Air in the condenser...

[Marty]

One time when I was on a boat to China, I had the job of baby sitting the refrigerated container vans. One of the 'reefers' developed a leak in the evaporater. Since the set point was -13F and the refrigerant was R134a air leaked into the evaporater. Then the air migrated into the condenser and caused a reduction in cooling ability and high discharge pressure. Now here is the part I don't understand. What the 'reason' why the air migrated into the condenser??????????????

[r.bartlett]

it doesn't migrate there it gets pumped by the compressor and due to the nature of non condensables air gets trapped as it can't condense and flow out of the liq line

cheers

richard

[HeatMan]

As I see it, virtually all the refrigerant would have had to leak out to allow air to get into the system.

How low did the refrigerant level get?

[Bert]

Wouldn't the evap be in a vacuum at that temp or maybe a pump-down system?

MikeB

[PrecisionMachinisT]

Somewhere in the system the pressure got below 1 bar.

[Vicki Szaszvari]

Nope, just enough that the low side was in a vacuum.

[Marty]

Yes the evaporator went into a vacuum because very low temperature and the type of refrigerant. If the set point on the reefer was say

+32F then refrigerant would have leaked out of the evaporator.

[Marty]

I know it can't condense, but why doesnt't it flow. Because the air is now separated from the refrigerant? Shouldn't liquid refrigerant still be able push the air along the liquid line.

[Marty]

The refrigerant level was normal. Refrigerant was not leaking out of the unit air was leaking into the system.

[Stormin Mormon]

Try to imagine a big, glass, about a galon pickle jar.

drill a hole in the bottom of the pickle jar. Put a tube on the bottom. Put in an inch or so of water.

Drill a hole along the side, near the top. Pump in a little air, and some water.

Keep draining water out of the bottom. The air is still trapped in the jar.

Crude, but the kind of idea.

The air is above the liquid refrig. the liquid line to the evaporator comes off the bottom of the condensor.