Emergency Shutdown Procedures for Refrigeration Station

The compressor shall be subjected to emergency shutdown upon occurrence of faults including power failure, lube oil pump malfunction, explosion, fire,

loss of cooling water, loss of instrument air, and uncontrollable compressor surge. In case of system fire, rapidly cut off the propylene feed source and perform nitrogen purging while maintaining system pressure.

• Trip the compressor for emergency shutdown either locally or in the control room. If practicable, measure and record the coast-down time. Switch the compressor primary seal gas to medium-pressure nitrogen.

If the oil circulation system remains operational (no power outage and low-pressure nitrogen supply is available), engage barring immediately after the rotor comes to rest. In the event of plant-wide power failure,

turn the operating pushbuttons of jet water pumps, condensate pumps and lube oil pumps to the OFF position in a timely manner to prevent automatic pump startup upon power restoration.

Close the compressor second-stage discharge valve.
Close the main propylene inlet and outlet valves of the refrigeration system.
Stop the jet water pump and shut off the shaft sealing steam when vacuum approaches zero.
Adjust the recycle flow as required; slightly open the supplementary demineralized water valve if necessary. Shut down the condensate pump after closing the ejector inlet valve.
Investigate and identify the root cause of the emergency shutdown.