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Yes it is quite a little monster. No CPU Evaporator for this one; it's destined for other things. Besides with the wattage requirements of the present generation CPUs, this little guy was just a bit too small, and would have required a bigger compressor, and most likely higher flow captubes. Something that I'll leave up to others to pursue.Quote:
Btw when u add cpu evap to this autocascade monster ?
Well I've been running this thing non-stop since Tuesday morning, and I am happy to report that all seems well.
Below I have attached a cut-n-paste from the chart that is running on a remote PC at work connected to 5 temperature points on the AC-2 unit (I am presently at home right now --- gotta love remote view software). Unfortunately our current version of test software doesn't support pressure read-outs, so the running pressures are: ???
The other problem is that the software crashes after a few days, and then I have to restart it (hence the 38:XX hour:min point listing at the bottom of the chart).
An explanation of the various temperature points being monitored:
Comp Dschrg = Compressor Discharge Line (within 2" of compressor body exit point)
Comp Suction = Well I guess this one is pretty obvious
Ambient = Air temperature of the AC-2's surroundings
Probe Middle = This is a taped on TC at the middle of the Evaporator Cold Probe (aluminum metal tape and several turns of black electrical tape)
Average In/Out = Feed and Return TC's on Cold Probe connection tied together to yield an "average" temperature across the probe (this will eventually be connected to a permanent panel mounted TC meter)
As can be seen; there is a little bit of oscillation in temperatures, but it is extremely small (worse case = +/- 1/2 degree C, even less on the cold end). If we were going to have an issue with oil freezing out, I'm sure it would have shown itself by now, with the cold end warming up considerably.
Keep in mind that I never changed the oil in the compressor, so it is most likely a standard temperature variety of AB as supplied by the factory. This would have a typical freezing point of -40 to -50C. Also there is no oil separator in use. This really shows how good the phase separation is working to return the oil, as well as the excellent miscibility of the oil with several of the refrigerants selected.
Mikey likes it :up:
Does that average really work? I'd imagine it might read very false results if TC's act like resistors, as resistors in parallel result in less then the two combined... might give you a warmer or colder temp then you might otherwise see, but they might read completely different so might be totally off.
I love your reading and control system though, it really is very elegant.
It works perfect so long as the TC's are of the same length (See excerpt below --- obtained from: Lessons in Electric Circuits).Quote:
Does that average really work? I'd imagine it might read very false results if TC's act like resistors, as resistors in parallel result in less then the two combined... might give you a warmer or colder temp then you might otherwise see, but they might read completely different so might be totally off.
Edit: You can also see this to be true if you compare the last 2 strip charts in my previous post. One of them is an average obtained by taping a TC to the actual middle of the Cold Probe, and the other is obtained by 2 identical length TCs attached at the FEED and RETURN points of the Cold Probe's coil. The readings are less than 1 degree apart, with the "averaged" TC's showing a slightly lower temperature and oscillation (due to the 1/4" tubing's smaller mass being more responsive to temperature change vs. the higher mass of the Cold Probe's 2 1/8" copper tubing).
Thanks :) It's nice to chart temperatures in real time instead of only using a TC meter. Makes for an easier determination of improvement when making refrigerant additions as well.Quote:
I love your reading and control system though, it really is very elegant.
Ah perfect! That really is very useful! :)
The new machined front panel for my AC-2 unit has arrived!
It looks very nice and shiny, and was shipped on a laminated card, and packaged inside of a sturdy box with inflated air-bag packing. As I said in an earlier post; the people at Front Panel Express do a great job :up:
As you can see; I didn't have much room for the TC Meter, hence the necessity for mounting it so close to the top edge. But as you may recall from some of my earlier photos, the expansion tank really fills up most of this area to the left, and the foamed stack takes up all the space to the right. I just hope that I planned this layout properly, and that everything fits :hrhr:
I'll be buttoning up the unit later today, so hopefully I'll have some pics of the completed unit by tomorrow.
Nice!! :D
Now that is a beautiful thing!! Great design there mate!
looking nice
is that lasercut engraved or a sticker?
won't try to say on quality as no compliment will do it justice
Quote:
Originally Posted by mytekcontrols
That is BEAUTIFUL. :up:
First of all; thank you everyone for very kind words :)
It is all engraved, and then filled with paint. not sure if it is laser cut or machined, but judging by the quality of the fine lined print it wouldn't surprise me in the least that it was laser cut.Quote:
is that lasercut engraved or a sticker?
Yep I am very happy with how it turned out. It's always a tricky thing to figure out how to best layout such a thing, and to get everything in just the right place, and to the right dimensions.Quote:
Great design there mate!
Well as it turns out, I did get it right, and everything went together smoothly when I did the final assembly today. I will have pics to show you guys tomorrow, complete with frost on the cold probe.
Is it tomorrow already? No, I just couldn't wait so here are some more pics showing the completely assembled unit, and as promised some frost :D
Note: the unit had been running for approximately 2 hours when the frosty pics were taken --- not bad temps for the cold probe being in free air
Hot damn
Cold damn
I left the unit running when I left the shop. It'll be quite interesting to see how much ice I have tomorrow morning, and how much colder the probe is with the ice acting as insulation.
Hopefully it isn't like one of those horror movies where the thing has grown to 20 times its original size, and starts freezing people :shock2:
Oh man I cannot wait to see this HAHAQuote:
Originally Posted by mytekcontrols
I'll be sure to post a picture. That is... if I don't get caught in its icy stare and freeze to death ;)Quote:
Oh man I cannot wait to see this HAHA
Looks great with the new front. :D
Question, why can you not move the flex line when it's cold ?
Actually the flexline itself doesn't care, but the insulation that surrounds it will become very brittle when cooled down to the temperatures that this unit can produce. So if you move it, the insulation will crack.Quote:
Question, why can you not move the flex line when it's cold ?
Why not that would be awesome, it would probably obey you as you created it, and it would aid in your ultimate quest of world domination!Quote:
Originally Posted by mytekcontrols
Well it didn't turn into a 10 foot tall ice creature (I know you guys are disappointed), but it was very frosty.
Next and last test will be in the actual application. That being in a deep vacuum on a Helium Mass Spectrometer.
Man, I wish I could have snuck in and placed a heavy duty humidifier right next to the evaporator....and then removed it before you arrived in the morning. That might have made for some hilarious results.
OMG, how did i miss this thread :shakes:.... its damn cold!
Better yet, get a big drum of olive oil, proper it under, would have frozen it all up, and when you removed the bucket it would be incredibly wierd looking as the outside started to melt!