bluuebunny/crossref_metadata_2025 huggingface dataset:
Research stand for studying the hydraulic drive of adaptive drilling machines
Authors: Lemeshko M A , Kozhemyachenko A B , Khanikadze I T
Published: June 2022

The work relates to mining, in particular to machines used in mining. The article is devoted to the improvement of rotary type drilling machines and methods for investigating the effectiveness of drilling machines. The research complex is described in detail - a stationary stand for the study of rotary drilling, for the study of hydraulic-driven drilling machines. The research complex is made on the basis of a commercially available drilling machine “UBG.00” and allows you to carry out studies of rotary-type drilling machines used in geological exploration, mining, drilling technological wells and experimental drilling machines with adaptation properties. The stand allows, within the limits of regulation, to change drilling modes, to investigate the effect on the process of adaptation of the strength of the drilled rock, blunting of the cutting tool, to investigate power and dynamic characteristics. Adaptation is performed by redistributing the supplied power between the torque and the feed force. The description of the stand design is given, the technical characteristics of a hydraulic-driven drilling machine are given. The limitations adopted during experimental studies, taking into account the characteristics of the hydraulic drive, are formulated. It is shown that in an experimental adaptive drilling machine, the throttle elements of the hydraulic drive have external control and are programmatically controlled to change drilling modes and control methods. External control is performed by a programmable controller and allows drilling in various modes: “free feed”, “forced feed”, “drilling at constant speed”, “adaptive drilling” and others.
Methodological Bases of the Fire Hazard Reduction in Internal and External 0.38 kV Electrical Networks with Unbalancing Power Consumption
Authors: Naumov I V , Podyachikh S V , Yakupova M A , Fedorinova E S
Published: June 2022

The article shows that the operation modes in three-phase four-wire 0.38 kV electrical networks are objectively associated with unbalancing power consumption. As a result, significant additional electrical energy thermal losses occur in the neutral conductor’s internal electrical networks and external electrical networks l elements, which not only increase the electrical energy consumption, but also create conditions for the fire-hazardous occurrence single-phase short circuits. A mathematical model is proposed, an algorithm and a program for calculating the limit zero sequence values flows in external neutral conductors and internal 0.38 kV electrical networks are developed. Numerical calculations are made and tabular these limit values data for different conductors’ sections made of various conductive materials are presented. The unbalancing operation modes calculations in operating external and internal 0.38 kV electrical networks have been made, on the basis of which the proposed methodology has been tested. The technical means use effectiveness for the operating modes balancing in existing electrical networks with unbalance power consumption is proved.
Main directions for the formation and development of the “green” nature management in Tajikistan
Authors: Isaynov R H , Arabov F P , Sodikov K A , Bobohonzoda Kh R , Asomuddin K R , Israilova R A
Published: June 2022

The article summarizes the ways of forming a “green nature management” and its prospective development in the republic. The theoretical aspects of the formation of a green nature management are considered. It is noted that the foundations for the formation of the concept of a green nature management were laid within the framework of the concept of sustainable development back in the late 80s of the last century. According to the definition of scientists, sustainable development includes three dimensions - economic, social and environmental. Only by observing the requirements of sustainability in relation to each of these dimensions can sustainable development as a whole be achieved. Confirmation that the issues of formation and development of the “green nature management” concern, among other things, Tajikistan, is the active sup-port of international cooperation and a constant participant in processes in the field of water problems, ecology and sustainable development at the global, regional and national levels. ... The article notes that in the republic, 98% of electricity production is accounted for by hydropower, which is considered “green” energy and is a valuable contribution of Tajikistan in solving global environmental problems. The article studies the world experience in the development of the “green nature management” and it shows that at present in various countries of the world efforts are being made to develop the “green nature management” and the introduction of its constituent elements, such as: increasing the share of environmentally friendly and renewable energy sources: hydropower, wind, solar, biogas and biofuels. In general, analyzing the ways of formation and development trends of the “green nature management”, the article proposes the main priority sectors of the national economy, in which in the future it will be possible to attract investment both from internal sources (from the budget of the republic) and foreign investments (foreign investments): energy, industrial production, transport, tourism, agriculture and urban economy.
Formation of a network of Khabarovsk City protected areas
Authors: Debelaya I D , Yu Morozova G
Published: June 2022

The process of forming a protected areas network is being held in Russian cities that are focused on sustainable development as well as abroad. The retrospective analysis of various levels of the protected areas network formation took place in Khabarovsk – large city in the Russian Far East. The first protected areas were organized in the Khabarovsk City in 1995. The next stage of rapid expansion and growth of the total area and the range of categories of protected areas began in 2014 and is currently ongoing process. The network of the protected lands of Khabarovsk includes 29 areas (585.45 ha): 5 areas (212.43 ha) of regional significance and 24 areas (373.02 ha) of local significance. The predominance of protected sites of local importance and variety of categories (natural monuments, natural park, park areas, nurseries, small public gardens and natural recreational complexes) is the main feature of the formation of the city’s protected areas network. The insignificant share of the protected areas in the total area of the land territory of the city (2.57 %) indicates the necessity for the areas expansion and landscape diversity. The variety of plants is noted in park areas, natural monuments and natural recreational complexes. The results may apply in: environmental planning of urban territory.
Project of basin nature management of the Vorskla river within the boundaries of Prokhorovsky district
Authors: Melentyev A A
Published: June 2022

