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1.
通过对网箱框架、网衣在风、浪、流作用下的受力分析 ,建立网箱锚泊系统缆绳受力计算的数学模型。以国家十五“86 3”计划课题—“深海抗风浪网箱的研制”所设计的网箱为例 ,选定山东荣成市寻山海域 1 0年一遇的灾害海况为设计计算条件 ,根据 Morison公式 ,采用 Goodman- L ance方法求得单个网箱的锚泊力为 6 5 .6 7k N。在此基础上对网箱的锚泊系统进行设计 ,确定了锚泊系统每只锚重 2 5 0 kg,锚链重为 1 5 0 kg,缆绳长度为 33m。  相似文献   

2.
圆柱形沉浮式深海养殖网箱的受力分析   总被引:9,自引:0,他引:9  
应用一系列力学关系,研究了深海圆柱形沉浮式养殖网箱所承受的波浪力情况。导出深海沉浮式养殖网箱的运动方程,并给出数值计算。在网箱波浪力的研究中采用绕射理论和Morison方程,讨论了在波高、波长及周期变化下水动力的变化趋势,得出网箱所受到的水平波浪力远大于竖直波浪力,波高的变化对波浪力的影响最大的结论,为深海网箱的设计校核提供1种参考方法。  相似文献   

3.
柔性结构养殖网箱的抗风浪性能试验报告   总被引:8,自引:1,他引:8  
本文报道了以柔性绳索作为承爱和传递波浪作用力的主结构的柔性养殖网箱的抗风浪性能试验结果。在9914号特大台风的正面袭击下,这种网箱能基本保持完好,表明它具有十分优越的抗风浪性能。通过对试验环境的初步分析表明,该网箱系统能抵抗住海面波高在4.7米以下、波长在76.95米以内的台风浪袭击,可满足福建省大部分近海海面在十年一遇台风重现期条件下的近海网箱抗风浪养殖的要求。  相似文献   

4.
HDPE深水网箱抗风浪流性能的海区验证试验   总被引:5,自引:0,他引:5  
吴常文  朱爱意  沈建林 《海洋工程》2007,25(2):84-90,97
对HDPE深水网箱2000~2004年间的抗风浪流性能进行了海区验证试验.通过对HDPE深水网箱扶栏、框架、网具以及固泊系统受损率的统计,根据扶栏、框架、网具以及固泊系统在整个深水网系统中的重要程度,分别给予一定的权重统计出深水网箱的整体受损率,能比较客观地反映深水网箱的抗风浪流性能.海区验证试验结果表明,HDPE深水网箱抗风力达35 m/s、抗浪高6 m、抗流速1.0 m/s,与其设计参数基本相同.同时,为了增加HDPE深水网箱的抗风浪流性能,建议扶手管从110 mm改为125 mm、主浮管从250 mm改为300 mm、扶栏高度从1 m降低为0.8 m或0.6 m.风力主要影响扶栏系统,流速主要影响网具系统,而波浪对HDPE圆形浮式深水网箱的框架、网具、固泊系统以及网箱整体结构均有明显影响.  相似文献   

5.
浅谈深海抗风浪网箱养鱼业   总被引:2,自引:1,他引:1  
1发展深海抗风浪网箱养鱼业的意义随着生活水平的不断提高,人们对水产品的需求量不断增加。由于海洋自然鱼类资源日趋衰退,所以水产养殖业在全国沿海得到了迅猛发展,致使中国的近海内湾海域已处于高度的饱和状态,不少内湾海域已破坏了生态平衡,导致病害频发,产量下滑,效益降低,严重制约了中国海水养殖业的健康可持续发展。但是湾外广阔的深海水域资源受环境和技术条件的限制,长期处于荒废闲置状态。  相似文献   

