Condenser outlet lower than receiver inlet.

[Pawel_Wisnik]

We applied solution in installation where condenser’s discharge outlet was at lower position than liguid receiver inlet fig(1). In order to avoid condenser to be flooded, a 1,5 meters long Ø64 mm horizontal pipe as “pre-liqud receiver” with volume at least twice than pipe riser. Our goal was to avoid flooding at all. I ask you for comment whether such solution makes sense at all, or we could do that just as simple as on fig (2).
Other datas:
-R 404A
-minus range
-air cooled condenser
-vertical liq. receiver
-horizontal distance between liquid receiver inlet-condenser header ~2,5 m
-condensate line diameter Ø35 mm

brgpavelfig(1).jpg

fig(2).jpg

[LRAC]

We applied solution in installation where condenser’s discharge outlet was at lower position than liguid receiver inlet fig(1). In order to avoid condenser to be flooded, a 1,5 meters long Ø64 mm horizontal pipe as “pre-liqud receiver” with volume at least twice than pipe riser. Our goal was to avoid flooding at all. I ask you for comment whether such solution makes sense at all, or we could do that just as simple as on fig (2).
Other datas:
-R 404A
-minus range
-air cooled condenser
-vertical liq. receiver
-horizontal distance between liquid receiver inlet-condenser header ~2,5 m
-condensate line diameter Ø35 mm
]

Hi Pawel_Wisnik

I cannot see the benefits on your system of not flooding the condenser, this will occur under normal operating conditions as the condensor will do just that and condense the refrigerant.

Unless this is a new design theory or application that i'm not aware of?

Regards
Lrac

[koosjr]

Me too can see no benefit. If a condenser starts running cold, it will automatically flood to balance the heat transfer no matter where the outlet. In fact, I did it once by accident and there was absolutely no difference in how the condenser worked.

That is precisely the reason for a receiver: To keep enough liquid to flood the condenser under cold ambient conditions and still supply the evaporator with liquid.

I won't try to avoid condenser flooding at all. It is essential for any working system

[Pooh]

If there is a problem most of the condensing units I have seen over the years would suffer from the problem, I thought it was the pressure from the compressor that moved the liquid not gravity. Please let us know if there is something we are missing.

Ian

[The Viking]

I've worked on a system in the distant past that did suffer from a flooded condensor.
But that was a bit special, the receiver were 4 floors above the condensor and the discharge line were undersized. As a result it tripped on HP before it started to circulate the refrigerant in (Swedish)cold conditions.
If my memory serves me right it was an old R12 unit but it might have been R502.

As far as I remember, we sorted this by fitting a non return valve after the condensor.

[DeB]

Most small condensing units are fitted with a vertical receiver and an inlet pipe higher than the condenser outlet. This does not pose a serious problem as the amount of liquid that will back up will depend on the volume of liquid in the vertical column and the PD in the condenser. If the volume in the vertical drain line is small then there should not be a significant problem to worry about. You could always install a balance line between the top and bottom of the condenser to overcome the PD.

[DeB]

Most small condensing units are fitted with a vertical receiver and an inlet pipe higher than the condenser outlet. This does not pose a serious problem as the amount of liquid that will back up will depend on the volume of liquid in the vertical column and the PD in the condenser. If the volume in the vertical drain line is small then there should not be a significant problem to worry about. You could always install a balance line between the top and bottom of the condenser to overcome the PD.

[Pawel_Wisnik]

Hi All,
many thanks for your hints & remarks. Now all my doubts are dispelled.

Brgpawel