Electrolyte Design for Low‑Temperature Li‑Metal Batteries:Challenges and Prospects

Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases.Herein,this review critically outlines electrolytes’limiting factors,including reduced ionic conductivity,large de-solvation energy,sluggish charge transfer,and slow Li-ion transportation across the electrolyte/electrode interphases,which affect the low-temperature performance of Li-metal batteries.Detailed theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen understanding.Emerging improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously compared.Perspectives on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries.

An innovative approach to effective breeding blanket design for future fusion reactors

An effective breeding blanket is critical to support tritium self-sufficiency for future fusion reactors.The difficulty is to achieve tritium breeding ratio(TBR)target of 1.05 or more.This paper presents a new design approach to the blanket design process.It indicates that fusion blanket design is affected by universal functions based on iterations.Three aspects are worth more attention from fusion engineers in the future.The first factor is that the iterations on the material fractions affect not only structure scheme but also TBR variation.The second factor is the cooling condition affecting final TBR due to the change of the structure material proportion.The third factor is temperature field related to the tritium release.In particular,it is suggested that the statistical calculation of effective TBR must be under reasonable control of the blanket temperature field.This approach is novel for blanket engineering in development of a fusion reactor.

Strength Design Method for Tubing Hanger of Subsea Christmas Tree Against Big Temperature Difference

The tubing hanger is an important component of the subsea Christmas tree, experiencing big temperature difference which will lead to very high thermal stresses. On the basis of API 17D/ISO 13628-4 and ASME VIII-1, and by comprehensively considering the erosion of oil and the gravity load of the tubing, a calculation model is established by regarding design pressure and thermal stress, and the method for designing the tubing hanger of the horizontal Christmas tree under big temperature difference condition is developed from the fourth strength theory. The proposed theory for strength design of the tubing hanger in big temperature difference is verified by numerical results from ABAQUS.

Study on neutronics design of ordered-pebble-bed fluoride-salt- cooled high-temperature experimental reactor

This paper presents a neutronics design of a 10 MW ordered-pebble-bed fluoride-salt-cooled high-temperature experimental reactor. Through delicate layout, a core with ordered arranged pebble bed can be formed,which can keep core stability and meet the space requirements for thermal hydraulics and neutronics measurements.Overall, objectives of the core include inherent safety and sufficient excess reactivity providing 120 effective full power days for experiments. Considering the requirements above, the reactive control system is designed to consist of 16 control rods distributed in the graphite reflector. Combining the large control rods worth about 18000–20000 pcm, molten salt drain supplementary means(-6980 to -3651 pcm) and negative temperature coefficient(-6.32 to -3.80 pcm/K) feedback of the whole core, the reactor can realize sufficient shutdown margin and safety under steady state. Besides, some main physical properties, such as reactivity control, neutron spectrum and flux, power density distribution, and reactivity coefficient,have been calculated and analyzed in this study. In addition, some special problems in molten salt coolant are also considered, including ~6Li depletion and tritium production.

Estimation of the Equivalent Design Temperature of a Pavement in Burkina Faso

The bituminous pavements of the city of Ouagadougou(Burkina Faso)are made using old design methods which take into account the climate from the notion of equivalent temperature.Thus an equivalent temperature of 30°C is often used for the design of bituminous pavements.The observation that has been made is that this temperature does not currently make it possible to reduce the problems of early degradation of the pavements linked to meteorological fluctuations.The objective of this article is to propose a numerical approach for determining the equivalent temperature from temperature measurements taken at the surface of the pavement.This approach consists in jointly using the Alizé-Lcpc sizing software and the Comsol Multiphysics software using the finite element method.For a four-layer bituminous pavement,located at 12.38°North and 1.48°West,in Ouagadougou,consisting of a surface course of bituminous concrete of 8 cm and a base course of gravel bitumen of 16 cm,an equivalent temperature of 35°C was obtained.

