Techno-economic Analysis of MEA CO2Capture from a Cement Kiln - Impact of Steam Supply Scenario

This paper present the techno-economic assessment of an MEA-based CO2capture from a cement plant and the importance of the steam supply on the costs. The evaluations present the energy performances of the CO2capture process based on a cement plant with a clinker capacity of 3,000 t/d. The cost evaluation lead to a cost of cement of 45 â¬/tcementwithout capture, while the cost of cement with CO2capture is estimated to 81 â¬/tcement, resulting in a CO2avoided cost of 83 â¬/tCO2,avoided. As the steam consumption accounts for close to half of the CO2avoided cost, the impact of six alternative steam supply scenarios are considered. The evaluations show that the CO2avoided cost can decrease by up to 35% depending on the steam supply and electricity price. However the possibility of these steam supply alternatives are specific to the considered cement plant, emphasizing therefore that CO2avoided cost from cement shall rather be given as a range depending on the steam supply than as a unique value as often illustrated in the literature

Enabling Participants to Play Rhythmic Solos Within a Group via Auctions

The paper presents the interactive music system SoloJam, which allows a group of participants with little or no musical training to effectively play together in a ``band-like'' setting. It allows the participants to take turns playing solos made up of rhythmic pattern sequences. We specify the issue at hand for allowing such participation as being the requirement of decentralised coherent circulation of playing solos. This is to be realised by some form of intelligence within the devices used for participation. Here we take inspiration from the Economic Sciences, and propose this intelligence to take the form of making devices possessing the capability of evaluating their utility of playing the next solo, the capability of holding auctions, and of bidding within them. We show that holding auctions and bidding within them enables decentralisation of co-ordinating solo circulation, and a properly designed utility function enables coherence in the musical output. The approach helps achieve decentralised coherent circulation with artificial agents simulating human participants. The effectiveness of the approach is further supported when human users participate. As a result, the approach is shown to be effective at enabling participants with little or no musical training to play together in SoloJam

Drop and Recovery of Sensor Nodes Using UAVs

The goal of this project is to make a system able of executing drop and recovery of sensor nodes at sea by the use of UAVs.The sensor node will be a lightweight packet that can contain different sensors depending on the mission. These sensor nodes will be dropped into the sea where they will float on the surface. Examples of use for the sensor nodes can be to log temperature, currents, salinity or water quality. Hence they can be very useful in for instance climate research or for detectingoil spills.This project is a continuation of a project executed by the author [Voldsund, 2013] where a drop and recovery mechanism to be mounted on a multicopter UAV was developed. The mechanism has been further developed in this project and integrated to an UAV. A control structure for the UAV has been developed and tested using simulator, software-in-the-loop tests and tests in the lab. Simulations and software-in-the-loop tests showed that the control structure was able to execute drop and recovery. But the needed accuracy for recovery of sensor nodes using the mentioned mechanism was not achieved in the lab tests.Measures that could be taken to enhance accuracy to make the system able to conduct dropand recovery of sensor nodes are discussed in this thesi

Estimation and Verification of Hydrodynamic Parameters of an ROV using CFD

The hydrodynamic added mass and damping of a Remotely Operated Vehicle (ROV) are estimated using Computational Fluid Dynamics (CFD) based on OpenFOAM. The estimated hydrodynamic parameters are verified with recorded data from an operating ROV at Snorre B (SNB). Then, the added mass and damping are adjusted to assess if a more accurate fit with the recorded data can be obtained. The ROV under investigation is the Merlin UCV, a work-class ROV. The UCV is first simplified to perform CFD. Two simplified versions are made, and the thin side plates are included in the more complex version. Two mesh convergence studies are conducted to verify the mesh and the computational domain. The Reynolds number is set to be $2.25 \times 10^6$. Numerical simulation based on Steady- and Unsteady-Reynolds-Averaged Navier–Stokes combined with the k-$\omega$ Shear Stress Transport (SST) turbulence model are performed to obtain the hydrodynamic parameters. By studying the influence of the side plates, it is found that the drag increases considerably when the plates are directly exposed to the flow. When there is a constant flow in sway, the value of $C_d$ is 1.4682 when the side plates are not considered. However, when side plates are introduced, the value of $C_d$ increases by 15 \% to 1.6880. Three different experiments are recreated numerically to find the added mass and damping in all Degrees Of Freedom (DOF) as a result of respective acceleration and constant velocity in the corresponding direction. The first numerical simulation is the towing tank test conducted to find the damping in the translational directions. Steady-Reynolds-Averaged Navier–Stokes (RANS) is used, and a constant velocity in the applicable directions are implemented. Then, rotating arm simulations are conducted to find the damping in the rotational directions. A similar procedure is used for the towing tank simulations, but a constant angular velocity is implemented. Planar Motion Mechanism (PMM) simulations are performed to obtain the added mass and inertia in all 6 DOF. Oscillatory linear and angular movements are executed to find the added mass and inertia in the translational and rotational directions. Since the movement is oscillatory, Unsteady-Reynolds-Averaged Navier–Stokes (URANS) is used to capture the time-varying flow. Furthermore, the numerical model used to estimate hydrodynamic parameters is validated by being compared to recorded data of an operational ROV at SNB. The recorded data were logged using the SPRINT, consisting of linear and angular position and velocity. A simulator code built on the classical equations of motion is made to simulate the movement data. Moreover, the CFD estimated added mass and damping are implemented in the equations. In the present study, the simulated movement of the ROV is later fitted with the recorded data. The fit between the recorded and simulated movement is satisfactory using the CFD estimated parameters. The added mass and damping are then adjusted, and an improved fit with the recorded data is achievable. Therefore, the conclusion is to adjust the hydrodynamic parameters if recorded data is available. This method is more efficient than CFD and gives more accurate results. However, if recorded data is unavailable, CFD can provide an efficient method to accurately predict the damping and added mass.Masteroppgave i havteknologiHTEK3995MAMN-HTEKMAMN-HTE

