PLATE HEAT EXCHANGER
We attended a callout to a chiller in alarm, on arrival we found a system short of refrigerant. We carried out a full pressure test and could not find a leak, even though our test pressure was falling. A re-think was needed, everything pointed to a failed Evaporator Plate Heat Exchanger.
We decided to separate the Condenser and Evaporator Plate Heat Exchanger and recover the refrigerant from the other system. We also isolated the chilled water system around the Evaporator Plate Heat Exchanger. We pressure tested the systems and found a cross leak between System 1 and the Chilled Water circuit. A new Evaporator Plate Heat Exchanger was required.
We went to the Manufacturer who supplied a replacement Evaporator Plate Heat Exchanger with different dimensions and centre lines; they did warn a little re-engineering was required…… During the works we noticed that the suction line exit from the old Evaporator Heat Exchanger was severely restricted by makeshift fittings, certainly impacting the unit’s efficiency. We re-engineered the suction line, installed new EEV Valves using the existing drivers. A successful pressure test with a triple evacuation procedure to dry out the systems saw a final Vacuum Rise Test indicating no leaks and no moisture present. A virgin refrigerant recharge of R407C and a recommission brought the chiller back into service for process cooling.