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Thinking more of the is it a cooler or a heater???
Depending on the temperature of the excess fuel as it leaves the high pressure pump, as it enters the cooler/heater it is at least cooled/heated to engine coolant temperature 70 odd degrees as the coolant lines come from the bottom of the radiator, then back to the tank.
At rest the fuel in the tank can't get any hotter than ambient surrounding air temperature so there is no risk of high flash point, not that it is a problem with diesel fuel.
Same thing happened to mine about 5 years ago, a blade of grass took out the plastic coolant hose. Got rid of cooler and ALL plastic lines and replaced with rubber fuel hose (and fitted a fuel filter with built in hand primer). Beautiful.
Its a fuel cooler, its purpose/reasons on any common rail diesel is (in the most basic explanation):
*Diesel engine power will be typically measured at fuel temperatures of 50 C (deg C), the higher the diesel fuel temp, the less density it has, less density, less power.
*A typical common rail diesel on the high pressure side of the fuel system will be around 30,000psi, high operating pressures cause excessive heated diesel.
*Diesel fuel is also used to cool (and lubricate) fuel system components, so the fuel also acts as a heat sink (heat exchange).
*Most common rail fuel systems have a high volume of fuel going through the fuel circuit, aprox 80% of fuel delivered to the engine goes back to the tank via the return line.
*The fuel cooler (heat exchanger) is what removes excess heat from the return diesel fuel, airflow also aids heat dispersion.
*The coolant lines connected to the fuel cooler, or rather the "Heat exchanger" are not at that coolant temperature of 80 - 90 deg C, but (like a lot of the cooling system) are typically round 50 deg C.
*The coolant removes excess heat from the heat exchanger.
*The cooled return diesel fuel can be round 40 deg C.
*The cooled return diesel fuel temperature will be closer to that of the fuel in the tank.
*The less differential between return diesel fuel and whats in the tank reduces the possibility of condensation.
*Cooler diesel fuel improves efficiency in combustion and reduces emissions.
*Cooler fuel in the tank reduces overall tank temperatures, with reduced radiated heat through the body.
Often what seems a basic component with a simple purpose has quite a complicated role with many factors taken into account. This is where mechanical engineers really are worth their wait in gold.
Less worth is the person/engineer that missed such basic items as making a TD5 fan belt that 5mm longer to add installation etc etc...
Hope that helps..
Regards
Daz
It helps prevent condensate in your fuel tank aswell, common rails don't like even the slightest bit of water!
After 11 days with the courier, my fuel cooler cover and steering guard have arrived and been fitted. Quality of design/materials/precision of the APT Fabrication products is of the highest standard: as a grumpy Fitter/Welder this is hard won praise!
As a side note, on removal of the OE steering protection bar I found that the two outside securing stays were full of rather noxious black water. I would recommend a couple of small drain holes to anyone staying with the standard setup.
Anyhow, hopefully it will be a while before I have another of these Photo Opportunities.
Rich.
The OE steering guard is rubbish and always full of that black water.Quote:
Originally Posted by FV1601
All APT Fabrications gear I have seen and fitted have always been well made and nicely finished. The APT Steering Guard is another good bit of kit.
Regards
Daz
I think the black water is factory fitted, had it in week. 1
Fitted the APT fuel cooler guard yesterday & it fits a treat. Only problem is my floor creeper seems to have grown bigger wheels, as it was a little tight underneath - probably should have jacked the front & put some axle stands in place. Or could have just been Christmas, New Year & Australia Day, only Chinese New Year to pass & I can get back to skinny!:D