Research on the Effect of Refrigerant Solubility on the Lubrication Characteristics of Connecting Rod Bearings

doi:10.3901/JME.2021.15.146

Abstract

Abstract: The actual lubrication environment in refrigeration compressors is mixed lubrication in the state of impure oil. The refrigerant dissolves in the lubricating oil will cause the lubricating performance of the connecting rod bearings of the compressor to decline. At present, no in-depth research has been carried out on it. The refrigerant R600a/Azmol mineral oil mixed liquid phase is used as the lubricating medium to establish a lubrication model based on the solubility of the refrigerant, and to study the effect of solubility on the lubrication characteristics of the connecting rod bearings of small refrigeration compressors under different load conditions. The results show that under different working conditions, after considering the effect of solubility, the minimum oil film thickness of the bearing is reduced by a maximum of 18.51%, the maximum oil film pressure is increased by a maximum of 7.08%, the friction power consumption is decreased by a maximum of 19.90%, and the end discharge flow is increased by a maximum of 29.62%. The solubility lubrication model provides a new idea for the analysis of the failure mechanism of the connecting rod bearing friction pair of small refrigeration compressors, and has important guiding significance for the compressor overload condition design, bearing clearance and environmental temperature control.

Key words: small refrigeration compressor, connecting rod bearing, solubility, lubrication characteristics, overload condition

CLC Number:

TB652

HU Jianfeng, JIN Huaqiang, GU Jiangping, HUANG Yuejin, SUN Zhe, WANG Xinlei, SHEN Xi. Research on the Effect of Refrigerant Solubility on the Lubrication Characteristics of Connecting Rod Bearings[J]. Journal of Mechanical Engineering, 2021, 57(15): 146-159.

References

[1] ZHANG Jie, DONG Qiangbing. Lubrication performance analysis of crankshaft bush in compressor[J]. Engineering Failure Analysis, 2018, 90:277-289.
[2] 聂涛, 刘振明, 刘楠, 等. 内燃机径向滑动轴承润滑特性及影响因素研究[J]. 计算机仿真, 2019, 36(1):270-274. NIE Tao, LIU Zhenming, LIU Nan, et al. Research on the lubrication characteristics and influencing factors of the journal bearing in internal combustion engine[J]. Computer Integrated Manufacturing Systems, 2019, 36(1):270-274.
[3] 毕凤荣, 刘博, 刘春朝, 等. 基于热弹流模型的柴油机连杆小头轴承润滑研究[J]. 内燃机工程, 2018, 39(4):15-22. BI Fengrong, LIU Bo, LIU Chunchao, et al. Research on diesel engine connecting rod small end bearing lubrication based on thermal elastic hydrodynamic model[J]. Chinese Internal Combustion Engine Engineering, 2018, 39(4):15-22.
[4] ILMAN M N, BARIZY R A. Failure analysis and fatigue performance evaluation of a failed connecting rod of reciprocating air compressor[J]. Engineering Failure Analysis, 2015, 56:142-149.
[5] STROZZI A, BALDINI A, GIACOPINI M, et al. A repertoire of failures in connecting rods for internal combustion engines, and indications on traditional and advanced design methods[J]. Engineering Failure Analysis, 2016, 60:20-39.
[6] SINGH N, AWASTHI R K, SINGH D, et al. Modeling and simulation of bearing clearance effects on journal center motion trajectories[J]. Materials Today:Proceedings, 2018, 5(9):17585-17596.
[7] PROFITO F J, ZACHARIADIS D C, DINI D. Partitioned fluid-structure interaction techniques applied to the mixed-elastohydrodynamic solution of dynamically loaded connecting-rod big-end bearings[J]. Tribology International, 2019, 140:105767.
[8] LEE K H, KIM J W, HUH Y J, et al. Optimum design of dynamically-loaded journal bearing with R600a refrigerant application[C]//International Compressor Engineering Conference, 1998:1232.
[9] GRANDO F P, PRIEST M, PRATA A T. Lubrication in refrigeration systems:Numerical model for piston dynamics considering oil-refrigerant interaction[J]. Proceedings of the Institution of Mechanical Engineers, Part J:Journal of Engineering Tribology, 2006, 220(3):245-258.
[10] 史正良, 郭小青, 胡余生, 等. 冷冻机油与制冷剂的溶解特性研究[J]. 制冷与空调, 2017(9):30-33. SHI Zhengliang, GUO Xiaoqing, HU Yusheng, et al. Research on miscibility characteristics of refrigeration oil and refrigerant[J]. Refrigeration and Air-Conditioning, 2017(9):30-33.
[11] WANG Chuang, XING Ziwen, HOU Feng, et al. Research on axis orbit of the journal bearing lubricated with oil and refrigerant mixtures in a twin-screw refrigeration compressor[J]. International Journal of Refrigeration, 2018, 90:1-11.
[12] ZHELEZNY V P, SCRIPOV V P. Determination of the pseudocritical parameters for refrigerant/oil solutions[J]. Fluid Phase Equilibria, 2003, 212(1-2):285-302.
[13] ZHELEZNY V P, PROCENKO D A, ANCHERBAK S N. An experimental investigation and modelling of the thermodynamic properties of isobutane-compressor oil solutions:Some aspects of experimental methodology[J]. International Journal of Refrigeration, 2007, 30(3):433-445.
[14] ZHELEZNY V P, SECHENYH V V, SEMENYUK Y V, et al. An experimental investigation and modelling of the viscosity refrigerant/oil solutions[J]. International Journal of Refrigeration, 2009, 32(6):1389-1395.
[15] 吴建华, 雷源, 王刚, 等. 往复式冰箱压缩机曲轴动态特性与轴承润滑计算分析[J]. 西安交通大学学报, 2015, 49(2):55-61. WU Jianhua, LEI Yuan, WANG Gang, et al. Numerical analysis for the crankshaft's dynamic behavior and bearing lubrication of reciprocating refrigerator compressor[J]. Journal of Xi'an Jiaotong University, 2015, 49(2):55-61.
[16] 郎骥, 杨建刚, 曹浩, 等. 滑动轴承热效应分析及流场等效温度的合理确定[J]. 润滑与密封, 2012, 37(10):70-73. LANG Ji, YANG Jiangang, CAO Hao, et al.Thermal effect analysis and fluid field average temperature reasonable determination of journal bearing[J]. Lubrication Engineering, 2012, 37(10):70-73.
[17] PONT A, LOPEZ J, RIGOLA J, et al. Numerical dynamic analysis of reciprocating compressor mechanism:Parametric studies for optimization purposes[J]. Tribology International, 2017, 105:1-14.
[18] 胡启龙, 何文强, 管文生, 等. 滑动轴承内轴颈涡动引发的热效应分析[J]. 热能动力工程, 2020, 35(9):22-28. HU Qilong, HE Wenqiang, GUAN Wensheng, et al. Analysis on thermal effect caused by journal whirl in sliding bearing[J]. Journal of Engineering for Thermal Energy and Power, 2020, 35(9):22-28.