The design of, and preliminary on-sun tests on, an 8 cm × 8 cm microchannel supercritical carbon dioxide (sCO2) receiver is presented. The receiver has a laminated design, wherein sheets of Haynes 230 nickel superalloy are patterned and diffusion bonded to form microscale flow passages. The microscale pattern is in the form of square pins with width and height of 500 μm and 200 μm respectively. The pins are arranged in an in-line pattern with respect to the flow direction. The longitudinal and transverse pitch ratios of the micro pin fins are identical and equal to two times the side width of the pillar. A sCO2 test facility is developed with the ability to supply sCO2 at 200 bar pressure and at temperatures between 300–500°C to the receiver inlet. The sCO2 facility is coupled to a seven meter diameter parabolic dish with a 25 kW rating and a concentration ratio of about 800. On-sun tests are performed at a receiver inlet pressure of 150 bar and a receiver inlet temperature between 110–130°C. Receiver and thermal efficiencies in excess of 0.91 and 0.96 respectively for the incident heat flux ranging from 8 to 80 W/cm2, and average surface temperatures ranging from 150–550°C are obtained in these experiments.
{"title":"On-Sun Characterization of Microchannel Supercritical Carbon Dioxide Solar Thermal Receivers: Preliminary Findings","authors":"E. Rasouli, C. Mande, M. M. Stevens, V. Narayanan","doi":"10.1115/es2019-3898","DOIUrl":"https://doi.org/10.1115/es2019-3898","url":null,"abstract":"\u0000 The design of, and preliminary on-sun tests on, an 8 cm × 8 cm microchannel supercritical carbon dioxide (sCO2) receiver is presented. The receiver has a laminated design, wherein sheets of Haynes 230 nickel superalloy are patterned and diffusion bonded to form microscale flow passages. The microscale pattern is in the form of square pins with width and height of 500 μm and 200 μm respectively. The pins are arranged in an in-line pattern with respect to the flow direction. The longitudinal and transverse pitch ratios of the micro pin fins are identical and equal to two times the side width of the pillar. A sCO2 test facility is developed with the ability to supply sCO2 at 200 bar pressure and at temperatures between 300–500°C to the receiver inlet. The sCO2 facility is coupled to a seven meter diameter parabolic dish with a 25 kW rating and a concentration ratio of about 800. On-sun tests are performed at a receiver inlet pressure of 150 bar and a receiver inlet temperature between 110–130°C. Receiver and thermal efficiencies in excess of 0.91 and 0.96 respectively for the incident heat flux ranging from 8 to 80 W/cm2, and average surface temperatures ranging from 150–550°C are obtained in these experiments.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127544025","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}
Philipp N Ahrend, A. Azizi, J. Brouwer, G. Samuelsen
The simulation of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) hybrid system for a locomotive application is presented. Using Matlab Simulink, a 2.8 MW SOFC system was combined with a 500 kW GT and simulated to travel the route from Bakersfield to Mojave in California. Elevation data was imported using the Google API Console and smoothed in order to calculate the dynamic power demand for the SOFC-GT system, assuming 480 tons of freight per 120 ton locomotive traveling at an average speed of 45 mph. The SOFC-GT system model follows this demand without causing a significant disruption to the speed of the locomotive. A lithium-ion battery was included into the system model to improve the net system efficiency and make the operation smooth enough for the highly dynamic route. The overall efficiency along the simulated route has been calculated as 57% operating on partially pre-reformed natural gas fuel. These results suggest the development of a physical prototype of the simulated system and are very promising for the future of freight rail transportation throughout the US. CO2 and particulate matter emissions are significantly reduced compared to current diesel-electric locomotives and it is also possible to operate the system on hydrogen, i.e., completely emission-free. A techno-economic analysis to assess the economic feasibility of this system is currently being prepared.
