Risks Associated with the Use of Hydrogen as an Energy Carrier or Source
Abstract
2905 18305
Risks Associated with the Use of Hydrogen as an Energy Carrier or Sourceby
Abstract
Hydrogen is a dangerous gas due to its low ignition energy, wide flammability range, promotion of the embrittlement of steel, and its high coefficient of permeation for polymers. The fracture toughness and failure elongation of pipe steels are strongly impacted by hydrogen embrittlement, whereas yield stress and ultimate strength are moderately impacted. Specific tools are required for the pipe defect assessment used for the transport of hydrogen, which is pure or blended with natural gas. The safety factors associ [...] 2905 18305 |
Study of Hydrogen Embrittlement in Pipelines and Nuclear Power Plants: Estimates for DurabilityAbstract
Due to the increasing need to further develop the world gas and oil industry and the increased public attention to clean energy sources, studying and preventing Hydrogen Induced Cracking is one of the main safety concerns in nuclear power plants, oil pipelines and platforms. In this article, the growth and incubation times for internal Hydrogen Induced Cracks (HIC) are examined. Specifically, these times are modeled in two separate phases - the first phase (I) is a long time approximation, when the crack growth is [...] 1646 10528 |
Artificial Neural Networks and Gradient Boosted Machines Used for Regression to Evaluate Gasification Processes: A ReviewAbstract
Waste-to-Energy technologies have the potential to dramatically improve both the natural and human environment. One type of waste-to-energy technology that has been successful is gasification. There are numerous types of gasification processes and in order to drive understanding and the optimization of these systems, traditional approaches like computational fluid dynamics software have been utilized to model these systems. The modern advent of machine learning models has allowed for accurate and computationally ef [...] 1358 10195 |
Incentivizing Alternative Fuel Vehicle Transactions: Analysis of Cash-for-Clunkers Transactions for New Alternative Fuel VehiclesAbstract
Monetary incentives to accelerate the transition of private vehicle fleets to zero emissions promote sustainability in the transportation sector. Clean Cars for America to incentivize transactions for new battery power vehicles is a program in furtherance of sustainable transportation goals in the United States. Unfortunately, data on transactions for new alternative fuel vehicles (AFVs) are scarce so empirical research to explore the costs and/or the benefits of such programs is also scarce. Analysis of transactio [...] 1179 7099 |
From Food to Foot: The Energy and Carbon Flows of the Human Body at Walking and CyclingAbstract
The carbon footprint of motorized transport modes per unit length traveled encompasses the unit share of the vehicle lifetime emissions, that of the transport infrastructure, and those of the motor energy, considered both from “well to tank” and from “tank to wheel”. In the active modes of transport, i.e., walking and cycling, the counterpart of motor energy is human energy, which is associated with two kinds of carbon flows: the carbon footprint of food intake, – which we call the Food to Body component – and the [...] 2285 15604 |
Numerical Study to Understand the Conservation of Hydrogen Through a Dynamic Fuel Supply System in Proton Exchange Membrane Fuel Cells (PEMFCs)Abstract
Reducing and conserving fuel usage is pivotal for any engineering system for the development of a sustainable energy solution. Proton exchange membrane fuel cells (PEMFCs) are one of the promising renewable energy systems that consume hydrogen as their source of fuel to generate electricity. This paper investigate the necessity of the constant supply of fuel (hydrogen) in the PEMFC system to ensure stable operation. We propose that a dynamic supply of fuel could help achieve similar performance and reduce the amoun [...] 1243 8663 |
Surface Treatment of Flexible Barrier Film for Improved Stability of Organic Photovoltaic Mini Modulesby
Abstract
The lifetime and stability of organic photovoltaics (OPVs) are the key factors that influence the technology used to scale up and commercialize OPVs. High-performing and reliable devices are used to fabricate the devices of choice. Materials and methods that can be used to prevent the degradation of organic materials, enabling better OPV applications, are being increasingly researched in recent years. Herein, we present the surface modification process of a commercial, flexible barrier film based on polyethylene te [...] 1675 10767 |
Analysis of LoRa Transmission Delay on Dynamic Performance of Standalone DC MicrogridsAbstract
One important aspect toward proper and stable functioning of a communication-based controlled microgrid is data transmission. Consequently, an analysis of the effect of data transmission delay is of significance for any chosen communication protocol. This paper focuses on the effect of employing LoRa for data transfer at the secondary control level of a standalone DC microgrid. It analyses the effect of LoRa transmission delay on the dynamic performance of DC microgrids. This paper simulates a community DC microgri [...] 1409 9881 |
Controller Evaluation for Solar-Latent Thermal Energy Applicationsby
Abstract
