【摘要】：調查表明，人員有80%以上的時間是在室內(nèi)度過的，因此有必要研究高效的通風方式，為人員營造健康舒適的室內(nèi)環(huán)境。置換通風提高了房間的通風效率，但存在冬季使用受限等技術問題；而射流通風不僅可以營造出類似于置換通風的氣流組織效果，亦可全季節(jié)運行，尤其適用于辦公建筑的機械通風。因此，本文以射流通風技術為研究點，對其多工況下的室內(nèi)氣流組織特性及影響因素進行了數(shù)值模擬研究。 首先，建立了射流通風的物理模型，并對所選擇的湍流模型、壓力差值格式和壁面條件處理方法擬合9種不同的定解條件進行數(shù)值模擬研究，基于前期學者的實驗數(shù)據(jù)驗證模型的正確性；其次，分向室內(nèi)送冷風和熱風兩種工況，對碰撞射流通風和豎壁貼附射流通風下室內(nèi)氣流組織特性進行了模擬實驗研究，并與置換通風進行對比研究，從室內(nèi)氣流組織分布特性和通風效率兩個層面，分析了基于射流通風的室內(nèi)溫度場、速度場、空氣齡、空氣分布不均勻系數(shù)、能量利用系數(shù)、空氣分布特性指標等的變化規(guī)律；最后，對影響碰撞射流通風和豎壁貼附射流通風的關鍵因素進行了研究，建立了送回風口模型，探討了送回風口不同布置形式對射流通風效果的影響，歸納出最佳的送回風口布置方案。 研究表明，對于室內(nèi)氣流組織，采用湍流的RNG k-ε模型、標準壁面函數(shù)法和Body-force-weighted壓力差值格式可以取得較好的數(shù)值模擬結果； 研究發(fā)現(xiàn)，射流通風向室內(nèi)送冷風時，室內(nèi)溫度場有明顯的分層現(xiàn)象，和置換通風相比，碰撞射流通風使房間地面“空氣湖”的溫度高出2℃，豎壁貼附射流通風使房間地面“空氣湖”的溫度高出3℃；室內(nèi)空氣齡縱向分層現(xiàn)象明顯，和置換通風相比，房間z=1.2m平面以下的空氣齡與置換通風類似，房間z=1.2m平面以上的空氣齡在比置換通風低100~200s，空氣品質較好。當向室內(nèi)送熱風時，射流通風方式可使室內(nèi)z=0.1m平面以下的溫度比上部的溫度高出1~2℃，整個流場的空氣齡分布無明顯的分層現(xiàn)象。 研究還發(fā)現(xiàn)，，碰撞射流通風和豎壁貼附射流通風夏季工況下能量利用系數(shù)為2.021和1.609，冬季工況下為1.08和1.21，均大于1，存在節(jié)能空間，并且夏季節(jié)能空間較大。射流通風下室內(nèi)氣流組織的分布與送、回風口的布置有較大的關系。
[Abstract]:The investigation shows that more than 80% of the time is spent indoors, so it is necessary to study the efficient ventilation method to create a healthy and comfortable indoor environment for the personnel. Displacement ventilation improves the ventilation efficiency of the room, but there are some technical problems such as limited use in winter, and jet ventilation can not only create the effect of airflow organization similar to displacement ventilation, but also run all season. Especially suitable for mechanical ventilation of office buildings. Therefore, this paper takes jet ventilation technology as the research point, and carries on the numerical simulation research to the indoor airflow organization characteristic and the influence factor under the multi-working condition. First of all, the physical model of jet ventilation is established, and the selected turbulence model, pressure difference scheme and wall condition processing method are used to simulate nine different definite solution conditions. Based on the experimental data of previous scholars, the validity of the model is verified. Secondly, the indoor airflow distribution characteristics under impact jet ventilation and vertical wall attached jet ventilation are simulated. Compared with the displacement ventilation, the indoor temperature field, velocity field, air age, air distribution uneven coefficient and energy utilization coefficient are analyzed from two aspects of indoor air distribution characteristics and ventilation efficiency, including the indoor temperature field, velocity field, air age, air distribution and energy utilization coefficient based on jet ventilation. Finally, the key factors influencing the ventilation of impact jet and vertical wall attached jet are studied, and the model of return tuyere is established. The influence of different layout forms of return tuyere on the effect of jet ventilation is discussed, and the best layout scheme of return tuyere is concluded. The results show that the RNG k- 蔚 model of turbulence, the standard wall function method and the Body-force-weighted pressure difference scheme can obtain good numerical simulation results for indoor airflow. The indoor temperature field has obvious stratification phenomenon. Compared with the displacement ventilation, the air lake temperature of the room floor is 2 鈩

本文編號：2135651