Clean-energy substitution technology for existing residential buildings in cities is an inevitable choice for sustainable development and low-carbon ecological city construction.In this paper,the current status of ene...Clean-energy substitution technology for existing residential buildings in cities is an inevitable choice for sustainable development and low-carbon ecological city construction.In this paper,the current status of energy-saving renovation and renewable-energy applications for existing residential buildings in various cities in China was summarized by using statistical methods.The geographical distribution of clean-energy power generation in primary energy production in China was explored in depth.According to different climatic divisions for existing urban residences,clean-energy production and consumption were analyzed and predicted based on the STIRPAT model.The results show that the energy consumption of urban residential buildings in 2016 increased by 43.6%compared with 2009,and the percentage of clean energy also increased from 7.9%to 13.4%.Different climatic regions have different advantages regarding clean energy:nuclear power generation leads in the region that experiences hot summers and warm winters,whereas wind and solar power generation lead in the cold and severely cold regions.The present results provide basic data support for the planning and implementation of clean-energy upgrading and transformation systems in existing urban residences in China.展开更多
At high tem perature, the oxide redox reactions of ceria can split H2O and CO2 to produce H2 and CO, so porous ceria with high temperature resistance and high specific surface area has an important foreground in clean...At high tem perature, the oxide redox reactions of ceria can split H2O and CO2 to produce H2 and CO, so porous ceria with high temperature resistance and high specific surface area has an important foreground in clean energy applications. In this work, a reticulated porous ceria ceramic material with interconnected porous structure was prepared by the impregnation technique using organic polyurethane sponges as template. The influences of pretreated sponge, dipping time length, pore size and sintering temperature on the porosity and strength of the porous ceria ceramics were system atically studied. With the increasing sintering temperature, the glass phase occurred and led to an increase in strength, but an decrease in porosity. Eventually, we analyzed the relationships betw een porosity and strength of these porous materials, aiming to provide theoretical and practical references for its application in clean-energy field.展开更多
The wireless electric vehicle(EV) charging system is highly safe and flexible. To reduce the weight and cost of EVs, the wireless charging system, which simplifies the structure inside an EV and utilizes the transmitt...The wireless electric vehicle(EV) charging system is highly safe and flexible. To reduce the weight and cost of EVs, the wireless charging system, which simplifies the structure inside an EV and utilizes the transmitter-side control method, has become popular. This study investigates the transmitter-side control methods in a wireless EV charging system. First, a universal wireless charging system is introduced, and the function of its transfer power is derived. It is observed that the transfer power can be controlled by regulating either the phase-shift angle or the DC-link voltage. Further, the influence of the control variables is studied using numerical analysis. Additionally, the corresponding control methods, namely the phase-shift angle and the DC-link voltage control, are compared by calculation and simulation. It is found that:(1) the system efficiency is low with the phase-shift control method because of the converter switching loss;(2) the dynamic response is slow with the DC-link voltage control method because of the large inertia of the inductor and capacitor;(3) both the control methods have limitations in their adjustable power range. Therefore, a combined control method is proposed, with the advantages of high system efficiency, fast dynamic response, and wide adjustable power range. Finally, experiments are performed to verify the validity of the theoretical analysis and the effectiveness of the proposed method. This study provides a detailed and comprehensive analysis of the transmitter-side control methods in the wireless charging system, considering the sensitivity of parameters, converter losses, system efficiency,and dynamic performance, with the dead-time effect taken into consideration. Moreover, the proposed control method can be used to realize the optimal combination of the phase-shift angle and the DC-link voltage with good dynamic performance, and it is useful for the optimal operation of the wireless charging system.展开更多
基金This research was funded by the National Key Research and Development Plan(2018YFC0704800).
文摘Clean-energy substitution technology for existing residential buildings in cities is an inevitable choice for sustainable development and low-carbon ecological city construction.In this paper,the current status of energy-saving renovation and renewable-energy applications for existing residential buildings in various cities in China was summarized by using statistical methods.The geographical distribution of clean-energy power generation in primary energy production in China was explored in depth.According to different climatic divisions for existing urban residences,clean-energy production and consumption were analyzed and predicted based on the STIRPAT model.The results show that the energy consumption of urban residential buildings in 2016 increased by 43.6%compared with 2009,and the percentage of clean energy also increased from 7.9%to 13.4%.Different climatic regions have different advantages regarding clean energy:nuclear power generation leads in the region that experiences hot summers and warm winters,whereas wind and solar power generation lead in the cold and severely cold regions.The present results provide basic data support for the planning and implementation of clean-energy upgrading and transformation systems in existing urban residences in China.
基金financial supports from the fund of the State Key Laboratory of Solidification Processing in NWPU (SKLSP201704)
文摘At high tem perature, the oxide redox reactions of ceria can split H2O and CO2 to produce H2 and CO, so porous ceria with high temperature resistance and high specific surface area has an important foreground in clean energy applications. In this work, a reticulated porous ceria ceramic material with interconnected porous structure was prepared by the impregnation technique using organic polyurethane sponges as template. The influences of pretreated sponge, dipping time length, pore size and sintering temperature on the porosity and strength of the porous ceria ceramics were system atically studied. With the increasing sintering temperature, the glass phase occurred and led to an increase in strength, but an decrease in porosity. Eventually, we analyzed the relationships betw een porosity and strength of these porous materials, aiming to provide theoretical and practical references for its application in clean-energy field.
基金supported by the International Science and Technology Cooperation Program of China(Grant No.2016YFE0102200)
文摘The wireless electric vehicle(EV) charging system is highly safe and flexible. To reduce the weight and cost of EVs, the wireless charging system, which simplifies the structure inside an EV and utilizes the transmitter-side control method, has become popular. This study investigates the transmitter-side control methods in a wireless EV charging system. First, a universal wireless charging system is introduced, and the function of its transfer power is derived. It is observed that the transfer power can be controlled by regulating either the phase-shift angle or the DC-link voltage. Further, the influence of the control variables is studied using numerical analysis. Additionally, the corresponding control methods, namely the phase-shift angle and the DC-link voltage control, are compared by calculation and simulation. It is found that:(1) the system efficiency is low with the phase-shift control method because of the converter switching loss;(2) the dynamic response is slow with the DC-link voltage control method because of the large inertia of the inductor and capacitor;(3) both the control methods have limitations in their adjustable power range. Therefore, a combined control method is proposed, with the advantages of high system efficiency, fast dynamic response, and wide adjustable power range. Finally, experiments are performed to verify the validity of the theoretical analysis and the effectiveness of the proposed method. This study provides a detailed and comprehensive analysis of the transmitter-side control methods in the wireless charging system, considering the sensitivity of parameters, converter losses, system efficiency,and dynamic performance, with the dead-time effect taken into consideration. Moreover, the proposed control method can be used to realize the optimal combination of the phase-shift angle and the DC-link voltage with good dynamic performance, and it is useful for the optimal operation of the wireless charging system.
