Problem - Liquid Unable To Become Vapor During Suction

[hongyunref]

Hi All, I'm not expert in Engineering Work,

Currently I faced a big problem regarding liquid unable to become vapor during suction and some liquid will return to compressor.

This screw compressor was a 90HP's Chiller Medium Temp Compressor with Old Multi-System and MODIFIED to 150HP's Freezer Low Temp Compressor with 4 Blowers Currently, Temperature can up to -25'C.

Will this problem link to orific, expansion valve or suction accumulator?

Hope everyone could lend me a hand to solve this problem.

Thanks...

[Sumit]

Hi,

How u come to know that liquid refrigerant is entering in the compressor ? As per my knowledge, the amount of the refrigerant entering the evaporator is not properly controlled(which is dependent on the load on chiller).Hence the problem is associated with orifice.

[Done it all]

Are you sure liquid is coming back to compressor? Ice on suction line and compressor is normal as suction line temp will be below 0°c, this does not mean floodback.
If it is floodback, fault will be either expansion valve is faulty, feeding too much refrigerant for some reason. Or evaporator is not absorbing enough heat load from room, due to faulty fans or iced up.

[hongyunref]

Hi,

How u come to know that liquid refrigerant is entering in the compressor ? As per my knowledge, the amount of the refrigerant entering the evaporator is not properly controlled(which is dependent on the load on chiller).Hence the problem is associated with orifice.

Hi, Thanks for your reply,
Because the noises from compressor, so I suspect that liquid return to compressor.
Besides, the model for the compressor is Bitzer OSN-7471K with economizer system, will this system affect the floodback?

[RusBuka]

Provide data: SH, SC, DSH, current on full load, delta T in and out.
Expansion valve of economizer system can be locked in one position.

[Gary]

Start here:

http://www.refrigeration-engineer.com/forums/showthread.php?19701-Refrigeration-101

[nike123]

Will this problem link to orific, expansion valve or suction accumulator?


Thanks...

Have you got installed suction accumulator on that circuit?