Closed loop cooling

[drwayne]

54+ twin cat LMT 12S x457+ dreaming 90+mph

closed loop cooling
Water or glycol.. any details/reasons why/not ?

Thanks .. !

[LuckyDuc]

Electric pump circulating denatured alcohol with dry ice pellets added to the tank.

[drwayne]

I want to race this, not drink it. !
Dry ice expands during melt.. a sealed system here, m8.
My 1:1 jetboat has a heat exchanger .. but the practicality of that here is doubtful.

Thx for the thought !
W

[raptor347]

I've seen it done in a big cat with just ice and water. Very effective. Mr. U did a great job with the setup.

[LuckyDuc]

Re: Dy ice and alcohol... If you put a top side vent on the tank the gas can leave through it.

[Fluid]

Dry ice and alcohol risks over-cooling the ESC, causing breakage of parts and epoxy not designed for sub-zero temps. Far better to use ice and water; both have a high specific heat, meaning they absorb a lot of heat over time; both are easily obtained and are not flammable. We don't need or want the ESC and motor to be too cold.



.

[keithbradley]

any details/reasons why/not ?

Thanks .. !

Reason why not?
I don't get why people keep bringing this up.

You're working completely backwards by going to a closed loop system. You have an extremely large supply of cool water, the only reason to circulate the same water is if you were using it to heat something. You're ignoring the one advantage boats have and handicapping yourself.

[Prop-a-Gator]

I too like to contemplate complex, breakthrough water cooling designs but water and ice is still probably best for a closed system. The phase change absorbs a tremendous amount of heat, and you know it's compatible with your cooling components. For SAW purposes on a boat that size, you probably have plenty of room for enough water & ice to last longer than your batteries. Easy enough to replenish between heats if you design for it. No need for any external heat exchanger since your medium will be colder than ambient.

Edit: I understood the OP to be asking about cooling media for a closed loop - not whether or not to use a closed loop system. I presume he has his reasons. (less drag?)

[srislash]

Reason why not?
I don't get why people keep bringing this up.

You're working completely backwards by going to a closed loop system. You have an extremely large supply of cool water, the only reason to circulate the same water is if you were using it to heat something. You're ignoring the one advantage boats have and handicapping yourself.

Keith,the Doc is in Australia and it never drops below 30 degrees celsius. We are lucky in the cooling aspect near the 49th parallel with cool water temps.Granted sometimes too cool(solid).
Shawn

[properchopper]

I've seen it done in a big cat with just ice and water. Very effective. Mr. U did a great job with the setup.

You can see the plastic bottle water resevoir in the back of the boat. Kevin and Gilbert are impeccable builders, and now hold a SAW record with this HPR.

Zi6_0532-1.jpg

[drwayne]

Keith,the Doc is in Australia and it never drops below 30 degrees celsius. We are lucky in the cooling aspect near the 49th parallel with cool water temps.Granted sometimes too cool(solid).
Shawn

Hi.
Im at the 35th ... in what is acknowledged as the driest state of the driest continent on Earth... and I run rc boats.. go figure the sense in that !
My summers range 30->45'c (85-120'f)
However, when days are that hot I tend to stay near the bar frisge

Closed loop cooling, because.. ...
1. cools things when speeds are slow.. esc heat more at partial throttle....
2. when water tempt is high ( +25'c +78'f) , cooling is dar less efficient
3. in 3 years Ive fried 2 esc due pickup blockages
4. I need ballast ( 55+ cat )
5. I thrive on complexity ( Phd Robotics )
6. consistency of water temp.. no high flow then slow flow scenarios .

I already have 6V pumps and water bags ( Sub ballast tanks) etc.
good for 1L/min ( 1Gal in 3.6min )
These shoot water 6' into air from 5/32 pipe.. water pickups dont get that range .. barely 18" at best. !

contemplating 1/2 Gal (2L) closed loop fed to both esc via 2 pumps etc.

asked here for that light bulb moment in case what I plan has flaws !

Thx




Im angling for ideas / experience / observations.

.

[keithbradley]

Something you might want to consider if you haven't already:

If you use a tank to store your half gallon of water, consider using a series of dividers inside the tank with small holes drilled in the bottom. If you have no dividers and a decent mass of water, you may experience handling issues from the sloshing water.

I assume you are using ice water and no heatexchanger, as you obviously won't get a heat exchanger to cool the water better than lake temperature. The dry ice or alcohol ideas aren't bad. You could use a large water cooling plate mounted in an methanol bath or in dry ice to act as a heat exchanger. It's definitely over-complicated but I assume that's what you are going for.

