Abstract:In order to clarify motion characteristics of the ring inlet valve in a reciprocating compressor the expansion or suction process in the compressor was simulated with CFD approach by exploring the unsynchronizing motion of valve plates. During the unsteady flow simulations, a user defined C subroutine was composed to involve the motion functions of piston and four valve plates, displacement boun-dary conditions, impact criteria between valve plate and seat or lift limiter, displacement constrains for impact and rebound velocity boundary, eventually the displacement increments of four valve plates were determined at the end of each time step. Besides, the moving mesh technique was applied to update the mesh to realize a dynamic simulation of motion of various valve plates. Based on the mesh-independent feature identified, the effects of spring stiffness and crank shaft speed on the motion of the four valve plates and the flow rate through them were investigated. The simulated results show that the unsynchronizing motion of valve plates magnifies itself by showing different opening and closing angles from inner to outer of the plates. With increasing spring stiffness and decreasing crankshaft speed, the unsynchronizing motion among four valve plates becomes more and more evident. Additionally, the inner or the first valve plate flutters initially at the speed of 300 r/min, however, when the spring stiffness is increased to 6 000 N/m from 4 000 N/m, the second valve plate starts to flutter, and the flow rate is reduced to 0.8 times the flow rate without unsynchronizing motion. This suggests that the unsynchronizing motion must be considered when a flow rate is under determination.
[1]杨保江.往复式压缩机组的振动机理及其控制[J].化工设备与管道,2012,49(4):39-43. Yang Baojiang.Mechanism of vibration occurred in reciprocating compressor set and control measures[J].Process Equipment & Piping, 2012,49(4):39-43.(in Chinese)[2]刘德基,张慢来,张琴,等.往复式压缩机进气阀运动规律的理论研究[J].石油机械,2013,41(3):80-83. Liu Deji, Zhang Manlai, Zhang Qin, et al. Theoretical research on the motion law of reciprocating compressor inlet valve[J].China Petroleum Machinery, 2013, 41(3): 80-83.(in Chinese)[3]Almbauer R, Lang W, Nagy D, et al. Application of computational fluid dynamics for the thermodynamic development of a new generation of hermetic reciprocating compressor[C]//Proceedings of the International Compressor Engineering Conference, 2010:1230.[4]王嘉骏,李良超,顾雪萍,等.搅拌反应器内气液两相流的CFD研究进展[J].化工设备与管道,2012,49(1):1-4. Wang Jiajun, Li Liangchao, Gu Xueping, et al. Progress on CFD simulation of gas-liquid two-ghase flow in stirred tank reactor[J].Process Equipment & Piping, 2012,49(1):1-4.(in Chinese)[5]Nakano A, Kinjo K. CFD applications for development of reciprocating compressor[C]//Proceedings of the International Compressor Engineering Conference, 2008:1326.[6]Kinjo K, Nakano A, Hikichi T, et al. Study of CFD considering valve behavior in reciprocating compressor[C]//Proceedings of the International Compressor Engineering Conference, 2010:1256.[7]翟江,赵勇刚,周华.水压轴向柱塞泵内部空化流动数值模拟[J].农业机械学报,2012,43(11):244-249. Zhai Jiang, Zhao Yonggang, Zhou Hua. Numerical si-mulation of cavitating flow in water hydraulic axial piston pump[J].Transactions of the Chinese Society for Agricultural Machinery, 2012, 43(11): 244-249.(in Chinese)[8]Mistry H, Bhakta A, Dhar S, et al. Capturing valve dynamics in reciprocating compressors through computational fluid dynamics[C]//Proceedings of the International Compressor Engineering Conference, 2012:1210.[9]Rigola J, Lehmkuhl O, Ventosa J, et al. Numerical si-mulation of the turbulent fluid flow through valves based on Low Mach models[C]//Proceedings of the International Compressor Engineering Conference, 2012:1375.[10]岳向吉,巴德纯,苏征宇,等.基于CFD的滚动活塞压缩机泵腔气流噪声分析[J].振动与冲击,2012,31(3):123-126. Yue Xiangji, Ba Dechun, Su Zhengyu, et al. Gas flow noise analysis in pump chamber of rolling piston compressors based on CFD[J]. Journal of Vibration and Shock, 2012, 31(3): 123-126.(in Chinese)[11]王洋,王维军,刘洋,等.多级潜水电泵非定常流动数值模拟及性能预测[J].江苏大学学报:自然科学版,2013,34(5):519-523. Wang Yang, Wang Weijun, Liu Yang, et al. Numerical simulation and performance prediction of unsteady flow in multi-stage submersible centrifugal pump[J].Journal of Jiangsu University:Natural Science Edition, 2013,34(5): 519-523.(in Chinese)