Cryogenic refrigeration for the XFEL facility. Current status of the commissioning. Wilhelm Hanspeter Grenoble, June 4th, 2015

2 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

3 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

4 Introduction. New experiment: the European XFEL. XFEL: X-ray Free-Electron Laser —Ultra short X-ray flashes: times/s —The brilliance is a billion times higher than that of the best conventional X-ray radiation sources Key figures: —Length of accelerator: 1700m —Length of facility: 3400m —Accelerator modules: 100 —Max. electron energy: 17.5GeV —Max. wavelength : 0.5nm —Start of commissioning: 2016

5 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

6 Refrigeration process. Requirements. Cooling loopUnitMin. required wo overcapacity Specified incl overcapacity 2KkW Cold Comprs.g/s K shieldkW K shieldkW

7 Refrigeration process. Main features. Main features —2 coldboxes supplying cold Helium in single or parallel operation —2 thermal shields, isothermal cooling at 2.0K —In coldbox41/43: 7 gas beared expansion turbines in 4 turbine strings —4 cryogenic cold compressors with a compression ratio of > 45 Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41 C. Comp CB44 XFE L Dewar

8 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

9 Phase 1. Commissioning concept. Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41 Testbox 51 Phase 1 Dewar 51 Purpose: Comissioning & test of «over-atmosheric» components with testbox with jumper lines & simulation heaters. Functional tests: —Initial controller setup, system stabilisation. —Verification of modified components. Performance tests: —Single coldbox operation CB41 & CB43. scope of supply

10 Phase 2. Commissioning concept. Cold Compressor CB44 Distance: ~10m ΔHeight: 0m Phase 2 Testbox 44 Dewar 51 Purpose: test of complete refrigeration plant wo the influence of cryolines, installation of cold compressor CB44 and testbox 44 at coldbox hall Functional tests: —Controller setup, test of CC startup & pumpdown —Establish stable operation at nominal conditions of CC Performance tests: —None Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41

11 Phase 3. Commissioning concept. Cold Compressor CB44 Distance: 150m Height: -22m Phase 3 Testbox 44 Dewar 51 Purpose: Performance test of complete plant. CB44 installed at final location. Functional tests: —Controller setup, adaption to changed geometries —Normal & part load operation of cold compressors Performance tests: —Single coldbox operation CB43 and CB41 with cold compressors —Double coldbox operation with cold compressors Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41

12 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

13 Phase 1. Single Coldbox Operation. Performance tests: —Minimum requirements 2 of DESY achieved —Test run time: ≥ 24 hours Functional tests: —Initial system controller setup as basis for first performance tests 1) Thermal simulation of cold compressors by heaters from 4-20K. Massflow acc. Q=mdh 2) As per specification, for 17.5 GeV case, without overcapacity LP return TU strings Cold Compressors Dewar 40-80K Shield 5-8K Shield 2K Load Heat inleak 2K HP supply main process flows cold turbomachines cryogenic cooling loads Cooling Loop Uni t Measure d CB41 Measure d CB43 Min. required wo overcapacity Specified incl overcapacity 2K Loop 1 kW Cold Comprs 1 g/s K shieldkW K shield kW

14 Functional test: —Fully automated sequence for CC Startup & pumpdown —CC Startup time < 1h Phase 2. Single Coldbox Operation. main process flows cold turbomachines cryogenic cooling loads LP return TU strings Cold Compressors Dewar 40-80K Shield 5-8K Shield 2K Load Heat inleak 2K HP supply

15 Phase 3. Single Coldbox Operation. HP supply LP return TU strings Cold Compressors Dewar 40-80K Shield 5-8K Shield 2K Load Heat inleak 2K main process flows cold turbomachines cryogenic cooling loads Performance tests: —Minimum requirements 2 of DESY achieved —Test run time: ≥ 24 hours Functional tests: —Pressure stability = +/ mbar suction 1) Thermal simulation of 2K Loop by heaters 2) As per specification, for 17.5 GeV case, without overcapacity Cooling Loop Uni t Measure d CB41 Measure d CB43 Min. required w/o overcapacity Specified incl overcapacity 2K Loop 1 kW Cold Comprsg/s K shieldkW K shield kW

16 Content. 1.Introduction 2.Refrigeration Process 3.Commissioning Concept 4.Results 5.Status and open issues

17 Status & open issues. Performance tests: —Single coldbox performance test with CB43 and cold compressors. —Single coldbox performance test with CB41 and cold compressors. —Parallel coldbox operation incl. max. performance test —Demonstrate long term reliability of refrigerator plant: test run of 800 consecutive hours. Functional tests: —Part load operation of cold compressors with CB41 —Functional tests refrigerator & compressor system —Functional tests cold compressor in progress. outstanding

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19 Refrigeration process. Plant concept. Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41 Cold Compressor CB44 Distance: 150m Height: -22m XFEL OverhaulModify New Dewar 51

20 Refrigeration process. Requirements. Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41 C. Comp CB44 XFE L Dewar Cooling loopUnitMin. required wo overcapacity Specified incl overcapacity 2KkW CCg/s K shieldkW K shieldkW

21 Refrigeration process. Main features. Main features —2 coldboxes supplying cold Helium in single or parallel operation —2 thermal shields, isothermal cooling at 2.0K —In coldbox41/43: 7 gas beared expansion turbines in 4 turbine strings —4 cryogenic cold compressors with a compression ratio of > 45 Compressor System 3 Coldbox CB43 Distri- bution Box DB54 Compressor System 1 Coldbox CB41 C. Comp CB44 XFE L Dewar