西部煤矿立井冻结器吸热能力强化机理与冷量优化调控

In the construction of vertical shaft of coal mine in western china, there are less water-resisting layers among cretaceous stratums and also there are closely hydraulic connection among stratums. For the full depth freeze model, the installed capacity of refrigeration is suspiciously large, so the consumption of electricity is too much. In addition, partial closure plan of frozen wall is hard to complete for the difference of extension speed in different stratums, which bring about schedule delays. It is difficult to solve problems effectively just depend on some experiences such as improving brine flow rate, lowering brine temperature, prolonging freeze time and so on, even these experiential method have caused several failures of freeze projects. According to this problem, the project team seek the resolution of the issue from the aspects of improving freezing apparatus' s heat absorption capacity and optimizing cold energy distribution among stratums. On the base of field synergy principle, a new type of freezing apparatus was manufactured by changing the brine flow state and studying augmentation mechanism between brine and freezing pipes. The relationship of the pipes' heat absorption capacity and the frozen soil's temperature variation was explored by both theoretical analysis and experiment verification, and revealed the heat exchange mechanism between freezing pipes and soil which provide a basis for optimizing freeze design. Through adjust heat absorption of freezing pipes in different depth, the cold energy distribution was optimized in different depth and stratums, the method not only saves energy and resources but also reduces freeze time, and provides technical support and theoretical basis for solving freeze problem in cretaceous strata.

我国西部白垩系地层中的煤矿立井建设中,因地层间通常缺少稳定的隔水层，且各地层间存在水力联系，多采用全深冻结的模式，导致在制冷装机容量过大，消耗电能过多。加之地层间冻结壁扩展速度的差异性，往往出现局部地层交圈困难，造成工程延期。单纯依靠提高冻结管内盐水流速、降低盐水温度、延长冻结时间的经验做法，往往难以奏效，已造成多起冻结失效事故。针对该难题，本项目从强化冻结器吸热能力和地层间冷量调控的角度入手，根据场协同理论，采用改变冻结器内盐水流态办法，研究盐水和冻结管间的对流换热强化机理，研发新型冻结器。通过实验和理论分析，探索冻结管吸热能力与周围冻土温度场变化之间的作用规律，揭示冻结管与土体间的传热机理，为制定优化冻结方案提供理论依据。通过调节不同深度冻结管的吸热能力,实现冷量在不同深度和不同地层中的优化分配，达到既节能降耗，又缩短冻时间的目的，为解决白垩系地层冻结难题提供理论及技术支持。

我国西部白垩系地层中的煤矿立井建设中,因地层间通常缺少稳定的隔水层，且各地层间存在水力联系，多采用全深冻结的模式，导致在制冷装机容量过大，消耗电能过多。加之地层间冻结壁扩展速度的差异性，往往出现局部地层交圈困难，造成工程延期。单纯依靠提高冻结管内盐水流速、降低盐水温度、延长冻结时间的经验做法，往往难以奏效，已造成多起冻结失效事故。针对该难题，本项目从强化冻结器吸热能力和地层间冷量调控的角度入手，根据场协同理论，采用改变冻结器内盐水流态办法，研究盐水和冻结管间的对流换热强化机理，研发新型冻结器。通过实验和理论分析，探索冻结管吸热能力与周围冻土温度场变化之间的作用规律，揭示冻结管与土体间的传热机理，为制定优化冻结方案提供理论依据。达到既节能降耗，又缩短冻时间的目的，为解决白垩系地层冻结难题提供理论及技术支持. 项目执行期间，基于该项目共发表论文10篇，其中EI检索5篇，核心期刊5篇。根据阶段性研究成果，在国际学术会议上做特邀报告1次，在国内学术交流会议上做学术报告2次。其中将研究成果“冻结器传热的冷源相似准则”和“缩短核磁共振测定冻土未冻水含量实验时间的方法”引入个人主讲的课程"地下工程特殊施工方法"的实验课堂中，将研究成果“水平不均匀地压作用下力井井筒的内力计算”引入个人主讲的课程“建井工程结构”课程中。授权发明专利2项，研发了1项科研仪器设备，用于教学演示和工程实际。该项发明专利成果已经进行了技术转让，并应用于工程建设实际。基于该项目培养硕士2名。按期完成研究任务，按基金委的要求及时送交有关报告。