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Latest developments in cryogenics at CERN

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					  Proceeding of 20th National Symposium on Cryogenic held at
                   NIT, Surat, February 2006

                         Latest Developments in Cryogenics at CERN
                                              Laurent Tavian
                     CERN, Accelerator Technology Department, 1211 Geneva, Switzerland.


The use of cryogenics has started at CERN in the 1960s for cooling high energy physics detectors requiring
low temperature technologies to achieve the desired performances. From the 1980s onwards, cryogenics
has also been used in CERN accelerators for cooling superconducting accelerating cavities and high field
magnets. Today, cryogenics is largely used in the LHC project under construction at CERN for cooling the
27 km magnet ring which requires the largest 1.8 K helium refrigeration and distribution systems in the
world as well as its two largest detectors (ATLAS and CMS), which incorporate a variety of cryogenic
equipment. In addition,cryogenics is used for cooling specific experiments not related to the LHC complex.
After a brief historical review, the present status and latest developments in cryogenics at CERN are
reviewed.


          Superconducting Cyclotron Project and Related Cryogenic Activities
                                 at VECC, Kolkata
                                      Rakesh K. Bhandari (for VECC Staff)
                     Variable Energy Cyclotron Centre, Department of Atomic Energy, Kolkata 700 064


A superconducting cyclotron is under construction at the Variable Energy Cyclotron Centre, Kolkata. This
cyclotron will deliver heavy ion beams up to a maximum of 80 MeV/nucleon energy. Fabrication and
development of most of the major systems have advanced significantly. The cryostat housing the
superconducting coil has been installed in the magnet structure. Installation of the cryogenic delivery line
has been completed. Cool down of the main coil has started. The energization of the superconducting coil
(stored energy about 22 MJ at full excitation) will start as soon as the coil is cooled to 4.5K temperature in
a stable way. The radiofrequency system is under fabrication and will be delivered at site by mid 2005. The
design and fabrication work of injection line and the external beam line is in progress.

                 An overview of Cryogenic Storage & Distribution System
                                              Parag P. Kulkarni
                   Inox India Limited, ABS Tower, 4th Floor, Old Padra Road Vadodara 390007


                      Challenges In Cryogenic Propulsion Development
                                                 N.K. Gupta
                              C25 Project,LPSC/ISRO, Valiamala P.O. Trivandrum

Geo-synchronous Satellite Launch Vehicles (GSLV) use Cryogenic Engines for their upper stage due to
higher specific impulse. The cryogenic propellants differ from the Earth Storable Propellants in terms of
their operating temperatures and storability.Liquid Propulsion Systems Centre is developing Cryogenic
stages for its various GSLVs. This paper present the details of the technological challenges faced during the
development and also the current status of development.

                                           Space Simulation
                                              N.NARASIMHAN
                             Space Applications Centre, ISRO, Ahmedabad-380015
The spacecraft has to perform its intended function reliably in the hostile space environment during its
design lifetime. The thermal design of the spacecraft is validated in the space simulation chamber
simulating the effects of hard vacuum, radiative heat sink of space in addition to Sun radiation. The
functional performance is tested under thermal vacuum condition. This paper describes the cryogenic
engineering aspects of the space simulation chamber. The advances in cryo pumping technology to produce
pumping speed of millions of liters /sec, the methods to achieve 100 K on the thermal shroud to simulate
radiative heat sink of space, the customized cryo targets to cool the infrared detectors of the remote sensing
payloads and the cryo targets in the temperature range of 10 K - 100 K to calibrate sensitive payloads are
discussed.

            Mixed Refrigerant Cycle Refrigeration and Liquefaction Systems
                                     G. Venkatarathnam and M. Siva Sankar
                 Refrigeration and Airconditioning Laboratory, Deptt. of Mechanical Engineering
                             Indian Institute of Technology Madras, Chennai 600036

Mixed refrigerant cycle refrigerators and liquefaction systems are under development in our laboratory.
The main advantage of these processes is the requirement of low working pressures, typically less than 20
bar. The cost of the system is quite low since single stage traditional refrigeration (R22) compressors can
be used in these systems. In case of nitrogen liquefiers, nitrogen pressures of 5 to 6 bar is adequate in many
processes. In this paper, we present some results obtained with our mixed refrigerant refrigerator
prototypes.

                                       Cryogenics Applications in Defence
                                             V D Abraham, SM
                Commanding Officer,Faculty of Instrumentation Technology,EME School, Baroda



  Superconducting Linear Accelerator : Analysis of Measured Load at 4.2 K from
                              Total Linac System
 T. S. Datta, S. Kar, A. Choudhury, J. Antony, C. Jacob, M. Kumar, S. Babu, R. S. Meena, S. A. Krishnan , A. Roy,
                          Nuclear Science Centre, Aruna Asaf ali Marg. New Delhi – 110067

Cryogenic system for the ongoing project on superconducting linear accelerator at Nuclear Science Centre
has been established and is operational for last three years.The main system consists of helium and nitrogen
refrigerators, five cryostats to house the superconducting RF cavities and cryogen transfer lines, connecting
refrigerators and cryostats. The system has been operated several times to cool down the LINAC and to
maintain the temperature at 4. 2 K with present cold mass of approx. 600 kg from partly established
LINAC. Individual heat load measurement had been carried out earlier on each subsystem. Recently
attempts have been made to measure the total load at 4. 2 K from the integrated cryosystem by balancing
the refrigerator operation with an external heater. This paper will be highlighting the procedure followed to
measure the total load along with the analysis of heat load from past and present measured parameters.

          Development of Helium Refrigeration/Liquefaction System at BARC
                     Trilok Singha, Anindya Chakravartyb, Rajendran Menon, Mukesh Goyal,
                                        Naseem Ahmed and Piyush Prasad
                   Cryogenic Technology Division,Bhabha Atomic Research Centre, Mumbai-85
          Email : tsingh@magnum.barc.ernet.in, b Email : c_anindya1@rediffmail.com

Turboexpanders constitute the most critical component of most modern cryogenic process plants. All the
critical components of this system has been designed and developed. These include expansion turbine,
Brake compressor tilting pad bearings,Spiral groove thrust bearings and turboexpander shaft. This system
has been in use in an experimental Helium refrigerator capable of producing 1kW at 20K temperature.
Stable operation of this plant has been achieved and valuable operational data obtained. The paper throws
light on the constituents of a Cryogenic Turboexpander, some fabrication aspects as well as results from
some initial experiments of a turboexpander based experimental helium refrigerator.
           New Generation of Vortex Tubes - Development and Experiments
                                                  Jacob. S.
                     Centre for Cryogenic Technology, Indian Institute of Science, Bangalore-560 012,

The use of CFD techniques to arrive at optimum design parameters of vortex tubes is described. The
optimum cold end diameter (dc), the length to diameter (L/D) ratios and other critical parameters for
obtaining the maximum temperature difference between the hot end gas exit and the cold end gas exit are
obtained through CFD analysis and validated by experiments. Studies of LOX separation from pre-cooled
air flow show that conical vortex tube gives highest LOX purity of ? 96% and higher separation efficiency
of ? 61% compared to straight vortex tubes.

  Recent Research & Development in the area of Cryogenics and Superconducting
                    Magnets at National Physical Laboratory
                                   R.B. Saxena, M.A. Ansari and Hari Kishan
                   National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi - 110012

In recent years, many projects involving development of cryogenic infrastructure, accessories & cryostats
and R & D on superconducting magnets have been carried out at National Physical Laboratory. These
include developments of a) Long hold liquid helium cryostat with a room temperature bore for SC magnet
for 100 MHz NMR spectrometer, b) Bucket type 25 litres capacity, 164mm bore liquid helium cryostats, c)
Liquid nitrogen transfer pumps and level detectors, d) Rig for testing of cryogenic valves, e) R-T
measurements set-up using closed cycle cryo-cooler, f) 7 Tesla 50 mm bore Superconducting magnets, g) A
3.5 Tesla insert type SC magnet with 28 mm working bore, h) A 2.35 Tesla high homogeneity
Superconducting magnet using Nb-Ti conductor, suitable for NMR applications, i) An 11 Tesla SC magnet
(a hybrid magnet with outer coil of Nb-Ti conductor and inner coil of Nb3Sn conductor) and j)One of the
largest size SC magnet based on Nb-Ti technology in the country with a working bore of 255 mm and an
overall length of 680 mm.



