The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power sys...The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power system with REGs.In this paper,the critical short circuit ratio(CSCR)is defined as the corresponding SCR when the system voltage is in the critical stable state.Through static voltage stability analysis,the mathematical expression of the CSCR considering the impact of GIR is derived.The maximum value of CSCR is adopted as the critical value to distinguish the weak power system.Based on the static equivalent circuit analysis,it is proved that the CSCR is still effective to evaluate critical system strength considering the interactive impact among REGs.Finally,we find that the GIR can be neglected and the SCR can be used individually to evaluate the system strength when SCR>2 or GIR>5.The correctness and rationality of the CSCR and its critical value are validated on ADPSS.展开更多
In response to the actual demands of the energy storage type organic Rankine power generation cycle,this study proposes a new type of jacketed shell and tube heat exchanger with integrated cold storage and heat exchan...In response to the actual demands of the energy storage type organic Rankine power generation cycle,this study proposes a new type of jacketed shell and tube heat exchanger with integrated cold storage and heat exchange.N-tedecane is selected as the phase change material for cold storage,low-temperature water as the cold source,and R134a as the heat source.The phase change material for cold storage is filled inside the jacket tube of the heat exchanger.Cold fluid is introduced into the inner tube to cause the phase change material to condense and store cold.After the cold storage is completed,R134a flows in from the shell side and condenses through heat exchange with the solidified phase change material for energy storage.This study discusses the influence laws of different cold water mass flow rates and temperatures on the cold storage performance of this heat exchanger,and analyzes the condensation effect of R134a.The results show that when the mass flow rate is 0.5 kg/s and the cold water temperature is between 3 and 4℃,the average power of the energy storage heat exchanger in the condensation experiment is 80W,and the average convective heat transfer coefficient is 110.73 W/(m^(2)⋅K).This research provides an experimental basis for the development of energy storage organic Rankine power generation cycles.展开更多
Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational ...Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational stability under moisture,heat,and light;toxic lead leakage from degraded films.Metal-organic frameworks(MOFs),with their unique framework structure,large specific surface area,high heavy metal capturing capacity,and tunable conductivity,offer promising solutions to these issues.Recent studies have integrated MOFs into PSCs architectures to enhance performance and durability.This comprehensive review begins with an in-depth discussion of the structure,optical properties,electrical characteristics,and stability of MOFs,as well as their theoretical compatibility with perovskites.Subsequently,it provides a detailed analysis of how MOFs enhance charge carrier transport,promote perovskite crystallinity,improve device stability,and suppress lead leakage in PSCs.In summary,this review examines the research progress and potential of integrating MOFs with perovskites to address the critical PSCs challenges of efficiency,instability,and toxicity.展开更多
Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites...Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites and the occurrence of significant side reactions.Herein,sucralose(SCL),as an electrolyte additive,has been used to promote the exposure of the Zn(002)texture.The introduction of SCL can adjust the Zn~(2+)nucleation and diffusion along different crystal facets,promoting the exposure of the Zn(002)texture.By substituting water molecules in the[Zn(H_(2)O)_(6)]~(2+),SCL reconfigures the hydrogen bond network in the electrolyte,reconstructing the solvation structure and suppressing the hydrogen evolution reaction.Consequently,the Zn//Zn symmetric battery exhibits long-term cycling stability of over 4900 h at 1 mA cm^(-2)-1 mAh cm^(-2).Even at a harsh condition of 30 mA cm^(-2)-30 mAh cm^(-2)(DOD=73.3%),it can stably cycle for 171 h.The CE of the Zn//Cu half battery reaches 99.61% at 0.2 mA cm^(-2)with 0.2 mAh cm^(-2).Employing the optimized electrolyte,after 500 cycles,a high specific capacity of 420 mAh g^(-1)can be retained for the NH_4V_4O_(10)//Zn full battery at 500 mA g^(-1),corresponding to a capacity retention of 90.7%.展开更多
