Introduction to Generator Hydrogen Gas Cooling System

The gas unit for generator gas cooling comprises the components necessary to fill the generator with hydrogen, maintain it under pressure, check the gas purity and evacuate the generator. To prevent the formation of explosive gas mixtures, the air in the generator is expelled with CO2 prior to filling with H2.

Generator Hydrogen Gas Cooling Area

H2 gas is then pumped in, displacing the C02. When evacuating the generator, the order is reversed. The H2 is first expelled with CO2; afterwards the CO2 is expelled with compressed air (dry and oil-free).

What is A Steam Turbine?

According to Wikepedia, steam turbine is a mechanical device that extracts heat energy from pressurize steam converts into the mechanical motion. 86% of electric generation in the world is using steam turbine. The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam. A turbine contains dozens of louvers or angled blades mounted to a central shaft. The turbine output shaft is connected to a massive generator. The wheels and shaft begin to rotate at high speed when the dry super heated steam ported into the turbine. Meaning that its depend on heat source (boiler) to change the water into super heated steam. Manjung Power Plant is using burning coal in generate or produce power.

Lumut or Segari Power Plant

Lumut Power Plant

Lumut Power Plant and also known Segari Power Plant is a combine cycle power plant. Owned by Segari Energy Ventures Sdn Bhd (SEV), a subsidiary company of Malakoff Berhad. Located at Mukim Pengkalan Baru, District of Manjung in Lumut Perak with 80 acre site on old tin mining land. It is located 30 km from Manjung Coal Fired 3X700 MW Power Plant which owned by Tenaga Nasional Berhad. Segari combine cycle power plant is designed with net output 1,300 MW power generation making it is the biggest gas fired power plant in Malaysia.

To comply with the Department of Environment Malaysia (DOE), Segari Power Plant is designed with the latest technology to reduce emissions and effluents below the good level requirement. 

Generally, Segari or Lumut Power Plant is made up of two identical 650MW blocks. Each consisting of three 143MW ABB GT13E2 gas turbines, three ABB CE natural circulation HRSGs and one ABB 231MW double casing condensing steam turbine generator unit.

Unit No.1 LP Heater No.4 Normal Level Control Valve Diaphragm Leak

Operation called to check control valve which only open 70% but feedback position is 100%

• By manual from DCS open the valve 0%– 100 % : ok
• Physical check from field has small leak at the diaphragm nut hole, try retighten the bolt but still leak from opposite side.
  
• Inform operation to raised defect, need to replace with the new diaphragm and calibrate the valve.
  

Follow up defect

Operation allows replacing the leak diaphragm. Get the new one from the store and replace the defect diaphragm. Calibrate and do stroke check. Everything back to normal operation and permit was cancelled.

GP Joran Coal Fired Power Plant 2008 Among Staff Updated

This fishing competition caught the staffs’ interest especially the sport fishing lover. Find my previous post before. Beside it is also good event to show appreciation from the management to build good relationship between company and their staffs. This competition took place on January 26, 2008 from 0800 am to 1200 pm, drew 50 participants from our staff along the seaside behind the pump house. See photos below;

1) First photo: Coal Fired Power Plant from small jetty behind the Pump House.
2) 2.5 kg weight (Siakap)- awarded as a winner for this tournament.
3) Prize for winners.
4) Participants.
5) Electro Chlorination Plant scene from small jetty at the events.
6) Participants fishing location, finding their own spot.

The rest of the photo for this event. You can find it's more clearer at this flickr.

Many go fishing all their lives without knowing that it is not fish they are after. It is all about the feeling when at first you got a fish. You better to try it out. Patience is virtue!

GP Joran Coal Fired Power Plant 2008

Today our management doing another event in station. GP Joran Coal Fired Power Plant 2008! This is only internal events for our staff and not open to the public.

I will post the photo on this event later. More information will be update soon. Don't forget to come back again...

Band Screen Vega Radar Level Transmitter Trending

I have posting before the new type change of this Vega Hydrostatic Level Transmitter. The current trending is using the old type which often make trouble. As you can see as per photo below, the reading quite hunting.

