1 |
Hydrogen storage systems : Methodology and model development for hydrogen storage systems performance evaluation based on a transient thermodynamic approachMargaritari, Kreshnik January 2023 (has links)
The overall performance of a hydrogen storage system can be affected by various parameters, such as operation and design parameters, but also by the state of the hydrogen contained inside the storage tanks. In this work, a methodology is developed to evaluate the state of the hydrogen during the filling process and its impact on the overall system performance under variable operation conditions and design parameters. To approach as close as possible hydrogen as real gas, the thermodynamic properties of it are obtained from experimental thermodynamic tables. Based on those thermodynamic tables, a discrete database for each thermodynamic property is constructed. To minimize the error and achieve acceptable execution time, a searching method based on curve fitting techniques is developed to derive the thermodynamic properties from the discretized data. The evaluation of the hydrogen state is done based on a developed method that derives the pressure and temperature based on calculated thermodynamic properties during the filling process. The interaction between the contained hydrogen and tank during the filling process is taken into account during the methodology development. Furthermore, energy requirements for the compression system of the hydrogen storage system, including the cooling demand, are also included in the methodology. Based on the developed methodology, a transient model that can evaluate the hydrogen state condition, storage tank wall temperature condition, and energy requirement of the storage system is developed. Validation against experimental and simulation results for an actual filling event of a hydrogen storage tank is done, showing good agreement in the results. The model was used to simulate the performance of a hydrogen storage system, inspired in terms of layout by a real-world HRS storage system. The results showed that the total amount of filled hydrogen and the filling duration of the charging process are greatly affected by the compression and heat transfer phenomena occurring inside the tank. The storage tanks with lower volumes and higher operation pressure tend to be more affected by compression and heat transfer phenomena. Operation parameters such as inlet mass flow and inlet temperature, can have an impact on the system, both in terms of energy consumption and filling performance. Furthermore, based on the investigation of compression stages, the results showed that the number of stages can affect the compression ratio of each stage, resulting in lower or higher efficiency, which directly affects the energy consumption of the compression system. A parametric investigation of the upper operation pressures of the hydrogen tanks showed that the total amount of stored hydrogen is affected when the respective upper pressures vary. Last, it was shown that there is an optimal upper pressure level for each bank that can result in lower specific compression energy, indicating that the model could be used for optimization purposes.
|
2 |
Advancing the Filling Process in Agricultural Machinery : Hopper observation technology for improved filling in Väderstad´s Seed Hawk 600-900C / Förbättring av fyllningsprocessen i jordbruksmaskiner : Övervakningssystem av sålådor för bättre påfyllning av Väderstads Seed Hawk 600-900CAbou Shkair, Ali, Augustini, Jakob January 2024 (has links)
This master’s thesis was conducted in the spring of 2024 at Väderstad AB, a companyknown for producing high-performance agricultural machines, such as seeding machines. Among these machines, the Seed Hawk 600-900C is an important machine for thecompany’s future. The innovation department at Väderstad has developed an automatic Bag Slicer, capable of slicing large bags of seeds/fertilizer without requiring the farmer to climb onto the machine, a cumbersome and hazardous task. Several challenges arisein integrating the Bag Slicer onto their machines, which has hindered its implementation.These challenges have been thoroughly investigated, and one has been selected as thepriority for resolution: enabling the observation of the filling process without the need for climbing onto the hopper. To address this challenge, theoretical studies, concept development, and investigations in the 3D software Blender have been conducted. Creo Parametric was utilized to assemble the Bag Slicer onto the Seed Hawk machine and design other essential components. Coloring, animations, and renderings were created in Blender to create a configuration of cameras, lights, cables, and investigate their properties. This configuration provides users witha comprehensive overview of the filling process and enables operation of the Bag Slicerin the field from the safety of a tractor or wheel loader. Consideration has been given to the conditions occurring inside and around the Seed Hawk machine when specifyingall the different components and operational requirements. The entire configuration was compiled into a complete list of specifications, constituting the main result of this thesis.
|
3 |
Obosnovanie parametrov kovšej zemlečerpatel'nych snarjadov dlja glubokovodnoj dobyči organo-mineral'nych osadkov / Bucket tool design for mining deep-sea organic-mineral sedimentsShepel, Taras 21 April 2015 (has links) (PDF)
The thesis is devoted to determining the parameters of the bucket to increase productivity of dredgers while mining deep-water organic-mineral sediments. It was achieved by increasing the fill factor through determining the rational geometrical parameters of the bucket. Analytical dependencies of the rational height and length of the bucket on the cutting parameters and physical-and-mechanical properties of the excavated sediments were determined. Expressions for defining forces while digging plasticity water-saturated soils were developed. Experimental investigations of the process of digging deep-water organic-mineral sediments in laboratory conditions and in the real conditions of operating single-bucket dredger in the Black Sea at the depth of 1885 m were carried out. The technique for calculation of the bucket\'s parameters was developed.
|
4 |
Obosnovanie parametrov kovšej zemlečerpatel'nych snarjadov dlja glubokovodnoj dobyči organo-mineral'nych osadkovShepel, Taras 21 April 2015 (has links)
The thesis is devoted to determining the parameters of the bucket to increase productivity of dredgers while mining deep-water organic-mineral sediments. It was achieved by increasing the fill factor through determining the rational geometrical parameters of the bucket. Analytical dependencies of the rational height and length of the bucket on the cutting parameters and physical-and-mechanical properties of the excavated sediments were determined. Expressions for defining forces while digging plasticity water-saturated soils were developed. Experimental investigations of the process of digging deep-water organic-mineral sediments in laboratory conditions and in the real conditions of operating single-bucket dredger in the Black Sea at the depth of 1885 m were carried out. The technique for calculation of the bucket\'s parameters was developed.
|
Page generated in 0.0828 seconds