Jinghong Peng, Jun Zhou, G. Liang, Cao Peng, Chengqiang Hu, Dingfei Guo
Salt cavern underground gas storage (UGS) has attracted more and more attention worldwide for high peak shaving efficiency and high short-term throughput. To ensure the safe operation of this type of UGS, it is necessary to evaluate and analyze its stability. This paper investigates the influences of interlayers and cavern interactions on salt cavern UGS' stability. A 3D geomechanical model of double salt caverns UGS with interlayers is established based on the geological data and creep constitutive relation of salt rock. Based on the long-term creep numerical simulation, the influences of interlayer number, interlayer thickness, interlayer dip angle, interlayer stiffness, cavern spacing, and cavern pressure difference on the deformation of caverns and stability performance of UGS are studied. The results show that the UGS with greater interlayer numbers have larger cavern deformation. The increase in interlayer thickness will improve the deformation resistance of caverns, but the effect is not obvious. The UGS with an interlayer dip angle of 12.5° has the best stability. Soft interlayer will decrease the deformation resistance of caverns, while hard interlayer has the opposite effect. In addition, the UGS stability can be enhanced by reducing the pressure difference between adjacent caverns. It is reasonable that the cavern spacing is twice the cavern diameter, which is beneficial to the UGS stability and will not cause a waste of salt rock resources. Finally, the corresponding production and construction control measures are discussed according to each factor's influence degree.
{"title":"Investigation on the long term stability of multiple salt caverns underground gas storage with interlayers","authors":"Jinghong Peng, Jun Zhou, G. Liang, Cao Peng, Chengqiang Hu, Dingfei Guo","doi":"10.1115/1.4056938","DOIUrl":"https://doi.org/10.1115/1.4056938","url":null,"abstract":"\u0000 Salt cavern underground gas storage (UGS) has attracted more and more attention worldwide for high peak shaving efficiency and high short-term throughput. To ensure the safe operation of this type of UGS, it is necessary to evaluate and analyze its stability. This paper investigates the influences of interlayers and cavern interactions on salt cavern UGS' stability. A 3D geomechanical model of double salt caverns UGS with interlayers is established based on the geological data and creep constitutive relation of salt rock. Based on the long-term creep numerical simulation, the influences of interlayer number, interlayer thickness, interlayer dip angle, interlayer stiffness, cavern spacing, and cavern pressure difference on the deformation of caverns and stability performance of UGS are studied. The results show that the UGS with greater interlayer numbers have larger cavern deformation. The increase in interlayer thickness will improve the deformation resistance of caverns, but the effect is not obvious. The UGS with an interlayer dip angle of 12.5° has the best stability. Soft interlayer will decrease the deformation resistance of caverns, while hard interlayer has the opposite effect. In addition, the UGS stability can be enhanced by reducing the pressure difference between adjacent caverns. It is reasonable that the cavern spacing is twice the cavern diameter, which is beneficial to the UGS stability and will not cause a waste of salt rock resources. Finally, the corresponding production and construction control measures are discussed according to each factor's influence degree.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42992251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shi Huang, Yu-long Zhao, Mingdi Zhang, Houjie Zhou, Langtao Zhu, Zhang Tao
Carbonate reservoirs contribute the highest proportion of natural gas production around the world, and commingled production is frequently used to increase production for the multilayer reservoirs. However, the complex pore structure including pore, fracture and cavity, and the presence of edge/bottom water increase the difficulties in evaluation its commingled production performances. In this work, three comingled patterns of digital rocks are reconstructed based on the CT scanning images, and the lattice Boltzmann method is used to investigate the commingled production with water invasion. The results show that the fracture and cavity commingled production pattern has the largest interlayer heterogeneity, and the production ratio between the two layers can reach 6.7. Commingled production for the system with different interlayer pressure may lead to backflow phenomenon. Especially, if the interlayer heterogeneity is large and the initial pressure of the low-permeability layer is lower, the backflow volume would be very large. The water invasion during commingled production can influence the flow capacity of the other gas layers even there is no pressure interference. In addition, if the water-invaded layer has larger pressure, the produced water will continuously flows backs to the gas layer until the pressure of the two layers becomes balanced. The coupled effects of pressure interference and water invasion significantly damage the commingled-production performance. This work revealed the gas-water two-phase flow behaviors during commingled production, which provide fundamental support for the scientific development of multilayer carbonated reservoir.
