Influence Of Operating Temperature Research Articles

Exploring the application of hydrazine hydrate in protonic ceramic fuel cells: Strategies and performance improvements

Hydrazine hydrate, characterized by its high hydrogen content and eco-friendliness, garners extensive attention in the field of fuels. Its high energy density and rapid decomposition capabilities render it a promising fuel option for Proton-Conductor Solid Oxide Fuel Cells (PCFCs). Given the unique properties of hydrazine hydrate, this study employs a dendritic porous anode structure to facilitate faster fuel transport. Additionally, the influence of operational temperature and concentration of hydrazine hydrate as fuel on cell performance is analyzed. An effective vapor management strategy is implemented to address its decomposition into water vapor, resulting in a significant 23.17 % increase in the maximum power density (MPD) of the cell. To further enhance the performance of hydrazine hydrate fuel in PCFCs, a Pt–Al spherical catalyst is integrated within the anode structure of the cell. This approach notably improves the cell performance, yielding an additional 14.98 % increase in MPD. This design not only augments the electrical output but also effectively mitigates the degradation of the interface between the anode and the electrolyte. These optimization measures significantly improve the lifespan and reliability of the cell. The outcomes of this study demonstrate the practical feasibility of using hydrazine hydrate as a fuel in PCFCs.

Influence of Operating Temperature on the Service Life of Aluminum Extrusion Dies.

sThe article investigates the effect of temperature and annealing time on the surface quality of WNLV nitrided steel used for the production of dies for extrusion of aluminum alloys. Eight annealing variants were tested, differing in the total annealing time at temperatures of 460 °C and 590 °C. The results show the effect of the annealing time on the width of the diffusion layer, which increased with the increasing length of the annealing time. The hardness decreased as the annealing time increased. It was found that annealing of the steel causes its oxidation. The oxide layer formed consisted of two layers, more specifically, an Fe2O3 oxide layer and a lower Fe3O4 oxide layer adhering to the steel surface. The surface of sections pressed on oxidized matrices was tested. The roughness of the surface of the oxide layers was also tested. The research revealed that an increase in the surface roughness of the oxides deposited on the matrices causes an increase in the roughness of the extruded sections. These results can potentially be used to improve the efficiency of the extrusion process and the quality of the extruded sections.

Influence of practical operating temperature on the Cr poisoning for LSCF-GDC cathode

The influence of operating temperature on Cr poisoning effect on solid oxide fuel cells (SOFCs) cathode was comprehensive studied. The La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.90Gd0.10O1.95 (LSCF-GDC) symmetric cells were investigated at 550, 600, 650, 700, 750 °C respectively in the presence of Crofer 22 APU. After aging in the air for 200 h, the cell operated at 650 °C expressed the most serious degradation. At the operating temperature lower than 650 °C, the degradation rate was accelerated with the increased operating temperature. At the operating temperature higher than 650 °C, the degradation rate slowed down with the increased operating temperature. Combined the experimental results with first principles calculation, the mechanism could be put forward that competition existed between the oxygen reduction reaction (ORR) activity and the formation reaction of SrCrO4. The activity of ORR and the formation of SrCrO4 at different operating temperatures codetermined the fluctuating degradation rate of LSCF-GDC cathode. This result could offer a valuable guidance for the rational application of LSCF-GDC cathode in SOFCs.

Methane steam reforming reaction in solid oxide fuel cells: Influence of electrochemical reaction and anode thickness

The influence of operation temperature, inlet gas composition, current density and the anode thickness on the methane steam reforming reaction over nickel yttria-stabilized zirconia anodes was experimentally studied in solid oxide fuel cells. The experimental results were analyzed using data fitting in Power-Law and Langmuir–Hinshelwood kinetic models. Similar trends of dependence of methane and steam partial pressures were observed in both models. The methane reaction order is positive. Negative influence of steam partial pressure on the methane steam reforming reaction rate are found. The electrochemical reaction and anode thickness affect the reforming kinetics parameters. The anodes thickness shows particular influences on the steam reaction order, and the activation energy when a current is produced. The model evaluation suggests that the two models are comparable and the extra parameters within the Langmuir–Hinshelwood kinetic model are contributing to the lower mean absolute percentage error and higher coefficient of determination R 2 . • Current promotes the methane steam reforming reaction rate. • Anode thickness influences the fitted activation energy. • More experimental data is helpful in getting a reliable rate expression. • Importance of studying effect of mass-transfer on the global MSR kinetics.

