Arduino-based GUI for active grille block

[Piwoslaw]

Originally Posted by CigaR007

I have been observing the coolant temperature for the past few days. With the shutters SHUT, at constant speeds, as soon as the coolant temp reaches 95-96C, it stabilizes and gradually drops to 91C. The cycle repeats every 5 minutes or so.

This leads me to consider that the Radiator fan is running on low speed and the trigger temp seems to be around 96C.

This is a good example why knowing when the radiator fan is ON is useful.

That does seem correct. My turbodiesel's fan turns on at 98C and off when the temp drops below 90 or 91C.
The fan goes into 2nd stage, or high, if the coolant temp rises above 104C, iirc.

Ecodriving goal: Drive so efficiently that the engine does not waste enough energy to heat up to 96C.

[CigaR007]

Question then becomes : which of the following has a higher penalty ? The aero drag with shutters half-open or the increased electrical load to power the Rad Fan at low speed ?

Considering the vehicle has no alternator, the engine load might not change much given that the Hybrid DC-DC converter ultimately provides the power through the small 12V battery...

Soon enough, with colder temperatures, the coolant will probably not reach 95-96C.

[CigaR007]

Considering the Electric Fan turns ON (low speed) earlier than expected (96C), I modified the logic circuit to accommodate that.

I don't know how much power the radiator fan consumes on low speed.

I think the fan circuit is on a 30A fuse.

So theoretical electrical load would be 12.6V x 30A = 378 Watts on full speed. Not sure, but Low speed could be half that, so around 190 Watts.

I would assume the aero drag would be higher than 190 Watts with shutters 50 % open.

Keeping shutters SHUT and allowing the fan to run on low speed might be more efficient, but the trade-off would be increased wear and tear on the fan motor. Which is why I considered an approach that allows a more gradual cooling.

Trigger points :

Below 90C : shutters SHUT
Above 90C : shutters open @ 25 %
Above 93C : shutters open @ 50 %
Above 96C : shutters open @ 100 %
Fans ON : shutters open @ 100 %

[Logic]

[QUOTE=CigaR007;697639]
Trigger points :

Below 90C : shutters SHUT
Above 90C : shutters open @ 25 %
Above 93C : shutters open @ 50 %
Above 96C : shutters open @ 100 %
Fans ON : shutters open @ 100 %
/QUOTE]

Cant argue with that er... logic.

Any plans to expand this to be able to control the temperatures at wich the fan/s come on at their various speeds?
Control other stuff like alternator on/off, aircon pump off during acceleration etc?

[CigaR007]

Originally Posted by Logic

Any plans to expand this to be able to control the temperatures at wich the fan/s come on at their various speeds?

You mean to change the actual trigger temperature commanded by the ECU/PCM to trigger the Fan relays ?

Originally Posted by Logic

Control other stuff like alternator on/off, aircon pump off during acceleration etc?

Highly unlikely given the complexity. There is no alternator, just a DC-DC converter that powers the accessories and maintains the 12V battery charged. It's probably pretty efficient as-is (>90%).

[CigaR007]

Been working on a PCB for the logic controller. I am using an open-source software called KiCAD to build the electronic circuit. Once the circuit is created, there is an option to create a PCB. Pictures below show the rendered PCB with the components. Looks promising when the design will be finalized after the testing phase.

[Logic]

Originally Posted by CigaR007

You mean to change the actual trigger temperature commanded by the ECU/PCM to trigger the Fan relays ?

Possibility? But not necessarily.
I'm out of my depth here and just wondering if your system is expandable to control more of cars cooling system/s and if you are thinking in that direction?

Originally Posted by CigaR007

Highly unlikely given the complexity. There is no alternator, just a DC-DC converter that powers the accessories and maintains the 12V battery charged. It's probably pretty efficient as-is (>90%).

Ah; a hybrid.
(Is the 12v battery also Lithium?)