ESS Cooling System - Interface with RFQ 1 John Jurns Cooling System Engineer

What is the purpose of the cooling system? The cooling and heat recovery system of the ESS plant shall be designed to meet the following requirements: Provide reliable and efficient cooling of all parts of the ESS site that requires water cooling Transfer as much heat as possible from the cooling system to the city of Lund district heating system and/or other external waste heat recovery systems What systems are included in our scope of work? The scope of the cooling system design is primarily to manage the flow of heat in the technical infrastructure (i.e. – the machine). Cooling is accomplished primarily with water. Systems in scope include: Accelerator – klystron gallery and linac tunnel Target – interface at target internal cooling systems boundary Cryoplant – compressor and helium cooling Instruments – cooling as required for instruments and instrument support equipment Conventional Facility – interface with conventional HVAC

Cooling system parameters Majority of cooling provided by closed loop water-water heat exchanger and pump systems. Water temperature range approximately deg C Water system pressure nominally 10 bar Three primary cooling loops – low, medium & high temperature ranges. Total flow through each loop ~ 8000 liter/minute Primary cooling loops interface with: Substations located close to cooling loads Central utility building where cooling loops interface with external District Heating system Secondary cooling loops interface with individual cooling loads and substations Linac will have two cooling substations. One of these substations will manage heat from the RFQ

ESS cooling system overview

Cooling loads Cooling substation To Central utility building Typical cooling substation flow Cooling load

Lo beta Ion source Klystron gallery Tunnel Accelerator Cold end substation Accelerator cooling system piping cold end substation Hi beta HEBTCouplers, etc. J. Jurns 24 October 2012 To Central utility building

RFQ cavity Klystron gallery Tunnel Accelerator Warm end substation Accelerator cooling piping – warm end substation RFQ/DTL DTL cavity Warm end high accuracy temperature control Spokes To Central utility building

RFQ cooling ? RFQ Cooling Substation TBD Interface

RFQ cooling assumptions & questions 1500 kW input X 2.91μS X 14 Hz = 61 kW average power input. Assume that approximately 50% of this power is heat that must be cooled. Questions for RFQ cooling: RFQ cooling temperature deg C? Temperature control limits? That is - ± x,x deg C? Cooling medium – glycol? Water? RFQ cooling controls & interface requirements? Cooling system architecture Separate dedicated cooling subsystem for RFQ? Integrated cooling subsystem for RFQ & DTL? Separate fluid loop for RFQ cooling, or direct supply from cooling system? If direct, any specifications on water quality?