Adriana S. Valencia, Hugo Jativa Cervantes, Eduardo E. Castillo, Oguier A. Garavitto, Guillermo Soriano, L. Castro
Fast-growing cities are a challenge for its current energy demand, especially in developing countries. Replacement of micro-turbines instead of dropping pressure valves in urban-water pipelines may assist in supplying energy to the electrical grid. The understanding of turbine design and its operational characteristics can help for efficient energy harvesting in these cities. The aim of this work is to design a cheap and versatile hydrokinetic vertical axis spherical turbine for extracting energy from water pipelines of 800 mm in diameter. The turbine runner is based on a NACA0018 airfoil. Performance prediction is obtained by implementing a double multiple stream tube (DMST) based model. Computational fluid dynamics (CFD) and finite element analysis are used for performance and design improvements. Based on the analysis, the turbine can generate an output power of approximately 1.71 kW with a dropping pressure head of 0.4 m and an internal flow velocity of 2.07 m/s with an efficiency of approximately 42.7%. The proposed method allows determining the available energy of 390 kW in the city of Guayaquil, Ecuador.
{"title":"Analysis of a Vertical-Axis Spherical Turbine for Energy Harvesting in Urban Water Supply Systems","authors":"Adriana S. Valencia, Hugo Jativa Cervantes, Eduardo E. Castillo, Oguier A. Garavitto, Guillermo Soriano, L. Castro","doi":"10.1115/imece2019-10643","DOIUrl":"https://doi.org/10.1115/imece2019-10643","url":null,"abstract":"\u0000 Fast-growing cities are a challenge for its current energy demand, especially in developing countries. Replacement of micro-turbines instead of dropping pressure valves in urban-water pipelines may assist in supplying energy to the electrical grid. The understanding of turbine design and its operational characteristics can help for efficient energy harvesting in these cities. The aim of this work is to design a cheap and versatile hydrokinetic vertical axis spherical turbine for extracting energy from water pipelines of 800 mm in diameter. The turbine runner is based on a NACA0018 airfoil. Performance prediction is obtained by implementing a double multiple stream tube (DMST) based model. Computational fluid dynamics (CFD) and finite element analysis are used for performance and design improvements. Based on the analysis, the turbine can generate an output power of approximately 1.71 kW with a dropping pressure head of 0.4 m and an internal flow velocity of 2.07 m/s with an efficiency of approximately 42.7%. The proposed method allows determining the available energy of 390 kW in the city of Guayaquil, Ecuador.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81137710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Combined Heat and Power (CHP) systems are one of the solutions to save energy by utilizing waste heat for addressing global warming and the global energy crisis. In many CHP technologies, the Stirling engine is outstanding since it has the advantage of various energy sources such as solar, geothermal, and industrial heat waste. The regenerator plays a key role in building a high efficiency Stirling Engine. Since it works as an energy storage component in the Stirling engine, its performance directly affects the Stirling engine efficiency. In the previous research, a new regenerator called the robust foil regenerator was designed to improve the performance of the regenerator. The regenerator was manufactured through the method of additive manufacturing techniques since the thickness of each flow channel is 0.3mm. In this research, a test bench was designed and manufactured to reveal the characteristics of the regenerator experimentally. By measuring the pressure drop and the temperature difference through the regenerator, the friction coefficient and the Nusselt number correlations were derived respectively. These correlations were compared to the published friction factor and Nusselt number correlations. In addition, to evaluate the geometrical configuration of the regenerator, the NPH/NTU ratio was calculated using the derived friction coefficient and Nusselt number.
