bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of 10 L/s liquid hydrogen pump with integrated inducer and centrifugal impeller
Authors: Li Ziwei , Lv Cui , Wang Jinzhen , He Ming , Wu Jihao , Gong Linghui 
Published: July 2024

Abstract
With the global focus on energy and environmental issues, hydrogen energy development has become more and more important. The liquid hydrogen centrifugal pump is an important equipment for hydrogen transportation. In this paper, we designed an integrated impeller and the space guide vane used in 10L/s hydrogen pump. The integrated impeller which is closed structure combined of an inducer and an centrifugal impeller shows better performance than traditional Semi-open impeller. We optimized the structure of the pump and finally obtained the performance curves. This results provide a guidance for the manufacture of the liquid hydrogen pump, and also provide a reference for the design and manufacture of other liquid hydrogen pumps.
Study of backflow volume due to check valve’s lag motion in liquid hydrogen piston pump
Authors: Wu W , Yang S Q , Xie X J , He M , Gong L H 
Published: July 2024

Abstract
The liquid hydrogen piston pump is the key equipment in the process of storage, transportation, and refueling of liquid hydrogen. The timely motions of suction and discharge valves are beneficial to the transport performance and volumetric efficiency of the pump. This study sets up an operation frame of the liquid hydrogen piston pump in which reciprocating pistons and check valves with a conical spool interact. Backflow occurs when there is a delay in the spool’s motion, which is more common in suction valves than in discharge valves. The influence of spring stiffness and spool-head angle of the valve cone on the suction valve’s backflow volume is analyzed and further optimized. The results indicate that there exists an optimal spool-head angle and spring stiffness for minimizing backflow volume during the closing phase of the suction valve. This research contributes to enhancing the volumetric efficiency of the liquid hydrogen piston pump.
Optimization investigation for heat transfer enhancement of fins for plate-fin heat exchangers in cryogenic helium systems
Authors: Zou Zhongyu , Zhu Zhigang , Zhang Qiyong , Yang Pengcheng 
Published: July 2024

Abstract
In order to further improve heat transfer performance and high compactness of plate-fin heat exchangers (PFHEs) in cryogenic helium systems, a new type of perforated-serrated fins is proposed by combining traditional serrated and perforated fins. In this paper, the flow and heat transfer characteristics of helium in perforated-serrated fins and serrated fins channels at low-temperature are investigated using numerical simulations. The numerical model invokes the properties of low-temperature helium by NIST-Real-Gas-Model. Meanwhile, Colburn factor j, friction factor f and JF factor are qualitatively evaluated for pressure drop, heat transfer performance and thermo-hydraulic performance, respectively. The results show that new perforated-serrated fins have better heat transfer performance. The j factor of the new fins increases by 32.58% to 15.63% compared with serrated fins. The flow performance of perforated-serrated fins is slightly worse than that of serrated fins, but the overall thermo-hydraulic performance is better, especially at low Reynolds number. Compared with serrated fins, the JF factor of perforated-serrated fins is significantly higher and increase by 25.95% to 10.86%. The optimizing method of fins structure can be used in the actual design of PFHEs in cryogenic helium systems.
Numerical study of heat transfer characteristics of intermittent flow cold storage surface heat exchanger
Authors: Cui W H , Gong L H , Jia Q M , Li Z Y , He M , Zhu W P , Zhang M M 
Published: July 2024

Abstract
The intermittent flow cold storage surface heat exchanger is a key component of the new pulse tube expansion cryogenic refrigerator, which is responsible for the periodic heat transfer of cold and hot helium, and its heat exchange efficiency directly affects the thermodynamic efficiency of the whole machine. In this study, a three-dimensional model of the heat exchanger unit is established, and numerical simulation is employed to investigate its heat exchange characteristics. The analysis focuses on understanding the internal temperature distribution patterns within the heat exchanger and explores the influence of wall materials on its heat transfer characteristics. Results show that the existence of the temperature lag loop minimizes the effective heat transfer temperature difference, consequently decreasing the heat exchanger’s efficiency. Moreover, the choice of wall material significantly affects the performance of the heat exchanger, with optimal thermal conductivity and volumetric specific heat enhancing its efficiency. This research provides valuable insights for future design and improvement of similar heat exchangers.
Design, configuration, and thermal optimization of advanced cryostats
Authors: Shu Quan-Sheng , Demko Jonathan , Fesmire James , Duckworth Robert 
Published: July 2024

