柱塞式注肥泵内流动瞬态特性数值模拟与试验  

Numerical simulation and experiment of transient flow characteristics in a piston injection pump

作　　者：康邵暄 黎耀军[1,2] 严海军[1,2] 王晶晶[1,2] KANG Shaoxuan;LI Yaojun;YAN Haijun;WANG Jingjing(State Key Laboratory of Efficient Utilization of Agricultural Water Resources,China Agricultural University,Beijing 100083,China;Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System,China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学农业水资源高效利用全国重点实验室,北京100083 [2]中国农业大学北京市供水管网系统安全与节能工程技术研究中心,北京100083

出　　处：《农业工程学报》2024年第16期75-83,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：山东省重点研发计划(重大科技创新工程)项目(2022CXGC020707);“十四五”国家重点研发计划项目(2023YFD1900703);国家现代农业产业技术体系项目(CARS-03);水利技术示范项目(SF-202311)。

摘　　要：柱塞式注肥泵是水肥一体化系统肥液注入的关键设备,为探明柱塞往复运动过程中柱塞式注肥泵的内部流动特征及外特性,该研究基于RNG k-ε湍流模型和动网格技术,构建注肥泵内流动三维动态数值模拟模型,对不同柱塞行程比和往复频率工况的泵内瞬态流动进行非定常数值模拟,预测柱塞泵外特性并分析额定工况的泵内流场特征,通过与试验数据及理论计算结果的对比,验证数值模拟模型的可靠性。结果表明:不同行程下模拟所得的时间平均流量与试验结果最大相对误差为3.58%,数值模拟所得瞬时流量大小及变化趋势与理论计算结果吻合良好,最大相对误差为3.17%;泵排出、吸入过程的初始阶段,分别存在进、出口单向阀阀芯闭合滞后现象,伴随形成回流;受阀芯闭合滞后导致的回流影响,注肥泵瞬时流量存在突变,其突变时刻与阀芯闭合时刻一致;注肥泵平均流量与柱塞行程和往复频率均呈线性正相关,泵容积系数随柱塞行程的减小而降低,但随柱塞往复频率的变化不明显,变频调控可更准确调节注肥泵流量,是水肥一体化系统中注肥流量调节的优选方式。研究结果可为柱塞式注肥泵设计与运行调控提供依据。Fertigation technology plays a crucial role in the fertilizer utilization efficiency and sustainable development of modern agriculture.Among them,the piston-type fertilizer injection pump serves as the vital equipment for the uniform fertilizer injection in the large-scale irrigation systems.In this study,the numerical investigation and experimental validation were presented on the internal flow and external performance of the piston-type fertilizer injection pump during reciprocating motion.A three-dimensional numerical simulation model for the transient flow in the piston fertilizer injection pump was established based on the dynamic mesh and the RNG k-εturbulence model.The gap between the dynamic mesh boundary and the static boundary was treated by the gap model with zero mass flux into the gap grid.The motion of the valve core in the flow field was analyzed by the six degrees of freedom(6DOF)solver.The external properties of the piston injection pump under different conditions were investigated,and the internal flow field characteristics of the pump under nominal condition were analyzed.The reliability of the numerical simulation model was verified by comparing the predicted flow rate with the experimental and theoretical data.It was found that the maximum relative error between the predicted and the experimental time-averaged flow rates was 3.58%for different strokes.The instantaneous flow rates were obtained from the numerical simulations and theoretical calculations.A high degree of consistency was demonstrated in both magnitude and trend,with the maximum relative error of 3.17%.The high velocity zone was concentrated in the flow channel of the outlet check valve,with the maximum velocity of 7.74 m/s,during the discharge phase of the pump.While a significantly increased pressure observed in the pump chamber with the maximum relative static pressure of 69.1 kPa.In the suction stage of the pump,the high flow velocity area was mainly concentrated in the inlet check valve channel.The maximum flow velocity of

关 键 词：泵 试验 柱塞式注肥泵 单向阀 动网格 数值模拟 

分 类 号：S277.94[农业科学—农业水土工程] TV136.2[农业科学—农业工程]