6.
为了促进深远海养殖装备朝智能化方向发展,解决电能供给困难的问题,克服抗风浪网箱受波流耦合作用对太阳能和风能利用的局限性的问题,针对养殖区域的低流速海域,提出了一种适用于深远海可升降网箱的横轴半潜式潮流能发电装置,建立了Savonius型水轮机叶片受力数学模型,分析了叶轮中心与水面的距离对水轮机捕能效率的影响,利用Fluent软件数值模拟了导流增速浮体的速度场情况,设计了发电装置整体结构及锚泊系统,搭建了发电装置试验模型,开展了物理模型试验,测试了不同水流速度情况下与叶轮相对离水距有关的各参数变化情况,并对试验数据进行分析。试验结果表明,在不同的水流流速下,随着离水距的不断增加,捕获功率呈先增加后减小的趋势,当叶轮中心高出水面1/4个叶轮直径时,叶轮的输出功率最大。  相似文献   

7.
随着近海渔业的枯竭,海洋养殖业逐渐向深远海发展,但深远海养殖易受极端天气影响,本文基于海洋采油平台设计了一种八边形单元升降式网箱,为降低极端天气对养殖效益的影响提供了可能。针对单元升降式网箱结构安全性问题,本文基于ANSYS/Mechanical建立了单个单元网箱和四单元网箱在水面和水下两种状态的分析模型,通过相位角搜索程序确定不同状态下的工况,最终计算出两组网箱在两种状态下的应力和变形情况,完成对网箱强度的校核。仿真计算结果表明:单元升降式网箱可以通过下降到水面以下的方式有效应对极端天气;支撑桩腿与套筒之间的连接处是单元升降式网箱的结构薄弱处。单元升降式网箱为模块化、高效益化、灵活化深海养殖提供了一种解决方案。  相似文献   

8.
针对深海运载器海底岩芯原位取样作业需求,对基于水下运载器的深海原位取芯钻机在深海低温、高压、底层流速多变等特点条件下的作业机理及受力进行分析,并选取硬质合金钻头和PDC钻头进行了取芯钻头的轴向力、切向力和切削功率的数学力学对比计算,确定了单环四齿周向均布的金刚石复合片(PDC)钻头设计方案。在理论分析基础上,针对深海钴结壳设计了台架试验,开展钻进试验研究。通过理论计算和实验研究,探寻了一种基于深海运载器的钴结壳小型钻机设计方法,确定了钻机功率、转速、钻进正向压力和取芯率等基本参数选取范围,对开展海底岩芯原位取样作业具有重要的指导意义。  相似文献   

9.
浅海抗风浪网箱养鱼技术研究   总被引:1,自引:0,他引:1  
浅海网箱养殖是现代海水养殖业发展的重要途径。由于我国东南沿海多台风和热带风暴 ,加上现有海水网箱结构大多属于小型简陋型 ,结构非规范化 ,抵御海洋自然灾害能力弱。而国外开发的抗风浪网箱养鱼技术投资成本很高 ,技术复杂 ,在我国推广有一定的难度。因此 ,开发适合我国国情的浅海抗风浪网箱养鱼技术就成为必要。有关浅海抗风浪网箱养鱼技术至今未见报道。本文将作者近年在这方面开展的研究所获成果报道如下。1材料与方法1.1材料分别选择浙江乐清湾中心水域的抛西海区、大坦海区和湾口外侧的南排山海区为试验区。水深10m ,底质为…  相似文献   

10.
一种适用于网箱耐流特性有限元分析的网目群化方法   总被引:3,自引:0,他引:3  
养殖网箱耐流特性是网箱工程设计中的重要问题之一,探求对这一问题的数值解法在近几年得到了空前的重视。但是,由于深水抗风浪网箱箱体规模大,如果在有限元分析中单纯以网衣网目脚为单元进行数值计算,其计算量相当庞大。文中介绍1种可供网箱箱体有限元分析的网目群化方法,根据保持群化前后网衣水中重量和投影面积相等以保证网箱网衣总体水动力相同的原则,将若干个真实网目群化为1个虚拟的计算网目,以达到有效减少计算单元、提高运算效率和节省运算时间的目的。通过不同群化条件下数值例的计算结果与实验值的比较,验证网目群化方法的可行性。在一般条件下,8×8群化或6×6群化能够有效实现计算精度与计算效率的兼顾。  相似文献   

