计及风量损耗的油浸风冷外置冷却系统散热效率优化方法

doi:10.19595/j.cnki.1000-6753.tces.230091

Abstract
Figure/Table
References (0)
Related Citation (10)

Download: PDF (2511 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract

To help improve the energy efficiency of transformer cooling systems, "lightweight and miniaturization" is a development trend. The precise configuration of the fan diameter ensures efficient heat dissipation and reasonable air volume distribution while avoiding the problems of high cost, heavy mass, and large air loss, which is in line with the "light" and "small" concepts. The main means to study the cooling performance of transformers is often based on computational fluid dynamic (CFD) tentative modeling and improvement, to explore the cooling effect of the configuration structure, but CFD numerical simulation can obtain the required high precision results, but the pre-processing such as equal scale 3D modeling, mesh drawing and multi-physics field simulation consumes a lot of computational resources and time, and the process is complicated and the optimization objective is single. Thus, a fast iterative optimization model is constructed for a radiator with natural oil circulation forced air cooling (ONAF).
First, the analytical model includes the momentum analysis of the overall oil circulation, the cooling air intensity analysis based on the local air loss coefficient, and the heat transfer analysis of the internal oil flow and external air of the radiator. Among them, the momentum analysis of oil circulation is the core of radiator temperature rise calculation, and the local loss coefficient of air volume is closely related to wind speed, fan diameter, cooling air distance, and duct perimeter, and directly affects the Nusselt number (Nu), which is the most important dimensionless number reflecting convective heat transfer strength. Matlab is then used to iteratively calculate the flow-heat characteristic parameters of the analytical model to obtain the radiator import and export oil temperature difference, the relationship between air loss and heat dissipation efficiency is finally integrated and controlled to achieve efficient heat dissipation in the cooling system.
Second, to verify the accuracy of the analytical model, a combined flow-thermal simulation and test platform was also established based on the PC2600-22/520 radiator with an equal scale. The k-epsilon model was selected for the simulation, and the physical parameters of mineral oil, air, and heat sink were defined. In the test, three types of fans with diameters of 455 mm, 655 mm, and 855 mm were used to record the temperature difference between the inlet and outlet of the radiator, and a hot-wire anemometer was used to measure the air velocity and the temperature between the radiator fin.
Finally, the research shows that the fan diameter has a non-linear effect on the oil temperature difference, and the wind loss is positively correlated with the diameter. With the PC2600-22/520 radiator as the verification object, the temperature difference can reach the desired value when the wind speed is 3.5 m/s and the fan diameter is 1.2~1.5 times the width of the radiator fin, at which time the heat dissipation efficiency and the wind loss collaborate to enter the optimal interval. In addition, the average relative error between the model calculated cooling air flow rate of the adjacent air duct at the center of the radiator fin and the test and simulation results is less than 6%, and the average relative error of the outlet oil temperature is less than 2%, which saves more than 98.56% of time cost. The work of this paper provides a new idea for the lightweight design of radiator structure under forced air cooling, cooling efficiency improvement and cooling air intensity distribution calculation.

Key words： Lightweight radiator wind loss oil temperature difference heat dissipation efficiency

Received: 19 January 2023

PACS:

TM411

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Wang Lujia
	Cai Zhenlu
	Qiu Yabo
	Zhang Lebin
	Yang Haitao
	Zhang Jianwen

Cite this article:

Wang Lujia,Cai Zhenlu,Qiu Yabo等. Heat Dissipation Efficiency Optimization Method for ONAF External Cooling System Taking into Account Airflow Losses[J]. Transactions of China Electrotechnical Society, 0, (): 230091-230091.

URL:

https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.230091 OR https://dgjsxb.ces-transaction.com/EN/Y0/V/I/230091

