Explanation of single stage, dont get it!?

[floshey]

Okay i'm kinda new to the whole phase-change, or actually i'm not.
I've been reading a whole lot of how to make a single stage or chiller and so on, but there is one thing i just can't understand.

The compressor compresses the gas into a liquid, right right, thats easy, and then the liquid continues to the condenser , and then to the filter removing moisture or impurities, from there the liquid continues in the cap tube, what lenght to use has Gary described in an earlier thread. but THEN, fx on my vapochill, the cap tube disappears in a isolated hose. And i can see the insulation begins on the compressor, which means the cap tube and the discharge line will have something in common? (The sunction line is connected to the condenser, right?) Can someone please tell me how the evaporating process works.

(I'm not sure, when the refrigerant is in liquid form or gas form?)

I'm thinking of making a chiller, or copying asetek's work and make a homemade vapochill, to get some experience to start off with. (Dreaming of a cascade with ethylene as 2nd stage gas, but i know i don't have the experience to make it, hehe ;))

[SlackeR]

the gas goes from the compressor to the condenser, where it is cooled down and condenses. that is the point it turns liquid. it is filtered, runs through the captube, which on your vapo is run either inside the suction line or wrapped around it. the liquid gas evaporates in the evap head and is run through suctionline to compressor. suction and captube is insulated together. this has the sideeffect that when pressure drops through captube the captube gets cold and cools the now hot refrigerant in the suction hose.

[100]

compressor(HOT GAS)->condensor(LIQUIFIED COLD GAS)->capillary tubing(LIQUID)->evaporator(GAS)->suction line back to compressor(COLD GAS)

[floshey]

Ok, but i still don't get the sunction line/captube. Can you run the cap tube INSIDE the sunction line? And is this possible on all compressors

Thanks for the replies.

[bh2k]

I always thought it was backwards....condeser condensed it then it was compressed into a liquid and put through the evao then returned to the condeser through the cap tube to be re condensed and compressed...

[HawainPanda]

floshey, look at this pickture, it moves clockwise
http://www.refrigerationbasics.com/1024x768/loop_charging2.jpg

[HawainPanda]

except, instead of the txv, theres a captube and no accumulator(that cylinder after the condenser)

[floshey]

If were talking direct die phase change, the cap tube will go all the way down inside the evaporator and apply the liquid to the surface of the evaporator, then the liquid turns into a gas, and goes through the sunction line into the compressor where the cycle continues. Please tell me this is correct or my head will explode

[Pandrone]

Originally posted by floshey
If were talking direct die phase change, the cap tube will go all the way down inside the evaporator and apply the liquid to the surface of the evaporator, then the liquid turns into a gas, and goes through the sunction line into the compressor where the cycle continues. Please tell me this is correct or my head will explode

Yepp, that's correct.

[floshey]

So what would be the advantages/disadvantages of running the cap tube inside the sunction line instead of running it outside?

[Redwolf]

More subcooling of the liquid refrigerant. Subcooling mean liquid cooled below its saturation point. So that can of soda you have sitting there.. is subcooled. Because its below its boiling point and above its freezing point.

Now the reason why we want to subcool the liquid is simple. The closer we get the liquid to the accual saturation tempature of our evap the more Watts (Btu/hr) we will get out of it. Every little bit counts.

Btw.. there is no accumulator. The vessal after the condensor is called the receiver.

[floshey]

So the smartest thing to do, is find out what length of cap tube you are going to use, circle it around before it enters the sunction line and just make a straight cap tube inside the sunction line down to the evaporatpr, or will it be better to get more mass of the cap tube inside the sunction line. fx running the cap tube directly to the sunction line, and then bend it so most of the cap tube mass will be inside the sunction line?

(Hope you can understand my bad english :))

[SlackeR]

i dont think it is good to stuff ti all into suction line. eventually you could run it inside suction and wrap the rest around it to ensure good subcooling.

[HawainPanda]

acummulator...receiver samething? no?

[Redwolf]

Run the captube straight thru the suction line. Then coil up the rest before it enters the suction line.
Raping the captube around the suction line works too.

An acummulator is in the suction line. Its job is to catch any liquid refrigerant that might make its way out of the evap.

A receiver is a pressure vessal which stores exess liquid and helps to insure pure liquid going to the metering device.

[100]

"Ok, but i still don't get the sunction line/captube. Can you run the cap tube INSIDE the sunction line? And is this possible on all compressors"

yes, no problem. that is what the commercially sold systems do.

[Gary Lloyd]

Most commercial systems have the cap tube wrapped around the suction line and/or soldered to the suction line. Running it inside the suction line does the exact same thing. It cools the liquid in the cap tube, while warming the vapor in the suction line.