bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a high-effectiveness slotted plate cryogenic heat exchanger
Authors: Sheehan E , Pfotenhauer J , Miller F 
Published: June 2020

Abstract
High-effectiveness heat exchangers are a ubiquitous component of cryogenic systems, but their performance typically falls short of model-based expectations. The following paper summarizes modeling efforts of a heat exchanger designed to achieve an effectiveness in excess of 99% within a prescribed envelope of volume, weight, pressure drop, and operating conditions. Simulation efforts focus on employing minimal assumptions and accounting for many loss mechanisms to avoid overestimation of predicted effectiveness. Axial conduction and parallel passage flow imbalance are major contributing factors to heat exchanger inefficiency. Consequently, a staggered stacked slotted plate geometry, also known as a matrix heat exchanger, was chosen as the most promising type to achieve the desired effectiveness. High thermal conductivity, high surface area finned copper plates separated by low thermal conductivity, low cross-sectional area stainless steel spacers achieve high stream-to-stream heat transfer while limiting axial conduction and allowing for fluid redistribution between plates. The number of design parameters was reduced based on manufacturing limitations and conceptual reasoning. ANSYS Fluent computational fluid dynamics was used to form Nusselt number and Darcy friction factor correlations for the geometry and flow conditions. A finite difference MATLAB model accounted for axial conduction, parasitic heat loads, and material property variation with temperature and pressure. The Fluent-derived correlations were used as inputs to the MATLAB model. The MATLAB model was validated by comparing its results to an analytic, constant property effectiveness-NTU solution for stacked plate heat exchangers, as well as experimental data collected from a similar heat exchanger. Trade-offs between weight, pressure drop, and effectiveness were studied.
Effect Of Leading-edge Geometry Parameters On The Performance Of Miniature Cryogenic Expansion Turbine
Authors: Ke C L , Xiong L X , Peng N , Dong B , Li K R , Liu L Q 
Published: June 2020

Abstract
The numerical simulation included solid blades with four different leading-edge thicknesses and four different leading-edge geometries. One of the geometries was square, one was ellipse A(ellipse ratio is 1), one was ellipse B(ellipse ratio is 2), and the other was ellipse C(ellipse ratio is 3). The four thicknesses were 0.7mm, 0.6mm, 0.5mm, 0.4mm. The results show increased efficiency loss for increased leading-edge thickness for square geometry. For ellipse geometries, there was no significant difference when the leading-edge thickness changed at the positive incidence range. For the same leading-edge thickness(0.7mm), square leading-edge caused more loss than ellipse leading-edge. For square geometry, the optimal incidence angle was about -8 degree(0.7mm). For ellipse geometries, the optimal incidence angle was about -30 degree(0.7mm). And with the decrease of leading-edge thickness, the square’s optimal incidence angle was toward to zero degree, the ellipse’s optimal incidence angle was toward to larger negative angle.
Development of a kw-class Stirling cryocooler for liquefaction of natural gas (NG)
Authors: Park J , In S , Ko J , Kim H , Hong Y , Yeom H , Park S 
Published: June 2020

Abstract
Our research group has developed a kW-class Stirling cryocooler. The Stirling cryocooler adopts a ‘gamma-type’ configuration operated with a linear compressor. The cold-end of the Stirling cryocooler is equipped with heat exchangers that can accept and eventually liquefy natural gas (NG). The liquefied natural gas (LNG) is stored in an auxiliary reservoir. In this research paper, the experiments as a proof of concept has been carried out. The Stirling cryocooler has been independently tested prior to adopting the heat exchanger as the aforementioned above. It has been confirmed that the Stirling cryocooler can exert over 1 kW cooling capacity at 110 K cold-end temperature with 9 kW compressor input. This research paper mainly focuses on (1) relevant technical issues during the cooler development process and (2) demonstrating the liquefaction of argon gas (instead of using NG for the sake of safety regulation). The system presented in this paper, therefore, can be a good candidate for a small-scale liquefier does not require oil-involved maintenance.
Experimental study on a 20W/80K high frequency pulse tube cryocooler
Authors: Liu Xuming , Chen Liubiao , Wu Xianlin , Wang Jue , Zhou Yuan , Wang Junjie 
Published: June 2020

