Emission regulations applied to marine industry for amongst others the propulsion system of a vessel are becoming stricter due to governmental agreements to lower the greenhouse gas emissions. Engine manufactures are enhancing their engine designs to reduce the engine fuel consumption, which is commonly done by implementing a turbocharger to downsize the engine. One large drawback which comes with a turbocharged engine is the low torque development for the low to mid engine speed range due to limitations set to prevent unstable turbocharger phenomena. Moreover, the engine is not able to follow the power request almost instantaneously due to a time delay between the engine and turbocharger response. Formula One engineers close this gap by introducing an integrated electric machine into the turbocharger structure (hybrid electric turbocharger) to, first, take power out from the turbocharger to increase the system efficiency, and second by assisting the turbocharger to improve the engine power delivery response. However, the understanding of the effects of a hybrid electric turbocharger on both the system efficiency as well as the engine loading capability is lacking. One turbocharger limit, the compressor surge, is not concerned in most literature what rises the need for further research up to which extent the engine can be assisted with the hybrid electric turbocharger. In this work, the effect of taking power from the turbocharger to increase the system efficiency, called turbocompounding, is investigated. Turbocharger assistance is investigated for both steady state as well as dynamic operation. The effect of assisting the turbocharger for steady state operation is investigated to increase the engine’s operating envelope. Dynamic operation comprises the investigating up to which extent the assisting mode improves the dual fuel engine’s loading capability for four types of engine loading. These types of engine loading are: one instant load step, three consecutive load steps from 0 - 100% load, a load ramp and, last, a sinusoidal engine loading. This has been done with a simulation-based study wherein a mean value dual fuel engine model is composed based on merging two available mean value engine models, after which it is verified and validated. Thereafter power take in/out together with an air excess ratio control strategy is included by means of adding/taking torque to/from the turbocharger shaft and limiting it with eight boundary controllers to avoid impractical situations. With turbocompounding the system efficiency can be increased at the expense of a deteriorated gas exchange and increased thermal loading of the engine. The maximum quantity of recovered energy to be obtained, requires a hybrid electric turbocharger which replaces a waste gated turbocharger instead of a non-waste gated single stage turbocharger. Taking power from the turbocharger lowers the power available for the compressor which leads to reduced inlet receiver pressure and corresponding lowering of the air excess ratio and deterioration of the scavenging process. Assisting the turbocharger for steady state operation leads to a smaller operating envelope due to the limitation of compressor surge. Combining turbocharger assistance with gas exchange bypass valves, to avoid compressor surge, results in a rise of the low speed torque output up to an almost constant engine torque output. The system efficiency can be improved for the low speed region when the turbocharger is assisted in combination with the gas exchange valves. The load step capability, found by limiting the minimum air excess ratio during the load step event, cannot be increased with turbocharger assistance which starts to speed up the turbocharger immediately after the load step is applied to the engine. However, the recovery time needed before a second load step can be taken, is reduced with turbocharger assistance compared to the baseline engine. When the turbocharger assistance starts to speed up the turbocharger a couple of seconds before the load is applied, the load step capability can be improved. A load ramp can be taken in a shorter period of time with turbocharger assistance enabled. For cyclic loading, the hybrid electric turbocharger operates in turbocompounding mode for the lower load frequencies, and assistance is used for the higher load frequencies. With turbocharger assistance the air excess ratio does follow the sinusoidal engine load while the air excess ratio of the non-assisted engine always lags due to the turbocharger lag. Further research should be done with regard to a hybrid electric turbocharger for the natural gas combustion of the dual fuel engine. Using the engine speed drop should be implemented as limitation for the loading capability determination instead of the minimum allowable air excess ratio applied in this thesis.

A conventional dynamic positioning system is used to control vessel motions in the horizontal plane, i.e. surge, sway and yaw. However, the safety and operability of several offshore operations can be increased when also the roll motion is actively controlled, especially in beam seas. A control system model is proposed for combined thruster induced roll reduction and DP station keeping when the vessel is operating in beam seas. The proposed control system model is applied to a offshore construction vessel and the performance is demonstrated by time domain simulations. The DP footprint is compared to a conventional dynamic positioning control model. The proposed control model enables active roll reduction while the effect on the station keeping performance is unaffected.