This problem only occured when the sea water level at low tide. At the high tight, no problem and the reading is quite stable. I am not so sure why it's behaviour like this. Already change a few times, but nothing change especially when the sea level at the low tide. Now, I have call Vega personal already and asked them to install a new type Vega Radar Level Transmitter. The result should be better.

Conductivity Analyser High Alarm Operated at The Generator Panel

High alarm operated. Permit issued to check probe and termination at panel. Service and tighten termination then get reading 0.13 μS/cm. High alarm reset (>0.20 μS/cm). Conductivity range is 0.00 – 1.00 μs/cm. I already list out in the purchasing for next order. You can check the thing here before together with ABB products.

Condenser Hotwell Conductivity Sensor
Manufacturer: ABB 2085-4085
Specification: K = 0.1

Change New Type Bandscreen Level Transmitter

The old type hydrostatic level transmitter cause few pump trips and need to be change as possible. From the photo below you can see that barnacles growth on the probe itself. Then we change to new Vega Radar Level Transmitter.



The Old Type Of Vega Hydrostatic Level Transmitter



The New Type of Vega Radar Level Transmitter

Bandscreen is water intake screen at the pump house.

Wet Coal Cause Bunker Level Transmitter Fluctuate

The bunkers level start problem when bunkering with new coal. The situation seems that the problem occurred due to dust extraction filters too dirty which are covered with wet coal. Therefore the dust extraction filters have been cleaned and serviced by coal and ash maintenance team. After that bunkers level reading back to normal.

I am suspected that hot coaling had caused condensation in bunkers atmosphere and make dust inside the bunker becomes wet. When dust extraction does not function efficiently, wet coal dust accumulates at the bunker level transmitter. On Instrument side, temporary solution for the time being is to service and clean the level transmitter very often.

ECP Flow Switch Already Delivered Today

If you remember my previous post about this flow switch, the stock already zero at our store. At the moment the ECP Flowtech flow switch give a lot of problem to us.

10 New Pieces ECP Flowtech Flow Switch Delivery in a Box

The root cause of the problem it is always broken or the spring easily drop off because of the chlorine which we know that it's create corrosion. We got 10 pieces. Anyway need to modify to 2.5 inch and put some weightage at the end of the rod. The project to change to the new non-contact sensor still in progress. Will update later.

WTP ACID DAY TANK LEVEL MAGNETIC SWITCH FAULTY

Acid Day Tank Level Magnetic Switch faulty today as per photo below. Need to replace with the new. Try to get the original specification from the switch itself but nothing was found. Except it's brand Jola.

Need to get a new brand from local supplier and easy to purchase. Anyway, we still have three spares at the store before everything finish and have the time to manage.

Microrec Alarm Came Back

Last week, we already attended the Microrec alarm defect but the alarm came again on last Saturday morning.

- Protection Fault 01MAY10EU249XC8

- Calculated Trip Test Fault 01MAY10EU276XC9

- Protection Test Fault 01MAY10EU281XC9

As we are aware the fault alarms were triggered during the microrec self test (every 24 hours) which involved the opening and closing of all the dump valves. Therefore it is very likely that the fault has to do with the speed of valve opening and closing or open and close switches make contact.

Look like it requires adjustment on the dump valves during outage to permanently clear the alarms.

My suggestion: While the unit is still in service we will reset the alarm before valve freedom test.

Washdown Water Sump Level Switch

Washdown Water Sump Level Switch
09ETK90CL010 & CL011 TT4

Defect – Operator called to check Low Level Alarm cannot be reset and High Level Alarm not activate. This will caused pump can’t cut in to pump water from drain pit. The reason to drain water is to allow mechanical team clear sludge from pit.

Check at local simulate both signal for Low and High Level for pump cut in. After all water cleared normalize back simulation. Inform operator to monitor again water level after mechanical team clear the sludge.

