Xeon
you could not be more correct.
the word is baseline, it has to start somewhere.
again this applies all widgets. you can model till the cows come home
as well as grow rapid prototypes all day, but until you have a working physical
piece to conduct your baseline it is just a guess.
regardless of simulations with software.
read my post guys, I didn't say anything about @itors evap.
back on topic please, this is about ron's evap.
Well, it seems to me that we might be able to at least agree upon a few things on evap design:
1. The cap-tube-over-core design does not allow adequate exposure of evap to liquid refrigerant, as much of the liquid will likely be swept away.
2. The suction-over-core design provides a more ideal mix of liquid/gas over the core, but is difficult to charge because too much refrigerant will mean liquid entering the suction, while too little means inadequate cooling above the core. This is compounded by variable load temps.
Seeing these two designs and their issues, it seems only natural to pick the third, less-often mentioned solution: an off center cap tube and suction. While this design would likely have it's own host of engineering problems (like harder mounting), it seems to me, at least, the best of both worlds. It would allow for both constant flooding of the core region, as any leftover liquid will still have the chance to evaporate on it's way out, and the partial-evaporation of the liquid before it reaches the core, allowing for a more efficient evaporation process.
I'm thinking along the lines of the ms paint drawing below. Yeah, it's crude, and yeah, a real evap design is gonna be more complex, but it should give you an idea of what's in my head.
But all theory aside, the Gosmeyer evap looks great to my noob eye. What I really want to see is some results. I personally thing that it has the potential to be great!
lets be a bit more accurate and im sure RunMC and gosmeyer wont disagree as RunMC said himselfOriginally Posted by Gray Mole
so this new evolution of elevens evap by RunMC and gosmeyer...
it all started here and eleven along other members of thelab.gr spend very much time to develop this evap
http://www.thelab.gr/showthread.php?...0&pagenumber=1
ive been using this evap for quite some time to both cascades and single stages with excellent results, cant say if its the best but its working remarkably well. even without sandblasted internals (im about to make a very special single stage soon which will have sandblaster evap) i never need to use an accumulator as there is no liquid returning to the compressor anytime whether thats idle, load idle or full load.
i hate to argue over forums!
i gave my tips on the setup RunMC should build to test it (cap tube, design, compressor) so lets sit back and wait for him to test it!
sorry for the edit, when im sleepy i forget to press buttons
Last edited by esdee; 04-23-2007 at 06:08 PM.
if this is your first night in xtremesystems,
you have to overclock.
Great evap Ron!
From my experience i can say that ive tested both situations, "suction over core / cap on side" and "cap over core / suction on side". This was tested on a unit specifically built to test evaps.
These tests were done over a year ago. The cap over core wins every time ive tried it, either on no-load or load situations. When i say "wins everytime" its a roughly a 2c degrees margin.
I can also share that the thinnest the base the better, been using 2mm base.
Also have tried 2 different evaps on the cascade, and my opinion is that -100 and -50 temperatures need different evaps, although this opinion is not proved on test unit. Maybe some1 can try to explain this in thermodynamic terms
Sorry, I don't even know how to spell thermidynamix, I'm a plumber.
From what I've read from other forums, and by stealing other people's original ideas...
I think you're right that at -100 and -50 the ideal evap would be different. Those smart people say that it's because there is an ideal velocity at which the balance of greater heat transfer (velocity promotes turbulence which promotes heat transfer), and the negative effect of turbulence (frictional pressure drop) are in the best balance. At -100C the vapor specific volume (inverse of density) is much greater than at -50C.
R507 has 26 times greater specific volume at -100C than at -50C. If there is a single "ideal" velocity, the ideal evap for -100C should have much larger refrigerant passages than the ideal evap for -50C.
You see what you did there? You got between me and the coffee, now this creates a SITUATION!
Part of this threads off topic conversation has become stupid, not to detract from the evap (it does look nice, machining is great) but people's opinions in general. This is a science, not voodoo, withchcraft or touchy feely and i just don't think i get 'it'
Erik,
I'm not so sure about the differences but please tell me if i'm wrong. If you were running r507 at -100C then it's not a fair comparison, maybe if you were evaporating at -50C with r507 then you could compare better to ethylene at -105C.
From this i think what you call specific volume of ethylene at -105C would be ~2x over r507 at -50C, so the passages wouldn't need to be that much wider...?
The main thing is that i think the minimum features still aren't anywhere near small enough. I wish i could machine features sub 1mm in a conventional evaporator. We need lasers
Tom
Last edited by SoddemFX; 04-24-2007 at 01:54 AM.
"What will become of us, will we evolve"
You guys mix gases and most don't have the tools to even reproduce the mix or can quantify it in any way .A hose of that, a piss of this, and a few drops of that =
So unless you are using a pure Rxxx refrigerant that has a published P/T chart the rest doesn't matter,does it?????
The Laws of Thermodynamics say:
Zeroth Law: "You must play the game."
First Law: "You can't win."
Second Law: "You can't break even."
Third Law: "You can't quit the game."
Do you wanna Play Thermodynamics ????????
you can make a 30W CO2 laser at home! it is the focusing aperture and control that will cost you.
Bring back natural selection! No more warning lables!
The one and Only MG Pony
I can make sour-kraut at home too
The Laws of Thermodynamics say:
Zeroth Law: "You must play the game."
First Law: "You can't win."
Second Law: "You can't break even."
Third Law: "You can't quit the game."
Do you wanna Play Thermodynamics ????????
walt: why are you talking about mixing gasses? nobody said anything about that in this thread.
xeon: a 30!!! watt laser?? do you have any idea how much that is for a laser? a 30 watt laser would probably require the same energy to power a small town.
ron: something I'm doing now with my silver evaps is make a sort of pyramide base. in the center the base is 3mm thick, and at the side 1mm. and declining in between. I do this because the further you go to the side of the evap the less heat flows trough it and the surface area at the side is closer to the core this way.
