基于灌溉系统的集中分配切换转阀设计与研究

发布时间：2018-01-28 03:07

本文关键词： 节水灌溉分区灌溉集中分配切换转阀结构设计　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：节水灌溉可有效提高作物水分利用率,降低水资源消耗。分区交替灌溉是后发展起来的一种节水灌溉技术,节水性好,有利于提升作物品质。但分区交替灌溉装置大多存在结构复杂、成本昂贵等问题,一定程度上限制了分区交替灌溉技术的应用与推广。本文在现有节水灌溉装置基础上,结合交替灌溉技术原理,设计了集中分配切换转阀,可实现不同路径的切换,对切换管道残留液及时回流,降低灌溉损耗。此外,还可实现多路供液,扩展集中分配切换转阀的功用范围。调节阀芯位置,控制阀口开度,可控制分配流量的大小,以满足不同灌溉需求。本文运用FLUENT软件,对集中分配切换转阀换向流道流场仿真,比较了圆形拐角换向流道和直角拐角换向流道在不同阀口开度下的压力场分布和速度场分布,表明圆形拐角和直角拐角两种换向流道的流场特性差别并不显著,从加工成本考虑,选用直角拐角作为集中分配切换转阀的换向流道。对集中分配切换转阀单路切换和多路切换两种供流模式的流场仿真,比较了不同阀口开度下的速度场分布、压力场分布及出口质量流量,分析了工作压力和阀口开度对两种供流模式的性能影响,表明单路切换和多路切换的最佳工作压力均为0.3～0.5MPa,最佳阀口开度分别为75%～100%和50%。运用FLUENT和ABAQUS软件对圆弧滑动面密封装置流场及应力应变仿真,表明星形密封结构较优,具有一定的自补偿功能,经试验密封性可靠。
[Abstract]:Water-saving irrigation can effectively improve crop water use efficiency and reduce water consumption. Alternate irrigation is a kind of water-saving irrigation technology developed after the development of good water-saving. It is beneficial to improve the quality of crops, but most of the alternative irrigation devices have complex structure and high cost. To a certain extent, the application and popularization of alternative irrigation technology is limited. Based on the existing water-saving irrigation equipment and combining with the principle of alternative irrigation technology, a centralized distribution switch valve is designed. It can realize the switch of different paths, return the residual liquid in time, reduce irrigation loss. In addition, it can realize multi-channel liquid supply, expand the function range of centralized distribution of switch valve, and adjust the position of valve core. Control valve opening can control the size of distribution flow to meet different irrigation requirements. In this paper, FLUENT software is used to simulate the flow field of the reversing channel of the centralized distribution switch valve. The pressure field distribution and velocity field distribution of circular corner commutative channel and right corner commutative channel under different opening degree of valve are compared. It shows that the flow field characteristics of circular corner and right corner are not significant. Considering the processing cost, the right corner is chosen as the reversing passage of the centralized distribution switch valve. The flow field simulation of the two flow modes of the centralized distribution switching valve is carried out, namely, the single-way switch and the multi-channel switching. The distribution of velocity field, pressure field and outlet mass flow under different opening degree of valve were compared, and the effects of working pressure and opening degree of valve on the performance of two flow modes were analyzed. The results show that the optimal working pressure for both single-channel switching and multi-channel switching is 0.3? 0. 5 MPA. The optimum opening of valve is 75% and 50% respectively. The flow field and stress strain of circular sliding surface sealing device are simulated by FLUENT and ABAQUS software, which shows that the star seal structure is better. It has certain function of self-compensation, and is reliable after testing.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S277.9

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