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Energy shortages and environmental pollution are becoming increasingly severe globally. The exploitation and utilization of renewable energy have become an effective way to alleviate these problems. To improve power production capacity, power output quality, and cost effectiveness, comprehensive marine energy utilization has become an inevitable trend in marine energy development. Based on a semi-submersible wind-tidal combined power generation device,a three-dimensional frequency domain potential flow theory is used to study the hydrodynamic performance of such a device. For this study, the RAOs and hydrodynamic coefficients of the floating carrier platform to the regular wave were obtained. The influence of the tidal turbine on the platform in terms of frequency domain was considered as added mass and damping. The direct load of the tidal turbine was obtained by CFX.FORTRAN software was used for the second development of adaptive query workload aware software, which can include the external force. The motion response of the platform to the irregular wave and the tension of the mooring line were calculated under the limiting condition(one mooring line breakage). The results showed that the motion response of the carrier to the surge and sway direction is more intense, but the swing amplitude is within the acceptable range. Even in the worst case scenario, the balance position of the platform was still in the positioning range, which met the requirements of the working sea area. The safety factor of the mooring line tension also complied with the requirements of the design specification. Therefore, it was found that the hydrodynamic performance and motion responses of a semi-submersible wind-tidal combined power generation device can meet the power generation requirements under all design conditions, and the device presents a reliable power generation system. 相似文献
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本文分析了固镇水利枢纽工程新、老节制闸现有启闭机的功率,提出在水闸安全检测中对启闭机功率的分析可以及时发现相关安全隐患,预防安全事故发生,有效保障水闸的安全运行。 相似文献
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《疫情期间豁免机组成员值勤期、飞行时间限制的实施办法》要求执行豁免航班(即不过夜休息航班)机组人员应对各种信号具有较高的检测能力。飞行员信号检测能力代表机组人员信息加工能力的准确性与决策效率, 高效的信息加工及决策效率能有效保障飞行安全。可见, 飞行员选择性注意、持续性警觉与阶段性警觉对飞行安全至关重要。基于信号检测原理, 设计了评估飞行员对选择性、持续性、阶段性3种刺激信号判别能力(d')与判断标准(β)的测试方法。收集了国内飞往北美洲的豁免与不豁免航班中18名飞行员在飞行过程中对上述3种信号的判断结果, 确定了辨别能力与判断标准, 绘制了受试者工作特征曲线(ROC)。结果表明: 在豁免与否2种模式下, 飞行员在去程降落后的疲劳自评感受差异最明显(卡罗琳斯卡嗜睡量表差值=2.333, 机组人员状态检查表差值=1.222);飞行员对选择性信号辨别能力(sig=0.337)与判断标准(sig=0.200)无显著性差异; 豁免航班飞行员对持续性信号的辨别能力(d'=4.149)高于不豁免航班(d'=3.137), 判断标准(β=0.616)低于不豁免航班(β=0.629);豁免航班中飞行员对阶段性信号判断能力(d'=3.916)高于不豁免航班(d'=2.994), 判断标准无显著性差异(sig=0.262)。总体而言, 豁免航班飞行员对3种信号辨别能力高于不豁免航班, 判断标准与平均反应时无显著差异。豁免航班飞行员信号检测能力不会对安全运行产生负面影响。 相似文献
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机电复合增压技术研究进展综述 总被引:3,自引:0,他引:3
传统内燃机近30%的燃油能量被排气带走而浪费,因而高效的余热利用技术是实现内燃机节能减排的核心举措。机电复合增压是基于涡轮增压技术、具有较高潜力的内燃机余热回收技术之一,针对机电复合增压技术的国内外研究进展进行了详细分析。阐述了现有机电复合增压技术的方案布局及其特点、适用范围,讨论分析了该技术与内燃机的匹配方法及控制策略研究进展,介绍了机电复合增压的主要部件(涡轮、压气机和电动机/发电机)研究概况,综述了机电复合增压技术在内燃机节能减排中的优势、发展趋势和须要重点关注的技术难点。 相似文献
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为探究拉索抗弯刚度以及相邻索之间的干扰因素对斜拉索体系自振特性的影响,以两拉索体系为研究背景,构建了可同时考虑拉索抗弯刚度、索力以及相邻索耦合效应的双梁力学模型。该模型上梁与下梁分别用来模拟拉索,中间层用来考虑拉索间的干扰因素,拉索的两端分别采用竖向和旋转弹簧模拟边界条件。基于双梁力学模型,首先给出了两拉索体系自由振动频率与模态函数的理论解;然后针对高阶超越方程无法直接求解的难题,给出了相应的高效的迭代算法;最后通过与有限元结果的对比验证了所提方法的正确性,并就可能影响拉索体系自振特性的几种典型外部因素进行了参数化分析。结果表明:1)所提方法具有较高的计算精度与效率,理论推导正确可靠;2)轴力越大拉索体系的自振频率越大,但轴力对体系的振动模态无影响;3)双梁模型中间支撑的刚度对缆索体系的振动频率与模态有较大的影响,尤其对体系的高阶振动更明显;4)边界条件对体系的自振频率与模态函数影响明显。提出的双梁模型可较好地考虑两拉索间耦合特性,可为求解同类拉索体系的动力响应提供参考。 相似文献