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1.
This paper proposes a parameter adjustable dynamic mass and energy balance simulation model for an industrial alkaline water electrolyzer plant that enables cost and energy efficiency optimization by means of system dimensioning and control. Thus, the simulation model is based on mathematical models and white box coding, and it uses a practicable number of fixed parameters. Zero-dimensional energy and mass balances of each unit operation of a 3 MW, and 16 bar plant process were solved in MATLAB functions connected via a Simulink environment. Verification of the model was accomplished using an analogous industrial plant of the same power and pressure range having the same operational systems design. The electrochemical, mass flow and thermal behavior of the simulation and the industrial plant were compared to ascertain the accuracy of the model and to enable modification and detailed representation of real case scenarios so that the model is suitable for use in future plant optimization studies. The thermal model dynamically predicted the real case with 98.7 % accuracy. Shunt currents were the main contributor to relative low Faraday efficiency of 86 % at nominal load and steady-state operation and heat loss to ambient from stack was only 2.6 % of the total power loss.  相似文献   
2.
‘Renewable energy is an essential part of our strategy of decarbonization, decentralization, as well as digitalization of energy.’ – Isabelle Kocher.Current climate, health and economic condition of our globe demands the use of renewable energy and the development of novel materials for the efficient generation, storage and transportation of renewable energy. Hydrogen has been recognised as one of the most prominent carriers and green energy source with challenging storage, enabling decarbonization. Photocatalytic H2 (green hydrogen) production processes are targeting the intensification of separated solar energy harvesting, storage and electrolysis, conventionally yielding O2/H2. While catalysis is being investigated extensively, little is done on bridging the gap, related to reactor unit design, optimisation and scaling, be it that of material or of operation. Herein, metals, oxides, perovskites, nitrides, carbides, sulphides, phosphides, 2D structures and heterojunctions are compared in terms of parameters, allowing for efficiency, thermodynamics or kinetics structure–activity relationships, such as the solar-to-hydrogen (STH). Moreover, prominent pilot systems are presented summarily.  相似文献   
3.
魏学勇 《甘蔗糖业》2021,(2):115-120
制糖企业与现代信息技术融合程度的加深,极大地优化了企业生产、管理,同时也带来了较为严峻的网络安全问题。文章通过对甘蔗制糖企业工控系统、网络安全等进行分析,总结了甘蔗制糖企业工控系统特点与网络安全现状,以此为基础对甘蔗制糖企业工控系统网络安全问题进行分析,最终完成了甘蔗制糖企业工控系统网络安全纵深防御体系的构建。本文旨在为甘蔗制糖领域企业信息化发展与网络安全防御提供理论与技术支撑,进而全面优化糖企与现代信息技术融合下的网络安全防御体系。  相似文献   
4.
《Ceramics International》2022,48(11):15227-15235
High-performance and low-carbon MgO–C refractories are important refractories for smelting ultra-low carbon steel and clean steel. Based on this, Cr3C2/C composite powders were synthesized by the molten-salt method, and used as an additive to prepare low-carbon MgO–C refractories under nitrogen atmosphere. The phase, morphology and oxidation kinetics of Cr3C2/C composite powders were studied. In addition, the effect of Cr3C2/C composite powders on the morphology, mechanical properties, thermal shock resistance, and corrosion resistance of MgO–C refractories was investigated. The results indicated that the Cr3C2/C composite powders exhibited superior oxidation resistance than flake graphite. Moreover, the Cr3C2/C composite powders were introduced into the MgO–C refractories. Compared with the sample without Cr3C2/C composite powders, the introduction of 1 wt% Cr3C2/C composite powders significantly improved the thermomechanical properties and corrosion resistance of the material, its CMOR, CCS before and CCS after thermal shock were 9.06 MPa, 50.40 MPa and 32.60 MPa, respectively, and the corrosion index was significantly reduced from 44.6% to 26.5%.  相似文献   
5.
Deicing technicians working from open baskets are exposed to ergonomic risks and fatigue. This study aims to assess the global risk of musculoskeletal injuries (MSIs) for this type of activity. An ergonomic study was conducted with the workers of a Canadian airport deicing operator during the winter of 2016–2017. Video recordings made it possible to observe the activities during the most intensive work shifts, as well as characterise and quantify (frequency and duration) the movements/postures of twelve human subjects. The resulting risk assessment identified the body structures submitted to exertion, analysed the efforts involved and globally assessed the forces exerted on the spine and upper limbs. This global risk assessment leads to the conclusion that the risks to the upper limbs are preoccupying and must be examined further.  相似文献   
6.
