Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Brisbane QLD 4072, Australia.
Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Brisbane QLD 4072, Australia; School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China.
Water Res. 2023 Oct 1;244:120441. doi: 10.1016/j.watres.2023.120441. Epub 2023 Aug 1.
Modelling heat transfer in sewers and the surrounding soil is important for effective sewer maintenance, and for heat recovery from wastewater. The boundary conditions, including both the thickness of the soil layer to be modelled and the temperature distribution around the boundary of the soil layer, directly determine both the efficiency and accuracy of the models. Yet there is no systematic method to establish these conditions. This study presents a novel and generic approach to establishing efficient boundary conditions for sewer heat transfer modelling. Fourier transform is applied to identify the dominant frequencies of the temperatures of the heat sources/sinks, namely the atmosphere, sewer air and wastewater. A simple data-driven model for determining the thickness of the soil-layer to be included, and three physics-informed models for predicting the temperatures at the soil-layer boundary are then learnt from mechanistic models for sewer heat transfer, taking into consideration the frequency spectra. The methodology achieved high fidelity to the mechanistic models in predicting the soil-layer boundary temperatures and sewer wall temperatures for real-life sewers. This approach offers an easy yet reliable way to obtain efficient boundary conditions that significantly improve both the accuracy and speed of sewer heat transfer modelling.
模拟污水管道及其周围土壤中的热量传递对于有效的污水管道维护以及从污水中回收热量非常重要。边界条件，包括要建模的土壤层的厚度和土壤层边界周围的温度分布，直接决定了模型的效率和准确性。然而，目前还没有一种系统的方法来确定这些条件。本研究提出了一种新颖且通用的方法，用于为污水管道热量传递建模建立有效的边界条件。傅里叶变换用于确定热源/汇，即大气、污水管道空气和污水的温度的主要频率。然后，从污水管道热量传递的机理模型中学习了一个简单的数据驱动模型，用于确定要包含的土壤层厚度，以及三个物理启发模型，用于预测土壤层边界的温度，同时考虑频谱。该方法在预测实际污水管道的土壤层边界温度和污水管道壁温度方面，与机理模型具有很高的相似度。该方法提供了一种简单而可靠的方法来获得有效的边界条件，显著提高了污水管道热量传递建模的准确性和速度。
