Ebook: New Energy and Future Energy Systems

This book contains selected papers from the 8th International Conference on New Energy and Future Energy Systems (NEFES 2023), which was held from November 21 to 24, 2023 in Matsue, Japan. About 60 participants from 20 countries (including China, Japan, USA, UK, Canada, Australia, India, Pakistan, Egypt, Saudia Aribia, Mozambique, Algeria, Sweden, Philippines, Ghana) attended the conference. The conference program included 3 keynote presentations, 26 oral presentations, and 10 poster presentations.

Twelve peer-reviewed papers were selected from 84 submissions for this book. The topics covered are power system operation, biomass energy, fuel energy, solar energy, thermal energy, energy materials, energy technology, and other related fields. It will be of interest to researchers, engineers, and educators working in the field.

The Organizing Committee would like to extend their gratitude to all the keynote speakers and participants, international reviewers and members of the technical program committee for their dedicated contribution and commitment to the conference.

The Conference Chairs of NEFES 2023

The Mediterranean is one of the most cyclogenetic regions in the world. One of the most significant cyclone characteristics that can influence power systems is lightning. Except in the Mediterranean basin, favorable conditions for convection development and lightning appearance can be developed in other warm and moist conditions and in the mountain area. Every season, heavy lightning appears in Croatia, a small Mediterranean country through which the Dinaric Alps stretch. Lightning can cause various damages to the power system network, but also cause wildfire that can lead to additional enormous damages. It is well known that lightning can be very well forecasted by combining different meteorological models and satellite data. Various satellite data can also be used in forest fire monitoring, analysis, and risk prediction. Among the others, fire spreading depends on the vegetation and soil moisture conditions that can also be obtained by satellite. Some climate projections indicate that in the future, it is possible to expect more extreme conditions, more thunderstorms on one side, and more droughts on the other side. Thunderstorms can cause fire development and spread, especially when there is not enough humidity for rain and showers. During the drought, due to soil moisture decrease and vegetation dryness, wildfire spreading becomes easier daily. This paper will present the analysis of lightning-induced wildfires, endangered power system components in Croatia, and a climatic review of wildfires. A method for wildfire protection, vegetation growth monitoring, and post-fire landscape recovery monitoring will be suggested. Conducted analysis and suggested methods can be applied in power system planning and everyday operation through N-k (N-1) analysis. In the analysis, various satellite, meteorological, climatological data, lightning location system, and power system data are used.

Background:

The rapid emergence of the COVID-19 epidemic has prompted a reevaluation of the current physical space environment. After the pandemic, the fragmented rural tourist era has returned, and new ideas for the development of public space in traditional villages have emerged, with resilient designs for rural public space planning and design taking into account disaster conditions.

Methods:

This study examines the link between the idea of resilience and the public space of traditional villages, the present application of the concept of resilience in their spaces, and the features of shifting spatial demands during an epidemic.

Results:

This article provides techniques for maximizing and enhancing resilience at three levels: responding to the catastrophe, adjusting to the disaster, and seeking development in the epidemic, to reshape the public space in traditional communities. Cuanxia Village in west Beijing is utilized as a practical object for the application of empirical evidence in order to increase the resilience of village public space and the catastrophe adaption and response capabilities of traditional villages.

Conclusions:

This research proposes a public space design method that integrates with normalized epidemics, enhances the catastrophe response and recovery capacities of conventional rural public spaces, and makes an essential multidisciplinary theoretical contribution.