Belgorod Oblast, which occupies 0.2% of the country’s territory, is among the leading subjects of the Russian Federation in terms of agricultural production. At present, about 61% of the oblast’s territory is occupied by arable land, at least half of which, to varying degrees, is eroded. High agricultural load combined with accelerated water erosion of soils has led to a significant deterioration of the resource and environmental condition of agricultural landscapes. Negative changes affected almost all components of agro-ecosystems. First of all, it affected their central component - the soil cover: as a result of long-term exploitation and increasing water erosion, the reserves of humus and mineral nutrients decreased significantly. The region’s river network has also undergone significant changes: over the last century, its length has decreased by 35% from its original state. The above trends in the development of degradation processes determine the need for geoplanning solutions to ensure the soil conservation organization of nature management in the Belgorod region. In the current situation it is necessary to scientifically justified transformation of agricultural landscapes into sustainable agro-ecosystems. In this case, it is necessary to use a comprehensive geo-ecological approach to the organization of the landscape envelope with a rational spatial combination of natural and economic components. This idea is the basis of a new synthetic direction of socio-economic geography - geoplanning. Geo-planning approach will allow to embody geo-ecological aspects of ecosystems functioning through a set of design solutions.
Testing of the new fertilizer “Multibar” for the agronomic properties of tomatoes in Armenia
Authors: Sarikyan K M , Hovhannisyan A A , Tsereteli I S , Grigoryan M G , Hovhannisyan F A
Published: June 2022

The article considers the testing of the fertilizer “Multibar” for biological, agronomic properties and biochemical characteristics of fruits of tomato varieties for fresh consumption - Noy, for canning - Renaissance, cherry type - Rubin in three options - 1. Without treatment (control), 2. Treatment with ammonium nitrate, 3. Processing “Multibar”. The results of the test showed that the use of the new fertilizer “Multibar” provided for an increase in crop efficiency and fruit quality. The new fertilizer “Multibar” can be effectively introduced in the republic and similar regions of the globe.
Results of use of heat flux sensors on liquid hydrogen tanks
Authors: Johnson W L , Balasubramaniam R , Hibbs R
Published: June 2022

Heat flux sensors were used to characterize the performance of insulation on the Structural Heat Intercept, Insulation, and Vibration Evaluation Rig (SHIIVER), a large-scale test article designed to simulate upper stage cryogenic propellant tank thermal performance in simulated space environments. Usually, the insulation heat loads are derived from calculations removing all other heat sources and attributing the residual heat load to the insulation system. Testing for SHIIVER included the tank being just insulated with spray-on-foam insulation as well as covering the domes with multilayer insulation while leaving the barrel section insulated with spray-on-foam. Heat flux sensors were located at multiple locations on both domes as well as on the barrel section of the tank. Results from the SHIIVER testing using the heat flux sensors are compared to other calculated heat inputs for both liquid nitrogen and liquid hydrogen testing as a function of tank fill level. Further investigation into the transient nature of the SHIIVER testing including the heat flux sensors provided insight into heat flow patterns that may not have been otherwise seen using temperature sensors and calculated insulation heat loads. While the demonstrated uncertainties in the absolute values in the heat flux sensors are high, the values and the trends match well with other calculation methods. The results of SHIIVER allow for the use of heat flux sensors for measurements of insulation performance and dynamic system thermal response for future applications.
Vapor cooling of a structural skirt for a large-scale hydrogen tank
Authors: Johnson W L , Balasubramaniam R , Hibbs R
Published: June 2022

The demonstration of vapor cooling on a structural skirt was one of the main objectives of the Structural Heat Intercept, Insulation, and Vibration Evaluation Rig (SHIIVER) testing. SHIIVER consisted of a 4-meter diameter stainless steel tank with an aluminum forward skirt. The forward skirt was cooled by directing effluent vapor from the tank through two flow channels that each went 360 degrees around the interior of the skirt in a helical pattern. Flow rates, temperatures, and pressures in the system were measured allowing for the calculation of heat load removed via cooling stream and heat load reduction into the tank. Testing occurred at fill levels between 25% and 90% full using both liquid hydrogen and liquid nitrogen. Boil-off rate was varied independent of the skirt performance by adding multilayer insulation over the spray-on-foam insulation on the tank domes, while leaving the barrel insulated only with spray-on-foam. The results from the testing, which demonstrate vapor cooling removed heat flow from the tank flange and reduces total propellant heat load by as much as 19%, are analyzed and discussed.
Architectural impacts of in-situ resource utilization production of oxygen for use as propellant in a Mars ascent vehicle
Authors: Krenn A , Trent D , Sanders G , Hoffman S , Chai P , Hinterman E
Published: June 2022