Yeah, I thought the same thing after I went to bed, R507 @-100 is something that would not be done, so a silly comparison. I guess my point was that vapor density drives (should drive?) evap design, so with different gasses and very low pressures, there are opportunities to build specialized evaps for specific purposes.
Nice catch Tom
You see what you did there? You got between me and the coffee, now this creates a SITUATION!
Very Sexy!
"If It Doesn't Overclock Its Broken"
"NexGen Overclocking"
"Overclocking, its a life style"
a watt is a watt 30 watt co2 laser will give you a nice facial,doctors use laser of that type and wattage all the time,Keep up those physic classes....... 30 tera-watt now you into military stuff but lasers are now in the penta-watt range10 to the 15 power,thats the range it will probably take to lase a missile down but thats a guess. we skipped kilowatt& megawatt to save server space
I just mentioned mixing gases because thats where you guys also need to start to quantify.If you think you got a super mix,how can you repeat it?????if your not mixing ingnore that statement, .
The Laws of Thermodynamics say:
Zeroth Law: "You must play the game."
First Law: "You can't win."
Second Law: "You can't break even."
Third Law: "You can't quit the game."
Do you wanna Play Thermodynamics ????????
those are femtosecond lasers walt, completly different thing. they only give very short pulses of high energy, there continues output isn't that high.
But I didn't know CO2 lasers are that much more efficient then other gas lasers.
the only gas lasers I worked with are argon lasers.
ontopic: do I understand correctly that with unseens evap the cap tube enters at the side as well? I always thought it enters at the center.
Last edited by Unknown_road; 04-24-2007 at 07:10 AM.
Yes the refrigerant enters from the outside of the evap and travels in to the center on the eleven, unseen, and esdee evap. Captube is on outside and suction is in the middle on unseens evap.
Q switched properly it will also blow a hole in your skull.
The thing to keep in mind, is that cpu's are no longer a small core under a large IHS.
With Quad core, we've seen someone pull the IHS off (crazy people) and it's very very spread out.
That means that a great deal more of the surface of the evap is going to be in contact with the source of the heat.
I would be interested to see this evap, one from in to out, and reversed also, and see the difference on a quad core cpu.
I have a feeling that the difference would be nil.
Gray
[SIGPIC][/SIGPIC]
although that's true gray it doesn't change the fact that your not using the surface area at the center.
We have it both ways.
Will just have to see what they do.
even with side cap tube entrance ive seen no liquid returning the comrpessor.
i modded an eleven evap today to have center entrance. ill might be able to test it in a couple of weeks
if this is your first night in xtremesystems,
you have to overclock.
Well, yes and no.
You're still using it, as you'll always have some refrigerant 'wasted' and returning into the suction line.
If you can keep that return of liquid further back from the compressor that's great, but it's not likely that it's going to 'eat' every drop of refrigerant before it get's to the center of the evap and into the suction line.
As said though, we'll see about how things end up working out, but I have a good feeling about it
Gray
[SIGPIC][/SIGPIC]
30Watt isn't that much, it takes a while the mirrors are the hardest but once you figure your resonator tube and focal point you can scale it up or down by the length of tube. tube length decides total output power, for my first try I used neon sign tubing and first phase silver mirrors the out put one I sanded to be partially silvered (Needless to say it wasn't a super performer.).
Look it up, you'd be surprised how many have don it. Great starter to read: http://www.technology.niagarac.on.ca.../LasersTEA.htm
Nitrogen lasers are just so dam neat and fun!
Bring back natural selection! No more warning lables!
The one and Only MG Pony
Someone correct me if I'm wrong as I don't design and test evaps, but heres what I think I know
at the end of a cap tube you have suction pressure acting on the refrigerant,so you have 2 phase flow beginning some where in the last 1/3 of cap tube ,may be much closer to end depending on refrigerant and P/T. The coldest part is not at the exit of cap tube as gas is flashing and rapidly expanding and the pressure will be higher if the channels is too small to allow expansion. The more wetted surface area the better. you want a wetted surface the whole way to where the suction is,(middle in this case)this it point inside evap with lowest pressure,thus largest delta=more heat transfer as long as mass flow is not restricted.....any liquid leaving the evap is wasted capacity as its boiling off in suction line offering no help
easily said but to test liquid/gas ratio from beginning of evap to suction is complicated.
I bet DetroitAC could correct me as he works in R&D of auto evaps. I would also bet that with no test knowledge at all a design that looks good may perform awful,just as a design that you think won't be so great may be the best. thermodynamic modeling can predict heat conduction and refrigerant heat absorption in fluid mechanics,Sinda/Fluint is a good modeling program but only Testing a proto type will give real results and by using real data you know if the follow up designs are moving in the right or wrong direction
The Laws of Thermodynamics say:
Zeroth Law: "You must play the game."
First Law: "You can't win."
Second Law: "You can't break even."
Third Law: "You can't quit the game."
Do you wanna Play Thermodynamics ????????
Let it be know that I am no engineer, college boy, or hvac/rI do however remember from the days of Gary Lloyd, him saying that the refrigerant wouldn't be at it's coldest point just as it leaves the cap tube. It must have time to expand, absorbing heat as it evaporates. When Eric and I were talking about where the refrigerant would enter the evap, we did have mixed feeling about which would work better. I kept thinking about what Gary had said so we moved the feed point just off center to try a capture the best of both worlds. Since we are going to try the evap feeding from both locations, we may possibly see a difference.
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