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Different drag laws and turbulence models were compared to evaluate gas distribution and fluid flow velocities in a Rheinstahl–Heraeus (RH) reactor. The discrete phase model was adopted to track injected gas bubbles, and the volume of fluid model was applied to describe a more actual free surface. The prediction accuracy of the numerical model was evaluated by the measured flow velocity in an air-water model and the measured circulation flow rate of molten steel in a real RH system. Results indicate that Morsi’s drag law predicts more accurate local velocity compared with Schiller’s and Harmathy’s laws. The influence of turbulent dispersion on the injected gas bubbles is non-negligible for predicting the gas–liquid flow in a RH reactor. In addition, although the large eddy simulation (LES) approach predicts more actual free surface fluctuation, the realizable k-e model shows better agreement with the measured local velocity in the furnace.

The experiments on deuterium plasma-driven permeation through liquid Ga and Li were conducted in a linear plasma device VEHICLE-1. Deuterium transport parameters such as diffusivity and surface recombination coefficient for Ga and Li were measured from the experiments. By using the measured transport parameters, deuterium dynamic retentions in Ga and Li under steady-state plasma bombardment were evaluated with the DIFFUSE code. It has been found that the deuterium dynamic retention in Ga is ~five orders of magnitude lower than that in Li under present experimental conditions. After exposed to the steady-state deuterium plasma at temperatures from 78 °C to 360 °C, deuterium static retentions in liquid Ga are measured by the thermal desorption spectroscopy. It has been found that the deuterium static retentions in Ga are close to the dynamic retentions when the exposure temperatures are below 250 °C.

The aim of this research is to investigate the effect of average grain size on electrical and electrochemical performances of La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM). For this purpose, the glycine-nitrate method is used to synthesize the LSGM electrolytes and subsequently sintered at 1350, 1400, 1450 and 1500 °C in a muffle furnace with temperature holding for 10 h. XRD study reveals that all of the sintered LSGM ceramic electrolytes crystallize to a single phase of orthorhombic perovskite structure without any impurity phases. Results from scanning electron microscopy (SEM) study demonstrate that increasing sintering temperature from 1350 to 1500 °C leads to increase in average grain size from 1.02 to 4.87 μm. Electrochemical AC impedance tests show that the bulk resistance is nearly independent on the average grain size, and the grain boundary resistance changes because of the difference in the average grain size. The LSGM sample sintered at 1500 °C achieves the maximum electrical conductivity 9.19 × 10−2 S cm−1 at 800 °C. The maximum power density of assembled cell with LSGM sintered at 1500 °C as an electrolyte is 0.76 W cm−2 at 800 °C in air atmosphere.

From the recent experiments on liquid metal plasma-facing components, convection appears to play an important role in maintaining reduced recycling conditions. Either it is natural or forced convection, the transport of the implanted particle is accelerated in the depth direction whereby the surface saturation would be delayed or avoided. Reviewed in this paper are some of the recent studies on particle recycling from liquid metals under plasma bombardment with the emphasis on liquid convection effects. Natural convection has been observed to enhance deuterium plasma-driven permeation. In addition, the effects of J × B forced convection on particle recycling have been extensively studied under steady-state hydrogen, deuterium, helium, and argon plasma bombardment. Also, preliminary fluid dynamics analysis has been conducted to interpret these experimental observations.

The nanofluidic chips with channels of 100-nm depth and 3-μm width were employed as molecular flow standard leak elements for vacuum technology applications in this paper. The nanofluidic chips are fabricated by MEMS technologies while the macro-micro connection is achieved using glass fusion bonding and standard Swagelok® Fitting. It is found that the choice of annealing temperature and holding time is a key issue regarding fusion bonding and the optimal processing parameters are 780 ℃, 5 min. Meanwhile, the sealing reliability of fusion bonding and the fitting connection is evaluated. Experiment shows that the flow conductance of the as-fabricated leak can reach 10−13 m3∙s−1 magnitude for He, N2 and Ar. This standard leak has the advantages of controlled dimensions, reliable connection, and constant flow conductance over a range of 105 Pa.

A series of experiments on deuterium plasma interaction with a liquid metal GaInSn alloy have been carried out to investigate the Lorentz-force (J × B-force) convection effects on particle recycling behavior over liquid metals under plasma bombardment. It has been found that deuterium recycling from the liquid is reduced, when forced convection is applied to the liquid. And deuterium recycling is reduced more as the current increases. A finite element analysis method has been applied to simulate the motion of the liquid and the deuterium transport process in the liquid. As a result, the deuterium transport in the liquid is accelerated by the convection.

The application of liquid metals as plasma-facing materials (PFMs) is a potential means to resolve the technical issues associated with power exhausting and particle handing in magnetic fusion devices. Natural convection is a phenomenon commonly present in liquids. To investigate the natural convection effects on deuterium transport behavior in liquid metals, a series of experiments on deuterium Plasma-Driven Permeation (PDP) through a liquid metal GaInSn alloy have been carried out. It has been found that deuterium permeation through the liquid is enhanced by one order of magnitude with natural convection. The motion of the liquid and the deuterium transport process in the liquid have been simulated by a finite element analysis method.

