单、双出口双蜗壳泵的压力脉动及径向力特性

为研究两种不同双蜗壳型式离心泵的水力特性,采用RNG k-ε湍流模型和滑移网格技术,对单出口双蜗壳及双出口双蜗壳离心泵进行了不同工况下三维非定常湍流数值模拟,得到不同型式双蜗壳泵内压力脉动情况,同时对两种型式泵的径向力进行定常计算对比分析.结果表明:单出口双蜗壳泵内压力脉动高于双出口双蜗壳泵内的压力脉动;在设计工况和非设计工况下,两种型式泵的隔舌及出口处压力脉动的频率均以叶片通过频率为主;在小流量工况下,单出口双蜗壳泵的出口及隔板起始端位置处频率以叶轮转频为主;两种型式双蜗壳离心泵在不同工况下都能有效地平衡径向力,由于单出口双蜗壳泵内存在较为明显的压力脉动,导致其叶轮受到的径向力较大.     

1 000 MW核主泵导叶体型线检测新方法

为了检测核主泵水力部件数控加工完成后叶片型线的偏离程度,提出了一套水力部件的检测和评定方法．采用逆向工程点云分析软件(PolyWorks)与三维扫描设备相结合,测量导叶体模型叶片与产品叶片进出口压力、吸力面三坐标,同时计算叶片型线偏离的均方根偏差．通过对叶片进出口型线测量数据的统计处理和理论分析,提出叶片进出口型线偏离角度Δβ的计算公式、叶片间叶距角Δφ的偏离公式以及部分叶片型线偏离的修正公式K．结果表明:该方法能够准确有效地检测水力机械叶片型线的分布,保证了各型线有相同的包角．以国内福建福清核电站12号机组以及秦山一期扩建工程方家山核电站主泵导叶体翼型的检测与评定分析为例,经主泵全流量试验验证表明,与数值分析结果相比,主泵流量满足规范偏离设计流量的±25％,扬程偏离±15％的要求．     

Mathematical Model and Operation Analysis of Semi-submerged Rotary Orifice Sewage Source Heat Pump Intake Machine

To solve the flow instability and adjustment difficulty of filtering dirt-removing device in the sewage source heat pump system, which affect the efficiency of heat exchanger, semi-flooded rotary orifice sewage auto-strainer was generated. According to establishing the mathematical model, the effect is analysed of pollutant concentration and liquid level height of sewage and rotation period of orifice plate to filtered flow rate, filtered load and filtering surface block coefficient. The result shows that: in the certain condition of sewage liquid level height and orifice plate rotation period, the increase of sewage will decrease the filtered flow rate of orifice plate, and increase filtering surface block coefficient; The effect of pollutant concentration change in the sewage to orifice plate filtered flow rate could be adjusted by regulating the sewage liquid level height and orifice plate rotation period, and the moderating effect of orifice plate rotation period is better than that of sewage liquid level height.     

Constant rate infusion for topical ocular delivery in horses: a pilot study

OBJECTIVE: To assess the efficacy and kinetics of a continuous infusion modality for topical ophthalmic drug delivery via subpalpebral lavage in horses. ANIMALS STUDIED: Five ophthalmically normal horses PROCEDURES: A constant-rate continuous delivery pump was used to apply 0.01% fluorescein solution to the eyes of five ophthalmically normal horses via subpalpebral lavage. Fluorescein was applied at a rate of 0.14 mL/h for 72 h. Tear samples were collected from the ventral conjunctival fornix at regular intervals via capillary tube and tear fluorescein concentrations were determined via spectral assay. Laboratory studies to evaluate the procedures used in the study also were performed. RESULTS: Overall mean tear film fluorescein concentration was approximately 20% of the applied concentration of fluorescein. However, tear film fluorescein concentrations varied considerably between horses and over time. Dilution varied from 0.62% to 60% of the applied concentration. Air pockets sporadically appeared in subpalpebral lavage tubing lines, resulting in discontinuous topical application of fluorescein. CONCLUSIONS: Constant-rate delivery of ophthalmic medications using a continuous infusion pump may provide a valuable method of topical drug delivery if tear film dilution of drugs is taken into account.     