With the continuous development of Chinas national economy, urban heating develops rapidly, and heating companies continue to increase. How to realize the reasonable and efficient production of heating network has bec...With the continuous development of Chinas national economy, urban heating develops rapidly, and heating companies continue to increase. How to realize the reasonable and efficient production of heating network has become an urgent problem. In recent years, with the gradual development of comprehensive environmental management in the country, thermal power companies have used the internet information platform to carry out technical updates in order to improve system management, save energy and reduce consumption, reduce heating costs and pollution. How to make heating users enjoy heat energy most economically and appropriately has become the most prominent problem for current heating users and even social environmental protection requirements. Household heating and metering system has become the leading system of current heating system. If heating users want to control the room temperature through temperature control valves according to their own needs, they must make the whole indoor temperature reach the appropriate temperature. However, people often ignore the heat source of heat exchange station or heating station, and there are also many links that can be optimized by pipeline design and heat source reuse. Users can not only adjust the indoor temperature by adjusting the indoor regulating valve, but also adjust the function of the equipment in the station, thereby playing the role of energy saving and emission reduction. Based on this, this paper studies and analyzes the energy saving and emission reduction of urban heating for reference. Based on this, this paper will analyze the reduction of energy and emissions of urban smart warming.展开更多
Reactive distillation(RD) process is an innovative hybrid process combining reaction with distillation, which has recently come into sharp focus as a successful case of process intensification. Considered as the most ...Reactive distillation(RD) process is an innovative hybrid process combining reaction with distillation, which has recently come into sharp focus as a successful case of process intensification. Considered as the most representative case of process intensification, it has been applied for many productions, especially for production of ester compounds. However, such problems existing in the RD system for ester productions are still hard to solve,as the removal of the water which comes from the esterification, and the separation of the azeotropes of ester–alcohol(–water). Many methods have been studying on the process to solve the problems resulting in further intensification and energy saving. In this paper, azeotropic–reactive distillation or entrainer enhanced reactive distillation(ERD) process, reactive extractive distillation(RED) process, the method of co-production in RD process, pressure-swing reactive distillation(PSRD) process, reactive distillation–pervaporation coupled process(RD–PV), are introduced to solve the problems above, so the product(s) can be separated efficiently and the chemical equilibrium can be shifted. Dividing-wall column(DWC) structure and novel methods of loading catalyst are also introduced as the measures to intensify the process and save energy.展开更多
Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromat...Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromatic hydrocarbon content,appropriate modification can increase its value and expand its energy storage applications.Current research progress on the common preparation methods of petroleum asphalt-based carbon materials,including template-assisted pyrolysis,molten salt treatment,activation,heteroatom doping,and pre-oxidation is reviewed,and its use in supercapacitors and alkali metal ion batteries,is also elaborated.Feasible solutions for the current problems with petroleum asphalt are proposed,with the aim of providing insights into its high value-added utilization.展开更多
The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by...The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.展开更多
Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the ...Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the aspects of energy efficiency. Different exploiting methods and different types of hydrate reservoir were selected to study their effects on energy efficiencies. Both laboratory studies and field tests have shown that the improved technologies can help to increase efficiency for gas hydrate exploitation. And it also showed the trend that gas hydrate exploitation started to change from permafrost to marine. Energy efficiency ratio （EER） and energy return on energy invested （EROI） were introduced as an indicator of efficiency for natural gas hydrate exploitation. An energy-efficient hydrate production process, called ＂Hydrate Chain Energy System （HCES）＂, including treatment of flue gas, replacement of CH4 with CO2, separation of CO2 from CH4, and storage and transportation of CH4 in hydrate form, was proposed for future natural gas hydrate exploitation. In the meanwhile, some problems, such as mechanism of C02 replacement, mechanism of CO2 separation, CH4 storage and transportation are also needed to be solved for increasing the energy efficiency of gas hydrate exploitation.展开更多
The performances of a hybrid energy system for decentralized heating are investigated.The proposed energy system consists of a solar collector,an air-source heat pump,a gas-fired boiler and a hot water tank.A mathemat...The performances of a hybrid energy system for decentralized heating are investigated.The proposed energy system consists of a solar collector,an air-source heat pump,a gas-fired boiler and a hot water tank.A mathematical model is developed to predict the operating characteristics of the system.The simulation results are compared with experimental data.Such a comparison indicates that the model accuracy is sufficient.The influence of the flat plate solar collector area on the economic and energy efficiency of such system is also evaluated through numerical simulations.Finally,this system is optimized using the method of orthogonal design.The results clearly demonstrate that the solar-heat pump-gas combined system is more convenient and efficient than the simple gas system and the heat pump-gas combined system,whereas it is less convenient but more efficient than the solarassisted gas system.展开更多
Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutr...Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutrality.However,water-energy nexus analysis and models for WWTPs have rarely been reported to date.In this study,a cloud-model-based energy consumption analysis(CMECA)of a WWTP was conducted to explore the relationship between influent and energy consumption by clustering its influent’s parameters.The principal component analysis(PCA)and K-means clustering were applied to classify the influent condition using water quality and volume data.The energy consumption of the WWTP is divided into five standard evaluation levels,and its cloud digital characteristics(CDCs)were extracted according to bilateral constraints and golden ratio methods.Our results showed that the energy consumption distribution gradually dispersed and deviated from the Gaussian distribution with decreased water concentration and quantity.The days with high energy efficiency were extracted via the clustering method from the influent category of excessive energy consumption,represented by a compact-type energy consumption distribution curve to identify the influent conditions that affect the steady distribution of energy consumption.The local WWTP has high energy consumption with 0.3613 kW·h·m^(-3)despite low influent concentration and volumes,across four consumption levels from low(I)to relatively high(IV),showing an unsatisfactory operation and management level.The average oxygenation capacity,internal reflux ratio,and external reflux ratio during high energy efficiency days recognized by further clustering were obtained(0.2924-0.3703 kg O_(2)·m^(-3),1.9576-2.4787,and 0.6603-0.8361,respectively),which could be used as a guide for the days with low energy efficiency.Consequently,this study offers a water-energy nexus analysis method to identify influent conditions with operational management anomalies and can be used as an empirical reference for the optimized operation of WWTPs.展开更多
Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipmen...Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.展开更多
Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive poly...Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive polymeric hydrogel based on the combination of excited state intramolecular proton transfer(ESIPT) molecule(Salicylic acid,Sal) and terbium(Ⅲ)(Tb^(3+)),as enabled by external stimuli to construct artificial light-harvesting antenna systems.Benefiting from unique photophysical properties of Sal,the synthesized hydrogel displays a temperature-dependent reversible opaque?transparent states transition,accompanied with an interesting photoluminescence behavior.Moreover,by further incorporating europium(Ⅲ)(Eu^(3+)) into the hydrogel,we demonstrate well-defined cascades of energy transfer that provides a tunable optical output from the collection of lanthanides by the excitation of a common sensitizer(Sal) upon base vapor stimulation.Efficient energy transfer efficiency from Tb^(3+) to Eu^(3+),as high as 97.8%,was also obtained as established by the time-resolved fluorescence spectroscopy analysis.展开更多
In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system...In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system simulation and ther^nodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance.展开更多
According to the year of 2009, calculated energy consumption quantity and energy consumption structure of building in Guangzhou to 2030, analyzed adjustment and approach of sustainable development and potential of ene...According to the year of 2009, calculated energy consumption quantity and energy consumption structure of building in Guangzhou to 2030, analyzed adjustment and approach of sustainable development and potential of energy conservation which can provide commendable technology progress in every department.展开更多
The concept of the energy management system （EnMS） standards comes from the worldwide concern on energy problems. The increasing conflicts between global economic development and energyrelated restrictions have wake...The concept of the energy management system （EnMS） standards comes from the worldwide concern on energy problems. The increasing conflicts between global economic development and energyrelated restrictions have wakened and strengthened people＇s awareness over energy dilemma. In the management of energy, it gradually comes to us that energy-saving technologies and equipment are just part of the solution which requires other inputs at the practice level, for example,展开更多