        NIT Rourkela - a New Centre for Education and Research in Cryogenic
                                   Engineering
                 Sunil Kr Sarangi, Director, National Institute of Technology Rourkela - 769 008

Education and research in the field of Cryogenic Engineering has been carried out in our country for nearly
three decades. Still, there is significant gap between what we need to sustain a large industrial economy and
what we have today. A new facility for education and research in the subject of Cryogenic Engineering has
been set up at the Department of Mechanical Engineering, NIT Rourkela. The major activities in the
laboratory include research on screw compressors, expansion turbines, cryogenic treatment of cutting tools,
low temperature heat transfer and development of heat transfer equipment. The paper presents a review of
the ongoing R & D projects, the academic programme and the infrastructure facilities that have been
created.

  Analytical Method for the Prediction of Freezing Time of Irregular Shaped Food
                                     Materials
                                  Sanoj Kumar, S.C.Pattanayak and H.Dasa
                 Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, India

Freezing is one of the most suitable methods for the preservation of perishable food products .The
determination of freezing time and temperature distribution inside the product dictate the design of the
freezing process. Three distinct periods during freezing are noticeable at any location inside the body of a
food material. The time period of precooling, phase change and freezing are the important parameters
required to be evaluated for adopting proper freezing technique of food items. The knowledge of this
complex processes is very important in order to arrive at an optimised condition. A simplified analytical
method is worked out in this paper for the prediction of freezing time of the irregular shaped food
materials. A suitable computer program using C language is developed using above analytical approach to
determine separately the time period for cooling, phase change and freezing during the freezing process.
This technique would be of very much important in the design of food freezing equipments.

                        Development of Grooved Journal Bearings for
                              Cryogenic turbo-expander rotors
                                              Tapas Kumar Nandi
                Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur - 721 302

One of the major problems of developing turbo-expander system for gas liquefaction plants is the
instability of the rotor at high rotational speed. Gas lubricated externally pressurized (aerostatic) bearings
consume process gas and they are suitable only upto a medium rotational speed. Present work is on the
development of herring bonegrooved aerodynamic type journal bearing. Some of the aspects of
development, including design, fabrication, and testing are presented. The shallow grooves are cut on the
rotor by chemical etching. The journal is rotated by expanding compressed air/Nitrogen through a turbine.
Aerostatic gas bearings are used to operate at the start-stop transients while an aerostatic thrust bearing is
used to take the axial load of the vertically placed journal.

             Mathematical Analysis of Oil Injected Twin Screw Compressor
                          N.Seshaiah, Subrata Kr. Ghosh, R.K. Sahoo, Sunil Kr. Sarangi
              Mechanical Engineering Department, National Institute of Technology, Rourkela, Orissa
                           Corresponding author mail ID: seshuet@yahoo.com

Mathematical analysis of oil injected twin screw compressor is carried out on the basis of the laws of
perfect gas, and standard thermodynamic relations. Performance of an oil injected twin-screw compressor
depends on a large number of design parameters. A computer model for calculating compressor
performance and to validate the results with experimental data is developed. The flow coefficients required
to calculate leakage flow rates for simulation are obtained from efficiency versus clearance curves. Some
numerical examples of P-V diagrams, influences of oil injection on volumetric efficiency etc for a given
compressor are presented.

                             Liquid Nitrogen Powered Prime Mover
                  S.A.Krishnan, S.Maji *, Manoj Kumar, R.S.Meena, Suresh Babu and T.S.Datta
                    Nuclear Science Centre, New Delhi, Delhi College Of Engineering, Delhi

A heat engine that operates between atmospheric temperature as a heat source and cryogenic temperature as
a heat sink called cryogenic heat (C-H) engine. A liquid nitrogen (LN2) powered heat engine is a best
alternative zero emission engine concepts compared to battery operated one. The development of this kind
of engine has been initiated at NSC to study its possibility as a prime mover for lightweight applications.
The preliminary stage of this project has been demonstrated by running a modified single cylinder, four-
stroke engine as a two-stroke cycle expander based on open Rankine thermodynamic cycle. The detail of
this developmental work is presented in this paper.

                     Operational Experience of Indigenously Developed
                            Automated Helium Purifier at NSC
            A Choudhury, T. S. Datta, M Kumar, R. S. Meena, S Kar, J Chacko, S. A. Krishnan, S Babu
                     Nuclear Science Centre, Aruna Asaf Ali Marg , New Delhi - 110067

An indigenously developed medium pressure (225 psi) helium gas purifier of capacity 40M3/hr was
commissioned at NSC in 2002. It works on the principle of adsorption of impure gases (N2, O2, etc) from
helium by charcoal at 78K. Since its installation, it has undergone 65 cycles of cool down operation till date
and has purified almost 5200M3 helium gas with an inlet impurity varying from 8% to 0.1%. The purifier
generally runs in the automatic mode to perform two operational cycles, purification and regeneration. This
paper will be highlighting the operational experience along with running data for purifier.
                        A setup for the studies of Freeze Drying Process
                               Arpita Mondal, Sanoj Kumar and S.C.pattanayak
                Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur - 721302

Freeze-drying, which is also known as lyophilization, is the process of removing moisture from a food
product by freezing it and then condensing the sublimated vapor at vacuum. In this work the condensation
process of moisture is replaced by adsorption using zeolite. It is estimated that 3.6 kg of zeolite is required
for adsorbing total moisture of 1 kg shrimp. A setup is designed and fabricated which consists of a Cu
cylinder of ID 10.5 cm and length 64.0 cm insulated by 5 cm thick polyurethane foam. The bottom of the
cylinder is closed and the top flange is connected to a vacuum pump. The top flange has the provision for
introducing the cabinet of perforated trays loaded alternatively with frozen shrimp and adsorbent. This
arrangement gives sufficient exposed surface area to adsorption process, which make the process more
efficient. Heat in-leak and the heat of adsorption to the system are sufficient to maintain the heat of
sublimation. However a nicrome made coil heater is kept inside for use if necessity arises. This setup has
been developed to study the following characteristics; 1.Adsorption rate of zeolite at different operating
condition. 2.Sublimation rate of a particular sample at different vacuum level. A detail description of the
developed freeze-drying setup is described in the paper.

               Different methods for the estimation for freezing time of food
                                   Sanoj Kumar, S.C.Pattanayak and H.Dasa
                  Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, India

The preservation of food is one of the most significant applications of refrigeration. In order of preserving
operations to be cost-effective, it is necessary to optimally design the refrigeration equipment. This requires
estimation of the freezing times of foods under different condition. Numerous methods for predicting food-
freezing times have been proposed. The designer is thus faced with the challenge of selecting an
appropriate estimation method from the plethora of available information. The present paper deals with the
semi-analytical/empirical food freezing time prediction methods that apply to regular and irregular shaped
food items. The performance of these various methods is quantitatively evaluated by comparing their
numerical results to a comprehensive experimental freezing time data compiled from the literature.

                             Revolution in Cryogenic-Cryotempering
                                     Shirish R. Gandhi and Gehlot Rajesh
                          Department of Mechanical Engineering L.D.C.E. Ahmedabad.

Cryogenic Treatment of metal parts can enhance metallurgical properties, which in turn, improve various
strengths of the treated parts. This paper presents the details of cryotempering, its method, importance,
application of this process. The test results shows the enhancement in various structural properties due to
permanent metallurgical changes that take place in the specimens during the cryogenic treatment. However,
no permanent change in the dimensions or surface finish of the specimen occurs. Such treated parts
improve the reliability and performances of the whole machine, thereby increasing its MTBF, wear
resistance & ductility. Cost factor limits its use in production phase of material industry.

                         Specific Heat For Metals At low Temperature
                      Puwar Dhairyapalsinh Narpatsinh (1), R. M. Shah (2), Nisha V. Bora (3)
               Mechanical -Cryogenic Engg. , L.D. College of Engg., Ahmedabad-380015
               Email: rajani_10_2@yahoo.co.in, Email: nisha_mech@engineer.com

In present section various theories representing specific heat of solids have been discussed briefly such as
Dulong and Petit law, Einstein theory, Debye theory and Sommerfeld theory. Then using Debye theory and
Sommerfeld theory, lattice specific heat (Cvl), electron specific heat (Cve), and total specific heat (Cvt) are
evaluated and plotted versus absolute temperature (T) for aluminum and the same can be followed for other
metals. Also (%Cvl) ?T and (%Cve) ? T have been plotted for aluminum. Furthermore method of
obtaining value of electron specific heat co-efficient (re) has been shown by plotting (Cvt /T)? (T2) for
aluminum.