{"title":"Water invasion into multi-layer and multi-pressure carbonate reservoir: A pore-scale simulation","authors":"Shi Huang, Yu-long Zhao, Mingdi Zhang, Houjie Zhou, Langtao Zhu, Zhang Tao","doi":"10.1115/1.4056891","DOIUrl":"https://doi.org/10.1115/1.4056891","url":null,"abstract":"\u0000 Carbonate reservoirs contribute the highest proportion of natural gas production around the world, and commingled production is frequently used to increase production for the multilayer reservoirs. However, the complex pore structure including pore, fracture and cavity, and the presence of edge/bottom water increase the difficulties in evaluation its commingled production performances. In this work, three comingled patterns of digital rocks are reconstructed based on the CT scanning images, and the lattice Boltzmann method is used to investigate the commingled production with water invasion. The results show that the fracture and cavity commingled production pattern has the largest interlayer heterogeneity, and the production ratio between the two layers can reach 6.7. Commingled production for the system with different interlayer pressure may lead to backflow phenomenon. Especially, if the interlayer heterogeneity is large and the initial pressure of the low-permeability layer is lower, the backflow volume would be very large. The water invasion during commingled production can influence the flow capacity of the other gas layers even there is no pressure interference. In addition, if the water-invaded layer has larger pressure, the produced water will continuously flows backs to the gas layer until the pressure of the two layers becomes balanced. The coupled effects of pressure interference and water invasion significantly damage the commingled-production performance. This work revealed the gas-water two-phase flow behaviors during commingled production, which provide fundamental support for the scientific development of multilayer carbonated reservoir.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45335671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to reveal the influence of thermal and dynamic loads coupling on vibration characteristic of steam turbine rotor, the high pressure cylinder anisotropic rotor of a 1000MW ultra-supercritical steam turbine was modeled by the lumped parameter method. The steam flow excited force of the front 8 stages obtained through the numerical simulation before and after the coupling was converted to the equivalent gas bearing and added on the rotor, and the influence of steam flow excited force on rotor vibration characteristics was obtained by the Riccati transfer matrix method. The results show that, considering the thermal and dynamic loads, the two ends of the ellipse trajectory are smaller and the middle is larger. Before and after coupling thermal and dynamic loads, the azimuth of ellipse trajectory increases with the increase of load and nodes. The greater the load, the greater the changing range of azimuth. As the load increases, the first-order natural speed of rotor increases and the second-order natural speed decreases, but the natural speed after the coupling is noticeably lower than that before the coupling. The change scope of the first-order amplitude shrinks with the load increasing. The first-order logarithmic decrement rate can be increased under the relatively higher load by coupling thermal and dynamic loads, but the stability margin of rotor is insufficient, which causes the instability.
{"title":"Anisotropic Vibration Characteristics Analysis of Steam Turbine Rotor Influenced by Steam Flow Excited Force Coupling Thermal and Dynamic Loads","authors":"Chuan Xue, Li-hua Cao, Heyong Si","doi":"10.1115/1.4056887","DOIUrl":"https://doi.org/10.1115/1.4056887","url":null,"abstract":"\u0000 In order to reveal the influence of thermal and dynamic loads coupling on vibration characteristic of steam turbine rotor, the high pressure cylinder anisotropic rotor of a 1000MW ultra-supercritical steam turbine was modeled by the lumped parameter method. The steam flow excited force of the front 8 stages obtained through the numerical simulation before and after the coupling was converted to the equivalent gas bearing and added on the rotor, and the influence of steam flow excited force on rotor vibration characteristics was obtained by the Riccati transfer matrix method. The results show that, considering the thermal and dynamic loads, the two ends of the ellipse trajectory are smaller and the middle is larger. Before and after coupling thermal and dynamic loads, the azimuth of ellipse trajectory increases with the increase of load and nodes. The greater the load, the greater the changing range of azimuth. As the load increases, the first-order natural speed of rotor increases and the second-order natural speed decreases, but the natural speed after the coupling is noticeably lower than that before the coupling. The change scope of the first-order amplitude shrinks with the load increasing. The first-order logarithmic decrement rate can be increased under the relatively higher load by coupling thermal and dynamic loads, but the stability margin of rotor is insufficient, which causes the instability.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42147998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Ge, H. Zhang, Zhou Zhe, Yudong Hou, Maolin Ye, Chengtian Li
A reasonable coal seam permeability model should be established to accurately estimate the extraction effectiveness of coalbed methane (CBM). Existing permeability models typically ignore the influence of pore structure parameters on the permeability, leading to an overestimation of the measured permeability, and consequently, the CBM production cannot be effectively predicted. This paper presents a novel permeability model based on discrete pore structures at the micro–nano scale. The model considers the interaction between the pore fractal geometry parameters, coal deformation and CBM transport inside these pores. The contributions of key pore geometry parameters, including the maximum pore diameter max, minimum pore diameter min, porosity f0, and fractal dimensions Df and DTm, to the initial permeability were investigated. A numerical analysis showed that the influence of fractal dimension on the permeability can be demonstrated by three structural parameters max, min, and f0. The initial permeability increases exponentially as min in proportion to max and f0. In addition, min, f0, and max are positively correlated with the macroscopic permeability of the coal, with min having the most significant influence on the permeability evolution process. This research provides a theoretical foundation for revealing the gas flow mechanism within coal seams and enhancing the extraction effectiveness of CBM.
