超声波防除积垢节能技术及设备开发

传热设备的积垢问题一直是人们急于解决的一大难题，不仅影响热能利用和生产正常运转，而且会降低产品质量，增加生产成本。通过机理研究、室内试验和工厂试验，揭示了超声波防除积垢的机理，筛选出最佳的声场参数，研制出一种新型的超声波防除积垢设备，室内试验和工厂试验结果表明，超声波技术不但可以防止新垢的产生，而且可以有效地去除已有积垢，显著地提高蒸发系统传热系数和生产能力，可停止使用化学清洗剂，从而延长传热设备使用寿命，避免污染环境，该技术有可能广泛地应用于制糖工业、化肥工业、制浆造纸工业等诸多领域。     

高压静电场抗垢性能的实验研究

通过静态和动态两种方法,进行了高压静电抗垢强化传热实验研究.静态实验结果表明,高压静电场能够使污垢晶体形态发生改变,由六面体结构变为树枝状和薄片状结构,并促进污垢晶体尺寸的增大.动态实验结果表明,成垢溶液经过高压静电处理以后,污垢热阻明显减小,流速的增大能够增强抗垢能力.     

超声波强化传热的链式反应机理与模拟研究

利用超声外场作用实现强化传热的技术越来越受到人们的关注。本文开展超声波强化传热技术的作用机理分析及数值模拟研究。在理论方面,提出了超声波强化传热机理的新解释——"空化链式反应";在数值模拟方面,建立了超声波强化换热的数值模型,验证了超声波对换热的强化作用。理论分析显示超声空化核心的链式破裂具有减薄边界层、增强换热的效果;模拟给出了不同波动压力和频率下的强化换热情况,当驱动压力为7 kPa和频率为20 kHz时,超声波对流体传热的强化效果最好。     

超声波对池沸腾换热影响

对不同超声强度和辐射距离条件下过冷池沸腾换热特性进行了实验研究.超声波有效强化了沸腾起始段换热,对高热流密度沸腾传热也有一定的强化作用.超声辐射距离越近,强度越大,强化传热效果越好.对单相对流和沸腾起始区传热,超声波强化传热机理为空化作用;高热流密度沸腾时超声波对强化传热的主要机理是声流作用.得到了传热实验关联式.     

超声波对脉动热管传热影响的实验研究

本文通过实验研究了超声波作用下不同操作温度对脉动热管传热性能的影响。实验结果表明,超声波对脉动热管的传热性能有强化作用,但超声波的强化传热作用会随着热负荷的升高而逐渐减小;超声波能有效减小脉动热管的热阻,且其减小量与操作温度有关,当操作温度由20℃增加至40℃时,超声波对脉动热管传热性能的强化作用会逐渐增强,当操作温度由40℃增加至60℃时,超声波对脉动热管的强化作用逐渐减弱。     

高压静电抗垢强化传热实验研究

在污垢热阻动态监测装置上,进行了高压静电抗垢强化传热实验研究．结果表明,成垢溶液经过高压静电处理以后在换热表面结垢减轻,污垢热阻明显减小,阻垢率可达到56．5％．对污垢晶体的扫描电镜观察表明,高压静电处理后污垢晶体形态发生了改变,由结构致密型的霰石改变为结构松散的不定形体,从而不易在换热表面结垢。     

气液固三相流载气蒸发的抗垢性能

分析了化工设备换热面上碳酸钙碱性污垢生成及其影响因素,认为液体在加热壁面上的过热是导致碳酸钙碱性污垢沉积的重要原因,降低料液在加热壁面上的过热度可收到明显的防垢抗垢效果。在蒸发器加热管内引入少量的惰性气体(载气)与流态化固体颗粒,使之形成气液固三相流载气蒸发,可显著强化传热,降低料液在加热壁面上的过热度。以碳酸钙模拟工业硬水的实验结果表明,气液固三相流载气蒸发过程表现出明显的防垢抗垢效果,且具有一定的在线清洗作用。     

超声波强化膜分离的研究进展

本文综述了超声波强化膜分离的机理，国内外超声波强化膜分离的研究现状以及影响超声波强化膜分离的因素(如声场参数、操作参数、料液性质等)；同时评述了该技术存在的问题。现有的研究成果表明：如何在利用超声波提高膜分离效率的同时，减小超声波对有机溶质及膜稳定性的影响，应是近期的研究重点。     

超声作用下不同粗糙度表面沸腾换热实验研究

本文以水为工质,不同粗糙度平板作为加热壁面,对有无超声波作用下的过冷池沸腾换热特性进行了实验研究。结果表明:有超声波辐射时,自然对流及沸腾起始阶段强化作用较强,有效消除了光滑加热面上形成的壁温过冲现象;在高热流密度段超声波对沸腾传热影响很小,一定声强下光滑表面沸腾传热甚至出现了阻碍作用。     