[1] 刘丛, 郝建, 李文平, 等. Box-in结构对特高压换流变压器散热性能影响的仿真分析[J]. 电网技术, 2022, 46(2): 803-811.
Liu Cong, Hao Jian, Li Wenping, et al.Simulation analysis of box-in structure influence on heat dissipation performance of UHV converter transformer[J]. Power System Technology, 2022, 46(2): 803-811.
[2] Fu Ronghuan, He Zhiguang, Zhang Xing.Life cycle cost based optimization design method for an integrated cooling system with multi-operating modes[J]. Applied Thermal Engineering, 2018, 140: 432-441.
[3] 靳艳娇, 乔光尧, 邓占锋, 等. 全环氧固封高频变压器散热优化设计研究[J]. 电网技术, 2022, 46(7): 2531-2537.
Jin Yanjiao, Qiao Guangyao, Deng Zhanfeng, et al.Heat dissipation optimization design of epoxy resin sealing high frequency transformer[J]. Power System Technology, 2022, 46(7): 2531-2537.
[4] 宋全刚, 王琦, 张承, 等. 基于ANSYS分析的水冷散热器多目标优化[J]. 流体机械, 2022, 50(4): 65-70.
Song Quangang, Wang Qi, Zhang Cheng, et al.Multi-objective optimization of a water-cooled heatsink based on ANSYS analysis[J]. Fluid Machinery, 2022, 50(4): 65-70.
[5] 魏本刚, 吴楠楠, 任晓明, 等. 基于有限体积法的分体式冷却变压器热学三维仿真技术[J]. 电力自动化设备, 2018, 38(2): 177-181.
Wei Bengang, Wu Nannan, Ren Xiaoming, et al.Three dimensional simulation technology of separated cooling type transformer based on finite volume method[J]. Electric Power Automation Equipment, 2018, 38(2): 177-181.
[6] Tălu M and Tălu S. Modelling of thermal processes of a hydraulic cooling system for a power transformer[J]. The Scientific Bulletin of Valahia University-Materials and Mechanics, 2011, 6(9): 224-227.
[7] Tălu S D L, Tălu M D L. Dimensional optimization of frontal radiators of cooling system for power transformer 630 kVA 20/0.4 kV in terms of maximum heat transfer[J]. University Politehnica of Bucharest Scientific Bulletin Seris C: Electrical Engineering and Computer Science, 2010, 72(4): 249-260.
[8] Kim Y J, Doo J H, Ha M Y, et al.Numerical study on the effect of the shape of the heat transfer plate on the thermal performance of the radiator[J]. Journal of Computational Fluids Engineering, 2015, 20(1): 65-76.
[9] Susa D, Lehtonen M, Nordman H.Dynamic thermal modelling of power transformers[J]. IEEE Transactions on Power Delivery, 2005, 20(1): 197-204.
[10] Radakovic Z, Feser K.A new method for the calculation of the hot-spot temperature in power transformers with ONAN cooling[J]. IEEE Transactions on Power Delivery, 2003, 18(4): 1284-1292.
[11] 徐永明, 刘飞, 齐玉麟. 基于流体网络的电力变压器绕组温度预测[J]. 高电压技术, 2017, 43(5): 1509-1517.
Xu Yongming, Liu Fei, Qi Yulin.Prediction of winding temperature in power transformers based on fluid network[J]. High Voltage Engineering, 2017, 43(5): 1509-1517.
[12] Raeisian L, Niazmand H, Ebrahimnia-Bajestan E, et al.Feasibility study of waste vegetable oil as an alternative cooling medium in transformers[J]. Applied Thermal Engineering, 2019, 151: 308-317.
[13] Mahdi M S, Khadom A A, Mahood H B, et al.Effect of fin geometry on natural convection heat transfer in electrical distribution transformer: numerical study and experimental validation[J]. Thermal Science and Engineering Progress, 2019, 14: 100414.
[14] Paramane S B, Joshi K, van der Veken W, et al. CFD study on thermal performance of radiators in a power transformer: effect of blowing direction and offset of fans[J]. IEEE Transactions on Power Delivery, 2014, 29(6): 2596-2604.
[15] 林弘毅, 伍梁, 郭潇, 等. 高功率密度SiC静止无功补偿器强迫风冷散热综合建模及优化设计方法[J]. 电工技术学报, 2021, 36(16): 3446-3456.