NASA is in the processes of evaluating various architectures that may support human missions to Mars. A multitude of concepts are being traded and associated sensitivities are being analyzed. Among these trades, several options for Mars Ascent Vehicle (MAV) propellant supply are being considered. Due to mass constraints on the Mars descent system and the in-space transportation system, landing a fully fueled MAV, that can launch humans from the surface of Mars, presents significant integrated architecture challenges. Consequently, MAV propellant must either be pre-positioned and transferred across the surface robotically or made on the surface via In-Situ Resource Utilization (ISRU) techniques. In each case, there are implications to the number of architecture elements, total system mass, power requirements, complexity of operations, and required technology developments. An analysis that compares an ISRU point solution to a similar point solution that pre-positions and transfers propellant is detailed.
Development of a surface cryogenic propellant transfer concept for Martian operations
Authors: Congiardo J , Krenn A , Martinez J , Dupuis M , Swanger A
Published: June 2022

NASA is currently evaluating architectures to support human missions to Mars. A multitude of concepts are being traded and associated sensitivities are being analyzed. Mars Ascent Vehicle (MAV) propellant supply is a key consideration. Mass constraints for the Mars descent system and in-space transportation present significant architectural challenges that may preclude landing a fully fueled MAV for crew use. In such a case, to ensure the ability of the crewed mission to meet its objectives, propellant should be supplied to the MAV prior to the arrival of the crewed mission from Earth. A concept to robotically transfer liquid oxygen from a separate storage tanker across the surface to the MAV is proposed. This concept makes use of an unpressurized rover and is optimized to maximize the amount of propellant conveyed per trip.
Three-dimensional fluid-structural interaction and thermal analysis of a large diameter horizontal cryogenic transfer line
Authors: Lohar Kailash , Raj Kunniyoor Keerthi , Ventateshwaran K.S. , Ghosh Parthasarathi
Published: June 2022

This paper focuses on the thermal stress analysis and the thermal bowing phenomenon in a large 12-inch diameter cryogenic transfer line during chill-down with liquid oxygen. To investigate the chill-down characteristics and corresponding thermal stress generation, a threedimensional fluid-structural numerical model has been adopted in this work. The numerical simulation is performed on a 2 m long transfer line having an internal diameter of 30.48 cm (12 inch). Three dimensional modelling has been performed to numerate the channel wall temperature distribution along with the flow, at the top and the bottom portions. Based on the temperature data from CFD calculations, transient structural analysis and deformation of the transfer line are studied using a finite element model. Results show that the bowing in the transfer line occurs when there is a strong circumferential variation in temperature. Furthermore, this study provides a numerical simulation that predicts the chill-down time and the time when a stratified flow occurs in the line. This numerical method has been found to be a useful tool for the evaluation, design, and development of a large diameter cryogenic transfer line for transportation of large quantity of cryogenic fluid.
Development of a 2∼4 K closed-cycle JT cryocooler for space application
Authors: Pan Xiaoshan , Liu Shaoshuai , Wu Yinong , Jiang Zhenhua , Ding Lei
Published: June 2022

Cryogenic system proving cooling capacity at liquid helium temperatures is one of the key technologies for space exploration missions. A closed-cycle Joule-Thomson cryocooler capacity of providing different cooling powers at 2∼4 K is developed in our lab. The cryocooler is precooled by a two-stage thermal coupled pulse-tube cryocooler with active phase shifter and driven by multi-stage valved linear compressors. The lowest temperature about 2.5 K and more than 50 mW at about 4.0 K can be obtained by adapting the suited charging pressures. The two-stage pulse tube cryocooler can provide pre-cooling capacity at 17 K and 76 K, respectively with an input power of about 350 W. A large pressure ratio of about 26 and a mass flow rate of 6.7 mg/s can be provide by the multi-stage valved linear compressors with a charge pressure of 0.6 MPa and a total electrical power of less than 110 W. The cooling-down time for the cryocooler from room temperature to about 4 K is less than 10 hours. The cooling system can provide a required cryogenic environment for future space applications.
An 880 mW@15 K thermal coupled pulse tube cryocooler with active phase shifter
Authors: Yin Wang , Liu Shaoshuai , Wu Yinong , Jiang Zhenhua , Ding Lei , Song Jiantang
Published: June 2022

A two-stage Stirling-type pulse tube cryocooler (SPTC) operating in 15 K is developed in our lab for cooling infrared detectors and precooling helium JT cryocooler. For easy adjustment, the driven compressor of the SPTC is designed as two independent linear compressors. The second stage cold finger uses an active warm displacer (AWD) as phase shifter to maximize the cooling performance. The variation of pre-cooling temperature and swept volume of the AWD will influence the cooling capacity of the SPTC. The cooling performance are experimentally tested and analyzed. With the pre-cooling temperature of 80 K, the second stage cold finger can obtain 470 mW at cooling temperature of 15 K with a total electric input power of 363 W. It can also obtain 880 mW at cooling temperature of 15 K with full input power of 527 W. A no-load temperature of 9.9 K can be obtained with an electric power of 180 W and 170 W for first and second stage. The experimental results also show that there exists an optimal pre-cooling temperature and swept volume of the AWD to achieve the maximum cooling capacity for 20 K applications.
Parasitic heat load in a miniature pulse tube cooler
Authors: Dherbecourt D , Duval J M , Garcia M , Lopes D , Guichard D , Branco M B C , Prouvé T
Published: June 2022