{"title":"A Solid Oxide Fuel Cell-Gas Turbine Hybrid System for a Freight Rail Application","authors":"Philipp N Ahrend, A. Azizi, J. Brouwer, G. Samuelsen","doi":"10.1115/es2019-3906","DOIUrl":"https://doi.org/10.1115/es2019-3906","url":null,"abstract":"\u0000 The simulation of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) hybrid system for a locomotive application is presented. Using Matlab Simulink, a 2.8 MW SOFC system was combined with a 500 kW GT and simulated to travel the route from Bakersfield to Mojave in California. Elevation data was imported using the Google API Console and smoothed in order to calculate the dynamic power demand for the SOFC-GT system, assuming 480 tons of freight per 120 ton locomotive traveling at an average speed of 45 mph. The SOFC-GT system model follows this demand without causing a significant disruption to the speed of the locomotive. A lithium-ion battery was included into the system model to improve the net system efficiency and make the operation smooth enough for the highly dynamic route. The overall efficiency along the simulated route has been calculated as 57% operating on partially pre-reformed natural gas fuel.\u0000 These results suggest the development of a physical prototype of the simulated system and are very promising for the future of freight rail transportation throughout the US. CO2 and particulate matter emissions are significantly reduced compared to current diesel-electric locomotives and it is also possible to operate the system on hydrogen, i.e., completely emission-free. A techno-economic analysis to assess the economic feasibility of this system is currently being prepared.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"411 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133587189","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}
Biogas production is an anaerobic waste-to-energy technology, involving waste degradation and stabilization. The sustainable, cheap and clean nature of biogas has led to the unprecedented rise in its use as an alternative energy source. Due to the increased interests, availability of conventional biodegradable organics has shrunk enormously over the years, necessitating the aggressive search for novel energy crops and substrate enhancement options. These novel options ensure feedstock security, optimize conventional biomass feedstocks, improve feedstock degradability and increase in biogas yield. Low biodegradability of most lignocellulosic wastes like okra waste, limits their use as a viable substrate in the anaerobic digestion process. Over the years, several elements, compounds and nanoparticles have been applied to anaerobic digestion systems as supplementary nutrients with a view to enhancing substrate degradation. Such supplements like iron-based additives have gained prominence in anaerobic digestion processes of wastes, owing to their electron donation abilities, promotion of solubilization, hydrolysis, acidification, and hydrogenotrophic methanogenesis. In a bid to enhance substrate degradation, reduce inhibitions, increase both biogas yield and methane content, a comparative study on the influence of four different iron-based additives (nanoscale zero-valent iron (nZVI), Polypyrrole-magnetic nanocomposite (Ppy-Fe3O4), Iron powder (Fe) and Hematite (Fe2O3)) on the entire anaerobic digestion of okra waste was done. Previously determined optimum doses, 20 mg, 20 mg, 750 mg, 750 mg and 0 respectively for nZVI, Ppy-Fe3O4, Fe, Fe2O3 and control were added to the bioreactors containing okra wastes in a 500 mL biomethane potential bioreactors under mesophilic temperature (37°C) for 20 days. The cumulative volumes of the biogas from different reactors were recorded and analyzed. The morphological deformation, structures and analysis of the undigested substrate, digestates of substrate supplemented with iron-based additives and the control were evaluated with scanning electron microscopy (SEM). Artificial neural network (ANN) model and the modified Gompertz model were validated with the experimental data. The ANN model showed better goodness of fit and was better correlated with the experimental data. Experimental data were subjected to analysis of variance at a 95% confidence level. Results showed that Ppy-Fe3O4 additives better enhanced both biogas yield and methane contents significantly when compared to the control. It was also observed that all iron-additive supplemented processes were more degraded when compared with the control.
