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
The solar interfacial evaporation has a broad application prospect in the fields of steam generation and seawater desalination to deal with the global shortage of fresh-water resources.Bamboo is a great material for s...The solar interfacial evaporation has a broad application prospect in the fields of steam generation and seawater desalination to deal with the global shortage of fresh-water resources.Bamboo is a great material for solar interface evaporators because of its low thermal conductivity and inherent micro-channel porous structure.In this paper,a novel bamboo-based solar interface evaporator with a bionic ripple wave surface structure has been proposed.The subsequent evaporation experiments have been conducted to investigate the salt resistance,stability and water absorption of the bionic ripple bamboo based solar interface evaporator.The results have exhibited that the bamboo's water absorption has been enhanced after carbonization modification.Besides,it should be pointed out that this bamboo-based evaporator’s evaporation rate has dropped during the prolonged simulated seawater evaporation experiment,yet it remained fairly consistent at approximately 1.626 kg·m^(-2)·h^(-1).The appearance for this experimental phenomenon is the decrease of the floatability of the evaporator constricted by the stored water body absorbed by the evaporator and the deposition of NaCl crystals at the photothermal interface.Besides,compared with the plate-structure evaporator,the salt deposition in the evaporator equipped with the bionic ripple wave surface structure is greatly improved.In regard to its advantages in low cost,environmental friendliness,good salt tolerance and high evaporation rate,the bamboo-based solar interface evaporator with a bionic ripple wave surface structure can provide a potential solution to the global problem of fresh-water shortage.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
Hydrogel has developed into a very important platform in solar interface evaporator.However,the current hydrogel evaporators are usually three-dimensional evaporators,which will consume a lot of raw materials.Thus,a n...Hydrogel has developed into a very important platform in solar interface evaporator.However,the current hydrogel evaporators are usually three-dimensional evaporators,which will consume a lot of raw materials.Thus,a new two-dimensional hydrogel evaporator is urgently needed to alleviate this problem.Here,a double layer hydrogel evaporator was designed by twice vacuum filtration.Furthermore,through the arched design and the introduction of concentrated brine drainage system,the hydrogel evaporator has enhanced water transportation and tailored water transportation path.Such a unique drainage evaporation system greatly improves the stability of the evaporator.Thereby,a good balance is established between photothermal conversion and water supply,and solar energy is utilized efficiently.It can remain stable in continuous evaporation for up to 12 h with an excellent evaporation rate of 2.70 kg m^(-2)h^(-1)under 1 sun irradiation.Meanwhile,the drainage system realized the 1.8×10^(-10)mol m^(-2)s^(-1)diffusion flux of concentrated brine.Through one-time freeze-drying preparation,an arch-shaped drainage evaporator was used to prepare an evaporation area of more than 20 cm^(2).With the self-made condensate collecting device in outdoor environment,the fresh water yield reaches 7.5 L m^(-2)d^(-1).This provides a new scheme for building a new hydrogel evaporator and solving the fresh water crisis.展开更多
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
Fiber fabrics have been wildly utilized for solar interracial evaporators to address freshwater scarcity.However,the complex and expensive manufacturing processes remain limited to their scalable development.Herein,a ...Fiber fabrics have been wildly utilized for solar interracial evaporators to address freshwater scarcity.However,the complex and expensive manufacturing processes remain limited to their scalable development.Herein,a fabric-based Janus interracial evaporator is efficiently fabricated on a large scale by integrating an extremely innovative self-designed melt-centrifugal spinning technology with spray coating technology.The prepared fabric-based Janus interfacial evaporator has differential hydrophilicity,uneven surfaces,and channels that allow moisture escape.Benefiting from the excellent photothermai conversion of graphene oxide and the charge transfer actions of titanium dioxide,such a multifunction evaporator can reach a high evaporation rate of 1.72 kg m^(-2)h^(-1)under 1 sun irradiation,a superior antibacterial rate of 99%,excellent photocatalytic degradation,and effective thermoelectric ability simultaneously.Moreover,it also shows fantastic performance in salt resistance,recyclable evaporation,and real desalination,This work demonstrates a high-efficiency,cost-effective,multifunctional,and scalable strategy for high-performance fiber fabrics solar interfacial evaporation.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
