bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model establishment and process analysis of liquid hydrogen energy storage
Authors: Zhang Zhaoxue , He Ming , Zhou Han , Gong Linghui 
Published: July 2024

Abstract
Under the general trend of energy reform, the key role of hydrogen energy has been becoming increasingly prominent. Hydrogen is not only an ideal efficient clean energy, but also commonly used as a cryogenic working medium, in the field of cryogenics and refrigeration. Compared with gas phase at high pressure, liquid hydrogen (LH2) has advantages such as high density and low transportation cost, which make it more suitable for large-scale development. As an energy storage medium, LH2 provides cold energy and electricity to smooth out fluctuations and reduce abandonment of wind and solar. However, there are few studies on the comprehensive LH2 industry chain of production-storage-transportation-utilization.
In this article, a model and analysis of the energy storage process utilizing LH2 is established. This includes purification and liquefaction, storage and transportation, regasification, power generation, and other related processes. The selection of appropriate methods and equipment is systematically addressed. Furthermore, an evaluation is conducted on its efficiency, economy, environmental impact and expansibility, in comparison with other energy storage methods. Ultimately, these findings aim to seek solutions for rationalizing efficient and low-cost utilization of LH2 energy storage, and provide novel insights into the practical application of hydrogen energy.
Ortho-parahydrogen catalyst test facility
Authors: Eisenhut S , Haberstroh C 
Published: July 2024

Abstract
With the growing interest in hydrogen as one pillar of the future energy economy, the relevance of hydrogen liquefaction for storage and transportation is increasing rapidly. However, the liquefaction process still offers much potential for improvement in terms of cost and efficiency. One problem faced with achieving more cost- and energy-efficient liquefiers is the uncertainty associated with the dimensioning of the ortho-para converters. Literature data on the existing ortho-para catalysts stem mainly from the 1950s and 1960s and are partly inconsistent. Therefore, a new facility for the comprehensive investigation of catalytic ortho-parahydrogen conversion was set up at the Dresden University of Technology (TU Dresden) as part of the government-funded HyCat (“Improvement of the Ortho-Para-Catalysts for Hydrogen Liquefaction”) project. It enables the testing of catalysts in the whole operational range of ortho-para converters in modern large-scale liquefaction plants by allowing the independent variation of temperature, pressure, flow rate, inlet ortho-para ratio, and sample reactor internal geometry. The setup has been tested and validated preliminarily. It can soon be used to produce new high-quality data sets on the performance of the commercial catalyst Ionex (hydrous ferric oxide), for the qualification of alternative catalysts, and for gaining a deeper understanding of the reaction kinetics involved.
Mobile hydrogen liquefaction and storage system
Authors: Glenn M , Kim H , Coleman B , Guerrero M , Goetchius B , Pratt R , Baik J , Fesmire J , Williams M 
Published: July 2024

Abstract
A mobile hydrogen liquefaction and storage unit has been developed to demonstrate the liquid hydrogen (LH2) value chain including hydrogen production, liquefaction, storage, transfer, and recovery. This unique LH2 technology demonstrator, or LS20 mobile system, is one of the primary systems for a multipurpose LH2 test platform that evaluates liquefaction, controlled storage, and zero-loss transfer (ZLT) methodologies. The LS20 system has been designed, fabricated, and tested at GenH2. The primary subsystems include an electrolyzer option, gas precooler, Ortho-Para hydrogen converter, cryocooler-based hydrogen liquefier, portable LH2 storage tank, ultralight LH2 vehicle tank for aviation application, safety devices and sensors, automated venting system, associated sensors, instrumentation, and control system. The system was successfully demonstrated by continuous hydrogen liquefaction according to the design specification with the help of an automated control system to maintain the liquid at a desired level without boiloff loss. In addition to liquefaction and controlled storage, the functions of zero-loss transfer, boiloff gas recovery, and re-liquefaction were also demonstrated. The results provide proof-of-concept data for future LH2 infrastructure design as well as the critical LH2 refilling and servicing methodology for many hydrogen mobility applications. The system design, fabrication, operational methodology, and test performance results are discussed.
Effects of throttle and heater input for reducing pressure surging in a liquid hydrogen tank pressurizer
Authors: Gitter Y K , Leachman J W 
Published: July 2024