Abstract
The cryocoolers working around the liquid nitrogen temperature have important applications in high temperature superconducting, infrared detectors and gas liquefaction. A cryocooler sometimes needs to work in different temperatures. For the high-frequency pulse tube cryocooler operating around the liquid hydrogen temperature, due to the limitation of the length of the regenerator, it is often impossible to simultaneously have higher performance around the liquid nitrogen temperature. Therefore, this paper enhances its performance around the liquid nitrogen temperature based on a high-frequency pulse tube cryocooler working around the liquid hydrogen temperature, by changing the effective length of the regenerator with filling different lengths of copper mesh. Firstly, the effect of filling different lengths and meshes of copper mesh on its 80 K refrigeration performance is simulated. Finally, the experimental verification is also carried out. Moreover, by further optimizing the phase modulation mechanism and operating parameters including working frequency and charge pressure, the cryocooler can provide 20 W cooling capacity at 78 K under the input electric power of 420 W. The relative Carnot efficiency is increased from the initial 9.8 % to 13.56 %.
Load map of sumitomo 415DP cryocooler in the temperature range of 40-400K
Authors: Wirths T. , Putselyk S. , Bekhti N. Ben , Fröhlich A. , Grenz O. , Konig F. , Naumann L. , Rahlf F. , Tiesing M. 
Published: June 2020

Abstract
In the last 20 years, 2-stage cryocoolers have been found to provide an optimum solution for a wide range of applications like low temperature physics, superconducting cold electronics, cryopumping and superconducting magnets. For a proper design of helium cryostats with significant cold masses connected to the first and second stages of cryocoolers, it is important to have a load map (also called “working field”) in order to estimate cool-down and warm-up time periods. Such load maps are either not presented in the open literature sources for “high” temperature ranges, or just given by manufacturing companies for general information but without any guarantee. In the present paper, the load map of a 2-stage Sumitomo 415DP cryocooler in the wide temperature range of 40-400 K is presented.
High-availability single-stage Stirling coolers with high power density
Authors: Willems D. , de Veer B. , Arts R. , Mullié J. , Bollens P. 
Published: June 2020

Abstract
Recent developments at Thales Cryogenics have been aimed at improving the performances of 100 W and 200 W input power class flexure bearing Stirling coolers.
The aim of these developments has been twofold: To enable multi-year operation with a vanishingly small failure probability (high availability) and to extend the usable range down to below 42 K (low temperature). As the starting point for development, the LSF9589 and LSF9340/LSF9350 cooler ranges were selected. By performing these upgrades, the usability range of the cryocoolers is extended.
Multiple upgrades will be shown such as tuning for low-temperature operations and material upgrades. Test results will be presented and potential future improvements will be discussed. The work performed was done for a variety of customers, with applications including nitrogen recondensers for zero boil-off dewars, high temperature superconducting filters, and low temperature longwave infrared detectors.
PIP-II Injector Test cryogenic transfer line
Authors: Wang Renzhuo , Hansen Benjamin , Hurd Joseph , Martinez Alexander , Klebaner Arkadiy 
Published: June 2020

Abstract
PIP-II Injector Test will test a nearly full-scale front end of PIP-II accelerator. The cryogenic transfer line will provide 2 K, 5 K and 40 K refrigeration for Half Wave Resonator and Single Spoke Resonator cryomodules. This paper will focus on design, installation and operation plan of the cryogenic transfer line.
Status of the LCLS-II Cryogenic Distribution System
Authors: Soyars W , Dalesandro A , Martinez A , Hansen B , Theilacker J , Klebaner A , Wands R 
Published: June 2020

