With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capabil...With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capability and excellent electromagnetic interference(EMI)shielding performance.Herein,an innovative biomass/MXene-derived conductive hybrid scaffold,cellulose nanocrystal(CNC)-konjac glucomannan(KGM)/MXene(CKM),was prepared by freeze-drying and thermal annealing,and then paraffin wax(PW)was encapsulated in CKM using vacuum impregnation method to obtain CNC-KGM/MXene@PW phase change composites(CKMPCCs).The results show that the obtained CKMPCCs possess considerable reusable stabilities,excellent EMI shielding properties,and thermal energy management capacities.Among them,the CKMPCC-6 with 2.3 wt.%MXene exhibits excellent solar-thermal and electro-thermal conversion capabilities.In addition,the EMI shielding effectiveness value is as high as 45.0 dB at 8.2–12.4 GHz and the corresponding melting enthalpy value is 215.7 J/g(relative enthalpy efficiency of 99.9%).In conclusion,the synthesized multifunctional phase change composites provide great potential for integrating outstanding EMI shielding and advanced thermal energy management applications.展开更多
After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust he...After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data： distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV （photovoltaic） panel, PCM （phase change material）, thermal storage, FCU （fan coil unit） and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.展开更多
基金the National Natural Science Foundation of China(No.U20A20299)Y.C.acknowledges the support from Guangdong Special Support Program(No.2017TX04N371).
文摘With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capability and excellent electromagnetic interference(EMI)shielding performance.Herein,an innovative biomass/MXene-derived conductive hybrid scaffold,cellulose nanocrystal(CNC)-konjac glucomannan(KGM)/MXene(CKM),was prepared by freeze-drying and thermal annealing,and then paraffin wax(PW)was encapsulated in CKM using vacuum impregnation method to obtain CNC-KGM/MXene@PW phase change composites(CKMPCCs).The results show that the obtained CKMPCCs possess considerable reusable stabilities,excellent EMI shielding properties,and thermal energy management capacities.Among them,the CKMPCC-6 with 2.3 wt.%MXene exhibits excellent solar-thermal and electro-thermal conversion capabilities.In addition,the EMI shielding effectiveness value is as high as 45.0 dB at 8.2–12.4 GHz and the corresponding melting enthalpy value is 215.7 J/g(relative enthalpy efficiency of 99.9%).In conclusion,the synthesized multifunctional phase change composites provide great potential for integrating outstanding EMI shielding and advanced thermal energy management applications.
文摘After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data： distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV （photovoltaic） panel, PCM （phase change material）, thermal storage, FCU （fan coil unit） and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.
