Liquid Metal Technology Research Articles

3-D Printing and Gallium-Based Liquid Metal Technologies for Microwave and Millimeter-Wave Components

3-D Printing and Gallium-Based Liquid Metal Technologies for Microwave and Millimeter-Wave Components

Thermohydraulic studies of alkali liquid metal coolants for justification of nuclear power facilities

The paper presents and discusses the results of experimental and computational studies obtained by the authors on hydrodynamics and heat exchange in fuel assemblies of the alkali liquid metal cooled fast reactor cores, and experimental data on hydrodynamics of flow paths in the heat exchanger and reactor header systems. Investigation results are presented on in-tank coolant circulation obtained using a well-developed theory of approximation simulation of the nonisothermic coolant velocity and temperature fields in the fast neutron reactor primary circuit and demonstrating stable stratification and thermal fluctuations in the coolant. Results are presented from experimental and computational simulation of the alkali liquid metal boiling process based on fuel assembly models during an emergency situation caused by an operational occurrence involving simultaneous loss of power for all reactor coolant pumps and the reactor scram rod failure. Objectives are formulated for further studies, achieving which is essential for the evolution of the liquid metal technology, as dictated by the need for the improved safety, environmental friendliness, reliability and longer service life of nuclear power facilities currently in operation and in the process of development.

A liquid metal MHD vortex generator for energy harvesting applications

Liquid metal (LM) technologies for energy harvesting are gaining attention due to their unique properties. An LM vortex magnetohydrodynamic generator is a suitable and robust option among different approaches used for energy harvesting. In this device, LM is driven into a cylindrical cavity to produce a swirling flow, interacting with an imposed axial magnetic field and inducing electric currents that can be extracted to power an external electrical system. However, to maximize the power output, the effect of the electrical resistance on the flow dynamics and electrical parameters must be evaluated. Here, an evaluation is carried out with both the commercial software COMSOL Multiphysics and a theoretical model, whose results are partially validated with the experimental data obtained from a device built for this purpose. In addition, the effect of the electrode size on the global electrical variables, such as voltage, current and electrical power, is investigated numerically. Figs 5, Refs 9.

Overview on Lead-Cooled Fast Reactor Design and Related Technologies Development in ENEA

The next generation of nuclear energy systems, also known as Generation IV reactors, are being developed to meet the highest targets of safety and reliability, sustainability, economics, proliferation resistance, and physical protection, with improved performances compared with the currently licensed plants or those presently being built. Among the proposed technologies, lead-cooled fast reactors (LFRs) have been identified by nuclear industries in both Western and developing countries as being among the optimal Generation IV candidates. Since 2000, ENEA, the Italian National Agency for New Technologies, Energy, and Sustainable Economic Development is supporting the core design, safety assessment, and technological development of innovative nuclear systems cooled by heavy liquid metals (HLM) and, most recently, fully oriented on LFRs. ENEA is developing world-recognized skills in fast spectrum core design and is one of the largest European fleets of experimental facilities aiming at investigating HLM thermal-hydraulics, coolant chemistry control, corrosion behavior for structural materials, and material properties in the HLM environment, as well as at developing corrosion-protective coatings, components, instrumentation, and innovative systems, supported by experiments and numerical tools. Efforts are also dedicated to develop and validate numerical tools for specific application to HLM systems, ranging from neutronics codes, system and core thermal-hydraulic codes, computational fluid dynamics (CFD) and fuel pin performance codes, including their coupling. The present work aims at highlighting the capabilities and competencies developed by ENEA so far in the framework of liquid metal technologies for Generation IV LFRs. In particular, an overview on the ongoing R&D experimental program will be depicted considering the current fleet of facilities, namely: CIRCE, NACIE-UP, LIFUS5, LECOR, BID-1, HELENA, RACHEL, and Mechanical Labs. An overview on the numerical activities performed so far and those presently ongoing is also reported. Finally, an overview of the ENEA contribution to the ALFRED Project in the frame of the FALCON international consortium is reported, mainly addressing the ongoing activity in terms of core design, technology development, and auxiliary systems design.

