Publicação
Numerical analysis of a hydrogen blending and injection in natural gas pipelines
| Resumo: | This work presents an innovative numerical analysis addressing the challenge of blending and injecting hydrogen into natural gas pipelines, developed within the context of the H2NG project (Hydrogen Blending and Injection Station for Natural Gas Networks). Its primary aim is to systematically assess how various injection parameters influence the homogeneity of hydrogen–methane mixtures under realistic operational conditions, specifically considering high-pressure and medium-pressure gas transmission networks.A robust methodological framework was employed, using Computational Fluid Dynamics (CFD) simulations via ANSYS Fluent. The study included pipeline geometries that were representative of the actual infrastructure. The CFD models were validated, and a detailed mesh independence study was conducted to ensure the accuracy of the results. The quality of gas mixing was quantified using established indicators, particularly the Coefficient of Variation (CoV) and Reynolds-based criteria, to pinpoint the optimal conditions that promote uniform blending and minimize undesirable stratification phenomena.Through an extensive parametric study, variables such as hydrogen concentrations (10%, 15%, and 20%), natural gas velocities, injection angles, and injector diameters were rigorously analyzed. Results demonstrated that optimal mixing conditions are consistently achieved using perpendicular injection angles, an injector diameter of approximately 1/7 of the main pipeline, and maintaining a velocity ratio between hydrogen and natural gas flows above 12. Notably, medium-pressure pipelines exhibited superior mixing performance compared to high-pressure systems, particularly at lower hydrogen concentration levels—a finding that challenges conventional assumptions within the sector.Ultimately, this research provides significant insights and practical guidelines to support the safe and effective integration of renewable hydrogen into existing natural gas infrastructure, thereby contributing directly to the broader effort of transitioning to a more sustainable and low-carbon energy future. |
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| Autores principais: | Reis, Beatriz dos Santos |
| Assunto: | Hydrogen blending CoV Natural gas networks CFD Energy transition Mistura de hidrogénio CoV Redes de gás natural CFD Transição energética |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Coimbra |
| Idioma: | inglês |
| Origem: | Estudo Geral - Universidade de Coimbra |
| Resumo: | This work presents an innovative numerical analysis addressing the challenge of blending and injecting hydrogen into natural gas pipelines, developed within the context of the H2NG project (Hydrogen Blending and Injection Station for Natural Gas Networks). Its primary aim is to systematically assess how various injection parameters influence the homogeneity of hydrogen–methane mixtures under realistic operational conditions, specifically considering high-pressure and medium-pressure gas transmission networks.A robust methodological framework was employed, using Computational Fluid Dynamics (CFD) simulations via ANSYS Fluent. The study included pipeline geometries that were representative of the actual infrastructure. The CFD models were validated, and a detailed mesh independence study was conducted to ensure the accuracy of the results. The quality of gas mixing was quantified using established indicators, particularly the Coefficient of Variation (CoV) and Reynolds-based criteria, to pinpoint the optimal conditions that promote uniform blending and minimize undesirable stratification phenomena.Through an extensive parametric study, variables such as hydrogen concentrations (10%, 15%, and 20%), natural gas velocities, injection angles, and injector diameters were rigorously analyzed. Results demonstrated that optimal mixing conditions are consistently achieved using perpendicular injection angles, an injector diameter of approximately 1/7 of the main pipeline, and maintaining a velocity ratio between hydrogen and natural gas flows above 12. Notably, medium-pressure pipelines exhibited superior mixing performance compared to high-pressure systems, particularly at lower hydrogen concentration levels—a finding that challenges conventional assumptions within the sector.Ultimately, this research provides significant insights and practical guidelines to support the safe and effective integration of renewable hydrogen into existing natural gas infrastructure, thereby contributing directly to the broader effort of transitioning to a more sustainable and low-carbon energy future. |
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