setting or checking delta pressures on liquid chillers
setting or checking delta pressures on liquid chillers
(OP)
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.





RE: setting or checking delta pressures on liquid chillers
RE: setting or checking delta pressures on liquid chillers
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.
RE: setting or checking delta pressures on liquid chillers
RE: setting or checking delta pressures on liquid chillers
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.
RE: setting or checking delta pressures on liquid chillers