Environmental regulations are continuously raising the bar towards more advanced diesel engine designs ca- pable of minimizing the emissions of polluting substances. The recent IMO Tier III legislation, entered into force in 2016, is forcing the engine manufacturers to meet a NOx reduction of more than 70% from Tier II for all the ships sailing in designated NOx Emission Control Areas (NECA). Although these zones are, up to now, limited to the North American and U.S. Caribbean Sea NECAs, future regions, such as the North Sea and Baltic NECA in 2021 as well as stricter national and port regulations, are increasing the uncertainty regarding the possible compliance methods. The Selective Catalytic Reduction (SCR) represents a flexible, proven and commercially available technology capable of reducing more than 80% of the NOx in the exhaust gas. Its adoption started in the ’70s and was aimed at the reduction of stationary source emissions. From early 2000, it has been extended to the automotive industry in order to meet the Euro and EPA legislation for heavy duty and light diesel engines. Despite the evident disadvantages of the high installation cost and the considerable space requirements, the application of the SCR is subjected to a number of operating limits such as the narrow optimal temperature window and the slip of byproducts originated from the chemical reactions. These limitations can be even more severe when the diesel engine undergoes transient and dynamic operations. The main objective of this research is to gain insights into the behaviour of the SCR technology under steady-state and dynamic operations of the diesel engine. After an accurate literature review of the working principles, reaction kinetics and modeling approach, a first principle model of the SCR has been developed to fulfill the scope. A 1D single channel approach, discretized along the reactor length, has been adopted to sim- ulate the heat exchange and the chemical reactions occurring in the catalyst. To facilitate the integration of the designed model with an existing diesel engine model available in the Maritime and Transport Technology Department of the 3me faculty, the resistance and volume approach has been selected. After the verification of the SCR model, the integrated system "SCR+Engine" has been tested under steady-state conditions, to an- alyze the effect that the added back pressure has on the engine performance, and under dynamic conditions, to simulate "real" load case scenarios that the SCR might experience. The designed model, although limited from the chemical reaction point of view, is able to predict NOx reduction and ammonia slip under steady-state and transient operations. It can be further used in an early design phase to investigate the feasibility of the SCR inclusion in the drive trains of ships. Future studies are recommended to optimize the model, by taking into account the sulphur influence on the reduction efficiency and the catalyst aging, and to validate it with real experiments on marine SCR systems.

After years of using fossil fuel, the transition to renewable energy sources need to be made to limit the increase in temperature and to support the future energy demand. To support and speed up the transition phase from fossil fuels to renewables it is necessary to decrease the costs. Offshore Wind Turbines are widely used for the production of renewable energy and several Offshore Wind Turbine projects are planned for the future. Most of the Offshore Wind Turbines are founded by monopile, large steel tube, to support the wind turbine. Nowadays, these monopile be installed by either jack-up vessel or moored floating vessel. However, these installation method come with a major drawback: the installation procedure is time consuming. A new installation method is propose to reduce the installation time. This thesis focus of the feasibility to install the monopile with a dynamically positioned (DP) vessel. The required station keeping situation is faster achieved with a DP vessel. Due to the footprint of the DP vessel relative to an earth fixed position, a vessel motion compensated pile gripper is used to maintain the upright position of the monopile and to decrease the interaction forces between vessel and monopile. Adding the monopile to the vessel is an off-design condition for the DP controller. During the early hammering phase of the monopile, the monopile have limited interaction with the soil and is unstable. The upright position is maintain by the gripper frame. The forces from the gripper frame on the monopile are reaction forces on the vessel. Beside these forces, environmental forces are acting on the monopile and via the gripper frame acting on the vessel. The forces on the vessel could lead to unstable behavior and/or increased vessel footprint. A simulation model is build to investigate the behavior of the DP vessel during the operation. A industry used DP simulator and a simulation model of the Bokalift1 is used. A model of a typical shallow water and deep water monopile is build. A hydraulic based gripper frame is simulated with an inclination controller and a induced vessel motion controller which need to maintain the upright position of the monopile. The inclination controller is tuned with a higher bandwidth compare to the bandwidth of the DP controller to prevent motions of the monopile is the same frequency range as the linear motions of the vessel. The forces from the gripper frame are fed into the Kalman filter of the DP controller. This is done to prevent a drift of the vessel when the gripper frame starts acting on the vessel. In all simulation cases with governing environmental conditions, the vessel could maintain stable behavior. The rotations of the monopile are in the same frequency as the first order wave forces on the vessel. This relative high frequency motions to not significantly amplify the position of the DP vessel. However, despite the fact of feeding the Kalman filter, a larger drift is observed in case of the large, deep water monopile in the operation stage when the gripper frame force is introduced to the vessel. This increase the requirement on the envelope of the gripper frame. The requirement on the gripper frame is given in terms of power, force and envelope based on governing environmental conditions. The requirements on the gripper frame are assumed to be within an acceptable magnitude. The operation seams to be promising in the future.