11.
A heaving-buoy wave energy converter equipped with hydraulic power take-off is studied in this paper. This wave energy converter system is divided into five subsystems: a heaving buoy, hydraulic pump, pipelines, non-return check valves and a hydraulic motor combined with an electric generator. A dynamic model was developed by considering the interactions between the subsystems in a state space form. The transient pressures caused by starting/stopping the buoy or closing/opening the check valves were predicted numerically using the established model. The simulation results show that transmission line dynamics play a dominant role in the studied wave energy converter system. The length of the pipeline will not only affect the amplitude of the transient pressures but also affect the converted power. The variation of the time-averaged converted electric power with the pipeline length is estimated using the simulation method for the buoy exposed to one irregular sea state. Finally, it is suggested how reduced power efficiency due to the pipelines may be ameliorated.  相似文献   

12.
为了解决振动水柱式波浪能转换装置收集多向波浪问题,本文设计了半球形多向聚合波道振荡水柱气室结构,以适合远海单点波浪能采集和发电。在规则波正向入射条件下,基于流体仿真分析软件(FLUENT)、流体动力学连续性假设和粘性不可压缩流体动量守恒的运动方程(Navier-Stokes方程)建立半球形振荡气室和三维数值波浪水槽模型。仿真结果表明:增设气室后壁,合理设计波道开口角度实现多向迎波捕获波浪能,优化前壁形状可降低波浪触底反射带来的能量耗散,同时提高了气室内空气压强和出气口速度,有效提升波浪能俘获效率,为后续发电的二次能量转换提供高效的空气动力。  相似文献   

13.
Energy harvesting is a topic of global interest in both academic research and practical application across many fields. The main concept in energy harvesting is to convert wasted ambient energy into useful electrical energy. In particular, piezoelectric materials can be used to convert strain energy into electric power directly, and piezoelectric materials can be used to harvest external vibration forces.This paper proposes and develops a highly flexible piezoelectric energy device (FPED) to harvest flow-induced vibration by converting ambient kinetic energy such as ocean, current and wind energy into electric power. The energy harvesting device uses piezoelectric layers (e.g. PVDF) and elastomer materials (e.g. rubber or silicone) to achieve high electric performance and efficiency. The design of the FPED was optimized by considering the aspect ratio, support system, initial tension and incorporates a bluff body to generate turbulence. A theoretical model based on the transfer matrix method was used with the initial tension force and natural frequency of the harvester. The model demonstrated the maximum electric performance and optimized the structural layers and size under the parameter studies. Numerical and experimental results proved the potential of the highly flexible piezoelectric energy device to convert ambient kinetic energy from flow-induced vibration into useful electrical energy.  相似文献   

14.
This paper presents the test of a ship model for the design of a backward-bent duct oscillating water column type wave energy conversion system, to supply electric power for a light ship. This system suggests a new way to produce electric power automatically for large light ships.  相似文献   

15.
提出了一种新型综合发电船,其主要由驳船、波浪能转换装置、风能转换装置、太阳能转换装置和其余发电相关设施五个部分组成;本装置基于驳船这一可移动载体,能够根据实时能源情况更改工作场地,是一个可移动的分布式能源供应系统,它能够综合利用选定区域内的波浪能、风能和太阳能进行发电,解决现有海上能源发电系统存在的发电效率低、稳定性差和单元发电成本高等问题。文中详细阐述了该发电装置的结构和工作原理,并从设计、运用等方面浅析了该发电装置的优点。这种综合发电船具有较大的推广性和实用性。  相似文献   