New Project Flow Switch at Electrochlorination Plant

Remember when I posted about the flow switch before? Now we have a new project to change all the old flow switch type which give us a lot of problem at the electrochlorination plant. The reason why this old type switch need to be change is because our ECP always tripped when the flow switch is broken. The new project actually to change the contact probe to non-contact which might increase the reliabilty of the plant process. I put here some photo for your review.



There are two vendors promoting their product for testing, Vega and Endress Hauser. Both already installed their products and the testing result will be after 1 months installation.

ABB Water Analyser Urgently Required

Below is the list for the spares that need urgently reorder today;

Chloride PCB Assembly ABB 8234
ABB 8230-130

Chloride Electrode ABB 8234
ABB 8234-150

Silica Magnetic Stirrer Bar- Mixer Block ABB 8241
ABB 0217-321

Silica Drain Pinch Valve ABB 8241
ABB 0234-021

Silica Photocell Housing Assembly Measuring ABB 8241
ABB 8241-158

Silica Temperature Sensor Assy. For Reaction Block ABB 8241
ABB 8240-124

Silica Pump Motor Assembly 50HZ-Terminated ABB 8241
ABB 8240-103

Silica 2-Stream Out-Put Board ABB 8241
ABB 8240-265

Spare Replacement Conductivity Transmitter ABB 4620
ABB 4620-500

DO2 Dissolved Oxygen Sensor
ABB 9435-300

Sodium Electrode Cable Assembly ABB 8037
ABB 1431-875

Condenser Hotwell Conductivity Sensor
Specification: K=0.1
ABB 2085-405

All of this spares are zero stock at our store and urgently required.

Bunker Level Transmitter Faulty

Unit No.1 Bunker 20

Unit No.2 Bunker 60 and 70

Remove bunker level transmitter and found transmitter detector dirty with wet coal dust. Service and clean then install back to bunker. Reading under monitoring by maintanance team. Picture attached for reference. As per maintanance team suspect dust extraction not working as well.

Fault Alarm at Microrec Appeared

Turbine Protection Alarm activated last night. After the checking, here we found that;

- Protection Fault 01MAY10EU249XC8

- Calculated Trip Test Fault 01MAY10EU276XC9

- Protection Test Fault 01MAY10EU281XC9

At microrec, a lot of logics need becarefully check since the software history itself given much trouble to unit.

Discussed in detail among us this morning examining the risks in re-setting this alarm and the conclusion reached is minimal risk, to be extra careful should be carried out at low loads and after evening peak.

More detail: the protection listed above has a self checking routine usually every 12/24 hours, this sequence has hung up on detection of some parameter not giving expected results and requires re-setting. If not re-set valve freedom tests cannot be carried out. It is expected that the fault will re-appear within 12/24 hours ideally the fault should be re-set just before valve freedom tests. Clearing the defect requires detailed investigation with the unit off load.

Here is some short cut step when we clearing the alarm (Many steps are not reveal here);

1) BO4Y010P CON#302 f0r to '0'

2) PO4GNTRT #Safeties_Set force to '0' then unforce back the logic.

3) BO4Y31SE SEQ12*700 from state '11' back to '0'.

Work done.

Feed Water Tank Pressure Transmitter Bar Absolute

This morning I got another email complaint on our instrumentation field device about Feedwater Tank Pressure Transmitter:

"I have been highlighting the Unit 1 Feedwater Tank Pressure Transmitters (01LAA11CP501A/B/C) since December 25^th. The transmitters should read Bars Absolute but have been set to Bars Gauge. This means that the FWT Pressure Control operates at 2.7 barg (3.7 bar abs) instead of 1.7 barg (2.7 bar abs).

Please use this opportunity to correct this defect."

Actually it was already 5 years the pressure transmitter range mode in bar gauge for all three unit in our Coal Fired Power Plant and nobody highlighted this issue before. The original range is 0 to 15 bars gauge. Then when to change to absolute mode the range become -1.013 to 13.987 bars absolute. Job done and the reading left as 1.4 bars absolute as per mimic picture.