In this study, the performance of a self-sufficient controller used for a solar-latent heat domestic hot water (DHW) production unit under real-world operating conditions was analyzed. The unit consists of a flat-plate solar collector and a latent heat storage tank. The controller is powered by a small solar panel and governs the charging and discharging of the system, ensuring maximum solar energy absorption, desired hot water temperature, and constant monitoring of the heat-storage tank’s capacity. The system is [...] 1166 7585 |
Improving the Engine Efficiency Using a New Combined Refrigeration Cycle for Low-Temperature Heat Source (Waste Heat Recovery)Abstract
Passenger and commercial internal combustion engines have relatively large dissipated thermal energy sources that can be used for initiating thermodynamic refrigeration cycles at low temperatures while improving engine efficiency. Researchers have focused on combined power-refrigeration cycles in past studies. This paper presents the operation and performance of a new combined refrigeration system driven by waste heat recovery within the internal combustion engines. For this purpose, the effects of several paramete [...] 1335 7843 |
Analysis of Correlations for the Prediction of the Entrainment Fraction of Droplets in Gas-liquid Annular Flowsby
Abstract
In gas-liquid flows, droplets that detach from the liquid film lining the internal walls of a pipe and merge with the gas flowing through the pipe follow an annular flow pattern. This work analyzes correlations for estimating the entrainment fraction of such droplets contained in the literature by comparing their predictions with experimental data also from the literature. The results of this comparative study demonstrate that the analyzed correlations do not accurately reproduce experimental conditions. This is du [...] 2167 12582 |
Non-Newtonian Flow in Bifurcated Piping and Arterial Networksby
Abstract
Flows in multi-branch piping systems are modeled for linear Newtonian and nonlinear Power Law, Bingham Plastic and Herschel-Bulkley fluids. The nonlinear models are often used to describe multiphase fluids consisting of liquid and solid phases, including cement slurries and drilling muds in petroleum engineering. Rheological and heterogeneous multiphase effects are important to blood flows in single and bifurcated arteries, capillaries and veins – biological applications are also emphasized to highlight their incre [...] 1398 10261 |
A Large Eddy Simulation Study of Cyclones: The Effects of Interparticle Collisions on Erosion Predictionby
Abstract
Cyclone separators are widely used in fluid catalytic cracking (FCC) units due to their lack of moving parts and relatively low-pressure drop. However, cyclone separators are prone to erosion-related issues, which is a major drawback. In this paper, a large eddy simulation (LES) of the particle-gas flow in a cyclone separator is investigated using a four-way Euler-Lagrange approach to model inter-particle collisions and the exchange of momentum between particles and fluid. The effects of inter-particle and particle [...] 1769 11357 |
Experimental Study of Lean-burning Limits of Hydrogen-enriched LPG Intended for Domestic UseAbstract
The lean-burning limits of hydrogen-enriched Liquefied Petroleum Gas (LPG) have been studied using a Bunsen burner. The lean-burning limits under different conditions are important design considerations in developing gas-fired domestic appliances. In this study, the lean-burning limits of hydrogen-enriched LPG have been obtained across a wide range of Reynolds numbers (600 to 1800) and H2 volumetric fractions (0% to 25%). The results show that the lean-burning limit is increased, on average, by 4.0% to 7.2% for eve [...] 2489 12945 |
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Open Access Short Communication Electrochemical Impedance Spectroscopic Studies of PHEV2 form-factor Lithium-ion Cells for Automotive ApplicationsAbstract
Prismatic PHEV2 form-factor lithium-ion cells with a nominal capacity of 25 Ah (as used for automotive applications) have been studied with electrochemical impedance spectroscopy (EIS). The data was evaluated using electrical equivalent circuits. Mathematical modeling, system identification, and the determination of model parameters of the lithium-ion cell were also carried out. While a study of the influence of temperature and state-of-charge (SOC) performed using pristine lithium-ion cells showed a nonlinear rela [...] 1745 10982 |
Solar Energy Policy for Commercial Buildings Sector: Recommendations for the Indian ScenarioAbstract
India is a rapidly developing nation and is heavily dependent on fossil fuels. Renewable energy presents an attractive solution to the growing challenges concerning energy needs. Solar energy is abundant in India, and thus, its application and use are rapidly advancing. This study assesses various government initiatives for off-grid Solar Photovoltaic/Solar Water Heating systems for commercial establishments in India and elucidates the need for improvements in their implementation, highlighting the problems in avai [...] 1488 9483 |
Adapted Time Slice Model of Pinch Analysis for Direct-Indirect Heat Recovery in Buildingsby
Abstract
