Global freshwater scarcity and energy shortages demand integrated solutions.To overcome limitations of traditional solar evaporators,such as salt accumulation,thermal dissipation,and material scalability issues,this s...Global freshwater scarcity and energy shortages demand integrated solutions.To overcome limitations of traditional solar evaporators,such as salt accumulation,thermal dissipation,and material scalability issues,this study presents a biomass-derived three-dimensional(3D)aerogel-based dual-function solar evaporator that simultaneously achieves ultra-high freshwater production and continuous electricity generation.By ingeniously integrating a superhydrophobic inner layer for thermal insulation and buoyancy with a hydrophilic photothermal outer layer for rapid water transport and solar absorption,our design overcomes the trade-offs between evaporation efficiency,salt resistance,and energy loss.The evaporator exhibits exceptional dual performance:an evaporation rate of 3.87 kg m^(-2)h-1(1 sun)and a sustained open-circuit voltage of 222.6 mV,surpassing most reported systems.This synergy originates from ion gradient-driven streaming potentials enabled by selective Na^(+) transport through–COOH/C–OH functionalized microchannels,as verified by molecular dynamics simulations.Crucially,the fabrication process utilizes low-cost biomass materials and scalable techniques,demonstrating significant potential for commercialization.This work not only provides a mechanistic understanding of ion-selective transport in dual-function evaporators but also establishes a paradigm for sustainable co-production of clean water and renewable energy,addressing two pressing global challenges through a single and scalable platform.展开更多
Enhancing wastewater treatment efficiency through innovative technologies is paramount in addressing global environmental challenges.This study explores utilizing stereoscopic hydrogel evaporators combined with renewa...Enhancing wastewater treatment efficiency through innovative technologies is paramount in addressing global environmental challenges.This study explores utilizing stereoscopic hydrogel evaporators combined with renewable energy sources to optimize wastewater treatment processes.A cross-linked super absorbent polymer(SAP)hydrogel was synthesized using acrylic acid and 2-hydroxyethyl methacrylate monomers and integrated with a light-absorbing carbon membrane to form a solar-assisted evaporator(MSAP).The MSAP achieved a high evaporation rate of 3.08 kg m^(-2)·h^(-1)and a photothermal conversion efficiency of 94.27%.It demonstrated excellent removal efficiency for dye-polluted wastewater,significantly reducing concentrations of pollutants.The MSAP maintained high performance in outdoor conditions,showcasing its potential for real-world applications.This approach,incorporating both solar and wind energy,significantly boosts water evaporation rates and presents a promising,eco-friendly solution for sustainable wastewater treatment within the circular development framework.展开更多
This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condens...This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests that heat loads are applied to both evaporators, the MLHP was stably operated as with a LHP with a single evaporator and a single condenser. The relation between the sink temperature and the thermal resistance was experimentally evaluated. In the test with the heat load to one evaporator, the heat transfer from the heated evaporator to the unheated evaporator was confirmed. In the heat load switching test, in which the heat load is switched from one evaporator to another evaporator repeatedly, the MLHP could be stably operated. The loop operation with the large temperature difference between the heat sinks was also tested. From this result, the stable operation of the MLHP in the various conditions was demonstrated. It was also found that a flow regulator which prevents the uncondensed vapor from the condensers is required at the inlet of the common liquid line when one condenser has higher temperature and cannot condense the vapor in it.展开更多
Multiple loop heat pipes which have two evaporators and two condensers in one loop are a kind of active heat transfer device. Since they have two evaporators and two condensers, the operating mode also becomes multipl...Multiple loop heat pipes which have two evaporators and two condensers in one loop are a kind of active heat transfer device. Since they have two evaporators and two condensers, the operating mode also becomes multiple. This work discusses the cases that multiple loop heat pipes were operated with one condenser at high temperature and the other at low temperature. To avoid the high temperature returning liquid and keep the multiple loop heat pipes work properly, the flow regulator which was made of polyethylene was designed, fabricated and applied in this test. The effect of flow regulator was confirmed and analyzed. In the test that large temperature difference existed between two sinks, it can be found according to the result that the flow regulator worked effectively and prevented the high temperature vapor to enter the inlet of common liquid line, which can keep the evaporators and returning liquid to operate at low temperature. With the increment of heat loads and the temperature difference between two sinks, the pressure difference between two condensers became larger and larger. When the pressure difference was larger than the flow regulator’s capillary force, the flow regulator could not work properly because the high temperature vapor began to flow through the flow regulator. According to the test data, the flow regulator can work properly within the sinks’ temperature 0°C/60°C and the two evaporators’ heat load 30/30 W.展开更多
Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop hea...Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop heat pipe were calculated by examining the change of heating rate of two evaporators. Calculation results showed that the vapor and liquid flow rates in the loop heat pipe and the thermal conductance of the heat pipe changed significantly depending on the distribution ratio of the heating rate of the multiple evaporators. The thermal performance of the vertical loop heat pipe with two evaporators was also examined and experimental results of flow direction and thermal conductance of the heat pipe agreed with the analytical results. The lumped network model analysis is therefore considered accurate and preferable for the practical design of a loop heat pipe with multiple evaporators.展开更多
The refrigerant flow distribution in the parallel flow microchannel evaporators is experimentally investigated to study the effect of header configuration.Six different configurations are tested in the same evaporator...The refrigerant flow distribution in the parallel flow microchannel evaporators is experimentally investigated to study the effect of header configuration.Six different configurations are tested in the same evaporator by installing insertion device and partition plate in the header to ensure the consistency of the other structure parameters.The results show that the uniformity of refrigerant flow distribution and the heat transfer rate are greatly improved by reducing the sectional area of header.The heat transfer rate can increase by 67.93%by reducing the sectional area of both inlet and outlet headers.The uniformity of refrigerant flow distribution and the heat transfer rate become worse after installing the partition plate in the insertion devices and changing the inner structure of the header further.展开更多
The flow field and flow state of thin-film evaporators are complex,and it is significant to effectively divide and quantify the flow field and flow state,as well as to study the internal flow field distribution and ma...The flow field and flow state of thin-film evaporators are complex,and it is significant to effectively divide and quantify the flow field and flow state,as well as to study the internal flow field distribution and material mixing characteristics to improve the efficiency of thin-film evaporators.By using computational fluid dynamics(CFD)numerical simulation,the distribution pattern of the high-viscosity fluid flow field in the thin-film evaporators was obtained.It was found that the staggered interrupted blades could greatly promote material mixing and transportation,and impact the film formation of high-viscosity materials on the evaporator wall.Furthermore,a flow field state recognition method based on radial volume fraction statistics was proposed,and could quantitatively describe the internal flow field of thin-film evaporators.The method divides the high-viscosity materials in the thin-film evaporators into three flow states,the liquid film state,the exchange state and the liquid mass state.The three states of materials could be quantitatively described.The results show that the materials in the exchange state can connect the liquid film and the liquid mass,complete the material mixing and exchange,renew the liquid film,and maintain continuous and efficient liquid film evaporation.展开更多
Objective To prevent the maldistribution of two phase refrigerant in dry expansion evaporators composed of parallel coils, a distributor is needed to supply refrigerant into the coils. Methods A simplified model of...Objective To prevent the maldistribution of two phase refrigerant in dry expansion evaporators composed of parallel coils, a distributor is needed to supply refrigerant into the coils. Methods A simplified model of dry expansion evaporator was proposed. The flow and heat transfer in distributing pipes and evaporator coils were simulated with a numerical method. Results The heat flow rate decreases while the refrigerant is distributed unequally to evaporator coils. Conclusion In order to maintain the heat flow rate, larger heat transfer area should be arranged to make up the effect of maldistribution. The larger the discrepancy of mass flow rate is, the more heat transfer area is needed.展开更多
The development of tellurium(Te)-based semiconductor nanomaterials for efficient light-to-heat conversion may offer an effective means of harvesting sunlight to address global energy concerns.However,the nanosized Te(...The development of tellurium(Te)-based semiconductor nanomaterials for efficient light-to-heat conversion may offer an effective means of harvesting sunlight to address global energy concerns.However,the nanosized Te(nano-Te)materials reported to date suffer from a series of drawbacks,including limited light absorption and a lack of surface structures.Herein,we report the preparation of nano-Te by electrochemical exfoliation using an electrolyzable room-temperature ionic liquid.Anions,cations,and their corresponding electrolytic products acting as chemical scissors can precisely intercalate and functionalize bulk Te.The resulting nano-Te has high morphological entropy,rich surface functional groups,and broad light absorption.We also constructed foam hydrogels based on poly(vinyl alcohol)/nano-Te,which achieved an evaporation rate and energy efficiency of 4.11 kg m^(−2)h^(−1)and 128%,respectively,under 1 sun irradiation.Furthermore,the evaporation rate was maintained in the range 2.5-3.0 kg m^(−2)h^(−1)outdoors under 0.5-1.0 sun,providing highly efficient evaporation under low light conditions.展开更多
Frost accumulation on the evaporator fins of air source heat pumps(ASHPs)severely degrades heat transfer performance and overall system efficiency.To address this,the present study employs computational fluid dynamics...Frost accumulation on the evaporator fins of air source heat pumps(ASHPs)severely degrades heat transfer performance and overall system efficiency.To address this,the present study employs computational fluid dynamics(CFD)to investigate how fin spacing influences frosting behavior,emphasizing the coupled evolution of frost thickness,density,airflow,and temperature distribution within fin channels.Results reveal that fin spacing is a key parameter governing both the extent and rate of frost growth.Wider fin spacing enhances frost accumulation,with a final frost mass of 6.41 g at 12 mm,about 71.8%higher than at 4 mm.In contrast,narrower spacing suppresses frost formation by accelerating airflow.The frost layer exhibits a distinct two-stage growth pattern:at 12 mm spacing,the early-stage average thickness growth rate reaches 0.021 mm/min,nearly 4.3 times that at 4 mm.Frost density follows similar initial trends across different spacings but diverges later due to thermal resistance and airflow variations.展开更多
Solar-driven interfacial evaporation has shown great potential for achieving desalination with high energy conversion efficiency.However,maintaining a high evaporation rate is challenging due to salt accumulation on s...Solar-driven interfacial evaporation has shown great potential for achieving desalination with high energy conversion efficiency.However,maintaining a high evaporation rate is challenging due to salt accumulation on solar evaporators(SEs),leading to a long-standing trade-off between stable evaporation and salt accumulation in conventional SEs.Inspired by the salt secretion and brine transport mechanisms in mangroves,we present a bio-inspired solar evaporator(BSE)featuring an external photothermal layer and an internal water supply channel.This design enables efficient and continuous evaporation from near-saturated brine using less photothermal material.The BSE exhibits high evaporation performance(3.98 kg m^(–2)h^(–1)for 25 wt% brine),effcient salt collection(1.27 kg m^(–2)h^(–1)for 25 wt% brine),long-term durability(7 d in 25 wt% brine),and zero liquid discharge desalination.Notably,the BSE achieves a record-high water production rate of 3.50 kg m^(–2)h^(–1)in outdoor tests.Furthermore,it can purify World Health Organization-standard freshwater from various types of contaminated water.Importantly,the universality of BSE design is validated by extending it to other solar desalination systems.This work demonstrates a universal SE design,providing key insights into the design of next-generation SEs for efficient and stable evaporation in continuous high-salinity brine desalination.展开更多
Solar-driven interfacial water evaporation technology offers a zero-carbon,sustainable solution for extracting clean water from seawater and wastewater,presenting an effective strategy to address the global water cris...Solar-driven interfacial water evaporation technology offers a zero-carbon,sustainable solution for extracting clean water from seawater and wastewater,presenting an effective strategy to address the global water crisis.This study has employed finite element simulation to investigate the solar interfacial evaporation process,elucidating the interactions between heat,water,and salt during evaporation.Additionally,the internal water channels of the evaporator are optimized and designed using topology optimization techniques.In this project,a cylindrical evaporator model with vertical micropores is developed from carbon-based polymer materials.The impact of pore diameter and spacing on the evaporation rate is analyzed,alongside the effects of thermal conductivity,solar radiation intensity,and ambient wind speed on the evaporator's performance.Simulations have revealed that with a pore diameter of 20μm and a spacing of 0.55 mm,the evaporator achieves the highest evaporation rate of 0.91 kg·m^(-2)·h^(-1).The findings indicate that smaller pore sizes substantially enhance the evaporation rate,while larger pore spacings initially increase,and then decrease the rate.Further optimization involves using 20μm-diameter round pores and adjusting the cross-sectional shapes of the pores based on topological configurations with a material volume factor of 0.5.The optimized structure demonstrates an evaporation rate of 2.91 kg·m^(-2)·h^(-1),representing a 219.78%increase over the unoptimized design.These optimized structures and simulation results provide valuable insights for future evaporator designs.展开更多
Interfacial solar evaporation(ISE)has emerged as a promising technology to alleviate global water scarcity via energy-efficient purification of both wastewater and seawater.While ISE was originally identified and deve...Interfacial solar evaporation(ISE)has emerged as a promising technology to alleviate global water scarcity via energy-efficient purification of both wastewater and seawater.While ISE was originally identified and developed during studies of simple double-layered two-dimensional(2D)evaporators,observed limitations in evaporation rate and functionality soon led to the development of three-dimensional(3D)evaporators,which is now recognized as one of the most pivotal milestones in the research field.3D evaporators significantly enhance the evaporation rates beyond the theoretical limits of 2D evaporators.Furthermore,3D evaporators could have multifaceted functionalities originating from various functional evaporation surfaces and 3D structures.This review summarizes recent advances in 3D evaporators,focusing on rational design,fabrication and energy nexus of 3D evaporators,and the derivative functions for improving solar evaporation performance and exploring novel applications.Future research prospects are also proposed based on the in-depth understanding of the fundamental aspects of 3D evaporators and the requirements for practical applications.展开更多
By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,t...By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.展开更多
While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfa...While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.展开更多
Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have bee...Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have been proven to increase the evaporation rate by harnessing the energy from the surroundings,further development is still required in terms of convenient fabrication with potential scalability.Herein,we propose to overcome this challenge by using a high internal phase emulsion(HIPE)to template the synthesis of 3D hierarchically porous evaporators.The HIPE‐templated synthesis combined with a molding process can efficiently fabricate the desired 3D shape without wasting any materials and generate a hierarchically porous internal structure for continuous water supply.Engineering the overall shape and internal pores produces a 3D evaporator that can suppress conduction heat loss and efficiently collect thermal energy from its surroundings,boosting the evaporation rate to 2.82 kg/(m2 h)under 1‐sun illumination,which is significantly higher than conventional 2D evaporators.HIPE‐templating synthesis is an easy but effective way to produce various porous polymers,promising for a wide range of applications where easy production,excellent shape control,and potential scalability are critical.展开更多