Stretchable self-tuning MRI receive coils based on liquid metal technology (LiquiTune)

Magnetic resonance imaging systems rely on signal detection via radiofrequency coil arrays which, ideally, need to provide both bendability and form-fitting stretchability to conform to the imaging volume. However, most commercial coils are rigid and of fixed size with a substantial mean offset distance of the coil from the anatomy, which compromises the spatial resolution and diagnostic image quality as well as patient comfort. Here, we propose a soft and stretchable receive coil concept based on liquid metal and ultra-stretchable polymer that conforms closely to a desired anatomy. Moreover, its smart geometry provides a self-tuning mechanism to maintain a stable resonance frequency over a wide range of elongation levels. Theoretical analysis and numerical simulations were experimentally confirmed and demonstrated that the proposed coil withstood the unwanted frequency detuning typically observed with other stretchable coils (0.4% for the proposed coil as compared to 4% for a comparable control coil). Moreover, the signal-to-noise ratio of the proposed coil increased by more than 60% as compared to a typical, rigid, commercial coil.

Recent Development in Liquid Metal Materials.

Liquid metals (LM) have shown a very broad development prospect over the past decades. This review article focuses on the latest research dedicated to liquid metal materials and their applications in five significant areas: stretchable conductive composite, intelligent sensing electronic skin, catalysis, 3D printing material, and driving machines. The fabrication, specific properties and application of stretchable liquid metal‐polymer composites that can be used as self‐healing materials have been summarized. Liquid metal deposition printing technology, liquid phase 3D printing, suspension 3D printing technology, micro‐contact printing technology, and in vivo 3D printing molding technology have also been reviewed. Furthermore, the application of liquid metal catalyst in aldehyde reaction, photocatalysis, and electrocatalysis have been discussed. We have shown that electricity, magnetism, sound, light and heat could stimulate the movement of liquid metal. Through this comprehensive overview of the latest research, the main practical application, development, and mechanism of liquid metal were summarized and described. The future development of liquid metal technology was prospected, thus providing a strong basic research support for the further development of LM materials and their applications.

State of development of the heavy coolant quality support and control system for NF BREST-OD-300

Liquid lead has been chosen as the coolant for nuclear power plants with inherent safety in Russian Federation. Its physical and chemical properties offer distinct advantages over other types of coolants in FR with inherent safety, but this coolant also possesses certain technological challenges in the course of reactor operation. Heavy liquid metal technology management system for BREST-OD-300 reactor consists of a number of high-end technological devices designed to operate and maintain crucial parameters of lead coolant for decades. Development of these devices required innovative and creative approach as well as strong verification procedures. This presentation will give recent updates on the development of oxygen sensors, mass-exchange devices, hydrogen purification system, coolant filter, hydrogen sensors, which combined present Coolant quality control and management system.

Rise of the Liquid Metal Science, Technology and Industry: Advancements and Opportunities

The room temperature liquid metal and its allied materials are a class of emerging functional matters with diverse species. Recently, with breakthrough discoveries made on liquid metals, tremendous exciting applications were raised and many new materials that had never been anticipated before were invented. As a result, the latest achievements on liquid metals were ascribed as the second revolution of human beings over the process of utilizing metals. This article briefly summarized typical advancements, fundamental sciences, and key technological and industrial areas thus initiated which include but are not limited to: chip cooling and energy utilization, printed electronics and 3D printing, biomedical materials, as well as smart soft machines. In addition, historic background to propose and establish “The China Liquid Metal Valley” and the basic strategy to mold a brand new industry of liquid metal were outlined. The core values to strengthen future research on liquid metal material genome engineering and thus build up corresponding databases were summarized. Overall, liquid metals are important frontiers for science, technology, and industry integrating both fundamental and practical issues together. Further continuous endeavors would lead to pivotal progress of human civilization and thus reshape social production and lifestyle. Its impact for both China and the world to explore next generation revolutionary science, technology, and industry will be huge.

