330MW火电机组热系统节能诊断

利用火电厂热力系统节能诊断理论，对陕西蒲电二期N330-17．75／540／540型机组的热力系统运行方式、热力参数等进行了节能潜力分析和定量计算。利用等效热降理论进行定量诊断计算得出总节能潜力达到3．2g／kWh，可以显著地提高机组运行的经济性。     

虚拟仪器技术在雷达系统测试中的应用

分析了现代雷达系统对新一代雷达测试系统的要求,总结了虚拟仪器的发展、优势和关键技术,并对新一代雷达测试系统进行了展望.     

Catalytic Upgrading of Phenolic Oil by Etherification with Methanol

Catalytic etherification of phenolic oil with methanol was investigated to decrease the polarity and acidity of the product oil. The catalyst KH₂PO₄/activated alumina (AA) provided the best performance due to its excellent dehydration and anti‐coking property. When catalyzed by KH₂PO₄‐AA, the content of aryl ethers increased with rising temperature during the early stage but decreased at 500 °C. Alkoxy phenols had an inhibiting effect on etherification of alkyl phenols due to adsorption competition. Aryl ethers were mostly generated from alkyl phenols, while alkoxy phenols also contributed by simultaneous conversion to dialkoxybenzenes and diphenols, with a higher selectivity to diphenols. This explained the reduced alkoxy phenols and more generated alkyl phenols and aryl ethers at 350 °C.     

Levitation Performance Study of Bulk HTSC over Monopole PMG Consider Different Cross-Section Configuration with 3D-Modeling Numerical Method

Magnetic levitation force of bulk high temperature superconductors (HTSCs) above monopole permanent magnet guideway (PMG) is simulated using finite element method (FEM). The models are formulated by H-formulation and resolving codes is developed using Finite Element Program Generator (FEPG). The E–J power law is used to describe the electrical field vs. current density nonlinear characteristic of HTSC. By the method, the levitation performance is studied consider different cross-section configure of the monopole PMG. The simulation results show that the maximum levitation force (MLF) of the bulk HTSC will increase when the height/width of the PMG rises while fixing the width/height of the monopole PMG cross-section. The increasing trends to slow when the absolute differential value of the height and the width of the PMG cross-section become larger and larger. For a certain cross-section area of the monopole PMG, the economical levitation cost may be achieved while the ratio of height to width of the cross-section changes between 0.475 and 0.525.     

Feature selection and hyper parameters optimization for short-term wind power forecast

Applied Intelligence - Accurate wind power forecasting plays an increasingly significant role in power grid normal operation with large-scale wind energy. The precise and stable forecasting of wind...     

Multi‐scale modelling of the tensile behavior of lithium ion battery cellulose separator

As a satisfactory green material for a lithium ion battery separator, cellulose possesses better wettability and superior thermal and chemical stability compared to commercial polyolefin separators. The macroscopic mechanical properties of the separator are determined by structural parameters on different dimensional scales. In this paper, a two‐scale modelling method is proposed for a cellulose separator. At micro‐scale, a single fiber structural model was established with a cross‐sectional profile extracted through image processing, combined with the fiber helix angle. At meso‐scale, a representative volumetric element model and a two‐dimensional random fibrous model for the fibrous network of the cellulose separator were developed. The elastic modulus in the machining direction (MD) and transverse direction (TD) of the two models were calculated by finite element simulation and compared with experimental data. The results show that the elastic modulus of the models is slightly larger than that from experiments. Compared to experiments, the relative errors in the MD and TD of the representative volumetric element model are 2.80% and 6.78%, respectively. The relative errors in the MD and TD of the two‐dimensional random fibrous model are 6.70% and 8.47%, respectively. Consequently, multi‐scale modelling is proven to have considerable value in investigating the properties of fibrous materials. © 2019 Society of Chemical Industry     

Analysis of indoor particles and gases and their evolution with natural ventilation

The air composition and reactivity from outdoor and indoor mixing field campaign was conducted to investigate the impacts of natural ventilation (ie, window opening and closing) on indoor air quality. In this study, a thermal desorption aerosol gas chromatograph (TAG) obtained measurements of indoor particle‐ and gas‐phase semi‐ and intermediately volatile organic compounds both inside and outside a single‐family test home. Together with measurements from a suite of instruments, we use TAG data to evaluate changes in indoor particles and gases at three natural ventilation periods. Positive matrix factorization was performed on TAG and adsorbent tube data to explore five distinct chemical and physical processes occurring in the indoor environment. Outdoor‐to‐indoor transport is observed for sulfate, isoprene epoxydiols, polycyclic aromatic hydrocarbons, and heavy alkanes. Dilution of indoor species is observed for volatile, non‐reactive species including methylcyclohexane and decamethylcyclopentasiloxane. Window opening drives enhanced emissions of semi‐ and intermediately volatile species including TXIB, DEET, diethyl phthalate, and carvone from indoor surfaces. Formation via enhanced oxidation was observed for nonanal and 2‐decanone when outdoor oxidants entered the home. Finally, oxidative depletion of gas‐phase terpenes (eg, limonene and α‐pinene) was anticipated but not observed due to limited measurement resolution and dynamically changing conditions.