Pub Date : 2020-12-31DOI: 10.15231/JKSC.2020.25.4.047
Hae-ji Ju, J. Cho, Jeongjae Hwang, Min Kuk Kim, H. Kim, W. Lee
This study investigated the effect of the outer recirculation zone(ORZ) on the combustion characteristics and NOX emissions. Numerical simulation and experimental test were conducted for the combustors with two types of the burner outlet. The ORZ is formed conspicuously for a flat type with sudden expansion outlet while it is formed in a negligible size for a curved type with gradual expansion outlet. In a higher adiabatic flame temperature(AFT) condition of 2020 K, the NOX emission of the flat type is increased by 19% compared with the curved type as the ORZ has long residence time and high temperature enough to produce the thermal NOX. On the other hand, the NOX emission of the flat type is decreased slightly in a lower AFT of 1850 K as the temperature of the ORZ is not high enough to significantly produce the thermal NOX. The tendency of the calculated NOX emission is consistent with the experiment results.
{"title":"Investigation on the Effect of the Burner Outlet Configuration on the Combustion Characteristics of a Swirl-premixed Burner","authors":"Hae-ji Ju, J. Cho, Jeongjae Hwang, Min Kuk Kim, H. Kim, W. Lee","doi":"10.15231/JKSC.2020.25.4.047","DOIUrl":"https://doi.org/10.15231/JKSC.2020.25.4.047","url":null,"abstract":"This study investigated the effect of the outer recirculation zone(ORZ) on the combustion characteristics and NOX emissions. Numerical simulation and experimental test were conducted for the combustors with two types of the burner outlet. The ORZ is formed conspicuously for a flat type with sudden expansion outlet while it is formed in a negligible size for a curved type with gradual expansion outlet. In a higher adiabatic flame temperature(AFT) condition of 2020 K, the NOX emission of the flat type is increased by 19% compared with the curved type as the ORZ has long residence time and high temperature enough to produce the thermal NOX. On the other hand, the NOX emission of the flat type is decreased slightly in a lower AFT of 1850 K as the temperature of the ORZ is not high enough to significantly produce the thermal NOX. The tendency of the calculated NOX emission is consistent with the experiment results.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49624544","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}
Pub Date : 2020-12-31DOI: 10.15231/JKSC.2020.25.4.008
Yeonse Kang, J. Ahn, Keunseon Sim, Keeman Lee
Experimental and numerical studies were conducted to clarify the extinction mechanism in mutually interacting SNG (synthetic natural gas) air premixed asymmetric counter-flow flames. The detailed kinetic mechanism of UC San Diego with which the priority of predicting measured extinction boundaries was validated was adopted to analyze various aspects via up and downstream interactions on extinction boundaries in the flame stability map. The flame stability map was presented with a functional dependency on methane mole fractions in the cold stream ejecting from upper and lower nozzles by varying the global strain rate. Increasing global strain rate lead gradually slanted and configuring of island flammable region and finally only one flammable condition at 740 s -1 through the shrinkage of flammable region. The interacting lean-lean asymmetric flames of extinction boundaries have flame speed of positive (negative) depending on the deviation of methane mole fraction for two reactants. The extinction mechanism of those flames was explained and discussed by emphasizing important role of downstream chemical interaction (via H and CO) and upstream thermal interaction (via conductive heat loss from stronger flame to unburned mixture).