The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate ...The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate scraping action of the scraper introduces gas into the liquid film,leading to the formation of a gas ring along the wall.This process subsequently reduces wall heat flow,thereby affecting heat transfer.Computational fluid dynamics(CFD)is used to simulate the flow field of the non-Newtonian fluid in the ATFE.The investigation focuses on understanding the mechanism behind the formation of gas rings in the liquid film and proposes methods to prevent their formation.The results demonstrate a transition of the gas from a gas ring suspended in the liquid to a gas ring attached to the wall after entering the liquid film.The scraping action around the circumference of the scraper helps to expel gas rings,indicating the necessity of adjusting the scraper arrangement and increasing the frequency of scraping to enhance gas ring expulsion.The spiral motion of the bow wave serves as the source of gas entry into the liquid film.Therefore,the rotation speed can appropriately increase to reduce the size of the bow wave,thereby inhibiting the formation of the gas ring from the source.This research investigates the mechanism of gas ring generation and expulsion,offering theoretical guidance for processing high-viscosity non-Newtonian materials in the flow field of the ATFE.展开更多
The loop heat pipe with a flat evaporator is mainly divided into two forms:rectangular evaporator and disk-shaped evaporator.The rectangular evaporator has advantages such as low heat leakage,a thin shell,and a large ...The loop heat pipe with a flat evaporator is mainly divided into two forms:rectangular evaporator and disk-shaped evaporator.The rectangular evaporator has advantages such as low heat leakage,a thin shell,and a large contact area compared to the disk-shaped evaporator.However,most of the research on rectangular evaporators focuses onworking fluids such as water,methanol,and acetone,when theseworking fluids are in operation,the internal pressure of the evaporator is less than atmospheric pressure.Ammonia,propylene,and other working fluids can also be utilized in the loop heat pipe,these working fluids demonstrate better performance when operating within other temperature intervals,for example,the operating temperature range of ammonia is−20℃to 50℃,however,in an atmospheric pressure environment,it is very difficult for the shell of the rectangular evaporator to withstand the saturated vapor pressure of the working fluid.This paper designs a rectangular flat plate loop heat pipe that can use ammonia as the working fluid.The internal reinforcing structure is used to improve the pressure strength of the shell.The secondary wick connects the compensation chamber and the capillary wick hydraulically.The experiment indicates that this kind of rectangular evaporator is unaffected by the position,and the secondary wick can effectively supply liquid under different angles.The thermal resistance of the evaporator wall was analyzed,and it was found that the thermal resistance of the evaporator wall was the main component of the thermal resistance of the system.The heat transfer capacities of 460 W@0.5 m and 200W@10 m were tested.The test results indicate that by setting a reinforcing structure inside the flat plate evaporator,the evaporator can withstand internal pressure.Combined with the design of the secondary wick,the flat plate evaporator can use working fluids with different pressures,expanding the range of available working fluids.展开更多
The dynamics of vapor−liquid−solid(V−L−S)flow boiling in fluidized bed evaporators exhibit inherent complexity and chaotic behavior,hindering accurate prediction of pressure drop signals.To address this challenge,this...The dynamics of vapor−liquid−solid(V−L−S)flow boiling in fluidized bed evaporators exhibit inherent complexity and chaotic behavior,hindering accurate prediction of pressure drop signals.To address this challenge,this study proposes an innovative hybrid approach that integrates wavelet neural network(WNN)with chaos analysis.By leveraging the Cross-Correlation(C−C)method,the minimum embedding dimension for phase space reconstruction is systematically calculated and then adopted as the input node configuration for the WNN.Simulation results demonstrate the remarkable effectiveness of this integrated method in predicting pressure drop signals,advancing our understanding of the intricate dynamic phenomena occurring with V−L−S fluidized bed evaporators.Moreover,this study offers a novel perspective on applying advanced data-driven techniques to handle the complexities of multi-phase flow systems and highlights the potential for improved operational prediction and control in industrial settings.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
