某船用柴油机SCR系统匹配性能试验分析

针对某船用柴油机,在D2试验循环模式下进行原机和加装SCR系统后的性能对比试验,分析SCR反应器在无尿素喷射时对柴油机排气特性和经济性的影响,同时还分析按氮氨比为1∶1进行尿素喷射时SCR系统的工作性能。试验结果表明:柴油机安装SCR系统后,排气背压和排气温度均有所上升;经济性略有下降,额定工况下降低幅度在1%左右;虽然增压器后NOX排气浓度增大,但NOX质量流量下降幅度较大,额定工况下降幅度为12.3%,尿素基本喷射量标定计算应以加装SCR反应器后的柴油机排气参数为依据;NOX加权比排放由原机的12.63 g/k Wh降低到11.52 g/k Wh,降低了8.7%。按氮氨比为1∶1的比例进行尿素喷射时,SCR系统能满足Tire III的NOX排放限值要求。研究结果可为SCR系统设计和尿素喷射量的标定提供一定的指导依据。     

基于正交设计的船用柴油机燃烧系统参数匹配及优化

为研究柴油机燃烧系统参数匹配对柴油机动力和排放性能的影响,首先分别利用AVL_BOOST和AVL_FIRE仿真软件建立4190ZLC-2型船用柴油机整机模型和缸内燃烧高压循环模型,然后基于已建模型应用正交试验设计方法安排柴油机进气系统、喷油系统和燃烧室结构尺寸参数匹配仿真计算。研究结果表明,通过极差分析可以得出燃烧系统参数对4190ZLC-2型柴油机性能的影响主次顺序。以柴油机指示功率为评价指标时,参数组合0.26 mm-28°CA-160°-0.9-145 mm-2.6 mm-22 mm(喷孔直径-喷油提前角-油束夹角-涡流比-喉口直径-凸台高度-凹坑半径)对应的指示功率为63.40 k W,比原机仿真值高15%;以NOX排放为评价指标时,参数组合0.30 mm-24°CA-140°-0.4-135 mm-6.6 mm-14 mm(喷孔直径-喷油提前角-油束夹角-涡流比-喉口直径-凸台高度-凹坑半径)对应的NOX排放质量分数为0.015 7%,比原机仿真值低30.2%。     

玻璃钢防腐蚀材料检测方法

针对海洋环境下混凝土结构易遭受海水侵蚀导致结构破坏、而高性能混凝土等技术措施不能满足高耐久技术要求的现状,采用玻璃钢包覆防腐蚀技术以提高海工混凝土结构耐久性。对玻璃钢包覆防腐蚀材料的原材料和耐久性检测方法进行分析,提出原材料和耐久性检测方法,以利于玻璃钢防腐材料施工质量的控制。     

单侧边载作用下黏土中单桩负摩阻力特性模型试验研究

桩基础边载作用会在桩周产生负摩阻力,进而危及软土地区高桩码头、人工岛、路基等工程的安全。通过开展黏土中单侧堆载作用下单桩室内模型试验,测定桩身应变、桩顶沉降和水平位移,研究边载作用距离和桩型对桩身轴力及弯矩的影响,探讨桩身负摩阻力、桩顶沉降和水平位移在黏土固结过程中的时间效应。结果表明:边载作用距离对桩身最大轴力和最大弯矩有较大影响;翼板桩会增加桩身最大轴力和最大弯矩;负摩阻力和有效应力系数随时间增长且增速趋缓;增加边载作用距离和添加翼板都会提升桩身中性点位置,在这两组试验中均提升了8.33%。     

Analysis of occupational accidents encountered by deck cadets in maritime transportation

The 2010 Manila amendments to the Standards of Training, Certification and Watchkeeping Code (STCW) was adopted by the idea to render the profession more attractive to the seafarers, particularly to cadets. It is possible to ensure greater attraction only by providing suitable and safe working conditions on board to cadets. This study analyses occupational accidents and near misses encountered by ocean going deck cadets, who received A-II/I training, during their sea training. The aim of this study was to determine causal factors influencing work accidents and to propose several recommendations for the safety of deck cadets. A total of 857 officer candidates, who received maritime education at university level in Turkey, were interviewed. The Analytic Hierarchy Process (AHP) method was used in the study to analyse the occupational accidents. As a result of this study on deck cadets, the most risky areas for work accidents were found to be the deck (39.9%), cargo areas (35.7%), areas used for manoeuvring operations (including winch areas and areas in which berthing, unberthing, and anchoring operations take place) (16.1%), and accommodation areas (8.3%). The most important root causes for occupational accidents were identified as not using personal protective equipment (24.2%), haste (22.6%), and presence in inappropriate places (13.6%). This study offers some important insight into the prevention of occupational accidents, and includes suggestions and advisory opinions of sector representatives. As a result of this study, several recommendations for the prevention of accidents are proposed.     