      Design and Analysis of Psa Based Nitrogen Separation System for a Liquid
                                   Nitrogen, Plant
                                     Rohit Kumar.N.Mehta1 , R.M.Shah2
              Mechanical Engineering department, L.D.College of Engineering Ahmedabad - 380015

Distillation has been the process for separation of gases and producing liquefied gases. Atmospheric air
contains about 76% nitrogen and the rest being oxygen, argon and rare gases. One of the major draw back
of distillation process being high energy consumption for the separation of particular species of gas, as the
complete mixture has to be liquefied and the liquefied gases are separated based on difference in boiling
points. Thus if 76% nitrogen is to be separated the rest 24% part of the air also needs to be liquefied. The
energy spent on this un- used mass of gas could only be saved by providing additional heat exchangers,
which would make the system cost prohibitive or the system will utilize higher quantum of energy.
Adsorption process is the solution, which would provide energy efficient separation for small scale plants,
by separating out first the species of gas to be liquefied at room temperature utilizing only a fraction of
work consumed by a cryo cooler for separation. In this paper Design of Adsorption based air separation
plant using carbon molecular sieves as the adsorbent working at room temperature was done for product
recoveries of 30% and 40% . Analysis was carried out on a proto type and results were tabulated for purity
of the product (gaseous nitrogen) at different flow rates. The cycle of Adsorption was a 6 valved process
based Barbau-Forschung cycle and capable of producing 30 L/ Hr of liquefied nitrogen.


                 Some Aspects of Pinch Technology Applied to Cryogenic
                                    Heat Exchangers
                                      H. V. Panchasara* and R.M.Shah**
              Mechanical Engineering Department, L.D. College of Engineering, Ahmedabad-380015

The paper aims to explain the fundamentals of the Pinch Technology for the analysis of the heat exchanger
network synthesis. It is a well-established synthesis and analysis-tool for the exchange of heat within the
network of heat exchangers. This paper presents a simple methodology for systematically analyzing the
process utility streams with the help of first and second law of thermodynamics. The concept of the theory
is basically dependant on the 'Pinch Point' or 'Pinch Condition' or 'Closest Approach' which is the
temperature level at which the ?Tmin is observed which in turn defines the minimum driving force allowed
in the exchanger unit. The points to be discussed are the analysis of the Pinch point or Pinch region for the
cryogenic heat exchangers, the benefits, objectives and applications of the Pinch analysis or Pinch
Technology.

               Development of Cryogenic Adsorber Based Helium Purifier
                                 at VECC, Kolkata
                       Trijit Kumar Maiti, S. Banerjee, Abanindra Mukherjee, U. Panda,
                           Nirmalya Datta, Jagdishkumar Parate, Ananda Das, R. Dey
                  V.E.C.C, Deptt of Atomic Energy, 1/AF Bidhannagar, Kolkata 700064, India

For ongoing project of Superconducting Cyclotron at VECC, Kolkata, liquid helium plant constitutes an
essential component of cryogenic system. This plant is equipped with an integral internal purifier working
at impurity level of 2%. During simultaneous operation of liquefier as well as purifier, liquefaction rate
reduces considerably and may become insufficient for Super-conducting Cyclotron operating at full swing.
For experimental purpose, we designed and fabricated one module of cryogenic adsorber based helium
purifier, tested and result was encouraging. Also conducted rigorous cryoshocking of insulated tape heater
meant for regeneration. Now we are developing a fully integrated helium purifier to meet Grade 'A' helium
requirement of Superconducting Cyclotron.

      Operation , Instrumentation and Control of Psa Based Adsorption System
                                      Rohit Kumar.N.Mehta1 , R.M.Shah2
                  Mechanical Engineering department, L.D.College of Engineering Ahmedabad -15

All modern day air separation industry and users of compressed air for pneumatic actuation of controls use
Adsorption process. They can be classified as purification process if the impurity to be adsorbed in the fluid
is about 3 to 5% as in the case of moisture and carbon di oxide removal and separation if the fluid to be
removed is of the order of 20 to 80% as in the case of separation of oxygen and nitrogen. The sequence of
cycle and the quantum of purging for reactivation varies . These variations are due to continuous
development in Adsorbents and in improvement in the cycle of operation. In this paper we have discussed
unitary, unmanned operation of an adsorption system, the instrumentation required, the controls and
interlocking arrangement for full proof operation of air separation plant for separation of nitrogen has been
discussed has been discussed.



                  Innovative Techniques for recycling the recovered CFC's
                                                   S.S. Verma
                    National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi - 110012

The utilization of large quantities of CFC's in Industries as well as in Refrigeration and Airconditioning has
rendered the environment more susceptible to mankind due to its ozone depleting characteristics. A
decision was already made at the Montreal protocol's 4th meeting to phase out the production and
consumption of CFC's. The mechanism to recover and recycle the CFC's are established in the developed
countries and in India, there is hardly any awareness on large scale, to recover, recycle the flons. A system
has been established to collect flon from refrigerated warehouses and large air-conditioners, walk-in-
coolers etc. After refining by distillation, it is returned to the users. Flon is collected at the gas stations and
repair workshops. Small devices are employed to refine the collected flon by filtration, moisture adsorption
by zeolite and oil water separation have been developed and are functional. Some other devices are
employed to cool and liquefy and collect the flon at low temperatures. The decomposition of CFC's are still
at an experimental stage to make the end product environmentally friendly or reusable. A device is under
development to decompose the CFC's by plasma decomposition method using radio frequency inductively
coupled plasma reaction system achieving a temperature of 5000? C -10000? C to decompose the CFC's.



                    Design of Turboexpander For Cryogenic Applications
                           Subrata Kr. Ghosh *, N. Seshaiah, R. K. Sahoo, S. K. Sarangi
                          Department Of Mechanical Engineering, NIT, Rourkela, Orissa.
                          Corresponding author mail ID: subratarec@yahoo.co.in

The indigenous design and development of turboexpander have been started at NIT, Rourkela. This paper
briefly discuses the design methodology and the fabrication drawings for the whole system, which includes
the turbine wheel, nozzle, diffuser, shaft, brake compressor, two types of bearing, and appropriate housing.
With this method, it is possible to design a turboexpander for any other fluid since the fluid properties are
properly taken care of in the relevant equations of the design procedure.
Nomenclature
b blade height
C absolute velocity
Cr mean radial clearance
Cn chord length of nozzle
ds specific diameter
D diameter
d0 feed hole or orifice diameter of bearing
h enthalpy (J / kg)
hbg bearing clearance
Kbg bearing radial stiffness
L axial length of the journal bearing
.m
mass flow rate
ns specific speed
N rotational speed (rev/ min)
nh number of holes in the bearing
p pressure
P power produced
Q volumetric flow rate (m3 / s)
Rj radius of journal
rt0 feed hole pitch circle radius of thrust
bearing
rt1 outer radius of thrust bearing
rt2 inner radius of thrust bearing
T0,in turbine inlet temperature
t thickness of blades
U circumferential velocity
WL load capacity of bearing
w width of flow passage
z number of blades
Greek symbols
? rotational speed (rad/s)
e ratio of tip diameter to turbine wheel
diameter
e eccentricity ratio of the bearing
? ratio of hub diameter to tip diameter
? isentropic efficiency
f power input factor
? slip factor
? relative velocity angle
? specific heat ratio of bearing gas
? density of gas
Subscripts
0 stagnation condition
1 inlet to nozzle
1 inlet to brake compressor
2 inlet to turbine wheel
2 outlet to brake compressor
3 inlet to the diffuser (exit to wheel)
ex discharge from diffuser
hub hub of turbine wheel
tip tip of turbine wheel
m meridional component
s isentropic condition
s supply
tr turbine wheel
b brake compressor
n nozzle
t throat
bg bearing
c choking
d discharge
Figure 1 Longitudinal section of the expansion
turbine displaying the layout of the components.
This turbine is comparable in characteristics to
that developed earlier at IIT Kharagpur [1,2] and
drawn heavily from that experience.
Design Methodology

    Design of a Cryotreatment Chamber and Studies on Cryogenic Treatment on
                                    Metals
                   Nadig D. S., Jacob. S., Kasthurirengan. S., Karunanithi R. and Geetha Sen*
             Centre for Cryogenic Technology, Indian Institute of Science, Bangalore - 560 012, India
                             * Liquid Propulsion Science Centre, ISRO, Bangalore.

Studies in the thermal, mechanical and electrical properties of metals at cryogenic temperatures are
important for many scientific and technical applications. To study the changes in properties, a
cryotreatment test unit has been designed and developed. This unit incorporates a PUF insulated
cryotreatment chamber made of SS 304. The controlled liquid Nitrogen supply to the chamber is carried out
by using a solenoid valve activated by a PID controller. To gradually cool the test specimens to cryogenic
temperature with out a direct contact with the liquid nitrogen droplets, a concept of cold nitrogen gas forced
convection has been employed. The system has the capability of cooling the test specimens to ~ 98 K and
holding at that temperature for desired durations. Experiments have been carried out to study the effect of
cryogenic treatment on wear resistance properties of molybdenum based HSS tools (M42). There has been
significant improvement in the properties after cryogenic treatment.

