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Collaborating Authors
Cai, Wei
Environmental-Economical Evaluation of Xijiang Waterway Decarbonization Using a Ship LCA-LCC Evaluation Method
Cai, Wei (Green & Smart River-Sea-Going Ship Cruise and Yacht Research Center, Wuhan University of Technology / School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology / Sanya Science and Education Innovation Park of Wuhan University of Technology) | Sun, Hongfang (School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology) | Liu, Wushuai (School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology)
ABSTRACT In order to comprehensively consider the environmental and economic performance of ship in life cycle and facilitate enterprises to make scientific decisions, proposing a comprehensive assessment method of the ship's environmental effect based on life cycle cost analysis, which is LCA-LCC method, namely, through the social willingness to pay method, the potential cost of ship environmental impact is integrated into the whole life cycle environmental analysis, and the integrated model of ship LCA-LCC is established to realize the integrated analysis for ship environmental performance and economic performance. In this project, the LCA-LCC integrated analysis method is applied to the demonstration of the construction and transformation of Xijiang LNG powered ship. The results show that the Xijiang LNG powered ship, which can reduce the comprehensive impact of the ship, is a reasonable substitute for diesel ship when considering the economic and environmental performance. In the future research, LCA-LCC evaluation method can be used to evaluate the comprehensive performance in the design stage, so as to provide a basis for the subsequent decision. INTRODUCTION Xijiang waterway is a waterway with a total length of 854 kilometers. It is the second largest inland river after the Yangtze River, with Nanning, Guigang, Wuzhou, Zhaoqing, Guangzhou, Zhuhai and other important ports along the river. At present, the local government is vigorously promoting the project of "gasification of the Pearl River and greening of the Xijiang River". In order to make a scientific decision, environmental performance and economic performance must be considered comprehensively when ship power system is reformed and ship type is selected. However, the results of the LCA only reflect the impact of the assessed ship type on the environment and cannot be related to its economy. For this reason, it is urgent to establish a set of quantitative analysis methods through environmental impact costs, so as to carry out a more comprehensive assessment.
- Asia > China > Guangxi Province > Nanning (0.24)
- Asia > China > Guangdong Province > Zhuhai (0.24)
- Asia > China > Guangdong Province > Guangzhou (0.24)
- Transportation > Passenger (1.00)
- Transportation > Marine (1.00)
- Energy > Oil & Gas > Midstream (0.72)
- Transportation > Ground > Road (0.47)
In order to accurately determine the abnormal geological structure in front of the tunnel excavation, migration imaging must be carried out in processing seismic data acquired at the tunnel walls for advanced geological prediction. In the tunnel construction environment, the seismic observation line is usually arranged in the underground space along the tunnel axis direction, and the observed seismic wave field is from any direction of the underground space, which leads to the migration artifacts easily during the depth migration and thus causes difficulties for the geological interpretation. In view of the above problems, we use the polarization characteristics of different types of waves in Kirchhoff migration method, in order to speculate the spatial orientation of the real reflection interface, so as to reduce the impact of migration artifacts and reduce the difficulty of geological interpretation.