It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and ener...It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and energy efficiency has not been investigated thoroughly.In this paper,the process to exploit hydrates from flue gas was established.Firstly,flue gas is injected into hydrate reservoirs after it is pressurized.The hydrates in reservoirs partially experience thermal decomposition while the rest is replaced with flue gas,so CH_(4)-CO_(2)-N_(2)mixture is formed.Secondly,the concentrated CH_(4)-CO_(2)mixture is got after N_(2)is separated and removed by using membrane component.And thirdly,the CH_(4)eCO_(2)mixture is delivered to the original electric power plant.This process was simulated by using the software Aspen Plus to analyze the production/injection ratio in the process of flue gas replacement under different injection pressures,the methane replacement ratio,and the energy consumption and energy efficiency in the whole process.It is indicated that the energy in the process of hydrate exploitation from flue gas is mainly consumed at the pressurized injection stage,and the injection pressure increase correspondingly results in the increase of energy consumption at pressurization and membrane separation stages,and to some extent improves the recovery ratio of pressure energy.Besides,when the injection pressure is 5e16 MPa,the production/injection ratio in the process of flue gas replacement is 0.03-0.26,the methane replacement ratio is 19.9-56.2%,the unit energy consumption in the whole process is 2.15-1.05(kW$h)/kgCH_(4),and the energy return on investment(EROI)is 7.2-14.7.It is concluded that the energy efficiency of hydrate exploitation from flue gas can be effectively improved by increasing the injection pressure in the range of 5e10 MPa.展开更多
The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consi...The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.展开更多
Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In vi...Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.展开更多
The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-orga...The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China(No.XT71-20-014).
文摘The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power system with REGs.In this paper,the critical short circuit ratio(CSCR)is defined as the corresponding SCR when the system voltage is in the critical stable state.Through static voltage stability analysis,the mathematical expression of the CSCR considering the impact of GIR is derived.The maximum value of CSCR is adopted as the critical value to distinguish the weak power system.Based on the static equivalent circuit analysis,it is proved that the CSCR is still effective to evaluate critical system strength considering the interactive impact among REGs.Finally,we find that the GIR can be neglected and the SCR can be used individually to evaluate the system strength when SCR>2 or GIR>5.The correctness and rationality of the CSCR and its critical value are validated on ADPSS.
基金the the basic scientific research Funds project of Heilongjiang Universities[grant numbers 2024-KYYWF-0554].
文摘In response to the actual demands of the energy storage type organic Rankine power generation cycle,this study proposes a new type of jacketed shell and tube heat exchanger with integrated cold storage and heat exchange.N-tedecane is selected as the phase change material for cold storage,low-temperature water as the cold source,and R134a as the heat source.The phase change material for cold storage is filled inside the jacket tube of the heat exchanger.Cold fluid is introduced into the inner tube to cause the phase change material to condense and store cold.After the cold storage is completed,R134a flows in from the shell side and condenses through heat exchange with the solidified phase change material for energy storage.This study discusses the influence laws of different cold water mass flow rates and temperatures on the cold storage performance of this heat exchanger,and analyzes the condensation effect of R134a.The results show that when the mass flow rate is 0.5 kg/s and the cold water temperature is between 3 and 4℃,the average power of the energy storage heat exchanger in the condensation experiment is 80W,and the average convective heat transfer coefficient is 110.73 W/(m^(2)⋅K).This research provides an experimental basis for the development of energy storage organic Rankine power generation cycles.
基金financially supported by the National Natural Science foundation of China(grants nos.52272176)。
文摘Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational stability under moisture,heat,and light;toxic lead leakage from degraded films.Metal-organic frameworks(MOFs),with their unique framework structure,large specific surface area,high heavy metal capturing capacity,and tunable conductivity,offer promising solutions to these issues.Recent studies have integrated MOFs into PSCs architectures to enhance performance and durability.This comprehensive review begins with an in-depth discussion of the structure,optical properties,electrical characteristics,and stability of MOFs,as well as their theoretical compatibility with perovskites.Subsequently,it provides a detailed analysis of how MOFs enhance charge carrier transport,promote perovskite crystallinity,improve device stability,and suppress lead leakage in PSCs.In summary,this review examines the research progress and potential of integrating MOFs with perovskites to address the critical PSCs challenges of efficiency,instability,and toxicity.