The parasitic heat load represents the heat flow disturbing the cold end of cryocoolers due to conduction, convection and radiation. On-board space missions, cryocoolers such as pulse tubes are typically employed in a cold redundancy scheme. Therefore, the heat flow through a pulse tube cooler in OFF state directly affects the cold performance of the operating cooler, bringing in heat and limiting the total available cooling power at the cold tip. The reference pulse tube is a miniature pulse tube cooler, developed for 2 W cooling at 80 K with a low input power. This study aims first to measure the parasitic heat load through three methods, which results are compared and confronted with numerical evaluation based on well-known correlations. Then a novel way in design is proposed, integrating an element of lower conduction replacing a part of the regenerator in order to reduce the heat load. The impact of this modification on the performance is measured and compared with its influence on the heat load.
Numerical analysis and experimental research of a 2W/35 K Stirling-type pulse tube cryocooler
Authors: Gao Z Z , Yang B , Chen L B , Wang J J
Published: June 2022

Cooling to the temperature of liquid nitrogen to liquid hydrogen is a necessary working prerequisite for some infrared detectors. The development of compact and efficient miniature cryocoolers is of great significance for the space application of the detectors. The pulse tube cryocooler driven by a dual-opposed linear compressor is prospective in space applications due to the advantages of no low-temperature moving parts, compact structure, and high reliability. In this paper, a 2W/35K Stirling-type pulse tube cryocooler with a single-stage structure has been designed and tested. The influences of structural parameters of the phase shifters such as inertance tube, as well as the operating parameters such as operating frequency and charging pressure, on the cooling performance were investigated through numerical calculations and experiments.
A thermal-coupled/gas-coupled hybrid high-frequency pulse tube cryocooler attaining the liquid-helium temperature
Authors: Yang Biao , Gao Zhaozhao , Xi Xiaotong , Chen Liubiao , Wang Junjie
Published: June 2022

High-frequency pulse tube cryocooler (HPTC) has become an attractive method for space cooling in the liquid-helium temperature range, due to its advantages of potential high efficiency, no moving parts at the cold end, small size, and light weight. However, key problems such as large regenerator losses and insufficient phase-shifting ability challenge it to obtain the liquid-helium temperature. A thermal-coupled/gas-coupled hybrid refrigeration process of HPTC has been designed to obtain the liquid-helium temperature. One HPTC working in the liquid-nitrogen temperature range is used as a pre-cooling stage, and another two-stage gas-coupled structure is employed to obtain liquid-helium temperature. The simulation results show that the lowest no-load temperature is 3.6 K and a cooling power of 84 mW can be provided at 6 K with a total input PV power of 128 W and 10.9 W/77 K pre-cooling power when Helium-4 is chosen as the working gas. An experimental prototype was designed, built, and tested. The simulation and experiment results will be introduced in detail in this paper.
Analysis of radiation energy between light source, optical window and cryogenic sample
Authors: Wu S S , Wang J , Zhang H C , Shen F Z , Huang C J , Li L F , Zhou Y
Published: June 2022

The cryogenic mechanical properties of materials are particularly important in cryogenic engineering fields. The digital image correlation technique is a method to measure strain and displacement with high precision without contact. The optical window is necessary for DIC technology to obtain the cryogenic mechanical properties of materials. However, the thermal radiation energy between the light source, the glass and the sample greatly affects the limit temperature of the cryogenic mechanical measurement. In this paper, the spectral radiation properties of the glass and sample surfaces for the wavelength of 0.38-25 μm were measured. The thermal radiation energy between the power density emitted by the light source, the radiation energy emitted by the glass surface and the radiation energy emitted by the sample were analyzed. Finally, the effects of illumination distances on the radiation energy density and the sample temperature were studied. The results indicate that the power density emitted by the light source accounts for the main part of the radiant energy density received by the sample, and the radiant energy on the glass and the sample surface are negligible. Moreover, increasing the illumination distance is effective to reduce the radiation energy and temperature rise of the sample.
Analysis of pump tube and orifice for a 4He sub-Kelvin sorption cooler
Authors: Lei Y L , Zhao Y N , Quan J , Hong G T
Published: June 2022

The sub-Kelvin sorption cooler (SKSC) has become one of the most significant refrigerators in the space sub-Kelvin temperature range due to its high reliability, long life, no interference, and portability. The refrigeration temperature of SKSC is determined by the saturated vapor pressure above the liquid working medium in the evaporator, which is not only related to the adsorption capacity of the adsorption compressor but may also be restricted by the flow resistance of the pump tube and the orifice (for 4He SKSC). In addition, the pump tube and the orifice will also affect the heat leakage of superfluid 4He and the heat insulation between the adsorption compressor and the evaporator. Therefore, when designing a 4He SKSC, the pump tube and the orifice are critical. In this paper, the above issues are comprehensively considered, and the allowable size range of the pump tube and the orifice under a given design condition is discussed.
Visualization study of a cryostat with a large diameter flow channel for flowing high-pressure cryogenic fluid
Authors: Xie S Y , Zhang Z Z , Xu D , Lyu B K , Li L F
Published: June 2022