S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB...S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB)degradation.The effects of two different mixing routes were identified on the MB degradation performance.Particularly,the catalyst obtained by the alcohol solvent evaporation(MOF-AEP)mixing route could degrade 95.60%MB(50 mg/L)within 4 min(degradation rate:K=0.78 min^(-1)),which was faster than that derived from the direct grinding method(MOF-DGP,80.97%,K=0.39 min^(-1)).X-ray photoelectron spectroscopy revealed that the Co-S content of MOF-AEP(43.39at%)was less than that of MOF-DGP(54.73at%),and the proportion of C-S-C in MOF-AEP(13.56at%)was higher than that of MOF-DGP(10.67at%).Density functional theory calculations revealed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton,which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond(-2.86 eV).Thus,the C-S-C sites might provide more contributions to activate PMS compared with Co-S.Furthermore,the degradation parameters,including pH and MOF-AEP dosage,were investigated.Finally,radical quenching experiments and electron paramagnetic resonance(EPR)measurements revealed that ^(1)O_(2)might be the primary catalytic species,whereas·O~(2-)might be the secondary one in degrading MB.展开更多
The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the p...The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the performance of solar energy evaporation and minimizing material degradation during application can be achieved through the design of novel photothermal materials.In solar interfacial evaporation,photothermal materials exhibit a wide range of additional characteristics,but a systematic overview is lacking.This paper encompasses an examination of various categories and principles pertaining to photothermal materials,as well as the structural design considerations for salt-resistant materials.Additionally,we discuss the versatile uses of this appealing technology in different sectors related to energy and the environment.Furthermore,potential solutions to enhance the durability of photothermal materials are also highlighted,such as the rational design of micro/nano-structures,the use of adhesives,the addition of anti-corrosion coatings,and the preparation of self-healing surfaces.The objective of this review is to offer a viable resolution for the logical creation of high-performance photothermal substances,presenting a guide for the forthcoming advancement of solar evaporation technology.展开更多
Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit ...Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit a rapid shift toward higher energy channels during the flare's rising phase,followed by a gradual decrease during the decay phase.Through precise energy calibration,the centroids are determined with high accuracy.Temperature and velocity are then self-consistently derived by comparing the centroids with those calculated from the synthesized line features using the latest CHIANTI atomic database(ver.10.1).The calculated maximum velocity reaches up to 710±60 km s-1,which significantly exceeds the previously reported values.Our results suggest that the entire shift of soft X-ray lines may occur during the process of chromospheric evaporation.展开更多
Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.Thi...Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.This paper presents a high-fidelity numerical study of liquidatomization and spray combustion under high-pressure conditions,emphasizing the effects of pres-sure oscillations on the flow evolution and combustion dynamics.The theoretical framework isbased on the three-dimensional conservation equations for multiphase flows and turbulent combus-tion.The numerical solution is achieved using a coupling method of volume-of-fluid and Lagran-gian particle tracking.The Zhuang-Kadota-Sutton(ZKS)high-pressure evaporation model andthe eddy breakup-Arrhenius combustion model are employed.Simulations are conducted for amodel combustion chamber with impinging-jet injectors using liquid oxygen and kerosene as pro-pellants.Both conditions with and without inlet and outlet pressure oscillations are considered.Thefindings reveal that pressure oscillations amplify flow fluctuations and can be characterized usingkey physical parameters such as droplet evaporation,chemical reaction,and chamber pressure.The spectral analysis uncovers the axial variations of the dominant and secondary frequenciesand their amplitudes in terms of the characteristic physical quantities.This research helps establisha methodology for exploring the coupling effect of liquid atomization and spray combustion.It alsoprovides practical insights into their responses to pressure oscillations during the occurrence ofcombustion instability.This information can be used to enhance the design and operation ofliquid-fueled propulsion engines.展开更多
文摘Global freshwater scarcity and energy shortages demand integrated solutions.To overcome limitations of traditional solar evaporators,such as salt accumulation,thermal dissipation,and material scalability issues,this study presents a biomass-derived three-dimensional(3D)aerogel-based dual-function solar evaporator that simultaneously achieves ultra-high freshwater production and continuous electricity generation.By ingeniously integrating a superhydrophobic inner layer for thermal insulation and buoyancy with a hydrophilic photothermal outer layer for rapid water transport and solar absorption,our design overcomes the trade-offs between evaporation efficiency,salt resistance,and energy loss.The evaporator exhibits exceptional dual performance:an evaporation rate of 3.87 kg m^(-2)h-1(1 sun)and a sustained open-circuit voltage of 222.6 mV,surpassing most reported systems.This synergy originates from ion gradient-driven streaming potentials enabled by selective Na^(+) transport through–COOH/C–OH functionalized microchannels,as verified by molecular dynamics simulations.Crucially,the fabrication process utilizes low-cost biomass materials and scalable techniques,demonstrating significant potential for commercialization.This work not only provides a mechanistic understanding of ion-selective transport in dual-function evaporators but also establishes a paradigm for sustainable co-production of clean water and renewable energy,addressing two pressing global challenges through a single and scalable platform.
