1. Inter University Accelerator Centre, New Delhi
Study of inter stage cooling for enhancement of LHe production with a GM cryocooler
Anup Choudhury, Santosh Sahu - (IUAC)
Lokesh Posa, Navneet Suman - (NITR)
ICEC26 - ICMC March, 2016

2. Inter University Accelerator Centre, New Delhi
Motivation
Technical challenges
Inter stage heat transfer studies
Liquefaction studies
conclusion
Plan of talk
ICEC26 - ICMC2016, March, 2016

3. Inter University Accelerator Centre, New Delhi
Motivation
Oxford make cryostat rejuvenation.
Evaporation rate measurement (12 lpd).
Experience available with cryocooler LN2 liquefier and LHe re-condensor.
Literature survey.
ICEC26 - ICMC2016, 7-11 March, 2016

4. Inter University Accelerator Centre, New Delhi
Specifications:-
Liquid Capacity = 30 liters
Magnetic field = 8 T
VTI insert = 1.5 K – 350 K
Evaporation rate = 12 lpd of LHe capacity
Oxford cryostat
Static heat load measurement of Oxford cryostat
ICEC26 - ICMC2016, 7-11 March, 2016

5. Inter University Accelerator Centre, New Delhi
Helium recondensor
Specifications 1.
Cryocooler cooling capacity
= K 2.
Cryocooler made by
Cryomech, USA 3.
Cryocooler model no
:AL300 (50 Hz) 4.
Dewar capacity
= 250 liters 5.
Nitrogen purity
>= 98% 6.
LN2 production capacity
= 64 lpd
Cryocooler based LN2 liquefier
ICEC26 - ICMC2016, 7-11 March, 2016

6. Inter University Accelerator Centre, New Delhi
Thermal study of inter-stage of
GM cryocooler
US PATENT NO
ICEC26 - ICMC2016, 7-11 March, 2016

7. Inter University Accelerator Centre, New Delhi
8K, 20 lpd
40K, 5 lpd
1st stage
35 50 K
2nd stage K
Technical challenges :
How much enthalpy is available in the inter-stage area?
How the enthalpy can be extracted?
Sumitomo cryocooler
SRDK 415
ICEC26 - ICMC2016, 7-11 March, 2016

8. Inter University Accelerator Centre, New Delhi
Extra cooling effect available in inter-stage
300 K
50 K
10.67 K
L He (17.44 lpd)
5 W
LHe (more than 25 lpd)
7 K
9 W
ICEC26 - ICMC2016, 7-11 March, 2016

9. d Inter University Accelerator Centre, New Delhi 32.5 W T1 T2 Pex T3
Baffle heating experiment in vacuum
ICEC26 - ICMC2016, 7-11 March, 2016

10. Inter University Accelerator Centre, New Delhi
1st baffle heating
2nd baffle heating
3rd baffle heating
Result of baffle heating experiment in vacuum
ICEC26 - ICMC2016, 7-11 March, 2016

11. Inter University Accelerator Centre, New Delhi
Schematic Details of expt.
ICEC26 - ICMC2016, 7-11 March, 2016

12. Inter University Accelerator Centre, New Delhi
Heater on
17.4 lpd
Cooldown curve for the liquefier (Best scenario)
ICEC26 - ICMC2016, 7-11 March, 2016

13. Inter University Accelerator Centre, New Delhi1 2 3
Expt. No
Description
 T6 (K)
Production
rate (lpd) 1.
Basic coaxial design with HX-1 and HX-2, no nylon cover for regenerator.
17.4 2.
Basic coaxial design with HX-1 and HX-2, and nylon covers for regenerator.
14.1 3.
Repeat of expt. no 1 with HX-2 removed.
17.0 4.
Repeat of expt. No 1 with both HX-1 and HX-2 removed.
16.8
- Best scenario
- Worst scenario
ICEC26 - ICMC2016, 7-11 March, 2016

14. Inter University Accelerator Centre, New Delhi
Inter stage cooling capacity map fully configured.
Liquefaction run undertaken for various HX configuration.
Maximum production rate achieved = 17.4 lpd in natural convection mode.
Possibility of production increase exists with baffles attached to the inter stage area.
Conclusions
ICEC26 - ICMC2016, 7-11 March, 2016

15. THANKS FOR YOUR ATTENTION
Inter University Accelerator Centre, New Delhi
THANKS FOR YOUR ATTENTION
ICEC26 - ICMC2016, 7-11 March, 2016