Comparison of methods for discharging an isochoric compressed air tank in compressed air energy storage systemsKubala, Piotr; Gryboś, Dominik; Markowski, Jan; Leszczyński, Jacek
doi: 10.1088/1742-6596/2812/1/012020pmid: N/A
Renewable energy sources are characterized by intermittent operation, which creates the need to store surplus energy and release it at the time of demand. Energy storage systems that keep energy in compressed air can be a solution to this problem. Therefore, it is necessary to identify the method of releasing compressed air and select the most efficient one. In the study conducted, two particular ways of controlling the expansion of air stored in the tank emerged: control through a cut-off function of air supplied into cylinder and through the use of pressure regulator. To indicate which solution is more cost-effective from an energy point of view, a series of simulations were carried out using the Matlab environment. Operation with the highest efficiency and with the highest sustainability was achieved using a PID (proportional-integral-derivative) controller and a function controlling the level of opening of the valve passing air to the expander. The method considering the presence of the buffer tank provided rotation stability in a much shorter system operation time, while the baseline scenario (which did not include any form of system control) was characterized by instability, short operation time and low efficiency.
Analysis of combustion models of hydrogen-air mixtures using ANSYS FLUENTWyszyński, Patryk; Porowski, Rafał
doi: 10.1088/1742-6596/2812/1/012016pmid: N/A
This paper details an experimental investigation into flame propagation of a stoichiometric hydrogen mixture within a fixed 40 cm3 volume channel, utilizing ANSYS Fluent for simulation. The geometry was delineated as a 200x20 mm plane, with ignition positioned at the center. Certain input parameters were determined using MATLAB’s Cantera. The study explored different configurations of ANSYS Fluent’s channel combustion models, specifically examining both laminar and turbulent scenarios. Overpressure within the chamber was gauged at points 50 mm from the channel’s center to assess the impact of the relaxation factor on these measurements. These models underwent comparative analysis with actual experimental results, focusing on the highest achieved pressures and the flame’s shape at 1.9 ms, 2.9 ms, and 4.8 ms post-ignition. The findings underscore the complexity of modelling hydrogen mixture combustion in enclosed channels, highlighting the necessity for a specialized approach. Standard modules struggled to accurately replicate pressure variations over time, leading to significant discrepancies between the resulting models.
Prefacedoi: 10.1088/1742-6596/2812/1/011001pmid: N/A
This Volume contains the papers presented at Eurotherm Seminar 118 on Hydrogen Energy Technologies held in Krakow, Poland from 08–10 May 2024 and accepted for Proceedings published in the Journal of Physics: Conference Series. Eurotherm Seminar 118 is being organized under the auspices of the EUROTHERM Committee.Hydrogen is recognized as a clean energy source and a key chemical raw material. Currently, more than 90% of hydrogen is produced from fossil fuels via reforming. Therefore, hydrogen production powered by renewable energy sources (e.g., solar, wind, hydro) is highly desired for realizing a sustainable, carbon-neutral energy future.This seminar is connected with 20 years of cooperation between AGH University of Krakow and Shibaura Institute of Technology in Tokyo.The aims of the cooperation are as follows:• Enhancing cooperation and networking;• Developing new partnerships and strengthening existing ones;• Exchanging existing and creating new knowledge;• Enhancing level of science and technology;• Increasing impact of research and development activities.The aims of seminar was to collect presentations dealing with hydrogen energy technologies: production, storage, utilization and transport phenomena.List of Organizing Committee, Scientific Committee and Acknowledgments are available in this Pdf.
Peer Review Statementdoi: 10.1088/1742-6596/2812/1/011002pmid: N/A
All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single Anonymous• Conference submission management system: Morressier• Number of submissions received: 33• Number of submissions sent for review: 31• Number of submissions accepted: 24• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 72.7• Average number of reviews per paper: 2.125• Total number of reviewers involved: 9• Contact person for queries:Name: Marcin MozdzierzEmail: [email protected]: AGH University of Krakow
Heat transfer optimization via finned surface with the use of CFDDrag, Tomasz; Tokarski, Mieszko
doi: 10.1088/1742-6596/2812/1/012017pmid: N/A
Finned tubes are widely used in many industries such as the automotive, petrochemical, refining, and energy industries. They are applied to increase heat transfer efficiency between fluids through the use of protruding fins on the outer or inner surface of the tube, which aim to increase the surface area of heat exchange. The efficiency of an externally finned tube made of copper is increased by maximizing heat transfer and minimizing costs using the Ansys package. Heat exchange efficiency is improved and production costs are lowered by optimizing finned tubes. Firstly, a finned pipe fragment was modeled and meshed. Then, heat exchange between hot free flowing air around the tube and cold water flowing through the pipe were simulated. The foundation width and fin length were optimized in the ranges of 0.38mm-3.63mm and 4.9mm-14.9mm, respectively, using the simulation as a base. After the optimization certain cases were calculated analytically. It was found that the thickness of the fin should be optimized regarding its impact on mass, and the length of the fin should be optimized regarding its impact on heat transfer. Additionally in straightforward cases, analytical results are similar to simulation results.
