Engine running on passage

Diesel engines

Hi,
Most diesel engines have a watchkeeping panel, especially with regards to Lub. oil to prevent a catastophic failure.
Carbon build up is common in manifolds during low load running, due to gas byepass from the pistons,as they are not at their correct operating temp. due to expansion.Low load running can be seen normally by exhaust gases from the funnel/exhaust system being of an oily nature.
The Royal Navy have normally 4 generators onboard, 2 online....split switchboard( for normal/alternative power supplys)which we need during a war situation.Often was the case that these gen sets would operate underloaded, so we used to try and switch on as much equipment as possible, reducing exhaust scatter temperatures.
In harbour I would regularly get a load barge alongside,and load up the diesels..to 110% overload,checking governer stability,response and droop.
This would clear all carbon deposits and reduce exhaust temps. dramaticlly.
Bill

Hi,

Thanks for the info.

I didn't question the provision of basic Safety Systems ( Lube Pressure, Temp, Water Temp)on the engines merely questioned the optional features like remote level monitoring.

I understand the carbon fouling of the exhaust side of things during light load running .It was the build up of carbon in the Inlet Manifold as stated in your post that I was after more info about.

Diesels

Hi,

Sorry to confuse,but during my time overhauling diesels,Paxman,CAT,MTU,Crossley Pielsticks,it was evident of carbon build up of both exhaust and inlet manifold,,,,heavy carbon deposits around the valve guide area also.I would just like to add my engineering experience to others on this forum,because i feel this is a great website and would like to be involved in it.Diesels are old hat these days...play with a gas turbine, or water jet...more fun!!!!
Cheers Bill

Hi, people.

Bill Arthur, are You serious ?
1." Carbon build up is common in manifolds during low load running, due to gas byepass from the pistons,as they are not at their correct operating temp. due to expansion."
???????????????????????????????

2." Low load running can be seen normally by exhaust gases from the funnel/exhaust system being of an oily nature."
???????????????????????????????

3. "it was evident of carbon build up of both exhaust and inlet manifold,,,,heavy carbon deposits around the valve guide area also."

I think, this sentence explains a lot...., especially how oil can get into oil in inlet manifold.

A few questions:

1. Was crankcase ventilation ok ?
2. Have You ever performed "comb. chamber leak test" ?
3. Was oil level ok ? (May be higher than max. ?)
4. Some engines have a turbo, which is lubricated and cooled by system oil, so, there are some oil seals in turbos...
5. What was ER ambient pressure ?
6. Your engines running MGO/MDO or HFO ?
7. Piston rings were ok ? Liners ovality was in range ?
8. What were rhrs since last overhaul ?

Interesting, interesting .....

rgds,

Andrei

Diesels

Sir,
All I was trying to do on this forum was to express my experience with diesels.....I was never looking for an argument..I was just expressing my own experience.Diesels in the Royal Naval world are kept at their optimum maintenance periods,which is often overlooked in the civilian sector.

Regards
Bill

Diesels

Dear Estonia Person.
The diesels I was refering to were gen sets 1mw/4mw not main engines.Ran on mil spec dieso.Please if you want to give me grief get your termanoligy correct,ER ambient pressure??? for god sakes.....Ambient is a temperature related subject!! Not pressure

Bill

service

Bill,
Please dont be discouraged. Keep contributing. As a shore side service company I have little experience with the day to day maintenance. The information and expierence you have to share invaluable. Keep it coming.

Northern lights

Hi,

I came on this website to try an be a mentor to junior engineers/sailors.
I do not need people trying to get the better of me, or trying to be cool or smart.I would just like to pass on the knowledge,If people dont like it, then I wont waste my time.

Regards,

Bill

Hi Bill and welcome to YF,

I don't think Andrei was taking exception with you, but merely trying to understand more. If you check his profile, you will find he is interested in all things mechanical and specifically diesels. We can all learn from each other and this is the purpose of a forum... collective knowledge.

If you share information, experience or knowledge on YF, be prepared to answer some questions. People come here to learn and provide help to others. There's nothing personal intended when someone questions a statement.