{"title":"Stirling Engine Robust Foil Regenerator Efficiency","authors":"Koji Yanaga, Yuan Gao, Ruijie Li, Songgang Qiu","doi":"10.1115/imece2019-11382","DOIUrl":"https://doi.org/10.1115/imece2019-11382","url":null,"abstract":"\u0000 Combined Heat and Power (CHP) systems are one of the solutions to save energy by utilizing waste heat for addressing global warming and the global energy crisis. In many CHP technologies, the Stirling engine is outstanding since it has the advantage of various energy sources such as solar, geothermal, and industrial heat waste. The regenerator plays a key role in building a high efficiency Stirling Engine. Since it works as an energy storage component in the Stirling engine, its performance directly affects the Stirling engine efficiency. In the previous research, a new regenerator called the robust foil regenerator was designed to improve the performance of the regenerator. The regenerator was manufactured through the method of additive manufacturing techniques since the thickness of each flow channel is 0.3mm. In this research, a test bench was designed and manufactured to reveal the characteristics of the regenerator experimentally. By measuring the pressure drop and the temperature difference through the regenerator, the friction coefficient and the Nusselt number correlations were derived respectively. These correlations were compared to the published friction factor and Nusselt number correlations. In addition, to evaluate the geometrical configuration of the regenerator, the NPH/NTU ratio was calculated using the derived friction coefficient and Nusselt number.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89958917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Bower, M. Bielski, E. Mangan, D. Schell, K. Ghahremani, D. Gee
The purpose of this project was to explore the feasibility of powering a climate control system solely from a renewable energy source. The off-the-shelf cooling system components were taken from a ca. 1986 R-12 residential refrigerator and then reassembled onto a custom enclosure which was constructed to serve as the climate-controlled compartment. The enclosure design was purposefully simple: a rectangular shaped box constructed out of plywood and mounted on wheels together with a plexiglass door which was substituted for the front face. The overall design provided for enhanced mobility while also allowing for easy observation of the interior temperature via an interior-mounted, digital, commercial residential thermostat integrated into the control system. The system, nominally, is triggered by incident solar radiation; the initial set-point temperature was 21 °C. Compressor power was derived solely from renewable energy. Specifically, a pair of 100W 12V monocrystalline silicon photovoltaic solar panels was used to generate electricity which was subsequently stored in a deep-cycle battery. Under steady-state AC operation, the compressor draws approximately 2.1A. Due to system inefficiencies, the corresponding DC current draw is necessarily higher and approaches 22.3A. For a compressor duty cycle ranging from 50–100%, the current draw over a model 9 hr day would range from between 100.1–200.3 A-H. The lower limit is within the energy storage capacity for the fully-charged system, as currently designed.
该项目的目的是探索完全由可再生能源为气候控制系统供电的可行性。现成的冷却系统组件取自一台大约1986年的R-12家用冰箱，然后重新组装到一个定制的外壳上，作为气候控制隔间。外壳的设计非常简单:一个由胶合板制成的矩形盒子，安装在轮子上，有机玻璃门代替了前面的面板。整体设计提供了增强的机动性，同时也允许通过集成到控制系统中的内部安装的数字商业住宅恒温器轻松观察室内温度。名义上，该系统是由入射太阳辐射触发的;初始设定点温度为21℃。压缩机的动力完全来自可再生能源。具体来说，使用一对100W 12V单晶硅光伏太阳能电池板发电，随后将其存储在深循环电池中。在交流稳态运行下，压缩机的耗电约为2.1A。由于系统效率低下，相应的直流电流消耗必然更高，接近22.3A。对于压缩机占空比范围为50-100%，模型9小时每天的电流消耗范围为100.1-200.3 a - h。下限是在目前设计的完全充电系统的能量存储容量范围内。
{"title":"Achieving Climate Control With Renewable Energy","authors":"D. Bower, M. Bielski, E. Mangan, D. Schell, K. Ghahremani, D. Gee","doi":"10.1115/imece2019-10751","DOIUrl":"https://doi.org/10.1115/imece2019-10751","url":null,"abstract":"\u0000 The purpose of this project was to explore the feasibility of powering a climate control system solely from a renewable energy source. The off-the-shelf cooling system components were taken from a ca. 1986 R-12 residential refrigerator and then reassembled onto a custom enclosure which was constructed to serve as the climate-controlled compartment. The enclosure design was purposefully simple: a rectangular shaped box constructed out of plywood and mounted on wheels together with a plexiglass door which was substituted for the front face. The overall design provided for enhanced mobility while also allowing for easy observation of the interior temperature via an interior-mounted, digital, commercial residential thermostat integrated into the control system. The system, nominally, is triggered by incident solar radiation; the initial set-point temperature was 21 °C. Compressor power was derived solely from renewable energy. Specifically, a pair of 100W 12V monocrystalline silicon photovoltaic solar panels was used to generate electricity which was subsequently stored in a deep-cycle battery. Under steady-state AC operation, the compressor draws approximately 2.1A. Due to system inefficiencies, the corresponding DC current draw is necessarily higher and approaches 22.3A. For a compressor duty cycle ranging from 50–100%, the current draw over a model 9 hr day would range from between 100.1–200.3 A-H. The lower limit is within the energy storage capacity for the fully-charged system, as currently designed.