Abstract When polar ship navigates in the Arctic region, the ship side structure may be impacted by different shapes of ice floes, which may produce certain permanent plastic deformations. Therefore, based on a simplified ice-side structure collision scenario, a series of laboratory model tests of ice-plate impact are conducted to investigate the dynamic responses of plate and ice damage. In these tests, the ice geometries are changed by using different shapes of the front end of ice models. The parametric analysis for different ice shapes is carried out to study the mechanisms of the influences of ice crushing characteristics on plastic deformations of plates under ice impacts. Besides, the critical load case and ice impact scenario can be found by comparing the plastic deformations of plate specimens obtained from the model tests, providing some guidance for strength assessment of ship plates under ice floe impacts. Introduction Due to global warming, more and more voyages will cross the Arctic water nowadays, while ice floes in the polar channels give a great potential threat to them. Statistics show that ice collision is one of the main causes of the polar ship accidents. According to the Hรคnninen's report (2005), 30% of the damages were caused by ice-ship interaction and 15% of hull damages occurred in the ice regions under compression in the severe winter during 2002-2003. During the ice and ship impact process, much of the energies will be absorbed by the ship in a short time, which will produce the permanent plastic deformations or damages of ship plates. Moreover, different shapes of the ice floes impacting the plate will cause different degrees of damage due to different ice crushing characteristics. Much works has been done to study the dynamic behavior of ship structures under ice impact by full-scaled tests or scaled model tests. The full-scaled test can predict really the dynamic responses of ship structures under ice impact. Gagnon (2008) used a new Impact Panel to measure forces and pressures during collisions of a ship (CCGS Terry Fox) with bergy bits and a small iceberg, and found that pressure on the hard zones increased as the hard zone area increased. Johnston et al (2008) described the forces that were measured on the CCGS Terry Fox during just over 50 collisions with glacial ice. Ritch (2008) carried out a field test program with the CCGS Terry Fox. From the pressures measured, pressure-area curves were developed, total forces were calculated and the correlation between various parameters such as velocity and bergy bit mass was analyzed.
Application of Failure Mode and Impact Analysis to Cruise Ship Lifesaving System
Zhang, Tao (School of Transportation, Wuhan University of Technology / Cruise and Yacht Design Institute, Wuhan University of Technology) | Cai, Wei (School of Transportation, Wuhan University of Technology / Cruise and Yacht Design Institute, Wuhan University of Technology)
ABSTRACT In order to effectively evaluate the performance of the cruise ship lifesaving system, this paper proposes a method of performance evaluation for cruise ship lifesaving system based on the failure mode and effect analysis (FMEA). This method first adopts the fuzzy set theory to set up the various failure modes, and then it adopts the grey relational theory to calculate the grey degree of relation between the failure modes, which is used to determine the risk priority of the failure modes. Afterward, priorities for further corrective actions will be given to the recognized FMs with a higher grey relational degree in order to ensure the safety performance of the cruise lifesaving system to meet requirements. Finally, a case study is carried out to demonstrate the proposed approach, and the results verify that the performance evaluation of the cruise ship lifesaving system based on FMEA can be effective and feasible, and the results will help improve the safety performance of cruise ship lifesaving system. INTRODUCTION It cannot be denied that the fact seafaring can be counted as one of the world's most dangerous business (HรฅVold, 2005), and this clearly indicates the importance of safety issues in passenger ship design. According to the accident data provided by IMO GIS and MAIB (IMO GISIS, 2017; UK MAIB, 2001), most people (more than 90%) died from evacuation, escape and rescue processes in the accidents of passenger ships. Thus, the whole lifesaving system plays an important role in the success of a passenger ship evacuation. In order to reduce the risk of injury or death in an accident and improve the safety level of a cruise ship, it is necessary to pay special attention to the safety and technical conditions of the lifesaving equipment provided by the cruise ship, so as to enhance the possibility of people survival and escape in case of an emergency.
- Transportation > Passenger (1.00)
- Transportation > Marine (1.00)
Construction and Baseline Fitting of EEDI-LCA Ship Energy Efficiency Model
Wan, Shuqiao (Wuhan University of Technology / High-performance ship Ministry of Education National Defense Laboratory) | Cai, Wei (Wuhan University of Technology / High-performance ship Ministry of Education National Defense Laboratory) | Mei, Menglei (Wuhan University of Technology / High-performance ship Ministry of Education National Defense Laboratory)
ABSTRACT In order to adapt to more international regulations and regional environmental standards, two energy efficiency models introducing the whole life cycle assesment are established. Based on the current energy efficiency system and emission reduction policies of the shipping industry, these models aim at fuel life cycle emissions, evaluate the energy efficiency level of the ship forms more scientifically and comprehensively. The research results show that the LCA(Life Cycle Assessment) method can be used as an energy efficiency assessment tool and a supplementary tool of the IMO(International Maritime Organization) supervision mechanism EEDI(Energy Efficiency Design Index) to more comprehensively reflect the energy efficiency level of ships. INTRODUCTION In order to demonstrate our determination in energy conservation, emission reduction and promote sustainable development, China had promised (Wang,2014) in 2009 that the carbon intensity per unit of GDP(Gross Domestic Product) will decrease 40% to 45% compared with 2005 by 2020. The State Council successively proposed to build a green manufacturing technology system based on the product life cycle and establish a comprehensive evaluation index based on the whole life cycle concept in 2016. In the same year, the state launched a 1 billion special financial funds to support LCA-related work. The application of LCA in the marine industry is relatively late, but the study on the life cycle research of ships has been carried out constantly. DNV(Det Norske Veritas) and the University of Oswald (Johnsen,1999) used the simplified LCA method to study the life cycle of passenger rolling ships in order to verify the feasibility of applying LCA method to the environmental impact assessment of ship life cycle. "The Energy Efficient Ship" project(EU, 2002)applied the LCA method to the ship design process to help designers identify major emissions issues during the ship's life cycle. Cai (2004) proposed the concept of ship greenness and established a ship greenness evaluation index system and calculated the ship's greenness by using a simplified life cycle value analysis method. The Japan Maritime Research Institute (2005) conducted a detailed inventory survey of shipbuilding and ship operation stage. It developed a targeted inventory analysis software. Zhou et al(2009)proposed the LCA technical framework for ships based on ISO14040 standard, which was the first time in China to apply LCA method on ships. Bengtsson (2011) completed the construction of ship life cycle assessment model with reference to ISO14040 and ISO14044 standards, who compared the environmental impact of different fuels used by ships. Fang (2015) established the space-time model of ship life cycle carbon footprint by LCA method.
- North America > United States (0.68)
- Asia > China > Hubei Province (0.15)
- Transportation > Marine (1.00)
- Transportation > Freight & Logistics Services > Shipping (1.00)
Dynamic Analysis of Ship Plates Under Repeated Ice Floes Impacts Based on a Simplified Ship-Ice Collision Model
Zhu, Ling (Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Wuhan University of Technology) | Cai, Wei (Wuhan University of Technology) | Chen, Mingsheng (Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Wuhan University of Technology) | Li, Yinggang (Wuhan University of Technology) | Zhang, Shengming (Global Technology Centre, Lloyd's Register EMEA)
ABSTRACT Polar ships and offshore platforms frequently experience repeated ice floe impacts in Arctic region, and these impacts may result in some permanent structural deformations and may cause some negative effects on their work performance. In this paper, based on a simplified ship-ice collision model, nonlinear finite element simulations are performed using LS-DYNA to study the dynamic behavior of plate under repeated ice wedge impacts. For each impact, the ice damage, structural energy absorption, and permanent deflections of plate are intuitively obtained and discussed. From these simulation results, the conclusions can be drawn that, as the number of impacts increases, permanent deflections of plate increase gradually, while the permanent deflection increment decreases significantly, besides, the energy absorption of plate has a downward tendency while the energy dissipation of ice damage has increased. INTRODUCTION Since the global warming became a global topic of interest, there are evidences revealing that the ice caps in Arctic region have been shrinking year by year. According to the statistics, the sea ice extent and thickness have diminished over the past few years due to the global warming, which make the marine transportation in Arctic region and exploitation of polar resources possible. However, the increased glacial surge and the increasing human activities in Arctic region may cause larger number of ice floes. The increased ship traffic and resources exploitation activities in these waters may enhance the probability of impacts between ice floes and ship and offshore structures, which necessitates the assessment of the consequences of these impacts to ensure safe operations. As shown in Fig. 1, ice floes with different sizes repeatedly hit the ship side structure resulting in some permanent deformations to the plates, which may cause great insecurity and threats to the navigation of polar ships. Besides, the dynamic behavior of conical structures caused by repeated drifting ice impact has also been studied in the literature by Tian and Huang (2013). The assessment of the dynamic structural behavior of plate structure under repeated ice floe impacts is an important issue to improve the safety of ships and offshore structures in Arctic region.
- Asia (0.47)
- North America > United States (0.28)
- Transportation > Marine (0.75)
- Energy > Oil & Gas > Upstream (0.66)
ABSTRACT In order to provide support to the green design of ships and relate marine structures, a practical and accurate evaluation model of life cycle carbon emissions is established. Based on the study of carbon emission characteristics at all stages of ship life cycle, this model adopts the life cycle assessment theory and introduces the uncertainty correction factors to accurately quantify carbon emissions. And the results can help guide the low-carbon design of ships. Finally, the feasibility and effectiveness of this model are verified by taking a 943 TEU river-sea-going container ship as an example. INTRODUCTION Carbon emissions give rise to several global environmental effects, like global warming and related sea level rise, ocean acidification, etc. In 2007, the total CO2 emissions in the shipping industry reached 1.046 billion tons. It represented 3.3% of the global emissions and the international shipping industry accounted for 2.7%. CO2 emissions from the shipping industry will grow by 150-250% in 2050 compared with 2007 if associated mitigation measures not be taken (Hui, 2016). Low-carbon design of ship has become one of the hot spots of green ship research. Sulaiman et al. (2013) demonstrated that the conceptual design stage of the ship has already determined 80% of the full life cycle environmental impact of the ship. Accurate evaluation of carbon emissions is the precondition to implement low-carbon design. Therefore, it is important to evaluate the carbon emissions of the ship life cycle in the preliminary design stage. Life cycle assessment (LCA) is an important tool used to assess the environmental impact of the products and services in a "cradle to grave" perspective (BSI, 2006). Many researchers used the LCA theory to carry out researches on ship carbon emissions. Li (2010) analyzed the carbon emissions of a 180,000-ton bulk carrier by using the PAS2050 method, and pointed out that reducing the fuel consumption in the operation stage was an important way to reduce the ship carbon emissions. Based on the LCA theory, Chatzinikolaou et al. (2013) established a ship air emission analysis model to calculate the emissions of an oil tanker from four stages of ship life cycle (shipbuilding, operation, maintenance and dismantling). Fang (2015) expanded the study of ship carbon emissions into time and space dimensions, and analyzed the spatiotemporal distribution of ship carbon emissions in a life cycle perspective. Pommier et al. (2016) compared the environmental impacts of four kinds of hull materials (aluminum, composite, exotic wood and maritime pine) by using the LCA theory and ISO 14040 standards, and pointed out that wood had better environmental performance. The above studies generally analyzed the carbon emission characteristics of ship in the main life cycle stages, and demonstrated that the LCA theory can be employed for the ship carbon emission evaluation greatly. However, during the calculation of ship carbon emissions, the stochastic variation of the parameters at each stage of the life cycle will bring uncertainties to the calculation results, which will reduce the credibility of the results. Therefore, this paper takes the uncertainty into consideration and analyzes the influence of uncertain parameters on the ship carbon emissions so as to more accurately identify the carbon emission characteristics of ship in different life cycle stages.
- Transportation > Freight & Logistics Services > Shipping (1.00)
- Energy > Oil & Gas (1.00)
- Energy > Coal (1.00)
ABSTRACT The whole yacht shape consists of overwater formative part and underwater hull part, demanding novel and practical design with excellent appearance and performance. However, conventional design methods are difficult to create satisfactory shape. In this paper, a bionic design method is proposed to obtain the yacht shape, which has the basic features of the bionic object and conforms to the general pattern of yacht design. First, general mathematic laws about yacht shape are deduced by analyzing yacht data. The initial 3D model of the bionic yacht is subsequently created based on key features of the bionic object. Finally, Differential Evolution (DE) is adopted to optimize the feature points of the initial model. An example verified the feasibility of the method, and some performance parameters of the ultimate model were checked. INTRODUCTION The design of yacht shape includes two parts, overwater formative design and underwater hull design, which have intimate connection (Dai, 2013). The former mainly considers that a yacht should possess good navigation performance, while the latter focuses on the visual beauty of a yacht. They required to be carried out in an interactive way to get superior yacht shape (Zeng, 2015). As the rapid expansion of the yacht industry, yacht shape has developed with a trend of monotony, which discords with the novelty and uniqueness of a yacht's nature. This paper tries to put forward a bionic design method for yacht shape, because theoretically natural creatures have evolved to acquire beautiful and practical external forms, and they have been providing inspiration for engineering design (Li and Cai, 2007; Quinn, 2010). Many scholars have studied the method applying bionics to engineering fields. Zhao and Ma (2008, 2010, 2011) developed a standard methodology for bionic mechanical structures with dead-load reduction and performance improvement. Chang and Liu (2016) designed a biomimetic stubble cutter to reduce the cutting resistance, inspired by the Cryptotympana atrata nymph's excellent ability to cut and dig soil.