Influence of Operating Temperature on the Static Characteristics of an Externally Pressurized Thrust Bearing Lubricated with Refrigerant Gas

Influence of Operating Temperature on the Static Characteristics of an Externally Pressurized Thrust Bearing Lubricated with Refrigerant Gas

Temperature-dependency performance of InGaAsP semiconductor laser amplifiers

We report a theoretical analysis on the influence of operation temperature on the static and dynamic properties of an InP/InGaAsP semiconductor Laser amplifier (SLA). We use a numerical wideband steady-state model and numerical algorithm, to study the (I-P) curves, gain bandwidth, noise figure, outpout noise power and outpout OSNR in a range between - 20 °C and 100 °C. InP/InGaAsP SLA exhibited a thershold curent as low as 55mA at 100 °C and the characteristic temperature (T0) of the SLA was found to be 142.8 0C, which confirms the high temperature operation of the device. Moreover, the results show that InP/InGaAsP SLA can cover 3dB operating at signal wavelengths between 1.54µm and 1.58µm with gains of up to 25dB at -20 0C. This peak slightly decreases with temperature. Furthermore, a high out power saturation of 7 dB was exhabited at -20 °C and a low noise figure of around 2.8 dB was achieved in the deviece. Finally, our model shows the elegant performance of InGaAsP/InP SLA in the range between -20 °C and 100 °C, which makes it a promising candidate for integrated photonics.

The Influence of Operating Temperature on the Performance of BIPV Modules

To investigate the effect of the operating temperature on the performance of building integrated photovoltaic modules, two different crystalline silicon (c-Si) module types (glass/backsheet and glass/glass) with two different mounting configurations (ventilated and insulated) were installed in Canobbio, Switzerland and monitored over more than four years outdoors. The differences in the performance loss rates (PLRs) between module types and mounting configurations were determined by using the year-over-year methodology. The glass/backsheet module was markedly affected by the higher operating temperature: PLR changed from 0.01%/yr for ventilated to $-$ 0.42%/yr for insulated. However, the glass/glass module showed an opposite and unexpected trend: PLR changed from $-$ 0.10%/yr for ventilated to 0.26%/yr for insulated. Analysis of the IV curve parameters revealed that the decreased performance of the insulated glass/backsheet module was chiefly due to the loss in the fill factor with increased resistance; however, the gain in the short-circuit current ( I sc) was the main driver for the increased performance of the insulated glass/glass module. Real-world temperature coefficients were further examined and they were mostly found to be in line with the values measured indoors. Lower power–temperature and higher current–temperature dependence of the insulated glass/glass module, compared to the ventilated construction, supported the observed performance and current behavior of this module.

Nitrite accumulation stability evaluation for low-strength ammonium wastewater by adsorption and biological desorption of zeolite under different operational temperature

How to achieve stable nitrite accumulation was still a huge challenge for low-carbon and energy-saving biological nitrogen removal of low-strength ammonium wastewater. This study proposed a new way to solve this problem with zeolite biological fixed bed (ZBFB) by cycle operation of adsorption and biological desorption. In order to evaluate nitritation performance of this reactor, the influence of operational temperature on nitrite accumulation stability was investigated by 126 cycles operation in four parallel ZBFB reactors for low-strength ammonium wastewater (50 mg/L NH4+-N). It was found that higher operational temperature (i.e., 36.0 °C), rather than other temperature (i.e., 27.0 °C, 30.0 °C, 33.0 °C), could maintain stable nitrite accumulation with nitrite production rate of 0.312 kg NO2–-N·m−3 zeolite·day−1 and nitrite accumulation ratio higher than 95.0% after biological desorption. High-throughput sequencing analysis results showed that bacterial structure significantly changed in ZBFB under different operational temperature, and obvious enrichment of genus Nitrosomonas (AOB) and gradually enhanced free ammonia (FA) inhibition on genus Nitrospira and Nitrobacter (NOB) were found by elevation of operational temperature, leading to different nitrite accumulation performance in ZBFB reactors. The mechanism for stable nitrite accumulation performance by ZBFB might be attributed to overwhelming growth rate of AOB than NOB, faster ammonium desorption and enhanced FA inhibition on NOB under operational temperature (i.e., 36.0 °C). All in all, keeping high temperature for biological desorption step should be extremely crucial for stable nitrite accumulation by ZBFB, which could facilitate further low-carbon and energy-saving biological nitrogen removal for low-strength ammonium wastewater treatment.

