Applied Thermal Engineering最新文献

{"title":"Mechanical-thermal coupling design on battery pack embedded with concave quadrilateral cellular structure","authors":"Ying Zhao ,&nbsp;Jibo Hao ,&nbsp;Jianfeng Hu ,&nbsp;Keming Zhou ,&nbsp;Bin Chen ,&nbsp;Xingjun Hu ,&nbsp;Chenguang Lai","doi":"10.1016/j.applthermaleng.2024.124973","DOIUrl":"10.1016/j.applthermaleng.2024.124973","url":null,"abstract":"<div><div>To comprehensively investigate mechanical-thermal coupling properties and function-oriented design of battery pack, a novel battery pack with triangular micro-channel cold plate and the optimal embedded concave quadrilateral cellular structure (CQCS) is proposed. Firstly, mechanical properties of CQCS are derived based on beam theory and homogenization theory. Then, thermal conductivity expressions of the CQCS are derived in accordance with Maxwell-Eucken model and negative thermal expansion design of the CQCS is ingeniously conducted to inhibit thermal runaway of battery pack. Moreover, the relations between mechanical properties and thermal properties of CQCS are innovatively investigated through the medium of structural parameters of CQCS. Secondly, modal analyses, collision analyses on conventional battery pack are conducted. Meanwhile, thermal characteristics of battery modules are derived and temperature field distributions are acquired through simulation analysis to provide reference for the design of thermal management system. Subsequently, the embedded CQCS is taken as the medium to conduct mechanical-thermal coupling design of battery pack. Multi-objective optimization models of the CQCS between battery cells and the CQCS between modules are established to obtain the optimal CQCS with the needs of high heat dissipation efficiency, superior temperature uniformity, outstanding collision performances, and more lightweight space of battery pack. Moreover, a convection triangular micro-channel cold plate is chosen as heat dissipation structure and variable density design of micro-channel cold plate is executed to ensure heat dissipation efficiency and temperature uniformity of battery pack. Eventually, the mechanical performances and thermal performances are compared to verify the superiority of the proposed novel battery pack. Compared with conventional battery pack, lower stress levels and more uniform stress distributions can also be achieved, and the resonance between battery pack and autobody can also be avoided effectively. Moreover, compared with conventional battery pack, the maximum temperature differences of battery pack with the optimal CQCS decrease by 10 %, 8.7 %, 10.91 % and 8.75 %, which demonstrates the superiority of the embedded CQCS in decreasing maximum temperature difference of battery pack. Moreover, the temperature differences of novel battery pack decrease by 26.67 %, 27 %, 28.57 %, and 32.88 % in comparations with those of battery pack with the optimal CQCS, which proves that variable density design on triangular micro-channel cold plate can improve temperature uniformity of battery pack effectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124973"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive thermodynamic, environmental, and economic analyses of a modified waste heat recovery process for a gas turbine cycle producing power, cooling, and hydrogen","authors":"Quan Xiao ,&nbsp;Yuzhuo Wang ,&nbsp;Junlun Mei","doi":"10.1016/j.applthermaleng.2024.124982","DOIUrl":"10.1016/j.applthermaleng.2024.124982","url":null,"abstract":"<div><div>Gas turbine cycles generate significant waste heat, and recovering this heat can lead to higher efficiency and valuable by-products. The current study introduces an effective trigeneration setup for power and hydrogen production, along with the gasification of liquid natural gas. This setup includes a gas turbine cycle integrated with a transcritical CO₂ power cycle, an organic Rankine cycle, and a proton exchange membrane electrolyzer. The setup’s performance is analyzed using energy, exergy, environmental, and economic approaches. The exergy analysis brings out a total exergy destruction rate of 138592 kW, and reveals that the highest irreversibility occurs in the gas turbine cycle, accounting for about 70.6 % of the total exergy destruction. The overall energy and exergy efficiencies of the setup are 46.69 % and 40 %, respectively. The cost of hydrogen production is estimated at about 4.35 $/kg, while the energy production cost is 21.81 $/GJ. From an environmental perspective, the setup’s CO₂ footprint is about 0.423 kg/kWh, which is 56.18 % lower compared to hydrogen production via coal. The findings of this study underscore the significant potential of integrating advanced cycles and systems for enhancing the efficiency and sustainability of energy production. The proposed trigeneration setup not only improves energy and exergy efficiencies but also offers substantial environmental benefits, aligning with the goals of reducing greenhouse gas emissions and promoting cleaner energy alternatives.