Fuel cooling - optimal diesel temperature???

[jtanguay]

I can't say exactly what the optimal diesel temp is , but i do know that the temp you want it is below what you want to run WVO.

Yes, we've found that WVO needs to be a minimum of about 180F in order to run well.

but 200+F fuel can't be good for the pump??? a way to regulate temperature would really help with fuel economy and pump longevity.

[clbanman]

The reason for the temp in WVO is to reduce viscosity.  I asked the Detroit Diesel tech at work the question on diesel fuel temps today.  He couldn't give me a definite number but said it should be about room temperature.

[jtanguay]

The reason for the temp in WVO is to reduce viscosity.  I asked the Detroit Diesel tech at work the question on diesel fuel temps today.  He couldn't give me a definite number but said it should be about room temperature.

hmmm seems like not too many people pay attention to fuel temp.

the controller i'm envisioning will be capable of +-1.5C temp range, so the car performs as it should (year round).  it will be able to hold those temps regardless of the outside temp.  i just need to develop circuitry that will not only control it, but something to shut it off in the event that it sucks too much electricity (it will be around 350 watt, and most of the energy will be used when the temp is -0) so this thing will be very quick reacting.  i'm also contemplating a system that will switch modes from 100, 200 and 350 watt in the event of charging system overload (especially TDI's with the glow plug heater, and N/A's with the pewny 50 amp alt)

the system would also have two power inputs.  one would be setup for diesel specific temp (adjustable) and WVO specific temp (adjustable) so you could easily adapt it to work in conjunction with your veggie setup by using the power source to control a relay which in turn controls the mode on the fuel temp controller.

i'm slowly learning about circuitry, so we'll see how far i can get  :lol:

[Sprockets]

Jtanguay:  The circuitry involved here is relatively simple, and I would be more than happy to look over/contribute to your design.  I suddenly have some free time, so my projects have started again!

From your power specs I'm assuming you will be utilising some form of peltier setup? I'll throw a few more ideas out aswell.  Will need a fair area/coverage to actually produce some effect on the temperature delta, perhaps using an OEM based cooler as a platform?  Would need some testing aswell to see what flow rates we are dealing with here to get an efficient design.  Would need two temperature inputs, one of incoming fuel temp and one of outgoing.  Obviously a lot of the factors depending on fuel temp stability extend to how much of a reserve (the fuel tank) you have.

That was just a quick brainstorm, but a very simple microcontroller could be used, or, you could even just go with some simple analog circuitry utilising a couple of comparators.

Just ideas

-Gavin

[AdAm84]

The Duramax diesels use a fuel cooler also. It is located in the return line going back to the tank. This makes sense since the fuel pressures of these common rail set-ups see 20,000+ psi. Just a bit of input if it helps.  

BTW, the DB rotory pumps use an orfice type of vent to regulate the transfer pressure variations caused by viscosity and RPM (if it wasn't regualted the pressure would continue to rise as the RPM's do). The viscosity differences would be caused by temperatures. There is a chart for this but they are in my factory manuals at work.    I will try to get a copy of this if I can.

[jtanguay]

Jtanguay:  The circuitry involved here is relatively simple, and I would be more than happy to look over/contribute to your design.  I suddenly have some free time, so my projects have started again!

From your power specs I'm assuming you will be utilising some form of peltier setup? I'll throw a few more ideas out aswell.  Will need a fair area/coverage to actually produce some effect on the temperature delta, perhaps using an OEM based cooler as a platform?  Would need some testing aswell to see what flow rates we are dealing with here to get an efficient design.  Would need two temperature inputs, one of incoming fuel temp and one of outgoing.  Obviously a lot of the factors depending on fuel temp stability extend to how much of a reserve (the fuel tank) you have.

That was just a quick brainstorm, but a very simple microcontroller could be used, or, you could even just go with some simple analog circuitry utilising a couple of comparators.

Just ideas

-Gavin

sounds good!  the 350 watt peltier junction is ideal for this situation.  i'm considering running the fuel heater/cooler in a closed loop from the fuel tank.  a small solid state fuel pump will ensure about 5-6 psi in the closed loop, so as motor burns the fuel, the pump will introduce more fuel into the loop.  this will lessen the load on the fuel heater/cooler, and also give better cold/hot starts.  if any of you have doubts about this setup... don't.  although i'm not currently running like this, i will be in the future.  a friend of mine is running like this, and he's never had better cold starting, and running.  come summertime the fuel will get too hot though, and thats where the fuel cooling function will really come in handy  

i've been thinking of using resistors to limit the current draw.  the problem is finding some that are economically priced.  the resistor on the rad fan would make a good candidate for testing,  but it is a little bit expensive... i have found some resettable fuses which would handle the load, and 'pop' if the peltier sucked too much power, and then it automatically resets itself, very cool!

i think a big problem will be getting a big enough heatsink without making the unit so big it won't fit anywhere  :lol:

i'd really like to go with a valve system that would send fuel through a heatsink to cool it, but electronic valves are so expensive, and very prone to breaking...

please get a copy of the viscosity differences caused by temps chart if you can AdAm84

[DA-BRT]

I suggest that you first find out what temerpature of your fuel is at the moment.

Perhaps it's a good idea to use a custom heater with one or 2 glowplugs. There are enough fuel coolers I think (haven't looked into that.

I got a 12v digital temperature controller with relay output. You can set the temperature where you want to switch the magnetic valve (2/3-way) and this way you can cool or heat the fuel. Also turn on the heaters when then the relay is switched.