發(fā)布時間：2018-11-17 10:59

【摘要】：目的:探索高揚程條件下4mm虹吸管內(nèi)氣體集聚現(xiàn)象對虹吸流速的影響,并對傳統(tǒng)虹吸流速水力學(xué)計算公式進行修正。創(chuàng)新點:1.通過對比物理模型實驗值和計算值,得出了高揚程虹吸流速的控制因素及傳統(tǒng)虹吸流速計算公式在高揚程條件下的不適用性;2.通過分析實驗數(shù)據(jù),對有壓管流水力學(xué)公式進行修正,使之適應(yīng)高揚程條件下的虹吸流速計算。方法:通過物理模型試驗,揭示高揚程虹吸流速的特征(圖3);將高揚程虹吸流速實驗值和傳統(tǒng)虹吸流速水力學(xué)公式計算值進行對比(表3和4);通過分析實驗數(shù)據(jù),結(jié)合有壓管流水力學(xué)公式,得出高揚程虹吸流速經(jīng)驗公式(公式(5)和(8))。結(jié)論:1.在高程差H_1一定時,虹吸流速與揚程呈負(fù)相關(guān);在揚程H0一定時,虹吸流速隨高程差H_1的增大而流速加快,直至達到最大流速,并保持穩(wěn)定狀態(tài);虹吸流速與管長呈負(fù)相關(guān)。2.高揚程虹吸排水由于管內(nèi)氣壓降低析出大量氣泡,形成氣液二相流,影響虹吸流速的計算;目前采用的有壓管流水力學(xué)計算公式不適用高揚程4mm虹吸管的虹吸水流。3.當(dāng)H_12ΔH,虹吸流速的控制因素為高程差H_1;當(dāng)H_1≥2ΔH,虹吸流速的控制因素為當(dāng)?shù)睾缥鼧O限揚程H_(max)和H_0的差值ΔH;4.對于高揚程4mm虹吸管虹吸流速的確定,一是可以直接實驗測定,查找相關(guān)數(shù)據(jù),二是可以采用經(jīng)驗公式來確定相關(guān)的虹吸流速。
[Abstract]:Aim: to investigate the effect of gas accumulation in 4mm siphon on siphon velocity under high lift conditions, and to modify the traditional formula of siphon velocity hydraulic calculation. Innovation: 1. By comparing the experimental and calculated values of the physical model, the control factors of the high head siphon velocity and the inapplicability of the traditional siphon velocity calculation formula under the condition of high head are obtained. 2. By analyzing the experimental data, the mechanics formula of pressurized pipe flow is modified to adapt to the siphon velocity calculation under the condition of high head. Methods: the characteristics of high head siphon velocity were revealed by physical model test (Fig. 3), and the experimental values of high head siphon velocity were compared with those calculated by traditional siphon velocity formula (tables 3 and 4). By analyzing the experimental data and combining the pressure pipe flow mechanics formula, the empirical formulas of high head siphon velocity (5) and (8).) were obtained. Conclusion: 1. The siphon velocity is negatively correlated with the head when the elevation difference H _ 1 is fixed, and the siphon velocity increases with the increase of the height difference H _ 1 until the maximum velocity is reached, and the state of the siphon velocity remains stable. The siphon velocity was negatively correlated with the tube length. 2. A large number of bubbles are released from high head siphon drainage due to the reduction of air pressure in the pipe, which results in gas-liquid two-phase flow, which affects the calculation of siphon velocity, and the current calculation formula of pressure pipe flow mechanics is not suitable for siphon flow of high head 4mm siphon pipe. When H12 螖 H, the control factor of siphon velocity is elevation difference H _ 1, and when H _ 1 鈮，

本文編號：2337533