> From: Dana Linscott <[EMAIL PROTECTED]>
> Reply-To: biofuel@yahoogroups.com
> Date: Tue, 11 Dec 2001 07:46:15 -0800 (PST)
> To: biofuel@yahoogroups.com
> Subject: Re: [biofuel] SVO/WVO conversion - VEG-Therm-
>
>
> Thanks Ed,
>
> I was hoping you would join in as I consider you our
> resident SVO expert.
>
> I am forming the opinion from the studies I have seen
> that an optimum system (for maximum engine life) would
> warm the SVO to 170*C but coolant in engines only gets
> up to about 170*F. At 170*F SVO is approx. the
> viscosity of diesel at 10*C...I think. Would it be
> possible AND a good idea to warm the SVO further via
> electric heaters to closer to that optimum temperature
> e.g. 170*C? I realize this would require high temp
> components "downline" of such a heater and wonder if
> an electric heater could be applied to the metal fuel
> line between the injector pump and the injectors. I
> can't imagine the injectors would not be able to take
> the higher temp. but you would likely be more
> qualified to make that call.
Dana - I have seen a lot of different "optimum" temperatures for SVO in
varous studies, and these range from 70¼C to 300¼C (!).
It depends on the engine type (DI or IDI) and the fuel (type of vegoil) to
some extent, but in general DI engines, it seems, really should have higher
temps, or thinner fuel blends than is required for IDI engines. That's why I
posted on the idea of ethanol blending with SVO a few times. That brought
the required temp. (in that study, on that DI engine, on rapeseed oil), down
from 150¼C to 80¼C. and also gave significant further particulate emissions
reductions compared to rapeseed oil alone, already quite a bit lower than
petrodiesel.
So as we see wider availability of fuel grade ethanol, that will be
interesting to follow since it coincides with wider use of DI engines.
Steve mentioned a number of times the role of biodiesel as start/stop fuel
and its solvent effect being beneficial in keeping deposits under control
and I agree with that. If I am not using biodiesel, I personally use the
premium diesel (in winter, for example) as start/stop fuel to get the
benefit of the extra additives (Shell Ultra, is what I normally use), since
that's what is available locally).
I think that the Tessol-NADI product we are now making, blended @ 10% or so
in the diesel fuel, may also be useful for this purpose (blending into
regular diesel start/stop fuel), and will reduce the emissions of the
cold-start-on-diesel phase, the high emissions stage on all engines.
So despite its higher cost, as an additive for this purpose it may be of
interest in SVO systems if biodiesel is not locally available for blending
in with the diesel in winter or use @ B100 in warm weather.
I think that trying to heat SVO to the high temperatures you mention might
lead to other problems, amperage draw being the greatest problem certainly.
>
> This may only be needed for DI engines as I also
> understand that indirect injection engines are able to
> warm the SVO enough after injection in the prechamber
> to avoid deposit accumulation.
The IDI engine provides for better mixing and combustion, bascially
compensating for the higher viscosity of SVO relative to diesel fuel, even
SVO heated to the usual ~70¼C.
Unfortunately more and
> more DI engines seem to be manufactured and fewer
> vehicles are available with DI as time progresses. I
> would like to broaden the choice of vehicles for those
> that wish to convert to SVO and especially with
> computer controlled DI the only way to cope would seem
> to be to match the SVO viscosity to diesel as closely
> as possible. What is your opinion? Would this be
> redundant/overkill on a indirect inj. engine?
Yes it would be overkill. IDI engines do not need the same tactics and
temperatures as DI, and especially computer controlled DI which requires the
most effort and cost for SVO use and about which there is the most debate
re: longer term use of SVO. We still advise against use of SVO in DI engines
and especially computer controlled DI, the computer can't deal with even
slight changes in viscosity. Since these engines are cleaner in the first
place, my opinion is that we want to focus for right now on the millions of
older IDI engines that will be in use for decades , and offer affordable
systems and devices for those first.
>
> As I first posted a perfect conversion would use "off
> the shelf" components as much as possible and I am
> very glad that Neoteric Fuels is able to provide many
> of them. I am very interested in the heater available
> from Neoteric and also felt that the do it yourself
> heaters I mentioned seem pretty crude in
> comparison...but I am trying to bring together ALL the
> info I can to provide a complete overview. I have seen
> one reference to a fuel heater that is essentially a
> length of metal pipe with a positive electrical
> connection on one end and a ground on the other.
> Current was run through this heating the length of
> pipe in between via elec. resistance. The fuel being
> run through the section of pipe is warmed as it passes
> through. Temperature is controlled by a probe on the
> end of the pipe where fuel comes out. Seemed very
> simple/reliable but couldn't find it as an off the
> shelf component. Is this similar to the fuel heater
> Neoteric sells?
