目的 提出水轮发电机组碳刷/集电环工作环境的优化,提高碳刷-集电环载流摩擦系统的运行可靠性。方法 在可控气氛载流磨损试验设备上,开展45钢（集电环）/碳（电刷）在20~40 ℃温度和40%~60%湿度下的载流摩擦磨损试验,分别评价其摩擦学性能与载流性能,并通过影响的显著性和表面损伤进行分析。建立环境温湿度对载流摩擦磨损影响的机理图,以及接触电阻等效模型。结果 环境温度和湿度对载流摩擦特性有着显著的影响。在35 ℃、50%RH环境下,平均摩擦系数最小为0.129 7,相较于25 ℃、55%RH环境下,平均摩擦系数（最高为0.242 7）降低了46.6%。在25 ℃、50%RH与40 ℃、45%RH环境下,平均接触电阻最小为1.52 Ω,相较于25 ℃、40%RH环境下,平均接触电阻（最高为2.27 Ω）降低了49.3%,磨损率在环境湿度为50%下最小。当湿度不变时,随着温度的增加,摩擦副的接触温度先增加、后减小、再增加,大致呈“N”形变化。湿度一定时,提高环境温度,有利于氧化反应的进行,但高温下会导致水汽减少,并且摩擦表面水分子脱附,不利于水膜的形成。温度为30 ℃时,摩擦系数、磨损率和接触电阻达到较小值。当温度不变时,湿度增加碳刷表面粗糙度越小,表面越光滑。结论 水汽是影响磨粒磨损和黏着磨损的一个关键因素。在相对湿度为50%附近,黏着磨损程度最低。高温或高湿环境下,不利于碳刷/集电环的载流摩擦性能。
Abstract
The work aims to optimize the operating environment of carbon brush/slip-ring assemblies in hydroelectric generator units to improve the operational reliability of the carbon brush/slip-ring current-carrying friction system. Current-carrying friction and wear experiments were conducted with a controlled-atmosphere tribological test apparatus. A friction pair composed of 45 steel (slip ring) and carbon material (brush) was selected to simulate practical operating conditions. The tests were performed under ambient temperatures ranging from 20 ℃ to 40 ℃ and relative humidity levels from 40% RH to 60% RH. During the experiments, key tribological and electrical parameters, including the friction coefficient, wear loss, wear rate, contact resistance, and contact temperature, were continuously measured. In addition, the coefficients of variation of the friction coefficient and contact resistance were calculated to evaluate the stability of the current-carrying friction process. The experimental results were further analyzed in terms of effect significance and surface damage characteristics. Based on the experimental observations, a mechanistic schematic was established to illustrate the coupled effects of environmental temperature and humidity on current-carrying friction and wear, and an equivalent contact resistance model was proposed.
The results demonstrate that ambient temperature and humidity have significant and coupled effects on the current-carrying tribological characteristics of the carbon brush/slip-ring pair. Under a relative humidity of 50% RH and an ambient temperature of 35 ℃, the minimum average friction coefficient of 0.129 7 was obtained, representing a reduction of 46.6% compared with the maximum average friction coefficient of 0.242 7 observed at 25 ℃ and 55% RH. The average contact resistance reaches its minimum value of 1.52 Ω at 25 ℃ and 50% RH as well as at 40 ℃ and 45% RH, which corresponds to a 49.3% reduction compared with the maximum average contact resistance of 2.27 Ω at 25 ℃ and 40% RH. The coefficient of variation of the friction coefficient is lowest 23% at 25 ℃ and 55% RH, while the coefficient of variation of contact resistance reaches its minimum value of 3.7% at 25 ℃ and 60% RH, indicating enhanced operational stability under these conditions. The wear rate exhibits a strong dependence on environmental humidity and temperature. The minimum wear rate of 47.35 mg/(m²·s) occurs at 50% RH and 30 ℃, whereas both the wear rate and wear volume reach their maximum values at 60% RH and 30 ℃, with a wear rate of 378.79 mg/(m2·s) and a wear volume of 3 mg. At constant humidity, the contact temperature of the friction pair shows an "N"-shaped variation with the increasing ambient temperature. The lowest contact surface temperature of 50.1 ℃ is recorded at 20 ℃ and 55% RH, which is 29.3% lower than the maximum value of 70.9 ℃ at 25 ℃ and 55% RH.
From a mechanistic perspective, increasing ambient temperature under constant humidity promotes oxidation reactions at the friction interface. However, excessive temperature reduces water vapor content and induces desorption of water molecules from the friction surfaces, thereby inhibiting water-film formation. At constant temperature, increasing humidity reduces the surface roughness of the carbon brush, leading to a smoother contact interface. Water vapor is identified as a key factor governing abrasive and adhesive wear, and adhesive wear is minimized near an optimal humidity of approximately 50% RH. Overall, excessively high temperature or high humidity conditions are detrimental to the current-carrying tribological performance of carbon brush/slip-ring assemblies.