To reduce global warming and air pollution, the maritime industry is searching for solutions to reduce fuel consumption. This thesis focuses on the reduction of generator running hours and fuel consumption of Dynamically Positioned (DP) vessels. In this ship type, redundancy of the power generation system is regularly achieved by running on one generator more than strictly necessary in every engine room. Thereby, these vessels make superfluous running hours and unnecessary fuel consumption. Previous research in this field focused on installing a hybrid system in every separate engine room to replace this redundant running generator and achieve the power generation redundancy by a battery which is temporarily used in case of a generator failure. Since DP vessels normally operate on two separate engine rooms for safety, this results in two separate hybrid systems, i.e. a double-battery hybrid system. To reduce investment costs of a hybrid DP vessel, this thesis concentrates on finding a power management strategy that allows a single hybrid system to be installed on board, which is only connected to one of the engine room grids in case of a generator failure. A single-battery hybrid system cannot be connected to both engine room grids continuously -in contrary to the double-battery hybrid system- because this would cancel the independence of the separate engine rooms. Therefore, in the single-battery hybrid system, no back up power is present in case of an increase in power demand in one of the engine rooms. In present DP vessels, this back up power is supplied by the redundant generator. When using a double-battery hybrid system, this back up power is supplied by the continuously connected hybrid system. Therefore, for a single-battery hybrid system, the starting control decision algorithm of the power management system (PMS) should decide on starting an additional generator prior to a rise of the power demand. Two methods for this starting decision algorithm were tested. Firstly, a mathematical-statistical method using a mathematical model for DP load forecasting and a statistical model for pipe laying load forecasting was tested. This model was found not to work properly. Secondly, a multiple linear regression model that predicts the height of power peaks based on environmental parameters like wind and waves was tested which was found to work appropriately. To assess the feasibility of using either a double-battery hybrid system in combination with a simple starting decision algorithm, or a single-battery hybrid system in combination with a smart starting decision algorithm, these two hybrid system options were compared to the current situation that uses a redundant generator in every engine room. These three system options were compared in terms of investment costs, fuel consumption, generator running hours, planned maintenance costs, and reliability. For this comparison, the DP pipelaying vessel Pioneering Spirit was used as a case vessel. To find the investment costs, a hybrid system was designed for this purpose. To find the fuel consumption, generator running hours, and planned maintenance costs, full year time domain simulations of the hybrid systems in operation were performed using measured power demand data from the case vessel during pipelaying. For this analysis, a mathematical model of the power generation system was used. The reliability assessment of the different systems was performed using fault tree analysis. The single- and double-battery hybrid systems both show a significant fuel consumption reduction of 8.4 and 9.0% respectively. When also taking into account the investment costs, generator maintenance cost reduction, and battery depreciation, the payback time of these hybrid systems is 0.9 and 1.7 years respectively. The difference in payback time is mainly caused by the difference in investment costs between the single- and the double-battery hybrid system. For a single-battery hybrid system for DP vessels, a multiple linear regression model based starting decision algorithm works appropriately. However, although the multiple linear regression model based starting decision algorithm was tested positively in simulations using the available power data, in case of an unforeseen power peak that was not related to one of the input parameters of the regression model, the power generation system lacks back up power. Therefore, the reliability of the single-battery hybrid system is insufficient when using it for DP applications. Especially when taking into account the minor absolute difference in payback time, for the replacement of the redundant generators in DP vessels, the robust and simple double-battery hybrid system is preferred over the small and smart single-battery hybrid system.

