water cooling system of petra iii11/08/2004 jensen / wanning - mkk - 3 introduction • rebuilding...

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MAC - Meeting at DESY

Water Cooling System of PETRA III

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Overview:

• Introduction• General Design• Scheme of water cooling systems• Temperature stability of the cooling water• Temperature measurements at DORIS• Magnet and chamber cooling in the old octants• RF water cooling system • Magnet vibration by throttling the cooling water• Cross section of the tunnel and experimental hall

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Introduction

• Rebuilding of ~ 300 m of the storage ring from PETRA-hall NE to E

• Building an experimental-hall with 13-15 measuring positions

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PETRA hall NE

PETRA hall E

PETRA III with the Experimental Hall

Water cooling station NE

RF water cooling station PETRA South

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Water Cooling Design:2 locations for the water cooling supply:• PETRA hall NorthEast:

– magnet and vacuum chamber cooling– chilled water production and cooling water supply

for the experimental hall

• PETRA hall South: RF cooling

• 2 water circuits for aluminium and copper magnet coils• Hybrid dry coolers for recooling are designated

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Overview of the Water Cooling System

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Technical Data of the Water Cooling System

• Temperatures of the cooling water:• Return pipe of the hybrid coolers: 28 °C• Supply temperature for tunnel: 30 °C • Temperature stability better than ± 0,5 °C • Achievable stability ± 0,2 °C

• Variable fan speed for long time regulation• 3 directional control valve for short time regulation• Water pumps with variable speed against pressure fluctuation

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Scheme of water cooling circuit

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Pressure and Temperature Fluctuations

• Pressure fluctuations cause fluctuations of the temperatures in the water cooling system

• Assumption: ∆p = 0.2 bar 3 % @ 7 bar

• ∆p ≈ ∆V2

• ∆V = √1.03 = 1.014• 1.4 % @ 30 °C • → ∆T = 0.43 °C• Temperature fluctuation has be damped by the regulation

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Temperature Measurements at DORIS

long time stability

short time stability

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Conclusion of the DORIS water temperature measurements

• ± 0,5 °C is state of the art• ± 0,2 °C for short time stability is achievable• ± 0,1 °C in topping up mode should be feasible

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Magnet Cooling in the old 7 Octants

• Synchrotron radiating power is 100 W/m @ 200 mA• one water circuit for vacuum chamber and magnet cooling:

– serial connection of vacuum chamber magnet coils• cooling water supplies first the vacuum chamber • and than flows through the magnet coils of the dipole,

quadrupole and sextupole• this leads to temperature rise of 2 °C @ 200 mA along the

vacuum chamber over 7 m

• this fulfils the requirement

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Vacuum Chamber and Magnet Cooling

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RF Water Cooling System

• 2 RF-Systems are located at hall SR and SL• The water cooling supply is at hall SR• The cooling water flows first through the

cavities and than through RF absorbers• The circulators have a constant 30°C inlet

temperature from a heated buffer tank

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Sketch of RF Water Cooling System

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Magnet Vibration• Vibration caused by cooling water throttling

investigated• Measuring setup in experimental hall 1• Quadrupole and Sextupole unit of PETRA• 3 sensors in x-, y-, z-plane on the sextupole

– S0 vertical plane– S1 horizontal plane– S2 longitudinal plane

• Sensor S3 on the quadrupole as a reference

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Magnet unit of PETRA

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Sensor Disposition

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Measurements

• Vibration measurement – without water flow– with unthrottled water flow– with throttled water flow

at nominal value

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Measurement Results

Vibration measurement without water flow

Amplitude in mm

S 0 y-plane

S 1 x-plane

S 2 z-plane

S 3 y-plane quadrupole

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Vibration measurement with unthrottled water flow

Amplitude in mm

S 0

S 1

S 2

S 3

Measurement Results

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Vibration measurement with throttled water flow

Amplitude in mm

S 0

S 1

S 2

S 3

Measurement Results

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Conclusion of the investigation

• No significant differences without and with water flow

• Amplitude is about 0,001 mm

• Throttling the water flow has no effect on the vibration

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Pipe and Bus Bar Installation in the Tunnel

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Cross Section of the Experimental Hall