基金financially supported by the“Qing-Lan”Project of Jiangsu ProvinceTop-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)the start-up fund from Yangzhou University。
文摘Enhancing wastewater treatment efficiency through innovative technologies is paramount in addressing global environmental challenges.This study explores utilizing stereoscopic hydrogel evaporators combined with renewable energy sources to optimize wastewater treatment processes.A cross-linked super absorbent polymer(SAP)hydrogel was synthesized using acrylic acid and 2-hydroxyethyl methacrylate monomers and integrated with a light-absorbing carbon membrane to form a solar-assisted evaporator(MSAP).The MSAP achieved a high evaporation rate of 3.08 kg m^(-2)·h^(-1)and a photothermal conversion efficiency of 94.27%.It demonstrated excellent removal efficiency for dye-polluted wastewater,significantly reducing concentrations of pollutants.The MSAP maintained high performance in outdoor conditions,showcasing its potential for real-world applications.This approach,incorporating both solar and wind energy,significantly boosts water evaporation rates and presents a promising,eco-friendly solution for sustainable wastewater treatment within the circular development framework.
文摘This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests that heat loads are applied to both evaporators, the MLHP was stably operated as with a LHP with a single evaporator and a single condenser. The relation between the sink temperature and the thermal resistance was experimentally evaluated. In the test with the heat load to one evaporator, the heat transfer from the heated evaporator to the unheated evaporator was confirmed. In the heat load switching test, in which the heat load is switched from one evaporator to another evaporator repeatedly, the MLHP could be stably operated. The loop operation with the large temperature difference between the heat sinks was also tested. From this result, the stable operation of the MLHP in the various conditions was demonstrated. It was also found that a flow regulator which prevents the uncondensed vapor from the condensers is required at the inlet of the common liquid line when one condenser has higher temperature and cannot condense the vapor in it.
文摘Multiple loop heat pipes which have two evaporators and two condensers in one loop are a kind of active heat transfer device. Since they have two evaporators and two condensers, the operating mode also becomes multiple. This work discusses the cases that multiple loop heat pipes were operated with one condenser at high temperature and the other at low temperature. To avoid the high temperature returning liquid and keep the multiple loop heat pipes work properly, the flow regulator which was made of polyethylene was designed, fabricated and applied in this test. The effect of flow regulator was confirmed and analyzed. In the test that large temperature difference existed between two sinks, it can be found according to the result that the flow regulator worked effectively and prevented the high temperature vapor to enter the inlet of common liquid line, which can keep the evaporators and returning liquid to operate at low temperature. With the increment of heat loads and the temperature difference between two sinks, the pressure difference between two condensers became larger and larger. When the pressure difference was larger than the flow regulator’s capillary force, the flow regulator could not work properly because the high temperature vapor began to flow through the flow regulator. According to the test data, the flow regulator can work properly within the sinks’ temperature 0°C/60°C and the two evaporators’ heat load 30/30 W.
文摘Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop heat pipe were calculated by examining the change of heating rate of two evaporators. Calculation results showed that the vapor and liquid flow rates in the loop heat pipe and the thermal conductance of the heat pipe changed significantly depending on the distribution ratio of the heating rate of the multiple evaporators. The thermal performance of the vertical loop heat pipe with two evaporators was also examined and experimental results of flow direction and thermal conductance of the heat pipe agreed with the analytical results. The lumped network model analysis is therefore considered accurate and preferable for the practical design of a loop heat pipe with multiple evaporators.
基金the Key Industry Common Key-Technology Innovation Project of Chongqing Municipal Science and Committee(No.cstc2015zdcy-ztzx60001)
文摘The refrigerant flow distribution in the parallel flow microchannel evaporators is experimentally investigated to study the effect of header configuration.Six different configurations are tested in the same evaporator by installing insertion device and partition plate in the header to ensure the consistency of the other structure parameters.The results show that the uniformity of refrigerant flow distribution and the heat transfer rate are greatly improved by reducing the sectional area of header.The heat transfer rate can increase by 67.93%by reducing the sectional area of both inlet and outlet headers.The uniformity of refrigerant flow distribution and the heat transfer rate become worse after installing the partition plate in the insertion devices and changing the inner structure of the header further.