{"title":"The Extinction Characteristics of Interacting SNG-Air Lean Premixed Asymmetric Flames","authors":"Yeonse Kang, J. Ahn, Keunseon Sim, Keeman Lee","doi":"10.15231/JKSC.2020.25.4.008","DOIUrl":"https://doi.org/10.15231/JKSC.2020.25.4.008","url":null,"abstract":"Experimental and numerical studies were conducted to clarify the extinction mechanism in mutually interacting SNG (synthetic natural gas) air premixed asymmetric counter-flow flames. The detailed kinetic mechanism of UC San Diego with which the priority of predicting measured extinction boundaries was validated was adopted to analyze various aspects via up and downstream interactions on extinction boundaries in the flame stability map. The flame stability map was presented with a functional dependency on methane mole fractions in the cold stream ejecting from upper and lower nozzles by varying the global strain rate. Increasing global strain rate lead gradually slanted and configuring of island flammable region and finally only one flammable condition at 740 s -1 through the shrinkage of flammable region. The interacting lean-lean asymmetric flames of extinction boundaries have flame speed of positive (negative) depending on the deviation of methane mole fraction for two reactants. The extinction mechanism of those flames was explained and discussed by emphasizing important role of downstream chemical interaction (via H and CO) and upstream thermal interaction (via conductive heat loss from stronger flame to unburned mixture).","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46985600","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}
Pub Date : 2019-12-31DOI: 10.15231/JKSC.2019.24.4.018
Hyunwook Jegal, Kyu Tae Kim
{"title":"주파수 이조에 의한 다중 연소기 상호작용: 결합확률분포 분석","authors":"Hyunwook Jegal, Kyu Tae Kim","doi":"10.15231/JKSC.2019.24.4.018","DOIUrl":"https://doi.org/10.15231/JKSC.2019.24.4.018","url":null,"abstract":"","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":"24 1","pages":"18-24"},"PeriodicalIF":0.4,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67351151","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.009
Cheon Hyeon Cho, Karam Han, C. Sohn, Jeong-sik Han
Flow reactors are classified into laminar flow, turbulent flow and jet-stirred reactors depending on flow condition. Laminar flow reactor is a device that measures oxidation process of gaseous fuel and vaporized liquid fuels. Propene oxidation process was observed in a laminar flow reactor with a specified residence time at 6 atm, 968 K, and equivalence ratio of 0.71 and compared with numerical simulations. The Aramco 2.0 chemistry was adopted as a kinetic mechanism which includes 493 species and about 2,700 reaction steps. Oxygen, carbon monoxide, and carbon dioxide concentrations were measured. Numerical results with a time shift of 0.216 s show a good agreement with experimental results. And, a reduced kinetic mechanism was generated and validated based on the Aramco 2.0. The reaction steps are reduced by 23%.
{"title":"An Experimental Study of Propene Reaction of a Laminar Flow Reactor and Validation of its Reduced Mechanism","authors":"Cheon Hyeon Cho, Karam Han, C. Sohn, Jeong-sik Han","doi":"10.15231/jksc.2019.24.3.009","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.009","url":null,"abstract":"Flow reactors are classified into laminar flow, turbulent flow and jet-stirred reactors depending on flow condition. Laminar flow reactor is a device that measures oxidation process of gaseous fuel and vaporized liquid fuels. Propene oxidation process was observed in a laminar flow reactor with a specified residence time at 6 atm, 968 K, and equivalence ratio of 0.71 and compared with numerical simulations. The Aramco 2.0 chemistry was adopted as a kinetic mechanism which includes 493 species and about 2,700 reaction steps. Oxygen, carbon monoxide, and carbon dioxide concentrations were measured. Numerical results with a time shift of 0.216 s show a good agreement with experimental results. And, a reduced kinetic mechanism was generated and validated based on the Aramco 2.0. The reaction steps are reduced by 23%.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42914224","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.041
Junho Song, Seohee Cho, Keeman Lee
An experimental study was conducted to determine laminar burning velocity and Markstein length of SNG fuel from spherical propagating flames at normal and elevated pressure conditions. In order to make accurate results, combustion chamber was verified using methane/air mixture to find suitable extraction method and flame radius range in SNG fuel. In addition, ARAMCO 2.0 mechanism was selected to compare experimental results with numerical values. As results of this study, there were found that the laminar burning velocities and Markstein lengths of SNG fuel decreased as initial pressure rose. Pressure exponent tended to increase and decrease as the equivalence ratio increased.
{"title":"Laminar Burning Velocity Measurement of Spherical Propagating SNG-air Premixed Flames through Verification of Combustor","authors":"Junho Song, Seohee Cho, Keeman Lee","doi":"10.15231/jksc.2019.24.3.041","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.041","url":null,"abstract":"An experimental study was conducted to determine laminar burning velocity and Markstein length of SNG fuel from spherical propagating flames at normal and elevated pressure conditions. In order to make accurate results, combustion chamber was verified using methane/air mixture to find suitable extraction method and flame radius range in SNG fuel. In addition, ARAMCO 2.0 mechanism was selected to compare experimental results with numerical values. As results of this study, there were found that the laminar burning velocities and Markstein lengths of SNG fuel decreased as initial pressure rose. Pressure exponent tended to increase and decrease as the equivalence ratio increased.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44878194","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.017
C. Cha, S. Hwang
In response to the tight regulation of CO2 emissions, studies on gas turbines for aviation based on hydrogen fuel have recently become more important. Especially the Micro-mix combustion method is one of the promising combustion technologies that inherent safety against flash-back and low NOx emission due to a very short residence time of reactants in the flame region. In order to analyze the stability and low NOx emission characteristics of a gas turbine combustion system using hydrogen fuel and micro-mix technology, a series of numerical approach were performed in this study. The results show that, as the supplied fuel flow rate and the diameter of the fuel supply nozzle were increased, a stable hydrogen micro-mix combustion flame was formed.
