【摘要】：隨著礦井開采深度的增加和機(jī)械化程度的不斷提高，礦井熱害日益突出。礦井高溫高濕環(huán)境嚴(yán)重危害井下工作人員的身體健康和安全，影響工作效率，已成為制約礦井安全開采的重大問題之一。因此，深入開展深井熱害防治對于保障我國深部煤炭資源安全、高效的開采具有重大的理論與現(xiàn)實意義。礦用空冷器是礦井降溫系統(tǒng)的末端設(shè)備，為降低礦井工作面溫度提供保障，其性能好壞直接影響降溫效果，所以，礦用空冷器一直被業(yè)界作為重點研究對象。 礦用空冷器在使用過程中，礦塵易沉積在其表面，高濕也會導(dǎo)致其表面結(jié)露而粘附更多的顆粒，從而形成污垢，，既而影響其換熱效率，影響降溫效果。本文主要研究礦用空冷器的外表面污垢對其換熱的影響。 本文從理論上分析了礦用空冷器外表面污垢的形成及其對空冷器換熱性能的影響。以某煤礦深井降溫系統(tǒng)為原型，研究了礦用空冷器外表面污垢的厚度和污垢熱導(dǎo)率對空冷器換熱性能的影響，得到空冷器總傳熱系數(shù)隨污垢厚度的增加而減小；污垢熱導(dǎo)率不同時，污垢對其的影響不同，污垢對總傳熱系數(shù)的影響隨著污垢熱導(dǎo)率的增大而減弱；當(dāng)取煤灰的熱導(dǎo)率為1.93W/（m·K）時，空冷器的總傳熱系數(shù)基本不變，污垢的影響可忽略。 本文利用Gambit建立了空冷器的簡化三維模型，利用FLUENT軟件模擬研究了不同污垢厚度和污垢熱導(dǎo)率對礦用空冷器換熱效果的影響，通過模擬計算得到空冷器出口空氣平均溫度隨污垢厚度的增加而升高，即換熱效果減弱；污垢熱導(dǎo)率越大，污垢對空冷器換熱性能的影響越小，當(dāng)取煤灰的熱導(dǎo)率為1.93W/（m·K）時，污垢對空冷器換熱性能的影響較小，可以忽略。 通過對模擬計算結(jié)果與實測數(shù)據(jù)的對比，驗證了模型的相對正確性。利用驗證的模型模擬計算得到了實際工況下不同污染程度時經(jīng)礦井降溫設(shè)備處理后的空氣平均溫度值，預(yù)測降溫系統(tǒng)在實際運行的過程中，污垢的存在將直接減弱空冷器的換熱，降溫效果減弱，且隨著污垢厚度的增加而惡化，礦井環(huán)境溫度將達(dá)不到設(shè)計要求。同樣的運行條件下，空冷器外表面污垢厚度每增加0.1mm，礦井環(huán)境溫度升高約0.3~0.4℃。 利用所建模型，考慮污垢的影響，對運行參數(shù)風(fēng)流流速和空冷器結(jié)構(gòu)參數(shù)橫向管間距進(jìn)行了優(yōu)化，得到了污垢對礦用空冷器換熱的影響隨風(fēng)流流速的降低而減弱，即在滿足降溫所需風(fēng)量要求的情況下，選擇較低的風(fēng)速可以減弱污垢的影響，和St/do=1.5（St為橫向管間距，do為管外徑）時污垢的影響較弱，以減弱污垢對礦用空冷器換熱性能的影響。 總結(jié)了目前換熱器的常用污垢防治技術(shù)，在此基礎(chǔ)上提出了針對礦用空冷器的污垢防治對策。
[Abstract]:With the increase of mining depth and mechanization, the thermal damage of mine is becoming more and more serious. The environment of high temperature and high humidity in mine seriously endangers the health and safety of underground workers and affects the working efficiency, which has become one of the major problems restricting the safe mining of mines. Therefore, it is of great theoretical and practical significance to carry out deep well thermal hazard prevention and cure in order to ensure the safety of deep coal resources in our country and to exploit coal efficiently. Mine air cooler is the terminal equipment of mine cooling system, which provides guarantee for reducing the temperature of mine face, and its performance directly affects the cooling effect. Therefore, the mine air cooler has been regarded as the key research object by the industry all the time. In the process of application of mine air cooler, ore dust is easy to deposit on its surface, and high humidity will also lead to the surface dew and adhesion to more particles, thus forming dirt, which will affect the heat transfer efficiency and the cooling effect. In this paper, the influence of external surface fouling on heat transfer of mine air cooler is studied. In this paper, the formation of fouling on the outer surface of mine air cooler and its influence on the heat transfer performance of air cooler are analyzed theoretically. Based on a deep well cooling system in a coal mine, the influence of the fouling thickness and fouling thermal conductivity on the heat transfer performance of the air cooler is studied. The total heat transfer coefficient of the air cooler decreases with the increase of the fouling thickness. The influence of fouling on total heat transfer coefficient decreases with the increase of fouling thermal conductivity, and when the thermal conductivity of coal ash is 1.93W/ (m K), the total heat transfer coefficient of air cooler is basically unchanged. The effects of dirt are negligible. In this paper, the simplified three-dimensional model of air cooler is established by Gambit, and the effects of different fouling thickness and fouling thermal conductivity on the heat transfer efficiency of mine air cooler are simulated by FLUENT software. The results show that the average air temperature at the outlet of the air cooler increases with the increase of the fouling thickness, that is, the heat transfer efficiency weakens, the larger the fouling thermal conductivity, the less the influence of fouling on the heat transfer performance of the air cooler, when the thermal conductivity of coal ash is 1.93W/ (m K), Fouling has little effect on the heat transfer performance of air cooler and can be neglected. The relative correctness of the model is verified by comparing the simulation results with the measured data. By using the verified model, the average air temperature value after treatment by mine cooling equipment under different pollution levels under actual working conditions is obtained, and the temperature drop system is predicted in the actual operation process. The existence of dirt will directly weaken the heat transfer of air cooler and the cooling effect will be weakened. With the increase of fouling thickness, the temperature of mine environment will not meet the design requirements. Under the same operating conditions, with the increase of 0.1 mm in the thickness of fouling on the outer surface of the air cooler, the ambient temperature of the mine is increased by about 0.3 ~ 0.4 鈩

本文編號：2272322