基金National Natural Science Foundation of China(Nos.51905089 and 52075093)Special Fund for Basic Research and Operating Costs of Central Colleges and Universities,China(No.22320D-31)Open Fund for National Key Laboratory of Tribology of Tsinghua University,China(No.SKLTKF20B05)。
文摘The flow field and flow state of thin-film evaporators are complex,and it is significant to effectively divide and quantify the flow field and flow state,as well as to study the internal flow field distribution and material mixing characteristics to improve the efficiency of thin-film evaporators.By using computational fluid dynamics(CFD)numerical simulation,the distribution pattern of the high-viscosity fluid flow field in the thin-film evaporators was obtained.It was found that the staggered interrupted blades could greatly promote material mixing and transportation,and impact the film formation of high-viscosity materials on the evaporator wall.Furthermore,a flow field state recognition method based on radial volume fraction statistics was proposed,and could quantitatively describe the internal flow field of thin-film evaporators.The method divides the high-viscosity materials in the thin-film evaporators into three flow states,the liquid film state,the exchange state and the liquid mass state.The three states of materials could be quantitatively described.The results show that the materials in the exchange state can connect the liquid film and the liquid mass,complete the material mixing and exchange,renew the liquid film,and maintain continuous and efficient liquid film evaporation.
文摘Objective To prevent the maldistribution of two phase refrigerant in dry expansion evaporators composed of parallel coils, a distributor is needed to supply refrigerant into the coils. Methods A simplified model of dry expansion evaporator was proposed. The flow and heat transfer in distributing pipes and evaporator coils were simulated with a numerical method. Results The heat flow rate decreases while the refrigerant is distributed unequally to evaporator coils. Conclusion In order to maintain the heat flow rate, larger heat transfer area should be arranged to make up the effect of maldistribution. The larger the discrepancy of mass flow rate is, the more heat transfer area is needed.
基金the Science and Technology Innovation Council of Shenzhen(Grant Nos.JCYJ20200109105212568,KQTD20170810105439418,JCYJ20200109114237902,20200812203318002,and 20200810103814002)the National Natural Science Foundation of China(Grant No.12274197)the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023A1515030240,2019A1515010790,2021A0505110015).
文摘The development of tellurium(Te)-based semiconductor nanomaterials for efficient light-to-heat conversion may offer an effective means of harvesting sunlight to address global energy concerns.However,the nanosized Te(nano-Te)materials reported to date suffer from a series of drawbacks,including limited light absorption and a lack of surface structures.Herein,we report the preparation of nano-Te by electrochemical exfoliation using an electrolyzable room-temperature ionic liquid.Anions,cations,and their corresponding electrolytic products acting as chemical scissors can precisely intercalate and functionalize bulk Te.The resulting nano-Te has high morphological entropy,rich surface functional groups,and broad light absorption.We also constructed foam hydrogels based on poly(vinyl alcohol)/nano-Te,which achieved an evaporation rate and energy efficiency of 4.11 kg m^(−2)h^(−1)and 128%,respectively,under 1 sun irradiation.Furthermore,the evaporation rate was maintained in the range 2.5-3.0 kg m^(−2)h^(−1)outdoors under 0.5-1.0 sun,providing highly efficient evaporation under low light conditions.
基金supported by the Shandong Provincial Natural Science Foundation(ZR2023QE325).
文摘Frost accumulation on the evaporator fins of air source heat pumps(ASHPs)severely degrades heat transfer performance and overall system efficiency.To address this,the present study employs computational fluid dynamics(CFD)to investigate how fin spacing influences frosting behavior,emphasizing the coupled evolution of frost thickness,density,airflow,and temperature distribution within fin channels.Results reveal that fin spacing is a key parameter governing both the extent and rate of frost growth.Wider fin spacing enhances frost accumulation,with a final frost mass of 6.41 g at 12 mm,about 71.8%higher than at 4 mm.In contrast,narrower spacing suppresses frost formation by accelerating airflow.The frost layer exhibits a distinct two-stage growth pattern:at 12 mm spacing,the early-stage average thickness growth rate reaches 0.021 mm/min,nearly 4.3 times that at 4 mm.Frost density follows similar initial trends across different spacings but diverges later due to thermal resistance and airflow variations.
基金supported by Taishan Young Scholar Program(tsqn202306267)the National Natural Science Foundation of China(51802168)the Natural Science Foundation of Shandong Province(ZR2023ME172 and ZR2024ME182)。
文摘Solar-driven interfacial evaporation has shown great potential for achieving desalination with high energy conversion efficiency.However,maintaining a high evaporation rate is challenging due to salt accumulation on solar evaporators(SEs),leading to a long-standing trade-off between stable evaporation and salt accumulation in conventional SEs.Inspired by the salt secretion and brine transport mechanisms in mangroves,we present a bio-inspired solar evaporator(BSE)featuring an external photothermal layer and an internal water supply channel.This design enables efficient and continuous evaporation from near-saturated brine using less photothermal material.The BSE exhibits high evaporation performance(3.98 kg m^(–2)h^(–1)for 25 wt% brine),effcient salt collection(1.27 kg m^(–2)h^(–1)for 25 wt% brine),long-term durability(7 d in 25 wt% brine),and zero liquid discharge desalination.Notably,the BSE achieves a record-high water production rate of 3.50 kg m^(–2)h^(–1)in outdoor tests.Furthermore,it can purify World Health Organization-standard freshwater from various types of contaminated water.Importantly,the universality of BSE design is validated by extending it to other solar desalination systems.This work demonstrates a universal SE design,providing key insights into the design of next-generation SEs for efficient and stable evaporation in continuous high-salinity brine desalination.
