螺旋吸气式增氧机的性能测试与分析

本文是对螺旋吸气式增氧机性能测试的总结、分析。该机的关键部件为扩散器和螺旋器等。测试结果表明：扩散器的直径、长度和转达与形成的负压大小成正比；螺旋器的直径、螺距比和转速与进气量成正比例关系。该机的增氧百分率达６８．７％；混合速度为１．０５亩·ｍ／ＫＷ·ｈ；当电机功率为０．７５—２．２ＫＷ时，其负荷水面为１．５—５亩。据测试结果分析，该型增氧机的综合性能良好，适于高密度养殖。     

水车式增氧机中太阳能的应用研究

根据目前我国增氧机动力设备的配置情况和布置型式,通过对太阳电池利用的可行性分析,提出增氧机太阳能供电系统方式,并在比较各种增氧机结构、性能的基础上,选择水车式增氧机作为研究应用对象,提出了双车岸置固定式系统方案、双车机置固定式系统方案和单车机置移动式系统方案。实现节约电能、减少环境污染的目标,同时也为太阳电池在水产业中的应用提供了一条途径。     

涌浪式增氧机性能研究

为研究涌浪式增氧机的性能,对13台样机按照标准规定的方法进行增氧性能试验,并对结果数据进行统计分析,同时在养殖池塘中进行提水性能和造浪性能的试验。结果显示:涌浪式增氧机的绝对增氧能力与同功率水车增氧机相近,在标准水池试验的平均增氧能力Q_S和动力效率E_S达到SC/T6017—1999《水车式增氧机》标准的要求;1.5 kW涌浪式增氧机的提水性能可以达到3 006.05 m~3/h,提水动力效率为1 869.4 m~3/kW·h,理论上,一台1.5 kW的涌浪式增氧机运行1 h可以完成一个100 m×50 m标准养殖池塘底层水体和上层水体的交换;涌浪式增氧机可以在距离固定位置30 m的水面形成波幅为80 mm的波浪。研究表明:在实际使用中,涌浪式增氧机的增氧效率优于水车式增氧机;在相同面积的养殖池塘中,使用相同功率涌浪式增氧机的数量比叶轮式增氧机的要少。     

螺旋吸气式增氧机混合性能的简易测试方法

本文介绍了一种测试增氧机混合性能的简易方法,该方法需用仪器设备少,操作方便,精确性较好,易于选用。     

基于实时水质参数的智能养殖装备设计

针对现有水产设备机械化和自动化程度较低,增氧机作用范围有限和投饲机无法自适应投饲的问题,研究设计了一种新型的基于实时水质参数的智能养殖装备。该装备硬件上利用传感器对水质参数进行实时监测,采用太阳能与交流电源混合供电。其中,移动式太阳能增氧机使用超声波测距进行避障,可随机行走、增大增氧机的工作范围;太阳能智能投饲机使用称重传感器进行饲料称重,以实现精确定量投饲。该装备软件上支持个人计算机和手机等多个平台客户端,实现实时水质参数查询、远程增氧、远程投饲、远程智能控制等功能。池塘应用试验结果表明,该装备的监测水质数据可信度高,实时通讯丢包率低于0.2%,在保证增氧能力的情况下,增氧机作用范围比传统水车式增氧机提高10%;能够在良好的水质环境中完成精确定量投饲。研究表明,该装备的应用有助于推进水产设备智能化、自动化的发展,实现节能降耗、绿色环保的目标。     

移动式太阳能增氧机、水质调控机应用效果试验

<正>渔业是对能源、资源高度依赖和对环境生态影响较大的行业,渔业节能减排是指在渔业生产过程中节约能源、降低能源消耗、减少污染物排放。在节能减排已然成为全民行动的大形势下,作为水产行业,也在大力推行新的节能减排的养殖模式和应用一些节能减排的新设备。移动式太阳能增氧机和水质调控机的应用是降低水产养殖过程中能耗的一个关键措施。现选用同等养殖条件的池塘进行应用效果试验,报告如下。     

渔船用太阳能充电器电路设计与测试

针对传统渔船上安装的太阳能电池板所供电压与电流值不稳定和不确定性缺陷,提出一种能检测太阳能电池板两端电压和回路中电流值,并能自动调整对蓄电池充电电流大小的电路设计与实现方法。采用单片机来检测输入端电压和电流值,并判断和选取最合适的蓄电池充电电压和电流,以保证蓄电池能从太阳能电池板上获得最大的充电功率。结果显示,该太阳能充电器能稳定地输出功率,且最大功率点(MPPT)跟踪动稳态精度高,电压连续可调(9~30 V),额定输出电流可达4 A以上,其能量转换效率达96.5%以上。经过在渔船上的试用,其性能和技术指标已基本达到国内外同类产品的先进水平。     

提高叶片式液压泵的效率

叶片泵特别是双作用叶片泵,由于流量均匀、旋转平稳、噪音小、流量大、体积小、效率高而得到广泛应用。它的缺点是对油质要求高和定子曲线较难加工。近来因液压油的清洗过滤已不成难题,定子曲线在专用工夹具下也好解决,如能把它的效率再提高一步,必能得到更大的发展和应用,取得更高的经济效益。 1990年,我厂为了开发远洋作业拖网渔船,采用引进的23/30主机。在起网绞纲时,主机前端输出轴宜用650r/min到700r/min转速驱动液压泵。我厂的SP20液压泵只适用于380r/min以下的转速,故不能直接使用。当时国内也没有适用的液压泵,迫使我们将SP20泵改进设计为SP26泵。其设计工作转速定为700r/min,流量为2600L/min。在试制和座台试验中,攻克了几个难题后获得了成功,并试制了四台机器,经过近海、远洋渔船试用,至今没发现大的问题。     

冰冻杂鱼切块机精准自动控制技术研究

为提高渔业养殖效率,改变现有杂鱼块不平整和破碎率较高等缺点,研制了一种自动化程度较高的冰冻杂鱼切块机。采用变频调速技术,以通用串行通信接口通讯协议实现西门子PLC与MM440变频器通讯,用普通齿轮减速电机进行杂鱼切块宽度调节,用测距传感器进行精确测距,对射式光电计数器进行切块计数。通过PLC控制变频器参数,设置减速电机的运行参数,再运用PLC与上位机之间的串口通讯,实现良好的人机交互,从而完成切块机精准自动控制。性能测试结果显示,在额定电压400 V条件下,切块速度25~35块/min,可将600 mm×400 mm×80 mm的杂鱼板切成宽60~90 mm,宽度可调;空载状态下,功率0.26 k W,负载运行时的转速、功率、扭矩成正比。在指定宽度下,切块精度为±5%,切块个数准确。研究表明,该控制系统可靠,适合在沿海渔业养殖中应用推广。     

菲律宾蛤仔清洗分级整机设计及参数优化

针对捕捞后菲律宾蛤仔清洗不彻底、分级精度低、破损率高、效率缓慢等难题，本研究设计了一种菲律宾蛤仔清洗分级一体机以实现菲律宾蛤仔清洗与分级作业。确定了毛刷辊配合高压喷淋的清洗方法、滚筒式筛分的分级方式，完成了滚筒筛筛分机构、高压水喷淋结构等关键部件设计、选型。开展了清洗分级一体机作业参数的EDEM离散元仿真分析。仿真结果显示：当毛刷辊转速3 r/min、滚筒筛转速15 r/min、滚筒筛倾角3°时，分级精度为91%。经过样机作业测试，在此参数下分级精度达到91%,蛤仔破损率在1%～2%之间，其壳体附着泥沙冲洗干净。研究表明，该清洗分级一体机实现了对菲律宾蛤仔的高效率、高品质的清洗分级。     

基于GSM的对虾养殖场增氧机监控系统设计

增氧机是实现高密度、高产量对虾养殖的重要设备。为保障增氧机连续可靠运行,减少因增氧机故障给养殖户带来的损失,研究并设计了一套基于GSM通信网络的增氧机监控系统。该系统由手机终端和监测执行终端组成,监测执行终端以STC12C5A32S2为主控芯片,并采用AC电流检测电路及SIM900模块对增氧机运行状态进行监测及远程通信。通过手机终端,养殖户可实现对增氧机运行状态的实时监测和控制。当增氧机工作异常时,系统会立即以电话方式通知养殖户,并开启本地声音报警;如果养殖户配备了备用增氧机,系统会自动打开备用增氧机。实际应用效果显示,该系统能够满足养殖户对增氧机实时监控的需求,运行稳定、装配简易、操作方便,可有效降低养殖户巡查和维护的强度。     

Design Characteristics of Spiral Aerator

In this study, the performance of a spiral aerator, a modified design of the paddlewheel aerator, was evaluated to determine its applicability in aquaculture ponds. The aeration characteristics of the spiral aerator were determined by conducting aeration experiments in a cement concrete tank of dimension 5 × 5 × 1.5 m. Nondimensional numbers related to oxygen transfer (E) and power consumption (Ne) were proposed and expressed as functions of geometric (number of handles per shaft, n) and dynamic (Froude and Reynolds number) parameters. Simulation equations for oxygen transfer and power consumption based on the Froude criterion were developed. The maximum brake power standard aeration efficiency was achieved at n = 13. Finally, an economic analysis was performed assuming a typical Indian major carp culture pond to determine the optimum rotational speed of the aerator at different pond volumes and dissolved oxygen concentration present in the pond at which the aeration cost is minimized. The results showed that the least aeration cost is achievable when rotational speed of the spiral aerator is only 70 rpm for pond volumes up to 700 m³ and from 120 to 220 rpm for pond volumes exceeding 700 m³.     

Retinomotor responses of juvenile bluefin tuna Thunnus thynnus

SUMMARY: In bluefin tuna culture, a high mortality of juveniles is caused by bumping into the tank and net-pen walls at dawn. This bumping can possibly be attributed to visually disoriented behavior of the fish. To examine this possibility, the authors carried out retinomotor response experiments with juvenile bluefin tuna (50.7–96.8 mm total length, at which they were transferred from a indoor tank to a sea net-pen) and measured ambient light intensity at the culture site at dawn. The light intensity at which the transition from scotopic to photopic vision takes place was 7.52 lx and the time taken by the transition was 15 min. At dawn, the ambient light intensity rapidly increased from scotopic light intensity level and attained photopic light intensity level in 10 min. This incompatibility of the retinal adaptation with the change in the ambient light intensity could cause the visual disorientation of the fish. It is therefore possible that the visually disoriented juveniles cannot control their high power swimming and thus bump into the walls at dawn.     

电麻醉对西伯利亚鲟幼鱼行为特性与血清离子浓度的影响

研究了不同强度电麻醉对西伯利亚鲟幼鱼行为特性与血清离子浓度的影响。西伯利亚鲟电麻醉阶段包括部分失去平衡期、完全失去平衡期、完全麻醉期和鳃动停止期等4个时期。电麻醉时西伯利亚鲟呈现趋阳性;随着电压升高,到达各麻醉阶段时间与恢复时间逐渐缩短。西伯利亚鲟到达完全麻醉期时间在15 V、20 V、25 V、35 V组间均有显著差异,在30 V与35 V时分别仅为97.0 s和68.8 s,而恢复时间为0 s。各试验组西伯利亚鲟在电麻醉时鳃动频率均增加,而恢复阶段均降低。电麻醉对西伯利亚鲟摄食与活动状态均无显著影响。随着电压升高,钾离子与镁离子浓度先下降后上升,钙离子则先上升后下降。钠离子与氯离子浓度变化较大,均是15 V组时浓度最低,20 V时浓度最高。磷离子浓度呈现增高趋势。pH值在麻醉后降低,对照组与其余各组均有显著性差异。因此西伯利亚鲟幼鱼适宜电麻醉强度为25~30 V,电麻醉是种较好的麻醉方法,具有广泛的应用前景。     

Diversified aeration facilities for effective aquaculture systems—a comprehensive review

The growing intensive aquaculture system around the world maintains a high stocking density, wherein it is essential to increase and sustain the optimum dissolved oxygen concentration (DO) through the provision of artificial aeration systems. The selection of an aerator is a crucial aspect of aquaculture operations. The selected aerator must be economically efficient and should be able to fulfill the requirement of oxygen supply in the pond water. The present study provides an extensive literature review on the importance of artificial aeration in aquaculture, the standard method of test for performance evaluation of an aerator, various aeration systems and their mechanisms, method to determine the numbers of aerator requirement, comparative studies of different type of aerators, and economic consideration in selection of aerators. In addition, a thorough analysis has been done to suggest the type of aerator that is economically viable and efficient for different pond volumes based on the performance data reported in the reviews. Therefore, this study may help the end-users (fish farmers) to select the best aerator based on their requirements.

     

水车式增氧机性能试验研究

研究了水车式增氧机在清水试验中的增氧能力、动力效率以及实际养殖池塘试验中上下水层溶解氧变化。结果表明,水车式增氧机对于水深为1 m以内的养殖水体具有良好的增氧和搅拌效果,开启100 min左右,可使距增氧机10 m、水深0.9 m处水体溶氧值从6.5 mg/L左右上升到8.7 mg/L左右,和上层水体溶氧值趋于一致;运转时可形成一股较大的定向水流,对鳗鱼等喜好水流的鱼类较为适合。但水车式增氧机对<1.5 m的底层水体增氧作用较弱。本研究为水车式增氧机池塘养殖的运用提供了有益的借鉴。     

Water circulation induced by mechanical aerators in a rectangular vessel for shrimp aquaculture

A water streamer was designed for the purpose of enhancing cost-efficient circulation between the water surface and bottom of shrimp aquaculture ponds. We took direct measurements of the water current field induced by the designed aerator in a large rectangular reservoir of dimensions (L)50 × (W)19 × (D)1.3 m³ and compared the results with those of a standard Taiwanese paddle-wheel aerator. Vertical circulation between the surface and the bottom induced by the paddle wheel aerator was less than that by the designed aerator. Furthermore, the paddle-wheel aerator consumed more electric power than the designed aerator. The structures of water current induced by the two aerators are elucidated, and the advantages and disadvantages of the aerators are discussed.Auxiliary employment of the designed aerators may contribute to delivery of high DO water throughout the pond, which is more efficient than a paddle wheel aerator.     

电麻处理对低温贮运鲫生理生化的影响

研究电麻处理对低温贮运鲫生理生化的影响,确定适宜的电麻电压和时间.对鲫(Carassius auratus)用不同电压(0,10,15,20,25,30 V)电麻5 min及用20 V电压电麻不同时间(0,2,4,6,8,10 min)后低温贮运,测定其存活率、血液生化指标、氨氮排泄量.结果表明.电麻处理可降低鲫对暂养水温急剧变化的应激反应,20 V电麻4～6 min时存活率最高,电麻组鲫的皮质醇、血糖、乳酸脱氢酶、谷草转氨酶活性及氨氮排泄量均低于对照组,其中用20 V电麻6 min时鱼体内血液指标活性最低,低温贮运保活效果最好.     

Aerator energy use in shrimp farming and means for improvement

Estimates of aeration energy use in shrimp farming varied from 11.4 to 41.6 GJ/t shrimp (average = 19.8 GJ/t). Several opportunities for reducing energy use in aeration are available. Many farms adopt an excessive yield to installed aeration capacity ratio. Moreover, the proportion of installed aerator capacity in use and duration of aerator operation per day are often more than necessary during the initial two‐thirds of grow‐out, because adjustment is not made for the quantity of shrimp biomass. Farm‐made, long‐arm aerators used in Asia have several features leading to energy inefficiency and could be replaced by more efficient factory‐made, long‐arm aerators. Asian aquaculture aerator manufacturers should redesign aerators to include design features shown in research to improve efficiency. Dissolved oxygen concentration monitoring essential for verification of aeration performance is seldom performed by shrimp farmers. With good aeration technique, energy use for aeration should not exceed 10–15 GJ/t shrimp.