Cylinder Data

I managed to shoot a picture today while running the compressor in MN.

These pictures were at about 70% torque, with a very lean mixture, RPM @ 330 and ignition timing 10 BTDC

Interesting data. Jim

You can see the differences in cylinder pressures and the time of the peak, this is mostly due to inconsistencies in mixture. The computer can balance the pressures by making differences in individual injectors, I do not know if it did before this picture. The turbo was producing about 16 PSI

This is the lean burn with pre combustion chambers, AFR runs about 38:1, or almost twice stoichiometric.

That is really a lean mixture. What is the efficiency? Whhat part of the cycle is the fuel injected?

Let's build me a car that runs on 38:1 !

What brand and type of pressure pickups are being used to feed the information to the controller?

Rich

The pressure transmitters are made by Kistler, I have attached a link.

Each building has gas and flame detectors, the safety system will de-energize the building and close gas valves to the building and vent to atmosphere. If the building does not show safe within five minutes the valves will close to block off and vent the entire site. I really feel safe in them, do not think there have been any issues in the buildings that have the upgraded safety systems. All personnel in the buildings must wear fire retardant clothes (FRC) when gas is present.

There is a compressor station about every 50-100 miles along a pipeline. This site has a total of about 20,000 horsepower available for compression, other sites can be up to 100,000 total. This engine is 4000 HP, with is about average for the recips, the largest one I have worked in is 10,000 HP. JD D does work on the turbines, they can easily go many times larger.

This engine had the turbo sizing issues, the new one was too big. The old turbo was put back on for the winter, it looks like about 50 degrees out is the limit for it, so the new one will need corrected and installed before spring. The engine needs more air now because we are running it much leaner to reduce the NOx.
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What is the peak firing pressure for this engine?

Enjoy your post. Spent 27 years in a compressor station.

Didn't think to zoom into the picture

Great info. My day job is weed control contractor. We do weed control work up and down pipelines from Memphis. I have always been in awe of the big recips (piston engines) that I have seen at places like Texas Gas and Trunkline.
Question:It seemed like ten or more years ago some of the pipelines were installing turbine engines, but they rarely ran them. How do the recips compare to the turbines as far as fuel efficiency, power, and service life? Seems to me that some of the big recips date back to the 40's and still run 24-7.

Hey Blue

We had a turbine sta. that had two large GE units (Auburn, Al.) which they said were not very efficient but they could move some gas. One unit could pump into the other, both were centrifugal compressors. This sta was built in the late 1960s.

In 2002 company started a lot of compressor sta additions. Most were electric recep. The contractor that came to our location said it was odd that he was installing an electric unit because the last few jobs he did was pulling out electric and installing turbines. Ours was a 7000 hp electric. Auburn sta got a 18000 hp so did others on the system.

It all comes down to epa standards. We had 5 engines that were installed in 1953, Clark hba-5t that were not required to meet epa standards.

With compressor sta automation so common now how easy to start an engine is an important consideration also. Try to get five 1953 anything's to crank and shut down flawlessly day after day can be a challenge.

The recips are much more efficient and versatile than the turbines, but the turbines are so compact and low maintenance. A centrifugal compressor has a very narrow operating range of differential pressure and flow.

It is a trade off.

Do the engines run on the gas that is being compressed or other fuel?

Our engines ran on natural gas. We had a
fuel gas building that took it from line
pressure to 150 psi and also passed thru a
meter. At each engine it was cut from 150
to 30 psi. Engine would run at top speed of
300 rpm on about 10 or 12 psi.

Other stations may have used a different
pressure. Engines can be different as well
as fuel systems on similar engines.