Coastal Tourist Interest in Value-Added,Aquaculture-Based,Culinary Tourism Opportunities

Despite increasing focus on sustainable aquaculture investment in the U.S. coastal zones, the aquaculture industry continues to face skepticism among consumers due to perceived negative environmental impacts, and health and food safety concerns. Partnering with culinary tourism and local food promotion efforts has potential for improving public outreach about the benefits of aquaculture, especially in coastal destinations where sustainable marine aquaculture and tourism are both occurring. Culinary tourism implies that local foods reflect the local livelihood and culture, and may be important to the tourist's experience. Aquaculture is becoming increasingly valuable to coastal destinations for assuring the steady availability of local seafood to meet demand and retaining commercial fisheries as a means to differentiate themselves to tourists. This study examined the role of subjective knowledge and attitude about aquaculture, and their effect on intention to participate in value-added culinary aquaculture tourism experiences. The study found that tourists' subjective knowledge and attitude about aquaculture influenced intentions to participate in culinary aquaculture tourism. In order for farmers or tour operators to be successful in diversifying with value-added culinary aquaculture, attention needs to be paid to educating consumers, which may be possible through strategic partnerships with tourism organizations, chefs, and restaurants.     

Papahānaumokuākea: Integrating Culture in the Design and Management of one of the World's Largest Marine Protected Areas

Papahānaumokuākea Marine National Monument is one of the world's largest marine protected areas and was designated the first mixed conservation site in the United States due to its natural and cultural importance. It is also the world's first cultural seascape, being recognized for its continuing connections to indigenous people. As the westernmost place in the Hawaiian universe, many believe these islands and seas are the pathway that Native Hawaiians travel after death, returning to pō (night; realm of the gods). This intimate kinship has profound implications for contemporary management. Current management emphasizes integration of science, policy, cultural knowledge, traditions, and practices to create successful management strategies appropriate for both natural and cultural resources. This management is based on Native Hawaiian values and practices that incorporate observation and understanding of the natural world, indigenous principles and philosophies, cultural norms, community relationships, and unique epistemologies deeply imbedded in and formed by relationships of people with place. A cornerstone of this effort has been the direct involvement of cultural practitioners in policy, management, education, and research. This biocultural approach has led to more effective management of the monument and serves as a model for conservation around the world.     

Sea Cucumber Moratorium and Livelihood Diversity in Papua New Guinea

Livelihood diversity factors such as flexibility within fisheries, geographical mobility, reallocation of fishing effort into the broader economy, and the non-material benefits that fisheries provide are important areas of research in marine policy. We use two small-scale fisheries related socio-economic surveys of communities in the Tigak Islands of Papua New Guinea. The first conducted 5 years before a ban on the harvesting of sea cucumbers was imposed and the second from the present day, 5 years after the initiation of the ban—with the objectives of exploring changes in household fishing strategies (types and numbers of species targeted) and to identify any important socioeconomic factors that help explain those changes. Fishing's contribution to total household income has increased significantly (p = 0.019) up from 61% in 2004 to 73% in 2014 with the percentage of female residents living in a household now positively and significantly (p = 0.018) associated with fishing income. The average number of species categories targeted per household increased insignificantly while households with more women are significantly (p = 0.018) less likely to target more species than households with more men. Moreover, customary management practices contribute to this difference. Together, these results show that households are not worse off financially 5 years after the ban on sea cucumber harvesting and that gendered seascape use has implications for the role of livelihood diversity as a marine policy tool.     

重载情况下船舶及主机加速问题分析

针对目前一些船舶在恶劣海况下遇到的加速问题,以及通过转速禁区时间过长的问题,从螺旋桨匹配和主机内部设计两方面进行原因分析。围绕转速禁区功率裕度,结合相关案例,从轻螺旋桨裕度、转速禁区及MAN主机输出扭矩能力等方面入手,提出改进措施。     

船用柴油机12PA6B超负荷性能试验研究

我国船用柴油机功率标准规定柴油机应能够在超负荷功率(即110%标定功率)下连续运转。超负荷工况各参数变化可以反映柴油机的整体性能,是船用柴油机负荷试验的重要工况点。本文通过陕柴重工生产的12PA6B柴油机的负荷试验,研究证实该机型在超负荷工况下能保持较低的燃油消耗率和烟度排放,以及较高的功率和扭矩输出。