Oversized Liquid Recievers?? Problems??

[nickjh]

Are there any problems associated with using oversized liquid recievers.

Basically i have pumpdown 15-16kg of charge, thus require about 18kg of pumpdown capacity. However have 28kg liquid reciever.

Is there problems with using oversized liquid reciever?? Will this result in gas being sucked out of liquid reciever back into the cycle thus reducing efficiency of system.

Also what problems are there associated if gas state refrigerant is drawn out of liquid reciever back into the cycle

[Peter_1]

The only problem you will have is that it is more expensive. It can never be tto big but it is many times too small.

[LRAC]

The only problem you will have is that it is more expensive. It can never be tto big but it is many times too small.

Spot on Peter-1 the amount of jobs we go to and you can't pumpdown properly.

Kind regards
Lrac

[taz24]

Are there any problems associated with using oversized liquid recievers.




Also what problems are there associated if gas state refrigerant is drawn out of liquid reciever back into the cycle


I agree with the others.
You will not done any harm if the receiver is over sized.
It will have no detrimental effect to the system at all.
If vapour passes out of the reciever then you have other problems, these will not have any bearing to the size of the reciever.

Cheers taz.

[US Iceman]

Also what problems are there associated if gas state refrigerant is drawn out of liquid reciever back into the cycle


On one system where this was done we found the receiver had a tendency to collect oil. My believe was the gas drawn off of the receiver (similar to a cool gas defrost system) allowed the receiver to operate as a distillation device and concentrate the oil accumulation in the receiver.

[old gas bottle]

only thing i can think of is it makes for a bigger system that just needs more gas,it will need filling upto the dip tube if its horizontal for the liquid supply, that if it was smaller would take less refrigerant, so as the guys state,better that way than not enough, jump up and down on it a bit to resize it !:D

[Brian_UK]

Well, that's his college question answered for today ;)

[nh3wizard]

Well, that's his college question answered for today ;)

I wonder how many people RE has put through college?:confused:

[US Iceman]

We should work out an arrangement with the members for training costs!:D

[Brian_UK]

We're back to to going rate for doughnuts (donuts) I think ;)

[nickjh]

Not a college student, but yes im learning on the job.

Adding more refrigerant charge to the system?? could you please elaborate on this, is there any issues of adding extra charge to the sytem. Also the liquid reciever is going to be functioning in a ship enviroment hence the concern about drawing gas in rough seas. Is there any functional issues/concerns if gas is being drawn. There is not room to mount vertically to overcome inclination issues.



only thing i can think of is it makes for a bigger system that just needs more gas,it will need filling upto the dip tube if its horizontal for the liquid supply, that if it was smaller would take less refrigerant, so as the guys state,better that way than not enough, jump up and down on it a bit to resize it !:D

[US Iceman]

Shipboard refrigeration systems are a special breed that require some additional considerations. Once of those is what you mentioned about the ship rolling and pitching.

In a standard receiver the diptube (where the liquid comes out of the receiver) is normally cut at a 45° angle and located just above the inside shell radius. Obviously, if the ship rolls the liquid refrigerant follows the angle of the ship.

You may have to use a receiver with an deep enough sump under the diptube to provide sufficient sealing of the diptube. The sump would also have to have sufficient volume to accommodate the refrigerant volume flow at full load during the worse condition.

One of our regular members (Tycho) may be able to offer some additional insight into this problems also.

[old gas bottle]

the plot thickens !, i dont work on ships but can see the pit falls,i,am not sure a vertical one will be the best solution as you may end up with a reduction in capacity, do they not make one for this application ,horizontal but with a deep diptube and some baffles inside ? that may help in rough seas,:eek: