Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature i...Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature is still up to about 300℃.Owing to with development of global emphasis on energy conservation energy saving and discharge reduction,it's significant to lower the discharge temperature to below 200℃, for the sake of achieving rational use of waste heat resource.Through the analysis of the existing heat recovery system by this study,it is proved that mixing low temperature with flue gas in high temperature standard will increase the capacity of the flue gas and deteriorate the quality of remaining heat resource.In stead of that,increasing the combustion air temperature to 600℃on the basis of stability temperature for the prerequisite of recuperator design,and giving priority to reducing fuel consumption are the better way.The recovery and recycle of low temperature gas are also be introduced.It is demonstrated by the way of setting a secondary recuperator at the exit of the primary recuperator,and using low temperature flue gas to heat the air used for drying the strip steel,the exhuast temperature of flue gas can be reduced to lower than 200℃.At the same time,the steam required for heating air is saved,the energy reserve as high as 2 300 t of standard coal per year.展开更多
James Watt contributed significantly to the development of the thermodynamics of energy conversion as a science. Several of his ideas are now integral part of thermodynamics, but Watt as their creator is not mentioned...James Watt contributed significantly to the development of the thermodynamics of energy conversion as a science. Several of his ideas are now integral part of thermodynamics, but Watt as their creator is not mentioned. This paper presents some of Watt’s concepts of energy conversion, including his thermodynamic analysis of the Newcomen steam engine that marks the beginning of thermal engineering. The analysis illuminated the causes of the enormously high heat losses in the installation and showed the ways for their reduction. This led him to a new conception of the steam engine with a separate condenser. Not less important was Watt’s determination of some physical properties of water and steam used as the working substance. In the experiments he observed the decrease of the latent heat of steam with increasing temperature and its disappearance at very high temperature led him to postulate the existence of a thermodynamic critical state of water. He introduced the work associated with volume change into thermodynamics and illustrated it graphically. Several of Watt’s numerous ideas deserve to be included into the history of the thermodynamics of energy conversion but they are rarely mentioned in the scientific literature. Arguably the most important is the First Law of Thermodynamics, which he introduced in his 1769 patent and related works in 1774 and 1778.展开更多
Thermal energy conversion and also storage system is to advance knowledge and develop practical solutions at the intersection of micro and nano-scale engineering,energy conversion,and sustainability.This research addr...Thermal energy conversion and also storage system is to advance knowledge and develop practical solutions at the intersection of micro and nano-scale engineering,energy conversion,and sustainability.This research addresses the challenge of enhancing these critical aspects to ensure prolonged system performance and durability in the context of evolving energy technologies.This research analyses the anti-oxidation and filtration behaviours of micro and nano-scale structures in the context of electro-and photo-thermal energy conversion and also storage systems.A micro multiscale hierarchical structure strategy is presented to fabricate multi-scale double-layer porous wick evaporators with the electrospun nanofibers made of gelatin-polyamide 6(GPA6)and Ti_(3)C_(2)T_(x)MXene/silver nanowire with Cellulose Micro/NanoFibers(CMNF)cryogens by using spark plasma sintering(SPS)based high-pressure hydrothermal treatment model.An excellent anti-oxidation effect was offered by coating the film in thermal conditions and the anti-oxidation properties were further examined from 500℃to850℃.The results are analysed using Matlab software to improve the efficiency of energy conversion processes by integrating nanostructures into thermal systems,to increase energy output while minimizing losses.The silver nanowire is with a heat transfer coefficient of 78%,a mass remaining rate of 98.7%,and an energy storage efficiency of 23.8%.This study enhances energy density and duration by integrating nanostructures into thermal systems while minimizing energy losses,and it not only exhibits excellent anti-oxidation properties but also possesses superior filtration capabilities for designing and engineering multifunctional nanomaterials.展开更多
Pb(Mg_(0.5)W_(0.5))O_(3)–Pb(Ni_(1/3)Nb_(2/3))O_(3)–Pb(Zr_(0.5)Ti_(0.5))O_(3)(PNN–PMW–PZT)piezoceramics were sintered at a low temperature of 900℃by the mixed metal oxide powder solid-state reaction route.CaCO_(3)...Pb(Mg_(0.5)W_(0.5))O_(3)–Pb(Ni_(1/3)Nb_(2/3))O_(3)–Pb(Zr_(0.5)Ti_(0.5))O_(3)(PNN–PMW–PZT)piezoceramics were sintered at a low temperature of 900℃by the mixed metal oxide powder solid-state reaction route.CaCO_(3)and Li_(2)CO_(3)as sintering aids and Yb_(2)O_(3)as a dopant were added into the PNN–PMW–PZT ceramic system for low-temperature sintering and enhancement of electrical properties,respectively.The effects of different Yb_(2)O_(3)doping amounts on the microstructure,dielectric,piezoelectric and ferroelectric properties of the samples were systematically investigated.The piezoceramics doped with 0.1 mol%Yb_(2)O_(3)have optimal electrical properties(d_(33)=563 pC/N,k_(p)=0.66,ε_(r)=2728(1 kHz),tanδ=0.0176(1 kHz),and T_(C)=301℃).While the piezoceramics doped with 0.3 mol%Yb_(2)O_(3)have optimal energy conversion properties:the piezoelectric voltage coefficient g_(33)=26.7×10^(-3)Vm/N and the effective piezoelectric energy conversion coefficient d_(33)×g_(33)=14366×10^(-15)m^(2)/N.展开更多
The iterative layer theory approach is applied to the analysis of double sided and single sided induction heating systems for continuous heating of thin metal strips. The excitation is transverse to the direction of s...The iterative layer theory approach is applied to the analysis of double sided and single sided induction heating systems for continuous heating of thin metal strips. The excitation is transverse to the direction of strip motion and can be three phase or single phase. Nonmagnetic as well as ferromagnetic strips are employed. The important system parameters, namely, strip resistance, reactance, induced power and electromagnetic force are introduced. Accuracy of the method is verified with measurement of practical induction heating system together with comparison to numerical and analytical methods.展开更多
The Linear Mirror II is an innovative system to concentrate solar energy, developed by Isomorph SRL. In this paper, a solar-air heat exchanger of new conception is presented and tested together with a Linear Mirror II...The Linear Mirror II is an innovative system to concentrate solar energy, developed by Isomorph SRL. In this paper, a solar-air heat exchanger of new conception is presented and tested together with a Linear Mirror II. The heat exchanger surface is selective with respect to direction and position of light absorption and emission and once heated by the Linear Mirror II, can reach an air temperature of up to 230°C.展开更多
文摘Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature is still up to about 300℃.Owing to with development of global emphasis on energy conservation energy saving and discharge reduction,it's significant to lower the discharge temperature to below 200℃, for the sake of achieving rational use of waste heat resource.Through the analysis of the existing heat recovery system by this study,it is proved that mixing low temperature with flue gas in high temperature standard will increase the capacity of the flue gas and deteriorate the quality of remaining heat resource.In stead of that,increasing the combustion air temperature to 600℃on the basis of stability temperature for the prerequisite of recuperator design,and giving priority to reducing fuel consumption are the better way.The recovery and recycle of low temperature gas are also be introduced.It is demonstrated by the way of setting a secondary recuperator at the exit of the primary recuperator,and using low temperature flue gas to heat the air used for drying the strip steel,the exhuast temperature of flue gas can be reduced to lower than 200℃.At the same time,the steam required for heating air is saved,the energy reserve as high as 2 300 t of standard coal per year.
文摘James Watt contributed significantly to the development of the thermodynamics of energy conversion as a science. Several of his ideas are now integral part of thermodynamics, but Watt as their creator is not mentioned. This paper presents some of Watt’s concepts of energy conversion, including his thermodynamic analysis of the Newcomen steam engine that marks the beginning of thermal engineering. The analysis illuminated the causes of the enormously high heat losses in the installation and showed the ways for their reduction. This led him to a new conception of the steam engine with a separate condenser. Not less important was Watt’s determination of some physical properties of water and steam used as the working substance. In the experiments he observed the decrease of the latent heat of steam with increasing temperature and its disappearance at very high temperature led him to postulate the existence of a thermodynamic critical state of water. He introduced the work associated with volume change into thermodynamics and illustrated it graphically. Several of Watt’s numerous ideas deserve to be included into the history of the thermodynamics of energy conversion but they are rarely mentioned in the scientific literature. Arguably the most important is the First Law of Thermodynamics, which he introduced in his 1769 patent and related works in 1774 and 1778.