基金supported by the Anhui Provincial Science and Technology Innovation Initiative(202423i08050051)the Anhui Provincial Natural Science Foundation(2408085MB029)+1 种基金the HFIPS Director’s Fund(YZJJGGZX202201)the Natural Science Foundation of Hebei Province of China(B2024402018)。
文摘Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites and the occurrence of significant side reactions.Herein,sucralose(SCL),as an electrolyte additive,has been used to promote the exposure of the Zn(002)texture.The introduction of SCL can adjust the Zn~(2+)nucleation and diffusion along different crystal facets,promoting the exposure of the Zn(002)texture.By substituting water molecules in the[Zn(H_(2)O)_(6)]~(2+),SCL reconfigures the hydrogen bond network in the electrolyte,reconstructing the solvation structure and suppressing the hydrogen evolution reaction.Consequently,the Zn//Zn symmetric battery exhibits long-term cycling stability of over 4900 h at 1 mA cm^(-2)-1 mAh cm^(-2).Even at a harsh condition of 30 mA cm^(-2)-30 mAh cm^(-2)(DOD=73.3%),it can stably cycle for 171 h.The CE of the Zn//Cu half battery reaches 99.61% at 0.2 mA cm^(-2)with 0.2 mAh cm^(-2).Employing the optimized electrolyte,after 500 cycles,a high specific capacity of 420 mAh g^(-1)can be retained for the NH_4V_4O_(10)//Zn full battery at 500 mA g^(-1),corresponding to a capacity retention of 90.7%.
文摘With the continuous development of Chinas national economy, urban heating develops rapidly, and heating companies continue to increase. How to realize the reasonable and efficient production of heating network has become an urgent problem. In recent years, with the gradual development of comprehensive environmental management in the country, thermal power companies have used the internet information platform to carry out technical updates in order to improve system management, save energy and reduce consumption, reduce heating costs and pollution. How to make heating users enjoy heat energy most economically and appropriately has become the most prominent problem for current heating users and even social environmental protection requirements. Household heating and metering system has become the leading system of current heating system. If heating users want to control the room temperature through temperature control valves according to their own needs, they must make the whole indoor temperature reach the appropriate temperature. However, people often ignore the heat source of heat exchange station or heating station, and there are also many links that can be optimized by pipeline design and heat source reuse. Users can not only adjust the indoor temperature by adjusting the indoor regulating valve, but also adjust the function of the equipment in the station, thereby playing the role of energy saving and emission reduction. Based on this, this paper studies and analyzes the energy saving and emission reduction of urban heating for reference. Based on this, this paper will analyze the reduction of energy and emissions of urban smart warming.
基金Supported by the National Key Research and Development Program of China(2017YFB0602500)the Basic Research Program of Hebei Province(16964502D)
文摘Reactive distillation(RD) process is an innovative hybrid process combining reaction with distillation, which has recently come into sharp focus as a successful case of process intensification. Considered as the most representative case of process intensification, it has been applied for many productions, especially for production of ester compounds. However, such problems existing in the RD system for ester productions are still hard to solve,as the removal of the water which comes from the esterification, and the separation of the azeotropes of ester–alcohol(–water). Many methods have been studying on the process to solve the problems resulting in further intensification and energy saving. In this paper, azeotropic–reactive distillation or entrainer enhanced reactive distillation(ERD) process, reactive extractive distillation(RED) process, the method of co-production in RD process, pressure-swing reactive distillation(PSRD) process, reactive distillation–pervaporation coupled process(RD–PV), are introduced to solve the problems above, so the product(s) can be separated efficiently and the chemical equilibrium can be shifted. Dividing-wall column(DWC) structure and novel methods of loading catalyst are also introduced as the measures to intensify the process and save energy.
文摘Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromatic hydrocarbon content,appropriate modification can increase its value and expand its energy storage applications.Current research progress on the common preparation methods of petroleum asphalt-based carbon materials,including template-assisted pyrolysis,molten salt treatment,activation,heteroatom doping,and pre-oxidation is reviewed,and its use in supercapacitors and alkali metal ion batteries,is also elaborated.Feasible solutions for the current problems with petroleum asphalt are proposed,with the aim of providing insights into its high value-added utilization.
基金Project(2010CB227103) supported by the National Basic Research Program of ChinaProjects(50930007,50836005) supported by the Key Program of the National Natural Science Foundation of ChinaProject(U1034005) supported by the National Natural Science Foundation of China
文摘The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.
基金supported by the National Natural Science Foundation of China (51176051 and 51106054)the Fundamental Research Funds for the Central University (2015ZM057, 2013ZZ0032 and 2014ZP0007)+1 种基金China Postdoctoral Science Foundation (2015M572321)the Petro China Innovation Foundation (2013D-5006-0107)
文摘Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the aspects of energy efficiency. Different exploiting methods and different types of hydrate reservoir were selected to study their effects on energy efficiencies. Both laboratory studies and field tests have shown that the improved technologies can help to increase efficiency for gas hydrate exploitation. And it also showed the trend that gas hydrate exploitation started to change from permafrost to marine. Energy efficiency ratio （EER） and energy return on energy invested （EROI） were introduced as an indicator of efficiency for natural gas hydrate exploitation. An energy-efficient hydrate production process, called ＂Hydrate Chain Energy System （HCES）＂, including treatment of flue gas, replacement of CH4 with CO2, separation of CO2 from CH4, and storage and transportation of CH4 in hydrate form, was proposed for future natural gas hydrate exploitation. In the meanwhile, some problems, such as mechanism of C02 replacement, mechanism of CO2 separation, CH4 storage and transportation are also needed to be solved for increasing the energy efficiency of gas hydrate exploitation.
文摘The performances of a hybrid energy system for decentralized heating are investigated.The proposed energy system consists of a solar collector,an air-source heat pump,a gas-fired boiler and a hot water tank.A mathematical model is developed to predict the operating characteristics of the system.The simulation results are compared with experimental data.Such a comparison indicates that the model accuracy is sufficient.The influence of the flat plate solar collector area on the economic and energy efficiency of such system is also evaluated through numerical simulations.Finally,this system is optimized using the method of orthogonal design.The results clearly demonstrate that the solar-heat pump-gas combined system is more convenient and efficient than the simple gas system and the heat pump-gas combined system,whereas it is less convenient but more efficient than the solarassisted gas system.
基金the financial support from the National Key Research and Development Program of China(2019YFD1100204)the National Natural Science Foundation of China(52091545)+2 种基金the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(2021TS03)The Important Projects in the Scientific Innovation of CECEP(cecep-zdkj-2020-009)the Open Project of Key Laboratory of Environmental Biotechnology,Chinese Academy of Sciences(kf2018002).
文摘Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutrality.However,water-energy nexus analysis and models for WWTPs have rarely been reported to date.In this study,a cloud-model-based energy consumption analysis(CMECA)of a WWTP was conducted to explore the relationship between influent and energy consumption by clustering its influent’s parameters.The principal component analysis(PCA)and K-means clustering were applied to classify the influent condition using water quality and volume data.The energy consumption of the WWTP is divided into five standard evaluation levels,and its cloud digital characteristics(CDCs)were extracted according to bilateral constraints and golden ratio methods.Our results showed that the energy consumption distribution gradually dispersed and deviated from the Gaussian distribution with decreased water concentration and quantity.The days with high energy efficiency were extracted via the clustering method from the influent category of excessive energy consumption,represented by a compact-type energy consumption distribution curve to identify the influent conditions that affect the steady distribution of energy consumption.The local WWTP has high energy consumption with 0.3613 kW·h·m^(-3)despite low influent concentration and volumes,across four consumption levels from low(I)to relatively high(IV),showing an unsatisfactory operation and management level.The average oxygenation capacity,internal reflux ratio,and external reflux ratio during high energy efficiency days recognized by further clustering were obtained(0.2924-0.3703 kg O_(2)·m^(-3),1.9576-2.4787,and 0.6603-0.8361,respectively),which could be used as a guide for the days with low energy efficiency.Consequently,this study offers a water-energy nexus analysis method to identify influent conditions with operational management anomalies and can be used as an empirical reference for the optimized operation of WWTPs.
