In subway artificial ground freezing projects,the freezing system's cooling operation mode is often monolithic and lacks dynamic change,which will cause significant energy waste during construction.Therefore,based on the calculation model of the cooling capacity of the single-tube freezer,the cooling energy supply on demand operation mode for group freezing pipes was established.This mode incorporated the calculation method of heat transfer efficiency of the brine within the freezer and the equivalent calculation model of the group freezing pipes.It realized the quantitative solution for the cooling capacity of the freezing system.The results show that the cooling energy supply on demand calculation method could effectively reflect the dynamic variation in the refrigerating capacity of the freezer,with the calculation accuracy meeting engineering requirements.Parameters such as frozen wall shape,soil thermal conductivity,brine temperature are the critical factors affecting the freezing capacity of the freezer.For specific projects,the frozen wall shape is key to determining the freezing capacity of the freezer.Different freezing pipes produce inconsistent frozen walls.To accurately calculate the refrigeration capacity of the entire freezing system,the longitudinal temperature solution method or longitudinal temperature measurement technology should be used to precisely determine the conditions of each freezing pipe or each layer of the freezing pipe.Then the equivalent substitution method is used to determine the required cooling capacity.The experimental results show that the calculation error is 1.7％,satisfying the engineering accuracy requirements.The relevant research findings will provide a technical basis for the efficient and low-carbon operation of freezing systems in various subway freezing projects.
关键词
地铁/人工冻结法/按需供冷/运行模式/地层吸冷量/群孔冻结/模型试验
Key words
Subway/Artificial ground freezing/Cooling energy supply on demand/Operation mode/Cooling energy absorbed by soil/Group freezing/Model test
维普
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