For abundant cryogenic experiments, systems, and so on, visualization is necessary to observe the cryogenic fluid. Therefore, the visualization methods of cryogenic fluid have been widely studied, such as shadowgraph technique, schlieren technique, and laser holographic interferometry technique. A cryostat for visualization study must have optical windows to meet the requirement of various image acquisition equipment. Due to the difference of shrinkage between transparent glass and device materials at low temperatures, especially at large diameter flow channels, it is difficult to meet the requirement of visualization. This paper studies a kind of cryogenic visualization device with an inner diameter of 200 mm, which can meet the visualization requirements of cryogenic fluid with the maximum working pressure at 0.7 MPa and the lowest temperature at 77 K. Liquid nitrogen was used to test the visualization of the device at low temperatures. The device was also subjected to vibration conditions to test the ability of the device to withstand harsh environments. The results show that the device has good sealing performance and can meet the visualization requirements well.
An innovative approach for the design of cryogenic electrical and process control systems at CERN: the cryogenic Continuous Integration project
Authors: Barbe T , Pezzetti M , Martin S , Tovar-Gonzalez A , Fluder C , Wolak T
Published: June 2022

Designing, building, commissioning, operating and maintaining multiple complex cryogenics process control systems involves many challenges. For several years, CERN has developed various solutions to help with the whole lifecycle of a cryogenic process control system. This has allowed the production of quality and highly reliable cryogenic control and electrical systems. This paper will present the use of these innovative and automated tools and their evolution; focusing in the first part on continuous integration practices applied to the production of Programmable Logic Controller (PLC) software. The second part will develop the practical applications for software upgrades implemented for the cryogenics processes of non-LHC detectors and test facilities at CERN. Finally, a detailed description of the approach to a standardized generation of electrical drawing for cryogenic systems will be presented along with concrete solutions already successfully implemented in operation.
In-flow measurement of the composition of a binary gas mixture
Authors: Tolboom A.H. , Vermeer C.H. , Holland H.J. , ter Brake H.J.M.
Published: June 2022

The performance of many cryocoolers that utilize the Joule-Thomson effect can be improved by using a gas-mixture as the working fluid. This paper presents a measurement setup to characterize a sorption compressor operating with a binary mixture. The composition of the binary mixture delivered by the sorption compressor is determined in-flow by correlating the outputs of a Coriolis flow meter and a thermal mass-flow meter. Based on this method, the composition of a binary mixture was measured continuously with an error of ±0.02. Multiple sorption cycles with three different mixtures of ethane and nitrogen using the same compressor were measured, allowing for the observation of the dynamic desorption behavior of a mixture.
Design of cryogenic test platform for the seal structure in superfluid helium temperature
Authors: Li Z , Zhou Z , Zhang Q , Wang G , Huang J
Published: June 2022

A cryogenic test platform was conceived and designed with a variable temperature from 1.8K to 300K to accomplish the research of cryogenic seal performance, and the main research object of this platform is to test the seal capacity of the flange structure in superfluid helium condition. This platform mainly includes a cryostat, a set of vacuum pumps, a sealed test chamber, a cryogenic physical property test chamber, a leak detection system, a superfluid helium acquisition system, and temperature control systems. The cold source is supplied by 1.5K superfluid helium, which will be obtained by combining throttling with decompression. Mechanical structure designs and detailed parameters of the entire platform will be presented in this paper.
Performance study of preloaded cryogenic bearings in liquid hydrogen pump
Authors: Su H , Lv C , Shang J , Huang B H , Feng Y , Wu J H
Published: June 2022

As a clean and efficient energy, liquid hydrogen has become an important solution for the energy restructuring in the future. The centrifugal liquid hydrogen pump has been applied in the storage, transportation and distribution of liquid hydrogen. As the support of pump rotor, the performance of cryogenic bearings are essential to the dynamic characteristics and design optimization of liquid hydrogen pump. In this paper, an improved quasi-static model for cryogenic bearing in liquid hydrogen pump was introduced, in which the effects of high-speed centrifugal expansion and shrinkage under cryogenic condition on bearing rings were considered. Based on this model, the effects of rotating speed and axial preload on bearing dynamic characteristics were studied. At the same time, the friction within the cryogenic bearing was analysed and calculated. Finally, the load variation of bearing preload disc spring at cryogenic temperature was calculated and experimentally studied. The results of this paper will provide theoretical suggestions for further engineering design and applications of cryogenic bearings in liquid hydrogen pump.
Stability analysis on gas-lubricated bearing for high speed cryogenic turbo-expander
Authors: Zheng L W , Zhang X H , Peng N , Yan H , Ke C L , Li K R , Liang Y W , Xiong L Y , Dong B , Li J , Liu I Q
Published: June 2022

