Energy Storage and Saving最新文献

{"title":"Energy, exergy, and economic analysis of compression-absorption cascade refrigeration cycle using different working fluids","authors":"Yuhan Du,&nbsp;Chenhan Chi,&nbsp;Xiaopo Wang","doi":"10.1016/j.enss.2024.02.003","DOIUrl":"https://doi.org/10.1016/j.enss.2024.02.003","url":null,"abstract":"<div><p>Compression-absorption cascade refrigeration cycle (CACRC) combined with vapor-compression refrigeration and absorption refrigeration cycle attracts great interest due to the less electricity consumption and utilization waste heat. In this work, the performance of the CACRC system was investigated using 16 refrigerants in the vapor compression section and H₂O-LiBr in the absorption refrigeration section. Energy, exergy and economic analysis of the CACRC system were carried out and the results were compared. Results show that RE170/H₂O-LiBr presents the better coefficient of performance and exergy efficiency amongst all the studied fluids. In addition, the economic optimization, multi-objective optimization, and thermodynamic optimization of the CACRC system based on the RE170/H₂O-LiBr working fluid were also carried out.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"3 2","pages":"Pages 87-95"},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683524000049/pdfft?md5=267507a83f6d6811a1a0c652f0ef49aa&pid=1-s2.0-S2772683524000049-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140180933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experiments and numerical study on heat transfer of moist silica aerogel composites at high temperatures","authors":"Dong Li ,&nbsp;Zhan-Wei Cao ,&nbsp;Xiang-Qian Xie ,&nbsp;Xin Chen ,&nbsp;Ya-Ling He","doi":"10.1016/j.enss.2024.02.002","DOIUrl":"10.1016/j.enss.2024.02.002","url":null,"abstract":"<div><p>Silica aerogel composites have promising applications in high-temperature heat storage insulation. However, the impact of high temperatures and moisture on their insulation performance remains unclear. To reveal the influences of high temperature and moisture absorption property on the heat transfer of silica aerogel composites, an experimental and numerical study was conducted to explore the micromorphology, thermophysical parameters, moisture absorption characteristics, and temperature response. The service temperature limit of the silica aerogel composite has been clarified. Measurements have conducted for the thermal conductivity, specific heat capacity, thermal diffusivity, specific surface area, density, porosity, and pore size distribution of the heated silica aerogel composite (at temperatures of 600, 800, 1,000, 1,100 and 1,200 °C). The moisture absorption characteristic curve at 20 °C has been obtained. Thermal testing of silica aerogel composites under varying heating temperatures and moisture content has been completed. Additionally, a numerical method has been developed to calculate the temperature curve of moist silica aerogel composites. The insulation performance of silica aerogel composite with varying moisture content depends on the game between thermal conductivity and latent heat. Compared with the negative effect of the moisture content on insulation performance, the positive influence of moisture evaporation and heat absorption is dominant in situations involving temperatures higher than the phase transition temperature.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"3 2","pages":"Pages 73-86"},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683524000037/pdfft?md5=c1314375f65068917cbc2f67eb073dce&pid=1-s2.0-S2772683524000037-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139890978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimum insulation thickness and exergy savings of building walls in Bamenda: a comparative analysis","authors":"Fodoup Cyrille Vincelas Fohagui ,&nbsp;Yemeli Wenceslas Koholé ,&nbsp;Njimboh Henry Alombah ,&nbsp;Derek Ajesam Asoh ,&nbsp;Ghislain Tchuen","doi":"10.1016/j.enss.2024.01.001","DOIUrl":"10.1016/j.enss.2024.01.001","url":null,"abstract":"<div><p>The goal of this study is to examine the energetic, entransy, and exergetic methodologies employed to estimate the ideal insulation thickness for construction walls in terms of cost and ecological impact. To achieve these goals, the life cycle cost analysis-based insulating thicknesses of the various methods are evaluated along with the overall costs, yearly cost reductions, and total expenses. The fuel consumption, CO₂ emissions, and ecological effects are then compared using an environmental analysis based on the three methodologies. The savings of hollow concrete brick (HCB), compressed stabilized earth brick (CSEB), and sundried earth brick (SEB) walls are evaluated along with the insulation thicknesses in terms of cost and ecological impact. As a result, it is determined that the exergetic technique is better suited for optimizing insulating width. For CSEB, SEB, and HCB walls, the economic ideal insulation thicknesses are 0.01 m, 0.016 m, and 0.02 m, with yearly financial savings of 5 $/m², 7.5 $/m², and 9 $/m². For CSEB, SEB, and HCB walls, accordingly, the ecological optimal insulation thicknesses are 0.023 m, 0.032 m, and 0.040 m, with net savings of exergetic ecological impact equal to 59 mPts/m², 55 mPts/m², and 51 mPts/m².