LukeXE`s autocascade for Xtreme Competition

[LukeXE]

Hey

I wanna show you my autocascade, that I have done for Xtreme 2006 Autocascade Competition. I`m in CO2 division, so I have hard job to do with that gass.

Now spec of unit:

Compressor -- Rotary 1HP
Condenser -- steel, about 2kW
Evap -- a`la chilly1 one, made in poland :D
Cap tube lenght -- high stage 2,35m, low stage 3m
Interstage HX -- my innovative project, insulated well with foam.
Phase Separator -- modded empty mapp gas bottle.
Gasses -- R22/R290/CO2
Cut off switch from Hatemi

and here some picks:

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070178.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070180.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070181.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070183.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070184.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070185.jpg

http://gorajec.net/lukexe/autocascade/working%20auto-c/P1070186.jpg

That`s all for now, tomorrow I will try to tune it well with 150W dummy load :toast:

Cheers !

[n00b 0f l337]

Whats your lowside pressure?

[LukeXE]

~ 1 bar, so really I must tune it to make pressures smaller.

[n00b 0f l337]

Still for 1bar doesnt that seem like the evaporator is too warm... I think your getting some r22 in the evaporator, the propane is lighter after all.

[LukeXE]

I wanna install fans that will blow on phase sep to make it colder a little bit , maybe it will help with good separation

[n00b 0f l337]

I doubt it, does the top of your phase seperator have a way to block liquid?

EDIT: Maybe provide more cooling (preferably sub ambient - SLHX sorta? ) to the mixture before it enters the phase seperator.

[LukeXE]

No, It doesn`t.

I will try do something to make it working good, but sth like slhx on pipe that enters to the phase sep isn`t good (I could be wrong), because if there will be too low temp, co2 will condense too. Maybe very, very small HX will be good

[n00b 0f l337]

Then look for a spot down your suction where its cold, but not cold enough. I don't think CO2 condensing would be a problem because I don't think you'll manage that that early.

[LukeXE]

I`ll add it today or tomorrow, small HX before phase sep, but now I must use R290 because I don`t have now any R22 :(

[[XC] gomeler]

r290 and CO2 seems like a good mix, especially with r290's tendancy to carry oil :) Looks good though, I love the huge blog of insulation.

[LukeXE]

I have added a SLHX before phase sep, vacuuming now :) Maybe now high stage refrigerant won`t go to the evap...I hope

I have small problem because I don`t have R22 and R290 now :( ;( and I`m still waiting for preso from Hatemi, it`s should be in my house in next 2-3 days

[Brettbeck]

Looking good Luke:). So if you use Co2 as a refrigerant how do you prevent it from forming dry-ice?

[LukeXE]

The CO2 tripple point is -56,6*C at (from what I read) 5 bar pressure (I`m not sure about that).

But now I don`t have any problems with dry ice, I hope I won`t have any :D

The one solution is to feed evap with high stage gas, that will flush the dry ice from evap.

[Brettbeck]

So the high stage gas would be the R290 that has run through the HX?

[LukeXE]

That`s right

you can just add second cap tube to the evap, one with co2 and one with R290.

[sl4ck]

where come from the cap with r290 that feeds the evap?
This won´t steal performace from the HX low stage ?

[LukeXE]

That cap goes from that same place, that goes cap tube to the HX :) (High stage liquid side).
And you think good, this will steal performance from HX, so I won`t use this method.

Today at 14 I will have package with cut-off switch and ethylene :D :D :D I will install it and make some photos :)

[sl4ck]

That cap goes from that same place, that goes cap tube to the HX :) (High stage liquid side).

so it has to be tunned like a dual head?

[Brettbeck]

I dont know if it would need to be tuned as all it would be doing was preventing dry-ice from forming...so it wouldnt matter how much was flowing through. Someone correct me if im wrong!

[kayl]

so ya getting some ethylene hey.
cant wait to see the results hey

[LukeXE]

I`m wondering, maybe I will use that ethylene in that auto-c, but really I don`t know how it will work :( Kayl, Have you used ethylene in your previous auto-c ?

[hatemi]

It worked pretty good. 1.7hp and 34cc tough :D IIRC 180w in the -70c range with half of the compressor under ice because too cold suctiongas :D

[LukeXE]

Hm, so maybe I will charge with that gas...I hope there is enough gas for that auto-c and cascade :)

BTW, What discharge pressure did you have ?