Abstract
The LINAC Coherent Light Source II (LCLS-II) located at SLAC National Accelerator Laboratory (SLAC) in Menlo Park, CA, is a U.S. Department of Energy project tasked to design and build a world-class x-ray free-electron laser facility for scientific research. The Linac has superconducting radio frequency cryomodules that are connected to the cryogenic plant by the Cryogenic Distribution System (CDS), which consists of distribution boxes with heat exchangers and reliefs, feed caps, end caps, and surface, vertical, and bypass transfer lines. The CDS components were designed and built to specification by industry. The components have been delivered and their installation at SLAC will be discussed. The as-built relief system design will be presented, showing minimization of relief inlet pressure drops while meeting capacity requirements. The relieving flow pressure drops along the lengths of the CDS to centrally located reliefs at the distribution box were analysed to satisfy Pressure Vessel and Process Piping Code criteria to ensure relief performance. The sub-atmospheric 2 K circuit relieving approach will be discussed, which includes a three-way diverter isolation valve suitable for sub-atmospheric service. The component anchoring load design approach and installation into concrete floor will be discussed. This addresses loading, including seismic loading, along the component’s load path to floor anchoring system.
Design and fabrication of the Mu2e cryogenic distribution system
Authors: White Mike , Lamm Mike , Hocker Andy , Arnold Don , Tatkowski Grzegorz , Kilmer James , Poloubotko Valeri , Tope Terry , Huang Yuenian , Elementi Luciano , Badgley Karie , Voirin Erik , Young Ian , Dhanaraj Nandhini , Brandt Jeff , Feher Sandor , Hess Charles 
Published: June 2020

Abstract
The muon-to-electron conversion (Mu2e) experiment at Fermilab will be used to search for the charged lepton flavor-violating conversion of muons to electrons in the field of an atomic nucleus. The Mu2e experiment is currently in the design and construction stage and is expected to begin operations in 2022. The Mu2e experiment uses four large superconducting solenoid magnets including a Production Solenoid (PS), an Upstream and Downstream Transport Solenoid (TSu and TSd) and a Detector Solenoid (DS).
This paper will focus on the cryogenic distribution system for these four solenoid magnets. Liquid helium will be supplied from two re-purposed Tevatron satellite refrigerators. A large cryogenic distribution box (DB) is located in the Mu2e building to distribute the required cryogens to each of the four solenoid magnets. Each solenoid magnet will have a dedicated transfer line and cryogenic feed box (FB). The solenoid magnets each require two liquid helium circuits and two liquid nitrogen circuits.
The most unique feature about this cryogenic system is that the assemblies for the start of the superconducting portion of the power leads are mounted in feed boxes that are in the range of 23 m to 31 m away from the solenoid magnets. The cryogenic feed boxes are located remotely to provide protection from radiation damage and high magnetic fields. The power leads are NbTi superconducting cable stabilized with high conductivity aluminum. The 6061-T6 aluminum grade was selected for the transfer line piping so that the piping would thermally contract at the same rate as the power lead. A major concern for this transfer line is that a small helium leak could create an electric discharge arc due to the Paschen effect. This paper includes a description of the design features and testing done to ensure that the power leads are protected from the Paschen effect while still being adequately cooled to liquid helium temperatures.
Effect of solid surface in vicinity of multi-bubble array in cryogenic environment
Authors: Mondal J , Mishra A , Lakkaraju R , Ashokkumar M , Ghosh P 
Published: June 2020

Abstract
Multiple bubble interactions in initially quiescent liquid are often accompanied by generation of jets, shockwaves and light. At cryogenic temperature (< 123 K) when certain materials (particularly bcc-type) become brittle, such afore-mentioned physical effects can be effective in disintegrating them to smaller fragments. CFD techniques based on direct numerical simulations can help to understand this phenomenon that may benefit nanotechnology-based industries and oil-gas exploration-firms working with air-gun arrays. In this paper, multiple bubble-pairs are simulated in a co-centric manner around a centrally located solid target (5 mm radius). The ambient fluid is liquid nitrogen (77 K) and the bubbles are gaseous nitrogen (87 K). 2D numerical simulation using the VOF method in compressible domain is carried out neglecting the effect of phase change and gravity. The stand-off distance between the solid target and bubble-pairs are varied systematically and its influence on the fluid-dynamic effects (e.g. pressure shockwave & jets) are compared. Initial calculations suggest that for stand-off distance of 0.93 mm, shockwaves measure above 10 times the ambient pressure and liquid jet speeds around 30 m/s in cryogenic environment, at multiple locations very close to the solid target. These consecutive physical impacts can foster ample liquid-hammer pressures, making it promising for solid wear at 77 K when juxtaposed against room-temperature cases.
FRIB cryogenic system status
Authors: Casagrande F , Ganni V , Knudsen P , Wright M , Jones S , Nguyen C , Fila A , Hassan N , Vargas G , Joseph N , Stanley S 
Published: June 2020