我国水泵产品质量及其原因分析

根据近年来对国产水泵的抽查检验结果,分析了我国水泵行业在产品结构、生产规模、技术水平、产品质量等方面与国外行业之间存在的差距,剖析了我国部分水泵产品质量低下的原因,提出了解决这一问题的途径。     

热泵式低温循环谷物干燥机控制系统设计与试验

针对以空气源热泵为热源系统的低温循环谷物干燥机存在的一体化控制程度不足问题,设计了一种热泵式低温循环谷物干燥机控制系统。为实现低温循环谷物干燥机和热泵系统的一体化控制,利用可编程逻辑控制器（PLC）技术进行硬件电路设计和软件设计,系统实现了谷物干燥过程的自动和手动等多模式控制,并支持干燥参数的人工调节和设置、谷物含水率及干燥温度的实时监控等功能。试验表明,干燥机在不同模式下均工作正常;所开发的逻辑控制系统具有自动化程度高、稳定性好、安全性高等优势。稻谷干燥试验表明,在不同环境温度下,热泵热风温度平均误差为0.95℃,标准差为0.93℃,系统具有较好的控制精度与稳定性,粮食温度稳定在33℃左右,满足低温循环式谷物干燥机的作业要求。     

The Key Parameters Method of Calculating Geothermal Heat Exchanger Length

The geothermal heat exchanger is the key component of ground coupled heat pump systems. We discuss the key parameters method of calculating geothermal heat exchanger length based on line source theory. Typical meteorological year data is used to determine the hottest month, the coldest month and annual average surface temperature. The building hourly load can be obtained by introducing the concept of equilibrium temperature. The cooling fraction and the heating fraction then can be calculated using building hourly load and performance parameters curve fit of a water source heat pump unit. The method for selecting the hottest and lowest entering fluid temperature and calculating the borehole and ground thermal resistance is given. A vertical U tube heat exchanger length calculation procedure is proposed.     

液泡膜质子泵与植物耐盐相关性研究

土壤盐渍化是一个世界性的资源问题和生态问题,盐分胁迫几乎会影响植物所有重要的生命活动,造成植物的减产或其他不利影响.液泡膜质子泵(H~+-ATPase和H~+-PPase)在植物细胞的跨膜物质转运、胞内pH值平衡等诸多生理活性方面都发挥关键作用.因此,在植物对环境胁迫的响应过程中,液泡膜质子泵活性的调节对植物的耐盐性具有重要意义.本文结合植物液泡膜H~+-ATPase和H~+-PPase的分子结构、生理功能及其在盐胁迫下调节机理的研究结果,阐述了植物液泡膜质子泵的生理功能与植物耐盐性的相关性,并对其仍未解决的问题进行了展望.     

基于支持向量自回归的水泵振动预测模型研究

为了预测水泵在运行中的振动状态,提高水泵运行的安全性和经济性,采用了统计学习理论中的核心算法--支持向量机与自回归方法相结合,建立了水泵振动预测模型(SVAR).并通过实例,与基于灰色理论建立的预测模型(GM)和基于自回归方法建立的预测模型(AR)进行了比较.结果表明:基于支持向量自回归的水泵振动预测模型(SVAR)具有精度高、速度快、易于建模的特点.应用该方法建立的预测模型能够很好地预测水泵运行中的振动情况.有效地避免水泵运行中由振动引起的故障.     

基于PLC的水泵测试控制系统设计

研究了以PLC为控制核心的水泵测试控制系统.采用VB.NET程序设计语言,在Windows操作系统环境下实现上位计算机与下位PLC的串行通信,以实现上位机对下位机的信号采集和实时监控.该系统能够实现对水泵测试过程的实时控制和安全保护.现场测试结果表明,该系统性能稳定,能满足测试要求.