Gas Turbine

[Wolskis]

The row 3 shroud blocks on these .05 machines can eat up some time to remove. Apparently these blocks warp over time and this is typical. When I left at 1800 five blocks remained.

 

[Wolskis]

The craft are pulling with a come along and pushing with an air gun and sometimes with a hydraulic ram.

 

[Wolskis]

Repairs made from post 28. I'm good with this. Notice the number of studs? I did when seeing the HRSG under construction.
Twenty five years ago they were twice or more apart. This area sees the highest velocity and this can rattel the plates like a tarp over a trailer going down the freeway at 80mph. The plates will get ripped out and thrown against the tube bundle. I've seen them turned into the shape of a basketball.
Oh, and the insulation underneath gets sucked out and cloggs the SCR and CO catalyst.
Studs close together = good. Very impressed with the boilermakers. Three day repair and 15k. All is good in the HRSG world.

 

[Wolskis]

This 135T crane is acting up again. It gets a mind of it's own with a load on. Not good. It's been pulled and a 35T is in it's place. But we need it back in play by Sunday evening for the turbine upper half lift. Plan B is a bigger crane stationed on the opposite side.

 

[Wolskis]

Steam pipe

 

[Wolskis]

This was 1500 yesterday. Half the stage 3 buckets to remove. The tarp is to catch the pins.

 

[Wolskis]

Cold weather ops for us starts in September. We go thru a checklist of items, salt, shovels, kerosene for the heaters, extension cords, etc. Insulation is the biggie. Specifically related to instrumentation.
I mentioned in the thread related to the power issues Texas went thru that instrument failures play a hugh role.
I was pleasantly surprised to find the heat trace at this plant is designed to 15 degrees F.
These are O'Brien boxes, they contain 1 or 2 pressure or flow transmitters along with a heater. The heater status is brought into the DCS and will alarm. An on duty technician is sent out to correct the issue.

Example of a DCS or distributed control system.

 

[Wolskis]

From the process source, steam for this post, are several isolation valves.
We have a damaged heat trace cable. This needs another layer of insulation then the cable. Not a priority during this outage plus spring is around the corner.

 

[Wolskis]

We call the black hose the "Anaconda". Each are custom made to length and contain 3/8" SS tubing, insulation and heat trace. It gets connected at the source and lands at the instrument.

 

[Wolskis]

Building out the shaft. Stage 3 buckets were installed last night. Now installing stage 1.

 

[Wolskis]

Placing stage 2 buckets. Build out will continue tonight. Upper cover goes on Monday afternoon

 

[Wolskis]

Build out of the upper turbine cover.

 

[Wolskis]

3rd stage nozzle seals on the shaft.

 

[Wolskis]

Random

 

[Wolskis]

All buckets installed.

 

[Wolskis]

Upper half cover built out.

 

[Wolskis]

About 80% of the HGP parts that will be sent off for repair. Our next unit will have the same inspection this November.

used parts

youtube.com

 

[Wolskis]

Access to the turbine is now restricted. FME (foreign material exclusion) zones setup.

 

[Wolskis]

Received permission to the turbine deck. Here row 2 nozzle segment install.

 

[Wolskis]

At the 22 second mark watch for an object fall between his legs. This is a seal strip.

 

[Wolskis]

Craft is waist deep in the nozzle cavity. Took 15 minutes.

 

[Wolskis]

Getting ready for a 0600 startup on unit 2 and the steam turbine around 1000.

 

[Wolskis]

To much going on at the gas turbine to get in the way. Tonight they will roll the upper half on it's side and clean the matting surface. Plan is to land the upper half tonight or tomorrow. Then build out the combustion section. Transition pieces, liners, cans and nozzles.

 

[Wolskis]

Let's walk thru the steam turbine building. 3 videos

 

[Wolskis]

A little longer

 

[Wolskis]

Better walk around. Hearing protection required. About 95db.

 

[Wolskis]

This combined cycle plant thru the boiler creates 3 primary steam pressures and 1 secondary. The highest is the main steam (MS) at 2200 psig, hot reheat (HRH) at 600 psig and low pressure (LP) at 100 psig.

