内燃机泄放失效机油存在的问题及解决方法

指出了内燃机油底壳上放油螺丝在使用中存在的问题 ,分析由此而引起的后果 ,提出了排放失效机油过程中所需达到的要求 ,介绍了内燃机机油专用放油阀门     

循环式燃油系统故障仿真及特征分析

介绍了一种船舶柴油机用循环式燃油系统的结构特点,详细分析了这种燃油系统的燃油压力波形特征。对该不同燃油粘度、不同燃油比重和１２种典型故障下的燃油喷射过程进行了计算机仿真计算和特征参数的相对偏差分析,揭示了各种故障的燃油压力波形特征及与系统故障的内在联系,分析了各特征参数对不同故障的敏感特性。     

Fatigue damage calculation for oil tanker and container ship structures

The fatigue behaviour of longitudinal stiffeners of oil tankers and container ships, subjected to dynamic loads, is analysed. The following dynamic load components are considered: hull girder vertical wave bending moment, alone and combined with the horizontal wave bending moment, hydrodynamic pressure and inertial forces caused by cargo acceleration.

The spectral method was selected to calculate the fatigue damage, based on S—N curves and Miner's rule. Following this approach, the fatigue damage may be calculated as a function of a stress parameter Ω_p, which represents the cumulative effect of wave induced loads in the unit of time and incorporates the combined effects of stress level and its occurring frequency.

Simple formulas for Ω_p of oil tankers and container ships are given, obtained from the results of hydrodynamic analyses performed on several ships, in different wave environments.

Several examples show the applicability of the methods to real ship structures. The method, however, still needs to be calibrated because of the simplifying hypotheses introduced in the loading conditions.     

湿式离合器出油口甩出油温度预测方法

为了实现对湿式离合器出油口甩出油温度传感器的冗余校验和自我诊断，提出了一种基于粒计算约简的离合器出油口甩出油温度的模糊预测方法。首先分析出油口甩出油温度的影响因素，将主要影响因素作为预测输入量，并采用模糊推理理论预测当前离合器出油口甩出油温度。在设计模糊预测方法的过程中，通过分析实车数据得到车辆行驶时离合器处于高滑摩功率过程和低滑摩功率过程的不同特性，分别确定相对应的隶属度函数和模糊预测规则，从而进一步提高出油口甩出油温的预测精度。为了提高模糊预测算法的实时性，基于模糊预测规则创建模糊决策表，模糊输入量和模糊输出量分别作为决策表的条件属性集与决策属性集。利用粒计算理论对模糊决策表的条件属性集进行属性约简，通过削减冗余信息有效降低模糊输入量和模糊预测规则的个数。最后利用实车采集的数据对比分析约简前后模糊预测算法的单步运行时间和预测误差等性能指标。试验结果表明：基于粒计算约简的模糊预测算法能够有效保障预测精度，同时拥有更少的模糊预测规则数和模糊输入量，有效解决了模糊预测算法占用资源较多以及实用性较差的问题。     

关于中速柴油机机油消耗率问题的探讨

阐述了中速柴油机机油消耗率的影响因素及针对这些因素可采取的降低机油消耗率的几点措施.     

The Offshore Wind Power Debate: Views from Cape Cod

Wind power resources on the eastern U.S. continental shelf are estimated to be over 400 GW, several times the electricity used by U.S. eastern coastal states. The first U.S. developer proposes to build 130 large (40 story tall) wind turbines in Nantucket Sound, just outside Massachusetts state waters. These would provide 420 MW at market prices, enough electricity for most of Cape Cod. The project is opposed by a vigorous and well-financed coalition. Polling shows local public opinion on the project almost equally divided. This article draws on semistructured interviews with residents of Cape Cod to analyze values, beliefs, and logic of supporters and opponents. For example, one value found to lead to opposition is that the ocean is a special place that should be kept natural and free of human intrusion. One line of argument found to lead to support is: The war in Iraq is problematic, this war is “really” over petroleum, Cape Cod generates electricity from oil, therefore, the wind project would improve U.S. security. Based on analysis of the values and reasoning behind our interview data, we identify four issues that are relevant but not currently part of the debate.     

洗扫车清扫液压系统热平衡研究

针对洗扫车作业过程中液压油温过高造成的液压系统运转不正常的问题,在理论分析的基础上运用AMESim软件建立液压系统的热力学模型,对其热平衡特性进行仿真分析,并依据仿真结果为清扫液压系统匹配合适的散热器。在建立模型的基础上,针对产热和散热部件进行优化分析,为液压部件选型提供参考。仿真结果表明,优化方案合理。     

舵柄与舵杆无键液压套合连接推入量计算

介绍了舵柄与舵杆无键液压套合工艺的优点。对这种工艺的工作原理、受力计算及液压套合推入量计算作了分析并探讨其实用的计算方法和计算公式。     

深水定位系统的安全管理(英文)

Based on relevant in-service experience, this paper discusses how risks associated with station-keeping systems can be controlled through adequate design criteria, inspection, repair and maintenance practice, as well as quality assurance and control of the engineering processes. Particular focus must be placed on quantitative design for system robustness. The application of structural reliability analysis to quantify safety is briefly reviewed. In particular it was emphasized that reliability predictions based on normal uncertainties and variability yielded lower failure rates than those experienced for predictions of hulls and catenary mooring systems; gross errors in design, fabrication and operation were responsible. For this reason the broad safety management approach mentioned above was proposed. Moreover, it was found that this approach needed to be supported by a quantitative risk assessment. Finally, the challenges in dealing with the effects of human factors in risk management are outlined, along with means to deal with them in a qualitative manner, by the so-called barrier method to limit risk.     

液态硫磺运输船热煤油加热系统及罐体保温研究

针对液态硫磺的物理特性及运输条件,使用热煤油加热系统对液态硫磺进行保温、加热.对液态硫磺船加热系统中的硫磺罐保温层、热煤油加热系统做了分析,提出硫磺热煤油加热系统的可行性设计方法、经济保温层的计算公式,阐述了硫磺罐加热盘管设计应注意的问题.