Undulator Hall Air Temperature Fault Scenarios

Sevilla, J. ; Welch, J. ; /SLAC

关键词: AIR;    AIR CONDITIONING;    AMBIENT TEMPERATURE;    FLOORS;    HEATING;    HVAC SYSTEMS;    REGULATIONS;    REMOVAL;    SHUTDOWN;    TUNING;    VENTILATION;    VULNERABILITY;    WIGGLER MAGNETS;   

DOI  :  10.2172/992868
RP-ID  :  SLAC-TN-10-038
PID  :  OSTI ID: 992868
Others  :  TRN: US1008031

美国|英语

来源: SciTech Connect

【 摘 要 】

Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.