Management of compressed air expansion dynamics in piston expander by pressure and heat impingementMarkowski, Jan; Gryboś, Dominik; Leszczyński, Jacek; Kubala, Piotr
doi: 10.1088/1742-6596/2812/1/012019pmid: N/A
Scientists and engineers recognise the main disadvantage of microscale compressed air energy storage (CAES) installations as their low round-trip storage efficiency. This is attributed to the unstable generation of electrical energy, associated with pressure fluctuations during the discharge of the air tank, and the exothermic and endothermic nature of the compression and expansion processes. Here, we focus on operational processes where Hutchinson’s theory of impinging pressure feeding the piston expander and Steinfeld’s experiments on thermal energy storage will be implemented. Hutchinson’s theory involves air wave impinging on a cylinder, transporting energy and momentum that are converted into the motion of the piston. Control of the heat input is crucial to increase the thermodynamic efficiency of the gas expansion process in the expander, involving the selection of the input location and method to achieve a process as close to isothermal as possible. The essence of this approach lies in selecting a compressed air expansion and heat injection strategy to be pulsed, intermittent, or continuous to achieve the highest possible expander efficiency. Computer simulations showed that with proper heat management efficiency can increase by 0.12.
A mathematical model of an off-grid hybrid energy system utilizing the reversible solid oxide fuel cellSarwa, B; Buchaniec, S; Kimijima, S; Moździerz, M
doi: 10.1088/1742-6596/2812/1/012023pmid: N/A
The current energy transition focuses on decentralizing energy systems by implementing alternative energy sources. Integrating distributed energy sources into functional hybrid energy systems has proven to be a difficult task. To solve this problem, it is important to conduct an in-depth analysis of the energy system through the preparation of a mathematical model. The study aims to model and simulate the operation of an off-grid self-sustainable energy storage system for single-family household use by utilizing solid oxide technology. The proposed system consists of photovoltaic modules and an energy storage system including batteries, reversible solid oxide fuel cells, and hydrogen storage tanks. To integrate these energy resources into one system, an energy management system, in which the solid oxide stack is used as a backup generator or a hydrogen production device, is implemented. Finally, a numerical simulation of the system’s operation is run to estimate the system’s performance over a one-year time period. The prepared model can find many practical applications, such as optimizing system costs, environmental impact, or the energy management system.
Development of a hydrogen permselective silica membrane and its application to the thermochemical water splitting methodNomura, Mikihiro
doi: 10.1088/1742-6596/2812/1/012001pmid: N/A
The thermochemical water splitting IS process is one of the hydrogen production method to use a heat directly. The temperature of the thermal decomposition of water (4000 K) can be reduced under 700 K by introducing I2 and SO2 as recycling catalysts. One of the problems in the IS process is that the conversion of the HI decomposition reaction is low at about 20%. If a membrane reactor with the H2 permselective membrane is applied to the HI decomposition reaction, the hydrogen can be extracted to improve the HI conversion. We focus on a counter diffusion CVD method for the preparation method of the membranes. Two reactants (e.g. silica precursor and oxidant) are provided at the opposite side of the porous substrates and hybrid silica is deposited inside the pore of the substrate. The pore sizes are controlled by introducing organic functional groups to silica precursor. In this study, the silica hybrid membrane with high H2 permeation performance and high H2/HI selectivity were developed by introducing organic functional groups. Effects of the organic functional groups were summarized by using a pore model. The HI gas and other inorganic gases permeation performance were tested through silica hybrid membranes.
Application of the electrospinning technique in the preparation of selected electrode materials for solid oxide fuel cellsPrajsner, M; Winiarz, P
doi: 10.1088/1742-6596/2812/1/012008pmid: N/A
The electrospinning technique was applied to prepare cathode materials for solid oxide fuel cells (SOFCs). The research aimed to determine the influence of the Poly(vinylpyrrolidone) (PVP) content in the solution of a Sm0.5Ba0.25Sr0.25Co0.5Cu0.5O3-d perovskite oxide on the properties of the spun material, and consequently, on the performance of the fuel cell. The chosen material, commonly used as a cathode material for SOFCs, has been altered by the replacement of toxic barium and cobalt with less harmful strontium in the A-site and copper in the B-site. A single-phase perovskite structure was obtained after annealing at 900°C for two hours. The research included a process of preparing the precursor solution and obtaining samples by the electrospinning technique, followed by a series of studies to determine the morphology and phase composition, electrode and cell fabrication, and characterization of their electrochemical properties. The results indicated that material derived from a precursor with the addition of 15 wt.% PVP had the lowest polarization resistance values (e.g. 0,865 Ω cm−2 at 800 °C) between 600°C - 900°C temperature range. This material was then screen-printed on a commercial anode-supported fuel cell as a cathode layer, which allowed to achieve a promising power density value close to 300 mW cm−2 at 800 °C.
Alkaline composite inorganic membrane for high temperature carbon dioxide separationIto, Itsuki; Yanai, Daiki; Tsuyuki, Hiroto; Nomura, Mikihiro
doi: 10.1088/1742-6596/2812/1/012014pmid: N/A
The development of carbon dioxide separation and capture technologies is necessary to achieve a carbon-neutral society. Focusing on Direct Air Capture (DAC), a technology for the direct capture of carbon dioxide from the atmosphere. Although Li4SiO4-based membranes have been reported as a separation membrane development using alkali ceramics, the carbon dioxide desorption temperature of Li4SiO4 is high, around 700°C. To use it for CO2 methanation and methanolation reactions, it’s necessary to develop separation membranes for m-DAC using materials that can desorb CO2 at around 300°C. This hasn’t yet been considered. Therefore, the aim of this study was to develop an effective alkaline adsorbent for CO2 recovery that absorbs and desorbs CO2 at around 300°C. Membranes with Na2CO3 supported on an α-Al2O3 substrate showed a permeability of 3.58 x 10−10 [mol m−2 s−1 Pa−1] for N2 and 3.93 x 10−10 [mol m−2 s−1 Pa−1] for CO2 after two coatings, which is selective for CO2. However, the membranes didn’t show CO2 adsorption and the substrate broke after three coatings, suggesting that the α-Al2O3 substrate was alkali-sensitive and that the thermal decomposition of Na2CO3 wasn’t advanced.