Thermodynamic Analysis of High‐Temperature Energy Storage Concepts Based on Liquid Metal Technology

Within the thermal energy storage (TES) initiative NAtional Demonstrator for IseNtropic Energy storage (NADINE), three projects have been conducted, each focusing on TES at different temperature levels. Herein, technical concepts for using liquid metal technology in innovative high‐temperature TES systems are dealt with. This approach implies some challenges; first, the unit costs are relatively large which makes a reduction of the mass inventory necessary. Second, the high thermal diffusivity, which is beneficial in any heat exchanger unit, reduces the efficiency in a single‐tank TES due to the fast degradation of the thermocline. These limitations can be overcome using a nonexpensive solid filler material, and, if properly designed, similar performance as in state‐of‐the‐art molten salt systems can be obtained, while maintaining the advantage of operating at temperatures well beyond their upper limit. Optimization strategies are presented for a reference case including transient behavior of the whole system. The sensitivity of multiple parameters, e.g., porosity, particle size, and influence of storage capacity regarding the discharge efficiency, is investigated.

Forefront of liquid metal technologies for fusion reactors

Fusion reactor is an innovative power plant, which is necessary for a sustainable society. The important issue is the development of key components, i.e. tritium breeding blanket and divertor. Liquid metal Li and Pb-16Li are candidate tritium breeders, which also function as a reactor coolant. Liquid Sn is a promising coolant of liquid surface divertor, which is responsible for power exhaust and impurity removal through guided plasma exhaust in magnetic plasma confinement fusion reactors. The design studies on the liquid breeder blanket and the liquid surface divertor are being conducted toward fusion DEMO reactor. The chemical behaviours of liquid metals have been studied to improve the tritium transfer and the material compatibility. This paper reviews recent studies on the liquid metal technologies for the fusion reactors.

ТЕПЛОФИЗИКА ЩЕЛОЧНЫХ ЖИДКИХ МЕТАЛЛОВ. ЧАСТЬ 2: ФИЗХИМИЯ, ТЕХНОЛОГИЯ И ИННОВАЦИОННЫЕ ПРИЛОЖЕНИЯ (РЕТРОСПЕКТИВНО-ПЕРСПЕКТИВНЫЙ ВЗГЛЯД)

The article presents the results of experimental and analytical studies carried out at the SSC RF - IPPE in the field of physical chemistry, mass transfer, technology and innovative applications of alkaline liquid metal coolants. An integrated approach to the study of coolants as a complex multi component heterogeneous system, the state of which is determined by the interaction of coolant - impurities - structural (technological) materials - protective gas, was substantiated. Thermodynamic analysis and experimental studies of the coolants properties and the kinetics of their interaction with air, water, hydrogen, structural and technological materials determined the sources of impurities and their intensity. It is shown that for temperature parameters of modern NPPs, the required concentration of impurities in sodium and sodium-potassium alloy, can be provided by purification the coolants by cold traps. The deeper purification of ciilants required for use in high-temperature installations of niobium, tungsten, vanadium, tantalum is achieved by getters (hot traps). This method can also be applied when limiting the weight and size characteristics, for example, for a space NPP. A fundamentally new combined purification system from impurities was proposed and substantiated for a high-temperature NPP for the production of hydrogen with a sodium coolant temperature of ~900 °C. As a result of the development of alkaline liquid metal coolants, liquid metal technology has been proposed in various technical applications: sodium at nuclear power plants with fast neutron reactors, sodium and sodium potassium in the metallurgical and chemical industries; sodium-potassium, cesium, lithium - in space installations; lithium - in fusion reactors - thermonuclear reactors.