In order to concentrate the diluted sulfuric acid from the titanium dioxide(TiO2)production of sulphate process,a new concentration process was proposed by coupling chemical dehydration and multi-effect evaporation.Th...In order to concentrate the diluted sulfuric acid from the titanium dioxide(TiO2)production of sulphate process,a new concentration process was proposed by coupling chemical dehydration and multi-effect evaporation.The ferrous sulfate monohydrate(FeSO4·H2O),as the dehydrant,was added to the diluted sulfuric acid to form ferrous sulfate heptahydrate(FeSO4·7H2O)according to the H2SO4-FeSO4-H2O phase diagrams,which partially removes the water.This process was named as Chemical Dehydration Process.The residual water was further removed by two-effect evaporation and finally 70 wt%sulfuric acid was obtained.The FeSO4·H2O can be regenerated through drying and dehydration of FeSO4·7H2O.The results show that FeSO4·H2O is the most suitable dehydrant,the optimal reaction time of chemical dehydration process is 30 min,and low temperature is favorable for the dehydration reaction.45.17%of the entire removed water can be removed by chemical dehydration from the diluted sulfuric acid.This chemical dehydration process is also energy efficient with 24.76%saving compared with the direct evaporation process.Furthermore,51.21%of the FeSO4 dissolved originally in the diluted sulfuric acid are precipitated out during the chemical dehydration,which greatly reduces the solid precipitation and effectively alleviates the scaling in the subsequent multi-effect evaporation process.展开更多
A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distr...A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distribution.Water and polyformaldehyde particle(POM)were used as the liquid and solid phases,respectively.The effects of operating parameters such as the amount of added particles,circulating flow rate,and particle size were systematically investigated.The results showed that the addition of the particles increased the pressure drop in the vertical tube bundle.The maximum pressure drop ratios were 18.65%,21.15%,18.00%,and 21.15%within the experimental range of the amount of added particles for POM1,POM2,POM3,and POM4,respectively.The pressure drop ratio basically decreased with the increase in the circulating flow rate but fluctuated with the increase in the amount of added particles and particle size.The difference in pressure drop ratio decreased with the increase in the circulating flow rate.As the amount of added particles increased,the difference in pressure drop ratio fluctuated at low circulating flow rate but basically decreased at high circulating flow rate.The pressure drop in the vertical tube bundle accounted for about 70%of the overall pressure drop in the up-flow heating chamber and was the main component of the overall pressure within the experimental range.Three-dimensional phase diagrams were established to display the variation ranges of the pressure drop and pressure drop ratio in the vertical tube bundle corresponding to the operating parameters.The research results can provide some reference for the application of the fluidized bed heat transfer technology in the industry.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
Solar interface water evaporation has been demonstrated to be an advanced method for freshwater production with high solar energy utilization.The development of evaporators with lower cost and higher efficiency is a k...Solar interface water evaporation has been demonstrated to be an advanced method for freshwater production with high solar energy utilization.The development of evaporators with lower cost and higher efficiency is a key challenge in the manufacture of practical solar interface water evaporation devices.Herein,a bamboo leaf-derived carbon-based evaporator is designed based on the light trace simulation.And then,it is manufactured by vertical arrangement and carbonization of bamboo leaves and subsequent polyacrylamide modification.The vertically arranged carbon structure can extend the light path and increase the light-absorbing area,thus achieving excellent light absorption.Furthermore,the continuous distribution of polyacrylamide hydrogel between these vertical carbons can support high-speed water delivery and shorten the evaporation path.Therefore,this evaporator exhibits an ultrahigh average light absorption rate of~96.1%,a good water evaporation rate of 1.75 kg m^(-2) h^(-1),and an excellent solar-to-vapor efficiency of 91.9%under one sun irradiation.Furthermore,the device based on this evaporator can effectively achieve seawater desalination,heavy metal ion removal,and dye separation while completing water evaporation.And this device is highly available for actual outdoor applications and repeated recycling.展开更多