{"title":"Pore permeability model based on fractal geometry theory and effective stress","authors":"Z. Ge, H. Zhang, Zhou Zhe, Yudong Hou, Maolin Ye, Chengtian Li","doi":"10.1115/1.4056890","DOIUrl":"https://doi.org/10.1115/1.4056890","url":null,"abstract":"\u0000 A reasonable coal seam permeability model should be established to accurately estimate the extraction effectiveness of coalbed methane (CBM). Existing permeability models typically ignore the influence of pore structure parameters on the permeability, leading to an overestimation of the measured permeability, and consequently, the CBM production cannot be effectively predicted. This paper presents a novel permeability model based on discrete pore structures at the micro–nano scale. The model considers the interaction between the pore fractal geometry parameters, coal deformation and CBM transport inside these pores. The contributions of key pore geometry parameters, including the maximum pore diameter max, minimum pore diameter min, porosity f0, and fractal dimensions Df and DTm, to the initial permeability were investigated. A numerical analysis showed that the influence of fractal dimension on the permeability can be demonstrated by three structural parameters max, min, and f0. The initial permeability increases exponentially as min in proportion to max and f0. In addition, min, f0, and max are positively correlated with the macroscopic permeability of the coal, with min having the most significant influence on the permeability evolution process. This research provides a theoretical foundation for revealing the gas flow mechanism within coal seams and enhancing the extraction effectiveness of CBM.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41466412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Aliyu, M. Nemitallah, A. Abdelhafez, S. Said, P. Okonkwo, M. Habib
The combustion characteristics of oxygen-enriched air-methane (i.e., O2/N2/CH4) flames in a premixed mode are investigated using both experimentally and numerically under atmospheric conditions for emissions reduction purposes. The investigation is carried out using a gas turbine model combustor equipped with a multi-hole burner that mimics gas-turbine micromixer burners. The resulting flame is of jet type, and the velocity of the jet is kept at 5.2 m/s for all the considered flames. Models used in the numerical study include large eddy simulation, discrete ordinate, and partially premixed combustion for turbulence, radiation, and species models respectively. The numerical results are validated and a suitable agreement is achieved with experimental data. The results indicated that the temperature distribution, shape, and size of O2/N2/CH4 flames are predominantly controlled by adiabatic flame temperature (Tad). However, the oxygen fraction, rather than Tad, is responsible for the reaction progress. The emission of NO, CO, and CO2 increases with an increase in oxygen fraction, and the product formation in O2/N2/CH4 flames is less compared to their oxy-fuel (i.e., O2/CO2/CH4) counterparts, because N2 is mostly inert, compared to CO2. The latter participates significantly in flame reactions, which increases the rate of product formation in O2/CO2/CH4 flames.
