Aww common Gray Mole. Unknown's just heavily trying to level the play field. It won't be the same without you in this.
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Aww common Gray Mole. Unknown's just heavily trying to level the play field. It won't be the same without you in this.
I have a few rule clarifications I would like:
1: Are commercial sight glasses aloud?
2: - there are no condenser limitations as longas the ambient temps are above 20C -
This just means that the room temperature has to be above 20C, correct? I have been told that this may mean the condensing temperature of the first stage must be above 20C. I would say I don't really like that rule... it would seem to rule out all kinds of things, like having a suction line heat exchanger on the first stage. basically it would mean your first stage can't be below 20C anywhere but the evap... please clarify.
I think they mean that any air to refrigerant or water to refrigerant heat exchangers may not be below 20C. As for sightglass'es, its dangerous to have people attempting to build there own.
yes, but the definition of ambient is: "of the surrounding area or environment".Quote:
Originally Posted by n00b 0f l337
So the rule basically says "The temperature of the surrounding area or environment must be over 20C."
That, I have no problem with.
dont quit Gray Mole, Unknown Road is just upset case when he did his autocascade ages back he never actually got it to autocascade :stick: let alone hold 200w :DQuote:
Originally Posted by Gray Mole
i would say ambient room temp has to be above 20c.Quote:
Originally Posted by eshbach
really any parts should be allowed commercial / non-commercial, its not gonna help that much, its more how ppl put their system together, metering devices and refrigerant ratios.
Im a little scared that Redwolf has joined, his autocascade at TeampUSS is one mean AUtoC:slapass:
A pressure releif valve is more important than a pressure cut off switch.As pressure can continue to rise even after compressor is off. BOTH should be used.
Okey, I just changed this to: "-there are no condenser limitations." and now is ok :DQuote:
Originally Posted by eshbach
cool, thanks very much for clearing it up.Quote:
Originally Posted by LukeXE
I didn't say anything about the ice lolly?! I thought it was one of the funniest posts I've seen in a while over here.Quote:
Originally Posted by Gray Mole
and If you want to use r4** gasses I don't mind! I just give advice that the gasses will seperate and thus don't work properly.
about the heatload, I would like if people would tune the autocascade on 200watt cpu heatload. But majority doesn't so that's fine with me, I didn't rattle on about it. just said it once.
I'm absolutly not trying to take the fun out of it. sorry if some of my posts seem harsh or anything. please join in with the compo.
maybe I'm even in since we aren't limited to co2 anymore.
@kayl: your right :) Stil can't get the damn thing to work the way I want.
@wdrzal: a pressure relief valve will make lots of people crazy. takes you days to tune the autocascade, blood, sweat and cries, and what does the damn valve do, it trows away the whole balance in a second :D
And the relief should be ducted to outside to make it safe. I wouldnt want to be next to one that blows refrigerant to my face at 300+psi :S or in the same room for that matter.
just a valve or a solenoid with the high pressure cut off between high and low side. :)
thats the way they do it in commercial phase-change install's
i know they have a pressure relief to but thats a waste of refrigerant.
Hey Gray, Don't leave the compotition man. This IS for fun, and its not like there are any prizes so let all just have fun with it. Like I said I don't care what the rules are, im game. I see this a purely a learning opportunity, and if I happen to get it to work...then GREAT! if not, i'll probably have learned alot. But I've always found the people in the Phase section of XS to be some of the best. You don't see people flaming or arguing over stupid Sh*t. We all have 2 things in common, We all like computers, and we all like making Sh*T COLD!!! (usually lose go together eh! :D) Those were probably big misunderstandings, and it no reason to drop out man, you've help me alot since I've started getting into this hobby and I'd hate to see ya quit.
@ Unknown, yeah actually I really appreciate that advice, as I said im still learning and see this a another way to further my knowledge. Thanks for letting me know, cause I would have hated to find out the hard way. I value highly constructive critizism, as I want to give this my best attempt and I can learn SO much from you guys!
I'm really looking forward to the competition. Why don't the judges decide on the rules, and make it final, so that we can all get to the fun part eh!
Brandon J
I think it's a good idea to think over the rules and compromise on what you guys want. We don't want anyone upset a little down the road because of a rule they don't agree with. I'm with Fhqwhgads6680 on his viewpoint. It will be a learning experience for all of us and a good way to join together for some fun.
BTW - Forane r507 says to liquid charge on the container. ;)
@ Grey Mole :buddies:
I thought it wouldn't separate like the 4xx gases would? anyone know about this as im about to buy gases soon....if not I guess I can always go with R290, but I was wanting something with a little more umpf incase I chose a higher pressure gas like R23 to make it easier to condense...
I not in this, but this is how its set up for safe operation. a pressure shut down switch should be set at no more than 350 to 375. to sut down compressor. if pressure continues to rise at 400 psi the internal compressor bypass will open, this allows pressure to the low side for more internal volume. only after these to mesures fail, does a releif valve open releasing refrigerant into the atmosphere. about outside well not really just in a safe direction. these system don't have a large volume and it wouldn' even stay open for a fraction of a second to lower the pressure.
It would only open as a last resort. If you guys ever heard a valve discharge at 450 psi you would have a lot more respect for pressure.
guys think of a line rupturing or a bad braze failing, at of 400 psi the hot oil can be swept out of the compressor and sprayed all over you. Have you ever seen someone sprayed and burnt with hot oil, You would have change your user name, since you wouln't look the same as before the accident.