{"title":"Comparative Studies on the Effect of Selected Iron-Based Additives on Anaerobic Digestion of Okra Waste","authors":"S. Ugwu, C. Enweremadu","doi":"10.1115/es2019-3820","DOIUrl":"https://doi.org/10.1115/es2019-3820","url":null,"abstract":"\u0000 Biogas production is an anaerobic waste-to-energy technology, involving waste degradation and stabilization. The sustainable, cheap and clean nature of biogas has led to the unprecedented rise in its use as an alternative energy source. Due to the increased interests, availability of conventional biodegradable organics has shrunk enormously over the years, necessitating the aggressive search for novel energy crops and substrate enhancement options. These novel options ensure feedstock security, optimize conventional biomass feedstocks, improve feedstock degradability and increase in biogas yield. Low biodegradability of most lignocellulosic wastes like okra waste, limits their use as a viable substrate in the anaerobic digestion process. Over the years, several elements, compounds and nanoparticles have been applied to anaerobic digestion systems as supplementary nutrients with a view to enhancing substrate degradation. Such supplements like iron-based additives have gained prominence in anaerobic digestion processes of wastes, owing to their electron donation abilities, promotion of solubilization, hydrolysis, acidification, and hydrogenotrophic methanogenesis. In a bid to enhance substrate degradation, reduce inhibitions, increase both biogas yield and methane content, a comparative study on the influence of four different iron-based additives (nanoscale zero-valent iron (nZVI), Polypyrrole-magnetic nanocomposite (Ppy-Fe3O4), Iron powder (Fe) and Hematite (Fe2O3)) on the entire anaerobic digestion of okra waste was done. Previously determined optimum doses, 20 mg, 20 mg, 750 mg, 750 mg and 0 respectively for nZVI, Ppy-Fe3O4, Fe, Fe2O3 and control were added to the bioreactors containing okra wastes in a 500 mL biomethane potential bioreactors under mesophilic temperature (37°C) for 20 days.\u0000 The cumulative volumes of the biogas from different reactors were recorded and analyzed. The morphological deformation, structures and analysis of the undigested substrate, digestates of substrate supplemented with iron-based additives and the control were evaluated with scanning electron microscopy (SEM). Artificial neural network (ANN) model and the modified Gompertz model were validated with the experimental data. The ANN model showed better goodness of fit and was better correlated with the experimental data. Experimental data were subjected to analysis of variance at a 95% confidence level. Results showed that Ppy-Fe3O4 additives better enhanced both biogas yield and methane contents significantly when compared to the control. It was also observed that all iron-additive supplemented processes were more degraded when compared with the control.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114468724","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}
J. Hertel, Miriam Ebert, L. Amsbeck, B. Gobereit, Jens Rheinländer, Alexander Hirt, C. Frantz
A direct absorption receiver using ceramic particles (CentRec) has been successfully developed by DLR and tested under solar conditions at the Juelich Solar Power Tower, demonstrating receiver outlet temperatures of more than 900 °C. The next step towards commercial application of the technology is to demonstrate a cost-effective, high temperature heat extraction and transfer to a process medium. Besides e.g. steam for electricity generation in a steam turbine, hot air can be used to supply heat to industrial processes with energy demand at high temperature level. A great potential for higher efficiencies and lower costs has been identified for a moving bed heat exchanger. Several concepts of direct contact heat exchangers have been analyzed and evaluated. The selected concept is a combination of several crossflow-sections that are arranged in series with fluid-mixing-chambers between each crossflow-section. Based on the selected design a heat exchanger prototype with 10 kW thermal power and a design air outlet temperature of 750 °C has been built and integrated into a test setup. The test setup provides particles at 900 °C that are heated up electrically inside a hopper on top of the heat exchanger. Hot particles are then moving downwards (moving bed) from the hopper through the direct contact heat exchanger driven by gravity. Cold air supplied by a compressor flows through the particle bed in cross-flow and is heated up. The hot air flow leaves the heat exchanger with a temperature of 750 °C. The particle mass flow is controlled by an oscillating mass flow controller, positioned under the heat exchanger. The cold particles are collected in a container on the bottom. The particle cycle is closed by transporting them back to the hopper. A measurement and control system is implemented to carry out the tests. The test setup has undergone successful commissioning in October and an extensive testing phase started in January 2019. This paper presents the development and manufacturing as well as the successful commissioning of the heat exchanger prototype.