Abstract
Ensuring uniform flow from a liquid hydrogen storage vessel to a consumer requires pressure maintenance within ullage space. Large changes in volume during vaporization of liquid hydrogen allow a percentage of flow to be diverted from the consumer for tank ullage pressure maintenance. The return state of the hydrogen should be close to saturated vapor at comparable volumetric flow rates for liquid extraction and smooth operation. This paper details the theory, design, and experimental performance of a hydrogen pressurization system for controlling this return state. A cartridge heater, throttle, and manual valve are utilized to vaporize, reduce pressure and pressure oscillations, and control flow. Experimental measurements are compared with theoretical predictions for liquid nitrogen and liquid hydrogen flows. The end results demonstrate the performance of the heater and throttle for pressure maintenance of ullage within a liquid hydrogen tank.
Model Based Exploration of Physical Parameters for Liquid Hydrogen System Insulation Performance
Authors: Maynard N , Louriou C , Estebe B 
Published: July 2024

Abstract
Cryogenic Systems require a highly efficient insulation so as to limit the heat ingress and boil-off, which is generally achieved through the use of vacuum combined with an insulated media. The performance of Multi layer Insulation (MLI) will be investigated with detailed thermal models developed to account for all the heat transfer contributions, solid conduction, gaseous conduction and radiation. Results are presented for an usual cold vacuum pressure (CVP) corresponding to high vacuum (<10−6 torr) and compared with available experimental measurements for state of the art technologies. The nominal thermal performances are then evaluated for a cold temperature of 20K (representative of liquid hydrogen storage temperature), for a degraded CVP with hydrogen and nitrogen as residual gasses and for increased hot boundary temperatures. Other parameters are also discussed such as, the number of layers, material, layers density, venting options, assembly process and material optical properties. Finally, a sensitivity of the thermal performance is also presented with a pressure gradient through the insulation thickness, that could be induced by cryopumping, materials outgassing, pumping times or small leakages.
Impact of Internal Baffle Designs on Liquid Hydrogen Sloshing in Cryogenic Aircraft Fuel Tanks
Authors: Ryali L , Stautner W , Mariappan D 
Published: July 2024

Abstract
Hydrogen because of its zero carbon emissions and highly energy-dense nature has a strong potential to be used as an aviation fuel. There are currently two main ways that hydrogen is being considered for use in aircraft: it can be vaporized and mixed with air before being burned in the jet engine, or it can be used to power fuel cells that generate electricity, which can be used to power electric motors. Both these scenarios would require storing liquid hydrogen (LH2) in cryogenic tanks on board as it minimizes the tank size. But a major challenge with cryogenic hydrogen storage is the dynamic movement of the fuel which can lead to fuel boil off and bubble formation. In the current paper, the sloshing motion of LH2 in a CHEETA type thin-walled composite fuel tank, under acceleration data obtained from an Airbus A-320 in cruising conditions, is investigated. The dynamic fluid structure interaction problem is solved numerically using the Coupled Eulerian-Lagrangian (CEL) technique in ABAQUS. The developed modelling strategy is then employed to study the impact of various internal baffle designs on the sloshing behavior of the fuel under different fill levels. This study not only establishes that sloshing is a major cause for concern when it comes to LH2 aircraft fuel storage, but also advances our understanding in devising potential mitigative strategies.
Development of a research cryostat for direct thermoacoustic cooling and conversion of hydrogen
Authors: Shenton M P , Leachman J W , Matveev K I 
Published: July 2024

Abstract
Hydrogen thermoacoustics is a relatively unexplored but promising topic for development of new cryocoolers and hydrogen liquefaction. This paper describes a new research cryostat designed to investigate hydrogen as a working fluid in thermoacoustic systems. The cryostat is a modular, turbo-molecular pump driven, vacuum chamber with a 4.2 K pulse-tube cryocooler capable of 45 W of cooling at 50 K. Using this cryostat, a feasibility study of direct thermoacoustic cooling with ortho-parahydrogen conversion is initiated. An acoustic resonator system is designed to have the fundamental acoustic mode excited via imposed temperature gradient in a porous stack between the ambient environment and cold bar connected to the cryocooler. The generated acoustic waves transfer heat inside another porous stack to produce a refrigeration effect at cryogenic temperatures. In addition, the regenerator solid matrix will be catalyzed for ortho-parahydrogen conversion to demonstrate a novel combination of cooling and conversion of cryogenic hydrogen in a single device. Design, construction, and performance of the cryostat and modelling results for one thermoacoustic system are reported.
Commissioning of the hydrogen cryostat of the cryogenic moderator system of the European Spallation Source (ESS) for test purposes at the ZEA-1
Authors: Rosenthal E , Bessler Y , Hannot M , Natour Prof G 
Published: July 2024

