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Check these photo's out, bet your Trane chiller can't do this. First photo is design data, second is flow across evaporator barrel and third is operating data. Under these conditions I have 4650 gpm across the evap, doing approx 1898 tons. The design is 1600 tons. No oil problems everything was running smooth.
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Have you been experimenting with colder condenser water? I have been reading in our YK's engineering manual that you can use an equation to calculate the condenser water temp. According to my calcs we can use condenser water as cold as 40f. I am scared to try it though. When you do that with a YS you'll knock the oil right out of it.
Our BMS controls the cooling tower bypass. I could put that equation in program and let it determine the condenser water set point. Right now it's fixed at 65 F.
Professional Member
YK's are much different than YS's...you can still have tower water that is too cold and it will give you problems, but the YK is much more tolerant than the YS.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Regular Guest
Well 40 does seem kind of low but I would like to test out some colder water. But I don't wont to ruin my good chiller because it runs and always has run great
Professional Member
4650 GPM when design is 2740?Originally Posted by chad_nc
Professional Member
The max gpm for that evap barrel is around 5400 gpm, I have had them as high as around 4900. I dont want to push it to much. When the machine comes off of the plate heat exchanger over to mechanical cooling the condenser water is in between 47 and 48, It takes a couple of hours to warms the water up to the setpoint of 60 but it runs great. obviously we cant run that much water across the evap in the summer when we have 80 degree condenser water coming back on it.
Professional Member
have exp on cooler cond water temp it started to surge did not like it went back to flat plate .
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I have a couple 900 ton CVHF's that take on river water.. Their heat exchanger was down for repair and i had water coming in at 42 haha. No oil loss problems. obviously i had to throttle down on the condenser water to keep it running.
Regular Guest
Would running your condenser water temp that low have any effect on your VSD coolant?
Professional Member
All bets are off when any chiller is operating outside of it's design envelope. This goes for water volume and temperature. Manufacturers shouldn't pitch a customer on the efficiency of their machine based on conditions they may only see a few times a year.
I know for a fact that you can run Tranes as low as 55 deg F without special accommodations like throttling valves and whatnot. We rarely see condenser water temps that low here, and then only for a few days out of the year.
I got a question for the OP, can your York run those low condenser water temps without it's liquid level control, variable orifice, and it's associated controls?
Don't pick the fly crap out of the pepper.
Professional Member
I'm not the OP, but before the variable orifice came into being the only requirement for the condenser water was it had to be warmer than the leaving chilled water. I've run York YTs with fixed orifice at 50*F without any problem. Remember the variable orifice is there to insure the subcooler remains flooded. The entering condenser water temperature isn't a factor in its operation.
Professional Member
I got a question for the OP, can your York run those low condenser water temps without it's liquid level control, variable orifice, and it's associated controls?
I am sure it could, with those controls and the cold condenser water it causes the chiller to stack more refrigerant in the condenser which obviously means less in the evaporater. So if the level is set to high under design conditions (which they are not) it could possiblly cause the machine to trip on low evap pressure. Most places around here you dont have the capability to flow that much h2o across the evap, I just thought it would be fun to experiment a little bit. I dont run these machines at those conditions all the time. Also these machines do not have vsd's, they are medium voltage SSS, so I dont have to worry about the starter fluid getting to cold.
Regular Guest
Is this one of the infamous "Chad's" from Greensboro?? Haha
Professional Member
On Yorks the lowest you can run condenser water is 15 degrees above leaving chilled water setpoint. Anything below that the oil usually doesn't come back, especially at part load.
Edit: auto correct wreaks havoc on anything technical I try to post from my phone.
Sent from my SPH-L900 using Tapatalk 2
Professional Member
Not true, but if you want to run at 15*F above CHW setpoint that's fine. I've had chillers running with condenser water as low as 10*F above leaving CHW temperature. Oil return is generally not a problem with York chillers and it improves as the PRV go toward closed. The only problem I experienced running cold condenser water temperatures was a slightly elevated oil temperature because there wasn't enough differential pressure to feed the oil cooler properly.
Professional Member
15 above was always what I was told to go for from the factory , most likely because of those oil temp issues you mentioned. I never really pushed it but obviously it can be done as seen in the OP's picture. The only time I really see oil problems on Yorks are when they stay unloaded.
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