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124982"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-operating-condition performance improvement strategy and optimal design of a two-stage ejector with auxiliary secondary flow for MED-TVC systems","authors":"Qingyang Han ,&nbsp;Hailun Zhang ,&nbsp;Wenxu Sun ,&nbsp;Haoyuan Xue ,&nbsp;Zhizheng Zhang ,&nbsp;Lei Jia","doi":"10.1016/j.applthermaleng.2024.124957","DOIUrl":"10.1016/j.applthermaleng.2024.124957","url":null,"abstract":"<div><div>Periodic fluctuation of steam-source pressure occurs in the thermal vapor compression multi-effect distillation (MED-TVC) systems. Because ejectors are sensitive to the boundary conditions, as a key component for recovering excess steam in systems, ejectors experience a rapid decline in performance when the steam-source pressure fluctuates and does not satisfy the design condition. This decline negatively impacts the overall system performance and reduces the energy utilization efficiency. Therefore, a two-stage ejector with auxiliary secondary flow (ASF-TSE) and a full-operating-condition performance improvement strategy were developed in this study to enhance the ejector performance under full working conditions and broaden the efficient operation range of ejectors. The flow field characteristics and performance of the ASF-TSE, single ejector (SE), and two-stage ejector (TSE) in the low and design-pressure ranges were compared and investigated. The results showed that within the design-pressure range, the maximum and average increase ratios of the ASF-TSE for entrainment performance compared with the TSE are 17.53 % and 13.43 %. Moreover, the entrainment capacities of the three ejectors were compared and analyzed in the full operating range. Simulation results show that compared with the SE and TSE, the entrainment performance of the ASF-TSE is improved by 87.5 % and 8.0 %, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124957"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new dynamic control strategy for a solar-driven absorption thermal energy storage system: Modeling and performance evaluation","authors":"Rundong Chen ,&nbsp;Ding Lu ,&nbsp;Tao Shen ,&nbsp;Maoqiong Gong","doi":"10.1016/j.applthermaleng.2024.124983","DOIUrl":"10.1016/j.applthermaleng.2024.124983","url":null,"abstract":"<div><div>Solar heating is a vital technology to promote the decarbonization of building energy supply systems. However, the mismatch between the intermittency of solar energy supply and the fluctuating heating demands poses significant challenges to its application. Current heat storage systems often exhibit low energy density, significant heat losses, and limited temperature regulation capabilities, which restrict their effectiveness in practical applications. This paper proposed a new real-time control strategy for a solar-driven absorption thermal energy storage system, integrated with an absorption heat pump, which can resolve the mutual constraints between solar energy utilization efficiency and the heating temperature, and then improve the system flexibility. The dynamic control strategy is implemented to manage concentration and temperature by regulating the inlet and outlet flow rates of three tanks, namely the absorbate tank, the weak solution tank, and the strong solution tank. A thermodynamic model is developed based on Aspen Plus and Matlab. Results show that within a 24-hour cycle, the system, driven by intermittent solar energy, can effectively meet the varying user-side heating demands through flow rate regulation. An optimized tank design, based on flow variation analysis, reduces the total volume by approximately 35 %. Additionally, the system can recover low-grade heat from the environment through the absorption heat pump, achieving an energy storage efficiency of 1.07 and an energy storage density of 56.13 kWh/m³. The proposed system and its dynamic control method are well-suited to intermittent solar energy, increasing the system flexibility, and thus expanding renewable energy utilization potential, especially those involving multi-energy complementary systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124983"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vapor chamber thermal performance: Partially heated with different heating areas at the center and supported by numerical analysis for the experimental setup","authors":"Yasin Varol ,&nbsp;Hakan Coşanay ,&nbsp;Enes Tamdoğan ,&nbsp;Murat Parlak ,&nbsp;Şafak Melih Şenocak ,&nbsp;Hakan F. Oztop","doi":"10.1016/j.applthermaleng.2024.124978","DOIUrl":"10.1016/j.applthermaleng.2024.124978","url":null,"abstract":"<div><div>This paper presents the design of a partially heated Vapor Chamber (VC) system utilizing a passive cooling technique, analyzed under various inclination angles. The Finite Volume Method (FVM) is utilized to compare the results with experimental measurements conducted. Additionally, all results obtained with the tested VC are compared to a copper plate of identical dimensions to demonstrate the VC’s impact on thermal management issues. The dimension of the copper VC is established as 56 × 56 mm2. Two distinct partial heating dimensions at the evaporator block, measuring 10 × 10 mm2 and 20 × 20 mm2, are evaluated under various heat flux loads. The study is further expanded to include varying temperatures between the evaporator block and the condenser block. While a chiller controls the temperature on the condenser block side, the power supply to the evaporator block is adjustable to facilitate heating. The inclination angle of the system is identified as an additional parameter for investigation, as it may influence the thermal performance of the vapor chamber due to gravitational effects. At the conclusion of the study, significant results indicated that a higher thermal resistance value was observed for a heating area of 10 × 10 mm2 for both VC and copper plate. The comparison between the copper plate and VC indicates a 7 % reduction in thermal resistance with VC across both selected heating areas. Furthermore, a higher temperature that increases proportionally with heat flux is observed in the case of the copper plate. The effect of inclination appears to be negligible for the parameters examined.