Indigenous Development of Helium
Liquefier and Cyclic Refrigerators
P K Kush
Head, Cryo Engineering and Cryo Module Development Section
Raja Ramanna Centre for Advanced Technology,
Indore, INDIA
Email: kush@rrcat.gov.in
Web: www.rrcat.gov.in
India’s First Indigenously
Developed Helium Liquefier
Components of a Helium Liquefier
 Expansion Devices
 Heat Exchangers
 Thermal Insulation system (Cold Box)
 Process Control Components
 Thermally Insulated Transfer Lines
 Main Dewar (To collect Liquid)
 Cyclic Compressor
Schematic of a Helium Liquefier
Cryogenic Expansion Engine
Expansion Engine:
A Critical part in Claude/ Collins cycle based cryogenic
refrigerators and liquefiers
Types of Expansion Engines
Reciprocating Type
Turbine Type
Reciprocating Type Expansion Engine




High Expansion Ratio
Low Flow Rate
Constant Efficiency Over Wide Range of Operating Conditions.
Less Sensitive to Contamination and Power Fluctuation
Problems
 Control of Speed/ Flow Rate is Easier
Expansion Engines
3D Model of expansion engine developed at RRCAT
Photograph showing expansion engine along with
heat exchangers and auxiliary components.
1. Cryogenic Expander,
2. Work extraction mechanism,
3. 1st heat exchanger,
4. Flywheel
Expansion Engines
Actual P-V
Diagram, near
Room Temperature
Expansion Cycle
Actual P-V
Diagram, at low
Temperature
Expansion Engines
Graph showing condition when both Inlet and
exhaust valves are leaking
Distorted P-V Diagram due to
valve leakage
Graph showing condition better leak tightness of valves
Valves to seal at Cryogenic Temperature
Expansion Engines
Parameters for 1st Expansion Engine
Diameter: 75 mm, Stroke: 50 mm, Engine speed: 120 rpm
Inlet cam opening angle: 50 deg Inlet gas pressure: 17.21 bara,
Inlet Temp., K
Expander Eff., %
Mass flow rate, g/s
300
77
0.22
80
68
0.80
50
64
1.26
Parameters for 2nd Expansion Engine
Diameter: 50 mm, Stroke: 50 mm, Engine speed: 120 rpm
Inlet cam opening angle: 45 deg, Inlet gas pressure: 17.21 bara,
Inlet Temp., K
Expander Eff., %
Mass flow rate, g/s
300
86
0.08
80
81
0.29
25
75
0.92
Expansion Engines
Stress analysis of expander liner
Temperature profile
Temperature profile using 80K anchoring
Heat Exchangers
 Low losses of use full refrigeration
through

