In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influenc...In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat–work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat–work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed.Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied.展开更多
In large helical device （LHD）, antenna loadings are different for minority ion cyclotron heating （MICH with 38.47 MHz） and mode-converted ion Bernstein wave heating （MC-IBW with 28.4 MHz）, and it is necessary to...In large helical device （LHD）, antenna loadings are different for minority ion cyclotron heating （MICH with 38.47 MHz） and mode-converted ion Bernstein wave heating （MC-IBW with 28.4 MHz）, and it is necessary to improve antenna loading with low heating efficiency to avoid arching on transmission line. To design a new ion cyclotron range of frequencies （ICRF） antenna in LHD, calculation for a simple antenna model is conducted using three-dimensional electrical magnetic code （high frequency structure simulator, HFSS） for an water loading as an imaginary plasma with low heating efficiency. At resonant frequencies, antenna loading is sensitive to strap width, and resonant frequencies are strongly related to strap height. There is no differences of RF current profile on the strap surface between resonant frequency and non-resonant frequency. The strap should be perpendicularly placed against the magnetic field line, since Faraday-shield angle will lead to a decrease in the effective antenna height.展开更多
Based on decreasing the flexibility of the power grid through the integration of large-scale renewable energy,a multi-energy storage system architectural model and its coor-dination operational strategy with the same ...Based on decreasing the flexibility of the power grid through the integration of large-scale renewable energy,a multi-energy storage system architectural model and its coor-dination operational strategy with the same flexibility as in the pumped storage power station and battery energy storage system(BESS)are studied.According to the new energy fluctuation characteristics and the different peak valley parameters in the power grid,this paper proposes a electricity heat hydrogen multi-energy storage system(EHH-MESS)and its coordination and optimization operational model to reduce the curtailment of wind power and photovoltaic(PV)to the power grid and improve the flexibility of the power grid.Finally,this paper studied the simulation model of an energy storage optimization control strategy after the multi-energy storage system is connected to the distribution networks,and analyzed three operational modes of the multi-energy storage system.The simulation results show that the EHH-MESS proposed in this paper has a better power grid regulation flexibility and economy,and can be used to replace the battery energy storage system based on MATLAB.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51376101 and 51356001)
文摘In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat–work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat–work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed.Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied.
基金supported partially by the JSPS-CAS Core-University program in the field of 'Plasma and Nuclear Fusion'
文摘In large helical device （LHD）, antenna loadings are different for minority ion cyclotron heating （MICH with 38.47 MHz） and mode-converted ion Bernstein wave heating （MC-IBW with 28.4 MHz）, and it is necessary to improve antenna loading with low heating efficiency to avoid arching on transmission line. To design a new ion cyclotron range of frequencies （ICRF） antenna in LHD, calculation for a simple antenna model is conducted using three-dimensional electrical magnetic code （high frequency structure simulator, HFSS） for an water loading as an imaginary plasma with low heating efficiency. At resonant frequencies, antenna loading is sensitive to strap width, and resonant frequencies are strongly related to strap height. There is no differences of RF current profile on the strap surface between resonant frequency and non-resonant frequency. The strap should be perpendicularly placed against the magnetic field line, since Faraday-shield angle will lead to a decrease in the effective antenna height.
基金This project was supported by National Key Research and Development Plan(2017YFB0902100).
文摘Based on decreasing the flexibility of the power grid through the integration of large-scale renewable energy,a multi-energy storage system architectural model and its coor-dination operational strategy with the same flexibility as in the pumped storage power station and battery energy storage system(BESS)are studied.According to the new energy fluctuation characteristics and the different peak valley parameters in the power grid,this paper proposes a electricity heat hydrogen multi-energy storage system(EHH-MESS)and its coordination and optimization operational model to reduce the curtailment of wind power and photovoltaic(PV)to the power grid and improve the flexibility of the power grid.Finally,this paper studied the simulation model of an energy storage optimization control strategy after the multi-energy storage system is connected to the distribution networks,and analyzed three operational modes of the multi-energy storage system.The simulation results show that the EHH-MESS proposed in this paper has a better power grid regulation flexibility and economy,and can be used to replace the battery energy storage system based on MATLAB.