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124978"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric study of absorption-compression hybrid refrigeration cycle with multi-stage heat recovery","authors":"Zhian Zhang,&nbsp;Zeyu Li,&nbsp;Hongkai Chen","doi":"10.1016/j.applthermaleng.2024.124985","DOIUrl":"10.1016/j.applthermaleng.2024.124985","url":null,"abstract":"<div><div>Traditional absorption-compression hybrid refrigeration cycles, e.g., two-stage and cascade cycles, can reduce the electricity consumption of chillers in low-temperature scenarios such as cold storage. However, their heat consumption cannot be fully covered by the heat supply of small- and moderate-scale heat sources, which adversely affects the operational reliability and hinders the actual applications. In this regard, an absorption-compression hybrid refrigeration cycle with multi-stage heat recovery is proposed to effectively address this issue. In this study, the thermodynamic analysis of the proposed cycle was performed. Performance comparisons with traditional systems are conducted to demonstrate the advantages of the proposed system. Then, the effects of inter-stage pressure were analyzed in detail. Finally, trends in the optimal inter-stage pressure for different conditions were fitted and obtained using artificial neural networks. A case study showed that the internal heat recovery enhanced the exergy efficiency and heat power coefficient of performance by 26.9% and 109.7%, respectively. The novelty of this study lies in the proposal of a novel absorption-compression hybrid refrigeration cycle to reduce the heat consumption per unit production of cooling capacity, and to obtain the design criteria for inter-stage pressure under different conditions. This study achieves energy savings in cold-storage refrigeration systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124985"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pressure response and interface evolution on initiation of boiling liquid expanding vapor explosion (BLEVE): A numerical study","authors":"Zhixuan Hu ,&nbsp;Yi Zheng ,&nbsp;Gangtao Liang","doi":"10.1016/j.applthermaleng.2024.124976","DOIUrl":"10.1016/j.applthermaleng.2024.124976","url":null,"abstract":"<div><div>Liquefied petroleum gas (LPG) is usually stored at a high pressure in the spherical containers. In the event of a failure of the container, a risk of boiling liquid expanding vapor explosion (BLEVE) takes place. A two-dimensional numerical model is built up to study the initiation of BLEVE process of LPG in the present investigation. The effects brought by initial pressure, liquid filling ratio, orifice diameter of relief opening, and temperature stratification on pressure response and interface evolution are discussed in detail. Results indicate that an increase in both the initial pressure and liquid filling ratio causes an augmentation in the total energy of liquid working medium, which in turn leads to an increase in the pressure rise. Conversely, an increase in the degree of the thermal stratification is accompanied by a reduction in the pressure rise. It is also interesting that as the orifice diameter of relief opening increases, the pressure rise displays a non-monotonic pattern, exhibiting an initial increasing trend before declining subsequently. This study provides a fundamental understanding regarding initiation of BLEVE in the scenario of leak of hazardous chemicals.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124976"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and optimization of the performance of closed heat pump dryer based on zeotropic mixtures","authors":"Hui Ni,&nbsp;Peng Hu,&nbsp;Yuchen Li","doi":"10.1016/j.applthermaleng.2024.124916","DOIUrl":"10.1016/j.applthermaleng.2024.124916","url":null,"abstract":"<div><div>Compared with traditional electric heating dryers, heat pump dryers are more energy efficient and environmentally friendly. In this work, a novel heat pump dryer with zeotropic mixtures as working fluids and recuperators is studied and compared with the cycle using the corresponding pure working fluid. The effects of the evaporation temperature, and the components and mass fractions of the zeotropic mixtures on the performance of the system are investigated. After comprehensively considering various performance coefficients, this work selects a CO₂/R290 (mass fraction of 20/80) mixture as the optimal working fluid of the heat pump dryer system. Compared with R134a, it significantly improves the coefficient of performance (COP), specific moisture extraction rate (SMER), volumetric heating capacity (VHC), and pressure ratio (PR), with maximum performance improvements of 33.66 %, 41.50 %, 181.44 %, and 46.55 %, respectively. The zeotropic mixture also has significant performance advantages in terms of less charge and exergy destruction. Moreover, the addition of CO₂ as a nonflammable refrigerant to the components reduces the flammability of the working fluid compared with that of pure R290, which improves safety in practical applications.