Lin Hongyi, Wu Liang, Guo Xiao, et al.A comprehensive model of forced air cooling and optimal design method of high power density SiC-static var generator[J]. Transactions of China Electrotechnical Society, 2021, 36(16): 3446-3456.
[16] 刘刚, 王晓晗, 马永强, 等. 基于控制体-迎风有限元法的变压器绕组二维流体场-温度场耦合计算方法研究[J]. 高压电器, 2021, 57(6): 1-9.
Liu Gang, Wang Xiaohan, Ma Yongqiang, et al.Study on coupled calculation method of two dimensional fluid and temperature field of transformer winding based on control volume-upstream FEM[J]. High Voltage Apparatus, 2021, 57(6): 1-9.
[17] 蒋惠中, 魏本刚, 文杰, 等. 分体式油浸自冷变压器三维温度场和流场仿真与分析[J]. 高压电器, 2021, 57(2): 63-69.
Jiang Huizhong, Wei Bengang, Wen Jie, et al.Numerical simulation of 3D temperature and flow fields in separated oil-immersed cooling transformer[J]. High Voltage Apparatus, 2021, 57(2): 63-69.
[18] 王泽忠, 李明洋, 宣梦真, 等. 单相四柱式变压器直流偏磁下的温升试验及仿真分析[J]. 电工技术学报, 2021, 36(5): 1006-1013.
Wang Zezhong, Li Mingyang, Xuan Mengzhen, et al.Temperature rise test and simulation of single-phase four-column transformer under DC-bias[J]. Transactions of China Electrotechnical Society, 2021, 36(5): 1006-1013.
[19] 唐钊, 刘轩东, 陈铭. 考虑流体动力学的干式变压器热网络模型仿真分析[J]. 电工技术学报, 2022, 37(18): 4777-4787.
Tang Zhao, Liu Xuandong, Chen Ming.Simulation analysis of dry-type transformer thermal network model considering fluid dynamics[J]. Transactions of China Electrotechnical Society, 2022, 37(18): 4777-4787.
[20] 程书灿, 赵彦普, 张军飞, 等. 电力设备多物理场仿真技术及软件发展现状[J]. 电力系统自动化, 2022, 46(10): 121-137.
Cheng Shucan, Zhao Yanpu, Zhang Junfei, et al.State of the art of multiphysics simulation technology and software development for power equipment[J]. Automation of Electric Power Systems, 2022, 46(10): 121-137.
[21] 赵志刚, 张学增. LLC平面变压器绕组损耗与漏感改进有限元计算方法[J]. 电工技术学报, 2022, 37(24): 6204-6215.
Zhao Zhigang, Zhang Xuezeng.Improved finite element method of winding loss and leakage inductance for planar transformer used in LLC converter[J]. Transactions of China Electrotechnical Society, 2022, 37(24): 6204-6215.
[22] 朱涛, 王丰华. 地磁感应电流作用下大型变压器的温升特性计算[J]. 电工技术学报, 2022, 37(8): 1915-1925.
Zhu Tao, Wang Fenghua.Calculation of temperature rise of large transformer under geomagnetically induced current[J]. Transactions of China Electrotechnical Society, 2022, 37(8): 1915-1925.
[23] Karsai K, Kerenyi D, Kiss L.Large power transformers[M]. New York: Elsevier, 1987.
[24] Fay J A.Introduction to fluid mechanics[M]. Cambridge.: MIT Press, 1994.
[25] Rodriguez G R, Garelli L, Storti M, et al.Numerical and experimental thermo-fluid dynamic analysis of a power transformer working in ONAN mode[J]. Applied Thermal Engineering, 2017, 112: 1271-1280.
[26] El Wakil N, Chereches N C, Padet J.Numerical study of heat transfer and fluid flow in a power transformer[J]. International Journal of Thermal Sciences, 2006, 45(6): 615-626.
[27] 孔珑. 工程流体力学[M]. 4版. 北京: 中国电力出版社, 2014.
[28] 周利军, 勾小凤, 袁帅, 等. 轻量化车载牵引变压器风道局部损失系数及冷却风分布计算[J]. 中国铁道科学, 2021, 42(6): 152-161.
Zhou Lijun, Gou Xiaofeng, Yuan Shuai, et al.Calculation of local loss coefficient and cooling air distribution in air duct of lightweight on-board traction transformer[J]. China Railway Science, 2021, 42(6): 152-161.
[29] Churchill S W, Chu H H S. Correlating equations for laminar and turbulent free convection from a vertical plate[J]. International Journal of Heat and Mass Transfer, 1975, 18(11): 1323-1329.
[30] Churchill S W.A comprehensive correlating equation for forced convection from flat plates[J]. AIChE Journal, 1976, 22(2): 264-268.