Design Optimization and Operating Performance of S-CO_(2) Brayton Cycle under Fluctuating Ambient Temperature and Diverse Power Demand Scenarios

The supercritical CO_(2)(S-CO_(2)) Brayton cycle is expected to replace steam cycle in the application of solar power tower system due to the attractive potential to improve efficiency and reduce costs.Since the concentrated solar power plant with thermal energy storage is usually located in drought area and used to provide a dispatchable power output,the S-CO_(2) Brayton cycle has to operate under fluctuating ambient temperature and diverse power demand scenarios.In addition,the cycle design condition will directly affect the off-design performance.In this work,the combined effects of design condition,and distributions of ambient temperature and power demand on the cycle operating performance are analyzed,and the off-design performance maps are proposed for the first time.A cycle design method with feedback mechanism of operating performance under varied ambient temperature and power demand is introduced innovatively.Results show that the low design value of compressor inlet temperature is not conductive to efficient operation under low loads and sufficient output under high ambient temperatures.The average yearly efficiency is most affected by the average power demand,while the load cover factor is significantly influenced by the average ambient temperature.With multi-objective optimization,the optimal solution of designed compressor inlet temperature is close to the minimum value of35℃ in Delingha with low ambient temperature,while reaches 44.15℃ in Daggett under the scenario of high ambient temperature,low average power demand,long duration and large value of peak load during the peak temperature period.If the cycle designed with compressor inlet temperature of 35℃ instead of 44.15℃ in Daggett under light industry power demand,the reduction of load cover factor will reach 0.027,but the average yearly efficiency can barely be improved.

Temperature effect on performance of nanoparticle/surfactant flooding in enhanced heavy oil recovery

Recently,nanoparticles have been used along with surfactants for enhancing oil recovery.Although the recent studies show that oil recovery is enhanced using nanoparticle/surfactant solutions,some effective parameters and mechanisms involved in the oil recovery have not yet been investigated.Therefore,the temperature effect on the stability of nanoparticle/surfactant solutions and ultimate oil recovery has been studied in this work,and the optimal concentrations of both SiO2 nanoparticle and surfactant(sodium dodecyl sulfate)have been determined by the Central Composite Design method.In addition,the simultaneous effects of parameters and their interactions have been investigated.Study of the stability of the injected solutions indicates that the nanoparticle concentration is the most important factor affecting the solution stability.The surfactant makes the solution more stable if used in appropriate concentrations below the CMC.According to the micromodel flooding results,the most effective factor for enhancing oil recovery is temperature compared to the nanoparticle and surfactant concentrations.Therefore,in floodings with higher porous medium temperature,the oil viscosity reduction is considerable,and more oil is recovered.In addition,the surfactant concentration plays a more effective role in reservoirs with higher temperatures.In other words,at a surfactant concentration of 250 ppm,the ultimate oil recovery is improved about 20%with a temperature increase of 20°C.However,when the surfactant concentration is equal to 750 ppm,the temperature increase enhances the ultimate oil recovery by only about 7%.Finally,the nanoparticle and surfactant optimum concentrations determined by Design-Expert software were equal to 46 and 159 ppm,respectively.It is worthy to note that obtained results are validated by the confirmation test.

Solar versus Non-Solar Urine Diversion Dehydration Toilets—Evaluation of Temperatures inside the Vaults of Different UDDT Systems

The Urine Diverting Dehydration Toilet (UDDT) is one of a wide range of technologies Ecological Sanitation (Ecosan) offers. A commonly used type is the so called solar UDDT, constructed with inclined vault doors or panels which are usually made from black iron sheets to increase the temperature inside the vaults and therefore would facilitate dehydration and hygienisation. The study aims to give recommendations on the most appropriate system by comparing solar and non-solar UDDT systems. Existing building standards for UDDTs were reviewed, 133 UDDT sites visited and a comparative temperature study of the temperature inside the vaults of different UDDT systems carried out. The temperature study needed to assess if solar UDDTs would actually succeed in raising the temperature inside the vault. Programmed temperature loggers were placed in the vaults of solar and non-solar UDDTs. The review of building standards showed that the system recommended most is the solar UDDT. The field visits identified a number of problems related to the construction of solar UDDTs. The temperature study showed that solar UDDTs do not necessarily increase the temperature inside the vault significantly and therefore are not speeding up dehydration and pathogen destruction. The study hence concludes that before a solar UDDT system is chosen the climatic conditions have to be assessed carefully. The recommended standard design should be a non-solar UDDT system. It is hoped that the study will facilitate a move towards the construction of non-solar UDDTs.