Here, instead of using static characteristics of gas journal bearing such as the damping coefficients and the misalignment angle for stability analysis, a linear method is presented for studying the whirl stability of a rigid rotor supported on both cylindrical bearing and externally pressurized bearing. First, by using linearization method, the gas film forces can be represented as 8-coefficents, and they are calculated through perturbation method, the static performance is validated by published literature. Then, based on the Routh-Hurwitz criterion, the stability threshold is determined and graphically presented regarding several non-dimensional system parameters, which reflects the effects of both the eccentricity and supply pressure on the system’s linear stability. This effective and computationally cheap method of stability analysis is helpful for the prior design of gas bearing.
Design of Cryogenic Heat Exchangers and associated Sub-Systems for Controlled Cool-down and Testing of Superconducting Magnets at FRIB
Authors: Hasan N. , Ganni V. , Fila A. , Casagrande F.
Published: June 2022

The Facility for Rare Isotope Beams (FRIB) is a continuous wave heavy ion beam linear accelerator designed for a maximum beam energy of 400 kW and using in-flight (fragment) production and separation to generate rare isotope beams. Spatial separation of the isotopes is achieved by using superconducting magnets with a high magnetic field, large aperture, and iron-dominated core. There are a total of 14 superconducting magnets used in the fragment separator section of the facility. Designs for these magnets are relatively new, and it poses challenges in several aspects of the cryogenic design and operation such as, compact coil and cryostat design, thermal shield design, and a controlled cool-down to the operating temperature while avoiding high thermal stresses. Helically coiled finned-tube cryogenic heat exchanger designs are considered for the controlled cool-down of superconducting magnets with up to 22.4 tonnes of cold mass. These heat exchangers use liquid nitrogen cooled helium gas to cool the superconducting magnets. They demonstrate high thermal effectiveness and mechanical flexibility that are essential for the variable operating temperatures (300 – 80 K) experienced during a cool-down process. This paper presents an overview of the process design, analysis, fabrication and operation of cool-down heat exchangers and their associated sub-systems developed at FRIB.
Entropy optimization of an additively manufactured heat exchanger with a dual stage Gifford-McMahon cryogenic refrigerator for hydrogen liquefaction
Authors: Raymond J , Bunge C , Pesek L , Leachman J
Published: June 2022

Small-scale hydrogen liquefaction has emerged as an approach to fuel small aircraft powered by fuel cells. However, limited research on the design and optimization of small-scale hydrogen liquefiers, specifically the heat exchangers, is available. This paper describes a minimum entropy design for a heat exchanger mounted on a dual stage Gifford-McMahon cryogenic refrigerator. To minimize entropy generation the heat exchanger utilizes a bifurcating flow structure with varying wall thickness. Numerical optimization indicates that the heat exchanger will generate half of the entropy of a single coiled tube, significantly reducing the required heat exchanger length by 91.4% and the thermal mass by 43.8%. The heat exchanger was 3D printed with an aluminum alloy and the interior coated with a ruthenium-based catalyst for ortho-parahydrogen conversion. Hydrogen entering the heat exchanger near 293 K and 653 kPa is cooled to 28.1 K and full ortho-parahydrogen conversion is assumed before entering the storage dewar. The resulting experimental tests indicate a potential to increase heat exchanger efficiency in a more compact form factor, as well as a promising future for additively manufactured components in cryogenics.
Status of the PIP-II Cryoplant
Authors: Jia Y. , Hansen B. , Creus Prats J. , Atassi O. , Klebaner A. , Chakravarty A. , Goyal M. , Kumar J.
Published: June 2022

The Proton Improvement Plan-II (PIP-II) is an essential upgrade to the Fermilab accelerator complex featuring a new 800-MeV Superconducting Radio-Frequency (SRF) linear accelerator (Linac). The Linac contains 23 SRF cryomodules with the SRF cavities operating at 2 K, a high temperature thermal shield at 40 K and low temperature intercepts at 4.5 K. The PIP-II cryoplant will provide the necessary cooling for the cryomodules and the cryogenic distribution system interconnecting cryoplant and cryomodules. This paper describes the evolution of the PIP-II cryoplant conceptual design and specifications, including the expected heat loads, required cooling features and the integrated design. The cryoplant capacity margin analysis and fast cool-down mode will also be discussed.
Commissioning of a replacement subatmospheric cold box for Jefferson Lab’s Central Helium Liquefier
Authors: Mastracci B , Yang S , Creel J , Dixon K , Norton R , Thompson S , Wieliczko J , Wijeratne T
Published: June 2022

Jefferson Lab’s Cryogenics Department has designed, fabricated, installed, and commissioned a new subatmospheric cold box to replace one of the two existing units within our Central Helium Liquefier (CHL). The replacement cold box, dubbed SC1R, pumps saturated helium vapor at 0.0385 atm from Jefferson Lab’s continuous electron beam accelerator facility (CEBAF) cryomodules to maintain an operating temperature of nominally 2.1 K. This is accomplished using a five-stage cryogenic centrifugal compressor (cold compressor) system and a brazed aluminum plate-fin heat exchanger operating between 2.1 K and 4.5 K. In this paper we will describe our experience commissioning the SC1R cold box. We will discuss pump-down of the system to 2.1 K and steady-state operation at the cold compressor design flow rates of 170, 200, and 250 g/s. Performance of the heat exchanger and cold compressors has been mapped across a range of flow rates and optimized for CEBAF operations. This commissioning data will be used to monitor future performance and adapt to changing load requirements.
Large-scale 20K helium refrigeration system for the European Spallation Source
Authors: Arnold P , Zhang J , Kolev N , Ressel M
Published: June 2022