[JIM MARCUM]

Gd'ay Aussie Doc Wayne. Your work is very interesting. Exactly what type/brand of water pumps are you using? I need to know where to buy a couple. I'd like to duplicate your closed loop system to cool the ESC only in my 10S2P 56" Seagad SAW cat (pic above).

Im considering using dry ice & methanol in a +- quart, baffeled container. Is Jay "Fluid" correct: "Dry ice and alcohol risks over-cooling the ESC, causing breakage of parts and epoxy not designed for sub-zero temps."? My ESCs have no moving parts, so what's to break?

I will be running twin Castle Hydra ICE2 200 Amp escs, Twin Turnigy 240 Amp ESCs for backups if the Castles smoke.

The next SAW for me is in October in LA. Legg Lake temp will likely be mid to upper 70s, and is only 10' deep. Opinions please! JIM

[properchopper]

Gd'ay Aussie Doc Wayne. Your work is very interesting. Exactly what type/brand of water pumps are you using? I need to know where to buy a couple. I'd like to duplicate your closed loop system to cool the ESC only in my 10S2P 56" Seagad SAW cat (pic above).

Im considering using dry ice & methanol in a +- quart, baffeled container. Is Jay "Fluid" correct: "Dry ice and alcohol risks over-cooling the ESC, causing breakage of parts and epoxy not designed for sub-zero temps."? My ESCs have no moving parts, so what's to break?

I will be running twin Castle Hydra ICE2 200 Amp escs, Twin Turnigy 240 Amp ESCs for backups if the Castles smoke.

The next SAW for me is in October in LA. Legg Lake temp will likely be mid to upper 70s, and is only 10' deep. Opinions please! JIM

My opinion only (after attending close to twenty SAW's) :

The majority of SAW boats don't use cooling ; short runs make it pretty much a luxury.

Gilbert and Kevin's HPR is not a purpose-built SAW boat; they do run it for sport so their longer runtimes make the closed loop system appropriate.

Hyper cooling won't save an overstressed setup.

Just my 2 rupies

[scottw]

Tony

is there a build thread on that HPR?

scott

[properchopper]

Tony

is there a build thread on that HPR?

scott

Scott, unfortunately, no. Next chance I get I'll capture some interior pictures. The level of engineering that went into the build will take your breath away for sure !

[mtbenjamin77]

I don't know if this applies here or not but I thought I'd throw it out there. When I was running nitros I took a good sized ESC cooling plate and attached it to a small aluminum box the same size as the cooling plate. I made the box out of al. with a vented lid. I put a small block of dry ice in it and hooked it up in line with my raw water cooling system. It helped the engine maintain temp on the hotter days here in florida. I was also able to adjust the temp by changing the location of where I spliced it in line. the closer to the engine the more cooling the farther away the less. It worked good.

[JIM MARCUM]

"My opinion only (after attending close to twenty SAW's) :

The majority of SAW boats don't use cooling ; short runs make it pretty much a luxury.

Gilbert and Kevin's HPR is not a purpose-built SAW boat; they do run it for sport so their longer runtimes make the closed loop system appropriate.

Hyper cooling won't save an overstressed setup."

Thanks Tony, that will save me a lot of unecessary work. 105.932 MPH!!! Geez, how fast could they go with a pure SAW build???JIM

[drwayne]

Reason why not?
I don't get why people keep bringing this up.

You're working completely backwards by going to a closed loop system. You have an extremely large supply of cool water, the only reason to circulate the same water is if you were using it to heat something. You're ignoring the one advantage boats have and handicapping yourself.

Dont do it , it's a dumb ass idea, ok.

Something you might want to consider if you haven't already:

If you use a tank to store your half gallon of water, consider using a series of dividers inside the tank with small holes drilled in the bottom. If you have no dividers and a decent mass of water, you may experience handling issues from the sloshing water.

I assume you are using ice water and no heatexchanger, as you obviously won't get a heat exchanger to cool the water better than lake temperature. The dry ice or alcohol ideas aren't bad. You could use a large water cooling plate mounted in an methanol bath or in dry ice to act as a heat exchanger. It's definitely over-complicated but I assume that's what you are going for.

And here you're full of advice and details. Im confused, should I listen to 'how to do it' or 'dont do it' Keith ?

Am hoping for real world experiences here, people.

Gd'ay Aussie Doc Wayne. Your work is very interesting. Exactly what type/brand of water pumps are you using? I need to know where to buy a couple. I'd like to duplicate your closed loop system to cool the ESC only in my 10S2P 56" Seagad SAW cat (pic above).

Im considering using dry ice & methanol in a +- quart, baffeled container. Is Jay "Fluid" correct: "Dry ice and alcohol risks over-cooling the ESC, causing breakage of parts and epoxy not designed for sub-zero temps."? My ESCs have no moving parts, so what's to break?