基金Project(2011B061200043)supported by the Guangdong Provincial Department of Science and Technology,China
文摘Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.
基金Project supported by the National Natural Science Foundation of China(21771050)the Natural Science Foundation of Hebei Province(B2018202134,B2016202149,B2016202147)Outstanding Innovative Topics of Hebei Province(220056)。
文摘Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive polymeric hydrogel based on the combination of excited state intramolecular proton transfer(ESIPT) molecule(Salicylic acid,Sal) and terbium(Ⅲ)(Tb^(3+)),as enabled by external stimuli to construct artificial light-harvesting antenna systems.Benefiting from unique photophysical properties of Sal,the synthesized hydrogel displays a temperature-dependent reversible opaque?transparent states transition,accompanied with an interesting photoluminescence behavior.Moreover,by further incorporating europium(Ⅲ)(Eu^(3+)) into the hydrogel,we demonstrate well-defined cascades of energy transfer that provides a tunable optical output from the collection of lanthanides by the excitation of a common sensitizer(Sal) upon base vapor stimulation.Efficient energy transfer efficiency from Tb^(3+) to Eu^(3+),as high as 97.8%,was also obtained as established by the time-resolved fluorescence spectroscopy analysis.
基金Sponsored by the Liaoning Provincial Science and Technology Program Project(Grant No.2012219024)
文摘In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system simulation and ther^nodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance.
文摘According to the year of 2009, calculated energy consumption quantity and energy consumption structure of building in Guangzhou to 2030, analyzed adjustment and approach of sustainable development and potential of energy conservation which can provide commendable technology progress in every department.
文摘The concept of the energy management system （EnMS） standards comes from the worldwide concern on energy problems. The increasing conflicts between global economic development and energyrelated restrictions have wakened and strengthened people＇s awareness over energy dilemma. In the management of energy, it gradually comes to us that energy-saving technologies and equipment are just part of the solution which requires other inputs at the practice level, for example,
文摘It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and energy efficiency has not been investigated thoroughly.In this paper,the process to exploit hydrates from flue gas was established.Firstly,flue gas is injected into hydrate reservoirs after it is pressurized.The hydrates in reservoirs partially experience thermal decomposition while the rest is replaced with flue gas,so CH_(4)-CO_(2)-N_(2)mixture is formed.Secondly,the concentrated CH_(4)-CO_(2)mixture is got after N_(2)is separated and removed by using membrane component.And thirdly,the CH_(4)eCO_(2)mixture is delivered to the original electric power plant.This process was simulated by using the software Aspen Plus to analyze the production/injection ratio in the process of flue gas replacement under different injection pressures,the methane replacement ratio,and the energy consumption and energy efficiency in the whole process.It is indicated that the energy in the process of hydrate exploitation from flue gas is mainly consumed at the pressurized injection stage,and the injection pressure increase correspondingly results in the increase of energy consumption at pressurization and membrane separation stages,and to some extent improves the recovery ratio of pressure energy.Besides,when the injection pressure is 5e16 MPa,the production/injection ratio in the process of flue gas replacement is 0.03-0.26,the methane replacement ratio is 19.9-56.2%,the unit energy consumption in the whole process is 2.15-1.05(kW$h)/kgCH_(4),and the energy return on investment(EROI)is 7.2-14.7.It is concluded that the energy efficiency of hydrate exploitation from flue gas can be effectively improved by increasing the injection pressure in the range of 5e10 MPa.
文摘The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.
基金supported by the National Key Research and Development Program of China for Young Scientists(Grant No.2023YFB4104100)the National Natural Science Foundation of China(Grant 52176057)+3 种基金the National Key Research and Development Program of China(Grant No.2023YFB4104201)supported by the Unveiling and Commanding Foundation of Liaoning Province(Grant 2023JH1/10400003)the Shenzhen Science and Technology Program(No.JCYJ20220818095605012)supported by the Young Changjiang Scholars programme of China。
文摘Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.
基金supported by the National Natural Science Foundation of China(Nos.52308300,52370025,52108266).
文摘The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.