{"title":"Effects of adiabatic flame temperature and oxygen concentration in CH4/N2/O2 non-swirl jet flames: Experimental and numerical study","authors":"M. Aliyu, M. Nemitallah, A. Abdelhafez, S. Said, P. Okonkwo, M. Habib","doi":"10.1115/1.4056892","DOIUrl":"https://doi.org/10.1115/1.4056892","url":null,"abstract":"\u0000 The combustion characteristics of oxygen-enriched air-methane (i.e., O2/N2/CH4) flames in a premixed mode are investigated using both experimentally and numerically under atmospheric conditions for emissions reduction purposes. The investigation is carried out using a gas turbine model combustor equipped with a multi-hole burner that mimics gas-turbine micromixer burners. The resulting flame is of jet type, and the velocity of the jet is kept at 5.2 m/s for all the considered flames. Models used in the numerical study include large eddy simulation, discrete ordinate, and partially premixed combustion for turbulence, radiation, and species models respectively. The numerical results are validated and a suitable agreement is achieved with experimental data. The results indicated that the temperature distribution, shape, and size of O2/N2/CH4 flames are predominantly controlled by adiabatic flame temperature (Tad). However, the oxygen fraction, rather than Tad, is responsible for the reaction progress. The emission of NO, CO, and CO2 increases with an increase in oxygen fraction, and the product formation in O2/N2/CH4 flames is less compared to their oxy-fuel (i.e., O2/CO2/CH4) counterparts, because N2 is mostly inert, compared to CO2. The latter participates significantly in flame reactions, which increases the rate of product formation in O2/CO2/CH4 flames.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46614969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayoub Boutaghane, A. Arabi, N. Ibrahim-Rassoul, A. Al-sarkhi, A. Azzi
In horizontal configuration, the gas-liquid intermittent flow can be plug or slug flows. Different works have demonstrated that the two-phase flow pattern, despite their similarity, are different. Thus, it is important to differentiate between them in order to develop more robust predictive models. The limit of the existing model to predict the plug-to-slug flows transition were demonstrated firstly. After that, eleven existing slug liquid holdup (HLS) models were used in order to test their potential utilization for predicting the plug-to-slug flows transition. Using HLS = 0.9 as the criterion to distinguish between the two regimes, the relationship between the superficial velocities of the two phases was generated. The obtained transition lines were compared with visual observations collected from several published works in order to test the predictions of each model, and for different operating conditions. It was concluded in this paper that the slug liquid holdup models can be easily used for this purpose. Meanwhile, the prediction level of each model depends on the pipe diameter and the viscosity of the liquid phase.
{"title":"Analysis, comparison and discussion on the utilization of the existing slug liquid holdup models to predict the horizontal gas-liquid plug-to-slug flow transition","authors":"Ayoub Boutaghane, A. Arabi, N. Ibrahim-Rassoul, A. Al-sarkhi, A. Azzi","doi":"10.1115/1.4056889","DOIUrl":"https://doi.org/10.1115/1.4056889","url":null,"abstract":"\u0000 In horizontal configuration, the gas-liquid intermittent flow can be plug or slug flows. Different works have demonstrated that the two-phase flow pattern, despite their similarity, are different. Thus, it is important to differentiate between them in order to develop more robust predictive models. The limit of the existing model to predict the plug-to-slug flows transition were demonstrated firstly. After that, eleven existing slug liquid holdup (HLS) models were used in order to test their potential utilization for predicting the plug-to-slug flows transition. Using HLS = 0.9 as the criterion to distinguish between the two regimes, the relationship between the superficial velocities of the two phases was generated. The obtained transition lines were compared with visual observations collected from several published works in order to test the predictions of each model, and for different operating conditions. It was concluded in this paper that the slug liquid holdup models can be easily used for this purpose. Meanwhile, the prediction level of each model depends on the pipe diameter and the viscosity of the liquid phase.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47123805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Primary cementing is the well construction operation where drilling fluid is displaced from the annular space behind the casing string, and replaced by a cement slurry. The annular cement sheath is a critical barrier element that should provide zonal isolation along the well and prevent uncontrolled flow of formation fluids to the environment. We present a combined experimental and computational study of reverse circulation displacement of the annulus, corresponding to operations where cementing fluids are pumped down the annulus from the surface. We focus on iso-viscous displacements in a vertical and concentric annulus, and vary the density hierarchy among the fluids to study both stable and density-unstable displacement conditions. While the interface between the two fluids is advected according to the laminar annular velocity profile for density-stable and iso-dense displacements, considerable secondary flows and fluid mixing is observed for density-unstable cases. Increasing the imposed velocity from the top is seen to provide a certain stabilizing effect by suppressing backflow of the lighter fluid and reduce the magnitude of azimuthal fluctuations. Computational results are in qualitative agreement with the experiments, and support the categorization of the displacement flows as either inertial or diffusive, in accordance with previous work on buoyant pipe displacements.