{"title":"Numerical Study on Combustion Characteristics of Hydrogen Gas Turbine Combustor using Cross flow Micro-mix System","authors":"C. Cha, S. Hwang","doi":"10.15231/jksc.2019.24.3.017","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.017","url":null,"abstract":"In response to the tight regulation of CO2 emissions, studies on gas turbines for aviation based on hydrogen fuel have recently become more important. Especially the Micro-mix combustion method is one of the promising combustion technologies that inherent safety against flash-back and low NOx emission due to a very short residence time of reactants in the flame region. In order to analyze the stability and low NOx emission characteristics of a gas turbine combustion system using hydrogen fuel and micro-mix technology, a series of numerical approach were performed in this study. The results show that, as the supplied fuel flow rate and the diameter of the fuel supply nozzle were increased, a stable hydrogen micro-mix combustion flame was formed.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46015782","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.033
Jung-keuk Park, Sangho S. Kim, Jinje Park, Seunghan Yu, C. Ryu
Biochar from pyrolysis is emerging as a new option for biomass utilization for various purposes including soil amelioration and carbon sequestration. This study investigated the slow pyrolysis characteristics of wood pellet in a continuous reactor varying the heat transfer type (direct and indirect contact) at various temperatures (400~700°C) with different carrier gas compositions (inert, O2 2%, and O2 4%). Direct contact heat transfer by preheated carrier gas accelerated the heat up of biomass, promoting the pyrolysis process as well as the temperature increase of indirect contact cases. The presence of O2 in the carrier gas resulted in limited oxidation reactions with pyrolytic vapor, increasing the reactor temperature to 529.4°C and 591.7°C at 2% and 4% O2, respectively, compared to the inert case having a final temperature of 492.4°C. This can be exploited to save the external heat supply but a careful temperature control is required to yield uniform biochar properties. The pyrolysis products from different test conditions were characterized for mass yield and detailed properties of biochar, bio-oil, and non-condensable gases.
{"title":"Experimental Study on Slow Pyrolysis of Biomass by Direct and Indirect Contact Heat Transfer in a Continuous Reactor","authors":"Jung-keuk Park, Sangho S. Kim, Jinje Park, Seunghan Yu, C. Ryu","doi":"10.15231/jksc.2019.24.3.033","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.033","url":null,"abstract":"Biochar from pyrolysis is emerging as a new option for biomass utilization for various purposes including soil amelioration and carbon sequestration. This study investigated the slow pyrolysis characteristics of wood pellet in a continuous reactor varying the heat transfer type (direct and indirect contact) at various temperatures (400~700°C) with different carrier gas compositions (inert, O2 2%, and O2 4%). Direct contact heat transfer by preheated carrier gas accelerated the heat up of biomass, promoting the pyrolysis process as well as the temperature increase of indirect contact cases. The presence of O2 in the carrier gas resulted in limited oxidation reactions with pyrolytic vapor, increasing the reactor temperature to 529.4°C and 591.7°C at 2% and 4% O2, respectively, compared to the inert case having a final temperature of 492.4°C. This can be exploited to save the external heat supply but a careful temperature control is required to yield uniform biochar properties. The pyrolysis products from different test conditions were characterized for mass yield and detailed properties of biochar, bio-oil, and non-condensable gases.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46207187","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.026
Sungwook Park
The purpose of the present study is to better understand the pressure effect on NO formation in H2/CO/air premixed flames. A recently developed detailed chemical kinetic model by merging AramcoMech 3.0 and a comprehensive nitrogen chemistry is first compared against experimental data of H2/CO mixtures including NO formation in premixed flames. Freely propagating H2/CO/air premixed flames are then simulated over a pressure range 1-20 atm and temperatures of 1886 and 1986K. NO formation via N2O becomes important between reaction zone and postflame region with increasing pressure, but NO concentrations in the reaction zone is not sensitive to increasing pressure. Thermal NO production pathways lead to the total NO formation in the postflame zone and the total NO formation rate increases with increasing pressure.