Abstract
To address new challenges in the design of current and future advanced cryostats, guidelines can be developed by leveraging successful technical experience with existing cryostat assemblies. A brief review of eleven representative advanced cryostat designs is presented, based on six typical cooling methods, including cryogen baths, dry cryostats, mixed-cooling method, continuous cryogen flow, dilution refrigeration, and demagnetization. Also provided are engineering figures, tables-plots, and equations that can be used to design, configure, and optimize the thermal performance of cryostats. The following technical data are introduced: optimal Carnot power versus temperature for various two heat intercept stations in cryostat support, ten representative performances of different MLI blankets at various (Th-Tc), and a graphical summary of the ‘MLI patch-cover-crack’ experiments, among others. The cold mass thermally isolated in cryostats could be a quantum apparatus, test specimen, instruments in-space, or superconducting (SC) devices. The cryostat must provide all functional interfaces for obtaining the required data. The design methodologies for crucial components of a cryostat are discussed in-depth, including: 1) creating a lightweight support structure and placing thermal anchors in optimal locations, 2) designing MLI systems with cost-effective thermal shields, and 3) constructing sophisticated structures to accommodate heavy RF couplers or current leads.
Research on matching supply of power and cold energy of liquid hydrogen cold chain logistics vehicles
Authors: Wang J Z , Chao B H , Lv C , Gong L H , He M , Zhang M M , Wu J H 
Published: July 2024

Abstract
Liquid hydrogen cold-chain logistics vehicle (LHCCLV) is a special vehicle using liquid hydrogen (LH2) as the source of both power and cold energy. A significant weakness of LH2 is its high energy consumption during the hydrogen liquefaction process, thus the utilization of cold energy in LHCCLV can improve the economic performance and competitiveness of LH2. Because of the high energy storage density of LH2 and the relatively high efficiency of fuel cells, we find that cold energy can not meet the demand of LHCCLV. Therefore, we consider enlarging the cold energy by efforts including the para-ortho hydrogen conversion (POC), whose reverse reaction consumes an energy level exceeding 20% during the hydrogen liquefaction process. In this paper, numerical models of discharging hydrogen from the LH2 and subcooling hydrogen tank are established, and the influence of POC and other efforts on the supply of cold energy is analyzed. The changes in instantaneous and total cold energy supply under different working conditions are analyzed, and the important influence of POC and other efforts is confirmed. The beneficial effect of POC is quantified in the paper, especially for the cold energy supply. This paper provides an essential reference for the research and development of LHCCLV. Also, it guides the comprehensive utilization of cold energy in other situations to promote the improvement of the economy of hydrogen energy utilization routes in the form of LH2.
Simulation test platform for the controlled storage and transfer of liquid hydrogen
Authors: Fesmire J , Guerrero M , Williams M , Glenn M , Coleman B 
Published: July 2024