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86294966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Free Piston Stirling Engine is an external combustion engine, which can use diversified energy resources, such as solar energy, nuclear energy, geothermal energy, biomass, industrial waste heat etc. and is suitable for the remote area power generation due to the advantage of robustness, durability, reliability, and high efficiency. In this work, a Free Piston Stirling Engine has been designed based on the numerical simulation results and previous experimental experience. Direct Metal Laser Sintering method has been adopted for the manufacturing of the key components including the displacer cap, displacer body, piston housing, cold heat exchanger, and regenerator. One dimension analysis using Sage software has been conducted. The designed engine has a power output of 65W with the hot and cold end temperature is 650°C and 80°C respectively, and charge pressure is 1.35 MPa. Finite Element Method has been used to analyze the structural stress of the engine, which is operated at the high temperature and high pressure, to determine if it is able to tolerate the operating condition designed by the Sage according to the Section VIII Division 2 of the ASME Boiler and Pressure Vessel (BPV) Code. In addition, Computational Fluid Dynamics (CFD) method has been used to investigate the flow distribution in heat exchangers (heat acceptor, regenerator, and heat rejecter), as the heat exchanger performance affect the engine performance greatly. Considering the large mesh number, a quarter of the heat exchangers have been investigated, in order to reduce the mesh numbers and accelerate the calculation speed.
{"title":"Design of a Free Piston Stirling Engine Power Generator","authors":"Ruijie Li, Yuan Gao, Koji Yanaga, Songgang Qiu","doi":"10.1115/imece2019-10403","DOIUrl":"https://doi.org/10.1115/imece2019-10403","url":null,"abstract":"\u0000 Free Piston Stirling Engine is an external combustion engine, which can use diversified energy resources, such as solar energy, nuclear energy, geothermal energy, biomass, industrial waste heat etc. and is suitable for the remote area power generation due to the advantage of robustness, durability, reliability, and high efficiency. In this work, a Free Piston Stirling Engine has been designed based on the numerical simulation results and previous experimental experience. Direct Metal Laser Sintering method has been adopted for the manufacturing of the key components including the displacer cap, displacer body, piston housing, cold heat exchanger, and regenerator. One dimension analysis using Sage software has been conducted. The designed engine has a power output of 65W with the hot and cold end temperature is 650°C and 80°C respectively, and charge pressure is 1.35 MPa. Finite Element Method has been used to analyze the structural stress of the engine, which is operated at the high temperature and high pressure, to determine if it is able to tolerate the operating condition designed by the Sage according to the Section VIII Division 2 of the ASME Boiler and Pressure Vessel (BPV) Code.\u0000 In addition, Computational Fluid Dynamics (CFD) method has been used to investigate the flow distribution in heat exchangers (heat acceptor, regenerator, and heat rejecter), as the heat exchanger performance affect the engine performance greatly. Considering the large mesh number, a quarter of the heat exchangers have been investigated, in order to reduce the mesh numbers and accelerate the calculation speed.