CFD modelling of the CIRCE facility

CIRCE is a test facility designed and realized by the Italian agency ENEA to support the heavy liquid metal technology for nuclear fission plants. Within the H2020 projects SESAME and MYRTE, various experiments are performed in this facility, using two different heat exchangers (namely ICE and HERO), resembling nominal operation and accident scenarios of a Liquid Metal Fast Reactor (LMFR). Simultaneously, within these projects different thermal-hydraulics models of CIRCE are created to gain experience in the modelling of such a facility and to help future development of LMFRs. At NRG and CRS4, CFD models of CIRCE in the two different configurations are created. The present paper describes the steps taken to create these models. Results obtained with the models are, where possible, compared with experimental results, both for steady-state and transient conditions. For the steady-states, generally good agreement is found. The main features of the stratification forming in the pool are recovered, though they appear quite sensitive to the local heat balance. The transient simulation performed recovers some of the main features of the experiment, however excessive cooling is found. The causes of discrepancies found between numerical and experimental results are currently under investigation.

MYRRHA primary heat exchanger experimental simulations on CIRCE-HERO

In the frame of the MYRRHA ADS technological development, an intense research effort has been undertaken by European Commission, in particular for the Heavy Liquid Metal technology assessment. In this scenario, EURATOM HORIZON2020 funded the SESAME & MYRTE projects, coordinating a series of thermal hydraulics experiments and simulations for the safety assessment of liquid metal fast reactors. In particular, in the MYRTE project, a dedicated activity has been defined, consisting of a low pressure experimental campaign realized at the ENEA Brasimone Research Centre and concerning a double wall Steam Generator Bayonet Tube (SGBT), aiming at supporting the development of the Primary Heat Exchanger (PHX) of MYRRHA.The CIRCE (CIRColazione Eutettico) pool facility hosts a devoted Test Section (TS) named HERO (Heavy liquid mEtal pRessurized water cOoled tubes). HERO consists of seven double wall bayonet tubes, with an active length of 6 m, arranged in a hexagonal geometry. This solution aims at improving the plant safety reducing the possibility of water-lead/leadalloy interaction thanks to a double physical separation between them and allowing an easier control of potential leakages of the coolant by pressurizing the separation region with inert gas.The experimental campaign in CIRCE-HERO has been supported by a pre-test analysis using system thermal-hydraulic codes (i.e. RELAP5). A sensitivity analysis has been performed considering the mass flow rate and HERO inlet temperature for both the water and LBE, fixing the operating pressure at 16 bar.A test matrix, as produced as output of the sensitivity analysis and aimed at reproducing as faithfully as possible the thermal-hydraulic behaviour of the MYRRHA PHX under different operating conditions, is here presented. The experimental results collected from the low pressure tests on HERO test section are reported and discussed.

Engineering design and development of lead lithium loop for thermo-fluid MHD studies

In the frame of the design and development of Liquid breeder blankets, a number of R & D activities are in progress in the area of liquid metal technology development. In presence of strong plasma confining toroidal magnetic field, motion of electrically conducting liquid metal leads to Magneto Hydro Dynamic (MHD) phenomena, as a consequence of which liquid metal flow profile changes inside the flow channels of liquid breeder blankets and additional pressure drop occurs due to the flow opposing Lorentz force (J × B). For the design and development of liquid breeder blankets, 3D MHD flow needs to be studied for various flow configurations as present in the liquid breeder blankets. A lead lithium (Pb-Li) MHD loop is being developed at IPR to perform MHD experiments for Pb-Li flow in various flow geometry such as U-bend, transition zones, circular pipes, sudden expansion and contraction, etc. The test mock ups will be placed in a uniform magnetic field up to 1.4 T, produced by a C-shaped Iron core electromagnet with a pole gap of 370 mm. Both Isothermal and thermo-fluid MHD experiments are being planned for MHD database generation and code validation.