{"title":"Development and Test of a Direct Contact Heat Exchanger (Particle - Air) for Industrial Process Heat Applications","authors":"J. Hertel, Miriam Ebert, L. Amsbeck, B. Gobereit, Jens Rheinländer, Alexander Hirt, C. Frantz","doi":"10.1115/es2019-3818","DOIUrl":"https://doi.org/10.1115/es2019-3818","url":null,"abstract":"\u0000 A direct absorption receiver using ceramic particles (CentRec) has been successfully developed by DLR and tested under solar conditions at the Juelich Solar Power Tower, demonstrating receiver outlet temperatures of more than 900 °C. The next step towards commercial application of the technology is to demonstrate a cost-effective, high temperature heat extraction and transfer to a process medium. Besides e.g. steam for electricity generation in a steam turbine, hot air can be used to supply heat to industrial processes with energy demand at high temperature level.\u0000 A great potential for higher efficiencies and lower costs has been identified for a moving bed heat exchanger. Several concepts of direct contact heat exchangers have been analyzed and evaluated. The selected concept is a combination of several crossflow-sections that are arranged in series with fluid-mixing-chambers between each crossflow-section.\u0000 Based on the selected design a heat exchanger prototype with 10 kW thermal power and a design air outlet temperature of 750 °C has been built and integrated into a test setup.\u0000 The test setup provides particles at 900 °C that are heated up electrically inside a hopper on top of the heat exchanger. Hot particles are then moving downwards (moving bed) from the hopper through the direct contact heat exchanger driven by gravity. Cold air supplied by a compressor flows through the particle bed in cross-flow and is heated up. The hot air flow leaves the heat exchanger with a temperature of 750 °C. The particle mass flow is controlled by an oscillating mass flow controller, positioned under the heat exchanger. The cold particles are collected in a container on the bottom. The particle cycle is closed by transporting them back to the hopper. A measurement and control system is implemented to carry out the tests.\u0000 The test setup has undergone successful commissioning in October and an extensive testing phase started in January 2019.\u0000 This paper presents the development and manufacturing as well as the successful commissioning of the heat exchanger prototype.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126090548","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 University of the Philippines is the Philippines’ national university. It is mandated to be the leader in innovation and research. The electricity consumption of the flagship campus, the University of the Philippines Diliman, rose from 13.97 GWh in 2006 to 15.26 GWh by 2015 [1]. The electricity consumption must be managed as the university desires more students to graduate, do progressive research and creative works, and produce quality extension services. An appropriate energy policy incorporating minimum equipment standards in procuring energy consuming devices is wanting. Standardization controls the varying energy demand of equipment without compromising the quality of services delivered. The objective is to establish minimum equipment specification standards for university procurement. A framework for determining equipment standardization was developed, end-users’ need assessments and energy audits were conducted, equipment specifications were formulated, stakeholders were consulted, and equipment policy to ensure energy efficiency and sustainability were suggested. The electricity consumption was primarily due to air-conditioning (55.3%) and lighting (26.3%). Electricity savings is attained by adopting a higher standards of air conditioning energy efficiency ratio (45%), and changing to light emitting diode for lights (31%) and for monitors (5%). It is recommended that usage profiling be conducted for all the buildings.
{"title":"Academic Building Equipment Standardization for Sustainability","authors":"F. Manegdeg, J. Balbarona, Roderaid Ibañez","doi":"10.1115/es2019-3872","DOIUrl":"https://doi.org/10.1115/es2019-3872","url":null,"abstract":"\u0000 The University of the Philippines is the Philippines’ national university. It is mandated to be the leader in innovation and research. The electricity consumption of the flagship campus, the University of the Philippines Diliman, rose from 13.97 GWh in 2006 to 15.26 GWh by 2015 [1]. The electricity consumption must be managed as the university desires more students to graduate, do progressive research and creative works, and produce quality extension services. An appropriate energy policy incorporating minimum equipment standards in procuring energy consuming devices is wanting. Standardization controls the varying energy demand of equipment without compromising the quality of services delivered.\u0000 The objective is to establish minimum equipment specification standards for university procurement. A framework for determining equipment standardization was developed, end-users’ need assessments and energy audits were conducted, equipment specifications were formulated, stakeholders were consulted, and equipment policy to ensure energy efficiency and sustainability were suggested.\u0000 The electricity consumption was primarily due to air-conditioning (55.3%) and lighting (26.3%). Electricity savings is attained by adopting a higher standards of air conditioning energy efficiency ratio (45%), and changing to light emitting diode for lights (31%) and for monitors (5%). It is recommended that usage profiling be conducted for all the buildings.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121028787","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 utilization of solar energy is attracting rapidly increasing researches due to its many advantages, and an important application is to satisfy the refrigeration demand of residents with the solar-assisted absorption chillers. However, the simple solar-assisted refrigeration system cannot always meet the cooling demand of residents due to the mismatch between solar power and the refrigeration load. Therefore, the thermal energy storage device is introduced into the solar-assisted system to increase the stability of the refrigeration system and reduce the waste of solar energy. In this contribution, a solar-assisted absorption chiller system together with the TES device is presented and optimized to minimize the operation cost of the system. The system is modeled using the newly proposed heat current method and its global constraints are constructed, which largely reduces the number of the constraints comparing to the traditional equation-oriented approach. Optimization results present that the optimized design of the system reduces the total operation cost effectively.