I will be running twin Castle Hydra ICE2 200 Amp escs, Twin Turnigy 240 Amp ESCs for backups if the Castles smoke.

The next SAW for me is in October in LA. Legg Lake temp will likely be mid to upper 70s, and is only 10' deep. Opinions please! JIM

ebay RC.SUB.WORKSHOP

Ok, here are a few thoughts on the valid comments so far.
1. methanol/alcohol in a boat filled with 'sparks' .. Hmm
2. if the dry ice cooled system was static ( no flow ) for a period, the water could freeze in line
3. overcooling is bad ? only if system is quench cooled.. a continuous flow is most appropriate before during and partially after a heat cycle.
4. pre-chilled water is an easier option here.. no need the logistically difficult dry ice option, nor the EPA ( Environmental Protection Agency) concerns over flammable/toxic liquids on some the reservoirs ..

We have ( I had to think hard here ) NO free water where we can run inside this state .. literally all the water is govt/developer owned and/or drinking reservoirs.



Tony, I look forward to a few detailed shots of the HPR.


Wayne

[keithbradley]

Dont do it , it's a dumb ass idea, ok.
And here you're full of advice and details. Im confused, should I listen to 'how to do it' or 'dont do it' Keith ?

Am hoping for real world experiences here, people.

If that's the height of your comprehension skills I'll just check out of this thread.

It is a stupid idea, absolutely, if you want to be frank. It's an exercise in creating a problem for yourself, and then trying to find a solution to said problem. You made it clear in your prior post that you enjoyed over-complicating things, so with that in mind I ignored the fact that this may not be the best or easiest way of doing things, rather something different for you to try. I am aware that many of us will create things that are made to be interesting designs, but not neccesarily the most logical. It was with this in mind that I posted for the second time, attempting to be helpful, instead of just crapping on your idea. It is apparent now that the former was a mistake, and not welcome.

In terms of "real world experience", that's where my posts were derived. I wouldn't even comment in this thread if I didn't have the experience.

I leave you to your idea/design. Best of luck and good day sir.

[properchopper]

After reading many threads on cooling, this one included, I've come to realize that I'm uniquely unqualified to offer any valid empirically-based info. I do have lots of experience-based observations, however. One thing that disqualifies me from being able to contribute is the fact that ALL of my boats are rigged for oval, 2-lap, or SAWS (with the exception of offshore). My max runtime never exceeds 2 1/2 - 3 minutes except for offshore which is 4.5 minutes. All of my setups use "overkill" speedys with max headroom, and most boats have independent (dual) water pickups for the motor & speedy. I just installed a cooling fan on the endbell of a Spec-powered offshore cat as well. ( I know, not much circulation but better than nothing - NAMBA rules prevent re-insulating the 3-wire hotspot)

High performance sport running (with extended runtimes) is another story, and maximizing cooling isn't a bad idea , I'll give that. Using techniques that have been discussed here and in previous threads will definitely enhance reliability and prevent equipment failure from excessive heat buildup. But I'll still hold on to the concept that all the cooling in the world won't save a setup that generates undue heat buildup from overstressing the components. Which leads me to the thought that if cooling is a preventative measure designed to protect the equipment, why not (the way a LVC protects batteries) have thermal sensors on both the motor and speedy which feed a thermal cutoff circuit the way that some speedys "thermal" but extended to the motor as well. We already have temperature logging sensors-why not have them feed a protection circuit which shuts things down before the dreaded smoke escapes ?

I know why Kevin and Gilbert devoted so much attention to the cooling on their HPR - Some time ago they were running a high-volt Aeromarine Hydro which got a "little too hot" - it burnt to the waterline right in front of them; all that was salvaged was the rudder; @ 6K up in smoke !

Dr. Wayne, I applaud your efforts to add reliability to a 90+ mph 54" twin cat but (please don't take this the wrong way, I really respect your knowledge and aspirations) - keeping a boat on the water at 90+ mph may not consistantly result in runtimes long enough to get things into the high-temp danger zone

http://www.youtube.com/watch?v=H4nkk_AWdfI

http://www.youtube.com/watch?v=z5Rsqt7Vo-s

[drwayne]

I enjoy OSE for it's wealth of knowledge from experienced and talented people, volunteering information to threads like this asking.
Assist is always appreciated.
Equally Ive learned the confusion of replies sometimes brings pearls of wisdom.
Perhaps the comprehension difficulty is deciding who knows, and who knows not.

Keith : thanks for your words, glad you added detail, pity you've left and unable to read this ..

Some areas we run boats have not the best quality water.
Our rivers have salt and sediment stirred up..ecoli and algae blooms an infrequent visitor the CBD waterways.. !
Our clubsite experience one or two closures a year due the quality.
A closedloop system would avail me of continuous flow and quality.

