Keel cooling design for electric inboard

[yabert]

28:00 there's brass radiator raw water cooled .

Sadly, I can't see this video in Canada.
Do you have another link or screen shot of this brass radiator.

 

[montero]

It's difficult . I paste Chinese version of great movie "Murphy's War " Due copy rights I can't find full movie at YT .
You can watch this movie somewhere. At 0:28 scene there's brass radiator. Great movie btw.

 

[montero]

Inside system fouling can be low, provided the sealed system is protected from corrosion, and kept clean.
Sea water side fouling can be covering a wide range of values, and neglected cleaning can lead to this thermal resistance becoming dominant. I have seen outside surface fouling more than several inches thick on ships well overdue for drydocking, virtually destroying any chance of adequate cooling. Of course, your situation can be well controlled with manual cleaning.

Primitive idea of cooling radiator by raw water looks nice .

How do you and others guys think of efficiency water spray cooled radiator ? I know this way was used in motor sport for intercoolers . Vaporisation heat seems to be big.

 

[gonzo]

With salt water it will be fouled in minutes.

 

[yabert]

think of efficiency water spray cooled radiator ?

I'm actually really happy with all I learn here and the fact I can build brass cooler for less than 100$.
Sound to me like the best way to go to cool down my electric motors.

 

[montero]

With salt water it will be fouled in minutes.

For fresh water use it seems to be interesting .
For salt water use it depend of kind of radiator , kind of nozzles . Honestly it tempting me to make some experiments . Easiet way is use a car without thermostat.

 

[montero]

Do you guys have knowledge about brass radiator build ? Are all of them cooper/brass radiators ?

 

[montero]

Brass vs. Bronze; Know your Underwater Alloys – Editorial: Boat Show Season is Upon us Once More | Steve D'Antonio Marine Consulting https://stevedmarineconsulting.com/know-your-underwater-alloys/

 

[yabert]

Brass vs. Bronze

Man! Based on this article, my plan to use brass underwater is bad.
Brass 272 tube contain at least 35% zinc and that will disappear under water...fu*k!!!
Everywhere it's possible to read that brass 272 have good corrosion resistance. I bet that exclude salt water.

Well, back to SS and his poor conductivity. I've even think another time about aluminum (good conductivity, cheap) with an anode. Why not?

 

[yabert]

More information about brass in salt water (not good for my plan to use brass 272 tube):

 

[yabert]

I think I've find a really effective and low cost solution.
A simple flush 1/8'' copper plate at the exterior and two 1/2 NPT 90° brass fitting weld on the copper plate to allow flow of coolant.

I really like the small copper area and the cooler flush to the hull.
But I'm a bit worried about the fact that cooler is hold in place with sealant. Well, sealant on copper and I can hold the cooler with some mechanism inside the hull (pic 3 and 4).
Any thought?

 

[Heimfried]

[...]
But I'm a bit worried about the fact that cooler is hold in place with sealant. Well, sealant on copper and I can hold the cooler with some mechanism inside the hull (pic 3 and 4).
Any thought?

You pay too much attention to the heat conductivity of the metals and apparently don't notice the bottleneck of heat transfer you are creating with this sealing. It has to have some thickness to compensate different thermal expansion of the metal components and is a bad heat conductor. What you most need is area of heat exchange. Area is the key!

 

[yabert]

bottleneck of heat transfer you are creating with this sealing... is a bad heat conductor

Sure, I understand.
Sealant is between hull and cooler, but don't interfere with heat transfer in my designs.
The sealant is only around the coper plate (blue line) to seal water ingress. Brass fitting are weld on the copper plate, so the heat transfer is good (but, I admit, quite small).

 

[gonzo]

I think you are getting a simple system and making it very complicated.

 

[yabert]

I think you are getting a simple system and making it very complicated.

And it's really sad as I'm huge fan of K.I.S.S.
But in this situation, this solution seem more simple than typical saltwater + heat exchanger + dual pumps.
My point is to find the most reliable solution instead of the most simple.

It's maybe my lack of ''marine'' experiment, but I don't see how to design a simple and reliable cooler out of copper pipe.