Controllable dispersion and reunion of liquid metal droplets

Liquid metal (LM) micro-droplets have been widely used in microfluidics, drug-loaded nano-system and micro-nano machine due to its excellent properties. However, there still exist difficulties in succinctly dispersing a bulk of LM into micro-droplets due to the large interfacial tension. Besides, the controllable switching between droplet dispersion and reunion is yet to be realized. Herein, a practical and efficient method for dispersing LM was proposed and the controllable switching between dispersion and reunion of LM droplets was achieved. LM micro-droplets were produced by vibrating the LM immersed in a mixture of N , N -dimethylformamide (DMF) and polyvinyl chloride (PVC). The experimental results show that the size distribution of LM micro-droplets could be tuned by controlling the vibration frequency. More intriguingly, the dispersion and reunion of LM droplets can be switched intelligently through tuning the vibration frequency and amplitude. Furthermore, optical properties of the LM micro-droplet coating were evaluated to display potential applications. A self-driven motion of PVC-coated LM could be achieved by utilizing the produced LM micro-droplets based on the Marangoni effect, which holds promising value for developing future transport tool of LM droplets. The present work suggests an entirely feasible method for dispersing and utilizing LM droplets, which is of great significance for promoting the development of LM micro-droplet science and technology.

GEN-IV LFR development: Status & perspectives

Since Lead-cooled Fast Reactors (LFR) have been conceptualized in the frame of Generation IV International Forum (GIF), great interest has focused on the development and testing of new technologies related to Heavy Liquid Metal (HLM) nuclear reactors. In this frame, ENEA developed one of the larger European experimental fleet of experimental facilities aiming at investigating HLM thermal-hydraulics, coolant chemistry control, corrosion behavior for structural materials, and at developing components, instrumentations and innovative systems, supported by experiments and numerical tools.The present work aims at highlighting the capabilities and competencies developed by ENEA so far in the frame of the liquid metal technologies for GEN-IV LFR.In particular, an overview on the ongoing R&D experimental program will be depicted considering the actual fleet of facilities: CIRCE, NACIE-UP, LIFUS5, LECOR and HELENA.CIRCE (CIRColazione Eutettico) is the largest HLM pool facility presently in operation worldwide. Full scale component tests, thermal stratification studies, operational and accidental transients and integral tests for the nuclear safety and SGTR (Steam Generator Tube Rupture) events in a large pool system can be studied.NACIE-UP (NAtural CIrculation Experiment-UPgraded) is a loop with a HLM primary and pressurized water secondary side and a 250 kW power Fuel Pin Simulator working in natural and mixed convection.LIFUS5 (lithium for fusion) is a separated effect facility devoted to the HLM/Water interaction. HELENA (HEavy Liquid metal Experimental loop for advanced Nuclear Applications) is a pure lead loop with a mechanical pump for high flow rates experiments. LECOR (LEad CORrosion) is a corrosion loop facility with oxygen control system installed.All the experiment actually ongoing on these facilities are described in the paper, depicting their role in the context of GEN-IV LFR development.

A novel system for high-purity hydrogen production based on solar thermal cracking of methane and liquid-metal technology: Thermodynamic analysis

A novel zero-carbon-emission system for producing high-purity hydrogen and carbon nanoparticles was proposed in this paper. Concentrated solar energy as the only energy source was utilized in a cascaded way. That is to say, concentrated solar energy was first used to provide heat with high temperature for the thermal cracking of methane, and then used to drive the heat-to-power cycle for the output of mechanical work or electricity. The produced mechanical work or electricity was used for separating hydrogen from the unreacted methane based on the membrane technology. The performances of the whole system and its major facilities were studied through the first law thermodynamics. The results showed that, receiver loses about 35% of the input energy due to the high operating temperature, and about 59% of the input energy is used for the purification of hydrogen. The system performance is mainly affected by four key parameters including the heat loss of receiver, the conversion rate of methane in the reactor, the operating pressure of the membrane separator, and the heat-to-power rate of the power generation cycle. Decreasing the operating pressure of the membrane separator is one of the most efficient ways to improve the system efficiency. With the partial pressure of hydrogen in the retentive-side of separator decreasing from 791 to 200 kPa, the ideal system efficiency increases from 0.4 to 0.8.

