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mohamed khamis
09-05-2006, 04:13 AM
Hello forum users

I wonder if the accumulator can be used in the system which involves TXV and receiver-direr without causing operational problems. My knowledge is that the accumulator is only used with the capillary tube not with TXV. Any help is greatly appreciated. Thank you

best regards

afeef
09-05-2006, 07:25 AM
hi mohammed
the suction accumulator is used with tev systems
it give stability to system and constant suction pressure
regards

mohamed khamis
09-05-2006, 08:04 AM
Hi afeef

Thank u for ur kind reply. However, my experience is that the TXV regulates the refrigerant flow correspondingly to the imposed cooling load on the system by adjusting the degree of superheat. Thereby, the TXV ensures that the refrigerant will be passed to the compressor is almost 100% dry. Therefore, the accumulator is not negated in this case and will be effective only during the existence of capillary tube, correct me if i am wrong. Regarding to the action of its function as absorber for moisture and to remove debris from the system, this role is taken by the receiver-drier which is necessary to be installed with TXV. So now all the roles of the accumulator are already accomplished by TXV and receiver-drier. In addition, the system does not need the accumulator in this case unless it is necessitated more protection for the compressor from ref. liquid with taking into account the more suction side pressure drop. Enlighten me if it is not true.

Best regards

afeef
09-05-2006, 08:21 AM
hi mohammed
you are right about the purpose of accumulator.
i find the accumultor instauled with tev system , also it instauled in capllary systems
thanks for explanation
good day

mohamed khamis
09-05-2006, 09:09 AM
Thank you afeef. Have a nice day .

my regards

Dan
10-05-2006, 02:08 AM
Hi Mohamed


My knowledge is that the accumulator is only used with the capillary tube not with TXV. Any help is greatly appreciated. Thank you

Accumulators are used very often with TXV systems. Especially in refrigeration systems. I cannot say that I wholeheartedly agree with their use, but I can provide some rationals.

On heat pumps and simple hot gas defrost systems, they are there to provide a safety tank for unevaporated refrigerant that has been switched to travel back down the suction line from the evaporator.

With low temperature refrigeration systems, iced up coils occur often enough to permit the exansion valves to overfeed and flood back to the compressors.

Accumulators are not without their drawbacks. They are often made of steel and will rust through. They can plug the oil return oririfice and starve the compressor of oil. And finally... just how large should the accumulator be?

Julian
10-05-2006, 04:21 AM
Hi Mohammed

Suction line accumulators are just for added protection, if coils ice or your evaporator fans trip trip you run the risk of getting liquid refrigerant back to the compressor.

Accumulators are selected by the by the system capicty @the deign SST

mohamed khamis
10-05-2006, 04:47 AM
Hi Dan
Thank you so much for wealthy information and good explanation.

regrads

mohamed khamis
10-05-2006, 04:53 AM
Hi Julian
Thanks for your clarification of accumulator purpose

dogma
10-05-2006, 06:42 AM
Hi Mohamed



Accumulators are used very often with TXV systems. Especially in refrigeration systems. I cannot say that I wholeheartedly agree with their use, but I can provide some rationals.

On heat pumps and simple hot gas defrost systems, they are there to provide a safety tank for unevaporated refrigerant that has been switched to travel back down the suction line from the evaporator.

With low temperature refrigeration systems, iced up coils occur often enough to permit the exansion valves to overfeed and flood back to the compressors.

Accumulators are not without their drawbacks. They are often made of steel and will rust through. They can plug the oil return oririfice and starve the compressor of oil. And finally... just how large should the accumulator be?


I agree completely. Although, a good service tech should purge with N2 while braising so there should be nothing in the system to block the oil return orifice.

Unless there has been a burnout where the burnout dryer should be place prior to the suction accumulator. As for "rusting"? If it is installed in a location where the system is prone to corosion I'd sujest giving it a coat of Kirby coat or Kill rust to be ultra safe. Will only cost you 50cents for that piece of mind. You would usually find a CPR valve after the accum. where there is H/G defrost. Applications with H/G defost in my opinion MUST have an accumulator.

;) :D

frank
10-05-2006, 09:02 PM
Applications with H/G defost in my opinion MUST have an accumulator.

Exactly the same statement that I made a short time age in a thread started by LC_shi regarding a de-humidifier project.

Our friend M.O'b queried this stating that it was not necessary.

Any comments anyone??

US Iceman
10-05-2006, 09:22 PM
My experience with TXV's and refrigeration systems is one where I suggest an accumulator on any system. Sooner or later the system will exhibit some behavior where someone will wish they had installed one before the compressor went to pieces.

It is simply cheap insurance for a lot of problems that can and do occur. Of course for some, the problem is simply being cheap and saving the upfront cost of the accumulator.

Indeed, for hot gas systems the potential for liquid flood back is much higher and I would agree with the previous statement.

Andy
12-05-2006, 09:14 PM
Exactly the same statement that I made a short time age in a thread started by LC_shi regarding a de-humidifier project.

Our friend M.O'b queried this stating that it was not necessary.

Any comments anyone??
Needs an accumulator, or a re-evaporation coil. As per the thermostore set uo Iceman posted previous.

Me I use an accumulator;)

Kind Regards, Andy:)

US Iceman
12-05-2006, 10:00 PM
HI Andy,

Those Thermobank units were some of the first ones I found that were built without accumulators. And as usual they should have been supplied by the factory.

Later versions are provided.

Did not make for a very happy customer I can tell you.:(