The paper presents the results of development and investigation of a copper miniature loop heat pipe (LHP) with acetone as a working fluid. The device was equipped with a flat evaporator measuring 80 × 42 × ...The paper presents the results of development and investigation of a copper miniature loop heat pipe (LHP) with acetone as a working fluid. The device was equipped with a flat evaporator measuring 80 × 42 × 7 mm and vapor and liquid lines with an outside diameter of 3 mm, whose lengths were 145 mm and 175 mm, respectively. The LHP was tested at heat loads from 5 W to 60 W, different orientations in the gravity field and heat-sink temperatures from -40°C to +50°C. It is shown that the LHP retains its efficiency at all testing conditions. It is also mentioned that at a heat-sink temperature of +50°C the device operates in the mode of constant conductivity in the whole range of heat loads, and in this case a minimum thermal resistance of the “heat source-heat sink” system equal to 0.16°C/W is achieved, which is independent of the LHP orientation in the gravity field.展开更多
Solar-driven hydrogel evaporator used for water purification demonstrates great potential in seawater desalination and domestic sewage treatment.However,much uncertainty still exists about the most efficient design to...Solar-driven hydrogel evaporator used for water purification demonstrates great potential in seawater desalination and domestic sewage treatment.However,much uncertainty still exists about the most efficient design to obtain cost-effective drinkable water.In this paper,a natural rich biomass Nicandra physalodes(Linn.)Gaertn.polysaccharide was introduced into the polyvinyl alcohol network to control the water distribution during evaporation and build a low-cost hybrid hydrogel solar evaporator with a total material cost of$7.95 m^(−2).The mixed evaporator works stably in a long-span acid–base range(pH 1–14)and salinity range(0–320 g kg^(−1)).Its daily water purification capacity can reach 24.4 kg m^(−2)with a water purification capacity of 3.51 kg m^(−2)h^(−1)under sunlight.This paper provides a new possibility for a highly efficient and cost-effective water desalination system with guaranteed water quality by focusing on the dynamic regulation of water molecules at the evaporation interface.展开更多
The global energy demand increases with development and population rise. Most electrical power is currently generated by conventional methods from fossil fuels. Despite the high energy demand, the conventional energy ...The global energy demand increases with development and population rise. Most electrical power is currently generated by conventional methods from fossil fuels. Despite the high energy demand, the conventional energy resources such as fossil fuels have been declining and harmful combustion byproducts are causing global warming. The Organic Rankine Cycle power plant is a very effective option for utilization of low grade heat sources for power generation. In the Organic Rankine Cycle heat exchangers such as evaporators and condensers are key components that determine its performance. Researches indicated that shell tube heat exchangers are effectively utilized in this cycle. The design of the heat exchanger involves establishing the right flow pattern of the interacting fluids. The performance of these exchangers can be optimized by inserting baffles in the shell to direct the flow of fluid across the tubes on shell side. In this work heat exchangers have been developed to improve heat recovery from geothermal brine for additional power generation. The design involved sizing of heat exchanger (evaporator) using the LMTD method based on an expected heat transfer rate. The heat exchanger of the model power plant was tested in which hot water simulated brine. The results indicated that the heat exchanger is thermally suitable for the evaporator of the model power plant.展开更多
The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, d...The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.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
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financially supported by the National Natural Science Foundation of China(12,405,179)the Natural Science Foundation of Hunan Province(2023JJ40744)+1 种基金the Natural Science Foundation of Hunan Province(2025JJ50227)the High Performance Computing Center of Central South University(2025JJ50226).