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88560698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Upstream wind turbine turbulence can negatively impact the aerodynamic performance of downstream wind turbines. It is important to understand and evaluate the characteristic nature of this inflowing turbulence. Computational Fluid Dynamics (CFD) is a foundational analytical tool used to help predict and describe both boundary layer behavior and the resulting downstream turbulence for both these upstream turbines and the impacted downstream turbines. Increasing the predication accuracy of turbulence models, particularly at the higher Reynolds number regimes, commonly encountered at the outer radius of wind turbine blades, remains a fundamental consideration in such CFD analysis. The work discussed here focuses on understanding how CFD simulations can be impacted by basic CFD approaches and configurations. Commonly use unstructured grids and incremental positive angles of attack around the well-studied NACA0012 airfoil were used to assess how these basic set-up parameters can influence CFD turbulence results. Navier-Stokes equations were solved for incompressible flow to assess downstream turbulence using the SST k-ω (two equation) turbulence model within ANSYS Fluent (SIMPLE solution method). Two airfoil configurations with respect to angle of attack (α) were of interested and studied, with one configuration defined as “fixed-position” and the second configuration defined as “changed-position”. Fixed-position refers to a single common airfoil/grid configuration and changing incoming ux, vy velocity vectors to yield different angle of attack (α) values. Changed-position refers to a utilizing a single ux velocity vector and physically rotating the impacted airfoil in the computational field to yield different angles of attack. A two-dimensional unsteady state SST k-ω turbulence model was used at a Reynolds of 3.0 × 106. The resulting data from the system setup models studied here (fixed and changed-positions) were successfully validated by comparing the computed lift and drag coefficients at these varying α values to common values found in literature. Downstream pressure contours, along with Ux and Vy, and net-velocity contours at various distances from 1.5 cord lengths up to 12.0 cord lengths from the leading edge of the airfoil at incremental angles of attack were studied. The authors review how such variations in rudimentary approaches impact the CFD downstream output results.
{"title":"How Variations in Downstream Computational Fluid Dynamics Turbulence Studies Can Be Impacted When Employing Commonly Used Initial Set-Up Configuration Parameters for Airfoils","authors":"Hussein Al-Qarishey, R. Fletcher","doi":"10.1115/imece2019-11257","DOIUrl":"https://doi.org/10.1115/imece2019-11257","url":null,"abstract":"\u0000 Upstream wind turbine turbulence can negatively impact the aerodynamic performance of downstream wind turbines. It is important to understand and evaluate the characteristic nature of this inflowing turbulence. Computational Fluid Dynamics (CFD) is a foundational analytical tool used to help predict and describe both boundary layer behavior and the resulting downstream turbulence for both these upstream turbines and the impacted downstream turbines. Increasing the predication accuracy of turbulence models, particularly at the higher Reynolds number regimes, commonly encountered at the outer radius of wind turbine blades, remains a fundamental consideration in such CFD analysis.\u0000 The work discussed here focuses on understanding how CFD simulations can be impacted by basic CFD approaches and configurations. Commonly use unstructured grids and incremental positive angles of attack around the well-studied NACA0012 airfoil were used to assess how these basic set-up parameters can influence CFD turbulence results. Navier-Stokes equations were solved for incompressible flow to assess downstream turbulence using the SST k-ω (two equation) turbulence model within ANSYS Fluent (SIMPLE solution method). Two airfoil configurations with respect to angle of attack (α) were of interested and studied, with one configuration defined as “fixed-position” and the second configuration defined as “changed-position”. Fixed-position refers to a single common airfoil/grid configuration and changing incoming ux, vy velocity vectors to yield different angle of attack (α) values. Changed-position refers to a utilizing a single ux velocity vector and physically rotating the impacted airfoil in the computational field to yield different angles of attack.\u0000 A two-dimensional unsteady state SST k-ω turbulence model was used at a Reynolds of 3.0 × 106. The resulting data from the system setup models studied here (fixed and changed-positions) were successfully validated by comparing the computed lift and drag coefficients at these varying α values to common values found in literature. Downstream pressure contours, along with Ux and Vy, and net-velocity contours at various distances from 1.5 cord lengths up to 12.0 cord lengths from the leading edge of the airfoil at incremental angles of attack were studied. The authors review how such variations in rudimentary approaches impact the CFD downstream output results.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82089225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.