Pool temperature stratification analysis in CIRCE-ICE facility with RELAP5-3D© model and comparison with experimental tests

In the frame of heavy liquid metal (HLM) technology development, CIRCE pool facility at ENEA/Brasimone Research Center was updated by installing ICE (Integral Circulation Experiments) test section which simulates the thermal behavior of a primary system in a HLM cooled pool reactor. The experimental campaign led to the characterization of mixed convection and thermal stratification in a HLM pool in safety relevant conditions and to the distribution of experimental data for the validation of CFD and system codes. For this purpose, several thermocouples were installed into the pool using 4 vertical supports in different circumferential position for a total of 119 thermocouples [1][2].The aim of this work is to investigate the capability of the system code RELAP5-3D© to simulate mixed convection and thermal stratification phenomena in a HLM pool in steady state conditions by comparing code results with experimental data. The pool has been simulated by a 3D component divided into 1728 volumes, 119 of which are centered in the exact position of the thermocouples. Three dimensional model of the pool is completed with a mono-dimensional nodalization of the primary main flow path. The results obtained by code simulations are compared with a steady state condition carried out in the experimental campaign. Results of axial, radial and azimuthal temperature profile into the pool are in agreement with the available experimental data Furthermore the code is able to well simulate operating conditions into the main flow path of the test section.

Carbon dioxide free production of hydrogen

The present report summarizes the theoretical modelling and experimental investigation results of the study on the direct thermal methane cracking. This work is a part of the LIMTECH-Project (Liquid Metal Technologies) funded of Helmholtz Alliance and was carried out from 2012 to 2017. The Project-part B5 “CO2-free production of hydrogen” focused on experimental testing and particularly on modelling the novel methane cracking method based on liquid metal technology. The new method uses a bubble column reactor, filled with liquid metal, where both the chemical reaction of methane decomposition and the separation of gas fraction from solid carbon occur. Such reactor system was designed and built in the liquid metal laboratory (KALLA) at KIT. The influences of liquid metal temperature distribution in reactor and feed gas flow rate on methane conversion ratio were investigated experimentally at the temperature range from 930°C to 1175 °C and methane flow rate at the reactor inlet from 50 to 200 mLn/min. In parallel with experimental investigations, a thermochemical model, giving insight in the influence of the above mentioned parameters has been developed at KIT and a CFD model was developed at LUH to get an overview about the bubble dynamics in the reaction system. The influence of different bubble sizes and shapes, multi-inlet coalescence effects as well as the potential of electromagnetic stirring have been investigated.

Final LIMTECH Colloquium and International Symposium on Liquid Metal Technologies

Preface: Final LIMTECH Colloquium and International Symposium on Liquid Metal Technologies (LIMTECH) Sept. 19-20, Dresden GermanyThis volume of IOP Conference Series – Materials Science and Engineering represents a selection of contributions presented at the Final LIMTECH Colloquium and International Symposium on Liquid Metal Technologies (LIMTECH) held at Helmholtz-Zentrum Dresden – Rossendorf (Dresden, Germany) on Sept. 19-20, 2017.Inspired by both the growing societal interest and awareness in energy and resource efficiency and the enhanced measurement and computational capabilities being available nowadays, liquid metal research has recently regained increased attendance. Helmholtz-Zentrum Dresden - Rossendorf (HZDR) and the Karlsruhe Institute of Technology (KIT), both being members of the German Helmholtz Association of Research Centres, therefore took the initiative to synthesize a multi-directional program in order to■ bridge the Helmholtz activities within the Helmholtz energy R&D programs,■ foster collaboration with the knowledge driven university research,■ utilize jointly the infrastructures of Helmholtz centres and universities,■ stimulate collaboration with industrial partners and international research groups,■ enhance talent development in a competitive ambience.