【摘要】：翻車機(jī)系統(tǒng)是一種非常專業(yè)化的散裝物料卸料系統(tǒng),它用于火車裝載的散狀物料的自動翻卸。隨著這些企業(yè)規(guī)模的擴(kuò)大及現(xiàn)代化程度的提高,受到越來越多工程行業(yè)的重視。但是,翻車機(jī)系統(tǒng)在翻卸散裝物料的過程中,由于落差較大,翻車機(jī)體積龐大,煤排開的大量空氣攜帶粉塵到處飛揚(yáng),造成翻車機(jī)室空氣嚴(yán)重污染,影響工人健康。通風(fēng)除塵是做好粉塵防治的基本措施之一。在揚(yáng)塵空間設(shè)置局部集氣罩,通過合理的氣流組織控制有害物是工業(yè)通風(fēng)的重要技術(shù)手段。所以研究集氣罩罩口氣流分布的規(guī)律對于有效捕集粉塵十分重要。了解罩口吸氣口和吹氣口的氣流的運(yùn)動規(guī)律是合理設(shè)計集氣罩及通風(fēng)系統(tǒng)的基本依據(jù)。本論文以C型單車翻車機(jī)的卸料過程為依據(jù),建立了物理模型,并對研究對象的物理模型做了適應(yīng)的假設(shè)和簡化。針對料斗兩種不同結(jié)構(gòu)分別對翻車機(jī)卸料過程造成的揚(yáng)塵使用ANSYS14.5軟件進(jìn)行數(shù)值模擬,其中湍流模型選擇RNGk-e模型,兩相流模型選擇是歐拉-拉格朗日離散項模型,并用實驗驗證了模型選擇的可靠性。通過分析受煤坑內(nèi)的流場特性,確定料斗為對稱結(jié)構(gòu)更好,且料斗底部揚(yáng)塵速度約為1.5~4.5m/s。根據(jù)翻車機(jī)卸料的間歇性特點(diǎn)對卸料過程分為兩個過程進(jìn)行數(shù)值模擬,主要模擬雙側(cè)吸式和吹吸式兩種除塵方案。通過分析受煤坑和料斗內(nèi)的流場特性隨集氣罩的布置位置和罩口風(fēng)速變化,確定最佳位置和風(fēng)速。綜合比較兩種方案對粉塵控制效果和所需風(fēng)量,得知吹風(fēng)罩在抽風(fēng)罩分別安裝在兩側(cè)且吹風(fēng)罩在下面的結(jié)構(gòu)最優(yōu),最佳的吹吸氣風(fēng)速為吹氣氣流風(fēng)速為4m/s,吸氣氣流風(fēng)速為5m/s。在該情況下,實現(xiàn)對粉塵完成控制時所需要的風(fēng)量最小,且其系統(tǒng)較簡單,初投資也小。依據(jù)相似原則對受煤坑進(jìn)行1:16縮小,對單側(cè)吸式、雙側(cè)吸式和吹吸式三種除塵方案進(jìn)行試驗,測定在相同的風(fēng)量下逸出的粉塵濃度。試驗結(jié)果顯示吹氣風(fēng)速小于吸氣風(fēng)速時,吹風(fēng)口氣流可以將粉塵稀釋并擴(kuò)大了吸風(fēng)口粉塵捕集范圍。在所需風(fēng)量相同時,雙側(cè)吸式和吹吸式的除塵方案比單側(cè)吸式除塵效果好,雙側(cè)吸式和吹吸式兩種除塵方案的粉塵濃度比較接近,試驗結(jié)果與模擬結(jié)果相吻合。
[Abstract]:The dumper system is a specialized bulk material unloading system, which is used for automatic dump of bulk material loaded by train. With the expansion and modernization of these enterprises, more and more attention has been paid to the engineering industry. However, in the process of dumping and unloading bulk materials, because of the large drop, the volume of the dumper is huge, a large amount of air discharged by coal flies everywhere with dust, which results in serious air pollution in the dumper room and affects the health of the workers. Ventilation and dust removal is one of the basic measures for dust prevention. It is an important technical means of industrial ventilation to set up local gas collecting cover and control the harmful matter through reasonable airflow organization in the dust-raising space. Therefore, it is very important to study the law of air distribution at the hood mouth for effective dust capture. It is the basic basis for reasonable design of air collecting hood and ventilation system to understand the moving law of the air flow at the suction and blowing ports of the hood. Based on the unloading process of C type bicycle dumper, the physical model is established in this paper, and the adaptive assumption and simplification of the physical model of the research object are made. According to two different structures of hopper, ANSYS14.5 software is used to simulate the dust caused by the unloading process of the dumper. The RNGk-e model is chosen as the turbulence model, and the Euler-Lagrangian discrete term model is chosen as the two-phase flow model. The reliability of model selection is verified by experiments. By analyzing the flow field characteristics in the coal pit, it is found that the hopper is of symmetrical structure, and the dust velocity at the bottom of the hopper is about 1.5 ~ 4.5 m / s. According to the intermittent characteristics of unloading of dumper, the unloading process is divided into two kinds of numerical simulation, mainly simulating two kinds of dust removal schemes: double suction type and blowing suction type. By analyzing the variation of flow field characteristics in coal pits and hoppers with the arrangement of the collecting hood and the wind speed at the hood mouth, the optimum position and wind speed are determined. By comparing the effect of the two schemes on dust control and the required air volume, it is found that the air blowing cover is installed on both sides of the exhaust hood and the air blowing cover is below the optimal structure. The best inspiratory velocity is 4 m / s. The inspiratory wind speed is 5 m / s. In this case, the minimum amount of air is needed to complete the dust control, and the system is simple and the initial investment is small. According to the principle of similarity, the coal pit was reduced at 1:16, and the dust concentration was measured under the same air volume by testing the three schemes of single suction, double suction and blowing suction. The experimental results show that when the air velocity is less than the suction velocity, the dust can be diluted and the range of dust capture can be enlarged. When the required air volume is the same, the dust-removal schemes of bilateral suction and blow-suction are better than those of single-side suction. The dust concentration of the two schemes is close, and the experimental results are in good agreement with the simulation results.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TD714.4

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本文編號：2323451