Underground coal gasification can convert deep coal into synthesis gas for use in the production of electricity, fuels and chemicals. This paper provides a review of the fundamental physical phenomena in underground coal gasification and associated modeling efforts. The relevant fundamentals of coal gasification are described and the phenomena of cavity growth at the sidewall and roof of the underground cavity are examined in detail. The transport phenomena and chemical reactions occurring in the permeable bed of char and ash and the void space are reviewed. The modeling of the transport of heat and mass, including contaminants, in the near- and far-fields surrounding an underground coal gasifier are also summarized. An overview of the geomechanical phenomena and the coupled interactions between transport and mechanical phenomena are provided. Finally, integrated UCG models are reviewed and recommendations for future model development are provided. (C) 2018 Elsevier Ltd. All rights reserved.

中文翻译：

---

地下煤气化 – 第二部分：基本现象和建模

地下煤气化可以将深层煤转化为合成气，用于生产电力、燃料和化学品。本文综述了地下煤气化中的基本物理现象和相关的建模工作。描述了煤气化的相关基本原理，并详细研究了地下空腔侧壁和顶部的空腔生长现象。综述了炭灰渗透床和空隙空间中发生的输运现象和化学反应。还总结了地下煤气化炉周围近场和远场中热量和质量（包括污染物）传输的建模。提供了地质力学现象的概述以及传输和力学现象之间的耦合相互作用。最后，对集成的 UCG 模型进行了审查，并为未来的模型开发提供了建议。(C) 2018 Elsevier Ltd。保留所有权利。