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Hello,
I am thinking about system balancing.
What we do with capillary tube if we use the same compressor for another unit with smaller heat exchanger, should we lengthen or shorten it to get maximum capacity. :eek:
For charging I usually adjust the superheat.
Appreciate any logical explanation.
.
When you use a capillary tube you charge the refrigerant to an exact weight
and that is because the capillary tube has no control.
The weight of refrigerant is designed to be just enough so the liquid is
turned back to vapour inside the evaporator just before it exits the evaporator.
If there was too much liquid, the liquid would spill out of the evap and flood back to the comp.
If there was too little liquid, there would not be enough inside the evaporator so performance will suffer.
The balance is having the correct amount for when the system is at normal operating temperature.
If you change the size of the heat exchanger all your calculations will be wrong.
Your capillary may still be ok but you would put less refrigerant in.
It is not a straight forward, easy to answer solution though, because you
would have to redesign the system and then run on test to prove all is ok.
Regards
Rob
.
Hi
in order to design a balanced system ; compressor should be selected ±7% evaporator capacity. You cannot use the same compressor for a smaller capacity heat exchanger as that would lead into liquid flood back into the compressor
Regards,
Sendhil
Thank you Rob and Sendhil for your comment.
I am working in repair company for commercial refrigerator, and dealing with quick fixing. Howeaver also interesting in design, could you give any link about detailed design.
Not if you charge less refrigerantQuote:
Originally Posted by sendhilkmar