Air conditioning (AC) system is the one with asynchronous and uncertain nature. In this paper, the fuzzy discrete event system (FDES) is introduced to the research of AC energy-saving control. A fuzzy automaton modeli...Air conditioning (AC) system is the one with asynchronous and uncertain nature. In this paper, the fuzzy discrete event system (FDES) is introduced to the research of AC energy-saving control. A fuzzy automaton modeling is given for AC energy-saving control and effectiveness optimization is made. To facilitate the implement of the control and energy saving, priorities have been assigned to the major control steps based on logical reasoning. Forward-looking tree modeling based on FDES has been simplified to help further optimization, and a simple and concrete example has been put forward illustrating energy-saving control in AC system.展开更多
For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and...For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.展开更多
Good learning outputs in schools require an acceptable physical environment inside schools. Whatever the climatic context that surrounds any school buildings, energy flows of different types should be provided. Concer...Good learning outputs in schools require an acceptable physical environment inside schools. Whatever the climatic context that surrounds any school buildings, energy flows of different types should be provided. Concerns may include thermal environment, luminous environment and acoustics environment. Types of energy used are an important variable that contributes to thermal comfort. Physical structure of the school building is another factor to be taken into consideration. This article established a relationship between thermal comfort inside schools and types of energy flows which have been consumed to maintain the level of comfort required, controlled by the building fabric and consequent economic factors that affect energy consumption of school buildings. Different approaches were applied in order to achieve the research objectives. Field surveys, field measurements and analyzing historical data were the most approaches followed to implement this study. The final outputs of this work have a national value nationwide： establishing a relationship among thermal comfort, energy flows and building fabric is of importance. Furthermore, it is of great importance to the decision maker for educational facilities. Research will also establish a wide platform based on scientific investigations for developing climate responsive school architecture in Jordan.展开更多
We investigate the low-temperature statistical properties of a harmonic oscillator coupled to a heat bath, where the low-frequency spectrum vanishes. We obtain the exact result of the zero point energy. Due to the low...We investigate the low-temperature statistical properties of a harmonic oscillator coupled to a heat bath, where the low-frequency spectrum vanishes. We obtain the exact result of the zero point energy. Due to the low frequency shortage of environmental oscillators＇ spectral density, the coordinate and momentum correlation functions decay as T^-4 arid T^-6 respectively at zero temperature, where T is the correlation time. The low-temperature behavior of the mean energy does not violate the third law of thermodynamics, but differs largely from the Ohmic spectrum case.展开更多
There is a great potential of both supply and consumption in oil ＆ gas market in Northeast Asia, and the prospects of further cooperation is very broad. Sino-Russia cooperation on oil ＆ gas will lay a crucial founda...There is a great potential of both supply and consumption in oil ＆ gas market in Northeast Asia, and the prospects of further cooperation is very broad. Sino-Russia cooperation on oil ＆ gas will lay a crucial foundation for building a regional oil ＆ gas market, and an increasingly opened trading system for oil ＆ gas will also meet Japan and South Korea＇s need in building a diversified and stable assurance system of oil ＆ gas supply. The strategic role played by Kozmino Port in Far East Russia and Shanghai oil and gas trading platform in China will be highlighted. Competition and cooperation through market mechanism will help to activate the interactions of resource flow and capital flow in Northeast Asia region, thus can also help energy consuming countries in the region to promote their disclosure power in global pricing system and gradually eliminate the Asian Premium.展开更多
Based on the finite-volume coastal ocean model （FVCOM）, a three-dimensional numerical model FVCOM was built to simulate the ocean dynamics in pre-dam and post-dam conditions in Bachimen （BCM）. The domain decomposi...Based on the finite-volume coastal ocean model （FVCOM）, a three-dimensional numerical model FVCOM was built to simulate the ocean dynamics in pre-dam and post-dam conditions in Bachimen （BCM）. The domain decomposition method, which is effective in describing the conservation of volume and non-conservation of mechanical energy in the utilization of tidal energy, was employed to estimate the theoretical tidal energy resources and developable energy resources, and to analyze the hydrodynamic effect of the tidal power station. This innovative approach has the advantage of linking physical oceanography with engineering problems. The results indicate that the theoretical annual tidal energy resources is about 2x 108 kwh under the influence of tidal power station; Optimized power installation is confirmed according to power generation curve from numerical analysis; the developable resources is about 38.2% of theoretical tidal energy resources with the employment of one-way electricity generation. The electricity generation time and power are 3479 hours and 2.55~104KW, respectively. The power station has no effect on the tide pattern which is semi-diumal tide in both two conditions, but the amplitudes of main constituents apparently decrease in the area near the dam, with the ME decreasing the most, about 62.92 cm. The tidal prism shrinks to 2.28×107 m3, but can still meet the flow requirement for tidal power generation. The existence of station increases the flow rate along the waterway and enhances the residual current. There are two opposite vortexes formed on the east side beside the dam of the station, which leads to pollutants gathering.展开更多
Numerical approximations of Cahn-Hilliard phase-field model for the two-phase incompressible flows are considered in this paper.Several efficient and energy stable time discretization schemes for the coupled nonlinear...Numerical approximations of Cahn-Hilliard phase-field model for the two-phase incompressible flows are considered in this paper.Several efficient and energy stable time discretization schemes for the coupled nonlinear Cahn-Hilliard phase-field system for both the matched density case and the variable density case are constructed,and are shown to satisfy discrete energy laws which are analogous to the continuous energy laws.展开更多
基金PhD Programs Foundation of Ministry of Education of China( No.20060255006)Cultivation Fund of the Key Scientific and Technical Innovation Project from Ministry of Education of China (No.706024)
文摘Air conditioning (AC) system is the one with asynchronous and uncertain nature. In this paper, the fuzzy discrete event system (FDES) is introduced to the research of AC energy-saving control. A fuzzy automaton modeling is given for AC energy-saving control and effectiveness optimization is made. To facilitate the implement of the control and energy saving, priorities have been assigned to the major control steps based on logical reasoning. Forward-looking tree modeling based on FDES has been simplified to help further optimization, and a simple and concrete example has been put forward illustrating energy-saving control in AC system.