Heat integration techniques such as pinch analysis can play a significant role in saving energy in the design of buildings. The application of pinch analysis in this sector encounters difficulties due to the highly time-dependent behavior of energy streams such as waste heat and solar thermal collectors, as well as the possible need for heat storage units (HSUs). The existing pinch models in the literature either bear little relation to reality because they ignore the time dependency of the streams, or they do not [...] 1405 10756 |
Building New Nuclear in Finland: Crises Challenging Core Beliefs around Nuclear EnergyAbstract
This paper examines the building of a new nuclear plant as a greenfield operation in Pyhäjoki, Finland. A newly-founded energy company, Fennovoima, was granted a license by the Finnish parliament to build a new power plant in 2010. In the years following this Decision in Principle the project faced several obstacles. Through interviews with key actors, this paper identifies the interests and core beliefs associated with building the plant. It posits that, in Finland, the underlying ideas and values surrounding nucl [...] 1384 12843 |
Thermo-rechargeable Batteries Fabricated Using Low-cost Materialsby
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We fabricated three thermo-rechargeable batteries using low-cost transition metal hexacyanoferrate and determined the thermal voltage (Vcell) and discharge capacity (Qcell) per unit weight of the total active material in the cathode and anode. The obtained values were compared with the calculated values, which were determined by analyzing the temperature and capacity coefficients of the redox potential. 1502 9287 |
Electrochemical Synthesis of Germanium-Polypyrrole Composite Nanomaterials in Ionic Liquids for the Fabrication of Lithium-Ion BatteriesAbstract
Herein, we report the coating of nanostructured germanium using a polypyrrole (PPy) polymer coat as a composite anode material for the fabrication of lithium-ion batteries. The Ge/PPy composites were synthesized following the direct electrochemical deposition method in an ionic liquid (IL). The results revealed that the coating of PPy on Ge helped realize stable battery cycling and reversible capacities, which were not observed in uncoated Ge. The PPy layers could effectively inhibit side reactions between the elec [...] 1621 10982 |
A Rechargeable Aqueous Lithium-Air Battery with an Acetic Acid Catholyte Operated at High Pressureby
Abstract
Acidic aqueous lithium-air batteries are attractive candidates for use as energy sources in electric vehicles because of their high energy and power densities and ability to operate under ambient conditions. An aqueous lithium-air battery with an acetic acid catholyte has a high theoretical energy density of 1,478 Wh kg-1, and the reaction product is soluble in the catholyte. In this study, we have studied the cell performance of a Li/interlayer electrolyte/NASICON-type solid lithium-ion conductor/acetic acid catho [...] 1623 12496 |
Operation of AC Microgrids with PV Panels’ Output Power Curtailment for Minimizing the Use of Energy Storageby
Abstract
In this paper, a method for operating AC microgrids in both off-grid or standalone and grid-connected modes is proposed to minimize the use of energy storage by increasing the number of PV panels and curtailing their output power. When the intensity of daylight decreases, power is imported from the main grid through an AC/DC/AC converter or solid-state transformers in parallel to compensate for the shortage. By using a three-phase transformer in Δ-Y connection with Y’s neutral connected to its local grounding syste [...] 1278 8929 |
An Open Source LoRa Based, Low-Cost IoT Platform for Renewable Energy Generation Unit Monitoring and Supervisory ControlAbstract
SCADA provides real-time system monitoring by constant communication and data exchange between various system devices to achieve data visualization and logging. Presently, in industrial systems, commercial SCADA systems are being used for data monitoring and control. These systems can be expensive, and as such can only be afforded by select industries. Even at these costs, the commercial SCADA systems face some challenges, which include interoperability and scalability issues. Research has shown that these problems [...] 1783 20292 |
Using SIRES to Enhance Resilience in Remote & Rural Communitiesby
Abstract
Rural and remote communities are more vulnerable to damage caused by extreme events as compared to urban areas. Natural disasters can disrupt basic supplies such as domestic water supply and cooking needs in addition to electricity outages. The recognition of the interlinked nature of food, water and energy has gained momentum over the past few years. Smart Integrated Renewable Energy System (SIRES) has been proposed to handle basic needs such as cooking, domestic and irrigation water supply, and electricity to rem [...] 1293 9360 |
Converting CO2 from a Harmful Gas to a Renewable Source of Matter and Energy: A ReviewAbstract
The emission of greenhouse gases, specifically CO2, has reached non-acceptable levels causing global warming with adverse effects. Owing to rigorous ongoing research, these harmful substances might be converted to beneficial sources. The main objective of this study was to review the most effective processes that might utilize carbon dioxide to produce various substances, chemicals, and energy. For this, different existing and projected short-term and long-term strategies have been presented and discussed. Specific [...] 1747 10050 |
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