Coolant level controlled fan or shutters

[user removed]

Most of an engines waste is heat.

How about controlling the coolant fan with a coolant level sensor-actuator.

Basically a float that tells you what the level of coolant is in the recovery bottle and maintains that level with shutters and the normal cooling fan, mostly electric.

Shutters to get it hotter and the fan when it needs to be cooler. Inflatable grille block for air flow regulation, too cold blow them up, too hot deflate them.

Simple cheap and easy.

regards
Mech

[mechman600]

The coolant level in the recovery bottle is determined by the coolant temp. As the coolant warms up and expands, it starts to fill the bottle proportional to temperature.

You propose to indirectly measure temperature by the level in the recovery bottle. In order for this to work, the cooling system must have a precise amount of coolant in it. Any change in coolant quantity will throw the temp calibration out. Wouldn't it make more sense to measure the temperature directly like they do already? It would be easy to take a LM34 sensor, plug it into an Arduino and let the chip to the rest.

[user removed]

No, it would not make more sense to measure coolant in any specific spot, that does not give you the ability to regulate the average temperature of the whole cooling system.

The system I am proposing would maintain the same average temp in the regardless of the ambient temp. In normal systems the temperature of the coolant exiting the radiator changes dramatically and contributes to wintertime MPG losses.

regards
Mech

[Cobb]

How about blocking off the front end of the car for better aero and let the fan do its job when its warm enough? Maybe use the heater setting to help offset the cooling needs?

[user removed]

That was the inflatable grille blocks job.

Restrict air flow to bring the cooling system to the desired AVERAGE temperature. Deflate them when it starts to get too hot, then only add the electric fan after the grille block has deflated for max air flow. Now you are controlling the temperature of the coolant ENTERING the engine after going through the radiator. THAT temp varies greatly depending on ambient temps but this would control the radiator EXIT coolant temperature. Normal thermostats control the coolant temp as it leaves the engine but there is no real control of the temp of the coolant ENTERING the engine.

The hotter the coolant entering the engine the less heat absorbed from the engine, part of why summer mileage is better.

Think of it as varying the size of the radiator to match the ambient temperature.

regards
mech

[RobertISaar]

not sure what kind of terrain you deal with, but this would be quite difficult to impliment around here without some significant signal filtering.....

uphill, downhill, uphill, downhill, uphill with 10,000 unavoidable potholes, left, right, down.......

it's a pain.

what could be done using "dumb" hardware is to setup a resistor/capacitor to smooth out a float signal, which would be used by a schmitt trigger to control whatever you want. setup the RC filter so that it takes an instant movement of the float from minimum to maximum to take(for instant) 60 seconds for the voltage to match reality and it could do well, but it wouldn't take very happily to rapidly changing conditions.

the schmitt trigger is setup to use a hysteresis, so it won't cause the opposite action to happen at the same voltage level, so instead of (for instance) the grill block closing again once the coolant level is at 87.5% of maximum(more instance examples), you could set it up so that it would wait until the level dropped to 50% of maximum.....



of course, using a lot of the same hardware, you could use a temperature sensor instead of a float and control it using that.



for the ultimate in control...... you have to go with some type of logical controller(meaning, writing code), you could go so far as to write some self-learning subroutines and have the controller learn how much grill opening is required to maintain your target temp at various road speeds and ambient air temperatures.

i realize this sounds complicated, but as someone who has written a lot of 6800 assembly, i tend to simplify things that are in reality quite difficult for anyone that has no programming experience.

[yoyoyoda]

You stole my idea you *******!!!

http://ecomodder.com/forum/414485-post31.html
http://ecomodder.com/forum/414487-post33.html

[Cobb]

How about using a blower to make an air curtain like they use at some stores to go across the grill, then it turns off with a reverse relay when cooling is needed so air can go through the grill. Then when its cool again it powers up and the air curtain returns?

[2000mc]

So if you had a small loss of coolant, wouldnt things spiral away?

[RobertISaar]

that is actually a good point.... and certainly the worst failure mode possible.