[hatemi]

It did have high startup preasure but when running properly it was quite reasonable. You might want to try with butane and propane to get the startup preasures lower. I was going to, but got bored before that :(

[jinu117]

Don't think you can lower starting pressure too much on mixed gas really without sacrificing temp too much. After all, the the high pressure gas is non condensable till quite a bit later :P

[LukeXE]

Ok, I charged unit with ethylene, but I have forgotten to install thermocouple on evap and I don`t know evap temp lol ! :)

But, Pressures:

Discharge -- 20 bar (290PSI)
Suction -- 0,8bar (11,6PSI)

Start pressure is pretty high, about 25 bar !

HX temp -- -33*C (R507)

Tomorrow I will play with that unit, I must say, that I`m out of ethylene, in bottle was enough gas for one unit...I hope that I won`t add ethylene to that unit now, huh :D

[LukeXE]

Hey everyone

I haven`t got enough ethylene for even just one charge, so I must go back to play in co2 division.

I pulled vacuum, cuted low stage captube (from 3m to 2,7m) and wraped it on suction line and insulated.

Then, I pulled vacuum three times and charged with propane-butane to 4bar, then to 6 bar with CO2.

I starded the unit and added propane to flush the HX. When HX temps droped, I started to add co2 to the system. After few minutes I had this :

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010225.jpg

That temp was at 3psi low side pressure.

Few shots how looks auto-c now :

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010213.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010214.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010216.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010217.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010221.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010222.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010224.jpg

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010226.jpg

That was to big temp for me, so I started tune the auto-c to got the lowest temp possible...

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010233.jpg

Hmm...too big !

Lower...:toast: :woot: :toast: :woot:

http://gorajec.net/lukexe/autocascade/f....ggoodworkingauto-c/P1010237.jpg

That temp was at big, big vacuum (-0,9bar)...On evap was -94,6*C, but accu from my digicam said "no!" :/

But I`m happy, I say ":banana::banana::banana::banana:ing" happy with that temp !

Tomorrow I will play with dummy load, and I`ll try to go to -100*C (without load of course :p)

Cheers !

[sl4ck]

:eek: :eek: :eek:

-94ºC Auto-C !!! Amazing :toast:

[godmod]

dont you think that hd pressure will be very high with ethene?

[LukeXE]

But I don`t use ethylene, that temps are on CO2.

Yes, I had ethylene from Hatemi, but there wasn`t enough gas for even one charge, so I vacuumed unit and charged with CO2 and propane again.

[LukeXE]

I wanna ask you, my friends, for one thing.

I have got hx before phase separator, and As you can see, I didn`t insulate the "back line from hx" that is going directly to phase sep, because I`m worry that there will be too cold, and all co2 will condense before phase sep :D

So, insulate it with phase sep (phase sep is very cold at the bottom, and water condense on it) or leave it like is now ?

[godmod]

do you know the pressure at both hx outlets? would be helpful!

[LukeXE]

16-17 bar discharge

[jinu117]

Damn nice Luke :)

[aasmaukr]

Very nice, how does it perform loaded?

[Xeon th MG Pony]

http://www.ept.ntnu.no/fag/tep32/Pensum/CO2.pdf < All about CO2 as a refrigerant, may help

[LukeXE]

Today I have done some load tests with 155W dummy load and...I must say, it works good :)

http://gorajec.net/lukexe/autocascade/load%20temps/P1070431.jpg

http://gorajec.net/lukexe/autocascade/load%20temps/P1070433.jpg

Temp goes from -61*C to -62*C, I tested it 1h and some more for tuning and calibrating, but I`ve got it :D

http://gorajec.net/lukexe/autocascade/load%20temps/P1070435.jpg

Frost on dummy when running.

http://gorajec.net/lukexe/autocascade/load%20temps/P1070436.jpg

Condensed water on phase sep.

http://gorajec.net/lukexe/autocascade/load%20temps/P1070437.jpg

Whole unit :)

Cheers

[aasmaukr]

Wow, that's real nice :D!

[jinu117]

Finally something worthy for linkage in auto-c... too bad Johan's is bit of semi-auto cascade. You are the only one in link now Luke :) Guys time to beat luke into it now... hurry up lol :)

[LukeXE]

huh, thanks :D