关键词
载流摩擦磨损 /
水轮发电机组 /
环境温湿度 /
碳刷/集电环 /
损伤机制
Key words
current-carrying frictional wear /
hydroelectric generator sets /
ambient temperature and humidity /
carbon brushes/collector rings /
damage mechanism.
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] POLJANEC D, KALIN M, KUMAR L. Influence of Contact Parameters on the Tribological Behaviour of Various Graphite/Graphite Sliding Electrical Contacts[J]. Wear, 2018, 406/407: 75-83.
[2] YANG H J, CHEN G X, GAO G Q, et al. Experimental Research on the Friction and Wear Properties of a Contact Strip of a Pantograph-Catenary System at the Sliding Speed of 350 km/h with Electric Current[J]. Wear, 2015, 332/ 333: 949-955.
[3] REN W J, CHEN G X, DONG B J, et al.Experimental Study of the Effect of Contact Line Profiles on the Wear Mechanism of a Skateboard[J]. Tribology International, 2024, 192: 109317.
[4] CYRIAC F, TEE X Y, CHOW P S.Tribological Performance of Polymeric Friction Modifiers under Sliding Rolling Contact Condition[J]. Lubrication Science, 2024, 36(2): 119-134.
[5] CHEN G X, HU Y, DONG B J, et al.Experimental Study on the Temperature of the Contact Strip in Sliding Electric Contact[J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2017, 231(10): 1268-1275.
[6] JI D H, XIAO L, HU Q, et al.The Effect of Temperature on the Current-Carrying Tribological Behaviour of C/Cu Contact Pairs in High Humidity Environments[J]. Tribology Letters, 2024, 72(2): 63.
[7] BARNAWI E, SAWA K, MORITA N, et al.The Effect of Various Atmospheric Temperature on the Contact Resistance of Sliding Contact on Silver Coating Slip Ring and Silver Graphite Brush[C]//Proceedings of the 2011 IEEE 57th Holm Conference on Electrical Contacts (Holm). Minneapolis: IEEE, 2011.
[8] LIU R T, CHENG K, CHEN J, et al.Friction and Wear Properties of High Temperature and Low Temperature Sintered Copper-Graphite Brushes at Different Ambient Temperatures[J]. Journal of Materials Research and Technology, 2020, 9(4): 7288-7296.
[9] 李含欣. 不同服役温度下环境湿度对碳/铜接触载流摩擦学行为的影响[D]. 南昌: 华东交通大学, 2023.
LI H X.Effects of Ambient Humidity on Tribological Behavior of Carbon-Copper Contact Current-Carrying at Different Service Temperatures[D]. Nanchang: East China Jiaotong University, 2023.
[10] 孙逸翔. 湿度对纯铜载流磨损的影响[D]. 洛阳: 河南科技大学, 2017.
SUN Y X.Effect of Relative Humidity on the Triboelectric Wear of Copper[D]. Luoyang: Henan University of Science and Technology, 2017.
[11] 胡道春, 孙乐民, 上官宝, 等. 紫铜/铬青铜摩擦副在干摩擦和水雾条件下的载流摩擦磨损性能研究[J]. 润滑与密封, 2007, 32(11): 105-107.
HU D C, SUN L M, SHANGGUAN B, et al.Tribological Characteristics of T2/QCr0.5 Rubbing Pairs under Electric Current with and without Water[J]. Lubrication Engineering, 2007, 32(11): 105-107.
[12] HUANG M, YANG B, RONG Y X, et al.Study on Friction and Wear Properties of Copper-Impregnated Carbon Slide Plate under Different Humidity Conditions[J]. Tribology Transactions, 2023, 66(5): 953-964.
[13] 胡道春, 王蕾. 紫铜摩擦集电材料在阴雨环境中的腐蚀与磨损行为[J]. 腐蚀与防护, 2011, 32(2): 90-93.
HU D C, WANG L.Corrosion and Abrasion Behaviors of T2 Sliding-Collecting-Current Material in Rainy Environment[J]. Corrosion and Protection, 2011, 32(2): 90-93.
[14] 李含欣, 季德惠, 沈明学, 等. 环境湿度对碳/铜滑动接触副载流摩擦学行为的影响[J]. 摩擦学学报, 2022, 42(4): 709-718.
LI H X, JI D H, SHEN M X, et al.Effect of Environmental Humidity on Tribological Behavior of Carbon/ Copper Current-Carrying Sliding Contact Pairs[J]. Tribology, 2022, 42(4): 709-718.
[15] 何可欣, 关金发, 韩峰, 等. 空气湿度对滑板磨耗及温升的影响研究[J]. 电气化铁道, 2023, 34(S2): 61-63.
HE K X, GUAN J F, HAN F, et al.Study on the Influence of Air Humidity on Skateboard Wear and Temperature Rise[J]. Electric Railway, 2023, 34(S2): 61-63.
[16] CAO Z F, XIA Y Q, LIU L H, et al.Study on the Conductive and Tribological Properties of Copper Sliding Electrical Contacts Lubricated by Ionic Liquids[J]. Tribology International, 2019, 130: 27-35.