Next-generation innovative reactors have a new value of their flexibility with variable renewable energy. A sodium-cooled fast reactor (SFR) can make flexibility by coupling a thermal energy storage (TES) system with molten salt. New challenges for the SFR coupled with TES are to develop a safety design approach and a heat exchanger (HX) between sodium and molten salt. On that account, since 2022, a three-year project has been performed to develop 1) a safety design approach and risk assessment methodology of the SFR with TES, 2) a performance evaluation technology of an HX between sodium and molten salt, and proposal of heat transfer improvement measures, and 3) an evaluation technology of chemical reaction characteristics between sodium and molten salt, and proposal of safety improvement measures. This paper describes the project overview and recent progress. For 1), this study investigated the record of operation and incidents or troubles of a TES system that uses molten salt as a heat storage medium for concentrating solar thermal power generation, which includes about 50 commercial facilities. These data could serve as a reliability database for risk assessment. For 2), this study selected a straight shell-and-tube type HX as a result of investigating several types of HXs. Using the intermediate HX of the experimental SFR in Japan as a reference, the heat transfer performance of the HX was evaluated by a simple method. This study developed the most promising HX type by improving the heat transfer performance with parameters of heat transfer tube diameter, heat transfer tube pitch ratio, heat transfer tube material change, primary side/secondary side replacement, and cross flow. For 3), this study preliminarily evaluated the chemical reaction characteristics using an equilibrium phase diagram with thermodynamic equilibrium calculation software. No database for the reaction of nitric acid molten salt and sodium was confirmed, so that a basic reaction experiment is necessary. This study prepared a glove box and reagents in 2022, and a thermal analysis-related equipment is also introduced in 2023.

In the present article, a two-step optimization strategy for the production of micro and meso- pores carbonaceous material has been proposed. The waste pistachio shell is utilized as precursor material to synthesize activated carbon on account of its high carbon and low ash content. The synthesization of pistachio shell-derived activated carbon (PSAC) includes carbonization and KOH-activation. The proposed mathematical modeling for the first step of optimization considers the effect of moisture content, the molecular mass of carbon and hydrogen constituents present in the carbonized samples, and the H/C ratio. The carbonized product is found to be best at the carbonization temperature of 562.5 °C based on the biochar throughput (TP) and percentage stable carbon content (%C_s). However, the second step of the optimization has been carried out on the basis of N₂ adsorption-desorption analysis and it recommends the best PSAC with the highest specific surface area of 703 m²/g with more than 55% of micropore volume. Further, the CO₂ capture assessment alongwith characterization is carried out, and PSAC2 is found to be the best adsorbent in terms of the highest amount of CO₂ capture.

Gas Insulated Switchgear (GIS) ultra high frequency (UHF) live test presently stands as the most widely employed technique for partial discharge detection in the field. With the ongoing digital transformation of the power grid, the imperative has arisen to advance partial discharge detection toward intelligence and automation. Accordingly, this paper puts forth a digital twin modeling approach for GIS live test, through a comprehensive examination of digital twin technology. This approach encompasses the establishment of a GIS digital twin model, the assessment of both internal and external UHF signals of the GIS, as well as the intelligent guidance for the deployment of UHF sensors, among other aspects. The findings of this study hold significant implications for the maintenance and servicing of GIS equipment.

Climate change forces policy-makers to undertake actions to reduce human impact on socio-environmental system. One of the directions is to shift into low-carbon economy, also by increasing the role of renewable energy sources (RES) in energy sector. Therefore, there is a need to support local stakeholders with a knowledge-based approaches in order to implement RES more effectively. There are some systems assessing natural potential for RES installations, however, legal regulations are not always making it possible everywhere. The aim of this research is to expand existing functions of the decision support system for hybrid RES by the feasibility assessment of selected locations due to legal regulations. The developed tool was applied and presented on the case of a selected Polish region. The RES potential is assessed based on the universal databases (Global Wind Atlas, Global Solar Atlas, CORINE Land Cover), however, it was customized to local legal regulations, which allows the solution to be more practical and helpful for implementation in a low-carbon economy. Promotion of decision support systems for RES planning may constitute effective solution to reach goals set in the European Green Deal.