{"title":"Heat Current Method Based Modeling and Optimization of a Solar-Driven Absorption Chiller for Residential Houses","authors":"Qun Chen, Tian Zhao","doi":"10.1115/es2019-3853","DOIUrl":"https://doi.org/10.1115/es2019-3853","url":null,"abstract":"\u0000 The utilization of solar energy is attracting rapidly increasing researches due to its many advantages, and an important application is to satisfy the refrigeration demand of residents with the solar-assisted absorption chillers. However, the simple solar-assisted refrigeration system cannot always meet the cooling demand of residents due to the mismatch between solar power and the refrigeration load. Therefore, the thermal energy storage device is introduced into the solar-assisted system to increase the stability of the refrigeration system and reduce the waste of solar energy. In this contribution, a solar-assisted absorption chiller system together with the TES device is presented and optimized to minimize the operation cost of the system. The system is modeled using the newly proposed heat current method and its global constraints are constructed, which largely reduces the number of the constraints comparing to the traditional equation-oriented approach. Optimization results present that the optimized design of the system reduces the total operation cost effectively.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123573312","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}
Carmakers, regulatory agencies, and consumers share an interest in accurately determining a vehicle’s fuel efficiency under operating conditions that match the expected use. Previous studies have shown that a vehicle’s air conditioning (A/C) system is the most energy-intensive non-propulsive system and significantly reduces fuel economy. This study aims to design and validate a new method of improving fuel economy estimates obtained on non-climate-controlled chassis dynamometers, as such laboratories are limited to measuring fuel economy with the A/C system deactivated. The methodology proposed herein uses a chassis dynamometer to measure the fuel economy penalty caused by the A/C system at different steady-state conditions. The hypothesis is that these penalties can be imposed accordingly for a given drive cycle to obtain an additional fuel consumption due to A/C. To validate the proposed methodology, a vehicle was outfitted with a data acquisition system and was driven 50 times around a predefined route using varying A/C settings. The proposed method was then used to estimate the additional fuel consumption due to A/C usage for each of the runs. Comparing the calculated and actual fuel economies showed an average error of 1.924%. It was concluded that the proposed methodology is a viable alternative to existing procedures.
{"title":"Improving Fuel Economy Estimates on a Chassis Dynamometer Using Air Conditioner Correction Factors","authors":"J. Reyes, E. Quiros","doi":"10.1115/es2019-3821","DOIUrl":"https://doi.org/10.1115/es2019-3821","url":null,"abstract":"\u0000 Carmakers, regulatory agencies, and consumers share an interest in accurately determining a vehicle’s fuel efficiency under operating conditions that match the expected use. Previous studies have shown that a vehicle’s air conditioning (A/C) system is the most energy-intensive non-propulsive system and significantly reduces fuel economy.\u0000 This study aims to design and validate a new method of improving fuel economy estimates obtained on non-climate-controlled chassis dynamometers, as such laboratories are limited to measuring fuel economy with the A/C system deactivated. The methodology proposed herein uses a chassis dynamometer to measure the fuel economy penalty caused by the A/C system at different steady-state conditions. The hypothesis is that these penalties can be imposed accordingly for a given drive cycle to obtain an additional fuel consumption due to A/C.\u0000 To validate the proposed methodology, a vehicle was outfitted with a data acquisition system and was driven 50 times around a predefined route using varying A/C settings. The proposed method was then used to estimate the additional fuel consumption due to A/C usage for each of the runs. Comparing the calculated and actual fuel economies showed an average error of 1.924%. It was concluded that the proposed methodology is a viable alternative to existing procedures.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130214052","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}
S. Richter, S. Brendelberger, Felix Gersdorf, T. Oschmann, C. Sattler