RTDs Converter

Related to the previous problem at the Turbine Generator, we find no spares to replace the faulty converter module. The picture and the specification of the RTDs Converter Module as below:



Related article to view:
U3 Generator Stator Terminal Connection RTDs

Unit No.3 Generator Stator Terminal Connection RTDs

I got this email last week;

During the unit 3 trip on Saturday 29^th December, it was noted that one of the Stator terminal connection point cooling water RTD devices 03MKA11CT611 went off scale, returning to normal about 5-6 hours later. Also, all of the time 03MKA11CT612 was sitting at zero. See attached trend.

While it might look as if the behavior of CT611 is genuine (not fluctuating or spiking), the Alstom Generator expert doesn’t believe that it can genuinely go that high after the generator tripped.

I took the opportunity myself to check the actual loop connections at the DCS and Generator (mA & RTD side of the transducers at the generator marshalling box) – all appear OK.

Could you ask someone to check the RTDs by direct measurement and the RTD-mA transducers by simulation, just to prove that they are working OK.

Also, if you get the chance, the RTD for Stator outlet winding temperature 03MKA11CT505 has been sat at 73-74 degC for the last few weeks without changing.

It would be preferable to do these checks before Unit 3 comes back on load, hopefully within the next day or 2.

Many thanks for your help in advance.

Here is our finding to that problem:

03MKA11CT505 ( Reading high at DCS )

Number cable	Number cable	Result ( Ω )
1	3	113.9
1	2	114

INPUT ( Ω ) OUTPUT ( mA )

mA	Reading at DCS	Reading at DCS
4	0	0
8	38	40
12	79	80
16	118	119
20	159	159

Remark Status

1. Check RTD resistant OK

2. Inject mA at DCS OK

3. Check mA at converter card reading 11.36mA converter card

after disconnect cable at converter card reading still 11.36mA faulty.

03MKA11CT611

Number cable	Number cable	Result ( Ω )
1	3	115.5
1	2	115.4

A	Reading at DCS	Reading at DCS
4	0.8	0.8
8	40.5	40.5
12	79.9	79.9
16	119.9	119.9
20	159.7	159.7

Remark Status

1. Check RTD resistant OK

2. Inject mA at DCS OK

3. Check mA at converter card reading 7.69mA OK

03MKA11CT612 ( Reading at DCS bad Q )

Number cable	Number cable	Result ( Ω )
1	3	113.9
1	2	113.8

A	Reading at DCS	Reading at DCS
4	0.2	0.2
8	39	39
12	78.4	78.4
16	119.6	119.6
20	159.04	159.04

Remark Status

1. Check RTD resistant OK

2. Inject mA at DCS OK

3. Check mA at converter card reading 3.5mA reading converter card

at output converter card low faulty.

Water Analyser QUZ Cabin

Purpose of the Water Analyser System in Coal Fired Power Plant

● To ensure that steam and water are of a consistently high quality, they are sampled and chemically analysed at several points in the steam water cycle to monitor their quality. The information from the analyses is used by the operator to control the chemical dosing system.

● To detect a circulating water leakage in the tube sheets of the condenser. The steam and water chemical sampling equipment is designed to condition samples of feed water, boiler water and steam, by reducing the pressure and temperature of the samples to a suitable level such that their chemical composition may be determined by the appropriate dedicated analysers.

Waltron Sodium Analyser 9001 Series

Three people from Centrionics Sdn Bhd came to my office yesterday and claimed that they are local Waltron representative for this product in Malaysia. The reason why they are here is to promote their product and hopefully will be used in our Coal Fired Power Station. I enclosed here their proposal and specification for you to review.

Waltron sodium Analyser Proposal
Waltron sodium Analyser Specification

Since we have problem on Rosemount Sodium Analyser at Water Treatment Plant and the unit not available for a long time, more than 3 agents had came to promote their products to solve the problem. Anyway, I ask them to give us full quotation and their proposal should be completed properly before submitting to management level to be reviewed.