Optimization on selenium and arsenic conversion from copper anode slime by low-temperature alkali fusion process

A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.

Effect Factors on Measurement Precision of the Embedded Temperature Sensing Fabric

The embedded temperature sensing fabric was designed and woven according to the heat transmission model of the fabric.The temperature sensors were embedded into the multi-layered fabric that weft yarns were high-shrinkage polyester filaments.And the fabric was treated by a self-designed partial heat device,which can make the sensor be fixed in the fabric.The effects of yarn type,yarn linear density,fabric warp density,fabric structure,fabric layer numbers where the sensor is located,and the ambient temperature on the temperature measured value were investigated.The results demonstrated that when the higher thermal conductivity of yarns and lower density yarns were applied in the fabric as rawmaterials,they were favored to improve the measurement precision.Meanwhile,there were many factors that could make the measured values closer to the real value of the body,such as the plain fabric,the increased warp density of the fabric,the multiple-layer fabric where the sensor was located,the raised ambient testing temperature and the prolonged test time in the certain range.

Optimization of low-temperature alkaline smelting process of crushed metal enrichment originated from waste printed circuit boards

A novel low-temperature alkaline smelting process is proposed to convert and separate amphoteric metals in crushed metal enrichment originated from waste printed circuit boards. The central composite design was used to optimize the operating parameters,in which mass ratio of Na OH-to-CME, smelting temperature and smelting time were chosen as the variables, and the conversions of amphoteric metals tin, lead, aluminum and zinc were response parameters. Second-order polynomial models of high significance and3 D response surface plots were constructed to show the relationship between the responses and the variables. Optimum area of80%-85% Pb conversion and over 95% Sn conversion was obtained by the overlaid contours at mass ratio of Na OH-to-CME of4.5-5.0, smelting temperature of 653-723 K, smelting time of 90-120 min. The models were validated experimentally in the optimum area, and the results demonstrate that these models are reliable and accurate in predicting the smelting process.

Procedure for a Temperature-Traffic Model onRubberized Asphalt Layers for Roads and Railways

The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the averageseasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weathersituation, Barber＇s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessmentof improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber （particlesize 0.2-4 mm） by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mixdesign compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials withattention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirecttensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complexmodulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained andthe comparison with a conventional HMA （hot mix asphalt） show that these dry rubber bituminous mixtures are particularly effective indamping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has beenachieved for the assessment of its behavior in sub-ballast/base layers.

Development and testing of the code for automatic generating of multi-temperature continuous-energy neutron cross section libraries

In the nuclear reactor design, a code for automatically generated multi-temperature continuous-energy neutron cross section data library, which is called AMTND for short, was designed and developed to meet the need of the reactor core design coupled with thermal-hydraulic design. The code can provide a point-wise crosssection at any temperature for a Monte Carlo neutron transport program, such as MCNP. In ensuring that the nuclear data produced by AMTND meets the testing of critical benchmark experiments, the time-consumed by the nuclear data generating of AMTND compared with NJOY's was carried out and the result shows the code's excellence. In order to test the accuracy of the code, the Doppler coefficient test benchmark was also carried out and the results verified the code preliminarily.

Optimal Design of Tapered Roller Bearings Based on Multi⁃Physics Objectives Using Evolutionary Algorithms

Rolling element bearing is the most common machine element in rotating machinery.An extended life is among the foremost imperative standards in the optimal design of rolling element bearings,which confide on the fatigue failure,wear,and thermal conditions of bearings.To fill the gap,in the current work,all three objectives of a tapered roller bearing have been innovatively considered respectively,which are the dynamic capacity,elasto-hydrodynamic lubrication(EHL)minimum film⁃thickness,and maximum bearing temperature.These objective function formulations are presented,associated design variables are identified,and constraints are discussed.To solve complex non⁃linear constrained optimization formulations,a best⁃practice design procedure was investigated using the Artificial Bee Colony(ABC)algorithms.A sensitivity analysis of several geometric design variables was conducted to observe the difference in all three objectives.An excellent enhancement was found in the bearing designs that have been optimized as compared with bearing standards and previously published works.The present study will definitely add to the present experience based design followed in bearing industries to save time and obtain assessment of bearing performance before manufacturing.To verify the improvement,an experimental investigation is worthwhile conducting.