Influence of Operation Temperature on Rolling Bearings

Rolling bearings are among the most widely widespread components in the engineering industry. A critical issue is damage to functional surfaces of rolling bearings, which has arisen during the operation. An important area is the monitoring of production temperature and its impact on components. We undertook this study to damage of functional surfaces bearings. It was decided that the optimal procedure is comparing three samples, each with another type of damage. This procedure will aid determine the cause of damaged bearings. This work has shown the adverse effect of residual austenite and residual stresses caused by the production process on the dimensional stability of the bearing components.

Insight into the distribution of metallic elements in membrane bioreactor: Influence of operational temperature and role of extracellular polymeric substances.

The distribution of metallic elements in a submerged membrane bioreactor (MBR) was revealed at different temperatures using inductively coupled plasma-optical emission spectrometry (ICP-OES), and the role of extracellular polymeric substances (EPS) was probed by integrating scanning electron microscopy (SEM) with confocal laser scanning microscopy (CLSM) over long-term operation. More metallic elements in the influent were captured by suspended sludge and built up in the fouling layer at lower temperature. The concentration of metallic elements in the effluent was 5.60mg/L at 10°C operational temperature, far lower than that in the influent (51.35mg/L). The total contents of metallic elements in suspended sludge and the membrane fouling layer increased to 40.20 and 52.19mg/g at 10°C compared to 35.14 and 32.45mg/g at 30°C, and were dominated by the organically bound fraction. The EPS contents in suspended sludge and membrane fouling layer sharply increased to 37.88 and 101.51mg/g at 10°C, compared to 16.87 and 30.03mg/g at 30°C. The increase in EPS content at lower temperature was responsible for the deposition of more metallic ions. The strong bridging between EPS and metallic elements at lower temperature enhanced the compactness of the fouling layer and further decreased membrane flux. This was helpful for understanding the mechanism of membrane fouling at different operational temperatures and the role of EPS, and also of significance for the design of cleaning strategies for fouled membranes after long-term operation.

The Influence of Operation Temperature and Variations of the Illumination on the Performance of Integrated Photoelectrochemical Water‐Splitting Devices

AbstractRenewable and storable fuel hydrogen can be produced through light‐driven water splitting using photovoltaic‐biased electrosynthetic (PV‐EC) devices. The required voltage to drive the reaction is approximately 1.5 V, which can be provided using multi‐junction silicon solar cells. To generate these voltages at the operation point, the solar cells are electrically optimized with respect to the standard test conditions. However, if such devices were to be used outdoors, a wide range of different illumination conditions has to be considered. Herein, we discuss the dependence of the solar‐to‐hydrogen efficiency on the spectral quality, the incident illumination intensity and the operation temperature. It is found that in the case of high irradiation intensities (e. g. 1 sun), high operation temperatures reduce the PV performance, but the overall PV‐EC device performance remains almost unchanged due to improved kinetics in the EC part. In contrast, when the illumination intensity is reduced, the loss in PV performance cannot be compensated by improved EC performances due to higher temperatures.

