Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the thr...Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.展开更多
Thermodynamic concepts required for the thermodynamic calculation of the potentials of electrodes for high temperature applications are briefly reviewed. A thermodynamic approach to the calculation of half cell potent...Thermodynamic concepts required for the thermodynamic calculation of the potentials of electrodes for high temperature applications are briefly reviewed. A thermodynamic approach to the calculation of half cell potentials and the standard chemical potential of an electron at high temperatures which are related to the Standard Hydrogen Electrode(SHE) is discussed. As examples, an external Ag/AgCl reference electrode and a YSZ(Ag|O_2) pH sensor for high temperature applications are analyzed by using the thermodynamic approach to derive a high temperature pH measurement equation. The two electrodes are employed to measure high temperature pH and the measured pH was compared with the calculated pH by using a solution chemistry method. Concepts and principles for electrode kinetics are also briefly introduced and a modification to the Tafel equations is suggested.展开更多
The receiver is an important element in solar energy plants.The principal receiver’s tubes in power plants are devised to work under extremely severe conditions,including excessive heat fluxes.Half of the tube’s cir...The receiver is an important element in solar energy plants.The principal receiver’s tubes in power plants are devised to work under extremely severe conditions,including excessive heat fluxes.Half of the tube’s circumference is heated whilst the other half is insulated.This study aims to improve the heat transfer process and reinforce the tubes’structure by designing a new receiver;by including longitudinal fins of triangular,circular and square shapes.The research is conducted experimentally using Reynolds numbers ranging from 28,000 to 78,000.Triangular fins have demonstrated the best improvement for heat transfer.For Reynolds number value near 43,000 Nusselt number(Nu)is higher by 3.5%and 7.5%,sequentially,compared to circular and square tube fins,but varies up to 6.5%near Re=61000.The lowest friction factor is seen in a triangular fin receiver;where it deviates from circular fins by 4.6%,and square fin tubes by 3.2%.Adding fins makes the temperature decrease gradually,and in the case of no fins,the temperature gradient between the hot tube and water drops sharply in the planed tube by 7%.展开更多
The safety of lithium-ion batteries is an essential concern where instant and accurate temperature sensing is critical.It is generally desired to put sensors inside batteries for instant sensing.However,the transmissi...The safety of lithium-ion batteries is an essential concern where instant and accurate temperature sensing is critical.It is generally desired to put sensors inside batteries for instant sensing.However,the transmission of internal measurement outside batteries without interfering their normal state is a non-trivial task due to the harsh electrochemical environment,the particular packaging structures and the intrinsic electromagnetic shielding problems of batteries.In this work,a novel in-situ temperature sensing framework is proposed by incorporating temperature sensors with a novel signal transmission solution.The signal transmission solution uses a self-designed integrated-circuit which modulates the internal measurements outside battery via its positive pole without package breaking.Extensive experimental results validate the noninterference properties of the proposed framework.Our proposed in-situ temperature measurement by the self-designed signal modulation solution has a promising potential for in-situ battery health monitoring and thus promoting the development of smart batteries.展开更多
High-temperature warnings frequently occurred at the Power Distribution System(PDS)of the Alpha Magnetic Spectrometer(AMS).To investigate the fundamental reasons,a theoretical model for the AMS PDS was established und...High-temperature warnings frequently occurred at the Power Distribution System(PDS)of the Alpha Magnetic Spectrometer(AMS).To investigate the fundamental reasons,a theoretical model for the AMS PDS was established under the International Space Station(ISS)normal and special operating conditions.With the model,the study investigated the external heat fluxes and the temperature responses of the PDS.The effects of ISS special operations on the PDS’s thermal environment were also investigated.Results reveal that the total external heat flux at the PDS reaches its maximum value when the angleβis around–25°,where high-temperature warning frequently occurs.Under the ISS normal operating condition,the temperature response hysteresis at the PDS varies from 116 s to 230 s.When the ISS performed special operations,locking the ISS solar arrays had the greatest influence on the PDS’s external heat fluxes,and the average temperature at the PDS fell by 1.7°C.When the ISS performed multiple special operations,simultaneously locking the ISS solar arrays and adjusting the ISS flight attitude were the most frequent operations,of which the influences on the PDS temperature were the largest,i.e.,the changes in peak temperature reached up to+2.5°C.展开更多
基金Key project from the Natural Science Foundation of China (59836250)
文摘Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.