Firstly, this paper proposes the definition and characteristics of micro energy networks, and describes the transformation and construction purposes of various energy forms in micro energy networks. We have established mathematical models for various forms of energy, including wind power, photovoltaic, natural gas, and electrical energy storage. We have established a mathematical model for the energy hub matrix, which provides a computational basis for the transformation of various forms of energy. Then, based on the previous research, an optimization function for the maximum of energy supply capacity of micro energy networks was proposed, which is a mixed integer linear programming problem and solved. Finally, based on a project example in China, calculations and analysis were conducted, and conclusions and suggestions were drawn.

Ultra low permeability reservoirs are significantly affected by the pressure sensitive effect, resulting in severe permeability loss, leading to a larger starting pressure gradient and increasing the difficulty of establishing effective displacement. At present, the existing technical limit well spacing formulas only consider the static starting pressure gradient and do not consider the reservoir pressure sensitivity effect, which leads to the problem of dynamic changes in the starting pressure gradient, resulting in the calculation results not being consistent with the actual situation of the mine. In response to this issue, a formula for calculating displacement pressure near oil and water wells considering pressure sensitivity effect and a formula for calculating variable starting pressure gradient were first established. Combined with the traditional formula for calculating the maximum well spacing, a formula for calculating the maximum well spacing between injection and production wells that can establish displacement considering dynamic starting pressure gradient was derived. The relationship between the permeability of ultra-low permeability reservoirs in Chaoyang Gou Oilfield and the technical limit well spacing was calculated. The analysis results indicate that compared with traditional methods, the new method needs to reduce the well spacing by 10m; The technical limit well spacing of Y-3 block is 47m; The demonstration results and case analysis results demonstrate the correctness and applicability of the formula. The results of this article can provide theoretical guidance for infill adjustment and potential tapping measures in ultra-low permeability reservoirs.

The aging state of transformer insulation papers was not assessed accurately. In this paper, multi-feature comprehensive assessment method was proposed to convert the nonlinear problem into a linear problem fitting for assessing the aging state of insulation papers. The whole aging process was divided into two stages with the degree of polymerization of 500 as the dividing point. The backward multiple linear regression analysis model was established and the error of the fitting results was analyzed. Most of the relative assessment errors were within ± 5 %. It compensated for the deficiency of aging assessment of transformer insulation paper based on single feature, and the accuracy of assessment results was improved.

In this paper, based on the energy analysis method is established across the critical CO₂ two-stage compression refrigeration system simulation model. LabVIEW software was used to write simulation programs, and the operation of the refrigeration system under different working conditions was simulated through different parameter Settings. Data analysis of the simulation results was conducted to explore the main factors that affect the COP of the system. The results show that the COP of the system increases with the rise of suction superheat of the compressor. As the evaporation temperature increases, the COP of the system gradually increases. There is an optimal intermediate pressure corresponding to COP

The construction of sponge cities has been ongoing for nearly a decade, during which we have made significant achievements and important contributions to ecological preservation. However, the process of planning, designing, implementing, operating, and maintaining sponge cities has also revealed numerous issues. This article provides an analysis of the current state of sponge city construction and the main problems that have emerged during the process. It emphasizes that the construction of sponge cities is a gradual and progressive journey, particularly in the current low-carbon context. The article reflects on the future development of sponge cities and provides suggestions for sustainable growth.

Full-scale field installation test of an offshore wind power suction pile jacket foundation with pile penetration depth to diameter ratio about 2.0 was carried out, where the structure stress of the suction pile side wall, connection joint stress, pore water pressure and earth pressure distribution were monitored. Measured shaft stress results are affected by the applied pressure difference, and reverse tension and compression stress were identified at the same depth, indicating that the suction pile shaft was under bending. After self-weight penetration the foundation inclination was 5.0°, as a result the measured connection joint stress reached 100∼150 MPa after being leveled at the suction penetration stage. Measured pore pressure results reveal the reason of large foundation inclination at the self-weight penetration stage, and the attenuation law of pressure difference in different soil at the suction penetration stage. Total and effective earth pressure are obtained on both sides of the suction pile, which are also affected by the applied suction. The field test provides valuable monitoring data of suction pile jacket foundation installation, which can be used in further mechanism study.