Abstract
Clean-energy propulsion machines, including trucks, tractors, ships, and aircraft, for heavy-duty and long-range mobility have moved, by necessity, to onboard liquid hydrogen (LH2). However, the established method of storage and transfer is problematic due to losses and for any duty-cycle of a sporadic or on/off nature. Integral servicing system methodology is needed for both safety and cost effectiveness in the key drivers of time savings, product savings, and venting exposures. Modern controlled storage technology enables quick and effective vehicle servicing at the point of use. Simulations of controlled storage/transfer (CS/T) methodologies are performed using a multi-purpose LH2 simulation test platform comprised of two primary systems: Cryostat CS900 tank and transfer system and the LS20 liquefaction/refrigeration and storage system. Testing includes both steady-state and transient modes of operation to demonstrate both zero boiloff (ZBO) and zero-loss transfer (ZLT) modes. Technical areas of use include product development for tanks, refrigeration, transfer systems (lines, dispensers, pumps, valves); experimental validation of analytical models and thermofluidic properties; thermal insulation performance test data under relevant conditions; thermophysical characterization of materials and structures; instrumentation and sensors development; tank boiloff and heat flux engineering design data. Descriptions and preliminary test results are given along with thermal performance analyses from real-world testing and experimentation.
Assessment of insulation systems for aircraft liquid hydrogen tanks
Authors: Johnson W L , Baltman E , Koci F D 
Published: July 2024

Abstract
Liquid hydrogen (LH2) has ~2.8 times more energy per pound of fuel than Jet-A, however, it requires ~4 times the volume for the same energy. As a result, LH2 aircraft developments are highly dependent on the hydrogen tankage as well as the insulation system requirements. To better understand the sensitivities that hydrogen puts onto the aircraft as a system, Georgia Tech investigators, as part of a NASA preliminary evaluation activity, have developed a single-aisle LH2 passenger jet. As a part of the activity, NASA and Georgia Tech developed the ability to integrate a tank set into the aircraft including insulation systems. Assessments are made on several insulation system options to assess the amount of venting as well as the impacts to aircraft fuel consumption. Based on the results, it is observed that even though polyurethane foam is lightweight, the associated boil-off losses drove the system level mass higher than vacuum jacketed insulations. Composite tanks are observed to decrease fuel system dry mass by several hundred kg over AL5083 tanks.
Liquid hydrogen tank chill and no-vent fill prediction using computational fluid dynamics
Authors: Pesich J M , Hauser D M , Yamashita K G , Baker M C , Sakowski B A 
Published: July 2024

Abstract
Cryogenic tank chill and fill is an important cryogenic fluid management technology that supports and enables many of NASA’s long-duration space missions. For no-vent fill, the receiver tank pressure remains below the supply tank pressure during the entire duration of the fill so that the tank does not require venting. This is especially advantageous for tank fill operations in low gravity where the position of the liquid is not always known and venting the tank may cause loss of propellant by venting liquid. In lieu of expensive tests conducted on-orbit, accurate computational models capable of predicting receiver tank pressure during cryogenic propellant tank fill may be used to reduce system and propellant mass as well as mission risk. However, these numerical models must be validated or anchored to test data. This study presents computational fluid dynamics (CFD) models with conjugate heat transfer that are used to predict a liquid hydrogen tank chill and no-vent fill ground test conducted at Lewis Research Center (now Glenn Research Center) in 1991. The specific test case chosen for model validation implemented an upward-facing jet near the bottom of a cylindrical 34 liter tank. CFD predictions are compared to experimental measurements of tank pressure, fill level, and wall temperature. The CFD results show reasonable agreement to the test data but overpredict the pressure collapse near the end of the fill despite the liquid jet penetrating the liquid-vapor interface.
Development of a measurement system to measure in-situ the ortho/para concentration of liquid hydrogen
Authors: Hannot M. , Beßler Y. , Rosenthal E. , Natour G. 
Published: July 2024

