箱式变电站损耗及热问题研究

发布时间：2018-02-06 07:32

本文关键词： 箱式变电站通风散热 CFD数值模拟优化设计　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国经济的不断发展,输电电网不断扩大,城网变电所迅速覆盖市区。城网变电所位于市中心,承担重要的供电任务,并向小型化、节地、节能发展,因此带来箱式变电站的迅猛发展。由于箱式变电站的结构特点,其极易出现因温升过高而导致的设备安全问题,在夏季温度较高时更加危险。因此需要合理的通风散热方案,以保证主变压器的安全运行。本文以某箱式变电站为研究对象,采用试验、理论分析和数值仿真相结合的方法,基于CFD数值模拟技术,通过磁-流-热耦合分析计算,对箱式变电站整体的通风换热效果进行了仿真分析,本文主要针对下面几个问题进行分析:(1)分析箱式变电站内部损耗组成;通过有限元分析软件对7600kVA干式变压器进行电磁计算,分析其主磁通及短路阻抗、漏磁场分布,并与试验值进行对比;分析其铁心损耗分布、负载损耗及附加损耗分布;(2)基于传热学与流体动力学理论,对变压器内部、高低压控制柜内部生热、散热过程进行理论分析。针对一台1600kVA干式变压器在无外壳及有外壳两种工况下的温度场及流体场分布进行数值仿真,并将仿真值与试验值进行对比,对计算方法的有效性进行验证;(3)以某箱式变电站为设计基础,建立合理的数学模型和物理模型,通过对其速度场和温度场进行数值模拟,分析不同出风口速度对于变压器温升以及整体通风散热效果的影响。在原模型基础上,分别在箱变变压器室底部、箱变棚顶增加通风孔,分析变压器温升、箱变整体温度场和流体场分布,为已建的箱式变电站的通风散热及空气流动提供理论基础;固定出风口位置,分别改变进风口位置以及进风口高度,研究箱变内部温度场和流体场的变化规律;对比各方案温度场、速度场分布,分析其分别对于通风散热的影响。总结出合理的节能设计方案,为设计人员提出参照。
[Abstract]:With the development of economy in our country, the power transmission network is expanding, and the urban network substation covers the urban area rapidly. The urban network substation is located in the center of the city, undertakes the important power supply task, and develops towards miniaturization, land saving and energy saving. As a result, the rapid development of box-type substation, because of the structural characteristics of the box substation, it is easy to occur because of the high temperature rise caused by the equipment safety problems. In order to ensure the safe operation of the main transformer, it is more dangerous in summer when the temperature is higher. Therefore, a reasonable ventilation and heat dissipation scheme is needed to ensure the safe operation of the main transformer. In this paper, a box substation is taken as the research object and the test is adopted. The method of combining theoretical analysis and numerical simulation, based on CFD numerical simulation technology, through magnetic-fluid-heat coupling analysis and calculation, the overall ventilation heat transfer effect of box substation is simulated and analyzed. This paper mainly analyzes the following several problems: 1) analyzing the internal loss composition of the box substation; The electromagnetic calculation of 7600kVA dry transformer is carried out by finite element analysis software. The main flux, short circuit impedance, leakage magnetic field distribution are analyzed and compared with the test results. The distribution of core loss, load loss and additional loss are analyzed. Based on the theory of heat transfer and fluid dynamics, heat is generated inside the transformer and inside the high and low voltage control cabinet. The numerical simulation of temperature field and fluid field of a 1600kVA dry transformer under two working conditions without shell and shell was carried out. The validity of the calculation method is verified by comparing the simulation value with the experimental value. Based on the design of a box substation, a reasonable mathematical and physical model is established, and its velocity field and temperature field are simulated numerically. The effect of different outlet velocity on temperature rise of transformer and overall ventilation heat dissipation effect is analyzed. Based on the original model, the ventilation holes are added at the bottom of the box transformer chamber and the roof of the box variable shed is added, and the transformer temperature rise is analyzed. The whole temperature field and fluid field distribution of box transformer substation provide the theoretical basis for ventilation, heat dissipation and air flow of the built box substation. At the same time, fixed the outlet position, changed the inlet position and the inlet height, studied the variation law of temperature field and fluid field inside the box; By comparing the distribution of temperature field and velocity field of each scheme, the influence of temperature field and velocity field on ventilation and heat dissipation is analyzed, and the reasonable energy saving design scheme is summarized, which is a reference for designers.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63

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