{"title":"Pressure Effect on NO Formation in H₂/CO Premixed Flames","authors":"Sungwook Park","doi":"10.15231/jksc.2019.24.3.026","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.026","url":null,"abstract":"The purpose of the present study is to better understand the pressure effect on NO formation in H2/CO/air premixed flames. A recently developed detailed chemical kinetic model by merging AramcoMech 3.0 and a comprehensive nitrogen chemistry is first compared against experimental data of H2/CO mixtures including NO formation in premixed flames. Freely propagating H2/CO/air premixed flames are then simulated over a pressure range 1-20 atm and temperatures of 1886 and 1986K. NO formation via N2O becomes important between reaction zone and postflame region with increasing pressure, but NO concentrations in the reaction zone is not sensitive to increasing pressure. Thermal NO production pathways lead to the total NO formation in the postflame zone and the total NO formation rate increases with increasing pressure.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47277881","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}
Pub Date : 2019-09-30DOI: 10.15231/jksc.2019.24.3.001
Jun Woo Jung, Y. Lim, H. Suh
This study investigated the effect of target species changing on the mechanism reduction in DRGEP(Directed Relation Graph Error Propagation) method. To achieve this goal, the automatic mechanism reduction scheme of reaction workbench which includes DRGEP method was introduced and the 0-D combustion analysis of CHEMKIN-PRO was executed to confirm the error rate of ignition delay between the detailed mechanism and reduced mechanisms. To consider various target species, the skeletal mechanism for biodiesel and n-heptane mechanism were merged and the various environments were considered to decide the environment of the mechanism reduction by changing the relative and absolute tolerance associated with the mechanism reduction. As a result, it was confirmed that the target species has a great influence on the reduction of the mechanism, and it was appropriate to consider chemical species, as the target species, associated with exhaust emissions.
{"title":"The Effect of Target Species Changing on the Mechanism Reduction in DRGEP Method","authors":"Jun Woo Jung, Y. Lim, H. Suh","doi":"10.15231/jksc.2019.24.3.001","DOIUrl":"https://doi.org/10.15231/jksc.2019.24.3.001","url":null,"abstract":"This study investigated the effect of target species changing on the mechanism reduction in DRGEP(Directed Relation Graph Error Propagation) method. To achieve this goal, the automatic mechanism reduction scheme of reaction workbench which includes DRGEP method was introduced and the 0-D combustion analysis of CHEMKIN-PRO was executed to confirm the error rate of ignition delay between the detailed mechanism and reduced mechanisms. To consider various target species, the skeletal mechanism for biodiesel and n-heptane mechanism were merged and the various environments were considered to decide the environment of the mechanism reduction by changing the relative and absolute tolerance associated with the mechanism reduction. As a result, it was confirmed that the target species has a great influence on the reduction of the mechanism, and it was appropriate to consider chemical species, as the target species, associated with exhaust emissions.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45740761","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}
Pub Date : 2019-06-30DOI: 10.15231/JKSC.2019.24.2.034
Jihoon Jang, Karam Han, G. Yu, Wook Ryun Lee, HyeonSoo Lim, H. Park
Devolatilization behavior of pulverized coal in a drop tube furnace (DTF) has been calculated with the measured gas temperature and velocity. The particle temperature and velocity were calculated from the energy and momentum equations of particle by using the fourth order Runge-Kutta method. The volatile evolved from the particle along with the reactor tube was also calculated varying the wall temperature of reaction tube as well as the particle diameter. The optimal kinetic parameters of subbituminous coal were obtained from the volatile evolution data of the devolatilization experiment in the DTF by error minimization.
{"title":"Numerical and Experimental Studies on Devolatilizaton Behavior of Pulverized Coal in a Drop Tube Furnace","authors":"Jihoon Jang, Karam Han, G. Yu, Wook Ryun Lee, HyeonSoo Lim, H. Park","doi":"10.15231/JKSC.2019.24.2.034","DOIUrl":"https://doi.org/10.15231/JKSC.2019.24.2.034","url":null,"abstract":"Devolatilization behavior of pulverized coal in a drop tube furnace (DTF) has been calculated with the measured gas temperature and velocity. The particle temperature and velocity were calculated from the energy and momentum equations of particle by using the fourth order Runge-Kutta method. The volatile evolved from the particle along with the reactor tube was also calculated varying the wall temperature of reaction tube as well as the particle diameter. The optimal kinetic parameters of subbituminous coal were obtained from the volatile evolution data of the devolatilization experiment in the DTF by error minimization.","PeriodicalId":42247,"journal":{"name":"Journal of the Korean Society of Combustion","volume":"1 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41725571","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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