Cooling water systems for accelerator components at the Advanced Photon Source.

As in most accelerators at the Advanced Photon Source, water is the media of choice for absorbing heat generated by a multitude of accelerator components. A large cooling water distribution system with flow rate of nearly 10,000 gpm in the primary circuit and small closed-loop water systems with flow rates of less than 100 gpm are installed at the APS. The central plant houses primary water distribution pumps, heat rejection equipment, and polishing and make-up systems. All water used for heat rejection by accelerator equipment is deionized and filtered to provide minimum resistivity of 3 M{Omega}-cm and maximum particle size of 0.5 microns. Water temperature and pressure are being controlled at 35 secondary systems before water is delivered to the accelerator components. Temperature of various water systems is controlled to as tight as + 0.1 deg F. With most accelerator components interlocked on water flow and temperature, it is imperative that both are maintained with a high degree of reliability. It is also necessary for water systems to be designed with sufficient flexibility to allow for easy modifications, additions, and expansions. From the time original water systems were installed a number of system upgrades to improve reliability and to integrate new operating parameters were completed. Additional improvements are being planned. Lessons learned will be discussed.