In 2016 Linde was awarded the contract to deliver the largest of its kind 20K helium refrigeration system to the European Spallation Source (ESS) in Lund, Sweden called Target Moderator Cryoplant (TMCP). A linear proton accelerator provides a high energetic pulsed beam to a rotating tungsten spallation target, generating fast neutrons. The TMCP helium cryogenic system will cool the liquid hydrogen circulating through the cryogenic moderator(s) which surround the spallation target. Thereby the neutrons are decelerated to form a useful radiation for the neutron instruments. The scope of delivery seems usual: cold box, two parallel compressors, oil removal and gas management systems and a jumper spool for performance testing. The requirements and the TMCP are unique: the refrigeration system is capable of a large range of cryogenic loads – guaranteed is from 4.9kW to above 30.3kW– with focus on maintaining efficiency over this range. The paper and presentation will cover the process design, the control strategies and the main results of the performance testing.
The design of an extended length helium pulsating heat pipe experiment
Authors: Kossel L , Pfotenhauer J , Miller F
Published: June 2022

Pulsating heat pipes, also known as PHPs, are passive two-phase heat transfer devices capable of moving heat at cryogenic temperatures with high effective thermal conductivities around two orders of magnitude higher than copper. A recent Helium Pulsating Heat Pipe experiment demonstrated a surprising phenomenon, where Helium PHPs of different lengths (300 mm and 1000 mm) displayed the same thermal conductance at equal heat loads. The purpose of this research is to experimentally characterize this apparent length-independence and determine the size limits for Helium PHPs. An experimental approach is developed where three additional Helium PHP experiments will be conducted with the same operating parameters as the original experiment except with extended adiabatic lengths – 1.25 m, 1.5 m, and 1.75 m. All PHPs considered in this study are in the vertical orientation and are bottom-heated. This will give five complete sets of data from which the influence of length on helium pulsating heat pipes’ performance may be analysed. This paper serves as a work-in-progress report describing the experimental design and fabrication of these Helium PHP experiments.
Design, construction, and commissioning of a deployable liquid hydrogen production and fueling system for unmanned aerial systems
Authors: Richardson I , Raymond J , Boettner D , Saelid G , Gitter Y , Harfst L , Dimmer S , Kurtz J , Coleman J , Mei A , Gardner H , Leachman J
Published: June 2022

Liquid hydrogen has historically been limited in proximity to baseload liquefiers and research laboratories. This accessibility barrier is a primary limitation to the development of advanced aircraft and is exacerbated by recent trends in unmanned aerial systems to convert to electric propulsion systems. This article describes the design, construction, and commissioning of a self-contained, automated, and deployable liquid hydrogen production and fueling system. Housed within a mil-spec shipping container, the system utilizes a water purifier, proton exchange membrane electrolyzer, cryogenic refrigerator, and custom liquid hydrogen dewar. The system requires only water, electricity, and periodic helium purge gas input for continuous operation. Overall system performance specifications are provided. The system demonstrates the capability of field deployable hydrogen liquefiers and fueling systems.
Design, fabrication, and installation of the cryogenic distribution system for FRIB target and fragment pre-separator superconducting magnets
Authors: Hasan N , Wright M , Ganni V , Casagrande F , Jones S , Nguyen C , Fila A , Joseph N
Published: June 2022

The target and fragment pre-separator segment of the continuous wave heavy ion beam linear accelerator at FRIB consists of fourteen superconducting magnets. The cryogenic distribution system for these superconducting magnets include six cryogenic process pipes (two each for 4.5 K helium, cool-down and thermal shield) housed in an approx. 175 m long vacuum jacketed transfer line, along with associated distribution boxes, cool-down heat exchanger, utility piping (such as magnet lead flow return, purge gas etc.) and a liquid helium storage vessel for magnet quench management. Due to the physical constraints in the routing of the beam-line at this segment, designs for these magnets and the associated cryogenic distribution system are complex in nature. It poses challenges in several aspects of the design process such as, routing of the transfer line, design of piping supports and anchors, thermal shielding, mechanical flexibility etc. Design of most of the elements of the cryogenic distribution system are carried out from the ground up, and in-house at FRIB. This paper presents an overview of the process design, analysis, fabrication and installation the target and fragment pre-separator cryogenic distribution system at FRIB.
Status of LBNF/DUNE near site liquid argon proximity and external cryogenics systems development.
Authors: Creus Prats J , Montanari D , Adamowski M , Cline G , Matichard F , Delaney M , Lawrence A
Published: June 2022