   Thermal Analysis of Antistokes Fluorescent Cryocooler Using Finite Difference
                                     Methods
                                      Biju T. Kuzhiveli *, Subhash Jacob
                             Indian Institute of Science, Bangalore, India - 560 012
                     Department of Mechanical Engineering, VJCET, Kerala, India - 686 670,
                                         Email: btkuzhiveli@yahoo.com

A new type of solid state cryocooler based on laser induced anti stokes fluorescence is being developed.
Design studies indicate that the fluorescent cryocooler could operate for years with efficiencies and cooling
powers comparable to current low capacity cryocoolers. The most important attributes of such a cryocooler
is that it has no moving parts, no vibrations, electrically isolated and hence not susceptible to EMI, rugged
and reliable that would not adversely affect the electronic or mechanical component components with
which they are used, cools to 77 K, weighs less than 2 kg/W of useful refrigeration, life time of 10 years of
continuous operation. The cryocooler can be deployed to cool detectors and electronics to cryogenic
temperatures for space based missions and ground applications. In order to develop laser induced anti
stokes fluorescent cryocooler, it was required to develop numerical tools that support the thermal design. It
is expected that, with improved materials and optical and thermal designs, future cryocoolers could be over
twice as efficient as present day optical coolers to cool to cryogenic temperature. The improvements in
materials along with a better thermal design as a result of the developed computer program could make the
efficiency and temperature range of optical cryocooler superior to those of small mechanical cryocoolers in
near future. This paper presents the details of development of a mathematical model and the subsequent
development of a computer program for the application of thermal design of components and the system as
a whole in an antistokes fluorescent Cryocooler.

Performance Prediction and Experimental Investigations to Study the Effect of Hot
        End Heat Exchanger Volume on Orifice Pulse Tube Cryocooler
                                   Gawali B. S.1 and Narayankhedkar K.G.2
             1 Mechanical Engineering Department,Walchand College of Engineering, Sangli-416415,
                 2 Mechanical Engineering Department, I.I.T, Bombay, Powai, Mumbai-400076

A theoretical model based on cyclic analysis has been developed for the analysis of the Pulse Tube
cryocooler to calculate the ideal refrigerating effect and ideal power requirements. Based on Martini's
second order analysis, different losses have been considered to analyze the actual behavior of the orifice
pulse tube cryocooler, to predict the actual refrigerating effect and power required. Theoretical model is
applied to predict the performance of the cryocooler. The model is also applied to predict the effect of hot
end heat exchanger volume. A linear Pulse Tube cryocooler was designed and developed. Experimental
investigations were carried out. To study the effect of hot end volume, the hot end heat exchanger volume
was varied using spacers. A comparison of the theoretical and experimental results for this cryocooler is
also presented in the paper.

         Determination Of Apparent Thermal Conductivity Of Perlite Powder
                                          Pankaj I. Jagad, Prof. M.B. Jain
                         Institute of Technology, Nirma University, Ahmedabad - 382 481

At very low temperatures it becomes economical to conserve the cold using insulating material rather than
to produce it because of the requirement of very large amount of energy to produce very low temperature.
Therefore the cryogenic storage vessels, transport vessels and transfer lines are insulated. Perlite powder at
atmospheric pressure and under vacuum is a common insulating material used for these purposes. For
estimation of heat transfer, thermal conductivity must be known. A double guarded cylindrical boil off
calorimeter, an absolute method of determining thermal conductivity, is discussed. The apparatus consists
of a main vessel in the middle and two guard vessels located at top and bottom. These vessels are housed in
a cylindrical vessel. For determining the thermal conductivity of perlite powder under vacuum, the powder
is filled in the annular space and pressure is reduced to 1X 10-2 Pa. The test and guard vessels are filled
with liquid nitrogen. The heat transferred to the main vessel results in formation of nitrogen vapour. From
the amount of vapour formed the heat transfer rate and subsequently the apparent thermal conductivity of
perlite powder is estimated. The set up is helpful in determination of the thermal conductivity of different
sizes of perlite as well as vermiculite powders.


                                    Some studies on a LN2 Freezer
                             S.Kumar, R.M.Khadatkar*, S.C.Pattanayak and H.Dasa
                  Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, India
                               *Mechanical Engg Department, HCST, Agra, India

A batch type top loading LN2 freezer is developed, with the provision of precooling by exit GN2 and
forced air-cooling. The two chambers can change alternately either as precooler or freezer by set point
temperature. A set of studies are carried out to optimize the performance of cryofreezer and to predict the
freezing time as follows; (1) cooldown characteristics of cryofreezer at different flow rates of LN2 (2)
cooldown time for different setpoint temperatures and flow rate. (3) LN2 consumption for different set
point temperature and flow rates. (4) temperature history of the surfaces of the sample holder (tray) and its
enclosed chambers (5) study on two-phase flow in helical-tube heat exchangers (6) uniformity of airflow in
freezing chamber The present paper deals with the results obtained from the above experiments.


                          Design & Development of LN2 Batch Freezer
                           Sanoj Kumar, R.M.Khadatkar*, S.C.Pattanayak and H.Dasa
                  Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, India
                              *Mechanical Engg. Department, HCST, Agra, India,

An improved batch type, LN2 freezer has been designed, developed and commissioned with the following
features:
(1) Top loading and convenient door system.
(2) No handling of food during the process.
(3) Arrangement of alternate use of chambers as freezer and precooler.
(4) Arrangement for air stirring system with variable Reynold number
(5) Temperature controlled automatic fluid distribution system.
(6) Simplified design of freezer and cooler.
Experimental data on different characterization and optimization of energy and LN2 consumption are
reported in another paper. The paper deals with the different aspects of fabrication, fluid circuit and
temperature control arrangement for achieving
a particular condition.
Additional energy requirement for an O2-N2 distillation column using pinch analysis
            and its comparison with Ponchon-Sovarit graphical method
                        Bhavsar Hardik Prakashchandra(1), Aditi Oza(2) and R M Shah(3)
                L.D. College of Engg, Ahmedabad-380015 E-mail: hardik_bhavsar@rediffmail.com

In cryogenic air separation, distillation column is the most energy consuming part. The pinch technology is
used for generating column composite curve and column analysis of distillation column. This paper
presents the use of column composite curve and column grand composite curve for minimization of
additional energy required in condenser and reboiler of distillation column by changing parameters such as
reflux ratio, feed conditioning and number of plates. Ponchon-Sovarit graphical method is used in the
construction of column composite curve and column grand composite curve. Results obtained using the
graphical approach is compared with the analytical approach.

                  Theoretical Optimization Of Claude Liquefaction Cycle
                        Bhavsar Hardik Prakashchandra(1), Aditi Oza(2) and R M Shah(3)
                        Mech-Cryogenic Engg, L.D. College of Engg, Ahmedabad-380015
                                    E-mail: hardik_bhavsar@rediffmail.com

To liquefy gas, enormous amount of energy is required. To have minimum operating and maximum yield,
parameters affecting the liquefaction system should be optimum. This paper presents theoretical
optimization of Claude liquefaction system. The parameters like presents work required per unit mass of
gas liquefied as function of (i) pressure (ii) expander inlet temperature of fluid and (iii) expander mass flow
rate ratio.




          Magnetic Refrigeration, its Developments and it's Utility in Magnetic
                                 Hydrogen Liquefier.
                               Aditi Oza (1) Hardik Bhavsar (2) R.M.Shah (3)
              Mech-Cryogenic Engineering, L.D.College of Engineering, email:aditioza@yahoo.com

Low-temperature refrigeration and the quest to attain absolute zero have paved the path for the system of
magnetic refrigeration producing temperatures from room temperature down to milli-kelvin temperature.
The basic idea of magnetic refrigeration, magneto-caloric effect, and magnetic materials and till date
developments taken place around the globe for low temperature magnetic refrigeration to that of room
temperatures and also magnetic refrigeration for aiding gas liquefiers is described. Liquid hydrogen is a
promising medium as an alternative fuel source. This paper presents the merits of magnetic liquefiers and
the basic design of 100ton/day magnetic hydrogen liquefier.

                    Design of Low Capacity Vertical LOX Storage Vessel
                                              Bhargav Hitesh A.
                Mechanical Department, Charotar Institute of Technology, Changa-388421(Gujarat).

          An increasing use of low temperatures in the various fields of science and technology has been
necessitated, the development of effective system for storage of liquid cryogen. Vertical DEWAR vessel is
ideal for stationary application vertical design ensures minimum floor space for installation, in comparison
to horizontal vessel of the same capacity. Also it gives higher natural head. Low capacity LOX vessel is
more suitable for laboratory purposes, hospitals, electronics industries and automobile industries. For better
mechanical strength and easy fabrication, suggested design length = diameter. By providing elliptical head,
it reduces the discontinuity stress at the joint.



