The Relativistic Heavy Ion Collider (RHIC) Refrigerator System at Brookhaven National Laboratory: Phase III of the System Performance and Operations Upgrades for 2006

摘要

An ongoing program at Brookhaven National Laboratory (BNL) consists of improving the efficiency of the Relativistic Heavy Ion Collider (RHIC) cryogenic system and reducing its power consumption. Phase I and II of the program addressed plant operational improvements and modifications that resulted in substantial operational cost reduction and improved system reliability and stability, and a compressor input power reduction of 2 MW has been demonstrated. Phase III, now under way, consists of plans for further increasing the efficiency of the plant by adding a load "wet" turbo-expander and its associated heat exchangers at the low temperature end of the plant. This additional stage of cooling at the coldest level will further reduce the required compressor flow and therefore compressor power input. This paper presents the results of the plant characterization, as it is operating presently, as well as the results of the plant simulations of the various planned upgrades for the plant. The immediate upgrade includes the changes associated with the load expander. The subsequent upgrade will involve the resizing of expander 5 and 6 to increase their efficiencies. The paper summarizes the expected improvement in the plant efficiency and the overall reduction in the compressor power.