Performance of RHIC Refrigerator IV: Heat Exchangers

In February 1996, the RHIC Refrigerator was successfully cooled to liquid helium temperature with 10 kilowatts of heat input at 4.5 K, 53 kilowatts of heat input at 60 K and 44 grams per second of liquid extraction. A comprehensive analysis was performed to evaluate the performance of the refrigerator including the turbines, the cold vacuum compressor and heat exchangers. Because of the amount of data and number of charts involved, the report is divided into five technical notes on, respectively: 1) Flowmeters, 2) Turbines, 3) Cold Vacuum Compressor, 4) Heat Exchangers and 5) Refrigerator Overall Performance. This technical note describes the performance of the Turbines.