                           Role of Vacuum Technology in Cryogenics
                                               P. Gopi Kishore
                        Bharat Heavy Plate and Vessels Limited Visakhapatnam - 530012
                                         gopikishore_bhpv@sify.com

Advances in Vacuum Technology are one of the reasons for the wide spread applications of Cryogenics
whether in the field of Gas Separation, cryogenic fluid transfer, Simulation Chambers etc. Whereas the
Cryogenic techniques are relied upon for obtaining the Ultra High Vacuum, Vacuum Technology is utilised
for effective thermal insulation which is an essential condition to be able to retain the cryogenic
temperatures obtained through various techniques. At Cryogenic temperatures, the predominant mode of
heat leak is through Radiation. Heat Leak through radiation can be controlled to a very little extent by
selection of materials with effective properties viz. emmissivity etc. However, substantial measures to
tackle the heat loss through radiation can be obtained through vacuum technology. The annular space
between the inner and outer vessels of a typical cryogenic container is evacuated to calculated limits by
means of appropriate vacuum pumping methods. After these vacuum limit s are obtained, suitable insulating
materials and techniques are employed to retain it.


       Design Approach And Constructional Features Of Cryorefrigerator For
                          Cryopumping Applications
                           C. R. Sonawane*, M. C. A. Naidu** and Dr. L. N. Patel***
                 * Mechanical Engg. Dept., Sankalchand Patel College of Engineering, Visnagar
     ** Space Application Center, ISRO, Ahmedabad, *** Sankalchand Patel College of Engineering, Visnagar

A cryopump operates over a wide range of pressure varying from 760 torr to 10-10 torr. It captures gases
by freezing them out. Thus, it does not return unwanted gases to the vacuum system. A typical cryopump
consists of a cryogenic refrigerator that provides refrigeration at two temperature stages, which are used to
cool two extended surfaces of cryopanels on which the gas can freeze out. The first stage of the refrigerator
usually operates in the range of 50 K - 70 K. It is used to cool the outer cryopanel that provides radiation-
shielding for the colder panel and cools the louvers across the inlet of the pump on which water vapor
freezes out when it hits the pump, very much as liquid nitrogen cooled cold trap freezes out water vapor.
The second, or the cold stage of the refrigerator, which usually operates between10 K - 20 K is used to cool
the inner cryopanel that is used to freeze out nitrogen, oxygen and argon, which pass through the louvers.
The gases that would not freeze out at this temperature are cryosorbed by charcoal, which is inside of the
cold panel. This cooling at both stages is achieved by cryorefrigerator. As we are operating at 20 K, it is
necessary to use helium, as it is the only working medium available in gaseous form used in Gifford –
McMahon cryorefrigerator. In this paper design aspects of cryorefrigerator for cryopumping applications
are discussed. Design considerations of the regenerator, which is a critical component of this type of
refrigerator and the vacuum system used in cryopumping are explained.

         Design of An Energy Efficient Large Cryogenic Liquid Storage Cewar
                                        M. I. VYAS*, R. M. SHAH**
                   * Mech. Engg. Dept., L. D. College of Engineering, Ahmedabad - 380 015.

This paper aims to discuss some of the design aspect of energy efficient storage vessels for cryogenic fluid.
Basic areas, such as material selection, insulationselection, vessel and support system design and piping
design etc. have been considered. Total heat in leak is made up of three major components viz. - heat in
leak through vessels walls, support system and piping. An effort has been made to analyze percent
contribution of each of the above factors in total heat in leak rate. Cost of boil of loss has been shown to
arrive at cost effective storage of cryogenic liquid.


            Insulation Performance Study by Low Temperature Calorimeter
                    R.S. Meena, S.A. Krishnan, A.Choudhury, Manoj Kumar, S .Kar, S. Babu,
 J Chacko, R.G Sharma and T.S. Datta,                                                                       Inter
                    University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi-110067
To reduce the static heat load at 4.2 K, an efficient thermal insulation like the multilayer insulation (MLI) is
widely used. This insulation is, however, not suitable for our LINAC cryostat as it's superconducting
resonators need very clean and high vacuum environment. We have evaluated the performance of an
aluminum tape as an alternate cryogenic insulation using a double guard calorimeter technique. Number of
experiments have been carried out in the temperature range of 300 -78 K and 78 -4.2 K with different
configurations of MLI and a single layer of Al -tape on a bare SS-304 surface to measure the total heat
load. It is observed that in vacuum better than 10-5 Torr, the performance of a single aluminum tape is
comparable with that of the MLI. Experimental details with results will be presented in the paper.

                             Design and Development of Vortex Tube
                                        M.V. Suresh Babu. and T.S.Datta
                                              IUAC, New Delhi

The Vortex Tube is a device, which is capable of producing low temperature from a high-pressure gas. At
present a few companies abroad are manufacturing these devices and are available commercially in various
capacities. There may be further scope to improve this device's dimensional and other parameters to
produce maximum temperature difference. An attempt has been made to develop similar device and study
the main features, which determine its performance. This paper explains in detail about the various designs
of devices and the analysis of experimental data generated from the indigenous device. Achieved minimum
temperature is - 40oC with a drop of 60 oC from inlet temperature of air 20 oC at a pressure of 7-bar.
Performance of these devices with respect to dimensions, pressure, flow and inlet temperature will be
discussed.

      Two-Stage Stirling Cycle Cryocooler Development for Space Applications:
                              Preliminary Test Results
           A.Ramasamy, Padmanabhan, C.S.Gurudath, P.P.Gupta, D.R.Bhandari and H.Narayanamurthy
               Thermal Systems Group, ISRO Satellite Centre, Vimanapura, Bangalore - 560017

A two-stage stirling cycle cryocooler for cooling IR detector to 30K is being developed for space
applications at ISRO Satellite Centre, Bangalore under advanced R&D activities. This paper outlines the
preliminary test results of the two-stage split stirling cycle cryocooler (Lab.Model). The present laboratory
model provides 250mW of heat lift at 30K at the second stage and no load at the first stage for the total
input power of 70W. This unit has achieved a base temperature of 22.2K for the input power of 76.5W.

     Loss Analysis of Stirling Cryorefrigerator with Two-Component Two-Phase
                                    Working Fluid
                                   N.G. Pandya*, N.V. Bora**, L.N. Patel***
                              * Mechanical Engg. Department, L.D.C.E.,Ahmedabad

Stirling cryorefrigerator operates on a closed regenerative thermodynamic cycle with compression and
expansion of the working fluid occurring at different temperature levels. Generally hydrogen or helium is
used as a (single component) working fluid in such cryorefrigerators. Analytical / experimental
investigations show that the use of "two-component two phase working fluid" improves the performance
of the Stirling cryorefrigerator. In this novel approach the pressure range is wide relatively. This increases
the available refrigerating effect, of course, with a correspondingly higher input power. Thus, a given
cryorefrigerator can provide higher liquefaction capacity while working with a two-component two-phase
working fluid. Alternately, for a fixed liquefaction capacity the maximum cycle pressure can be kept lower
than the maximum cycle pressure with a single component working fluid. The change over from single
component to a two -component working fluid does not involve any change in the cryorefrigerator
configuration. In this paper a computer simulation of two-component two-phase working fluid using
second order cyclic analysis has been carried out for PLN-106 cryorefrigerator. The results obtained for a
two-component two-phase working fluid are compared with a single component working fluid with the
same maximum cycle pressure for a given cryorefrigerator.

     Experimental Investigations on a Linear, Inertance Pulse Tube Refrigerator
                Pingale L. B., Naik J. M., Mulani B. S., Pandav R. S., Awasare S. S., Gawali B. S.
              Mechanical Engineering Department, Walchand College of Engineering, Sangli-416415

Affordable, minimal vibration, long life and more capable active refrigerators must be developed to meet
many current and future commercial and military needs. Modern Pulse Tube refrigerators can potentially
satisfy these combined advanced requirements better than other types of known refrigerators. Different
configurations are reported in literature to improve the performance of the Pulse Tube refrigerators like
Orifice Pulse Tube Refrigerator (OPTR), Double Inlet Pulse Tube Refrigerator (DIPTR), and Inertance
Pulse Tube Refrigerator (IPTR). Theoretical model is developed for the analysis of counter flow linear
integral inertance Pulse Tube Refrigerator. Theoretical model is used to design the refrigerator.
Experimental model is developed to demonstrate the concept of counter flow linear inertance Pulse Tube
refrigerator. Preliminary results obtained using air as working media are presented. Lowest temperature of -
2.5? C is measured using 3.5 Kg/Cm2 charge pressure.

