From: Greg (czechsix@cox.net)
Date: Thu Jul 17 2003 - 20:33:29 PDT
Hi Gene,
Here's an article that might help you out. I found it interesting, even
though I don't really agree with some of the things he says (an engine that
doesn't produce any heat? errrr.........)
But still an interesting article.
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Diesel Power
Ensuring Long-Term Operation of
Diesel Engines and Proper
Fuel Storage
By
Emory Warner
Diesel engines have increasingly become the power plant of choice for
contingency planner. Long term fuel storage and the durability of diesel
engines offer many advantages over other power plants. This article is
intended to aid the contingency planner in proper fuel storage and in the
long term maintenance of the diesel engine.
Diesels differ from other internal-combustion engines in that they do not
use a spark to ignite the fuel-air mixture in the cylinder. The diesel use a
phenomenon known as "heat of compression" which is no more than air at
ambient temperature suddenly compressed to about 4,000 psi. This increases
the air temperature to about 1,500 to 2,000 degrees F., which is hot enough
to ignite a spray of diesel fuel. As such, the diesel fuel has no electrical
system, except for starting the engine and operating accessories. The fuel
is precisely metered into the engine cylinders in turn by an "injection
pump" which controls power by varying the amount of fuel injected.
When a diesel is idling, the engine is using only the amount of fuel
necessary to overcome its own internal friction - so little that idling a
diesel engine to warm it up is usually a fruitless endeavour! It does not
burn enough fuel at idle to produce any heat. The reader may find it
interesting that they most efficient engine ever produced was a General
Motors/EMD Division 1,800 HP stationary engine.
The primary reason that diesel engines are first choice among contingency
planners is the large quantities of diesel fuel may be safely stored for
very long periods with little special treatment or care. Diesel fuel is very
low on volatility: it is difficult to ignite on purpose, and almost
impossible to ignite by accident. We have attempted to ignite a can of
diesel fuel with tracer, API and incendiary rounds to no avail. We found
that it was easier to ignite tyres, than the fuel.
Diesel fuel is no more than #2 fuel oil. The reader may find data to the
contrary, but there is no difference between #2 fuel oil and #2 diesel oil.
The federal government has recently required that oil refineries dye #2
heating fuel oil red, off-road #2 diesel fuel blue-green, and highway use
diesel is left undyed, so that roadside inspectors could determine that
truckers were using fuel on which road taxes were paid. Northeast, oil heat
is fairly widespread and #2 is frequently sold as "home heating oil" or
simply "heating oil". Farming communities will also have access to #2 as the
diesel powered tractor has become standard equipment. When ordering diesel
fuel, blue-green dyed #2 is most often available, designated as "heating oil
or off-road diesel fuel only".
As far as storage is concerned, diesel fuel has two interrelated problems:
water and sludge formation. Water comes essential from two sources -
condensation in the tank and direct absorption from the air. Diesel fuel is
somewhat hygroscopic in that is will absorb moisture directly from the air.
Condensation is best eliminated by locating the storage tank in an area
where temperatures are fairly stable. The best location is a direct burial,
closely followed by an underground vault. The writer's first choice is to
install the tank in a basement or a shed attached to a heated building. The
least favoured choice is outdoors above ground. Even an open shed would, at
least keep the tank from heating by solar effect. In any case, the tank
should be installed with a pressurised vent cap to prevent moisture entrance
and reduce evaporation.
The second problem is sludge. This black gunk is actually anaerobic bacteria
that eats the sulphur in the fuel, and lives in water in the fuel tank.
Quite similar to the bacteria in the septic tank, sludge bacteria will
eventually grow to fill the entire tank, ruining the fuel. There are several
solutions to the sludge problem. First, assure that there is no water in the
fuel tank. Second, treat the fuel with a biocide to kill whatever
sludge-forming bacteria are present. Remember that sludge will not form
without water, so treat the fuel with a moisture remover like Dri-Gas or
methanol.
Always use a fuel filter in the delivery line from the storage tank, and
closely monitor its condition.
The final fuel-related problem with diesel fuel is extreme cold weather
operation. Diesel fuel contains some paraffin wax dissolved in the fuel.
Below 20 degrees F., the wax begins to settle out of the fuel, (the "cloud
point") turning the fuel milky and clogging the fuel filter with wax
crystals. At 0 degrees F., the fuel reaches its "pour point" where it turns
into a Jell-O-Like consistency and stops flowing. Both problems can be
eliminated at the same time by adding a "thinner" to the diesel fuel. Just
add 25 per cent kerosene (paraffin in Queens English) , 10 per cent
gasoline, or a commercial fuel supplement to the tank. Excessive gasoline
will not harm the engine: it just will not run on gasoline.
Engine Operation and Maintenance
Diesel engines do have different operating characteristics than other
internal-combustion engines and must be operated in a different manner for
maximum longevity. A diesel engine will overheat rapidly under heavy load,
and due to its operating characteristics, will overheat more rapidly at l
throttle than at wide open throttle. When operating under full-load
conditions, maintain a close watch on the engine temperature gauge, and do
not overheat the engine beyond 220 degrees F. coolant temperature or severe
engine damage will result. Act quickly to reduce engine load but do not shut
down the engine until coolant temperature returns to normal. Try to cool the
engine as slowly as possible: rapid cooling will also cause engine damage.
Cold weather operation also requires different procedures. Diesel engines
can be very difficult to start in cold weather, and impossible to start if
the wrong fuel is used. Most diesel vehicles and even stationary power
plants often come equipped with electric engine heaters and it is highly
recommended that they be used. In an emergency, thw writer has used a hubcap
filled with burning charcoal under the oil pan of a diesel loader to warm
the engine sufficiently to start.