Electrochlorination Plant (ECP) Flow Switch

Called by operation to check ECP no.1 flow switch failed at stream A. From operation feedback, ECP No 1 tripped on no flow on stream A. Operation tried putting ECP No 1 in service early morning today. It could be the following:-

1. Flow switch faulty. Based on our discussion our instrument team (C&I) worked on the flow switch last Saturday.

2. Actual no flow due to wrong isolation, clogging of the inlet pipe, clogging of the outlet pipe.

Permit issued and found switch spring disconnected. Repair the spring and fixing back the switch. Waiting operation to test run. Currently we are lack of this flow switch type and need to reorder. The specification and the photo as below:

Electrochlorination Plant (ECP) Flow Switch

Flotech Flow switch
Model = V8
Supply :125/250 VAC , 5 A
Manufacturer : Dwyer Intruments INC. Michigan City, Indiana, USA

Combustion Air Flow

Even today is Saturday, I am going to my office to finish some paper work which need to be submitted end of next week. Also get bored at home and need to do better things. I am not posting my work for today, but this data or report is contributed by my colleague.

Regarding of the fluctuating right hand side (RHS) combustion air flow, minor leak was found at air inlet continuous air purge. Some action has been taken to clear the defect.

Action taken:

1) Search the leakage using snoopy. Found as per picture above.

2) Tighten all fittings or connections from sensing line to transmitter manifold.

3) Also tighten the leak parts unfortunately the leakage still exist. The only way to do is dismantle the purge air flow regulator seems that the origin fittings of flow regulator doesn't fitted very well with the white tape.

How to Reboot Microrec

First of all, all breakers should be OFF as per sequence below:

1) Upper Level Normal
2) Upper Level Standby
3) Base Level 1
4) Base Level 2
5) Base Level 3
6) Protection

Then follow by ON the breakers by this sequence:

1) Upper Level Normal
2) Base Level 1
3) Base Level 2
4) Base Level 3
5) Protection
6) Upper Level Standby

But remember before you reboot the microrec processor, you must check which upper level normal and upper level standby is active or pursuit (standby) at the time.

Manjung Coal Fired 3X700MW Power Plant

Manjung Coal Fired 3X700MW Power Plant

Project Description :

The Manjung Power Plant, a three-unit, 2100-Megawatt coal-fired power station. Each 700-Megawatt unit consists of a steam generating boiler, high pressure steam turbine with condenser, a generator, other equipment for electrical supplies, and plant controls which incorporate a high degree of automation and safety protection.

The Manjung Plant also features the first triple-flue stack built in the country and also the highest stack in Malaysia at 197 metres. Other key features of this plant include:

· Use of sub-bituminous and bituminous coals with low sulphur grades.

· State-of-the art Pulverised Fuel Firing combustion technology

· Boilers equipped with low-NOx burners.

· Electrostatic Precipitators (ESPs) that can achieve up to 99.9% dust removal.

· A wet-type seawater scrubber Flue Gas Desulphurisation (FGD) system is installed to ensure SOx emissions are within international limits.

· An ash pond around which the Bentonite Cut-off Wall technique is used to contain leachates and prevent any contaminated water from leaking into the surrounding aquatic environment.

The civil construction requirements of the Manjung Power Plant project include 250,000 cubic metres of concrete, 25,000 tonnes of steel reinforcement, a 1.5 kilometre-long offshore cooling intake, a 100-metre long offshore outfall, and 30,000 tonnes of structural steel.

This article take from www.pecd.com.my.

Welcome to My Work Place!

Coal Fired 3X700MW Power Plant

Welcome to my work place! Year 2008 becomes more challenging and there is a lot of thing I have to cover especially gaining experiences in my job career. The idea to create this blog is to share among readers my work experience on the power plant technology especially on instrumentation and process control. At the same time, hopefully this blog can be used as a learning process platform to gain more knowledges. Thanks for visiting and reading this site. Continue enjoy this reading. Any comments and ideas are welcome! I will update more later.