Xtreme 2006 Autocascade Competition

using ethylene doesn't sound like a good idea to me though.

I think the same about it like cold_ice, c'mon 1 refrigerant for auto's.
ethylene might be too dangerous like U_R saids, we don't want anyone to get hurt.

R23, CO2...?

its a competition, try to do your best to find another refrigerant

5 months are good i supose, and for the high press cut-off.
maybe a group order with unseen(i know he can get them fairly cheap)
i can get my own but its a little more expensive due high taxes

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Originally Posted by n00b 0f l337

Its not fair to allow anything else cold_ice. I have no 2 stage gases atm and neither do a lot of others. If we all had ethylene that's what we'd use, but co2 is the current DIY.
Why not make classes based on HP of compressors?

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thats not a good reason, i mean why doesn't everyone on xs make an auto? because they don't know it, they don't have the money, they don't have the balls.
if your not ready for an auto, don't make it then.

How much do these normally cost?

25 euro's here:)

Ah, I just didnt want to learn they were 200USD or something. :)
I geuss I'm in, I always liked the idea of autocascades. And i've got some designs planned.

I'm up for this :)

I think it isn't a good idea too allow only CO2. I don't think it is a good gas for an cascade/autocascade, maybe R23 or any other are alot better for this job.
If we stick only to CO2 the result will be like the first competition, no real good working units. It would be nice if we can find a much better gas for this purpose, without all the problems the guys with CO2 had (dry ice problems etc.)

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Originally Posted by cold_ice

I think it isn't a good idea too allow only CO2. I don't think it is a good gas for an cascade/autocascade, maybe R23 or any other are alot better for this job.
If we stick only to CO2 the result will be like the first competition, no real good working units. It would be nice if we can find a much better gas for this purpose, without all the problems the guys with CO2 had (dry ice problems etc.)

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Cold ice has a very good point here. :)

dry ice forming wasn't the only reason why all those systems didn't work 100% :D

Then what about those without that gas or the funds to purchase it?

they need to find something for it.

i don't understand the problem behind this?

thats like participate with dragrace if you can't even buy a car.

R23 doesnt sound bad, but we'd need to find spots for everyone to buy from

Count me in. R290/CO2.

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Originally Posted by n00b 0f l337

R23 doesnt sound bad, but we'd need to find spots for everyone to buy from

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almost every big hvac supplier can get that afaik

We could really use a list of places to get these things for US, I bought my r22 from r22.org or whatever. :(

The trick I've found to making CO2 work in a Cascade system is to mix it with R22 in the second stage. This really cuts down on the dry ice problems and doesn't hurt the evap temperature too much.

In an autocascade, If you're using R22 (or a similar first stage gas), you're already going to have that mix, but after phase-seperation, I'm not sure that you can keep the R22 mixed in with the CO2 as well, which could easily lead to dry ice in the cap tube being quite the problem.

Of course, limiting pepole to CO2 could force us to make some creative innovations to get the system working, but it could also lead to a bunch of people with poorly-functioning autocascades...

I was considering this as well, but I may have to switch off captubes for CPEV's if I ever figure em out.

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Originally Posted by n00b 0f l337

I was considering this as well, but I may have to switch off captubes for CPEV's if I ever figure em out.

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I wish I could find some CPEV's up here. Oh well, I have a few months to find some, so it shouldn't be too bad.

Count me in:banana:, don't know what my specs will be yet, I have a 1.4hp rotary, but obviously too large, will have to get a smaller one. I'm happy with CO2, here obtaining any other refrigerants (apart from R290) is next to impossible if you aren't a fridgy, or are very good friends with one, and even then he wouldn't commonly use the low temp refrigerants and that would mean purchasing a whole bottle (read: expensive):(

Okey guys, gas for II stage is free, but we`ll play without r1150. So CO2, R23 and others are allowed :)

@Runmc, Unknown_road --> Can I add you guys to members list ? ;)

We can create two groups, first with only CO2 as II stage refrigerant, and second with free gas as stage II (but without r1150), but I don`t think so that it will be needed.

I might try and get in on this competition, I haven't had any time for refrigeration lately due to school (batchelor of mechanical engineering)

Carlz0r - i found out that cpevs arent the best solution for a-cascades, but if you want some pm me

Maybe make 01.10.2006r. as a goal time ?? It's end of student's holidays :)

Why eg. R23 might be and R1150 not ?? :rolleyes:

I have only R1150 and R744, maybe R410a (but who know it would be I or II stage refrigerant ? ;) ) .

Regards
Peter

ethylene is just to high pressure gas to experiment with. the HX in an autocascade doesn't get to -40 in a second (if it even ever will do that) but you are already pushing the ethylene in it. Start-up pressures will probably be in the range of 35bar when you got it working "properly", imagine what they would be when it doesn't work "properly" yet. Using r410a as a first stage gas also isn't a good idea.

@luke: I don't know if I'm in yet, maybe.

Also, is a evap on a flex line manditory? Or can people do a striaght vertical copper pipe for there suction from the evap.