基金supported by the National Natural Science Foundation of China(No.52476064,No.52106085)National Key Research and Development Program of China(No.2022YFE0210200)+2 种基金China Postdoctoral Science Foundation(No.2023T160164)Natural Science Foundation of Heilongjiang Province(No.LH2023E043)Fundamental Research Funds for the Central Universities(No.2022ZFJH04,No.HIT.OCEF.2023021)。
文摘Solar-driven interfacial water evaporation technology offers a zero-carbon,sustainable solution for extracting clean water from seawater and wastewater,presenting an effective strategy to address the global water crisis.This study has employed finite element simulation to investigate the solar interfacial evaporation process,elucidating the interactions between heat,water,and salt during evaporation.Additionally,the internal water channels of the evaporator are optimized and designed using topology optimization techniques.In this project,a cylindrical evaporator model with vertical micropores is developed from carbon-based polymer materials.The impact of pore diameter and spacing on the evaporation rate is analyzed,alongside the effects of thermal conductivity,solar radiation intensity,and ambient wind speed on the evaporator's performance.Simulations have revealed that with a pore diameter of 20μm and a spacing of 0.55 mm,the evaporator achieves the highest evaporation rate of 0.91 kg·m^(-2)·h^(-1).The findings indicate that smaller pore sizes substantially enhance the evaporation rate,while larger pore spacings initially increase,and then decrease the rate.Further optimization involves using 20μm-diameter round pores and adjusting the cross-sectional shapes of the pores based on topological configurations with a material volume factor of 0.5.The optimized structure demonstrates an evaporation rate of 2.91 kg·m^(-2)·h^(-1),representing a 219.78%increase over the unoptimized design.These optimized structures and simulation results provide valuable insights for future evaporator designs.
基金financial support from Australian Research Council(FT 190100485,DP 220100583,DP 230102740,and DP 240101581)。
文摘Interfacial solar evaporation(ISE)has emerged as a promising technology to alleviate global water scarcity via energy-efficient purification of both wastewater and seawater.While ISE was originally identified and developed during studies of simple double-layered two-dimensional(2D)evaporators,observed limitations in evaporation rate and functionality soon led to the development of three-dimensional(3D)evaporators,which is now recognized as one of the most pivotal milestones in the research field.3D evaporators significantly enhance the evaporation rates beyond the theoretical limits of 2D evaporators.Furthermore,3D evaporators could have multifaceted functionalities originating from various functional evaporation surfaces and 3D structures.This review summarizes recent advances in 3D evaporators,focusing on rational design,fabrication and energy nexus of 3D evaporators,and the derivative functions for improving solar evaporation performance and exploring novel applications.Future research prospects are also proposed based on the in-depth understanding of the fundamental aspects of 3D evaporators and the requirements for practical applications.
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024RC3003)the Central South University Innovation-Driven Research Programme(2023CXQD012)the Initiative for Sustainable Energy for its financial support。
文摘By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.
基金supported by National Key Research and Development Program of China(2022YFB3804902,2022YFB3804900)the National Natural Science Foundation of China(52203226,52161145406,42376045)the Fundamental Research Funds for the Central Universities(2232024Y-01,2232025D-02).
文摘While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.
基金supported by the University of California Riverside and the Korea Institute of Materials Science through the UC‐KIMS Center for Innovation Materials for Energy and EnvironmentJinxing Chen acknowledges the support of the National Natural Science Foundation of China(Grant No.51901147)the Su‐Zhou Key Laboratory of Functional Nano and Soft Materials,Collaborative Innovation Center of Suzhou Nano Science and Technology,and the 111 Project.The authors also thank Ms.Jessica Lujia Yin and Mr.Zirui Zhou for their kind assistance.
文摘Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have been proven to increase the evaporation rate by harnessing the energy from the surroundings,further development is still required in terms of convenient fabrication with potential scalability.Herein,we propose to overcome this challenge by using a high internal phase emulsion(HIPE)to template the synthesis of 3D hierarchically porous evaporators.The HIPE‐templated synthesis combined with a molding process can efficiently fabricate the desired 3D shape without wasting any materials and generate a hierarchically porous internal structure for continuous water supply.Engineering the overall shape and internal pores produces a 3D evaporator that can suppress conduction heat loss and efficiently collect thermal energy from its surroundings,boosting the evaporation rate to 2.82 kg/(m2 h)under 1‐sun illumination,which is significantly higher than conventional 2D evaporators.HIPE‐templating synthesis is an easy but effective way to produce various porous polymers,promising for a wide range of applications where easy production,excellent shape control,and potential scalability are critical.