</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"3 1","pages":"Pages 60-70"},"PeriodicalIF":0.0,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683524000013/pdfft?md5=93889bb57b40b17dafdcd1ed8975a3eb&pid=1-s2.0-S2772683524000013-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of thermal and electric contact resistance on the material design in segmented thermoelectric generators","authors":"Junwei Zhao ,&nbsp;Zhengfei Kuang ,&nbsp;Rui Long ,&nbsp;Zhichun Liu ,&nbsp;Wei Liu","doi":"10.1016/j.enss.2023.12.001","DOIUrl":"10.1016/j.enss.2023.12.001","url":null,"abstract":"<div><p>Segmented thermoelectric generators (STEGs) can exhibit present superior performance than those of the conventional thermoelectric generators. Thermal and electrical contact resistances exist between the thermoelectric material interfaces in each thermoelectric leg. This may significantly hinder performance improvement. In this study, a five-layer STEG with three pairs of thermoelectric (TE) materials was investigated considering the thermal and electrical contact resistances on the material contact surface. The STEG performance under different contact resistances with various combinations of TE materials were analyzed. The relationship between the material sequence and performance indicators under different contact resistances is established by machine learning. Based on the genetic algorithm, for each contact resistance combination, the optimal material sequences were identified by maximizing the electric power and energy conversion efficiency. To reveal the underlying mechanism that determines the heat-to-electrical performance, the total electrical resistance, output voltage, <em>ZT</em> value, and temperature distribution under each optimized scenario were analyzed. The STEG can augment the heat-to-electricity performance only at small contact resistances. A large contact resistance significantly reduces the performance. At an electrical contact resistance of <em>R</em>_E = 10^–3 K·m²·W⁻¹ and thermal contact resistance of <em>R</em>_T = 10^–8 Ω·m², the maximum electric power was reduced to 5.71 mW (90.86 mW without considering the contact resistance). And the maximum energy conversion efficiency is lowered to 2.54% (12.59% without considering the contact resistance).</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"3 1","pages":"Pages 5-15"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000572/pdfft?md5=c6491112d2401b822617091a933c114b&pid=1-s2.0-S2772683523000572-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139024688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strength analysis of molten salt tanks for concentrating solar power plants","authors":"Zhiyi Tang,&nbsp;Wen-Quan Tao","doi":"10.1016/j.enss.2023.08.003","DOIUrl":"10.1016/j.enss.2023.08.003","url":null,"abstract":"<div><p>Promoting the development of concentrating solar power (CSP) is critical to achieve carbon peaking and carbon neutrality. Molten salt tanks are important thermal energy storage components in CSP systems. In this study, the cold and hot tanks of a 100 MW CSP plant in China were used as modeling prototypes. The materials and geometric models were determined based on related specifications and engineering experience. Mechanical characteristics of the tanks under steady condition, including the deformation, stress distribution, and stress concentration, were simulated and calculated. Furthermore, the strength of the tank walls was evaluated. The findings can be used as a reference for designing the molten salt storage tank and reducing the risk during the operation.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 571-577"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000407/pdfft?md5=4f0171ab85937795616d55807f71c268&pid=1-s2.0-S2772683523000407-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81185371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase change material-based rooftop on public transport for thermal management✰","authors":"Md Araf Hossan,&nbsp;Shams Al Deen Aryan,&nbsp;Md. Sajadul Haque Noman,&nbsp;Dewan Hasan Ahmed","doi":"10.1016/j.enss.2023.08.001","DOIUrl":"10.1016/j.enss.2023.08.001","url":null,"abstract":"<div><p>Phase change materials (PCMs) are used in buildings and automobiles to control the interior temperature, following to their high thermal storage capacity and energy efficiency. In summer, controlling the interior temperature of vehicles can be difficult, especially in cities where public transportation is excessively crowded. Typically, heating, ventilation, and air-conditioning systems are included to provide thermal comfort inside vehicles, but they use a significant amount fuel, which ultimately have negative impacts on the environment. In this study, a prototype bus model was developed from an actual bus and scaled-down to 1/20th size. A bulb was used as an internal heat source and experiments were conducted under the sun in summer to reflect scenarios of buses stuck in traffic. Various cases were considered by opening and closing the windows and doors and placing the PCM layer on the roof and covering the bulb. The results demonstrate that when the PCM is used to cover the bulb and roof, the interior temperature can drop to the ambient temperature and remain there for a longer period of time. In fact, keeping the windows and doors open results in a significantly lower indoor temperature than when they are closed. The results show that the heat from the engine makes a major contribution to raising the temperature inside of the vehicle. The results from the opened cases can be applied to various forms of public transportation worldwide, but for many closed vehicles, additional ducting systems integrated with a PCM may be the best option.