【作者】 陈磊；

【导师】 程树康；

【作者基本信息】 哈尔滨工业大学 ， 电机与电器， 2011， 博士

【摘要】 旋转式机电热换能器,是一种新型电磁加热装置。它将机、电、热系统和以水为媒质的热交换系统有机地组合在一起,利用磁滞、涡流和二次感应电流综合加热。其与电动机、风机、水轮机等动力机械装置配套使用,能实现电能、风能、水能等多种清洁能源的综合利用。除输出热能外,换能器中的旋转电磁场还会对水媒质产生磁化作用,将其软化,达到除垢和抑垢的效果。对换能器热功率和换热的计算方法和变化规律、旋转电磁效应对水媒质的磁化作用机理等进行研究,将深入揭示其工作机理,形成工程计算方法,为换能器的广泛应用奠定基础。本文从传统电机损耗与温升反问题角度出发,对旋转式机电热换能器进行了理论分析和实验研究,主要研究内容如下:首先,建立换能器的三维电磁场方程组,结合物理意义给出其边界条件,运用分离变量法得到方程的解析解。在方程解析解的基础上,推导出换能器端部系数的计算式,在此基础上改进了基于二维有限元法的热功率算法。优化了热功率的实验方法,以一台样机为例验证改进后热功率算法的准确性。这些研究将为换能器热功率的深入研究提供基础。其次,推导热功率与极对数、气隙长度、铁心长度、定子内径等结构参数的解析表达式,并分析这些结构参数对热功率的影响。提出定子热功率透入深度的概念,给出其具体计算公式,分析透入深度随转速的变化规律,并归纳出其在换能器热功率设计中的作用。而后利用改进的热功率算法和透入深度的概念,分析不同转速时,闭口槽、开口槽、半开口槽和铜套四种不同定子结构的换能器热功率密度的变化规律。计算不同定子结构时,热功率在定子侧和转子侧的分布情况。实际研制了两台不同定子结构的样机,对其热功率进行测试,并与原有样机进行比较,验证理论分析的正确性。再次,建立换能器二维换热模型,提出热功率-换热耦合算法,利用此算法分析换热过程。提出功率调整率的指标来评价换能器的换热性能,并分析了实际热功率和水流温升特性。针对原有换热结构的弊端,提出一种新的换热结构,实际分析了气隙长度、铁心长度、透入深度、转子侧热功率等因素对功率调整率的影响。研制了换热测试平台,进行了相关换热测试。理论分析和实验结果证明该换热结构与原有结构相比,换热性能大为提高。实验研究结果表明,换能器内部的旋转电磁场使水媒质的物理化学特性发生变化。为揭示其变化规律和机理,本文进行了相关理论和实验研究。用分子动力模拟的方法计算了磁场作用下水分子间氢键的变化情况。而后设计磁场发生装置,分别用恒定磁场和交变磁场处理不同浓度的NaCl溶液,测试其电导率的变化规律,并结合实验结果探讨磁场对电解质溶液电导率作用的机理。用一定浓度的CaCl₂和Na₂CO₃溶液反应生成晶体,并用恒定磁场和交变磁场分别处理其中一种溶液,利用X射线衍射光谱和扫描电镜分析磁场作用前后CaCO₃晶体的变化,并结合实验结果探讨了磁场对CaCO₃晶体的影响机理。本文提出了换能器热功率和换热的计算方法,分析了其热功率和换热的变化规律,优化了原有的设计,研究了旋转电磁效应对水媒质的作用。为旋转式机电热换能器的深入研究和广泛应用提供了理论和实验基础。更多还原

【Abstract】 The rotational electric–mechanical-thermal transducer is a novel electromagnetic heating device. By properly combining the system of electricity, magnetism and heat with heat transfer system using water as medium, it produces heat utilizing hysteresis, eddy currents and secondary induced current. Assisted with propulsion units, such as motors, blowers and hydroturbines etc., multi-purpose utilization of electric energy, wind energy and hydropower can be achieved. Except for outputting heat, the rotational electromagnetic field in the transducer can also soften the water flowing by so that to reduce scale. Research on the calculation method and variation regularity of its thermal power and heat transfer, and principle of rotational electromagnetic effect on water medium, will deelply explain its working principle, form the engineering calculation method, and establish the foundation of its wide application. Based on the inverse problem of loss and temperature rise in traditional electrical machines, this paper provides theoretical analysis and experimental researches on the transducer, the main content is approached as followings.Firstly, the three dimensional electromagnetic field equations of transducer is established, and the boundary condition is given considering its physical property, and the analytical solution is obtained by separation of variables. The expression of end coefficient is deduced so that the thermal power algonithm based on 2D finite element method of transducer is improved. The experimental method of thermal power is optimized, and its accuracy is tested based on a prototype. The further researches on transducer heat power is based on the works mentioned above.Further, the analytical expression of thermal power with pole pairs, air gap length, steel core length and stator inner diameter etc. is put forward. Proposed the concept of the penetration depth of thermal power density on the stator, given the specific formula of it, analyzed the discipline of the penetration depth variation with different speed, and found the effect of the penetration depth in the tranducer thermal power design. Then used the improved algorithm of thermal power and the concept of the penetration depth, analysed the discipline of thermal power density with different speed, closed slot, open slot, half-open slot and copper in the stator structure. Calculate the distribution of the thermal power density in both of stator and rotor sides with different stator structures. Actually we developed two prototypes with different stator structures, and tested its thermal power, and compared with the original prototype, to verify the theoretical analysis is correct. Established the tranducer 2D heat transfer model, give a coupled algorithm of thermal power and heat transfer. Using this algorithm, analyzed the procedure of the transducer heat transfer. The indicator of power regulation is proposed, to evaluate the heat transfer performance of the transducer, and the actual thermal power density and the characteristics of the water flow temperature rise are analyzed. As there are some foibles of the original heat transfer structures of the tranducer, a new heat transfer structure is given up, and analyzed the influence of the power regulation with the air gap length, core length, penetration depth and the rotor thermal power. A heat tranfer test platform is developed for the relevant heat transfer test. Theoretical analysis and experimental results indicate that the heat transfer structure, compared with the original structure, its heat transfer performance greatly improved.Experimental results show that the rotational electromagnetic field in the transducer changes the physical and chemical performances of water. To reveal its principle, this paper made related theoretical and experimental research. Molecular dynamic simulation is used to compute the changes of hydrogen bond between water molecules when exposing to magnetic field. Then a magnetic field generating device is designed, the constant and alternating magnetic field is used separately to process the NaCl solutions with different concentrations, the variation of conductivity is tested and the magnetic field effects on the principle of conductivity of electrolyte solution based on the experimental results are discussed. CaCO3 crystals are produced with solutions of CaCl2 and Na2CO3 of a certain concentration, each solution is treated with constant and alternating magnetic field. The X-ray diffraction spectrum of the crystal is tested and its composition changes are analyzed,and the magnetic field effects principle on the CaCO3 crystals based on the experimental results are discussed.This paper proposes the method to calculate the thermal power and heat transfer of the transducer, analyzes its variation of thermal power and heat transfer, optimizes the original design of the transducer, and investigate the effect alternation electromagnetic field on water medium. The research provides the theoretical and experimental foundation for the further research and the widespread application of the transducer.更多还原