查看更多>>摘要：Biomass carbon has the advantage of a wide spectral absorption range,which makes it great potential for solar thermal utilization.In this study,porous skeleton support materials of sugarcane-derived carbon were prepared by freeze-drying-high-temperature carbonization method using natural sugarcane as raw material,and the characterization results demonstrate that the porous skeleton of sugarcane-derived carbon has outstanding porous support properties.By combining CuS with sugarcane-derived carbon,a porous material with outstanding photo-thermal conversion performance was synthesized.Four photo-thermal composite phase change materials(CPCMs)were prepared,the maximum loading mass of the support material C600 to the phase change materials(PCMs)reached 79.77％.The C600-CuS-OC had excellent thermal storage properties with an enthalpy of melting of 276.3 J/g and a thermal conductivity of 0.61 W·m-1·K-1.The photo-thermal conversion efficiency of C600-CuS-OC was 83.2％.Sugarcane carbon-based CPCMs are a low-cost and high-efficiency solar thermal storage material,which has great potential for applications in solar thermal storage,biomass utilization,and thermal management.
查看更多>>摘要：Dead-ended proton exchange membrane fuel cells(PEMFC)using pure hydrogen oxygen can improve fuel effi-ciency and simplify fuel cell systems have been wildly used for a closed space.But the dead-ended operation of the PEMFC will cause difficulties in water management,especially in the cathode side,resulting in deteriorating of fuel cell stability.For this reason,gravity assisted drainage method,static drainage method are designed to migrate the water out of the cell.However,even with these methods,the reliability of the water removing from the cell remains questionable.Therefore,this paper introduces a novel water removal method to solve these problems and visualisation techniques were used to a more comprehensive knowledge of water transport mechanisms in dead-ended PEMFCs.A pressure-swing operation is realized by controlling the inlet of PEMFC solenoid valve to remove water and recycle oxygen during purging.The dynamic response characteristics of this system under different current densities,pressure differences,cell temperature and purging intervals are exper-imentally investigated in detail.It found that the water removal rate of the cathode flow channel of dead-ended PEMFC was as high as 99.25％,and the fuel utilisation of the cell was close to 100％in this water management mode.
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