Hongli Chen

The direct liquefaction of sawdust in tetralin

Abstract Hydrogen liquefaction of sawdust in tetralin was performed in an autoclave at below conditions: temperature range from 200°C to 350°C; initial cool hydrogen pressure range from 4 to 10 MPa; reaction time range from 10 to 100 min. The effect of variables on the process of sawdust liquefaction was examined. The results indicate that the oil yield may range from 6.8 to 67.1% at different liquefaction conditions. Temperature has a remarkable effect than initial cool hydrogen pressure and reaction time on the process of sawdust liquefaction. With increasing temperature (200°C–350°C) the conversion, gas yield, H2 consumption and oil yield are all increased, but the yield of preasphaltene and asphaltene (PA + A) increases first (200°C–300°C) and then decreases (300°C–350°C). The high heating value of the products is higher than that of the feedstock. With the increase in initial cool H2 pressure (4–10 MPa), the conversion and gas yield are almost unchanged, the oil yield increases (36.86–57.06%), while the yield of PA + A decreases (28.07–16.27%). With increasing reaction time (10–100 min), both the conversion and the product distribution change little. The existence of H2 or tetralin improves both the conversion of sawdust and the oil yield.

Characteristics of edge pedestals in LHW and NBI heated H-mode plasmas on EAST

By using the recently developed Thomson scattering diagnostic, the pedestal structure of the H-mode with neutral beam injection (NBI) or/and lower hybrid wave (LHW) heating on EAST (Experimental Advanced Superconducting Tokamak) is analyzed in detail. We find that a higher ratio of the power of the NBI to the total power of the NBI and the lower hybrid wave (LHW) will produce a large and regular different edge-localized mode (ELM), and a lower ratio will produce a small and irregular ELM. The experiments show that the mean pedestal width has good correlation with , The pedestal width appears to be wider than that on other similar machines, which could be due to lithium coating. However, it is difficult to draw any conclusion of correlation between ρ * and the pedestal width for limited ρ * variation and scattered distribution. It is also found that T e/ T e is ~2 cm, which is the same as the AUG (ASDEX Upgrade), DIII-D and JET (Joint European Torus) results.

Preliminary safety analysis for the Chinese ITER Dual Functional Lithium–Lead Test Blanket Module

Safety analysis is part of the ITER Test Blanket Module (TBM) design process ensuring that the TBM does not adversely affect the safety of ITER. To get the licence for TBM as a whole with ITER, relevant safety analysis is required for each TBM system proposed by each party. The safety analysis for the Chinese Dual Functional Lithium–Lead Test Blanket Module (DFLL-TBM) has been performed based on the latest DFLL-TBM design. In this paper, the following safety considerations, such as source terms, operational releases, accident sequence analyses and waste assessment, were analysed. Both the deterministic approach and the complementary systematic approach starting with failure mode and effects analysis studies were adopted in the accidental analysis. The preliminary results showed that the DFLL-TBM system at normal operating conditions and under accident scenarios did not add additional safety hazards to the ITER machine and could meet the ITER safety requirements and additional safety requirements for the TBM system.

Determination of the Mode of Occurrence of As, Cr, and Hg in Three Chinese Coal Samples by Sequential Acid Leaching

Abstract Sequential acid leaching was used to leach minerals and the trace elements they contain. One-step leaching uses concentrated nitric acid as solvent, while three-step leaching uses 5M hydrochloric acid, concentrated hydrofluoric acid, and concentrated hydrochloric acid as solvents. The sequential acid leaching by three-and one-step leach was also examined. The results showed that one-step leaching could leach over 80% of arsenic from coal samples, and also could leach mercury to a certain degree. During one-step leaching, little chromium is removed, but it is available to leach by three-step leaching; and during the sequential acid leaching by three- and one-step leaching, almost 98% of ash is leached. The result of acid leaching could also give detailed information on mode of occurrence of As, Cr, and Hg, which could be classified into: silicate association, pyrite association, organic association, and carbonates and sulfates association. Over half of chromium in the three coals is associated with organic matters and the rest is associated with silicates. The mode of occurrence of arsenic and mercury is mainly associated with different mineral matters depending on the coal samples studied.

