HH
H.K.J. Heller
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2 records found
1
Electromagnetic heating assisted energy storage
Laboratory study
Energy storage is increasingly becoming a possible solution worldwide to aid the energy supply and demand. The objective of this study is to determine whether thermal energy storage can be effectively and efficiently achieved by ways of electromagnetic (EM) radiation. To serve this purpose, an experimental setup was designed in order to subject core flooding experiments to EM heating using a MW source. Temperature data is obtained and used to construct temperature profiles as well as energy absorption and storage profiles. The experiments vary from EM radiation under no flow conditions to experiments inducing flow in order to determine the effect of flow on energy absorption and storage amounts. The results obtained show that a significant amount of energy is absorbed by the core and that the introduction of flow at the chosen flowrates during EM heating does not diminish the energy absorption ability of water inside the core. Flow does however increase the rate of energy decline within the core when EM heating is stopped thus reducing the amount of energy stored. Nevertheless, around 40% of the energy absorbed after 150 seconds of EM heating is stored in the core after a cooling period of 60 minutes. This amount declines significantly when flow in implemented throughout heating and cooling. Even though the experimental setup performed accordingly, the large amounts of energy losses are an area that should be subject to improvement. When this technology is implemented in reservoirs or aquifers, the MW antenna is placed in the pay zone. This results in lower energy losses due to the over- and underlying formations functioning as insulation. Subject to improvements, this study concludes that EM stimulated core flooding is a legitimate and viable technology with significant potential for thermal energy storage purposes."
...
Energy storage is increasingly becoming a possible solution worldwide to aid the energy supply and demand. The objective of this study is to determine whether thermal energy storage can be effectively and efficiently achieved by ways of electromagnetic (EM) radiation. To serve this purpose, an experimental setup was designed in order to subject core flooding experiments to EM heating using a MW source. Temperature data is obtained and used to construct temperature profiles as well as energy absorption and storage profiles. The experiments vary from EM radiation under no flow conditions to experiments inducing flow in order to determine the effect of flow on energy absorption and storage amounts. The results obtained show that a significant amount of energy is absorbed by the core and that the introduction of flow at the chosen flowrates during EM heating does not diminish the energy absorption ability of water inside the core. Flow does however increase the rate of energy decline within the core when EM heating is stopped thus reducing the amount of energy stored. Nevertheless, around 40% of the energy absorbed after 150 seconds of EM heating is stored in the core after a cooling period of 60 minutes. This amount declines significantly when flow in implemented throughout heating and cooling. Even though the experimental setup performed accordingly, the large amounts of energy losses are an area that should be subject to improvement. When this technology is implemented in reservoirs or aquifers, the MW antenna is placed in the pay zone. This results in lower energy losses due to the over- and underlying formations functioning as insulation. Subject to improvements, this study concludes that EM stimulated core flooding is a legitimate and viable technology with significant potential for thermal energy storage purposes."
Permeability of layered glass bead samples
Effect of grain size mixing in layer boundaries
Geotechnical projects are successful when there is a lot of knowledge about the soil implemented in safe sustainable solutions. Existing models of hydraulic flow in soils need to be tested and confirmed again and again to make sure it’s trustworthy. With the use of three-layered samples containing 1mm and 3mm glass bead sizes a simplified model of the fining upward (1mm top layer) and coarsening upward (3mm top layer) stratification was made. The top and bottom layers consist of a uniform glass bead size. The middle layer is a binary mixed one with different volumetric percentages to mimic the gradual increase of grain sizes like fining and coarsening upward sediment deposits. A decrease in the permeability was observed as the volume percentage of the smaller glass beads increased. The influence of a possible transition/mixed zone between layers was not clear because of the small ratios of the used glass beads. This is also the case for the effect of the porosity on the permeability. In addition, test samples were prepared to calculate the theoretical harmonic permeability to be able to compare it with the actual measured permeability. This theoretical harmonic permeability seems in the case of the coarsening upward samples smaller than the actual measured permeability as was expected from findings of another research. This study confirms the influence of the relative positioning of the layers with their specific properties on the overall permeability and the deviation from the theoretical harmonic permeability. Future prediction of the permeability’s in layered deposits is a little bit more educated with the findings of this study.
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Geotechnical projects are successful when there is a lot of knowledge about the soil implemented in safe sustainable solutions. Existing models of hydraulic flow in soils need to be tested and confirmed again and again to make sure it’s trustworthy. With the use of three-layered samples containing 1mm and 3mm glass bead sizes a simplified model of the fining upward (1mm top layer) and coarsening upward (3mm top layer) stratification was made. The top and bottom layers consist of a uniform glass bead size. The middle layer is a binary mixed one with different volumetric percentages to mimic the gradual increase of grain sizes like fining and coarsening upward sediment deposits. A decrease in the permeability was observed as the volume percentage of the smaller glass beads increased. The influence of a possible transition/mixed zone between layers was not clear because of the small ratios of the used glass beads. This is also the case for the effect of the porosity on the permeability. In addition, test samples were prepared to calculate the theoretical harmonic permeability to be able to compare it with the actual measured permeability. This theoretical harmonic permeability seems in the case of the coarsening upward samples smaller than the actual measured permeability as was expected from findings of another research. This study confirms the influence of the relative positioning of the layers with their specific properties on the overall permeability and the deviation from the theoretical harmonic permeability. Future prediction of the permeability’s in layered deposits is a little bit more educated with the findings of this study.