户用沼液泵的研究与开发

发布时间：2018-06-27 17:13

本文选题：沼液泵 + 水力设计　；参考：《兰州理工大学》2011年硕士论文

【摘要】：近年来,在国家一系列惠农政策的推动下,农村沼气建设得到了快速发展。但是在沼气池的使用过程中,由于沼渣沼液中含有残余沼气,致使沼渣沼液难以清除,在农村废弃沼气池的现象较为普遍。为了解决农村沼气池除渣除液难的问题,本课题结合农户用电、沼气池结构、容积以及目前沼渣沼液清除的状况研发双流道式户用沼液泵。本课题以沼液泵作为研究对象,通过对沼液泵全流场水力设计、过流部件三维造型及CFD数值模拟,对其性能进行了预测与分析,取得的研究成果如下: 1.根据我国农村地区大力推广的地下式沼气池结构、容积,确定了沼液泵的设计参数和结构形式。该泵电机置于池面、泵体潜入沼液,电机采用220伏交流电动机,沼液泵重量轻、移动方便、操作简单、安全可靠。 2.流道中线的确定是双流道泵设计的关键技术。本课题比较了两种阿基米德螺旋线的曲率变化情况,给出了双流道叶轮流道中线方程的选择依据。 3.利用Pro/Engineer软件良好的三维造型功能,对沼液泵过流部件进行三维造型。通过编入阿基米德螺旋线公式的方法生成叶轮流道中线,这样生成的流道中线快速、准确,叶轮的实体造型更加精确。 4.本课题结合分析了流道中线对叶轮造型的影响。在叶轮实体造型过程中,流道断面在空间中容易相交,导致叶轮流道造型失败。因此,单纯的叶轮平面水力设计不能保证形成光滑的内流道。此时叶轮的三维实体造型可以对其进行校核。在不能生成光滑的内流道时,可以依次修改断面空间安放角度、流道过流断面面积变化规律、流道中线方程,最终得到光滑的叶轮流道。 5.利用CFD技术对沼液泵在清水、固液两相介质下进行全流场定常数值模拟计算。为了得到固相颗粒直径、浓度对泵性能的影响规律,对沼液泵在设计工况下分别输送相同固相浓度、不同颗粒直径和相同颗粒直径、不同固相浓度的固液两相介质进行模拟计算。通过对内部流场数值模拟结果分析得到了沼液泵在输送两相流介质时的水力性能变化及流道磨损情况,为进一步深入研究沼液泵奠定了一定理论基础。 6.研究表明,本课题所设计的沼液泵符合给定设计参数及性能的要求;说明沼液泵的水力设计是合理的;双流道泵作为沼液泵能满足户用沼气池清除沼渣沼液的要求;该结构形式的沼液泵具有重大的推广价值。
[Abstract]:In recent years, under the promotion of a series of favorable agricultural policies, rural biogas construction has developed rapidly. However, in the use of biogas digesters, the residue biogas contained in the biogas sludge is difficult to remove, and the phenomenon of waste biogas digesters in rural areas is relatively common. In order to solve the problem that it is difficult to remove sludge from rural biogas digesters, this project combines household electricity consumption, biogas digester structure, volume and current situation of biogas sludge removal to develop a double-channel household biogas pump. This paper takes the biogas liquid pump as the research object, through the hydraulic design of the whole flow field of the biogas liquid pump, the three-dimensional modeling of the flow parts and the numerical simulation of CFD, the performance of the biogas pump is predicted and analyzed. The research results are as follows: 1. According to the structure and volume of underground biogas digesters popularized in rural areas of China, the design parameters and structural forms of biogas liquid pumps are determined. The pump motor is placed on the surface of the pool, the pump body submerges into the biogas liquid, the motor adopts 220V AC motor, the biogas pump is light in weight, easy to move, easy to operate, safe and reliable. The determination of flow channel midline is the key technology in the design of double channel pump. In this paper, the curvature changes of two Archimedes helix are compared, and the selection basis of the middle line equation of the double channel impeller runner is given. Using the good 3D modeling function of Pro / engineer software, the flow parts of biogas liquid pump are modeled. Through the method of compiling Archimedes helix formula to generate the impeller runner midline, the flow channel midline is fast and accurate, and the solid shape of impeller is more accurate. 4. In this paper, the influence of runner midline on impeller modeling is analyzed. In the process of impeller solid modeling, the flow channel section intersects easily in space, which leads to the failure of impeller runner modeling. Therefore, the simple hydraulic design of impeller plane can not guarantee the formation of smooth internal flow channel. The three-dimensional solid modeling of impeller can be checked. When the smooth inner passage can not be generated, the angle of section space can be modified in turn, the changing law of flow passage cross section area, the middle line equation of runner can be obtained, and the smooth impeller passage can be obtained finally. 5. CFD technique is used to simulate the steady flow field of biogas pump in clear water and solid-liquid two-phase medium. In order to obtain the influence of solid particle diameter and concentration on pump performance, the biogas liquid pump was used to transport the same solid concentration, different particle diameter and the same particle diameter respectively under the design conditions. The solid-liquid two-phase medium with different solid concentration was simulated and calculated. Through the analysis of the numerical simulation results of internal flow field, the hydraulic performance of biogas liquid pump and the wear of flow channel are obtained, which lays a certain theoretical foundation for further study of biogas fluid pump. The research shows that the biogas liquid pump designed in this paper meets the requirements of the given design parameters and performance, and shows that the hydraulic design of the biogas pump is reasonable, and that as the biogas liquid pump, the double-channel pump can meet the requirements of the household biogas digester for the removal of biogas residue biogas. The biogas liquid pump with this structure has great popularizing value.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH38

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