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Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

(OP)
Maybe this type of thing is already on the market...if not, I may be providing for free the description of a patentable product - in which case I'm copyrighting it here and now! [big smile]

Thumbnail sketch: piezo-electric transducers - connected using low-thermal-conductivity piping - are hooked up to each cylinder of a reciprocating engine, and used to provide instantaneous pressure values at one-millisecond intervals or other suitable time scale to an appropriate display screen, on the Y axis. If desired, different trace colors can be used for multiple cylinders simultaneously.

A rotary encoder is used to provide a degree displacement 0-359° for use in developing and tracing the position of the pistons. The angular displacement would be plugged into a formula using crank throw and connecting rod length, and TDC would be specified for each piston as being at yay degrees of encoder displacement. The derived positions for each piston would be displayed on the X axis.

Purpose would be to provide real-time engine performance data as an index to valve timing adjustments by way of an on-the-fly "indicator diagram."

Let the ridicule begin...smile

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

Before you start your "patent search" may I suggest that you look at what might be under way at universities since I can't help but think that something like this wouldn't have already come onto the 'radar screen' of a group doing internal combustion research. For example, while the level of detail in the description referenced below, some of what is mentioned does have a vague resemblance to what you've suggested, is not complete, there are references to the lead researchers involved so you could follow-up is you wish. Anyway, on the page below, in the section labeled "Ongoing Projects", I would suggest that you expand the item titled "Sensor Evaluation and Fusion for Closed Loop Combustion Control (CLCC) for SI Engines" and see if this might be relevant:

http://www.mtu.edu/mechanical/research/thrusts/aps...

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

(OP)
Thanks, John; had a boo, looks like a worthwhile night shift website... smile

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

We did that in the engine development lab I in worked in 40 years ago. Not real time and we only cared about the interval between +/-90 degrees from firing TDC. Data acquisition consisted of a CRT oscilloscope and a Polaroid camera. I'm sure all the engine manufactures have very sophisticated data acquisition packages these days. No need for it in production vehicles once you have it all mapped out.

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

(OP)
But as a real-time operating aid for multi-cylinder steam engines with continually manually adjusted non-automatic valve timing...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

I have been around both permanent and test bed system from Kistler for medium speed marine and EPG engines, https://www.kistler.com/?type=669&fid=7&mo...
Kistler also makes a spark plug pressure sensor that has been used in development of some of the larger CAT/Mak gas engines.

A company in Holland called Sensata provides their CPOS sensor that is also used on some medium speed engines.

A company called Optrand is recently pushing a fiber optic cylinder pressure transducer to help reduce costs, haven't actually seen one yet but was recently reading up on it.

ABB has the Cylmate system, mainly for larger engines but have heard they are starting to look at some of the medium speed market as well.

Not sure if these would apply to steam engines but they seem to becoming more common on larger diesel engines.

Hope that helps, MikeL.

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

We use Kistlers all the time on the dynos. You can't use them for the full life of the engine, they aren't robust enough, and are far too expensive.

A more robust solution would be a load cell under the cylinder head bolt.

Cheers

Greg Locock


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RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

Funny, I've been on a few vessels with Kistlers full time monitoring system and the crew was pretty happy with them,

https://www.kistler.com/us/en/applications/automot...

I know they make several different sensors, CAT has used them in the test cells at the Tech Center and in Kiel.

Maybe for larger engines a better fit, I've never dealt with cylinder pressure monitoring in engines less than about 4500 bhp.

MikeL.

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

(OP)
Thanks, all; query popped into my mind because if all goes well will be riding the SS Badger across Lake Michigan next week. Vessel has Skinner compound unaflow steam engines, the cut-off and lead of which are both manually adjusted as part of engine operation, and I may have a chance to ask the Chief Engineer by what means the correct/proper/optimal valve lead adjustment is achieved.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

given it was +4 decades back, in my undergraduate,
I worked on a graduate's project where my responsiblity was to provide an instaniuos pressure/rotation plot (scope displayed).

The project was interesting but never saw where it was devolped: using cylinder tangental air injection to reduce wall quench and stratified charge

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

crshears,

I remember back in college a very long time ago, watching a PV diagram of a GM six cylinder engine on an oscilloscope. This was all part of their dynamometer kit.

--
JHG

RE: Reciprocating Engine "Indicating" System - Does Such A Beast Exist?

(OP)
Turns out they're not really all that interested/concerned...thanks for all the responses, though; plus, you never know where something may lead...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

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