Equation of Energy Injection to a Dielectric Barrier Discharge Reactor**supported by National Natural Science Foundation of China (No. 11575159), Zhejiang Provincial Natural Science Foundation of China (No. LY13B070004), Program for Zhejiang Leading Team of S&T Innovation (No. 2013TD07), and National Natural Science Foundation of China (No. 51206146)

The electric energy injection from a pulsed power supply to a planar type of dielectric barrier discharge (DBD) reactor at atmospheric pressure was studied. Relations of the energy injection with barrier materials, barrier thickness, peak voltage, gap distance, electrode area, and operation temperature were experimentally investigated. The energy injection is a function of relative permittivity, barrier thickness, peak voltage, gap distance, and electrode area. The influence of operation temperature on energy injection is slight in the range of 27–300 °C but becomes obvious in the range of 300–500 °C. A model was established using which the energy injection can be easily predicted.

Novel biocatalysts for glycerol conversion into 2,3-butanediol

Bioconversion of biodiesel-derived waste glycerol into high-value products is proposed as a solution to improve economic viability of biorefineries. Several microorganisms are able to metabolize glycerol into 2,3-butanediol (2,3-BD), a promising bulk chemical with wide applications: solvent, fuel additive, and feedstock for synthetic rubber production, among them. In the present work, a wide screening of microorganisms present both into the waste water treatment system in a biodiesel industry and in culture collections was carried out in order to evaluate their potential as new 2,3-BD producer biocatalysts. Two microorganisms for 2,3-BD production from glycerol as sole carbon source have been selected, namely Raoultella planticola CECT 843 and Raoultella terrigena CECT 4519. Raoultella strains belong to the non‐pathogenic bacteria class (biosafety level 1). This genus has not been previously described as biocatalyst for the studied process. The influence of operational temperature, organic acid addition, and yeast extract concentration on 2,3-BD yield and productivity have been studied through Taguchi design methodology as well as initial glycerol concentration. Based on these results, the feasibility of the process employing pure glycerol and different samples of raw glycerol has been demonstrated.

The Influence of Operating Temperatures on Wax Deposition During Cold Flow and Hot Flow of Crude Oil

The authors examined the effect of operating temperatures on the wax deposition by using the cold finger device and high-temperature gas chromatography. The decreases in coolant temperature have been observed to result in increases in the amount of total deposit, but decreases in the amount of high carbon number components in deposit. When the bulk oil temperature increases from the gelling, cold flow, and hot flow conditions, the deposition rate decreases first, then increases, and then finally decreases while the wax content and the percentage of high carbon number component increase all the way.

Microbial community structure and dynamics in anaerobic fluidized‐bed and granular sludge‐bed reactors: influence of operational temperature and reactor configuration

SummaryMethanogenic community structure and dynamics were investigated in two different, replicated anaerobic wastewater treatment reactor configurations [inverted fluidized bed (IFB) and expanded granular sludge bed (EGSB)] treating synthetic dairy wastewater, during operating temperature transitions from 37°C to 25°C, and from 25°C to 15°C, over a 430‐day trial. Non‐metric multidimensional scaling (NMS) and moving‐window analyses, based on quantitative real‐time PCR data, along with denaturing gradient gel electrophoresis (DGGE) profiling, demonstrated that the methanogenic communities developed in a different manner in these reactor configurations. A comparable level of performance was recorded for both systems at 37°C and 25°C, but a more dynamic and diverse microbial community in the IFB reactors supported better stability and adaptative capacity towards low temperature operation. The emergence and maintenance of particular bacterial genotypes (phylum Firmicutes and Bacteroidetes) was associated with efficient protein hydrolysis in the IFB, while protein hydrolysis was inefficient in the EGSB. A significant community shift from a Methanobacteriales and Methanosaetaceae towards a Methanomicrobiales‐predominated community was demonstrated during operation at 15°C in both reactor configurations.

Low temperature synthesis of hexagonal ZnO nanorods and their hydrogen sensing properties

The growth of hexagonal ZnO nanorods was demonstrated by low temperature chemical synthesis approach. X-ray diffraction (XRD) analysis revealed a wurtzite hexagonal structure of the ZnO nanorods. The optical properties were measured by UV–vis spectrophotometer at room temperature. X-ray photoelectron spectroscopy (XPS) confirmed high purity of the ZnO nanorods. The hydrogen sensor made of the ZnO nanorods showed reversible response. The hydrogen gas tests were carried out in presence of ambient air and the influence of operation temperature on the hydrogen gas sensing property of ZnO nanorods was also investigated.