        Analysis and design of two-stage miniature Stirling cryocooler for space
                                      applications
                               V.K. Bhojwani, S.L. Bapat and K.G. Narayankhedkar
                           Indian Institute of Technology, Bombay, Powai, Mumbai - 76

Small capacity Stirling cryocoolers are used in space applications for cooling of IR detectors. These coolers
are compact which utilize compressor with opposed piston configuration. Both the compressor and
displacer are driven by linear drive. Since the direct linear motion is obtained, the components required to
convert rotary to linear motion are absent. This increases the life, reduces the wear and maintenance, which
are necessary requirements of space applications for life durations of 3 to 5 yrs of continuous operation.
The current work reports analysis and design of a two-stage Stirling cycle cryocooler with a cooling
capacity of 2W at 100 K (Stage - I) and 0.5 W at 50 K (Stage - II). The performance predicted by the
analysis is presented in this paper.

                    Design and development of Stirling Cycle Cryocooler
                                 Lele M. M., Bapat S. L and Narayankhedkar K.G
                         Indian Institute of Technology Bombay, Powai, Mumbai-400076.

The cyclic analysis is the most important tool for designing Stirling Cycle cryocooler. Based on this
analysis the Stirling Cycle Cryocooler was designed, developed and tested. The above analysis takes care
of all possible losses like temperature swing loss, loss due to regenerator ineffectiveness, loss due to shuttle
conduction, loss due to pumping action, loss due to conduction, P-V loss etc. The particular application
discussed here is, to meet the specification of 3W at 80 K. The experimental results of initial trials are
reported.


            Theoritical Analysis of GM Type Orifice Pulse Tube Refrigerator
                             K. P. Desai *, H. B. Naik* and K. G. Narayankhedkar **
            * Mechanical Engineering Department, S. V. National Institute of Technology, Surat 395 007
              ** Mechanical Engineering Department, Indian Institute of Technology, Mumbai 400076

Cryogenics is mainly concerned with design and development of cryocoolers. The pulse tube refrigerator
consists of a thin-walled tube, with heat exchangers at both ends, connected to a pressure oscillator via
regenerator. The heat exchange may be attributed to the surface heat pumping and/or enthalpy flow. The
absence of moving parts in the cold region, high reliability, better temperature stability, economy of
manufacturing and quiet vibration free operation have given promising future to the pulse tube
refrigerators. The performance of a pulse tube refrigerator is sensitive to many operating parameters and
using a suitable model performance prediction can be carried out. Various researchers [4-12] have
attempted to develop analytical and numerical models for better understanding for the physical process. In
the present work an analytical model for cyclic simulation of G-M type orifice pulse tube refrigerator is
developed assuming ideal gas behavior, sinusoidal pressure variation, isothermal heat exchange and
adiabatic compression and expansion of working gas. Frictional and viscous effects, convective heat loss to
the atmosphere and losses due to oscillating flow are neglected. The parametric investigations were carried
out.

      Experimental Investigations on G-M Type Orifice Pulse Tube Refrigerator
                            K. P. Desai *, H. B. Naik* and K. G. Narayankhedkar **
            * Mechanical Engineering Department, S. V. National Institute of Technology, Surat 395 007

The prospect of inexpensive and reliable cooling with very little magnetic and mechanical interference has
stimulated research and development of pulse tube refrigerators. In orifice pulse tube refrigerator, the warm
end of the pulse tube is connected via an orifice (usually realized by a needle valve) to a buffer reservoir
[1]. The orifice pulse tube refrigerator has a higher efficiency than the basic pulse tube refrigerator. An
experimental setup has been designed and fabricated for experimental investigations on G-M type orifice
pulse tube refrigerator. It also includes the development of a distribution valve to generate the necessary
pulse. The necessary instrumentation for measurement of cold end temperature, refrigeration power and
recording of pressure waveform is provided. Experiments were carried out to investigate the effect of
pressure, frequency, and opening of orifice valve, on the performance of orifice pulse tube refrigerator. The
results obtained are reported. The lowest no-load temperature of 72.1 K was obtained. The refrigeration
power of 3.73 W at 100 K was obtained.

              Double Inlet Pulse Tube Refrigerator capable of reaching 48 K
                             K. P. Desai *, H. B. Naik* and K. G. Narayankhedkar **
            * Mechanical Engineering Department, S. V. National Institute of Technology, Surat 395 007
              ** Mechanical Engineering Department, Indian Institute of Technology, Mumbai 400076

The prospect of inexpensive and reliable cooling with very little magnetic and mechanical interference has
stimulated research and development of pulse tube refrigerators. Double-inlet pulse tube refrigerator
(DIPTR), introduced in 1990 by Zhuet al. [1], can achieve higher efficiency than orifice pulse tube
refrigerator. An experimental setup has been designed and fabricated for experimental investigations on
double inlet pulse tube refrigerator. The experimental investigations for double-inlet pulse tube refrigerator
were carried out. The performance of doubleinlet pulse tube refrigerator was evaluated in terms of no-load
temperature and refrigeration power. The lowest no-load temperature of 47.9 K was obtained. The
refrigeration power of 4.35 W at 80 K and 7.35 W at 100 K was obtained. The results obtained are in
qualitative agreement with those available in the literature.

        Design Methodology for Free Piston Free Displacer Stirling Cryocooler
                           Biju T. Kuzhiveli *, S. L. Bapat and K. G. Narayankhedkar
     Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Mumbai, India - 400 076,
  * Department of Mechanical Engineering,VJCET Kerala, India - 686 670, Email: btkuzhiveli@yahoo.com

Many applications such as IR detector cooling in Satellites, imaging cameras in battle tanks and laboratory
spot cooler require cryogenic cooling in the range of 60-80 K with a cooling power varying from mW to a
few Watts. This paper deals with the analysis of Free Piston Free Displacer (FPFD) system and the
development of a design methodology for miniature Stirling cycle cryocooler. The major modules involved
in the program are design of magnet, linear motor, regenerator, dynamic components and heat dissipation
system. However the focus of the description shall be on linear motor design and magnet design. This
methodology has been applied to existing cryocoolers and it found that the predicted values were in a
reasonably good agreement with the actual results.

    Validation of Design Methodology and Experimental Investigation of Stirling,
                                   Cryocooler
                            Biju T. Kuzhiveli *, S.L. Bapat and K.G. Narayankhedkar
     Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Mumbai, India - 400 076,
 * Department of Mechanical Engineering, VJCET, Kerala, India - 686 670, Email: btkuzhiveli@yahoo.com

Some of the modern scientific applications including space applications have a demand for cryogenic
cooling in the range of 60-80K with a cooling power varying from fraction of a watt to few watts of
refrigeration, low weight, compact size, trouble free operation, no usage of oil, high reliability and high
endurance limit. Cryocooler working on Stirling cycle with free piston free displacer (FPFD) concept is one
candidate for such an application that meets the above requirements. This paper deals with the experimental
investigations conducted on two miniature FPFD Stirling cryocoolers. The endurance limit, cool down
characteristics, cooling power with varying pressure, cooling power with varying input power and the
measurement of cooling power from no load temperature below 60 K to 200 K are experimentally found
out and the results discussed.

                      Quench Results of 1/5th Scale of K-500 Superconducting
                                Cyclotron Main Magnet
   J. Pradhan, Md. Z. A. Naser, U. Bhunia, T. K. Bhattacharrjee, A. Sarkar, A. Sur, S. Saha,             R.
                 Ranganathan* and R. K. Bhandari, V.E.C.C,1/AF Bidhan Nagar, Calcutta 700 064,
                Email: jpradhan@veccal.ernet.in, *Saha Institute of Nuclear Physics, Kolkata

The super-conducting cyclotron having K value of 500 is in commissioning state at VECC, Kolkata [1].
The main magnet coil is made up of multi filamentary composite superconducting wire of Nb-Ti having
copper to superconductor ratio of 20:1. A 1/5th scale of this main superconducting magnet coil made in-
house is tested in liquid helium. The stability of coil is verified by energizing the coil beyond the operating
current of K-500 cyclotron. The magnet is forced to quench by means of heater placed close to the magnet
coil and studied the quench propagation. The test has also been carried out to verify dump circuit along
with quench detection circuit made in-house this paper describes the test set-up along with the test results
obtained.

             Thermal analysis for temperature transients during VEC K-500
                         Superconducting magnet cool down
                       C Nandi, T K Bhattacharyya, G Pal, J Chaudhuri and R K Bhandari
                     Variable Energy Cyclotron Center, 1/AF Bidhan Nagar, Kolkata 700064
Abstract
A superconducting cyclotron is being constructed at VEC Centre, Kolkata. The cyclotron magnet has a
superconducting NbTi coil. The iron core is, however, at room temperature. Liquid helium cools the NbTi
coil. The coil is surrounded by liquid nitrogen cooled thermal radiation shield to reduce heat in leak to
liquid helium system. A Helium refrigerator, Helial 50, supplied by M/s Air Liquide, France will deliver
liquid helium to magnet coil through an efficient cryogen delivery system. During cool down from room
temperature, the refrigerator will directly deliver cold gas to magnet coil. After attaining a temperature of
about 20K, liquid helium will be supplied to magnet coil from liquid helium dewar. This paper presents
detailed cool down procedure, the thermal model and results of transient behavior of superconducting
magnet coil during cool down.