The synergistic effect between coal macerals during hydropyrolysis

Abstract Using TGA technology, the volatile matter yields during hydropyrolysis of Chinese Shenmu coal and its derived high purity macerals under different heating rates and pressures were investigated. The Δ W, calculated by the difference between the volatile matter yield of parent coal and that of macerals, is used to evaluate the synergistic effect of macerals during hydropyrolysis. The results showed that with increasing pressure and decreasing heating rate, the Δ W increases. At temperature of 500°C and pressure of 3 MPa, the difference of volatile matter yield between parent coal and vitrinite reaches the maximum and the Δ W also occurs the highest value of 14.1%, suggesting the existence of the synergistic effect between macerals during hydropyrolysis. Based on the structural characteristics of macerals and the basic knowledge of hydropyrolysis, the possible explanation for the synergism are proposed.

Effect of FCI Electrical Conductivity on MHD Flow in Channels With Multi-Layer Inserts for Fusion Blanket

Fusion blanket is a key component for energy transformation and extraction in fusion reactor, in many kinds of blanket designs, the flow channel insert (FCI) made of a silicon carbide composite (SiCf/SiC) is a key element, which serves as electric and thermal insulator. In the high temperature liquid metal blanket (HTL) of fusion-based hydrogen production reactor (named FDS-III),. The multilayer flow channel inserts (MFCI) are put into the breeding zone to achieve the LiPb outlet temperature around 1000°C for high efficient production of hydrogen. However, the flow of liquid metal meandering through MFCI will cause strong magnetohydrodynamic (MHD) effect under the influence of the intense fusion magnetic field and the liquid metal in the neighboring channels will effect each other. When the FCI conductivity varies, the influence varies coresspondingly. So MHD effect of different FCI electrical conductivity is a key issue which should be concerned in HTL blanket.In this work, the numerical study aims at clarifying the MHD effect for liquid metal LiPb in the multi-layer flow channel inserts of different conductivity by using a code named MTC-H 2.0. The MHD flows with Special geometry of the HTL flow channels with MFCI were considered, velocity and FCI electrical conductivity’s effect on electromagnetic coupling are discussed.Copyright

CFD Analysis of Circumferential Temperature Distribution on Fuel Cladding Surface of China Lead Alloy Cooled Research Reactor (CLEAR-I)

Because of heterogeneity of sub-channels geometry, a circumferential temperature distribution will exit in the fuel cladding surface during operating condition of a nuclear reactor, which will increase the maximum cladding surface temperature (MCST). However, this phenomenon cannot be obtained in single channel or sub-channel analyses approach. Computational Fluid Dynamics (CFD) is a good method to study this problem. In this paper, the circumferential temperature distribution on the fuel cladding surface of different sub-channels of China Lead-Alloy Cooled Research Reactor (CLEAR-I) were studied using FLUENT 14.0. Obvious circumferential temperature distributions were presented in results and the maximum circumferential temperature difference is 13°C in edge-channels. This study will improve the precision in the MCST calculation of CLEAR-I and be a good guideline to the optimum design of CLEAR-I sub-channels configurations.Copyright

NUMERICAL ANALYSIS OF MHD FLOW IN A POLOIDAL CHANNEL OF THE CHINESE DFLL-TBM WITH A FLOW CHANNEL INSERT

Abstract A Chinese dual-functional lithium lead test blanket module was proposed for testing in ITER. The flow channel insert (FCI) was inserted in LiPb flow channels to reduce magnetohydrodynamic (MHD) effects and to increase the outlet temperature of coolant LiPb. The FCI has a big influence on the LiPb flow characteristics under the high magnetic field. In this paper, the LiPb MHD flow characteristics both in the gap between the FCI and the channel wall and inside the FCI was numerically calculated using an MHD code named MTC-H 2.0 in a poloidal channel. The influence of the FCI on flow distribution was analyzed. The pressure drop was compared to the case without the FCI, and the pressure equalization was assessed for both sides of the FCI with pressure equalization openings. The impact of electrical conductivity of the FCI material was analyzed.