{"title":"Development of a New Stoichiometric Equilibrium-Based Model for Wood Chips and Mixed Paper Wastes Gasification by ASPEN Plus","authors":"Sahar Safarianbana, Runar Unnthorsson, Christiaan Richter","doi":"10.1115/imece2019-10586","DOIUrl":"https://doi.org/10.1115/imece2019-10586","url":null,"abstract":"\u0000 Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82513003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A pico-scale Francis turbine (or energy harvester) was designed, fabricated and tested for pressure regulation and power generation application. The prototype energy harvester contains pivotable guide vanes and a controllable load to change the runner speed. This allows the simultaneous variation of the pressure drop and the output power. A computational fluid dynamics (CFD) model of the turbine was developed in ANSYS CFX 18.1 to evaluate the turbine’s sensitivity to geometric parameters such as the clearance gap size of the guide vane and its modularity. In conjunction to the CFD model, the electric generator’s characteristics were used to predict the turbine performance at varying guide vane angles. The turbine was prototyped and tested using a custom-built experimental set-up. The pico-scale turbine, with a runner diameter of 1.42 inches, was able to output up to 100 W of electrical power at its rated flowrate of 29 GPM. By varying the guide vane angles, the pressure drop and the hydraulic efficiency varied between 3–22 psi and up to 60% respectively. When validated against the experimental results, the CFD model showed a good agreement despite its low computational cost. The energy harvester’s initial characteristics demonstrate its potential as a game changer in the control valve market.
{"title":"Modelling and Experimental Validation of a Controllable Energy Harvester for Pressure Regulation","authors":"Y. Ko, Shi M. Yu, A. Bilton","doi":"10.1115/imece2019-11514","DOIUrl":"https://doi.org/10.1115/imece2019-11514","url":null,"abstract":"\u0000 A pico-scale Francis turbine (or energy harvester) was designed, fabricated and tested for pressure regulation and power generation application. The prototype energy harvester contains pivotable guide vanes and a controllable load to change the runner speed. This allows the simultaneous variation of the pressure drop and the output power. A computational fluid dynamics (CFD) model of the turbine was developed in ANSYS CFX 18.1 to evaluate the turbine’s sensitivity to geometric parameters such as the clearance gap size of the guide vane and its modularity. In conjunction to the CFD model, the electric generator’s characteristics were used to predict the turbine performance at varying guide vane angles. The turbine was prototyped and tested using a custom-built experimental set-up. The pico-scale turbine, with a runner diameter of 1.42 inches, was able to output up to 100 W of electrical power at its rated flowrate of 29 GPM. By varying the guide vane angles, the pressure drop and the hydraulic efficiency varied between 3–22 psi and up to 60% respectively. When validated against the experimental results, the CFD model showed a good agreement despite its low computational cost. The energy harvester’s initial characteristics demonstrate its potential as a game changer in the control valve market.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89596295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The new generation of Concentrated Solar Power (CSP) plants requires high temperature and high energy density storage system with good cyclic stability. The potential solution satisfying such requirements is the thermochemical energy storage (TCES) using gas-solid redox reaction. Design of efficient storage reactor is very critical for applications of such storage systems. Packed bed reactors have a simpler design with no moving components and are more cost-effective compared to other available moving bed design configurations while having high-pressure drop is their main drawback. Any improvement in the pressure drop makes the design more suitable for commercial applications, especially at high temperature operating conditions. Cobalt oxide redox reaction has been considered for this study because of its unique features, especially high enthalpy of reaction (energy density) and high reaction temperature. A rectangular cross-section packed bed reactor with a large aspect ratio is selected as a reference conventional packed bed reactor. The novel split-flow packed bed reactor design configuration is proposed in which a portion of heat transfer fluid is passed through adjacent side channels. The split flow ratio of 1/3 has been considered for the case study. The transient two-dimensional numerical model is developed for solving mass, momentum, and energy equations for both gas and solid phases using suitable reaction kinetics for the reversible reduction and re-oxidation process. Complete storage cycle, including both the charging and discharging mode, has been simulated using finite element method. The split flow design performance is compared with the reference case considering the same size of the reaction bed. It is shown that the conversion time is increased while the pressure drop reduced below half of the pressure loss of the conventional design. Reduced mass flow rate passing through the bed results in considerable improvement in required pressure work with a penalty of storage performance. Further study is needed to optimize the split flow ratio and the surface heat transfer characteristics of the bed. The proposed design configuration could be a breakthrough in packed bed reactors, especially for high-temperature storage applications.