For many maritime applications Li-Ion batteries are foreseen as energy storage units that can improve the performance of the on-board power system in terms of continuity of service, fuel consumption, emissions and running hours of main engines. However, one of main limitations of battery application in on-board power systems is the aging of batteries. Applications of instantaneous power input/output such as propulsion dynamic assistance and heavy seas operation of ships, have an adverse effect on battery lifetime meaning that degradation of energy capacity over time is accelerated. Additionally, limited by their maximum current rating, batteries cannot deliver effectively high C-rates and therefore are not able to fully absorb the engine fluctuations. A typical solution for this problem is to over-size the battery system. By paralleling more batteries, the max. C-rate is lowered, and battery lifetime can be extended. On the other hand, an over-sized battery system will result in additional capital cost and weight. Therefore, it is evident that in conventional approaches there is an undesirable trade-off between battery aging and battery size. As an alternative practical approach into this problem, this thesis proposes an on-board hybrid energy storage system (HESS) that comprises of a battery and a supercapacitor component. By placing the supercapacitor in parallel to the battery and by using it for high peak currents, it is possible to reduce the stress on the battery and thus extend battery lifetime while improving the availability and the reliability of the power system. In addition, by taking advantage of the high specific power of the supercapacitor and the high specific energy of the battery it is possible to optimize sizing of the energy storage system for high power applications. In this thesis, a parametric approach of combined sizing and energy management for hybrid energy storage system is developed and integrated into a typical DC shipboard power system . Based on a case load profile, the HESS operation is simulated and benchmarked to battery-only installations. The static outputs of the sizing process and the dynamic outputs of the simulation are extracted in the form of design exploration maps and arrays that are used to correlate them to the key design variables. Finally, through this work, it is demonstrated that for high power applications with significant fluctuations, the proposed battery-supercapacitor HESS, can lead into smaller and more cost-effective installations, without compromising battery lifetime and while maintaining same levels of reliability performance.

The rapid rate in technological advancements leaves little to none options for our environment to react. The excessive use of "conventional" energy is bringing planet Earth to its knees. However, people started recognizing the value of renewable energy sources. One of the major renewable sources is the wind energy. The wind energy can be divided in two categories; onshore and offshore wind energy. Offshore wind energy has many advantages in comparison with onshore but comes with a major disadvantage, the installation cost. Since installing an offshore wind turbine is far more complex than installing the same wind turbine onshore, different ways needs to be developed to compensate for the excess costs. Even though the cost is a significant aspect, it is not the most critical one. Since more power is required, bigger offshore wind turbines are needed, thus larger foundation structures and bigger water depths. The conventional Jack-Up Barge that was being used for such operations so far is driving to a saturation on its operability due to limitations on maximum crane capacity and maximum water depth. For the aforementioned reasons, a floating vessel is considered to install bigger foundations but this leads to the loss of fixed ground that the Jack-Up Barge provided. This creates a significant problem that motions are generated and disturb the installation process. For this reason, a compensating strategy should be developed to allow such installations. Such solution comes from TWD with the Motion Compensating Pile Gripper. In order to reduce the installation costs and to allow installation of wind turbines in higher depths of water, a floating vessel has to be deployed instead of the conventional Jack-Up Barges. The use of a floating vessel though, generates motions that disturb the installation procedure. This is the reason that TWD came up with a compensating gripper. This gripper uses hydraulic cylinders to generate forces for the monopile and vessel in order to counteract unwanted motions and to keep the monopile in the required position. In this thesis, initially a functional design is conducted. This analysis concludes with the possible design strategies that can restrict the monopile through the lowering operation. After the possible design strategies are established, a simulation model is generated that involves environmental loads, a vessel model, a monopile model and a gripper model. Through that simulation model, the different alternatives are tested and imulated in order to evaluate the performance of each and observe their responses. Finally, after all the alternatives are simulated, a Multi-Criteria Analysis takes place that evaluates each one of the possible strategies based on various criteria in order to conclude to the winning strategy that is then suggested to be implemented in the lowering operation of the monopile erection process.