This morning one half of the plant started up, 1 gas turbine (GT) and the steam turbine (ST). All systems are a go, the operator will press the GT start button, it will accelerate to 650 rpm and hold that speed for 20 minutes. This requirement by code exchanges 3 times the boiler volume pushing out any possible combustible gases. Because this speed is too fast for combustion the control system will slow the speed to about 200 rpm, at this point the GT will again accelerate. At 550’ish rpm’s the ignitor’s will turn on and gas valves open, within seconds of that the flame scanners must detect UV light in 4 combustion cans or the GT will stop. It will now continue up to 3600 rpms. The breaker will close once it sync’s to the grid and the operator selects a load set point of 110mw. The GT will continue to the set point at 12mw per minute.

The GT is now in environmental air compliance. The heat input will cascade thru the boiler. As each section of tubes start to absorb this heat, steam is created. At this time all ST admission valves are closed. This steam is considered wet or saturated steam. The ST needs dry or superheated steam. Water in the steam impacting metal will cause severe damage.

To make this happen the steam flows will take various paths. MS steam (black line) exits the boiler and comes to the HP bypass valve which is open and drops the pressure to 600 psig, this steam enters the cold reheat (CRH) (blue) piping system and heads back to the boiler. The CRH meets up with the intermediate steam (IP) (green) and enters the boiler again to pick up more heat. This HRH steam (purple) still at 600 psig heads to the ST but because it’s wet will be bypassed to the condenser. Turned back into water and reused. The low pressure steam (LP) (red) takes it’s own path to the condenser for the same reason.

When superheated steam is reached the operator will make selections on the control system. As the ST admission valves open the HP, HRH and LP bypass valves close. Startup is now complete. A lot more is going on but this is the basic.

 

[Wolskis]

Cover is on

 

[Wolskis]

Combustion can build continues.

 

[Wolskis]

Looking into the chamber. You can see the 1st stage nozzles at the bottom.

 

[Wolskis]

Liners going in

 

[Racey]

Random
View attachment 984125 View attachment 984126 View attachment 984127 View attachment 984128

One of my very good friend's company specializes in manufacturing many of the internals for the T-56 turbines used by the C-130 Hercules and also a lot in smaller scale industrial power generation, oil rigs etc. They make many of the interals including all of the turbine section blades as well as the compressor side blades. Those motors are obviously much much smaller, but the parts are very similar in their assembly and design.

Their machine shop is pretty insane, 5 axis grinding machines to cut those dovetail joints, wire and sinker edm for the cooling ports and expansion joints. Crazy expensive parts, when you see how they are made from the specialized casting processes all the way through the machining and 100% NDT on every piece it makes a lot more sense why they are so damn expensive to rebuild

 

[Wolskis]

Steam exits the steam turbine under a vacuum down this pipe and up the risers. This structure is a big radiator and these fans are pulling in ambient air to change the steam to water.

 

[Wolskis]

One of my very good friend's company specializes in manufacturing many of the internals for the T-56 turbines used by the C-130 Hercules and also a lot in smaller scale industrial power generation, oil rigs etc. They make many of the interals including all of the turbine section blades as well as the compressor side blades. Those motors are obviously much much smaller, but the parts are very similar in their assembly and design.

Their machine shop is pretty insane, 5 axis grinding machines to cut those dovetail joints, wire and sinker edm for the cooling ports and expansion joints. Crazy expensive parts, when you see how they are made from the specialized casting processes all the way through the machining and 100% NDT on every piece it makes a lot more sense why they are so damn expensive to rebuild

Gas turbines are cool machines. From the micro up to the frame units. At the time I worked for Calpine they purchased PSM which were I believe ex pratt engineers. I had the chance to visit their FL office. The 3-D modeling was just insane. To watch the modeling of a combustion can flame and how a 2 pound change of gas pressure effects flame stability had me hooked. The metallurgy and coatings have allowed the continuous growth in power output.

 

[Wolskis]

Seven cans to install along with air piping. Wind is picking up tonight which could delay the roof install.

 

[Wolskis]

1 more can after this. This one fits into #13 hole. Plans are to finish #14 and then move the crane to the opposite side before dark. Night shift will lift the front half of the roof on before the wind picks up around 0200 Friday morning. GE's lift plan has 20mph wind as the stopping point for all lifts. This could delay the completion by 2 shifts.

 

[Wolskis]

These were take during night shifts

 

[Wolskis]

Roof sections set last night just prior to the wind strom. Now it's re-term all electrical & instruments. Install piping and apply the insulation. Start up scheduled for Monday at noon.

 

[Wolskis]

Converting steam to water with ambient air

 

[Wolskis]

What we call Mechanically Complete. No open holes. Insulators come in tomorrow and do their thing.

 

[Wolskis]

Push the go button Monday at 1130 for breaker close at noon