    The Cryogenic System For The TIFR-BARC Superconducting Linac Booster
                P. B. Patil, K. S. Parab, J. N. Karande, S. S. Jangam, P. B. Thakkar and R. G. Pillay
                             Tata Institute of Fundamental Research, Colaba, Mumbai-05

The first phase of LINAC Booster was inaugurated in September 2002 and is operational since March
2003. An energy gain of 49 MeV for Si13i has been achieved with one superbuncher and three cryostats
comprising twelve cavities operating at 149.105 MHz. A LINDE TCF-50S refrigerator of 300 W rated
capacity (without LN2 precooling) provides liquid He at 4.5 K. Actual total heat load of 134 W is observed
for the first phase. This paper presents the details of the refrigerator, indigenously developed cryogenic
distribution system, related instrumentation and the control system.

       Development of Multilayer Insulation Blanket for Spacecraft Application
                   S.C.Rastogi, R. Rathnakar, V.Sasidara Rao, Suresh Babu, Idikulla Vergheese.
                                       H.Bhojraj, P.P.Gupta, D.R.Bhandari
                     Thermal Systems Group, ISRO Satellite Centre, Bangalore 560017, India
Multi Layer Insulation Blanket is a passive thermal control element used to control the geosynchronous and
polar spacecraft temperatures. The multilayer insulation blanket consists of number of layers of low
emissivity radiation shields interspaced by low conductivity spacer. Top and bottom layers are aluminized
kapton selected to achieve desired optical characteristics of the surface. MLI blankets were developed for
APPLE spacecraft. The technologies for fabrication of blankets, mounting technique on spacecraft were
developed and qualification tests were conducted to demonstrate the suitability of system for space use.
Electrostatic discharge grounding technique was developed and implemented on spacecraft blankets. The
thermal performances of the blanket for different configurations and at different hot and cold boundary
conditions were measured and the same was used in design of spacecraft thermal control system. Using the
developed technology MLI blankets were fabricated for structure/thermal model, electrical model of
APPLE spacecraft and subsequently on flight models of APPLE, SROSS and other spacecrafts of ISRO.

   Thermal Performance of 20 K Cryotarget Simulators for Space Environ- ment
      Simulation of Metsat VHRR Radiant Cooler Thermal Balance Testing
 N.k. Mishra1, D.P. Karnik1, P. Govindan1, S.C. Rastogi2, Madhu prasad2, Basavaraj S.A.2, Sant ram2, T. Selvan2,
           Subramanya2, A.K. Shrivastava2, Satish wani2, D.W. Tijare2, P.P. Gupta2 & D.R. Bhandari2
                  1 Environmental Test Facility, ISRO Satellite Centre, Bangalore 560017, India

Thermal Balance Test on METSAT Cooler Assembly was conducted in space simulation chamber
simulating space condition of vacuum and space sink by achieving vacuum better than 10-6 mbar and
shroud of 100K. To simulate deep cold space and to achieve low temperature on cooler cold stage, a
cryotarget simulator is utilized achieving a temperature of 20K. It consists of cryotarget plate, closed cycle
helium refrigerator, temperature indicator. The refrigerator system consists of three scroll compressor, oil
removal and gas control unit, three refrigerators (cold heads) and interconnecting hoses. The solar heat
input and incident IR heat input to cooler is simulated by supplying the precalculated power supply through
on-board heaters mounted on cooler assembly. Thermal Balance Tests were conducted for winter solstice,
summer solstice for Beginning of Life (BoL) and End of Life (EoL) conditions. The thermal performance
of 20K cryotarget simulator was evaluated for different test cases. The performance of 20K cryotarget
simulator was found satisfactory and met all the specifications and requirement of METSAT VHRR radiant
cooler thermal balance testing.

                 Non-metal Liquid Helium Cryostat for SQUID operation
                R. Karunanithi*, S. Jacob*, S. Kasthurirengan*, K. Tamizhanban* and K. Gireesan#
                    *Centre for Cryogenic Technology, Indian Institute of Science, Bangalore,
                #Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam

Design, development and performance evaluation of a non-metal cryostat for use with liquid helium for
operation of SQUIDs for NDT studies are reported in this paper. The cryostat is made of Fibre-glass
Reinforced Plastic (FRP) except the top flanges, which are stainless steel. The distance between the pick-up
coil at 4.2K and the outer vessel bottom flange is about 6mm (including the flange thickness) and the
radiation shields are made of carbon fabric. The capacity is about 5 liters for liquid helium with a neck and
tail inner diameter of about 50mm. The steady state evaporation rate without the dipstick is about
175ml/hour of liquid helium.

              Application of Cryogenics in Nuclear Power Plants operations
                                  and Nuclear Science
                           R C Khandelwal, Head HWMG & R G Pathak, SCE, KAPS
                                   Kakarapar Atomic power station, NPCIL

In a nuclear power plant operation especially PHWR type cryogenics has a very important role to play in
tritium activity reduction, positive isolation of process equipments, operation of HPGe detector for gamma
ray spectroscopy and for heavy water vapour recovery operation.

                            Cryo Technology For Space Applications
                                             Vinod Kumar Manglik
                           Deptt. of Mech.Engg.ADIT, New Vallabh Vidyanagar,Anand
The cryo technology has good potential for space applications and remarkable progress is made in last
decade or so. The use of cryogenic cooled detectors have brought un-precedent advantages over the
competitive technology. Continuous improvements in reliability, simplicity of operation and long life have
covered large range of instruments which are using cryogenic system to meet their goal easily and
accurately. Several technologies need to be improved for further enhancement of their applications and that
include improving COP for active cryo coolers, thermal insulations, high heat transfer at cryo temperatures.

                               Cryogenic applications of composites
                                 RS Praveen#, G Ayyappan#, Asha S Kumar*
           # LS, gsLVM3 Project, VSSC-ISRO, Trivandrum, Lecturer in Chemistry, SN College, Kollam

Composite materials find place in strategic cryogenic applications, both in thermal as well as structural
areas. This paper deals with some of the specific applications in space research including its limitations and
complexities in addition to its specific advantages to metals. Only limited work has been carried out
elsewhere in this area and this paper consolidates the efforts of eminent scientists worldwide in this field to
give an insight into what is already known. Further investigations in this area are required to understand the
behavior of these materials for various service conditions.




    Studies on Regeneration of Cryopanel in K-500 Superconducting Cyclotron in
                                      VECC
                              U. Bhunia*, Md.Z.A.Naser, J. Pradhan, A. Sur, R. K. Bhandari
   Variable Energy Cyclotron Centre, Department of Atomic Energy, 1/AF, Bidhan Nagar, Kolkata-700 064, India.
                                       *ubhunia@veccal.ernet.in
Ultra high vacuum in the median plane of K-500 superconducting cyclotron is achieved by three cryopanels
placed in the valley regions of the median plane. The cryopanel gets saturated after certain period of
operation and needs to be regenerated. This paper describes two regeneration possibilities such as by
temperature controlled resistive heating and convective heating by dry gas. The heater wattage required for
first kind of regeneration for liquid helium cooled cryopanel and it's transient temperature response during
regeneration is studied. The effect of the central screw material for liquid helium cooled panel on its
conduction cooling is found. Possibility of regeneration by convective heating by dry nitrogen and helium
gas for nitrogen panel and helium panel respectively is also studied.


      Electrical transport properties of K-doped La1-XKXMnO3 (x=0.05,0.1,0.15)
                           Prepared by pyrophoric method
                                              S. Das and T. K. Dey
                Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur - 721 302

The effect of monovalent alkali metal substitution into the La-sites in La1-xKxMnO3 with =0.05,0.1,0.15
on the electrical transport behavior from room temperature to 10K is reported. All the samples show the
broad metal-insulator transition which increases with increasing the K-doping and resistivity decreases
correspondingly. Below 50K, all the samples show a field-dependent shallow minimum, which is explained
by intergrain tunneling model. The conduction mechanism in the insulating region (T>TMI) is explained by
means of adiabatic small polaron hopping model, whereas in metallic region, below ~120K, resistivity is
explained by small polaron coherent motion involving a relaxation due to a soft optical phonon mode along
with twomagnon scattering. These hase separated conduction models at different temperature regions are
combined by using a henomenological model considering the energy required to form the two phases and
corresponding temperature dependence of the volume fraction is supposed to follow the Boltzmann
distribution of a two energy-level system.
   Quantum Hall Resistance Measurement using Direct Current Comparator and
                        Cryogenic Current Comparator
                                          N D Kataria and H.K. Singh
                    National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi-110012

We report on the progress towards the establishment of a quantized Hall resistance (QHR) measurement
system for calibrating a reference resistor maintained at a fixed temperature. The system consists of a
quantum Hall device, a 9 T superconducting magnet installed in a LHe cryostat, a room temperature direct
current comparator bridge (DCC) and a temperature controlled oil bath. We discuss the measurements
required to transfer the quantized Hall resistance to the reference resistor by DCC and the cryogenic current
comparator (CCC) being developed for future use.


