State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Water Res. 2017 Oct 1;122:317-328. doi: 10.1016/j.watres.2017.06.003. Epub 2017 Jun 4.
The effect of aeration on the pile matrix temperature was investigated using thermocouples and Infrared Thermal Imager (IRI) for temperature sensing, and Computational Fluid Dynamics (CFD) for modelling of temperature variation during aeration in a full-scale sludge biodrying plant. With aeration saving of 20%, the improved strategy speeded up biodrying from 21 days to 14 days, while achieving similar drying effect. A persistent thermocouple recorded the one-dimensional (1D) total temperature variation of all aeration strategies. The IRI captured the rapid two-dimensional (2D) pile temperature dropped from 72.5 °C to 30.3 °C during 6 min of aeration, which mechanism suggested as the latent heat of moisture evaporation and sensible heat of air exchange. The CFD three-dimensional (3D) CFD results highlight the importance of latent heat rather than sensible heat. Therefore, the pile temperature drop inferred is ΔT = 5.38 °C theoretically and ΔT = 5.17 ± 4.56 °C practically, per unit of MC removed. These findings also emphasize the possibility of a pile temperature valley, due to excessive aeration under unsaturated vapour conditions. Surface temperature monitored by IRI coupled with 3D temperature simulated by CFD rapidly gives a clear matrix temperature evolution, empowering biodrying by more accurate temperature and aeration.
使用热电偶和红外热像仪（IRI）进行温度感应，以及计算流体动力学（CFD）对充气过程中温度变化进行建模，研究了充气对堆体基质温度的影响。在全尺寸污泥好氧干化厂中，采用充气节省 20%的节能策略，将好氧干化时间从 21 天缩短至 14 天，同时达到相似的干燥效果。持续的热电偶记录了所有充气策略的一维（1D）总温度变化。IRI 在 6 分钟的充气过程中捕捉到了快速的二维（2D）堆体温度从 72.5°C 下降到 30.3°C 的情况，其机制被认为是水分蒸发的潜热和空气交换的显热。CFD 三维（3D）CFD 结果强调了潜热的重要性，而不是显热。因此，理论上推断的堆体温度下降为 ΔT = 5.38°C，实际上为 ΔT = 5.17 ± 4.56°C，每去除单位 MC。这些发现还强调了在不饱和蒸汽条件下过度充气可能导致堆体温度下降的可能性。IRl 监测的表面温度与 CFD 模拟的 3D 温度相结合，快速给出了清晰的基质温度演变，通过更准确的温度和充气来实现好氧干化。