文摘The solar interfacial evaporation has a broad application prospect in the fields of steam generation and seawater desalination to deal with the global shortage of fresh-water resources.Bamboo is a great material for solar interface evaporators because of its low thermal conductivity and inherent micro-channel porous structure.In this paper,a novel bamboo-based solar interface evaporator with a bionic ripple wave surface structure has been proposed.The subsequent evaporation experiments have been conducted to investigate the salt resistance,stability and water absorption of the bionic ripple bamboo based solar interface evaporator.The results have exhibited that the bamboo's water absorption has been enhanced after carbonization modification.Besides,it should be pointed out that this bamboo-based evaporator’s evaporation rate has dropped during the prolonged simulated seawater evaporation experiment,yet it remained fairly consistent at approximately 1.626 kg·m^(-2)·h^(-1).The appearance for this experimental phenomenon is the decrease of the floatability of the evaporator constricted by the stored water body absorbed by the evaporator and the deposition of NaCl crystals at the photothermal interface.Besides,compared with the plate-structure evaporator,the salt deposition in the evaporator equipped with the bionic ripple wave surface structure is greatly improved.In regard to its advantages in low cost,environmental friendliness,good salt tolerance and high evaporation rate,the bamboo-based solar interface evaporator with a bionic ripple wave surface structure can provide a potential solution to the global problem of fresh-water shortage.
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.
基金the financial support of the National Natural Science Foundation of China(No.52075309)the Youth Innovation Team of Shaanxi Universities(21JP021)。
文摘Hydrogel has developed into a very important platform in solar interface evaporator.However,the current hydrogel evaporators are usually three-dimensional evaporators,which will consume a lot of raw materials.Thus,a new two-dimensional hydrogel evaporator is urgently needed to alleviate this problem.Here,a double layer hydrogel evaporator was designed by twice vacuum filtration.Furthermore,through the arched design and the introduction of concentrated brine drainage system,the hydrogel evaporator has enhanced water transportation and tailored water transportation path.Such a unique drainage evaporation system greatly improves the stability of the evaporator.Thereby,a good balance is established between photothermal conversion and water supply,and solar energy is utilized efficiently.It can remain stable in continuous evaporation for up to 12 h with an excellent evaporation rate of 2.70 kg m^(-2)h^(-1)under 1 sun irradiation.Meanwhile,the drainage system realized the 1.8×10^(-10)mol m^(-2)s^(-1)diffusion flux of concentrated brine.Through one-time freeze-drying preparation,an arch-shaped drainage evaporator was used to prepare an evaporation area of more than 20 cm^(2).With the self-made condensate collecting device in outdoor environment,the fresh water yield reaches 7.5 L m^(-2)d^(-1).This provides a new scheme for building a new hydrogel evaporator and solving the fresh water crisis.
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the National Key Research and Development Program of China(Grant No.2022YFC3901902)the National Natural Science Foundation of China(Grant Nos.52203037,52103031,and 52073107)。
文摘Fiber fabrics have been wildly utilized for solar interracial evaporators to address freshwater scarcity.However,the complex and expensive manufacturing processes remain limited to their scalable development.Herein,a fabric-based Janus interracial evaporator is efficiently fabricated on a large scale by integrating an extremely innovative self-designed melt-centrifugal spinning technology with spray coating technology.The prepared fabric-based Janus interfacial evaporator has differential hydrophilicity,uneven surfaces,and channels that allow moisture escape.Benefiting from the excellent photothermai conversion of graphene oxide and the charge transfer actions of titanium dioxide,such a multifunction evaporator can reach a high evaporation rate of 1.72 kg m^(-2)h^(-1)under 1 sun irradiation,a superior antibacterial rate of 99%,excellent photocatalytic degradation,and effective thermoelectric ability simultaneously.Moreover,it also shows fantastic performance in salt resistance,recyclable evaporation,and real desalination,This work demonstrates a high-efficiency,cost-effective,multifunctional,and scalable strategy for high-performance fiber fabrics solar interfacial evaporation.