Abstract
Molecular hydrogen occurs in two forms, the so-called ortho-hydrogen and para-hydrogen. At a temperature of 293 K and above, hydrogen has 75% of ortho- and 25% para-content. The content of para-hydrogen increases with falling temperature. At a temperature of 20 K almost 100% para-hydrogen is present. While hydrogen is cooled down and liquefied the exothermic natural conversion starts, but much slower than the liquefaction itself. However, the conversion can be accelerated by using a catalyst. To avoid an unintentionally evaporation due to the exothermic ortho to para conversion it is important to verify that the conversion is completed before the liquid hydrogen is stored, transported or used. To accelerate and to ensure a complete conversion an oversized ortho/para-catalyst is normally used. However, the activity of the catalyst decreases over time. Therefore, a continuous in-situ measurement of the ortho/para-ratio can contribute to effective use of the catalyst and can help to reduce hydrogen losses due to unintentional evaporation. A measurement system based on Raman-spectroscopy is currently being developed at the ZEA-1. First tests with the measuring system show promising results on a laboratory scale. The aim of these investigations is to develop a compact measuring system that measures the ortho/para concentration of liquid hydrogen in-situ.
Multi-scale systematization of damage and failure modes of composite cryogenic hydrogen vessels according to the Fault Tree method
Authors: Schlegel David , Hurtado Antonio , Gude Maik 
Published: July 2024

Abstract
Achieving a safe and lightweight design of composite liquid hydrogen (LH2) vessels without much empirical data requires advanced reliability assessment. An approach based on the Fault Tree method is proposed, to allow the systematization and modelling of functional and structural failure modes and their interactions. A hierarchical system model spanning across the length scales of the LH2 vessel down to the composite material is established. Subsequently, the failure probability of the composite material is estimated in dependence on temperature and load case using Weibull analysis. Using the accident data of US Air Carriers operating under 14 CFR 121 between 2012 and 2019, the probabilities of the load cases are derived, allowing a quantitative reliability analysis of the selected failure modes. Requirements for material and system design are derived in dependence of the maximum allowable failure probability.
Liquid deuterium cold source concept for the NIST neutron source
Authors: Jurns J , Cook J C , Celikten O , Arnold P 
Published: July 2024

Abstract
The National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) houses an aging reactor that serves more than 40 % of all cold neutron research needs in the U.S. First critical in 1967, the National Bureau of Standards Reactor (NBSR) is now more than 50 years old. NCNR engineers have initiated a design effort for a replacement reactor, namely the NIST Neutron Source or NNS. The NNS is conceived as a 20-MWth light-water cooled and moderated, and heavy-water reflected compact core design. The NNS will include two liquid deuterium cold sources to moderate neutrons to effective temperatures well below that of thermal neutrons. These cold neutron sources will require new cryogenic infrastructure to operate. This report describes a preliminary proposed design concept for the NNS cold sources and associated ancillary infrastructure.
Dynamic simulation of DALS test facility cryoplant
Authors: Sun Z , Wang X L , Hu L B , Xu L , Shi X 
Published: July 2024

Abstract
Dalian Advanced Light Source (DALS) test facility program requires a 370 W cryoplant to meet the cooling requirements of four testbenches. The utilization of dynamic simulation holds significant potential for diverse applications such as process design, control logic optimization, and virtual commissioning. These applications are helpful in facilitating the subsequent stages of commissioning and operation. This paper describes the establishment of a model for the DALS test facility cryoplant based on the Ecosimpro software. The model includes the main components of the cryoplant, incorporating most control loops and sequential control strategies. The simulation encompasses three operation modes, namely liquefaction mode, refrigeration mode and fast cooldown mode. The simulation results match the Temperature-Entropy (T-S) diagram from the manufacturer well. This model will be used in the upcoming commissioning of the cryoplant for resolving challenges that may arise in future operation.
Installation, commissioning, and testing of the HB650 CM at PIP2IT
Authors: White M , Makara J , Ranpariya S , Pei L , Barba M , Subedi J , Dong J , Hansen B , Akintola A E T , Holzbauer J , Ozelis J , Chandrasekaran S , Roger V 
Published: July 2024

Abstract
The Proton Improvement Plan-II (PIP-II) is a major upgrade to the Fermilab accelerator complex, featuring a new 800-MeV Superconducting Radio-Frequency (SRF) linear accelerator (LINAC) powering the accelerator complex to provide the world’s most intense high-energy neutrino beam. This paper describes the conversion of the PIP-II Injector Test Facility (PIP2IT) cryogenic system into a test stand for PIP-II High-Beta 650 MHz (HB650) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). A description of the associated mechanical, electrical, and controls modifications necessary for testing HB650 cryomodules are provided. The cooldown and warmup requirements, procedures and associated controls logic is described.
The first cooldown of SCL3 cryogenic system
Authors: Yoon S. , Ki T. , Yoo J. , Lee M. , Meyer T. A. , Bodin E. J. A. , Daoudi K. 
Published: July 2024