A mathematical model for calculating river hydrographs using high resolution digital elevation models

Prediction of floods is important to prevent damage to human lives, build- ings or infrastructure, and we have developed a simulation model to address this. The model is a so-called distributed rainfall-runoff model, which accounts for spatial variations within the watershed; it is based on a distributed version of the time-area method (Clark, 1945). Travel times are calculated by assuming that the flow can be modelled as creeping flow, and the resulting velocity field is used to solve the so-called time-of-flight/Eikonal equation. Both topographical and heterogeneous properties can be accounted for by the model, which ideally can be used for both gauged and ungauged watersheds after calibration. An automatic watershed delineation algorithm has been implemented to delineate the river s watershed using the D8 Algorithm (O Callaghan and Mark, 1984). To test our model, we create artificial rainfalls, and calculate the hydrograph re- sponse at the watershed outlet. The model works well given the simplifications, and is a framework which can be expanded upon and made more complex

Modelling and Control of Offshore Ploughing Operations

Summary: In this thesis work, mathematical models required to simulate an offshore ploughing operation has been derived. This includes a surface vessel model, a model of the plough and its friction force due to seabed sediment and a towline model. A Dynamic Positioning control system has been derived in order to regulate the vessel to a desired location based on the plough’s desired position. A supervisor module has been derived in order to generate the vessel’s reference position in a smooth manner. And finally the total system has been implemented and simulated in the Simulink_TM environment. The surface vessel model derived in this assignment is based on an offshore supply vessel from the ”MatLab Marine GNC Toolbox” in Simulink_TM. The vertical motion of the vessel has been kept constant during simulations, based on the assumption that the buoyancy force of the vessel is large compared to the vertical towline force. The plough’s friction force due to penetration of the seabed sediment has been modeled, based on the content in reference [5], to get a realistic picture of the sediment forces involved in ploughing operations. It was found that the plough’s friction force profile changed with different operational boundaries. The boundaries are the ocean depth and the ploughing speed. For the boundaries in this assignment the resulting ploughing force equation were found to be nonlinear and shaped as a sigmoid function. In this assignment the lumped mass model has been derived for the towline’s motion and proven to give reasonably good numerical results when implemented in the Simulink TM environment. To get a realistic towline motion in seawater, a hydrodynamic quadratic damping force has been added to the equations. This hydrodynamic damping had effect on the towline’s tangential and normal motion components. The DP controller derived in this assignment consists of a PD-controller with feed forward signal from the horizontal towline tension. Feed forward signals are often influenced by noise and must be filtered to obtain low-frequency signals. In this assignment a ordinary 1st-order low-pass filter has been used in order to damp out oscillations from the towline. This filter has been proven to give a good damping effect when the towline was exposed to underwater currents. The DP controller provides good position tracking quality. The supervisor module designed in this assignment consists of a reference generator an a reference model. The supervisor module is responsible for converting input signals for the plough’s desired path into a smooth tracking signal for the vessel’s control system. The reference generator produces smaller intermediate reference signals, as input to the reference model, from a final desired vessel position. A circle of acceptance has been introduced in order to change reference values at a convenient vessel location. This has been proven to give a nice effect on the vessel’s and the plough’s behavior. The reference model has been designed with a speed saturation element, in order to bound the speed of the ploughing operation. During the case simulations it was found that by defining the operation over a longer distance, a more efficient operation is gained. When crossing longer distances the plough will reach the vessel’s speed and underwater current disturbances are small compared to the ploughing force that has gotten time to be built up. Underwater currents has great influence on the towline when the towline’s pulling force is small. In appendix A a CD can be found. On this CD this report can be found, the original work schedule, pictures and the Simulink program for the ploughing operation