The Deep Underground Neutrino Experiment (DUNE) near site located at Fermilab will host the neutrino beam complex. It includes a high voltage liquid argon time projection chamber located 60-meter underground used as beamline instrumentation. The LAr cryogenic system provided by the Long-Baseline Neutrino Facility (LBNF) regulates thermohydraulic conditions of the membrane cryostat hosting the detector with 285 Ton purified LAr. The purification system uses molecular sieve and copper oxide pellets to manage the argon contamination below 100 ppt (parts per trillion) oxygen equivalent. The detector and its cryogenics are capable to move a stroke of 30 meters on/off beam. The cryogenic system modes of operation include the cryostat pressure test, purge in open loop, detector cooldown, cryostat fill, closed loop purification, liquid empty, and purification system activation/regeneration process. The system design status and schedule, and technical details such as operating modes and interfaces are reported in this paper.
Conceptual design of DALS test facility cryogenic system
Authors: Sun Z , Huang L , Shi X , Wang XL
Published: June 2022

Dalian advanced light source (DALS) is a new project proposed by Dalian Institute of Chemical Physics (DICP) aiming to produce high-quality electron beam with repetition rate up to 100 kHz and the project is subject to central government approval. The cryomodules and superconducting cavities need to be tested before assembled in the real accelerator so the test facility is necessary. The Accelerator module test facility (AMTF) project has been funded by Dalian local government and is currently under construction as the pre-research project for DALS, it consists of four testbenches, one Horizontal testbench (HTB) for cryomodule test, one Vertical testbench (VTB) for cavity test, one Cryogenic testbench (CTB) for cryogenic test and one Injector testbench (ITB) for beam test. A Test facility cryoplant (TFCP) with capacity of 370 W@2 K will be used for cooling testbenches. This paper presents the design and current progress of the TFCP system, which includes the refrigerators, helium compressors, process vacuum pump system (PVPS), gas storage system, recovery and purification system.
Fabrication and installation of the Mu2e cryogenic distribution system
Authors: White M , Lamm M , Hocker A , Arnold D , Tatkowski G , Kilmer J , Poloubotko V , Tope T , Huang Y , Elementi L , Badgley K , Voirin E , Young I , Brandt J , Feher S , Hess C , Markley D
Published: June 2022

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 construction stage. The scope of this paper is the cryogenic distribution system and superconducting power leads for four superconducting solenoid magnets: Production Solenoid (PS), an Upstream and Downstream Transport Solenoids (TSu and TSd) and Detector Solenoid (DS). The design of the cryogenic distribution system and the fabrication of several sub-systems was reported previously. This paper reports on additional fabrication and installation progress that has been performed over the past two years. Lessons learned during fabrication and testing of the cryogenic distribution system components are described. In particular, the challenges and solutions implemented for aluminum welding are reported.

A description of the process used to qualify the welding procedure and welders for welding the aluminium stabilized NbTi superconducting power leads is provided. Additionally, the progress made with regards to installing the power leads into the cryogenic Feedboxes is covered.
Introduction of the liquid nitrogen transfer line for TPS beamline endstation
Authors: Liao W R , Li H C , Chuang P S , Tsai H H , Hsiao F Z , Chiou W S , Chang S H , Liu D G
Published: June 2022

At Taiwan Photon Source (TPS), the main liquid-nitrogen (LN2) transfer line of length 600 m for beamline endstations was installed in 2015. It formerly supplied LN2 to maximum 24 beamline endstations. Beamline endstation 13A, of which the aim is advanced and general studies of biological structures and structural kinetics in solution or condensed forms under environmental simulations, from atomic to micrometre scale and time resolution from microsecond to minute, was installed during 2018 and 2019. We designed and self-manufactured one LN2 transfer line according to the requirement of beamline endstation 13A, to supply LN2 into the double-crystal monochromator (DCM), to solve the problem of thermal deformation of the crystal. Otherwise the keep-full device was designed to replace the phase separator of the chiller. In this paper we present the pipeline design, performance testing, keep-full device, pressure reducer, noise reduction and heat-load measurement.
Experiment and optimization of a large scale xenon/krypton cryogenic distillation system
Authors: Zhou W , Yonglin J , Xiangyi C , Xiangdong J , Jianglai L
Published: June 2022

A highly efficient cryogenic distillation system has been designed, developed and assessed to remove radioactive krypton-85 (85Kr) from xenon (Xe), which is commonly used as a valuable medium for dark matter detectors. By using the self-designed distillation system, the concentration of krypton (Kr) in a commercial xenon product can be reduced from 10−9 to 10−12 mol/mol with 99% xenon collection efficiency at maximum flow rate of 5 kg/h. Over 1000 kg of xenon has been purified and employed as the detection medium in project Panda X, the first dark matter detector developed in China. In this present paper, detailed process simulation was conducted to refine the working parameters and to define the optimum operating conditions for the cryogenic distillation system. The predicted results were compared with those of experimental data obtained from the distillation system. The influence of comprehensive factors was investigated. Simultaneously, a dynamic model for the cryogenic distillation system was established to provide an in depth analysis of the dynamic characteristics of the system.