垂直套管环隙内汽液固三相流动沸腾传热的实验研究

符号表C。固体颗粒在液q热通量kw／mZu。固体颗粒与液体中的含量voL％，液体汽化游热kJ／kg体的滑移速度m／s小固体颗粒直径mm或mTi流体温度”CP；液体的密度kg／m’D实验段当量直径mm或mTw加热壁面温度“CP。固体颗粒的密度kg／m’h传热膜系数kw／m’K。1循环液速m／sH液相粘度mPa。k液体导热系数W／inK1前言自MatchL．P．等人首次将固体颗粒引入换热器应用于地热利用山后，对这种流化床换热器的研究开始增多【‘－‘］。研究结果均表明，固体颗粒的引入，可显著强化传热，并有较好的防垢抗垢性能。本文的研究是在液体在垂直套管环…     

电磁抗垢强化传热技术机理的实验研究

在自行设计建立的电磁抗垢、减垢实验装置上,对冷态工况下低频电磁抗垢、减垢技术机理进行了实验研究。冷态单次通过、循环实验和高倍扫描电镜结果表明,低频电磁能使污垢晶体的结构发生明显变化并有抑制污垢晶体尺寸长大的作用。     

强化管型对超声波除垢影响的实验研究

结垢问题长久存在于电力、化工、石油等领域,将超声波应用在除垢上具有十分显著的优势。为研究不同管道内结垢和超声波除垢情况,本文采用实验方法,针对三种不同形状(圆管、波纹管和横纹管)管道进行结垢和超声波除垢研究。结果表明,波纹管内结垢量较其它两根管较少,而横纹管的超声波除垢效率最高。由此,可为工程实际中特殊管道的除垢及传统圆管可否进行管型改进提供一定的理论依据。     

Thermal measurements using ultrasonic acoustical pyrometry

Reflections from geometric discontinuities can be used with ultrasonic energy to predict the temperature of an interface where classical temperature measurement techniques are impractical because of physical access limitations or harsh environmental conditions. Additionally, these same ultrasonic measurements can be used with inversion methods commonly applied to ill-posed heat transfer problems to increase the accuracy of the measurement of surface temperature or heat flux at the surface of interest. Both methods for determining surface temperature are presented, along with a comparison of results both from a verification example and using data gathered in a field test of the methods. The results obtained with these two methods are shown to be in good agreement with an empirical relationship used in the design of large caliber guns.     

State-of-the-art on ultrasonic oil production technique for EOR in China

Ultrasonic oil production technique for enhanced oil recovery (EOR) attracts more attention due to its high adaptability, simple operation, low cost and zero pollution to the oil reservoir. In this paper, recent new downhole tools used for enhanced oil recovery developed in China are summarized. Furthermore, research advance on some key problems that affect the widespread application of ultrasonic oil production technique in China are also summarized in view of what are the primary factors that influence crude oil paraffin inhibition and viscosity reduction, whether ultrasonic excitation is better than chemical agent for any plugs removal and whether ultrasound-chemical combination plug removal technology has the best plugs removal effect. The purpose of this paper is to provide reference for the broad application of ultrasonic oil production for enhance oil recovery.     

空气耦合超声检测复合材料研究综述*

复合材料普遍具有高比强度、高比刚度、高模量、耐腐蚀等优异性能,广泛应用于飞机机翼、导弹外壳、航空发动机壳体等部位。制造和服役过程中各类缺陷影响复合材料的力学性能和服役性能,必须采用有效的方法准确检测和评估复合材料中各类缺陷。空气耦合式超声检测具有完全非接触、非侵入、无损伤和无需耦合剂的特点,能够很好地运用于复合材料的在线和在位检测。该文就近年来空气耦合超声检测技术的研究现状进行了系统综述,简明扼要地分析和介绍了当前空气耦合超声检测的研究热点及进展,重点介绍了1-3型压电复合材料换能器、信号处理技术、相控聚焦式空气耦合超声检测、超声在复合材料的传播特性及其与缺陷交互作用的研究现状,探讨了空气耦合超声无损检测技术与仪器的发展方向,总结了目前空气耦合超声检测的研究热点问题,最后展望了空气耦合超声检测的发展趋势和应用前景。     

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications.     

The development of recent high-power ultrasonic transducers for Near-well ultrasonic processing technology

With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology.With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology     

基于超声红外技术对金属管内壁缺陷的检测

为提高管道的运送效率,及时检测排除管道内壁的缺陷非常重要。提出利用超声红外无损检测方法对管道内部进行检测。超声主动热激励试件,高频红外热像仪记录试件表面温度变化,结合了超声摩擦生热和红外热成像的优点。对壁厚约为3.3mm检测难度较大的金属管内壁缺陷进行了检测。通过对采集数据和热图的处理分析,准确快速地确定缺陷所在的位置。实物对比分析表明：超声热激励红外无损检测技术可以对金属管道内壁缺陷进行准确检测定位。