文摘Thermodynamic concepts required for the thermodynamic calculation of the potentials of electrodes for high temperature applications are briefly reviewed. A thermodynamic approach to the calculation of half cell potentials and the standard chemical potential of an electron at high temperatures which are related to the Standard Hydrogen Electrode(SHE) is discussed. As examples, an external Ag/AgCl reference electrode and a YSZ(Ag|O_2) pH sensor for high temperature applications are analyzed by using the thermodynamic approach to derive a high temperature pH measurement equation. The two electrodes are employed to measure high temperature pH and the measured pH was compared with the calculated pH by using a solution chemistry method. Concepts and principles for electrode kinetics are also briefly introduced and a modification to the Tafel equations is suggested.
文摘The receiver is an important element in solar energy plants.The principal receiver’s tubes in power plants are devised to work under extremely severe conditions,including excessive heat fluxes.Half of the tube’s circumference is heated whilst the other half is insulated.This study aims to improve the heat transfer process and reinforce the tubes’structure by designing a new receiver;by including longitudinal fins of triangular,circular and square shapes.The research is conducted experimentally using Reynolds numbers ranging from 28,000 to 78,000.Triangular fins have demonstrated the best improvement for heat transfer.For Reynolds number value near 43,000 Nusselt number(Nu)is higher by 3.5%and 7.5%,sequentially,compared to circular and square tube fins,but varies up to 6.5%near Re=61000.The lowest friction factor is seen in a triangular fin receiver;where it deviates from circular fins by 4.6%,and square fin tubes by 3.2%.Adding fins makes the temperature decrease gradually,and in the case of no fins,the temperature gradient between the hot tube and water drops sharply in the planed tube by 7%.
基金This work was supported by the Beijing Municipal Science and Technology Commission(Grant Z191100002719007)the National Natural Science Foundation of China(Grant 11672341).
文摘The safety of lithium-ion batteries is an essential concern where instant and accurate temperature sensing is critical.It is generally desired to put sensors inside batteries for instant sensing.However,the transmission of internal measurement outside batteries without interfering their normal state is a non-trivial task due to the harsh electrochemical environment,the particular packaging structures and the intrinsic electromagnetic shielding problems of batteries.In this work,a novel in-situ temperature sensing framework is proposed by incorporating temperature sensors with a novel signal transmission solution.The signal transmission solution uses a self-designed integrated-circuit which modulates the internal measurements outside battery via its positive pole without package breaking.Extensive experimental results validate the noninterference properties of the proposed framework.Our proposed in-situ temperature measurement by the self-designed signal modulation solution has a promising potential for in-situ battery health monitoring and thus promoting the development of smart batteries.
基金support from Shandong Universitysponsored by the Fundamental Research Fund of Shandong University,China。
文摘High-temperature warnings frequently occurred at the Power Distribution System(PDS)of the Alpha Magnetic Spectrometer(AMS).To investigate the fundamental reasons,a theoretical model for the AMS PDS was established under the International Space Station(ISS)normal and special operating conditions.With the model,the study investigated the external heat fluxes and the temperature responses of the PDS.The effects of ISS special operations on the PDS’s thermal environment were also investigated.Results reveal that the total external heat flux at the PDS reaches its maximum value when the angleβis around–25°,where high-temperature warning frequently occurs.Under the ISS normal operating condition,the temperature response hysteresis at the PDS varies from 116 s to 230 s.When the ISS performed special operations,locking the ISS solar arrays had the greatest influence on the PDS’s external heat fluxes,and the average temperature at the PDS fell by 1.7°C.When the ISS performed multiple special operations,simultaneously locking the ISS solar arrays and adjusting the ISS flight attitude were the most frequent operations,of which the influences on the PDS temperature were the largest,i.e.,the changes in peak temperature reached up to+2.5°C.