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124916"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation and experimental investigation on the thermal-fluid-solid multi-physical field coupling characteristics of wet friction pairs considering cavitation effect","authors":"Qiliang Wang ,&nbsp;Xingbo Zhang ,&nbsp;Dagang Wang ,&nbsp;Hongwei Cui ,&nbsp;Shuai Zhang ,&nbsp;Jianmei Wang","doi":"10.1016/j.applthermaleng.2024.124955","DOIUrl":"10.1016/j.applthermaleng.2024.124955","url":null,"abstract":"<div><div>The coupling characteristics of thermal-fluid-solid multi-physical fields are crucial in determining the operational performance and service life of wet clutches. However, the underlying mechanism behind the influence of cavitation effect on these coupling characteristics remains unclear. Therefore, we propose a numerical solution method for considering cavitation effect in the coupling characteristics based on the multi-physical field coupling platform MPCCI combined with ABAQUS and FLUENT. The distribution patterns and intercoupling relationships among temperature field, flow field, and stress-strain field are comprehensively analyze. The influence of relative speed, cross-sectional shape of oil grooves, and oil flow on the coupling characteristics is investigated. Experimental validation confirms that the proposed model accurately predicts temperature variation by accounting for cavitation effect. The temperature distribution of steel discs is notably affected by the cavitation effect, leading to an elevation in the maximum temperature and uneven distribution characterized by localized hot spots along the circumferential direction. Accounting for the cavitation effect reduces errors between calculated and experimental values of temperature rise. The convective heat transfer coefficient gradually decreases radially, with a more pronounced decrease in the cavitation region. An increase in relative speed and a decrease in oil flow both lead to greater cavitation volume, resulting in higher temperature of steel discs. Among three different cross-sectional shapes of oil grooves investigated, rectangular grooves exhibit larger areas affected by cavitation compared to triangular grooves. These research findings provide a theoretical basis and technical support for accurate prediction of thermal characteristics within high-power wet clutches.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124955"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combustion characteristics of ammonia-hydrogen mixture with turbulent jet ignition","authors":"Dong Han ,&nbsp;Kunlun Song ,&nbsp;Jinlu Huo ,&nbsp;Xiaolu Li ,&nbsp;Cangsu Xu","doi":"10.1016/j.applthermaleng.2024.124995","DOIUrl":"10.1016/j.applthermaleng.2024.124995","url":null,"abstract":"<div><div>Ammonia and hydrogen are promising zero-carbon fuels that can help combustion engines achieve the zero-carbon emissions target. However, ammonia features high ignition energy demand and slow flame propagation speed. Pre-chamber turbulent jet ignition, with high ignition energy and enhanced in-cylinder turbulence, shows potential for achieving efficient and stable engine combustion with low-reactivity fuels. The optical constant volume combustion chamber simulates the process of pressure environment in the engine cylinder during the compression stroke to push the unburned gas into the pre-chamber, and simulates the process of jet ignition during the pressure environment in the main combustion chamber at the end of the compression stroke. The effects of different parameters such as ambient pressure, hydrogen fraction, and orifice diameter on the turbulent jet ignition combustion were investigated. The results indicate that jet ignition is a more effective means than spark ignition to accelerate the ammonia-hydrogen mixture combustion. A hot jet carrying heat and active radicals is injected into the main chamber due to the pressure difference, and then ignites the ammonia-hydrogen mixture. With increased hydrogen volume fraction, the ignition process is advanced due to the earlier formation and higher reactivity of the hot jet. Meanwhile, the enhanced fuel reactivity and turbulent disturbance accelerate turbulent flame propagation with increased hydrogen addition. The ignition delay time and jet flame axial development are accelerated with increase in equivalence ratio from 0.6 to 1.0. With increased orifice diameter, the pre-chamber jet flame is observed due to the weakened quenching effect, leading to shortened ignition delay and extended combustion duration.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"260 ","pages":"Article 124995"},"PeriodicalIF":6.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}