Context

Hiya,

Ok I`m new to this forum, and i would just like to add my engineering marine knowlegde I`m not a commercial mariner, but see things in the Armed forces context, which commercial marine have copied for years.So please I`m not trying to be funny,just trying to inform the guys of what my experiences are.
Anybody needs info on Rolls-Royce /GE Turbines please ask me.

Regards

Bill

Hi,

I've got no wish to argue.

Sorry for "AMBIENT"... English is not my mother tongue.
Will learn it ... Thank You.

Regarding diesels...

Of course, every experience is appreciated.

But,
Statement, that "carbon builds up in inlet manifold due to low load" is very strange and unexplainable. And confusing for others as well.

Mostly carbon build up in air receiver occurs due to:

1. Oil leakages in turbo / mechanical blowers (if any).
2. Valve guides / valves are worn down.
3. Worn down liners.
4. Compression / oil scraping rings are worn down.
5. Exhaust passage is not clean / straight.
6. Valves are not tight enough.

Regarding "cleaning" of engine by running it 110 %:
1. Yes, I agree, that exhaust temperatures will be lower after that. Carbon will burn away. I also had to do this in some emergency cases.
But, if it has to be done from time to time, then the reason is not a low load (if running on MDO/MGO).
Normally the reason is a "not complete burning process".
This can be caused by many factors...
Injection, dirty air cooler, dirty turbo (nozzle ring, blades),
Intake air temperature, engine construction, etc...
2. This is a dangerous action. I have seen connecting rods coming out of crankcase...

Kindest regards,

Your dear Estonian friend

P.S. Peace ?...

My dear estonian friend

Your knowledge of diesels is obviously outstanding.
But depending on the ship/engine room conditions,state of maintenance,then all diesels have a different history.My last project had 4 crossley pielsticks,which never had been turned over for a year,and had 2 siezed blowers.And a pakistani workforce trying to take crank deflections,raft heights while we were still on the hardstand(synchro lift).
Keep the faith...starting to like you...LOL

Kind regards

Bill

Diesels

Sir,
During setting to work of a diesel gen set,normally 1meg,we had to test it to 110% overload.This was due to it was a warship and needed this capability.Obviously on the load bank we tested governor response,stability,droop factor,power factor etc.
The need to test it to 110% was the fact on a warship we need this capability, having many auto change over switches to keep our operating capacity to the full during any warfare action.Yes i have seen con rods coming out of crankcases and tappets burying themselves in the rocker covers,

Bill

Ok, seems like peace !

Yes, 110 % is used at every engine's delivery by means of load bank or water breaker.
And some "smartest" Class Surveyer may request such testings within a Special Survey (Class Survey)...
Uffff... hate this...

rgds,

Andrei











rgds,

Andrei

Hi,

Both terms-Ambient Temperature and Pressure do exist.

I think what TSI AV was trying to get accross is the importance of having a positive pressurised engine room to ensure that there is sufficient air for the stoichiometric combustion process to be completed.

Ambient

Hi,

Oooops,
Thought so...

Looks like my English is not so bad ....

rgds,

Andrei

110 % overload

Bill Arthur,
Is the post on load testing accurate. 110% overload or was the machine run at 110%. Was it diesel or turbine. I witnessed, but was not apart of a load test that the load bank operator took a 48 KW machine to 100% overload for about an hour. The machine was stamped 90KW, but when the machine was fit up and wired single phase the installer did not derate the KW for the application. A 90 KW 480/240 three phase machine derates to 48 KW in a single phase wiring configuration. The electrical end caught on fire. Short duration fire, but fire was coming from the windings. The mismatch of the electrical end to the hp allowed this to occur. Normally you take a machine much above 130% and it stalls the diesel and or it bogs down. The interesting thing about a generator is that I can get 100KW out of a 5KW end if I can keep the winding cooled and I have enough HP.

Spread the Knowledge

Hi,

I would from my own personal experience say that the load factor whilst being referred to as 110% that the load is actually only 10% over the maximum continuous rating of the machine.