A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building...A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building： Xijindu exhibition hall, which is located in Zhenjiang city in China. Numerical studies on the thermal comfort and energy consumption of the system are carded out by using TRNSYS software. The results indicate that the system with the radiant floor method or the radiant ceiling method shows good thermal comfort without mechanical ventilation in winter. However, the system with either of the methods should add mechanical ventilation to ensure good comfort in summer. At the same level of thermal comfort, it can also be found that the annual energy consumption of the radiant ceiling system is less than that of the radiant floor system.展开更多
Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied ....Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.展开更多
In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in pr...In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in preparing them as thermoelectric materials. Structure and phase composition of the obtained materials were investigated by X-ray diffraction （XRD）. The electrical conductivity, Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K. It is found that Mg2Si1-xSnx solid solutions are well formed with excessive content of 5% （molar fraction） Mg from the stoichiometric MgESil.xSnx under microwave irradiation. A maximum dimensionless figure of merit, ZT, of about 0.26 is obtained for Mg2Si1-xSnx solid solutions at about 500 K for x=0.6.展开更多
Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently availa...Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics ~f thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.展开更多
A combined conduction and radiation heat transfer model was used to simulate the heat transfer within wafer and investigate the effect of thermal transport properties on temperature non-uniformity within wafer surface...A combined conduction and radiation heat transfer model was used to simulate the heat transfer within wafer and investigate the effect of thermal transport properties on temperature non-uniformity within wafer surface. It is found that the increased conductivities in both doped and undoped regions help reduce the temperature difference across the wafer surface. However, the doped layer conductivity has little effect on the overall temperature distribution and difference. The temperature level and difference on the top surface drop suddenly when absorption coefficient changes from 104 to 103 m-1. When the absorption coefficient is less or equal to 103 m-1, the temperature level and difference do not change much. The emissivity has the dominant effect on the top surface temperature level and difference. Higher surface emissivity can easily increase the temperature level of the wafer surface. After using the improved property data, the overall temperature level reduces by about 200 K from the basis case. The results will help improve the current understanding of the energy transport in the rapid thermal processing and the wafer temperature monitor and control level.展开更多
Based on particles in a dynamical geometry, extending the Parikh ＇s method of quantum tunneling, radiation, we deeply investigate the quantum tunneling radiation of Kerr-NUT bhck hole. When self-gravitating action, e...Based on particles in a dynamical geometry, extending the Parikh ＇s method of quantum tunneling, radiation, we deeply investigate the quantum tunneling radiation of Kerr-NUT bhck hole. When self-gravitating action, energy conservation, and angular momentum conservation are taken into account, the emission rate of the particle on the event horizon is related to the change of Bekenstein-Hawking entropy and the emission spectrum is not precisely thermal, but is consistent with an underlying unitary theory.展开更多
From the viewpoint of field synergy principle and dipole radiation theory, the interaction between the incident thermal radiation wave and materials is analyzed to reveal the mechanism of selective absorption of incid...From the viewpoint of field synergy principle and dipole radiation theory, the interaction between the incident thermal radiation wave and materials is analyzed to reveal the mechanism of selective absorption of incident thermal radiation. It is shown that the frequency of the incident thermal radiation and the damping constant of damping oscillators in materials are of vital importance for the thermal radiation properties (reflectivity, absorptivity, transmissivity, etc.) of materials.展开更多
We simulated the heat transfer phenomena of the heating module that is primarily based on the radiant energy in the near-infra-red(NIR) domain.In the module,the power emitted by the lamp filament is distributed to the...We simulated the heat transfer phenomena of the heating module that is primarily based on the radiant energy in the near-infra-red(NIR) domain.In the module,the power emitted by the lamp filament is distributed to the lamp glass,reflector,and the target medium,which are cooled by an air flow.The radiant heat transfer is simulated by using the ray-tracing scheme,in which the spectral characteristics of the emission and the materials are incorporated.The heat transport from the lamp glass to the cooling air is analyzed by using the finite volume method.As the lamp-filament temperature rises in the range of 3000-3400K,the NIR radiant power on the target medium increases.However,the lamp-glass temperature also rises,and the proportion of the NIR power to the entire radiation has a peak in the temperature range.The spectral distributions of the absorbed energies in all the components in the module are highly non-uniform,and a monochromatic model of the radiant heat transfer may result in a significant discrepancy.展开更多