Heat Conduction through solid
material – long length

Through radiation – lower surface
area
300 K
 Very low pressure drops – critical
pressure for helium: 2.2 bar absolute
 Heat Transfer – One side high pressure
helium (about 230 psig) – Other side
Very low pressure Helium (about 2 psig)
80 K
Heat Exchangers
Heat Transfer area/ Volume (m2/ m3)
High Pressure
Hot Gas Stream
Low Pressure
Cold Stream
700
Heat Exchangers
Photograph of heat exchanger HX-6 before final welding
Specifications of heat exchangers
HX- #
Efficiency, (%)
Fin Tube Heat transfer area (m2)
HX-1
95.5
2.45
HX-2
95.7
2.14
HX-3
94.7
1.53
HX-4
94.9
0.53
HX-5
96.6
0.72
HX-6
95.7
0.92
Cyclic Compressor
Make: Sulzer India,
Four Stage, air cooled, oil Lubricated,
Reciprocating type (Suitably modified
for using it with above expansion
engine)
Oil Removal System:
Designed, Processed and commissioned by us.
(Fabricated by local fabricator)
Process Integration of Components
 Cyclic Compressor
– Suitable compressor lubricating oil
– Efficient oil removal system
 Quality welding and brazing – problem of
“cold leaks”
 Processing of components
 Pressure Control and Helium Gas
management system – 740 liters (NTP)
produces 1 liter liquid
Helium gas recovery compressor and Gas recovery bags
Helium Liquefier Developed at RRCAT
Liquefaction
Temperature reading of the sensor put inside the liquid helium collection container after J-T valve, when
liquefaction was approached for the first time.
Present Status
• Helium Liquefier developed at RRCAT has
been operated more than 6 times so far
• Each time it was operated till the main
Dewar was filled to safe limit - 200 liter
• Nearing 1,000 hours of operation – no
breakdown
Team Members
Samir Ranjan Sardar,
Om Prakash,
Krishna Kant Mahawar,
Ravindra S. More,
Pawan Kumar,
Radha Krishan Pathak,
Nakka Sathi Babu,
S K Joshi,
Ashok Kumar Dewangan,
M S Ansari,
Ravi Sharma,
Chetan Singh
Sunil Kamthre.
Development of Cyclic Refrigerators
– 30 K Cryocoolers
– 10 K Cryocoolers
– Cryopump with pumping speed of
1,200 liters/sec for air
• Cryocoolers like domestic refrigerator
require only electricity to produce low
temperature. The Cryocoolers developed at
RRCAT are based on Gifford McMahon
Cycle. They produce 30K in a single-stage
system and 10K in a two-stage system. The
entire cryocooler is made of indigenously
available components.
• The Cryocooler consist of two parts, an
expander module and a compressor module.
• The Cryocooler uses Helium gas as working
fluid.
Development of Cyclic Refrigerators
30 K Cryocooler
10 K Cryocooler
3D Design Model
Product Photograph
Reference: “Low-power cryocooler survey”,H.J.M. ter Brake, G.F.M. Wiegerinck,
Cryogenics 42 (2002) 705–718. (Data of 235 cryocoolers made world wide)
Cryocooler developed by RRCAT:
Compressor power 2.19 kW. Cooling
power 27.89 w at 80 K
30 K CCR supplied to user Labs.
06 Numbers of 30 K systems are supplied to different labs
+ One Compressor Module matched with imported unit
and supplied to BARC, Mumbai, Year 2002.
(1) One 30 K Cryocooler supplied during first half of year 2004 (Laser
Physics Applications Division, RRCAT),
It is being used for study of “Temperature Dependent Transient
Photoconductivity & Photoluminescence of Organic Semiconductors”
Sample Holder
(2) Another 30 K Cryocooler was supplied to Semiconductor Laser Section,
RRCAT during year 2004. It is being used to study “Temperature
Dependent Electrical Transport measurements
a) Hall Mobility, Carrier Concentration, Resistivity
b) Study of J – V and e – V characteristics at low Temperature
On semiconductors thin films and optoelectronic structures like lasers,
detectors – Regularly grown using MOVPE system at RRCAT
(3) Another 30 K Cryocooler was supplied to Laser Physics
Applications Division , RRCAT. It is being used to study
“Temperature Dependent Carrier Dynamics measurements by
Ultra Fast Pump Probe Spectroscopy”
(4) One 30 K Cryocooler is coupled to a specrofluorometer of
Jobin-Vyon (Model no- Fluoromax-3) suitable for
experiments in Temperature range of 40 to 300K. This is
being used in a Photoluminescence setup at BARC
Spectroscopy Lab RRCAT Indore.
(5) Another 30 K Cryocooler was supplied to Materials, Advanced
Accelerator Science Div.: , RRCAT. On this Cryocooler a
cryogen free ac-susceptometer working over a wide temperature
range (30-400K) is developed. Which amongst other things is
capable of precision measurements of phase transition
phenomenon in magnetic materials and superconductors.
(6) Materials, Advanced Accelerator Science Div.:
Resistivity versus Temperature Measurements.
10K Cryocooler
Lowest Temperature –
Temperature Stability -
<8K
± 0.5 deg
Cryocoolers Developed at RRCAT
One cryocooler producing a minimum temperature of 7K is installed in
Photophysics beamline at Indus-1 for Matrix Isolation Spectroscopy setup
being developed by BARC and IGCAR.
3D Model during Designing
Product Photograph
Cryopump Using Our 10K G-M Cryocooler
•
Ultimate Vacuum: 4 x 10E-8 mbar
•
Pumping Speed
– Nitrogen: 1200 Liter/sec
– Argon: 900 Liter/sec
•
Max. Throughput: 2 mbar. Liter/sec
•
Impulsive gas load (Cross over) Tolerance:
60 mbar-Liter
•
Gas Capacity for Nitrogen: 300 Std. liters
Compressor Modules Developed at RRCAT
Problems Related with Helium Compressor:
•
•
•
•
Helium gas compressors of suitable size are not
available in open market.
High heat of compression for Helium Gas
Suitable Lubricating Oil for clean operation
On line Oil removal system for ultra clean high
pressure Helium gas
All the above problems solved by
modifying Commercially available AirConditioner Compressor for helium gas.
Completed more than 3,000 hours of
operation.
Thank You