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 549-558"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000419/pdfft?md5=2c87aa3d2194727b0d4963526f30f621&pid=1-s2.0-S2772683523000419-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74542571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composition-specific granulation characteristics of molten slag at improved throughput and high temperature of 1723 K","authors":"Junjun Wu ,&nbsp;Yu Tan ,&nbsp;Yuxiang Fu ,&nbsp;Hong Wang ,&nbsp;Xun Zhu ,&nbsp;Qiang Liao","doi":"10.1016/j.enss.2023.08.007","DOIUrl":"10.1016/j.enss.2023.08.007","url":null,"abstract":"<div><p>Centrifugal granulation is one key step to enable waste heat recovery from the molten slag in the iron and steel industry. Yet, it remains unknown about the granulation characteristics of molten slag with different chemical compositions, especially at high throughput. In this work, we provided an experimental study on centrifugal granulation with four types of molten slags. The stage-specific centrifugal granulation was recorded and analyzed at first. Both effects of atomizer configuration and chemical compositions on granulation were investigated in detail. The cup-type atomizer favors film-mode disintegration and possesses better anti-adhesion capacity although the final granule size was not strongly affected by the atomizer configuration. Most importantly, centrifugal granulation has been demonstrated with appreciable adaptability to composition-specific blast furnace (BF) slag with binary basicity of 0.9–1.3. The present study not only sheds light on the modest effect of the chemical composition of molten slag on centrifugal granulation characteristics, but also gains credit for the adaptivity of CGATER.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 586-596"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000432/pdfft?md5=84a797f2452ae929db127a489f6a8f5d&pid=1-s2.0-S2772683523000432-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84460580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrification and decarbonization: a critical review of interconnected sectors, policies, and sustainable development goals","authors":"Icaro B. Boa Morte,&nbsp;Ofélia de Queiroz F. Araújo,&nbsp;Cláudia R.V. Morgado,&nbsp;José Luiz de Medeiros","doi":"10.1016/j.enss.2023.08.004","DOIUrl":"10.1016/j.enss.2023.08.004","url":null,"abstract":"<div><p>Climate actions (SDG-13) aim at limiting global warming by targeting carbon emissions reduction. With the energy industry recognized as a significant CO₂ emitter, SDG-13 policies mostly translate energy transition to renewables (SDG-7) and the electrification of end-users, both energy-demanding sectors and society (cities, households, and mobility). The double-layered actions parallel the classical “cascade control” employed in industrial sectors. For achieving deep decarbonization, the ambitious net-zero emissions (NZE), large-scale deployment of renewables demand storage, with hydrogen as a prominent chemical storage alternative, and carbon capture &amp; storage (CCS) for hard-to-electrify sectors. Infrastructure developments need policy and capital investments, and geopolitics and resource availability challenge and offer opportunities. Since decarbonization and electrification have multiple realization paths and impact the industrial metabolism, SDGs are interconnected with synergies and trade-offs. Prioritization of SDGs by policymakers is necessary for resilience and robustness in achieving climate goals within a systems dynamics approach. This critical review identifies niches in decarbonization and electrification, enlightening the industrial metabolism under the lens of SDGs.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 615-630"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000456/pdfft?md5=c5f0ccddabcd7ae1b2fd663fc4d8a8d1&pid=1-s2.0-S2772683523000456-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80524963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Promotion and implementation of Polish mining investments in foreign markets on the example of Latin America","authors":"Joanna Kulczycka ,&nbsp;Ewa Dziobek ,&nbsp;Michał Nowosielski","doi":"10.1016/j.enss.2023.08.008","DOIUrl":"10.1016/j.enss.2023.08.008","url":null,"abstract":"<div><p>Foreign investments are essential in deepening economic relations between the EU and Latin America. As Latin America is fortunate enough to have deposits of metals that have become particularly desirable due to the green industrial revolution, it remains one of the dominant directions of exploration and investment in the mining sector. To intensify cooperation