The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E ...The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E and momentum p of photonic eigenmodes, and essentially determines the optical properties of materials. As EepT is defined in momentum space(k-space), the experimental method to detect the energy distribution, that is the spectrum, in a momentum-resolved manner is highly required. In this review, the momentum-space imaging spectroscopy(MSIS) system is presented, which can directly study the spectral information in momentum space. Using the MSIS system, the photonic dispersion can be captured in one shot with high energy and momentum resolution. From the experimental momentumresolved spectrum data, other key features of photonic eigenmodes, such as quality factors and polarization states, can also be extracted through the post-processing algorithm based on the coupled mode theory. In addition, the interference configurations of the MSIS system enable the measurement of coherence properties and phase information of nanophotonic materials, which is important for the study of light-matter interaction and beam shaping with nanostructures. The MSIS system can give the comprehensive information of nanophotonic materials, and is greatly useful for the study of novel photonic phenomena and the development of nanophotonic technologies.展开更多
The parietodynamic wall, a type of dynamic insulation, has been recognized as an effective technology to reduce energy loss in buildings by recovering heat energy through forced convection. However, current research o...The parietodynamic wall, a type of dynamic insulation, has been recognized as an effective technology to reduce energy loss in buildings by recovering heat energy through forced convection. However, current research on the thermal performance of parietodynamic walls has overlooked the influence of thermal radiation, a crucial factor in energy transfer within the air layers of these walls. To bridge this gap, an innovative simulation model was developed and experimentally validated. Employing simulation methods, we investigated the impact of thermal radiation on the thermal behavior of parietodynamic walls under various influencing factors. Our findings reveal that thermal radiation markedly increases heat loss. Specifically, at an emissivity of 1, thermal radiation contributes up to 80.7% to the heat transfer coefficient (HTC) of the parietodynamic wall. Moreover, for a parietodynamic wall without insulation, the HTC of this wall will increase by more than 268% when thermal radiation is taken into account, compared to when it is not considered. These revelations deepen our comprehension of the role of thermal radiation in parietodynamic walls and offer valuable guidance for the development of more energy-efficient buildings.展开更多
基金The National Natural Science Foundation of China(No. 51036001 )the Natural Science Foundation of Jiangsu Province(No. BK2010043)
文摘A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building： Xijindu exhibition hall, which is located in Zhenjiang city in China. Numerical studies on the thermal comfort and energy consumption of the system are carded out by using TRNSYS software. The results indicate that the system with the radiant floor method or the radiant ceiling method shows good thermal comfort without mechanical ventilation in winter. However, the system with either of the methods should add mechanical ventilation to ensure good comfort in summer. At the same level of thermal comfort, it can also be found that the annual energy consumption of the radiant ceiling system is less than that of the radiant floor system.
基金Natural Science Foundation of Zhumadian City(058002)
文摘Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.
基金Project(2009BB4228) supported by the Natural Science Foundation of Chongqing City,ChinaProject(CK2010Z09) supported by the Research Foundation of Chongqing University of Science and Technology,China
文摘In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in preparing them as thermoelectric materials. Structure and phase composition of the obtained materials were investigated by X-ray diffraction （XRD）. The electrical conductivity, Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K. It is found that Mg2Si1-xSnx solid solutions are well formed with excessive content of 5% （molar fraction） Mg from the stoichiometric MgESil.xSnx under microwave irradiation. A maximum dimensionless figure of merit, ZT, of about 0.26 is obtained for Mg2Si1-xSnx solid solutions at about 500 K for x=0.6.
基金Project(2009AA05Z215) supported by the National High Technology Research and Development Program of China
文摘Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics ~f thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.
基金Project(N110204015)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2012M510075)supported by the China Postdoctoral Science Foundation
文摘A combined conduction and radiation heat transfer model was used to simulate the heat transfer within wafer and investigate the effect of thermal transport properties on temperature non-uniformity within wafer surface. It is found that the increased conductivities in both doped and undoped regions help reduce the temperature difference across the wafer surface. However, the doped layer conductivity has little effect on the overall temperature distribution and difference. The temperature level and difference on the top surface drop suddenly when absorption coefficient changes from 104 to 103 m-1. When the absorption coefficient is less or equal to 103 m-1, the temperature level and difference do not change much. The emissivity has the dominant effect on the top surface temperature level and difference. Higher surface emissivity can easily increase the temperature level of the wafer surface. After using the improved property data, the overall temperature level reduces by about 200 K from the basis case. The results will help improve the current understanding of the energy transport in the rapid thermal processing and the wafer temperature monitor and control level.