No. Ours is not an on/off resistance heater. It varys output (and therefore
amperage draw) according to sensed SVO temperature, to a maximum of 70¼C in
current form, for flow rates typical up to 4-5 cylinder engines. As the fuel
is warmed by recirculation back to the tank, hose in hose, reduced flow rate
(idling), etc., the amperage varies. It was designed with an assumed inlet
temp. of 25¼C (the "warm day" approach), and this was quite deliberate - to
keep the amperage within reason. At max. it will draw ~ 30 amps. So if you
want to do more than that with electric, you have to start beefing up
everything else. So, not a good thing to go too high on the amperage demands
on a VW, Mercedes, etc., you have to strike a balance.
The heater as designed is meant for sole use in warm climates on IDI
engines, and with additional glycol heating of other pre-heating of the SVO
to that ~ 25¼C inlet temp. to be used as booster heater for SVO use in
colder climate systems. We therfore also use it in our basic SVO $299 "warm
climate" system, and use it along with HIH and tank loop in our $399 "colder
climate" system.
(The heater was designed to come as close to our requirements as possible
by a specialist PhD working in applications of this type of heater, BTW, and
he advised on what could be achieved on 12 and a pre-determined max. of ~
30 amps.).
Higher flow rates on a V8 with a load of gravel coincide with greater
alternator output, and we have used two in series successfully for that
application. On the Ford F250 (1988, 7.3 Navistar), which has a well
developed HIH on it, the SVO temp was running about 60-65¼C most of the time
(sender located near the injection pump) on HIH only, and now runs ~ 80¼C
with the HIH plus the two -in -series VEG-Therms, so in this case I think
the heater is compensating for heat loss from the HIH system as fuel exits
the HIH, passes through the filter, etc. It might also be a high reading
(instrument error), yet to be determined - we are working on getting more
accurate readings on this.
>
> If not what is the max. temp Neoterics' fuel heater
> can achieve?
Spec. on it is 70¼C max.
>
> Has anyone considered running an electrical resistance
> wire down the inside of the fuel/return lines? Kind of
> a simpler version of the pipe within a pipe concept.
> Low voltage/wattage? This could be used to warm the
> fuel enough to allow it to reach around 70*F so it
> would flow easily and thereby not strain either the
> injector pump or alternator.
A good HIH is the best for frequent temperatures that run well below
freezing. With good tubing and fitting that are up to the task and good
assembly, no problems. Do not use cheap tubing, I have heard of a few
cracking stories when guys used cheap stuff. Make sure it is overspec for
the temps. and fluids it will be exposed to.
The SVO would then flow
> through a small under hood tank where its temperature
> would be boosted to coolant temp. and then pass
> directly to the fuel pump via a solenoid valve.
The small heat exchanger I mentioned before would be best for simple
underhood glycol heat exchange, then also use electric, if we are dealing
with temperatures well below freezing and no HIH.
> Connections could be made on this tank for a vacuum
> gauge, a temp. probe, and a vent(for air purging w/ a
> vacuum source).
> What is your opinion Ed? If you have not tried this
> are you open to a collaboration?
We return lines to tank to purge any air, no loops. Also use 6-port valves
for ease of use. A small amount of cross-fuel ( a bit of SVO in diesel and
vice versa) has not caused any problems. Temp sender and vacuum connections
are easily done with tees.
>
> Thanks for your input.
> Dana
>
Thanks for the opportunity to discuss.
Edward Beggs
www.biofuels.ca
> snip
>
> __________________________________________________
> Do You Yahoo!?
> Check out Yahoo! Shopping and Yahoo! Auctions for all of
> your unique holiday gifts! Buy at http://shopping.yahoo.com
> or bid at http://auctions.yahoo.com
>
>
> Biofuel at Journey to Forever:
> http://journeytoforever.org/biofuel.html
> Please do NOT send "unsubscribe" messages to the list address.
> To unsubscribe, send an email to:
> [EMAIL PROTECTED]
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
------------------------ Yahoo! Groups Sponsor ---------------------~-->
Tiny Wireless Camera under $80!
Order Now! FREE VCR Commander!
Click Here - Only 1 Day Left!
http://us.click.yahoo.com/75YKVC/7.PDAA/ySSFAA/FGYolB/TM
---------------------------------------------------------------------~->
Biofuel at Journey to Forever:
http://journeytoforever.org/biofuel.html
Please do NOT send "unsubscribe" messages to the list address.
To unsubscribe, send an email to:
[EMAIL PROTECTED]
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
