A) Since discoloring and high return oil temperature values indicate oil starvation ,the Orifices kept in the Oil supply lines to NDE Journal as well as Thrust bearing were removed. B) Swapping of ACTIVE and INACTIVE PADS was done, since inactive pad’s surface was found to be in good condition ,and no spare pads were immediately available at site. The pump was boxed up on 17.03.2010 and taken into service. Following were the parameters observed at full load of turbine after attending the problem.
TECHNICAL SERVICES / PSSR
24
APRIL
TS TIDINGS
2010
Turbine Load BFP-A speed Active pad temperature (Top /Bottom) Inactive pads temp.(Top/Bottom) Oil pressure to BFP Thrust bearing Lo Header pressure LO supply temperature Bearing Return oil temp.
: : : : : : : :
500MW 5405rpm 85/69 Deg C 55/56 deg C 2.00KSC 2.1KSC 44 Deg C 55.5DegC
The problem was thus been resolved and pump has been released for continuous operation. However the difference between Active side top /Bottom temperatures around 15-20 deg C still remain and needs BHEL, Hyderabad’s analysis since this has been a characteristic behavior of this 500 MW BFP.
