possibility of running an AVA2 on hfo

[jcover_ja]

I have the opportunity of getting a Petter AVA2 that needs a bit of fixing but I don't want to get it if I can't convert the engine to run on 250 cst Heavy fuel oil (HFO).
I work on a diesel power plant that uses HFO so I have an idea of the difficulties of using this fuel.

I know for a fact that the HFO has to be heated to around 120-135C to obtain a viscosity of 16-6 cts  for the power plant engine to run properly and not blow out the injection pump seals. At these high temp how would the AVA2 injection pump and injector handle these temp and how difficult would it be to change any rubber seals to viton.

All of this is to try and get cheaper electricity because the utility rate here in jamaica is over $0.16/kwh US and if this works I would try scale up to 12Kw generator sets to try and sell.

[compig]

I could be wrong but I don't think that the pump or injector on that engine have any rubber seals. Would be useful to ask a diesel injection specialist if that temperature would bother the pump otherwise.

[jcover_ja]

I just did some number crunch and based on the following figures converting there engine to run on HFO is pretty vaible.

Now these figure are based in Jamaican currency

$1 us = $90 jd

Current electrical rate : $19/kwh min
HFO price: $36/liter
HFO energy content 130,500 btu/gal (36.4mj/l)
Engine consumption (2pv-14): 169 - 172 grams/hp-hour (226.6 g/kwh or 9308 btu/kwh)
Generator Efficiency: 85%

What all this works out to is around $10/kwh (fuel cost) to run these engines. with the low natural low maintenance cost of the engines I suspect actual run cost would be around $12-13/kwh with is over 30% cost under the current utility rate.


This prove that this is some thing to look into for a Jamaican economy

[prof.blink]

jcover, a cust of mine burned heavy furnace oil in a M/B 300d by cutting w/2oil. the inj pump was wrecked in less than 6 mos. i believe the heavy oils are abrasive if not heated and spun. also the small engs must meter minute amounts w/o using seals on the plunger and barrel. blink

[oliver90owner]

Lister manual says no residual fuels, must be a distillate.  Dino has not changed a lot over the last 70 years.

Regards, RAB

[jcover_ja]

Prof:
Like I said earlier, I will be heating the fuel, this is a most do. I plan on using the engine hot exhaust gas to do this with the aid of a heat exchange.

oliver:
True dino oil hasn't change since the last 70 years but Technology sure has. After passing the fuel through a centrifuge separator I should get fuel that is allot less abrasive. One of most abrasive element in the fuel is aluminum, silicon and water and all of those elements will be significantly reduced by the centrifuge.

No I don't plan on buying a $60,000 us centrifuge just to run a single 8 hp engine but I would buy it to clean the fuel and sell it to clients who I have already sold the engines to.

I just have to make sure the engine can handle the fuel.

[jcover_ja]

Here is the heat exchanger concept to heat he fuel via the exhaust gas

The exhaust gas will first pass through a 3 way divertor valve.

Discharge 1 of the divertor valve well be sent to heat exchange

Discharge 2 will by pass the heat exchange

The heat exchanger consist of a large computer cpu heat sink.

The heat sink is placed in an enclosed that covers all the fins and forms a seal around the edge of the heat sink base, leaving it exposed. This configuration would allow the hot gas to only come in contact with the fins only.

A small reservoir made from a block of aluminum is attached to the heat sink base. In this reservoir the hfo will be heat up to 120-130 along with a temperature probe.

The temperature probe is a seal vesicle with a copper\wax mixture. as it heats up it expands and move a plunger.

The plunger is mechanically connect to the 3 way divertor valve and once the correct temperature is reach the divertor valve will redirect the hot gasses to by pass the heat exchanger. The opposite happen as the probe cools

This action will help regulate the fuel temp

[Doug]

Well a Mico injector and pump for each cylinder will set you back around 250 USD plus shipping ( two of each ).

So its not that expensive if the fuel destroy the parts

[prof.blink]

jcover, a centrifuge minimizes abrasives,it will not eliminate them. it will only buy time. do you have a manufactured centrifuge or a homespun unit? blink

[jcover_ja]

Prof:
Yes is will only buy time but I have to compare the cost of a new pump because the costfor a new one once a year may be insignificant to the cost savings.

Jen:
This is only my first concept for the proptotype. I have to agree that the 3 way is a bit complex.

Regarding soot I plan on using a fuel mill and chemical catalist to reduce it. its dose push up fuel cost but reduces maintanance

[billswan]

yes what is a fuel mill???

Billswan

[jcover_ja]

Billswan
A fuel mill is basically a high shear force mixer used to homogenize the fuel oil. The fact is, HFO consist of carbon chain molecule of varying length, density and viscosity, which can show up as small clomps on the microscopic level. If the clomps are big enough they can some times be hard for the engine to combust especially if it consist primarily of heavy waxes and asphalts. The  Fuel mill brakes ups these clumps in to an evenly distributed mixture with the rest of the HFO allowing for a more complete combustion of the fuel. This results in a more efficient engine with less soot production.

Jen
There are HFO treatments that are used, especially in the shipping industry to improve fuel performance. just do a google search for hfo catalyst or additive and you should find what I'm talking about. We are actually going to start a trial run with the treatments at the power plant that I work at.

[oliver90owner]

Doug,

Well a Mico injector and pump for each cylinder will set you back around 250 USD plus shipping ( two of each ).

Don't forget the injectors will be treated the same way.

Regards, RAB

[mobile_bob]

also don't forget any grit that makes it through the injection system ends up in the cylinder
where it accellerates ring/cylinder wear, and some ends up in the crankcase, where it wears every other
moving part.

back in the 50's cummins ran destructive tests on an engine in the lab
they determine exactly how much dust it took to ruin the engine,, interestingly
it didn't matter how the dust got into the engine, whether through the air intake, added into the
oil or added into the fuel. the result was always the same

so you might wanna factor in a complete engine overhaul on a regular basis, regularity will be established
through empirical means.

fwiw, because the lister/oid has no full flow lubrication filtration the problem will probably be worse than in
an engine that has such filtration.

i think i would want to process that oil as much as i could within economic reason before i did my testing
milling, heating, centrifuge, more heat, followed by a couple stages of filtration oughta get you close?

how does bunker oil compare in price per gallon to pump diesel?

interesting project though, look forward to how it works out for you
bob g

[jcover_ja]

Hi Bob

Bunker C oil is roughly half the prices of regular automotive diesel so in Jamaica diesel is $2.93/gal and HFO is $1.49/gal ($us)

You have to realize that My diesel engine at the power plant burns buncker c fuel and the injector pumps have lasted over 5 years now. The injection pumps are actually made by Bosch with cobalt plungers and if you look at the picture bellow the the unit on the power plant generator have a similar design to the one on the lister engine

http://www.flickr.com/photos/44544856@N00/3747746211/

We all know that old Lister engines are significantly over engineered and I hope that this also applies to the injector pumps

One thing that dose concern me regarding the piton and liner is the build up of carbon on the upper edger of the piston walls that can get thick enough to start robing on the liner causing it to become polished. The solution for this in the power plant engine is having a steel ring installed at the top of the cylinder. The ring inner diameter is just smaller than the liner's and it scrapes off the excess carbon from the top of the piston crown keeping is from reaching the the liner wall. Eventually this ring dose wear and has to be replaced but the ring is cheaper than a new liner. I may have to do this modification to the lister.

Another modification to the engine will be to increase the oil sump volume to extend the time between oil changes. Also I have a contact at Exxon Moblie oil company and they a lube oil that is very resilient to contamination for HFO particles. We are talking about a super detergent lube oil.