{"title":"Split Flow Modified Packed Bed Reactor for Cobalt Oxide Based High-Temperature TCES Systems","authors":"N. Vahedi, A. Oztekin","doi":"10.1115/imece2019-10740","DOIUrl":"https://doi.org/10.1115/imece2019-10740","url":null,"abstract":"\u0000 The new generation of Concentrated Solar Power (CSP) plants requires high temperature and high energy density storage system with good cyclic stability. The potential solution satisfying such requirements is the thermochemical energy storage (TCES) using gas-solid redox reaction. Design of efficient storage reactor is very critical for applications of such storage systems. Packed bed reactors have a simpler design with no moving components and are more cost-effective compared to other available moving bed design configurations while having high-pressure drop is their main drawback. Any improvement in the pressure drop makes the design more suitable for commercial applications, especially at high temperature operating conditions. Cobalt oxide redox reaction has been considered for this study because of its unique features, especially high enthalpy of reaction (energy density) and high reaction temperature. A rectangular cross-section packed bed reactor with a large aspect ratio is selected as a reference conventional packed bed reactor. The novel split-flow packed bed reactor design configuration is proposed in which a portion of heat transfer fluid is passed through adjacent side channels. The split flow ratio of 1/3 has been considered for the case study. The transient two-dimensional numerical model is developed for solving mass, momentum, and energy equations for both gas and solid phases using suitable reaction kinetics for the reversible reduction and re-oxidation process. Complete storage cycle, including both the charging and discharging mode, has been simulated using finite element method. The split flow design performance is compared with the reference case considering the same size of the reaction bed. It is shown that the conversion time is increased while the pressure drop reduced below half of the pressure loss of the conventional design. Reduced mass flow rate passing through the bed results in considerable improvement in required pressure work with a penalty of storage performance. Further study is needed to optimize the split flow ratio and the surface heat transfer characteristics of the bed. The proposed design configuration could be a breakthrough in packed bed reactors, especially for high-temperature storage applications.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90271034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present experimental study aims to determine the effect of two different gas diffusion layers in the performance of a 5-cm2 proton exchange membrane (PEM) fuel cell. The gas diffusion layers consisted of a carbon cloth gas diffusion (GDL-CT) and a non-woven carbon paper (Sigracet 25 BC, Sigracet 29, and BC Sigracet 35 BC). The effect of the GDL parameters on the fuel cell performance was evaluated by the polarization curve. Based on the polarization curve results, it was confirmed that the carbon cloth gas diffusion layer had a better performance than the non-woven carbon. Different temperatures, hydrogen flow rates and inlet pressures were tested. Images from the scanning electron microscopy were obtained to visualize the internal structure of a carbon paper GDL and a carbon cloth GDL; it was observed different surface structures between them.
