F. Njuguna, Hiram Ndiritu, B. Gathitu, Meshack Hawi, J. Munyalo
{"title":"高温下流化床流体动力学的数值和实验研究","authors":"F. Njuguna, Hiram Ndiritu, B. Gathitu, Meshack Hawi, J. Munyalo","doi":"10.4028/p-a41tm2","DOIUrl":null,"url":null,"abstract":"Fluidized bed gasifiers operate at elevated temperatures, and experimental measurements for the hydrodynamic parameters at high temperatures are difficult and time consuming, making computational fluid dynamics simulation useful for such investigation. In this study, Opensource computational fluid dynamics code, OpenFOAM, was used to investigate temperature effect on the fluidized bed hydrodynamics on a 3D fluidized bed model using Eulerian-Eulerian approach. Silica sand of particle sizes of 500, 335 and 233 m was used as the bed materials under temperatures between 25 and 400 °C. To validate the simulation model, a laboratory scale fluidized bed unit was used to conduct experiments for the same range of temperature and sand particle sizes. The results revealed that the temperature of the bed materials greatly affect fluidized bed hydrodynamics. The minimum fluidization velocity increased with the sand particle diameter but decreased with the temperature. On the other hand, the bed porosity at the minimum fluidization point increased marginally with both the temperature and the particle size of the bed materials. Further analysis showed that the expanded bed height increased with the temperature for a specific superficial velocity while the bubbles grew in size with both the air flow rates and the temperature. The numerical model results were compared with the experimental results based on minimum fluidization velocity, bed porosity and pressure drop at the minimum fluidization point. The hydrodynamic results of the numerical model were in good agreement with the experimental results.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Numerical and Experimental Investigation of Fluidized Bed Hydrodynamics at Elevated Temperatures\",\"authors\":\"F. Njuguna, Hiram Ndiritu, B. Gathitu, Meshack Hawi, J. Munyalo\",\"doi\":\"10.4028/p-a41tm2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Fluidized bed gasifiers operate at elevated temperatures, and experimental measurements for the hydrodynamic parameters at high temperatures are difficult and time consuming, making computational fluid dynamics simulation useful for such investigation. In this study, Opensource computational fluid dynamics code, OpenFOAM, was used to investigate temperature effect on the fluidized bed hydrodynamics on a 3D fluidized bed model using Eulerian-Eulerian approach. Silica sand of particle sizes of 500, 335 and 233 m was used as the bed materials under temperatures between 25 and 400 °C. To validate the simulation model, a laboratory scale fluidized bed unit was used to conduct experiments for the same range of temperature and sand particle sizes. The results revealed that the temperature of the bed materials greatly affect fluidized bed hydrodynamics. The minimum fluidization velocity increased with the sand particle diameter but decreased with the temperature. On the other hand, the bed porosity at the minimum fluidization point increased marginally with both the temperature and the particle size of the bed materials. Further analysis showed that the expanded bed height increased with the temperature for a specific superficial velocity while the bubbles grew in size with both the air flow rates and the temperature. The numerical model results were compared with the experimental results based on minimum fluidization velocity, bed porosity and pressure drop at the minimum fluidization point. The hydrodynamic results of the numerical model were in good agreement with the experimental results.\",\"PeriodicalId\":45925,\"journal\":{\"name\":\"International Journal of Engineering Research in Africa\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2023-06-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Engineering Research in Africa\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4028/p-a41tm2\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ENGINEERING, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Engineering Research in Africa","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4028/p-a41tm2","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}
Numerical and Experimental Investigation of Fluidized Bed Hydrodynamics at Elevated Temperatures
Fluidized bed gasifiers operate at elevated temperatures, and experimental measurements for the hydrodynamic parameters at high temperatures are difficult and time consuming, making computational fluid dynamics simulation useful for such investigation. In this study, Opensource computational fluid dynamics code, OpenFOAM, was used to investigate temperature effect on the fluidized bed hydrodynamics on a 3D fluidized bed model using Eulerian-Eulerian approach. Silica sand of particle sizes of 500, 335 and 233 m was used as the bed materials under temperatures between 25 and 400 °C. To validate the simulation model, a laboratory scale fluidized bed unit was used to conduct experiments for the same range of temperature and sand particle sizes. The results revealed that the temperature of the bed materials greatly affect fluidized bed hydrodynamics. The minimum fluidization velocity increased with the sand particle diameter but decreased with the temperature. On the other hand, the bed porosity at the minimum fluidization point increased marginally with both the temperature and the particle size of the bed materials. Further analysis showed that the expanded bed height increased with the temperature for a specific superficial velocity while the bubbles grew in size with both the air flow rates and the temperature. The numerical model results were compared with the experimental results based on minimum fluidization velocity, bed porosity and pressure drop at the minimum fluidization point. The hydrodynamic results of the numerical model were in good agreement with the experimental results.
期刊介绍:
"International Journal of Engineering Research in Africa" is a peer-reviewed journal which is devoted to the publication of original scientific articles on research and development of engineering systems carried out in Africa and worldwide. We publish stand-alone papers by individual authors. The articles should be related to theoretical research or be based on practical study. Articles which are not from Africa should have the potential of contributing to its progress and development.