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National Natural Science Foundation of China(No.51905089)Fundamental Research Funds for the Central Universities,China(No.2232020D-31)。
文摘The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate scraping action of the scraper introduces gas into the liquid film,leading to the formation of a gas ring along the wall.This process subsequently reduces wall heat flow,thereby affecting heat transfer.Computational fluid dynamics(CFD)is used to simulate the flow field of the non-Newtonian fluid in the ATFE.The investigation focuses on understanding the mechanism behind the formation of gas rings in the liquid film and proposes methods to prevent their formation.The results demonstrate a transition of the gas from a gas ring suspended in the liquid to a gas ring attached to the wall after entering the liquid film.The scraping action around the circumference of the scraper helps to expel gas rings,indicating the necessity of adjusting the scraper arrangement and increasing the frequency of scraping to enhance gas ring expulsion.The spiral motion of the bow wave serves as the source of gas entry into the liquid film.Therefore,the rotation speed can appropriately increase to reduce the size of the bow wave,thereby inhibiting the formation of the gas ring from the source.This research investigates the mechanism of gas ring generation and expulsion,offering theoretical guidance for processing high-viscosity non-Newtonian materials in the flow field of the ATFE.
基金Science Foundation for Distinguished Young Scholars 2020-JCJQ-ZQ-042.
文摘The loop heat pipe with a flat evaporator is mainly divided into two forms:rectangular evaporator and disk-shaped evaporator.The rectangular evaporator has advantages such as low heat leakage,a thin shell,and a large contact area compared to the disk-shaped evaporator.However,most of the research on rectangular evaporators focuses onworking fluids such as water,methanol,and acetone,when theseworking fluids are in operation,the internal pressure of the evaporator is less than atmospheric pressure.Ammonia,propylene,and other working fluids can also be utilized in the loop heat pipe,these working fluids demonstrate better performance when operating within other temperature intervals,for example,the operating temperature range of ammonia is−20℃to 50℃,however,in an atmospheric pressure environment,it is very difficult for the shell of the rectangular evaporator to withstand the saturated vapor pressure of the working fluid.This paper designs a rectangular flat plate loop heat pipe that can use ammonia as the working fluid.The internal reinforcing structure is used to improve the pressure strength of the shell.The secondary wick connects the compensation chamber and the capillary wick hydraulically.The experiment indicates that this kind of rectangular evaporator is unaffected by the position,and the secondary wick can effectively supply liquid under different angles.The thermal resistance of the evaporator wall was analyzed,and it was found that the thermal resistance of the evaporator wall was the main component of the thermal resistance of the system.The heat transfer capacities of 460 W@0.5 m and 200W@10 m were tested.The test results indicate that by setting a reinforcing structure inside the flat plate evaporator,the evaporator can withstand internal pressure.Combined with the design of the secondary wick,the flat plate evaporator can use working fluids with different pressures,expanding the range of available working fluids.
基金supported by the open foundation of State Key Laboratory of Chemical Engineering(SKL-ChE-22B01)the Natural Science Foundation of China(22008169).
文摘The dynamics of vapor−liquid−solid(V−L−S)flow boiling in fluidized bed evaporators exhibit inherent complexity and chaotic behavior,hindering accurate prediction of pressure drop signals.To address this challenge,this study proposes an innovative hybrid approach that integrates wavelet neural network(WNN)with chaos analysis.By leveraging the Cross-Correlation(C−C)method,the minimum embedding dimension for phase space reconstruction is systematically calculated and then adopted as the input node configuration for the WNN.Simulation results demonstrate the remarkable effectiveness of this integrated method in predicting pressure drop signals,advancing our understanding of the intricate dynamic phenomena occurring with V−L−S fluidized bed evaporators.Moreover,this study offers a novel perspective on applying advanced data-driven techniques to handle the complexities of multi-phase flow systems and highlights the potential for improved operational prediction and control in industrial settings.