Abstract
RAON, Rare isotope Accelerator complex for ON-line experiments, is the first superconducting linear accelerators in S. Korea. It will have three linear accelerators (Linac), SCL1, SCL2, and SCL3. Now, construction of the SCL3, the third superconducting Linac was finished in the middle of 2022 and the commissioning of its cryogenic system was done July, 2022. The first cooldown of the Linac with the cryogenic system was started from September, 2022 and their temperature was reached at 2.05 K in January, 2023. The first cooldown was successfully completed and the static and dynamic heat loads of the Linac were measured. This paper shows the results of the first cooldown and the heat load tests.
Effect of a thermal fluctuation caused by a proton beam injection on the ESS large-scale 20 K helium refrigeration system
Authors: Tatsumoto H , Arnold P , Boros M , Horvath A 
Published: July 2024

Abstract
In the European Spallation Source (ESS), a large-scale 20 K helium refrigeration system with a cooling capacity of 30.2 kW at 15 K, which is called Target Moderator CryoPlant (TMCP), has a function to cool the cryogenic moderator system (CMS) that provides subcooled liquid hydrogen with a temperature of 17.5 K to two hydrogen moderators (to be increased to four in the future) and remove nuclear heating generated of 6.7 kW and 17.2 kW for two and four moderators at the proton beam power of 5 MW. The commissioning has been completed by December 2022. We studied the stability of the TMCP operation when the heat load of 5.92 kW and 17.5 kW was rapidly applied and how to mitigate the propagation of the temperature fluctuation in order not to affect the CMS supply temperature.
Cryogenic Testing of Molecular Sieve Materials for use in Hydrogen Liquefaction
Authors: Richardson I. , Saelid G. , Shokrian M. 
Published: July 2024

Abstract
As hydrogen continues to gain momentum as a clean fuel and energy carrier in industrial sectors, hydrogen liquefaction has emerged as an essential part of the supply chain to reduce transportation and storage costs. Hydrogen is typically produced from either electrolysis, steam-methane-reforming, or as a biproduct from chemical processing, which leads to a broad range of potential impurities in the hydrogen feed gas. Molecular sieve materials have traditionally been used to remove impurities in the hydrogen feed to prevent impurities from freezing out during liquefaction, creating blockages which disrupt operations. This work presents a new experimental system that has been developed to study cryogenic purification materials over a broad range of cryogenic temperatures and impurity levels. Results of common molecular sieve materials are presented.
2 K J-T cooler for quantum detection: emphasis on the Stirling-type pulse tube pre-cooler
Authors: Latella T , Prouvé T , Duval J M 
Published: July 2024

Abstract
Quantum detection of single photon achieves its highest sensitivity for temperature below 2 K. The cooling requirements for such application are very low, a few milliwatts for current harness heat intercept and radiation shielding. For that purpose, we are developing a compact cryocooler based on a 4He JT cooler. A high frequency pulse tube will provide the pre-cooling of two intermediate stages on the JT. The pulse tube is the key component for miniaturization and energy consumption. With low cooling power goals, a miniaturization work has been done on the pulse tube with the aim of reducing the size and power of compressor units. The pulse tube configuration is using two cold fingers, connected together by a heat intercept providing precooling for the lowest temperature stage. Cooling power at the cold tip as well as intercept heat flow have been measured. Numerical simulations have been conducted in parallel to study the impact of the size of the pulsation tube and of the regenerator on the pulse tube performances. Three cold units pulse tubes have been tested in similar conditions. Net cooling power, power at the intercept and impact of the tube and regenerator size on performances will be discussed.