基金Project(2009GK2009) supported by the Science and Technology Program of Hunan Province,China
文摘For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.
文摘Good learning outputs in schools require an acceptable physical environment inside schools. Whatever the climatic context that surrounds any school buildings, energy flows of different types should be provided. Concerns may include thermal environment, luminous environment and acoustics environment. Types of energy used are an important variable that contributes to thermal comfort. Physical structure of the school building is another factor to be taken into consideration. This article established a relationship between thermal comfort inside schools and types of energy flows which have been consumed to maintain the level of comfort required, controlled by the building fabric and consequent economic factors that affect energy consumption of school buildings. Different approaches were applied in order to achieve the research objectives. Field surveys, field measurements and analyzing historical data were the most approaches followed to implement this study. The final outputs of this work have a national value nationwide： establishing a relationship among thermal comfort, energy flows and building fabric is of importance. Furthermore, it is of great importance to the decision maker for educational facilities. Research will also establish a wide platform based on scientific investigations for developing climate responsive school architecture in Jordan.
文摘We investigate the low-temperature statistical properties of a harmonic oscillator coupled to a heat bath, where the low-frequency spectrum vanishes. We obtain the exact result of the zero point energy. Due to the low frequency shortage of environmental oscillators＇ spectral density, the coordinate and momentum correlation functions decay as T^-4 arid T^-6 respectively at zero temperature, where T is the correlation time. The low-temperature behavior of the mean energy does not violate the third law of thermodynamics, but differs largely from the Ohmic spectrum case.
文摘There is a great potential of both supply and consumption in oil ＆ gas market in Northeast Asia, and the prospects of further cooperation is very broad. Sino-Russia cooperation on oil ＆ gas will lay a crucial foundation for building a regional oil ＆ gas market, and an increasingly opened trading system for oil ＆ gas will also meet Japan and South Korea＇s need in building a diversified and stable assurance system of oil ＆ gas supply. The strategic role played by Kozmino Port in Far East Russia and Shanghai oil and gas trading platform in China will be highlighted. Competition and cooperation through market mechanism will help to activate the interactions of resource flow and capital flow in Northeast Asia region, thus can also help energy consuming countries in the region to promote their disclosure power in global pricing system and gradually eliminate the Asian Premium.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11010201
文摘Based on the finite-volume coastal ocean model （FVCOM）, a three-dimensional numerical model FVCOM was built to simulate the ocean dynamics in pre-dam and post-dam conditions in Bachimen （BCM）. The domain decomposition method, which is effective in describing the conservation of volume and non-conservation of mechanical energy in the utilization of tidal energy, was employed to estimate the theoretical tidal energy resources and developable energy resources, and to analyze the hydrodynamic effect of the tidal power station. This innovative approach has the advantage of linking physical oceanography with engineering problems. The results indicate that the theoretical annual tidal energy resources is about 2x 108 kwh under the influence of tidal power station; Optimized power installation is confirmed according to power generation curve from numerical analysis; the developable resources is about 38.2% of theoretical tidal energy resources with the employment of one-way electricity generation. The electricity generation time and power are 3479 hours and 2.55~104KW, respectively. The power station has no effect on the tide pattern which is semi-diumal tide in both two conditions, but the amplitudes of main constituents apparently decrease in the area near the dam, with the ME decreasing the most, about 62.92 cm. The tidal prism shrinks to 2.28×107 m3, but can still meet the flow requirement for tidal power generation. The existence of station increases the flow rate along the waterway and enhances the residual current. There are two opposite vortexes formed on the east side beside the dam of the station, which leads to pollutants gathering.
基金supported by the National Science Foundation(No. DMS-0915066)
文摘Numerical approximations of Cahn-Hilliard phase-field model for the two-phase incompressible flows are considered in this paper.Several efficient and energy stable time discretization schemes for the coupled nonlinear Cahn-Hilliard phase-field system for both the matched density case and the variable density case are constructed,and are shown to satisfy discrete energy laws which are analogous to the continuous energy laws.