{"title":"Reverse circulation displacement of miscible fluids for primary cementing","authors":"M. Ghorbani, Arsalan Royaei, H. J. Skadsem","doi":"10.1115/1.4056843","DOIUrl":"https://doi.org/10.1115/1.4056843","url":null,"abstract":"\u0000 Primary cementing is the well construction operation where drilling fluid is displaced from the annular space behind the casing string, and replaced by a cement slurry. The annular cement sheath is a critical barrier element that should provide zonal isolation along the well and prevent uncontrolled flow of formation fluids to the environment. We present a combined experimental and computational study of reverse circulation displacement of the annulus, corresponding to operations where cementing fluids are pumped down the annulus from the surface. We focus on iso-viscous displacements in a vertical and concentric annulus, and vary the density hierarchy among the fluids to study both stable and density-unstable displacement conditions. While the interface between the two fluids is advected according to the laminar annular velocity profile for density-stable and iso-dense displacements, considerable secondary flows and fluid mixing is observed for density-unstable cases. Increasing the imposed velocity from the top is seen to provide a certain stabilizing effect by suppressing backflow of the lighter fluid and reduce the magnitude of azimuthal fluctuations. Computational results are in qualitative agreement with the experiments, and support the categorization of the displacement flows as either inertial or diffusive, in accordance with previous work on buoyant pipe displacements.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44119173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The vibration generated by diesel engines may influence air and gaseous fuel mixing in dual-fuel mode. This study is performed on the manifolds of single and twin-cylinder engines in diesel-bioCNG dual-fuel mode. It examines the effect of the engine vibration and variable manifold pressure on the flow behaviour of the air-bioCNG mixture. The objective is to observe the flow inside the manifolds and mixture quality at the outlet. The mentioned work has found little attention till date. The computational comparison of the flow characteristics inside the intake manifold of the single-cylinder engine is done for an F-shape manifold of the twin-cylinder engine during suction stroke. The experiments are conducted to record both the engines' vibration signature and cycle data. For this, the same operating parameters are maintained: compression ratio of 16.5, engine speed of 1500 rpm, engine load range (0 Nm to 34 Nm) and 80% bioCNG substitution. It employs the boundary conditions, such as the vibration amplitude along three axes, variable manifold pressure, and the mass flow rates of air and bioCNG. The parameters to analyse the mixture flow are pressure, velocity, turbulence, helicity and mass fraction of CH4. The mixture at the manifold outlet of the single-cylinder engine improved to average uniformity index of 0.9924, indicating better homogeneity. Further, the manifold of twin-cylinder engine attained the indexes of 0.1484 and 0.2401 for its two cylinders, showing non-homogeneity.
{"title":"Effect of vibration and pressure on the air-bioCNG mixture inside the manifolds of dual-fuel diesel engines","authors":"Akash Chandrabhan Chandekar, B. Debnath","doi":"10.1115/1.4056842","DOIUrl":"https://doi.org/10.1115/1.4056842","url":null,"abstract":"\u0000 The vibration generated by diesel engines may influence air and gaseous fuel mixing in dual-fuel mode. This study is performed on the manifolds of single and twin-cylinder engines in diesel-bioCNG dual-fuel mode. It examines the effect of the engine vibration and variable manifold pressure on the flow behaviour of the air-bioCNG mixture. The objective is to observe the flow inside the manifolds and mixture quality at the outlet. The mentioned work has found little attention till date. The computational comparison of the flow characteristics inside the intake manifold of the single-cylinder engine is done for an F-shape manifold of the twin-cylinder engine during suction stroke. The experiments are conducted to record both the engines' vibration signature and cycle data. For this, the same operating parameters are maintained: compression ratio of 16.5, engine speed of 1500 rpm, engine load range (0 Nm to 34 Nm) and 80% bioCNG substitution. It employs the boundary conditions, such as the vibration amplitude along three axes, variable manifold pressure, and the mass flow rates of air and bioCNG. The parameters to analyse the mixture flow are pressure, velocity, turbulence, helicity and mass fraction of CH4. The mixture at the manifold outlet of the single-cylinder engine improved to average uniformity index of 0.9924, indicating better homogeneity. Further, the manifold of twin-cylinder engine attained the indexes of 0.1484 and 0.2401 for its two cylinders, showing non-homogeneity.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63503529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prabhu L, D. K., T. Alahmadi, Sulaiman Ali Alharbi, Gaweł Sołowski, Dhinakaran Veeman
