[en] The numerical modelling of hydraulics of countercurrent flow in vertical tubes has been presented and the algorithm of multi-fluid mathematical models has been developed. According to calculational analysis, the new co-relation group for mathematical model has been presented, hydraulics of countercurrent flow have been analyzed, the possibility of analysis on the flooding phenomena of this mathematical model has been evaluated

[en] The author presents the analysis on the possibility for COBRA-TF to model thermal-hydraulics of SG (Steam Generator) secondary side, numerically analyzes the thermal-hydraulic processes of heater section of SG secondary side of Qinshan Nuclear Power Plant, the results are compared with those from ALBERTINE-2

[en] COBRA-TF Code is a multi-dimensional two phase flow computer program, used to analyze the thermal hydraulics in reactor system. By analyzing the difference between COBRA-IV and COBRA-TF, the author describes the characteristics of mathematical and physical model used in COBRA-TF. Numerical analysis of reflooding process in reactor system is presented

[en] COBRA-TF code is a multi-dimensional multi-field computer program, used for analysis of the thermal hydraulics in reactor system. According to the characteristics of steam generator in a nuclear power plant, the validation of using of COBRA-TF code to analyze the thermal hydraulics of the heater of the secondary side of steam generator has been made. The results are compared with those from ALBERTINE-2

[en] Experimental study of phase separation of air-water two phase bubbly, slug flow in the horizontal T-junction is carried out. The influences of the inlet mass quality X1, mass extraction rate G3/G1, and fraction of extracted liquid QL3/QL1 on phase separation characteristics are analyzed. For the first time, the authors have found and defined pulsating run effect by the visual experiments, which show that under certain conditions, the down stream flow of the T-junction has strangely affected the phase redistribution of the junction, and firstly point out that the downstream geometric condition is very important to the study of phase separation phenomenon of two-phase flow in a T-junction. This kind of phenomenon has many applications in the field of energy, power, petroleum and chemical industries, such as the loss of coolant accident (LOCA) caused by a small break in a horizontal coolant pipe in nuclear reactor, and the flip-flop effect in the natural gas transportation pipeline system, etc

[en] This paper presents the analysis on the possibility for COBRA-TF to model thermal-hydraulics of Steam Generator (SG) secondary side, which was applied to the thermal-hydraulic processes of heater section of SG second side of Qin San Nuclear Power Plant. The results are compared with those from ALBERTINE-2. (author)

[en] The on-line graph processing measure system is equipped with and experimental study of phase separation of air-water bubbly flow in the horizontal T-junction is carried out. For the first time, the author have found and defined the new type of complete phase separation, by the visual experiment, which shows that under certain conditions, the air flow entering the T junction will flow into the run outlet completely, which had never been reported in the literature Also, the pressure wave feed back effect and the branch bubble flow reorganization effect were found and analyzed. The complexity of this phase separation phenomenon in the T junction has been further revealed via the on-line graph processing technology. Meanwhile the influences of the inlet mass flow rate W1, the inlet mass quality X1, and the mass extraction rate G3/G1 on phase separation were analyzed

[en] In some scenarios of severe accidents of light water reactors, a layer of molten metal from internal structural components of the pressure vessel is predicted to occur on top of a ceramic core debris in the lower head. The layer transfers the heat generated in the ceramic pool to the side wall of the vessel, causing the latter to melt. This problem has been investigated by Theofanous et al. for the advanced light water reactor AP600 in the context of the accident management strategy of ex-vessel cooling, and the conclusion was drawn that the melting does not seriously compromise the integrity of the pressure vessel

[en] The glow discharge polymer (GDP) films were fabricated by plasma polymerization technology at various parameters. The chemical structure of GDP films was characterized by Fourier transform infrared (FT-IR) spectrum. The hardness and modulus of GDP films were measured by nanoindentation. It is found that when work pressure and T₂B/H₂ flow ratio gradually decrease, SP³(CH₃)group decreases, while SP²(CH₂)and SP³(CH_1,2)group increase in the GDP films. The hardness and modulus of GDP films increase with decreasing pressure and T₂B/H₂ flow ratio. The hardness and modulus of GDP films are mainly influenced by such factors as SP³(CH₃)group, branched chain,double bond content and degree of cross-linking of carbon network in GDP films. (authors)

[en] Highlights: • Nonprecious coral-like cobaltous sulfide/N,S-codoped carbon with hierarchical pores was synthesized. • The ORR activities of Co_xS_y/NS-HPC synthesized in different molar ratio of S:Co were investigated by CV and RRDE. • The catalyst CoS_1.097/NS-HPC synthesized with S:Co of 3:1 exhibits the best ORR performance. • CoS_1.097/NS-HPC is superior to Pt/C in limiting current density, durability and methonal tolerance. To develop efficient nonprecious electrocatalysts for the oxygen reduction reaction (ORR) on cathode in fuel cell is urgently required. Herein, a promising coral-like N,S-codoped hierarchical porous carbon with supported cobaltous sulfide nanoparticles (Co_xS_y/NS-HPC) with different molar ratio of S:Co was successfully fabricated via an economic method. The role of thiourea in the preparation process was found to be triplex. It is not only as a sulfur source, but also as sulfur-nitrogen dopant, and most importantly it participates in the formation of the hierarchical porous carbon which will reduce the diffusion resistance of the reactants and expose more active sites. Benefited from the carbon support, the hybrid architecture CoS_1.097/NS-HPC (S:Co = 3:1) possesses high specific surface area (549 m²/g) and more active sites, as result it was developed as decent ORR electrocatalyst for fuel cell. Surprisingly, we found that CoS_1.097/NS-HPC provides a more positive onset potential, higher cathodic current density and half-wave potential in alkaline media than CoS_1.097 NPs and CoS_1.097 supported on conventional mesoporous carbon (CoS_1.097/MC). More importantly, compared with commercial Pt/C, CoS_1.097/NS-HPC manifests higher current density, better durability, and more excellent methanol tolerance.