Abstract
The Facility for Rare Isotope Beams (FRIB) cryogenic plant has been successfully commissioned, including compressor system, 4.5 K cold box system, sub-atmospheric (2 K) cold box system, and the distribution system for two of the three linear accelerator (Linacs) segments. This plant uses the Ganni-Floating pressure process, allowing the compressor discharge and 4.5 K cold box supply pressure to automatically vary from 6 to 21 bar, without introducing additional exergetic losses to reduce the capacity (e.g., throttling turbine inlet valves, load heaters, etc.). The 2 K (31 mbar) load is supported using five stages of centrifugal compressors, housed within the sub-atmospheric cold box, which recompress the helium to 1.15 bar (and around 30 K). In 2012, FRIB assumed the responsibility, in collaboration with JLab to design and procure the sub-systems after the decision to move away from an industry supplied turn-key system. FRIB was responsible for procurement of all systems, all onsite activities, including the installation and integration of all the subsystems, development of the control systems, as well as, the integration, commissioning, and testing of each sub-system. At present this has culminated in the production of the first beam through the first Linac segment. An overview of the planning and execution of the project will be presented, which allowed meeting of scheduled goals and anticipated performance, and prevented the need to store or ‘double-handle’ any equipment.
The ESS Test and Instruments Cryoplant – First test results and operation experiences
Authors: Arnold P , Barbier A , Bigeard S , Goncalves R , Gourlet P , Nilsson P , Su X T 
Published: June 2020

Abstract
The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The world’s most powerful linear proton accelerator shoots protons against a rotating tungsten target where neutrons are knocked off (“spallate”) and are guided to the neutron instrument suites. Three cryogenic plants and a vast cryogenic distribution system serve the cooling needs of the superconducting RF cavities in the accelerator, the cold hydrogen moderators in the target, a cryomodule test stand and the sample environments for neutron instruments. The project’s demand of schedule and economic feasibility requires a high degree of parallel work for installation and commissioning of the cryogenic and auxiliary systems. The first of the three plants, the Test and Instrumentation Cryoplant (TICP) has been installed, commissioned and acceptance tested in 2018 by Air Liquide Advanced Technologies (ALAT). The plant consists not only of a standard compressor system and coldbox but also of a process vacuum system for 2K operation, internal and external helium purifiers, liquid helium tank, filling and boil of station and a helium recovery system. It is heavily integrated in the overall cryogenic installations at ESS. The paper describes some project challenges, acceptance test results and first operation experience.
Effect of mass flow rate on gas propagation after vacuum break in a liquid helium cooled tube.
Authors: Garceau Nathaniel , Bao Shiran , Guo Wei 
Published: June 2020

Abstract
Vacuum break in particle accelerators is a major concern due to risks associated with personnel and extensive equipment damage. Continuing research in our lab focuses on the sudden loss of vacuum in the liquid helium cooled beam-line tubes of superconducting particle accelerators. In our previous research, we studied nitrogen gas propagation in a uniform tube system immersed in both normal helium (He I) and superfluid helium (He II). It was observed that He II has a stronger effect in slowing down the gas propagation compared to He I, but this effect was largely due to the variation of the point where condensation and deposition of the nitrogen gas on the tube inner wall. Here, we discuss our modifications to the tube system that now allow us to accurately control the starting location of gas condensation in both the He I and He II experiments. Systematic studies of gas propagation were conducted using this new tube system by varying the nitrogen mass flow rate at the tube inlet.
Use of Galinstan as a Contact Agent for Additively Manufactured Components in Cryogenic Engineering
Authors: Stautner W , Budesheim E , Chen R 
Published: June 2020

