Wouldn't it be cool...

[jviss]

...if one had a refrigeration unit dedicated to blowing cold air into the alternator, onto the regulator, and in general, cooling the engine compartment? A/C for the engine compartment. It would only run when the engine is run, so no battery drain. Expensive, yes, but, oh, so cool! (Pun intended.)

 

[PaulK]

Aren't they (and the engine) designed to operate at higher temperatures because they are close to the engine? What would be the point?

 

[jviss]

Aren't they (and the engine) designed to operate at higher temperatures because they are close to the engine? What would be the point?

1. the alternator's "rated" output is determined primarily by its temperature. If you want to pull lots of Amps, you must keep it cool;
2. the regulator should be kept cool, for similar reasons;
3. things will generally run better and last longer if they run cooler.

 

[dlochner]

Mount the regulator outside of the engine compartment, that will address the cooling it.

Keeping the alternator cooler will allow it to generate higher currents for longer time periods, however the electrical cost of cooling may limit the benefit. The cooling system will be battling the engine heat generation and the cool air will be consumed by the engine.

The best bang for your buck for alternator cooling may be to have a the air flow for the engine combustion drawn in over the alternator. The engine consumes a lot of air and that air flow would cool the alternator a few degrees.

 

[rgranger]

The best bang for your buck for alternator cooling may be to have a the air flow for the engine combustion drawn in over the alternator. The engine consumes a lot of air and that air flow would cool the alternator a few degrees.

That makes too much sense

 

[jviss]

That makes too much sense

Well, that's what is essentially happening anyway, as the diesel sucks enormous amounts of air, and as it flows into the engine compartment the alternator fan will suck some of it through the alternator. But, it won't be "fridge cool."

 

[Justin_NSA]

If I remember correctly, the integrated regulator on my '99 Cadillac was water cooled.

 

[Maine Sail]

If you want the alternator to run cool rip out the internal rectifier and build an external rectifier..That's how I ran my alternator for 10+ years. Otherwise fit large frame alt and run it at a current limited output.

 

[jviss]

If you want the alternator to run cool rip out the internal rectifier and build an external rectifier..That's how I ran my alternator for 10+ years. Otherwise fit large frame alt and run it at a current limited output.

That's a great idea! What inspired you to do that? How did you mount the external rectifiers?

 

[dlochner]

Well, that's what is essentially happening anyway, as the diesel sucks enormous amounts of air, and as it flows into the engine compartment the alternator fan will suck some of it through the alternator. But, it won't be "fridge cool."

Depends on where the air enters the engine compartment. On my boat most of the air enters at the bottom aft end of the engine, away from alternator. The alternator will produce about 60 amps at 60°C for long periods of time which is about .3C. The regulator is temp compensated for the battery and alternator.

 

[Maine Sail]

That's a great idea! What inspired you to do that? How did you mount the external rectifiers?

In an aluminum box with a heat-sink and fan

 

[dlochner]

How many years do the alternators in your cars and trucks last and they run in a much hotter environment than your boat you may not think so but it's true a boat is over top of water a car engine is over top a very hot Pavement in the middle of the summer this temperatures can reach over 200° I think not that I've measured

The demands on an auto alternator are much lower than the demands on a boat's alternator. An externally regulated high amperage alternator may be called upon to run for hours at high amperage to charge a deeply discharged battery. An auto alternator only needs to supply a limited about of current to recharge the batter after starting and to run lights and other electrical devices on the car.

The engine compartment of a car is a well ventilated area, the engine compartments of most boats are not.

 

[Maine Sail]

How many years do the alternators in your cars and trucks last and they run in a much hotter environment than your boat you may not think so but it's true a boat is over top of water a car engine is over top a very hot Pavement in the middle of the summer this temperatures can reach over 200° I think not that I've measured

The stockalternator on my truck is 150A. With everything running the most my truck can pull is about 30A.. On a boat with a big bank or LifePo4 the batteries can accept way more than the alt can deliver thus they cook themselves and die

 

[SBO Police Bot]

Reminder; If you don't have anything nice to say please keep your fingers off the keyboard.

 

[Stu Jackson]

Reminder; If you don't have anything nice to say please keep your fingers off the keyboard.

Is this warning directed for the original post OR to who those of us who would "attempt" to point out the foolishness of the concept to begin with?

 

[jviss]

Teslas use the AC and heat to cool or heat the batteries as necessary when charging or discharging. I don't think it's so crazy to cool air you're blowing on the alternator to keep it cool so it doesn't fry when you're, for example, charging a big LiFePo4 bank. Maybe a liquid cooled alternator is in our future.

 

[dlochner]

Teslas use the AC and heat to cool or heat the batteries as necessary when charging or discharging. I don't think it's so crazy to cool air you're blowing on the alternator to keep it cool so it doesn't fry when you're, for example, charging a big LiFePo4 bank. Maybe a liquid cooled alternator is in our future.

Cooling batteries is much easier than and more practical than cooling alternators.

 

[jviss]

Cooling batteries is much easier than and more practical than cooling alternators.

O.K., but I can't imagine how or why. The Tesla battery cooling scheme is quite complex. I'm just suggesting blowing cooler air into the alternator, i.e., chilling the air it would normally ingest by virtue of its fan.

 

[jaysweet]

Teslas use the AC and heat to cool or heat the batteries as necessary when charging or discharging. I don't think it's so crazy to cool air you're blowing on the alternator to keep it cool so it doesn't fry when you're, for example, charging a big LiFePo4 bank. Maybe a liquid cooled alternator is in our future.

I haven't thought it all out, but I strongly suspect this would amount to creating energy out of nothing. If you diverted cooler room air over the alternator, or cool sea water through some sort of heat exchanger, then sure, no problem. I can see that you might be able to get more energy out of the cooler alternator than you used to cool it.

But on the other hand, if you take electrical power generated by the alternator (you'd certainly want to assume you weren't using previously stored power to run the AC), used it to power an air conditioner, and then used the output of that AC to cool the alternator, I'm pretty sure you couldn't generate as much extra power from the now cooler alternator as you had to expend to run the AC. If you could, I think you might just have invented a perpetual motion machine, essentially. Free energy from nowhere.

Although on second thought, I may be confusing things if it's not that the cooler alternator produces more energy. Maybe it's just that the voltage regulator adjusts to cause the alternator to produce less energy to avoid physically damaging the alternator.

Similarly, electric cars cool the batteries so that the batteries don't get damaged from the heat. In that case, it only has to do with prolonging battery life. (I have a Bolt and a Volt.)

 

[jviss]

Although on second thought, I may be confusing things if it's not that the cooler alternator produces more energy.

The most you're going to use to cool is about 5A, but that's going to potentially allow you to drive many more Amps from the alternator, since its output without burning up is dependent on its temperature. Not a perpetual motion machine, the power is coming from the diesel!