Active Area Determination of Porous Pt Electrodes Used in Polymer Electrolyte Fuel Cells: Temperature and Humidity Effects

This paper discusses the proper measure of the electrochemically active area (ECA) of carbon supported Pt catalyst in polymer electrolyte fuel cells employing in situ cyclic voltammetry. The charges of the hydrogen underpotential deposition and CO stripping peaks obtained in situ are compared, and the influence of operation temperature and relative humidity (40%–90%) is discussed. The results show that the charges of the decrease with rising temperature, while the corresponding charges of the CO stripping peak are essentially independent of temperature, at least at high relative humidity. The unexpectedly small charges are explained by the significant overlap with the hydrogen evolution reaction in a fuel cell at elevated temperatures. According to our results, it is proposed that a more reliable value of Pt ECA is estimated from the CO stripping charge. However, with decreasing humidity the charges of both and CO stripping peaks decrease, which is probably an effect of increasing blockage of Pt active sites by hydrophobic domains in the electrode ionomer. Some implications of varying cell conditions on the estimated Pt ECA and its correlation with fuel cell activity are discussed in an example from a fuel cell degradation test.

Fabrication and gas sensing properties of In2O3 nanopushpins

The growth of nanopushpin-like In2O3 nanostructures was demonstrated on the silicon substrate by catalyst-free chemical vapor deposition method. Structural analysis revealed single-crystalline nature of the In2O3 nanopushpins with a cubic crystal structure. The hydrogen sensor made from the In2O3 nanopushpins showed swift response and excellent stability. The influence of operation temperature on the hydrogen gas sensing property of In2O3 nanostructures was also investigated. Our results reveal that the sensor response of In2O3 nanopushpins increases with increasing the operation temperature.

Absorption and desorption of gaseous toluene by an absorbent microcapsules column

Heavy solvents absorption appears to be very attractive in recovering of volatile organic compounds (VOCs) from industrial tail gas. Their high viscosities make good dispersion required but difficult to reduce mass transfer resistance. Microencapsulation techniques provide a candidate solution. In this paper, vapor pressures for toluene+poly(dimethylsiloxane) (PDMS) mixtures were measured at temperature ranging from 273.2K to 343.2K. Polyacrylonitrile (PAN) hollow microspheres, prepared by orifice dispersion plus solvent extraction method, was used to immobilize PDMS. The capacity was adjusted from 2.3g to 9.3g PDMS/g PAN by addition of cyclohexane in PDMS during solvent impregnation. The breakthrough curves of column packed with PDMS/PAN microcapsules were determined, indicating shapes close to ideality, high absorption efficiencies and considerable absorption capacities before breakthrough. The influence of operational temperature, concentration of feed and gas feed flow rate on the absorption process were investigated as well. A mathematical model, suitable for dilute gas absorption process, was used to simulate the breakthrough curves. This model has proved to be useful to fit curves and analyze the absorption kinetics of PDMS/PAN microcapsules column. After absorption, the column can be regenerated completely by gas stripping. Enrichment of toluene was founded by increasing desorption temperature. Through absorption and desorption by turns, the stability of PDMS/PAN microcapsules column was verified.

微粉炭火力用電気集じん器の性能に及ぼす操作温度および石炭灰性状の影響

Electrostatic precipitator (ESP) is a major dust collection technology for pulverized coal combustion boilers in Japan. Although the collection efficiency of ESP is over 99%, the performance of ESP is affected by dust properties, especially by the electric resistivity of dust. In Japan, many kinds of coal are imported from countries overseas and used in pulverized coal combustion boiler. The property of coal ash formed by the pulverized coal combustion is different by coal species. It is very important to develop a high performance electrostatic precipitator for various types of coal ash. In this paper, the influence of operation temperature from 363K to 623K on the performance of ESP for pulverized coal combustion boiler is investigated, and the relationship between the coal ash property including electric resistivity and alkalic metal concentration and the collection efficiency of ESP is obtained.