文摘Thermal energy conversion and also storage system is to advance knowledge and develop practical solutions at the intersection of micro and nano-scale engineering,energy conversion,and sustainability.This research addresses the challenge of enhancing these critical aspects to ensure prolonged system performance and durability in the context of evolving energy technologies.This research analyses the anti-oxidation and filtration behaviours of micro and nano-scale structures in the context of electro-and photo-thermal energy conversion and also storage systems.A micro multiscale hierarchical structure strategy is presented to fabricate multi-scale double-layer porous wick evaporators with the electrospun nanofibers made of gelatin-polyamide 6(GPA6)and Ti_(3)C_(2)T_(x)MXene/silver nanowire with Cellulose Micro/NanoFibers(CMNF)cryogens by using spark plasma sintering(SPS)based high-pressure hydrothermal treatment model.An excellent anti-oxidation effect was offered by coating the film in thermal conditions and the anti-oxidation properties were further examined from 500℃to850℃.The results are analysed using Matlab software to improve the efficiency of energy conversion processes by integrating nanostructures into thermal systems,to increase energy output while minimizing losses.The silver nanowire is with a heat transfer coefficient of 78%,a mass remaining rate of 98.7%,and an energy storage efficiency of 23.8%.This study enhances energy density and duration by integrating nanostructures into thermal systems while minimizing energy losses,and it not only exhibits excellent anti-oxidation properties but also possesses superior filtration capabilities for designing and engineering multifunctional nanomaterials.
基金financially supported by the Key Research and Development Program of the Sichuan Provincial Science and Technology Plan(No.2023DYF0173)the Fundamental Research Funds for the Central Universities(Nos.20826041E4280 and 20826041F4235).
文摘Pb(Mg_(0.5)W_(0.5))O_(3)–Pb(Ni_(1/3)Nb_(2/3))O_(3)–Pb(Zr_(0.5)Ti_(0.5))O_(3)(PNN–PMW–PZT)piezoceramics were sintered at a low temperature of 900℃by the mixed metal oxide powder solid-state reaction route.CaCO_(3)and Li_(2)CO_(3)as sintering aids and Yb_(2)O_(3)as a dopant were added into the PNN–PMW–PZT ceramic system for low-temperature sintering and enhancement of electrical properties,respectively.The effects of different Yb_(2)O_(3)doping amounts on the microstructure,dielectric,piezoelectric and ferroelectric properties of the samples were systematically investigated.The piezoceramics doped with 0.1 mol%Yb_(2)O_(3)have optimal electrical properties(d_(33)=563 pC/N,k_(p)=0.66,ε_(r)=2728(1 kHz),tanδ=0.0176(1 kHz),and T_(C)=301℃).While the piezoceramics doped with 0.3 mol%Yb_(2)O_(3)have optimal energy conversion properties:the piezoelectric voltage coefficient g_(33)=26.7×10^(-3)Vm/N and the effective piezoelectric energy conversion coefficient d_(33)×g_(33)=14366×10^(-15)m^(2)/N.
文摘The iterative layer theory approach is applied to the analysis of double sided and single sided induction heating systems for continuous heating of thin metal strips. The excitation is transverse to the direction of strip motion and can be three phase or single phase. Nonmagnetic as well as ferromagnetic strips are employed. The important system parameters, namely, strip resistance, reactance, induced power and electromagnetic force are introduced. Accuracy of the method is verified with measurement of practical induction heating system together with comparison to numerical and analytical methods.
文摘The Linear Mirror II is an innovative system to concentrate solar energy, developed by Isomorph SRL. In this paper, a solar-air heat exchanger of new conception is presented and tested together with a Linear Mirror II. The heat exchanger surface is selective with respect to direction and position of light absorption and emission and once heated by the Linear Mirror II, can reach an air temperature of up to 230°C.