基金The project supported by National Natural Science Foundation of China under Grant No. 10347008 and Science Foundation for Fundamental Research of Sichuan Province under Grand No. 05JY029-092. We would like to thank Prof. Zhang Jing-Yi and Dr. Ren Jun for their beneficial discussions.
文摘Based on particles in a dynamical geometry, extending the Parikh ＇s method of quantum tunneling, radiation, we deeply investigate the quantum tunneling radiation of Kerr-NUT bhck hole. When self-gravitating action, energy conservation, and angular momentum conservation are taken into account, the emission rate of the particle on the event horizon is related to the change of Bekenstein-Hawking entropy and the emission spectrum is not precisely thermal, but is consistent with an underlying unitary theory.
文摘From the viewpoint of field synergy principle and dipole radiation theory, the interaction between the incident thermal radiation wave and materials is analyzed to reveal the mechanism of selective absorption of incident thermal radiation. It is shown that the frequency of the incident thermal radiation and the damping constant of damping oscillators in materials are of vital importance for the thermal radiation properties (reflectivity, absorptivity, transmissivity, etc.) of materials.
基金supported by the Korea Research Foundation Grant funded by the Korean Government(MOEHRD,Basic ResearchPromotion Fund)(KRF-2008-331-D00076)
文摘We simulated the heat transfer phenomena of the heating module that is primarily based on the radiant energy in the near-infra-red(NIR) domain.In the module,the power emitted by the lamp filament is distributed to the lamp glass,reflector,and the target medium,which are cooled by an air flow.The radiant heat transfer is simulated by using the ray-tracing scheme,in which the spectral characteristics of the emission and the materials are incorporated.The heat transport from the lamp glass to the cooling air is analyzed by using the finite volume method.As the lamp-filament temperature rises in the range of 3000-3400K,the NIR radiant power on the target medium increases.However,the lamp-glass temperature also rises,and the proportion of the NIR power to the entire radiation has a peak in the temperature range.The spectral distributions of the absorbed energies in all the components in the module are highly non-uniform,and a monochromatic model of the radiant heat transfer may result in a significant discrepancy.
基金supported by the National Key Basic Research Program of China(2016YFA0301103,2016YFA0302000 and 2018YFA0306201)the National Natural Science Foundation of China(11774063,11727811,and 91963212)supported by the Science and Technology Commission of Shanghai Municipality(19XD1434600,2019SHZDZX01 and 19DZ2253000)。
文摘The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E and momentum p of photonic eigenmodes, and essentially determines the optical properties of materials. As EepT is defined in momentum space(k-space), the experimental method to detect the energy distribution, that is the spectrum, in a momentum-resolved manner is highly required. In this review, the momentum-space imaging spectroscopy(MSIS) system is presented, which can directly study the spectral information in momentum space. Using the MSIS system, the photonic dispersion can be captured in one shot with high energy and momentum resolution. From the experimental momentumresolved spectrum data, other key features of photonic eigenmodes, such as quality factors and polarization states, can also be extracted through the post-processing algorithm based on the coupled mode theory. In addition, the interference configurations of the MSIS system enable the measurement of coherence properties and phase information of nanophotonic materials, which is important for the study of light-matter interaction and beam shaping with nanostructures. The MSIS system can give the comprehensive information of nanophotonic materials, and is greatly useful for the study of novel photonic phenomena and the development of nanophotonic technologies.
基金supported by the National Key R&D Program of China(2022YFB3706505)the National Natural Science Foundation of China(51978212).
文摘The parietodynamic wall, a type of dynamic insulation, has been recognized as an effective technology to reduce energy loss in buildings by recovering heat energy through forced convection. However, current research on the thermal performance of parietodynamic walls has overlooked the influence of thermal radiation, a crucial factor in energy transfer within the air layers of these walls. To bridge this gap, an innovative simulation model was developed and experimentally validated. Employing simulation methods, we investigated the impact of thermal radiation on the thermal behavior of parietodynamic walls under various influencing factors. Our findings reveal that thermal radiation markedly increases heat loss. Specifically, at an emissivity of 1, thermal radiation contributes up to 80.7% to the heat transfer coefficient (HTC) of the parietodynamic wall. Moreover, for a parietodynamic wall without insulation, the HTC of this wall will increase by more than 268% when thermal radiation is taken into account, compared to when it is not considered. These revelations deepen our comprehension of the role of thermal radiation in parietodynamic walls and offer valuable guidance for the development of more energy-efficient buildings.