Abstract
A helium-cooled hydrogen cryostat for the European Spallation Source (ESS) was developed, built and tested at the ZEA-1 of the Forschungszentrum Jülich. In order to be able to carry out the final factory acceptance test (FAT), a nitrogen mixing system was developed with which the cryostat could be cooled down and operated in a controlled manner. During the test phase, the cryostat was operated exclusively with nitrogen instead of helium and hydrogen. Nevertheless, all functions of the cryostat system could be checked and key figures could be determined.
Spallation Neutron Source reliability improvement projects for the Cryogenic Moderator System
Authors: DeGraff B , Armstrong R , Denison J , Howell M , Pinion L , Stewart S 
Published: July 2024

Abstract
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) operates the Cryogenic Moderator System (CMS) which provides supercritical hydrogen cooling at 20K to three neutron moderators. A helium refrigerator provides 8 kW of cooling capacity to three parallel hydrogen circuits. Several projects have been completed to improve the operational reliability of the CMS. The status of helium compressor oil removal system, helium oil processor, helium purity monitoring, hydrogen circulator bearing investigation and operational procedure improvement will be presented. Future plans for sustained reliable operation at design capacity will also be presented.
Design, development and commissioning of the control system for the cryogenic distribution system at ESS
Authors: Asensi E , Arnold P , Van Velze P , Magnusson E , Nilsson P , Zhang J , Domagala D , Binczyk W , Gaj W , Maciocha W 
Published: July 2024

Abstract
The cryogenic distribution system (CDS) at the European Spallation Source (ESS) connects the refrigeration plant with the linear accelerator, consisting in 13 spoke and 30 elliptical cryomodules that are cooled at 2K via multi-transfer lines, individual valveboxes for every cryomodule and an endbox. The designed control system monitors and controls the cooling helium flow through the CDS. The controls architecture for the CDS is based on one Programmable Logic Controller (PLC) per valvebox and another one for the endbox, which are integrated into EPICS through the Controls Network and takes care of the process functions, making it a total of 44 PLCs. This type of integration allows for the remote operation of the CDS from the control room and the necessary interaction of the control system with other related systems and EPICS services like archiving, alarms and save-and-restore. Pre-commissioning activities like loop checks, temperature curve validation, pressure sensor calibration and valve initialization started in summer 2022. Eventually, the system was ready for commissioning and a first cooldown was performed in December 2022. The paper describes the design, development and commissioning of the control system and diverse challenges during the deployment and commissioning activities. Future activities are discussed including the implementation of a sequencer for automatic cooldown and warmup, integration with the cryomodule controls and a master PLC to handle the helium management.
A protocol for accurately calibrating thermocouples at cryogenic temperatures
Authors: Purandare A S , Vanapalli S 
Published: July 2024

Abstract
To study the quenching characteristics of materials in a cryogenic liquid bath transient temperature measurements of high accuracy are necessary. Thermocouple is an ideal tool for this application because of its low self-heat capacity. However, they require calibration before usage that require multiple fixed-point temperatures. The common fixed-point temperatures are the water-ice melting temperature, the dry ice sublimation temperature, and the boiling temperature of liquid nitrogen. It is important to note that there are uncertainties associated with dry ice sublimation and liquid nitrogen boiling temperature inherent to the heat and mass transport phenomenon at their phase-changing interface or inside the bulk medium. The dry ice temperature is influenced by the mass transport phenomenon occurring at the interface between the dry ice and the ambient surrounding it. In a typical lab environment, dry ice temperature is significantly lower than the commonly quoted sublimation temperature of -78.5 °C at 1.013 bar. In the case of liquid nitrogen stored in a cryostat, temperature gradients develop in the liquid bath. This paper describes a protocol for calibrating thermocouples by accurately defining and using fixed-point temperatures of dry ice in a saturated environment and a liquid nitrogen slush.
Development of test rig for optical diagnostics of cryogenic spray
Authors: Patil Bhushan R , Twarog Kyle , Mannaa Ossama , Sung Chih-Jen 
Published: July 2024