[17] 袁文征, 邱明, 李喜军, 等. 不同湿度环境中钢/铜配副摩擦磨损性能研究[J]. 润滑与密封, 2010, 35(4): 24-27.
YUAN W Z, QIU M, LI X J, et al.Study on Tribological Properties of Steel-Copper Couples in Different Humidity Environments[J]. Lubrication Engineering, 2010, 35(4): 24-27.
[18] 孙浩然, 张迪, 贾磊, 等. 超音速等离子喷涂NiCrBSi-金刚石复合涂层的微观组织与性能[J]. 材料保护, 2025, 58(3): 60-69.
SUN H R, ZHANG D, JIA L, et al.Microstructure and Properties of Supersonic Plasma Sprayed NiCrBSi-Diamond Composite Coatings[J]. Materials Protection, 2025, 58(3): 60-69.
[19] HOLM R.Electrical Contact[M]. New York: Springer, 1979.
[20] WANG X, YAO P P, LI Y X, et al.Effects of Material Transfer Evolution on Tribological Behavior in CuCrZr Alloy Paired with 7075 Al Alloy under Current-Carrying[J]. Tribology International, 2023, 179: 107960.
[21] 谢宝志, 何志江, 邓磊, 等. 考虑温度作用的浸金属碳滑板磨损量预测方法研究[J]. 铁道标准设计, 2022, 66(10): 179-184.
XIE B Z, HE Z J, DENG L, et al.Wear Prediction of Metal-Impregnated Carbon Strip Considering Temperature Effect[J]. Railway Standard Design, 2022, 66(10): 179-184.
[22] 秦红玲, 王锦涛, 李洪波, 等. 运行工况对碳刷/集电环摩擦副表面膜形成的影响[J]. 表面技术, 2023, 52(9): 178-188.
QIN H L, WANG J T, LI H B, et al.Effect of Operating Conditions on Friction Surface Film Formation of Carbon Brush/Slip Ring Assemblies[J]. Surface Technology, 2023, 52(9): 178-188.
[23] LYU Y Z, ZHU Y, OLOFSSON U. Wear between Wheel and Rail: A Pin-on-Disc Study of Environmental Conditions and Iron Oxides[J]. Wear, 2015, 328/329: 277-285.
[24] SEO J W, JUN H K, KWON S J, et al.Effect of Friction Modifier on Rolling Contact Fatigue and Wear of Wheel and Rail Materials[J]. Tribology Transactions, 2018, 61(1): 19-30.
[25] PAYAM A F.Modeling and Analysis of the Capillary Force for Interactions of Different Tip/Substrate in AFM Based on the Energy Method[J]. ACS Measurement Science Au, 2023, 3(3): 194-199.
[26] LI Q, WANG X Y, PEI Z B, et al.Influence of Rust Layer on Corrosion-Critical Humidity in Outdoor Environments Based on Corrosion Sensors[J]. Materials, 2025, 18(10): 2299.
[27] 杜三明, 张永振, 上官宝, 等. CrNiMo钢在不同氧气含量气氛中的高温摩擦磨损性能[J]. 润滑与密封, 2010, 35(8): 12-14.
DU S M, ZHANG Y Z, SHANGGUAN B, et al.Tribological Properties of CrNiMo Steel in Different Content of Oxygen and Elevated Temperature Ambient[J]. Lubrication Engineering, 2010, 35(8): 12-14.
[28] 岳洋, 孙逸翔, 孙毓明, 等. 载荷和电压对纯铜滚动载流摩擦学性能的影响[J]. 摩擦学学报, 2018, 38(1): 67-74.
YUE Y, SUN Y X, SUN Y M, et al.Effect of Load and Voltage on the Tribo-Electric Behaviour of Rolling Cu Pairs[J]. Tribology, 2018, 38(1): 67-74.
[29] CHENG K, LIU R T, XIONG X, et al.The Effect of Sintering Temperature on the Microstructures and Properties of Resin-Bonded Copper-Graphite Brush Materials[J]. Tribology Letters, 2019, 67(3): 77.
[30] PARK J H, NATESAN K.Oxidation of Copper and Electronic Transport in Copper Oxides[J]. Oxidation of Metals, 1993, 39(5): 411-435.
[31] ZAIDI H, CHIN K J, FRENE J.Analysis of Surface and Subsurface of Sliding Electrical Contact Steel/Steel in Magnetic Field[J]. Surface and Coatings Technology, 2001, 148(2/3): 241-250.
[32] 朱茂桃, 唐杰, 李娜, 等. 采用正交试验与RSM的车辆冷却风扇降噪研究[J]. 重庆理工大学学报(自然科学), 2022, 36(4): 9-18.
ZHU M T, TANG J, LI N, et al.Research on Automotive Cooling Fan Noise Reduction with Orthogonal Experiment and RSM[J]. Journal of Chongqing University of Technology (Natural Science), 2022, 36(4): 9-18.
基金
国家自然科学基金（52475202）; 高端轴承摩擦学技术与应用国家地方联合工程实验室开放基金项目（202607）
PDF(4957 KB)
渝公网安备 50010702501715号 渝ICP备15012534号-3