The principal reason to warm the engine is to allow the starter to spin the
engine quickly enough to start. Most industrial and tractor engines are also
equipped with a compression release to allow the starter to spin the engine
up before the starte has to overcome compression. We highly discourage the
use of starting fluids: the use of starting fluid often causes the engine to
attempt to turn backwards, causing severe engine damage. Follow the engine
manufacturer's recommendations for cold weather operation and starting
procedures.
The operator may also use either #1 fuel (kerosene = paraffin) or even lower
grades of jet fuel in prolonged cold weather operations. Kerosene produces a
cleaner burn, at the expense of slightly reduced power and fuel economy.
Battery and starting system conditions are even more critical in a diesel
vehicle than in a comparable spark-ignition vehicle.
Periodic maintenance of the diesel engine is far simpler than for a spark
ignition engine. There is no ignition system to service, nor any periodic
tune-uo procedure. Engine oil and filters should be changed about twice as
often as for a gasoline engine, and the fuel and air filters changed every
third or fourth oil change. Maintain a close watch on the fuel filter and
water trap, if so equipped. Water in the fuel can cause sludge and rust the
fuel tank, which will destroy the injection pump in short order. Flush and
clean the fuel tank if water shows in the fuel filter.
Emergency Operations
An overlooked advantage of the diesel engine is its ability to run on other
fuels. We have already mentioned kerosene as an alternative fuel: there are
others. The most readily available is commercial cooking oil. Behind ever
restaurant is a large tank of used coooking oil that will readily power a
diesel engine. In 1993, four women drove from coast to coast in a Chevy
diesel van, fuelling it exclusively with sued cooking oil obtained from
restaurants. Soybean oil is another alternate fuel, as is under commercial
investigation as an alternative in high pollution areas. Peanut and
vegetable oils tend to gum in the injection pump, as does animal lard. The
possible advantage of fuelling a diesel with cooking oil is that it does not
smell like a diesel engine: it smells like a fast food restaurant.
Virtually any flammable liquid with a fairly low ignition temprature will
run a diesel engine. Paint thinner, turpentine, tung oil, and varnolene have
all been used with some degree of success. The only fuels that will not work
are gasoline and alcohol. Although highly volatile, gasoline and alcohol
both have a high ignition temperature that is beyond the capability of a
compression-ignition engine. However, either may be mixed with the above in
a maximum of 30 per cent to extend a short fuel supply of correct a jelling
problem. Lower grade jet fuels may also be used, as mentioned under cold
weather operation. JP-4 or JP-5 jet fuels should have a lubricant added to
protect the injection pump. One quart of SAE 30 motor oil added to 200
gallons of jet fuel will be sufficient.
Fuel Storage Methods
Once again very little special preparation is needed to store diesel fuel.
One method that we have used is a series of 55-gallon drums in a storage
shed, using a hand pump to dispense fuel. This is highly cost-effective and
a very flexible method of dual storage. Reconditioned 55-gallon drums are
available just about everywhere for $5 to $15 each, and the more resourceful
can usually scrounge them for free from garages, contractors, paint shops,
and the like. We have not used plastic drums: diesel fuel may attack
plastic, causing the drum to fail. Most fuel-oil suppliers have a minimum
100 gallon delivery, so at least two drums will be necessary. The chief
advantage of the multiple drum system is that each individual drum may be
kept sealed until use, protecting the fuel from both evaporation and
moisture entrance. The disadvantage is that a pump is necessary to dispense
the fuel, unless the planner is adept with a siphon-hose (known colloquially
as a "West Virginia Credit Card"). Drums are also somewhat portable in the
event that the storage location must be abandoned.
The second method is to use a standard fuel storage tank. The standard
residential 275-gallon tank may be found in both horizontal and vertical
models, and cost about $150 or less from a plumbing and heating wholesaler.
Used tanks are frequently available in the area where oil-fired home heating
is used, usually free for the hauling including whatever fuel is in them.
Direct-burial tanks are available in up to 2,000 gallon capacity, and
above-ground skid mounted tanks are also available in capacities from 500 to
1,500 gallons. The most cost effective method (if available) is a multiple
tank system of 275 gallon tanks if the tanks are available on the used
market. As a side note, few if any plumbing and heating contractors want to
deal with the removal and disposal of use fuel tanks. An industrious
individual with a suitable truck could make a fairly decent living removing
and disposing of old fuel tanks, possibly re-selling the better quality
tanks. This is about the dirtiest work available, and pays surprisingly
well.
We should not overlook the most basic storage system: the fuel can. Diesel
fuel cans are colour coded yellow (BLACK in Europe!!) and are widely
available. The writer has use 5-gallon poly kerosene cans for his ready
storage, using metal cans for kerosene only. If only a small amount of fuel
is to be stored, the can system is highly cost-effective. Under no
circumstances use galvanised steel can! The diesel fuel will penetrate the
galvanising, lifting it from the steel and producing metal particles in the
fuel. This will destroy an injection pump in short order.
No matter what method is used, some fuel treatment is in order for long-term
storage. Clean the tank thoroughly, particularly if the tank is a used one.
Be certain to remove any moisture or sludge present. Flush the tank with a
sufficient quantity of kerosene or gasoline to remove any foreign matter.
When filling the tank, add a biocide (frequently sold as sludge remover),
methanol or Dri-Gas to deal with moisture, and a fuel supplement if cold
weather is anticipated. Always use a fuel filter designated for motor fuel
service in the fuel delivery hose. The above items are readily available
from the local farm supply store or your fuel supplier.
Diesel engines are increasingly is use among the well-prepared, for obvious
reasons. The reader should find this article useful is designing an
individual storage system, as well as extending the service life of diesel
powered equipment..
ARTICLE SOURCE:
American Survival Guide, June 1997, pages:- 20, 21 & 90. Author:- Emory
Warner.
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