Trigeneration with frying oil

[beaver faithful]

Hello everybody

I just got hold of a former army group based on a Lombardini LDW3 water-cooled 1503-cylinder diesel engine that trigenerates a 12KW three-phase generator.

For the moment I can only do cogeneration because this engine does not have an exhaust manifold equipped with an exchanger and it is an option that does not exist for this type of engine and from this manufacturer.

My question is the following :

How best to recover the heat that comes out of the exhaust pipe?
For the moment, the group is planned to be installed in a "bunker" for its soundproofing and its exhaust pipe passes through a horizontal stainless steel casing 167 mm in diameter and 15m long before opening into a chimney.
I tried to make short for this first question but I remain at your disposal and thank you in advance for your suggestions.

[beaver faithful]

I see that my subject does not excite much.

Finally I went through all the posts talking about near or far on this subject and I found for about fifty euros a small oil boiler of 22kW.

I will connect the outlet of the group exhaust pipe to the inlet of the old boiler burner.
It will serve me as an exhaust and gas / water exchanger.

Thanks to the passage to the writings of Chatelot16 which allowed me to orient myself towards this solution.

[beaver faithful]

I see that my subject does not excite much.

Finally I went through all the posts talking about near or far on this subject and I found for about fifty euros a small oil boiler of 22kW.

I will connect the outlet of the group exhaust pipe to the inlet of the old boiler burner.
It will serve me as an exhaust and gas / water exchanger.

Thanks to the passage to the writings of Chatelot16 which allowed me to orient myself towards this solution.

[Flytox]

Hello welcome

I just got hold of a former army group based on a Lombardini LDW3 water-cooled 1503-cylinder diesel engine that trigenerates a 12KW three-phase generator.

How powerful is your engine and what does it drive apart from the generator?

For the moment, the group is planned to be installed in a "bunker" for its soundproofing and its exhaust pipe passes through a horizontal stainless steel casing 167 mm in diameter and 15m long before opening into a chimney.

Bigre 15 m + chimney that is a lot (of back pressure). Watch out if you have a leak you're going to suffocate in your bunker.

I see that my subject does not excite much.

Your subject is very interesting but a little double, triple. That's why you didn't get an answer.

The solution of the old boiler as an exchanger / silencer seems to me quite judicious according to the recommendation of Chatelot16.

[beaver faithful]

@flytox
Thank you for your reply.
I'm also worried about the release of combustion gases outside the normal circuit and I bought a CO2 detector in anticipation of the risk. ..
The engine is 22CV and apart from the generator it drives nothing else.
I even planned to remove the water pump and the fan since the cooling water will come from two tanks of 2660l capacity each that I am isolating.

[the boulle]

beautiful project!

for the exhaust, an old oil boiler, yes, or if space is available, make a linear exchanger (like 4 to 6 meters) with 2 coaxial tubes, central tube or pass the burnt gases, between the central and the tube l outside pass water, a simple silencer at the end for noise

pass the cold return (water) through it.

lots of courage, is a beautiful project!

yes, personally I would not remove the water pump

I would make a primary circuit to heat your tanks, in secondary you could draw your calories from the tanks via a circulator when needed ...

umm I'm envious of a beautiful engine like that !! (I look for....)

[chatelot16]

it's a CO detector you need

CO2 detector without interest because it is not toxic and there are everywhere without too much danger

the problem is the same as for any boiler, it is necessary that the draft of the chimney puts all the circuit in depression

when you put a good heat recovery on a boiler you need a fan to make a forced draft, and avoid that the slightest leak lets out of the C0

for an engine exhaust we find ourselves in the same case

for a fan to ensure perfect security it should not be placed at the bottom of the chimney, but rather at the outlet of the chimney to put the entire chimney in depression ... but I don't like the chimney: too complicated

I prefer the outlet by a pipe flush with the ground, and extend the pipes far enough so as not to be bothered by odors: pipes slightly buried

when the heat recovery is effective the buried pipe can be PVC

if all the assembly is of good quality one can do without vacuum cleaner, and be satisfied to often check the tightness: especially the exhaust pipe

the ideal would be to make an exhaust pipe with water cooling as in the big marine engine, that takes part in the recovery of heat, and avoids the overheating of the pipe, thus avoids the leaks ... but on these small engine which are not planned for it is difficult

if there is a certain length of hose between the engine and the recovery boiler it may be useful to make a double hose with water around it ... otherwise the hose rises at high temperature and loses a lot of heat in a few meters

insulating an exhaust pipe is a trap because it overheats even more and prevents you from seeing leaks

put a diameter of pipes much larger than what is usual in engine: rather kind of furnace pipes than exhaust pipes, to avoid pressure loss and risk of leakage

[beaver faithful]

Hello,

Sorry for my mistake, this is a carbon monoxide detector that I ordered!
http://cgi.ebay.fr/RARE-DETECTEUR-MONOX ... 2a28714961

Thank you for your feedback.
I would put photos of my installation as the assembly progressed.

Right now I'm isolating the tanks with recovered foam mattresses (a good ten!).
The foam is glued to the Neoprene.
I fitted my tanks with two 25 m crowns of corrugated stainless steel tube, diameter 20.
The engine will cool directly with the tank water while the upper ring of the tanks is intended to supply the underfloor heating.
The lower ring is designed to be connected to solar thermal panels.
Below the interior of one of my tanks:


Between the inlet of the former oil boiler and the collector outlet there will simply be a flexible hose 30 cm long and 50 mm in diameter which was included in the group supply.
To do this, I will mount the boiler on a mechanically welded chassis so that its inlet is level with respect to the group's manifold outlet and the connection is as short as possible.
It is on that I regret not having an exchanger manifold on this model of engine but I have had practically everything I wanted elsewhere:
speed 1500rpm, water cooling, pump injectors at 140 bars (good for vegetable oil), engine parts followed by the manufacturer so I'm going to be content with that because it's been a while since I've been looking for this type of group.

[Flytox]

I'm also worried about the release of combustion gases outside the normal circuit and I bought a CO2 detector in anticipation of the risk. ..

Good game!

I even planned to delete the water pump and the fan since the cooling water will come from two tanks of 2660l capacity each that I am isolating.

Removing the water pump is dangerous! The engine will make hot spots in the cylinder head and you will screw everything up (cracks / auto-ignition / detonation etc ...). For good performance, the cylinder head temperature must remain well controlled within the original range. The thermosiphon effect it works well only on particularly windy machines / little compressed / often with low consumption.

By cons turn the fan is a good plan, it unnecessarily absorbs in your case a significant power.

[Macro]

The radiator must be removed and replaced by a water-tubular water exchanger. in one part of the exchanger you will pass the LDR in the other you will circulate water to be heated Attention it will be necessary that this water has a temperature lower than that of your LDR if the delta between the cooling water and lDR is important you will be surprised at the size of the exchanger required if the delta is 20 ° ... Well it will take a fairly substantial ...