Musculoskeletal injuries are well-known disorders among the agricultural tractor operators. Overexertion is a critical factor which can agitate these injuries. Physical body characteristics should be measured for an ergonomically best-fit-optimal design for the operators. In this study, a designed setup was employed to derive the applied forces by tractor operators on the control tools. The different muscle strengths including leg/foot strength, hand push/pull strength, and torque strength applied by both hands were measured. A comparison was made for the obtained values for different strengths by considering the effects of hand dominance. The obtained data were used to estimate the maximum allowed forces in these tools. In contrast to the previous studies, the minimum allowed actuating forces of the pedals were calculated using reasonable assumptions. These values could provide more comfort and less exhaustion for the tractor operators. The obtained ranges were benchmarked against corresponding recommended values in some standards (ISO, ISIRI, and ASABE family). The results revealed the unsuitability of evaluated standards for a proper design and the excessive overestimation of those recommended values (in some cases more than 3 times). In all of the design procedure, a suitable attention was paid to accommodate it with more than 90% of target population.Relevance to industryA prosperous industry which considers ergonomic factors in the design of agricultural machine workplace can overcome the disorders and generate more comfort. Evaluating more exact mechanical forces can result in a suitable design of workplace.  相似文献   
7.
This research evaluates the shear strength properties of unreinforced and geogrid-reinforced ladle furnace slag (LFS), electric arc furnace slag (EAFS) and a blend comprising 50% LFS and 50% EAFS (LFS50+EAFS50) using the large direct shear testing apparatus (DST). The large DST results of unreinforced steel slags indicated that LFS had the lowest shear stress ratio at the peak shear strength among all samples, while LFS50+EAFS50 samples (both unreinforced and reinforced) demonstrated the highest shear stress ratio amongst the tested samples. A higher apparent cohesion value was achieved with the inclusion of biaxial geogrid in LFS and EAFS samples as compared to the triaxial geogrid interface. The observed behavior can be attributed to the larger aperture size of the biaxial geogrid compared to the triaxial geogrid leaving more void planar space for a direct interaction between slag particles. In contrast, the apparent cohesion of LFS50+EAFS50 without a geogrid interface was high and did not change significantly with the insertion of geogrid. Given, the range of internal friction angles for ordinary soils, studied slag by-products achieved internal friction angles in excess of 59° (with no geogrid interface) and these significant values proved highly beneficial application for these waste materials in pavement construction.  相似文献   
8.
9.
With the increase of population in big cities, urban industrial districts are constantly seeking new development to realize the conversion from single-functional to multifunctional systems, to equip the city with diverse public spaces. The Port of Houston operates at the dynamic confluence of industry, transportation, and ecological systems, and has been a major driver of Houston’s economic growth over the last century. However, behind the prosperous economic growth, the port suffers from the isolation with the surrounding communities. Based on the “2045 Port Houston Master Plan,” the Landscape Planning and Design for the Port of Houston project focuses on urban space activation and ecological environment restoration through landscape planning and design methods, while facing the challenges of ecological environment, urban spatial pattern repositioning, and other urban issues. The project is expected to build an economically, socially, and ecologically healthy industrial waterfront zone. Port Houston, beyond its primary function as an economic driver, becomes a more visible and substantial force in urban governance of advancing the region’s activation and resilience.  相似文献   
10.
The catalytic conversion of CO2 to CH4 (Sabatier reaction) has been studied to develop an after-treatment process at vehicles exhausts. Three different formulations of Ru commercial catalysts, two in powder and one in pellets shape, were tested and characterized by means of X-ray powder diffraction, scanning electron microscopy (SEM-EDX), N2 adsorption at −196 °C and temperature-programmed reduction (TPR).Experimental results show a high CO2 conversion (XCO2 = 0.96 @ T = 280 °C) for one powder catalyst formulation whereas the other one has maximum CO2 conversion = 0.69. In both cases a high CH4 selectivity is measured. High CO2 conversion (XCO2 = 0.92 @ T = 300 °C) is obtained also with pellet catalysts but only at lower GHSV values. The different behavior of the catalysts was ascribed to the different physicochemical properties and the key parameters for the application development of the process were identified. In particular, the possibility to use pellets or monolithic reactors, thus minimizing the pressure drops in the reactor, makes possible a commercial application in the treatment of vehicles exhausts.  相似文献   
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