In contrast to thermal receivers that provide heat for steam cycles, in solar thermochemistry often receiver-reactors are used, where materials undergo a reaction while being irradiated by concentrated sunlight. When applied to two-step redox cycles, multiple processes take place in such receiver-reactors, though on different time scales. This leads to design compromises and to high technical requirements for the implementation. A concept for an indirect particle-based system for thermochemical cycles was therefore proposed in which the heat required for the reduction of redox particles is provided by inert heat transfer particles that absorb concentrated solar radiation in a dedicated particle receiver. The novel and central component in this indirect system is the particle mix reactor. It functions by mixing the two particle types for heat transfer and establishing a controlled atmosphere under decreased oxygen partial pressures in a common reactor chamber. The design of an experimental setup for demonstration and investigation of the particle mix reactor is presented in this work. Potential operation modes and design options for particle heater, mixing unit and oxygen partial pressure decrease are discussed and illustrated. The selection of a mixer type is based on the homogeneity of the obtained mixture. It is supported by the use of Discrete Element Method (DEM) simulations, which were compared to experimental results from a separate setup. Heat loss estimations for the mixing process in the selected mixer geometry are performed for alumina heat transfer particles and strontium iron oxide redox particles. The components’ geometries, the overall experimental setup design as well as operation steps are presented.
{"title":"Demonstration Reactor System for the Indirect Solar-Thermochemical Reduction of Redox Particles: The Particle Mix Reactor","authors":"S. Richter, S. Brendelberger, Felix Gersdorf, T. Oschmann, C. Sattler","doi":"10.1115/es2019-3902","DOIUrl":"https://doi.org/10.1115/es2019-3902","url":null,"abstract":"\u0000 In contrast to thermal receivers that provide heat for steam cycles, in solar thermochemistry often receiver-reactors are used, where materials undergo a reaction while being irradiated by concentrated sunlight. When applied to two-step redox cycles, multiple processes take place in such receiver-reactors, though on different time scales. This leads to design compromises and to high technical requirements for the implementation. A concept for an indirect particle-based system for thermochemical cycles was therefore proposed in which the heat required for the reduction of redox particles is provided by inert heat transfer particles that absorb concentrated solar radiation in a dedicated particle receiver. The novel and central component in this indirect system is the particle mix reactor. It functions by mixing the two particle types for heat transfer and establishing a controlled atmosphere under decreased oxygen partial pressures in a common reactor chamber.\u0000 The design of an experimental setup for demonstration and investigation of the particle mix reactor is presented in this work. Potential operation modes and design options for particle heater, mixing unit and oxygen partial pressure decrease are discussed and illustrated. The selection of a mixer type is based on the homogeneity of the obtained mixture. It is supported by the use of Discrete Element Method (DEM) simulations, which were compared to experimental results from a separate setup. Heat loss estimations for the mixing process in the selected mixer geometry are performed for alumina heat transfer particles and strontium iron oxide redox particles.\u0000 The components’ geometries, the overall experimental setup design as well as operation steps are presented.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122786590","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 cooling, heating and power generation (CCHP) systems can be utilized for commercial or multi-family residential buildings as efficient and reliable means to satisfy building power requirements and thermal loads. In the present paper, a CCHP system consist of a Bryton cycle, an Organic Rankine cycle (ORC) and an absorption Ammonia-water cycle is considered. A detailed model is developed via MATLAB to assess the performance of the considered cycle from energy, exergy and economic perspectives. Appropriate ranges for inputs are considered and the first law efficiency, second law efficiency and ECOP of the cycle are determined as 77.17%, 33.18% and 0.31 respectively for the given inputs. Exergy destruction rates are found to be greatest primarily in the generator and the absorber of refrigeration cycle followed by the combustion chamber. The total exergy destruction rate in the system is found as 5311.51 kW. The exergoeconomic analysis is performed using SPECO approach to evaluate cost flow rate equations of the complete system and its individual components. Summation of capital investment cost rates and cost rates associated with the exergy destruction for the whole system is found as $18.245 per hour. A parametric study is also performed to provide an understanding on the effect of total pressure ratio and turbine inlet temperature of ORC on the performance of the system.