Lets promote safety here at XS , and be proud of it !!!!!!!!!!!!!
my thought on condensor temps 20c/68f air or water or above thats room temp or guys will be putting heat exchangers or condensors in freezers or running chilled water thru them. The idea behind a auto is to get a gas that condenses at room temp (1 stage gas) to condense a 2nd stage gas. true auto cascading should reach same temps as a cascade.
doing this would be essentlly cheating and will not advance the goal to get a unit to auto cascade.
I think the judges should set the rules, allowing anyone else too, each person is going to want the rules to favor his design and no one will agree.
rules should be simple , 1 compressor, complete unit must be at or above 20c at start up........ pick a heat load it must maintain for 15 to 30 min. safety devices must be used.
just suggestions.
Very good post Walt. I havent seen an oil burst+burn but have heard of one that happened while testing an engine in an test bench/dyno. One of the brake oil lines burst and the oil hit the exhaust manifold resulting on a garage full of flames! Luckily the garage is rather small and did not have enough oxygene to make the whole thing burn. The roof and waals were pretty much filled with burn marks after that!
it dosn't even have to ingnite, the oil is hot enough to cause 3rd degree burns without ingniting. While every knows severs burns to the skin will disfigure and kill you,most people who die quickly, die because they inhaled the super heated vapor thats in the air. It burns your lung sacs and they no longer are able to transfer o2 to your blood.
20 years go a good freind of mine was a employee of a yamaha dealership. he was working on a 3 wheeler that wouldn't start. He pulled the spark plug and hit the electric start button to check for spark. Wellthe cylinder was full of gas and it sprayed in the air and ingnited!!!!! while he suffered 2nd & 3rd degree burns to his face ,neck chest,arms and hands. It was inhaleling superheated vapor that almost killed him. he was lifeflighted to a burn unit where he hung on the edge of death for 2 weeks, he remained there for over 2 months and had to wear thight elastic wraps around his chest arms and neck to minamize scaring for 2 more years .
I wish I could some how transfer all the visual immages that are locked in my brain forever from accidents, then you would know why I,m so safety concious. Accidents ARE PREVENTABLE ,don't let one happen to you.
It doesn't take much heat to turn the water in the atmosphere to a super heated vapor, you don't actually have to breath the burning fuel, just hot vapor to die.
well I don't know about that but in theory r5** gasses don't seperate and thus can be used in an autocascade.Quote:
Originally Posted by runmc
I don't know if people want to know but I'll explain something about how to pick your first stage gas:
We all know (from datasheets) that in a normal system when the discharge pressure is lower the suction pressure is lower, aka compression ratio.
to make things not to complicated consider all first stage refrigerants have the same capacity.
so most efficient you pick a first stage refrigerant that condenses the second stage refrigerant at about the same pressure as the first stage refrigerant condenses in the condensor. Offcourse this is very hard to think about before you have build the system and see you it performs but I thought people maybe would like to know this. Now I see everyone picking the first stage refrigerant the coldest refrigerant they've got.
when you use r507 for instance and this gives you a HX temp of -40*C. the CO2 condenses at 10 bar. While the r507 probably needs around 15bar to condens. so the r507 is overkill and in fact reducing efficiency. Interesting or not! :D
Right, so r22 and co2 is more efficienct. Or other such items.
depends on the system, especially suction pressure.
LOLQuote:
Originally Posted by kayl
I let that thing run for a long time... Some time in the 5th month it blew off the bottom of the evap plate. Simply due to the shear force of the dry ice shooting of the captube. My guess on longevity was correct.... won't last.
Yes 507 has to be charged as a liquid. Its not a stable refrigerant. Meaning. R507 does have a slight temperature glide, >1F.
As for the condensor which condenes the first stage refrigerant issue.. I see very large loop holes in the "what ever you want to use". Think it should be simply air cooled in some way... air to air or water to air. No ground loops, no ice in the water, no LN2, no dry ice, or what the hell ever else one can think of.
Would be nice for all the ppl to have to supply a data recording of atleast 24hrs of run time. Showing ambient and evap temps. This way a fair measurement of the data can be judged. Because TD and Time are both taken into condieration.
I consider the autocascade redwolf build as one of the only real autocascades (that worked) no tricks like suction line HX. piece of art if you ask me. Too bad it blew, weird that it happend must have been some force.
Ok Ok, yes I'm a big girl. Yes, I'm a grouchy ba5tard. Yes I'm staying in the competition of that's still ok.
Thanks for the hug, Ron :D
I'll agree with the pressure relief as well if that's going to be in the rules of safety as well.
To be honest, even a properly running Auto will still kick out some serious startup pressures and that would be just one more thing to stay safe :)
Sorry Unknown, shouldn't have taken a swing at you. I haven't been laid in 4 years and as ugly as I am, likley won't EVER again. So hopefully the prozac kicks in soon ;)
For condensing temps I totally agree, though I'll have to wait for summer to get mine up that high. I normally struggle in the winter to keep my ambient up there, and the chances of my wife letting me run a rotary in the house for 1 hour much less 24 are something like 0, or close to it :rolleyes:
Gray
Cheers REdwolf:mad: My ground loop was within the rules until now;)
Regards
John.