基金financially supported by the National Natural Science Foundation of China(Nos.51602018 and 51902018)the Natural Science Foundation of Beijing Municipality(No.2154052)+3 种基金the China Postdoctoral Science Foundation(No.2014M560044)the Fundamental Research Funds for the Central Universities(No.FRF-MP-20-22)USTB Research Center for International People-to-people Exchange in Science,Technology and Civilization(No.2022KFYB007)Education and Teaching Reform Foundation at University of Science and Technology Beijing(Nos.2023JGC027,KC2022QYW06,and KC2022TS09)。
文摘S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB)degradation.The effects of two different mixing routes were identified on the MB degradation performance.Particularly,the catalyst obtained by the alcohol solvent evaporation(MOF-AEP)mixing route could degrade 95.60%MB(50 mg/L)within 4 min(degradation rate:K=0.78 min^(-1)),which was faster than that derived from the direct grinding method(MOF-DGP,80.97%,K=0.39 min^(-1)).X-ray photoelectron spectroscopy revealed that the Co-S content of MOF-AEP(43.39at%)was less than that of MOF-DGP(54.73at%),and the proportion of C-S-C in MOF-AEP(13.56at%)was higher than that of MOF-DGP(10.67at%).Density functional theory calculations revealed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton,which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond(-2.86 eV).Thus,the C-S-C sites might provide more contributions to activate PMS compared with Co-S.Furthermore,the degradation parameters,including pH and MOF-AEP dosage,were investigated.Finally,radical quenching experiments and electron paramagnetic resonance(EPR)measurements revealed that ^(1)O_(2)might be the primary catalytic species,whereas·O~(2-)might be the secondary one in degrading MB.
基金supported by Zhejiang Provincial Natural Science Foundation of China(No.LR23C160001)Scientific Research Startup Foundation of Zhejiang Ocean University(No.11034150220006).
文摘The utilization of solar-driven interfacial evaporation technology is highly important in addressing the energy crisis and water scarcity,primarily because of its affordability and minimal energy usage.Enhancing the performance of solar energy evaporation and minimizing material degradation during application can be achieved through the design of novel photothermal materials.In solar interfacial evaporation,photothermal materials exhibit a wide range of additional characteristics,but a systematic overview is lacking.This paper encompasses an examination of various categories and principles pertaining to photothermal materials,as well as the structural design considerations for salt-resistant materials.Additionally,we discuss the versatile uses of this appealing technology in different sectors related to energy and the environment.Furthermore,potential solutions to enhance the durability of photothermal materials are also highlighted,such as the rational design of micro/nano-structures,the use of adhesives,the addition of anti-corrosion coatings,and the preparation of self-healing surfaces.The objective of this review is to offer a viable resolution for the logical creation of high-performance photothermal substances,presenting a guide for the forthcoming advancement of solar evaporation technology.
文摘Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit a rapid shift toward higher energy channels during the flare's rising phase,followed by a gradual decrease during the decay phase.Through precise energy calibration,the centroids are determined with high accuracy.Temperature and velocity are then self-consistently derived by comparing the centroids with those calculated from the synthesized line features using the latest CHIANTI atomic database(ver.10.1).The calculated maximum velocity reaches up to 710±60 km s-1,which significantly exceeds the previously reported values.Our results suggest that the entire shift of soft X-ray lines may occur during the process of chromospheric evaporation.
基金supported by the National Natural Science Foundation of China(Nos.U23B6009 and 12272050)。
文摘Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.This paper presents a high-fidelity numerical study of liquidatomization and spray combustion under high-pressure conditions,emphasizing the effects of pres-sure oscillations on the flow evolution and combustion dynamics.The theoretical framework isbased on the three-dimensional conservation equations for multiphase flows and turbulent combus-tion.The numerical solution is achieved using a coupling method of volume-of-fluid and Lagran-gian particle tracking.The Zhuang-Kadota-Sutton(ZKS)high-pressure evaporation model andthe eddy breakup-Arrhenius combustion model are employed.Simulations are conducted for amodel combustion chamber with impinging-jet injectors using liquid oxygen and kerosene as pro-pellants.Both conditions with and without inlet and outlet pressure oscillations are considered.Thefindings reveal that pressure oscillations amplify flow fluctuations and can be characterized usingkey physical parameters such as droplet evaporation,chemical reaction,and chamber pressure.The spectral analysis uncovers the axial variations of the dominant and secondary frequenciesand their amplitudes in terms of the characteristic physical quantities.This research helps establisha methodology for exploring the coupling effect of liquid atomization and spray combustion.It alsoprovides practical insights into their responses to pressure oscillations during the occurrence ofcombustion instability.This information can be used to enhance the design and operation ofliquid-fueled propulsion engines.
