Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device usin...Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device using by-products from the steel industry as heat storage materials, similar to a battery cell, which is easily scalable and accomplishes the steam-solid particle-steam energy conversion. Investigation parameters include temperature distribution, power variation, and cycle efficiency for different charging and discharging modes. Results indicate that the charging mode II outperforms mode I in temperature uniformity, charging flow rate, and pressure loss, yielding higher charging power and total convective heat transfer coefficients at 13 kW and 275 W/(m^(2) K), respectively. The pilot device demonstrates commendable insulating properties. Its heat dissipation rate is approximately 33.33%, which surpasses that of reported thermal storage devices. Moreover, the mode II exhibits superior temperature non-uniformity during heat release, ensuring that 40 kg/h of superheated steam at 220 ℃ can be produced continuously for 5 min. The cycling efficiency is noteworthy, reaching 65% in low flow rate discharge, accompanied by 79% charging efficiency and 82% discharging efficiency. A temperature difference cloud map elucidates the primary phase change region, emphasizing preheating, evaporation, and superheating segments. Experimental results provide new ideas for combining waste elimination in the steel industry and energy storage in thermal power plants.展开更多
Electrocatalytic nitrogen reduction reaction(NRR)is regarded as a potential routine to achieve environment-friendly ammonia production,because of its abundant nitrogen resources,clean energy utilization and flexible o...Electrocatalytic nitrogen reduction reaction(NRR)is regarded as a potential routine to achieve environment-friendly ammonia production,because of its abundant nitrogen resources,clean energy utilization and flexible operation.However,it is hindered by low activity and selectivity,in which con-dition well-designed catalysts are urgently in need.In this work,a binary Mo/Ir nanodots/carbon(Mo/Ir/C)hetero-material is efficiently constructed via microfluidic strategy,of which the nanodots are ho-mogeneously distributed on the carbon skeleton and the average size is approximately 1 nm.Excellent performance for NRR is obtained in 1 mol L^(-1) KOH,of which the optimized ammonia yield and faradic efficiency are 7.27μg h^(-1) cm^(-2) and 2.31%respectively.Moreover,the optimized ammonia yield of 6.20μg h-1 cm-2 and faradic efficiency of 10.59%are also obtained in 0.005 mol L^(-1) H_(2)SO_(4).This work achieves the continuous-flow synthesis and controllable adjustment of hetero-materials for favorable morphologies,which provides an innovative pathway for catalyst design and further promotes the development of ammonia production field.展开更多
Printing of metal bottom back electrodes of flexible organic solar cells（FOSCs） at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to ac...Printing of metal bottom back electrodes of flexible organic solar cells（FOSCs） at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to achieve because often the interfacial properties of those printed electrodes, including conductivity, roughness, work function,optical and mechanical flexibility, cannot meet the device requirement at the same time. In this work, we fabricate printed Ag and Cu bottom back cathodes by a low-temperature solution technique named polymer-assisted metal deposition（PAMD） on flexible PET substrates. Branched polyethylenimine（PEI） and ZnO thin films are used as the interface modification layers（IMLs） of these cathodes. Detailed experimental studies on the electrical, mechanical, and morphological properties, and simulation study on the optical properties of these IMLs are carried out to understand and optimize the interface of printed cathodes. We demonstrate that the highest power conversion efficiency over 3.0% can be achieved from a full-solution processed OFSC with the device structure being PAMDAg/PEI/P3 HT：PC61BM/PH1000. This device also acquires remarkable stability upon repeating bending tests.展开更多
基金This work was supported by the Fundamental Research Funds for the Central Universities(grant No.2022ZFJH04)。
文摘Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device using by-products from the steel industry as heat storage materials, similar to a battery cell, which is easily scalable and accomplishes the steam-solid particle-steam energy conversion. Investigation parameters include temperature distribution, power variation, and cycle efficiency for different charging and discharging modes. Results indicate that the charging mode II outperforms mode I in temperature uniformity, charging flow rate, and pressure loss, yielding higher charging power and total convective heat transfer coefficients at 13 kW and 275 W/(m^(2) K), respectively. The pilot device demonstrates commendable insulating properties. Its heat dissipation rate is approximately 33.33%, which surpasses that of reported thermal storage devices. Moreover, the mode II exhibits superior temperature non-uniformity during heat release, ensuring that 40 kg/h of superheated steam at 220 ℃ can be produced continuously for 5 min. The cycling efficiency is noteworthy, reaching 65% in low flow rate discharge, accompanied by 79% charging efficiency and 82% discharging efficiency. A temperature difference cloud map elucidates the primary phase change region, emphasizing preheating, evaporation, and superheating segments. Experimental results provide new ideas for combining waste elimination in the steel industry and energy storage in thermal power plants.
基金supported by the National Natural Science Foundation of China(grant Nos.22025801 and 22208190)National Postdoctoral Program for Innovative Talents(grant No.BX2021146)Shuimu Tsinghua Scholar Program(grant No.2021SM055).
文摘Electrocatalytic nitrogen reduction reaction(NRR)is regarded as a potential routine to achieve environment-friendly ammonia production,because of its abundant nitrogen resources,clean energy utilization and flexible operation.However,it is hindered by low activity and selectivity,in which con-dition well-designed catalysts are urgently in need.In this work,a binary Mo/Ir nanodots/carbon(Mo/Ir/C)hetero-material is efficiently constructed via microfluidic strategy,of which the nanodots are ho-mogeneously distributed on the carbon skeleton and the average size is approximately 1 nm.Excellent performance for NRR is obtained in 1 mol L^(-1) KOH,of which the optimized ammonia yield and faradic efficiency are 7.27μg h^(-1) cm^(-2) and 2.31%respectively.Moreover,the optimized ammonia yield of 6.20μg h-1 cm-2 and faradic efficiency of 10.59%are also obtained in 0.005 mol L^(-1) H_(2)SO_(4).This work achieves the continuous-flow synthesis and controllable adjustment of hetero-materials for favorable morphologies,which provides an innovative pathway for catalyst design and further promotes the development of ammonia production field.
基金supported by the Research Grant Council of Hong Kong(No.PolyUC5015-15G)the Hong Kong Polytechnic University(No.G-SB06)the National Natural Science Foundation of China(Nos.21125316,21434009,51573026)
文摘Printing of metal bottom back electrodes of flexible organic solar cells（FOSCs） at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to achieve because often the interfacial properties of those printed electrodes, including conductivity, roughness, work function,optical and mechanical flexibility, cannot meet the device requirement at the same time. In this work, we fabricate printed Ag and Cu bottom back cathodes by a low-temperature solution technique named polymer-assisted metal deposition（PAMD） on flexible PET substrates. Branched polyethylenimine（PEI） and ZnO thin films are used as the interface modification layers（IMLs） of these cathodes. Detailed experimental studies on the electrical, mechanical, and morphological properties, and simulation study on the optical properties of these IMLs are carried out to understand and optimize the interface of printed cathodes. We demonstrate that the highest power conversion efficiency over 3.0% can be achieved from a full-solution processed OFSC with the device structure being PAMDAg/PEI/P3 HT：PC61BM/PH1000. This device also acquires remarkable stability upon repeating bending tests.