16.
An energy conversion system based on deep-sea pressure   总被引:1,自引:0,他引:1  
A novel seawater pressure energy conversion system that utilizes seawater pressure to generate electricity has been studied in this paper. The energy conversion system utilizes the pressure difference between the pressurized seawater and the empty pressure container to drive hydraulic motor and the coaxially coupled generator to generate electric power. The output electric energy is recorded by the data logger throughout the process. In the current study, technical analysis is performed with the emphasis on conversion efficiency between seawater pressure energy and output electric energy. The analysis is conducted at various pressure differences through the throttle valve so as to obtain maximum conversion efficiency. Research shows that the optimum pressure difference through the throttle valve and the maximum conversion efficiency can be theoretically calculated when the properties of the conversion system are given. Simulation results have demonstrated the influence of pressure difference on conversion efficiency. The test apparatus has been designed, built and tested in 2004. It successfully generated electric energy of approximately 0.85 kW h at the depth of 2400 m with empty pressure container's holding capacity of 200 L in the voyage “DY105-16” in South China Sea on June 12, 2004. The actual conversion efficiency from seawater pressure energy to electric energy reaches as high as 63.8% which is attractive for underwater equipments. The success of the experiment has tested the feasibility of utilizing seawater pressure energy and brings a new power supply way for long-term in-situ underwater equipments.  相似文献   

17.
A new approach to automatic solar disk state detection by all-sky images using machine learning methods is developed and implemented. The efficiency of the most widely used machine learning algorithms is analyzed. The effect of reducing the dimensionality of the feature space on the classification accuracy is estimated. The multilayer artificial neural network model has shown the best accuracy in terms of the true score. The operation result demonstrates the effectiveness of machine learning methods applied to solar disk state detection by all-sky images.  相似文献   

18.
以低功耗、多参数、安全可靠为设计目标,提出一种基于北斗卫星通信的海洋多要素观测系统设计。设计以嵌入式微控制器STM32F103RET6为核心,实现以漂流浮标为载体的海洋环境噪声测量,同时实现对海洋气温、气压、风速、风向及表层海温的多要素观测;以可充电锂电池组和太阳能电池板组合方式供电,同时进行必要的电源管理,有效提高漂流浮标的工作寿命;采用我国自主知识产权的北斗系统进行定位及双向通信,安全性高。实验表明,基于北斗通信的海洋多要素观测系统设计具有可行性,满足低功耗、多参数、安全可靠的设计要求,为以表面漂流浮标为载体的海洋多要素数据采集控制提供新的硬件设计方法。  相似文献   

19.
The hydrostatic energy of high-pressure seawater is a renewable and green energy source for ocean exploration and have been used to replace underwater electrical energy transmission through the cable and underwater battery pack to power seafloor equipment. The advantage of the energy supply method is the cost-effective and the robustness. In the paper, the energy performance of the existing hydrostatic seafloor sediment samplers powered by seawater hydrostatic energy are modelled and analyzed and compared. In view of the common shortcoming of existing technology, a novel hydrostatic seafloor sediment sampler is proposed. The model of energy conversion of the new sampler is built, and its energy performance is obtained. The analysis results indicate that the energy conversion efficiency of the novel sediment sampler is much higher than the existing ones, which means that the new sampler can collect much longer sample with the limited amount of hydrostatic energy. The seawater hydrostatic energy conversion system of the new sampler can also be used to power other seafloor equipment.  相似文献   

20.
利用雷雨、大风等灾害天气资料和电力事故历史数据资料,分析了电力事故发生的时空分布特征及其与雷雨、大风、日平均气温等天气要素之间的关系。进而利用事件概率回归(regression estimation of event probability,REEP)和Logistic回归分析方法,得到了日照市电力事故发生概率与雷雨、大风和日平均气温之间关系的预警模型。研究结果表明:1)雷雨、大风是造成日照市电力事故的重要气象因素。2)雷雨、大风和高温等灾害天气对电力事故的发生虽都有促成作用,但影响能力存在较大差距。3)两种回归分析模型对因子和变量之间关系均有较好的拟合效果,相较而言,REEP模型更为直观,Logistic回归分析方法更为客观,适用性更强。4)回归分析结果建立在客观资料基础上,回归模型具有准确性、实用性,可为电力事故预警发布系统提供理论和技术支持。  相似文献   

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