You designed the unit very well, how ever vibration will work harden the tubing leading to cracking in the tubing prematurely. hence the vibration dampener between condenser and compressor.
Other then that very nice well layed out system!
You designed the unit very well, how ever vibration will work harden the tubing leading to cracking in the tubing prematurely. hence the vibration dampener between condenser and compressor.
Other then that very nice well layed out system!
Bring back natural selection! No more warning lables!
The one and Only MG Pony
Thanks for your coments Xeon, as said in post 10, i have overcome the vibration problem by mounting the condensors on rubber mounts so this should take up any vibration as both the compressor and condensors will both be able to move when the comprssor is starting and running.
No this will not as torquing forces within the tube leading to the condenser will still be exerted and the inertial mass of the condensers will yield the loading on the joints. The rubber will remove harmonics being transfered to the case but will not cancel out the stresses being imposed onto the tubing.
When the compressor starts force must be exerted on the tubing to get the condensers to move, this force will harden and then eventually crack the tube.
Bring back natural selection! No more warning lables!
The one and Only MG Pony
But if the compressor and the condensors are mounted on the same platform that moves with each outher then how can there be stress on the pipwork when they are both moving in tandam
inertial lag, you can only accelerate the condensers so fast. All tubing work hardens, but with proper allowances we can greatly delay the effects.
Bring back natural selection! No more warning lables!
The one and Only MG Pony
I don't know exactly how those systems are designed but I know that exist and perform very well. Maybe they're using a bit of the liquid return to decrease the discharge gas temperature of the LBP stage, If I get a new SC10G I think I'll couple it with a nl11f, just for fun.
About cascaded system, I've though about that :
1st : SC12G (MBP) - R507C @ -20° evap (sth like 3 bar)
2nd : SC12G (MBP - R170 @ - -65° evap (sth like 3 bar)
3rd : nl11f (LBP) - R1150 @ -110° (sth like <1bar) //or SCxxCLX
Each compressor would work with pressures it's designed for and @ these temperatures, SC12G can become very powerfull (600w and even more), more over the COP will be around >2, that's good for power comsumption![]()
Well guys as promised I have finally sorted out the S/S unit and have some temperature results for you all to see, as you can see I have used my load tester which is within +- 2 watts and the fluke is also within +- 1c, so after other commitments and a few problem of which are sorted now here are some pics for your viewing.
-68c, First run up know load, very small amount of flood back at compressor, 5 minute run
50 watt load applied, -54.5c, know flood back at all.10 minute run
151 watt applied -51.5c,1 hour run
254 watts applied -48.1c,1 hour run.
272 watts applied -38.4c,1 hour run.
282 watts applied -32.3c, 1 hour run, this was the limit of the unit as when i tried for 290 watts it started to drop below -20,
Then back to the start again with know load, notice that this is slitly higher then when i started as the unit is very hot now. -59.5c.
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Last edited by sacha35; 06-03-2007 at 08:21 AM.
didn't you finish this around christmas?
aer you waterboy from extremeoverclocking?
mentally confused and prone to wandering
looks good, seems to hold pretty massive loads!
Great job sacha! I notice the case is now black too? Any pics of the entire unit?
Nice temps even at high load.
Good job.
Thanks for all the comments guys, well in the end i did use a mix of refrigerants, the main part is 402a about 85%, then 15% of 410a which brought the pressure up-to 270 PSI on the high side under full load so i added a about 5% of 134a which seems to give a nice all-round use of temps under different loads and has drooped the high side pressure down to about 245-250 under full 282watts of load and this was run for over an hour at this load and stayed within -32c - 33c and has been test again over a few days just to make sure nothing has changed.
Again this has not been an easy build with its complexity, but i think you will all agree that with the load temperatures i have got from this unit it has turned out very well for a small NL11 compressor
I have got a lot of cleaning and finishing touches to do to this unit and then i will post some final pics for your viewing.
Thanks again everyone for your kind comments,
I would also like to thank SoddemFX which helped me in the design of this unit, also Bazx which has been a great help, 4Qman without his garage we would have been stuck,also the guys that i bought these parts from, Chilly1 evap, the new one works so much better than his old one, Unseen for his controller that works like a charm.
Again this has not been an easy build with its complexity, but i think you will all agree that with the load temperatures i have got from this unit it has turned out very well.
Nice compressor you got there!
At 250 watts suction pressure is 0 as i can see from temp, and high side at 250 psi... wow my nl11f cant hold that compression ratio. Good job !
OK Guys as requested some more pics of the finished item, one question for you guys now, what do you think is more important to you, out right performance from a S/S or looks or both.
Thanks again for your coments.
sacha35
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Last edited by sacha35; 06-07-2007 at 08:23 AM.
One in the same as far as I'm concerned.
Nice job!
Nice one Sacha!
I think it depends who is going to use the single-stage as to whether outright performance or looks is the most important thing.
If it's a benching unit for at home then I don't think there's any need to make it look all that fancy (if it's going to cost). Are you going to sell it or keep it yourself?
it looks brilliant Sacha and the testing results are great imo.
Im making a load tester something like yours with a variac a 3amp mcb and 300watt heat cartridge Id like to pick your brains about wiring it up right if you dont mind Im going to use a plug in wattage and current meter to messure the watts.
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I think it is one of the cooler builds here on xs
The design ROX.
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