【作者】 张鹏；

【导师】 郭斌；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2008， 博士

【摘要】 从电机损耗与温升的反问题出发,利用电磁理论将输入的能量充分、有效地转换为热能,即将“损耗”转化为有效热能输出的动态电磁感应加热方法,构成高热效率的环保型旋转电磁热机,通过调节励磁绕组的电磁参数可以对旋转电磁场进行控制。利用可控电磁场对水媒质产生磁化效应,可以实现抑垢缓蚀。在充分分析电机运行过程损耗的基础上,介绍了旋转电磁效应的技术实施以及数学模型。通过有限元模拟,分析了转速和铁心长度等因素对致热效率以及磁场分布等的影响。利用旋转电磁热机进行了致热实验,结果表明,该新型热机致热效果明显,并且使水媒质产生了一系列物理化学性质变化。水质变化机理主要是旋转电磁效应导致水中氢键断裂。当水的温升速度较快时,水质变化主要是温度引起;而在升温缓慢或无温度变化时,则以交变电场和交变磁场的协同作用为主。热循环系统的工程应用表明,旋转电磁效应的抑垢效果良好,并且长时间运行后具有明显的降浊降硬作用。采用激光共聚焦显微镜、扫描电镜以及XRD等方法研究了水垢样的形貌及成分,分析了旋转电磁效应的抑垢机理,主要是旋转电磁效应一方面改变了水媒质的物理化学性质,另一方面影响了碳酸钙结晶过程,水垢样主要为霰石碳酸钙晶型,而蒸汽锅炉水垢样表面则主要为方解石碳酸钙晶型。采用失重法对热循环系统用45钢和紫铜进行热流动腐蚀实验,结果表明,随着腐蚀过程的持续进行,45钢的腐蚀速度先下降后上升,紫铜的腐蚀速度下降,随后趋于平缓。成分分析表明,45钢和紫铜试样主要为基体及其氧化物。开始阶段试样表面氧化膜的形成减缓了腐蚀,随着氧化膜的脱落与溶解,腐蚀继续进行。通过试样表面腐蚀二维和三维形貌可以看出,45钢流过腐蚀过程为剥层腐蚀,紫铜流动腐蚀过程为孔蚀。采用电化学腐蚀实验研究了45钢和紫铜在旋转电磁处理海水中的腐蚀电化学机理。极化曲线测试表明,旋转电磁效应对45钢和紫铜的缓蚀效率分别为16.66%和89.14%。通过扫描电镜照片可以看出,在旋转电磁处理海水中电化学腐蚀后试样表面比在3.5%NaCl溶液和人工海水中的试样要致密。成分分析表明,45钢试样表面腐蚀产物主要有Fe₂O₃、Fe₃O₄和FeCl₂·6H₂O,紫铜试样表面腐蚀产物主要有Cu₂O和CuCl₂。旋转电磁处理使溶液的溶解氧能力增强,使金属更容易地发生氧腐蚀,形成表面氧化膜,阻止了内部金属的继续腐蚀。基于电化学腐蚀实验结果,分析了腐蚀电极/电解质溶液界面液相传质过程。对电极/电解质溶液界面双电层电容量进行了理论计算以及实验分析。根据腐蚀过程表面状态变化,基于高斯滤波建立了电极表面双电层基准面模型。通过所建立的模型,计算出流动腐蚀过程中金属表面真实的双电层吸附面积变化。更多还原

【Abstract】 From the view of temperature rise of electric machine, the thermal dissipation can be transformed to the effective thermal energy based on the principle of rotating electric machine through electromagnetic theories. So, the environmental protective thermal equipment can be manufactured. The fluid in pipe can be magnetized by the magnetization of electromagnetic fields, which can implement the antiscale and anticorrosion of the system.Technical implement and mathematic model of rotating electromagnetic effect was introduced based on analysis to the dissipation of electric machine during its operational process. Effect of rotational speed and iron length on thermal power and magnetic field distribution were analyzed using finite element simulation. Experiment using electromagnetic equipment was carried out. The experimens indicate that the novel rotating electromagnetic heat engine not only has the merits of high efficiency, high temperature ascending grads, but also has effects of magnetization on the water medium.According to engineering practice of rotating electromagnetic effect, its antiscaling effect is better. The mechanism was investigated usingconfocal laser scanning microscope, scanning electron microscopy/energy dispersive analysis system of X-ray （SEM/EDAX） and X-ray diffraction （XRD）. Antiscaling mechanism of rotating electromagnetic effect is that it changes water quality; at the same time, it influences the crystal of calcium carbonate. The scale incrustation through rotating electromagnetic effect treatment is mainly aragonite, while the scale of steam boiler is calcite chiefly.Flow experiment of 45 steel and copper used in thermal recyling system was investigated using weight loss method. The result shows that the flow corrosion rate of 45 steel decreases at the initial segment, then increases at the final segment. However, the flow corrosion rate of copper decreases, then drives to gentleduring the corrosion process. Component analysis shows that corrosion products of 45 steel and copper are their oxidates. According to two dimensional and three dimensional topographies, it can be observed that flow corrosion process of 45 steel is runaway corrosion, but flow corrosion process of copper is pitting.The corrosion characters of 45 steel and copper in rotating electromagnetic feld treated sea water were investigated using electrochemical test. From polarization curve, it can seen that anticorrosion efficient of rotating electromagnetic effect on 45 steel and copper is 16.66% and 89.14%, respectively. From SEM images, the specimen in magnetized sea water is compact compared with the specimen in 3.5% NaCl and sea water, only a few pores exist. Component analysis shows that the corrosion products of 45 steel are Fe₂O₃, Fe₃O₄ and FeCl₂·6H₂O, while the corrosion products of copper are Cu₂O和CuCl₂ chiefly.Mass transport process of corroding electrode/solution interface was analyzed based on experiment results of electrochemical corrosion. The capacitance of electric double layer was calculated using theoretical calculation and experiment. According to topography variation of electrode surface during corrosion process, the surface model of samples during the corrosion process was built based on Gaussian filter. The topography characterizations of metal corrosion process can be described using the proposed surface model. The true superficial area of electric double layer during the corrosion process can be calculated through this model.更多还原