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the State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization of China for its financial supportthe financial support of National Natural Science Foundation of China(Grant No.21576168)Science and Technology Cooperation Fund of Sichuan University-Panzhihua(No:2018CDPZH-23-SCU)。
文摘In order to concentrate the diluted sulfuric acid from the titanium dioxide(TiO2)production of sulphate process,a new concentration process was proposed by coupling chemical dehydration and multi-effect evaporation.The ferrous sulfate monohydrate(FeSO4·H2O),as the dehydrant,was added to the diluted sulfuric acid to form ferrous sulfate heptahydrate(FeSO4·7H2O)according to the H2SO4-FeSO4-H2O phase diagrams,which partially removes the water.This process was named as Chemical Dehydration Process.The residual water was further removed by two-effect evaporation and finally 70 wt%sulfuric acid was obtained.The FeSO4·H2O can be regenerated through drying and dehydration of FeSO4·7H2O.The results show that FeSO4·H2O is the most suitable dehydrant,the optimal reaction time of chemical dehydration process is 30 min,and low temperature is favorable for the dehydration reaction.45.17%of the entire removed water can be removed by chemical dehydration from the diluted sulfuric acid.This chemical dehydration process is also energy efficient with 24.76%saving compared with the direct evaporation process.Furthermore,51.21%of the FeSO4 dissolved originally in the diluted sulfuric acid are precipitated out during the chemical dehydration,which greatly reduces the solid precipitation and effectively alleviates the scaling in the subsequent multi-effect evaporation process.
基金supported by the open foundation of State Key Laboratory of Chemical Engineering (SKL-ChE-18B03)the Municipal Science and Technology Commission of Tianjin (No. 2009ZCKFGX01900)
文摘A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distribution.Water and polyformaldehyde particle(POM)were used as the liquid and solid phases,respectively.The effects of operating parameters such as the amount of added particles,circulating flow rate,and particle size were systematically investigated.The results showed that the addition of the particles increased the pressure drop in the vertical tube bundle.The maximum pressure drop ratios were 18.65%,21.15%,18.00%,and 21.15%within the experimental range of the amount of added particles for POM1,POM2,POM3,and POM4,respectively.The pressure drop ratio basically decreased with the increase in the circulating flow rate but fluctuated with the increase in the amount of added particles and particle size.The difference in pressure drop ratio decreased with the increase in the circulating flow rate.As the amount of added particles increased,the difference in pressure drop ratio fluctuated at low circulating flow rate but basically decreased at high circulating flow rate.The pressure drop in the vertical tube bundle accounted for about 70%of the overall pressure drop in the up-flow heating chamber and was the main component of the overall pressure within the experimental range.Three-dimensional phase diagrams were established to display the variation ranges of the pressure drop and pressure drop ratio in the vertical tube bundle corresponding to the operating parameters.The research results can provide some reference for the application of the fluidized bed heat transfer technology in the industry.
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supports from Zhejiang Provincial Key Research and Development Project(2019C02037)the Fundamental Research Funds for the Provincial Universities of Zhejiang(2020YQ005)+3 种基金Zhejiang Provincial Natural Science Foundation of China(LY20E020004)National Natural Science Foundation of China(31870548)Research Foundation of Talented Scholars of Zhejiang A&F University(2020FR069)151 Talent Project of Zhejiang Province.
