Greetings to all: I promise, I have been working on the car. Just not much to report or to take pics of....until now.
The subject of a cold plate has comes up from time to time. There are about 3-4 different versions that are in use.
1. One version has two halves with milled channels and is bolted together.
I am leery of the way the hose barbs are screwed into the plate in the crack between them. Pipe fittings are a tapered thread and you are wedging the plates apart possibly causing a leak later.
2. The other versions are OK if you have room for them, but I am in a tight spot and my plate can not be more than 1" thick at most.
Then I met Ivan, a fellow EV'er. He is a very talented guy with a thirst to build and create. His past projects include an electric bike, a diesel Gen Set, a CNC table and an airplane. He can be contacted at email@example.com
or go to his web site http://ivanbennett.com
He has designed a really simple, effective cold plate that fits into a small space but yet is arguably the most efficient I've seen. He was kind enough to bring me a unit to try on my Roadster build.
OK, This might generate some hate mail, but here it goes.....
Heat conduction through metal takes time. The thicker the metal, the longer it takes. The best design would have been if Curtis had just made passages in the controller, which would have been the best and done us all a great favor. Some motor and controller makers do it all the time. The single down side of this approach is corrosion over time.
Lets get real. An automotive ICE requires 240+ degrees and thousands of heat/cold cycles to see the corrosion we are used to in our cooling systems. Even then, Aluminum radiator cores are .040-.060 thick and take years to corrode through.
Our usage is a lot different. Without a converter, an automatic transmission gets about 140 Degrees F. This leaves the controller as the hottest thing in the system. My system has 2-3 gallons of fluid capacity. It uses a 20 pound heat exchanger and three dedicated pumps. It sounds like overkill and probably is, but the radiator holds the nose of the car and to remove it and build a tubing frame, just to replace it with another heat exchanger was expensive and just wrong somehow.
My point is that I am never going to see over maybe 140 Degrees F, ever. Given the proper fluid, I am looking at a lifetime of use with minimal corrosion.
This cold plate uses an open face and runs the fluid directly against the 1" thick aluminum controller base. .........<he ducks>......
It is 5/8" thick with a 1/2" deep fluid chamber. My inlet is on the bottom and outlet is on the top/right corner to eliminate any trapped air. I have a solid 3/8" thick aluminum sub-base bolted to my firewall. This just sandwiches between the controller and the sub base using anerobic sealer and heat sink paste on the sub plate for a little extra heat conduction....(ok more overkill)
I will be installing it today. Miz