The ever-growing intercontinental maritime trade and transporthave identified the need for the ship and passengerssafety, energy efficiency and environmental pollution to be considered as dominant issues within shipping industry and academia. Recently introduced safety regulations, known as Safe-Return-to-Port, and ‘green’ regulations, by the IMO, came into force to address and, indirectly, couple the above objectives through the enforcement of specific safety performance requirements of ship systems after a casualty and mandatory environmental measures for GHG emissions limitation, for the former and the latter regulations respectively. This thesis focus is on improving the safety and the energy efficiency of ships during design and operation by adopting approaches assessing the safety critical systems availability at emergencies and estimating performance requirements of electrical energy onboard ships over their life cycle. Through the adoption of methodologies successfully applied in damage stability, the probabilistic assessment of systems safety is employed with the logical modelling of the system into the ship environment and the application of statistical flooding damages to be initiated. Critical zones for the systems location are investigated with topological and geometrical optimisation to be performed identifying ‘enhanced-availability areas’ onboard targeting, also,the components redundancies reduction. First principles were introduced for the numerical modelling of the electrical energy systems onboard aiming to evaluate the energy performance of the ship. However, the great number of input parameters and computational problems shown up during the systems development, especially for larger vessels such as passenger, triggered necessary simplification considerations for the design.Investigation was considered for the identification of the key design parameters, with a verification process based on energy simulations to have been used for constructing guidelines and indicating acceptable assumptions. Investigation results were used for the systems optimisation in energy efficiency and cost perspectives during the design through the development of the Power Management System, with the latter’s functionality to be extended also during operation aiming fuel consumption minimisation. The amount of consumed fuel were quantified for both case, and results were used to create design and operation guidelines for power generation sets sizing and loading respectively. All findings were used to form methodology for the design of the electrical energy systems aiming to increase the energy efficiency through the appropriate sizing of the power generation sets and also, for the case of passenger vessels, to increase systems safety through the optimisation of their onboard location. Implementation of the methodology was exhibited with two case studies, one for a cargo and one for a passenger ship. The work undertaken and the derived results clearly demonstrate the applicability of probabilistic assessment for the quantification of systems availability post-casualty not only for rules compliance but also for the increased results accuracy and the integration to ship survivability concept. In addition, the introduction of Dynamic Energy Modelling concept as a platform in shipping to support life-cycle energy management were concluded through the electrical energy systems simulations during operation and design considering simplification during the latter’s process. Those concepts could be applied under the multi-objective optimisation platform in order to explore the whole design space concerning systems common parameters. All these constitute significant developments in shipping.
|Date of Award||5 Dec 2016|
- University Of Strathclyde
|Supervisor||Dracos Vassalos (Supervisor)|