{"title":"An Energetic and Exergoeconomic Analysis of a CCHP System With Micro Gas Turbine, Organic Rankine Cycle and Ammonia-Water Absorption Refrigeration Cycle","authors":"Ganesh Doiphode, H. Najafi","doi":"10.1115/es2019-3928","DOIUrl":"https://doi.org/10.1115/es2019-3928","url":null,"abstract":"\u0000 Combined cooling, heating and power generation (CCHP) systems can be utilized for commercial or multi-family residential buildings as efficient and reliable means to satisfy building power requirements and thermal loads. In the present paper, a CCHP system consist of a Bryton cycle, an Organic Rankine cycle (ORC) and an absorption Ammonia-water cycle is considered. A detailed model is developed via MATLAB to assess the performance of the considered cycle from energy, exergy and economic perspectives. Appropriate ranges for inputs are considered and the first law efficiency, second law efficiency and ECOP of the cycle are determined as 77.17%, 33.18% and 0.31 respectively for the given inputs. Exergy destruction rates are found to be greatest primarily in the generator and the absorber of refrigeration cycle followed by the combustion chamber. The total exergy destruction rate in the system is found as 5311.51 kW. The exergoeconomic analysis is performed using SPECO approach to evaluate cost flow rate equations of the complete system and its individual components. Summation of capital investment cost rates and cost rates associated with the exergy destruction for the whole system is found as $18.245 per hour. A parametric study is also performed to provide an understanding on the effect of total pressure ratio and turbine inlet temperature of ORC on the performance of the system.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124702480","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}
N. Royer, Ryan T. Hamilton, J. Collins, John W. Drazin, D. McLarty
A commercially available Anode Supported Cell (ASC) with an active area of 81 cm2 was characterized at pressures up to 9 bar at 750 °C using a custom-built pressurized test stand. Open Circuit Voltage (OCV) measurements of the cell indicated the existence of an intercell leak due to a cracked cell. Voltage characteristic curves were measured at 1, 3, and 9 bar using 50/50 N2/H2 (1.2 SLPM) and bottled air (1.5 SLPM). Measured current density at 0.70 V increased from 0.37 A·cm−2 to 0.43 A·cm−2 as a result of pressurization from atmospheric to 9 bar. Subsequent measurements were taken while flowing 100% dry hydrogen at 1.5 SLPM and 100% oxygen at 1.5 SLPM. Under these conditions at 9 bar the current density increased to 0.5 A·cm−2. The OCV and peak power density increased more than suggested by theory, suggesting that the balanced anode and cathode flow rates reduced the pressure differential across the cell resulting in less leakage. These preliminary measurements validate the significant potential for improved operational performance under pressurized conditions.
{"title":"Performance of Pressurized Anode Supported Solid Oxide Fuel Cell","authors":"N. Royer, Ryan T. Hamilton, J. Collins, John W. Drazin, D. McLarty","doi":"10.1115/es2019-3912","DOIUrl":"https://doi.org/10.1115/es2019-3912","url":null,"abstract":"\u0000 A commercially available Anode Supported Cell (ASC) with an active area of 81 cm2 was characterized at pressures up to 9 bar at 750 °C using a custom-built pressurized test stand. Open Circuit Voltage (OCV) measurements of the cell indicated the existence of an intercell leak due to a cracked cell. Voltage characteristic curves were measured at 1, 3, and 9 bar using 50/50 N2/H2 (1.2 SLPM) and bottled air (1.5 SLPM). Measured current density at 0.70 V increased from 0.37 A·cm−2 to 0.43 A·cm−2 as a result of pressurization from atmospheric to 9 bar. Subsequent measurements were taken while flowing 100% dry hydrogen at 1.5 SLPM and 100% oxygen at 1.5 SLPM. Under these conditions at 9 bar the current density increased to 0.5 A·cm−2. The OCV and peak power density increased more than suggested by theory, suggesting that the balanced anode and cathode flow rates reduced the pressure differential across the cell resulting in less leakage. These preliminary measurements validate the significant potential for improved operational performance under pressurized conditions.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126763186","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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