Abstract
We introduce a new, demountable, brush-on thermal interface material for cryogenic applications. A process has been developed that allows to removably provide contact e.g. between an additively manufactured component and its interface. The use of Galinstan as an industrial material for cryogenic applications and in particular for those materials used in additive manufacture is reviewed and explained. Thermal contact conductance values are also presented for dissimilar materials, that have not been investigated before.
Jlab Chl1 2K Cold Box Replacement
Authors: Yang S , Dixon K , Laverdure N , Norton R , Butler C , MacDuffie C , Rath D , Brown R , Thompson S , Creel J , Sprouse R , Renzo T , Hasan N 
Published: June 2020

Abstract
A new sub-atmospheric cold box (SC1R), which hosts five technologically superior, water-cooled compressors and one similar 4K-2K refrigeration recovery heat exchanger, was proposed in July 2017, to replace the existing 2K cold box. The design of the new 2K cold box and the external support system have been completed. The project is in the fabrication and assembly phase, which will be completed at JLab. We present the design features, fabrication, installation and commissioning schedule for the new 2K cold box.
Sorption compressor efficiencies of different designs
Authors: Davidesko A , Tzabar N 
Published: June 2020

Abstract
Sorption compressors do not have moving parts and are suitable for driving Joule-Thomson cryocoolers. This allows a complete cryogenic cooling system with the absence of moving parts, which is attractive especially for space applications, as well as for other applications. Sorption compressors are thermally driven, meaning, they operate in heating and cooling cycles. The main drawback of sorption compressors is their low efficiency, relative to mechanical compressors. The compressor efficiency is defined as the PV power divided by the heat which is supplied to the compressor, it is limited by the Carnot efficiency, and practically it is significantly lower. In addition, we define a thermal efficiency of a compressor, by the heat which is transferred to the adsorbent divided by the total heat which is supplied to the compressor. In the frame of our ongoing research on sorption applications we develop a numerical model for the heat and mass transfer in a sorption cell. The model allows investigating the performance of a variety of sorption cell configurations, including different geometries, dimensions, and materials. In the current paper we show preliminary results of sorption compressor efficiencies for different sorption cell designs. An investigation on the heater configuration, general dimensions, and different adsorbents is presented. The results show that a sorption cell configuration, which provides a maximum compressor efficiency, is not necessarily the cell configuration which provides the maximum thermal efficiency
Thermal analysis and cryogenics of the Baby-IAXO magnet
Authors: Silva H F P , Dudarev A , Bykovskiy N , de Sousa P Borges , ten Kate H H J 
Published: June 2020

Abstract
Baby-IAXO is a new helioscope, a demonstration version of the proposed full-size IAXO, the International Axions Observatory. It is currently under design and once installed it will search via the Primakoff effect for axions or axion-like particles (ALPs) originating in the Sun. Axions can transform into photons in the presence of a significant magnetic field, and then be detected. The superconducting magnet for Baby-IAXO comprises two 10 m long racetrack coils, spaced by 0.8 m, operated in a quadrupole configuration and generating an average magnetic field of 2.1 T in the two 700 mm diameter free bores for axion-to-photons decay positioned in between the coils. Cool down and operational cryogenic requirements are handled by a combination of single and double stage cryocoolers. For the cool down of the 18.5 t cold mass within 22 days and for current leads cooling, the use of powerful single stage cryocoolers is of paramount importance. The cooling power is distributed across the cold mass and thermal shield using helium gas flow enforced by cryocirculators. The design of the 10 kA conduction cooled current leads is presented as well, since at 70 K these represent the dominant heat load. The cryogenic system allows for a constant heat load of 1.2 kW at the first stage and 8.5 W at the 4.2 K cold mass. Alternatively, the magnet may be operated in persistent mode, thereby reducing the heat load and the number of cryocoolers. It requires a more complex cooling circuit, implementation of a 10 kA persistent mode switch, and a delicate balance of energizing and operational heat loads.