A series of first-of-a-kind laboratory-scale experiments on the JxB -force convected liquid metal divertor concept have been carried out in the temperature range from room temperature to ∼200 °C, employing a eutectic alloy: Ga 67 In 20.5 Sn 12.5 , the melting point of which is 10.5 °C. The electrical current conducted through the alloy is set at about 70A and the magnetic field is set at about 700 G. It has reproducibly been observed that hydrogen as well as helium particle recycling is noticeably reduced under steady state plasma bombardment when the liquid is convected by the JxB force.

Ni 1 − x Cu x bimetallic-based composite anodes were investigated for intermediate temperature solid oxide fuel cells. Ni 1 − x Cu x O and SDC were synthesized using a glycine nitrate process. The electrical conductivity of the Ni 0.90 Cu 0.10 is higher than Ni. The electrical conductivities of the Ni 1 − x Cu x –SDC increase with increasing Cu content (from x = 0 to x = 0.10) and then decrease at x = 0.15. Addition of appropriate amounts of Cu into Ni–SDC to form Ni 1 − x Cu x –SDC anodes obvious improves the electrochemical performance of solid oxide fuel cells.

NdBa 1 − x Co 2 O 5 + δ (NB 1 − x CO, x = 0.00, 0.02, 0.04, and 0.06) have been synthesized and evaluated as cathode materials for use in intermediate temperature solid oxide fuel cells (IT-SOFCs). The effect of Ba deficiency on the structure, thermal and electrochemical properties of NB 1 − x CO is systematically investigated. NB 1 − x CO have a tetragonal layered-perovskite structure. Iodometric titration indicates that the oxygen content decreases and the concentration of oxygen vacancy increases with increasing Ba deficiency. The thermal expansion coefficient decreases with increasing Ba deficiency. An inflection occurs on the slope approximately 300 °C for NBCO that changes to 250 °C for NB 1 − x CO. The results suggest that introduction of Ba deficiency is beneficial for the release of lattice oxygen. Among all of the samples, NB 0.96 CO exhibits the lowest polarization resistances. Increasing oxygen vacancy by introduction Ba deficiency promotes the area conductivity of the oxygen ion transfer at the interface between the cathode and the electrolyte and the area conductivity of the reduction reaction of atom adsorbed oxygen into adsorbed oxygen ion. Our results demonstrate that the NB 0.96 CO electrode is a potential cathode material for IT-SOFCs.

Ba 1−x Sr x Co 0.7 Fe 0.2 Nb 0.1 O 3−δ (x = 0.0–0.2) are proposed as the electrodes for intermediate temperature solid oxide fuel cells (IT-SOFCs) for the first time. The minimum polarization resistance value is achieved at Ba 0.8 Sr 0.2 Co 0.7 Fe 0.2 Nb 0.1 O 3−δ (BSCFN). In this work, BSCFN-xSDC(x = 0–40wt.%) are investigated as the cathodes for IT-SOFCs with SDC electrolyte. The structures of the cathodes are characterized by X-ray diffraction and SEM. The electrode performance of BSCFN-xSDC is measured at various temperatures and oxygen partial pressures. Comparison of the results demonstrate that introduction of ionic conductive SDC to BSCFN-xSDC composite cathode can make the oxygen reduction reaction processes from the three processes into two processes, the charge transfer process and the adsorption and dissociation of gaseous oxygen process. The charge transfer process is the major rate limiting step when oxygen partial pressure is higher than 0.05 atm. The microstructure of BSCFN-30SDC is characterized by more appropriate grain size and more adequate porosity. The area conductivity of adsorption and dissociation of gaseous oxygen process for BSCFN-30SDC is the highest. Comparison of the power density of single cell results demonstrate that BSCFN-xSDC composite cathode has higher power density than BSCFN cathode. BSCFN-30SDC electrode exhibits the highest cathode performance among BSCFN-xSDC composite cathodes.

The composites of Ce 0.85 Sm 0.15 O 1.925 (SDC) and BaCe 0.83 Y 0.17 O 3− δ (BCY) are investigated as electrolytes for solid oxide fuel cells (SOFCs). The electrolyte materials SDC and BCY are synthesized by the glycine–nitrate route and the sol–gel process, respectively. Composite electrolytes are then prepared by mixing SDC and BCY in weight ratios of 9:1 (SB91), 8:2 (SB82), 7:3 (SB73) and 5:5 (SB55). Results from X-ray diffraction (XRD) demonstrate that Sm 3+ can diffuse from SDC to BCY. The SEM results reveal that the average grain size decreases with increasing BCY content. Impedance spectroscopy measurements reveal that the grain boundary resistance can be significantly reduced by adding 10–20 wt.% BCY to SDC. Among all of the samples, SB91 exhibits the lowest total resistance. In the impedance spectra of SB73 and SB55, two grain boundary responses can be identified. Compared with SDC and BCY, the composite electrolytes exhibit lower electrode interfacial polarization resistances. Single cells based on the electrolytes are fabricated using Ni 0.9 Cu 0.1 O x /SDC as anode and LaSr 0.25 Ba 0.75 Co 2 O 5+ δ as cathode. The cell based on SB91 electrolyte exhibits the lowest total resistance under open circuit conditions and the maximum power density of the cell based on SB91 electrolyte reaches 0.495 W cm −2 at 800 °C.