Abstract
Spray cooling is the primary method for conducting chilldown and fill of cryogenic propellant tanks. In a typical spray injection process, a liquid sheet/jet that exits the spray nozzle undergoes primary breakup by the development of surface instabilities. Droplets and ligaments generated after the primary breakup undergo secondary breakup to create a dispersion of droplets, which extract heat on impact with the tank walls. In the existing literature, there is limited data on the primary breakup of cryogenic sprays and their detailed visualization. Moreover, an insight into the spray characteristics such as primary breakup length and cone angle is vital to the development of computational models. In this investigation, optical diagnostics of cryogenic spray breakup and measurements of cryogenic spray characteristics have been conducted. Liquid nitrogen is the selected cryogen for the present analysis. To capture the transient nature of spray breakup after the injection, a novel shadowgraph technique is developed to photographically freeze the spray motion. Cryogenic spray characteristics such as cone angle and primary breakup length are obtained from the shadowgraph. In addition, droplet velocity measurement using Particle Image Velocimetry is explored. The comprehensive experimental dataset obtained herein not only provides insights into the mechanism of spray formation for cryogenic fluids but also helps in designing of spray cooling system for tank chilldown.
Capacitance-based measurement of volume fraction, velocity, and mass flow rate of cryogenic nitrogen two-phase flow
Authors: Straiton Benjamin J , Charleston Matthew A , Marashdeh Qussai M 
Published: July 2024

Abstract
Cryogenic fluid flow is a critical measurement parameter but is difficult to properly measure due to the extreme environmental conditions and the frequent presence of multiphase flow during saturated liquid transfers. Multiphase flow proves challenging for most flow measurement methodologies; furthermore, additional measurements of volume fraction, quality, and slip velocity are often required. In-line capacitance-based sensors have the potential to overcome these limitations. In this paper, a capacitance sensor in a multiphase cryogenic flow loop is evaluated for its ability to measure liquid volume fraction, gas phase velocity, and total mass flow rate for two-phase cryogenic nitrogen flow.
LCLS-II Helium Refrigeration System Automation
Authors: Shrishrimal S , Norton R , Keenan M , Robinson D , Fauve E , Ravindranath V , Apte A , Pflueckhahn D , Vyawahare S , Rama B , Pucci J , Creel J 
Published: July 2024

Abstract
SLAC National Accelerator Laboratory has upgraded to LCLS-II, featuring a 4 GeV superconducting linear accelerator composed of 37 cryomodules and two large helium refrigeration systems with a cooling capacity of 4 kW at 2.0 K. This paper focuses on the Helium Refrigeration System (HRS) controls and automation. It presents the various automated functions, sequences, control logics and machine protections embedded in the system. It highlights the design choices selected and experiences in integrating and commissioning of LCLS-II Cryogenic control system.
LCLS-II Cryogenic System Instrumentation
Authors: Robinson D. , Shrishrimal S. , Keenan M. , Fauve E. , Pflueckhahn D. , Ravindranath V. , Apte A. , Vyawahare S. , Pucci J. , Wilson A. , Creel J. , Norton R. 
Published: July 2024

Abstract
SLAC National Accelerator Laboratory has upgraded to LCLS-II, featuring a 4 GeV superconducting linear accelerator composed of 37 cryomodules and two large helium refrigeration systems with a cooling capacity of 4 kW at 2.0 K. In this paper, we provide an overview of the instrumentation and controls for the Cryoplant, Cryodistribution, and Cryomodules, spanning from the instruments themselves, to the PLC I/O cards, and finally to the Human-Machine Interface (HMI). We also discuss the best practices and lessons learned during the commissioning process, which contributed to the successful implementation of the instrumentation and controls.
Commissioning of the cryogenic distribution system of the ESS superconducting linac
Authors: Arnold P , Asensi E , Elias N , Fydrych J , Nilsson P , Zhang J , Polinski J , Duthil P , Petersson A 
Published: July 2024

