We have a 13.5 HP glycol chiller running a mix of 30 and 60 bbl tanks. This unit has been in operation for 4 years and has had zero issues to this point, routinely crashing tanks to 32 F in the heat of Florida summer. 3 hp product pump and 1.5 hp glycol pump, 200 gal reservoir filled well over the minimum.
Issue is the chiller can drop a 30 bbl tank from 75 F down to 38-40 F in <12 hrs, but stops there. I do not believe it is a loop/piping issue. The glycol inside the unit hangs in the low-mid 30's and never reaches its 26 F setpoint, even with minimal load on the system. Have read a lot about flowing glycol too fast preventing proper heat exchange... But our tank farm has not really changed since we started having this problem, and we still are not reaching 26 F inside the chiller.
Glycol concentration is at 35%, per manufacturer spec. Compressor was recently replaced, after days of testing and discussion between our HVAC techs and the manufacturer. After continuing to have issues (although not as bad as before -- the compressor was clearly dying), the TXV was replaced as well.
On the refrigerant side, the suction pressure is somewhat low. And at the TXV's manufacturer-spec'd adjustment, we don't get sufficient cooling, i.e. we can barely pull down loads. Opening it up a touch helps, but too much and we slug refrigerant into the compressor. It seems to be a catch 22. What the manufacturer is specifying and what we then achieve do not line up.
Wondering if we have managed to clog or foul the chiller's heat exchanger. Not sure how, with a Y-strainer on the glycol return, and not sure it makes sense with a decreased flow across it that we're able to crash tanks, yet not pull the glycol temp down...
Issue is the chiller can drop a 30 bbl tank from 75 F down to 38-40 F in <12 hrs, but stops there. I do not believe it is a loop/piping issue. The glycol inside the unit hangs in the low-mid 30's and never reaches its 26 F setpoint, even with minimal load on the system. Have read a lot about flowing glycol too fast preventing proper heat exchange... But our tank farm has not really changed since we started having this problem, and we still are not reaching 26 F inside the chiller.
Glycol concentration is at 35%, per manufacturer spec. Compressor was recently replaced, after days of testing and discussion between our HVAC techs and the manufacturer. After continuing to have issues (although not as bad as before -- the compressor was clearly dying), the TXV was replaced as well.
On the refrigerant side, the suction pressure is somewhat low. And at the TXV's manufacturer-spec'd adjustment, we don't get sufficient cooling, i.e. we can barely pull down loads. Opening it up a touch helps, but too much and we slug refrigerant into the compressor. It seems to be a catch 22. What the manufacturer is specifying and what we then achieve do not line up.
Wondering if we have managed to clog or foul the chiller's heat exchanger. Not sure how, with a Y-strainer on the glycol return, and not sure it makes sense with a decreased flow across it that we're able to crash tanks, yet not pull the glycol temp down...
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