- Asia > China (0.30)
- North America > United States (0.28)
Establishment of a Comprehensive Fleet Optimization Model for River -Sea-Going Ships under Low-Carbon Economy
Liu, Chao (Wuhan University of Technology) | Cai, Wei (Wuhan University of Technology) | Mei, Menglei (Wuhan University of Technology) | Huang, Guoliang (CNOOC Energy Technology & Services-oil Production Services Co.)
Abstract A comprehensive optimization model is set up to optimize the configuration and speed of river-sea-going fleet within specific transportation environment. This model aims at minimizing the fleet's annual running cost and carbon emission under the condition of meeting the forecasted cargo demand. Genetic algorithm is applied to solve this non-linear problem with multi-variables and multirestrictions. The best ship-type configuration and segmental speed of the fleet can be determined through this optimization, thus providing suggestions for the formation and operation of river-sea-going fleet under low-carbon environment. Introduction River-sea-going transportation is the transportation mode which ship sails directly from inland to sea area with cargo immediately transported from origin port to destination port. This kind of transportation way attracts more and more Chinese shipping enterprises by its advantage of saving delivery costs and lay-time. After 20 years of development, river-sea-going transportation has become the fresh combatant of Yangtze shipping, but there are still many problems exist, which are mainly as follows: the technical level lags behind, and the ship types do not match the transportation environment. The capacities of river-sea-through container ships in Yangtze River are mostly less than 500 TEUs (20-foot equivalent units), which leads to the economic inefficiency and inconformity with the requirements of shipping market. In addition, the problems of ship aging, energy inefficiencies and mismanagement widely exist in inland fleet, which cause the hugeness of the running cost and carbon emission (Mei, 2009). Therefore, it's essential to research on the configuration and service speed of river-to sea fleet to facilitate the regeneration of ship types and achieve the goal of cost saving and low-carbon navigation. The traditional fleet optimization emphasizes on determining the scale and configuration of a fleet in the period of time of the future. Its research objects are the newly-built fleet and the existing one, and its research methodology mainly consists of linear programming and dynamic programming (Yang, 2010). John L Everett (1972) put forward a comprehensive fleet deployment model to optimize the composition of a newly-built American fleet in the next 10 years without considering the ships' sailing speed. Powell and Perkins (1997) proposed a new computing model with the combination of linear planning and integer planning to ascertain the optimal configuration of the fleet in different routes. Yang (2010) fully summarized the research status and solving method of fleet planning. All these researches above didn't mention the ship's speed, which can dramatically affect fuel cost and carbon emission.
- Transportation > Marine (1.00)
- Energy > Oil & Gas (1.00)
- Transportation > Freight & Logistics Services > Shipping > Container Ship (0.67)
Establishment and Analysis of a Comprehensive Economic Speed Model for Multi-purpose Marine Working Boats
Cai, Wei (Wuhan University of Technology) | Chen, Lu (Wuhan University of Technology) | He, Juan (Wuhan University of Technology) | Huang, Guoliang (CNOOC Energy Technology & Services-oil Production Services Co.)
Abstract In this paper, based on the characteristics of deepwater environment protection vessel, an economic speed model for the vessel is established, which is consisted of the fuel consumption function, the economic cost function and the environmental influence function. Under the ship actual operating conditions, the corresponding minimum value of such function is the economic speed. By calculation for an actual case and influence analysis, it shows that sailing with the economic speed can achieve the goal of energy saving, economy and environmental protection.
- Transportation > Marine (1.00)
- Transportation > Freight & Logistics Services > Shipping (0.68)
- Energy > Oil & Gas > Upstream (0.46)