LukeXE`s autocascade for Xtreme Competition

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/autocascad...c/P1070178.jpg

http://gorajec.net/lukexe/autocascad...c/P1070180.jpg

http://gorajec.net/lukexe/autocascad...c/P1070181.jpg

http://gorajec.net/lukexe/autocascad...c/P1070183.jpg

http://gorajec.net/lukexe/autocascad...c/P1070184.jpg

http://gorajec.net/lukexe/autocascad...c/P1070185.jpg

http://gorajec.net/lukexe/autocascad...c/P1070186.jpg

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

Cheers !

Whats your lowside pressure?

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

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.

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

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.

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

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.

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 :(

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.

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

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

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.

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

That`s right

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

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

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 :)

Quote:

---

Originally Posted by LukeXE

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?

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!

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

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 ?

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

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 ?

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 :(

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

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

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/autocascad...c/P1010225.jpg

That temp was at 3psi low side pressure.

Few shots how looks auto-c now :

http://gorajec.net/lukexe/autocascad...c/P1010213.jpg

http://gorajec.net/lukexe/autocascad...c/P1010214.jpg

http://gorajec.net/lukexe/autocascad...c/P1010216.jpg

http://gorajec.net/lukexe/autocascad...c/P1010217.jpg

http://gorajec.net/lukexe/autocascad...c/P1010221.jpg

http://gorajec.net/lukexe/autocascad...c/P1010222.jpg

http://gorajec.net/lukexe/autocascad...c/P1010224.jpg

http://gorajec.net/lukexe/autocascad...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/autocascad...c/P1010233.jpg

Hmm...too big !

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

http://gorajec.net/lukexe/autocascad...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 !

:eek: :eek: :eek:

-94ºC Auto-C !!! Amazing :toast:

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

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.

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 ?

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

16-17 bar discharge

Damn nice Luke :)

Very nice, how does it perform loaded?

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

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

http://gorajec.net/lukexe/autocascad...s/P1070431.jpg

http://gorajec.net/lukexe/autocascad...s/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/autocascad...s/P1070435.jpg

Frost on dummy when running.

http://gorajec.net/lukexe/autocascad...s/P1070436.jpg

Condensed water on phase sep.

http://gorajec.net/lukexe/autocascad...s/P1070437.jpg

Whole unit :)

Cheers

Wow, that's real nice :D!

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 :)

huh, thanks :D