The noise and vibration characteristics play a vital role in the effectiveness of engine operations and performance of internal combustion engines. Accumulation of the higher amplitude of both noise and vibration affects the comfort of the engine. So far most of the research done on the performance, combustion and emission characteristics only. The less importance is shown in the form engine vibration and sounds created by the engine operation. This paper presents and explores the importance and experimental results of noise and vibration by the compression ignition diesel engine with the fuels of diesel and microalgae biodiesel. The produced microalgae biodiesel blends were SMB10%, SMB20% and SMB30%. The experimental results were conducted at different engine loads varying across 25%, 50%, 75% and 100%. The inline, 4 cylinders, water cooled and naturally aspirated DI diesel engine was used as an experimental setup. From the comparative results between the diesel and microalgae biodiesel, it is found that the use of microalgae blended biodiesel reduced the noise and vibration. The higher the percentage of blends, the greater the reduction in sound and vibration will be. Apart from possessing the performance and emission qualities, the microalgae biodiesel blends proved to be the efficient fuel in reduced vibration and noise qualities too. In three directions, the vibrations were measured as lateral, longitudinal and vertical vibrations. The vibration in lateral direction was significantly reduced. Compelling the results, it is understood that use of the microalgae blends can be sustainable in the perspective of the engine wear and tear.
{"title":"How do microalgae biodiesel blends affect the acoustic and vibration characteristics of the direct injection engine: An experimental examination","authors":"Prabhu L, D. K., T. Alahmadi, Sulaiman Ali Alharbi, Gaweł Sołowski, Dhinakaran Veeman","doi":"10.1115/1.4056797","DOIUrl":"https://doi.org/10.1115/1.4056797","url":null,"abstract":"\u0000 The noise and vibration characteristics play a vital role in the effectiveness of engine operations and performance of internal combustion engines. Accumulation of the higher amplitude of both noise and vibration affects the comfort of the engine. So far most of the research done on the performance, combustion and emission characteristics only. The less importance is shown in the form engine vibration and sounds created by the engine operation. This paper presents and explores the importance and experimental results of noise and vibration by the compression ignition diesel engine with the fuels of diesel and microalgae biodiesel. The produced microalgae biodiesel blends were SMB10%, SMB20% and SMB30%. The experimental results were conducted at different engine loads varying across 25%, 50%, 75% and 100%. The inline, 4 cylinders, water cooled and naturally aspirated DI diesel engine was used as an experimental setup. From the comparative results between the diesel and microalgae biodiesel, it is found that the use of microalgae blended biodiesel reduced the noise and vibration. The higher the percentage of blends, the greater the reduction in sound and vibration will be. Apart from possessing the performance and emission qualities, the microalgae biodiesel blends proved to be the efficient fuel in reduced vibration and noise qualities too. In three directions, the vibrations were measured as lateral, longitudinal and vertical vibrations. The vibration in lateral direction was significantly reduced. Compelling the results, it is understood that use of the microalgae blends can be sustainable in the perspective of the engine wear and tear.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44249029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Meng, Longlong Li, Bao Yuan, Qianyou Wang, Xiaohui Sun, Ye Zhang, Dahua Li
Imbibition under overburden pressure can simulate the imbibition behavior in reservoir conditions during hydraulic fracturing, about which the mechanism is still unclear. This study investigated the imbibition with overburden pressure using a nuclear magnetic resonance displacement design. The main contribution of this study is that the initial imbibition rate under confining pressure can reflect the pore connectivity of reservoirs under overburden pressure and a method for appraising the pore connectivity under confining pressure was established. The tight sandstone samples were collected from the Upper Paleozoic Taiyuan and Shihezi Formations in Ordos Basin. The Taiyuan Formation presents apparent double-peak structure from nuclear magnetic resonance (NMR) spectra, and liquid fills into small pore preferentially as a whole. When the imbibition time is on a square root scale, the cumulative imbibition height at the initial imbibition period is not stable, which deviates from the linear principle, and the initial imbibition rate ranges from 0.077 to 0.1145. The Shihezi Formation shows a dominant peak structure from NMR spectra, and the liquid has no obvious filling order as a whole. When the imbibition time is on a square root scale, the cumulative imbibition height at the initial imbibition period also deviates from the linear principle, and the initial imbibition rate ranges from 0.0641 to 0.1619.
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