Abstract
The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. An essential part of the project is the linear 2.0 GeV proton accelerator. Its superconducting part is designed to comprise 13 spoke and 30 elliptical cryomodules that are cooled at 2K. The cryogenic distribution system (CDS) connects the refrigeration plant with the cryomodules via multi-transfer lines, individual valveboxes for every cryomodule and an endbox. It is designed, manufactured and installed under the responsibility of two ESS in-kind partners. The CDS for the spoke cryomodules (CDS-SL) is supplied by IJCLab, France, the CDS for the elliptical cryomodules (CDS-EL) is supplied by WUST, Poland. Pre-commissioning, commissioning and operation is done by ESS whereby IFJ PAN contributed with valuable advice. Pre-commissioning activities like loop checks, temperature curve validation, pressure sensor calibration or valve initialization and leak tightness tests followed after mechanical or electrical completion of the respective CDS parts and started in summer 2022. Eventually, the system was ready for commissioning and a first cooldown was performed in December 2022. Goal of this commissioning was to acceptance test and check off the system before pilot cryomodule installation in the tunnel started in March 2023. The paper describes diverse challenges regarding TAO and cryo operation. Test results, lessons learnt, and required modifications are discussed as well as preliminary results of retesting and an outlook.
Integration of a new Cryogenic Liquefier into the IB-1 Cryogenic Test Facility
Authors: Barba Maria , Hansen Benjamin , White Michael , Johnson Gregory , Atassi Omar Al , Dong Jun , Ranpariya Shreya , Soyars William , Faraj Ahmed , Patel Pratik , Besse Noelle , Machefel Annelise , Perrot Lois 
Published: July 2024

Abstract
The increase over the last years of the testing activities related to quantum systems, SRF cavities for the PIP-II and the LCLS-II projects, as well as superconducting magnets for the HL-LHC project and Fusion research activities, has required the addition of a new Helium cryogenic plant into the existing IB-1 Industrial Cryogenic Test Facility. The new cryogenic plant is composed of a cryogenic liquefier (Cold Box) able to provide up to 340 L/h, a 4 kL Dewar and two Mycom® compressors providing up to 120 g/s. AL-AT (Air Liquide Advanced Technologies) has taken part of this project by designing and manufacturing the cryogenic liquefier. This new cryogenic plant is connected through a cryogenic distribution system to a 10 kL Dewar, which is part of the existing cryogenic test facility, itself composed of another Cold Box and a Sullair® compressor. The new cryogenic plant has two main operating modes: one allows to transfer liquid helium at 1.7 bar between the two Dewars, the other allows to transfer supercritical Helium at 2 bar or more between the new Cold Box and the 10 kL Dewar. The entire industrial cryogenic facility is handled by a common Inventory Control System, composed of three control valves, and 9 tanks giving a total buffer volume of more than 1000 m3. This paper presents the technical features of the new Helium cryogenic plant, as well as the main results of the liquefier commissioning phase and details of the helium transfer between the two Dewars, making the connection between the cryogenic plants at the IB-1 Industrial Cryogenic Test Facility.
Simulation of the cool-down process for the ESS cryogenic moderator system
Authors: Tatsumoto H , Horvath A , Arnold P , Boros M 
Published: July 2024

Abstract
The ESS cryogenic Moderator System (CMS) has been designed to supply a subcooled liquid hydrogen (17.5 K and 1.0 MPa) to two hydrogen moderators where the nuclear heating is estimated to be 6.7 kW (to be increased to four in the future). The CMS is cooled by a helium refrigerator system with a cooling power of 30.3 kW at 15 K. In this study, a one-dimensional simulation code has been developed to understand temperature behaviors during the cool-down process. The operational methods and parameters have been optimized. The CMS cool-down process is divided into three phases (I: gaseous hydrogen above 36 K, II: condensation from 36 to 31 K, and III: liquid hydrogen below 31 K). It turns out from the simulation result that the CMS would be able to be cooled down to the nominal condition of 17 K within 27 hours.