本文選題：低壓管道灌溉 + 球閥��； 參考：《揚(yáng)州大學(xué)》2017年碩士論文

【摘要】：進(jìn)入21世紀(jì)后,隨著技術(shù)的進(jìn)步和經(jīng)濟(jì)的進(jìn)一步發(fā)展,人類(lèi)對(duì)節(jié)水、節(jié)地、生態(tài)、高產(chǎn)優(yōu)質(zhì)有了更高的要求,低壓管道輸水灌溉技術(shù)也成了現(xiàn)階段農(nóng)業(yè)發(fā)展的重要措施。要想加快發(fā)展速度,管材和配水裝置的研究是最重要的兩項(xiàng),目前管材的研制已普遍受到重視,而配水裝置的研制卻是一個(gè)薄弱環(huán)節(jié),嚴(yán)重阻礙了該項(xiàng)技術(shù)的推廣應(yīng)用,急需提出一種簡(jiǎn)易、低水頭損耗、密封性良好的新型放水閥。本文采用計(jì)算流體力學(xué)軟件FLUENT,通過(guò)UG構(gòu)建模型,采用四面體非結(jié)構(gòu)化網(wǎng)格自動(dòng)劃分網(wǎng)格,計(jì)算采用氣液二相流VOF模型,Standard k-ε紊流模型,以及SIMPLE算法。通過(guò)對(duì)下壓式擋板放水閥中一種過(guò)流能力最大的工況建立三維數(shù)值模型,利用Flunet軟件模擬的幾組流量情況,得出計(jì)算模型可靠的結(jié)論。同時(shí)對(duì)比了不同流量下相同斷面速度、流態(tài)、壓強(qiáng)的差異,分析了可能的原因。通過(guò)對(duì)新型低壓灌溉球型放水閥建立三維數(shù)值模型。利用Fluent模擬分析了在相同的工作水頭下,不同轉(zhuǎn)角下放水閥閥內(nèi)的水流流態(tài),水頭損失和過(guò)流能力,分析得出球閥的的適宜工作的轉(zhuǎn)角在0°至25°之間。同時(shí)模擬了相同過(guò)流流量下,球閥全開(kāi)工況與下壓式擋板放水閥全開(kāi)工況的水頭損失、壓強(qiáng)的對(duì)比,分析得到球型放水閥無(wú)論是在工作環(huán)境的適應(yīng)性、密封性能、過(guò)流能力還是減少水頭損失上都比下壓式擋板放水閥更具優(yōu)勢(shì)。本文研究的結(jié)果將用于分析閥體結(jié)構(gòu)內(nèi)部水流情況,分析閥體內(nèi)部對(duì)水流的阻力,為對(duì)進(jìn)一步優(yōu)化閥體結(jié)構(gòu)減小水流阻力提供參考和依據(jù)。
[Abstract]:After entering the 21st century, with the progress of technology and the further development of economy, people have higher requirements for water saving, land conservation, ecology, high yield and good quality. The irrigation technology of low pressure pipeline water conveyance has also become an important measure for the development of agriculture at this stage. In order to speed up the development, the research of pipe and water distribution device are the two most important items. At present, the development of pipe material has been paid more attention to, but the development of water distribution device is a weak link, which seriously hinders the popularization and application of this technology. It is urgent to put forward a simple, low head loss, good sealing new discharge valve. In this paper, the computational fluid dynamics software fluent is used to construct the model by UG, the tetrahedron unstructured grid is used to mesh automatically, the gas-liquid two-phase flow VOF model is used to calculate the standard k- 蔚 turbulence model, and the SIMPLE algorithm is used. By establishing a three-dimensional numerical model for a working condition with maximum overflow capacity in a downpressure baffle discharge valve, and using several groups of flow conditions simulated by Flunet software, the reliable conclusion of the calculation model is obtained. At the same time, the differences of the same cross section velocity, flow state and pressure under different flow rate are compared, and the possible reasons are analyzed. A three-dimensional numerical model was established for a new type of low-pressure irrigation ball discharge valve. The flow pattern, head loss and overflow capacity of the valve under the same working head are simulated by Fluent. The suitable working angle of the ball valve is found to be between 0 擄and 25 擄. At the same time, the comparison of the head loss and pressure between the ball valve and the downpressure baffle valve under the same overflow flow rate is simulated. The results show that the ball outlet valve is fit for the working environment and the sealing performance is not only in the working environment, but also in the whole open condition. Overflowing capacity or reducing head loss are superior to lower pressure baffle discharge valves. The results of this paper will be used to analyze the internal flow of the valve body and the resistance of the body to the flow, which will provide a reference and basis for further optimization of the valve body structure to reduce the flow resistance.
【學(xué)位授予單位】：揚(yáng)州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：S277.9
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本文編號(hào)：1948386