New to Forum, Facing problems related with TRANE Chiller

[neerajpuranik]

Dear Friends,
Hello to all the refrigeration experts here. I want to improve my knowledge in this field with help & support of you guys. I am basically a Instrumentation Engineer & my contact with Trane chillers is just 2 years old. In my last job I had opportunity to work on Trane RTAD & RTHD. I had my good & bad days with them in Democratic Republic of Congo working for a Palm Oil refinery. I thought I will not see them again with a new job & new country but here I go again.
In a Palm Oil Refinery chillers are used for Factionation & good quality of Oil output depends upon chilling system.
We have Trane RTWA212 & the problem I am facing is " High Oil Temperature ". The Setpoint is 5 Deg but on load it is seldom reached. As per my observation when the water entering Evaprator is at temperature 11 Deg C while water leaving evaprator is around 9.5 deg i.e Delta T of 1.5 deg only. It has a water cooled condenser. The water entring in condenser from cooling tower is at 22 Deg C while water is leaving condenser at 27 Deg C. The cooling tower temperatures are low as the weather in Kenya is bit cold compared to other African countries. This is a 10 yr old unit & was working trouble free all these years. Detais of unit:
ERTWA212
EKH4698 – 1997

[Lowrider]

When running, are both compressors running and if so at which RLA?

1.5 K delta T across the evaporator and chiller in full load,which it sounds like according to the delta T across the condensor the flow across the evaporator is too high!

[frank]

I would agree.

the first thing to do is to restrict the water flow through the evap. If you do not have any flow meter then you can do it by temperature readings. Target differential is 5 or 6K

The high oil temp alarm is caused by the high superheat (lack of cooling suction gas.)

As you slow the water flow through the evaporator, keep an eye on the temps in the condenser. If they get too high, adjust this flow as well.

[nike123]

Dear Friends,
Hello to all the refrigeration experts here. I want to improve my knowledge in this field with help & support of you guys. I am basically a Instrumentation Engineer & my contact with Trane chillers is just 2 years old. In my last job I had opportunity to work on Trane RTAD & RTHD. I had my good & bad days with them in Democratic Republic of Congo working for a Palm Oil refinery. I thought I will not see them again with a new job & new country but here I go again.
In a Palm Oil Refinery chillers are used for Factionation & good quality of Oil output depends upon chilling system.
We have Trane RTWA212 & the problem I am facing is " High Oil Temperature ". The Setpoint is 5 Deg but on load it is seldom reached. As per my observation when the water entering Evaprator is at temperature 11 Deg C while water leaving evaprator is around 9.5 deg i.e Delta T of 1.5 deg only. It has a water cooled condenser. The water entring in condenser from cooling tower is at 22 Deg C while water is leaving condenser at 27 Deg C. The cooling tower temperatures are low as the weather in Kenya is bit cold compared to other African countries. This is a 10 yr old unit & was working trouble free all these years. Detais of unit:
ERTWA212
EKH4698 – 1997

I would first check flow with some flow meter. If you have designed flow, than your chiller is loosed his cooling capacity for some reason. If you don't have designed flow, than you should adjust flow (in your case reduce flow). But, as you said that unit is worked 10 years trouble free, I doubt that it is sudden increase in flow possible, if nothing is changed in system.