Greenhouse gas emissions’ reduction goals of a 50% reduction by 2050 were established by the IMO. As a first step to achieve this reduction already by 2030 this project uncovers how much of the CO2 emissions it is possible to reduce by combining the available state of the art technology. The reduction of CO2 emissions is done in two steps. The first step consists in reducing the power demand in terms of auxiliary and propulsion systems. After that, cleaner power supply alternatives are considered to further reduce the emissions. In terms of auxiliary power, heavy consumers such the air conditioning, the lighting or water systems are considered. The reduction of auxiliary power is not only achieved with the introduction of more efficient equipment but also by the introduction of passive design strategies that enhance savings by reducing the loading on the systems. Altogether it is possible to reduce the auxiliary power demand by 33% in comparison with the benchmark design. The reduction of auxiliary power demand has a significant impact on the yearly consumption due to the significant percentage of operational time spent at anchorage. In terms of propulsion power demand, the reductions achieved are even more significant, 51% and 70% power demand reductions are possible at cruising and maximum speed, respectively. The introduction of the Van Oossanen’s Fast Displacement Hull Form (FDHF), the reduction of displacement by making an aluminium hull and the application of the patented Hull Vane® are the main reasons for such a significant propulsion power demand. Finally, the switch in power plant arrangement of the yacht results in further 10% reduction. In this case, simply the change from diesel direct arrangement to a hybrid arrangement leads to yearly savings, mainly because emissions at cruising are reduced due to the power take-off operational mode of the power plant, saving generator set emissions. All in all, it is possible to already achieve a reduction of approximately 41% of the yearly CO2 emissions on a 50 m motor yacht. One of the most important conclusions to be taken is that all these reductions are possible when finding the optimal interaction between components, from auxiliaries to power plant arrangement. Mainly, the CO2 emissions reduction followed from a fuel consumption reduction, not yet introducing power supply from renewable energies nor alternative fuels which despite being the way to the future are not yet fully mature and suitable for this specific case.

Pioneering Spirit, Allseas's largest pipelay vessel, will be outfitted with a novel Jacket Lift System (JLS). A jacket refers to the steel frame which supports the topside of a fixed offshore platform. The Pioneering Spirit was already capable of lifting the topsides of offshore platforms, like the former oil platform Brent Delta, but would have to leave the jacket behind. With the JLS it will also be able to remove and install jackets. In offshore ship mounted crane applications wave disturbances can create unwanted oscillations in suspended loads. Anti-sway control systems have been developed to aid the crane operator in decreasing these oscillations. But not all crane types have actuators suitable for this compensation. The JLS will be a derrick type crane which will be positioned above a jacket using the dynamic positioning of the ship. The hoist systems of the JLS are then lowered and connected to the jacket. During this lowering process the ship motion induced by wave disturbances create a large oscillation in the hoist system. In this thesis a controller is developed based on a proportional derivative controller found in literature to reduce the sway in the hoist system to make the connection process possible.

In this graduation thesis the feasibility of a camera as sensor for nautical operations is investigated. In aerospace and automotive industries autonomous vehicles are already widely tested and used. However the marine industry has fallen behind in this development. Therefore this research is focussing on automation in the maritime sector. First a system was developed which measures distance and heading from a video feed. Thereafter simulink models were made to develop a system that autonomously can perform nautical operations. For this research multiple operations have been modeled. First of all the platform approach and the replenishment approach. In these operations the system should be able to approach a stationary or moving target. Also station keeping after the approach is required. The complexity of the operations was increased with the choice for follow the leader from the maneuvering operations. Finally the avoidance of upcoming collisions was modeled. The models for all of these operations were rst developed and tested with an oine model. This enabled a quick and accurate controller tuning. The rst real test for these models was done in a ship handling simulator. Here the models were tested and the in uence of environmental conditions was measured. In the simulator all models performed quite well. However the performance is largely limited by the choice for the camera and environmental conditions. The most interfering conditions are lateral incoming waves, fog and light. Models for small scale testing were developed, but the communication between dierent components and the control system proved to be a large issue. Therefore these models could not be tested. All in all this research shows that after improving system component, a camera system can very well be used as a sensor for autonomous operations at sea.