Design and analysis of a high loss density motor cooling system with water cold plates

Aiming at reducing the difficulty of cooling the interior of high-density motors,this study proposed the placement of a water cold plate cooling structure between the axial laminations of the motor stator.The effect of the cooling water flow,thickness of the plate,and motor loss density on the cooling effect of the water cold plate were studied.To compare the cooling performance of water cold plate and outer spiral water jacket cooling structures,a high-speed permanent magnet motor with a high loss density was used to establish two motor models with the two cooling structures.Consequently,the cooling effects of the two models were analyzed using the finite element method under the same loss density,coolant flow,and main dimensions.The results were as follows.(1)The maximum and average temperatures of the water cold plate structure were reduced by 25.5%and 30.5%,respectively,compared to that of the outer spiral water jacket motor;(2)Compared with the outer spiral water jacket structure,the water cold plate structure can reduce the overall mass and volume of the motor.Considering a 100 kW high-speed permanent magnet motor as an example,a water cold plate cooling system was designed,and the temperature distribution is analyzed,with the result indicating that the cooling structure satisfied the cooling requirements of the high loss density motor.

The Temperature Intelligence Control System Based on Single Chip-Microprocessor

The paper introduces a temperature control systembased on AT89C51 single-chip-microprocessor, and discussesthe principle , hardware structure, and software design of thissystem in detail.

基于PLC的工业烧结炉温度控制系统设计与实现

工业烧结炉是一种广泛应用于冶金、陶瓷、玻璃、粉末冶金等领域的重要设备。它通过高温烧结过程,将粉末或颗粒状的原材料烧结成具有一定强度和性能的烧结体。工业烧结炉通常采用电热或燃气加热方式,具有较高的温度控制精度和均匀性。在烧结过程中,炉内的温度和气氛条件需要严格控制,以确保烧结体的质量和性能达到预期目标。我国的粉末冶金工业受到技术以及生产设备的限制,目前尚处于初步发展阶段。粉末冶金烧结的质量受到烧结温度的重要影响。合理的烧结炉温度控制方法能够保证烧结过程的稳定性和产品质量。本文综合分析了烧结炉的组成以及工作原理,探讨了烧结炉温度控制系统的设计原则以及系统设计方案,根据烧结工艺和设备特点确保烧结产品的质量和生产效率。

泳池式低温供热堆用衰减筒的设计

衰减筒是池式低温供热堆的主要部件,其功能是保证堆芯出口的放射性冷却水在衰减筒内的滞留时间不低于100s,使短周期放射性核素在池内大量衰减,从而使一回路的放射性水平显著降低。根据整体布置要求,该衰减筒的筒体结构为不规则扇形结构,并在内部设置有分流板和孔板。其设计工作主要包括结构设计、冷却水衰减时间计算以及结构件的强度分析计算,并通过相关计算结果对设计进行优化。最终的设计结果表明,衰减筒的结构设计满足功能要求,冷却水在衰减筒内的衰减时间不低于100s,且强度分析计算满足设计要求。

基于ARM的电阻炉炉温控制系统设计

在科学技术突飞猛进发展的背景下,现代工业生产中的电压、电流、开关量等都是重要的被控参数,在冶金制造业中,温度是器件生产过程中非常重要的物理参数,需要对各种加热炉的温度进行严格控制,对其温度变化进行实时监测,确保炉内温度满足制造器件的需求。电阻炉在金属热处理中具有较为广泛的应用,是进行金属锻压加热、烧结的重要工业设备。电阻炉温度控制多采用自动化控制系统,实现智能化管理,保证炉温的均匀度以及零件温度的均匀性,提高生产的可靠性和稳定性。从电阻炉温度控制的难点入手分析,结合电阻炉温度控制系统的设计原则,提出一种基于ARM处理器的电阻炉炉温控制系统设计方案,能够提高电阻炉温度控制的精度,保证工业生产的稳定性。