                    Microwave Characterization of Superconducting and
                      Dielectric Materials at Cryogenic Temperatures
                                          N D Kataria and H.K. Singh
                    National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi-110012

Microwave characterization of superconducting bulk and thin films is reported using sapphire loaded
dielectric resonator at microwave frequencies and temperature ranging from 10 K to the transition
temperature Tc. The Q-value of the resonator depends on the conduction losses of the enclosure besides
loss tangent of the dielectric material. Using High temperature superconducting thin films decreases the
conduction loss thereby increasing the Q-value of the resonator. Dielectric resonators are also used to
characterize dielectric ceramics.

   Design and Development of Cryogenic Test Facility for Evaluating hts Current
                                    Leads
                          L PRADEEP KUMAR BHAVANAM, SWAMINATHAN.G*
                         Heat Power- R&Ac, J.N.T.U College of Engineering - Anantapur
                           * Ceramic Technological Institute, BHEL-EPD - Bangalore

A cryogenic test facility for evaluating critical current characteristics of HTS current leads as a function of
temperature is described. The system was constructed by designing a multi purpose cryostat to work as
liquid Nitrogen as well as Helium Dewar. An optimum vapor cooled current lead assembly to power the
HTS leads at cryogenic environment from ambient temperature with low heat leak was designed using a C-
program keeping in view of above process.

   Development of Three-Stage Passive Radiant Cooler for Cryogenic Cooling of
 Infrared Detectors of Imager Meteorological Payload, of INSAT 3D Spacecraft of
                                     ISRO
             S.C. Rastogi*, Madhu Prasad, Basavaraj S Akkimaradi, Sant Ram, T. Selvan, Subramanya,
                     A.K. Shrivastava, D.W.Tijare, Satish Wani, P.P. Gupta & D. R. Bhandari
                        Thermal Systems Group, ISRO Satellite Centre, Bangalore - 560017

INSAT-3D IMAGER will provide imaging capability of the earth disk from geostationary altitude in one
visible in 0.55 to 0.75 ? m range and five infrared channels viz., Short Wave IR (SWIR) in 1.55 to 1.70 ?
m, Mid IR (MIR) in 3.8 to 4 ? m, Water Vapour IR (WV) in 6.5 ? m, Thermal IR-1 (TIR-1) in 10.5 to 11.5
? m range and Thermal IR-2 (TIR-2) in 11.5 to 12.5 ? m range. The MIR, WV, TIR-1 and TIR-2 are
maintained at cryogenic temperature of 95 to 100 K through three-stage passive radiant cooler and close
loop heater control. Passive radiant cooler utilizes the deepcold space sink to cool IR detectors. A passive
radiant cooler is developed and qualified for this application. The critical areas of development, (1) low
conductance FRP support assembly (2) High emittance cold stage, (3) Sun Shield with low emissivity and
high specular reflectance and (4) Cryogenic Electrical Wiring processes are highlighted. Thermal
mathematical model is developed considering specular/diffuse thermal control surfaces and complete
spacecraft surrounding. The on-orbit performance is predicted for different stages of cooler for all seasons
in space at Beginning of Life (BoL) and End of Life (EoL) cases. The cooler assembly, as part of
acceptance/qualification program will be subjected to various tests like (1) Sine and Random Vibration
Test, (2) Optical Alignment Test, (3) Thermal Balance Test etc. On the basis of Thermal Balance Test,
Cooler Mathematical Model will be updated to predict on-orbit temperatures.

                   Application of Cryogenic Systems in Space Simulation
                                               P. Gopi Kishore
                        Bharat Heavy Plate and Vessels Limited Visakhapatnam - 530012
                                    gopikishore_bhpv@sify.com
In order to produce a vacuum that approaches that of outer space, best method involves low temperatures.
In Space Simulation, the pressure of space is produced by Cryopumps cooled by gaseous helium - backed
by Diffusion pumps to remove the non condensibles. Cryopumping or Freezing out the residual gases will
result in Ultra High Vacuum.. Temperature of free space is simulated by cooling a shroud with integral
cryo fluid paths within the chamber to liquid nitrogen temperatures. Dense gaseous helium at cryogenic
temperatures or liquid helium is used to cool the Cryo Panels which freeze out the residual gases.

                                        Cryogenic Propulsion
                                    Shirish R. Gandhi, and Nisha V. Bora
                 Department of Mechanical Engineering, L.D.College of Engineering, Ahmedabad

         Cryogenic propulsion utilizing cryogens has dominated over the orthodox methods of propulsion.
Cryogenic propulsion for space exploration was investigated very early with initial development work on
space activities and rocket propulsion system using liquid oxygen and hydrogen. Use of slush hydrogen in
cryogenic propulsion system has solved many problems of using cryogenic propellants such as heat in-leak,
storage of low temperature liquid, thermal stratification etc.

                    Future Thermal Design Prospects of NiH2 Batteries
                              for Indian Space Applications
                        Alok Shrivastava, Dr. R.A.Katti*, Prof. K.G.Narayankhedkar**
                     *Thermal Systems Group, ISRO Satellite Centre, Bangalore - 560017,
                     ** Mechanical Engineering Department, IIT Bombay, Mumbai-400076

With the growing demand of communication needs, electrical power of spacecrafts is continuously
increasing from 2 kW to 6 kW. During sun-lit part of the orbit, solar cells generate power, while in eclipse
power is supplied by NiH2 Batteries. The working temperature regime for these batteries is comparatively
lower (-10 to +10 oC), and have a stringent requirement that the maximum temperature gradient within a
single battery is 5 oC. For earlier batteries, Passive Thermal Control Techniques were adequate; however
Active Thermal Technique is necessary for such high power batteries. Loop Heat Pipes (LHPs) and
Capillary Pumped Loop (CPLs) are chosen for low heat fluxes and preferably for diffusing the heat at
larger area. For thermal management of high heat flux electronic packages Mechanical Pumped Loop
(MPL) system is essential. The conceptual configuration and functioning of a MPL, under development
phase in ISRO, have been discussed in this paper.

   Transient Heat Transfer -Two Dimensional Mathematical Model for Cryogenic
                         Rocket Engine Thrust Chamber
                                   Biju T. Kuzhiveli* and V. Gnana Gandhi
               Liquid Propulsion Systems Centre, I.S.R.O, Valiamala, Trivandrum, India - 695 547
 * Department of Mechanical Engineering, VJCET, Kerala, India - 686 670, Email: btkuzhiveli@yahoo.com

This paper presents two-dimensional transient thermal computational model for a cryogenic rocket engine
thrust chamber. Modern cryogenic rocket engine thrust chambers are exposed to high pressure and high
heat flux environments due to high energy combustion and has presented some of the most challenging
engineering problems in the rocketry and space engineering. A commonly employed method to overcome
the problem due to high temperature arising out of high-energy combustion is to provide regenerative
cooling by passing liquid hydrogen through coolant channel passages through the thrust chamber. However
cooling the thrust chamber by passing cryogenic fluid results in wide range of temperature distribution
across the cross section and along the axis of the thrust chamber during transient and steady state conditions
and poses serious structural strength concerns. In order to have a thermal prediction that leads to optimal,
stable and economical structural design, an accurate accounting of heat transfer characteristics for the
complete spectrum of the thrust chamber is necessary. Hence it is essential to develop a tool which can
accurately predict the transient thermal characteristics of the thrust chamber. In order to meet the goal, a
computational model has been developed which takes into account of flow involved in the operation of
cryo engine and various boundary conditions. The flow involved in the operation is a complicated
phenomenon as it is turbulent, reactive and undergoes both subsonic and supersonic flow regimes. The
mathematical model presented here takes care of the transient temperature distribution along the axis and
across the cross section during transient and steady state conditions during chill down and hot test. First
phase of computer implementation is currently underway which gives promising results. The computer
program is capable of providing two dimensional , transient temperature distribution on the thrust chamber,
hot side and coolant side heat transfer coefficients, coolant temperature rise, coolant pressure drop and heat
flux etc.

				
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