文摘Solar interface water evaporation has been demonstrated to be an advanced method for freshwater production with high solar energy utilization.The development of evaporators with lower cost and higher efficiency is a key challenge in the manufacture of practical solar interface water evaporation devices.Herein,a bamboo leaf-derived carbon-based evaporator is designed based on the light trace simulation.And then,it is manufactured by vertical arrangement and carbonization of bamboo leaves and subsequent polyacrylamide modification.The vertically arranged carbon structure can extend the light path and increase the light-absorbing area,thus achieving excellent light absorption.Furthermore,the continuous distribution of polyacrylamide hydrogel between these vertical carbons can support high-speed water delivery and shorten the evaporation path.Therefore,this evaporator exhibits an ultrahigh average light absorption rate of~96.1%,a good water evaporation rate of 1.75 kg m^(-2) h^(-1),and an excellent solar-to-vapor efficiency of 91.9%under one sun irradiation.Furthermore,the device based on this evaporator can effectively achieve seawater desalination,heavy metal ion removal,and dye separation while completing water evaporation.And this device is highly available for actual outdoor applications and repeated recycling.
文摘The paper presents the results of development and investigation of a copper miniature loop heat pipe (LHP) with acetone as a working fluid. The device was equipped with a flat evaporator measuring 80 × 42 × 7 mm and vapor and liquid lines with an outside diameter of 3 mm, whose lengths were 145 mm and 175 mm, respectively. The LHP was tested at heat loads from 5 W to 60 W, different orientations in the gravity field and heat-sink temperatures from -40°C to +50°C. It is shown that the LHP retains its efficiency at all testing conditions. It is also mentioned that at a heat-sink temperature of +50°C the device operates in the mode of constant conductivity in the whole range of heat loads, and in this case a minimum thermal resistance of the “heat source-heat sink” system equal to 0.16°C/W is achieved, which is independent of the LHP orientation in the gravity field.
基金support of Chengdu University of Technology(10912-2019KYQD-07545)Sichuan Ministry of Science,Technology Project(22ZDYF2878).
文摘Solar-driven hydrogel evaporator used for water purification demonstrates great potential in seawater desalination and domestic sewage treatment.However,much uncertainty still exists about the most efficient design to obtain cost-effective drinkable water.In this paper,a natural rich biomass Nicandra physalodes(Linn.)Gaertn.polysaccharide was introduced into the polyvinyl alcohol network to control the water distribution during evaporation and build a low-cost hybrid hydrogel solar evaporator with a total material cost of$7.95 m^(−2).The mixed evaporator works stably in a long-span acid–base range(pH 1–14)and salinity range(0–320 g kg^(−1)).Its daily water purification capacity can reach 24.4 kg m^(−2)with a water purification capacity of 3.51 kg m^(−2)h^(−1)under sunlight.This paper provides a new possibility for a highly efficient and cost-effective water desalination system with guaranteed water quality by focusing on the dynamic regulation of water molecules at the evaporation interface.
文摘The global energy demand increases with development and population rise. Most electrical power is currently generated by conventional methods from fossil fuels. Despite the high energy demand, the conventional energy resources such as fossil fuels have been declining and harmful combustion byproducts are causing global warming. The Organic Rankine Cycle power plant is a very effective option for utilization of low grade heat sources for power generation. In the Organic Rankine Cycle heat exchangers such as evaporators and condensers are key components that determine its performance. Researches indicated that shell tube heat exchangers are effectively utilized in this cycle. The design of the heat exchanger involves establishing the right flow pattern of the interacting fluids. The performance of these exchangers can be optimized by inserting baffles in the shell to direct the flow of fluid across the tubes on shell side. In this work heat exchangers have been developed to improve heat recovery from geothermal brine for additional power generation. The design involved sizing of heat exchanger (evaporator) using the LMTD method based on an expected heat transfer rate. The heat exchanger of the model power plant was tested in which hot water simulated brine. The results indicated that the heat exchanger is thermally suitable for the evaporator of the model power plant.
基金This project is supported by National Key Technologies R&D Programme,China (No.2001BA501A22).
文摘The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.
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.
