| 摘要: | 許多研究人員已經開發出不同級別的模型，以預測旋轉鼓中的熱傳遞。離散元素法 (DEM)已廣泛用於研究顆粒系統。作為研究的主要重點，這項工作通過離散元素方法 (DEM)模擬進行闡述，以檢查壁面摩擦的影響，該影響分別由Dpw/Dp 和旋轉鼓內顆粒流的傳熱行為模式。在其他研究中，轉鼓建構為的兩個邊界不同，然後通過各種熱管阻力完成。通常用於此工作的鼓直徑為100毫米，深度為10毫米。轉鼓拱由64段壁面系統建構而成，其中32段壁面為獲取熱能，其他32個壁面則不為獲取熱能，每四個相鄰的壁段都吸收熱能，四個不吸收熱能，因此轉鼓在模擬1、2、4 (Dpw/Dp、模型、填充率)下會保持等效的熱能，此模型不適用於具有不同邊界的轉鼓模擬(模擬3) 。一些顆粒以相似的模式黏附在非加熱壁當中，直徑從0至5毫米不等，隨後產生不同的比例 (Dpw/Dp)。在相同Dpw/Dp下，轉鼓建構成五種模型: 模型_1、模型_2、模型_3、模型_4及模型_5 (模擬2)，第三個模擬闡述了之前的第二個模擬(不同的邊界)，也使用了30%、60%、90%的填充率來檢查轉鼓內顆粒物的平均溫度，整體模擬會控制轉鼓在10 rpm的速度。鼓壁和顆粒的初始溫度約為300 K，在模擬過程當中，將32個壁段充分加熱至800 K的恆定溫度，熱量通過間接傳熱機制傳遞給顆粒狀物質。結果顯示轉鼓在不同比例 (Dpw/Dp)產生大量平均溫度，此外模型的變化還影響轉鼓內顆粒物質的熱傳遞行為，該模擬還表明，增加熱導管阻力可以減少傳遞給顆粒的熱量，最後，提高填充率可以降低轉鼓內顆粒物的平均溫度。;Models at distinct levels have evolved by many researchers for predicting the heat transfer in rotating drums. The discrete element method (DEM) has widely used to investigate the granular system. As the main focus of the study, this work clarifies numerically by the discrete element method (DEM) simulation to examine the impact of wall friction that is denoted by the distinction of Dpw/Dp and pattern on heat transfer behavior of granular flow inside a rotating drum. In other investigations, the drum builds with two dissimilar boundaries then completed by various thermal pipe resistance. The impact of filling ratio as well investigate in this work. The drum typically applied to this work has 100 mm in diameter and 10 mm in depth. The drum arch is systematically structured by 64 segments wall 32 segment wall acquire the heat energy, while the other 32 not. Every four adjacent wall segments grabs the heat energy, and four wall segments neighboring them not. So, the drum sustains the equivalent heat energy for simulations 1, 2, and 4 (Dpw/Dp, pattern, and filling ratio). This model does not employ for the simulations on drums with different boundaries (simulation 3). Some particles are sticking in the non-heating walls in a similar pattern with various diameters from 0 to 5 millimeters later creates different ratios (Dpw/Dp). The drum is built into five models upon the same Dpw/Dp, which are pattern _1, pattern _2, pattern _3, pattern _4, and pattern 5 (simulation 2). The third simulation clarifies the second simulation before (different boundaries). 30, 60, and 90 % of filling ratios are also applied to review the average temperature of the granular matter inside the drum. Overall simulation control with 10 rpm of drum speed. The initial temperature for drum walls and particles is around 300 K. The 32 wall segments are heated sufficiently by the constant temperature of 800 K during the simulation. The heat transmits to the granular matter via an indirect heat transfer mechanism. The results exhibit the different ratios (Dpw/Dp) of the drum generating numerous average temperatures. Furthermore, the variation of patterns also affects for heat transfer behavior of granular matter inside the drum. The simulation also represents that the increase of thermal pipe resistant can reduce the heat conveyed to the particles. The last, enhance of filling ratio can decrease the average temperature of granular matter inside the drum. |
