AbstractUntil recently limited effort has been expended to improve energy performance in ships, due to relatively low operational costs and lack of stringent regulations concerning environmental impact. As a result, energy systems were designed to safeguard against worst case operational conditions and their design was based on experience or steady state calculations, which resulted in oversized ship components and plants, operating away from their optimum efficiency. Cruise ships operating in the Mediterranean use HVAC (Heating, Ventilation and Air Conditioning), which anecdotally represent 30% of the total energy consumption of the vessel (Boden 2014).
The aim of this study, was to identify the potential of solar Passive Design (PD) strategies (a proven architectural design approach) in reducing thermal loads on the HVAC system within the context of cruise ships operating in the Mediterranean (McCartan and Kvilums 2014a). This was achieved through the development of design tools adopting a bioclimatic methodology to support engineers and designers in making critical design decisions at the beginning of the design process - to effectively estimate the potential of PD for a given climatic range. The focus of this research was a quantitative thermodynamic analysis - through simulation - of the thermal environment of cruise ship cabins. This was executed using existing validated PD simulation tools from the architectural industry. Attention was placed on specific solar passive practices concerning the physical form of the façade and fenestration.
The simulation results showed the increase in shading depth from 0.5 to 2.0m in depth resulted in a decrease in annual combined heating and cooling loads of between 25.9% to 13.6% for a zone orientated in a northerly direction whilst a reduction between 60.5% to 40.2% was observed for zones orientated in a southerly direction. It appeared therefore, that zones in a southerly orientation benefited most from shading. Overall shading decreased annual sensible loads across all the test locations especially in locations with latitudes below 41.28°N. The application of solar passive technology reduced solar gains by as much as a 71.6% when a 2.0m shading device was added to south facing 80% glazed façade. A comparable decrease of 69.8% was also observed in relatively northerly territories such as Trieste for the same zone configuration. Overall, across all test locations a mean reduction of 54.6% is witnessed when shading is applied to a zone with an 80% glazed façade.
In addition to the physical adaptions made to the exterior façade, the optical and thermal characteristics of glazing systems were also considered; for a zone with an 80% glazed façade orientated south. The results indicated that combinations of glazing properties were found to VI produce relatively low annual combined heating and cooling loads, which were between 39.06% to 53.68% less than the glazing systems which produced the highest loads. Overall the parametric study indicated that combined passive strategies resulted in the lowest annual heating and cooling loads as well as the lowest solar gains.
Naval Architects and interior designers have a key role to play when it comes to the design of future low-energy cruise ships. The preliminary design tool developed in this thesis contributes to the need for further development of design tools for solar PD strategies within cruise ships. This focuses on user-friendly visual tools that are easily interoperable within current architectural modelling software packages, and which generate clear and meaningful results that are compatible with the needs of a future interdisciplinary workflow of the Naval Architect and interior designer. The limited knowledge of solar PD technologies within the Naval Architect community, suggest the need for further skills development amongst Naval Architects and tool development to accelerate the implementation of these technologies in future cruise ship designs (Kanters 2014).
|Date of Award||Sep 2017|
|Supervisor||Sean McCartan (Supervisor), James Shippen (Supervisor) & Shuli Liu (Supervisor)|