within the mining industries based on their complementarity, common goals, and shared values, the EU-Latin America Mineral Development Network Platform was established for all entities relevant to the mining sector, not only authorities but also businesses (including SMEs) and scientific and research units. To create a common European understanding of best practices in the processing and mining of raw materials in terms of social, environmental, and economic performance, voluntary EU principles for sustainable raw materials have been developed. Moreover, many EU countries working on updating or implementing (Poland) mineral policies, and more and more EU and Polish mining companies have been reporting non-financial aspects and impacts on local development, also in foreign countries. At the end of 2022, the European Commission proposed a Critical Raw Materials Act: securing the new gas &amp; oil at the heart of our economy initiative to enhance the diversification and supply of critical raw materials to Europe.</p><p>So far, the largest Polish foreign investment is a copper mine in Sierra Gorda in Chile, owned by KGHM Polska Miedź SA together with the Japanese Sumitomo Group (from February 2022, Australian mining group South32). Even according to KGHM CEO, Marcin Chludziński, the Sierra Gorda mine had needed restructuring and now is a demanding but very satisfying project. KGHM reported that the revised EBITDA for 2021 was the highest and achieved PLN 10.3 billion (ca EUR 2.3 billion) year on year (+56%) and for the first time, Sierra Gorda began to pay off its liabilities towards the owners. Moreover, the mine received an award in the category of large producers awarded by the State Mining Association in Chile (SONAMI). In addition to mining activities in the field of exploration and exploitation of deposits, Poland is developing cooperation in technology (mining machinery) and education. To ensure sustainable extraction of raw materials additional skills are required, in particular in the area of management and social sciences. The aim of the paper is to analyze and identify factors and best practices enhancing international cooperation and the environmental sustainability of minerals in line with the 2030 Agenda for Sustainable Development on the example of Polish investments in Chile. The analyzed case studies in a broader context, including the EU and Polish mineral policy, allow for the development of certain recommendations and tools for the promotion of foreign investments in the mining industry.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 608-614"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S277268352300047X/pdfft?md5=364d94c90efa60c4066da0881afc4566&pid=1-s2.0-S277268352300047X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81622006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental benefits for a geothermal power plant with CO2 reinjection: case study of the Kizildere 3 U1 geothermal power plant","authors":"María Dolores Mainar-Toledo ,&nbsp;Ural Halaçoğlu ,&nbsp;Hakan Alp Sahiller ,&nbsp;Tuğrul Hazar ,&nbsp;Claudio Zuffi ,&nbsp;Maryori Díaz-Ramírez ,&nbsp;Giampaolo Manfrida","doi":"10.1016/j.enss.2023.08.005","DOIUrl":"10.1016/j.enss.2023.08.005","url":null,"abstract":"<div><p>Geothermal power plants (GPP) with high non condensable gases (NCG) content geothermal fluid have shown to be environmental impacting relating to their energy production, which could be critical if no corrective actions are achieved. The GPP of Kizildere 3 U1, located in Türkiye (Denizli), in where the geothermal fluid contains high percentage of CO₂, 99% of the NCG fraction, which represents the 3% of the geothermal fluid mass, is taken as a relevant case study to implement a new innovation consisting of NCG reinjection to reduce the amount of NCGs released to the atmosphere. In order to calculate the present environmental impacts which the plant is causing (baseline); and the potential reduction of environmental impacts which can be achieved with the innovation (reinjection), a life cycle assessment (LCA) calculation were developed. Primary data were collected for all the relevant stages of the energy conversion cycle and complemented where necessary with secondary data from other geothermal power plants studies. The main results of the baseline environmental assessment show that the construction phase is the most impacting phase due to the materials used in the power plant building construction, electrical generation equipment and distributed machinery and infrastructures; the effects in the operation phase are dominated by the geothermal fluid composition. In this sense, the application of CO₂ reinjection at the Turkish site into the reservoir will prevent the emission of 1,700 tons·year⁻¹ in the pilot site and 10% of the total emissions released along the life span of the GPP.</p></div>","PeriodicalId":100472,"journal":{"name":"Energy Storage and Saving","volume":"2 4","pages":"Pages 631-638"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772683523000468/pdfft?md5=913af92ce96d48227ddbaa881ad77fab&pid=1-s2.0-S2772683523000468-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78729813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}