I once 'lost' a CMB101 head due corrosion&occlusion inside jacket !

So, without anymore ado... ideas with detail of closed loop cooling systems most appreciated !

Im here to play toy boats, not bicker over opinions.

Thx
W

[properchopper]

I'll get some more details of Kevin & Gilberts system next time I see them including photos. I do know that they fill the resevoir with iced water and IIRC use dual pumps. More when I see them. At Legg the water's fairly clean with the exception of those pesky duck and turtle particles.

duck.jpg

[drwayne]

I'll get some more details of Kevin & Gilberts system next time I see them including photos. I do know that they fill the resevoir with iced water and IIRC use dual pumps. More when I see them. At Legg the water's fairly clean with the exception of those pesky duck and turtle particles.

Infrequently there are more pesky duck and turtle particles after a days racing, I noticed.
A single tank with pump per side seems the norm, from photos shared .....

Thx
W

[Make-a-Wake]

I have thought of this more than once, what about an insulated container that would hold about a litre of "liquid", have brass cooling lines permanently mounted through the center and freeze it before each run. The liquid in the closed system would pass thru the container cooling it and not getting "mixed" with it. You could use diluted anti freeze or similar in the closed system, and when you're done just take out the container, pull the lines off each end and refreeze it...................just a thought.

[Jeff Wohlt]

https://forums.offshoreelectrics.com/...Practice/page5

Go read this...easy ways and work!

[drwayne]

https://forums.offshoreelectrics.com/...Practice/page5

Go read this...easy ways and work!

Bingo ! Cheers Jeff.

[Grazacind]

The next step is to cool the battery and motor wires.

Glycol would be a better medium than water I would think.

Cheers
Andrew

[drwayne]

The next step is to cool the battery and motor wires.

Glycol would be a better medium than water I would think.

Cheers
Andrew

Except for those 2 times when the castles self cremated, I dont overheated packs.

Packs work best when warmed through to a "hot blonde's body" temp of 37->40'c.
I see HC have LiPo cooling plates.. these introduce a temperature dynamic across the polymer which I assure you is bad for business.
Id prefer to use those as heat dissipators in a cooling loop system !

Tony's idea of thermal overload protection on battery/motor is a simple piece of electrckery, right up my alley.


This cat will run 2280s at 6Kw max . runtime 3->5 min at outside... calcs by batterys and ratings at hand

Planning 1000cc chilled coolantr fed to both via 2x 6Vdc pump capable 500ml.min feed under load.
Coolant cycled every 60 secs, give or take.. .
Will log delta temp in container first few runs and determine tank size requirements from there.

How hot is too hot ?

Will add thermostat to water bath. and set a failsafe throttle back .
Will set 50'c as the too hot spot.. unless someone suggests other wise ... ?

regs
W

[properchopper]

Except for those 2 times when the castles self cremated, I dont overheated packs.

Packs work best when warmed through to a "hot blonde's body" temp of 37->40'c.
I see HC have LiPo cooling plates.. these introduce a temperature dynamic across the polymer which I assure you is bad for business.
Id prefer to use those as heat dissipators in a cooling loop system !

Tony's idea of thermal overload protection on battery/motor is a simple piece of electrckery, right up my alley.


This cat will run 2280s at 6Kw max . runtime 3->5 min at outside... calcs by batterys and ratings at hand

Planning 1000cc chilled coolantr fed to both via 2x 6Vdc pump capable 500ml.min feed under load.
Coolant cycled every 60 secs, give or take.. .
Will log delta temp in container first few runs and determine tank size requirements from there.

How hot is too hot ?

Will add thermostat to water bath. and set a failsafe throttle back .
Will set 50'c as the too hot spot.. unless someone suggests other wise ... ?

regs
W

Learning a lot here. ( also learning to keep my mouth shut in some areas ) Had to remind myself that my "shorter runtime" POV doesn't universally apply to the genpop of most runners. Looking forward to seeing what develops, particularly in the area of overheat monitoring of components coupled with slowdown/shutdown logic circuitry fed by thermal sensors which already exist from the likes of EagleTree. After all (to reiterate), much has been devoted to protecting batteries with LVC's so it seems the logical next step could be to extend this protection to the other vulnerable components.
That being said, I'll still champion the concept that addressing the causes of heat buildup is the place to start. Balancing the setup should be the initial starting point [although we all like to push harder and harder and often finding the "point of balance" involves going past it and replacing the heat-failed items; then backing off]. A multiple-sensor protection circuit should make finding the point of no return ( a good analogy, eh?) less expensive in the long run.
Please accept my apologies for deviating from the main subject of this thread (closed loop cooling concepts) but sometimes good ideas pop up where they might. Wiki : "heuristic"