CAJ | 학술논문

为了解决污水处理用排污泵叶轮易堵塞和磨损问题，该文设计了一种新型后掠式双叶片污水泵叶轮结构。采用正交试验的方法，按照L9(34)正交表，选取了叶片出口安放角β2、叶轮进口直径Dj、叶片出口宽度b2以及叶轮出口直径D2等因素，设计出了9组方案，通过正交试验分析了4个几何参数对泵性能的影响，得出叶轮出口直径D2是影响效率和扬程的最主要因素，并提出了优化设计方案。基于k-ε湍流模型及离散相零方程模型，对污水泵进行了固液两相流数值模拟，并将数值模拟结果与样机试验结果进行了分析对比。结果表明，双叶片、大包角、叶片前缘后掠的设计方法，可使颗粒杂质向外输送至叶片外周边，保证了固体颗粒或纤维的顺利通过，大幅降低了叶片的磨损，从而提高了泵的使用寿命，同时还具有较高的效率。通过样机试验得到优化设计方案在额定流量点的效率为80%，扬程为11 m，效率高于国家标准2.5%，该水力设计方法对污水泵水力设计具有一定的参考价值。
위료해결오수처리용배오빙협륜역도새화마손문제，해문설계료일충신형후략식쌍협편오수빙협륜결구。채용정교시험적방법，안조L9(34)정교표，선취료협편출구안방각β2、협륜진구직경Dj、협편출구관도b2이급협륜출구직경D2등인소，설계출료9조방안，통과정교시험분석료4개궤하삼수대빙성능적영향，득출협륜출구직경D2시영향효솔화양정적최주요인소，병제출료우화설계방안。기우k-ε단류모형급리산상령방정모형，대오수빙진행료고액량상류수치모의，병장수치모의결과여양궤시험결과진행료분석대비。결과표명，쌍협편、대포각、협편전연후략적설계방법，가사과립잡질향외수송지협편외주변，보증료고체과립혹섬유적순리통과，대폭강저료협편적마손，종이제고료빙적사용수명，동시환구유교고적효솔。통과양궤시험득도우화설계방안재액정류량점적효솔위80%，양정위11 m，효솔고우국가표준2.5%，해수력설계방법대오수빙수력설계구유일정적삼고개치。
This article proposed a typical impeller structure of new type of sewage pump to solve the blocking and wear problem in sewage pumps. Using an orthogonal experiment of L9(34), which contains factors of outlet blade angleβ2, impeller inlet diameterDj, impeller outlet width b2, and impeller outlet diameterD2, nine groups of schemes were designed. Four geometric parameters were researched to analyze the influence on sewage pump performance by orthogonal experiments. Optimized design schemes were achieved, and we conclude that impeller outlet diameterD2 is the main factor that affects the efficiency and pump head. Second, the solid-liquid two-phase flow was studied on the basis of a turbulence model and a model of the discrete-zero equation. On the basis of the orthogonal optimization model, the back-swept angle was changed to study the different particle distributions associated with the back-swept angle and non-back-swept angle. We further explored the effect of the back-swept angle on sewage pump performance. The angles were 60 degrees, 80 degrees, 100 degrees, and 120 degrees, respectively. The research shows that the degree of swept-back angle has little influence on sewage pump head. Nevertheless, it has significant influence on pump efficiency when the solid particle diameter is 0.4 mm and the solid volume fraction is 5 percent. The optimization model was made into a prototype with the swept angle of 80 degrees in the plant of Nanjing LanShen Pump Co., LTD, to perform the experiment. The test system consisted of an electric pump, a torque sensor, and a pressure sensor. By comparing numerical results with experimental results, the result indicates that the double bladed, large wrap angle, and leading edge sweep design make the particles move around the outer perimeter of the blades to ensure the passage capacity and operational efficiency of sewage pumps and greatly reduce the wear of blade. Consequently, the service life of the sewage pump can be improved. The rotation of the impeller caused the velocity variation in the back-swept sewage pump and velocity circulation amount distributes around the flow field. The inlet velocity rotated with the impeller high-speed revolution, and the outlet velocity changed radically. The figure illustrates that the solid volume fraction in the pressure side is greater than that in the suction side. That is, particles move towards the pressure side of blade. Therefore, wear and tear on the pressure side is more serious than the suction side. The distribution of total pressure and solid volume fraction are different from the pressure to the suction side. When the back-swept angles are 60 degrees and 80 degrees on the suction side, the total pressure follows a declining trend from the suction side to the pressure side. It means that the field near the imports falls sharply, and then falls gently. However, the total pressure decreases initially and then begins to increase with the increase of the back-swept angle, when the angles are 100 degrees and 120 degrees. At the same time, the solid volume fraction exhibits a downward trend. According to the test results, the efficiency of the model pump can reach 80% with a pump head of 11 m at rated conditions. The test result is 2.5% higher than the National Standard.