setting or checking delta pressures on liquid chillers 1

[thelobster]

Hello All, My workplace has 13 water cooled liquid chillers for A/C only my duties have changed and Im starting to dig into these machines a little deeper. Im looking for info either web sites or literature on setting them up a little better, no drastic moves just trying to feel my way around them.

 

[joejoedancer]

Try the Trane website. They have excellent free engineer's newsletters that provide application assistance with chiller system configurations (parallel, series, variable primary, primary-secondary). They also have more in-depth info for a very nominal fee, many are comprehensive design manuals for 15 bucks or so.

 

[Pete130]

Try to be careful and log anything before you change it.
Any change to the water flow rate on either side has a direct effect on the refrigeration system.

i.e. if you reduce the evaporator flow rate because you appear to see a lower leaving water temperature due to the increase in delta T across the evap, the superheat (cooling to the compressor windings) may increase, causing the chiller to run less efficiently to say the least.

If you try to lower the chilled water setpoint, you may freeze the chiller, or overlap with the freeze setpoint causing trips. you could also reduce the ability of the chiller to return the oil to the compressor.

There are a million things that can go wrong because of small changes, so the message is don't change anything unless you a re 100% sure of the consequences. That being said, if the chiller was commissioned correctly initially, all safety parameters should be programmed to protect the chiller to a certain extent.

 

[thelobster]

Thanks for the advice, and info from both of you. Im in the research stages. I have my hands full with just getting these puppies and their towers ready for start up, once things settle down Im going to start looking at it more seriously. Thanks again .

 

[lilliput1]

Make sure there is a water treatment contractor taking care of the condenser water, chilled water and heating water.
Repair broken insulation & vapor barrier.
Read the building controls sequence of operations particularly in regards to lead/lag/alternation, chiller sequencing and start up.
Make sure each chiller has operating chilled water and condenser water flow switches to prove correspnding flows before allowing chillers to be energized.
Read each type chiller operating and maintenance manual. Confirm preventive maintaninance is being practice. Log each chiller service record on computer using Excel for easy reference. Include chiller data - model, serial number, when installed.
Get to know each chiller make, local rep.
Consider adding chiller graphics on the Building Automation System (BAS)workstation to allow BAS monitoring, leag, lag alternation, status check and logging.

 

[thelobster]

Ill have to say yes to all the above, I work for a college, I keep theses machines very well maintained. Trane ,York are contracted for certain things(i.e. winter maintenance on 400, 600 ton centrifugals) and the rest is up to me. Siemens provides our building automation.I also have some help taking care of a dozen air cooled chillers from 30 to 250 tons and tons and tons of packsge and split systems.Im pretty well versed in refrigeration, Im not so well versed in checking or setting up the waterside on some of these machines. I thank you all for your advice, Im going to stick with this forum, there is good stuff going on here.