{"title":"A 5-cm2 PEM Fuel Cell Gas Diffusion Layer Experimental Study and Scanning Electron Microscopy Visualization","authors":"Jose Montoya Segnini, Gerardo Carbajal","doi":"10.1115/imece2019-12018","DOIUrl":"https://doi.org/10.1115/imece2019-12018","url":null,"abstract":"\u0000 The present experimental study aims to determine the effect of two different gas diffusion layers in the performance of a 5-cm2 proton exchange membrane (PEM) fuel cell. The gas diffusion layers consisted of a carbon cloth gas diffusion (GDL-CT) and a non-woven carbon paper (Sigracet 25 BC, Sigracet 29, and BC Sigracet 35 BC). The effect of the GDL parameters on the fuel cell performance was evaluated by the polarization curve. Based on the polarization curve results, it was confirmed that the carbon cloth gas diffusion layer had a better performance than the non-woven carbon. Different temperatures, hydrogen flow rates and inlet pressures were tested. Images from the scanning electron microscopy were obtained to visualize the internal structure of a carbon paper GDL and a carbon cloth GDL; it was observed different surface structures between them.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77856196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Samba, H. A. Hassan, M. S. Munayr, M. Yusef, A. Eschweido, Hamed Burkan, M. Elsharafi
There are three types of oil production energy operations, primary recovery, secondary recovery and enhanced oil recovery (EOR). EOR consider as the last period for production operations. Where the EOR classify into many types such as thermal injection, gas injection, microbial EOR and chemical flooding. Chemical flooding classified into many types such as polymer, surfactant, alkaline and nanoparticles (NP). NP can be classified into many types such as Iron Oxide (Fe2O3), Aluminum Oxide (Al2O3) and Magnesium Oxide (MgO) etc. In this study NP Aluminum oxide (Al2O3) were used to enhance the oil recovery. The main objective of this study is to use the Nanoparticles EOR (Al2O3) and know it is effect on increasing the extraction of oil from cores. The big motivation of using Al2O3 that it is easy to extract it from raw clay. However, the raw clay is available in Libya and using it will be more economic than using other method of chemical EOR. Nanoparticles EOR Aluminum oxide (Al2O3) used as a spontaneous imbibition test for sandstone core samples after saturated by crude oil. A spontaneous imbibition test consisting of two scenarios of nanoparticle solution (Al2O3) with change temperature and compared with one scenario of distilled water. The spontaneous imbibition test was performed in this study at room temperature to oven temperature (30C°, 40C°, 50C°, 60C°, 70C°). The results shown that the oil recovery increases with the increase of the concentration of nanoparticle (Al2O3) and increase the temperature. The higher oil recovery was 76.04% at NP (Al2O3) concentration 1%. Finally, oil swelling and adsorption (NP (Al2O3) with oil drops) have been noticed during the extraction of oil. Thus, the gravity force will be higher than the capillary force.
{"title":"Nanoparticles EOR Aluminum Oxide (Al2O3) Used As a Spontaneous Imbibition Test for Sandstone Core","authors":"M. Samba, H. A. Hassan, M. S. Munayr, M. Yusef, A. Eschweido, Hamed Burkan, M. Elsharafi","doi":"10.1115/imece2019-10283","DOIUrl":"https://doi.org/10.1115/imece2019-10283","url":null,"abstract":"\u0000 There are three types of oil production energy operations, primary recovery, secondary recovery and enhanced oil recovery (EOR). EOR consider as the last period for production operations. Where the EOR classify into many types such as thermal injection, gas injection, microbial EOR and chemical flooding.\u0000 Chemical flooding classified into many types such as polymer, surfactant, alkaline and nanoparticles (NP). NP can be classified into many types such as Iron Oxide (Fe2O3), Aluminum Oxide (Al2O3) and Magnesium Oxide (MgO) etc. In this study NP Aluminum oxide (Al2O3) were used to enhance the oil recovery.\u0000 The main objective of this study is to use the Nanoparticles EOR (Al2O3) and know it is effect on increasing the extraction of oil from cores. The big motivation of using Al2O3 that it is easy to extract it from raw clay. However, the raw clay is available in Libya and using it will be more economic than using other method of chemical EOR.\u0000 Nanoparticles EOR Aluminum oxide (Al2O3) used as a spontaneous imbibition test for sandstone core samples after saturated by crude oil. A spontaneous imbibition test consisting of two scenarios of nanoparticle solution (Al2O3) with change temperature and compared with one scenario of distilled water. The spontaneous imbibition test was performed in this study at room temperature to oven temperature (30C°, 40C°, 50C°, 60C°, 70C°).\u0000 The results shown that the oil recovery increases with the increase of the concentration of nanoparticle (Al2O3) and increase the temperature. The higher oil recovery was 76.04% at NP (Al2O3) concentration 1%. Finally, oil swelling and adsorption (NP (Al2O3) with oil drops) have been noticed during the extraction of oil. Thus, the gravity force will be higher than the capillary force.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72973807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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